含偶氮苯侧链的新型三阶非线性聚炔材料的制备及性能

我们以中等产率成功的合成出一种含偶氮苯功能基团的、可溶解的、立体规整的、中等分子量的聚炔高分子.采用五步法合成了新颖的偶氮苯乙炔单体,2-[N-甲基-N-4-[(4-乙炔苯基)偶氮苯基]氨基]乙基丁酸酯.使用[Rh(nbd)Cl]2-Et3N将单体进行了聚合.采用FT-IR,UV-vis,GPC和NMR等对得到的聚炔高分子分子结构进行了表征.在8ns脉宽波长532 nm激光下采用Z-扫描技术对聚合物的溶液进行了非线性光学性能的测试.     

多功能聚炔的控制制备及热性能

提出一种多功能聚炔的制备新方法——点击化学制备法。有效地实现了多功能基团取代聚炔的制备,使用红外光谱(FT-IR)、核磁共振(1H-NMR)以及热重分析(TGA)对制得的高分子结构和热性能进行了详细表征,研究结果发现,该方法不仅制备条件温和,操作简单,而且产率高;同时芳基口恶唑基团的引入,有效地将电子传输和非线性吸收功能基团有效构筑于同一聚炔高分子中,实现多功能性,而且合成的高分子呈现高的热稳定性,热分解温度高达372.9℃。     

炔基化改性聚乙烯醇吸氢材料的制备及吸氢性能表征

以聚乙烯醇(PVA)高分子材料为基体,通过氨基甲酸酯化反应在PVA高分子链上引入炔基形成炔基功能化的高分子,利用核磁共振法对炔基化高分子的分子结构及接枝度进行表征。通过化学还原法制备出炔基化高分子负载纳米钯的复合材料,采用激光粒度仪确定纳米钯粒径分布。同时将不同接枝度炔基功能化的PVA和Pd/C催化剂,按照一定的比例采用研磨法制备出吸氢材料。利用PVT法对上述所有的吸氢材料的吸氢性能进行了研究。结果表明,氨基甲酸酯化改性PVA接枝度高的炔基化高分子与Pd/C混合研磨后的吸氢材料的吸氢效果最好,吸氢容量为0.8893 mol/kg。     

铁磁性高分子——稳定自由基取代聚合物的研究EI

介绍了稳定自由基取代聚合物作为铁磁性高分子材料的发展概况、种类、结构特点以及制造方法。并对铁磁性高分子材料,尤其是稳定自由基取代的聚丁二炔类聚合物的研究前景进行了较详为细的分析,指出了该领域目前尚存在的问题和发展前景。     

富炔高分子/纳米钯复合吸氢材料的制备及表征

以聚乙烯醇(PVA)为基体,分别通过醚化反应和氨基甲酸酯化反应在PVA高分子链上引入炔基形成富炔高分子,用红外、核磁共振法对富炔高分子的分子结构及接枝度进行表征。利用化学还原法制备出富炔高分子负载纳米钯的复合吸氢材料,采用透射电镜(TEM)对复合材料的形貌及微观结构进行表征,确定纳米钯的形貌、粒径分布以及其在富炔高分子基体中的分散情况。结果表明,溴丙炔醚化改性PVA因溶解性问题导致纳米钯分散性不好、团聚现象严重;而炔丙胺氨基甲酸酯化改性PVA负载的纳米钯粒径均一,分散性良好,为下一步吸氢性能的研究打下基础。     

FERROMAGNETIC POLYMER—POLYMER HAVING STABLE RADICALS AS SIDE GROUPS

本文主要介绍了稳定自由基取代聚合物作为铁磁性高分子材料的发展概况、种类、结构特点以及制造方法。并对铁磁性高分子材料尤其是氮氧自由基取代的聚丁二炔类聚合物的研究前景进行了较为详细的分析,指出了该领域目前尚存在的问题和发展前景。     

铁磁性高分子——稳定自由基取代聚合物

本文主要介绍了稳定自由基取代聚合物作为铁磁性高分子材料的发展概况、种类、结构特点以及制造方法。并对铁磁性高分子材料尤其是氮氧自由基取代的聚丁二炔类聚合物的研究前景进行了较为详细的分析,指出了该领域目前尚存在的问题和发展前景。     

