Investigation of Thermodiffusion Carbonitride Coatings on Titanium Alloys

We study specific features of the processes of phase formation and gas saturation in VT1-0, VT14, OT-4, and VT20 titanium alloys held in a carbon-and-nitrogen-containing medium for 5 h at 1100°C. Depending on the type of alloy, the TiC _x N _y carbonitride phases of different compositions are formed on the metal surface under the indicated conditions. The analysis of the corrosion and electrochemical behavior of alloys shows that the best protective properties are exhibited by the carbonitrides formed on the surface of VT20 alloy (whose composition is close to equiatomic and the surface roughness is minimum). __________ Translated from Fizyko-Khimichna Mekhanika Materialiv, Vol. 41, No. 4, pp. 59–65, July–August, 2005.     

垂直主振系冲击消振理论研究

基于主振系的传递函数对垂直冲击消振系统的时域响应进行理论推导;在建模的基础上,应用MATLAB语言开发简明实用的仿真软件,通过一个算例全面研究质量比、冲程、恢复系数、激励力和激励频率对减振效果的影响;为冲击消振器结构设计的参数优化和预报减振效果提供了依据.     

Thermodiffusion and the diffusion thermoeffect in the flow of low-temperature plasmas

An estimate is made of the contribution of the process of thermodiffusion and of the diffusion thermoeffect to the transport properties of low-temperature plasmas with reference to the example of the long-range trails appearing behind bodies during hypersonic re-entry into the atmosphere.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 55, No. 3, pp. 389–397, September, 1988.     

利用MTMD控制桥梁竖向振动的初步研究

利用三角级数法模拟轨道的不平顺,采用列车编组和桥梁组合的模型,通过建立车-桥-TMD动力系统振动方程,研究了TMD控制下桥梁的竖向位移响应.通过TMD质量比影响曲线得出了最佳质量比,并将MTMD与STMD进行了对比分析,给出了时程响应曲线,结果表明MTMD对桥梁竖向振动的减振效果更明显,且更适用于工程实践.     

垂直冲击试验及校准方法

介绍了垂直冲击机的结构、组成及工作原理;根据垂直冲击试验的各项技术要求建立校准系统,确立校准方法;采用计算机对整个校准过程的校准结果进行数据采集和波形分析,并针对不同试件调整其校准方法.     

冲击消振系统动力学初探

通过数值分析获得冲击消振系统典型的稳定周期响应相轨图,在相轨图中直接观察倍周期分叉,并在庞加莱（Poincare）截面中显示了该振冲系统的混沌运动性质。     

Thermodiffusion constant in liquid isotopic mixtures of certain brominated hydrocarbons

Using a nonstationary method values of the thermal diffusion constant in butyl, amyl, and heptyl bromide are determined.     

演播室灯光设备层发热量垂直分布规律分析

利用CFD软件对某演播室的气流组织进行了数值模拟,分析了不同送风口高度对气流组织的影响,从而得出灯光设备层发热量的垂直分布规律,为演播室设计提供一定的理论依据。     

Thermodiffusion of32S and34S in sulfur hexafluoride

The article describes the experimental investigation of the separation of sulfur isotopes in a thermodiffusion column.Notation T^*=kT/ reduced temperature - ¯T=(T₂ + T₁)/2; T₂, T₁ temperatures of the hot and cold surfaces, respectively - T=T₁ – T₁ K_c, K_d, H coefficients of the transport equation, see (3), (7) - size of the gap - P pressure - L height of the column - B perimeter of the gap - R gas constant - D, diffusion coefficient and coefficient of dynamic viscosity - density - q degree of separation, see (5) - thermodiffusion constant - M₁, M₂ masses of the isotopic molecules - K_p parameter taking parasitic convection into account - potential function Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 42, No. 1, pp. 65–71, January, 1982.     

Thermodiffusion mechanism of dynamic amplitude hologram recording in a two-component medium

An expression for the efficiency of dynamic amplitude hologram recording is obtained for a two-component medium with a concentrational nonlinearity caused by the thermodiffusion of differently absorbing particles.     

