外文文献翻译译文

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。

外文文献原稿和译文原稿DATABASEA database may be defined as a collection interrelated data store together with as little redundancy as possible to serve one or more applications in an optimal fashion .the data are stored so that they are independent of programs which use the data .A common and controlled approach is used in adding new data and in modifying and retrieving existing data within the data base .One system is said to contain a collection of database if they are entirely separate in structure .A database may be designed for batch processing , real-time processing ,or in-line processing .A data base system involves application program, DBMS, and database.THE INTRODUCTION TO DATABASE MANAGEMENT SYSTEMSThe term database is often to describe a collection of related files that is organized into an integrated structure that provides different people varied access to the same data. In many cases this resource is located in different files in different departments throughout the organization, often known only to the individuals who work with their specific portion of the total information. In these cases, the potential value of the information goes unrealized because a person in other departments who may need it does not know it or it cannot be accessed efficiently. In an attempt to organize their information resources and provide for timely and efficient access, many companies have implemented databases.A database is a collection of related data. By data, we mean known facts that can be recorded and that have implicit meaning. For example, the names, telephone numbers, and addresses of all the people you know. You may have recorded this data in an indexed address book, or you may have stored it on a diskette using a personalcomputer and software such as DBASE Ⅲor Lotus 1-2-3. This is a collection of related data with an implicit meaning and hence is a database.The above definition of database is quite general. For example, we may consider the collection of words that made up this page of text to be usually more restricted. A database has the following implicit properties:● A database is a logically coherent collection of data with some inherent meaning. A random assortment of data cannot be referred to as a database.● A database is designed, built, and populated with data for a specific purpose. It has an intended group of user and some preconceived applications in which these users are interested.● A database represents some aspect of the real world, sometimes called the miniworld. Changes to the miniworld are reflected in the database.In other words, a database has some source from which data are derived, some degree of interaction with events in the real world, and an audience that is actively interested in the contents of the database.A database management system (DBMS) is composed of three major parts: (1) a storage subsystem that stores and retrieves data in files; (2)a modeling and manipulation subsystem that provides the means with which to organize the data and to add, delete, maintain, and update the data; and (3) an interface between the DBMS and its users. Several major trends are emerging that enhance the value and usefulness of database management systems.●Managers who require more up-to-date information to make effective decisions.●Customers who demand increasingly sophisticated information services and more current information about the status of their orders, invoices, and accounts.●Users who find that they can develop custom applications with database systems in a fraction of the time it takes to use traditional programming languages.●Organizations that discover information has a strategic value; they utilize their database systems to gain an edge over their competitors.A DBMS can organize, process, and present selected data elements from the database. This capability enables decision makers to search, probe, and query database contents in order to extract answers to nonrecurring and unplanned questions that aren’t available in regular reports. These questions might initially be vague and/or p oorly defined, but people can “browse” through the database until they have the needed information. In short, the DBMS will “mange” the stored data items and assemble the needed items from the common database in response to the queries of those who aren’t programmers. In a file-oriented system, user needing special information may communicate their needs to a programmer, who, when time permits, will write one or more programs to extract the data and prepare the information. The availability of a DBMS, however, offers users a much faster alternative communications path.DATABASE QUERYIf the DBMS provides a way to interactively enter and update the database ,as well as interrogate it ,this capability allows for managing personal database. However, it does not automatically leave an audit trail of actions and does not provide the kinds of controls necessary in a multi-user organization .There controls are only available when a set of application programs is customized for each data entry and updating function.Software for personal computers that perform some of the DBMS functions has been very popular .Individuals for personal information storage and processing intended personal computers for us .Small enterprises, professionals like doctors, architects, engineers, lawyers and so on have also used these machines extensively. By the nature of intended usage ,database system on there machines are except from several of the requirements of full-fledged database systems. Since data sharing is not intended, concurrent operations even less so ,the software can be less complex .Security and integrity maintenance are de-emphasized or absent .as data volumes will be small, performance efficiency is also less important .In fact, the only aspect of a database system that is important is data independence. Data independence ,as stated earlier ,means that application programs and user queries need not recognize physical organization of data on secondary storage. The importance of this aspect , particularly for the personal computer user ,is that this greatly simplifies database usage . The user can store ,access and manipulate data at ahigh level (close to the application)and