PEG-IPDI-DMPA嵌段离聚体的合成与表征及其在水相中的溶液行为

采用溶液聚合法合成了PEG-IPDI-DMPA嵌段离聚体,通过FTIR、1H-NMR、GPC、DSC、TEM对其结构进行了表征;并通过粒径、比浓粘度、旋转粘度和电导率,对其在水相中的溶液行为进行了研究。红外光谱分析证实,合成获得了预期的聚氨酯结构嵌段离聚体;差示扫描量热分析证明,离聚体分子链段是由硬段和软段两相组成的嵌段共聚物;经透射电镜观察,嵌段离聚体在水溶液中呈现出较为规整的球形粒子状态。PEG-IPDI-DMPA嵌段离聚体粒径都在200nm左右;PEG-IPDI-DMPA嵌段离聚体是剪切变稀的。     

嵌段共聚物自组装模板--构造纳米结构的一种新方法

纳米结构的构造在整个纳米科技中有着特殊重要的意义．如何低成本、大规模地实现纳米结构材料的控制合成与组装一直是纳米加工中的热点问题．高分子嵌段共聚物分子结构独特，包含着热力学不相容的不同高分子嵌段，并由化学键相连．通过控制外界条件，嵌段共聚物可以自组装成高度规则的超分子结构，特征尺寸为10nln～100nm．以嵌段共聚物膜自组装相分离图案为模板，或把这种图案复制到其它材料上，通过刻蚀等技术可以制备纳米结构模板，再经纳米铸造得到相应结构的纳米材料和纳米器件，文中主要介绍嵌段共聚物自组装模板的原理、模板图案的调控方法和模板应用，并详细阐述了各自的发展状况。     

SPS及其离聚体的形态结构与热性能

通过ＤＳＣ、ＤＭＡ、ＴＥＭ、ＳＡＸＳ和ＴＧ对ＳＰＳ（磺化聚苯乙烯）及其离聚体的形态结构和热性能进行了研究。结果表明，在磺酸基含量为９．８３ｍｏｌ％的ＳＰＳ中有磺酸离子的聚集。金属离子的引入使ＳＰＳ离聚体的分子间作用力、微相分离程度增大。磺酸盐含量为４．７０ｍｏｌ％以上的ＳＰＳ离聚体中有离子聚集，离子簇直径为３～１０ｎｍ。在磺酸盐含量为１３ｍｏｌ％范围内，ＳＰＳＮａ离聚体基体的Ｔｇ１、离子微区的Ｔｇ２均随磺酸盐含量的增加而线性增大。ＰＳ磺化、中和成ＳＰＳ离聚体后，热稳定性增加，其顺序为：ＳＰＳＺｎ＞ＳＰＳＮａ＞ＳＰＳ＞ＰＳ。     

苯乙烯/异戊二烯渐变嵌段共聚物的负离子法合成和性能

一次加料延时加入极性结构调节剂四氢呋喃(THF)、以正丁基锂(n-BuLi)为引发剂、环己烷为溶剂,用活性负离子聚合技术合成了具有渐变嵌段结构的苯乙烯(St)/异戊二烯(Ip)共聚物(S/I)。使用核磁共振氢谱(¹H-NMR)和动态粘弹谱(DMA)等仪器表征共聚物的微观结构并测定共聚物的动态力学性能,研究了THF的加入时间和St含量对S/I共聚物微观结构和性能的影响。结果表明,加入THF的时间显著影响共聚物的微观结构、力学和动态力学性能。控制THF的加入时间能调控St和Ip单体的共聚合活性从而调控共聚物的微观结构和共聚物的组成及其分布,生成具有渐变嵌段结构的S/I共聚物,拓宽共聚物的玻璃化转变温度(T_g)区间。对S/I共聚物的结构和性能的变化过程也进行了理论分析。     

不同合成方法对稀土离聚体荧光性质影响

不同制备方法，即以丙烯酸丁酯与丙烯酸共聚物为基础，经离子交联而制得的稀土离聚体（方法Ⅰ）及以丙烯酸丁酯与盐基性单体丙烯酸稀土盐共聚而制得的稀土离聚体（方法Ⅱ）在荧光性质上的差异，研究了不同结构因素对它们的荧光性质的影响规律。随着体系中稀土金属离子含量的增大，方法Ⅰ所得离聚体出现了浓度淬灭现象，而方法Ⅱ所得离聚体则无此现象，从一个侧而反映了共聚集态差别。     

离聚体的聚集态结构特性及性质

介绍了离聚体的定义，发展过程，合成方法和目前的应用情况，研究了离聚体的聚集态结构，总结了目前离聚体的主要聚集态模型，研究了影响聚集态结构的主要因素，介绍了离聚体所特有的力学性质，介电谱和溶液性质，指出了目前尚待研究的问题。     

红外光谱法研究热历史对磺化聚苯乙烯离聚体结构的影响 Ⅱ.退火对离聚体离子聚集态的影响

将磺化聚苯乙烯钠盐和锌盐离聚体在其Ｔｇ以上（１２８℃）和Ｔｇ以下（１００℃）作退火处理。用红外光谱和动态粘弹谱考察了退火过程中离子聚集态的变化。退火使离聚体中原有的离子聚集平衡态被破坏，最终有利于离聚体中离子簇的形成。退火温度高于Ｔｇ时，由于链段的运动使离子簇形成明显加快。同样的退火温度下，钠盐离聚体比锌盐更易形成离子簇，这是由于二者的离子聚集单元对温度的敏感性不同所致。     

离聚体增韧聚甲醛体系的力学性能与亚微相态研究

考察了离聚体增韧聚甲醛(POM)体系及甲基丙烯酸。甲酯-苯乙烯-丁二烯共聚物(MBS)增容POM／离聚体共混体系的力学性能和亚微相态。研究发现，10％离聚体与POM共混可取得一定的增韧作用，乙烯-甲基丙烯酸-锌离聚体(EMMA—Zn)比乙烯-甲基丙烯酸-钠离聚体(EMMA-Na)具有更好的增韧效果。MB可成为POM与离聚体的增容剂。并具有协同增韧作用；亚微相态观察发现，离聚体在POM基体中呈“海-岛”结构分布；MBS可以提高离聚体的分散性及其与POM的界面粘结性，减小离聚体柱子的直径，最终提高了离聚体的增韧效果。     

红外光谱法研究热历史对磺化聚苯乙烯离聚体结构的影响：？…

将磺化聚苯乙烯钠盐和锌盐离聚体在其Ｔｇ以上（１２８℃）和Ｔｇ以下（１００℃）作退火处理。用红外光谱和动态粘弹谱考察了退火过程中离子聚集态的变化。退火使离聚体中原有的离子聚集平衡态被破坏，最终有利于离聚体中离子簇的形成。退火温度高于Ｔｇ时，由于链段的运动使离子簇形成明显加快。同样的退火温度下，钠盐离聚体比锌盐更易形成离子簇，这是由于二者的离子聚集单元对温度的敏感性不同所致。     

N-甲基苯基马来酰亚胺与苯乙烯嵌段共聚物的合成和研究

通过自由基聚合和负离子聚合两条途径合成了Ｎ－甲基苯基马来酰亚胺与苯乙烯的嵌段共聚物，并用自由基聚合的方法合成了二者的无规共聚物。研究并对比了它们的热失重性能和亲水－疏水性质，结果表明，嵌段共聚物具有较好的热稳定性，同时疏水性也较强。     

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.