共查询到19条相似文献，搜索用时 140 毫秒
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储罐无组织排放的定量估算是石化企业污染源核查的重要项目。通过对比分析美国国家环保局(EPA)、美国石油学会(API)及中国石油化工(CPCC)系统经验公式等3种常用定量方法的应用情况,选择储罐区预测大气污染物的最佳方法,进而确定对储油罐的油品蒸发损耗量。结果表明:采用浮顶罐可减少小呼吸损耗,设置油气回收设施可减少大呼吸损耗,EPA公式较适合轻质油品,CPCC公式较适合拱顶罐,并提出减少油品损耗量的防治措施。 相似文献
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介绍特殊仓库内易燃易爆场所在新规范下如何进行防雷工程的设计与施工,重点针对直击雷与感应雷防护措施的施工方案及施工要点进行分析。 相似文献
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本文根据多普勒天气雷达回波与闪电定位仪资料,结合雷电现场进行实地勘查的结果,探讨2006年8月7日发生在扬州市仪征油罐雷电灾害事故。综合分析发现当时强对流回波达55 dBz、顶高14 km;在距油罐1 km范围内有闪电13次,负电荷集聚、强度多在20~50 kA之间。此次雷灾事故的直接致灾原因是强大的感应雷电脉冲电流在储油罐罐体与浮顶两根连接电缆上产生较大的电压,导致储油罐罐体与浮顶之间在密封处产生闪络,引起油汽外泄燃爆成灾。为减少此类雷电灾害的发生,提出防护建议。 相似文献
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闭合气压系统中心位置指数的计算方案 总被引：1，自引：1，他引：0
王盘兴等在＂闭合气压系统环流指数的定义及计算＂一文中定义了闭合气压系统的面积指数S、强度指数P和中心位置指数（λc,φc）,并给出了它们的计算方案。但其中（λc,φc）的计算方案对低纬系统的计算存在明显误差,误差原因是原方案中的极点球面坐标系不适合低纬系统的计算。本文建立了一套原点位于搜索区Ω中心的新球面坐标系,通过坐标转换实现了低纬闭合气压系统中心位置指数（λc,φc）的准确计算。对7月南亚高压和1月蒙古高压中心位置指数（λc,φc）的实际计算表明,它既消除了低纬系统（南亚高压）（λc,φc）原计算方案的明显误差,又保持了与高纬系统（蒙古高压）（λc,φc）原计算方案计算结果的一致。因此,本文给出了适于计算任意纬度闭合气压系统中心位置指数（λc,φc）的计算方案。 相似文献
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移动终端的合法监管是国家安全部门保障移动网络安全的重要手段,获取移动终端身份标识是实现监管的基础.首先阐述了移动终端的主要身份标识,以及监管系统相关研究现状;然后给出一种面向双频点GSM网络和WCDMA网络的多制式移动终端身份感知系统设计方案,阐明系统技术原理与实现方法,并提出对该系统进行优化的技术方案;最后进行测试,验证了方案的可行性. 相似文献
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简述计算机网络综合布线系统的含义,设计了省气象局科技中心大楼的布线系统方案 相似文献
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本文研究了多切换模式下混沌系统的有限时同步控制问题.针对多个不同阶实变量混沌系统,研究了其多切换同步行为,给出了有限时多切换组合同步的定义,进而,在给出误差系统的基础上,设计了一类实现快速同步的有限时控制方案,并给出了误差系统有限时稳定的充分条件.最后,仿真结果表明所设计控制方案具有快速收敛性,较好地验证了有效性. 相似文献
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The impact of different vertical diffusion schemes in a three-dimensional oil spill model in the Bohai Sea 总被引：2，自引：0，他引：2
Vertical transport is critical to the movement of oil spills in seawater. Breaking waves play an important role by developing a well-defined mixing layer in the upper part of the water column. A three-dimensional （3-D） Lagrangian random walk oil spill model was used here to study the influence of sea surface waves on the vertical turbulence movement of oil particles. Three vertical diffusion schemes were utilized in the model to compare their impact on oil dispersion and transportation. The first scheme calculated the vertical eddy viscosity semi-empirically. In the second scheme, the vertical diffusion coefficient was obtained directly from an Eulerian hydrodynamic model （Princeton Ocean Model, POM2k） while considering wave- caused turbulence. The third scheme was formulated by solving the Langevin equation. The trajectories, percentages of oil particles intruding into water, and the vertical distribution structures of oil particles were analyzed for a series of numerical experiments with different wind magnitudes. The results showed that the different vertical diffusion schemes could generate different horizontal trajectories and spatial distributions of oil spills on the sea surface. The vertical diffusion schemes caused different water-intruding and resurfacing oil particle behaviors, leading to different horizontal transport of oil particles at the surface and subsurface of the ocean. The vertical diffusion schemes were also applied to a realistic oil spill simulation, and these results were compared to satellite observations. All three schemes yielded acceptable results, and those of the third scheme most closely simulated the observed data. 相似文献
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通过对钢质浮顶油罐雷电防护技术和施工工艺的研究,分析了钢质大型浮顶油罐的防雷技术措施;针对相关国家规范只有条文规定而无相应施工图集的问题,给出了相应的防雷施工工艺图,以供油库防雷设计和施工管理人员参考. 相似文献
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A laboratory study of the turbulent velocity characteristics in the convective boundary layer 总被引：4，自引：0，他引：4