基于点击化学的线性聚三唑高分子材料的制备与性能

基于"点击化学"方法,以1,4-二苄基叠氮(XDA)和2,2-二(4-炔丙氧基苯基)丙烷(PBP)(双炔基单体)为单体,采用(Cu(Ⅰ)AAC)作为催化剂,通过高效和高选择性的1,3-环加成点击化学反应,研究一种新型可溶性聚三唑树脂的控制制备;采用红外光谱(FT-IR)、核磁(1H-NMR)、激光光散射(LLS)、X射线衍射(WAXD)、差示扫描量热(DSC)和热重分析(TGA)等方法对其结构与性能进行表征。结果表明,通过单体结构的设计,可以制备出易溶解于普通极性溶剂,玻璃化转变温度134.76℃,熔融温度246.77℃,起始分解温度349.3℃的聚三唑高分子,并对高分子溶解性和热性能的提高进行了讨论与分析。     

PTMSP及其共聚物膜对有机液/水体系的PV分离

制备了聚三甲基硅丙炔均聚物 (PTMSP) .研究了PTMSP均质膜 ,三甲基硅丙炔(TMSP)与五甲基二硅丙炔 (PMDSP)共聚物膜对含少量有机溶剂水溶液的渗透汽化 (PV )特性 .所选用的有机溶剂包括乙醇、异丙醇、四氢呋喃、二氯甲烷、乙酸乙酯等 .从膜的溶胀特性、溶解度系数及扩散系数的测定结果 ,分析了膜材质的结构与PV特性之间的关系 .     

含磺酸甜菜碱的温敏聚合物胶束的制备及胶束温敏性EI北大核心CSCD

首先通过炔丁醇与2-溴异丁酰溴的酯化反应得到了一种带有炔基的ATRP引发剂,然后用其引发异丙基丙烯酰胺得到PNIPAm-alkyne,再通过点击反应将带有炔基的PNIPAm-alkyne接枝到侧链含有叠氮基团的聚己内酯-聚(甲基丙烯酸二乙氨基乙酯/N,N-二乙氨基甲基丙烯酸硫代甜菜碱酯)(P(CL-ACL)-b-PDEAS)上得到P(CL-g-PNIPAm)-PDEAS。通过核磁、红外、凝胶渗透色谱对聚合物的组成进行了分析,PNIPAm-alkyne的相对分子质量为5500和8300,相对分子质量分布为1.18和1.24,表明这种方法制备的聚合物相对分子质量及分布能够得到较好的控制。PNIPAm-alkyne点击到P(CL-ACL)30-PDEA7S3上制备的聚合物胶束的透射率随着温度的升高而降低,粒径亦由40 nm变到63 nm,并从透射电镜的结果分析了胶束表面高分子链发生构象转变,从而证实成功地制备了一种具有温敏特性的含有聚磺酸甜菜碱的聚合物胶束。     

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.     

From Industry 4.0 to Research 4.0. Development of High Performance Fibers in the Light of Digitization

We associate a variety of innovations with the term ＂Industry 4.0＂. The pioneer of many 4.0 modifications forms the basisfor the trend towards the integrated di...     

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.     

Roman iron and steel: A review

ABSTRACT

The production of ferrous metal increased during the Roman Late Republican period, Principate and Empire. The direct bloomery process was used to extract the metal from its ores using slag-tapping and slag-pit furnaces. The fuel was charcoal and an air blast was introduced by bellows-operated tuyères. Iron formed as a bloom, often as a spongy mass of metal, which contained impurities from the smelting process, including unreacted ore, fuel, slag and fragments from the furnace walls, while the metal was often inhomogeneous with varied carbon contents. Blooms were either smithed directly into bars or ingots or they were broken up, which also allowed the removal of gross impurities and a selection of pieces with similar properties to be made. These could then be forge-welded together and formed into characteristically shaped ingots. Making steel in the furnace seems to have been achieved: it depended on the ore and the furnace and conditions within it. Surface carburization was also carried out. Iron and steel were used extensively in construction and for tools and weapons. Fire welding was often used to add pieces of steel to make the edges of tools and weapons, which could be heat-treated by quenching to harden them.     

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