一种基于飞秒激光白内障手术的碎核轨迹设计

针对在飞秒激光辅助晶状体碎核中,需要根据白内障患者的晶状体浑浊等级选择不同的扫描方案,且其每一层的扫描轨迹不连续的问题,提出了一种参数化的螺旋形激光扫描碎核轨迹。对螺旋形扫描轨迹进行了整体参数化定义,解出了扫描轨迹的数学模型,并求解了轨迹中关键数据点的坐标值。最后对扫描轨迹数学模型建立了仿真,其仿真结果验证了所求解扫描轨迹数学模型的正确性。此种碎核方案的每一层轨迹连续,可通过改变相应参数实现不同的切割效果,为飞秒激光辅助白内障手术提供了一种新型的碎核方案,具有一定的实用价值。     

聚合物分散液晶膜的弯曲散射偏光效应

实验制备了聚合物分散液晶(PDLC)电控调光膜样品 。测试结果表明,样品散射雾度90%以上;施加电场透明透光率接近 80%;施加弯曲应力半透明最大透光率30%以上。分析了样品施加应力 后出现的弯 曲散射偏光现象,弯曲应力导致双极构型的双极连线有沿弯曲方向的大致沿面取向,使 得液晶 微滴中液晶分子有沿面大致取向,导致液晶微滴的折射率沿弯曲方向与聚合物折射率差别大 造成光散射,而沿垂直弯曲方向与聚合物折射率相等造成光透射。     

铝焊垫俄歇分析中荷电效应影响及其降低方法

铝焊垫表面残留物的检测是确保铝焊垫质量的重要指标.俄歇电子能谱仪(AES)由于检测区域小、表面分析灵敏度高,被广泛用于集成电路(IC)芯片制造中铝焊垫的表面成分分析,但荷电效应的存在常常会影响俄歇分析的结果.铝焊垫分析过程中,消除或者减少荷电效应是保证俄歇分析结果正确的前提.从优化俄歇电子能谱仪分析条件(比如降低入射电压、倾斜样品载物台、Ar+离子中和)和使用辅助方法改善样品导电性两大方面,介绍了几种减少荷电效应的有效方法,提出了铝焊垫俄歇分析的基本流程.结果表明,此分析流程能有效提高分析效率,为业内俄歇分析人员提供借鉴.     

PON与OBS网络互连结构的研究

光突发交换(OBS)网络的城域网应用需要解决与接入网的互连问题。针对基于集成节点的PON与OBS网络互连方案,研究了集成节点的功能与组成结构,分析了模块之间的信息交互,给出了集成节点结构的一种设计方案,并简单讨论了基于这一方案的汇聚机制和动态带宽分配算法。     

用于315/433MHz超再生接收机的射频前端关键技术

采用0.5μm CMOS工艺实现了用于315/433MHz超再生无线接收机的射频前端电路,包括射频放大器和超再生振荡器。文中提出了一种改进型有源电感,提高了射频放大器中谐振回路的品质因数。阐述了振荡器的自偏置效应以及振荡器输出信号幅度和电流源的关系,在此基础上实现了适用于包络检波的差分结构超再生振荡器。测试结果显示,电源电压范围为2.5V~5V,电流小于2.5mA,系统接收灵敏度优于-90dBm。     

Atomic Ni Anchored Covalent Triazine Framework as High Efficient Electrocatalyst for Carbon Dioxide Conversion

Electrochemically driven carbon dioxide (CO₂) conversion is an emerging research field due to the global warming and energy crisis. Carbon monoxide (CO) is one key product during electroreduction of CO₂; however, this reduction process suffers from tardy kinetics due to low local concentration of CO₂ on a catalyst's surface and low density of active sites. Herein, presented is a combination of experimental and theoretical validation of a Ni porphyrin‐based covalent triazine framework (NiPor‐CTF) with atomically dispersed NiN₄ centers as an efficient electrocatalyst for CO₂ reduction reaction (CO₂RR). The high density and atomically distributed NiN₄ centers are confirmed by aberration‐corrected high‐angle annular dark field scanning transmission electron microscopy and extended X‐ray absorption fine structure. As a result, NiPor‐CTF exhibits high selectivity toward CO₂RR with a Faradaic efficiency of >90% over the range from ?0.6 to ?0.9 V for CO conversion and achieves a maximum Faradaic efficiency of 97% at ?0.9 V with a high current density of 52.9 mA cm^?2, as well as good long‐term stability. Further calculation by the density functional theory method reveals that the kinetic energy barriers decreasing for *CO₂ transition to *COOH on NiN₄ active sites boosts the performance.     

云南甘蔗花叶病原的电镜诊断

甘蔗属禾本科甘蔗属作物，学名Saccharum L,多年生草本植物，是主要的糖料作物。甘蔗由于长期以营养体种茎进行无性繁殖，不可避免地会导致病毒病在种苗中的积累，从而造成品种退化，减产与糖份下降。随着云南省甘蔗面积的不断扩大，随之而来的甘蔗病毒病也日益加剧，致使甘蔗的产量和品质受到严重影响。为解决甘蔗病毒病给生产带业的危害，在有关项目资助下，通过采集大量甘蔗病样进行了电镜负染检测、     

Recursive Robust Filtering with Finite-Step Correlated Process Noises and Missing Measurements

In this paper, the robust filter design problem is studied for a class of uncertain dynamical systems with finite-step correlated process noises and missing measurements. The dynamical system under consideration is subject to both deterministic norm-bounded uncertainties in the measurement output and stochastic uncertainties on the system states. The process noises are assumed to be finite-step correlated. The missing measurement phenomenon is modeled as a binary switching sequence. Based on the min-max game theory, a recursive robust filter is designed that is suitable for online application. A particular feature is that, as the proposed robust filters work in a recursive fashion, there is no need to investigate the existence issue of the filters. A simulation example is presented to illustrate the usefulness of the proposed filter.     

基于GE交换的Gpbs无线传输平台ARQ算法的研究

基于千兆以太网（GE）交换的无线传输平台结构较之传统软件无线电平台具有强大的可编程能力和良好的可扩展性,配合多入多出-正交频分复用（MIMO-OFDM）技术,可实现达到1 Gb/s吞吐率（Gbps）的无线传输系统,针对Gbps高速无线传输的需求与平台特性,提出了一种自动重传请求（ARQ）机制,结合平台的结构特点,针对系统需求,在保证无线传输可靠性的前提下减小ARQ机制对传输吞吐率的开销,并可通过参数的优化适应于不同的应用场景。