基于三种方法的螺旋桨敞水性能数值预报

该文基于三种不同的CFD方法:多重坐标参考系法(MRF)、任意网格界面元法(AMI)和重叠网格方法(Overset)对某一四叶螺旋桨的敞水性能进行数值模拟和预报,并对螺旋桨周围的流场进行了分析。其中,对于任意网格界面元法(AMI)与多重坐标参考系法(MRF),分别采用开源CFD计算软件Open FOAM所提供的求解器pimple Dy MFoam与MRFSimple Foam进行计算;对于重叠网格方法(Overset),采用基于Open FOAM平台开发的具有重叠网格模块的船舶与海洋工程水动力求解器—naoe-FOAM-SJTU进行求解。通过与试验结果的对比以及方法间的比较,验证了三种方法在螺旋桨敞水性能预报中的可靠性和有效性,并总结了各方法的特征与优劣。同时也对螺旋桨附近的流场特征进行了讨论与分析。     

Measurements and characterization of power transformer and low voltage access network for NB‐PLC

Several techniques for a state‐of‐the‐art advanced metering infrastructure (AMI) within the smart grid are being extensively studied and evaluated around the world. Advanced metering infrastructure provides an enhanced and efficient energy management infrastructure that can facilitate the latest demands of electric utilities, consumers, and smart grid. In the past few years, standardization process for the implementation of AMI using narrowband power line communications (NB‐PLC) transceivers has been completed by ITU‐T and IEEE. This paper is focused on the utilization of CENELEC band of NB‐PLC for deployment aspects. The power transformer model of 200 and 75 kVA transformers for 9 to 90 kHz frequency range that lies in CENELEC‐A band of NB‐PLC is also proposed. The proposed model is more simple than previously presented models in the literature and has the capability to evaluate the transformers working not only under normal condition but also under resonance condition for frequency of interest. Moreover, the efficient procedure for field measurements that provides a generalized NB‐PLC channel model for low voltage access network to deploy AMI within Lahore, Pakistan, is presented. A Simulink model is developed to validate the results. The analysis of measured and simulated results illustrates a close agreement of channel transfer functions. This research work proposes an improved and more accurate NB‐PLC channel model especially for South Asian countries.     

基于ACE/TAO的远程方法调用的研究

介绍了ACE/TAO中常见的两种远程方法调用的原理,分析了其信息传递的步骤;并结合一个实例给出了这两种远程方法调用的实现方法,对比分析了这两种远程调用方法的优劣。     

应用量化参数研究d4T核苷酸类似物的结构与抗HIV-1活性的相关性

应用MM 分子力学法、量子化学AM1法计算了20个d4T核苷酸类似物的优势构象和电子结构,并用逐步回归分析方法寻找其量化指数与抗HIV(艾滋病)活性的关系。结果表明:1)d4T核苷酸类似物的油水分配系数LogP与活性参数间呈较好的抛物线关系,LogP处于0．95-2．45区间是d4T核苷酸类似物具有良好抗HIV活性的重要条件。2)建立了量化指数与活性之间的定量模型,取得了良好的结果,其模型相关系数为R=0．948;继以留一法(Leave-one-out,LOO)进行交互检验,复相关系数为R2C(?)=0．771,说明定量相关模型具有良好的稳定性和预测能力。     

基于AMI602传感器的载体姿态测试系统

针对捷联式载体姿态测试系统中存在的抗干扰能力差、不能很好地消除坐标误差以及姿态角测量范围的局限性等缺陷,提出了一种基于集加速度、地磁于一体的6维AMI 602动作传感器的姿态测试系统。通过AMI 602动作传感器输出6维数据结合加速度和地磁2个常量来确定载体在空间中的姿态。测试表明:该系统能解决上述缺陷,且具有精度高、功耗低、小型化等特点,可应用于GPS、手机、游戏设备等姿态测量领域。     

