Vibrating sample experiments as a probe of anisotropic torque in YBCO single crystals

Ultrasonic investigations of high-T_c superconductors have been quite successful in determining the magnetic field and temperature dependence of the interaction between magnetic vortices and defect structures in the superconducting state. Recent advances in ultrasonic techniques, allowing the separation of effects due to coupling of the vortex ensemble to modulations of the superconducting current density from those due to pinning, show evidence of reentrant softening of the vortex ensemble as precursor to reentrant melting. It is demonstrated how a related experimental setup can be used to study the magnetic field-induced torque acting on a sample. Torque experiments on highly anisotropic superconductors yield valuable information about the anisotropy of the reduced mass of charge-carriers and the penetration depth. Important advantages of the approach described here over conventional torque experiments are: (a) high sensitivity to small changes in torque even at high ‘bias’-torque; and (b) constant angle between applied magnetic field and sample during the whole experiment, a property that is most important when investigating highly anisotropic superconducting samples in the presence of a magnetic field. Experimental results on a test system show the principle of operation, and investigations of a high-T_c superconducting sample are presented.     

New insights into structural and electrochemical properties of anisotropic polymer electrolytes

The inter-relationship between the orthogonal alignment of polymer helices and improvement of lithium-transport properties of polymer electrolytes has been determined by scanning electron microscopy, differential-scanning calorimetry and dielectric spectroscopy. It is suggested that ordering of the polymer electrolyte accompanied by increased conduction properties is achieved by mutual coordination of local dipole moments of the polar CH₂-CH₂-O units during casting under a magnetic field.     

不同规模地质体剩余油的形成与分布研究

针对非均质多层砂岩油田高含水期剩余油分布的复杂性,通过室内物理模拟实验、检查井资料分析、矿场剩余油综合分析,从宏观到微观对油藏规模级、油层规模级、层内规模级和孔隙规模级等4种不同规模地质体剩余油的影响因素进行分析,研究不同规模地质体剩余油的形成、分布特征及成因类型.针对不同规模地质体的剩余油类型,指出相应的挖潜方法.图4表2参39     

The analysis of corrosion performance of car bodies coated by no nickel and low nickel zinc phosphating processes

In today's automotive industry in order to protect car bodies from corrosion, spray or immersion type zinc phosphating processes are applied. In both types, nickel and chromium are widely used though they are harmful to human health and environment. In this study, car body's corrosion performance, coated by no nickel (0 ppm) and low nickel (100, 200, 300 ppm) immersion type zinc phosphating (without chromium passivation) processes, are compared to the bodies that are coated by spray and immersion type processes including nickel (500–700 ppm) and chromium. After analyzing coating weight, composition, morphology of the crystals and salt spray test corrosion performance of car bodies specimens coated by no nickel and low nickel processes are as good as the ones coated by spray and immersion phosphating processes including nickel and chromium. In developing environment consciousness, it is inevitable to favor no nickel or low nickel processes since they give no harm to nature and human health.     

真空灭弧室横向磁场触头间磁吹力的计算分析

对螺旋槽型和杯状型两种横磁触头进行了研究,仿真分析了不同电弧位置和触头结构参数下触头间磁场的分布,同时计算分析了触头间电弧所受的磁吹力,可为横向磁场触头的研究与应用提供参考。     

Elastic anisotropy and magnetic phase transition of yttrium garnet ferrite

Temperature dependences of elastic moduli describing elastic anisotropy in the rage from room temperature to 600 °C are shown. These temperature dependences are in agreement with available values of elastic moduli and temperature coefficients of the elastic moduli at room temperature. They are in agreement with modern quasi-harmonic theory of crystal lattices. Near 285 °C critical changes of effective elastic moduli due to magnetic phase transition are observed. A correlation was made between experimental and theoretical critical changes of longitudinal and transverse elastic wave velocities for different crystallographic directions. It is proved that the critical change of ultrasound wave velocities of this crystal is connected with the single-ion magnetostriction.     

槽道中方形障碍物绕流的大涡模拟

本文应用二阶全展开ETG有限元离散格式与大涡模拟相结合的方法对固定在槽道一侧的方形障碍物的绕流进行了数值模拟，计算了雷诺数为40000的湍流情况下的绕流流场，将模拟结果与实验结果及他人的数值结果进行了对比，符合较好，表明大涡模拟与所论的具有较高精度的数值算法相结合，适合于具有大尺度涡的绕流运动流场的分析。     

Upgrading a rutile concentrate produced from Athabasca oil sands tailings

A rutile concentrate recently produced by Lakefield Research Ltd and Syncrude Canada Ltd from athabasca oil sands tailings was characterized and attempts were made to upgrade it to market-grade. The rutile concentrate contained 75.5% TiO₂, 18.7% Fe₂O₃, 1.03% Al₂O₃, 1.94% SiO₂, and 563 ppm Th+U. The amount of rutile (anatase) in the concentrate was estimated to be about 10-17%, and the remaining TiO₂ came from ilmenite in various altered forms. Magnetic separation could remove the Fe from the concentrate but it increased the SiO₂ content from 1.94 to 6.01%. A reverse flotation process was developed to remove the SiO₂. Although the fine dissemination of SiO₂ in the rutile matrix limited the removal of SiO₂, the upgraded rutile concentrate, containing 87-89% TiO₂, could be used as a feedstock to the chloride titanium pigment processes.