Energy
Procedia
GHGT-10
Development of post-combustion CO2 capture with CaO/CaCO3 looping
in a bench scale plant
Chin-Ming Huang, Heng-Wen Hsu, Wan-Hsia Liu, Jui-Yen Cheng, Wei-Cheng
Chen, Tzeng-Wen Wen, Wang Chen
Industrial Technology Research Institute, H s i nc h u310, T ai wa n, R.O.C
Elsevier use only: Received date here; revised date here; accepted date here
Abstract
Several systems for CO2capture using CaO as regenerable sorbent are under development at Industrial Technology Research Institute (ITRI). CaO/CaCO3 looping of carbon dioxide capture system can also be used for both pre-combustion and post-combustion carbon dioxide capture. At present, ITRI has established a post-combustion 1
kW CaO/CaCO3looping of carbon dioxide capture system device in Taiwan. The carbonator is for the bubbling fluidized bed and the calciner is for the moving bed. The device made up 0.1 kg/hour of new CaO which has been under 57 hours of continuous operation. Capture efficiencies above 99% have been obtained under realistic flue gas conditions in the carbonator reactor.
In the future, power generation, petrochemical industry and steel and iron industries
are the first to be considered for reduction of CO2 emissions. Our goal is to establish a 1 MW （5 thousand tons of CO2 every year）pilot plant in 2011, 10 to 30 MW（50 to 150 thousand tons CO2 every year）demonstration plant in 2020 and a commercial plant
in 2027 for post-combustion capture. In addition, ITRI has to research and develop the
CO2capture technologies from flue gases including Gasification or Integrated Gasification Combined Cycle (IGCC), CaO/CaCO3 looping and innovative meso-porous nanomaterials for CO2 adsorption.
? 2010 Elsevier Ltd. All rights reserved
c?2011Published by Elsevier Ltd.
Keywords: CO2 Capture; CaO /CaCO3 looping; Carbonator; Calciner; Pilot testing
doi:10.1016/j.egypro.2011.01.183
C.-M.Huang et al./Energy Procedia4(2011)1268–12751269
1.Introduction
Carbon dioxide the comes from combust ion of fossil fuel is the major contributor of the greenhouse effect. The control and decrease of anthropogenic CO2emissions from fossil fueled power plants abatement play important roles for at mospheric CO2concentration reduct ion. Generally, there are several options for atmospheric carbon dioxide concentration controlling, such as the subst itution of nuclear power for fossil fuels, power efficiency improvement of the fossil plants and the CO2capture prior to its emission. The emission controlling technology of carbon dioxide by using the sorption/desorption concept with the sorbent is a widely applied met hod for the Fluidized Bed Combustor (FBC) flue gas process. From the energy point of view, therefore, the separat ion of carbon dioxide from the emiss ion source, such as coal-fired power plants, has been considered as an effect ive mit igation option for climate change.(1,2,3)
Solid sorbents for CO2separat ion include sodium and potassium oxides, zeolites, carbonates, amine-enriched sorbent, and etc. One of them, the calcium sorbents (CaO) is used widely in fluidized bed combust ion for emiss ion control of sulfur contaminants due to its low cost. In addit ion, it has been well known that the fresh calcined lime can be carbonated rapidly by carbon dioxide at suitable temperature. Thus, the calcium-based sorbents has been suggested to be an attractive material for carbon dioxide removes due to its low cost, high adsorpt ion capacity and high reversibilit y of CO2.The mechanism of CO2capture/release of calciu m sorbent can be divided into two step, carbonat ion and calcination:
CaO+CO2àCaCO3 (1)
CaCO3àCaO+CO2 (2) The calcinat ion of CaCO3is an endothermic, mean t he forward react ion is higher temperature favorable.(4,5)
CO2separat ion from flue gas by CaO-based sorbents in fluidized bed combust ion (FBC) system is an intensively invest igated technology for the reduct ion of CO2emission.The t ypical scheme of the CO2remove process could be depicted as Figure 1.
Flue gas
CO
2 Figure 1 The scheme o f CO2separat ion loop by CaO-based sorbent s.
1270 C.-M.Huang et al./Energy Procedia4(2011)1268–1275
According to the ment ioned above, the carbonat ion process of calcium sorbents (CaO) with CO2is t he basis reaction for the capture technology in this high temperature CaO/CaCO3cycle system. In fact, all CaO sorbents used in this loop come from the calcinat ion process of CaCO3, at around 800~900o C. In the carbonator, the high porous CaO sorbents were treated wit h a diluted CO2 stream and further formed CaCO3at a temperature of over 600o C. Act ive sorbents were regenerated by a calcinat ion reaction at higher temperature between 850~900o C, and the CO2component were separated from the loop. After being reduced in separate (cracker) vessel, the CaCO3transfers to CaO and further returns to the carbonat ion vessel for CO2 capture.