基于开放服务网关规范的面向服务高级量测体系

提出了一种基于开放服务网关规范的面向服务高级量测体系(AMI)的设计和实现方案。以Web服务组件作为OSGi平台对外服务发布/订阅的中介,OSGi技术构建的用户与电力公司之间的信息交互平台,面向服务的设计、封装与动态配置符合面向服务影响(SOA)体系架构。详细分析了以服务为导向的高级量测体系的功能部署,并以用户需求响应为例,采用MyEclipse搭建仿真系统,验证了该方案的可行性。     

急性心肌梗死患者经皮冠状动脉介入术后CD40L和sCD40L的变化及意义

通过急性心肌梗死（AMI）患者急诊经皮冠状动脉介入治疗（PCI）术前及术后CD40L和sCD40L的水平变化,探讨CD40L和sCD40L对AMI患者预后的评估作用。选择明确诊断为急性心肌梗塞,且6 h内行急诊PCI治疗的住院患者80例,将上述AMI组又分为AMI存活组和AMI死亡组。取同阶段冠脉造影完全正常或冠脉最大狭窄〈50%的患者80例作为对照组。于PCI术前0.5 h、术后即刻、12h、24 h、48 h取静脉血,检测血小板CD40L和sCD40L。结果显示：AMI组CD40L和sCD40L水平在PCI术前及术后即刻、12 h、24 h、48 h均高于对照组（P〈0.05）。AMI组CD40L和sCD40L水平在术后即刻较术前有显著增高,差异有显著性（P〈0.05）。术后12 h、24 h、48 h逐渐回落,48 h与术前比较无显著性差异（P〉0.05）。对照组CD40L和sCD40L在术后各时间点平均无统计学差异（P〉0.05）。AMI存活组PCI手术各时间点CD40L、sCD40L水平均低于AMI死亡组（P〈0.05）。AMI死亡组术后24 h内明显高于术前（P〈0.05）。结果证明AMI患者PCI术后CD40L和sCD40L水平增高,CD40L和sCD40L是AMI患者PCI后早期免疫炎症反应及预后的重要标志。     

肌酸激酶同工酶CK-MB快速检测试剂的研制

为了实现心血管疾病的早期诊断,减少死亡率,建立一种基于近红外荧光免疫层析技术的肌酸激酶同工酶CK-MB快速检测技术.该检测方法使用激发光和发射光分别为777、792 nm的Dylight800作为荧光标记物,通过测量T线峰面积与C线峰面积的比值计算样品中CK-MB的浓度,实现了低成本、快速定量检测.通过25例临床标本检测并将结果与生化仪检测结果进行比对发现,本研究中建立的方法具有良好的相关性,R2=0.98.建立的CKMB检测试剂可以满足急诊病人急性心肌梗死(AMI)快速检测的需求.     

Recharging method of active medical implant using wearable incoherent light source

A new method for recharging active medical implant(AMI) in vitro based on incoherent light source and results of the simulation experiments are proposed. Firstly, the models of the AMI recharging method based on incoherent light source in vitro are developed, which include the models of an incoherent light source and skin tissue. Secondly, simulation experiments of the incoherent light source of the AMI recharging process in vitro based on the Monte Carlo (MC) method are carried out. Finally, absorbed fractions of different layers and distributions of density along x axis of the tissue model and other important conclusions have been achieved.     

A Key Management Scheme for ZigBee in AMI of Smart Grid

Advanced metering infrastructure (AMI) is a critical part of the smart grid, and ZigBee is playing an increasingly important role in AMI. The cyber security is the prerequisite to ensure the reliable operation of AMI. To guarantee the ZigBee communication security in AMI, a key management scheme based on the elliptic curve cryptosystem (ECC) is proposed. According to the ways of information transformation in AMI, the scheme is categorized as unicast communication key management process and multicast communication key management process. And in the scheme, the selection of elliptic curve, the calculation of ZigBee node’s ECC public key and private key, the establishment and distribution of the link key in unicast communication, and the establishment and distribution of the network key in multicast communication are elaborated. The analysis results show that the proposed key management scheme is secure, and consumes less memory and energy, thus, can meet the demands of communication security of AMI.