Experimental Study of Structure Shock Vibration in Soil Caused by Explosion of Conventional Weapons     

FENG Jinji  XIE Qingliang  ZHAO Dayong 《天津大学学报(英文版)》2006,12(Z1)

When hitting underground structures directly or exploding in rock-soil media near underground structures, the conventional weapons with large charge weight will make underground structures be subjected to strong shock vibration and cause personal casualty and damage of precision electronic equipments. The shock vibration has become one of the cardinal killing means of weapons. However, the existing methods of predicting structure shock vibration are limited evidently. In this paper the coupling coefficient of acceleration in clayey soil is obtained firstly. Subsequently based on repeated experiments of chemical explosion, after dimension analysis and by using method of multivariate stepwise regression, the calculation formulae of shock vibration acceleration for the underground structure are obtained finally. The formulae consider top and side explosion respectively, taking into account the effects of penetration depth, charge weight, distance to explosion center, rock-soil media, size of structure and buried depth. They are easy to use with high practicability and degree of confidence, and can provide credible evidence for prediction of shock vibration and vibration isolating design of underground structure.  相似文献   

论灵敏度分析方法在预测项目经营现金净流量中的运用     

张薇 《常熟理工学院学报》2007,21(1):17-20

灵敏度分析方法目前主要被运用于利润预测分析,而很少被运用到长期投资项目评估特别是对经营现金净流量的预测中。这里拟对此方法用于经营现金净流量分析的适用性进行探讨,试图通过计算项目经营现金净流量的灵敏系数来把握经营现金净流量的变动规律,从而为正确计算净现值指标和项目最优决策提供依据。  相似文献   

Tampering with a Stable Process     

Timothy C. Krehbiel 《Teaching Statistics》1994,16(3):75-79

This article presents a variation of the funnel experiment made famous by W. Edwards Deming. Ideally suited for classroom use, this exercise illustrates the disastrous consequences resulting from tampering with a stable process.  相似文献   

民族器乐作品的标题研究     

马东风 《徐州师范大学学报(哲学社会科学版)》2005,31(3):129-132

从乐器的起源到独立的器乐曲标题的产生,从具有人文意义的标题命名到标题的完善,历经了一个漫长的历史演变过程,这个过程深深地烙下了我国音乐发展的历史印记。标题的源流、分类及其变易现象,标题性音乐与非标题性音乐的美学原则,音乐标题与文学之间的关系,标题中所反映出的民族审美心理特征等问题,反映了中国传统音乐文化传承中的一些特点。弄清这些关系,对于当代民族器乐作品的创作与欣赏有着重要的指导意义。  相似文献   

谐振子量子制冷循环性能的优化分析   总被引：1，自引：0，他引：1  

林比宏 《泉州师范学院学报》2005,23(6):27-33

基于量子主方程和半群逼近研究以谐振子系统为工质，由两个等温和两个等谐振子数过程组成的不可逆谐振子量子制冷循环的一般性能特性，导出了制冷循环的制冷系数、制冷率、输入功和熵产率等重要参数的一般表达式．并详细讨论了高温极限下谐振子量子制冷循环的优化性能，导出了最大制冷率和相应的制冷系数．所得结论可为非常规工质低温制冷循环的优化设计提供理论基础．  相似文献   

Equivalent Kelvin Impact Model for Seismic Pounding Analysis of Bridges     

DING Yang  YUE Fuqing  LI Zhongxian 《天津大学学报(英文版)》2006,12(Z1)

Based on Hertz contact theory, a method to determine the parameters of Kelvin impact model for seismic pounding analysis of bridges is proposed. The impact stiffness of Kelvin model is determined by the ratio of maximum impact force to maximum contact deformation, which is calculated based on Hertz contact theory with considering the vibration effect. The restitution coefficient which has great influence on the damping coefficient of Kelvin impact model is investigated by numerical analysis. Numerical results indicate that the impact stiffness of Kelvin impact model increases with the increment of the Hertz contact stiffness, approaching velocity or the length ratio of short to long girders. Vibration effect has remarkable influence on the impact stiffness and cannot be neglected. The restitution coefficient decreases when approaching velocity increases or the length ratio of short girder to long girder decreasing. The practical ranges of impact stiffness and restitution coefficient are obtained as 3×108-6×108 N/m and 0.6-0.95 respectively.  相似文献   

变系数一阶线性时滞微分方程的一个可积判据     

张学元 《邵阳学院学报(社会科学版)》2003,2(5):9-13

首先引入广义周期函数的概念．然后给出了变系数一阶线性时滞微分方程的一个实用的可积充分判据，从而扩大了常微分方程的封闭求积范围．  相似文献   

二阶变系数线性齐次方程的三个可积充分条件     

邹明辉  刘会民 《鞍山师范学院学报》2004,6(4):4-6

利用变量代换和凑项的方法,给出了二阶变系数线性齐次方程的三个可积充分条件,并得出求解方程的通解公式.  相似文献   

试析我国居民收入分配存在的问题、原因及对策   总被引：4，自引：0，他引：4  

张志超  王聪 《华侨大学学报(哲学社会科学版)》2001,(4):24-33

本试图对经济改革20余年来我国居民收入分配格局的变化，特别是近年来收入差距不断扩大问题进行初步研究。由于收入分配问题涉及面广，本只集中考察收入分配变化的一些重要方面。考虑到在我国经济转轨过程同现代经济发展过程并行这一特点，本从经济改革、体制调整等角度分析了我国居民收入差距变化的一般原因。章最后，本着公平与效率兼顾原则，就如何提高居民收入分配平等化程度提出某些有针对性的建议。  相似文献   

世纪末的"浪漫"绝响--论寻根文学的浪漫主义精神特质     

镇涛  周迎 《鄂州大学学报》2005,12(1):47-51

于寻根文学一般从现实主义和现代主义两个向度加以阐释，事实上寻根文学同样具有浓厚的浪漫主义精神特质，而且为世纪末的浪漫主义的发展提供了某种新质。寻根文学的浪漫主义精神特质体现在三个方面：一是现代化语境中文化主体焦虑的书写；二是对于原始文化生态的回归；三是执著于超越现实的理想主义情怀。同时寻根文学所提供的浪漫主义因素不同以往的新变体现在主体性、自然性内涵的衍变，理想主义与民间立场紧密相关等方面。  相似文献