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981.
介绍一款适用于织布机梭子飞行测试实验的频闪仪系统,分析了该系统的工作原理、硬件结构、技术参数及软件流程.系统采用ATMEL公司单片机系列中的AT89C2051来设计显示电路,选用高功率氙气灯作为光源,采用AD654压频转换器作为信号源.在织布机梭子飞行测试实验中,该频闪仪具有良好的使用效果.  相似文献   
982.
本系统以上位机为控制核心,通过现场传感器进行信号采集。两水源之间采用宽带网络进行通讯,二水源通过无线电台进行野外信号采集,这样能够增强系统的稳定性与实用性。  相似文献   
983.
Water-vapor source shift of Xinjiang region during the recent twenty years   总被引:2,自引:0,他引:2  
The aim of this paper is to investigate the climate water-vapor sources of Xinjiang region and their shifts during the past 20 years. First, the principle and steps are roughly regulated to seek the water-vapor sources. Second, the climate stationary water-vapor transport in troposphere is calculated to distinguish where the water vapor comes from by ERA-40 reanalysis. In addition, the collocation between the transport and the atmospheric column water vapor content is analyzed. The results show that the major vapor comes from the west side of Xinjiang for mid-month of seasons, apart from July while the water vapor comes from the north or northwest direction. The water vapor sources are different for different seasons, for example, the Caspian Sea and Mediterranean are the sources in January and April, the North Atlantic and the Arctic sea in July, and the Black Sea and Caspian Sea in October, respectively. In recent ten years more water vapor above Xinjiang comes from the high latitudes and the Arctic sea with global warming, and less from Mediterranean in comparison with the case of 1973—1986. In fact, the air over subtropics becomes dry and the anomalous water vapor transport direction turns to west or southwest during 1987—2000. By contrast, the air over middle and high latitudes is warmer and wetter than 14 years ago.  相似文献   
984.
针对大尺寸基底往复扫描条形离子束来实现大面积刻蚀的特点,实验测试了基于射频感应耦合等离子体离子源大型离子束刻蚀机的性能.利用法拉第筒扫描探测系统在线测量束流密度,通过控制气体流量、调节加速电压等,得到了纵向束流密度±5.3%均匀性的较好结果.刻蚀实验表明40 cm长度范围刻蚀深度均匀性为±5.4%,同时具有较好的束流稳定性.添加束阑,并结合掩模修正束流,会得到更好的束流密度与刻蚀深度均匀性.  相似文献   
985.
Hydrocarbon regeneration of marine carbonate source rock was simulated with thermal experiments in a laboratory. The results reveal that hydrocarbon regeneration does not simply continue the primary hydrocarbon generation process, and that, for marine carbonate source rock, discontinuous hydrocarbon generation differs greatly from the continuous generation. Several different features of hydrocarbon regeneration were observed in the experiments. First, the liquid hydrocarbon generation peak was always observed no matter what the initial maturity of the sample was. Moreover, the maturity and the liquid hydrocarbon yield corresponding to the peak varied with the sample’s initial maturity. Second, the hydrocarbon regeneration started earlier than the continuous one. In the experiments, the hydrocarbon could be re-generated when the sample maturity did not rise to any great extent. Third, the accumulative hydrocarbon-generating quantity during discontinuous generation was always more than that during continuous generation. And the hydrocarbon-generating quantity varied with the discontinuous generation history. Chemical kinetic analysis suggests that discontinuous hydrocarbon generation should not only be explained by the parallel reaction mechanism but also by the consecutive reaction mechanism which has been ignored in the traditional chemical kinetic model for continuous hydrocarbon generation.  相似文献   
986.