The object ive of this research is to develop high performance sorbents for CO2uptake at high temperatures. Due to the finit e t ime of exposure and low utilizat ion of the limestone, increasing the calcium ut ilizat ion efficiency would be attractive of lowering the cost of raw materials. In this work, CaO sorbents wit h porous structure and high capacit y of CO2 was developed for carbon dioxide capture. The micrographs, surface area, pore structural, act ivit y, cycle life, and characterist ic properties of CaO sorbents were also analyzed. In addit ion, an at mospheric small pilot CaO carbonat ion/ calcinat ion system was also established for practical applicat ion of carbon dioxide separat ion.
2.Experimental
Experiments have been conducted in a 1 kW test facility built at ITRI, made up of one bubbling fluidized bed carbonator and one moving bed calciner as shown in Figure 2. The bubbling fluidized bed is 2.5 m high wit h a 0.1 m internal diameter. The moving bed is 0.9 m long wit h a 0.05 m internal diameter. Solids from the bubbling fluidized bed to moving bed have completed half of the solid circulation loop. Solids are transferred from the carbonator to the calciner by a pipe. The pipe is 0.5 m long with 1 inch internal diameter. A mixture of gas containing CO2 (air from a blower and CO2 from a cylinder) is fed into the carbonator. Note that the fluidized gas in carbonator is mixing by 85% air and 15% CO2 in the percentage of volume. The air distributor is located at the gas entrance in the carbonator. Particles size of CaCO3are distributed between 250-500μm. Silicon carbide heating rods cover surround the carbonator and the calciner, which can maintain the moving bed at the temperature 800~900and the bubbling
℃
℃3 calcination/carbonation studies fluidized bed at the temperature 600~700. The CaCO
in these works which have two steps. One is continuous-mode operation and it makes up 0.1 kg fresh CaCO3per hour. In this mode which needs toe maintain the bubbling fluidized bed at the temperature of 600~700and the moving bed at the temperature
℃
℃ The bubbling fluidized bed at the bottom of ΔP between 100 ~ 150 cm-H2O, 800~900.
that gas velocities are varied between 0.2-0.4 m/s. The other is batch-mode operation without making up fresh CaCO3. In this mode which need to maintain the bubbling fluidized bed at the temperature of 600~700 and the moving bed at the temperature
℃of
C.-M.Huang et al./Energy Procedia4(2011)1268–12751271
℃ The bubbling fluidized bed at the bottom of ΔP between 100 ~ 150 cm-H2O, 600~700.
that gas velocities are varied between 0.2-0.4 m/s. The agitated gas in the calcination vessel is nitrogen gas. In the same place prepare for a hole when we use steam to calcination.
Prior to starting the operation, industrial grade limestone was subjected to
℃In addition CaO decomposition in the calcination vessel at the temperature around 850.
sorbents with highly porous structure and surface area were obtained when the limestone calcinated at high temperature for 30 min. In this process, approximately 8.4 kg of CaO were fluidized in the carbonator column and contacted with CO2 to form CaCO3. 7.6 kg of CaO remain in the moving bed, buffer tanks and transport system. On other hand, concentration of CO2at the exit of the system was also determined for efficiency
estimating of CO2 capture.
Figure 2 Schematic and site photo of the bubbling fluidized bed reactor and moving bed
reactor to test CaO/CaCO3 looping at ITRI.
3.Results and Discussion
We have operation of the continuous-mode and completed the continuous test of CaO/CaCO3looping bench scale experimental system for 57 hours. The CO2capture Tefficiency is more than 99%.(raw conc. of CO2is 14~16%). Figure 3 is continuous-mode operation during 57 hours which the original CO2 concentration of carbonator flue gas inlet and outlet. From start to finish we find the concentration of CO2 in the export value of less than one instrument (TESTO-350S) of the detection limit (0.1%). Our sampling points including the top of the carbonator and cyclone outlet. Figure 4 is the CO2capture efficiency during the 57 hours in the continuous -mode operation. In this figure we can see the CO2 capture efficiency is maintained at above 99%. Figures 3 and 4 by the comparison of the inlet can be found although the CO2concentration
1272 C.-M.Huang et al./Energy Procedia4(2011)1268–1275
changes over time are different, but outlet of the CO2 concentration are lower than the detection limit of carbon dioxide capture efficiency carbonator to maintain more than 99%. The CO2 can not through reactor after a long period of operation. Maybe add CaO 0.1kg per hour, excessive need to be reduced. Therefore carbonator CaCO3/CaO ratios inside the cover in determining the quantity of CaO becomes extremely important. Therefore need to operate the batch experiments. In addition to excessive so as to make up for capture efficiency can be maintained above 99%. Abanades et al. (2009) issued a 30kW test facility in the paper referred to two interconnected circulating fluidized bed reactors capture efficiency of 88%.(6)Although both are fluidized beds, but ITRI's carbonator is bubbling fluidized bed reactor and CSIC-INCAR's carbonator is circulating fluidized bed reactor. CSIC-INCAR the carbonation reactor furnace gas velocities is varied between 1.5-3.5 m/s compared with ITRI of gas velocities is varied between 0.2-0.4 m/s faster, CaO and CO2 may be insufficient reaction time caused by the difference between each other. ITRI's reaction time is about 5-10 seconds and CSIC-INCAR's
reaction time is about 0.9-2 seconds.
concentration of carbonator flue gas inlet and outlet.
