方柱状IPMC制备与驱动性能的研究

离子型聚合物金属复合物(ionic polymer-metal composites, IPMC)是一种离子型电致动聚合物材料,具有尺寸小、质量轻、驱动电压低、形变量大以及生物兼容性好等众多优点。但传统片状IPMC只能在单一方向上运动的缺点,极大地限制了IPMC的应用。因此,通过溶液浇铸和化学镀的方法制备出一种可实现多自由度运动的方柱状IPMC,并对其表面电极进行了SEM观测和驱动性能表征分析。通过对比方柱状IPMC在正弦、方波和直流电压信号下的末端位移和输出力变化情况,发现方柱状IPMC在这3种电压信号驱动下均具有较好的驱动性能,且在直流电压信号下末端位移和输出力最大。通过对方柱状IPMC在不同运动方向的测试结果进行对比分析,探究了方柱状IPMC在介入式手术导管导向装置上应用的可行性。     

介电型电活性聚合物圆柱形驱动器侧向特性的研究

电活性聚合物（EAP）在实际生活中有着广泛的应用,介电型EAP圆柱形驱动器作为其典型应用之一,其输出的侧向偏转力和侧向弯曲角度受到介电型EAP膜拉伸面积比例、介电型EAP膜卷绕层数和柔性电极涂抹面积比例的影响,需要深入研究来确定其作用规律。针对这些影响因素对介电型EAP圆柱形驱动器输出的侧向性能的影响,设计制作了试验测试装置,通过控制变量试验测得了大量试验数据;分析处理试验数据,初步得出了影响因素的作用规律。结果表明：介电型EAP圆柱形驱动器输出的侧向偏转力和侧向弯曲角度都会受到介电型EAP膜拉伸面积比例、介电型EAP膜卷绕层数和柔性电极涂抹面积比例的影响,这些因素对其输出的侧向性能产生不同的作用结果。     

具有梯度结构的三维IPMC的制备及表征

离子聚合物金属复合材料(ionic polymer metal composite,IPMC)是一种离子型电活性聚合物,具有驱动电压低、位移变形量大、反应迅速和质量轻等优点,作为新型的电致动材料具有广阔的应用前景。但是现有的IPMC电致动材料存在输出力小和非水工作时间短的缺点。通过制备厚度上具有梯度变化的三维IPMC来提高IPMC的驱动性能;采用不易电解挥发、稳定性较好的乙二醇作为IPMC的工作介质,延长IPMC的非水工作时间。研究结果表明,在相同幅值的正弦交流电压下,具有一定梯度结构的IPMC能够显著提高其形变位移和输出力,幅值为3.5V时,形变位移和输出力较相同质量厚度的平面型IPMC分别提升了7.0%和47.9%;用乙二醇置换水作为工作介质的平面型IPMC,其非水工作时间得到大幅提升,从150s延长至300s。IPMC电机械输出性能的提升和非水工作时间的延长对于IPMC在驱动领域的进一步应用开发具有重要意义。     

接枝己基噻吩共轭分子的电化学聚合和性能表征

利用斯蒂尔偶联反应合成了一种基于苯并硒二唑和己基噻吩的有机共轭单体,通过电化学方法制备导电聚合物,并对其进行了结构表征和电化学性能测试。核磁共振1H谱和13C谱验证单体与理论结构一致,红外结果验证了电化学聚合位点为己基噻吩的α位;循环伏安测试表明聚合物具有良好的电化学活性和稳定性,经过100圈循环扫描后电化学活性仍保持92.3%;光滑、均质连续的表面形貌有利于提高聚合物的电导率和电子传输性能、较高的热稳定性表明其能够应用在光电器件中;在0 V到1.2 V电压范围内,光谱电化学测试中聚合物薄膜颜色从淡蓝色到灰色的转变说明聚合物具有良好的电致变色特性;以上结论表明聚合物在电致变色材料中具有应用前景。     

