盐渍土与分散性针孔试验影响

通过具体实例,研究了新疆氯盐渍、硫酸盐渍土对针孔试验的影响,认为氯盐渍土因其胶结作用,随着盐量的增加,土样孔径大小、流量变化不大。硫酸盐渍土因其膨胀性,随着盐量的增加,土样孔径、流量减小,对土样的冲蚀破坏作用而不相同。     

洪家渡水电站左坝肩高边坡稳定及加固措施研究

贵州洪家渡水电站左坝肩高边坡开挖高度310 m,采用弹塑性有限元数值模拟方法对左坝肩高边坡施工期岩体应力应变状态进行分析研究,并结合现场变形观测资料对计算结果进行验证,从而对左坝肩高边坡的稳定性进行评价并提出相应的加固措施。     

基于复模态的有限元模型修正算法

针对地下结构地震响应分析中无限地基辐射阻尼问题，引入复模态情况下的具有非简化的堆积阻尼矩阵的阻尼模型，并针对具有集中质量阵的阻尼模型提出了合并与质量有关的阻尼和堆积阻尼的思想，并据此提出了一种修正此类有限元模型的两步法，首先从复模态参数中提取实模态参数，采用基于模态残余力的识别算法修正刚度矩阵，然后根据复模态参数和已得的刚度矩阵来识别阻尼模型中的刚度参与系数和质量阻尼堆积阻尼联合矩阵。     

城市防震减灾信息管理系统之研究

城市防震减灾信息系统是“数字福建”的一个组成内容。该文结合福建省城市防震减灾信息系统的建设工作 ,探讨了地理信息系统与防震减灾数值模型的集成方法 ,论述了城市防震减灾信息系统的结构、内容、功能和组织方式 ,分析了地震风险评估、建筑物易损性评价、生命与财产损失估算、救援与救灾管理调度等模型的集成方法 ,设计了城市防震减灾信息系统。     

Simulation of oasis breeze circulation in the arid region of the Northwestern China

In this paper, the process of oasis-desert circulation (ODC) is simulated by MM5V3.5 model through designing an ideal oasis-desert scheme and assuming that initial atmosphere is at rest (V = 0). The findings showed that the key of forming special oasis boundary structure is the difference of energy and water between oasis and desert. The evaporation of oasis surface consumes heat energy, and the low temperature of oasis causes an oasis breeze circulation (OBC), which drives an ODC with a downdraft over the oasis and an updraft over the desert. Later, the cold, dry and stable boundary over oasis is gradually formed, on the contrary,the atmospheric boundary over desert on the edge of oasis is hot, humid and unstable and its height is about 600 hPa. The updraft over the desert forms a wet ring that acts as a vertical wall weakening the low-level moisture exchange between the oasis and desert. The downdraft of OBC increases the atmospheric stability that reduces the oasis evaporation. The low-level outflow from the oasis (into the desert) prevents the dry, hot air flowing from the desert into the oasis.Thus an oasis self-preservation mechanism may be formed due to OBC. The horizontal area influenced by oasis is twice as oasis area and the vertical range is four times as oasis. The ODC is strong in the daytime and reaches the strongest at 17:00, and the influenced area is the largest at 20:00.     

Study of charge structure and radiation characteristic of intracloud discharge in thunderstorms of Qinghai-Tibet Plateau

The comprehensive observations on lightning discharges were conducted in Naqu area of Qinghai-Tibet Plateau in summer of 2002. The electric structures of thunderstorms and the characteristics of lightning discharges at initial stage were analyzed by using the observation data. The results show that most of intracloud (IC) lightning flashes were polarities inverted in thunderstorms with tripole electric charge structure and occurred between negative charge region located in the middle of the thunderstorm and positive charge region located at the bottom of the thunderstorm. The radiation characteristics of discharge processes in cloud with longer lasting time involved in Cloud-to-Ground (CG) lightning flashes were similar to that of IC discharges.A lot of radiation pulses were produced in these discharge processes. Because the IC discharges took place at the bottom of thundercloud and were near the ground, they may produce more serious damage to equipment on the ground therefore should not be neglected in lightning protection.     

Sedimentary environment and development controls of the hydrocarbon source beds:Middle and Upper Proterozoic in northern North China

Problem on development control of marine source bed hold in Chinese petroleum industry progression. The Hongshuizhuang Formation,Tieling Formation and Xiamaling Formation in the Middle and Upper Proterozoic are important hydrocarbon source beds in northern North China, and investigation of their sedimentary environments and the controls has great significance for petroleum exploration in North China. Based on sedimentology (sequence stratigraphy), palaeoecology, sedimentary geochemistry, and sedimentary palaeogeography, their development pattern is discussed. All these studies indicate that the development controls of the hydrocarbon source beds include a favorite palaeogeographic location, exceeding propagation of biomes in low and middle latitudes, anoxic environments, enrichment of phosphorus element and the adsorption of clay minerals during the preservation of organic matter in the marine carbonates.     

运用改进系统建模法对南海气象数据的建模研究

在系统建模理论的基础上,运用改进的动态数据建模方法,对南海气象数据中的温度进行建模并验证了模型的适用性.根据模型推导出格林函数、逆函数和自协方差函数等,并讨论了南海气象数据中温度模型的稳定性、可逆性和合理性.对系统的频率特性和谱函数进行分析讨论,并给出建模过程中的一些图像.根据模型的适用性检验发现,对所研究的气象数据而言,ARMA(4, 3)模型是最合适的,具有平稳可逆性.所有的建模和分析过程在MATLAB上实现.实验结果表明这种建模方案简便易行,能够快速准确地确定系统的合理模型.     

安徽铜陵矿集区海底喷流沉积体系的流体包裹体微量元素对比

铜陵矿集区与铜-金(多金属)矿床有关的热液活动主要有两大体系。即与海西期海底喷流沉积有关的热液体系和与矽卡岩矿化有关的燕山期岩浆热液体系。查明这两类热液体系的流体包裹体特征对区域找矿和矿床成因研究都有实际意义。在包裹体岩相学研究基础上，应用ICP-MS技术和热爆提取方法，研究了新桥、冬瓜山、峙门口、铜官山、朝山等矿床具代表性的热液石英中流体包裹体的微量元素、稀土元素特征。结果表明，两类热液体系在流体包裹体特征上有较大的区别，在流体的微量元素和稀土元素特征方面也很不相同。海底喷流沉积体系的热液石英中流体包裹体与岩浆热液体系的相比。稀土总量较高，LREE／HREE比值较大，δEu不明显。且Mo／(W Sn)比值较高，反映流体中成矿物质的深源特征；Ga／T1、Rb／Cs大。Zr／Hf低，也不同于岩浆热液体系。     

人工神经网络在岩体质量分级中的应用

结合四川省金沙江某水电站工程实例，应用BP人工神经网络方法建立3层BP网络模型，选取岩石单轴抗压强度等6个影响因素为输入变量，对坝基复杂岩体进行质量分级。通过机算机Visual C 语言编程实现神经网络模型，进行网络的学习和运算。以神经网络合理结构分析方法选取合理结构，确定合理隐层单元的数量，提高网络测试的精度。对测试结果的分析发现，经过优化的BP网络模型经多次学习后，测试精度提高，结果可靠，取得较好的实际应用效果。