This practice is intended for guidance and instruction of the aircraft and unmanned aircraft systems industries when addressing the requirements of Part 21.1.1 In this practice, certification procedures are provided for Unmanned Aircraft Systems (UAS) in the Light UAS Class and in the Remotely Operated Aircraft (ROA) UAS Classes. Unmanned Aircraft Systems in the Mini UAS and Micro UAS Classes are not considered in this practice, since they do not undergo airworthiness certification.1.2 Citations of Federal Aviation RegulationsWhen citing U.S. Federal Aviation Regulations in this practice, the citation references are based on the following Federal Aviation Regulation structure:1.2.1 The Code of Federal Regulations, Title 14 (14 CFR) comprises Aeronautics and Space Regulations. Chapter 1 of 14 CFR contains the regulations of the Federal Aviation Administration and is subdivided into subchapters and parts:The Parts are further subdivided into Subparts and sections.1.2.2 This practice uses Part 21 as a template. Within the text of the practice:14 CFR Chapter 1 means the whole of Chapter 1 of 14 CFR; andSubchapter C means all of the Parts of Subchapter C of 14 CFR.1.2.3 In compact notation, citation of section 1309 of Part 23, for example, may be designated as "section 23.1309."1.3 Unmanned Aircraft SystemsAn Unmanned Aircraft System (UAS) comprises an unmanned air vehicle, the remote control ground station that provides for the mission management and piloting of the air vehicle, data-links for the exchange of control and sensor payload data and all related interfaces. Any part of the overall system that could affect the airworthiness and safety of the aircraft is subject to the requirements of Part 21.1.4 &inch-pound-units;1.5 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.

定价： 0元 / 折扣价： 0 元

1.1 This specification establishes a group of requirements common to wrought copper alloy wire and shall apply to Specifications B16M, B99M, B159M, B197M, and B206M to the extent referenced therein. 1.2 The chemical composition, physical and mechanical properties, and all other requirements not included in this specification shall be prescribed in the product specification. 1.3 This specification is the SI companion to Specification B250. 1.4 SI units are the measurement standard.

定价： 0元 / 折扣价： 0 元

1.1 This guide covers guidelines for the acceptance testing frequency requirements for geonet and geonet drainage geocomposite materials describing types of tests, test methods, and recommended verifications.1.2 This guide is intended to aid purchasers, installers, contractors, owners, operators, designers, and agencies in establishing a minimum level of effort for product acceptance testing and verification. This is intended to ensure that the supplied geonet and/or geonet drainage geocomposite roll(s) meet accepted material specifications.1.3 This guide offers an organized collection of information or a series of options and does not recommend a specific course of action. This guide 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 guide 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 guide be applied without consideration of a project's many unique aspects. The word “Standard” in the title of this guide means only that the guide has been approved through the ASTM International consensus process.1.4 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall be used independently of the other, and values from the two systems shall not be combined.1.5 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.1.6 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： 515元 / 折扣价： 438 元 加购物车

This specification covers a group of general requirements for wrought seamless copper and copper alloy tube. The material shall be produced by either hot or cold working operations, or both, and shall be finished, unless otherwise specified, by such cold working and annealing or heat treatment as necessary to meet the properties specified. Dimensional requirements such as wall thickness are specified. The sampling requirements including lot size, portion size, and selection of sample pieces are given. Requirements for chemical analysis, and tension, microscopical examination, Rockwell hardness, grain size, expansion (pin), mercurous nitrate, and electrical resistivity tests are detailed. The material shall conform to the prescribed chemical composition, hardness, electrical resistivity, tensile strength, yield strength, elongation, and grain size.1.1 This specification covers a group of general requirements common to several wrought product specifications. Unless otherwise specified in the purchase order, or in an individual specification, these general requirements shall apply to copper and copper-alloy tube supplied under Specifications B68/B68M, B75/B75M, B135/B135M, B466/B466M, B643 and B743.1.2 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.1.3 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

This specification covers a group of general requirements for wrought seamless copper and copper alloy tube. The material shall be produced by either hot or cold working operations, or both, and shall be finished, unless otherwise specified, by such cold working and annealing or heat treatment as necessary to meet the properties specified. Dimensional requirements such as wall thickness are specified. The sampling requirements including lot size, portion size, and selection of sample pieces are given. Requirements for chemical analysis, and tension, microscopical examination, Rockwell hardness, grain size, expansion (pin), mercurous nitrate, and electrical resistivity tests are detailed. The material shall conform to the prescribed chemical composition, hardness, electrical resistivity, tensile strength, yield strength, elongation, and grain size.1.1 This specification covers a group of general requirements common to several wrought product specifications. Unless otherwise specified in the purchase order, or in an individual specification, these general requirements shall apply to copper and copper-alloy tube supplied under Specifications B68, B75, B135, and B466/B466M.Note 1—This specification is the SI companion to B251.

