基于ASAAC标准的星载功率分配器研制

为了解决原子钟输出高品质频率标准路数单一的问题,同时针对空间电子系统对高品质频率标准的多路需求,本文基于欧洲联合标准航空电子结构委员会（ASAAC）标准,完成了一款新型星载功率分配器的设计。采用先功分后隔离的设计思路,不仅具备频率基准信号的分发功能,可输出12路高隔离度的频率标准。并且通过增加控制单元并设计机内自测试系统,实现了故障检测及通信功能。通过采用主、备份设计,提高了该产品的可靠性,主备份切换通过OC指令完成。通过采用LRM连接器,实现了模块的快速插拔替换,增强了模块的可维修性。通过理论分析及测量结果,隔离度优于72 dB,输出功率大于6 dBm,谐波优于-62 dBc,杂波优于-90 dBc(200 MHz以内),验证了该功率分配器的可行性和有效性。     

形状相似性法的圆柱斜齿轮冷锻数值模拟

提出了锻件毛坯与齿轮形状相似性冷锻法,改善成形质量,同时锻坯中心孔分流,可降低成形力.用三维有限元仿真软件数值模拟圆柱斜齿轮的闭式冷锻过程,确定下端面带凹槽的齿轮锻坯形状,该形状能避免齿轮成形产生的折叠缺陷;通过对材料变形的应变场、应力场、速度场、加载曲线等规律的分析,确定变形严重的应力区和应变最大值分布位置,指出材料成形流动速度差过大,是产生成形折叠缺陷的原因.总之,形状相似性法的圆柱斜齿轮冷锻成形齿轮是可行和有效,具有工程实际应用意义.     

求解大规模TSP问题的混合算法

遗传算法求解大规模TSP时呈现出求解时间长、后期效率明显降低等缺陷。通过结合分块方法、局部搜索算法以及禁忌算法,本文提出一个求解TSP的混合算法,以提高初始解质量,减少计算量。利用遗传算法和混合算法对几个TSP进行数值实验,表明无论在结果的质量上还是在运行效率上,混合算法都明显优于遗传算法,而且,规模越大效果越明显。     

高速瓦楞辊机构的中高度及其动挠度曲线方程

论述了高速瓦楞辊机构扣高度的动力学特片，建立了相应的上、下瓦楞辊的设计中高度的数学模型，导出对应的动挠度曲线方程。     

Theoretical consistency test of steam transport properties

The kinetic theory of polyatomic gases is used to test the mutual consistency of the thermal conductivity, viscosity and specific heat of low-pressure steam from 100° to 700°C. No inconsistency exists within the cited tolerances of the skeleton tables recommended by the Sixth International Conference on the Properties of Steam, but there is some basis for suspecting that the high-temperature thermal conductivity values are slightly low. Methods for tightening the consistency bounds are suggested.     

基于Linux系统的分权设计与实现

The secure operating system is the foundation of secure enhanced information systems. As an open source software. Linux has robust functions and good compatibilities with Unix. This paper analyzes the hidden troubles and faults in secure aspect of it. and fully discusses the design and implementation of privilege divided Linux-based sys-tem. It mainly focuses on the modifications of access control, super users' least privilege division and so on.     

The effects of divided attention on encoding processes in memory: Mapping the locus of interference.

Despite the detrimental effects of divided attention at encoding on later memory performance, results described in the literature do not unequivocally specify which processes are interrupted during encoding by participants' occupation with a concurrent task. Using a processing analysis framework where the encoding process is viewed as a multiphase mental activity, the current research investigated this issue using a new differential temporal interference paradigm where the study phase of single words was interrupted at different temporal segments. In two experiments, we used performance on both memory and online choice reaction time tasks to assess whether such differential interference would produce different degrees of reduction in participants' later memory performance, as well as changes in the attentional resources required to execute each of the encoding phases. Measures of memory and concurrent task performance in the two experiments converged on similar patterns, showing that all phases of encoding are affected by the concurrent task. However, the initial encoding phase, which is tentatively associated with the initial registration of information, seems especially vulnerable to interference. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

基于变电站九区图调节的地区电网分层无功优化

根据地区电网的实际管理模式,提出了基于变电站九区调节的地区电网分层无功优化方法:将地区电网分成次输电电网和配电网。先对次输电网进行无功优化时,将配电网等效为负荷,此时控制变量少,采用传统算法可以快速求解。在此基础上,再采用九区图方法调整配电网的无功电压,进行迭代,逐层进行无功优化直到问题收敛。实际算例表明,这种方法优化了地区电网的运行,提高了无功优化的计算速度,并且更符合实际电网的管理模式,为地区电网无功电压调节提供了有益参考。     

托巴水电站古松料场开采运输方案研究

溜井运输方案在国内外的冶金、煤炭、建材等行业已被广泛采用,并在设计、运行方面取得了较为成功的经验,在国内龙滩、锦屏等水电工程的料场开采运输中也得到了成功的运用。托巴水电工程古松料场地形陡峻,开采边坡高约300m,开采运输道路修建困难,且距坝区较近,对坝区施工干扰较大。通过对"公路运输方案、溜井+公路运输方案、溜井+胶带机运输方案"3个开采运输方案进行比较,初步推荐采用"溜井+公路运输方案",以有效解决料场开采运输存在的问题。     

无中隔墩卧底式窄缝差动挑坎的设计研究

针对目前在多孔河岸式溢洪道上采用窄缝挑坎消能工，都是沿闸墩用长墩隔开，至出口段将墩体升高加厚、急剧收缩成窄缝的结构形式。全程隔墩混凝土用量大，加上强大侧向水压力荷载等影响到工程投资、结构安全与泄洪运行管理问题。该设计提出省去泄槽中部的长隔墩，只在溢洪道出口连续挑坎下部加入“卧底式窄缝”，借以实现继续应用收缩式消能工。经模型试验表明：通过“分段连续坎”与“窄缝”的差动作用，出射水舌抛射呈十、廿、卅字形，加大入水面积和碰撞机率，消能效果良好，并方便人为控制水舌落点。在水电工程中有扩大应用潜力。