势垒

Based on the model,the variations of the electrical parameters such as the potential barrier,the anode junction voltage drop,and the current amplification factor are studied and discussed.

在该模型的基础上，讨论了势垒、阳极结的电势降落和电流的放大因子等电参数的变化。

Electrons can be easily injected from thegraphitic matrix into the conduction rand of diamond under the high field which resultedfrom the projection field enhancemext.These injected electrons could reach the vacuumsurface and then emit into vacuum where the negative electron affinity or low electronaffinity could allow the electrons to re emitted more easily.

由于场增强效应，对镶嵌在非晶碳颗粒表面的金刚石晶粒来说，电子在高场作用下通过隧道效应越过金刚石晶粒与非晶碳形成的界面势垒，注入金刚石的导带，在电场的作用下迁移到表面，由于某些金刚石表面具有负电子亲和势或较小的正电子亲和势，电子较易发射进入真空。

ZHOU Zhangjian（Laboratory of Special Ceramics and Powder Metallurgy, USTBeijing, Beijing, 100083, China）Abstract:On the basis of analysisof developing background and theory of thermoelectric graded materials, p-type (Bi1-0.85Sb0.85)2Te3and PbTe two segments thermoelectrical graded materials with different barriers werefabricated by conventional hot-pressing process.

具有不同扩散势垒的p型(Bi1-0.85Sb0.85)2Te3和PbTe二元梯度热电材料的研制徐桂英葛昌纯高艳平周张健摘要：在分析了热电材料的发展背景和研究理论的基础上，采用热压法制备出单体和双层具有不同扩散势垒的(Bi1-0.85Sb0.85)2Te3与PbTe体系二元梯度热电材料。

The Ehrlich-Schwoebel barriers of an adatom Cu diffusing down an island of fcc Cu are calculated by molecular dynamical simulation.The two-dimensional(2D) and three-dimensional(3D) ES barriers are calculated and compared with the results of Al.

利用分子动力学中的静态结构弛豫方法对Cu原子在面心立方铜的台阶表面扩散过程中的Ehrlich-Schwoebel势垒进行了模拟计算，研究了二维和三维ES势垒的差别，并将Cu与面心立方Al的结果进行了比较。

Simultaneity, the adsorption energies of single Si adatom on the H-terminated Si (100) surfaces are specially mapped out in this paper, from which the favorite binding sites and possible diffusion pathways have been achieved. The variety of the diffusion anisotropy with the coverage transforming is obtained. The energy barriers of the adatom diffusion are found to be higher than that on the clean surface, because the H atoms saturate the dangling bonds of the surface Si atoms.

同时，本文研究了附加硅原子在理想H-terminated Si(100)表面的沉积扩散行为，计算得到了一系列沉积点和可能的扩散路径；讨论分析了扩散行为的各向异性以及氢覆盖率对各向异性影响的规律，并且发现附加硅原子在H-terminated Si(100)表面上的扩散势垒比在清洁Si(100)表面上的高，我们认为这主要是因为氢原子饱和了表面上硅原子的悬挂键，提高了扩散势垒。

The four reaction channels including hydroxyl-type benzaldoxime are endothermic reaction, thermodynamically non-spontaneous process, but the other four reaction channels including ion-type benzaldoxime participation are exothermic reaction and thermodynamically spontaneous process. The latter four reaction channels, which have lower reaction barriers, faster reaction velocities and bigger equilibrium constants than those of the former fours, are the chief reaction channels.

苯甲醛肟以羟基型参与反应的4个反应通道均为吸热反应和热力学非自发过程，它们均具有较高的反应势垒、较慢的反应速率和较小的平衡常数；而以离子型参与反应的四个反应通道均为放热反应和热力学自发过程，它们的反应势垒较低，反应速度较快，平衡常数也较大，故苯甲醛肟应主要以离子型参与反应。

The results show that this reaction proceeds in two step: 1 silylene and formaldehyde form an intermediate complex, which is a kind of exothermal reaction with no barrier; 2 the intermediate complex isomerizes to sive the product. The barrier for the second step is 51.4kJ·mol^-^1 at MP2/6-31G^*//6-31G^* level (with zero-point energies correction). In view of dynamics and thermodynamics, it is between 300～400K that the reaction will have not only larger spontaneous tendency and equilibrium constant but also quicker reaction rate.

