硫脲法提金浸取溶液中硫脲与Fe(Ⅱ)连续快速测定法

本文研究硫脲法提金浸取液中连续测定硫脲（TU）与Fe（Ⅱ）离子的适宜浓度范围、酸度影响及指示利使用量与校正等工作条件，建立了简便、快速、准确的连续测定方法，3～4min完成两个元素次的分析，相对标准偏差分虽低于0．1％与0．3％     

Electrochemical oxidation of ammonia borane on gold electrode

The electrochemical behavior of ammonia borane on an Au electrode in the absence and presence of thiourea (TU) was detailedly investigated by cyclic voltammetry (CV). In the absence of TU, the feature of the CV is fairly complex affected by both the hydrolysis and the direct oxidation of ammonia borane. With the aid of TU, known as an effective inhibitor for the formation and recombination of adsorbed H radicals associated with ammonia borane hydrolysis, the two peaks at 414 and 0 mV may be attributed to direct electrooxidation of ammonia borane at Au electrode. These two peaks are particularly important for the practical direct ammonia borane fuel cell (DABFC). Additionally, the Tafel slope (b = 0.15 V) and charge transfer coefficient (α = 0.604) were obtained as well as number of electrons exchanged (n = 2) in the ammonia borane oxidation at the Au/solution interface in the presence of TU.     

Developments in Gold Leaching: A Literature Survey

The gold industry has seen intense activity in the areas of exploration and metallurgy'in recent years. Many developments have taken piace through which ore bodies that were once considered uneconomical to exploit are becoming economical grade. Even the traditional cyanidation process has been modified during the course of time to make it more economical and efficient. Developments such as heap leaching, in-situ leaching, carbon-in-pulp (CIP), carbon-in-leach (CIL) resin-in-pulp (RIP), and pretreatment of refractory ores have already made an impact on gold industries. Research and development work is also being carried out on less toxic, more efficient lixiviants which may eventually replace the toxic cyanide, solving the disposal problem currently facing the industry. This paper aims at summarizing the developments in the extraction of gold using conventional, as well as unconventional, lixiviants. Some developments in the area of gold recovery from pregnant solutions have also been briefly discussed.     

利用电位传感器对H_2O_2检测的一种新方法

本文着重介绍使用纳米银固定过氧化物酶对过氧化氢进行检测的一种新方法。通过在银电极上自组装硫脲,再通过Ag-S共价键将纳米银自组装到对硫脲修饰的银电极上,最后通过静电吸附作用将过氧化氢酶固定到纳米银上从而制备得到电位传感器。根据酶促反应的专一性测定反应前后电极电位的变化证明,该电位传感器对过氧化氢响应的灵敏度高,其检测范围为10-7~10-2mol/L,检测下限为10-7。此外,本文还对对过氧化氢酶/纳米银/硫脲/银电极体系进行电化学表征,其结果验证了该传感器的成功制备。     

Electrochemical destruction of thiourea dioxide in an undivided parallel plate electrodes batch reactor

The paper presents the results of a study on the electrochemical destruction of pollutants present in a spent reducing bath of a textile factory. The investigations comprised the electro-oxidation of thiourea dioxide (TUD) (the main component of the reducing bath), sulphites and urea, which are formed during oxidation of TUD. The study performed in an undivided cell parallel plate electrodes reactor, using eight different anode materials under various hydrodynamic conditions, proved that electro-oxidation can be successfully applied for treatment of spent reducing baths. The best results of TUD and SO₃²⁻ electro-oxidation were obtained with a Ti/Pt electrode, which showed electrocatalytic effect for both the compounds, indicating a possibility of their direct electro-oxidation on the anode. Destruction of TUD and SO₃²⁻ proceeded also via indirect electro-oxidation, mediated by chlorine evolved on the anode. The process kinetics was mass transport controlled till Re=5000. No electrocatalytic effects were observed for urea with any of the tested anode materials. The elimination of urea resulted to proceed only by indirect electro-oxidation, mediated by chlorine. For elimination of urea a Ti/Pt–Ir electrode proved to be the best anode, probably due to its high efficiency in electro-oxidation of chlorides into chlorine.     