定价： 0元 / 折扣价： 0 元

This specification covers general workmanship and test method requirements of stainless steel suture needle holders intended for reuse in surgery. Materials of all component parts shall be fabricated from martensitic stainless steel type 410, 410X, 416, 420A, 420B, 420C, 420F, 420F Mod, and 440B. The material shall be heat treated and shall conform to the specified hardness, corrosion resistance, workmanship, finish, and appearance.1.1 This specification covers general workmanship aspects of stainless steel suture needle holders intended for reuse in surgery.1.2 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

This guide covers a group of requirements for carbon and alloy steel bars under each of the following specifications: hot-rolled carbon steel bars, cold-finished carbon steel bars, hot-rolled alloy steel bars, and cold-finished alloy steel bars. Heat and product analysis shall be performed on several grades of carbon steel bars, wherein the material shall conform to the required chemical composition for carbon, manganese, phosphorus, and sulfur. Several grades of alloy steel bars shall also undergo heat and product analysis and shall meet the required chemical composition for carbon, manganese, phosphorus, sulfur, silicon, nickel, chromium, and molybdenum. When compositions other than those indicated in the specified chemical components are required, the composition limits shall be prepared using the specified ranges and limits for carbon steel and alloy steel. The material shall undergo grain size test and shall conform to the specified grain size requirement. Mechanical tests shall also be performed on the steel test specimens.1.1 This specification2 covers a group of common requirements which, unless otherwise specified in the purchase order or in an individual specification, shall apply to carbon and alloy steel bars under each of the following ASTM specifications (or under any other ASTM specification which invokes this specification or portions thereof):Title of Specification ASTMDesignationAHot-Rolled Carbon Steel Bars:   Steel Bars, Carbon, Quenched and Tempered A321 Steel Bars and Shapes, Carbon Rolled from “T'' Rails A499 Steel Bars, Carbon, Merchant Quality, M-Grades A575 Steel Bars, Carbon, Hot-Wrought, Special Quality A576 Steel Bars, Carbon, Merchant Quality, Mechanical Properties A663/A663M Steel Bars, Carbon, Hot-Wrought, Special Quality, Mechanical Properties A675/A675M Carbon and Alloy Steel Bars for Springs A689Cold-Finished Carbon Steel Bars:   Steel Bar, Carbon and Alloy, Cold-Finished A108 Cold-Drawn Stress-Relieved Carbon Steel Bars Subject to Mechanical Property Requirements A311/A311MHot-Rolled Alloy Steel Bars:   Steel Bars, Alloy, Standard Grades A322 Carbon and Alloy Steel Bars Subject to End-Quench Hardenability Requirements A304 Steel Bars, Alloy, Hot-Wrought or Cold-Finished, Quenched and Tempered A434/A434M Steel Bars, Alloy, Hot-Wrought, for Elevated Temperature or Pressure-Containing Parts, or Both A739Cold-Finished Alloy Steel Bars:   Steel Bars, Alloy, Hot-Rolled or Cold-Finished, Quenched and Tempered A434/A434M Steel Bars, Carbon, Hot-Wrought or Cold-Finished, Special Quality, for Pressure Piping Components A696   A These designations refer to the latest issue of the respective specifications, which appear either in the Annual Book of ASTM Standards, Vol 01.05, or as reprints obtainable from ASTM.1.2 In case of any conflict in requirements, the requirements of the purchase order, the individual material specification, and this general specification shall prevail in the sequence named.1.3 The values stated in either inch-pound units or SI units are to be regarded separately as standard. The values stated in each system are not necessarily exact equivalents; therefore, to ensure conformance with the standard, each system shall used independently of the other, and values from the two systems shall not be combined.1.4 For purposes of determining conformance to this specification and the various material specifications referenced in 1.1, dimensional values shall be rounded to the nearest unit in the right-hand place of figures used in expressing the limiting values in accordance with the rounding method of Practice E29.NOTE 1: Specification A29/A29M previously listed dimensional tolerances for cold-finished bars; these are now found in Specification A108.1.5 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.1.6 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： 646元 / 折扣价： 550 元 加购物车

