三元液体混合物热导率的测量及数据关联

在恒温条件下,使用由程序控制的量热器测量液体混合物的热导率．这种方法不仅可测低热导率的有机溶液,而且可测高热导率的水溶液．实验中测定了５个三元体系,同时提出了一个计算液体混合物热导率的方法     

Electrical conductivity of melts: implications for conductivity anomalies in the Earth's mantle

Magmatic liquids, including silicate and carbonate melts, are principal agents of mass and heat transfer in the Earth and terrestrial planets, and they play a crucial role in various geodynamic processes and in Earth''s evolution. Electrical conductivity data of these melts elucidate the cause of electrical anomalies in Earth''s interior and shed light on the melt structure. With the improvement in high-pressure experimental techniques and theoretical simulations, major progress has been made on this front in the past several decades. This review aims to summarize recent advances in experimental and theoretical studies on the electrical conductivity of silicate and carbonate melts of different compositions and volatile contents under high temperature and pressure. The electrical conductivity of silicate melts depends strongly on temperature, pressure, water content and the ratio of non-bridging oxygens to tetrahedral cations (NBO/T). By contrast, the electrical conductivity of carbonate melts exhibits a weak dependence on temperature and pressure due to their fully depolymerized structure. The electrical conductivity of carbonate melts is higher than that of silicate melts by at least two orders of magnitude. Water can increase electrical conductivity significantly and reduce the activation energy of silicate melts. Conversely, this effect is weak for carbonate melts. In addition, the replacement of alkali-earth elements (Ca²⁺ or Mg²⁺) with alkali elements causes a significant decrease in the electrical conductivity of carbonate melts. A distinct compensation trend is revealed for the electrical conductivity of silicate and carbonate melts under anhydrous and hydrous conditions. Several important applications of laboratory-based melt conductivity are introduced in order to understand the origin of high-conductivity anomalies in the Earth''s mantle. Perspectives for future studies are also provided.     

Applications of water sensitivity in situ remediation at saltwater-freshwater interface

Based on the laboratory experiments with the saltwater and freshwater replacing each other in the level sand column, taking the kaolin, illite, smectite, bivalent hydrargyrum ion (Hg²⁺) and phenol (C₆H₅OH) as examples, this paper studies the applications of water sensitivity in situ remediation in saltwater-freshwater transition zone. In the water sensitivity process, the release and migration of clay minerals can make the hydraulic conductivity (HC) decrease and pollutants remove. A new type of low penetrable or impenetrable purdah can be built by adding clay minerals into the sand media to replace the underground concrete impenetrable wall to prevent seawater intrusion, and a number of the heavy metals and organic pollutants in the sand media can be removed by in situ remediation. The results show that the content of kaolin and illite influences the water sensitivity process slightly, and HC of the sand columns descends from 0.011 cm/s to 0.001 4 cm/s and 0.001 2 cm/s respectively even if the content reaches 12% (weight ratio, sic passim). However, for smectite, HC descends sharply to about 1×10⁻⁸ cm/s when its content reaches 4%, and no water can flow through the sand columns beyond 5%. The particle release and migration processes can remove the Hg²⁺ and C₆H₅OH out of the sand columns efficiently, the removing rate of Hg²⁺ is 31.68% when the freshwater and saltwater are filtered through the sand columns polluted by Hg²⁺, while it is 67.55% when the water sensitivity occurs. With the same method, the removing rates of C₆H₅OH under the fluid flow and water sensitivity are 55.71% and 43.43% respectively. Supported by National Natural Science Foundation of China (No. 40572142). HAN Zhiyong, born in 1976, male, Dr, associate Prof.     

电导法测定HCl在水和甘露醇混合溶剂中的活度系数

应用电导法测定了HCl在水和甘露醇混合溶剂中的活度系数,讨论了电解质溶液活度系数与温度和浓度的关系.     

Sap flow response of Eucaylyptus (Eucalyptus urophylla) to environmental stress in South China

Sap flow and environmental conditions were monitored at two Eucalyptus (Eucalyptus urophylla S.T.Blake)plantations at Hetou and Jijia, located in Leizhou, Zhanjiang, Guangdong Province. It was found that daily sap flux density (SFD) of Eucalyptus was closely related to daily atmospheric vapor pressure deficit (VPD) (R2=0.76, P=0.01 at Hetou and R2=0.7021, P=0.01 at Jijia) at both sites. No significant relationship existed between daily SFD and mean daily air temperature at both sites. Daily SFD varied with wind speed Y=-17585X3 15147X2-1250.7X 2278.4 (R2=0.68; P=0.01) at Hetou and Y=-101.67X3-1.65X2-376.4X 1914.8 (R2=0.40, P=0.05) at Jijia, where Ywas daily SFD, Xwas daily wind speed.Experimental observations yielded the following data: (1) the critical lower and upper daily VPD threshold were 0 and 2 kPa,slightly lower under high relative humidity (＞80%) compared with those at the Jijia site; (3) The upper and lower threshold     

肉品冷冻升华干燥层的热质传输特性

建立了冷冻升华干燥过程中物料干燥层有效导热系数和有效质扩散系数的数学模型 ,并应用实验测得的脱水量计算出干燥层的有效导热系数和有效质扩散系数 .据此数据计算出的干燥过程中物料内部的温度分布与实验测试结果基本吻合     

Excel2000软件在处理乙酸乙酯皂化反应速率常数中的应用

Microsoft Office软件中Excel2000具有良好的人机界面,使用灵活方便、快捷,具有较高的计算准确度及绘图精度,以Excel2000为工具对测定乙酸乙酯皂化反应的速率常数数据进行后续处理,结果令人满意.     

常用冷库结构性能分析

针对常用的冷库结构,从维护结构的传热量、蒸汽渗透率以及冷库投资运行费用等方面进行分析比较,从而找出低造价、高性能、低能耗的库体结构。     

A novel fabrication of meso-porous silica film by sol-gol of TEOS

INDRODUCTIONMeso-poroussilicafilmswithanexcellentheat-insulatingpropertyandtherelativelylowdielectricvalueplayparticularlyimportantroleinelectronicandmagneticdevices(Moonetal.,1997),etc.;thosewithporesizesof5nmto50nmarealsoofinterestforapplicationsinphotonics,optoelec-tronics,lightweightstructuralmaterialthermalin-sulation,opticalcoating(Moonetal.,1997;HusingandSchulert,1998;Davis,2002).Theirspecialnetworkstructureisusedinsounddetector(HusingandSchubert,1998);theirexcellentinsulatingpro…     

聚苯胺的电化学合成及性能测试

在硫酸介质中以苯胺为单体,用恒电压电化学方法合成了聚苯胺（PANI）,并对其进行了形貌、红外光谱、紫外-可见光谱、电导率和气敏性能的测定.结果表明：合成的样品为一维纳米线结构,表现出了聚苯胺的光谱特性,电导率为0.53 S/cm,对室内甲醛、苯、甲苯和氨气等表现出了较好的气敏性能,合成方法对电化学方法合成聚苯胺的工业化具有借鉴作用.