基于MZ干涉仪结构的量子时钟同步方案理论研究

经典时钟同步方案易受色散和重力势效应的影响而出现较大误差。为此,文中提出了一种基于量子理论的时钟同步方案,该方案设备架构主要基于Mach-Zehnder干涉仪结构,通过两方互相发送光子并测量相位差以得到时钟差值。相较于经典方案,该方案在同步过程中不需要传递实体钟和测量脉冲抵达时间,因此不受重力势的影响。理论证明其抗色散影响,可以达到更高的精度要求。     

桩—承台—土共同工作机理分析

本文分析了低承台复合桩基在承台作用下的桩-承台-土的共同工作机理,具体分析了它的荷载传递变化及其桩周土受荷变化,从中得出承台的作用使桩侧摩阻力,桩端阻力均有提高。     

Bifurcation analysis for an SMIB power system with series capacitor compensation associated with sub-synchronous resonance

In this paper,an introduction to the bifurcation theory and its applicability to the study of sub-synchronous resonance (SSR) phenomenon in power system are presented. The continuation and bifurcation analysis software AUTO97 is adopted to investigate SSR for a single-machine-infinite-bus power system with series capacitor compensation. The investigation results show that SSR is the result of unstable limit cycle after bifurcation. When the system exhibits SSR, some complex periodical orbit bifurcations, such as torus bifurcation and periodical fold bifurcation, may happen with the variation of limit cycle. Furthermore, the initial operation condition may greatly influence the ultimate state of the system. The time-domain simulation is carried out to verify the effectiveness of the results obtained from the bifurcation analysis.     

中国电信C网全国级业务平台迁移工程浅谈

一、背景 自2008年6月中国电信正式收购中国联通CDMA后,中国电信正式成为一个全业务运营商,目前中国电信已经全面推出其自有品牌的服务和业务。中国电信除了需要考虑新网元新业务在电信侧的部署外,还需要考虑实现联通侧原有网络和原有业务的平稳承接及迁移割接,以支撑电信新用户放号和老用户平稳过渡。由于C网全国级业务平台系统种类多、技术复杂,且与核心网络关联紧密,迁移割接方案的制定具有很高的技术难度。因此,中国电信专门成立项目小组进行原C网全国级业务平台的迁移割接工作。     

基于p-多重网格的间断Galerkin方法研究

文章采用规范正交基作为测试函数,基于p-多重网格的思想,建立了间断Galerkin方法的二重网格格式,并以此求解了Euler方程,数值模拟了绕NACA0012和RAE2822翼型的跨音速流场。其中,在网格交界处采用Roe的迎风型数值通量。沿时间方向,高阶格式和低阶格式上分别采用Runge-Kutta方法和LUSGS方法推进。通过对残值收敛曲线的比较,认为文中的p-多重网格算法取得了非常优良的加速收敛效果。     

限定领域的自动问答系统研究

目前,自然语言处理系统由于缺乏语义信息及知识理解和推理能力,因此存在很多缺陷,在自动问答领域中很难分清用户表达的真正意图,并给出用户满意的答案.本文就此给出基于句法语义的问句分析方法,采用本体构建技术构建答案库,在此基础上进行领域知识语义推理,实现智能问答.本研究以黄山旅游为限定领域建立问答系统,试验结果表明多策略的方法是有效的.     

语言学习策略和外语学习焦虑相关性初探

以非英语专业本科学生为对象,分析语言学习策略和外语学习焦虑两者的相关性;发现外语学习焦虑与其语言学习策略应用情况呈较显著负相关关系;参测学生普遍存在不了解、不重视语言学习策略的情况,大多数学生处于中高度焦虑状态。     

一类Bayes公式的推导及在小子样评估中的应用

工程中昂贵复杂系统的整机试验通常是小子样的,因此需要结合大量的先验信息进行系统评估,但这可能造成小子样的整机试验数据的信息被淹没。与通常考虑加权的融合方法不同,基于精度评估的正态逆伽玛分布推导了一类Bayes公式,将所有先验信息等价为单个整机试验数据,设计了相应的分布参数,结合等价先验样本量得到推导的后验结果,并给出案例分析了这类Bayes公式的应用范围和合理性。     

Lab-on-a-chip: a component view

Miniaturization is being increasingly applied to biological and chemical analysis processes. Lab-on-a-chip systems are direct creation of the advancement in the miniaturization of these processes. They offer a host of exciting applications in several areas including clinical diagnostics, food and environmental analysis, and drug discovery and delivery studies. This paper reviews lab-on-a-chip systems from their components perspective. It provides a categorization of the standard functional components found in lab-on-a-chip devices together with an overview of the latest trends and developments related to lab-on-a-chip technologies and their application in nanobiotechnology. The functional components include: injector, transporter, preparator, mixer, reactor, separator, detector, controller, and power supply. The components are represented by appropriate symbols allowing designers to present their lab-on-a-chip products in a standard manner. Definition and role of each functional component are included and complemented with examples of existing work. Through the approach presented in this paper, it is hoped that modularity and technology transfer in lab-on-a-chip systems can be further facilitated and their application in nanobiotechnology be expanded     

基于溶剂沥青的冷再生沥青混合料性能评价

传统的沥青混合料冷再生技术有乳化沥青和泡沫沥青冷再生,本研究尝试采用所开发的溶剂沥青作为结合料对废旧沥青混合料进行冷再生,提出了试件的成型和养生方法,进行了配合比组成设计并采用热拌沥青混合料的标准对溶剂沥青冷再生混合料的性能进行评价.试验结果表明,溶剂沥青冷再生混合料的水稳定性能、高温稳定性能均满足我国热拌改性沥青混合料规范的性能要求,低温性能虽然不满足改性沥青混合料的要求,但能满足普通沥青混合料规范的性能要求.