be totally shielded from the low level (close to the machine )details of data organization.DBMS STRUCTURING TECHNIQUESSpatial data management has been an active area of research in the database field for two decades ,with much of the research being focused on developing data structures for storing and indexing spatial data .however, no commercial database system provides facilities for directly de fining and storing spatial data ,and formulating queries based on research conditions on spatial data.There are two components to data management: history data management and version management .Both have been the subjects of research for over a decade. The troublesome aspect of temporal data management is that the boundary between applications and database systems has not been clearly drawn. Specifically, it is not clear how much of the typical semantics and facilities of temporal data management can and should be directly incorporated in a database system, and how much should be left to applications and users. In this section, we will provide a list of short-term research issues that should be examined to shed light on this fundamental question.The focus of research into history data management has been on defining the semantics of time and time interval, and issues related to understanding the semantics of queries and updates against history data stored in an attribute of a record. Typically, in the context of relational databases ,a temporal attribute is defined to hold a sequence of history data for the attribute. A history data consists of a data item and a time interval for which the data item is valid. A query may then be issued to retrieve history data for a specified time interval for the temporal attribute. The mechanism for supporting temporal attributes is to that for supporting set-valued attributes in a database system, such as UniSQL.In the absence of a support for temporal attributes, application developers who need to model and history data have simply simulated temporal attributes by creating attribute for the time interval ,along with the “temporal” attribute. This of course may result in duplication of records in a table, and more complicated search predicates in queries. The one necessary topic of research in history data management is to quantitatively establish the performance (and even productivity) differences betweenusing a database system that directly supports attributes and using a conventional database system that does not support either the set-valued attributes or temporal attributes.Data security, integrity, and independenceData security prevents unauthorized users from viewing or updating the database. Using passwords, users are allowed access to the entire database of the database, called subschemas. For example, an employee database can contain all the data about an individual employee, but one group of users may be authorized to view only payroll data, while others are allowed access to only work history and medical data.Data integrity refers to the accuracy, correctness, or validity of the data in the database. In a database system, data integrity means safeguarding the data against invalid alteration or destruction. In large on-line database system, data integrity becomes a more severe problem and two additional complications arise. The first has to do with many users accessing the database concurrently. For example, if thousands of travel agents book the same seat on the same flight, the first agent’s booking will be lost. In such cases the technique of locking the record or field provides the means for preventing one user from accessing a record while another user is updating the same record.The second complication relates to hardware, software or human error during the course of processing and involves database transaction which is a group of database modifications treated as a single unit. For example, an agent booking an airline reservation involves several database updates (i.e., adding the passenger’s name and address and updating the seats-available field), which comprise a single transaction. The database transaction is not considered to be completed until all updates have been completed; otherwise, none of the updates will be allowed to take place.An important point about database systems is that the database should exist independently of any of the specific applications. Traditional data processing applications are data dependent.When a DMBS is used, the detailed knowledge of the physical organization of the data does not have to be built into every application program. The application program asks the DBMS for data by field name, for example, a coded representationof “give me customer name and balance due” would be sent to the DBMS. Without a DBMS the programmer must reserve space for the full structure of the record in the program. Any change in data structure requires changes in all the applications programs.Data Base Management System (DBMS)The system software package that handles the difficult tasks associated with creating ,accessing and maintaining data base records is called a data base management system (DBMS). A DBMS will usually be handing multiple data calls concurrently.It must organize its system buffers so that different data operations can be in process together .It provides a data definition language to specify the conceptual schema and most likely ,some of the details regarding the implementation of the conceptual schema by the physical schema.The data definition language is a high-level language, enabling one to describe the conceptual schema in terms of a “data model “.At the present time ,there are four underling structures for database management systems. They are :List structures.Relational structures.Hierarchical (tree) structures.Network structures.Management Information System(MIS)An MIS can be defined as a network of computer-based data processing procedures developed in an organization and integrated as necessary with manual and other procedures for the purpose of providing timely and effective information to support decision making and other necessary management functions.One of the most difficult tasks of the MIS designer is to develop the information flow needed to support decision making .Generally speaking ,much of the information needed by managers who occupy different levels and who have different levels and have different responsibilities is obtained from a collection of exiting information system (or subsystems)Structure Query Language (SQL)SQL is a data base processing language endorsed by the American NationalStandards Institute. It is rapidly becoming the standard query language for accessing data on relational databases .With its simple ,powerful syntax ,SQL represents a great progress in database access for all levels of management and computing professionals.SQL falls into two forms : interactive SQL and embedded SQL. Embedded SQL usage is near to traditional programming in third generation languages .It is the interactive use of SQL that makes it most applicable for the rapid answering of ad hoc queries .With an interactive SQL query you just type in a few lines of SQL and you get the database response immediately on the screen.