多层堆码包装系统冲击动力学特性研究（Ⅰ）：冲击谱

研究多层堆码包装系统在半正弦脉冲激励下的冲击特性.建立多层堆码包装系统动力学模型,得到系统统一动力学方程并求解.依据结果提出评价系统冲击特性的组合冲击谱新概念,并讨论了脉冲幅值、材料阻尼及堆码层数对组合冲击谱的影响.结果表明,脉冲幅值对组合冲击谱没有影响,阻尼和堆码层数影响显著.     

多层堆码包装系统冲击动力学特性研究（Ⅱ）：破损边界

研究多层堆码包装系统在半正弦脉冲激励下的冲击特性.建立多层堆码包装系统动力学模型,得到系统动力学方程并求解.依据结果提出评价系统破损特性的组合破损边界曲线概念,并讨论了脉冲幅值、材料阻尼及堆码层数对组合破损边界的影响.结果表明,脉冲幅值对组合破损边界没有影响,阻尼和堆码层数影响显著.     

半正弦脉冲激励下斜支承包装系统冲击特性的研究

以斜支承包装系统为研究对象,建立了半正弦脉冲激励下系统的无量纲非线性冲击动力学方程,采用数值计算方法分析了系统加速度响应及冲击谱,探讨了无量纲脉冲激励幅值、无量纲脉冲激励时间、系统支承角以及阻尼对系统加速度响应及峰值的影响规律。研究表明:无量纲脉冲激励幅值、无量纲脉冲激励周期、系统支承角及阻尼等对系统响应峰值影响显著。     

矩形脉冲激励下斜支承系统易损件的冲击特性研究

以考虑易损件的斜支承包装系统为研究对象,建立了矩形脉冲激励下系统无量纲非线性冲击动力学方程。 利用龙格-库塔数值分析方法求解冲击动力学方程,以易损件加速度响应峰值与脉冲激励幅值之比为易损件的响应指标,脉冲激励时间、系统频率比作为变量,构建了易损件的三维冲击谱。 分析讨论了系统支承角、脉冲激励幅值以及质量比等对冲击响应谱的影响规律。 研究表明:随脉冲激励幅值增加,或随系统支承角减小,易损件加速度响应峰值增加且波动加剧;系统响应对低频率比较为敏感,增加频率比可抑制易损件加速度响应峰值,低频率比时增加质量比可降低易损件加速度响应峰值。 研究结果可为斜支承包装系统的设计提供理论依据。     

三次非线性多层堆码包装系统关键部件三维组合冲击谱研究¶

研究多层堆码包装系统关键部件在半正弦脉冲激励下的冲击特性。建立考虑关键部件的多层堆码包装系统动力学模型,得到系统动力学方程并求解。依据结果提出评价系统关键部件三维组合冲击谱新概念,并讨论了脉冲幅值、质量比、频率比、关键部件阻尼、材料阻尼及堆码层数对三维组合冲击谱的影响。结果表明,各因素影响显著。     

后峰锯齿脉冲激励下双曲正切包装系统的非线性动力学特性研究

建立了二自由度的双曲正切包装系统模型,并应用四阶龙格-库塔法对得到的冲击动力学方程进行数值求解,研究了其冲击响应特性。采用后峰锯齿脉冲作为激励,得到了关键部件的三维冲击谱,进一步讨论了频率比、脉冲激励幅值、包装材料阻尼和脉冲周期对关键部件冲击谱的影响规律。结果表明,频率比、脉冲激励幅值、包装材料阻尼和脉冲周期均对关键部件冲击响应峰值有显著影响。     

前峰锯齿脉冲激励下正切型非线性包装系统的冲击响应

研究具有正切型非线性特性的包装系统在前峰锯齿脉冲激励下的冲击响应,求得了产品包装系统的非线性动力学方程,讨论了相关参数对冲击谱曲线和边界破损曲线的影响。     

前峰锯齿脉冲激励下正切非线性包装系统的冲击响应

研究肯有正切型非线性特性的包装系统在前峰锯齿脉冲激励下的冲击响应，求得了产品包装系统的非线性动力学方程，讨论了相关参数对冲击谱曲线和边界破损曲线的影响。     

复合材料悬臂板系统的多脉冲同宿轨道

针对复合材料悬臂板系统的非线性动力学行为进行了分析。模型考虑高阶横向剪切效应、几何大变形和横向阻尼的影响,基于Reddy的高阶剪切变形理von Karman的大变形理论,利用Hamilton原理,Galerkin离散和多尺度法得到系统横向位移的平均方程。应用广义Melnikov方法研究了复合材料悬臂板的非线性混沌动力学行为。分析了在共振带附近,复合材料悬臂板系统存在的Shilnikov类型多脉冲跳跃同宿轨道。最后结合数值模拟,进一步揭示系统存在多脉冲跳跃现象。     

半正弦脉冲激励下考虑易损件的正切型包装系统冲击特性研究

研究考虑易损件的正切型包装系统在半正弦脉冲激励下的冲击特性.建立二自由度非线性产品包装系统模型,得到冲击动力学方程并数值求解.提出适合描述考虑易损件的产品包装系统三维冲击谱新概念,并进一步讨论了频率比、脉冲激励幅值和系统参数对易损件冲击谱的影响规律,结果表明,频率比、脉冲激励幅值和系统参数对易损件冲击响应峰值影响显著,研究结论为产品包装设计提供科学依据.     

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.……     

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.     

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     

Win-Win Cooperation

正The Chinese Premier Li Keqiang's recent trip to the UK has reinforced the China-UK comprehensive strategic partnership;just as the British Prime Minister David Cameron put it,"the relationship is gaining in strength,depth and understanding"after a bucket of business deals being inked worth more than 30 billion US dollars.From the first agreement signing in 2004 to the new agreement of mutual standards recognition and adoption in     

Systematic Approach for Emerging Industry

正A national directory of standards complexes for strategic emerging sectors was recently developed and released jointly by 12governmental departments,namely,SAC,NDRC,MOST,MIIT,MEP,MOA,AQSIQ,State Forest Administration,State Administration of Science and Technology for National Defense,State Oceanic Administration and National Railway Administration.     

Strictest Pollutants Emission Standards

正Four new national standards on air pollutant emission control offi cially issued by the Ministry of Environment Protection(MEP)together with AQSIQ and SAC has been brought into force from July 1,2014.The Emission standard for air pollutants of coal-burning,oil-burning and gasfi red boilers,which is the strictest emission standard historically,will tackle the stubborn pollution problem of boilers and waste incineration in most of China’s regions.     

Instructions to Authors

New Carbon Materials is a bimonthly journal published with the permission of the Ministry of Science and Technology and of the State News and Publication Agency.The journal is sponsored by the Institute of Coal Chemistry,Chinese Academy of Sciences,and is published by Science Press.Aims and Scope     

Progress on Standards Copyright Protection

正Recently,National Copyright Administration of China(NCAC)has rewarded 215 organizations and 179 individuals for their outstanding efforts on investigating standards copyright infringement and piracy in 2013.Hua Jianhua,the Deputy-Director of National Standards Copyright Protection Workgroup Office won a third prize of the national individual award.In 2012,SAC set up the national standards copyright protection working group,and developed policies to crack down standards infringement and piracy behaviors and to strengthen standards copyright protection.