失效分析技术

简要介绍了失效分析技术——痕迹分析技术、裂纹分析技术和断口分析技术等的基本概念、主要内容、一般程序和基本方法，以及它们在工程失效分析中的应用。     

雷达信号分析及软件设计

电子技术的快速发展大大提升了雷达的性能,同时也使得雷达系统的测试变得更为复杂。本文针对日益复杂的雷达系统测试和分析的需求,在对雷达信号分析技术进行阐述的基础上,探讨了雷达信号分析软件的设计与实现的相关问题。     

小波分析在空调负荷分析中的应用

根据小波分析的基本原理，应用小波分解和重构对空调负荷进行了分析，得到空调负荷的日变化趋势。研究结果表明，用小波分析应用于空调负荷的分析是可行的。     

煤质工业分析转换元素分析数学模型研究

依据煤的工业分析和元素分析的成分对应关系,从理论上提出了一个利用煤的工业分析快速计算元素分析的数学模型,并基于VB开发了应用程序,实现了煤质元素分析的自动化.选取8个具有代表性的煤样代入模型计算,并将模型输出结果与元素分析实验数据进行比较分析,得到最大误差为1.5%,证实数学模型输出结果准确可信.此外,依据以上结果还计算了锅炉热效率,得到锅炉热效率误差≤0.5%,进一步验证了数学模型输出可以满足锅炉经济性分析的要求.     

基于小波分析的解调分析方法

利用高斯小波的线性特性和带通特性,设计小波滤波器组.运用该滤波器组对调制信号进行解调分析,实现了选频、可变带宽包络分析.将传统的包络分析中信号的窄带带通滤波和包络分析结为一体.算法具有较强的适时性,为包络分析提供了一种新方法.     

基于小波分析的解调分析方法

利用高斯小波的线性特性和带通特性,设计小波滤波器组。运用该滤波器组对调制信号进行解调分析,实现了选频,可变带宽包络分析,将传统的包络分析中信号的窄带带通滤波和包络分析结为一体。算法具有较强的适时性,为包络分析提供了一种新方法。     

软件静态安全检测技术综述

静态分析可以从软件结构和代码中自动地提取软件运行时候的各种状态,从而发现软件之中的脆弱点。和其它软件安全检测相比,静态分析具有分析比较全面,自动化程度高等优点。本文研究软件漏洞检测技术的各种方法,讨论、总结软件静态安全检测技术的在软件检测方面的优势。     

基于Solid Works软件的有限元分析

利用Solid Works有限元分析插件simulation对双L环200L物料桶的三维模型进行堆码分析,验证所设计物料桶结构尺寸是否满足物料桶堆码要求;用有限元分析插件的优化分析功能对物料桶尺寸进行优化,通过对容器外形尺寸的优化提高容器抗堆码破损性能,延长物料桶寿命。     

氢氧化铝粉体粒度测量技术

氧化铝生产工艺分解过程中氢氧化铝粒度检测的结果对分解系统的稳定和产品氧化铝的粒度控制有着非常重要的意义。氢氧化铝粒度的测定方法很多,目前用来监测粒度的方法有筛分法、马尔文激光粒度法、库尔特全自动颗粒粒度分析、颗粒计数器分析等,综合各种分析结果可得到氢氧化铝的全粒度分布情况。     

全金属反射光学系统主镜的集成分析

光学集成分析是对外界力或热作用下系统光学性能的分析。全金属反射光学系统主镜的集成分析包括:在AutoCAD和Pro/E中进行结构设计,建立模型,于Ansys中进行有限元分析,在Zemax中进行光学分析。分析结果表明,横向20g加速度作用下主镜轴向变形最大,为0.869E-6m;轴向20g加速度作用下主镜的应力最大,为1.19MPa;在重力作用下,系统最大波前值分别为0.0387λ,在系统对光学性能0.05λ的要求范围内;在5~20g加速度范围内,主镜变形对系统RMS点尺寸的影响成近似的线性;近轴视场内,横向加速度对系统RMS点尺寸的影响比轴向的略小。光学集成分析可为光学系统的设计与评价提供更确切的依据。     

Insertion of triangulated surfaces into a meccano tetrahedral discretization by means of mesh refinement and optimization procedures

In this paper, we present a new method for inserting several triangulated surfaces into an existing tetrahedral mesh generated by the meccano method. The result is a conformal mesh where each inserted surface is approximated by a set of faces of the final tetrahedral mesh. First, the tetrahedral mesh is refined around the inserted surfaces to capture their geometric features. Second, each immersed surface is approximated by a set of faces from the tetrahedral mesh. Third, following a novel approach, the nodes of the approximated surfaces are mapped to the corresponding immersed surface. Fourth, we untangle and smooth the mesh by optimizing a regularized shape distortion measure for tetrahedral elements in which we move all the nodes of the mesh, restricting the movement of the edge and surface nodes along the corresponding entity they belong to. The refining process allows approximating the immersed surface for any initial meccano tetrahedral mesh. Moreover, the proposed projection method avoids computational expensive geometric projections. Finally, the applied simultaneous untangling and smoothing process delivers a high‐quality mesh and ensures that the immersed surfaces are interpolated. Several examples are presented to assess the properties of the proposed method.     

