基于ALE法的水陆两栖飞机船体着水性能分析

水陆两栖飞机的着水性能是体现其综合性能的重要因素之一.应用ALE法对三种水陆两栖飞机船体截面进行入水仿真计算,从着水载荷、喷溅性能及运动响应三个方面对着水性能进行综合评估.对比分析了直线型、带舭弯弧形、复合型三种构型截面在不同速度、不同重量下的压力分布、喷溅性能以及运动响应,得到了三种截面横向压力分布规律.计算结果显示相同状态下,喷溅性能复合型优于带舭弯弧形、带舭弯弧形优于直线型;过载复合型远大于带舭弯弧形,带舭弯弧形稍大于直线型,综合看来带舭弯弧形截面着水性能最佳.     

廊坊市市区水资源规划治理研究

水资源是人类赖以生存的资源,现今,水资源已成为制约我国民经济发展的障碍,如何在充分利用水资源、保护水资源的基础上发展经济,是实现可持续发展的重要条件。本文通过对废水排放量和规划用水量的预测,对廊坊市未来的水资源利用规划提出建议,实现可持续发展。     

水气动量交换的实验研究

在风浪槽中进行水气动量交换实验，测量了不同风速和风区下的波浪及空气湍流流场。测量数据表明水面上风速分布符合对数律，水气界面附近在小范围的动量交换常通量层。阻力系数ＣＤ随风速增加线性增长，随波龄增加而减小。这一趋向与理论分析及外海帝测结果一致。对风浪发展过程中波浪和空气湍流谱结构的分析证明了水气运动的耦合关系。     

平板上挡板前后涡核位置的测量

在水洞中用氢气泡法在平板上挡板前后的涡核位置进行了测量。本试验旨在确定挡板高度及其雷诺数对涡核装置的影响，结果表明，（ａ）对于单个挡板情况，涡核离开平板的高度和涡核与挡板的距离将随着挡板的高度增加而增加，但涡核的高度和距离与挡板高度的比例随挡板高度的增加而降低；（ｂ）对于两个挡板情况，挡板的高度和挡板之间的距离对涡核位置的影响是主要的。     

三硝基间苯二酚中硫酸测定的研究

本文研究了硫酸钡在氨水溶液中与ＥＤＴＡ的反应条件，提出用ＥＤＴＡ滴定法测定三硝基间苯二酚中的硫酸。本法准确度较高，稳定性好，操作简单，与样品标准值对照，结果满意。     

SQL Server数据复制在自来水数据库系统中的实现

介绍了Microson SQL Server数据复制的概念、工作原理和拓扑结构,并结合自来水公司的业务特点和应用需求,提出了适合企业业务发展的分布式系统解决方案.     

Integration of lessons from recent research for “Earth to Mars” life support systems

Development of reliable and robust strategies for long-term life support for planetary exploration must be built from real-time experimentation to verify and improve system components. Also critical is incorporating a range of viable options to handle potential short-term life system imbalances. This paper revisits some of the conceptual framework for a Mars base prototype which has been developed by the authors along with others previously advanced (“Mars on Earth^®”) in the light of three years of experimentation in the Laboratory Biosphere, further investigation of system alternatives and the advent of other innovative engineering and agri-ecosystem approaches. Several experiments with candidate space agriculture crops have demonstrated the higher productivity possible with elevated light levels and improved environmental controls. For example, crops of sweet potatoes exceeded original Mars base prototype projections by an average of 46% (53% for best crop) ultradwarf (Apogee) wheat by 9% (23% for best crop), pinto bean by 13% (31% for best crop). These production levels, although they may be increased with further optimization of lighting regimes, environmental parameters, crop density etc. offer evidence that a soil-based system can be as productive as the hydroponic systems which have dominated space life support scenarios and research. But soil also offers distinct advantages: the capability to be created on the Moon or Mars using in situ space resources, reduces long-term reliance on consumables and imported resources, and more readily recycling and incorporating crew and crop waste products. In addition, a living soil contains a complex microbial ecosystem which helps prevent the buildup of trace gases or compounds, and thus assist with air and water purification. The atmospheric dynamics of these crops were studied in the Laboratory Biosphere adding to the database necessary for managing the mixed stands of crops essential for supplying a nutritionally adequate diet in space. This paper explores some of the challenges of small bioregenerative life support: air-sealing and facility architecture/design, balance of short-term variations of carbon dioxide and oxygen through staggered plantings, options for additional atmospheric buffers and sinks, lighting/energy efficiency engineering, crop and waste product recycling approaches, and human factor considerations in the design and operation of a Mars base. An “Earth to Mars” project, forging the ability to live sustainably in space (as on Earth) requires continued research and testing of these components and integrated subsystems; and developing a step-by-step learning process.     

水平表面气流剪切作用下的水膜厚度

飞机结冰表面上的液态水受气流吹拂作用会发生向后溢流,从而影响结冰区域范围及防冰系统设计;为了获得水膜流动规律,对水平平板表面上气流剪切驱动的水膜流动进行了实验测量和建模分析。通过水膜流动风洞试验台产生高速气流驱动水膜的流动,使用色散共焦位移计测量同一位置的水膜在不同时刻的厚度变化,结果表明气-液界面由底层薄水膜和多种尺度的波动组成,具有变化速度快随机性强的特点。通过水膜厚度随气流速度及水膜雷诺数的变化规律,发现平均水膜厚度与两者均呈现出单调非线性的依赖关系。基于薄水膜流动理论和平均水膜厚度实验结果,提出了高速气流剪切作用下的气-液波动界面剪切因子计算式,适用于风速17.8~52.2m/s,水膜雷诺数26~128之间的平板水膜流动计算。     

高效离子电热水器的设计

描述一种由AT89C2051单片机控制的高效离子电热水器，该热水器使用安全，即开即热，转换效率高。     

水系统装置扬程的计算及泵的选型分析

为了提高水系统中水泵的实际运行效率和扬程利用率,降低发动机试验成本,减少能量浪费,以某型发动机台架试验水系统为研究对象,综合考虑了装置静扬程、管路的各种局部损失和沿程损失开展装置扬程的计算。同时根据水系统所需的装置扬程、流量及其变化规律,从泵的参数及其特性曲线入手,进行泵的选型分析,确定合适的泵的类型、台数及连接方式。通过水系统装置扬程的计算和泵的选型分析,结合泵带来的能效利用、工程投入和运行费用等因素,可在满足发动机试验需要的同时实现经济利益最大化,为今后类似水系统工程的设计提供借鉴和指导。