英文文献及翻译
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外文文献原稿和译文原稿Sodium Polyacrylate:Also known as super-absorbent or “SAP”(super absorbent polymer), Kimberly Clark used to call it SAM (super absorbent material). It is typically used in fine granular form (like table salt). It helps improve capacity for better retention in a disposable diaper, allowing the product to be thinner with improved performance and less usage of pine fluff pulp. The molecular structure of the polyacrylate has sodium carboxylate groups hanging off the main chain. When it comes in contact with water, the sodium detaches itself, leaving only carboxylions. Being negatively charged, these ions repel one another so that the polymer also has cross-links, which effectively leads to a three-dimensional structure. It has hige molecular weight of more than a million; thus, instead of getting dissolved, it solidifies into a gel. The Hydrogen in the water (H-O-H) is trapped by the acrylate due to the atomic bonds associated with the polarity forces between the atoms. Electrolytes in the liquid, such as salt minerals (urine contains 0.9% of minerals), reduce polarity, thereby affecting superabsorbent properties, especially with regard to the superabsorbent capacity for liquid retention. This is the main reason why diapers containing SAP should never be tested with plain water. Linear molecular configurations have less total capacity than non-linear molecules but, on the other hand, retention of liquid in a linear molecule is higher than in a non-linear molecule, due to improved polarity. For a list of SAP suppliers, please use this link: SAP, the superabsorbent can be designed to absorb higher amounts of liquids (with less retention) or very high retentions (but lower capacity). In addition, a surface cross linker can be added to the superabsorbent particle to help it move liquids while it is saturated. This helps avoid formation of "gel blocks", the phenomenon that describes the impossibility of moving liquids once a SAP particle gets saturated.History of Super Absorbent Polymer ChemistryUn til the 1980’s, water absorbing materials were cellulosic or fiber-based products. Choices were tissue paper, cotton, sponge, and fluff pulp. The water retention capacity of these types of materials is only 20 times their weight – at most.In the early 1960s, the United States Department of Agriculture (USDA) was conducting work on materials to improve water conservation in soils. They developed a resin based on the grafting of acrylonitrile polymer onto the backbone of starch molecules (i.e. starch-grafting). The hydrolyzed product of the hydrolysis of this starch-acrylonitrile co-polymer gave water absorption greater than 400 times its weight. Also, the gel did not release liquid water the way that fiber-based absorbents do.The polymer came to be known as “Super Slurper”.The USDA gave the technical know how several USA companies for further development of the basic technology. A wide range of grating combinations were attempted including work with acrylic acid, acrylamide and polyvinyl alcohol (PVA).Since Japanese companies were excluded by the USDA, they started independent research using starch, carboxy methyl cellulose (CMC), acrylic acid, polyvinyl alcohol (PVA) and isobutylene maleic anhydride (IMA).Early global participants in the development of super absorbent chemistry included Dow Chemical, Hercules, General Mills Chemical, DuPont, National Starch & Chemical, Enka (Akzo), Sanyo Chemical, Sumitomo Chemical, Kao, Nihon Starch and Japan Exlan.In the early 1970s, super absorbent polymer was used commercially for the first time –not for soil amendment applications as originally intended –but for disposable hygienic products. The first product markets were feminine sanitary napkins and adult incontinence products.In 1978, Park Davis (d.b.a. Professional Medical Products) used super absorbent polymers in sanitary napkins.Super absorbent polymer was first used in Europe in a baby diaper in 1982 when Schickendanz and Beghin-Say added the material to the absorbent core. Shortly thereafter, UniCharm introduced super absorbent baby diapers in Japan while Proctor & Gamble and Kimberly-Clark in the USA began to use the material.The development of super absorbent technology and performance has been largely led by demands in the disposable hygiene segment. Strides in absorption performance have allowed the development of the ultra-thin baby diaper which uses a fraction of the materials – particularly fluff pulp – which earlier disposable diapers consumed.Over the years, technology has progressed so that there is little if any starch-grafted super absorbent polymer used in disposable hygienic products. These super absorbents typically are cross-linked acrylic homo-polymers (usually Sodium neutralized).Super absorbents used in soil amendments applications tend to be cross-linked acrylic-acrylamide co-polymers (usually Potassium neutralized).Besides granular super absorbent polymers, ARCO Chemical developed a super absorbent fiber technology in the early 1990s. This technology was eventually sold to Camelot Absorbents. There are super absorbent fibers commercially available today. While significantly more expensive than the granular polymers, the super absorbent fibers offer technical advantages in certain niche markets including cable wrap, medical devices and food packaging.Sodium polyacrylate, also known as waterlock, is a polymer with the chemical formula [-CH2-CH(COONa)-]n widely used in consumer products. It has the ability to absorb as much as 200 to 300 times its mass in water. Acrylate polymers generally are considered to possess an anionic charge. While sodium neutralized polyacrylates are the most common form used in industry, there are also other salts available including potassium, lithium and ammonium.ApplicationsAcrylates and acrylic chemistry have a wide variety of industrial uses that include: ∙Sequestering agents in detergents. (By binding hard water elements such as calcium and magnesium, the surfactants in detergents work more efficiently.) ∙Thickening agents∙Coatings∙Fake snowSuper absorbent polymers. These cross-linked acrylic polymers are referred to as "Super Absorbents" and "Water Crystals", and are used in baby diapers. Copolymerversions are used in agriculture and other specialty absorbent applications. The origins of super absorbent polymer chemistry trace back to the early 1960s when the U.S. Department of Agriculture developed the first super absorbent polymer materials. This chemical is featured in the Maximum Absorbency Garment used by NASA.译文聚丙烯酸钠聚丙烯酸钠,又可以称为超级吸收剂或者又叫高吸水性树脂,凯博利克拉克教授曾经称它为SAM即:超级吸收性物质。
英文文献整篇翻译Title: The Impact of Climate Change on BiodiversityClimate change is a pressing issue that has significant impacts on biodiversity worldwide. Changes in temperature, precipitation patterns, and extreme weather events are altering ecosystems and threatening the survival of many species. The loss of biodiversity not only affects the natural world but also has implications for human societies.One of the major impacts of climate change onbiodiversity is the shifting of habitats. As temperatures rise, many species are forced to move to higher latitudesor elevations in search of suitable conditions. This can disrupt ecosystems and lead to the decline or extinction of species that are unable to adapt to the new conditions.In addition to habitat loss, climate change is also causing changes in the timing of biological events such as flowering, migration, and reproduction. These changes can disrupt the delicate balance of ecosystems and lead to mismatches between species that depend on each other for survival.Furthermore, climate change is exacerbating otherthreats to biodiversity such as habitat destruction, pollution, and overexploitation. The combination of these factors is putting immense pressure on many species and pushing them closer to extinction.It is essential that we take action to mitigate the impacts of climate change on biodiversity. This includes reducing greenhouse gas emissions, protecting and restoring habitats, and implementing conservation measures to safeguard vulnerable species. By addressing the root causes of climate change and protecting biodiversity, we canensure a sustainable future for both the natural world and human societies.气候变化对生物多样性的影响气候变化是一个紧迫的问题,对全球的生物多样性产生重大影响。
((英文参考文献及译文)二〇一六年六月本科毕业论文 题 目:STATISTICAL SAMPLING METHOD, USED INTHE AUDIT学生姓名:王雪琴学 院:管理学院系 别:会计系专 业:财务管理班 级:财管12-2班 学校代码: 10128 学 号: 201210707016Statistics and AuditRomanian Statistical Review nr. 5 / 2010STATISTICAL SAMPLING METHOD, USED IN THE AUDIT - views, recommendations, fi ndingsPhD Candidate Gabriela-Felicia UNGUREANUAbstractThe rapid increase in the size of U.S. companies from the earlytwentieth century created the need for audit procedures based on the selectionof a part of the total population audited to obtain reliable audit evidence, tocharacterize the entire population consists of account balances or classes oftransactions. Sampling is not used only in audit – is used in sampling surveys,market analysis and medical research in which someone wants to reach aconclusion about a large number of data by examining only a part of thesedata. The difference is the “population” from which the sample is selected, iethat set of data which is intended to draw a conclusion. Audit sampling appliesonly to certain types of audit procedures.Key words: sampling, sample risk, population, sampling unit, tests ofcontrols, substantive procedures.Statistical samplingCommittee statistical sampling of American Institute of CertifiedPublic Accountants of (AICPA) issued in 1962 a special report, titled“Statistical sampling and independent auditors’ which allowed the use ofstatistical sampling method, in accordance with Generally Accepted AuditingStandards (GAAS). During 1962-1974, the AICPA published a series of paperson statistical sampling, “Auditor’s Approach to Statistical Sampling”, foruse in continuing professional education of accountants. During 1962-1974,the AICPA published a series of papers on statistical sampling, “Auditor’sApproach to Statistical Sampling”, for use in continuing professional educationof accountants. In 1981, AICPA issued the professional standard, “AuditSampling”, which provides general guidelines for both sampling methods,statistical and non-statistical.Earlier audits included checks of all transactions in the period coveredby the audited financial statements. At that time, the literature has not givenparticular attention to this subject. Only in 1971, an audit procedures programprinted in the “Federal Reserve Bulletin (Federal