β放射性气体浓度计的新分度方法

本文介绍β放射性气体浓度计的一种新的分度方法——泄漏元件排气法。其特点是一只元件可分度放射性气体浓度计的许多读出数(甚至是几个量程),操作方便。     

秦山核电厂蒸汽发生器带钧波形板蒸汽干燥器的设计

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。     

ALUM SHALE BITUMEN MATURATION AND MIGRATION: IMPLICATIONS FOR GOTLAND'S OIL

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.     

三维Fuzzy数字拓扑及应用(Ⅰ)

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.     

TEM study of PLZT ceramics

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.     

An empirical formula for the prediction of rain attenuation infrequency range 0.6 - 100 GHz

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     

核电厂管系振动鉴定

本文介绍了核电厂管道振动鉴定概况,讨论了目前使用的管系振动的鉴定方法,给出了鉴定准则。     

A study on time schemes for DRBEM analysis of elastic impact wave

 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