国产Ru/Al2O3甲烷化催化剂的工业应用与探讨

对国产Ru/Al2O3催化剂研制开发、侧线试验及工业化试用情况进行了探讨,为国产Ru/Al2O3催化剂的推广应用提供了依据.     

苯和甲苯差分吸收光谱方法的实验室测量研究

本文介绍了差分光学吸收光谱法(DOAS)测量大气污染气体浓度的基本原理。DOAS方法就是利用氙灯发出的紫外—可见光，经望远镜准直后再经过一段距离的传输，由望远镜来接收．在传输中，由于各种不同的分子在不同的波段对光有不同的吸收特征，使光谱具有了污染物的特征，再通过与光源发出的光进行比较，反演这些气体在大气中浓度．我们将DOAS方法应用在监测有机物上，在分析光谱的过程中，应用多项式拟合和最小二乘法，从而精确地从测量光谱中来反演出大气中污染气体的浓度．文中用DOAS方法测量了苯和甲苯的样品，并分析了结果，结果和理论吻合．可为环境中有机污染物监测提供可靠的方法。     

Electromagnetic properties of ferroelectric-ferrite ceramic composites

The NiFe₂O₄ and Pb(Zr_0.52Ti_0.48)O₃ ceramic composites are prepared by conventional solid state reaction method. The microstructural and morphological properties of the composites are studied by X-ray diffraction analysis and scanning electron microscopy. Results indicate that the ferrite and piezoelectric phases can co-exist in the composites. The relationship between the dielectric constant and frequency (40 Hz–40 MHz) as well as temperature is also investigated. It is noted that the transition temperature of the composites is about 380 °C. A double electric hysteresis loop is observed in our composites. The magnetic properties are relatively weak according to the magnetic hysteresis loop. With increase in the content of the ferrite phase, the permeability increases. The electromagnetic properties of the as-prepared composites are tunable according to the content of the NiFe₂O₄ phase.     

A novel poly(p-phenylene vinylene)-b-poly(methyl methacrylate) rod-coil diblock copolymer

In this letter, a novel well-defined PPV-b-PMMA rod-coil diblock copolymer, consisting of PPV oligomer as its rod block and PMMA as its coil block, respectively, was prepared via ATRP for the first time. The structure of the copolymer was determined by the measurements of FTIR, ¹H NMR and gel permeation chromatography (GPC). The thermal and optical properties of the copolymers are investigated by DSC, TGA, UV-Vis and photoluminescence (PL) spectra. The results showed that, the introduction of PMMA coil block can improve both the thermal stability and optical properties of PPV oligomer. The highly ordered hexagonally honeycomb-structured film of the copolymer fabricated by vaporizing solvent is also investigated by optical microscope and SEM.     

天然气管道燃压机组的性能试验及见证

结合西气东输管道工程燃气轮机驱动压缩机组设备订货及验收中对性能试验项目的确定、工厂试验及见证过程,介绍了燃压机组性能试验项目所涉及的主要内容、执行标准、需要达到的技术指标,各种性能试验的基本情况,买方参加工厂试验见证中需要重点处理好的问题等。以期为我国其他大型长输天然气管道机组订货及试验见证工作提供借鉴。     

Studies of substrate specificities of lipases from different sources

Although lipases are widely applied in a wide variety of reactions, available information on the factors that are responsible for the substrate specificities of lipases from different sources is scarce. In this paper, nine lipase‐producing microorganism strains were isolated from oil‐containing samples. The properties of these enzymes, including pH optima, temperature optima, thermal stability, and pH stability, vary significantly with the different sources from which these lipases were isolated. The substrate specificities of the nine lipases, including fatty acid and positional specificities, were also studied. The fatty acid specificities of the nine lipases were observably different toward 15 substrates with different carbon chain lengths, different saturation degrees and different side chains. The lipases from S₃ Penicillium citrinum (PCL), MJ₁ Aspergillus niger (ANL), MJ₂ Aspergillus oryzae (AOL), YM Bacillus coughing (BCL), S₉ Geotrichum candidum (GCL), and S₁₁ Candida lypolytica (CLL) showed the strongest specificities to short‐chain esters, and the other lipases showed strong selectivity for medium‐ or long‐chain and branched esters. The positional specificities were examined by analyzing the hydrolytic products of triolein catalyzed by the nine lipases, using TLC. The lipases can be mainly classified into two groups by their specificities for the ester bond at position 2 of triglycerides; one group can selectively hydrolyze the ester bond at position 2 of the triglycerides, the other group cannot. All these nine lipases were divided into four groups by hierarchical clustering analysis on the basis of the results of fatty acid and positional specificities.     

不同品种甜菜类型甜菜光合特性的研究

水文研究了甜菜生育期中不同品种类型甜菜的光合特性，结果表明在生育前期，高糖型品种的叶绿素含量高，而生育中前期以丰产型高，标准型介于二者之间，ＲｕＢＰ竣化酶活性的动态变化亦显这种趋势；在叶丛形成期和块根增长期，丰产型品种光合速度最高，在糖分积累期则以高糖型品种光合速度高；不同品种不同叶位的叶绿素含量与光合速率中呈正相关。     

2—叠氮—1萘醌—5—磺酸生产工艺优化

研究以L-酸为原料,对合成用于制作PS版的2-叠氮1-萘醌-5-磺酸的亚硝化、还原及重氮化三步生产工艺进行最佳配比选优试验。结果表明对L-酸的总收率可达73-75％.获得了较高的收率。     

流延热释电厚膜陶瓷制备单元红外探测器

本文报道采用流延法制备的热释电厚膜陶瓷材料直接装配的单元红外探测器，该方法大大简化了目前探测器的制备工艺，极大地提高了材料的利用率，器件的性能也达到了目前探测器的水平。