利用Hook技术实现进程控制

Windows系统是基于消息,建立在事件驱动基础上的操作系统。Hook是Windows系统消息处理机制中的一个监视点。Hook机制允许应用程序截获消息并进行处理,它为我们实现进程的控制提供了条件。本文介绍了一些关于Hook的知识以及结合进程快照和动态链接库,利用Win32 Hook技术实现对进程控制的方法。     

寒冷地区高大联合厂房采暖通风设计

结合实际工程，对寒冷地区系统方案进行了比较。通过以天窗排风为主的自然通风和机械通风相结合的方式，解决屋顶风机过多带来的弊端，降低运行费用。利用热风系统作为中心区域补风，改善主生产区空气质量。采用置换通风形式，在地面上设置送风口，改善气流组织。并给出了运行效果及评价。     

非对称PCMA卫星信号的截获方法

近年来PCMA等卫星通信新技术的应用对卫星通信信号的截获提出了更高的要求,通过分析PCMA卫星通信系统的工作原理,借鉴多用户检测技术中串行干扰抵消的基本思想,提出一种针对非对称PCMA信号的截获方法,并进行了性能仿真。仿真结果表明,在没有任何先验信息的情况下,可以实现对非对称PCMA信号中双方信号的截获和解调。     

钻孔压灌超流态混凝土桩在深基坑支护中的应用

长螺旋钻孔压灌超流态混凝土一次性成桩工艺，克服了原有复杂的钻孔护壁灌注桩的弱点。用于基坑支护和取代旋喷桩用做桩间截水帷幕，具有工效高，造价低的优点。采用自进式锚杆，可以避免普通锚杆钻孔工程中塌孔等缺陷。     

Do highly anthropized hydrological conditions in marshes influence fish communities according to their life-history strategies?

Alterations of natural hydrology in aquatic ecosystems are known to strongly impact the community composition of different taxa. Surprisingly, literature on the potential influence of hydrology on fish community composition is still very scarce in agricultural marshes, where canals represent one of the few remaining aquatic habitats. This study is aimed to address this research gap by monitoring fish communities in independent hydrological units differing in hydrology management over a 6 years period. We predicted variable fish responses to the hydrological context according to different life-history strategies (opportunistic, equilibrium, or periodic species). Periodic and opportunistic species were the most frequently observed. Despite differences in hydrology between canals (but little variation over years), we found that hydrology explained only a very low proportion of variation in the composition of fish communities. In particular, the flooding duration of meadows in early spring did not influence the composition of fish communities, not even the abundance of periodic species expected to rely on such temporary habitats. Instead, fish communities were more influenced by local habitat variables (aquatic vegetation cover, turbidity, tree roots, and refuges under the canal banks). The hydrological management of most hydrological units for agricultural purposes (i.e., severe flood abatement in spring and shallow water depth in canals in summer) was found to be incompatible with conservation goals to promote more diverse fish communities between hydrological units. Therefore, we call for further investigations in similar habitats covering a larger range of hydrological conditions.     

Variation of biological and hydrological parameters and nitrogen removal optimization of modified Carrousel oxidation ditch process

To enhance the nitrogen removal, a systemic monitoring of the biological and hydrological parameters of Carrousel oxidation ditch in Chongqing Jingkou Wastewater Treatment Plant was carried out to study the feasibility of simultaneous nitrification and denitrification (SND). The variation and distribution of parameters such as flow velocity, concentration of dissolved oxygen (DO) and mixed liquor suspended solids (MLSS) in oxidation ditch were monitored and analyzed, which were major control factors for SND. The results showed that, the dimensional distribution of flow velocity, DO and MLSS were affected significantly by the operation condition of the aeration wheels. With all the four aeration wheels being in operation, DO and flow velocity were higher and the mixing of MLSS was sufficient. With three aeration wheels being in operation, the flow velocity in most of the bottom areas was enough to meet the basic requirements of no deposition, and the anaerobic region and aerobic region could exist simultaneously in one oxidation ditch, which was helpful to the process of SND. According to spatial distribution characteristics of the flow velocity, DO and soluble components under optimized condition, different functional zones of biochemical reaction in the Carrousel oxidation ditch system were defined, which might contribute to the optimization control and SND of Carrousel oxidation ditch.     

洛惠渠二支渠灌区末级渠系工程改造与管理

末级渠系改造是灌区节水改造的重要组成部分,加强改造工程管理是保障其发挥工程效益的关键。文中客观介绍洛惠渠灌区二支末级渠系工程现状和存在问题,探索其改造措施和加强管理途径,总结了工程改造效益。     

基于LS-DYNA的减震沟减震效应研究

为了研究减震沟的减震作用,运用大型动力分析软件LS-DYNA,基于具体工况分别对有减震沟和无减震沟的露天矿台阶爆破进行数值模拟.结果表明,减震沟距离爆源越近,减震效果越好,减震率最高可达77%,为减震沟的减震效应研究和类似工况提供了理论支持.     

Flow structure and channel change in a sinuous grass‐lined stream within an agricultural drainage ditch: Implications for ditch stability and aquatic habitat

Many drainage ditches in the Midwest have developed a geomorphological configuration characterized by vegetated bars, or benches, on the bottom of the ditch and a stream flowing within a channel inset into these bars or benches. Past work has focused on the sedimentology of the benches and the depositional processes involved in bench development. This study investigates the three‐dimensional flow structure and short‐term channel change in a small grass‐lined stream flanked by benches at the bottom of an agricultural drainage ditch in east central Illinois, USA. In particular, it focuses on the influence of channel curvature and bank vegetation on flow through the inset channel at two different stages and explores how the structure of the flow is related to documented patterns of channel change. Results indicate that the mean flow is characterized by a submerged high‐velocity core that mainly is confined to the centre of the channel by near‐bank zones of flow stagnation/separation induced by abrupt changes in channel alignment and by strong frictional effects of grasses extending into the flow along the channel margins. Where the high‐velocity core is close to the channel margins, minor erosional adjustments of the inset channel can occur in the form of bank erosion. Patterns of turbulence kinetic energy reflect the development of shear layers near the channel margins and surrounding the submerged high‐velocity core. Locations with strong turbulence also correspond to locations of minor bank erosion. The results indicate that the inset channel is a relatively stable feature, especially where the alignment of this channel is straight, but that erosion‐control treatments may be necessary locally where the inset channel impinges on the ditch bank. Although the development of benches, a geomorphic response to ditch maintenance, is commonly viewed as a threat to drainage efficacy, preserving or constructing benches and associated inset channels in drainage ditches can enhance aquatic habitat and water quality. Copyright © 2010 John Wiley & Sons, Ltd.     

利用HEC—RAS软件计算山洪沟水面线

本文以桦甸市某山洪沟为例,采用HEC—RAS软件,模拟分析了山洪沟在设计频率洪水下的水面线,为山洪沟治理工程的规模确定提供科学依据。计算结果表明,HEC—RAS软件在分析计算山区急流水面线时有较好的适用性,计算结果对工程有利,在山区河道及山洪沟治理工程中推荐使用该软件。