UV-LIGA深度光刻机平滑衍射技术研究

UV-LIGA深度光刻技术是加工微型机电系统的一项重要的微细加工技术。介绍了一种平滑衍射效应的位错强度叠加原理，它采用了蝇眼积分透镜去平滑衍射，并模拟数值计算了硅片表面的光强分布，最后给出了光刻结果。     

光网络接口信令系统容错设计的分析和验证

为实现动态指配光网络资源功能，提出了一种用户网络接口（UNI）信令协议系统，该协议系统基于层叠模型，支持多种类客户寻址，分析了协议系统设计的出错处理并采用时序逻辑描述和验证了其容错性质，验证结果表明，系统在网络正常和超时故障条件下均能确保对光通道的建立，修改、拆除和查询等操作无误。     

一种基于灰度连续区域分割的视频对象分割方法

针对目前许多分割方法中分割边界不精确、计算复杂和缓存帧多等问题，提出了一种结合空间区域分割和运动象素检测的自动分割方法：先将当前视频帧分割为不同的灰度连续区域，再利用二次帧差确定视频图像中的运动象素，然后按一定的规则确定哪些灰度连续区域属于运动区域，从而有效地从静止的复杂背景中分割出运动对象区域。实验结果表明这种分割方法计算简单、分割边界比较精确。     

一个新的门限多重代理多重签名方案

In the Paper, we proposed a threshold mult- proxy multi-signature with share verification.In the scheme,a subset of original signers allows a designated group to proxy signers to sign on behalf of the original group, A message m has to be signed of proxy signers who can represent the proxy group. Then, the proxy signature is sent to the verifier group.A subset of verifiers in the verifier group can also represent the group to authenticate the proxy signature.In othe words,some threshold values will be given to indicate the number of persons to represent a group to authorize the signing capability or to sign a messagye or to verify the proxy signature.     

Contact transition control via joint acceleration feedback

Stable and controllable transition from free motion to constrained motion is of central importance for robots in contact with the environment in many applications. In this paper, a joint acceleration feedback control scheme of high bandwidth is employed to damp oscillations during the contact transition when the approaching speed does not vanish. In this control scheme, a classical integral force controller is refined by means of joint acceleration and velocity feedback. This is intended to achieve a stable contact transition without need of adjusting the controller parameters adaptive to the unknown or changing environments. Extensive experiments are conducted on the third joint of a three-link direct-drive robot to verify the proposed scheme for the environments of various stiffnesses, including elastic (sponge), less-elastic (cardboard), and hard (steel plate) surfaces. Results are also compared with those by the transition control without the acceleration feedback. The proposed scheme is shown to be promising in terms of robustness, stability and adaptability     

SiC宽禁带功率放大器的设计与实践

介绍了SiC宽禁带功率器件的特性,与Si功率器件相比,该器件在输出功率、功率密度、工作频率、工作带宽、环境适应性、抗辐射能力等方面有卓越的性能.利用SiC宽禁带功率器件设计制作了L波段100W功率放大器.对SiC宽禁带功率放大器进行性能测试和环境实验,分析了SiC宽禁带功率器件的性能特点和优势.SiC宽禁带功率器件有利于提高功率放大器的工作带宽,改善功率放大器的环境适应性.     

Perovskite Single Crystals: Synthesis,Optoelectronic Properties,and Application

Recently, lead halide perovskite (PVSK) polycrystalline films have drawn much attention as photoactive material and scored tremendous achievements in solar cells, photodetectors, light-emitting diodes, and lasers owing to their engrossing optoelectronic properties and facile solution-processed fabrication. However, large amounts of grain boundaries unfavorably induce ion migration, surface defect, and poor stability, impeding PVSK polycrystalline film-based optoelectronic devices from practical application. In comparison with the polycrystalline counterparts, PVSK single crystals (SCs) with lower trap density serve as a better platform for not only fundamental research but also device applications. In light of this, the idea of using PVSK single crystals (SCs) to construct the optoelectronic devices is then proposed. Since then, a series of synthesis methods of PVSK SCs have emerged. In this review, recent progress of synthesis method of PVSK SCs is tried to be summarized and their advantages and limitations are analyzed. And then, the optoelectronic properties including carrier dynamic, defects, ion migration, and instability issues in these 3D and 2D PVSK SCs are overviewed and accordingly the proper device configurations of corresponding solar cells, photodetectors, X-ray, γ-ray detectors, etc., are proposed. It is believed that this review can provide the guidance for the further development of PVSK SCs and their applications.     

Charge Transportation and Chirality in Liquid Crystalline Helical Network Phases of Achiral BTBT-Derived Polycatenar Molecules

First examples of multichain (polycatenar) compounds, based on the π-conjugated [1]benzothieno[3,2-b]benzothiophene unit are designed, synthesized, and their soft self-assembly and charge carrier mobility are investigated. These compounds, terminated by the new fan-shaped 2-brominated 3,4,5-trialkoxybenzoate moiety, form bicontinuous cubic liquid crystalline (LC) phases with helical network structure over extremely wide temperature ranges (>200 K), including ambient temperature. Compounds with short chains show an achiral cubic phase with the double network, which upon increasing the chain length, is at first replaced by a tetragonal 3D phase and then by a mirror symmetry is broken triple network cubic phase. In the networks, the capability of bypassing defects provides enhanced charge carrier mobility compared to imperfectly aligned columnar phases, and the charge transportation is non-dispersive, as only rarely observed for LC materials. At the transition to a semicrystalline helical network phase, the conductivity is further enhanced by almost one order of magnitude. In addition, a mirror symmetry broken isotropic liquid phase is formed beside the 3D phases, which upon chain elongation is removed and replaced by a hexagonal columnar LC phase.     

结合局部能量与改进的符号距离正则项的图像目标分割算法

针对传统C-V模型对颜色不均匀图像分割失败并且对初始轮廓和位置敏感问题,以及现有符号距离正则项存在周期性振荡和局部极值问题。该文提出结合局部能量信息和改进的符号距离正则项的图像目标分割算法。首先,将全局图像信息扩展到HSV空间,并使用局部能量项信息分析每个像素及其领域内的统计特性,从而在较少的迭代次数内有效分割颜色分布不均匀图像。其次,改进现有符号距离正则项,改进后的符号距离正则项在避免水平集函数的重新初始化的同时,提高了计算效率,保证了水平集函数演化过程的稳定性。然后,定义阈值判断法的水平集函数演化的终止准则,使曲线准确演化到目标轮廓。该算法与同类模型的对比实验表明该模型具有较高的分割精度和对初始轮廓的鲁棒性。