双线平行地铁隧道盾构同向推进纵向安全间距研究

为加快双线地铁隧道施工,采用2台盾构机同时开挖,盾构横向间距不变情况下,纵向间距过近会加剧对土体的扰动,影响地表建(构)筑物安全。以武汉地铁三号线为工程背景,选取双线平行隧道盾构同向推进为研究对象,采用现场监测和数值模拟计算方法,综合分析盾构开挖时隧道横向、纵向地表变形特征,揭示双线平行隧道盾构同向推进时的纵向相互影响规律。结果表明:数值计算结果与现场监测数据相吻合;盾构通过后地表形成沉陷槽,隧道拱顶上方地表变形最大,距离隧道轴线越远,地表变形越小;开挖过程中盾首上方隆起值达到最大,盾构穿过后沉降迅速增加,最终趋于稳定;双线地铁隧道盾构同向推进中,盾构的二次扰动加剧了地表最终变形量,盾构纵向间距对地表最终变形量没有影响,随着盾构纵向间距增加,地表总体沉降速率减缓,当盾构纵向距离大于50 m时较为安全可靠。研究成果旨在为今后的地铁隧道安全快速的施工提供依据。     

EDA技术在微机接口技术实验教学中的应用

随着电子技术和计算机技术的不断发展,在涉及通信、国防、航天、仪器仪表等领域的电子系统设计工作中,EDA技术的含量正以惊人的速度上升,成为现代电子设计技术的核心。他打破了软件和硬件间的壁垒,代表了电子设计技术和应用技术的发展方向,已成为当今电子技术发展的前沿。因而在教学中引入EDA技术是当务之急。以键盘接口设计为例,主要阐述了EDA技术在微机接口技术实验教学中的应用。     

Energy subsidies,structure of electricity prices and technological change of energy use

This paper addresses the impact of the structure of energy prices on technological change in renewable energy sources. It operates on two fields of research that are often not related to each other. Firstly, the increasing interest in environmental economics for the determinants of green technological change, and secondly the impact of government policies aimed at subsidizing energy prices. Recent research claims a positive relationship between energy prices and the number of patents in the fields of energy efficiency. This paper extends this research by investigating the impact of the price structure of electricity on patent counts in 1) renewable energy sources, 2) wind energy and 3) solar power. In nearly all OECD countries in the period 1990–2006 industrial energy users pay a lower price per energy unit than households due, among others, to government subsidy policies. The empirical results show that reducing government subsidies and hence increasing the electricity price of (large) industrial electricity users relative to the price paid by (small) residential users provides a clear incentive to increase inventions as measured by number of patents in the technical fields of solar and wind energy. These results are an important input in the debate on reducing government support to large energy users.     

基于IP的高可用海量网络存储系统的研究

提出和实现了一种在IP下融合NAS(附网存储)、SAN(存储区域网)和对象存储技术的高可用海量网络存储系统(MNSS,mass network storage system)。在MNSS中通过统一多协议文件系统,实现了NAS设备、SAN设备和对象存储设备在IP上的融合,满足了应用开放性、高扩展和海量存储的需求;通过iSCSI软件模块,MNSS对存储资源提供统一的管理和优化,同时提供文件I/O和块I/O服务,使MNSS同时具有NAS和SAN的优点;通过自主存储代理模块,MNSS能同时提供服务器通道和附网高速通道,改善了系统的I/O性能,减少了服务器瓶颈;通过高可用系统设计,MNSS能为数据和应用提供更高的可用性,满足了企业高可用的存储需求。实验结果显示,MNSS有超高速的文件I/O和块I/O响应速度,能为网络提供高性能、高扩展性的对象存储设备,高可用性、高性/价比的海量存储系统。     

矩阵方阵最小二乘问题的定秩解

讨论了矩阵方程最小二乘问题的定秩解,利用矩阵对的广义奇异值分解,得到了定秩解的解集合;对于最小秩解的解集合Sm,得到了最佳逼近解.     

从认知角度谈读写结合的学习策略

从认知角度出发,对读写结合,以读促写的二语学习策略的认知基础、培养及其意义进行了讨论和分析.说明了阅读和写作构成了完整的输入-输出的信息处理过程,二者的有益结合将从多个方面提高学习者的写作能力.     

A Youla–Kučera parameterization approach to output feedback relatively optimal control

This paper presents a continuous time solution to the problem of designing a relatively optimal control, precisely, a dynamic control which is optimal with respect to a given initial condition and is stabilizing for any other initial state. This technique provides a drastic reduction of the complexity of the controller and successfully applies to systems in which (constrained) optimality is necessary for some “nominal operation” only. The technique is combined with a pole assignment procedure. It is shown that once the closed-loop poles have been fixed and an optimal trajectory originating from the nominal initial state compatible with these poles is computed, a stabilizing compensator which drives the system along this trajectory can be derived in closed form. There is no restriction on the optimality criterion and the constraints. The optimization is carried out over a finite-dimensional parameterization of the trajectories. The technique has been presented for state feedback. We propose here a technique based on the Youla–Kučera parameterization which works for output feedback. The main result is that we provide conditions for solvability in terms of a set of linear algebraic equations.     

美国哈町大学宗教教育访谈录——访David B．Burks校长，James Carr副校长，Milo Hadwin主任

作为一所基督教大学,哈町大学十分重视学生的宗教教育,将宗教与大学教学、生活融为一体,以此培养他们对上帝的信仰。陈国海教授于2009年访问哈町大学期间,就哈町大学的宗教教育对Burks校长、James副校长和Milo主任进行了访谈。该校领导认为宗教教育和对上帝的信仰在帮助学生建立正确的人生观、价值观和培养学生的良好品质方面起到了至关重要的作用。学生在哈町大学不仅要学习知识和技能,更要养成良好的习惯,学会帮助他人、感激他人。这一切不仅有助于完善学生人格,使学生懂得如何去追求美好的人生,更有助于学生为构建和谐美好的校园、国家和社会做出贡献。     

某桁架拱桥加固后静力试验分析

本文以加固后的克山老桥为研究对象,利用MIDAS/CIVIL桥梁专用分析软件计算结果与静载试验结果进行对比分析,表明该桥在活载作用下满足加固维修设计要求,为该桥加固工程验收提供依据,并为同类工程提供了参考.     

基于安全信誉机制的SET协议

针对安全电子支付协议不能刺激商家售后服务质量提高的弊端,文中提出了基于安全信誉机制SET支付协议的改进方案,并对该方案的安全性能进行分析。分析结果表明文中提出的改进方案不仅保持了原有SET协议的安全性,而且提高了商家对客户售后投诉的响应速度,避免了商家通过聘用托的合谋攻击问题,进一步保障了消费者的利益。