1.1 Scope For the purpose of compatible interconnection of data processing equipment via a local area network(LAN) using the token ring access method, this part of ISO/IEC 8802 a)Provides a general description of the token ring local area network (L

定价： 2366元 / 折扣价： 2012 元

5.1 This test method can be used for evaluating performance of commercially available anion-exchange materials regardless of the basic strength of the ion exchange groups. When previous operating history is known, a good interpretation of resin fouling or malfunction can be obtained by comparison against a reference sample of unused ion-exchange material evaluated in the same way.5.2 While resistivity has been chosen as the preferred analytical method for defining the exhaustion end point, with titration as the alternative, it is understood that observation of pH during rinse and the service run can yield useful information. The variations in pH observed with an ion exchange material suspected of having degraded, can be helpful in interpretation of performance when compared with similar data for a reference sample of unused material exhausted in the same way.1.1 This test method covers the determination of the operating capacity of anion-exchange materials when used for the removal of hydrochloric and sulfuric acid from water. It is designed to simulate operating conditions for strong acid removal and is intended for use in testing both new and used materials.1.2 The values stated in SI units are to be regarded as the standard. The inch-pound units given in parentheses are for information only.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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Foreword to ISO/IEC 8802-5 : 1998/Amd. 1: 1998 This International Standard is part of a family of International Standards for Local and Metropolitan Area Networks. This family of International Standards deals with the Physical and Data Link layers a

定价： 2958元 / 折扣价： 2515 元

5.1 The presence of water extractables in ion-exchange resins can cause fouling of other materials downstream and contamination of process water. The quantity of water extractables is sometimes used as a specification to indicate resin quality, and typical values are 0.01 to 0.1 %.5.2 It is recognized that this test method may not remove all potential sloughage products and does not measure volatile compounds. More extensive extraction and identification of compounds may be needed in specific cases.1.1 This test method covers the measurement of water soluble extractable residue from particulate ion-exchange resins based on elevated temperature extraction and gravimetric determination of residue.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

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5.1 This test method can be used to evaluate unused mixed bed ion exchange cartridges for conformance to specifications.5.2 This test method provides for the calculation of capacity in terms of the volume of water treated to a conductivity end point.5.3 The test method as written assumes that the ion exchange resins in the cartridge are either partially or fully converted to the H+ or OH– form. Regeneration of the resins is not part of this method.5.4 This test method provides for the calculation of capacity on a cartridge basis.5.5 This test method may be used to test different size mixed bed resin cartridges. The flow rate of test water and the frequency of sampling are varied to compensate for the approximate volume of resin in the test cartridge.1.1 This test method covers the determination of the performance of mixed bed ion exchange resin cartridges in the active form when used for deionization. The test can be used to determine the initial capacity of unused cartridges or the remaining capacity of used cartridges. In this case performance is defined as ion exchange capacity (or throughput) to two defined endpoints. The method does not measure organics and does not attempt to determine the ultimate water quality attainable by the cartridge.1.2 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 515元 / 折扣价： 438 元 加购物车

Computers are becoming an integral part of each testing laboratory. A variety of automated test devices which collect and store data now exist. A variety of software programs to perform calculations and produce reported results are used. There is no consistency in the formats used to store data. Consequently, it is time consuming and expensive to exchange computerized test data files among organizations. This guide presents a standard yet versatile format that can be used to exchange data across systems. This guide defines the principal data elements that are considered important and worth recording and storing permanently in a computerized data storage system from which larger databases may be prepared. These data elements are not intended to be requirements of any specific or single database. The format permits only those elements that a specific user may require. Additional data elements may be added using the general outline of this guide. Those elements must be added in a manner consistent with the definitions in this guide, such that a computer program written to follow this guide can successfully read the entire data file, including one that contains data elements not identified in this guide. This guide does not define how to obtain and record specific data. That activity is covered by each specific test method. This guide may be incomplete for some applications. It is intended that additions to the formats will be made as requests come from each ASTM subcommittee responsible for a particular standard. Those additions will be made without rendering older files unreadable. The recommended format in this guide does not require that all data elements be included in the data base. A user may elect to omit any data element without affecting the ability of the file format structure to work. However, those elements that are required in the report section of the relevant ASTM standard should be included in the standardized data file. Following ASTM recommended practice, all data are stored in SI units. 1.1 This guide covers recommended data formats for the exchange of mechanical test data for soils and rocks. From this guide, a standardized file of data can be prepared that can be read by others who use this guide.1.2 The format specified in this guide is used for the exchange of data between computer programs, users, agencies, etc. It is not necessary that test data for internal use be stored in this format, only that a program adhering to this guide have the capability to read, or write test data in this format, or both.1.3 This guide does not cover digital geospacial data which is treated Specification D 5714.1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.1.5 This guide offers an organized collection of information or a series of options and does not recommend a specific course of action. This document cannot replace education or experience and should be used in conjunction with professional judgment. Not all aspects of this guide may be applicable in all circumstances. This ASTM standard is not intended to represent or replace the standard of care by which the adequacy of a given professional service must be judged, nor should this document be applied without consideration of a project's many unique aspects. The word "Standard" in the title of this document means only that the document has been approved through the ASTM consensus process.

