高预倾角液晶显示器用聚酰亚胺定向材料的研究

报道了用于高预倾角液晶显示器的定向膜材料的研究，这类定向膜材料由链含长烷基链的聚酰亚胺组成。     

含联苯基团侧链聚酰亚胺液晶取向膜的研究

制备了含联苯液晶基元侧链的三种聚酰亚胺(C 6-DABBE/ODPA,C 2-DABBE/ODPA和DABBE/ODPA),并进行了表面摩擦取向,用偏光显微镜(POM)、原子力显微镜(AFM)等方法对取向膜诱导液晶分子取向能力和打磨后取向膜的微观形貌进行了考察,研究了预倾角与摩擦强度,固化温度的依赖关系。结果表明,含6个亚甲基柔性间隔基的C 6-DABBE/ODPA取向膜对液晶分子有很好的取向能力,能获得10°以上的预倾角。打磨后的取向膜表面出现了约30 nm深的沟槽。且取向方向与打磨方向一致;随着摩擦强度的增大,预倾角呈减小的趋势;随着固化温度的升高,酰亚胺化程度提高,取向膜的预倾角也随之增大;在230℃对取向膜进行退火处理,能明显改善其取向性能。     

聚酰亚胺取向材料表面排列性能的研究

合成了几种结构不同的聚酰亚胺取向材料。其中ＰＩ１～ｐＩ３用作标准３位半液晶显示屏的取向材料，在７０℃，９５％相对湿度下，经过７２ｈ试验后，除功耗电流略有增大外，表面排列性能良好。用ＰＩ４～ｐＩ６作取向材料制备试验盒，这些试验盒在１００℃Ｔ经２ｈ热处理后，具有２°～３°的预倾角。研究结果表明，对于含柔性长链添加剂的聚酰亚胺来说，固含量增大，预倾角呈上升趋势，而不含柔性长链添加剂的聚酰亚胺其预倾角与因含量无关。这些材料可用作ＴＮ－ＬＣＤ及简单８ＴＮ－ＬＣＤ的取向材料。     

含长柔性链的主链聚酰亚胺的合成性能及其应用研究

以4,4-二氨基二苯醚(ODA)、十二胺和3,3’,4,4’-二苯醚四羧酸二酐(ODPA)为聚合体系,制备得到主链含长柔性链的聚酰亚胺酸,并且考查了KH-550硅烷偶联剂的加入量、含氟类聚硅氧烷的添加对聚合物性能的影响。实验结果表明,当KH-550达到6%时得到的聚酰亚胺膜的附着力达到1级,当添加总量0.1%的含氟聚硅氧烷时聚酰亚胺的含水率显著下降。用红外表征合成的聚酰亚胺的结构,利用TG表征聚酰亚胺的热稳定性,同时取向能力、预倾角测试以及工业可靠性实验表明,制备的材料可以作为扭曲排列型液晶显示器(TN-LCD)的取向材料使用。     

胆固醇改性聚硅氧烷的合成和血液相容性

合成了胆固醇基团直接键合和通过长链烷基柔性链键合的胆固醇-聚硅氧烷接枝共聚物,研究了胆固醇改性聚硅氧烷的血液相容性.结果表明,未经长链烷基键合的共聚物不能形成液晶相,而经长链烷基键合的共聚物可以形成热致液晶.侧链液晶聚硅氧烷的液晶结构和材料的血液相容性具有独特的依赖性,热处理后形成的液晶相有助于提高材料的血液相容性.     

液晶种类及工艺条件对预倾角的影响

用均苯四羧酸二酐(PMDA),1,2,3,4-环丁烷四羧酸二酐(CBDA)和4((4-氨基苯基)-二(4-甲氧基苯基)甲基)苯胺共聚制备聚酰亚胺,并用做液晶取向膜。采用正交偏光显微镜和预倾角测试仪分别表征了液晶的取向效果及其预倾角;考察了液晶种类、二胺与二酐比例、摩擦深度、摩擦次数等工艺条件对预倾角的影响。结果表明,不同的液晶对预倾角有较大影响,普通液晶E7获得的预倾角只有3.5°左右,而ZLI-2293可获得4°以上稳定的预倾角,且液晶取向均匀良好。同时,得到了最佳的二胺与二酐配比、摩擦深度和摩擦次数。     

自组装囊泡的结构与单分子膜的性质

研究了具有不同主链分子量和侧链长度的N，N-双烷基化壳聚糖单分子膜的性质．结果表明，主链分子量越大，所形成的N，N-双烷基壳聚糖单分子膜的结构越紧密．在主链分子量相同的条件下，N，N-双烷基壳聚糖单分子膜的致密度随着侧链长度的增大而增大，表明N，N-双烷基化壳聚糖分子间的缠结嵌套和疏水相互作用力的增大．比较N，N-双烷基化壳聚糖单分子膜与相应自组装囊泡的性质发现，囊泡的药物平衡释放率随着其相应材料单分子膜压缩模量的增大而减小，呈现出一定的线性关系．单分子膜压缩模量的大小反映囊泡膜结构的紧密程度．     

高透过率透明液晶显示器的开发与实现

透明液晶显示器的发展和使用,给当前普通显示器市场带来相当大的冲击。当前普通显示器在使用时,显示器后置光源的功率一般比较大,这主要是为了在降低后置光源的情况下,使显示器达到高透过率的作用。彩膜样品实验是研究白坐标、色度域和透过率之间的关系,以此来确定透明液晶显示器与彩膜样品类型之间的关系,找到提高显示器透过率的方法。     

清华剑桥合作制备易加工的液晶弹性体智能材料

正液晶弹性体材料在热、光、电、磁等外界刺激下可发生形状的自发改变,作为致动器及感应器在人工肌肉、柔性机器人、盲人显示器等诸多领域的应用前景十分广阔。这种形状的改变是基于高分子内部的液晶有序性,通过光、热、磁等方式改变这种有序性将产生可逆的宏观形状变化。为了使液晶弹性体发生实际意义的形状改变,必须将液晶高分子链作单畴取向(单畴是指液晶分子链中很窄的或单一取向的区域)。     

液晶显示器用偏光片技术及市场分析

首先介绍偏光片在液晶显示器中的应用原理,接着介绍偏光片的基本结构与组成偏光片的各膜层材料,最后分析目前偏光片的主要的国内外生产企业和近几年偏光片的市场情况。     

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