译文数据库数据库可以被定义为一个相互联系的数据库存储的集合。

To connect SQL Server databaseFirst we introduce the basic knowledge of the database,be regarded as thewarm-up exercise that study database weave distance front!1.warm-up exerciseNeeding first avowal is relation database that database knowledge that we here introduce all point. The so-called relation database is to mean data as that the form gather, passing to establish simple form an a kind of database for of relation to defining construction.I ignore the watch at how saving way in physics in the document in database is,it can see to make an a line for with row, with electronics form is similar with the row.In relation database, the line were called the record, but the row then is called word segment.This form inside each an all in formations for is a record, it including particular customer, but each record then included the same type with the word segment of the quantity:Customer's number, name etc.Form is logic set that a kind of related information that press a line of arrangingwith row, similar in single form in work.Each row of the word a database form inside calls a word segment. Watch isfrom every kind of word a definition of its containment of, each word a data for describing its implying. While creating to set up a database, the beard assign for each word segment a the piece belongs to the sex with the other according to thetype,biggest length.The word segment can include every kind of word sign,arithmetic figure even sketch.An information of relevant customer deposits in the line of the form, is called record.By any large, arbitrarily two records for database form to create set up can't be same.Key be a certain word segment( or several words segment) of the form inside, it()for fast inspect but drive index. The key can be unique, and also can then the right and wrong is unique, being decided by it() whether admission repetition. Unique key can specify for main key, using each one that come to unique marking form.The norm turns the database design of mission be method that the data of buildup,but the data of buildup, should can dissolve otiose repetition, and for have the necessary information offering to check to seek the path quickly. For attaining this kind of target but separate information to the process gone to in every kind of independent form, be called the norm turn.It is complicated process to use many appointed rules to proceed the norm withthe type of the different Class that norm turn. That process studies and discuss already beyond the reach of textual scope.But,the norm of the simple database in majority turn and can use the simple experience in underneath rule completes: include the form of the information of repetition must be divided into independent a few forms dissolve repetition.If we have chosen to learn 12 curricular 1000 students, the each curricularandcurricular that choose to -many100 teacher the with show will elucidation eachstudent repeat once.To avoid this kind of low efficiency, should to turn the dichotomous and independent form in form to the norm,an is used to mean the student,the another uses mean the course.Now the form was turned by the norm, so, to changes the particular andcurricular course describe or data,as long as change a record all right.Is a basic knowledge concerning database above,this is what study database plait distance must.Although the database technique is used as a course,its depth is not this space and can describe with the wide degree of,be used as the primer with simple database plait the distance should be all right already.Like,underneath we can start practicing.We usually meet the database system is to registers the system,ignoring you are in the unit,or attend what buildup,the register is to cans not help of,and it of the construction is more simple,we take a register system as an example.The analysis is once a data for involving.2. understanding the elementsFor the register, want the on the trail of information include:name、sex、native place、age、date of birth、unit、address、postal service codes、telephone、FAX. Certainly,can create to set up a form in brief,make above each piece according to item to should a word segment.Need to point the form the main key in parties now, in order to unique marking each a record,increase register number conduct and actions unique key respectively in register form,guarantee a two records like this all different.To the database after making an above analysis,we can start establishing the database.3.set up the firm in campHere we study to establish the database how,needing to make sure the typethat to establish the database first.Pass in Visual Basic the data interview control piece or data interview object ( DAO) can visit the following database:1)The database of JET, namely Microsoft Access2)The database of ISAM, such as: DBase, etc. of FoxPro3)The database of ODBC,every follow the standard of ODBC customer/ server database. Such as: Microsoft SQL Server, OracleBy any large, if develop the personal small scaled database system, use Access database comparison accommodation, to develop the big and medium-sized database system uses the database of ODBC fester. But dBase with the database of FoxPro because of already dated,unless special circumstance,do not use otherwise.In our example, chose to use the database of Access certainly. Establish the database of Access contain two kinds of methods: While establishing the database in Microsoft Access. Click new set up button can establish the new form. Here we main introduction the second method: The usage can see to turn the data management machine, do not need to weave the distance and then can create to set up the database.Can see to turn the data management machine is the applied procedure of a great use,it is a VB business enterprise version is supplementary with theprofession version, in the catalogue\..