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291.
研究了铋、氧化铋、硫化铋在硝酸-硫脲中的溶解性。三价铋离子与硫脲溶液可形成黄色络合物,在波长为460nm处,反应温度为25℃,反应时间为6min,硝酸浓度为1.0mol/L,硫脲浓度为0.5mol/L,振荡速率为160r/min条件下铋含量在0.059—4.57μg/mL范围内服从郎伯-比尔定律,检出限为m=0.04μg。铋矿物的溶解性顺序大小为Bi2O3>Bi>Bi2S3。本方法操作简便,可靠,实验结果满意,具有广泛的实用意义。  相似文献   
292.
A highly sensitive chromo- and fluorogenic chemodosimeter for sulfide anion was developed based on its nucleophilicity. 2,4-Dinitrobenzenesulfonyl-fluorescein (I) is a weakly fluorescent compound. Upon mixing with sulfide anion in aqueous acetone solution, the 2,4-dinitrobenzenesulfonyl group of I was efficiently removed and highly fluorescent fluorescein was released, hence leading to the dramatic increases in both fluorescence and absorbance of the reaction solution. The fluorescence increment is linear with sulfide anion concentration in the range 50-1000 nmol L−1 with a detection limit of 4.3 nmol L−1 (3σ). The proposed chemodosimeter showed excellent selectivity toward sulfide anion and was successfully applied to the determination of sulfide anion in synthetic wastewater samples.  相似文献   
293.
丁二醇二丙烯酸酯、丙烯酸甲酯、丙烯酸β-氯乙酯或丙烯酸ω-氯己酯进行三元共聚,合成了两类4种带ω-氯侧基的交联型聚丙烯酸酯.它们以乙硫醇硫醚化,再与氯亚铂酸钾反应,得到4种交联型聚丙烯酸酯负载的硫铂络合物.这些络合物对癸烯-1、十二烯-1、苯基烯丙醚、苯乙烯与三乙氧基硅烷的硅氢加成反应具有良好的催化活性.讨论了温度、催化剂用量对催化性能的影响及催化剂的重复使用情况.  相似文献   
294.
研究了二乙氨基对苯胺与硫化物形成乙基硫堇的显色反应,十二烷基磺酸钠可提高测定S2-的灵敏度。该缔合物在675nm处有最大吸收,摩尔吸光系数为4.25×104L·mol-1·cm-1,S2-测定的线性范围为0~0.8μg/mL。该方法用于天然水中微量硫化物的测定,结果满意。  相似文献   
295.
ovel chiral β-amino alcohols containing sulfide or sulfonyl groups were synthesized from (R)-cysteine. Their chiral induction in the asymmetric borane reduction of prochiral ketones was investigated. Optically active secondary alcohols with moderate or high e. e. values were obtained, and the causes of different enantioselectivities between these two sulfur-containing chiral β-amino alcohols were researched.  相似文献   
296.
The key to understanding the sulfur history on Mars is to identify and determine sulfate and sulfide compositions and then to draw from them geologic clues about their environments of formation. To lay a foundation for use of remote LIBS to sulfur analysis in planetary exploration, we have undertaken a focused study of sulfur LIBS in geological samples in a simulated Mars atmosphere, with experimental parameters replicating the ChemCam LIBS instrument. A suite of twelve samples was selected, including rocks rich in minerals representative of sulfates and sulfides that might be encountered on Mars. Univariate analysis of sulfur emission lines did not provide quantitative information. Partial least squares (PLS) analysis was successful at modeling sulfur concentrations for a subset of samples with similar matrices. Sulfide minerals were identified on the basis of other siderophile or chalcophile peaks, such as those arising from Zn and Cu. Because the S lines are very weak compared to those of other elements, optimal PLS results were obtained by restricting the wavelength range to channels close to the most intense sulfur lines ~ 540-570 nm. Principal components analysis was attempted on the dataset, but did not differentiate the samples into meaningful groups because the sulfur lines are not strong enough. However, areas of the relatively weak S, H, and O peaks may be used to correctly classify all samples. Based on these outcomes, a flowchart that outlines a possible decision tree for identification and quantification of sulfur in remote LIBS analysis was constructed. Results suggest that LIBS data acquired under Mars conditions can meet the science requirements for the ChemCam instrument.  相似文献   
297.
