摘要：The effects of the composite-collector structure and the δ-doping density in InGaAs/InP DHBT on the Kirk current have been *** effective grade layer in the discretely graded layer goes into the InGaAs setback *** formulas of the maximum doping density,the maximum Kirk current,and the corresponding δ-doping density are derived under different Kirk-effect *** the maximum collector doping density and the maximum Kirk current are dependent on the δ-doping *** opti-mizing the delta doping,the Kirk current density can be greatly increased.

摘要：Nowadays Quantum Cellular Automata (QCA) as the leading technology in design of microelectronic systems has been raised. With respect to high velocity and density in low power and also simple concepts, this technology is a viable alternative to CMOS technology. In collector design, the primary component of each processor is very important. Due to the small elements in this technology, failure rate in manufacturing process technology is very high. In the other hand, the simulation shows that the intersection point of two wires is one of the critical points in QCA circuits. This means that defects in the manufacturing process around these points can cause malfunction in the circuit performance. In this paper, a collector in cross sections of wire in his new method used higher reliability against defects during manufacturing has been developed. QCA Designer software is used to simulate the case study system.

摘要：A new class of compact and lightweight S-band 1 kW traveling-wave tube (TWT) is being developed for a microwave power module (MPM) that will be used for phased antenna array radar applications. The proposed S-band MPM provides a tenfold peak power increase compared to state-of-the-art S-band MPMs. In this paper, the design of the vacuum power booster TWT part of the MPM is presented. The compact and lightweight S-band TWT is driven by a 6 kV, 0.9 A electron beam. The amplifier is predicted by large-signal simulations to generate over 1 kW at S-band with 25 dB saturated gain and over 40% efficiency. The stability from unwanted oscillations has been investigated. To suppress the oscillations, the helix circuit has been coated with carbon composite material. The coaxial input and output antennas have been fabricated. For efficiency enhancement, a multi-stage depressed collector (MDC) has been designed using a 3D particle-in-cell (PIC) simulator, VORPAL. The collector design makes use of a current loop based on a feedback mechanism for effective design process. The integrated designs of a helix circuit, an electron gun, a periodic permanent magnet (PPM), antennas, and a collector are presented.

摘要：Solar collectors can provide clean, renewable, and domestic energy. The tilt angle and horizontal direction of solar collectors significantly affect its efficiency. There are many good methods to search the optimum tilt angle and horizontal direction to realize the maximum total radiation on the solar collector within a particular day or a specific period. However, it is hard to realize it when solar collectors are placed under obstacle’s shadows;especially when some obstacles, such as trees, have irregular shapes. This paper presents algorithms to achieve the best tilt angle and horizontal direction for solar collector’s performance under the free-form surfaces 3D obstacle’s shadow. The solution process is composed of 4 steps. First, it creates a 3D scene, in which a unique color is given to the solar collector. Second, it employs orthographic projection from the point of view to get an image of the scene. Third, the number of pixels is used to represent the efficiency of the solar collector by counting the pixels of the unique color. Fourth, the efficiency of solar collector in each direction in a period of time is calculated with many images to further select the best direction.

摘要：基于复合抛物面型集热器(CPC)的光学特性,介绍了一种新型的选择性太阳光隧道,采用光线跟踪法分析并计算其冬夏两种工况下的光学特性。结果表明,选择性太阳光隧道利用冬夏两季太阳高度角的差异可实现不同的吸热效果,为设计改进太阳能集热器提供了理论依据。

摘要：报道了异丙基膦酸单烷基酯和烷基异丙基磷酸这两类新型捕收剂的合成方法。用浮选药剂分子设计的基团电负性方法和量子化学EHMO方法对这两类药剂的性能作了计算预测,指出它们适合用作盐类矿物的捕收剂,并以P—O—Ca的电荷控制作用方式在矿物表面发生化学吸附。