有机锗(锗-132)的示差脉冲极谱研究

用示差脉冲极谱法,在pH1.30H_2SO_4和3,4-二羟基苯甲醛(DHB)底液中,获得了有机锗(Ge-132)和无机锗Ge(Ⅳ)二个配位吸附极谱波,波峰分别为E_P2-0.62V和E_pl=-0.47V(υs.AgCI/Ag),Ge-132浓度在2.6×10_(-5)～3.1×10_（-3）mol/L范围内,Ge(Ⅳ)浓度在 3.1×10_（-5）～2.1×10_（-4）mol/L范围内分别与峰电流星线性关系.利用该示差脉冲极谱法可同时测定Ge-132和Ge(Ⅳ),用于有机锗营养口服液中Ge-132和Ge(Ⅳ)的测定结果满意.还探讨了Ge-132极谱波的性质,测定了有关动力学参数.     

铁系元素冠醚配合物的研究——V.三氯化铁与4′-溴苯并-15-冠-5固态配合物的合成和性质

本文报导了三氯化铁(水合物)与4′-溴苯并-15-冠-5(L)固态配合物的合成,对合成的新配合物,进行了元素定量分析及摩尔电导测定,并作了红外光谱、紫外光谱,热重和差热以及X-射线粉末衍射分析的性质表征。从而证明,该配合物中FeCl₃与配体L比为1:1,是溶化剂,含有结晶水的固态配合物。     

环己烷中苯甲酰苯胺的双重荧光--分子内电荷转移的直接光谱证据

自从O Connell等［1］报道苯甲酰苯胺(BA)在EPA玻璃体中异常的长波长荧光发射特性以来, 已有众多学者尝试解释该"异常"荧光的发射态性质［2～12］. Kasha等［2～7］认为长波长荧光是质子转移(PT)和电荷转移(CT)两种激发态发射的叠加, 而Azumaya等［8］则认为发射态只包含分子内扭转电荷转移(TICT)态. 应该指出的是, 在上述研究中, 电荷转移态的指认并无有力的实验事实, 而主要是依据与具有CT双重荧光的对二甲氨基苯甲氰［13,14］的类比. 显然, 有关苯甲酰苯胺的长波长荧光发射态的准确性质仍待实验阐明     

Application of thermo-electrochemistry to simultaneous leaching of sphalerite and MnO2

In order to enhance the electrogenerative leaching rate of sphalerite reasonably, the basic principle of generative process was applied to the simultaneous leaching of sphalerite in the presence of MnO₂. It was confirmed by experimental results that both mental ions and electric energy could be obtained in the simultaneous electrogenerative leaching process. The leaching cell had the open circuit potential about 1.0 V, about 2000 C of electric quantity was obtained, the optimal leaching ratio of Zn²⁺ and Mn²⁺ was 48.5, 39.6% respectively, after electrogenerative leaching for 11 h.     

Electrothermal atomic absorption spectrometric determination of ultra-trace amounts of tin by in situ preconcentration in a graphite tube using flow injection hydride generation with on-line ion-exchange separation

A method was developed for the ultra-trace determination of tin by in situ preconcentration in a graphite tube using a flow injection hydride generation technique with on-line ion-exchange separation. The sample was prepared in 2M hydrochloric acid before being passed through an incorporated micro-column packed with a strongly basic anion-exchanger D-201. The tin was retained as its chlorostannate complex and subsequently eluted by de-ionized water into the hydride generation system. The hydride and hydrogen gases evolved were separated from the liquid phase in a gas-liquid separator and transferred into a palladium-coated graphite tube pre-heated to 300 degrees C to collect the analyte, which was later atomized at 2300 degrees C. With the reported system, tin was determined at a sampling frequency of 30/hr with a detection limit (3sigma) of 0.01 mug/l. using 10.7 ml sample. The precision was 1.5% RSD at the 0.5 mug/l. level. The proposed method was applied to the determination of tin in tap water, hair, serum samples and geological reference samples.     

