排水管道沟槽支护结构经济指标测算研究

通常沟槽支护结构费用占排水工程费用比例较高。简要介绍上海市排水管道常用的沟槽支护结构,对各类沟槽支护结构的经济指标进行计算,分析影响沟槽支护结构经济指标的主要因素。通过案例分析,对应用的经济指标进行方案比选,并验证经济指标的有效性。研究结论能为造价估算提供便利,也为设计、施工合理选择排水管道沟槽支护结构提供借鉴和参考。     

防渗技术在石油化工项目中的应用

石化领域的环境保护越来越受到人们的重视,防渗处理成为石油化工项目设计过程中的新课题。以防渗技术在某石化装置中的应用为例,综合比对两种方案,确定采用HDPE土工膜防渗结构层作为实施方案,并且结合装置实际情况,对实施方案进行优化。其中,详细介绍了土工膜材质的选择和设计及施工要点。     

微槽竖嵌管道在城域网中的引入建议

论述了现行通信管道存在的问题,介绍了微槽竖嵌管道的施工方法、管材及适用光缆、人孔及接头、上／下压力及侧面压力,优点及缺点,阐述了引入微槽竖嵌管道的详细建议.     

深厚覆盖层防渗墙槽壁稳定性影响分析

深厚覆盖层地质条件复杂,槽壁稳定受到诸多因素的影响,对其进行分析研究,得出地质条件、泥浆性能、地下水位、槽段划分、施工机械是影响稳定的重要因素。针对这些影响因素,提出了解决深厚覆盖层防渗墙槽壁失稳的具体措施。     

Reduction of loading effects with the sufficient vertical profile for deep trench silicon etching by using decoupled plasma sources

This study presents the features of profile evolution in deep trench silicon etching, which is crucial for commercial wafer-processing applications. Experiments to minimize the macroscopic and microscopic loading effects were performed with anisotropic deep trench etching in high-density decoupled HBr/CF₄/Cl₂/O₂ and SF₆/CF₄/O₂ plasmas. The process parameters, including gas chemistry, pressure, source power, bias power, and dual electrostatic chuck system, were also optimized for these applications. Notching and trenching phenomena were effectively improved during the deep trench etching process. The optimized deep trench silicon process resulted in vertical profiles (87–90°) with a loading effect of <1% by using the SF₆-based chemistry, which was more effective than the HBr-based process. The bias constant verified the linear-etching parameter system, depending on the pattern density of the device, in order to commercialize deep trench silicon etching for mass production.     

Mechanism of high selectivity in ceria based shallow trench isolation chemical mechanical polishing slurries

dl-aspartic acid as a removal rate selectivity enhancer for shallow trench isolation chemical mechanical polishing slurries was investigated over a pH range. The effects of downward pressure, rotational speed of the turntable as well as the ceria abrasive loading were also examined. The selectivity is very sensitive to changes in the pressure but not to changes in the rotational speed. Select experiments were also conducted with other types of abrasives with and without the additive. A comparison of the pK_a values of the amino acid with the variation of the selectivity with pH indicates that the form of amino acid plays a vital role in determining the polishing behavior and the selectivity. Further, the results corroborate the hypothesis that chemically active sites on the abrasive may be blocked by certain forms of the amino acids, leading to changes in the selectivity.     

一种提高硅双极器件频率和功率的新技术

提出了一种能同时提高硅双极器件频率和功率的新技术－具有深阱终端结构的新型梳状深阱结构技术。采用ＭＥＤＩＣＩ模拟分析表明,该技术可交双极器件的击穿电压ＢＶＣＢ０提高到平行平面结的９０％以上;可减小寄生效应和漏电流,有助于提高小电流β０;可适当的增加集电区掺杂浓度,减小τｄ,同时提高ＩＣＭ和Ｐｏ。     

西南成品油管道工程龙江怀远段沉管施工

西南成品油输油管道穿越龙江段工程采取沿河床沉管浅埋敷设方式。穿江处河道水下地形复杂,水下礁石、河底暗河、溶洞发育,现场施工难度大。沉管施工中,采用水下爆破方法开挖沟槽,并选择现场拼装、分段焊接、水上连接、分段充水及整体翻转沉放管道的方案。沉管安装完成后,及时进行压重块安装及沟槽回填。工程完工一年后利用水下摄影和人工水下探摸,管道工程运行情况良好,河床形态未发生大的变化。     

运用开挖技术与非开挖技术的经济比较分析

对地下管线非开挖技术与开挖技术施工方法工程造价进行了比较分析,强调了地下管线工程建设中,重视技术经济性的重要性,分析了目前国内外地下管线施工的现状,提出了重视社会效益和环境意识对社会可持续发展的重要性。     

基于SURPAC的残矿开采堑沟巷道空间位置优化

由于残矿空间形态的复杂性,传统的剖切作图方法难以直观全面地掌握该类型矿体形态,进而难以精确指导采切工程的设计,而SURPAC软件采用三维建模方法,能很好地解决这一难题.以西石门铁矿堑沟底部结构诱导冒落法开采残矿为背景,采用SURPAC软件对堑沟内矿石量、金属量、品位等指标进行计算,将堑沟巷道所在的水平和垂直位置作为优化对象,经过对临界冒落跨度和现场工程技术条件的分析,得出堑沟巷道在两个方向上可布置的范围.依据该范围,设计了正交试验方案.以回采金属量和平均品位作为考核指标,对正交试验结果进行极差和方差分析,得出最优的堑沟巷道空间位置:堑沟巷道间距24 m,位于118 m水平.通过现场实施,取得理想的试验效果,实现了残矿的精细化开采.