人工深水湖渗流场及防渗方案三维仿真模拟研究

郑州市郑东新区龙湖规划水面面积为6．08km^2，为我国最大的城市人工湖。因其成湖地层主要为细砂，其建设存在开挖施工防渗、成湖后的有限防渗、地下水交换，以及防止周边地区浸没、盐渍化等问题。应用三维渗流有限元法数值模型对龙湖工程施工和运行期防渗方案进行了模拟仿真计算，给出了工程区地下水位、渗漏量、渗透坡降、渗流场的变化以及优化防渗方案。     

Measurement-based network monitoring and inference: scalability andmissing information

Using measurements collected at network monitors to infer network conditions is a promising approach for network-centric monitoring. In this context, an important question arises: given the number and locations of network monitors, how much network management resources (e.g., the number of measurements) are needed to obtain an accurate estimate of network states? We define the scalability of measurement-based network monitoring as the growth rate of the number of measurements required for accurate network monitoring/inference with respect to the size of a network. We develop a framework for investigating the scalability in the context of multicast inference with the monitors at the edges of a network. In such a framework, network monitoring/inference can be formulated as probability density estimation of network states. The growth rate is characterized through the sample complexity, which is the number of measurements needed to accurately estimate the density. The missing data framework is introduced to estimate the growth rate, where the missing data reflect unavailable measurements at the unobservable nodes without resident monitors, and the underlying nodal packet losses. We show that when the missing information is mainly due to the number of unobservable nodes, the number of measurements needed grows linearly with the size of the network, and the measurement-based inference approach is, thus, scalable. When the missing information is mainly due to the underlying nodal packet losses, the number of measurements needed grows faster than linear with the size of the network, and the measurement-based inference approach is, thus, not scalable. Our results provide guidelines for accessing feasibility of the measurement-based inference approach, and the number of probes required. We give numerical examples to illustrate some of our results     

大气光通信PAT子系统指标初步设计分析

分析了跟踪角速度，功率，跟踪精度等因素对大气激光通信系统中瞄准，捕获和跟踪子系统参数选择的影响，给出了波束发散角，扫描角范围，接收视场等主要参数的选择原则，对地面终端光通信系统设计背景提出了瞄准，捕获和跟踪了系统的相应指标。     

带疏水泵加热器出口主凝结水焓的计算方法

以火电厂热力系统热力单元矩阵分析法为基础，提出了一种更为科学有效的带疏水泵加热器出口主凝结水焓分析计算的新方法，应用表明，其结论与常规算法完全一致，图2表1参3。     

热环工作特性的理论分析与实验研究

热环是用于非相邻冷热源间热量传递或余热回收的节能装置。本文对热环的基本原理、特点进行了简要介绍 ,在此基础上 ,分析建立了热环的输热能力、输热系数、工作温度等性能指标的计算方程 ,并进行了较系统的实验研究     

墙改之路越走越宽标准严格政策绿灯

四部委发布实施<节能标准>的通知 日前,建设部、国家计委、国家经贸委、财政部联合发布了关于实施<夏热冬冷地区居住建筑节能设计标准>的通知.     

拉伸速率对PP/GB复合材料力学性能的影响

应用Instron材料试验机考察了室温下拉伸速率对玻璃微珠填充聚丙烯复合材料的弹性模量和屈服强度的影响，结果表明，随着微珠含量的增加，试样的弹性模量（Ec）增大，且与拉伸应变速率呈近乎幂律函数关系，而屈服强度（бyc）则随着微珠体积分数（Φf）的增加呈线性函数形式下降，并随着拉伸应变速率的增加呈幂律函数形式提高，此外，讨论了Ec、Φf与бyc三者之间的关系。     

纳米ZnO薄膜制备及液态源掺杂

用真空蒸发法在玻璃和单晶硅片 (10 0 )上制备Zn薄膜 ,然后对Zn薄膜进行氧化、热处理获得纳米ZnO薄膜。对在硅片上制备的Zn薄膜一次性进行高温掺杂、氧化获得纳米ZnO∶P和ZnO∶B薄膜。研究不同氧化、掺杂温度和时间对薄膜结构、电学性能的影响。结果表明 :氧化温度和时间对ZnO薄膜结构影响较大 ,液态源掺P可明显改善纳米ZnO薄膜的导电性能、结构特性和化学组分     

防洪物资调度决策分析

防洪物资调度是防洪抢险调度的重要组成部分,当发生较大洪水时,常伴随着不同程度险情的发生。每一次及时而有效的成功抢险,对防洪减灾往往起着决定性的作用。显然,每一个抢险措施,都涉及到抢险物资的调度与运输。因此,防洪物资调度具有重要的理论与应用价值。