液晶苯酚酯相变的研究

用低颅内耗及ＤＳＣ方法研究了反－４－丁基环己基甲酸－（４－丙基）环己基苯酚酯液晶的相变,通过比较低频内耗与ＤＳＣ的激活能。证实了液晶相变内耗峰的存在,论证了相变内耗峰的产生机制。     

苯乙烯/马来酸酐共聚物的氢键诱导液晶化

制备了以苯乙烯／马来酸４羧基酚酯共聚物（ Ｍ Ｅ Ｓ Ｍ Ａ）为质子供体,苯乙烯基吡啶（４ Ｓ Ｚ）为质子受体的氢键诱导液晶复合物。用 Ｄ Ｓ Ｃ和 Ｐ Ｏ Ｍ 研究二者复合前后的液晶行为。结果表明,４ Ｓ Ｚ含量在３０％ ～７０％ 的复合物表现为向列相液晶态,其中等摩尔比的复合物的热稳定性最高。并从 Ｉ Ｒ 结果讨论了 Ｍ Ｅ Ｓ Ｍ Ａ／４ Ｓ Ｚ二元组分的摩尔比与分子间氢键的关系,等摩尔比时,复合物以羧酸与吡啶环之间的氢键为主;而非等摩尔比时,存在羧酸之间的氢键。     

α，ω－对乙氧羰氧基苯甲酸聚乙二醇酯液晶的合成及转变性能研究

用模型化合物的方法，合成了一系列含柔性间隔链段芳香聚醚酯液晶化合物（ＰＥＥＣＢ－ｎ），通过１ＨＮＭＲ、ＤＳＣ、正交偏光显微镜、ＷＡＸＤ等手段，对其结构和液晶态转变进行了表征。     

聚硅氧烷侧链高分子液晶的合成

合成了烯丙氧基苯甲酸对甲氧基苯酚酯（ＡＢＰＭ）和烯丙基胆甾醚（ＡＣＥ），用ＮＭＲ及ＭＳ对其结构进行了鉴定。通过上述两种化合物的末端双键与含氢硅油的Ｓｉ－Ｈ进行催化加成反应，得到了含侧链的聚硅氧烷，红外光谱证明，大部分Ｓｉ－Ｈ已参加了反应。聚合物具有液晶性，聚物和共聚物的液晶相具有不同的特点，分属于向列型，近晶型和胆甾型。     

短烷基系列芳醛类液晶材料的合成及其相变规律研究

通过室温反应合成了系列C3和C5烷基取代的多环单酯基苯甲醛类液晶,研究了室温羧酸氯化有效抑制反式环己烷构型转化的机理,讨论了不同的端基、环体系对化合物液晶相变区间、焓变及熵变的影响。结果表明,该类芳香醛化合物端基与环体系的改变使化合物的液晶相温度范围、焓变及熵变呈现规律性的改变,且环体系对化合物液晶性质的影响远大于末端烷基。     

a,w—对乙氧羰氧基苯甲酸聚乙二醇酯液晶的合成及转变性能…

用模型化合物的方法，合成了一系列含柔性间隔链段芳香聚醚酯液晶化合物（ＰＥＥＣＢ－ｎ），通过ＨＮＭＲ、ＤＳＣ、正交偏光显微镜、ＷＡＸＤ等手段，对其结构和液晶态转变进行了表征。     

1，3－戊二烯阳离子聚合物链结构

采用以三氟甲基磺酸铝（（ＣＦ３ＳＯ３）３Ａｌ）为引发剂，二氯甲烷为溶剂的阳离子聚合方法制备了聚（１，３－戊二烯）。用ＩＲ、１ＨＮＭＲ和１３ＣＮＭＲ对聚合物结构进行了表征，并基于聚合物１ＨＮＭＲ谱对聚合物链结构进行了定量计算，聚合物环状和线型链结构分别占５４％和４６％，而线型链中的５种结构单元：反－１，４、顺－１，４、反－１，２、顺－１，２和３，４结构分别为２３％、１０％、１０％、１％和２％。     

手性近晶C(Sc*)相串型液晶共聚酯的合成与表征

以２,５－二「４－（Ｓ）－２－甲基丁氧基（苯甲酰氧基」对苯二酚,４,４′－二羟基－,α,ω－二苯氧丁烷和对苯二甲酰氯为单体,采用溶液共缩聚的方法。合成了一系列新的手性近晶Ｃ（Ｓｃ＊）相串型液晶共聚酯,单体的结构通过元素分析、ＩＲ、＾１Ｈ－ＮＭＲ和ＭＳ等方法确证,共聚物通过ＧＰＣ、ＤＳＣ、ＴＧ、ＷＡＸＤ、偏光显微镜和旋光仪等方法表征,发现所有共聚物加热至各自的熔点以上都能形成液晶态,在液晶态可以观察     

CC—IUMRS’94国外材料发展动向研讨会简介

ＣＣ—ＩＵＭＲＳ’９４国外材料发展动向研讨会简介ＣＣ—ＩＵＭＲＳ’９４国外材料发展动向研讨会于１９９４年４月２５—２９日在成都四川联合大学召开，同时举行了国际材联中国委员会（ＣＣ—ＩＵＭＲＳ）委员和中国材料研究学会（Ｃ—ＭＲＳ）常务理事扩大会．参加会...     

主链柔顺性对侧链液晶聚合物液晶性能的影响

由对羟基苯甲酸与对羟基甲醚反应得到了４－甲氧基－４’－羟基苯甲酸苯酯（ＭＰＨＢ）,ＭＰＢＨ再分别与环氧氯丙烷和甲基丙烯酰氯反应生成４－甲氧基－４’－（２,３－环氧丙基氧）苯甲酸苯酯（ＭＰＥＢ）和４－甲氧基－４’－甲基丙烯酰氧苯甲酸苯酯（ＭＰＭＡＢ）。用阳离子和自由基聚合法聚合得到了具有相同液晶元而主链结构和间隔基不同的聚合物ＰＭＰＥＢ和ＰＭＰＭＡＢ。用ＤＳＣ、热台偏光显微镜和Ｘ射线衍射仪对合成的聚     

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 ...     

Effect of Oxide Assisted Metal Nanoparticles on Microstructure and Morphology of Gallium oxide Nanowires

Several researches have been reported about the characteristic of β-Ga2O3 nanowires which was synthesized on nickel oxide particle. But indeed, recent researches about synthesis of β-Ga2O3 nanowires on oxide-assisted transition metal are limited to nickel or cobalt oxide catalyst. In this work, Gallium oxide (β-Ga2O3 ) nanowires were synthesized by a simple thermal evaporation method from gallium powder in the range of 700 - 1000℃ using the iron, nickel, copper, cobalt and zinc oxide as a catalyst, respectively. The β-Ga2O3 nanowires with single crystalline without defects were successfully synthesized at the reaction temperature of 850, 900 and 950℃ in all the catalysts. But optimum experimental condition in synthesis of nanowires varied with the kind of catalyst. As increasing synthesis temperature,the morphology of gallium oxide nanowires changed from nanowires to nanorods, and its diameter increased. From these results, we could be proposed that the growth mechanism of β-Ga2O3 nanowires was changed with synthesis temperature of nanowires. Microstructure and morphology of Synthesized nanowire was characterized by HR-TEM, FE-SEM, EDX and XRD.     

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