原子荧光光谱法测定环境水体中痕量锡研究

在对环境水进行检测时,一个非常重要的项目就是对锡含量进行检测,所以,运用准确、灵敏的测定方法对环境水体中痕量锡进行检测具有非常重要的意义。文章将结合实验,在对环境水体中的痕量锡进行测定时,运用原子荧光光谱法,对测定环境水体中痕量锡的方法进行了一定的研究。采用原子荧光光谱法测定环境水体中的痕量锡,方法检出限是0.10μg/L,相对标准偏差0.20%~0.90%,实际样品加标回收率为98%~102%,满足环境监测实验室分析测定要求,值得推广。     

Unexpected phenotypes of malformations induced in Xenopus tropicalis embryos by combined exposure to triphenyltin and 9-cis-retinoic acid

Xenopus tropicalis embryos were exposed for 48 hr to the mixtures of 5 g Sn/L triphenyltin(TPT), which is a well-known endocrine disruptor, and 0.25–5 g/L 9-cis retinoic acid(9c-RA), which is the natural ligand of retinoid X receptor. The phenotypes induced by combined exposure were more variable than those resulting from single exposure to either TPT or 9c-RA. The prominent phenotypes included underdeveloped head structures, abnormal eyes, narrow fins, enlarged proctodaeum, etc. Especially, combined exposure induced unexpected notochord malformations, which ranged from small swellings of the surface of the tails to the extension and extrusion of notochord out of the posterior tails. Compared with the 5 g Sn/L TPT-treated group, the index of fin deficiency was not affected, and the index of axis deficiency was significantly increased with increasing RA concentrations in the mixtures. Our results suggest that combined exposure to TPT and 9c-RA induced not only more variable phenotypes of malformations than exposure to single compound but also some new and unexpected phenotypes.     

柳州华锡集团

柳州华锡集团是一个有色金属探采选冶加工联合企业．1994年被确定为全国100家建立现代企业制度试点单位之一．同年被确认为国家特大型企业．1997年被确定为国家重点支持的512户重点企业之一.     

大井银铜锡矿体—一个潜火山热液矿床的特征和成因

大井银铜锡矿床是我国在金属组合上较为罕见的矿床之一。过去,该矿床曾被认为是与花岗岩有关的中深成热液矿床。作者从矿区潜火山侵入体与矿区东侧侏罗纪火山层序对比、矿床地质特征(包括矿体、矿石、金属矿物及金属分带)以及成矿作用地球化学等方面的资料和数据,论证了该矿床是一个浅成的潜火山热液矿床。     

PCB企业退焊锡废液治理再生研究

该文提出用巯基沉淀剂来沉淀硝酸型退铅锡废水中的重金属离子(Cu,Fe,Pb,Sn),实验结果表明,适宜的沉淀条件为:在搅拌下将巯基沉淀剂P按理论量加入,同时按每升废液通入还原性添加剂二氧化硫12 g和3～5 mL,1%(W/W)PAM(分子量为400 000)絮凝剂,沉淀过滤后其退锡速度和退锡容量等性能与原退锡液无异,该工艺可使PCB企业的退铅锡废水实现循环使用。      

206nm紫外光降解水相中的氯化三苯基锡

研究了氯化三苯基锡不同初始浓度、光照时间、初始pH值和添加H2O2等因素对光降解效果的影响.结果表明,弱酸条件更有利于氯化i苯基锡的降解;当pH=2.0时,120mg·1-1氯化三苯基锡溶液光照75min后,其降解率约为89.4%;氯化三苯基锡浓度愈低,其光降解效果愈好.在氯化三苯基锡水溶液中加入双氧水后,光照75min后光降解率基本能达到100%.根据产物GC-MS分析结果,初步探讨了氯化三苯基锡光降解的机理.     

凤凰涅磐 文明花开——广西华锡集团车河选矿厂创建全国文明单位纪实

群山环抱,山峦苍翠,是车河选矿厂依傍的胸怀;刁江溪水,碧绿清澈,是车河选矿厂静卧时伴唱的童谣……历经30年的创业风雨,车河选矿厂历久弥新,不仅经济生产指标成绩斐然,精神文明之树同样枝繁叶茂。     

Palladium-phosphinous acid complexes catalyzed Suzuki cross-coupling reaction of heteroaryl bromides with phenylboronic acid in water/alcoholic solvents

Highly active, air-stable and water-soluble palladium-phosphinous acid complexes have been applied to Suzuki cross-coupling reaction of heteroaryl bromides under mild conditions in water/alcoholic solvents. Suzuki cross-coupling reaction of heteroaryl bromides with phenylboronic acid occurred efficiently using palladium phosphinous acid complexes (POPd) and phase transfer catalyst (tetrabutylammonium bromide and polyethylene glycol) in water/ethanol mixture, water/propanol mixture and neat water respectively, the corresponding yields of cross-coupling heteroaryl-aryls were satisfied. The tert-butyl substituted ligand di-tert-butylphosphino in combination with POPd was found to be more active than the same family derived catalysts dipalladium complexes POPd1 and POPd2, and other two kinds of Pd-catalysts Pd(PPh₃)₄ and Pd₂(dba)₃. The mechanism of Suzuki cross-coupling reaction between heteroaryl bromides and phenylboronic acid in water was proposed with respect to the key role of phase transfer catalyst on the transmetallation step. Compared with other solid phase transfer catalysts, TBAB was tested as the ideal one. The alkalinity of base and the molar proportion between POPd and TBAB were investigated in water and alcoholic solvents. Notably, in the presence of TBAB adding alcoholic solvents into water enhanced the yields of target products. However in terms of the liquid phase transfer catalyst of PEGs, mixing water into PEGs could slightly decrease the yields with respect to the water free PEGs bulk phase, which was probably due to the homogenous liquid conditions in pure PEGs and weak interactions between PEGs and heteroaryl bromide molecules in water depending on their molecular chain lengths.     

水体痕量锑快速检测新方法研究

锑与二溴邻硝基苯基荧光酮(DBNPF)在酸性溶液、曲拉通X-100和碘离子存在条件下发生络合反应,络合物通过光谱修正法进行表征,结果表明,Sb与DBNPF络合比为1∶1,络合常数为3.39×10~6,吉布斯自由能为-36 kJ/mol,络合物Sb~(Ⅲ)-DBNPF在550 nm处的摩尔吸光系数为3.40×10~4L/(mol·cm)。在硫脲和酒石酸存在下,显色反应具有较高选择性,利用矢量色度方法测得锑检出限为0.010 mg/L,实际水样锑加标回收率87%～105%。     

铣削工艺参数对锡铋合金表面粗糙度特征影响及试验分析

目的对锡铋合金表面粗糙度特征进行研究分析,提高表面加工质量。方法采用正交试验设计方法,以最小表面粗糙度作为优化指标,以主轴转速、铣削深度、进给速度、铣削宽度作为影响因素,进行精密铣削试验研究。结果利用方差分析确定了进给速度是锡铋合金铣削表面粗糙度最重要的影响因素,并基于田口方法优化分析得到了锡铋合金铣削加工工艺最优组合。结论采用田口法对锡铋合金铣削工艺参数优化,有效地减少了加工表面粗糙度,提高了工件表面质量。