城市高架复合道路交通噪声垂直面声场研究

采用Cadna/A 软件研究高架复合路在不同路况条件下交通噪声垂直面声场的分布规律和建设高架路声屏障的降噪规律。高架桥使高架复合道路垂直面声场发生较大变化,由此需要研究高架桥对不同路况交通噪声垂直面声场分布的影响规律。国内在高架路上建设大量声屏障,但在很多情况下,这种声屏障的降噪效果并不理想。为了研究产生这种现象的原因,计算并分析不同路况下建设高架路声屏障的降噪效果,提出可以根据不同路况来决定是否应建造声屏障,以避免建造无效声屏障造成的浪费。     

霜层生长初期冰晶体分布状况实验研究

研究霜层的结构对于理解结霜现象有着重要的意义。利用自行研制的图像放大及采集系统,对霜层生长初期冰晶体的形态进行显微观测,得到了不同生长条件下冰晶体的图像。随后采用数字图像处理方法,将原图像转换为二值图。通过对图像的分析,发现霜层的生长初期冰晶体的分布与充分生长的霜层有所不同,此时霜层靠近冷表面固含率最大;随着高度的增长,固含率以近似线性的方式减小。实验还发现,对霜层生长初期影响最大的两个因素是冷表面的温度和空气的相对湿度。随着冷表面温度的降低,霜层的高度明显增长,冰晶体沉积量增加,而平均密度的变化则不明显;随着空气相对湿度的增加,霜层的高度、平均密度以及冰晶体总的沉积量都有所增加。空气温度对霜层生长的影响不明显。     

Transient Effect of Micro Vibration from Two Space Vehicles on Mixture During Thermodiffusion Experiment

Numerical modeling of thermodiffusion experiment for a binary mixture of water and isopropanol under micro-vibrations condition is presented. The vibrations obtained onboard ISS and FOTON-M3 are due to different activities. The effect of micro-gravity vibration level on the variation of mixture properties were investigated in detail. In this paper, the thermodiffusion experiment was investigated for two different g-jitter vibrations in the presence of a thermal gradient. The cavity is filled with a binary mixture of water and isopropanol with negative Soret. All physical properties including density, mass diffusion and thermodiffusion coefficients were assumed as functions of temperature and concentration. In order to understand the behavior of the mixture during the course of the experiment, five locations in the domain were chosen. It was found that a similarity between g-jitter vibration and induced velocity pattern exist. Micro vibration was found to have a minimal effect on the molecular and thermodiffusion coefficients.     

Heat and Mass Flux Effects on a Moving Vertical Cylinder with Chemically Reactive Species Diffusion

This paper presents the development of the free convection boundary layer flow of a viscous and incompressible fluid past an impulsively started semi-infinite vertical cylinder with uniform heat and mass fluxes and chemically reactive species. The governing coupled nonlinear partial differential equations have been solved numerically using the finite-difference scheme of Crank–Nicolson type. Graphical results for the velocity, temperature, concentration, local and average skin friction, Nusselt number and Sherwood number profiles are illustrated and discussed for various physical parametric values. It is noted that due to the presence of first-order chemical reaction the velocity decreases with increasing values of the chemical reaction parameter     

Importance of Initial Distribution for Iterative Calculation of Quantized Diffractive Elements

Abstract

The significance of the initial distribution for three iterative calculation techniques of diffractive elements; simulated annealing, direct binary search, and Fourier transform algorithm, is investigated. Depending on the initial distributions, convergence problems may occur. Techniques to calculate special initial distributions for the three methods are described: these significantly improve the capabilities of the iterative techniques.     

电真空器件热阴极加热功率与温度分布关系的测试与模拟

为确定电真空器件内热阴极区域的温度分布,以热阴极的热电子发射机理为基础,针对传统闸流管的经典热阴极构型,利用Comsol软件对一定几何结构的热阴极进行了物理建模,依据热传导的相关理论,合理地设定了模型边界的热量传递和交换条件,对热丝加热功率与阴极表面温度分布进行了模拟分析,所得结果与实际测试结果进行了对比,达到了相当吻合的程度;同时确定了绝缘陶瓷的有关物理参数是导致阴极温度不高的一个主要因素。从而说明本文所探寻的利用数值模拟方法分析热阴极构型的电真空器件内的温度分布是准确而有效的方法。     

微通道换热器两相分配特性对空调系统性能的影响

微通道换热器作为新一代换热器逐渐被使用在家电领域,其结霜、除尘、排水、分液等都是目前亟待解决的问题。通过R22家用空调系统的标准性能实验台,对三种流程数不同的微通道换热器用作冷凝器和蒸发器时,温度分布均匀性和其对系统性能的影响进行实验,研究发现,微通道换热器在用作冷凝器和蒸发器时,温度分布不均对系统性能的影响分别达到7.3%和3.5%,并且流程数对于温度分布均匀性的影响在作为冷凝器和蒸发器时是不同的。