This specification covers hot-worked alloy and carbon-boron steels designed to attain restricted depth of hardening in the end-quench test. These steel compositions are identified by the suffix letter “RH” added to the conventional grade number. The steel shall be made by one or more of the following primary processes: open-hearth, basic-oxygen, or electric furnace. The primary melting may incorporate separate degassing or ladle refining and may be followed by secondary melting using electroslag remelting or vacuum arc remelting. Where secondary melting is employed, the heat shall be defined as all the ingots remelted from a single primary heat. Immediately after hot working, the bars shall be allowed to cool when necessary to a temperature below the critical range under suitable conditions, to prevent injury by too rapid cooling. The steel shall have an austenitic grain size of five to eight. The grain structure shall be considered satisfactory when a minimum of 70% of the rated grains are within the specified size limits. Hardenability values specified are based on fine-grain steels and are not applicable to coarse-grain steel. All forged and rolled hardenability test specimens must be normalized prior to testing. Cast specimens need not be normalized.1.1 This specification covers hot-worked alloy and carbon-boron steels designed to attain restricted depth of hardening in the end-quench test. These steel compositions are identified by the suffix letter “RH” added to the conventional grade number.1.2 In general, steels with restricted hardenability (RH steels) will exhibit a hardness range not greater than 5 HRC at the initial position on the end-quench hardenability bar and not greater than 65 % of the hardness range for standard H-band steels (Specification A304) in the inflection region. Generally the restricted hardenability band follows the middle of the corresponding standard H-band. An example of the RH band compared with the H band is given for Grade 4140 in Fig. 1.FIG. 1 Comparison of H-Band and RH-Band for 4140 SteelA1.2.1 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in non-conformance with the standard.1.3 This specification is expressed in both inch-pound units and SI units. However, the material will be supplied to inch-pound units unless the purchase order specifies the “M” specification designation.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 specification covers a group of common requirements which shall apply to tin mill products. The steel shall be made by the open-hearth, electric-furnace, or basic-oxygen process. The steel shall conform to specified chemical composition requirements. Rockwell 30T hardness test shall be done to the plates. This test forms the basis for a system of temper designation. The mechanical properties of continuously annealed plate and batch annealed plate of the same Rockwell 30T temper designation are not identical. It is important to keep in mind, that the Rockwell 30T test does not measure all various factors which contribute to the fabrication characteristics of the plate.1.1 This specification covers a group of common requirements, which unless otherwise specified in the purchase order or in an individual specification, shall apply to tin mill products.1.2 In case of any conflict in requirements, the requirements of the purchase order, the individual material specification, and this general specification shall prevail in the sequence named.NOTE 1: A complete metric companion to Specification A623 has been developed—Specification A623M; therefore no metric equivalents are presented in this specification.1.3 The following safety caveat covers Annex A3 through Annex A10 of this specification: 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.

定价： 843元 / 折扣价： 717 元 加购物车

This specification covers carbon and low alloy steel castings having chemical analyses similar to that of the standard wrought grades. Several grades are covered, such as; SC 1020, SC 1025, SC 1030, SC 1040, SC 1045, SC 4130, SC 4140, SC 4330, SC 4340, SC 8620, SC 8625, and SC 8630. Castings shall be heat treated either by full annealing, normalizing, normalizing and tempering, or quenching and tempering. The steel shall conform to the requirements of chemical composition as specified.1.1 This specification covers carbon and low-alloy steel castings having chemical analyses similar to those of the standard wrought grades.1.2 Several grades are covered and are designated by chemical composition shown in Table 1.1.3 The values stated in either SI units or inch-pound units are to be regarded separately as standard. The values stated in each system may not be exact equivalents; therefore, each system shall be used independently of the other. Combining values from the two systems may result in nonconformance with the standard.1.3.1 Within the text, the SI units are shown in brackets.1.3.2 Inch-pound units are applicable for material ordered to Specification A915, and SI units for material ordered to Specification A915M.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： 515元 / 折扣价： 438 元 加购物车