Figure 4 It is CO2 capt ure efficiency during 57 hours in the continuous -mode
operation.
Figure 5~8 are 4 times the previous batch-mode operation. Figure 5 is the first cycle in the batch-mode operation of calcination/carbonation studies. In this figure we can find the beginning of the whole system CaO weighed 15 kg in 400 minutes when the carbonator maintained more than 80% capture efficiency. The first cycle's breakthrough curve reached below capture efficiency 10% after about 670 minutes. Figure 6 is the second cycle in the batch-mode operation of calcination/carbonation studies. In this figure we can find the beginning of the whole system CaO weighed 15 kg in 230 minutes when the carbonator maintained more than 80% capture efficiency. The second cycle's breakthrough curve reached below capture efficiency 10% after about 690 minutes. Figure 7 is the third cycle in the batch-mode operation of calcination/carbonation studies. In this figure we can find the beginning of the whole system CaO weighed 15 kg in 105 minutes when the carbonator maintained more than 80% capture efficiency. The third cycle's breakthrough curve reached below capture efficiency 10% after about 400 minutes. Figure 8 is the fourth cycle in the batch-mode operation of calcination/carbonation studies. In this figure we can find the beginning of the whole system CaO weighed 15 kg in 115 minutes when the carbonator maintained more than 80% capture efficiency. The fourth cycle's breakthrough curve reached below capture efficiency 10% after about 370 minutes.
The third cycles and the fourth cycles results are different from the thermogravimetric analyzer (TGA). Figure 9 shows the TGA data recorded CaCO3 at high temperature of conversion vs time. CaCO3 of the conversion by the TGA was reduced when calcination / carbonation cycle increased. The third cycle and the fourth cycle have the same result, so there are other reasons for that. Perhaps the particle size of the change is a likely cause. Table 1 is first to fourth cycles the particle size of the batch-mode operation. CaCO3of the part icle size during repeated experiment will become smaller in Table 1. CaCO3's and the fourth cycle's particle size are the same, perhaps it can be increased the capture efficiency.
Figure 5 Fir st cycle of bat ch-mo de
operat io n.Figure 6 Second cycle of bat ch-mo de
o peration.
C.-M.Huang et al./Energy Procedia4(2011)1268–12751273
Figure 7 Third cycle o f bat ch-mode
operat io n.Figure 8 Fourt h cycle of batch-mode
o peration.
one: Taiwan, part icle size 0.25-0.5 mm. Calcinat ion t emperature 850 °C, 30 min, N2:100 cc/min; car bonat io n temperat ure 650 °C, 40 min, CO2:100 cc/min.
Table 1 Fir st to fourth cycles t he part icle size of t he batch-mode operat io n.
Cycle First Second Third Fourth Original Mean Size(μm) 275.86 192.83 187.46 184.81 262.53 Median Size(μm) 252.13 195.20 190.63 186.76 255.00 Std. Dev.(μm) 128.76 120.33 86.53 63.08 385.15 4.Future work
The results presented above determine to use CaO/CaCO3 looping to capture CO2 is a viable technology. And a lot of new information published by other authors from their laboratory which identified with these results. As we recognized during the batch-mode operation with the problems and get the right to add, we'll continue to batch-mode 1274 C.-M.Huang et al./Energy Procedia4(2011)1268–1275
C.-M.Huang et al./Energy Procedia4(2011)1268–12751275 operation test. Now ITRI is able to stabilize the bubble fluidized bed operation but the moving bed operation is not stable. ITRI will be the end of the year is expected to change the rotary kiln calciner and the use of oxy-fuel to provide heat. The test facility will continue to be used to obtain more data after the calciner is finished changes. ITRI and Taiwan Power Company are planning to build 1MW scale pilot in 2011. These data will provide this pilot.
5.Conclusion
CaO/CaCO3looping is very promising concept for post-combustion CO2capture application. This work has shown that the bubble fluidized bed carbonator, works as a high effective CO2 absorber when it can maintain enough CaO in the carbonator. Particle size, CaO increase number and CaCO3/CaO ratios associated to the operation of the carbonator are relatively important. Pilot results from a 1 kW test facility designed, constructed and operated by ITRI have important viability of the operation. Projects have plan to add many experiments and get experience and design data for the 1 MW scale pilot.