Bulletin Stocks)” includedseveral references to sampling such as selecting the “few items” of inventory.Statistics and Audit The program was developed by a special committee, which later became the AICPA, that of Certified Public Accountants American Institute.In the first decades of last century, the auditors often applied sampling, but sample size was not in related to the efficiency of internal control of the entity. In 1955, American Institute of Accountants has published a study case of extending the audit sampling, summarizing audit program developed by certified public accountants, to show why sampling is necessary to extend the audit. The study was important because is one of the leading journal on sampling which recognize a relationship of dependency between detail and reliability testing of internal control.In 1964, the AICPA’s Auditing Standards Board has issued a report entitled “The relationship between statistical sampling and Generally Accepted Auditing Standards (GAAS)” which illustrated the relationship between the accuracy and reliability in sampling and provisions of GAAS.In 1978, the AICPA published the work of Donald M. Roberts,“Statistical Auditing”which explains the underlying theory of statistical sampling in auditing.In 1981, AICPA issued the professional standard, named “Audit Sampling”, which provides guidelines for both sampling methods, statistical and non-statistical.An auditor does not rely solely on the results of a single procedure to reach a conclusion on an account balance, class of transactions or operational effectiveness of the controls. Rather, the audit findings are based on combined evidence from several sources, as a consequence of a number of different audit procedures. When an auditor selects a sample of a population, his objective is to obtain a representative sample, ie sample whose characteristics are identical with the population’s characteristics. This means that selected items are identical with those remaining outside the sample.In practice, auditors do not know for sure if a sample is representative, even after completion the test, but they “may increase the probability that a sample is representative by accuracy of activities made related to design, sample selection and evaluation” [1]. Lack of specificity of the sample results may be given by observation errors and sampling errors. Risks to produce these errors can be controlled.Observation error (risk of observation) appears when the audit test did not identify existing deviations in the sample or using an inadequate audit technique or by negligence of the auditor.Sampling error (sampling risk) is an inherent characteristic of the survey, which results from the fact that they tested only a fraction of the total population. Sampling error occurs due to the fact that it is possible for Revista Română de Statistică nr. 5 / 2010Statistics and Auditthe auditor to reach a conclusion, based on a sample that is different from the conclusion which would be reached if the entire population would have been subject to audit procedures identical. Sampling risk can be reduced by adjusting the sample size, depending on the size and population characteristics and using an appropriate method of selection. Increasing sample size will reduce the risk of sampling; a sample of the all population will present a null risk of sampling.Audit Sampling is a method of testing for gather sufficient and appropriate audit evidence, for the purposes of audit. The auditor may decide to apply audit sampling on an account balance or class of transactions. Sampling audit includes audit procedures to less than 100% of the items within an account balance or class of transactions, so all the sample able to be selected. Auditor is required to determine appropriate ways of selecting items for testing. Audit sampling can be used as a statistical approach and a non- statistical.Statistical sampling is a method by which the sample is made so that each unit consists of the total population has an equal probability of being included in the sample, method of sample selection is random, allowed to assess the results based on probability theory and risk quantification of sampling. Choosing the appropriate population make that auditor’ findings can be extended to the entire population.Non-statistical sampling is a method of sampling, when the auditor uses professional judgment to select elements of a sample. Since the purpose of sampling is to draw conclusions about the entire population, the auditor should select a representative sample by choosing sample units which have characteristics typical of that population. Results will not extrapolate the entire population as the sample selected is representative.Audit tests can be applied on the all elements of the population, where is a small population or on an unrepresentative sample, where the auditor knows the particularities of the population to be tested and is able to identify a small number of items of interest to audit. If the sample has not similar characteristics for the elements of the entire population, the errors found in the tested sample can not extrapolate.Decision of statistical or non-statistical approach depends on the auditor’s professional judgment which seeking sufficient appropriate audits evidence on which to completion its findings about the audit opinion.As a statistical sampling method refer to the random selection that any possible combination of elements of the community is equally likely to enter the sample. Simple random sampling is used when stratification was not to audit. Using random selection involves using random numbers generated byRomanian Statistical Review nr. 5 / 2010Statistics and Audit a computer. After selecting a random starting point, the auditor found the first random number that falls within the test document numbers. Only when the approach has the characteristics of statistical sampling, statistical assessments of risk are valid sampling.In another variant of the sampling probability, namely the systematic selection (also called random mechanical) elements naturally succeed in office space or time; the auditor has a preliminary listing of the population and made the decision on sample size. “The auditor calculated a counting step, and selects the sample element method based on step size. Step counting is determined by dividing the volume of the community to sample the number of units desired. Advantages of systematic screening are its usability. In most cases, a systematic sample can be extracted quickly and method automatically arranges numbers in successive series.”[2].Selection by probability proportional to size - is a method which emphasizes those population units’recorded higher values. The sample is constituted so that the probability of selecting any given element of the population is equal to the recorded value of the item;Stratifi ed selection - is a method of emphasis of units with higher values and is registered in the stratification of the population in subpopulations. Stratification provides a complete picture of the auditor, when population (data table to be analyzed) is not homogeneous. In this case, the auditor stratifies a population by dividing them into distinct subpopulations, which have common characteristics, pre-defined. “The objective of stratification is to reduce the variability of elements in each layer and therefore allow a reduction in sample size without a proportionate increase in the risk of sampling.” [3] If population stratification is done properly, the amount of sample size to come layers will be less than the sample size that would be obtained at the same level of risk given sample with a sample extracted from the entire population. Audit results applied to a layer can be designed only on items that are part of that layer.I appreciated as useful some views on non-statistical sampling methods, which implies that guided the selection of the sample selecting each element according to certain criteria determined by the auditor. The method is subjective; because the auditor selects intentionally items containing set features him.The selection of the series is done by selecting multiple elements series (successive). Using sampling the series is recommended only if a reasonable number of sets used. Using just a few series there is a risk that the sample is not representative. This type of sampling can be used in addition to other samples, where there is a high probability of occurrence of errors. At the arbitrary selection, no items are selected preferably from the auditor, Revista Română de Statistică nr. 5 / 2010Statistics and Auditthat regardless of size or source or characteristics. Is not the recommended method, because is not objective.That sampling is based on the auditor’s professional judgment, which may decide which items can be part or not sampled. Because is not a statistical method, it can not calculate the standard error. Although the sample structure can be constructed to reproduce the population, there is no guarantee that the sample is representative. If omitted a feature that would be relevant in a particular situation, the sample is not representative.Sampling applies when the auditor plans to make conclusions about population, based on a selection. The auditor considers the audit program and determines audit procedures which may apply random research. Sampling is used by auditors an internal control systems testing, and substantive testing of operations. The general objectives of tests of control system and operations substantive tests are to verify the application of pre-defined control procedures, and to determine whether operations contain material errors.Control tests are intended to provide evidence of operational efficiency and controls design or operation of a control system to prevent or detect material misstatements in financial statements. Control tests are necessary if the auditor plans to assess control risk for assertions of management.Controls are generally expected to be similarly applied to all transactions covered by the records, regardless of transaction value. Therefore, if the auditor uses sampling, it is not advisable to select only high value transactions. Samples must be chosen so as to be representative population sample.An auditor must be aware that an entity may change a special control during the course of the audit. If the control is replaced by another, which is designed to achieve the same specific objective, the auditor must decide whether to design a sample of all transactions made during or just a sample of transactions controlled again. Appropriate decision depends on the overall