偏频锁定0.633μM碘吸收稳频激光

为了满足大尺寸精密干涉测量对干涉信号的信噪比要求，我们研制了偏频锁定氦氖０．６３３μｍ碘吸收稳频激光器，该系统激光的频率不稳定度为５．５×１０－１２（τ＝１０ｓ），系统的频率再现性为４×１０－１１，可连续锁定６个小时以上，无调制输出功率大于０．８ｍＷ。     

聚丙烯网络合成

用固相两步法合成了聚丙烯（ＰＰ）网络。首先将ＰＰ用马来酸酐（ＭＡＨ）功能化，再加入交联剂己二胺（ＨＤＡ）或聚乙烯醇（ＰＶＡ）使ＰＰ网络化。研究了在该方法中反应条件与ＰＰ网络的凝胶含量关系。结果表明，当引发剂过氧化苯甲酰（ＢＰＯ）用量低于０．８３×１０－３ｍｏｌ时，凝胶含量随ＢＰＯ增加而迅速升高，ＢＰＯ用量高于１．６５×１０－３ｍｏｌ时，凝胶含量基本不再变化，控制反应的最佳时间为２５～３０ｍｉｎ。     

工业铯钟速率变化主要因素的探讨

上海天文台（ＳＯ）原子时实验室的４台工业铯钟１９８３～１９９０年连续工作了４或７年，它们的速率的长期变化与钟房的环境参数和性能参数的变化有关。本文根据有关数据，用不同的方法进行了分析，得到了一些明晰的结果。１）钟的速率变化受湿度的季节性变化影响：在相对湿度变化１％时，Ｃｓ２（１２６７）和Ｃｓ４（１４５７４）的速率变化分别为１．８９５ｕｓ／ｄ（２．２×１０－１４）和０．６１８ｎｓ／ｄ（７．１×１０－１５）。ＳＯ的原子钟房的相对湿度的年变化为２０％～８５％，引起这两台钟的速率年变化分别为１．４３×１０－１２和４．６５×１０－１４２）钟的速率变化受钟的离子泵电流参数的线性变化（从钟束管寿命的中期开始）影响：在离子泵电流参数变化１μＡ时，Ｃｓ３（１６１８０）和Ｃｓｌ（１２９９７）的速率变化分别为０．４３９ｎｓ／ａ（５．０８×１０－１５）和０．５５２ｎｓ／ａ（６．３９×１０－１５）。这两台钟的离子系电流参数的年变化分别为１６．４７μＡ／ａ和６．５３μＡ／ａ，引起的频率漂移率分别为１．６７×１０－１３／ａ（０．０３９５ｎｓ／ｄ２）和８．３×１０１４／ａ（０．０１９７ｎｓ／ｄ２）     

4×155Mb／s频分复用（FDM）光纤通信系统的研究

报道了一个无故障工作时间大于２４小时的四路１５５Ｍｂ／ｓ频分复用（ＦＤＭ）光纤通信系统，实测系统误码率优于０×１０（－１４）。系统接收机包括解复用光滤波器，接收机灵敏度优于－３０ｄＢｍ（ＢＥＲ＝１×１０（－９），频道间距为０．１ｎｍ，四路ＦＤＭ信号－２０ｄＢ的总谱宽为０．７ｎｍ。系统采用国产ＤＦＢ激光器为光源，实际光纤传输距离１８ｋｍ。系统全部实现了脱离光学平台的模块化结构，在长期的系统实验中显示了优良的稳定性。这一成果为ＦＤＭ在光纤传输接入网中的进一步实用化开发铺平了道路。     

NIM对γ＇_p及2e／h的SI值的最新测定结果

中国计量科学研究院于１９９４年６月完成了对质子回旋磁比γ＇_ｐ及约瑟夫森频率与电压之商２ｅ／ｈ的ＳＩ值的新测定。结果分别为γ＇_ｐ（ａｂｓ）＝２．６７５１５３５（２３）×１０８Ｔ（－１）·ｓ（－１）和２ｅ／ｈ＝４８３５９７．８９（４３）ＧＨｚ／Ｖ，其不确定度分别为０．８６×１０（－６）和０．８８×１０（－６）。文中还对测量装置的改进作了介绍。     

一氧化碳和苯乙烯交替共聚物的合成与表征

利用乙酸钯和２，２′－联吡啶组成的催化剂体系催化一氧化碳和苯乙烯交替共聚合成出聚（１－氧代－２－苯基丙撑）（ＳＴＣＯ）。采用ＩＲ、ＮＭＲ、元素分析以及广角Ｘ光散射对该聚合物以表征。该共聚物晶体为单斜晶胞，晶胞参数为ａ＝１５．７×１０－１０ｍ，ｂ＝６．１７×１０－１０ｍ，ｃ＝７．４５×１０－１０ｍ，α＝９０．０°，β＝１０４．３°，γ＝９０．０°；晶胞体积为６９７．２×１０－３０ｍ３；空间点群为Ｐ２１／ｃ。此外，对该共聚物热降解进行了初步研究。     

NIM的微波－光学频率基准研究 ———复现米和秒定义

报道中国计量科学研究院（NIM）在微波－光学频率计量研究的新进展：用NIM４激光冷却－铯原子 喷泉钟复现国际单位制（SI）时间单位秒（s）,用飞秒（FS）光学频率梳间接复现长度单位米（m）并标定稳频 激光波长实际实施米定义。NIM４铯原子喷泉钟的不确定度达到５×１０－１５,飞秒（FS）光梳锁定到NIM４钟控制的 氢钟后,其频率不确定度为２畅２×１０－１４。在此基础上讨论铯原子喷泉钟、稳频激光、FS光梳的作用、意义和相互 关系。最后简要介绍NIM５铯原子喷泉钟的研究进展和２００６年起NIM立题研制锶原子存储     

聚苯硫醚合成反应的动力学研究

以脱水硫化钠和对二氯苯为单体，在六甲基磷酰三胺溶剂中常压下研究了聚苯硫醚合成的反应动力学。结果表明，该聚合反应符合二级反应动力学规律，在１８２、１９２、２０２和２１２℃条件下的聚合反应速率常数分别为１．７５×１０~（－４）、３．０２×１０~（－４）、５．５６×１０~（－４）和１．３１×１０~（－３）ｋｇ／ｍｏｌ·ｓ，反应的活化能为１２３ｋＪ／ｍｏｌ。     

氮气中ppm（10~（－6））级水的红外光谱法测定

利用日立２７０－３０光栅型红外光谱仪及配件１０ｍ气池进行了氮气中１０－６级水的测定研究。在该系统的优选条件下，可准确测定氮气中０～１９×１０－６水，分析灵敏度１．８５×１０－４ＡＢＳ／１０－６，最低检测浓度１×１０－６。     

对硝基苯甲酸钠体系中铁电极的电位特征

采用５种面积的丝束电极研究了３０℃，５．０×１０＾－３ｍｏｌ／Ｌ ＮａＣｌ体系中含有不同对硝基苯甲酸钠浓度（０￣５．０×１０＾－２ｍｏｌ／Ｌ）时，微电极自腐蚀电位的特征。结果表明，对硝基苯甲酸钠浓度、微电极面积对微电极自腐蚀电位值有明显影响，但没有一定的规律性，对硝基苯甲酸钠在电极表面的作用具有很强的随机性。     

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.