\ Devastation\ vb\ samples\ the Visdata is next, its interface is as follows the diagram.Click the menu document item is next newset up son item Microsoft ACCESS son item of edition 7.0 MDB item. Input thenew setting upthe name of the database in flick window way open register, appear the underneath show the window way:Want the born and new form, the single shot in right key database window way flicks the menu open, then the choice new form ordinaries,establishing in watch construction dialog box appeared later on a word for wanting segment. The every time faces to join in the form new word segment, single shot increment word segment button, will appear of increment word segment dialog box.Increment word a type for options in the dialog box, according to word segment.In our the register database that establish, the type of the each word segment.Want to notice of is, because the word segment registers the number be used unique marking record of, therefore, it can't be inputted by customer. So while defining the word's segment need to be defined for Long data type, the automatic born word segment item is valid, and picks out this item. Be the customer like this to input to record with other the different value every input a new record, system would on the word's segment automatically.In ACCESS database, the key word realizes with the index of, conduct andactions plait distance personnel at gather to weave the distance to the record of the form type,needs to adjust to use index.While searching,the technique of Rushmore uses the index information the excellent turning the search automatically. Aftercompleting the form definition, click increment index button, flick such aspen figure 5 show the window way.In window way the right side contain three optioned, its meaning, such as table,12.Increase the index dialog box options.After completing such as figure 6.Certainly, the academic association database establishes too not a dynasty the business of the one night, the reader no harm much practices once. Visit databases design and the development of the application procedures ofMS Visual Basics of the databases of the SQL Server. When design a system, the customer still needs to comprehend to use to come to visit the plait distance of ask the data of SQL Server to connect. The origin was detailed to elaborate that the usage open type database conjunction (the Open Database Connectivity, ODBC) adjusts to connect the objects to connect with the class, still having the data interviews object (the Data Access Objects, the DAO) and the long-range data objects.Design and weave to write large and complicated and applied procedure's database design for the software developer is a challenge, need to choose to weave the distance language and tools, do an accommodation for the SQL Server, choose the calculate way and the data structures, still need to design the sketch customer interface and the application procedures to connect. The decision within the most important software design is applied fixed position of the procedure. In other words, design must specify the system of which parts are data, business rule, and the data entrance procedure and used for circulating the code of other part. The MS Visual Basic supports the plait distance that some databases manage the systems connect, especially SQL Server. Adjust to connect to include the ODBC and DB-Libraries toconnect the, object to connect to include the data interview object (DAO), long range data object (the RDO), the OLE DB and the ActiveX Data Objects (ADO) with the class, todistributes mission the manage to Server SQL capable the returns that SQL the manage the object (the SQL Distributed management Objects, SQL-DMO) to connect. Connect the oculars right choice can improve the whole function of system and the development speed biggest. Design the large data warehouse system needs to choose the applied model properly. Traditional customer/ service's model depends on to join in the center layer but get the improvement to become three layer models. These three layers divide the line system as three parts: each layer is responsible for providing the service:(1) Data service( the Data Service) contain the maintenance data and the operation date such as the increment, modification, deletion and backups.These services maintenance data relation and contact,support backup and ually the data service is managed the system usage by the database.(2) business service( the Business Service) is handled the logic by the businessrule and data to constitute, such as the data legitimacy rule, the business processing support and the record backup logics. The main purpose of these services provides the data maintenance toward the application procedure Logic.(3) expression service( the Presentation Service)( or the customer service) support customer interface, control the customer data to input to express with data.