Indolepyruvate ferredoxin oxidoreductase: An oxygen-sensitive iron-sulfur enzyme from the hyperthermophilic archaeon Thermococcus profundus

Thermococcus profundus is a strictly anaerobic sulfur-dependent archaeon that grows optimally at 80°C by peptide fermentation. Indolepyruvate ferredoxin oxidoreductase (IOR), an enzyme involved in the peptide fermentation pathway, was purified to homogeneity from the archaeon under strictly anaerobic conditions. The maximal activity was?obtained above the boiling temperature of water (105°C), with a half-life of 62min at 100°C and 20min at 105°C. IOR was oxygen-sensitive with a half-life of 7h at 25°C under aerobic conditions. The specific activity of T.?profundus IOR was found to be dependent on the number of [4Fe-4S] clusters in the enzyme.     

新型四苯基卟啉衍生物及其锌(Ⅱ)配合物的合成与性质研究

以四苯基卟啉(TPP)为原料,经过硝化、还原、酰胺化等反应合成了一种新型四苯基卟啉衍生物及其锌(Ⅱ)配合物,通过FAB-MS、IR、1 H-NMR和元素分析等方法鉴定了目标产物的结构,并对其发光性质进行了研究。结果表明,四苯基卟啉衍生物及其锌(Ⅱ)配合物的紫外-可见光谱和荧光光谱均发生了明显红移。     

木聚糖酶纯化的研究进展

色谱技术由于具有高的分辨率一直以来都是木聚糖酶最重要的纯化技术.然而它耗时、低回收率和高花费的特点促使人们不断探索新的方法以满足工业应用上对木聚糖酶的需要.本文综述了木聚糖酶传统的纯化策略及最近其它较有发展前景的纯化技术,尤其是ATPS和CBM在纯化上的应用潜力.     

New developments in polymer science and technology using combination of ionic liquids and microwave irradiation

The purpose of this review is to provide appropriate details concerning the application of ionic liquids (IL)s associated with microwave-assisted polymer chemistry. From the viewpoint of microwave chemistry, one of the key significant advantages of ILs is their high polarity, which is variable, depending on the cation and anion and therefore can effectively be tuned to a particular application. Hence, these liquids offer a great potential for the innovative application of microwaves for organic synthesis as well as for polymer science. ILs efficiently absorb microwave energy through an ionic conduction mechanism, and thus are employed as solvents and co-solvents, leading to a very high heating rate and a significantly shortened reaction time. Since an IL-based and microwave-accelerated procedure is efficient and environmentally benign, we believe that this method may have some potential applications in the synthesis of a wide variety of vinyl and non-vinyl polymers. This review describes application of combination of ILs with microwave irradiation as a modern tool for the addition and step-growth polymerization as well as modification of polymers and it was compared with ILs alone and conventional polymerization method.     

Polymer membranes for high temperature proton exchange membrane fuel cell: Recent advances and challenges

Proton-exchange membrane fuel cells (PEMFCs) are considered to be a promising technology for efficient power generation in the 21st century. Currently, high temperature proton exchange membrane fuel cells (HT-PEMFC) offer several advantages, such as high proton conductivity, low permeability to fuel, low electro-osmotic drag coefficient, good chemical/thermal stability, good mechanical properties and low cost. Owing to the aforementioned features, high temperature proton exchange membrane fuel cells have been utilized more widely compared to low temperature proton exchange membrane fuel cells, which contain certain limitations, such as carbon monoxide poisoning, heat management, water leaching, etc. This review examines the inspiration for HT-PEMFC development, the technological constraints, and recent advances. Various classes of polymers, such as sulfonated hydrocarbon polymers, acid-base polymers and blend polymers, have been analyzed to fulfill the key requirements of high temperature operation of proton exchange membrane fuel cells (PEMFC). The effect of inorganic additives on the performance of HT-PEMFC has been scrutinized. A detailed discussion of the synthesis of polymer, membrane fabrication and physicochemical characterizations is provided. The proton conductivity and cell performance of the polymeric membranes can be improved by high temperature treatment. The mechanical and water retention properties have shown significant improvement., However, there is scope for further research from the perspective of achieving improvements in certain areas, such as optimizing the thermal and chemical stability of the polymer, acid management, and the integral interface between the electrode and membrane.     

