一种用于热阴极的高可靠热子

微波真空电子器件广泛应用于雷达、卫星通信、电子加速器等方面,热子又是微波真空电子器件中最为核心的部件之一,其性能好坏将直接影响微波源的可靠性和寿命。为了克服传统热子制备工艺的缺点,避免螺旋腿部分的钨或钨合金丝出现损伤,提供一种高可靠热子制备方法,采用高温焊料焊接技术将螺旋丝与插腿焊接在一起,从而制备出具有螺旋腿与插腿之间接触电阻小、耐震动性能好、抗热冲击性能好和可靠性高等优点的热阴极用热子。采用新方法制备的热子在1100℃高温下寿命已超过3000 h,没有出现断路现象,目前在各种微波管上使用了新方法制备的热子,没有出现一只断路。     

真空热蒸发镀CIAS薄膜

采用真空热蒸发方法在普通玻璃基底上制备Cu In0.7Al0.3Se2(CIAS)薄膜,并对之进行450℃真空硒化退火处理。结果表明,制备的CIAS薄膜具有黄铜矿结构并且以(112)晶面优先生长。真空硒化退火后,薄膜晶体结构更完整,晶粒长大,成分分布均匀,更接近CIAS晶体的化学计量比。薄膜为P型半导体,退火后的薄膜禁带宽度减小至1.38 e V,带电粒子数下降至2.41E+17 cm-3,带电粒子迁移率增加至5.29 cm2/(N·s),电阻率升高至4.9Ω·cm。     

A Versatile Buffer Layer for Polymer Solar Cells: Rendering Surface Potential by Regulating Dipole

Spin‐coated film of poly(vinylidenefluoride‐hexafluoropropylene) (P(VDF‐HFP)) acts as a cathode/anode buffer layer in polymer solar cells (PSCs) with conventional/inverted device structures. Such devices show optimized performances comparable with the controlled device, making P(VDF‐HFP) a good substitute for LiF/MoO₃ as a cathode/anode buffer layer. Ultraviolet photoelectron spectroscopy (UPS) and Kelvin force microscope (KFM) measurements show that increased surface potential of active layers improves cathode contact. In piezoresponse force microscopy (PFM) measurement, P(VDF‐HFP) responds to applied bias in phase curve, showing tunable dipole. This tunable dipole renders surface potential under applied bias. As a result, open‐circuit voltage of devices alters instantly with poling voltage. Moreover, positive poling of P(VDF‐HFP) together with simultaneous oxidation of Ag gradually improves performance of inverted structure device. Integer charge transfer (ICT) model elucidates improved electrode contacts by dipole tuning, varying surface potential and vacuum level shift. Understanding the function of dipole makes P(VDF‐HFP) a promising and versatile buffer layer for PSCs.     

A Graphene‐Based Vacuum Transistor with a High ON/OFF Current Ratio

A graphene‐based vacuum transistor (GVT) with a high ON/OFF current ratio is proposed and experimentally realized by employing electrically biased graphene as the electron emitter. The states of a GVT are switched by tuning the bias voltage applied to the graphene emitter with an ON/OFF current ratio up to 10⁶, a subthreshold slope of 120 mV dec^?1 and low working voltages of <10 V, exhibiting switching performances superior to those of previously reported graphene‐based solid‐state transistors. GVTs are fabricated and integrated using silicon microfabrication technology. A perfectly symmetric ambipolar device is achieved by integrating two GVTs, implying the potential of realizing vacuum integrated circuits based on GVTs. GVTs are expected to find applications in extreme environments such as high temperature and intense irradiation.     

ZN18真空断路器操作机构中合闸线圈烧坏原因分析

ZN18系列真空断路器合闸线圈为短时工作制线圈,由于构成合闸回路的元件多,若维护不当或不到位,使用运行中出现合闸线圈烧坏和面临烧坏的情况时有发生,所以对其各种故障原因加以分析,便于确保ZN18真空断路器的正常工作运行。     

炼油常减压装置常顶系统腐蚀分析及防护

本文详细阐述了常减压装置加工高硫原油时常压塔顶冷祷凝冷却系统的腐蚀情况,针对多次发生的泄漏,分析主要原因为：加工原油劣质化;常压塔顶注水量不足,初凝区后移;常压塔顶介质流速过大,冲刷腐蚀严重。针对上述原因采取了以下措施：优化原油采购及掺炼比例;完善工艺防腐措施,提高常压塔顶注水量;适当降低常压塔顶负荷等。这些措施实施后,取得了较好的防腐效果。     

板翅式铝合金散热器真空钎焊技术的发展

综述了板翅式铝合金散热器真空钎焊的原理、预处理工艺、装配状况、真空钎焊工艺等。结合生产实际和试验情况,着重探讨了目前板翅式铝合金散热器真空钎焊成功率低的原因及解决方法。     

Application of Diffusion Brazing in Stockage of Vacuum Electronic Devices

The vacuum electronic device is the key components widely used in the fields of radar, navigation, electronic warfare and so on. Multi-brazing process is adopted in the manufacturing, and the leakage is easy to happen at many parts, such as brazed seams and base materials of tube shell, leading breakage of the devices. But now the brazing filler metal used in the stockage of vacuum electronic devices is very seldom. For the safe of vacuum electronic devices, stockage temperature must be lower than the brazi...     

Study on Process Parameters of Vacuum Differential Pressure Casting

Vacuum differential pressure casting has advantages of smelting in vacuum, filling steadily, solidifying under high pressure. Process parameters of filling and solidification are important to the final castings’ forming properties, the parameters include vacuum degree, gas flow, filling velocity, filling pressure, rising pressure velocity, holding pressure and keeping pressure time. By casting copper alloy impeller, we calculated and deduced the gas flow, filling velocity, filling pressure, rising pressure ...     

真空度对TiB2/Al复合材料摩擦行为的影响（英文）

在不同真空度条件下(0.01、0.03、0.05、0.07和0.1MPa),采用销盘式摩擦磨损试验机研究气压对TiB2/Al复合材料的摩擦学行为的影响。结果表明:随着气压的增加,摩擦系数呈现下降的趋势,而磨损率变化不大。能谱分析表明,随着真空度的升高,磨损表面的Fe含量逐渐下降,与摩擦系数的下降趋势保持一致。