(Output) Notice in customer/ service's technical term, sometimes express the service definition as customer's machine (or head), the data service definition for server (or after carry), but the business service is in the center the layer (the middle layer). But important comprehend any two layers .The data service business service expresses the logic support GUI that the service maintenance database business rule and the processing data need, data importation and manifestation the correspondences can think to carry on between customer's machine and servers. For example, in the center the layer can think is a head.Server The physics realization of the system can carry on through many different paths.The underneath wills discuss three layer logic models three kinds of to carry out the method:1.Fat customer machine realizationMany layer (the multi tier) realizations of fat customer the machine realization three layer models of a kind of carry out the options is in the customer's on board movement business and expression services. This probably writes the most common path in the Visual Basic application procedure for the SQL Server. This kind of carries out the physics up only two layers:The server provides the data service only, this kind of method contain 2:00 shortage. First, was the applied procedure to compute the on board increment at the customer, customer's calculators need to be stronger, this will increase the system expense, because the system usually takes several customer's machines. When the system takes to have the number with thousand million of customer's machine, thiskind of method will become too expensive. Another 1:00 shortage is a possible increment maintenance expenses. Move to the change of legitimacy logic and the business rule of the system and will cause upgrade customer's machine procedure each time. If the system contain customer's machine of the equal quantity, this is a problem. The biggest advantage of the machine realization in fat customer is to reduce the network discharge, if the legitimacy and the business rules need not be decide by the database. Under this kind of circumstance, only pass the data of the legitimacy logic and can spread toward server. Be the example of the importation data legitimacy,suppose the reader to have a small form (for example national form of name) to put in customer's machine. If the data entrance mold piece checks the native watch but is not a more national name in main database, then will reduce the network discharge obviously. Another an important use is in the development process of the system.If the head developer was limited to the interview carry behind, for example, can't pass the data in the database to verify to input the legitimacy, so, this kind of method can make it right processing data.2. Thin customer machine realizationIn thin customer the machine realization, business the service locates the server,the business logic usually expresses for saving process.The Server, the saving process usages T-The SQL plait write. This kind of realization is like fat customer's machine to carry out the similar physics up only two layers.The advantage of this kind of method is to reduce the system expense, because thin customer's machine needs the less system resources, this have very important many systems of customer's machines to take. And, support the expenses to also compare the fat customer the machine system is a little less, because the code carries the concentrated control in the server. If the business rule is depend on in the data of the database, thin customer the machine realization reduces the network discharge. The main shortage of this kind of method is a saving process to lack the vivid. The Visual Basic provide stronger than the T-SQL the plait distance ability that have to have another. Notice three the thin customer of the layer model the machine physics realization sometimes is called the fat server (the fat Server) model to confuse with thin customer's machine/ server calculation model by avoid, the latter points a kind of thin customer the machine hardware equipments and techniques are for example the Citric.3. Many layer realizationMost in brief many layer realizations are three layer realizations, many possible three a kinds of the layer model physics realizations. In this kind of realization, Link the SQL Server usage data service business to serve the thin customer of the machine expression service data service business service of fat customer from the Visual Basic the machine expression service data business the service be an alone the progress circulate. That progress can install for serve in the data same set server of the place or at another one server of the dissimilarity. The key characteristics of this kind of realization is the data service, business to serve the different from expression serve to can do for separation of progress movement in calculator. Three layer realizations.连接SQL Server数据库我们先介绍一下数据库的基本知识，算是学习数据库编程前的热身运动吧!1. 热身运动首先需要声明是，我们这里介绍的数据库知识都是指的关系数据库。

Inventory managementInventory ControlOn the so-called "inventory control", many people will interpret it as a "storage management", which is actually a big distortion.The traditional narrow view, mainly for warehouse inventory control of materials for inventory, data processing, storage, distribution, etc., through the implementation of anti-corrosion, temperature and humidity control means, to make the custody of the physical inventory to maintain optimum purposes. This is just a form of inventory control, or can be defined as the physical inventory control. How, then, from a broad perspective to understand inventory control? Inventory control should be related to the company's financial and operational objectives, in particular operating cash flow by optimizing the entire demand and supply chain management processes (DSCM), a reasonable set of ERP control strategy, and supported by appropriate information processing tools, tools to achieved in ensuring the timely delivery of the premise, as far as possible to reduce inventory levels, reducing inventory and obsolescence, the risk of devaluation. In this sense, the physical inventory control to achieve financial goals is just a means to control the entire inventory or just a necessary part; from the perspective of organizational functions, physical inventory control, warehouse management is mainly the responsibility of The broad inventory control is the demand and supply chain management, and the whole company's responsibility.Why until now many people's understanding of inventory control, limited physical inventory control? The following two reasons can not be ignored:First, our enterprises do not attach importance to inventory control. Especially those who benefit relatively good business, as long as there is money on the few people to consider the problem of inventory turnover. Inventory control is simply interpreted as warehouse management, unless the time to spend money, it may have been to see the inventory problem, and see the results are often very simple procurement to buy more, or did not do warehouse departments .Second, ERP misleading. Invoicing software is simple audacity to call it ERP, companies on their