objective of the audit test.Verification of internal control system of an entity is intended to provide guidance on the identification of relevant controls and design evaluation tests of controls.Other tests:In testing internal control system and testing operations, audit sample is used to estimate the proportion of elements of a population containing a characteristic or attribute analysis. This proportion is called the frequency of occurrence or percentage of deviation and is equal to the ratio of elements containing attribute specific and total number of population elements. WeightRomanian Statistical Review nr. 5 / 2010Statistics and Audit deviations in a sample are determined to calculate an estimate of the proportion of the total population deviations.Risk associated with sampling - refers to a sample selection which can not be representative of the population tested. In other words, the sample itself may contain material errors or deviations from the line. However, issuing a conclusion based on a sample may be different from the conclusion which would be reached if the entire population would be subject to audit.Types of risk associated with sampling:Controls are more effective than they actually are or that there are not significant errors when they exist - which means an inappropriate audit opinion. Controls are less effective than they actually are that there are significant errors when in fact they are not - this calls for additional activities to establish that initial conclusions were incorrect.Attributes testing - the auditor should be defining the characteristics to test and conditions for misconduct. Attributes testing will make when required objective statistical projections on various characteristics of the population. The auditor may decide to select items from a population based on its knowledge about the entity and its environment control based on risk analysis and the specific characteristics of the population to be tested.Population is the mass of data on which the auditor wishes to generalize the findings obtained on a sample. Population will be defined compliance audit objectives and will be complete and consistent, because results of the sample can be designed only for the population from which the sample was selected.Sampling unit - a unit of sampling may be, for example, an invoice, an entry or a line item. Each sample unit is an element of the population. The auditor will define the sampling unit based on its compliance with the objectives of audit tests.Sample size - to determine the sample size should be considered whether sampling risk is reduced to an acceptable minimum level. Sample size is affected by the risk associated with sampling that the auditor is willing to accept it. The risk that the auditor is willing to accept lower, the sample will be higher.Error - for detailed testing, the auditor should project monetary errors found in the sample population and should take into account the projected error on the specific objective of the audit and other audit areas. The auditor projects the total error on the population to get a broad perspective on the size of the error and comparing it with tolerable error.For detailed testing, tolerable error is tolerable and misrepresentations Revista Română de Statistică nr. 5 / 2010Statistics and Auditwill be a value less than or equal to materiality used by the auditor for the individual classes of transactions or balances audited. If a class of transactions or account balances has been divided into layers error is designed separately for each layer. Design errors and inconsistent errors for each stratum are then combined when considering the possible effect on the total classes of transactions and account balances.Evaluation of sample results - the auditor should evaluate the sample results to determine whether assessing relevant characteristics of the population is confirmed or needs to be revised.When testing controls, an unexpectedly high rate of sample error may lead to an increase in the risk assessment of significant misrepresentation unless it obtained additional audit evidence to support the initial assessment. For control tests, an error is a deviation from the performance of control procedures prescribed. The auditor should obtain evidence about the nature and extent of any significant changes in internal control system, including the staff establishment.If significant changes occur, the auditor should review the understanding of internal control environment and consider testing the controls changed. Alternatively, the auditor may consider performing substantive analytical procedures or tests of details covering the audit period.In some cases, the auditor might not need to wait until the end audit to form a conclusion about the effectiveness of operational control, to support the control risk assessment. In this case, the auditor might decide to modify the planned substantive tests accordingly.If testing details, an unexpectedly large amount of error in a sample may cause the auditor to believe that a class of transactions or account balances is given significantly wrong in the absence of additional audit evidence to show that there are not material misrepresentations.When the best estimate of error is very close to the tolerable error, the auditor recognizes the risk that another sample have different best estimate that could exceed the tolerable error.ConclusionsFollowing analysis of sampling methods conclude that all methods have advantages and disadvantages. But the auditor is important in choosing the sampling method is based on professional judgment and take into account the cost / benefit ratio. Thus, if a sampling method proves to be costly auditor should seek the most efficient method in view of the main and specific objectives of the audit.Romanian Statistical Review nr. 5 / 2010Statistics and Audit The auditor should evaluate the sample results to determine whether the preliminary assessment of relevant characteristics of the population must be confirmed or revised. If the evaluation sample results indicate that the relevant characteristics of the population needs assessment review, the auditor may: require management to investigate identified errors and likelihood of future errors and make necessary adjustments to change the nature, timing and extent of further procedures to take into account the effect on the audit report.Selective bibliography:[1] Law no. 672/2002 updated, on public internal audit[2] Arens, A şi Loebbecke J - Controve …Audit– An integrate approach”, 8th edition, Arc Publishing House[3] ISA 530 - Financial Audit 2008 - International Standards on Auditing, IRECSON Publishing House, 2009- Dictionary of macroeconomics, Ed C.H. Beck, Bucharest, 2008Revista Română de Statistică nr. 5 / 2010Statistics and Audit摘要美国公司的规模迅速增加,从第二十世纪初创造了必要的审计程序,根据选定的部分总人口的审计,以获得可靠的审计证据,以描述整个人口组成的帐户余额或类别的交易。
Foreign material:Chemical Industry1.Origins of the Chemical IndustryAlthough the use of chemicals dates back to the ancient civilizations, the evolution of what we know as the modern chemical industry started much more recently. It may be considered to have begun during the Industrial Revolution, about 1800, and developed to provide chemicals roe use by other industries. Examples are alkali for soapmaking, bleaching powder for cotton, and silica and sodium carbonate for glassmaking. It will be noted that these are all inorganic chemicals. The organic chemicals industry started in the 1860s with the exploitation of William Henry Perkin’s discovery if the first synthetic dyestuff—mauve. At the start of the twentieth century the emphasis on research on the applied aspects of chemistry in Germany had paid off handsomely, and by 1914 had resulted in the German chemical industry having 75% of the world market in chemicals. This was based on the discovery of new dyestuffs plus the development of both the contact process for sulphuric acid and the Haber process for ammonia. The later required a major technological breakthrough that of being able to carry out chemical reactions under conditions of very high pressure for the first time. The experience gained with this was to stand Germany in good stead, particularly with the rapidly increased demand for nitrogen-based compounds (ammonium salts for fertilizers and nitric acid for explosives manufacture) with the outbreak of world warⅠin 1914. This initiated profound changes which continued during the inter-war years (1918-1939).Since 1940 the chemical industry has grown at a remarkable rate, although this has slowed significantly in recent years. The lion’s share of this growth has been in the organic chemicals sector due to the development and growth of the petrochemicals area since 1950s. The explosives growth in petrochemicals in the 1960s and 1970s was largely due to the enormous increase in demand for synthetic polymers such as polyethylene, polypropylene, nylon, polyesters and epoxy resins.The chemical industry today is a very diverse sector of manufacturing industry, within which it plays a central role. It makes thousands of different chemicals whichthe general public only usually encounter as end or consumer products. These products are purchased because they have the required properties which make them suitable for some particular application, e.g. a non-stick coating for pans or a weedkiller. Thus chemicals are ultimately sold for the effects that they produce.2. Definition of the Chemical IndustryAt the turn of the century there would have been little difficulty in defining what constituted the chemical industry since only a very limited range of products was manufactured and these were clearly chemicals, e.g., alkali, sulphuric acid. At present, however, many intermediates to products produced, from raw materials like crude oil through (in some cases) many intermediates to products which may be used directly as consumer goods, or readily converted into them. The difficulty cones in deciding at which point in this sequence the particular operation ceases to be part of the chemical industry’s sphere of activities. To consider a specific example to illustrate this dilemma, emulsion paints may contain poly (vinyl chloride) / poly (vinyl acetate). Clearly, synthesis of vinyl chloride (or acetate) and its polymerization are chemical activities. However, if formulation and mixing of the paint, including the polymer, is carried out by a branch of the multinational chemical company which manufactured the ingredients, is this still part of the chemical industry of does it mow belong in the decorating industry?It is therefore apparent that, because of its diversity of operations