热处理工艺对高温合金GH2132力学性能的影响

研究了时效处理对高温合金GH2132力学性能的影响,并分析了合金组织与性能变化的原因。结果表明,由于时效过程中析出物γ'的沉淀强化作用,合金强度得以提高,塑性下降。982 ℃固溶+718 ℃时效能使合金获得较好的综合力学性能。     

基于BIOCHLOR模型的敏感度分析

BIOCHLOR是一种用于模拟地下水溶解质运移的模型,它被广泛用于一维平流、三维弥散、线性吸附,及还原脱氯的生物转化过程分析。选取该模型7个参数模块中的平流参数模块、扩散参数模块、吸附参数模块、生物降解参数模块（一阶序列降解系数）4个参数,在其他参数不变的情况下,依次改变各个参数的值并运行模型,获取并比较模拟预测值,即污染羽内溶解质浓度。并分别绘出模拟预测值与各个分析参数的变化曲线,分析模型对各个参数的响应程度,从而为处理不确定因素（如误差等）提供依据。     

Measurement of the maximum charge and discharge powers of a nickel/metal hydride battery for hybrid electric vehicles

The determination of the maximum acceptable charge power and power output is of special significance in the development of hybrid electric vehicles. Theoretically, the maximum acceptable charge power and the power output can be defined as those relating to the maximum current levels before the occurrence of any side reaction. A new method has been developed to measure these maximum currents for nickel/metal hydride batteries used in hybrid electric vehicles. The method involves three step: (i) measurement of the transient voltage vs. current relation during charge or discharge by a sequence of pulse currents; (ii) calculation of the overall battery internal impedance at different times and current magnitudes; (iii) determination of the maximum current from the minimum point of the internal impedance. This method is based on the principle that, with increasing current level, mass transport becomes the rate-limiting step. Any extra increase in current can only cause the occurrence of a side reaction which will result in an increase in the battery internal impedance. The maximum current can thus be determined by the minimum internal impedance from a plot of this parameter against current. Experimental results show that the maximum current strongly depends on battery state-of-charge and also, battery structure. Increase in the surface area of the battery plates is an efficient way to increase the charge-acceptance and power output of the battery, and also to reduce the internal impedance.     

Acidified glycerol pretreatment for enhanced ethanol production from rice straw

Rice straw was pretreated using an industrial grade glycerol for ethanol production. The pretreatment was conducted at 130–210 °C for 1–24 h with 5% solid loading. The glucan content in the regenerated rice straw increased with increasing pretreatment temperature and time. The production of fermentable sugars initially increased as the pretreatment temperature and reaction time increased, but then decreased somewhat at the higher temperatures and with longer reaction duration. The highest amount of reducing sugar produced by the enzymatic hydrolysis was achieved at 190 °C for 10 h with 5% solid loading, optimal condition for the glycerol pretreatment of rice straw. Furthermore, it was observed that glycerol pretreatment with the addition of HCl improved the digestibility of fermentable sugars by 4–5 times that of untreated samples. Fermentation of hydrolysates resulted in an ethanol yield of 0.44 g/g sugar, corresponding to a theoretical yield of 84.3%. It was concluded that acidified glycerol is one of the good candidates of the organic solvent for the pretreatment of lignocellulosic biomass.     

A new route to prepare magnesium oxide whisker

This paper presents a new route to prepare magnesium oxide whisker. The preparation process consists of the synthesis of a precursor called magnesium oxysulfate (MOS) whisker, followed by the heat treatment of the synthesized whisker. The precursor whisker was prepared by hydrothermal synthesis reaction between MgSO₄ solution and MgO or Mg(OH)₂ preferably at 130–170 °C and at 3–8 atm. MgO whisker can then be easily obtained by simply heating the MOS whisker at temperatures higher than 900 °C. These two whiskers were characterized by X-ray diffraction (XRD) and scanning electronic microscopy (SEM).     

