无机粉末掺杂对低密度聚乙烯中空间电荷分布及陷阱能级的影响

本文利用激光脉冲压力波法(PWP)研究了纯低密度聚乙烯(LDPE)材料以及掺杂一定量(重量百分比0.5%)四种无机粉末(TiO2、SiO2、BaTiO3、Al2O3)后的低密度聚乙烯(LDPE)材料在高电场持续作用下体内空间电荷的动态分布和等温衰减情况,并结合热刺激放电法(TSC)分析了掺杂前后材料中的陷阱分布状态,更好地了解空间电荷的行为特性.实验表明,掺杂无机粉末能够改变材料中的陷阱能级状态,从而改变空间电荷的动态分布和等温衰减特性.其中掺杂BaTiO3 粉末的低密度聚乙烯(LDPE)材料中产生了最深的陷阱,抑制了空间电荷的电极再注入和体内运输.     

The Characterization of a Subependymal Giant Astrocytoma-Like Cell Line from Murine Astrocyte with mTORC1 Hyperactivation

Tuberous sclerosis complex (TSC) is a genetic disorder caused by inactivating mutations in TSC1 (hamartin) or TSC2 (tuberin), crucial negative regulators of the mechanistic target of rapamycin complex 1 (mTORC1) signaling pathway. TSC affects multiple organs including the brain. The neurologic manifestation is characterized by cortical tubers, subependymal nodules (SEN), and subependymal giant cell astrocytoma (SEGA) in brain. SEGAs may result in hydrocephalus in TSC patients and mTORC1 inhibitors are the current recommended therapy for SEGA. Nevertheless, a major limitation in the research for SEGA is the lack of cell lines or animal models for mechanistic investigations and development of novel therapy. In this study, we generated TSC1-deficient neural cells from spontaneously immortalized mouse astrocytes in an attempt to mimic human SEGA. The TSC1-deficient cells exhibit mTORC1 hyperactivation and characteristics of transition from astrocytes to neural stem/progenitor cell phenotypes. Rapamycin efficiently decreased mTORC1 activity of these TSC1-deficient cells in vitro. In vivo, TSC1-deficient cells could form SEGA-like tumors and Rapamycin treatment decreased tumor growth. Collectively, our study generates a novel SEGA-like cell line that is invaluable for studying mTORC1-driven molecular and pathological alterations in neurologic tissue. These SEGA-like cells also provide opportunities for the development of novel therapeutic strategy for TSC patients with SEGA.     

Thermal relaxation behaviors of phenylphosphonate-containing TDI-based polyurethane elastomers studied by thermally stimulated current technique with relaxation mapping analysis

TSC/RMA study on the thermal behavior of the phenylphosphonate-containing TDI-based polyurethane elastomers, reveals that the bulky phenylphosphonate moiety, which was sandwiched in the middle of the PPG soft chain, untightens the matrix and facilitates the cooperative motion at T_g transition, as indicated by the lowering of the T_g temperature. An additional relaxation transition, the T_global transition, in associated with the hard TDI-MOCA segment was detected and evaluated. Thermal windowing technique in RMA reveals the coexistence of two amorphous regions with one dominated by the urethanic segment and the other is the global/mechanical property associated with the TDI-MOCA hard segment. DSC thermogram showed only one T_g transition without detection of the crystalline domain, implicating that domain was not formed by the hard segment; The detection by TSC/RMA on the relaxation transition of the hard segment existed in the amorphous region may be significant and provide a tool to study the thermal behavior of the hard segment in the polyurethane matrix.     

一种新型静电计在高聚物热激电流测试中的应用

为提高热激电流测试的精确度和自动化程度,引入了Keithley 6517A新型高精确度静电计,利用Visual C .NET 2003软件编程,实现了计算机控制Keithley 6517A对TSC测试数据进行采集,给出主要程序及相关解释,得到满意结果.     

模糊控制TSC无功补偿控制器设计

提出了基于模糊控制的TSC无功补偿控制器的设计方法;讨论了无功补偿控制器中使用模糊控制表的设计步骤。通过实验证明,用该控制方法能较好地改进电压质量,控制无功功率范围,同时可防止系统在某一运行工况下出现小波动时引发的往复投切现象。     

应用于低压大容量冲击性负载的TSC动态无功补偿及谐波滤波系统

介绍了安阳钢铁公司第二轧钢厂轧机主传动冲击性负载的特点和电网状况,针对这种冲击负载的滤波任务,设计了独特的TSC(晶闸管投切电容器组)动态无功补偿及谐波滤波装置。通过测量装置投切前后的数据,显示出TSC装置运行快速、稳定,补偿和滤波效果良好。     

谐波和无功补偿装置在煤矿中的新应用

近年来,由于电力电子器件的大量应用,给煤矿电力系统造成了诸多的电能质量问题,从而使6.3 kV线路电能质量差,功率因数低。本文提出了TSC(晶闸管投切电容器)与APF(有源滤波器)联合应用,能够连续补偿大容量负载的无功和谐波分量。TSC补偿负载大部分基波无功功率,APF补偿剩余的无功功率和谐波,在实际应用中取得了较好的补偿和滤波效果。     

TSC低压动态无功补偿装置的设计与应用

介绍了一种适用于中低压配电网的TSC动态无功补偿装置及应用,可满足低压配电网基波无功补偿的快速性和实时性要求。分析了TSC主电路4种接线方式的特点,详细地阐述了多组电容器的自动分级投切、无功功率快速检测及晶闸管触发电路等关键问题的解决办法。     

离子注入PET薄膜微观结构变化及导电机理的研究

研究了离子注入PET薄膜引起的微观结构变化及导电机理,用傅立叶红外分析法(FTIR-ATR)及电镜扫描(SEM)对离子注入前后PET膜的表面微观结构的变化作了分析,用热刺激电流法(TSC)对离子注入后材料中的荷电粒子及种类作了分析研究。离子注入塑料薄膜是一个复杂的随机的过程,引起了高分子材料复杂的结构损伤和化学变化:新元素的注入,双健的生成,分子的断裂,小分子的放出等,这些因素导致了高分子材料导电性能的提高。