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971.
972.
Electroactive shape memory composites were synthesized using polybutadiene epoxy(PBEP) and bisphenol A type cyanate ester(BACE) filled with different contents of carbon black(CB). Dynamic mechanical analysis(DMA), scanning electron microscopy(SEM), electrical performance and electroactive shape memory behavior were systematically investigated. It is found that the volume resistivity decreased due to excellent electrical conductivity of CB, in turn resulting in good electroactive shape memory properties. The content of CB and applied voltage had significant influence on electroactive shape memory effect of developed BACE/PBEP/CB composites. Shape recovery can be observed within a few seconds with the CB content of 5 wt% and voltage of 60 V. Shape recovery time decreased with increasing content of CB and voltage. The infrared thermometer revealed that the temperature rises above the glass transition temperature faster with the increase of voltage and the decrease of resistance. 相似文献
973.
用不对称催化还原法以3’-氯-苯丙醇(CPNL)为原料制备了手性3’-氯-1-苯丙酮(CPNL),并用气相色谱法测定反应液中产品及剩留的原料的含量。选用2-甲基-苯丙醇为内标物,并用化学键合β-环糊精为固定相的手性毛细管色谱柱CP-Chirasil-Dex-CB对产品及原料进行分离。在所选条件下,不仅使CPNN与CPNL,还可使CPNL的右、左旋对映体相互有效分离。由于采有内标法,因进样不准而产生的误差得以克服,测得CPNN及(S)CPNL的检出限(3S/N)依次为13.14,18.75 mg·L-1。上述两种化合物的加标回收率依次为99.5%~101.8%及96.5%~100.4%范围内;两者测定值的相对标准偏差(n=6)分别为0.39%,0.74%(左、右旋对映体相同)。 相似文献
974.
975.
研究了无线POS机具的安全策略、GPRS的安全机制、防火墙的应用及银行前置的安全认证和数据加密的应用管理等内容。 相似文献
976.
977.
Kinetic Resolution of Racemic Allylic Alcohols by Catalytic Asymmetric Substitution of the OH Group with Monosubstituted Hydrazines 下载免费PDF全文
Liang Yan Jing‐Kun Xu Chao‐Fan Huang Zeng‐Yang He Ya‐Nan Xu Prof. Dr. Shi‐Kai Tian 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(37):13041-13045
A new strategy has been established for the kinetic resolution of racemic allylic alcohols through a palladium/sulfonyl‐hydrazide‐catalyzed asymmetric OH‐substitution under mild conditions. In the presence of 1 mol % [Pd(allyl)Cl]2, 4 mol % (S)‐SegPhos, and 10 mol % 2,5‐dichlorobenzenesulfonyl hydrazide, a range of racemic allylic alcohols were smoothly resolved with selectivity factors of more than 400 through an asymmetric allylic alkylation of monosubstituted hydrazines under air at room temperature. Importantly, this kinetic resolution process provided various allylic alcohols and allylic hydrazine derivatives with high enantiopurity. 相似文献
978.
Seokgeun Jin Byung Jun Jung Chung Kun Song Jeonghun Kwak 《Current Applied Physics》2014,14(12):1809-1812
We introduce a room temperature and solution-processible vanadium oxide (VOx) buffer layer beneath Au source/drain electrodes for bottom-contact (BC) organic field-effect transistors (OFETs). The OFETs with the VOx buffer layer exhibited higher mobility and lower threshold voltages than the devices without a buffer layer. The hole mobility with VOx was over 0.11 cm2/V with the BC geometry with a short channel length (10 μm), even without a surface treatment on SiO2. The channel width normalized contact resistance was decreased from 98 kΩ cm to 23 kΩ cm with VOx. The improved mobility and the reduced contact resistance were attributed to the enhanced continuity of pentacene grains, and the increased work function and adhesion of the Au electrodes using the VOx buffer layer. 相似文献
979.
在介绍了消息中心整体架构的基础上,详细探讨了与TcgChannel技术相结合的消息发布/订阅模式平台的实现.该平台符合实际的监控业务需求,很好地支持了各部门消息订阅、分布式监控以及多种监控通知方式等功能.各模块之间耦合度小,具有良好的可扩展性.适用于传统分布式的监控系统,并在实际应用中已得到验证. 相似文献
980.
Dynamical study on charge injection and transport in a metal/polythiophene/metal structure 下载免费PDF全文
The dynamical process of charge injection from metal electrode to a nondegenerate polymer in a metal/polythiophene (PT)/metal structure has been investigated by using a nonadiabatic dynamic approach. It is found that the injected charges form wave packets due to the strong electron-lattice interaction in PT. We demonstrate that the dynamical formation of the wave packet sensitively depends on the strength of applied voltage, the electric field, and the contact between PT and electrode. At a strength of the electric field more than 3.0 × 10^4 V/cm, the carriers can be ejected from the PT into the right electrode. At an electric field more than 3.0 × 10^5 V/cm, the wave packet cannot form while it moves rapidly to the right PT/metal interface. It is shown that the ejected quantity of charge is noninteger. 相似文献