阻燃电视高压线的研制

研究了阻燃电视高压线的配方及工艺过程,采用辐照交联低密度聚乙烯料制备绝缘层,采用耐热１０５℃的阻燃软聚氯乙烯材料制备护套层,以镀锡软圆铜线为导电线芯制成阻燃电视高压线。结果表明,所研制的４０ｋＶ阻燃电视高压线已达到电子工业部ＳＪ２９３３－８８标准的要求。     

影响苯乙烯丙烯腈在聚丁二烯乳胶粒上接枝共聚反应的因素

采用种子乳液聚合技术在聚丁二烯 ( PB)乳胶粒上接枝共聚苯乙烯 ( St)和丙烯腈 ( AN) ,合成了一系列 PB-g-SAN共聚物 ( ABS)。将这些共聚物用丙酮溶解并在超速离心机上将 PB-g-SAN和未接枝在 PB上的游离 SAN分离 ,计算出 SAN在 PB上的接枝率和接枝效率。通过改变共聚单体的组成和加料时间 ,研究了接枝率和接枝效率的变化。结果表明 SAN的接枝率随着 PB含量的增加而降低 ,在共聚单体中增加引发剂 ( CHP)和分子量调节剂 ( TD-DM)的含量 ,SAN在 PB上的接枝率和接枝效率表现出了下降的趋势 ,而共聚单体的配比 St/ AN和加料时间对接枝率和接枝效率的影响不大。     

小康型住宅设计浅谈

本文从现代人的居住行为模式、生理和心理需求等方面出发,谈谈小康型住宅内各功能空间－起居厅、门厅、卧室、厨房、卫生间等各部分的设计要求及各功能空间的有机结合。     

The effects of noradrenergic activation of the nucleus tractus solitarius on memory and in potentiating norepinephrine release in the amygdala.

Although it is known that norepinephrine (NE) modulates memory by acting on limbic areas, few studies describe how structures supplying NE to the limbic system such as the nucleus tractus solitarius (NTS) contribute to this process. The present study examined the effects on memory of activating the NE pathway between the NTS and the amygdala (AMYG). Rats received buffer or the β-noradrenergic agonist clenbuterol (CLN; 10, 50, or 100 ng/0.5 μl) into the NTS after footshock training in a Y-maze discrimination task. Infusion of 100 ng CLN significantly improved memory when retention was tested in the absence or presence of cues associated with the footshock. Experiment 2 used in vivo microdialysis to determine whether the mnemonic effects of CLN are mediated by influencing NE output in the AMYG. Subjects were given an intra-NTS infusion of CLN or phosphate buffered saline, footshock (0.8 mA, 1 s) and injected with epinephrine (EPI; 0.3 mg/kg ip) or saline. CLN or EPI injection produced a significant increase in NE sampled from the AMYG. These findings indicate that activation of NTS neurons that project to and release NE in the AMYG modulates memory storage processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

石油专用管材生产技术的现状及进展

概述了国内、外油井管生产技术的开发现状和发展趋势,介绍了其应用和开发过程中的关键问题,提出了我国油井管生产的发展方向。     

Silazane derived ceramics and related materials

This review highlights the synthesis, processing and properties of non-oxide silicon-based ceramic materials derived from silazanes and polysilazanes. A comprehensive summary of the preparation of precursor compounds containing Si–N–Si units, including commercially available materials, is followed by the discussion of various processing techniques. The fabrication of dense bulk ceramics in the Si/E/C/N systems is reported which involves cross-linking of the polymeric ceramic precursor followed by a polymer-to-ceramic transformation step. The cross-linked precursor can be milled, compacted and pyrolysed to form dense, additive-free, amorphous silicon carbonitride monoliths or polycrystalline composites which withstand oxidation in air at 1600°C. Furthermore, an overview is given on the fabrication of silazane derived powders and coatings involving chemical vapour deposition (CVD) methods utilising volatile precursors. Fibre spinning and fibre properties, as well as other processing techniques like infiltration of preforms, the preparation of porous ceramics and joining are briefly discussed. A state of the art of the mechanical properties of polymer derived amorphous Si/C/N and Si/B/C/N ceramics with respect to hardness as well as high-temperature creep and oxidation resistance is summarised. Finally, some important aspects of industrial applications will be considered. The review is in part based on our own work related to the polysilazane derived ceramics, but will also cover a comprehensive state of the art including the published literature in this field.     