6.Acknowledgement
The authors would like to acknowledge the support from the Energy Fund of Ministry of Economics Affairs, Taiwan.
7.References
- [1] Shimizu T, Hirama T, Hosoda H, Kitano K, Inagaki M, Tejima K. A twin fluid-bed reactor for removal of CO2 from combustion processes. Transactions of IChemE
1999;77(partA):62–8.
- [2] Salvador C, Lu D, Anthony EJ, Abanades JC. Enhancement of CaO for CO2 capture in an FBC environment. Chemical Engineering Journal 2003;96:187–195.
- [3] Abanades JC, Anthony EJ, Wang J, Oakey A. Fluidized bed combustion systems integrating CO2 capture with CaO. Environmental Science and Technology
2005;39:2861–6.
- [4] Prasannan PC, Ramachandran PA, Doraiswamy LK. A model for gas–solid reactions with structural changes in the presence of inert solids. Chemical Engineering Science 1985;40:1251–1261.
- [5] Duo W, Sevill JPsK, Kirkby NF, Clift R. Formation of product layers in solid–gas reactions for removal of acid gases. Chemical Engineering Science 1994;49:4429–4442. - [6] Abanades JC, Alonso M, Rodríguez N, González B, Grasa G, Murillo R. Capturing CO2 from combustion flue gases with a carbonation calcination loop. Experimental results and process development, Energy Procedia 2009;1:1147-1154.
中等分辨率制备分离的 快速色谱技术 W. Clark Still,* Michael K a h n , and Abhijit Mitra Departm(7nt o/ Chemistry, Columbia Uniuersity,1Veu York, Neu; York 10027 ReceiLied January 26, 1978 我们希望找到一种简单的吸附色谱技术用于有机化合物的常规净化。这种技术是适于传统的有机物大规模制备分离，该技术需使用长柱色谱法。尽管这种技术得到的效果非常好，但是其需要消耗大量的时间，并且由于频带拖尾经常出现低复原率。当分离的样本剂量大于1或者2g时，这些问题显得更加突出。近年来，几种制备系统已经进行了改进，能将分离时间减少到1-3h，并允许各成分的分辨率ΔR f≥（使用薄层色谱分析进行分析）。在这些方法中，在我们的实验室中，媒介压力色谱法1和短柱色谱法2是最成功的。最近，我们发现一种可以将分离速度大幅度提升的技术，可用于反应产物的常规提纯，我们将这种技术称为急骤色谱法。虽然这种技术的分辨率只是中等（ΔR f≥），而且构建这个系统花费非常低，并且能在10-15min内分离重量在的样本。4 急骤色谱法是以空气压力驱动的混合介质压力以及短柱色谱法为基础，专门针对快速分离，介质压力以及短柱色谱已经进行了优化。优化实验是在一组标准条件5下进行的，优化实验使用苯甲醇作为样本，放在一个20mm*5in.的硅胶柱60内，使用Tracor 970紫外检测器监测圆柱的输出。分辨率通过持续时间（r）和峰宽（w,w/2）的比率进行测定的（Figure 1），结果如图2-4所示，图2-4分别放映分辨率随着硅胶颗粒大小、洗脱液流速和样本大小的变化。
The smart grid Smart grid is the grid intelligent (electric power), also known as the "grid" 2.0, it is based on the integration, high-speed bidirectional communication network, on the basis of through the use of advanced sensor and measuring technology, advanced equipme nt technology, the advanced control method, and the application of advanced technology of decision support system, realize the power grid reliability, security, economic, efficient, environmental friendly and use the security target, its main features include self-healing, incentives and include user, against attacks, provide meet user requirements of power quality in the 21st century, allow all sorts of different power generation in the form of access, start the electric power market and asset optimizatio n run efficiently. The U.S. department of energy (doe) "the Grid of 2030" : a fully automated power transmission network, able to monitor and control each user and power Grid nodes, guarantee from power plants to end users among all the nodes in the whole process of transmission and distribution of information and energy bi-directional flow. China iot alliance between colleges: smart grid is made up of many parts, can be divided into:intelligent substation, intelligent power distribution network, intelli gent watt-hourmeter,intelligent interactive terminals, intelligent scheduling, smart appliances, intelligent building electricity, smart city power grid, smart power generation system, the new type of energy storage system.Now a part of it to do a simple i ntroduction. European technology BBS: an integration of all users connected to the power grid all the behavior of the power transmission network, to provide sustained and effective economic and security of power. Chinese academy of sciences, institute of electrical: smart grid is including all kinds of power generation equipment, power transmission and distribution network, power equipment and storage equipment, on the basis of the physical power grid will be modern advanced sensor measurement technology, network technology, communication