Preparation,characterization and sintering behavior of spherical iron oxide doped alumina particles

A continuous procedure for the preparation of homogeneous iron oxide doped alumina spherical particles is described. The method is based on the hydrolysis with ammonium hydroxide of liquid aerosols formed by spraying iron and aluminum nitrate aqueous solutions. The powder consisted of, according to X-ray diffraction and infrared spectroscopy, boehmite of low crystallinity. Heating of the as-prepared boehmite powders produced a series of transition aluminas that finally transform into the thermodynamically stable phase (α-Al₂O₃). It has been found that the temperature of such a transformation is lowered as iron oxide content in samples increases. Densification studies have shown that the presence of iron oxide has a beneficial effect on the sintering behavior of compacted powders. Thus, undoped samples did not achieve full density even after heating for 2 h at temperatures as high as 1500°C. In contrast, with 4 wt% iron oxide content full density microstructures, consisting of uniform equiaxed grains, were achieved after heating for 2 h at 1350°C.     

Anion exchange nature of emeraldine base (EB) polyaniline (PAn) and a revisit of the EB formula

The anion exchange nature of emeraldine base (EB), which is totally unexpected from the conventional EB formula, is reported here. Based on the ion exchange experiments of this work as well as published ESCA data, EB is suggested to be a mixture of undoped emeraldine with doped emeraldine, in which the counterion is hydroxide ion. This is in contrast to the commonly held concept that identifies EB as undoped emeraldine. Accordingly, a modified EB formula is proposed.     

氢化物原子荧光法测定饮料中总砷含量的不确定度评定

采用现代统计学方法对氢化物原子荧光光度法测定饮料中总砷含量的不确定度进行评估。通过建立数学模型,分析整个过程的不确定度来源,推导计算、合成扩展不确定度。结果表明,当饮料中总砷含量在定量限附近时,扩展不确定度为0.00082mg/L(k=2)。可如实反映测量的置信度和准确性,在实际的工作中具有较强的实用价值。     

Rational choice of bioactive conformations through use of conformation analysis and 3-way partial least squares modeling

Comparative molecular field analysis (CoMFA) has become widely used in three-dimensional (3D) QSAR studies. Although CoMFA has been of general use, there are some critical problems in the proper application. A major problem of CoMFA, including most other 3D QSAR methodologies, is that the results are dependent on the chosen bioactive conformations and the corresponding alignment rules of molecules. Recently, we have proposed a novel method with a 3-way PLS formulation for solving the conformation/alignment problem in 3D QSAR studies [K. Hasegawa, M. Arakawa, K. Funatsu, Chemom. Intell. Lab. Syst., 47 (1999) 33–40]. The purpose of the present study is to demonstrate the general utility of our approach by applying to a real CoMFA data set. The data set of Protein-Tyrosine Kinase (PTK) inhibitors was used as a test sample. The possible 3D conformations of all molecules were generated by conformational analysis and they were characterized by field variables of CoMFA. To each unique conformation of the most active compound, one sample-variable sheet comprising of the most similar conformations was defined. The 3-way arrays for 3-way PLS analysis were created by collecting all sample-variable sheets. From the regression coefficient values of the 3-way PLS model, conformations largely contributing to inhibitory activity were selected and the resulting final CoMFA model could give the reasonable 3D coefficient contour maps.     

Pilgrimage in graeco-roman and early christian antiquity seeing the gods Elsner,JaŚ and Rutherford,Ian (eds.)

ABSTRACT

This study is an ethnographic and conceptual analysis of religious objects, their uses, and mediation of authority within the Universal Church of the Kingdom of God (Universal Church) in Brazil. Drawing on scholarship within media studies, religion and media, and material religion, I distinguish between artifacts used to cement implicit contracts between Universal Church followers and their church community, which I call contractual media, or swag, and those that followers bring to meetings to be blessed and then take home to mediate both good and evil forces in family, work, and social life—these I call portable media. While portable object media are seen by their owners as powerful tools, contractual media, on the other hand, create implicit power relations that keep followers tied to the institutional church in a reciprocal exchange predicated upon expected prosperity as evidence of faithful attendance, fidelity, and personal sacrifice. The physical exchange of material goods in religious spaces constitutes a perpetuation rather than a disruption of institutional religious authority. As infrastructure, contractual object media establish and maintain conditions for otherwise mundane materials to mediate power on a daily basis. Through attention toward portable and contract object media, as part of what I am calling material microstructure, we can further complicate religious authority as it is mediated through objects, not just in one-way flows but as dynamic exchanges and trade-offs between personal empowerment and institutional control.