Layer-by-layer assemblies of chitosan/multi-wall carbon nanotubes and glucose oxidase for amperometric glucose biosensor applications

A novel amperometric glucose biosensor based on multilayer films containing chitosan, multi-wall carbon nanotubes (MWCNTs) and glucose oxidase (GOD) was developed. MWCNTs were solubilized in chitosan (Chit-MWCNTs) used to interact with GOD. Poly (allylamine) (PAA) and polyvinylsulfuric acid potassium salt (PVS) were alternately deposited on the cleaned Pt electrode surface ((PVS/PAA)₃/Pt). The (PVS/PAA)₃/Pt electrode was alternately immersed in Chit-MWCNTs and GOD to assemble different layers of multilayer films. PBS washing was applied at the end of each assembly deposition for dissociating the weak adsorption. Micrographs of MWCNTs were obtained by scanning electron microscope, and properties of the resulting biosensors were measured by electrochemical measurements. Among the resulting biosensors, the biosensor based on eight layers of multilayer films was best. The resulting biosensor was able to efficiently monitor glucose, with the response time within 8 s, a detection limit of 21 μM estimated at a signal-to-noise ratio of 3, a linear range of 1–10 mM, the sensitivity of 0.45 μA/mM, and well stability. The study can provide a feasible simple approach on developing a new immobilization matrix for biosensors and surface functionalization.     

Application of orange peel xanthate for the adsorption of Pb from aqueous solutions

Pristine orange peel was chemically modified by introducing sulfur groups with the carbon disulfide treatment in alkaline medium. The presence of sulfur groups on orange peel xanthate were identified by FTIR spectroscopic study. Equilibrium isotherms and kinetics were obtained and the effect of various parameters including equilibrium pH, contact time, temperature and initial ion concentration on adsorption of Pb²⁺ were studied by batch experiments. The maximum adsorption capacity of orange peel xanthate was 204.50 mg g⁻¹, which was found to increase by about 150% compared to that of pristine orange peel. The adsorption process can attain equilibrium within 20 min, and kinetics was found to be best-fit pseudo-second-order equation. Temperature has little effect on the adsorption capacity of orange peel xanthate. In addition, the adsorption mechanism was suggested to be complexation.     

基于Riccati不等式的微动隔振平台鲁棒性能控制器设计

针对辨识参数存在摄动的精密隔振平台系统的鲁棒性能控制器设计问题,基于参数摄动系统的鲁棒性能与Riccati不等式解之间的关系,推导出了一类参数摄动系统的输出反馈鲁棒性能控制器设计方法,将鲁棒性能控制器设计转化为参数确定的辅助系统的一般输出反馈鲁棒控制器求解,计算较方便.通过对单自由度微动隔振平台的仿真分析表明,空气弹簧支撑隔振平台虽能隔离地基的高频成分,但对低频成分以及台面直接干扰的隔振效果不好;采用所设计的鲁棒性能控制器,闭环系统能够在不确定参数较大的摄动范围内有效隔离地基的低频振动,而且对台面直接干扰和量测噪声也具有很好的鲁棒性.     

The effects of multiwalled carbon nanotubes on the hot-pressed 3 mol% yttria stabilized zirconia ceramics

The bulk composites of 3 mol% yttria stabilized zirconia ceramics reinforced by multiwalled carbon nanotubes were prepared by ball milling, spray-drying and hot-pressing processes. The effects of MWCNTs’ contents and heterocoagulation pretreatment on the mechanical properties of 3Y–ZrO₂/MWCNTs’ composites were investigated at room temperature. Experimental results showed that the heterocoagulation pretreatment played a vital role in homogeneous dispersion of MWCNTs in the ceramic matrix. The flexural strength of 989.8 ± 20.0 MPa and fracture toughness of 5.77 ± 0.06 MPa M^1/2 were obtained for the composite with 1.0 wt.% of MWCNTs’ content, which were 135.3 MPa (or 8.4%) higher in flexural strength and 0.92 MPa M^1/2 (or 21.1%) higher in fracture toughness than those of blank 3Y–ZrO₂, respectively. The mechanisms of strengthening and toughening of the composites could be attributed to the synergic effects of bridging, pulling out of MWCNTs and their promotive effects on the phase transformation of the ceramics.