发射电流跌落的机理较为复杂。
另一个是如何提高发射极发射电流的有效面积。
One of the commonly used methods to reduce this fall-off is by increasing the emitter area.
但不足之处是发射电流密度太小和有较大的栅极电流。
But it provides too small emission current density and gives a large gate current.
为削弱一次场的影响，减小探测盲区，需要记录发射电流波形。
To weaken the effect of the primary field and reduce the blind zone of exploration, the transmitting waveform needs to record.
在场致发射器件中，发射电流通常会随着工作时间的增加而跌落。
In field emission devices, the emission current sometimes degrades with the time.
研究了利用丝网印刷法制备碳纳米管阴极，以获取很大的发射电流。
A carbon nanotube cathode with high emission current has been fabricated with the screen printing method.
研究结果表明，温度、压力、电压对发射电流均有不同程度的影响。
The results of study show that the temperature, pressure and voltage can exercise an influence on emission current to various degrees.
目的研究金刚石场发射阴极处理工艺对场发射电流和阈值电压的影响。
Aim To study the effects of different dispersers and heat-treatment under different plasma atmospheres on field emission current and threshold value electric field.
应用转移矩阵法，求出了垂直于界面的量子能级，并计算了场发射电流。
By using the transfer matrix method, we calculated the quantum energy levels and emission current.
针对场致发射阵列建立了有效的三维有限元模型来分析单个尖锥的发射电流。
An effective 3-d finite element model was constructed for the field emission array to analyse the field emission current over a single tip.
本文设计实现了应用在全程瞬变电磁仪器系统发射机中的发射电流下降沿记录系统。
A record system of transmitted current used in All-time Transient Electromagnetic system transmitter is implemented in this thesis.
铁电阴极材料，作为一种新型的功能材料，以其高的发射电流密度等优点而受到重视。
Being a novel functional material, the ferroelectric cathode materials were studied well with the leaded materials for their high electron emission density.
提出了一种无需施加磁场、利用发射电流衰减速度测量真空开关灭弧室真空度的新方法。
A new method is presented for measurement of internal pressure of vacuum interrupters, having no use of magnetic fields but using decay velocity of emission current.
该冷电弧阴极在发射电流为150安培情况下已累计运行100小时以上并可继续运行。
The lifeime of the cathode at this current amounts to 100 hours and it is still capable of continuing the operation.
并讨论由此而导致的开启电场的变化、场发射电流密度的变化以及亮度和稳定性的变化。
Finally we discuss the differences of turn-on voltage, field emission current density and the stability of field emission display because the differences of the cathode of field emission.
实验数据还表明，快速报警响应时间与气体分子浓度和真空计规管灯丝的发射电流密切相关。
The results show that the alarm time depends strongly on both the gas concentration and the emission current of the ionization gauge.
碳纳米管薄膜机械强度高，化学稳定性好，并且有很低的发射场强阀值，较高的发射电流密度。
The aligned nanotube thin films are substantially strong, and chemically inertial with their onset field low and the emission current strong.
根据显象管阴极电流模拟值等于整幅图象的电流数字值之和的原理，可推出各象素的发射电流密度。
It is supposed that the relation between the analog current and the summation of the digital current value of picture element is equal.
计算了在100V门电压下不同顶端半径的场致发射电流。结果显示，场发射对顶端半径有很强的依赖性。
Field emission currents were calculated for different apex radii at the gate voltage of 100v, and the results indicated that the field emission largely depends on the apex radius.
该电子发射膜可以在其使发射电流流动时将场强限制为低水平，并且该电子发射膜具有均匀的电子发射特性。
The electron emission film can restrict the field intensity to a low level when it causes an emission current to flow, and has a uniform electron emission characteristic.
锥体上电位变化可以等效为一个与锥体形状与掺杂相关的串联电阻的作用，这一电阻对单尖发射电流有负反馈作用。
This resistance, which is concerned with the doping and shape of the emitter, has a negative feedback action to the emission current of the emitter.
利用磁路电子注发射方式针对不同的阴极发射电流进行了动态模拟，得到了不同发射电流条件下磁控管的工作特性。
Using beam emission models, the influence to the magnetron characteristics by the cathode current destiny can be obtained.
如果碳纳米管阴极附近的真空度太低，将产生打火、气体电离、离子回轰阴极等问题，将导致阴极发射电流的迅速衰减。
If the vacuum near the cathode is too poor, it will generate spark, gas ionization and ion bombardment on cathode, which can result in a fast attenuation of the emission current.
在以半腔为首腔的边耦合驻波加速管中观察到了电子反轰现象，由于电子反轰的结果，导致电于枪发射电流非正常增长。
The electron back bombardment phenomenon, which results in anomalous increase of gun current emission, has been observed in a series of our side coupled standing wave accelerating tubes.
影响碳纳米管阴极场发射稳定性和寿命的主要因素有真空度、场发射过程中的热效应以及场发射体对场发射电流的承载能力等。
Field emission stability and life time of CNT cathode is closely related with the vacuum level, thermal effects during the emission and the current transport capability.
对阴极温度的不均匀导致的发射电流偏差进行了计算分析，并首次得到了发射电流误差小于5%的阴极丝最小长度的计算公式。
Non uniform temperature distribution causes deviation in emission current, the error of which is less than 5% for the shortest length of diode cathode.
其电弧稳定与否，主要取决于电流过零瞬间的电弧空间电离度、电极发射电子能力及再引燃电压的上升速度。
The stability of the welding arc depends mainly on the voltage and the gas ionization when current zero-crossing as well as the electron emission ability of the electrode.
极大的射电流量同极小的角经集于一身，意味着这些发射源有难以置信的高表面亮度。
The combination of very large radio flux and exceedingly small angular size means that the sources have a fantastic surface brightness.
极大的射电流量同极小的角经集于一身，意味着这些发射源有难以置信的高表面亮度。
The combination of very large radio flux and exceedingly small angular size means that the sources have a fantastic surface brightness.
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