采用柔性集成与逻辑分支技术电缆的研制

随着武器装备的发展,电气连接与信号传输越来越复杂,对电缆网布线的空间大小、可靠性、电磁兼容、可辨性等提出了更高的要求。采用柔性集成与逻辑分支技术设计布线,可以节省布线空间,具有柔性好、重量轻、高可靠性、电磁兼容等特点,同时避免穿舱、辨色等一系列问题。这种布线技术对减轻武器装备重量、提高综合性能具有很高的实用价值。     

现浇正交异性钢筋混凝土空心板施工技术

以石棉水泥砂浆离心管作为内模衬管,浇筑混凝土后构成现浇混凝土空心板。该结构设宽扁梁或暗梁,可降低结构高度,增大使用空间,具有刚度大、自重轻、抗震好、用料省等优点,具有良好的经济效益与社会效益。     

一种增强型Z源逆变器的研究

针对在低功率因数以及Z源电感值较小的情况下,Z源逆变器二极管电流断续引起的直流链电压畸变的问题,研究了一种电容辅助增强型准Z源逆变器。深入分析Z源逆变器非正常工作状态产生的原因,利用Matlab/Simulink对电容辅助增强型准Z源逆变器和传统准Z源逆变器进行仿真分析。仿真结果表明,在低功率因素及Z源电感值较小的运行条件下,该增强型Z源逆变器可较好地解决直流链电压畸变的问题,有效改善逆变器输出电压的质量,简化Z源电感的设计。     

索式萃取法测定聚丙烯腈原丝的含油率

采用索氏萃取法测定聚丙烯腈(PAN)原丝的含油率,分析了萃取剂配比、萃取温度、萃取时间及萃取次数对测试结果的影响,探讨了原丝含油率与灰分含量之间的关系。结果表明:采用索氏萃取法测试PAN原丝含油率的最佳条件为萃取剂甲醇和氯仿体积比为1/1.5～1/2.5,萃取温度为80～85℃,萃取时间为2.5 h,萃取次数为1;此方法的回收率为97.8%～103.1%,相对标准偏差为1.14%,但该法只能测试PAN原丝表面的油剂含量,渗透至原丝内部的油剂难以萃取出来,可通过烧蚀后的灰分含量来反映。     

基于CiteSpace的核素扩散迁移问题的研究发展趋势分析

为探索放射性核素在环境中迁移扩散的研究热点与发展趋势,以CNKI上2001～2020年的相关文献为基础,应用CiteSpace软件进行文献计量处理,从作者合作、机构发文情况、关键词共现与聚类分析和关键词突现等方面对国内核素扩散迁移问题的科研力量、研究热点、发展趋势和研究前沿进行分析.结果表明:核素扩散迁移领域的研究成果...     

Comprehensive analysis on anomalous phenomenon of ethanol-soluble poly(vinyl butyral) membrane for ethanol recovery via pervaporation

Poly(vinyl butyral) (PVB) is selected as a promising ethanol-permselective membrane based on the solubility parameter theory; however, it exhibits anomalous water perm-selectivity in practical pervaporation (PV) process. Comprehensive analysis based on experimental and theoretical methods were carried out to explore the inherent mechanism of the anomalous performance. Firstly, sum frequency generation vibrational spectra and contact angle were developed to quantify the surface reconstruction of membrane in air and ethanol, which indicated that hydrophilic hydroxyl tended to expose on membrane surface with ethanol thus improving the membrane affinity to water. Meanwhile, swelling behaviors proved more water would accumulate in the ethanol swollen membrane. Furthermore, theoretical analysis in terms of sorption and diffusion process, based on the UNIFAC-FV model and Fujita free-volume theory, confirmed the mechanism of anomalous phenomenon of PVB membrane. The comprehensive investigation was expected to provide insights into the basic separation mechanism of PV process.     

高锰酸钾与粉末活性炭联用工艺絮体粒径变化规律的研究

以河水为原水,在选择适宜水力条件的基础上,考察了混凝剂为硫酸铝(AS)、氯化铁(FeCl3),投加粉末活性炭(PAC)和高锰酸钾(KMnO4)强化常规处理工艺时絮体粒径的变化规律。试验中采用激光粒度仪在线多次测量絮体平均粒径,然后利用软件对数据进行处理,考察了不同药剂投量工况组合时浊度、UV254的变化情况。试验结果表明,投加不同量的PAC后,原水的粒径变化不大,但在PAC投量不同的条件下投加相同量混凝剂后,形成的絮体粒径差异明显;在PAC投量与混凝剂投量不变的条件下,投加不同量的KMnO4对絮体粒径的影响也较大;相同条件下,使用50 mg·L-1 FeCl3形成的絮体比60 mg·L-1 AS的大、絮体增长达到稳定所需的时间更短。     

“任务驱动”在有机化学教学中的应用

从“任务驱动”教学法的基本特征入手,结合教学实际阐述了该教学法在有机化学课堂教学中的具体应用,并对在教学过程中有效实施该教学法进行了简单的探讨。     

Novel composite nanofilm of electropolymerization and self‐assembling on AA5052 surface as anticorrosion coating

Electropolymerization nanofilm was prepared by cyclic voltammogram with 6N,N‐diallylamino‐1,3,5‐triazine‐2,4‐dithiol monosodium (DAN) on the AA5052 surface in 0.15M NaNO₂ at 10°C, then octyl‐triethoxysilane (OTES) film was fabricated on the poly(6N,N‐diallylamino‐1,3,5‐triazine‐2,4‐dithiol) nanofilm (PDA) covered AA5052 surface by self‐assembling method to obtain the composite polymeric nanofilm (C‐PDA/OTES). The composite polymeric nanofilm was characterized by means of FTIR spectra, scanning electron microscope (SEM), contact angle, and potentiodynamic polarization. The results showed that the C‐PDA/OTES covered surface was more homogenous, compact, hydrophobic compared with PDA covered surface and had excellent protection efficiency. © 2011 Wiley Periodicals, Inc. J Appl Polym Sci, 2012