Occurrence,predication,and control of coal burst events in the U.S.

Coal burst represented a major hazard for some U.S. mining operations. This paper provides an historical review of the coal burst hazards,identifies the fundamental geological factors associated with these events,and discusses mechanisms that can be used to avoid their occurrences. Coal burst are not common in most underground mines. Their occurrence almost always has such dramatic consequences to a mining operation that changes in practice are required. Fundamental factors influencing coal burst events include strong strata,abnormal strata caving,elevated stresses,critical size pillars and the lack of sufficiently sized barrier pillars during extraction. These factors interact to produce excessive stress,seismic shock and loss of confinement mechanisms. Over the 90 years of dealing with these hazards,many novel prevention controls have been developed including novel mine designs and extraction sequences,most of which are site specific in their application. Without an accurate assessment of the fundamental factors that influence coal burst and knowledge of their mechanisms of occurrence,control techniques may be misapplied and risk inadequately mitigated.     

虚构·情理·美丑--从传奇剧《风筝误》看李渔创作思想的双重价值取向

李渔的传奇喜剧具有鲜明的双重价值取向,反映出明清之际中国文学家创作观念中的时代特色与传统桎梏共存的特征。     

APPLICATION OF HIGH-RESOLUTION MAGNETIC METHOD AND GRADIENT METHOD TO LOCATE ABANDONED BRINE-WELLS IN HUTCHINSON, KANSAS, U.S.A.

After successfully locating one abandoned brine well by an electromagnetic method during testing in 2001 and five abandoned brine wells by a high-resolution magnetic method during 2002, a high-resolution magnetic method was again proposed to search for wells in 2003 when a second sensor was employed to acquire data for calculating the pseudo-vertical gradient of magnetic fields. Total area surveyed in 2003 was 1,024,000 ft^2, which was divided into grids with an average size of 10,000 ft^2 and distributed across eight different sites. Magnetic anomalies and their vertical gradients from known brine wells were first recorded as signatures to identify anomalies caused by possible buried brine wells. Of fifty-one verified anomalies, thirty- one anomalies were due to wells buried at depths from 0 to 8. 5 ft： twenty-one 6- to 9-inch abandoned brine wells, seven 1.5- to 3-inch probable water wells, one 16-inch dewatering well for a construction site at a depth of 3 ft, and two 4-inch wells on the ground surface. Approximate monopole shaped anomalies were observed from all these wells after data corrections. However, the range of amplitudes of magnetic anomalies from 7,000 to 28,000 nT from these abandoned brine wells was measured. This range of anomalies is mainly due to the thickness and depth of buried wells. Anomaly amplitudes from 1.5- to 3-inch wells are 4,000 to 8,000 nT and linearly correlate with the buried depth. One 3-inch well that caused an anomaly of 13,000 nT could be the inner pipe of a brine well. Gradient anomalies are roughly in a range of 100 to 200 nT/inch for 1.5-to 3-inch wells and 200 to 300 nT/inch for brine wells. As indicated by the potential-field theory, gradient data possess higher horizontal resolution than the magnetic field itself. Gradient data provide valuable assistance in determining horizontal locations of anomaly sources for excavation. In practice, however, improvement in the horizontal resolution is limited by surveyline spacing. If only one sensor is used in a survey, there is rapid decrease in the horizontal resolution when sensor height increases from 14 to 44 inches. This indicates that it is critical to keep the sensor as close to the ground as possible when hunting buried wells that are close to each other. It also suggests that the downward continuation is useful to increase the horizontal resolution in well hunting.     

Dr. Gisela Bockenheimer-Lucius: Koordinierende Schriftleiterin, Diplomatin, Wissenschaftlerin, Ärztin

Ohne Zusammenfassung     

5·12汶川地震绵阳市区房屋震害统计与分析

历次大地震的经验总结是推动建筑抗震技术发展的重要途径。通过绵阳市区房屋在汶川大地震后的震害应急评估和调查,对市区各类房屋结构的震害进行了统计,总结分析各类房屋的震害特征和经验教训。得到一些启示和建议:绵阳市区按现行抗震规范设计的房屋基本经受住了地震考验;不同的结构体系表现出的抗震性能差别较大;老旧房屋始终是抗震薄弱环节,应有选择地进行抗震鉴定加固,开展砖混结构墙体抗震防裂措施研究,采取措施有效减轻框架结构中填充墙等非结构构件的震害,开展楼梯抗震设计计算与构造措施的研究。     

Ethik-Konsultationsdienst nach dem Konzept von J.C. Fletcher an der University of Virginia, Charlottesville, USA

Zusammenfassung.   Es wird die Arbeitsweise der klinischen Ethik-Konsultation am Klinikum der Philipps-Universit?t Marburg anhand eines konkreten Falles dargestellt. Grundlegend für diese Vorgehensweise ist die Theorie und Praxis eines Ethik-Konsildienstes, wie sie am Medical Center der University of Virginia von J.C. Fletcher, F.G. Miller und J.J. Fins entwickelt wurde.      

"激趣、学导、反馈、评价"教学模式在体育教学中的运用

学校体育是学校教育的重要组成部分,传统的体育教学模式已难以适应新形式的需要和发展,本文就如何运用新的教学模式提出相关建议,旨在为学校体育教学改革提供参考.     

哈尔滨市圣@索菲亚教堂环境整治设计

本文分析了圣索菲亚教堂的背景与现状，指出在市场经济的形势下该教堂及共环境所面临的挑战与机遇，提出了运用城市设计方法，对教堂周围地区进行开发和综合整治的构想和方案。     

浅析几何学在美国达拉斯音乐厅中的应用

几何学以其独特的感官效果被广泛运用到建筑设计中,使建筑简约而不失气势.以几何学为出发点,研究了几何空间自身的组成要素：线、面、体,阐述了其对建筑设计外观表现与空间组合的影响.达拉斯音乐厅充分运用了几何学的元素特性,合理巧妙地表现出了建筑外部的立面特色和内部多变的空间组合.