农田氮素非点源污染模型及年负荷估算研究   总被引:1,自引:0,他引:1  
研究了农田中氮素随径流动力输出的过程,并依据径流特征和农田氮肥施用情况,将全年区分为水田施肥期、水田生长期和非水田期.按试验时的天气条件,分别采用人工模拟降雨或农田实测降雨的资料,分析农田非点源污染回归模型.水田施肥期采用人工模拟集中降雨情形,降雨强度为2 mm&;#8226;min-1,模型氮素浓度范围为28~45 mg&;#8226;L-1;水田生长期和非水田期采用天然降雨,降雨强度为0.037 6~0.075 1 mm&;#8226;min-1,模型氮素浓度为0.2~4.0 mg&;#8226;L-1.在分析长系列降雨资料的基础上,综合运用修正SCS(Soil Conservation Service)法、单位线法和相关分析法,估算得到农田径流过程排放的氮素量,再加上地下水渗漏流失的氮素量,取得上海地区一般降水年份农田的氮素非点源污染年负荷量为26.5 kg&;#8226;ha-1.  相似文献   
987.
运用能量守恒和(火用)分析方法,对冷中子源氦制冷逆布雷顿循环过程进行热力分析和(火用)分析.找出了系统(火用)效率和各部件(火用)损失随着压缩机压比、膨胀机等熵效率、跑冷量、换热器冷热流体平均温差变化的规律,并提出减小循环跑冷量、换热器内冷热流体温差,以及提高压缩机压比、膨胀机等熵效率、物料分配均匀度以提高循环性能和系统(火用)效率的措施.基于换热器内部冷热流体温差分布对循环性能影响的分析,设计了膨胀机预冷循环方案,该方案的(火用)效率相对于基本循环提高了24 %.  相似文献   
988.
冶金企业中往往具有众多的工业污染源和排放种类多、数量大的污染物,这样就产生了如何确定企业污染防治重心的问题.本文对工业污染源的普查及评价方法进行了阐述,从而能使每个企业把握自身的污染防治重心,对企业环境污染状况的治理工作具有一定的借鉴意义.  相似文献   
989.
The issue of source of oil/gas in the platform basin area in Tarim Basin has been debated for a long time, and the debate is focused on whether the marine oil/gas resources that have been discovered in the basin were originated from hydrocarbon source rocks in the Cambrian-Lower Ordovician or in the Mid-Upper Ordovician. In this paper a summary was made in regard to the major points and supporting data by the predecessors, and a discussion was conducted toward the core issues related to the study on the oil source in the Tarim Basin area, such as choice of correlation parameters, influence of maturation and physical differentiation on oil source correlation parameters, and geological and geochemical significance of these relevant correlation indices. It is quite probable that different interpretation results could arise from the oil source correlation due to choice of parameters severely affected by the thermal maturation and physical differentiation effect, and insisted that only those parameters that come with clearly defined geochemical significance and are less affected by thermal maturation and variations occurring during secondary evolution process are valid ones. The marine crude in Tarim Basin covers contributions that were originated from two sets of hydrocarbon source rocks as mentioned above but dominated by the one from the Mid-Upper Ordovician hydrocarbon source rocks. Here oil of mixed sources occurs extensively, and crude from Cambrian sources was also discovered. It is suggested that for further study on the origin of marine crudes in Tarim Basin, the parameters used for correlation of oil sources shall be optimized, and a comprehensive set of geological and geochemical methods shall be adopted for this purpose.  相似文献   
990.
甲醇与葡萄糖为碳源在反硝化过程中的比较   总被引:16,自引:0,他引:16       下载免费PDF全文
在颗粒滤床反应器内 ,以葡萄糖或甲醇为碳源 ,碳源充足时 ,均可以比较完全地去除硝酸盐 ,但以葡萄糖为碳源的最佳碳氮比较甲醇为碳源高得多 ,为 6∶1~ 7∶1 (C6H1 2 O6∶NO-3 N)。当碳源不足时 ,反硝化过程存在亚硝酸盐积累现象 ,且葡萄糖为碳源时积累更严重。以CH3OH为碳源进行的反硝化速率较以C6H1 2 O6 为碳源的快得多 ,在相同条件下快 3倍。在本实验条件下 ,反硝化过程表现出 0级反应特征 ,k (CH3OH) =1 60mg/L·h ,k(C6H1 2 O6) =42mg/L·h。  相似文献   
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