Density Measurement of Liquid Ni-Ta Alloys by a Modified Sessile Drop Method

The density of liquid Ni- Ta alloys was measured by using a modified sessile drop method. It is found that the density of the liquid Ni- Ta alloys decreases with the increasing temperature, but increases with the increase of tantalum concentration in the alloys. The molar volume of liquid Ni- Ta binary alloys increases with the increase of temperature ancl tantalum concentration.     

40kg试验焦炉的研制

文章介绍了40kg试验焦炉，分析和比较了试验焦炉与生产焦炉的差异，指出它们之间的模拟条件是炭化室宽度、煤料堆密度、炼焦速度和单向传热。     

河道冲刷和清水水流河床冲刷率

在冲积河流里。水流条件变化如洪水、水库泄放清水、河道渠化等使挟沙力不饱和引起冲刷，称为河道冲刷。这与水工建筑造成的局部冲刷不同。河道冲刷深度主要决定于冲刷率和冲刷历时。本研究通过对各种泥沙大量实验，证明了河床冲刷率正比于水流提供的冲刷功率并依赖于泥沙粒径和容重，首次提出了冲刷率公式。经验证，该公式可以用于非恒定流输沙和河流洪水冲刷计算。     

基于非线性规划的指数自回归模型的辨识

讨论了指数自回归模型的辨识问题，证明了该模型最小二乘估计的目标函数的非凸性，并给出了使该函数为凸的条件，最后给出了辨识该模型的算法及该算法的收敛性，并以数值例子加以说明。     

Comparison of spatial compositional uniformity and dislocation density for organometallic vapor phase epitaxial Hg1−x CdxTe grown by the direct alloy and interdiffused growth processes

Etch pit density and spatial compositional uniformity data are presented for organometallic vapor phase epitaxial Hg_1−x Cd_x Te grown by the direct alloy and interdiffused growth methods. For alloy growth, composition variation is as low as Δx=0.004 and 0.02 over 2- and 3-in diam areas, respectively; while for growth on CdZnTe substrates, etch pit density values lower than 2×10⁵ cm⁻² have been achieved. For interdiffused growth on CdZnTe, etch pit density values lower than 5×10⁵ cm⁻² have been obtained, while the composition variation is usually Δx≤0.004 and 0.014 over 2- and 3-in diam areas, respectively. Data demonstrate that the choice of particular CdZnTe substrate strongly affects the subsequent etch pit density measured in the layer. Reasonably uniform n-type doping over 3-in diam area using the source triethylgallium is also reported for both growth methods.     

Volumetric properties of mixtures of 1,4-dioxane and water at high pressures

Densities of aqueous of 1,4-dioxane have been measured at temperatures from 298 to 348 K and at pressures up to 40 MPa by a vibrating-tube method. Molar volumes obtained with an estimated uncertainty of ±0.2°,% are correlated with pressure by the Tait equation within the experimental uncertainty. Pressure and composition dependences of the excess molar volume, partial molar volume, and isothermal compressibility are determined and they are compared with those of other aqueous solutions.     

预测井眼稳定性的力学化学耦合方法

在井眼力学稳定性评价的基础上，将硬脆性页岩水化后岩石强度等参数的变化规律用于页岩水化前后坍塌压力变化的对比分析，结果表明，地层坍塌压力当量密度随页岩水化程度的增加逐渐升高。给出了预测井眼稳定性的力学化学耦合方法，并将该方法应用于现场生产中，取得了较好的预测效果     

Fe73.5Cu1Nb3Si13.5B9非晶合金的晶化动力学

用ＤＴＡ结合ＸＲＤ了Ｆｅ７３．５Ｃｕ１Ｎｂ３Ｓｉ１３．５Ｂ９晶合金的晶化动力学。表明，该事金在５００℃时析出α－Ｆｅ（Ｓｉ）相。晶化初期激活能最小为２４２ｋＪ／ｍｏｌ，它随晶化量的增加，在ＸＣ为０．４－０．８时，呈极大值为５２０ｋＪ／ｍｏｌ。在６２４℃时析出Ｆｅ２Ｂ相。     

Superconductivity and magnetism in niobium doped YBa2Cu3O7 Related high Tc ceramics

Magnetic characterization has been performed on the members of the cuprateniobate RBa₂Cu₂NbO₈ (R = Pr, Nd, and La) series and R_1.5Ce_0.5Sr₂Cu₂NbO₁₀ (R = Pr, Eu, Nd, and Sm) series. The PrBCNO samples show a signature in the magnetization of a magnetic ordering at 12K. The PrCSCNO sample is nonsuperconducting and shows two distinct orderings at 17K and 53K. No such magnetic phase transition is observed down to 2K in the Nd and La based RBCNO materials or the Nd, Sm, and Eu based RCSCNO materials. Measurements of the lower critical field curve, dc irreversibility line, and critical curent densities are reported for each of the superconducting NdCSCNO, SmCSCNO, and EuCSCNO compounds.     

Liquid viscosities and densities of HFC-134a+glycol mixtures

Liquid viscosity and density of six binary mixtures of HFC-134a with glycols [ethylene glycol, diethylene glycol, triethylene glycol, polyethylene glycol (400), and polypropylene glycol (2000)] have been measured in the temperature range from 273 to 333 K. The viscosity was measured by a rolling-ball viscometer calibrated with standard liquids of viscosities and densities (JS5, JS10, JS20, and JS50). The density was measured with a glass pycnometer. The uncertainties of the measurements were estimated to be less than 3.4 % for viscosity and 0.04 % for density, respectively. An equation is given to represent the obtained viscosity values as a function of weight fraction and temperature.