高能同步辐射光源储存环快校正磁铁电源设计

高能同步辐射光源（HEPS）具有0.1 nm·rad的超低发射度，对束流稳定度提出了较高要求，研制1台高性能快校正磁铁电源用来提高快速轨道反馈系统（FOFB）的性能以提升束流稳定度。电源样机采用新颖的多电平级联拓扑结构提升电源样机的动态性能，使用基于数字控制的新颖控制方法实现样机的动态性能提升。软件仿真与样机试验数据证明，电源样机具有10 kHz小信号带宽、电源阶跃响应时间小于70 μs、输出电流纹波低于20 ppm，电源样机可很好地满足HEPS建设需求。     

Throughput-based fair bandwidth allocation in OBS networks

Fair bandwidth allocation (FBA) has been studied in optical burst switching (OBS) networks, with the main idea being to map the max-min fairness in traditional IP networks to the fair-loss probability in OBS networks. This approach has proven to be fair in terms of the bandwidth allocation for differential connections, but the use of the ErlangB formula to calculate the theoretical loss probability has made this approach applicable only to Poisson flows. Furthermore, it is necessary to have a reasonable fairness measure to evaluate FBA models. This article proposes an approach involving throughput-based-FBA, called TFBA, and recommends a new fairness measure that is based on the ratio of the actual throughput to the allocated bandwidth. An analytical model for the performance of the output link with TFBA is also proposed.     

超级计算机网络引导技术研究与分析

针对超级计算机系统中网络引导时间开销大的问题，提出网络引导分布算法是影响网络引导性能的主要因素之一，是优化网络引导性能的主要方向的观点。首先，分析了影响大规模网络引导性能的主要因素；其次，结合一种典型超级计算机系统，分析了超节点循环分布算法（SCDA）和插件循环分布算法（BCDA）的网络引导数据流拓扑结构；最后，量化分析了这两种算法对各个网络路径段的压力和可获得的网络性能，发现BCDA性能是SCDA性能的1~20倍。通过理论分析和模型推导发现，在计算节点和引导服务器之间使用更细粒度的映射算法可以在引导部分资源时使用尽量多的引导服务器，减少对局部网络资源的过早竞争，提升网络引导性能。     

Structural parameter design method for a fast-steering mirror based on a closed-loop bandwidth

When a fast-steering mirror (FSM) system is designed, satisfying the performance requirements before fabrication and assembly is vital. This study proposes a structural parameter design approach for an FSM system based on the quantitative analysis of the required closed-loop bandwidth. First, the open-loop transfer function of the FSM system is derived. In accordance with the transfer function, the notch filter and proportional-integral (PI) feedback controller are designed as a closed-loop controller. The gains of the PI controller are determined by maximizing the closed-loop bandwidth while ensuring the robustness of the system. Then, the two unknown variables of rotational radius and stiffness in the open-loop transfer function are optimized, considering the bandwidth as a constraint condition. Finally, the structural parameters of the stage are determined on the basis of the optimized results of rotational radius and stiffness. Simulations are conducted to verify the theoretical analysis. A prototype of the FSM system is fabricated, and corresponding experimental tests are conducted. Experimental results indicate that the bandwidth of the proposed FSM system is 117.6 Hz, which satisfies the minimum bandwidth requirement of 100 Hz.     

The analysis and comparison of two novel kinds of focusing elements as reflectors

In this article, two novel kinds of focusing elements as reflectors are analyzed and compared. One is the grooved Fresnel zone plate reflector with continuous phase‐correcting. The other called subzone paraboloid reflector, has the profile that consists of a series of paraboloids. Their diffraction efficiencies and bandwidths are described. The two elements still preserve the advantages of Fresnel zone plates, namely, low profile, high efficiency, and simple fabrication. Two dual‐reflector antennas using the proposed focusing elements as the main reflectors are simulated and the results show that these antennas have good radiation performances. © 2014 Wiley Periodicals, Inc. Int J RF and Microwave CAE 25:101–108, 2015.     

铁路反恐视频监控系统方案探究

本文通过分析反恐视频监控的需求，研究了普通红外线摄像机和激光摄像机的性能、铁路通信传输网通道容量和视频占用的资源量，推荐反恐视频监控方案采用数字激光摄像机。     

实时系统中分层调度机制研究

以Linux内核为例分析了实时应用方面的不足之处,并对近年来实时任务调度的研究进行综合分析,以此为基础提出了一种分层调度结构。该结构保证了实时应用的即时调度,较好地运用了已有的Linux内核资源,并使得实时与非实时任务间的相互通信更加通畅。     

走出资源和环境瓶颈的可行之路

国际、国内资源和环境的约束已成为国内经济产业链高速扩张的瓶颈，中国经济发展中所需要的资源不仅可以考虑国内外两种资源、两个市场，而且还要考虑国内外的两类资源：原生资源和再生资源。利用原生资源的产业并不必然的比利用再生资源产生的污染更少。转变经济增长方式，中国不仅要走出一条科技含量高、经济效益好、原生资源消耗低、环境污染少、人力资源优势得到充分发挥的新型工业化、现代化道路，而且要走充分挖掘再生资源潜力的路子。     

电动滚筒在带式输送机驱动装置应用中的问题

电动滚筒具有许多独特的优势和特点,但由于存在着制约其发展的技术瓶颈,致使大功率电动滚筒一直未能设计、制造出来,影响了在输送机行业的应用。但随着新技术的发展,现在完全可以应用变频和稀土永磁电机技术、电气启制动技术、新的油冷式技术来设计制造出大功率的电动滚筒,从而推动电动滚筒的广泛应用。     

可变带宽的基带信号发生器设计

基于8751系列单片机的可变带宽基带信号发生器由控制电路、时钟发生、波形存储、数据输出和放大滤波等单元组成.通过单片机控制时钟发生、波形存储、数据输出和放大滤波等数字电路,可产生不同频带宽度的基带正弦扫频信号或不同脉冲宽度的脉冲调制正弦信号.