and close links in many areas with other industries, there is no simple definition of the chemical industry. Instead each official body which collects and publishes statistics on manufacturing industry will have its definition as to which operations are classified as the chemical industry. It is important to bear this in mind when comparing statistical information which is derived from several sources.3. The Need for Chemical IndustryThe chemical industry is concerned with converting raw materials, such as crude oil, firstly into chemical intermediates and then into a tremendous variety of other chemicals. These are then used to produce consumer products, which make our livesmore comfortable or, in some cases such as pharmaceutical produces, help to maintain our well-being or even life itself. At each stage of these operations value is added to the produce and provided this added exceeds the raw material plus processing costs then a profit will be made on the operation. It is the aim of chemical industry to achieve this.It may seem strange in textbook this one to pose the question “do we need a chemical industry?” However trying to answer this question will provide(ⅰ) an indication of the range of the chemical industry’s activities, (ⅱ) its influence on our lives in everyday terms, and (ⅲ) how great is society’s need for a chemical industry. Our approach in answering the question will be to consider the industry’s co ntribution to meeting and satisfying our major needs. What are these? Clearly food (and drink) and health are paramount. Other which we shall consider in their turn are clothing and (briefly) shelter, leisure and transport.(1)Food. The chemical industry makes a major contribution to food production in at least three ways. Firstly, by making available large quantities of artificial fertilizers which are used to replace the elements (mainly nitrogen, phosphorus and potassium) which are removed as nutrients by the growing crops during modern intensive farming. Secondly, by manufacturing crop protection chemicals, i.e., pesticides, which markedly reduce the proportion of the crops consumed by pests. Thirdly, by producing veterinary products which protect livestock from disease or cure their infections.(2)Health. We are all aware of the major contribution which the pharmaceutical sector of the industry has made to help keep us all healthy, e.g. by curing bacterial infections with antibiotics, and even extending life itself, e.g. ß–blockers to lower blood pressure.(3)Clothing. The improvement in properties of modern synthetic fibers over the traditional clothing materials (e.g. cotton and wool) has been quite remarkable. Thus shirts, dresses and suits made from polyesters like Terylene and polyamides like Nylon are crease-resistant, machine-washable, and drip-dry or non-iron. They are also cheaper than natural materials.Parallel developments in the discovery of modern synthetic dyes and the technology to “bond” th em to the fiber has resulted in a tremendous increase in the variety of colors available to the fashion designer. Indeed they now span almost every color and hue of the visible spectrum. Indeed if a suitable shade is not available, structural modification of an existing dye to achieve this canreadily be carried out, provided there is a satisfactory market for the product.Other major advances in this sphere have been in color-fastness, i.e., resistance to the dye being washed out when the garment is cleaned.(4)Shelter, leisure and transport. In terms of shelter the contribution of modern synthetic polymers has been substantial. Plastics are tending to replace traditional building materials like wood because they are lighter, maintenance-free (i.e. they are resistant to weathering and do not need painting). Other polymers, e.g. urea-formaldehyde and polyurethanes, are important insulating materials f or reducing heat losses and hence reducing energy usage.Plastics and polymers have made a considerable impact on leisure activities with applications ranging from all-weather artificial surfaces for athletic tracks, football pitches and tennis courts to nylon strings for racquets and items like golf balls and footballs made entirely from synthetic materials.Like wise the chemical industry’s contribution to transport over the years has led to major improvements. Thus development of improved additives like anti-oxidants and viscosity index improves for engine oil has enabled routine servicing intervals to increase from 3000 to 6000 to 12000 miles. Research and development work has also resulted in improved lubricating oils and greases, and better brake fluids. Yet again the contribution of polymers and plastics has been very striking with the proportion of the total automobile derived from these materials—dashboard, steering wheel, seat padding and covering etc.—now exceeding 40%.So it is quite apparent even from a brief look at the chemical industry’s contribution to meeting our major needs that life in the world would be very different without the products of the industry. Indeed the level of a country’s development may be judged by the production level and sophistication of its chemical industry4. Research and Development (R&D) in Chemical IndustriesOne of the main reasons for the rapid growth of the chemical industry in the developed world has been its great commitment to, and investment in research and development (R&D). A typical figure is 5% of sales income, with this figure being almost doubled for the most research intensive sector, pharmaceuticals. It is important to emphasize that we are quoting percentages here not of profits but of sales income, i.e. the total money received, which has to pay for raw materials, overheads, staff salaries, etc. as well. In the past this tremendous investment has paid off well, leading to many useful and valuable products being introduced to the market. Examplesinclude synthetic polymers like nylons and polyesters, and drugs and pesticides. Although the number of new products introduced to the market has declined significantly in recent years, and in times of recession the research department is usually one of the first to suffer cutbacks, the commitment to R&D remains at a very high level.The chemical industry is a very high technology industry which takes full advantage of the latest advances in electronics and engineering. Computers are very widely used for all sorts of applications, from automatic control of chemical plants, to molecular modeling of structures of new compounds, to the control of analytical instruments in the laboratory.Individual manufacturing plants have capacities ranging from just a few tones per year in the fine chemicals area to the real giants in the fertilizer and petrochemical sectors which range up to 500,000 tonnes. The latter requires enormous capital investment, since a single plant of this size can now cost $520 million! This, coupled with the widespread use of automatic control equipment, helps to explain why the chemical industry is capital-rather than labor-intensive.The major chemical companies are truly multinational and operate their sales and marketing activities in most of the countries of the world, and they also have manufacturing units in a number of countries. This international outlook for operations, or globalization, is a growing trend within the chemical industry, with companies expanding their activities either by erecting manufacturing units in other countries or by taking over companies which are already operating there.化学工业1.化学工业的起源尽管化学品的使用可以追溯到古代文明时代,我们所谓的现代化学工业的发展却是非常近代(才开始的)。
Adult【成年人】Aged【老年人】Aged, 80 and over【老年人, 80以上】Catheterization, Central Venous/*instrumentation/methods【*导管插入术, 中心静脉/*仪器/方法】Cost-Benefit Analysis【费用效益分析】Equipment Design【设备设计】Equipment Failure【设备失效】Equipment Safety【设备安全性】Female【女(雌)性】Humans【人类】Infusion Pumps, Implantable/adverse effects/*economics【*输注泵, 植入型/副作用/*经济学】Male【男(雄)性】Middle Aged【中年人】Neoplasms/*drug therapy/pathology【*肿瘤/*药物疗法/病理学】Probability【概率】Prospective Studies【前瞻性研究】Risk Assessment【危险性评估】Sensitivity and Specificity【敏感性与特异性】Treatment Outcome【治疗结果】Vascular Patency【血管未闭】Venous Thrombosis/prevention & control【静脉血栓形成】Adolescent【青少年】Adult【成年人】Aged【老年人】Aged, 80 andover【老年人, 80以上】AntineoplasticAgents/*administration& dosage【*抗肿瘤药】*Catheters,Indwelling/adverseeffects/economics【*导管, 留置/副作用/经济学】Female【女(雌)性】Humans【人类】*Infusion Pumps,Implantable/adverse。
英文文献全文翻译全文共四篇示例,供读者参考第一篇示例:LeGuin, Ursula K. (December 18, 2002). "Dancing at the Edge of the World: Thoughts on Words, Women, Places".《世界边缘的舞蹈:关于语言、女性和地方的思考》Introduction:In "Dancing at the Edge of the World," Ursula K. LeGuin explores the intersection of language, women, and places. She writes about the power of words, the role of women in society, and the importance of our connection to the places we inhabit. Through a series of essays, LeGuin invites readers to think critically about these topics and consider how they shape our understanding of the world.Chapter 1: LanguageConclusion:第二篇示例:IntroductionEnglish literature translation is an important field in the study of language and culture. The translation of English literature involves not only the linguistic translation of words or sentences but also the transfer of cultural meaning and emotional resonance. This article will discuss the challenges and techniques of translating English literature, as well as the importance of preserving the original author's voice and style in the translated text.Challenges in translating English literature第三篇示例:Title: The Importance of Translation of Full English TextsTranslation plays a crucial role in bringing different languages and cultures together. More specifically, translating full English texts into different languages allows for access to valuable information and insights that may otherwise be inaccessible to those who do not speak English. In this article, we will explore the importance of translating full English texts and the benefits it brings.