PMN/CB/PF/ⅡR复合材料制备及其阻尼性能

以丁基橡胶为聚合物基体,酚醛树脂为硫化剂,通过加入压电陶瓷和导电炭黑,制得了一种高阻尼宽温域的聚合物基压电阻尼复合材料(PMN/CB/PF/ⅡR)。系统研究压电陶瓷和乙炔炭黑含量、极化、外加交变应力大小及频率、聚合物共聚基体等因素对复合材料阻尼性能的影响。研究表明:在相同的外力条件下,当外力施加频率与复合材料模量相匹配,PMN质量分数为50%,炭黑为5%时,PMN/CB/PF/ⅡR复合材料的阻尼系数峰值tanδmax达到最大0.81,阻尼温域范围为-35~60℃,复合材料的阻尼性能最好。而且,极化过的样品比未极化的样品具有更高的阻尼峰值。     

导电相对压电复合材料吸声性能的影响

为了研究新型环境声学功能材料, 在压电导电原理的基础上, 制备了以不同含量炭黑为导电相, 以聚氯乙烯为基体材料, 以锆钛酸铅为压电相的压电导电吸声复合材料。通过对复合材料体系的动态力学、电学和声学性能的测试分析, 探讨了压电导电复合材料体系中压电吸声途径的耗能机制。结果表明, 添加体积含量4 %炭黑粉的压电复合材料具有最高的吸声性能。      

0-3型PZN-PZT/PVDF压电复合材料的制备工艺条件优化

采用固相法合成了性能良好的PZN-PZT陶瓷粉体.将压电陶瓷粉体分散于PVDF基体中,制备了0-3型PZN-PZT/PVDF压电复合材料.研究了复合材料的复合工艺、极化参数与压电陶瓷的含量对复合材料压电性能的影响.结果表明,溶液混合工艺较好,且当极化电场强度为6kV·mm-1、温度为110℃进行极化20min时,陶瓷粉体质量分数为90%的复合材料的压电性能最好,压电常数d33值达35.9 pC·N-1.     

压电陶瓷/CIIR复合材料的阻尼性能的研究

以氯化丁基橡胶(CIIR)及其互穿网络为基体,加入压电陶瓷PMN和导电炭黑CB制备PMN/CB/CIIR复合材料,系统研究其的阻尼性能的影响因素以及机理,以获得高介电常数和高阻尼性能的压电陶瓷/聚合物基复合材料,拓展其在介电材料和阻尼材料领域的应用。     

锆钛酸铅/聚苯胺/聚氨酯三元阻尼复合材料

为减少压电陶瓷/导电填料/聚合物阻尼复合材料中填料的含量,制备了锆钛酸铅(PZT)/聚苯胺/聚氨酯三元复合材料,其中,聚苯胺(PANI)通过原位聚合的方法包覆于压电陶瓷粒子的表面.采用FTIR,TGA,SEM、EDS研究了PANI包覆PZT的组成和形态.用DMA评价了复合材料的阻尼性能.结果表明,通过原位聚合的方法能够制备PANI包覆的PZT粉末;三元复合材料的阻尼性能与PANI的导电率有关,在一定的PANI导电率时达到最大,并且在任意导电率下均高于单一聚氨酯.用PANI包覆的压电陶瓷与聚合物复合,能够提高聚合物的阻尼性能.通过调整PANI的导电率,可以使材料的阻尼性能达到相应振动频率下的最大值.     

炭黑填充聚丙烯复合材料的制备及性能

采用炭黑(CB)为导电组分填充聚丙烯制备复合型导电高分子材料。在分散剂作用下,炭黑可较好地分散在聚丙烯中,赋予材料导电性能,导电阚值为8％(质量)左右。采用差示扫描量热法(DSC)对该复合材料的热性能进行了分析。用扫描电子显微镜(SEM)和透射电子显微镜(TEM)研究了炭黑在复合材料中的分散形态,表明炭黑以葡萄状聚集体的形态存在是复合材料具有低导电阉值和良好导电性能的重要原因。     

PVDF/PZT/CB高分子复合材料的介电耗能机制

应用压电导电原理,研制了一种新型减振复合材料,通过对PVDF／PZT／CB复合体系的导电性能和动态介电性能的测试分析,探讨了该复合材料的介电耗能微观机制,认为该复合材料可通过界面极化和漏电电流两种介电耗能机制来达到减振目的。     

无机填料对PVC/CPE/CB复合材料导电性能的影响

研究了具有不同粒子形态的无机填料(球形的纳米二氧化硅、片状的滑石粉和纤维状的玻璃纤维),以及不同粒径的碳酸钙(纳米碳酸钙、超细碳酸钙)对聚氯乙烯(PVC)/氯化聚乙烯(CPE)/导电炭黑(CB)复合材料导电性能的影响。电性能测试和扫描电镜形态结构分析结果表明,添加纤维状填料比球形和片状填料更有利于复合材料导电性能的保持;粒径较小的纳米碳酸钙对复合材料的导电性能影响较小。当炭黑含量为12phr时,添加15phr纳米碳酸钙后复合材料的电阻率仅为6.04×106Ω.cm。     

0-3型橡胶基压电阻尼复合材料的制备及其性能

本文以通用橡胶为基体材料,以一定体积分数的锆钛酸铅粉体（PZT）为压电相、导电炭黑为导电相制备了0-3型压电阻尼复合材料。经过直流高温油浴极化处理后,获得了在低频下具有较高损耗因子的压电阻尼材料,并研究了其断面形貌、压电应变系数、损耗因子等各项性能。     

切割-填充法制备粗压电陶瓷纤维复合材料驱动器

采用切割-填充法制备了一种粗压电陶瓷纤维复合材料驱动器,该驱动器由叉指电极电路板、环氧树脂黏结层和粗压电陶瓷纤维复合材料层三部分组成。理论计算了粗压电陶瓷纤维复合材料的压电性能,并采用TF Analyzer 2000铁电分析仪和基于LabVIEW的动态应变采集系统测试了该驱动器的P-E回线和应变性能。结果表明:粗压电陶瓷纤维复合材料的理论压电常数d33和剩余极化强度Pr分别为634pC·N-1和31.4μC·cm-2。且在±1,000V正弦交变电压作用下,驱动器可以产生纵向和横向应变分别为30με和20με,即纵向和横向伸缩分别可达0.63μm和0.34μm。     

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.     

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.……     

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.