Thermodynamic properties of methane in the critical region

An equation of state is presented for the thermodynamic properties of methane in the vicinity of the critical point. It incorporates the scaled asymptotic critical behavior predicted theoretically and supplements a global analytic equation of state for methane recently developed by Setzmann and Wagner.     

颗粒状物料热物性的快速测定

报道了用正规状况法快速测定颗粒状材料的导温系数α和导热系数λ的测试技术，具体叙述了测试原理。实验测定的α和λ值与文献值较为接近，实验值的重复性好。     

圆筒形件不用压边多次拉深时的皱曲预报

在建立皱曲模型的基础上，由压缩塑性失稳临界载荷公式导出了圆筒形件不用压边拉深时的皱曲临界切向压应力的表达式。进而给出了不皱曲的判定式及其皱曲临界曲线。通过实验验证和对照分析，证明在实际生产中可直接使用不皱曲的判定式或皱曲临界曲线对拉深作皱曲预报，且精度和可靠性较高。     

Viscosity of CHF3 in the critical region

The gaseous visosity of trifluoromethane (CHF₃) was measured in the critical region. The experimental temperature range was between 299.150 and 303.150 K and the pressure range was up to 5.66 MPa. The measurements were obtained with an oscillating-disk viscometer, combined with local determination of the density at the position of the oscillating disk, and they have an estimated accuracy of 0.6% for the viscosity and 0.5% for the gas density. The viscosity of CHF₃ exhibits an anomalous increase near the critical point. The anomalous increase in viscosity was analyzed with the viscosity equation proposed by Basu and Sengers.     

开路缺陷的软故障关键面积研究

从软故障的产生机制出发,研究了软故障的作用模式.为了计算软     

Inverse resolution of the heat-transfer equation with internal heat source: Application to the quenching of steels with phase transformations

A method is described for calculating the time dependence of the temperature and heat flux (on heating and cooling) at the surface of a solid body. For a given ambient temperature and a known time-temperature function of an interior point, the surface heat flux is computed through an inverse conduction algorithm taking into account the nonlinear nature of the problem. Moreover, this algorithm includes the enthalpy of phase transformations. The influence of space and time steps on inverse calculations (precision, stability) is investigated. The method is then applied to thermal cases involving different transformations in steels.     

用小直径颗粒床改善池内沸腾的热滞后特性

对水平表面上小直径颗粒床的饱和池沸腾传热做了实验研究,发现热滞后特性获得了重大的改善,使温度过头现象可以消除,因而这种方法可能用以改进微电子元件的冷却。但沸腾传热在高热流下比平板时明显恶化。     

屈曲约束支撑在轴压力下整体稳定分析

根据屈曲约束支撑(BRB)的工作状态,推导了屈曲约束支撑(BRB)的临界荷载公式,并根据我国的钢材特性提出了保证屈曲约束支撑(BRB)整体稳定的计算方法。     

The influence of neutron irradiation on (B0.65C0.35)Ba1.4Sr0.6Ca2Cu3Oz superconducting phase: The role of the grain edge

Using the transport and magnetization measurements, the influence of neutron irradiation at a fluence of 5 × 10¹⁷ n cm⁻² on (B_0.65C_0.35)Ba_1.4Sr_0.6Ca₂Cu₃O _z has been investigated. The neutron irradiation was found to decrease critical temperature and transport critical current density, increase the residual and normal state resistivity, and improve the intragranular critical current density with 1.6 × 10⁵ A/cm² (at 77.3 K and in the applied field up to 160 kA m) and ΔM _irr/ΔM _nonirr ratio (up to factor of 3) at highest field used for investigation. The field dependence of this ratio, which is below the unity at very low field but higher than 1 at high fields, correlated with the shape of the hysteretic loops as well as with the change of the transport parameters after irradiation suggests the role of the irradiation-induced effects on the grain edges. We discuss these effects in the framework of the Bean-Livingstone surface barriers and geometrical barriers.     

水平旋转内消能泄水道的流态序列、分区特性及临界条件

本文给出竖井进流水平旋转内消能泄水道的基本流态序列、过渡特性及临界水力条件。这种泄水道的流态可根据空腔环流内的气体压强、空腔直径和通气孔的通气量的变化规律分为淹没流流态、吸允流流态和自由流流态；空腔环流形成的水力条件为(H-h)／h大于2．5或Fr大于0．46；各流态转变过程中有明显的过渡段性质；在不同的流态分区内物理量的变化规律是不同的。