so-called ERP can reduce the number of inventory, inventory control, seems to rely on their small software can get. Even as SAP, BAAN ERP world, the field ofthese big boys, but also their simple modules inside the warehouse management functionality is defined as "inventory management" or "inventory control." This makes the already not quite understand what our inventory control, but not sure what is inventory control.In fact, from the perspective of broadly understood, inventory control, shouldinclude the following:First, the fundamental purpose of inventory control. We know that the so-called world-class manufacturing, two key assessment indicators (KPI) is, customer satisfaction and inventory turns, inventory turns and this is actually the fundamental objective of inventory control.Second, inventory control means. Increase inventory turns, relying solely on the so-called physical inventory control is not enough, it should be the demand and supply chain management process flow of this large output, and this big warehouse management processes in addition to including this link, the more important The section also includes: forecasting and order processing, production planning and control, materials planning and purchasing control, inventory planning and forecasting in itself, as well as finished products, raw materials, distribution and delivery of the strategy, and even customs management processes.And with the demand and supply chain management processes throughout the process, it is the information flow and capital flow management. In other words, inventory itself is across the entire demand and supply management processes in all aspects of inventory control in order to achieve the fundamental purpose, it must control all aspects of inventory, rather than just manage the physical inventory at hand.Third, inventory control, organizational structure and assessment.Since inventory control is the demand and supply chain management processes, output, inventory control to achieve the fundamental purpose of this process must be compatible with a rational organizational structure. Until now, we can see that many companies have only one purchasing department, purchasing department following pipe warehouse. This is far short of inventory control requirements. From the demand and supply chain management process analysis, we know that purchasing and warehouse management is the executive arm of the typical, and inventory control should focus on prevention, the executive branch is very difficult to "prevent inventory" for the simple reason that they assessment indicatorsin large part to ensure supply (production, customer). How the actual situation, a reasonable demand and supply chain management processes, and thus set the corresponding rational organizational structure and is a question many of our enterprisesto exploreThe role of inventory controlInventory management is an important part of business management. In the production and operation activities, inventory management must ensure that both the production plant for raw materials, spare parts demand, but also directly affect the purchasing, sales of share, sales activities. To make an inventory of corporate liquidity, accelerate cash flow, the security of supply under the premise of minimizing Yaku funds, directly affects the operational efficiency. Ensure the production and operation needs of the premise, so keep inventories at a reasonable level; dynamic inventory control, timely, appropriate proposed order to avoid over storage or out of stock; reduce inventory footprint, lower total cost of inventory; control stock funds used to accelerate cash flow.Problems arising from excessive inventory: increased warehouse space andinventory storage costs, thereby increasing product costs; take a lot of liquidity, resultingin sluggish capital, not only increased the burden of payment of interest, etc., would affect the time value of money and opportunity income; finished products and raw materials caused by physical loss and intangible losses; a large number of enterprise resource idle, affecting their rational allocation and optimization; cover the production, operation of the whole process of the various contradictions and problems, is not conducive to improve the management level.Inventory is too small the resulting problems: service levels caused a decline in the profit impact of marketing and corporate reputation; production system caused by inadequate supply of raw materials or other materials, affecting the normal production process; to shorten lead times, increase the number of orders, so order (production) costs; affect the balance of production and assembly of complete sets.NotesInventory management should particularly consider the following two questions:First, according to sales plans, according to the planned production of the goods circulated in the market, we should consider where, how much storage.Second, starting from the level of service and economic benefits to determine howto ensure inventories and supplementary questions.The two problems with the inventory in the logistics process functions.In general, the inventory function:(1)to prevent interrupted. Received orders to shorten the delivery of goods fromthe time in order to ensure quality service, at the same time to prevent out of stock.(2)to ensure proper inventory levels, saving inventory costs.(3)to reduce logistics costs. Supplement with the appropriate time interval compatible with the reasonable demand of the cargo in order to reduce logistics costs, eliminate or avoid sales fluctuations.(4)ensure the production planning, smooth to eliminate or avoid sales fluctuations.(5)display function.(6)reserve. Mass storage when the price falls, reduce losses, to respond to disasters and other contingencies.About the warehouse (inventory) on what the question, we must consider the number and location. If the distribution center, it should be possible according to customer needs, set at an appropriate place; if it is stored in central places to minimize the complementary principle to the distribution centers, there is no place certain requirements. When the stock base is established, will have to take into account are stored in various locations in what commodities.库存管理库存控制在谈到所谓“库存控制”的时候，很多人将其理解为“仓储管理”，这实际上是个很大的曲解。