甲基丙烯酸酯嵌段共聚物的合成与表征

研究了ＭＭＡ和Ｃ７～９ＭＡ的阴离子共聚合，得到了Ａ－Ｂ型嵌段共聚物。讨论了嵌段顺序、温度、引发剂及ＰＣ７～９ＭＡ－活性链长对ＭＭＡ嵌段共聚的影响，认为，当第一嵌段单体为Ｃ７～９ＭＡ，Ｔ＝－２０℃，［Ｉ］＝５．０～５．４×１０－２ｍｏｌ／Ｌ，Ｍｎ（ＰＣ７～９ＭＡ－）＜１．６×１０４时，有利于ＰＣ７～９ＭＡ－ｂ－ＰＭＭＡ嵌段共聚物的合成；采用ＧＰＣ、ＩＲ、ＮＭＲ对所得嵌段共聚物进行了表征。     

红外激光波长计的原理及其研制

本文简介红外激光波长计的原理、结构及其技术参数．最后，对该仪器的数据处理进行了讨论．目前，仪器的测量范围在０．４μｍ～４μｍ，读数值为１×１０－６μｍ，波长测量的不确定度≤２×１０－６．     

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。     

磷酸盐陶瓷Ca_(1-x)Ba_xZr_4(PO_4)_6的制备及其零膨胀组成的耐热冲击性研究

Ｃａ１－ｘＢａｘＺｒ４（ＰＯ４）６（０≤ｘ ≤１,简称ＣＢＺＰ）是由具有相反热膨胀异向性的 ＣａＺｒ４（ＰＯ４）６和ＢａＺｒ４（ＰＯ４）６互溶形成的二元固溶体型ＮＺＰ族陶瓷,其热膨胀系数具有可裁剪性．本研究的主要目的是通过调整组成,制备具有较好耐热冲击性的零膨胀材料．为此,首次用共沉淀法合成了单相的 ＣＢＺＰ系列粉体。分别添加 ３％ＺｎＯ和 ４％ＭｇＯ为烧结助剂,制成Ｔ ＣＢＺＰ系列陶瓷材料,用热机械分析（ＴＭＡ）压缩法测定了试样在２０～１０００℃的平均线膨胀系数ａ２０／１０００,以及加热（２０～１０００℃）和冷却（１０００～４００℃）过程的热膨胀曲线．实验结果表明,添加 ＺｎＯ和 ＭｇＯ时的近零膨胀材料分别为Ｃａ０．８５Ｂａ０．１５Ｚｒ４（ＰＯ４）６（ｘ＝０．１５）和ＣａＺｒ４（ＰＯ４）６（ｘ＝０）,α２０／１０００依次为 ０．６×１０－６／°Ｃ和一０．８×１０－６／°Ｃ,但热膨胀曲线上却由于微裂纹的产生而呈现出较大的滞后环,耐热冲击性不理想．可见,对ＣＢＺＰ系列而言,调整组成虽然能实现零膨胀,但很难消除热膨胀异向性,提高其耐热冲击性的有效途径可能是适当抑制晶粒生长以避免产生过多的微裂纹．     

MB26合金超塑性的研究

研究了新型高强度镁合金ＭＢ２６超塑性拉伸、压缩的变形行为。结果表明，热挤压态ＭＢ２６合金不经过任何预处理即具有很好的超塑性。超塑性拉抻时，在４００℃、ε０＝１．１７×１０＾－２ｓ＾－１的变形条件下δ＝１４５０％，σ＝８．７ＭＰａ，ｍ值为０．６；超塑性压缩时，在４００℃、ε０＝８．３×１０＾３ｓ＾－１变形条件下，压缩真应变ε高达２．１８以上，σ＝１８ＭＰａ，ｍ值在０．４以上。     

乳状液膜法分离钨钼的研究弱碱性体系

进行了以氯化甲基三烷基铵（Ｎ２６３）为载体的乳状液膜在弱碱性条件下分离钨、钼的研究．利用钨、钼形成同多酸能力的差异，通过载体选择性迁移钨来分离钨、钼．考察了影响钨、钼分离的各种因素，得到了分离钨、钼的最佳操作条件．按某厂生产仲钨酸铵的料液中含钼８．９×１０－４ｍｏｌ／ｄｍ３计算，经一级间歇式分离即可降至１．６×１０－４ｍｏｌ／ｄｍ３达到要求（含钼低于２．１×１０－４ｍｏｌ／ｄｍ３）     

中国直流电动势副基准的现状

中国计量科学研究院（ＮＩＭ）的直流电动势副基准经多次与国内外约瑟夫森电压标准比对表明，七年中最大累积变化约为０．２１×１０－６，平均每年变化仅０．０３ｕＶ．从１９９５年１月１日起改值０．２０×１０－６后，可与国际电压值在３×１０－８误差范围内保持一致．     

推拉型偶氧化合物三阶非线性电极化率测量

本工作报道了由皮秒激光和Ｚ－扫描技术在两各推拉型偶氮化合物，在硝基苯偶氮－Ｎ，Ｎ－二甲基苯胺）ＮＰＡＤＭＰＡ）和对硝基苯偶氮－Ｎ－甲基苯胺（ＮＰＡＭＰＡ）的非共振吸收区测量与三阶非线性电极化率χ＾「３」有关的非线性折射率ｎ２。测得的ｎ２值分别为２．２×１０＾－８ｅｓｕ和１．８１×１０６－８ｅｓｕ。根据分子结构特征对这两种三队非线性光学材料的结构与性能的关系作了 。     

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。     

O＋HO2反应碰撞的理论研究

使用多体项展式分析势能函数，研究了Ｏ＋ＨＯ２反应碰撞的经典轨迹，指出存在二个反应通道，即（１）Ｏ＋ＨＯ２→ＯＨ＋Ｏ２和（２）Ｏ＋ＨＯ２→ＨＯ２＋Ｏ。在室温下，求得反应（１）的近似速度常数为（４．１±０．０６）×１０＾－１１ｃｍ＾３·ｍｏｌｃｃｕｌｅ＾－１·Ｓ＾－１，与实验值（５．４±０．９）×１０＾１１符合甚好；反应（２）的速度常数为５．４×１０＾－１３。对反应（１），总能量的７２．５％分配于产物     

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.     

Thixotropy of Systems with Shear Thinning and Plastic Flow Behavior

The definition of the thixotropy is a decrease in viscosity with time in shear and a subsequent recovery of viscosity after the shear deformation is removed.We ...     

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.