用不同原料和方法制备了不同类型的聚苯硫醚树脂,通过元素分析。红外光谱,激光拉曼光谱及X射线衍射分析等手段,对各种产品的结构进行了表征。对不同类型产品的结构差异进行了初步研究。结果表明,用不同的原料和方法都可制备聚苯硫醚树脂,各种聚苯硫醚树脂的结构基本接近,但具有细微差别。  相似文献   
298.
固态金属锂电池因其优异的安全性和高的理论能量密度被认为是最具前景的下一代储能电池体系之一。随着以硫化物为代表的高离子导率电解质被逐渐开发,金属锂与固态电解质界面成为限制固态电池应用的主要瓶颈。金属锂/电解质的固固界面存在着界面接触差、界面电荷传输阻力高等问题。本文以固态金属锂软包电池为研究对象,通过由1,1,2,2-四氟乙基-2,2,3,3-四氟丙基醚、乙二醇二甲醚与双三氟磺酰亚胺锂组成的局部高盐液态电解液(HFE-DME LiTFSI)对金属锂/固态电解质界面进行润湿,增加金属锂与固态电解质之间的离子接触,降低离子传输阻力,从而提高锂离子在界面的传输能力。在30 mm×30 mm Li|Li4Ti5O12(LTO)固态软包电池中,通过3.0μL·cm?2 HFE-DME LiTFSI局部高盐液态电解液润湿金属锂与固态电解质界面,软包电池的界面电阻从4366Ω·cm?2降低到了64Ω·cm?2。在0.1C与0.5C倍率下,LTO的放电比容量分别达到107与96 mAh·g?1。同时,Li-S固态软包电池在0.01C及0.02C下,比容量也达到了1100与932 mAh·g?1。  相似文献   
299.
《Analytical letters》2012,45(14):2871-2885
ABSTRACT

The catalytic effect of Se(IV) on the reduction reaction of thionine(TN) by sulfide ion is used for determination of trace amounts of selenium(IV) ion by a kinetic-spectrophotometric method. This new method is simple and highly sensitive. The reaction was monitored spectrophotometrically by measuring the decrease in absorbance of the reaction mixture at 598 nm. The fixed time method was used for the first 45s from initiation of the reaction. Under the optimum conditions, in the concentration range of 2-90 ng ml? of selenium(IV), a quite linear regression equation (r = 0.9984, n = 14) was obtained. The experimental detection limit of the method (S/N = 3) was 1.3 ng ml?. The relative standard deviation of ten replicate measurements is 2.51% for a 40 ng ml? solution of selenium. The proposed method is used to the study of selenium (IV,VI) speciation in water at ng ml? levels. This method was extended for the determination of selenium in real samples.  相似文献   
300.
采用超重力反应结晶法制备了纳米硫化锌粒子,并通过透射电子显微镜(TEM)、X射线粉末衍射仪(XRD)、X射线光电子能谱仪(XPS)、傅里叶红外光谱仪(FTIR)、紫外-可见光分光光度计(UV-Vis)和X射线能谱仪(EDX)对纳米硫化锌的形貌、结构、组成和光谱性能进行了细致分析。结果表明:超重力反应结晶法制备的纳米硫化锌粒子为球形,平均粒径为42 nm;XRD图谱表明纳米硫化锌呈现较好的闪锌矿晶型; XPS能谱表明纳米硫化锌的S(2p)的电子结合能为162.6 eV,Zn的2p3/2,2p1/2的电子结合能分别为1021.4, 1044.6eV。红外光谱研究表明纳米硫化锌在400~4 000cm-1范围内具有良好的红外透过率。紫外-可见光谱研究发现纳米硫化锌在200~340nm的紫外区域有较强的吸收,其禁带宽度为3.57eV。EDX能谱表明该法制备的纳米硫化锌具有较高的纯度。  相似文献   
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