四-（4-苯基）卟啉分光光度法测食品中铅

采用分光光度法,研究了铅与meso-四(4-苯基)卟啉(TPP)的配合反应,探讨了加热时间、NaOH用量、Tween-80用量等对配合物的生成及稳定性的影响。确定了反应的最佳条件为:1.4 mL NaOH,1.4 mL TPP,0.8 mL Tween-80,沸水浴中加热20 min。络合物的最大吸收波长为468 nm,当铅含量在0～0.5μg/mL范围时,测得的曲线呈线性关系,服从比尔定律,表观摩尔吸光系数为1.71×105 L/(mol.cm),重复性较好。将该方法用于测定儿童食品中铅的含量,取得了较满意的效果。     

Mathematical models for optimization of block diagrams and controller adjustment

The building of easily controlled production subassemblies is one of the urgent problems encountered in the development of heating systems for modern power plants. This paper describes a process by which a control system is built with subassemblies for the feed of basic condensate and steam to a deaerator by combined efforts of engineering and automation experts. __________ Translated from élektricheskie Stantsii, No. 8, August 2007, pp. 18–23.     

Monitoring peroxide value in fatliquor manufacture by Fourier transform infrared spectroscopy

A Fourier transform infrared (FTIR) spectrometer equipped with an attenuated total reflectance (ATR) sample handling accessory was used to rapidly monitor the peroxide value (PV) of oils undergoing catalytic oxidation to produce sulfonated fatliquors used in the leather industry. PV quantitation was based on the stoichiometric reaction of triphenylphosphosphine (TPP) with hydroperoxides to produce triphenylphosphine oxide (TPPO). By using a germanium ATR accessory that has a very short effective pathlength, the spectral contributions of the base oil could be subtracted out, eliminating any oil-dependent intereferences as well as providing a facile means of observing the spectral changes associated with the TPP/TPPO reaction. A calibration was devised by adding a constant amount of TPP-saturated chloroform to oils containing varying amounts of tert-butyl hydroperoxide (TBHP) to produce TPPO that had a measurable band at 1118 cm⁻¹. this band was linearly related to TBHP concentration and the calibration devised had an SD of ∼3.4 PV over the range of 0–250 PV. The ATR-PV method was standardized and the spectrometer programmed using Visual Basic to automate the analysis. the automated FTIR-ATR method was found to be a convenient means of tracking PV of oils undergoing oxidation, and the results correlated well with the PV values obtained using the AOAC iodometric method (r=0.94). The FTIR-ATR PV methodology provides a simple means of monitoring the PV of oils undergoing rapid oxidation and could serve as a quality-control tool in the production of sulfonated oils for the leather industry.     

纳米磷酸酯与环氧树脂在聚丙烯中阻燃效果的研究

制备了磷酸三苯酯/蒙脱土复合阻燃剂,研究了环氧树脂作为共阻燃剂时的X射线衍射,表明把磷酸三苯酯（TPP）插入蒙脱土层间形成了TPP纳米复合材料,热重分析说明了纳米TPP的挥发温度比TPP的高.加入聚丙烯中,发现极限氧指数有比较大的提高.研究了环氧树脂作为共阻燃剂时的极限氧指数,讨论了添加剂对力学性能的影响.     

二维和三维微/纳高效精密加工中的纳立体刻印工艺

双光子聚合（TPP）是通过光敏剂中的非线性双光子吸收过程所引发的,其作为一种新工艺,自问世以来,已在二维和三维加工聚合应用领域中得到广泛研究．对于二维纳米图案的加工,纳复制工艺已经演变为体素模板扫描方法．该方法用黑白双色2块图作为设计图案,并转排成体素模板以控制聚焦激光素的开关．复杂的三维微结构也可以采用多重断面分层叠加的方法进行加工,各断面的扫描数据从三维CAD数据中得到．在聚合反应后,没有固化的液态树脂,其采用在树脂上浇注类似于酒精之类溶剂的方法去除,从而显露出聚合的微结构．在前期的工作中,已经成功地加工出了高空间分辨力的三维微光学器件,分辨力约为100nm．微机械器件和光子晶体等的近期研究工作提高了其TPP的效率和精度．介绍了近来开发的基于TPP的一些微加工工艺．