第四篇示例:Abstract: This article discusses the importance of translating English literature and the challenges translators face when putting together a full-text translation. It highlights the skills and knowledge needed to accurately convey the meaning and tone of the original text while preserving its cultural and literary nuances. Through a detailed analysis of the translation process, this article emphasizes the crucial role translators play in bridging the gap between languages and making English literature accessible to a global audience.IntroductionEnglish literature is a rich and diverse field encompassing a wide range of genres, styles, and themes. From classic works by Shakespeare and Dickens to contemporary novels by authors like J.K. Rowling and Philip Pullman, English literature offers something for everyone. However, for non-English speakers, accessing and understanding these works can be a challenge. This is where translation comes in.Translation is the process of rendering a text from one language into another, while striving to preserve the original meaning, tone, and style of the original work. Translating afull-length English text requires a deep understanding of both languages, as well as a keen awareness of the cultural andhistorical context in which the work was written. Additionally, translators must possess strong writing skills in order to convey the beauty and complexity of the original text in a new language.Challenges of Full-text TranslationTranslating a full-length English text poses several challenges for translators. One of the most significant challenges is capturing the nuances and subtleties of the original work. English literature is known for its rich and layered language, with intricate wordplay, metaphors, and symbolism that can be difficult to convey in another language. Translators must carefully consider each word and phrase in order to accurately convey the author's intended meaning.Another challenge of full-text translation is maintaining the author's unique voice and style. Each writer has a distinct way of expressing themselves, and a good translator must be able to replicate this voice in the translated text. This requires a deep understanding of the author's writing style, as well as the ability to adapt it to the conventions of the target language.Additionally, translators must be mindful of the cultural and historical context of the original work. English literature is deeply rooted in the history and traditions of the English-speaking world, and translators must be aware of these influences in orderto accurately convey the author's intended message. This requires thorough research and a nuanced understanding of the social, political, and economic factors that shaped the work.Skills and Knowledge RequiredTo successfully translate a full-length English text, translators must possess a wide range of skills and knowledge. First and foremost, translators must be fluent in both the source language (English) and the target language. This includes a strong grasp of grammar, syntax, and vocabulary in both languages, as well as an understanding of the cultural and historical context of the works being translated.Translators must also have a keen eye for detail and a meticulous approach to their work. Every word, sentence, and paragraph must be carefully considered and translated with precision in order to accurately convey the meaning of the original text. This requires strong analytical skills and a deep understanding of the nuances and complexities of language.Furthermore, translators must possess strong writing skills in order to craft a compelling and engaging translation. Translating a full-length English text is not simply a matter of substituting one word for another; it requires creativity, imagination, and a deep appreciation for the beauty of language. Translators mustbe able to capture the rhythm, cadence, and tone of the original work in their translation, while also adapting it to the conventions of the target language.ConclusionIn conclusion, translating a full-length English text is a complex and challenging task that requires a high level of skill, knowledge, and creativity. Translators must possess a deep understanding of both the source and target languages, as well as the cultural and historical context of the work being translated. Through their careful and meticulous work, translators play a crucial role in making English literature accessible to a global audience, bridging the gap between languages and cultures. By preserving the beauty and complexity of the original text in their translations, translators enrich our understanding of literature and bring the works of English authors to readers around the world.。
Characterization of production of Paclitaxel and related Taxanes in Taxus Cuspidata Densiformis suspension cultures by LC,LC/MS, and LC/MS/MSCHAPTER THEREPLANT TISSUE CULTUREⅠ. Potential of Plant cell Culture for Taxane ProductionSeveral alternative sources of paclitaxel have been identified and are currently the subjects of considerable investigation worldwide. These include the total synthesis and biosynthesis of paclitaxel, the agriculture supply of taxoids from needles of Taxus species, hemisynthesis (the attachment of a side chain to biogenetic precursors of paclitaxel such as baccatin Ⅲ or 10-deacetylbaccatin Ⅲ), fungus production, and the production of taxoids by cell and tissue culture. This reciew will concentrate only on the latter possibility.Plant tissue culture is one approach under investigation to provide large amounts and a stable supply of this compound exhibiting antineoplastic activity. A process to produce paclitaxel or paclitaxel-like compounds in cell culture has already been parented. The development of fast growing cell lines capable of producing paclitaxel would not only solve the limitations in paclitaxel supplies presently needed for clinical use, but would also help conserve the large number of trees that need to be harvested in order to isolate it. Currently, scientists and researchers have been successful in initiating fast plant growth but with limited paclitaxel production or vice versa. Therefore, it is the objective of researchers to find a method that will promote fast plant growth and also produce a large amount of paclitaxel at the same time.Ⅱ. Factors Influencing Growth Paclitaxel ContentA.Choice of Media for GrowthGamborg's (B5) and Murashige & Skoog's (MS) media seem to be superior for callus growth compared to White's (WP) medium. The major difference between these two media is that the MS medium contains 40 mM nitrate and 20mM ammonium, compared to 25mM nitrate and 2mM ammonium. Many researchers have selected the B5 medium over the MS medium for all subsequent studies, although they achieve similar results.Gamborg's B5 media was used throughout our experiments for initiation of callus cultures and suspension cultures due to successful published results. It was supplemented with 2% sucrose, 2 g/L casein hydrolysate, 2.4 mg/L picloram, and 1.8 mg/L α-naphthalene acetic acid. Agar (8 g/L) was used for solid cultures.B. Initiation of Callus CulturesPrevious work indicated that bark explants seem to be the most useful for establishing callus. The age of the tree did not appear to affect the ability to initiate callus when comparing both young and old tree materials grown on Gamborg's B5 medium supplemented with 1-2 mg/L of 2,4-dichlorophenoxyacetic acid. Callus cultures initiated and maintained in total darkness were generally pale-yellow to light brown in color. This resulted in sufficient masses of friable callus necessary for subculture within 3-4 weeks. However, the growth rate can decline substantially following the initial subculture and result in very slow-growing, brown-colored clumps of callus. It has been presumed that these brown-colored exudates are phenolic in nature and can eventually lead to cell death. This common phenomenon is totally random and unpredictable. Once this phenomenon has been triggered, the cells could not be saved by placing them in fresh media. However, adding polyvinylpyrrolidone to the culture media can help keep the cells alive and growing. Our experience with callus initiationwas similar to those studies.Our studies have found that callus which initiated early (usually within 2 weeks ) frequently did not proliferate when subcultured and turned brown and necrotic. In contrast, calli which developed from 4 weeks to 4 months after explants were fist placed on initiation media were able to be continuously subcultured when transferred at 1-2 month intervals. The presence of the survival of callus after subsequent subculturing. The relationship between paclitaxel concentration and callus initiation, however, has not been clarified.C. Effect of SugarSucrose is the preferred carbon source for growth in plant cell cultures, although the presence of more rapidly metabolized sugar such as glucose favors fast growth. Other sugars such as lactose, galactose, glucose, and fructose also support cell growth to some extent. On the other hand, sugar alcohols such as mannitol and sorbital which are generally used to raise the sugars added play a major role in the production of paclitaxel. In general, raising the initial sugar levels lead to an increase of secondary metabolite production. High initial levels of sugar increase the osmotic potential, although the role of osmotic pressure on the synthesis of secondary metabolites is not cleat. Kim and colleagues have shown that the highest level of paclitaxel was obtained with fructosel. The optimum concentration of each sugar for paclitaxel production was found to be the same at 6% in all cases. Wickremesinhe and Arteca have provided additional support that fructose is the most effective for paclitaxel production. However, other combinations of sugars such as sucrose combined with glucose also increased paclitaxel production.The presence of extracellular invertase activity and rapid extracellular sucrose hydrolysis has been observed in many cell cultures. These reports suggest that cells secrete or possess on their surface excess amounts of invertase, which result in the hydrolysis of sucrose at a much faster rate. The hydrolysis of sucrose coupled with the rapid utilization of fructose in the medium during the latter period of cell growth. This period of increased fructose availability coincided with the faster growth phase of the cells.D. Effect of Picloram and Methyl JasmonatePicloram (4-amino-3.5.6-trichloropicolinic acid) increases growth rate while methyl jasmonate has been reported to be an effective elicitor in the production of paclitaxel and other taxanes. However, little is known about the mechanisms or pathways that stimulate these secondary metabolites.Picloram had been used by Furmanowa and co-workers and Ketchum and Gibson but no details on the effect of picloram on growth rates were given. Furmanowa and hid colleagues observed growth of callus both in the presence and absence of light. The callus grew best in the dark showing a 9.3 fold increase, whereas there was only a 2-4 fold increase in the presence of light. Without picloram, callus growth was 0.9 fold. Unfortunately,this auxin had no effect on taxane production and the high callus growth rate was very unstable.Jasmonates exhibit various morphological and