Preparation and Structure of Lithium-Ion-Conducting Mixed-Anion Glasses in the System LiBO2–LiBS2

Oxysulfide glasses were prepared in a wide range of compositions in the system LiBO₂-LiBS₂. Temperatures of glass transition ( T_g ), crystallization ( T_c ), and liquidus ( T_l ) were determined; a maximum of T_g was observed near the composition with 20 mol% LiBS₂. The electrical conductivity at 500 K ranges from 5×10⁻⁴ to 5×10⁻³ S·cm⁻¹ with the maxima in conductivity observed near the composition 55LiBO₂·45LiBS₂. This conductivity enhancement with a mixing of two components, which can be called the mixed-anion effect, is accompanied by a decrease in the degree of undercooling of glass expressed by the ratio ( T_l - T_g )/ T_l . The infrared and Raman spectra showed that the structural units with bridging oxygens B-O-B and nonbridging sulfurs B-S⁻ predominated rather than those with nonbridging oxygens B-O⁻ and bridging sulfurs B-S-B in these glasses.     

网上服务合成系统中的服务描述

为了解决服务合成中的服务描述这一关键问题,提出了一种基于输入-输出接口模型和数据流图模型的服务描述方法.用功能对象的概念表示通过网络连接的各种硬件、软件和多媒体资源,通过描述功能对象的输入-输出接口来表示用户所需要的资源.采用数据流图来表示所需资源之间的连接.根据以上基于输入-输出接口描述和数据流图的模型,提出了基于扩展标记语言(extensible markup language,XML)的服务描述规范,同时介绍了一个生成服务描述文档的客户端软件工具,并已应用于网上服务合成平台STONE(Service syn Thesizer On NEt)系统中.研究表明,基于输入-输出接口描述和数据流图的服务描述方法,是解决网上服务合成中服务描述的有效途径.     

基于形状变化的冗余机械手可操作性分析

受冗余机械手的可操作性理论和可操作性椭圆的启发,提出形状变化可操作性理论和形状变化可操作性椭圆。可操作性表示了冗余机械手在形状给定的前提下,它的每一个关节产生速度的性能;形状变化可操作性表示了当冗余机械手的手臂末端被给定任务时,其余中间关节产生速度的性能,即是形状变化性能,手臂末端执行给定的任务,如轨道追踪,因此不具备形状变化可操作性。对可操作性椭圆和形状变化可操作性椭圆进行比较和分析。通过对七关节机械手在二维平面内的轨道追踪和障碍物回避的实例分析、以及对三维空间内的不同姿势(即不同形状)下的七关节机械手所对应的不同形状变化可操作性椭圆的比较分析,能够认识到形状变化可操作性理论的提出对于评估和设计冗余机械手的结构和形状有着重要的实际意义。     

Infrared Spectra of Rapidly Quenched Glasses in the Systems Li2O-RO-Nb2O5 (R=Ba, Ca, Mg)

Twin-roller quenching produced wide ranges of glass formation in the systems Li₂O-RO-Nb₂O₅ (R=Ba,Ca,Mg). The glass-forming ability is improved with an increase in the ionic radius of R²⁺ ions. The crystallization temperature is increased as Li₂O is replaced by RO or the ionic radius of R²⁺ ions is increased. Infrared spectra revealed that the glass LiNbO₃ (=50Li₂O-0Nb₂O₅) was composed of six-coordinated NbO₆ octahedra, which were joined together by corner-sharing only. In the Li₂O-RO-Nb₂O₅ glasses there exist edge-shared as well as corner-shared NbO₆ octahedra. The edge-shared NbO₆ octahedra in the glasses are increased with an increase in the content of RO or Nb₂O₅, and also with an increase in the ionic radius of R²⁺ ions.     

Recent Progress in Plasma Control Studies on the Improvement of Plasma Performance in Heliotron J

Recent progress in plasma control studies on the improvement of plasma performance in Heliotron J is reviewed. The supersonic molecular beam injection (SMBI) fueling is successfully applied to Heliotron J plasma. A supersonic H2-beam is effectively injected to increase fueling efficiency and generate a peaked density profile. Local fueling with a short-pulsed SMBI can increase the core plasma density and avoid the degradation arising from edge cooling. Second harmonic electron cyclotron current drive (ECCD) experiments were conducted by launching a focused Gaussian beam with -0.05 ? N|| ? 0.6. Results show that the EC driven current is determined not only by N|| but also by local magnetic field structure where the EC power is deposited. Detailed analysis of the observed N|| and B dependences is in progress with a ray-tracing simulation using the TRAVIS code. Fast ion velocity distribution was investigated using fast protons generated by ion cyclotron resonant frequency (ICRF) minority heating. For the standard configuration in Heliotron J, charge exchange neutral particle analysis (CX-NPA) measurements show higher effective temperature of fast minority protons in the on-axis resonance case compared to that in the HFS (high field side) off-axis resonance case. However, the increase in bulk ion temperature in the HFS resonance case is larger than that in the on-axis resonance.     

FERROELECTRIC GATE FET MEMORY BASED ON CONDUCTION OF FERROELECTRIC-INSULATOR INTERFACE

ABSTRACT

A new type of ferroelectric gate field effect transistor (FET) using ferroelectric-insulator interface conduction has been proposed. Drain current flows along the interface between ferroelectric and insulator layers and needs no semiconductor. This FET consists of source and drain electrodes on ferroelectric film (Pb(Zr_0.52Ti_0.48)O₃(PZT)) prepared on Pt/TiO₂/SiO₂/Si substrate, and gate electrode on HfO₂ insulator film on the PZT film between the source and the drain electrodes. Drain current flows through the interface of the ferroelectric and the insulator. Drain current versus gate voltage characteristics shows clockwise hysteresis loop similarly to the conventional p-channel FET with ferroelectric gate. The FET shows that the On/Off ratio of the conduction current is about 10⁵ and the Off state current is about 10^{? 10}A.