Certification Institutions Expected to Update and Transfer Information on Present Standards

Standards are the basis for production enterprises to organize production, ex-factory inspection, trade (delivery) and technical exchanges, product certification, quality arbitration and supervision.……     

Flow calorimeter for enthalpy increment measurements on condensed gases

A flow calorimeter for enthalpy increment measurements on condensed gases is presented. A better knowledge of the properties of the liquefied natural gas is needed, and therefore a liquid loop has been designed for our flow calorimeter. The fluid loop in the calorimeter is designed in order to avoid the two-phase region, since two phases would give compositional disturbances in the measurements. The avoidance of the two-phase region is made possible by increasing the pressure of the test fluid after the measurement section, then heating the fluid at super-critical pressure past the critical point. Finally, the fluid is throttled to the low-pressure gas state at the inlet condition of the compressor that circulates the fluid. To perform the pressure increase, a new cryogenic pump has been designed. To evaluate the new equipment, measurements were taken on liquid ethane over the temperature range 146–256 K at pressure between 0.9 and 5.1 MPa.     

Refrigerators Enter a New Era of Health Preservation Frestech initiates the establishment of China's first standard for household sterilization refrigerators

On November 30, 2007, the China Association for Standardization (CAS) held a press conference at Beijing Diaoyutai State Guest House. Leaders from the China Household Electric Appliance Research Institute, the China Household Electric Appliance Association, and the China Consumers' Association attended and made speeches.……     

Optimum-Simulation von Ernteprozessen

Zusammenfassung Bei der Gestaltung von Ernteprozessen — beispielsweise des Prozesses Mähdrusch, Körnertransport und -abnahme — als transportverbundene Fließarbeitsverfahren mit mindestens zwei verschiedenen Arbeitsmitteln gibt es einen großen Optimierungsspielraum. Solche Prozesse sind mehrstufige Bedienungsprozesse mit gemischter Anordnung der Bedienungseinrichtungen. Außerdem besitzen sie stark ausgeprägte räumliche Aspekte. Es wird vor allem gezeigt, welche Merkmale solcher Prozesse in Simulationsmodellen abgebildet sein müssen, welche Zielgrößen in Abhängigkeit von welchen Einflußgrößen unter Berücksichtigung welcher Prozeßbedingungen ermittelt werden sollten und wie der Bewertungsprozeß zur Ermittlung der gewünschten Informationen gestaltet werden muß.     

A study of centrifugal cast high boron high speed steel

In the present study a high‐boron high speed steel (HSS) roll material was designed. Many expensive alloy elements have been substituted by cheap boron alloy, and high‐boron high speed steel roll has been manufactured by centrifugal casting method. The microstructures, mechanical properties and wear resistance of centrifugal casting high‐boron high speed steel roll have been investigated by optical microscopy (OM), scanning electron microscopy (SEM), and X‐ray diffraction (XRD) analysis, hardness test, impact test and wear test. The results indicated that the solidification microstructures of high‐boron high speed steel roll consisted of M₂(B,C), (W,Mo)₂(B,C), M₃(B,C), M₂₃(B,C)₆ type borocarbides and martensite, a small amount of retained austenite. Borocarbides were continuously distributed over the grain boundary. After quenching from 1050 °C, local broken network appeared in partial borocarbides, and fine secondary borocarbide precipitated from the matrix. After tempering from 525 °C, the amount of precipitated borocarbide increased significantly. After heat treatment, the hardness of high‐boron high speed steel roll excelled 60 HRC, and its impact toughness excelled 8.0 J/cm². The single groove steel rolling amount of high‐boron high speed steel rolls increases by 500% than that of bainite cast iron roll, when the rolls are used in K₁ mill housing of bar mill.     

Brainstorming for ISO Strategy 2016-2020

正Responding to ISO’s appeal for survey for the to-be-developed ISO Strategy Plan for 2016-2020,SAC hosted a special workshop over the needs and comments of various fi elds on June 8 in Beijing.The workshop was attended by ISO President-elect and Ansteel General Manager Zhang Xiaogang,SAC Vice-Administrator Yu Xinli,and 30 experts from     

CNAS Passes APLAC's PTP Review

正The review group of Asia Pacific Laboratory Accreditation Cooperation(APLAC)carried out a 4-day peer review of the proficiency testing provider(PTP)for China National Accreditation Service for Conformity Assessment(CNAS)from July 28 to 31,2014.CNAS passed the PTP review with excellent performance.Two senior peer reviewers of APLAC made a comprehensive,rigorous and detailed review of CNAS’s PTP accreditation activities,and made the on-spot inspection of the review groups in Shanghai and Shenzhen respectively.     

新闻(英文)

正China and Greece Sign the Standardization Cooperation Agreement Witnessed by Chinese Premier Li Keqiang and Greek Prime Minister Antonis Samaras,AQSIQ Minister Zhi Shuping and ELOT Chairman and Executive Director Angelos Tolkas signed the SAC-ELOT Standardization Cooperation Agreement.The Agreement is one of the critical cooperation documents signed during Li Keqiang’s visit in Greece,encouraging China and Greece to