超弹性介电型EAP圆柱形驱动器变激励电压下动态响应分析

超弹性电活性聚合物(electroactive polymer,EAP)圆柱形驱动器的动态特性是进行合理设计、使用及优化驱动器的重要依据。结合介电型EAP机电耦合方程,构建了驱动器轴向线性运动的动力学方程。通过计算得到驱动器的电压-轴向位移曲线,研究了驱动器在准静态点附近的稳定性。最后,分析了驱动器在施加阶跃和周期电压激励时的动态响应。结果表明,在有效工作范围内驱动器是稳定的,阶跃电压激励使驱动器在准静态点附近产生轴向振动,周期电压使驱动器产生包含自振的拟周期轴向振动。进一步分析表明,阶跃电压激励更易导致驱动器的电击穿失效。     

频率对VHB4910介电弹性体材料介电性能的影响

介电弹性材料是一种新型的电活性聚合物,在电激励下能产生较大的机械变形,可被广泛的用作致动器和传感器.其中3M公司的VHB4910系列丙烯酸薄膜是研究最广泛的介电弹性材料,其关键的电学参数,特别是介电常数,将影响整体的机电耦合性能.然而到目前为止,人们对于VHB4910介电材料介电常数取值的认识尚不统一,特别是频率对介电...     

一种具有电双稳特性的聚合物薄膜

发现了在室温下具有电双稳特性的聚合物材料聚对萘二甲酸乙二酯(PEN)。通过真空蒸发方法制备的PEN薄膜,其表面晶粒尺寸小于100nm,粗糙度也为纳米量级,而且具有较高的热稳定性。在3．5V电压作用下,PEN薄膜可从高阻状态跃变到低阻状态,跃迁时间小于20ns。该材料有可能用于大容量存储器的制作。     

管状介电弹性体驱动器电致应变特性分析

介电弹性体是电场型电活性聚合物的一种,在直流电场作用下,有良好的电致应变特性,去掉外加电场,可迅速恢复到原始尺寸,通过控制电压的大小,可以精确控制变形。本文基于NeoHookean应变能模型,采用ABAQUS有限元软件,开展了材质为丙烯酸聚合物管状介电弹性体驱动器在机电载荷作用下的力学性能有限元模拟,另外,考虑机械预拉伸的影响,开展了管状介电弹性体驱动器机电耦合特性的有限元仿真分析,为管状介电弹性体驱动器的力电特性、变形失效、稳定性的进一步研究提供了一定的理论依据。     

软体材料研究现状及进展

软体材料(杨氏模量通常在10~4～10~9 Pa之间)普遍具有弱影响引发强响应的基本特征。软体材料的范围十分广泛,有以橡胶、液晶等为代表的业已高度产业化应用的传统软体材料,也有以智能凝胶、电活性聚合物、形状记忆聚合物等为代表的智能软体材料。后者独特的刺激敏感特性使其在软体机器人、软体电子、生物医疗、航空航天等领域拥有广阔应用前景。面向工程科技前沿,首先介绍了可降解聚氨酯、水凝胶等的材料特性、制备工艺及其在生物医疗领域(如药物定向释放和组织工程)的应用,随后重点对以离子聚合物-金属复合材料(IPMC)和介电弹性体(DE)为代表的电活性聚合物(EAP),以及形状记忆聚合物(SMP)的基本特性与研究进展进行了梳理和介绍。最后分析了软体材料产业化应用所面临的问题,展望了智能软体材料与增材制造技术相结合的4D打印技术的发展趋势。     

光折变聚合物的研究进展

近年来，聚合物光折变材料越来越受到人在关注，因为民无机材料相比，聚合物材料有较高的电光系数，较高的光损伤阈值，低的直流电常数，而且易于加工，所以光折变聚合物材料显示光明的应用前景，文中介绍了光折变产生的简单的机理，以及目前国际上所研究的各类材料及发展状况。     

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.……     

The Research of Anti-Wear Properties of Organomolybdenum Compounds in the Engine Oils

