实现CDMA最佳多用户检测的神经网络方法

提出并讨论了两种实现码分多址系统中最佳多用户检测的神经网络方法。一种基于离散Ｈｏｐｆｉｅｌｄ神经网络，另一种基于采用反向传播算法的多层感知器神经网络。理论分析和计算机模拟都证实了这两种神经网络方法的可行性，优越性和实用性。前者适用“固定”用户情况；后者既可用于“固定”用户吼适用于移动用户的情况，因而在未来的ＣＤＭＡ个人通信网中有较好的应用前景。     

美国UCC公司项目实施八段法

国外工程公司的项目实施工作法是科技发展和经济发展的产物。公司为谋求生存和发展,必须采取先进的技术和科学管理,同时获得适当的利润回报。本文介绍美国UCC公司的项目工作八段法。     

用迁移率和载流子浓度研究碲镉汞中的深能级

获得了一种研究碲镉汞深能级的方法。通过分析迁移率 载子浓度与温度的关系，可以得到关于深能级的重要依据。     

强折射轴对称流场的干涉再现方法

利用光学方法测量气体状态参数的关键在于确定气体折射率场的变化。光线通过稳定的非均匀折射率场时发生偏折，并且在强折射对称场中会产生交叉，使得条纹位移量的判读困难。本文首先分析了光线在轴对称折射率场中的偏折效应，在此基础上，给出了一种利用成像透镜对强折射轴对称场中折射率的干涉再现方法。该方法与其它方法相比较能够精确地确定折射率ｎ（ｒ）的值。     

Polyspectral Analysis of Two-dimensional Mixed Processes and Coupled Harmonics

1　ＩｎｔｒｏｄｕｃｔｉｏｎＩｎｍａｎｙａｐｐｌｉｃａｔｉｏｎｓ,ｓｕｃｈａｓｒａｄａｒ,ｓｏｎａｒ,ｇｅｏｐｈｙｓｉｃｓ,ｒａｄｉｏｃｏｍｍｕｎｉｃａｔｉｏｎａｎｄｍｅｄｉｃａｌｉｍａｇ ｉｎｇ ,ｔｈｅｐｒｏｂｌｅｍｏｆｔｗｏ ｄｉｍｅｎｓｉｏｎａｌｆｒｅｑｕｅｎｃｙｅｓｔｉ ｍａｔｉｏｎｈａｓｒｅｃｅｉｖｅｄａｌｏｔｏｆａｔｔｅｎｔｉｏｎｉｎｒｅｃｅｎｔｙｅａｒｓ.ＩｎｔｈｅｃａｓｅｏｆａｄｄｉｔｉｖｅｗｈｉｔｅＧａｕｓｓｉａｎｎｏｉｓｅ,ｎｕｍｅｒｏｕｓｍｅｔｈｏｄｓｓｕｃｈａｓＭＥＭＰ[1 ] ,ＭＵＳ…     

Sidle的远程执行设备

Ｓｉｄｌｅ系统是运行在ＳＵＮ工作站网络上的一组实用程序，利用空闲的处理机资源进行大粒度的并行计算．同其它远程执行设备相比，它能支持程序内部并行和嵌套的远程执行，允许一个服务员机接受多个远程执行任务．本文介绍了这些特点和透明性的实现方法．     

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.     

Experimental densities for compressed R134a

This paper reports densities of compressed R134a (1,1,1,2-tetrafluoroethane) determined by using a contiuously weighed pycnometer at 20 K intervals between 180 and 380 K at pressures from slightly greater than the vapour pressure to 70 MPa. The results are accurate to within ±0.1%. Saturated liquid densities derived by extrapolation from the experimental values agree with other reported values to within ±0.3%.     

An equation of state for 1,1-difluroethane (HFC 152a)

An equation of state for 1,1-difluoroethane (HFC 152a, CH₃CHF₂) has been developed on the basis of reliable experimental data including PVT, liquid C_p, and saturated-liquid-density data measured by our group. It is a non-dimensionalized virial equation whose functional form is the same as that originally developed for 1,1,1,2-tetrafluoroethane (HFC 134a) in our group. The effective range is for pressures up to 15 MPa, temperatures from 230 to 450 K, and densities to 1000 kg m⁻³. The equation represents reliable PVT measurements within ± 1% in pressure for the superheated vapour and supercritical fluid, while within ±0.5% in density for the compressed liquid. In addition, it should be noted that the equation represents the other essential thermodynamic properties including vapour pressures, saturated-liquid/ vapour densities, isobaric/isochoric specific heats and sound velocity in both the liquid and gaseous phase of HFC 152a.     

Si_（1－x）Ge_x／Si定向耦合器的研制

在运用ＳｉＧｅ脊形波导单模条件和有效折射率法分析ＳｉＧｅ／Ｓｉ定向耦合器结构参数的基础上，采用分子束外延和各向异性腐蚀技术制备出Ｓｉ１－ｘＧｅｘ／Ｓｉ（ｘ＝０．０５）单模定向耦合器．在波长为１．３μｍ时，平均串音小于－１８．１ｄＢ，输出功率耦合效率达到９８．１％