MCNP源程序修改及应用

MCNP程序是一个大型多功能蒙特卡罗计算程序,它适应于核科学和工程方面的多种课题.虽然MCNP程序的通用性很强,可以满足大多数的实际应用,但针对一些特殊的应用还是需要用户对源程序进行修改并重新编译.目前,大多数MCNP程序用户对如何修改和编译源程序了解得比较少,与之相应的文献资料也很少见.有鉴于此,本文对该问题进行了总结并对如何处理作了详细的介绍,目的是为用户更好的理解程序构成、提高对程序的应用能力提供帮助.     

控制东营凹陷烃源岩排烃的几个关键因素

通过东营凹陷钻井取心的观察及不同结构烃源岩地质地球化学特征的比较,从内因、外因两个方面对烃源岩排烃的控制因素进行了分析,并且就烃源岩岩性结构对排烃及成藏的控制作用进行了初步研究.认为内因为有机质类型、丰度及成熟度,反映烃源岩中生烃母质的特征,东营凹陷大量样品测试结果显示烃源岩的生烃潜量、排烃量与有机质丰度呈良好的线性关系;外部因素包括源岩的结构、源岩内有效的运移通道、压力的分布及外部的构造运动等各种地质作用及内、外部环境.研究结果表明,东营凹陷主力烃源岩沙四上及沙三下段具有多种岩性结构形式,其中沙四上及沙三下下部主要发育纹层状泥页岩,油气以远距离侧向运移为主;沙三下上部及沙三中主要发育块状泥岩,油气以垂向运移为主.不同的排烃方式造成了油气分布的差异,沙四型原油分布于凹陷外围,沙三型原油分布于凹陷内围,混合型原油分布于中间地带.     

含不稳定电流源轴对称非静态场的计算

利用麦克斯韦方程组和场的轴对称性,首先导出了3个基本表达式,即磁感应强度B的径向分量表达式、轴向分量表达式以及电场强度E的切向分量表达式,然后,以对称轴的已知不稳定场量为初始值,以这3个表达式为基础,通过不断地迭代并总结各表达式的规律,得到了含不稳定电流源轴对称非静态电磁场的无穷级数表达式,并将结果代回到麦克斯韦方程组进行了验证。这一方法也可供其它类型的含不稳定源轴对称非静态场的计算借鉴。     

织布机梭子飞行实验专用频闪仪的研制

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.     

自来水厂扩建工程自动控制系统研究

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。     

Water-vapor source shift of Xinjiang region during the recent twenty years

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.     

条形射频源大口径离子束刻蚀机性能(英文)

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.     

Thermal simulation experiment on the hydrocarbon regeneration of marine carbonate source rock

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.     

农田氮素非点源污染模型及年负荷估算研究

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.     

通信侦察中通信复信号的盲源分离算法

针对目前大多盲源分离算法只适用于实信号,而在通信对抗中处理的一般都是通信复信号这一问题,推导了一种适用于通信复信号的盲源分离算法.该算法以Kullback-Leibler发散度作为信号之间独立性的测度准则.另外由于自然梯度比随机梯度性能更优,因此利用代价函数的自然梯度进行优化,根据白化后信号混合矩阵为正交矩阵的结论,对分离矩阵做正交性约束,推导出了算法的迭代公式.仿真结果表明,即使在有嗓环境下,该算法也能够有效地分离出源信号.