文献综述怎么写 1) 什么是文献综述? 文献综述是研究者在其提前阅读过某一主题的文献后，经过理解、整理、融会贯通，综合分析和评价而组成的一种不同于研究论文的文体。 2) 文献综述的写作要求 1、文献综述的格式 文献综述的格式与一般研究性论文的格式有所不同。这是因为研究性的论文注重研究的方法和结果，而文献综述介绍与主题有关的详细资料、动态、进展、展望以及对以上方面的评述。因此文献综述的格式相对多样，但总的来说，一般都包含以下四部分：即前言、主题、总结和参考文献。撰写文献综述时可按这四部分拟写提纲，再根据提纲进行撰写工作。 前言，要用简明扼要的文字说明写作的目的、必要性、有关概念的定义，综述的范围，阐述有关问题的现状和动态，以及目前对主要问题争论的焦点等。前言一般200-300字为宜，不宜超过500字。 正文，是综述的重点，写法上没有固定的格式，只要能较好地表达综合的内容，作者可创造性采用诸多形式。正文主要包括论据和论证两个部分，通过提出问题、分析问题和解决问题，比较不同学者对同一问题的看法及其理论依据，进一步阐明问题的来龙去脉和作者自己的见解。当然，作者也可从问题发生的历史背景、目前现状、发展方向等提出文献的不同观点。正文部分可根据内容的多少可分为若干个小标题分别论述。 小结，是结综述正文部分作扼要的总结，作者应对各种观点进行综合评价，提出自己的看法，指出存在的问题及今后发展的方向和展望。内容单纯的综述也可不写小结。 参考文献，是综述的重要组成部分。一般参考文献的多少可体现作者阅读文献的广度和深度。对综述类论文参考文献的数量不同杂志有不同的要求，一般以30条以内为宜，以最近3-5年内的最新文献为主。 2、文献综述规定 1. 为了使选题报告有较充分的依据，要求硕士研究生在论文开题之前作文献综述。 2. 在文献综述时，研究生应系统地查阅与自己的研究方向有关的国内外文献。通常阅读文献不少于30篇，且文献搜集要客观全面 3. 在文献综述中，研究生应说明自己研究方向的发展历史，前人的主要研究成果，存在的问题及发展趋势等。 4. 文献综述要条理清晰，文字通顺简练。 5. 资料运用恰当、合理。文献引用用方括号[ ]括起来置于引用词的右上角。 6. 文献综述中要有自己的观点和见解。不能混淆作者与文献的观点。鼓励研究生多发现问题、多提出问题、并指出分析、解决问题的可能途径，针对性强。 7. 文献综述不少于3000字。 3、注意事项 ⒈搜集文献应尽量全。掌握全面、大量的文献资料是写好综述的前提，否则，随便搜集一点资料就动手撰写是不可能写出好的综述。 ⒉注意引用文献的代表性、可靠性和科学性。在搜集到的文献中可能出现观点雷同，有的文献在可靠性及科学性方面存在着差异，因此在引用文献时应注意选用代表性、可靠性和科学性较好的文献。 ⒊引用文献要忠实文献内容。由于文献综述有作者自己的评论分析，因此在撰写时应分清作者的观点和文献的内容，不能篡改文献的内容。引用文献不过多。文献综述的作者引用间接文献的现象时有所见。如果综述作者从他人引用的参考文献转引过来，这些文献在他人
Application of α-amylase and Research α-amylase to be widely distributed throughout microorganisms to higher plants. The International Enzyme classification number is EC. 3.2.1.1, acting on the starch from the starch molecules within the random cut α a 1,4 glycosidic bond to produce dextrin and reducing sugar, because the end product of carbon residues as Α configuration configuration, it is called α-amylase. Now refers to α-amylase were cut from the starch molecules within the α-1,4 glycosidic bond from the liquefaction of a class of enzymes. α-amylase is an important enzyme, a large number of used food processing, food industry, brewing, fermentation, textile industry and pharmaceutical industries, which account for the enzyme about 25% market share. Currently, both industrial production to large-scale production by fermentation α-amylase. α-amylase in industrial applications 1.1 The bread baking industry, as a preservative enzymes used in baking industry, production of high quality products have been hundreds of years old. In recent decades, malt and microbial α-amylase, α-amylase is widely used in baking industry. The enzymes used for making bread, so that these products are much larger, better colors, more soft particles. Even today, baking industry have been α-amylase from barley malt and bacterial, fungal leaf extract. Since 1955 and after 1963 in the UK GRAS level validation, fungal amylase, has served as a bread additive. Now, they are used in different areas. Modern continuous baking process, add in f lour α-amylase can not only increase the fermentation rate and reduce dough viscosity (improving product volume and texture) to increase the sugar content in the dough, improved bread texture, skin color and baking quality, but also to extend the preservation time for baked goods. In the storage process, the bread particles become dry, hard, not crisp skin, resulting in deterioration of the taste of bread. These changes collectively referred to as degenerate. Each year simply because the losses caused by deterioration of bread more than 100 million U.S. dollars. A variety of traditional food additives are used to prevent deterioration and improve the texture and taste of baked goods. Recently, people started to pay attention enzyme as a preservative, preservative agent in improving the role of the dough, as amylopectin, amylase enzyme and a match can be effectively used as a preservative. However, excessive amylase causes a sticky bread too. Therefore, the recent trend is the use of temperature stability (ITS) α a amylase activity are high in starch liquefaction, but the baking process is completed before the inactivation. Despite the large number of microbes have been found to produce α-amylase, but with the temperature stability of the nature of the α-amylase only been found in several microorganisms. 