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定价： 1229元 / 折扣价： 1045 元

定价： 1547元 / 折扣价： 1315 元

This specification describes a medium access control (MAC) and physical layer (PHY) specification for wireless connectivity using dedicated short-range communications (DSRC) services. This standard is based on and refers to IEEE Standards 802.11, Wireless LAN Medium Access Control and Physical Layer Specifications, and 802.11a, Wireless LAN Medium Access Control and Physical Layer Specifications High-Speed Physical Layer in the 5 GHz Band, with permission from the IEEE society. This specification is meant to be an extension of IEEE 802.11 technology into the high-speed vehicle environment. The difference between IEEE 802.11 and IEEE 802.11a operating parameters required to implement a mostly high-speed data transfer service in the 5.9-GHz Intelligent Transportation Systems Radio Service (ITS-RS) Band is explained. Potential operations within the Unlicensed National Information Infrastructure (UNII) Band are also addressed, as appropriate.1.1 This specification2 describes a medium access control (MAC) and physical layer (PHY) specification for wireless connectivity using dedicated short-range communications (DSRC) services. This standard is based on and refers to IEEE Standards 802.11, “Wireless LAN Medium Access Control and Physical Layer Specifications,” and 802.11a, “Wireless LAN Medium Access Control and Physical Layer Specifications High-Speed Physical Layer in the 5 GHz Band,” with permission from the IEEE Society. This specification is meant to be an extension of IEEE 802.11 technology into the high-speed vehicle environment. As presented here, this specification contains just enough information to explain the difference between IEEE 802.11 and IEEE 802.11a operating parameters required to implement a mostly high-speed data transfer service in the 5.9-GHz Intelligent Transportation Systems Radio Service (ITS-RS) band. Potential operations within the Unlicensed National Information Infrastructure (UNII) band are also addressed, as appropriate.1.2 Purpose—The purpose of this specification is to provide wireless communications over short distances between information sources and transactions stations on the roadside and mobile radio units, between mobile units, and between portable units and mobile units. The communications generally occur over line-of-sight distances of less than 1000 m between roadside units and mostly high-speed, but occasionally stopped and slow-moving, vehicles or between high-speed vehicles. This specification also offers regulatory bodies a means of standardizing access to the 5.9-GHz frequency band for the purpose of interoperable communications to and between vehicles at line-of-sight distances on the roadway.1.3 Specifically, this specification accomplishes the following:1.3.1 Describes the functions and services required by a DSRC and IEEE 802.11-compliant device to operate in a high-speed mobile environment.1.3.2 Refers to IEEE 802.11 MAC procedures.1.3.3 Defines the 5.9-GHz DSRC signaling technique and interface functions that are controlled by the IEEE 802.11 MAC.1.3.4 Permits the operation of a DSRC-conformant device within a DSRC communications zone that may coexist with multiple overlapping DSRC communication zones.1.3.5 Describes the requirements and procedures to provide privacy of user information being transferred over the wireless medium and authentication of the DSRC or IEEE 802.11-conformant devices.1.4 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 843元 / 折扣价： 717 元 加购物车

