氧化亚铜微米晶的水热合成与生长机理

氧化亚铜是一种重要的P型半导体材料，目前因其独特的可见光催化性能在科研领域引起了广泛的重视。以CuSO4·5H2O为铜源，以α—D-葡萄糖为还原剂，并利用水热还原反应合成出了不同形貌的Cu2O微米晶。利用X射线粉末衍射分析（XRD）、透射电子显微镜（TEM）对合成的样品进行了形貌与结构的表征与分析。结果表明所合成的晶粒尺寸均匀且分散性好。讨论了不同条件下的晶粒生长机理，运用扩散机制与聚集机制解释了不同形貌的成因。     

A GROUP-CONTRIBUTION METHOD INVOLVING SPECIFIC GRAVITY AS A PARAMETER FOR ESTIMATING CRITICAL TEMPERATURES

A new group-contribution method involving specific gravity as a parameter is proposed for predicting criticaltemperature.Being appliable to all kinds of organic compounds,it gives an average percent deviation of 0.88%for 93 compounds and is particularly useful to those substances for which the normal boiling points are stillunknown.     

Micropuncture studies of glucose transport in the dog: mechanism of renal glycosuria

Clearance and micropuncture studies were performed in 23 dogs without glucose loading to examine the tubule mechanism of renal glycosuria. Studies were carried out in three groups of animals before and after 10% extracellular volume expansion, and administration of maleic acid in low dose at 150 mumol/kg and in high dose at 300 mumol/kg. Specific hexokinase methods were used for the determination of glucose in tubule fluid and urine. Under control conditios, glucose reabsorption occurred predominantly in the proximal tubule. In all three groups, proximal tubule reabsorption of both sodium and glucose was inhibited in the second phase, showing a good correlation between the two. In contrast, fractional urinary glucose excretion remained unchanged after volume expansion and low-dose maleic acid, indicating reabsorption of virtually all the increased glucose load at a further "distal" site. On the other hand, significant glycosuria developed after high-dose maleic acid that was a result of reduced glucose reabsorption in the distal nephron, in addition to the proximal effect. It was concluded that distal glucose transport plays a significant role in regulating urinary glucose excretion and maintains renal thershold for glucose,     

Sintering and Electronic Conducting Properties of Lao.7Ca0.3CrO3 Perovskite Synthesized by a Glycine-nitrate Process

La0.7 Ca0.3 CrO3 powder consisting of superfine and uniform particles （ 100-200 nm ） were synthesized using a glycine-nitrate process （ GNP ）. The sintering and electronic conducting properties of La0.7 Ca0.3 CrO3 were invetigated in the sintering temperature range of 1 200-1 450 ℃. The desired morphology of the powder significantly improved its sinterability. La0.7 Ca0.3 CrO3 ceramics sintered at 1 250-1 450 ℃ show high relative densities above 95 % . The ceramics sintered at 1 250-1 400 ℃ have very similar electronic conduct- ing properties, providing electronic conductivities around 55 Ω^-1 cm^-1 at a measuring temperature of 800 ℃ . Further increasing the sintering temperature to 1450 ℃ led to an apparent degradation of electronic conducting properties. This research demonstrates the advantage of the GNP in producing La0.7 Ca0.3 CrO3 with respect to the enhanced sintering properties and superior electronic conducting properties.     

工程机械中液压管路件常见故障原因分析及解决办法

液压管路件作为液压系统的一个重要组成部分,在实际应用中经常会产生诸如渗漏、开裂等故障,就工程机械中常见液压管路件的故障产生原因进行了分析,并提出相应的解决办法。     

基于GIS的供水管网水力计算模型

供水管网是将水从单一或多个水源地输送到用户的管线网络。文中就基于地理信息系统(Geographic InformationSystem,GIS)的供水管网水力计算模型的有关概念、建模方法、理论、实现等问题做了阐述,它将使管网工况分析工作从繁琐耗时变的简单快捷。     

热塑性木塑复合材料性能研究概况

木塑复合材料(WPC)是一种兼有木材和塑料优点的新型材料。本文阐述了国内外WPC的研究现状，重点介绍通过表面改性以及WPC中相容剂、偶联剂的应用，改善WPC的界面相容性与加工性能，以及一些新的研究手段。认为环保型WPC材料的研究应用会大有前途。     

Effect of FTY720 and ICAM-1 mAb mono and combination therapy in cardiac allo-transplantation in rats

Objective To observe the effect of FTY720 and ICAM-1 mAb mono and combination therapy in cardiac silo-transplantation in rats. Methods Rats were randomly assigned to 9 groups, heart allo-transplantation were performed in abdominal site with micro-surgical technique. Recipients with allografts were treated with different doses of FTY720 and(or) ICAM-1 mAb. Graft survival, histopathology andlevel of serum IL-2, IFN-γ, IL-4, IL-10were investigated. Results Low doses of FTY720 (lmg/kg) combined with ICAM-1 mAb achieved synergistic effect in the prolongation of cardiac graft survival, combination index(CD =0.67. Conclusion Concomitant therapy of FTY720 and ICAM-1 mAb achieved a synergistic effect in the prolongation of heart allograft survival in rats.