physiological activities when applied exogenously to plants. They induce transcriptional activation of genes involved in the formation of secondary metabolites. Methyl jasmonate was shown to stimulate paclitaxel and cephalomannine (taxane derivative) production in callus and suspension cultures. However, taxane production was best with White's medium compared to Gamborg's B5 medium. This may be due to the reduced concentration of potassium nitrate and a lack of ammonium sulfate with White's medium.E. Effect of Copper Sulfate and Mercuric ChlorideMetal ions have shown to play significant roles in altering the expression of secondary metabolic pathways in plant cell culture. Secondary metabolites,such as furano-terpenes, have been production by treatment of sweet potato root tissue with mercuric chloride. The results for copper sulfate, however, have not been reported. F. Growth Kinetics and Paclitaxel ProductionLow yields of paclitaxel may be attributed to the kinetics of taxane production that is not fully understood. Many reports stated inconclusive results on the kinetics of taxane production. More studies are needed in order to quantitate the taxane production. According to Nett-Fetto, the maximum instantaneous rate of paclitaxel production occurred at the third week upon further incubation. The paclitaxel level either declined or was not expected to increase upon further incubation. Paclitaxel production was very sensitive to slight variations in culture conditions. Due to this sensitivity, cell maintenance conditions, especially initial cell density, length of subculture interval, and temperature must be maintained as possible.Recently, Byun and co-workers have made a very detailed study on the kinetics of cell growth and taxane production. In their investigation, it was observed that the highest cell weight occurred at day 7 after inoculation. Similarly, the maximum concentration for 10-deacetyl baccatin Ⅲ and baccatin Ⅲ were detected at days 5 and 7, respectively. This result indicated that they are metabolic intermediates of paclitaxel. However, paclitaxel's maximum concentration was detected at day 22 but gradually declined. Byun and his colleagues suggested that paxlitaxel could be a metabolic intermediate like 10-deacetyl baccatin Ⅲ and baccatin Ⅲ or that pacliltaxel could be decomposed due to cellular morphological changes or DNA degradation characteristic of cell death.Pedtchanker's group also studied the kinetics of paclitaxel production by comparing the suspension cultures in shake flasks and Wilson-type reactors where bubbled air provided agitation and mixing. It was concluded that these cultures of Taxus cuspidata produced high levels of paclitaxel within three weeks (1.1 mg/L per day ). It was also determined that both cultures of the shake flask and Wilson-type reactor produced similar paclitaxel content. However, the Wilson-type reactor had a more rapid uptake of the nutrients (i.e. sugars, phosphate, calcium, and nitrate). This was probably due to the presence of the growth ring in the Wilson reactor. Therefor, the growth rate for the cultures from the Wilson reactor was only 135 mg./L while the shake flasks grew to 310 mg/L in three weeks.In retrospect, strictly controlled culture conditions are essential to consistent production and yield. Slight alterations in media formulations can have significant effects upon the physiology of cells, thereby affecting growth and product formation. All of the manipulations that affect growth and production of plant cells must be carefully integrated and controlled in order to maintain cell viability and stability.利用LC,LC/MS和LC/MS/MS悬浮培养生产紫杉醇及邓西佛米斯红豆杉中相关紫杉醇类的特征描述第三章植物组织培养Ⅰ.利用植物细胞培养生产紫杉的可能性紫杉醇的几个备选的来源已被确定,而且目前是全球大量调查的主题。
电气工程的外文文献(及翻译)文献一:Electric power consumption prediction model based on grey theory optimized by genetic algorithms本文介绍了一种基于混合灰色理论与遗传算法优化的电力消耗预测模型。
该模型使用时间序列数据来建立模型,并使用灰色理论来解决数据的不确定性问题。
通过遗传算法的优化,模型能够更好地预测电力消耗,并取得了优异的预测结果。
此模型可以在大规模电力网络中使用,并具有较高的可行性和可靠性。
文献二:Intelligent control for energy-efficient operation of electric motors本文研究了一种智能控制方法,用于电动机的节能运行。
该方法提供了一种更高效的控制策略,使电动机能够在不同负载条件下以较低的功率运行。
该智能控制使用模糊逻辑方法来确定最佳的控制参数,并使用遗传算法来优化参数。
实验结果表明,该智能控制方法可以显著降低电动机的能耗,节省电能。
文献三:Fault diagnosis system for power transformers based on dissolved gas analysis本文介绍了一种基于溶解气体分析的电力变压器故障诊断系统。
通过对变压器油中的气体样品进行分析,可以检测和诊断变压器内部存在的故障类型。
该系统使用人工神经网络模型来对气体分析数据进行处理和分类。
实验结果表明,该系统可以准确地检测和诊断变压器的故障,并有助于实现有效的维护和管理。
文献四:Power quality improvement using series active filter based on iterative learning control technique本文研究了一种基于迭代研究控制技术的串联有源滤波器用于电能质量改善的方法。
Geotextile reinforced by soft soil1. IntroductionGeotextile known, it has high tensile strength, durability, corrosion resistance, texture, flexibility, combined with good sand, to form reinforced composite foundation, effectively increase the shear strength , tensile properties, and enhance the integrity and continuity of soil. Strengthening mechanism for the early 60's in the 20th century, Henri Vidal on the use of triaxial tests found a small amount of fiber in the sand, the soil shear strength can improve the image of more than 4 times in recent years, China's rock Laboratory workers also proved in the reinforced sand can effectively improve the soil's bearing capacity, reduce the vertical ground settlement, effectively overcome the poor soil and continuity of overall poor performance. As with the above properties of reinforced soil and the characteristics of its low price, so the project has broad application prospects.2.1 Project OverviewThe proposed retaining wall using rubble retaining wall of gravity, the wall is 6 meters high, the bearing capacity of foundation soil required to 250kPa, while the basement geology from the top down as follows: ①clay to a thickness of 0.7 to 2 meters saturated, soft plastic; ② muddy soil, about 22 - 24 meters thick, saturated, mainly plastic flow, local soft plastic; ③ sand layer to a thickness of 5 to 10 meters, containing silty soil and organic matter, saturated, slightly wet; ④ gravel layer, the thickness of the uneven distribution points, about 0 to 2.2 meters, slightly dense; ⑤ weathered sandstone. Including clay and silty soil bearing capacity is 70kPa, obviously do foundation reinforcement.2.2 Enhanced Treatment of reinforced foundation cushion Reinforcement replacement method can be used for sand and gravel used forsoil treatment, but due to loose bedding, based on past experience, witha gravel mat to treat a large settlement of the foundation always exist, even the characteristics of poor, often resulting in cracks in the superstructure, differential settlement of the image, this works for6-meter-high rubble retaining walls, height and large, and because the walls are 3 meters high wall, if there is differential settlement of retaining walls, cracks, will result in more serious consequences and thus should be used on the cushion reinforcement through economic and technical analysis, decide on the sand and gravel stratum were reinforced hardening. Reinforcement treatment method: first the design elevation and the basement excavation to 200mm thick layer of gravel bedding, and then capped with a layer of geotextile, and then in the thick sand and gravel on the 200, after leveling with the yellow sand using roller compaction; second with loaded bags of sand and gravel laying of geotextile, the gap filled with slag, geotextile bags capped 100 thick gravel, roller compaction. Its on repeat laying geotextile → → compacted gravel, until the design thickness of the cushion, the bridge is 1 m thick cushion, a total of 4 layers of geotextile, two bags of sand.This method works fast, simple machine, investment, after years of use, that reinforce good effect, building and construction units are satisfied.3 ExperienceTo achieve the reinforced soil reinforcement effect, must be reinforced earth construction technology, construction strict quality control: 1, geotextile should increase the initial pre-stress, and its end should be a reliable anchor to play the tensile strength of geotextile, anchoring more firmly, more capacity to improve, the foundation of the stress distribution more uniform, geotextile side Ministry of fixed length by laying end to ensure the fold, the folded end wrapped sand to increase its bond strength to ensure that the use will not be pulled out duringthe period.Second, the construction process have a significant effect on the reinforcement effect, the construction should be as soon as possible so that geotextile in tension, tensile strength geotextile can be played only when the deformation, so do not allow construction of geotextile crease occurs, the earth Fabric tension leveling as much as possible. Geotextile in order to have enough by the early Dutch strain, according to the following procedure works: ① laying geotextile; ② leveled the tension at both ends; both ends of the folded package gravel and sand filling at both ends; ③ center fill sand; ④ 2 higher end of sand; ⑤ Finally, the center of sand filling. Click here to enable the construction method of forming corrugated geotextile being stretched as soon as possible, to play a role in the early loaded.Third, the construction of geotextile-reinforced cushion should the level of shop using geotextile geotextile and laying of gravel bags cushion the turn to play bag cushion integrated turn out good, flexural rigidity, and dispersion of good and peace bedding layer of the overall continuity of good advantages.4 ConclusionGeotextile reinforced by soft soil is an effective, economical, safe, reliable, simple method, but the literature describes only qualitative, experience more components, yet the lack of rigorous The theoretical formula, reliable test data to be adequate, these are yet to be theoretical workers and the general engineering and technical personnel continue to explore.土工织物加筋垫层加固软土地基1. 引言土工织物又称土工聚合物,它具有高抗拉强度,耐久性、耐腐蚀性,质地柔韧,能与砂土很好地结合,组合成加筋土复合地基,有效地提高土的抗剪强度、抗拉性能,增强土体的整体性和连续性。