This practice provides a common format that allows a computer design system to generate data that an output device can accurately reproduce independent of the hardware manufacturer.1.1 This practice describes a data format for transferring information from a sewn product computer aided design software program to a device that produces physical output, typically in the form of a printed or drawn image on paper.1.2 This practice is based on a subset of the Hewlett Packard Graphics Language HPGL/2. Supported syntax and limitations are listed in 7.2. Unsupported syntax is listed in X1.1.1.3 This practice only supports X-Y vector data and a limited set of additional functions. No provision is made to support bitmap/raster data used in applications like inkjet printing.1.4 This practice supports a single system of units, an image fixed at 100 % scale and 1:1 aspect ratio. Scaling and custom unit systems are not supported.1.5 This practice does not support curve interpolation or definitions. All curves are represented by discrete vectors (stroked) and are dependent on the resolution of the CAD software.1.6 This practice requires that all coordinates are absolute, not relative, as defined in the HPGL/2 reference.1.7 This practice only supports positive coordinates that are measured from a single X-Y origin point with coordinates 0,0.1.8 This practice only supports fixed width fonts. Variable width fonts are not supported.1.9 This practice intends to transfer a static image with no provision for editing.1.10 This practice assumes monochromatic output. It does not support implied output colors.1.11 This practice imposes no limits on the width or length of the plot data. Physical limitations imposed by the hardware and their effects on the output are the responsibility of the hardware manufacturer.1.12 This practice does not support frame advance commands or any methods that insert multiple origin points or floating coordinate systems.1.13 This practice limits the plot file to contain a single block of data demarked by a compatible header and terminator. Multiple blocks of data in a single file are not allowed.1.14 The intended application of this practice is limited to the class of output devices found in the sewn product industries that produce apparel, textiles, upholstery, and others that use soft or semi-rigid materials.1.15 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.

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4.1 Fine-grained soils are used in waste containment systems as barriers to flow and contaminant transport. Liquids contained by these barriers can contain ions that may interact with the mineral surfaces in fine-grained soils.4.2 The liquid passing through the pores of fine-grained soil can interact with the mineral surface, and affect the physical and chemical characteristics of the soil. This method can be used as part of an evaluation of these interactions.NOTE 1: The quality of the result produced by this standard depends on the competence of the personnel performing the test and the suitability of the equipment and facilities used. Agencies that meet the criteria of Practice D3740 are generally considered capable of competent and objective testing, sampling, inspection, etc. Users of this standard are cautioned that compliance with Practice D3740 does not in itself ensure reliable results. Reliable results depend on many factors. Practice D3740 provides a means of evaluating some of these factors.1.1 This test method describes the procedures for measuring the soluble and bound cations as well as the cation exchange capacity (CEC) of fine-grained inorganic soils. Clay minerals in fine-grained soils carry a negative surface charge that is balanced by bound cations near the mineral surface. These bound cations can be exchanged by other cations in the pore water, which are referred to as soluble cations. The cation exchange capacity is a measure of the negative surface charge on the mineral surface. The CEC generally is satisfied by calcium (Ca), sodium (Na), magnesium (Mg), and potassium (K), although other cations may be present depending on the environment in which the soil exists. This test method was developed from concepts described previously in Lavkulich (1981) (1)2 and Rhoades (1982) (2). In soils with appreciable gypsum or calcite, dissolution of these minerals will release Ca in solution that may affect the measurement.1.2 In this test method, the soluble salts from the mineral surface are washed off with de-ionized water and then the concentration of soluble salts within the extract is measured. The bound cations of the clay are measured by using a solution containing an index ion that forces the existing cations in the bound layer into solution. The total concentrations of bound and soluble cations in this solution are measured. The CEC is measured by displacing the index ion with another salt solution and measuring the amount of the displaced index ion.1.3 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety, health, and environmental practices and determine the applicability of regulatory limitations prior to use.1.4 All observed and calculated values shall conform to the guide for significant digits and rounding established in Practice D6026. The procedures in Practice D6026 that are used to specify how data are collected, recorded, and calculated are regarded as the industry standard. In addition, they are representative of the significant digits that should generally be retained. The procedures do not consider material variation, purpose for obtaining the data, special purpose studies, or any considerations for the objectives of the user. Increasing or reducing the significant digits of reported data to be commensurate with these considerations is common practice. Consideration of the significant digits to be used in analysis methods for engineering design is beyond the scope of this standard.1.5 Units—The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard. Reporting of test results in units other than SI shall not be regarded as nonconformance with this test method.1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.

定价： 590元 / 折扣价： 502 元 加购物车