0. 6 􀀁m CMOS 雷达天线专用控制芯片设计

雷达系统中天线控制电路完成上位机的初始化和扫描角度控制,要求具有高可靠性和低静态电流,用专用集成电路进行设计具有明显优势.采用Verilog HDL语言描述了系统的逻辑功能,超前进位结构的加/减法器提高了电路的工作速度.利用0.6 μm CMOS工艺完成了天线控制电路的物理实现,芯片面积为1.695 mm×1.631 mm.     

离子型共聚单体参与下的全氟丙烯酸酯无皂乳液共聚

离子型共聚单体参与下的全氟丙烯酸酯无皂乳液共聚;全氟烷基丙烯酸酯;无皂乳液;离子型共聚单体     

A 1.107 μm Yb3+-doped Phosphate Fiber Laser Pumped by a Ti:sapphire

Lasers and amplifiers in a single fiber have been developed rapidly, especially for optical fiber communication and various sensors, in the recent years. However, remarkable progress and achievement have been made mainly in silica fiber doped with rare earth elements. In this paper, we report the progress on the development of the Yb3+-doped phosphate fiber laser.     

Hydrophobic/hydrophilic solvation: inferences from Monte Carlo simulations and experiments

In this study Monte Carlo simulations are used to determine the solvation properties of model hydrophobic (xenon and hard sphere) and hydrophilic (dimethyl ether) solutes in SPC/E water. Various contributions to the experimental solvation entropy, including the solvent reorganization entropy, have been determined. The main conclusion drawn, which is in accord with solubility data, is that poor solubility correlates with poor solute-water interaction. At room temperature, energy dominates the aqueous solubility of both hydrophobic and hydrophilic solutes, rather than entropy. However, at higher temperatures the solubility can pass through a minimum, and then entropy becomes dominant. Another interesting finding is the presence of larger than expected cavities in water. Two different simulation results support this finding. This unexpected hollow structure in water explains why a hard sphere solute is more soluble in water than in a comparable hard sphere or Lennard-Jones solvent. Hydrogen bonding causes water to aggregate into clusters that produce a few large cavities rather than many smaller cavities. The propensity for clustering also explains why water gives the illusion of being a low density liquid. Sufficient theoretical apparatus is developed to connect theoretical solvation properties to those measured by simulation and experiment. Finally, based on gas solubility, an intuitive hydrophobic/hydrophilic scale is developed.     

A molecular dynamics study of carbon dioxide in water: diffusion,structure and thermodynamics

Atomistic simulations are reported of a model of CO₂ in water. CO₂ is modelled by partial charges and Lennard-Jones interaction sites on each atom; the SPC/E model for water is used. Good agreement with experiment is found for the translational diffusion constants. The variation of the dynamics with the potential parameter was investigated. As expected, the orientational correlation times increase as the magnitude of the quadrupole moment is increased, but the translational diffusion constants are found to be surprisingly insensitive to the magnitude of the CO₂ quadrupole moment. The translational friction coefficient was resolved into electrostatic, Lennard-Jones and cross-terms; the Lennard-Jones contribution is found to be the largest. Varying the Lennard-Jones size parameter affects both translational and reorientational motion. In order to try to understand these results further, the variation of solvation free energy was investigated and the solvent structure around carbon dioxide was examined as the electrostatic and Lennard-Jones parameters were changed. The temperature dependence of the self-diffusion constant of pure SPC/E water was determined.     

基于矩量法的螺旋天线设计

螺旋天线具有宽波束、圆极化等特性。以往的轴向螺旋天线多为端射式,辐射方向单一。为弥补这一不足,提出了一种新型的中馈轴向螺旋天线。基于RWG(Rao-Wihon-Glisson)边元的矩量法,采用MATLAB仿真计算出中馈螺旋天线的方向图、反射系数、增益等重要参数。又利用高频结构仿真软件(HFSS)对所设计的中馈螺旋天线进行了仿真。通过两种方法仿真得到的结果吻合较好,仿真结果的正确性得到了验证。实验结果表明:中馈轴向螺旋天线不仅具有以往轴向螺旋天线所具备的定向性好和高增益等优点,还具有两个反向且强度相同的辐射方向,同时天线增益可以达到8dB以上,半功率波束宽度可达33°。这种天线可以应用到多边通信及中继通信等领域。     

扭摆式微硅隧道加速度传感器

本文介绍了扭摆式隧道加速度传感器的结构、工作原理、简化的力学模型,设计了版图、工艺流程及关键工艺,并制备出样品,最后给出测试电路和结果。     

一种用于LCD驱动的电荷泵电路

基于GSMC0.18μm±9VCMOS三阱工艺,设计了一种用于LCD驱动的正、负压电荷泵电路。该电荷泵采用共享耦合电容的结构并,结合了一种新的衬底偏置技术,在较小的面积代价下,可达到较强的驱动能力和较高的效率。测试结果表明,该电荷泵在1mW的输出功率下,效率可达到60%,而电路面积仅为0.51mm2。     

STUDY OF THE MECHANISM OF 12C（d,d）12C AND 12C（d,p）13C* REACTIONS

A formalism for studying the interference between the direct reaction and the compound resonance processes is presented by the S-matrix theory; The mechanism of ¹²C（d, d） ¹²C, ¹²C（d, p₁） ¹³C* and ¹²C（d, p₂） ¹³C* reactions in the energy range E_d=1.63 MeV to 2.05 MeV is analysed.Te results show that: the interference between these two processes exists; and the quantitative relation between them is given. While the parameters of direct reactions and compound resonance processes, particularly for four resonance states with E_d=1.726, 1.767, 1.792 and 1.86 MeV are determined.     

关于微积分解题的两个注记

微积分是理工科大学生的一门非常重要的基础课.给出了微积分中求未定式极限时需注意采取的一个措施及由微分方程的通解求相应的微分方程的一般方法,并给出了算例.