Based on GSM module and AT89C51 connectiondesign and application---From 《GSM principle and its network optimization》chapter one---From 《New single chip microcomputer interface device and technology》chapter sixAbstractThis article through analyzed the GSM module and the monolithic integrated circuit connection design simply introduced the TC35i module commonly used instruction and the coding rule, introduced emphatically the TC35i module and the AT89C51 principle of work, the periphery connection electric circuit, the software control technology, at the same time has produced some TC35i module and the AT89C51 connection application procedure, proposed AT89C51 when receive data should pay attention question, thus designed has the GSM module the data transmission terminal.Key words: GSM network1 Summarize:Along with correspondence technique of development, according to the service function of the NTT DoCoMo net, just to industry control and control from a distance the realm have continuously extension of trend.Is orientation this kind of demand, Siemens company released a new generation wireless correspondence GSM mold piece-TC35i, according to should the short news function of the mold piece, can fast safety credibility realization customer information processing etc. function, special be applicable to control centre and terminal equipments distance very far, or inconvenience adoption wired correspondence lie quality etc. situation, for example the oil well information collect behind of deliver, the long range copy form system, city transportation direction etc. all according to the TC35i mold piece to realization.2 The application of GSM network:GSM is Global System for Mobile Communications acronym, which means Global System for Mobile Communications is the world's leading cellular systems inthe world. GSM is based on narrowband TDMA standard that allows radio frequency in a group call at the same time 8. GSM80 during the rise in Europe, put into use in 1991. The end of 1997, has operations in more than 100 countries, Europe and Asia has become the standard in fact, that by 2001, the world's 162 countries have already built a 400 GSM communications network. But the GSM system capacity is limited, users in the network overload, it had to construct additional network facilities. What is gratifying is that GSM performance in other areas, which in addition to providing a standardized list and signaling systems, but also opened up some of the more intelligent of the business such as international roaming and so on. The convenience of GSM mobile phone is that it provides a smart card, known as SIM cards, and card could be separated, so that the replacement of mobile phone users and custom personal information in this area are facilitated.GSM network to improve after years of development, is now very mature, less blind spots, signal stability, automatic roaming, and the communication distance from the impact of the surrounding environment. GSM short message in particular, flexible and convenient, you can cross-market, inter-provincial and even cross-border transmission, and each send a short message as long as one dime, very reliable and affordable. In addition, the mobile phone SIM card in recent years can apply for 0, some packages use lower cost than fixed. Therefore the use of mobile phone message to achieve alarm, ultra long-range remote control for industrial equipment, transmission of data is a very good choice.GSM module, is a similar mobile communication module, integrates a number of mobile phone functions on a single small circuit board, it can send SMS messages, calls and so on, the module is small, but it has a lot of mobile phone functionality, with its have equal is the core of the mobile phone, and it is in a lot of applications have a wide range of applications, GSM module through the use of AT commands to control it, modules can be connected to computer RS232 serial port, can also be used to carry out single-chip control . Below we cite some typical applications:2.1 mobile phone access control system:GSM Access Control System used to control the electric lock control, if you need to enter, as long as the cell phone call using GSM modules mobile number, will automatically open the door, and only you can set up cell phone numbers to open the door, and no costs.2.2 three billboard over the weather disaster emergency turn off:Over three billboards are constantly flip through the motor to achieve a number of ads displayed, because installed in the outdoors, when there is wind, hail and other weather disasters, billboards could easily be blown bad or damaged card die, when in need of emergency shut down, You can normally closed relay contact to control the power of advertising, when you need to do is send "turn off" control message, the billboard will automatically turn off, and automatically after a certain time delay automatically return to normal job (generally disastrous weather will not continue for a long time) in advance if you want to open a billboard, you can send "Open" control message.2.3 engineering system balance reminders:Some works are safe after the completion of the normal operation after a period of time to settle the balance, if the encounter malicious clients the outstanding purchase price, often installed side very headache, because equipment has been installed, if the loss of a great come back down, particularly in the field customer very costly when the client system can be installed in the GSM module, use it all the way to control system or the way some of the key points, when the customer paid in arrears when the malicious message can turn off some features, forcing customers to pay the purchase price then immediately open message, if you have a smooth recovery of the purchase price can also be the name of system maintenance by the GSM module removed from the client system.2.4 monitoring systems or Web servers and reset the alarm:Monitoring system or web server running after a long period after death may be wrong, this time to power on reset is the only solution at this time through the GSM module can control system power, and set to open automatically after 3 seconds turn off mode, can achieve power reduction, in addition, GSM module in some special application areas also played a very large role, such as: the disappearance of the main power supply, memory errors, fan shutdown, fuel depletion, it was the invasion and other information, are not people the ideal choice for monitoring the engine room.the remote control of home appliances:Through the message can easily achieve the remote control to open rice cookers, water heaters and other appliances by remote control or switch to repair mode can also control the air-conditioning GSM global wireless mobile communication network control alarm host, using the global GSM short message data transmission mode and voice-enabled platform for the completion of intelligent data transmission and remotecontrol alarm, set the host family, shops, office safety, electrical control, remote monitoring, such as Intelligent home functions, because of the global GSM wireless mobile communication network signal coverage area of Canton, and truly realize the low-cost high-quality ultra-long-distance convenient and flexible intelligent wireless control and alarm, to solve the fixed-line telephone or cable broadband network wired alarm limitations. GSM global wireless mobile communications network in popularity all over the world, the GSM global wireless mobile communication network control alarm can be widely used in a single host family, community property, electricity, transportation, petroleum, coal, railway, municipal and public security departments of the security industry prevention devices, data monitoring and remote monitoring system. Wireless Road, with 11 defense areas, 2-way Cable Standoff, different defense area alarm, alarm and message control, separate from a defended position, remote control, home appliance control, linkage to take photographs with the latest alarm center network characteristics.Features:1. Wireless suspects under strict surveillance, no wiring, and ease of installation.2. Cable suspects under strict surveillance, safe and reliable.3. Wireless remote control security / from a defended position, easy to operate.4. Adaptability widely used global-band wireless mobile networks.5. Password settings, confidentiality stronger.6. Alarm, the high-decibel alarm sound to deter thieves.7. Host automatically to six groups of mobile numbers to send SMS alerts. Alarm message and a telephone can be set up8. Host automatically dial the six groups of mobile or fixed telephone warning, start-site monitoring.9. Preset scene alarm and alarm message10. With emergency alarm function, can prevent thieves burglary, detection of gas leaks and smoke fire.11. Communicate electric missing Detect and alarm, to prevent the intentional destruction of the power system and power failure monitoring.12. Communicate after the loss of electricity automatically switch to a back-up battery. 13. Available through GSM network platform and networking alarm center.14. Supported message in Chinese or English instructions.15. Handset intercom mode: Matching intercom calls, and alarm can be two-wayintercom, real-time clear police intelligence to prevent unnecessary alarm.3 The TC35i mold piece introductionCurrently, domestic already beginning usage of the GSM mold piece have a lot, and these of function, method of using difference not big.What this design adoption is a Siemens TC35 the TC35i of the series.On this kind of wireless mold piece function and TC35 and permit, design tightly packed, consumedly contracted the physical volume of customer's product.The TC35i and GSM2/2 and permit,dual-band(GSM900/GSM1800), RS232 the data connect, should mold piece and radio frequency electric circuit and Ji take and integral whole, provide toward the customer standard of AT order connect, is data, speech, short news and fax provide fast, credibility, safety of deliver, convenience customer of application development and design.3.1 The GSM AT instruction introduction that the mold has something to do with SMS in the piec e:The order for provide of the GSM- powered mold piece match GSM07.05 and GSM07.07 norm.In the GSM07.07 definition of the AT Command connect and provided a kind of which GSM AT Instruction TC35i AT89C51move terrace and data terminal equipments of in general use connect;The GSM07.05 made to the short news detailed of provision.At short news mold piece receive network hair of short news, can send out a designation information through a string of, the data terminal equipments can send out toward the GSM mold piece various order.The instruction of GSM AT having something to do with SMS such as List1 to show.The instruction of GSM AT gather, is signed letter, Motorola and HP etc. factory house by Nokia, love to together develop for the GSM system of, among them include control SMS(Short Message Service).3.2 The PDU code rule:Send out short news in common use Text and PDU(Protocol Data Unit, agreement data unit) mode currently.The usage Text mode receive and dispatch a message code simple, realization get up very easy, but the biggest weakness be to can't receive and dispatch Chinese message;But PDU mode not only support Chinese message, also the ability send out English message.The PDU mode receive and