硫脲对氮肥增产效益的影响

在本试验条件下,硫脲对氮肥有明显的增产效益,可做为氮肥的增效剂。在水田中硫脲最佳施用量27.7kghm-2,1kg硫脲可增加水稻产量25.7kg,可使水稻增产9.0%,与氮肥的比例0.2∶1,可做为水稻生长发育及产量形成的安全用量。在玉米田中硫脲最佳施用量39.9kghm-2,1kg硫脲可提高玉米产量22.2kg,增产幅度10.2%,与氮肥的比例0.19∶1,可做为玉米生长发育及产量形成的安全用量。     

N-(Diethylaminothiocarbonyl)ferrocenecarbimidoyl chloride, a versatile reagent

N, N-Diethiyl-N′-ferrocenoylthiourea reacts with thiophosgene to form N- (diethylaminothiocarbonyl) ferrocenecarbimidoyl chloride, which yields N-(diethylaminothiocarbonyl)-N′-(aryl/alkyl)ferrocenecarbamidines when reacted with primary amines via nucleophilic substitution. The reaction of bis(N,N-diethyl-N′-ferrocenoylthioureato)nickel(II) with phosgene gives 2,6-bis(diethylamino)-4-ferrocenium-1,3,5-thiadiazinium-tetrachloroniccolat(II). The X-ray structure determination of N-(diethylaminothiocarbonyl)benzimidoyl chloride is presented.     

喹啉与硫脲在含饱和CO_2气井采出水中的协同效应

加注缓蚀剂抑制CO_2腐蚀是天然气开发过程中的常见工艺,利用缓蚀协同效应可以有效降低缓蚀剂的用量,减少对环境的污染,提高经济效益。为此,采用静态失重法、电化学极化曲线、阻抗谱(EIS)、扫描电子显微镜(SEM)及电子能谱等实验分析方法,研究了在含饱和CO_2模拟气井采出水腐蚀体系中,喹啉季铵盐(QN)与硫脲(TU)对N80碳钢的缓蚀协同效应。结果表明:①喹啉季铵盐和硫脲均能有效抑制N80碳钢的腐蚀;②喹啉季铵盐是一种以抑制阴极型为主的缓蚀剂;③硫脲对N80碳钢的阴极和阳极均具有较强的抑制作用,是一种混合型缓蚀剂;④当喹啉季铵盐与硫脲复配使用时,在较低的使用浓度下,喹啉季铵盐缓蚀剂与硫脲具有较好的缓蚀协同效应,当3 mg/L喹啉季铵盐缓蚀剂与7 mg/L硫脲复配使用时,缓蚀效果最佳,缓蚀率可达到93.59%;⑤喹啉季铵盐与硫脲相互作用在N80碳钢表面能形成稳定的吸附膜,较大程度地抑制N80碳钢的腐蚀过程。进而还对喹啉季铵盐与硫脲之间的协同作用机理进行了探讨。     

Spectral response of CdS/CdTe solar cells obtained with different S/Cd ratios for the CdS chemical bath

In this work, the influence of the variation of chemical bath thiourea concentration in the solution for depositing CdS layers upon the spectral response of chemical bath deposition (CBD)-CdS/CdTe solar cells is studied. Although changes in the short and long wavelength range for the spectral response of the cells were observed in dependence of the thiourea concentration, no significant changes were observed in the diffusion length of minority carriers in the CdTe layer, as determined from the constant photocurrent method, when the thiourea concentration is increased in the CdS deposition solution.     

Extraction of Palladium(II) from Nitric Acid Solutions with 1‐Benzoyl‐3‐[6‐(3‐benzoyl‐thioureido)‐hexyl]‐thiourea

The extraction of palladium (II) from HNO₃ solutions with 1‐Benzoyl‐3‐[6‐(3‐benzoyl‐thioureido)‐hexyl]‐thiourea (Ia) and several monodentate thiourea derivatives in 1,2‐dichloroethane has been studied. The effect of HNO₃ concentration in the aqueous phase and that of the extractant in the organic phase on the Pd(II) extraction is considered. The stoichiometry of the extracted complexes has been determined. The increasing number of thioamide groups in the molecule of Ia increases its extraction efficiency towards Pd(II). The potentialities of a polymeric resin impregnated with compound Ia for selective extraction of Pd(II) from nitric acid solutions are demonstrated.