结果表明，此反应历程由两步组成：1硅烯与甲醛生成一中间配合物，是一无势垒的放热反应，2中间配合物异构化为产物，此步势垒经零点能校正后只有51.4kJ·mol^-^1(MP2/6-31G^*//6-31G^*)；从热力学和动力学的综合角度考虑，该反应在300～400K温度下进行为宜，如此，反应既有较大的自发趋势和平衡常数，又具有较快的反应速率。

SBD is the use of metal and semiconductor contact with the formation of metal - semiconductor barrier made of, so it is a thermal emission diode, with the manufacturing process of continuous improvement and the emergence of special materials, Schottky barrier gate and high-speed FET Large-scale integrated circuit and ultra-large-scale integrated circuits wide field of applications, Schottky diodes on the application of more and more widely.

SBD是利用金属与半导体接触形成的金属-半导体势垒制成的，因此，它是一种热电子发射二极管，随着制造工艺的不断完善及特殊材料的出现，肖特基势垒栅FET及其高速大规模集成电路和超大规模集成电路领域的广泛应用，肖特基二极管的应用范围也越来越广。

SBD is theuse of metal and semiconductor contact with the formation of metal- semiconductor barrier made of, so it is a thermal emission diode,with the manufacturing process of continuous improvement and theemergence of special materials, Schottky barrier gate andhigh-speed FET Large-scale integrated circuit andultra-large-scale integrated circuits wide field ofapplications, Schottky diodes on the application of more and morewidely.

SBD是利用金属与半导体接触形成的金属-半导体势垒制成的，因此，它是一种热电子发射二极管，随着制造工艺的不断完善及特殊材料的出现，肖特基势垒栅FET及其高速大规模集成电路和超大规模集成电路领域的广泛应用，肖特基二极管的应用范围也越来越广。

These results show that the ring expansion of cyclopropylsilylene C3H5SiH to silacyclobutene is easy to occur with a barrier of 113.4kJ/mol, while the 1,2-H shift is not competitive to the ring expansion for its much higher barrier.

结果表明，环丙基硅烯经过113.4kJ/mol的势垒扩环重排为硅杂环丁烯为自发反应；而其1，2-氢迁移重排反应热垒为190.0kJ/mol，是非自发反应，难于进行，不能与扩环重排相竞争。

Cynanchum Lingtai apricot production in the average weight 65 grams, the brightly-colored fruit, juicy rich, sweet-sour taste, sweet from the nucleolus, when the late Qing Dynasty famous Shaanxi, Gansu provinces, the Qing imperial court Tongzhi tribute for years.

灵台生产的牛心杏平均单果重65克，果实色泽鲜艳，汁多味浓，甜酸适口，离核仁甜，清末时就驰名陕、甘两省，清同治年间曾为朝廷贡品。

Chenopodium album,Solanum nigrum, and Amaranthus retroflexus were very susceptible to the herbicides. Polygonum persicaria and Abutilon theophrasti were relatively less susceptible to the herbicides, and Lycopersicon esculentum was not susceptible to it. The relationship between reduction rates of weed biomass and PPM values of weed leaves 2,4, and 6 days after treatment was established.

供试的6种杂草对该混剂的敏感性存在显著差异：红心藜Chenopodium album、龙葵Solanum nigrum和反枝苋Amaranthus retroflexus对该混剂最敏感，ED90值分别为47.65、71.67和29.17g/hm2；春蓼Polygonum persicaria和苘麻Abutilon theophrasti敏感，ED90值分别为96.91、114.20g/hm2；而番茄不敏感。