A four-ball tester was used to evaluate the anti-wear performance of three kinds of organomolybdemun compounds in the engine oils, i. e., molybdenum dialkyldithiophosphate (MoDDP), molybdenum dialkyldithiocarbamate ( MoDTC), and sulphur and phosphorus freeorganomolybdeum (Molybdate). The results indicate that a low concentration of MoDDP doesn' t improve the anti-wear properties of the commercial engine oils, but a high concentration of MoDDP can obviously improve the anti-wear properties and the load-carrying capacity of the engine oils. MoDTC doesn' t improve the antiwear properties of the engine oils, but worsens the anti-wear properties of the oils. Signifi can timprove ment of frictional and wear characteristics is obtained with Molybdate added in the commercial engine oils and the formulated oils.     

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.     

Certification Becomes Important for the I Quality; and Safety Supervision of the Chinese Liquor Sector

The end of 2007, over 200 unit products of more than 80 Chinese firms have passed the quality grade certification for liquor products. These products involve distilled spirits, beer, wine, yellow wine, fruit syrup wine and others, and cover over 80% of the national top-branded liquor products.……     

Deposition and Coating Properties on CVD Tungsten

Surface characterization and microstructure studies are performed on chemical vapor deposited (CVD) tungsten coating. There is about 2 μm thickness diffusion layer of tungsten in the molybdenum substrate. The thermal shock test shows tungsten coating has good adhesion with molybdenum substrate, but the elements of oxygen and carbon in the tungsten coating have the bad affection to the adhesion. The result of high-temperature diffusion experiment is the diffusion rate from molybdenum substrate to tungsten coating is faster.     

Analysis of marine hydrobiont lipid extracts as possible cryoprotective agents

We studied a combined effect of the cryoprotectants both of lipid and carbohydrate origin at the presence of DMSO or without it on cell viability and the RNA synthesis in the embryonic mollusc and echinoderm cell cultures obtained at different developmental stages. Cryoprotective properties of exogenous lipids correlated with their thermotropic behavior. Lipid extracts from marine hydrobiontes, which thermal transitions are characterized by relatively small part of calorimetric thermogram area lying at temperatures above 0 °C (6–18%), were found to possess a considerable cryoprotective activity. The results are discussed in relation to the prediction of the cryoprotective activity of lipid extracts for marine animal cells. In addition, it was found that marine invertebrate cells can be cryopreserved without DMSO at the presence of trehalose and lipid extracts of some marine hydrobiontes.     

Low-Temperature Properties of Silver

Pure silver is used extensively in the preparation of high-temperature superconductor wires, tapes, films, and other configurations in which the silver not only shields the superconducting material from the surrounding materials, but also provides a degree of flexibility and strain relief, as well as stabilization and low-resistance electrical contact. Silver is relatively expensive, but at this stage of superconductor development, its unique combination of properties seems to offer the only reasonable means of achieving usable lengths of conductor. In this role, the low-temperature physical (electrical, thermal, magnetic, optical) and mechanical properties of the silver all become important. Here we present a collection of properties data extracted from the cryogenic literature and, to the extent possible, selected for reliability.     

Early ironwork in Biscay: Survey,excavation, experimentation and materials characterization. An integral study of the mountainside ironworks (ferrerías de monte or “haizeolak”)

ABSTRACT

The production of iron in Biscay (Basque Country, Spain) has been a hallmark of this territory of the North of the Iberian Peninsula throughout its history. The Archaeology team of the Basque Country Mining Museum has spent 13 years, so far, studying the origins of this activity through the evidences left at the old pre-hydraulic iron production workshops known as mountainside ironworks (ferrerías de monte) or haizeolak. It has catalogued 170 archaeometallurgical sites of this type in Biscay, and the archeological excavation of some of them has led to the knowledge of the different stages of the production process that took place in these workshops. The team has also experimentally reproduced the work carried out in a mountainside ironworks from the High Middle Ages, and it has currently started the characterization process of this type of activity through the study of the collected materials.     

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.