Capillary Electrophoresis of the Active Ingredients of Dioscorea bulbifera L. and its Medicinal Preparations

A method based on capillary electrophoresis with electrochemical detection has been developed for the separation and determination of epicatechin, isovanillic acid, vanillic acid and myricetin in Dioscorea bulbifera L. and its medicinal preparations. The effects of working electrode potential, pH and concentration of running buffer, separation voltage and injection time were investigated. Under optimum conditions, the analytes could be separated in a 40 mmol L^?1 borate buffer (pH 8.7) within 15 min. A 300 μm diameter carbon disk electrode has a good response at + 0.95 V (vs. SCE) for all analytes. The response was linear over three orders of magnitude with detection limits (S/N = 3) ranging from 3.0 × 10^?8 g mL^?1 to 1.0 × 10^?7 g mL^?1. The method has been successfully applied to the analysis of real samples.     

A New Biochemical Way for Conversion of CO2 to Methanol via Dehydrogenases Encapsulated in SiO2 Matrix

CO2 is converted to nethanol through an enzymatic approach using formate dehydrogenase(FateDH),formaldehyde dehydrogenase(FaldDH）and alcohol dehydrogenase(ADH)coencapsulated in silica gel prepared by modified sol-gel process as catalysts,TEOS as precursor,NADH as an electron donor.The highest yield of methanol was up to 92.1% under 37℃,pH7.0 and 0.3Mpa.     

Novel carboxylated oligothiophenes as sensitizers in photoelectric conversion systems

Novel carboxylated oligothiophenes with different thiophene units were designed and synthesized as photosensitizers in dye-sensitized solar cells (DSSCs) for efficient opto-electric materials. The introduction of -COOH into thiophene molecules can lead to a red shift of UV-visible absorption, increase light-harvesting efficiency, and enhance photoinduced charge transport by forming efficient covalent bonds to the substrate surface. A red shift of the absorption spectrum of oligothiophene is also achieved by the increase in the number of thiophene units. The DSSCs based on the oligomers have excellent photovoltaic performances. Under 100 mW cm(-2) irradiation a short-circuit current of 10.57 mA cm(-2) and an overall energy conversion efficiency of 3.36 % is achieved when pentathiophene dicarboxylated acid was used as a sensitizer. The incident photo-to-current conversion efficiency (IPCE) has a maximum as high as 80 %. In addition, photovoltage and photocurrent transients show that slow charge recombination in DSSCs is important for efficient charge separation and excellent photoelectric conversion properties of the oligomers. These initial and promising results suggest that carboxylated oligothiophenes are efficient photosensitizers.     

Effect of diluting agent on sensitivity in capillary electrophoresis with amperometric detection

Besides the running buffer, pH of buffer, separation voltage and sampling time, the diluting agent was studied in this paper as one of the important factors influencing the sensitivity in capillary electrophoresis (CE) with amperometric detection (AD) when electrokinectic sampling was used. Clonidine hydrochloride, hydrochlorothiazide and rutin, which are positively charged, neutral and negatively charged, respectively, in aqueous solutions, could be perfectly separated by CE with 25 mmol x L(-1) Na(2)B(4)O(7) - 50 mmol x L(-1) NaH(2)PO(4) as running buffer and detected by measuring their current responses with AD. Before CE running, some kinds of diluents including water, methanol, formamide, running buffer, hydrochloric acid and sodium hydroxide were, respectively, applied to dilute the stock solutions of above three analytes and their effects on the sensitivity of CE-AD were investigated. The results showed that for electrokinetic injection, the current responses of these three analytes were greatly affected in different ways when different diluting agents were used. This method was applied to simultaneously determine the active ingredients in one Chinese compound hypotensor named Zhen Ju Jiang Ya Pian, in which the contents of clonidine hydrochloride, hydrochlorothiazide and rutin is very different as 0.03 mg : 5 mg : 20 mg per tablet, and satisfactory results were obtained by adjusting their sensitivity by selecting the suitable diluting agent.     

光学活性含硅氨基酸的合成

光学纯的硅取代氨基酸是一类非天然的手性氨基酸合成子，在药物，植物保护 剂和精细化学品的合成具有极为广阔的应用前景，其合成方法包括化学不对称合成 及化学合成外消旋体－生物学拆分两种，综述了该方面的研究进展。