兆瓦级NBI加热系统弧流电源故障诊断方法探究

针对中国环流器2号A(HL-2A)装置弧流电源的特点,以及弧流电源故障诊断的条件与现状,提出了结合中性束注入(NBI)控制系统的相关功能模块与基于Matlab/Simulink仿真技术构建的故障字典,以实现弧流电源运行状态的在线监测及其故障模式的诊断。NBI控制系统在监测到弧流电源故障状态后,调用存储的弧流电源输出信号进行分析,提取信号的特征值,然后通过查找弧流电源故障字典以诊断出可能的故障模式。结合实验数据论证了该故障诊断法对弧流电源简单故障定位准确,对复杂故障能缩小定位范围,具有原理简单、可操作性强等优点。     

以Y/Ni为催化剂制备的单壁碳纳米管的拉曼光谱研究

采用电弧放电法以Y/Ni为催化制备了单壁碳纳米管（SWNTs），对样品进行了扫描电镜、透射电镜和拉曼光谱的研究。所制备的样品中单壁碳纳米管的含量较高。对单壁碳纳米管的共振拉曼散射增强效应进行了观察，随激光波长的不同，单壁碳纳米管的拉曼光谱也随之变化，尤其是低频区径向呼吸模的变化比较明显。利用布里渊区折叠法计算了单壁碳纳米管的电子态密度曲线，根据SWNTs电子态密度尖峰之间的能量差、管子的直径和呼吸模频率建立了一个图表，并对SWNTs的呼吸模进行了归属。分析结果表明：样品中单壁碳纳米管的直径分布在0.79-1.76nm范围，金属管和半导体管均存在，并且直径在1.45nm附近的碳管居多。     

电弧炉燃烧-红外法测定碳量与硫量

电弧炉与红外碳、硫分析仪配套，用于测定硅铁、金属锰、矿石、铬铁、钒铁、合金钢铸铁、水泥、微晶玻璃，阳极泥等物质中碳量和硫量，结果满意。     

骨架掺硼富勒烯的合成及表征

在富勒佛被合成后不久，Smalley等人就开始利用B、N、St等元素制备非碳富勒烯和骨架掺杂富勒烯的研究，合成出了骨架掺氮富勒佛一C59N，在质谱中观察到了微观量的骨架接棚富勒烯C。。B等［’－’］，但迄今尚未见非碳富勒烯和骨架掺棚富勒烯宏观是合成的报导．用础部分取代富勒     

Two-temperature modeling of an arc plasma reactor

In this paper a two-temperature plasma model is established and applied to the injection of cold gases into an atmospheric-pressure, high-intensity argon arc. The required nonequilibrium plasma composition and the non-equilibrium transport properties are also calculated. The results show that the arc becomes constricted at the location of gas injection due to thermal and fluid dynamic effects of the injected cold flow. Enhanced Joule heating in the constricted arc path raises the electron as well as the heavy-particle temperatures. This temperature increase resists, via secondary effects, the penetration of the cold gas into the hot arc core which behaves more or less as a solid body as far as the injected flow is concerned. The temperature discrepancy between electrons and heavy particles is most severe at the location of cold flow injection, a finding which may have important consequences on chemical reactions in an arc plasma reactor.     

Effects of Copper Vapor on Heat Transfer from Atmospheric Nitrogen Plasma to a Molten Metal Anode

As an object of nitrogen plasma operated with an arc current to 200 A, an arc length about 35 mm, we evaluated heating efficiency from arc plasma to the molten copper anode and the water-cooled solid copper anode. The heating efficiency to the molten anode is smaller than that to the solid anode by about 20%. We focused on copper vapor concentration in plasma as a possible cause for a decrease in heating efficiency, and estimated it by means of the Cu and the N spectral line measurement. Simple numerical analysis, taking into consideration measured copper vapor concentration, suggested that an increase in electrical conductivity due to copper vapor, made the plasma temperature change and consequently caused a decrease in thermal conductivity. We concluded that one of the reasons for a decrease in heating efficiency would be caused by copper vapor contamination.     

Effect of the Atmosphere on the Products of Arc Plasma Method

Plasma techniques have been used to synthesis of metal, metal compounds, and surface modification. In that processing, atmosphere is more important to the compositions and properties of nanoparticles and films. We found that the atmosphere has not only effected the compositions, but also plays a significant role on the morphologies of the products. By changing atmosphere based on different requirement, we obtained spherical Mn₃O₄ nanoparticles, mixture of hexangular Mn₃O₄ nanosheets and Mn+3O(OH) nanorods, and Mn₆N_2.58 nanoparticles coated with graphite layer. The compositions, structure and morphologies of the products were determined by x‐ray diffraction (XRD) and transmission electron microscopy (TEM), and electron diffraction (ED). Finally, we preliminarily discussed the reason of the effect of the atmosphere to the final products of arc plasma method.     

The directed profitable location Rural Postman Problem

In this paper we introduce an extension of the well known Rural Postman Problem, which combines arc routing with profits and facility location. Profitable arcs must be selected, facilities located at both end-points of the selected arcs, and a tour identified so as to maximize the difference between the profit collected along the arcs and the cost of traversing the arcs and installing the facilities. We analyze properties of the problem, present a mathematical programming formulation and a branch-and-cut algorithm. In an extensive computational experience the algorithm could solve instances with up to 140 vertices and 190 arcs and up to 50 vertices and 203 arcs.     

Device quality ZnO grown using a Filtered Cathodic Vacuum Arc

In this paper we report on the structural, electrical and optical characteristics of unintentionally doped ZnO films grown on a-plane sapphire substrates using the Filtered Cathodic Vacuum Arc (FCVA) technique. The resulting films showed considerable promise for device applications with properties including high transparency, moderate intrinsic carrier concentrations (10¹⁷–10¹⁹ cm⁻³), electron mobilities up to 30 cm²/Vs, low surface roughness (typically <2% of film thickness) and well-structured photoluminescence. Post-annealing in oxygen at temperatures up to 800 °C produced significant improvements in the properties of these films. Silver oxide Schottky diodes fabricated on FCVA ZnO showed ideality factors as low as 1.20 and good sensitivity to ultraviolet light.