5.1 This guide provides criteria for evaluating the capability of a laboratory to properly perform commercial cooking appliance energy consumption and cooking-energy efficiency evaluations, and to establish essential characteristics pertaining to the organization, personnel, facilities, and quality systems of the laboratory.1.1 The scope of this guide includes the laboratory and organizational requirements to test commercial cooking and warming appliances (for example, griddles, fryers, ovens, steam cookers, and hot food holding cabinets) for preheat energy consumption and time, idle energy rate, cooking-energy efficiency, and production capacity, in accordance with the appropriate ASTM test methods under the jurisdiction of Committee F26, including the following:Test Method F1275Test Method F1361Test Methods F1484Test Method F1496Test Methods F1521Test Method F1605Test Method F1639Test Method F1695Test Method F1784Test Method F1785Test Method F1786Test Method F1787Test Method F1817Test Method F1964Test Method F1965Test Method F1991Test Method F2093Test Method F2140Test Method F2142Test Method F2144Test Method F2237Test Method F2238Test Method F2239Test Method F2380Test Method F24731.2 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered 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.

定价： 590元 / 折扣价： 502 元 加购物车

This specification covers a group of common requirements which shall apply to tin mill products. The steel shall be made by the open-hearth, electric-furnace, or basic-oxygen process. The steel shall conform to specified chemical composition requirements. Rockwell 30T hardness test shall be done to the plates. This test forms the basis for a system of temper designation. The mechanical properties of continuously annealed plate and batch annealed plate of the same Rockwell 30T temper designation are not identical. It is important to keep in mind, that the Rockwell 30T test does not measure all various factors which contribute to the fabrication characteristics of the plate.1.1 This specification covers a group of common requirements, which unless otherwise specified in the purchase order or in an individual specification, shall apply to tin mill products.1.2 In case of conflict in requirements, the requirements of the purchase order, the individual material specification, and this general specification shall prevail in the sequence named.NOTE 1: A complete inch-pound companion to Specification A623M has been developed—Specification A623; therefore, no inch-pound equivalents are presented.1.3 The following safety hazards caveat covers Annex A1 through Annex A8 of this specification: 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.

定价： 843元 / 折扣价： 717 元 加购物车

This specification covers hot-rolled and cold-rolled steel sheet coated by the electrolytic process. Coatings can be comprised of pure metals or metal alloys. The product shall be coated on one or both surfaces with equal or differential coating masses on the two surfaces. The following seven-character format shall be used to identify the coating mass required: first and second characters; third character; fifth and fourth characters; sixth character; and seventh character. Heat analysis of the steel shall conform to the chemical requirements of the specification of the steel. Coating mass tests shall include weigh-strip-weigh method, X-ray fluorescence, Coulometric method, and referee method. Structural steel such as cold-rolled and hot-rolled sheets, shall also undergo coating bend test and shall conform with the bend test requirements.1.1 This specification covers hot-rolled and cold-rolled steel sheet coated by the electrolytic process. Coatings can be comprised of pure metals or metal alloys. For specific coatings, refer to Specifications A879/A879M and A918.1.2 The product shall be coated on one or both surfaces with equal or differential coating masses on the two surfaces. Sheet-coated with equal coating masses on each surface has similar levels of corrosion protection on each surface. Often, however, a higher level of corrosion protection is required on one surface than is required on the other. In these situations, one surface shall be specified with a heavier coating mass than the other. Either surface, when specified to be painted, will provide additional corrosion protection as compared to an unpainted surface.1.3 This coating process has essentially no effect on the base metal mechanical properties, and use is permitted on any grade of hot-rolled or cold-rolled steel sheet. The coated sheet is available as Commercial Steel (CS), Drawing Steel (DS), Deep Drawing Steel (DDS), Extra-Deep Drawing Steel (EDDS), Structural Steel (SS) High-Strength Low-Alloy Steel (HSLAS), High-Strength Low-Alloy Steel with Improved Formability (HSLAS-F), Solution-Hardened Steel (SHS), or Bake-Hardenable Steel (BHS).1.4 The values stated in SI units are to be regarded as the standard.1.5 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