Based on the measurement of the velocity field in the convective boundary layer （CBL） in a convection water tank with the particle image velocimetry （PIV） technique, this paper studies the characteristics of the CBL turbulent velocity in a modified convection tank. The experiment results show that the velocity distribution in the mixed layer clearly possesses the characteristics of the CBL thermals, and the turbulent eddies can be seen obviously. The comparison of the vertical distribution of the turbulent velocity variables indicates that the modeling in the new tank is better than in the old one. The experiment data show that the thermal＇s motion in the entrainment zone sometimes fluctuates obviously due to the intermittence of turbulence. Analyses show that this fluctuation can influence the agreement of the measurement data with the parameterization scheme, in which the convective Richardson number is used to characterize the entrainment zone depth. The normalized square velocity wi^2/w＊^2. at the top of the mixed layer seems to be time-dependent, and has a decreasing trend during the experiments. This implies that the vertical turbulent velocity at the top of the mixed layer may not be proportional to the convective velocity （w＊）. 相似文献
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William H. Snyder Robert E. Lawson Jr. Michael S. Shipman Jie Lu 《Boundary-Layer Meteorology》2002,102(3):335-366
A laboratory convection tank has been established following thepioneering work of Willis and Deardorff, but with many improvements and enhancements thattake advantage of modern technology. The main emphasis in the current design was toprovide the ability to conduct a virtually unlimited number of realizations under essentiallyidentical conditions in order to obtain reliable statistics on the dispersion of plumes and puffsreleased within the simulated atmospheric convective boundary layer. Described herein is the tankitself and its auxiliary systems, including a laser-induced-fluorescence and video-imaging system for makingnon-intrusive, full-field measurements of concentrations, and the interfacing of varioussubsystems with a master controller that automates essentially all operation and measurement functions.The current system provides unprecedented resolution, control, and data volumes. Exampleresults are presented from two types of releases: continuous plumes and instantaneous puffs.These data sets clearly show penetration of the highly buoyant plumes and puffs into theinversion above the convective boundary layer, gravity spreading within the inversion, andrapid diffusion within the mixed layer. They also show extreme `spottiness' in the instantaneousconcentration cross-sections. 相似文献
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膨胀云室可形成水汽、水面和冰面过饱和环境,是研究气溶胶粒子、人工影响天气冷暖催化剂核化过程和机理的重要实验设备。但长期以来,我国缺乏装备先进云雾粒子谱和图像测量系统的膨胀云室。2019年完成的我国自主研制的膨胀云室系统由云室主体、控制系统、通讯系统及环境和云雾测量系统4个子系统组成。该系统首次采用了国产云粒子谱仪和成像仪测量系统。测试结果表明:该云室具有良好的温度和压力控制能力,平均降温速率达到0.26℃·min-1,温度分布均匀,-40℃时舱内温差小于0.29℃;膨胀造雾过程4 min,雾可维持4 min,雾滴较小;可以实现从室温到-50℃低温环境的控制,具备压力膨胀成云雾模拟和微物理参数监测能力,解决了我国缺乏气溶胶粒子和暖云催化剂室内实验装备的状况,对验证暖云催化剂核化性能和提高暖云人工增雨科技水平有重要价值。 相似文献
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The analysis is given of the present situation and current preparedness of available approaches to the implementation of the Roshydromet concept of the improvement of environmental pollution monitoring system taking into account differences in goals and objectives that different components of this system should achieve at the federal, regional, and local levels. The structure and functional scheme of the National environmental pollution monitoring system is discussed. The approximate allocation of functions is put forward among the monitoring system components of different levels as well as the distribution of responsibilities and powers among stakeholders to ensure the implementation of these functions. The key issues of establishing an integrated monitoring system are discussed. The network-centric approach to the system management organization is proposed. Specific goals, objectives, and strategies can be set for different components of this system which may differ in terms both of algorithms and actual parameters. The development of the main technological components of the integrated environmental monitoring system (monitoring networks and information systems) is considered. 相似文献