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101.
沈长发  陈宝珍 《核动力工程》1989,10(3):13-17,39
文中详细介绍了秦山核电厂蒸汽发生器带钩波形板蒸汽干燥器的设计观点。  相似文献   
102.
Thermal maturation of Swedish Alum Shale kerogen and bitumen has been determined from core samples from Eastern and Central Sweden. In samples from Eastern Sweden (Öland and Gotland), the kerogen and bitumen are thermally immature with respect to petroleum generation. In some areas of Central Sweden (Närke, ÖstergÖtland, and Kinnekulle in VästergÖtland), the kerogen is immature, whereas the bitumen is marginally mature to mature. In other areas of Central Sweden (Halleberg-Hunneberg in VästergÖtland), the kerogen is supermature and the bitumen mature. This suggests that bitumen from a mature source-rock has migrated into the Alum Shales of Central Sweden. Migration in Central Sweden is further evidenced by the occurrence of obviously-migrated bituments in vugs and voids in the organicpoor Ordovician limestone overlying the Alum Shale in Central Sweden, and in concretions within the Alum Shale itself. Based on biomarker distributions of extracted bitumen, Alum Shale kerogen pyrolysate and obviously-migrated oils, and the fact that the Alum Shale in most of the areas studied is the only petroleum source-rock extant, it is suggested that the migrated bitumen in Central Sweden is from the Alum Shale itself. Bitumen has migrated from areas where the Alum Shale is in close proxmity to Permo-Carboniferous intrusions, such as Halleberg-Hunneberg, into nearby areas such as Närke and ÖstergÖtland, where there is no evidence of intrusion and the indigenous organic matter is thermally immature. Other areas, where Alum Shales were associated with intrusions and consequently sourced oil, may have been eroded away. There are producing wells on the island of Gotland, where the Alum Shale is also thermally immature. It is therefore assumed that heating which was responsible for generating Gotland's oil was very localized (such as by an intrusion) or that the oil has migrated from a thermally moremature, distant area. On the basis of reservoir rock porosity, and the fact that the Alum Shale of Gotland contains no migrated component, localized heating is favored.  相似文献   
103.
本文引入L-,l-连通度的概念,把Rosenfeld等人建立的三维数字拓扑模糊化;并在三维地震处理中找到了它的应用模型.  相似文献   
104.
The microscopic structures of PLZT(7.9/70/30 and x/65/35, x = 7 or 8) ceramics were studied by means of transmission electron microscopy. The presence of micro-regions in PLZTs was first verfied.  相似文献   
105.
An empirical formula for calculating the extinction cross section (ECS) by raindrops over a broad frequency range is first derived based on extensive calculations made on a widely varying in mean radius of modified Pruppacher and Pitter (MPP) raindrop models ranging from 0.25 to 3.5 mm. The expansion coefficients in the empirical formula are determined by least-squares curve fitting of numerical data obtained by the volume integral equation formulation (VIEF). The formula satisfies the frequency and raindrop size dependence. Numerical results obtained from the empirical formula for calculating the ECS are generally in good agreement with those calculated by the VIEF for raindrops with mean radius varying from 0.25 to 3.5 mm in the frequency range from 0.6 to 100 GHz. The average error in the ECS is less than 10%. The formula thus provides a simple and inexpensive method for calculating the ECS of raindrops, which otherwise requires complicated and expensive methods of calculation. By implementing this empirical formula of ECS into the rain attenuation equation, a new numerically empirical formula for calculating the specific rain attenuation is also proposed. The validity of the empirical formula for calculating the specific rain attenuation is also checked by comparing the obtained results of specific rain attenuation with those obtained from Li et al.'s (1995) solution, Yeo et al.'s (1993) measurement, and Olsen et al.'s (1978) power-law equation  相似文献   
106.
本文调查了油田212例受γ射线和中子混合辐射照射的作业人员和30例正常人的外周血淋巴细胞染色体畸变。作业人员受γ射线照射的人均年受照剂量为1.28mGy。调查结果表明,放射性测井人员与正常人相比染色体畸变率有显著差异。  相似文献   
107.
For batchwise radical chain solution multicomponent copolymerization, the minimum end time problem for the predetermined monomer conversion and number average molecular weight has been studied by considering the initiator concentration (or feed rate) and temperature as the two control variables. Applying the maximum principle and “unit segment treatment” (by which the co-polymerization can be treated as homo-polymerization in the kinetic analysis), it is found that for initiator addition processes the optimal initiator addition policy is to make the rate of initiation constant for the optimal temperature variation case, and the initiator concentration constant for the isothermal case as in homo-polymerization. For single charge of initiator processes, the optimal initial initiator concentration is such that it should be maintained at the lowest possible value (by which the polymerization is strongly dead-end) for the optimal temperature variation case without chain transfer steps, and at some optimal value (by which the polymerization is near dead-end) for the best isothermal case.  相似文献   
108.
云南省水环境状况及问题分析   总被引:2,自引:0,他引:2  
黄英 《人民长江》2002,33(7):23-24
根据2000年云南省主要河流水质监测评价结果,全省评价河段总长9280km中,水质为Ⅰ-Ⅲ类的河长占76.3%,总体上,云南省内各大水系水质良好,但水污染总体上正在加重,从1985-2000年,Ⅰ类河长年均减少2.3%,V类河长年均增长0.6%,废污水直接排入江河是引起污染的重要原因。水环境问题已成为社会经济可持续发展的关键问题,要切实加强水资源的保护,科学地开发利用水土资源,为了有效地改善水环境的质量,污染控制应从源头开始并采取综合治理措施。  相似文献   
109.
A study on time schemes for DRBEM analysis of elastic impact wave   总被引:1,自引:0,他引:1  
 The precise integration and differential quadrature methods are two new unconditionally stable numerical schemes to approximate time derivative with more than the second order accuracy. Recent studies showed that compared with the Houbolt and Newmark methods, they produced more accurate solutions with large time step for the problems where response is primarily dominated by low and intermediate frequency modes. This paper aims to investigate these time schemes in the context of the dual reciprocity BEM (DRBEM) formulation of various shock-excited scalar elastic wave problems, where high modes have important affect on traction response. The Houbolt method was widely recommended in many literatures for such DRBEM dynamic formulations. However, this study found that the damped Newmark algorithm was the most efficient and accurate for impact traction analysis in conjunction with the DRBEM. The precise integration and differential quadrature methods are shown inapplicable for such shock-excited problems due to the absence of numerical damping. On the other hand, we also found that to achieve the same order of accuracy, the differential quadrature method required much less computing effort than the precise integration method due to the use of the Bartels–Stewart algorithm solving the resulting Lyapunov matrix analogization equation. Received 6 November 2000  相似文献   
110.
秦山核电厂气载放射性释放的环境影响   总被引:3,自引:1,他引:2  
本文评价了秦山核电厂气载放射性流出物对环境的影响。应用现场及风洞大气扩释实验结果和厂址周围的人口与食谱调查资料,估算了秦山核电厂在正常运行和事故条件下释放的气载放射性流出物对公众产生的个人有效剂量当量和集体有效剂量当量。计算结果表明,正常运行时厂址边界(0.5km)处的最大个人有效剂量当量为2.7×10~(-2)mSv/a,该剂量的大部分来自~(137)Cs 的食入(主要由地表湿沉积引起);80km 范围内的集体有效剂量当量为1.1人·Sv/a,归一化集体有效剂量当量为3.7人·Sv/GW(e)·a。文中还给出了事故情况下剂量估算结果。  相似文献   
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