沉淀方式对纯银中As和Hg测定回收率的影响

采用不同沉淀剂(HCl和KSCN)分离银基体,研究沉淀方式对纯银中有害元素As和Hg的电感耦合等离子体发射光谱(ICP-AES)测定回收率的影响。结果表明,两种沉淀方式均不吸附As,但对Hg均有吸附,其原因是Hg与沉淀发生共沉淀;采用沉淀剂滴加-搅拌的方式,AgCl沉淀仍然吸附Hg,但可避免AgSCN对Hg的吸附;Hg测定加标回收率大于95%,相对标准偏差(RSD)小于5%,可满足杂质元素Hg测定要求。对吸附机理的探讨认为,由于AgCl沉淀密度较大、致密度高,与HgCl2可能形成共晶,因而难以通过慢沉淀-搅拌的方式消除对Hg的共沉淀吸附。     

基于笼型电动机转子断条故障的诊断分析

为了解决目前已有的故障诊断方法只能诊断出电机是否发生转子断条故障而不能诊断出转子断条数目的问题,对电机转子断条故障进行了仿真和断条数目诊断方法的研究。首先对Y2-132M-4型的鼠笼式三相异步电机进行了建模,利用建立的模型对发生不同断条数的电机故障进行了仿真研究。然后,提出了基于机器学习的对转子断条故障的断条数目进行诊断的算法。实验结果表明,所提出的故障诊断分类方法实现了电机不同数目的转子断条故障的智能诊断分类,且诊断分类准确率达100%。     

Mechanical,Water-Swelling,and Morphological Properties of Water-Swellable Thermoplastic Vulcanizates Based on High Density Polyethylene/Chlorinated Polyethylene/Nitrile Butadiene Rubber/Cross-Linked Sodium Polyacrylate Blends

A novel water-swellable rubber (WSR) had been prepared by dynamically vulcanized high density polyethylene (HDPE)/chlorinated polyethylene (CPE)/nitrile butadiene rubber (NBR) blends where a cross-linked poly(sodium acrylate) (CPNaAA) was used as a super water-absorbent resin. The mechanical, water-swelling and morphological properties of the WSRs were investigated. Increasing CPNaAA dosages, mechanical properties of WSRs decreased while water-swelling ratio were increased significantly; moreover, swelling ratio of WSRs with 70 phr CPNaAA was reached 956.7% at 55 h. Morphological studies showed that CPNaAA were dispersed randomly in the TPVs, and significant gaps could be found in the surface of dried WSRs.     

轮胎动态和静态臭氧老化现象研究

研究轮胎动态和静态臭氧老化现象。结果表明：动态臭氧老化试验中,轮胎受变应力作用会有较大的应变,应力集中在胎圈和胎肩位置,导致裂纹趋向于更加密集、细小;静态臭氧老化试验中,轮胎在充气状态下受恒定应力作用,受力均匀,裂纹趋向于稀疏、粗大;臭氧浓度越大,轮胎龟裂程度越明显;动态和静态耐臭氧老化产生的裂纹均为水平方向。     

测定吡虫啉农药制剂中有效成分的3种HPLC不同定量方法比较

采用高效液相色谱法测定吡虫啉农药制剂产品中有效成分含量,并对单点校正法、标准曲线法和标准加入法3种不同方法进行分析,比较了3种方法的差异性。利用Excel对3种定量方法的标准偏差、基质效应和测定结果进行F检验和t检验。结果表明,在显著性水平α=0.05时,单点校正法与标准曲线法、标准加入法标准偏差有明显差别,标准曲线法和标准加入法之间无显著性差异。对可湿性粉剂产品,基质效应无法忽略,3种方法测定结果间均具有显著性差别;对乳油产品,标准曲线法和标准加入法测定结果无明显差别,但单点校正法与其他2种方法具有显著性差异。建议对可湿性粉剂产品选择标准加入法定量,乳油产品选择标准曲线法定量。     

植物中药抗菌驱蚊再生纤维素膜的制备及性能研究

将植物中药香叶天竺葵提取物和薄荷精油微胶囊按照一定的配比添加到再生纤维素纤维纺丝原液中,通过相转化法的湿法成膜机理制备出具有抗菌、驱蚊功能的再生纤维素膜,并对其表观性能、力学性能、溶胀性能以及抗菌、驱蚊功能进行测试,根据各项测试结果得出:当香叶天竺葵提取物添加量为再生纤维素纤维纺丝原液中所溶解纤维素质量的6%,薄荷精油微胶囊的添加量为纺丝液质量的2%时,制备的再生纤维素膜性能最佳。     

新型抗菌除臭再生纤维素纤维性能的研究

为了使再生纤维素纤维具备抗菌除臭功能,通过共混法将绿茶提取物水溶液和咖啡炭粉末水化液按照一定配比添加到再生纤维素纤维纺丝原液中,利用湿法纺丝工艺制备出新型抗菌除臭再生纤维素纤维,测试其基本性能以及抗菌、除臭功能。结果表明:与普通再生纤维素纤维相比,其纵向结构未发生明显变化,断裂强力、初始模量、断裂功减小,断裂伸长率略有增大,比电阻减小,抑菌率达到了国家标准对抗菌效果的相关规定,除臭效果远超《SEK标志纤维制品认证基准》中规定的合格标准。     

Synthesis and characterization of novel photo‐crosslinkable fluorinated poly(phthalazinone ether)s for optical waveguides

A series of novel photo‐crosslinkable fluorinated poly(phthalazinone ether)s containing 1,1‐diphenylethylene segments in the polymer main chain, used for optical waveguide materials, were synthesized by polycondensation reaction of decafluorobiphenyl with a mixture of 4‐(4‐hydroxylphenyl)(2H)‐phthalazin‐1‐one (DHPZ), 4,4‐(hexafluoroisopropylidene)diphenol and 1,1‐bis(4‐hydroxyphenyl)ethylene (BHPE) as co‐reactant. The feed ratio of DHPZ to total bisphenols varied from 0 to 80 mol%, while that of BHPE remained at 20 mol% for all polymers. The obtained copolymers show good solubility in some common polar organic solvents. The resulting polymers were photo‐crosslinked after UV irradiation for 10 min in the presence of a photoinitiator. The cured polymers show good chemical resistance, high thermal stability (temperatures of 1% mass loss after curing of 472–496 °C under nitrogen) and high glass transition temperatures (160–249 °C) which could be further increased by about 10 °C after photochemical crosslinking. By adjusting the copolymerizing bisphenol content, the refractive indices of transverse electric and transverse magnetic modes (at 1550 nm) of films of the polymers were exactly tuned in the range 1.5029–1.5661 and 1.4950–1.5502, respectively. The propagation losses of the cured films were measured and found to be less than 0.3 dB cm^?1 at 1550 nm, indicating the promise of these materials for passive optical waveguide devices. Copyright © 2011 Society of Chemical Industry     

一起单芯电缆金属护套接地保护缺陷分析

随着电力电缆的广泛应用及运行时间变长,其运维管理面临着很多新挑战。文中对高压单芯电缆金属护套接地保护的问题进行分析,同时以某35k V单芯电缆金属护套接地线断裂缺陷为例,分析了电缆缺陷原因及处理过程,并对运行中单芯电缆护套接地保护方式的应用及维护提出了几点建议。