Phase Separation in the Neutral Falicov–Kimball Model

The Falicov–Kimball model consists of spinless electrons and classical particles (ions) on a lattice. The electrons hop between nearest neighbor sites, while the ions do not. We consider the model with equal numbers of ions and electrons and with a large on-site attractive force between ions and electrons. For densities 1/4 and 1/5, the ion configuration in the ground state had been proved to be periodic. We prove that for density 2/9 it is periodic as well. However, for densities between 1/4 and 1/5 other than 2/9 we prove that the ion configuration in the ground state is not periodic. Instead there is phase separation. For densities in (1/5, 2/9) the ground-state ion configuration is a mixture of the density 1/5 and 2/9 ground-state ion configurations. For the interval (2/9, 1/4) it is a mixture of the density 2/9 and 1/4 ground states.     

OPGW温升上限的确定及其测量

影响OPGW温升上限的因素较多，本文简要分析了这些因素，并介绍了几种OPGW短路电流和温升的测量方法。     

GSM无线网络容量规划方法新探

首先论述了无线网有效话务量与无线网理论处理能力的关系，得出了无线网络利用率的理想取值范围，然后提出了引入无线网络利用率的概念和计算GSM网基站配置的方法；最后提出了提高无线网络资源利用率的有效措施。     

Preliminary Flight Test Program on Telecom and Broadcasting Using High Altitude Platform Stations

Telecommunication and broadcasting systems using radio-relay/base stations on board the high altitude platforms are expected to create the largest business market among its possible applications. They could also be integrated with satellite- and terrestrial-based systems in the future to construct the more powerful mobile and/or broadband networks. Prototype onboard equipment and ground equipment are being developed on schedule in the fixed, mobile, and broadcasting services. The performance of them will be demonstrated and evaluated in the preliminary flight tests planned in 2002 using alternative aerial vehicles: a helicopter, a jet, and a solar-powered unmanned aerial vehicle (UAV), before flight tests using the high altitude airships. This paper presents activity in Japan on the R&D of wireless access systems using high altitude platform stations and the detail of the preliminary flight test program. This revised version was published online in July 2006 with corrections to the Cover Date.     

通用地面雷达杂波模拟器的设计与实现

描述了一种通用地面雷达杂波模拟器的设计及其系统实现，并且介绍了地面雷达杂波的建模与仿真方法。整个系统采用软硬结合的方法，在通用的硬件平台上，通过软件设置来满足各种地面雷达的杂波模拟。     

中小尺寸CdS和CdTe团簇结构与电子性质的第一性原理研究

基于密度泛函理论(DFT)的第一性原理方法(DMOL3程序),在广义梯度近似(GGA)下,计算了中小尺寸II~VI族(CdS)n和(CdTe)n团簇的基态结构、最高占据轨道(HOMO)和最低未占据轨道(LUMO)的能隙、结合能等,比较了(CdS)n和(CdTe)n两种团簇的基态结构,能隙与结合能随尺寸变化关系的差异等.     

OH分子基态（X2Π）的结构与势能函数

采用密度泛函理论的B3LYP方法和二次组态相互作用(QCISD(T))方法优化计算了OH分子基态(X²Π)的平衡结构、振动频率和离解能.根据原子分子反应静力学原理，导出了OH分子基态(X²Π)的合理离解极限，采用最小二乘法拟合Murrell-Sorbie函数得到了相应的势能函数和与该基态相对应的光谱常数(B_e，α_e，ω_e和ω_eχ_e)，计算结果与实验数据符合得相当好. 关键词： OH分子 2Π)')" href="#">基态(X²Π) 势能函数     

孤立的Eu2+在立方晶场中基态能级的分裂

用量子力学微扰论方法计算了Eu^2 在立方晶场中基态能级分裂的一级修正，并给出了相应能级的零级近似波矢。     

Lowest breathing mode of bosonic helium clusters

We analyze various microscopic calculations of vibrational frequencies for ⁴He_N clusters, N = 3-728. The lowest breathing frequency with total angular momentum J = 0 varies smoothly as a function of N, with a maximum around N = 50-120. Received 11 July 2001     

Sharing and Compatibility Study between Fixed Service Using High Altitude Platform Stations (HAPS) and Other Services in the 31/28 GHz Bands

In the World Radiocommunication Conference 2000 (WRC-2000), use of the 31 GHzand 28 GHz bands was permitted for the fixed service (FS) by using highaltitude platform stations (HAPS) in some countries. This paper examines thesharing and compatibility of the HAPS-based FS with the other services usingthe same and adjacent frequency bands and establishes the conditions of thecoexistence with those services. Feasibility of dynamic channel assignment(DCA) scheme among the different communication systems to facilitate thecoexistence is also studied.