6.1 Intended Use—Compliance with this practice provides the procuring organization with assurance that human users will be efficient, effective, and safe in the operation and maintenance of marine systems, equipment, and facilities. Specifically, it is intended to ensure the following:6.1.1 System performance requirements are achieved reliably by appropriate use and accommodation of the human component of the system.6.1.2 Usable design of equipment, software, and environment permits the human-equipment/software combination to meet system performance goals.6.1.3 System features, processes, and procedures do not constitute hazards to humans.6.1.4 Trade-offs between automated and manual operations results in effective human performance and appropriate cost control.6.1.5 Manpower, personnel, and training requirements are met.6.1.6 Selected HSI design standards are applied that are adequate and appropriate technically.6.1.7 Systems and equipments are designed to facilitate required maintenance.6.1.8 Procedures for operating and maintaining equipment are efficient, reliable, approved for maritime use, and safe.6.1.9 Potential error-inducing equipment design features are eliminated, or at least, minimized, and systems are designed to be error-tolerant.6.1.10 Layouts and arrangements of equipment afford efficient traffic patterns, communications, and use.6.1.11 Habitability facilities and working spaces meet environmental control and physical environment requirements to provide the level of comfort and quality of life for the crew that is conducive to maintaining optimum personnel performance and endurance.6.1.12 Hazards to human health are minimized.6.1.13 Personnel survivability is maximized.6.2  and Nature of Work—HSI includes, but is not limited to, active participation throughout all phases in the life cycle of a marine system, including requirements definition, design, development, production, operations and decommissioning. HSI, as a systems engineering process, should be integrated fully into the larger engineering process. For the government, the HSI systems engineering process is manifested in both a more formalized, full scale system acquisition, as well as a non-developmental item acquisition. For the commercial industry, the system acquisition process is less formal and more streamlined. Each process is described below.6.3 Government Formalized, Full Scale Acquisition—The U.S. Government's acquisition process is composed of six steps, as illustrated in Fig. 3. Each phase is briefly summarized below.6.6 Modernization—One key part of operations and support is modernization. In many cases in both government and commercial marine system development, existing designs are modified, retrofitted, or modernized to meet new mission requirements or to implement new technology. In these cases, design activities are focused on the modifications and their integration with the existing design rather than the complete marine system. These design activities follow a systems engineering process, much like new design.6.6.1 HSI activities during modernization may include any of those listed in the following sections but scaled to focus on the modifications and their integration with the existing design. HSI activities should focus on determining the impact of the modifications on existing manpower, personnel, and training (MPT) requirements and identifying how MPT considerations may need to be modified for successful integration. HSI activities also focus on ensuring that modifications are integrated into the existing marine system without any negative implications to human performance, safety, occupational health, survivability or habitability.

定价： 843元 / 折扣价： 717 元 加购物车

This specification covers carbon and alloy steel bars subject to end-quench hardenability requirements. The methods for estimating the hardness value of the material are presented. Method A is the minimum and maximum hardness values at any desired distance, Method B is the minimum and maximum distances at which any desired hardness value occurs, Method C is the two maximum hardness values at two desired distances, Method D is the two minimum hardness values at two desired distances, and Method E is any minimum hardness plus any maximum hardness. The heat analysis shall conform to the requirements as to chemical composition. The fine austenitic grain size requirements of the steel material are presented in details. The end-quench hardenability shall conform to the requirements specified on the purchase order. The test specimen requirements indicates that, the number and location of test specimens shall be in accordance with the manufacturers standard practice and shall adequately represent the hardenability of each heat, also, all forged or rolled hardenability test specimens must be normalized prior to testing. The grain size and end-quench hardenability test methods are presented in details.1.1 This specification covers hot-worked alloy, carbon, and carbon-boron steels in a variety of compositions and sizes, which may attain specified depth of hardening in the end quench test. These steel compositions are identified by the suffix letter “H” added to the conventional grade number.1.2 This specification provides for analyses other than those listed under Tables 1 and 2. Special hardenability limits are also permissible when approved by the purchaser and manufacturer.1.3 The values stated in inch-pound units are to be regarded as standard. No other units of measurement are included in this standard.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： 918元 / 折扣价： 781 元 加购物车