1.2 starch liquefaction and saccharification of the main α-amylase starch hydrolysis product market, such as glucose and fructose. Starch is converted into high fructose corn syrup (HFCS). Because of their high sweetness, are used in the soft drink beverage industry sweeteners. The liquefaction process is used in thermal stability at high temperature α-amylase. α-amylase in starch liquefaction of
New technique of the computer network Abstract The 21 century is an ages of the information economy, being the computer network technique of representative techniques this ages, will be at very fast speed develop soon in continuously creatively, and will go deep into the people's work, life and study. Therefore, control this technique and then seem to be more to deliver the importance. Now I mainly introduce the new technique of a few networks in actuality live of application. keywords Internet Network System Digital Certificates Grid Storage 1. Foreword Internet turns 36, still a work in progress Thirty-six years after computer scientists at UCLA linked two bulky computers using a 15-foot gray cable, testing a new way for exchanging data over networks, what would ultimately become the Internet remains a work in progress. University researchers are experimenting with ways to increase its capacity and speed. Programmers are trying to imbue Web pages with intelligence. And work is underway to re-engineer the network to reduce Spam (junk mail) and security troubles. All the while threats loom: Critics warn that commercial, legal and political pressures could hinder the types of innovations that made the Internet what it is today. Stephen Crocker and Vinton Cerf were among the graduate students who joined UCLA professor Len Klein rock in an engineering lab on Sept. 2, 1969, as bits of meaningless test data flowed silently between the two computers. By January, three other "nodes" joined the fledgling network.
Computer Program 1 Introduction Computer Program, set of instructions that directs a computer to perform someprocessing function or combination of functions. For the instructions to be carried out, a computer must execute a program, that is, the computer reads the program, and then follow the steps encoded in the program in a precise order until completion. A program can be executed many different times, with each execution yielding a potentially different result depending upon the options and data that the user gives the computer. Programs fall into two major classes: application programs and operating systems. An application program is one that carries out somefunction directly for a user, such as word processing or game-playing. An operating system is a program that manages the computer and the various resources and devices connected to it, such as RAM,hard drives, monitors, keyboards, printers, and modems,so that they maybe used by other programs. Examples of operating systems are DOS, Windows 95, OS\2, and UNIX. 2 Program Development Software designers create new programs by using special applications programs, often called utility programs or development programs. A programmer uses another type of program called a text editor to write the new program in a special notation called a programming language. With the text editor, the programmer creates a text file, which is an ordered list of instructions, also called the program source file. The individual instructions that make up the program source file are called source code. At this point, a special applications program translates the source code into machine language, or object code— a format that the operating system
