热电子发射

Tantalum is an ideal material for hot cathode. It has a low electronic work function, high melting-point, low evaporativity, and good mechanical, high-temperature, chemical properties. Especially in a PCVD ambient for diamond film deposition, its surface is transformed into tantalum carbide which has a much higher melting-point, lower evaporativity and better properties of electron emission.

钽是一种理想的热阴极材料，它具有电子逸出功低、熔点高、蒸发率小、良好的机械性能、高温性能、化学稳定性等优异特点，尤其是在辉光放电PCVD制备金刚石膜的特殊气氛中形成的碳化钽表面层，具有比钽更高的熔点、更低的蒸发率和更好的热电子发射特性。

It has no direct influence on the deposition of diamond films, but is a key region for the sustain of high current glow discharge.

在阴极的表面上，由于正离子轰击的二次电子发射和热电子发射两个过程，共同产生了初始电子。

This paper,by applying the theory of probability statistics,explains the relationship between the emission current I and the interelectrode voltage U in the thermoelectron emission phenomene,and then gives the expression of their relationship:I=ImΦ.

本文应用概率统计的理论对热电子发射现象中发射电流 I和两极间电压 U之间的关系进行了解释，得出它们的关系是： I=ImΦ，并给出关于参数 Im、 a、 b的确定方法。

In this paper, nanopowders of rare earth oxides and tungsten were prepared and 0-3 type nano-composit rare earth tungsten thermionic emission materials were fabricated with novel technics. The raw material selection, preparation technic parameter, structure, physical and chemical characteristic, the rare earth distribution and the emission behavior were studied. The influence between the active layer and the thermionic emission performance, rare earth elements diffusion and distribution along depth were investigated in detail. The surplus RE formation and the electron transfer were discussed in theoretically. The thermionic emission current density of the single surplus RE on the active layer was educed. We adopted "liquid-liquid mixing, freeze-drying and two stage-reduction" working step firstly to produce the RE-W nanopowders including La-W powder, Ce-W powder and Y-W powder.

本文采用细化显微组织的新工艺，制备了纳米稀土钨粉末和0-3型纳米复合稀土钨热电子发射材料，探讨研究其原料选择、制备工艺及参数、结构特征、物理和化学特性、稀土分布均匀性、以及热电子发射特性；系统研究了稀土元素的高温扩散情况、高温状态下活性层中稀土的纵向深度分布、以及表面活性物质和活性层厚度对热发射性能的作用；从理论上分析阐释了超额稀土的形成及其电子的传递过程；并从理论上推导了活性层中单个超额稀土的热电子发射电流密度。

We now know that this device operated by emitting electrons from the single electrode through a combination of field emission and thermionic emission.

现在大家都知道这个装置运作是电子从单一的电极通过结合场发射和热电子发射。

The liberation of electrons from a hot wire is called thermionic emission .

电子从热灯丝逸出，叫做热电子发射。

Aring; of nanometre LaOx particle . On the basis of the results of the previous chapters , a new thermionic emission mechanism was put forward.

薄膜"发射新观点，解释金属薄膜型阴极的热电子发射机理，更深入地揭示热电子发射的内在规律。"

According to the electron transport mechanisms through the metal-semiconductor-metal junctions, two kinds of I/V characteristics are possible. One is based on thermionic emission theory and the other is related to tunnelingmodel.

根据电子在金属半导体接触中的输运机理，课题中主要讨论了热电子发射理论和电子隧穿理论。

Aring; of nanometre LaOx particle . On the basis of the results of the previous chapters , a new thermionic emission mechanism was put forward.

薄膜&发射新观点，解释金属薄膜型阴极的热电子发射机理，更深入地揭示热电子发射的内在规律。&

It indicates that the theory of monoatomic layer can't explain perfectly emission mechanism of La2O3-Mo cathode;the excess active lanthanum is crucial element to the improvement of thermionic emission.

标 签 激光技术热电子发射发射机制脉冲激光沉积薄膜 laser technique thermionic emission emission mechanism pulse laser deposition thin film

With Death guitarist Schuldiner adopting vocal duties, the band made a major impact on the scene.

随着死亡的吉他手Schuldiner接受主唱的职务，乐队在现实中树立了重要的影响。

But he could still end up breakfasting on Swiss-government issue muesli because all six are accused of nicking around 45 million pounds they should have paid to FIFA.

不过他最后仍有可能沦为瑞士政府&议事餐桌&上的一道早餐，因为这所有六个人都被指控把本应支付给国际足联的大约4500万英镑骗了个精光。