激光束整形为正方框形光束的DOE的设计及实验

以几何理论为基础来设计将激光束整形为正方框形光束的衍射光学元件(DOE),推导出了衍射光学元件表面上的相位表达式;以高斯光束整形为例,将其整形为所需要的光强分布;进行了计算机模拟,得到了比较好的结果;同时也进行了实验验证,实验结果证明了设计方法、理论推导以及程序设计的正确性。     

掺杂元素对Ni-Mn-Ga合金结构与性能的影响

Ni-Mn-Ga合金是一种新型的智能材料,兼具铁磁性和形状记忆效应的双重优点,以对磁场的快速响应和大的宏观可恢复应变的特点有望成为传感器和驱动器的候选材料.通过掺入金属元素可以弥补该合金马氏体相变温度低,脆性大的不足.综述了掺杂元素对合金结构、相变温度、力学性能、形状记忆效应的影响,并提出了需要深入研究的问题.     

Design of the compact UHF RFID meander-line antenna loaded with CPW elements

In this paper, Coplanar Waveguide (CPW) elements are used to load UHF RFID meander-line antennas. Although, the insertion of these elements allow to design small antennas their gain decrease depending on the CPW structures are connected. In this sense, a new location to print CPW elements in the meander-line antenna is proposed aiming not to deteriorate the gain. A multi-objective optimization algorithm is applied in the meander-line antennas loaded with CPW elements in different positions and a comparison between their performances is done. To validate the computational model of the proposed antenna its input impedance is measured.     

句法分析与消解PCFG改进

概率型的句法分析模型具有一定的消岐能力,PCFG的最大特点上下文无关,对于开放领域的自然语言分析来说具有较长的鲁棒性。但上下文无关假设不可能很好地表示语言的特点,难t,X解决需要上下文信息才可以消解的句法分析岐义．而且它只考虑了词类信息而没有考虑词汇或语义信息,所以对语言的描述也是粗粒度的。本文结合知网定义句子成分结构语义关联度,对PCFG分析结果改进,句法岐义有效改善。     

大学生创新能力培养模式的探索与实践

研究创新人才培养规律,探索和实践创新人才培养模式,是当前高校教育教学改革的一个重要方向。针对我校自动化专业立足国防、面向社会的人才培养特色,提出了以“创新意识、创新精神、创新技能”为核心的学生创新能力培养理念,通过构建创新能力培养“全链”模式、优化创新能力培养的“微生态”环境,取得了突出的成效。     

Microstructure, solderability, and growth of intermetallic compounds of Sn-Ag-Cu-RE lead-free solder alloys

The near-eutectic Sn-3.5 wt.% Ag-0.7 wt.% Cu (Sn-3.5Ag-0.7Cu) alloy was doped with rare earth (RE) elements of primarily Ce and La of 0.05–0.25 wt.% to form Sn-3.5Ag-0.7Cu-xRE solder alloys. The aim of this research was to investigate the effect of the addition of RE elements on the microstructure and solderability of this alloy. Sn-3.5Ag-0.7Cu-xRE solders were soldered on copper coupons. The thickness of the intermetallic layer (IML) formed between the solder and Cu substrate just after soldering, as well as after thermal aging at 170°C up to 1000 h, was investigated. It was found that, due to the addition of the RE elements, the size of the Sn grains was reduced. In particular, the addition of 0.1wt.%RE to the Sn-3.5Ag-0.7Cu solder improved the wetting behavior. Besides, the IML growth during thermal aging was inhibited.     

Simulation of vertical merged MOS elements with optical power supply

Functional optoelectronic vertical merged MOS (OVMMOS) elements with optical power supply increasing the packaging density for advanced high-speed low-voltage low-power deep-submicron ULSI are considered. Two types of new OVVMOS logical elements are proposed, analyzed and simulated. The simple reduced but adequate numerical electrical-optical model for the OVMMOS is formulated. Low-voltage low-power OVMMOS with combined channels for electrons and holes to increase integration level are simulated using two-dimensional (2D)-numerical device simulators. The problems of low light power operations and optimizations of OVMMOS elements are investigated using 2D simulators.     

线性调频-捷变频对三元组目标定位精度的影响

在射频仿真系统中,精确的目标角位置通过“三元组”幅相控制实现,幅相控制误差直接影响阵列上目标位置的模拟精度。当工作频率发生变化时,受阵列系统瞬时带宽的限制,目标阵列角位置的模拟精度将发生变化。本文从目标阵列的角位置模拟原理出发,分析了线性调频和频率捷变引起的通路幅度和相位误差对三元组目标定位精度的影响,为研究线性调频和捷变频状态下的目标定位控制提供了一定的依据。     

半桥QRC印制板的电磁兼容研究

以半桥ZVS准谐振变换器作为研究对象,借助Cadence软件对开关电源PCB进行了建摸分析、提取寄生参数和电磁兼容仿真分析,并进行了优化布局设计。实现了开关电源PCB的计算机辅助电磁兼容分析和计算机辅助最优布局设计,从而可以在PCB设计阶段就对其潜在的电磁干扰源进行抑制,为开关电源电磁干扰的解决和PCB电磁兼容设计提供了一种较为合理有效的研究思路。     

湖南下寒武统石煤中的镍钼铂族元素的地球化学特征

从岩石学、矿床学、微量元素地球化学、稳定同位素方面对湖南下寒武统石煤中镍、钼、铂族元素为主的伴生元素的来源和富集成因进行了研究研究认为，含矿岩系中发育的硅岩是一种喷流岩；有海底喷流作用直接堆积的金属硫化物筒状富矿体；矿石中各种胶状结构发育；矿床具两套成矿系统；微量元素Ｓｅ，Ａｓ，Ｂａ高地壳丰度数倍至数万倍；矿层中硫同位素值为－１３００％～－１７６１％等证实了湖南下寒武统石煤中以镍、钼、铂族元素为主的伴生元素，其来源和富集并非陆源搬运沉积，而是与海底喷流作用有关