机械设计理论 机械设计是一门通过设计新产品或者改进老产品来满足人类需求的应用技术科学。它涉及工程技术的各个领域，主要研究产品的尺寸、形状和详细结构的基本构思，还要研究产品在制造、销售和使用等方面的问题。 进行各种机械设计工作的人员通常被称为设计人员或者机械设计工程师。机械设计是一项创造性的工作。设计工程师不仅在工作上要有创造性，还必须在机械制图、运动学、工程材料、材料力学和机械制造工艺学等方面具有深厚的基础知识。如前所诉，机械设计的目的是生产能够满足人类需求的产品。发明、发现和科技知识本身并不一定能给人类带来好处，只有当它们被应用在产品上才能产生效益。因而，应该认识到在一个特定的产品进行设计之前，必须先确定人们是否需要这种产品。 应当把机械设计看成是机械设计人员运用创造性的才能进行产品设计、系统分析和制定产品的制造工艺学的一个良机。掌握工程基础知识要比熟记一些数据和公式更为重要。仅仅使用数据和公式是不足以在一个好的设计中做出所需的全部决定的。另一方面，应该认真精确的进行所有运算。例如，即使将一个小数点的位置放错，也会使正确的设计变成错误的。 一个好的设计人员应该勇于提出新的想法，而且愿意承担一定的风险，当新的方法不适用时，就使用原来的方法。因此，设计人员必须要有耐心，因为所花费的时间和努力并不能保证带来成功。一个全新的设计，要求屏弃许多陈旧的，为人们所熟知的方法。由于许多人墨守成规，这样做并不是一件容易的事。一位机械设计师应该不断地探索改进现有的产品的方法，在此过程中应该认真选择原有的、经过验证的设计原理，将其与未经过验证的新观念结合起来。 新设计本身会有许多缺陷和未能预料的问题发生，只有当这些缺陷和问题被解决之后，才能体现出新产品的优越性。因此，一个性能优越的产品诞生的同时，也伴随着较高的风险。应该强调的是，如果设计本身不要求采用全新的方法，就没有必要仅仅为了变革的目的而采用新方法。 在设计的初始阶段，应该允许设计人员充分发挥创造性，不受各种约束。即使产生了许多不切实际的想法，也会在设计的早期，即绘制图纸之前被改正掉。只有这样，才不致于堵塞创新的思路。通常，要提出几套设计方案，然后加以比较。很有可能在最后选定的方案中，采用了某些未被接受的方案中的一些想法。
英文翻译 A comprehensive overview of substations Along with the economic development and the modern industry developments of quick rising, the design of the power supply system become more and more completely and system. Because the quickly increase electricity of factories, it also increases seriously to the dependable index of the economic condition, power supply in quantity. Therefore they need the higher and more perfect request to the power supply. Whether Design reasonable, not only affect directly the base investment and circulate the expenses with have the metal depletion in colour metal, but also will reflect the dependable in power supply and the safe in many facts. In a word, it is close with the economic performance and the safety of the people. The substation is an importance part of the electric power system, it is consisted of the electric appliances equipments and the Transmission and the Distribution. It obtains the electric power from the electric power system, through its function of transformation and assign, transport and safety. Then transport the power to every place with safe, dependable, and economical. As an important part of power’s transport and control, the transformer substation must change the mode of the traditional design and control, then can adapt to the modern electric power system, the development of modern industry and the of trend of the society life. Electric power industry is one of the foundations of national industry and national economic development to industry, it is a coal, oil, natural gas, hydropower, nuclear power, wind power and other energy conversion into electrical energy of the secondary energy industry, it for the other departments of the national economy fast and stable development of the provision of adequate power, and its level of development is a reflection of the country's economic development an important indicator of the level. As the power in the industry and the importance of the national economy, electricity transmission and distribution of electric energy used in these areas is an indispensable component.。Therefore, power transmission and distribution is critical. Substation is to enable superior power plant power plants or power after adjustments to the lower load of books is an important part of power transmission. Operation of its functions, the capacity of a direct impact on the size of the lower load power, thereby affecting the industrial production and power consumption.Substation system if a link failure, the system will protect the part of action. May result in power outages and so on, to the production and living a great disadvantage. Therefore, the substation in the electric power system for the protection of electricity reliability,