dispatch a message can the usage be 3 kinds of to code:7-bit, 8-bit and UCS2 code.7-the bit code to used for send out common of ASCII character list, 8-bitcode Be usually used for sending out data news, UCS2 code used for sending out Unicode character list.General PDU's code is constitute by ABCDEFGHIJKLM 13.A:The address length of the message center, 216 enter to make number(one word stanza)B:The number type of the message center, 216 enter to make number.C:Message center number, B+C length will from the data decisionD:Document head word stanza, 216 enter to make number.E:Information type, 216 enter to make number.F:Drive call number length, 216 enter to make number.G:Drive call number type, 216 enter to make number, take value togetherH:Drive call number, length from data within F decision.I:Agreement marking, 216 enter to make number.J:The data code a project, 216 enter to make number.K:Term of validity, 216 enter to make number. L:Customer data length, 216 enter to make number.M:Customer's data, its length from the data decision in the L.Enactment in J adoption UCS2 code, here is the Unicode character list of Chinese-English.4 the hardware of the TC35i and list slice machine connect a people'selectric circuitThe TC35i mold piece is main to save according to the processor, GSM radio frequency mold piece, power supply mold piece, Shan from the GSM, the ZIF conjunction machine, antenna connect six part constitute.Connect machine with a list slice machine realization electric circuit to connect through a ZIF, should connect read or send out the TC35i mold piece in of data.5 list slice the software of the machine and TC35i connect and controlprinciple8051 one-chip computer have four 8 walk abreast I/O port, call P0, P1, P2 and P3. Each port is 8 accurate two-way mouths, accounts for 32 pins altogether. Every one I/O line can be used as introduction and exported independently. Each port includes a latch (namely special function register ), one exports the driver and a introduction buffer . Make data can latch when outputting, data can buffer when making introduction , but four function of passway these self-same. Expand among the system of memory outside having slice, four port these may serve as accurate two-way mouth of I/O in common use. Expand among the system of memory outsidehaving slice, P2 mouth see high 8 address off; P0 mouth is a two-way bus, send the introduction of 8 low addresses and data / export in timesharingList slice the software of the machine and TC35i connect in fact be list slice the machine pass AT instruction control cellular phone of control technique, first constitution the TC35i mold piece of work mode:AT+CMGF=n, n=0 is a PDU mode;N=1 write an article this mode;Usually the constitution is a PDU mode, under this kind of mode, ability transmission or accept a transparent data.(customer from definition data)AT+CMGR=n in order to read the short news data of the TC35i mold piece, the n is a short news number.AT+CMGL=n in order to list the short news in the TC35i mold piece, n=0 is the short news which read, n=a the short news which have been already read, n=2 short news which sent out, n=3 for have already send out of short news n=4 is all short news.AT+CMGD=the n is the short news which delete the TC35i mold piece and the n is a short news serial number.6 Master routineThe software plait distance pass to write in toward the TC35i dissimilarity of AT instruction ability completion variety function, such as network debarkation, read SIM card top telephone number, send out SMS news and receive SMS news etc..The instruction sign, constant, PDU data...etc. of AT instruction all code form transmission by ASCII;The transmission transparent data have to pair of the TC35i mold piece of work mode constitution is PDU mode;List slice machine toward the TC35i mold piece after send out each instruction have to with return to car sign conduct and actions should instruction of be over, for example list slice the machine send out instruction in"AT+ CMGF=0" toward the cellular phone, its ASCII code sequence is"41 H, 54 H, 2 BH, 42 H, 4 DH, 47 H, 46 H, 3 DH, 30 H, 0 DH", the last word stanza 0 DH is to return to car sign, mean that instruction be over, if have no this to return to car sign, the cellular phone won't identify this instruction.When the AT instruction which receive to an integrity of the TC35i mold piece after, the TC35i mold piece not summary execution should instruction, but first just receive of the ASCII of the AT instruction code sequence all anti- send out;(contain 0 DH)Secondly send out a the ASCII which return to car sign with a carriage return sign to code, namely 0 DH with 0 AH;Then performance should instruction.The list slice machine read the PDU data of the TC35i mold piece, originality data should is 16 enter make number, but read back of data still is an ASCII mean of 16 enter make number.So a word stanza of 16 entered to make number and thenbecame 2 word stanza of ASMII code.But the PDU data data word stanza length within pack part still is actual character list length.But isn't the word stanza which become ASCII code length, this at plait distance should special attention, otherwise receive of data not integrity.The list slice machine is after receiving a PDU data pack data have to its instauration become 16 enter make a data, its calculate way as follows:Establish a for the ASCII code receive, b for the conversion is behind of 16 enter make number.So if a<39 H,b=a-30 H;If a>39 H, b=h-07 H a-30.End pair of in front and back two pieces merger is a word stanza.Concluding remark The usage cellular phone mold piece benefit is at the system integration, the cost be lower.Install correspondence circuit in secluded region etc. difficulty or uneconomical place, engineering service facilities can freedom vivid of constitution, no longer be subjected to geography condition of restriction.In fine, GSM mold piece the price be cheap, application extensive, application the foreground be captivating, pass with cellular phone mold the piece connect can very convenience of design customer demand of the data receive terminal.基于 GSM 模块与 AT89C51 的接口设计及应用的接口设计及应用-----摘自《GSM 原理及其网络优化》第一章-----摘自《新型单片机接口器件与技术》第六章摘要本文通过分析 GSM 模块与单片机的接口设计简单介绍了 TC35i 模块的常用指令及摘编码规则,着重介绍了 TC35i 模块与 AT89C51 的工作原理、外围接口电路、软件控制技术,同时给出了一些 TC35i 模块与 AT89C51 接口的应用程序,提出了 AT89C51 在接收数据时应该注意的问题,从而设计出具有 GSM 模块的数据传输终端。
输送带的二维动态特性3.1.1非线性梁架(构架)元如果只有带的纵向变形是主要素,那么梁架元就可用于模型的皮带弹性反应。
梁架元组成部分有如图2所示的两个结点, P和Q ,四个位移参数确定部分载体X:xT = [up vp uq vq] (1)对平面运动的梁架元有三个独立的刚体运动,因此(这公式)仍然是描述一个变形的参数。
图2 :梁架元的精确位移梁架元轴的长度变化, [ 7 ] :ε 1 = D1(x) = ∫¹ o ds² - ds²odξ(2) 2ds²oDSO是限元未变形的长度,DS是限元变形的长度,ξ是沿着有限元轴的无量纲长度。
图3 :张带的静态凹陷虽然带呈弯曲状态,但梁架元并没有变形,这可能考虑到带小数值凹陷的静态影响。
静态带凹陷的比率是有定义的(见图3 ):K1 = δ/1 = q1/8T (3)其中q是暴露在外面带和散装物料的重量在竖直方向上分布的荷载, 1是带轮间距,而T是带的张力。
,带凹陷的纵向变形影响取决于[ 7 ] :εs = 8/3 K²s (4)产生了非线性梁架元总的纵向变形。
3.1.2梁架元图4 :节点的精确位移和旋转的梁架元。
如果带的横向位移是主要因素,那么梁架元就可以用来模拟皮带。
同样对于拥有六个位移参数的梁架元的平面运动来说,相当于三个独立的刚体运动。
因此就剩下三个变形参数是:纵向变形参数ε 1 ,两个弯曲变形参数ε2和ε 3 。
图5 :梁架元的弯曲变形的梁架元弯曲变形的参数可以定义为梁架元的组成载体(见图4 ):xT = [up vp µp uq vq µq] (5)和如图5的变形结构e2p1pqε 2 = D2(x)=1o(6)ε 3 = D3(x) -eq21pq= 1o3.2绕过托辊及带轮的带运动当绕过托辊或带轮的时候,带运动是受到约束的。
为了说明(弄清楚)这些制约因素,影响制约因素(边界)的条件都必须添加到用来代模拟带的有限元中来。
这可以通过使用多体动力学进行描述。
多体机置动力学的经典描述,建立起由若干约束条件连接起来的刚体或刚性链接。
在(变形)输送带的有限元描述里,带被分离成多个有限元,有限元之间的联系是可变形的。
有限元是由节点连接的,因此分配了位移参数。
要确定带的运动,排除了刚体模型的变形模式。
如果一个带绕过托辊,,决定托辊上带的位置(如见图6)的带长度为ξ,被添加到组件矢量,如:式(6),因此产生了7个位移矢量参数。
图6 :由托辊支撑的带梁架元有两个独立的刚体运动,因此依然有五个变形参数存在。
其中已经在3.1中给出了ε 1 , ε2和ε 3 ,确定了带的变形。
剩下ε4和ε 5 ,确定带和托辊之间的相互作用,见图7 。
图7 :两个约束条件的梁架元有限元。
这些变形参数可以假设成无限刚度的弹性。
这意味着:ε 4 = D4(x) = (rξ + u ξ)e2 - rid.e2 = 0ε 5 = D5(x) = (r ξ + uξ)e1 - rid.e1 =0 (7)如果模拟的是ε 4 > 0的时候,那么带将脱离托辊,而描述带的有限元上的约束条件也将去除。
3.3滚动阻力为了使一种模型能应用于带式输送机有限元模型的滚动阻力,已经制定了一种计算滚动阻力的近似公式, [ 8 ] 。
带运动中,暴露在带外面的总滚动阻力的组成部分,这三部分是耗能的主要部分,可以区分为包括:压痕滚动阻力,托辊的惯性(加速滚动阻力)和轴承滚动阻力(轴承阻力)。
确定滚动阻力因素的参数包括直径和托辊的材料,以及各种带参数,如速度,宽度,材料,紧张状态,环境温度,带横向负荷,托辊间距和槽角。
总滚动阻力的因素,可以表示成总滚动阻力和带垂直负荷之间的比例,定义为:ft = fi + fa + fb (8)Fi是压痕滚动阻力的系数,FA是加速阻力系数,而FB是轴承阻力系数。
这些组成系数由下面的[9]确定:Fi = CFznzh nhD-nD VbnvK-nk NTnTMred ∂²ufa =Fzb ∂t²(9)Mffb =FzbriFZ是带垂直方向上分布的负载和散装物料的负载的总和, H是带的覆盖厚度,D 是托辊的直径,Vb是带速,KN是带负荷的名义百分之比,T是环境温度,Mred 是托辊的折算质量,B是带的宽度, U是带的纵向位移,MF是总的轴承阻力矩和RI是轴承内部半径。
在计算滚动阻力中,皮带的动力性能及机械性能和皮带上覆盖的材料发挥着重要作用。
这使得带的选择和带上覆盖材料,尽量减少由动力阻力引起的能源消耗。
3.4带驱动系统在稳定性的带运动情况下,为了能够测定带式输送机驱动系统的旋转组件的影响,这个带式输送机的总模型必须是含有驱动系统模型。
驱动系统的旋转元件,就像一个减速箱,参照了3.2节中所述的约束条件。
带有减速比的减速箱,可以用带两个位移参数的减速元件来代替, μp 和μq ,像一个刚体的(旋转)运动,因此就剩下一个变形参数:εred = Dred(x) = iµp + µq = 0 (10)要确定电式扭矩感应式电机,是否适应所谓的两轴式电动机。
该相电压的矢量v 可从(11)获得:v = Ri + ωsGi + L ∂i/∂t (11)在(11)式中I 是相电流矢量,R 是模型的相电阻, c 是模型的相电感抗,L 是模型的相感系数而ωs 是电机转子的角速度。
电磁转矩等于:Tc = iTGi (12)电机模型和驱动系统机械组件是由驱动系统的运动方程联系着的:Ti = Iij ∂²øj + Cik∂øk Kilø (13)∂t ² ∂t其中T 是扭矩矢量,I 是模型的惯量,C 是模型的阻尼,K 是矩阵刚度和ø是电机旋转轴的角速度。
模拟启动或停止程序控制反馈的程序可以添加到带式驱动系统模型中,用来控制驱动扭矩。
3.5运动方程整个带式输送机模型的运动方程可以得出潜在功率的原则, [ 7 ] :fk - Mkl ∂²x1 / ∂t ² = ζ1Dik (14)其中F 是阻力矢量,M 是模型的质量而ζ是拉格朗日乘数的矢量,可能解释为双重压力矢量to 张力矢量ε 。
为了解决带有X 这一组方程,方程一体化是必要的。
但是一体化的结果,必须确保满足约束条件。
如果(8)式中应变为零,那么必须纠正一体化结果,如见[ 7 ] 。
可以使用模型的反馈选择,例如限制提升物质垂直方向上的运动。
这种违逆动力学的问题可以用下面公式表示。
鉴于带模型及其驱动系统的提升运动众所周知,根据系统自由度和它的比例(速度)可以确定其他元件的运动。
它超出了本文所讨论关于此项的所有细节范围。
3.6实例为了在长距离带式输送机系统设计阶段能够正确设计,应用了有限元法。
例如带强度的选择,可以减少的尽量减少,使用模型模拟的结果确定传送带的最大张力。
以有限元模型的功能作为例子,应该考虑到在两个托辊位置范围之间稳定移动带的横向振动。
在运输机的设计阶段这必须被确定,才得以确保空带的共振。
对于皮带输送机的设计来说,托辊和移动带间相互作用影响是很重要的。
托辊的及带轮的几何不完善性,导致带脱离托辊和带轮能支撑的位置,在带和支撑带轮之间产生一种横向振动。
这对带施加了一部分的交互轴向应力。
如果这部分力是比皮带的预应力小,那么带将在它的固有频率中振动,否则带将被迫振动。
皮带是会受迫振动的,例如受托辊的偏心率影响。
在输送带返程中,这种振动特别值得注意。
由于受迫振动的频率取决于带轮和托辊的角速度,因此对于带的速度,确定在带轮和托辊之间,带在自然频率状况下,横向振动中带速影响,这个是很重要的。
如果受迫振动的频率接近于皮带横向振动的固有频率,将发生共振现象。
有限元模型的模拟结果可用于确定稳定移动的带的横向振动频率范围。
该频率是利用快速傅立叶技术从时域范围到频域范围,带横向位移变换后得到的结果。
除了使用有限元模型外也可以运用近似分析法。
皮带可以模拟成一个预应力梁。
如果皮带的弯曲硬度可以被忽略,横向位移比托辊间距还小,Ks << 1 ,并且带增加的长度相对于横向位移的原始长度来说是微不足道,带的横向振动可近似为下列线性微分方程,如见图15 :∂²v = (c²2 - C²b) ∂²v- 2Vb∂²v(15)∂t ²∂x²∂x∂t其中V是皮带的横向位移和C2是横向波的波速度,由(16)式定义:c2 = √g1/8Ks (16)首先,图5中带的横向固有频率范围可从公式(16)获得,如果假定v(O,t)=v(l,t)=0:fb =1 c2 (1 - ß²) (17)21 ß是无量纲的速比,由(18)式确定:ß = Vb / c2 (18)FB 是不同带的各自独立的频率范围,由于输送带长度方向上带张力变化。
托辊的受迫振动频率,使托辊产生了一个偏心率等于:fi = Vb / πD (19)其中D 是托辊的直径。
为了设计一个在托辊间距中无支撑的共振,这受到以下条件限制:L≠πD (1-ß²)(20) 2ß 由线性微分方程(16)所取得的成果不过是只适用于小数值的速比ß。
对于大数值的速比ß来说,如高速运输机或低的带张力,在(16)式中所有非线性条件就显得重要的。
因此,数值模拟的运用,有限元模型的开发,都是为了确定带横向振动线性和非线性频率之间的比例范围。
这些关系已被确定适合不同的数值的ß,例如说一个功能凹陷的比率Ks 。
使用快速傅里叶技术将横向位移结果的转化为频谱。
从这些频谱中获得的频率与公式(18)获得的频率相比,其产生了图8所显示的曲线。
从这一数字可见,对小于0.3的ß来说,计算误差很小。
对于大数值的ß来说,运用线性近似值法产生的计算误差达到10 %以上。
运用了皮带采用非线性梁架元的有限元模型,因此可以准确地确定大数值ß的横向振动。
对于小数值ß的横向振动的频率也可以用公式(18)准确地预测。
然而,它不能分析,例如带凹陷和纵向波的传播之间的相互作用,或者同样可以看成有限元模型的脱离托辊的皮带。
这决定带应力和横向振动频率之间的关系可以用于皮带张力监测系统。
图8 :由两个托辊支撑的带的横向振动线性和非线性频率之间的比例。
4 实验验证为了使模拟的结果能够得到验证,实验中使用了动态试验设备,如图9所示。
图9 :动态试验设施使用这试验设施能够确定的两个托辊的间距和卸荷扁带的横向振动,例如返程部分的。
声音装置是用来测量皮带的位移。
此外,还有在试验中为我们所知的张紧力,带速,电机转矩,托辊转子与托辊的距离。