外文翻译 英文原文 Belt Conveying Systems Development of driving system Among the methods of material conveying employed，belt conveyors play a very important part in the reliable carrying of material over long distances at competitive cost．Conveyor systems have become larger and more complex and drive systems have also been going through a process of evolution and will continue to do so．Nowadays，bigger belts require more power and have brought the need for larger individual drives as well as multiple drives such as 3 drives of 750 kW for one belt(this is the case for the conveyor drives in Chengzhuang Mine)．The ability to control drive acceleration torque is critical to belt conveyors’performance．An efficient drive system should be able to provide smooth，soft starts while maintaining belt tensions within the specified safe limits．For load sharing on multiple drives．torque and speed control are also important considerations in the drive system’s design. Due to the advances in conveyor drive control technology，at present many more reliable．Cost-effective and performance-driven conveyor drive systems covering a wide range of power are available for customers’ choices[1]. 1 Analysis on conveyor drive technologies 1．1 Direct drives Full-voltage starters．With a full-voltage starter design，the conveyor head shaft is direct-coupled to the motor through the gear drive．Direct full-voltage starters are adequate for relatively low-power, simple-profile conveyors．With direct fu11-voltage starters．no control is provided for various conveyor loads and．depending on the ratio between fu11-and no-1oad power requirements，empty starting times can be three or four times faster than full load．The maintenance-free starting system is simple，low-cost and very reliable．However, they cannot control starting torque and maximum stall torque；therefore．they are
一、激励理论的背景 在经济发展的过程中,劳动分工与交易的出现带来了激励问题。激励理论是行为科学中用于处理需要，动机，目标和行为四者之间关系的核心理论。行为科学认为人的动机来自需要，由需要确定人们的行为目标，激励则作用于人内心活动，激发，驱动和强化人的行为。哈佛大学维廉詹姆士研究表明：在没有激励措施下,下属一般仅能发挥工作能力的20%～30%，而当他受到激励后,其工作能力可以提升到80%～90%，所发挥的作用相当于激励前的3到4倍。日本丰田公司采取激励措施鼓励员工提建议，结果仅1983年一年，员工提了165万条建议，平均每人31条，它为公司带来900亿日元利润，相当于当年总利润的18%。由于激励的效果明显，所以各种组织为了提高生产效率，有些专家学者就开始了对激励理论的研究之中，探索激励的无穷潜力。 二、国外研究现状 国外对于激励理论有了大量的研究并获得了丰硕的成果。总体来说，可以分为两类激励理论。一类是以人的心理需求和动机为主要研究对象的激励理论，熟称“内容型激励理论”。另一类是以人的心理过程和行为过程相互作用的动态系统为研究对象的激励过程理论,它也被称作是“行为型激励理论”。 1 内容型激励理论 1.1 奠瑞的人类人格理论 这种理论认为，在面临着动态且不断变化的环境时，人们都是自适应的。它把需求分成了两种类型，即生理需求和心理需求。前者与人体基本生理过程的满足感有关，而后者所关注的是情绪上和精神上的满足感。 1.2 马斯洛的“需要层次”理论 美国心理学家马斯洛(A.H.Maslow)进一步发展了莫瑞的研究，在1954年出版的《动机与人格》一书中对该理论作了进一步的阐释。马斯洛认为人的需要可以划分为五个层次，从低到高依次为生理需要，安全需要，社交需要，尊熏需要，自我实现需要，且这五个层次的顺序，对每个人都是相同的。只有当较低层次的需要获得了基本满足后，下一个较高层次的需要才能成为主导需要。 1.3 赫茨伯格的激励—保健双因素理论 美国心理学家赫茨伯格因素理论打破了这一假设。他于1959年在《工作的激励》一书中提出了保健——激励因素理论，简称双因素理论。即保健因素和激励因素。保健因素可以用来体现高水平员工的不满意，激励因素可以用来体现高水平员工的满意度。他认为只有激励因素才能促发员工积极性,提高生产效率。 2 行为型激励理论 2.1 洛克的目标设置理论 2O世纪6O年代末，埃德温·A·洛克和他的同事们花了许多年的时间研究目标对于人类行为和绩效的效果。他们的研究导致了目标设置理论的创立并不断地得到验证，提出：指向一共同目标的工作意向是工作效率的主要源泉。他还提出了具体的设置目标的步骤。 2.2 亚当斯的公平理论 美国心理学家亚当斯(J.s.Adams)对员工受激励程度的大小与他人之间的关系进行研究，并在《工人关于工资不公平的内心冲突同其生产率的关系》(1962年与罗森合写)，《工
第一篇： 航空博物馆与航空展示公园 巴特罗米耶杰·基谢列夫斯基 飞翔的概念、场所的精神、老机场的建筑---克拉科夫新航空博物馆理性地吸取了这些元素，并将它们整合到一座建筑当中。Rakowice-Czyzyny机场之前的旧飞机修理库为新建筑的平面和高度设定了模数比例。在此基本形态上进一步发展，如同裁切和折叠一架纸飞机，生成了一座巨大的建筑。其三角形机翼是由混凝土制成，却如同风动螺旋桨一样轻盈。这个机翼宽大通透，向各个方向开敞。它们的形态与组织都是依据内部功能来设计的。机翼部分为3个不平衡的平面，使内外景观在不断变化中形成空间的延续性，并且联系了建筑内的视觉焦点和室外的展览区。 新航空展示公园的设计连接了博物馆的8栋建筑和户外展览区，并与历史体验建立联系。从前的视觉轴线与通道得到尊重，旧的道路得到了完善，朝向飞机场和跑道的空间被限定出来。每栋建筑展示了一个主题或是一段飞行史。建筑周围伸展出巨大的平台，为特殊主题的室外展览提供了空间。博物馆容纳了超过150架飞机、引擎、飞行复制品、成套的技术档案和历史图片。这里的特色收藏是飞机起源开始的各种飞行器，如Jatho1903、Grade1909、莱特兄弟1909年的飞机模型和1911年的鸽式单翼机。 The first passage: Museum for aviation and aviation exhibition park Bartiomiej Kislelewski The idea of flying, the spirit of place, the structure of the historic airfield – the new Museum of Aviation in Krakow takes up these references intellectually and synthesizes them into a building. The old hangars of the former airport Rakowice Czyzyny set the modular scale for the footprint and the height of the new building. Developed from this basic shape, as if cut out and folded like a paper airplane, a large structure has been generated, with triangular wings made of concrete and yet as light as a wind-vane propeller. The wings are generously glazed and open in all directions. Their form and arrangement depend on the interior uses. In the floor plans of the wings, the three offset