强度变化对崩坡积体堆积机制及稳定性影响研究   总被引：3，自引：0，他引：3  

尹小涛  王水林  马双科  刘志文 《岩土力学》2010,31(2):620-626

利用颗粒流PFC2D建立了岩土体物理模型,在此基础上设计了均以物理模型折减计算初始模型和以前一折减计算结果为下次折减计算初始模型两类计算条件,每一类又设计了只对凝聚力折减、仅对内摩擦角折减、强度参数同时折减3种计算方案,每种计算方案又包含折减1.0、0.50、0.10、0.01、0.0倍等5个计算工况。经对坡面演替、监测点x方向速度变化曲线等计算结果的对比分析发现：凝聚力对于岩土体的直立特性起控制作用,破坏模式多为崩塌倾倒模式;内摩擦角对于稳定坡角具有重要影响;强度参数同时衰减时,强度参数弱化幅度较大情况下岩土体呈散体物质破坏模式,为滑移渐进破坏模式,其中凝聚力弱化0.1倍前后（约10 kPa）后,破坏模式由崩塌破坏转变为滑移破坏。  相似文献   

Developmental expression pattern of calmodulin gene in amphioxus Branchiostoma belcheri tsingtauense     

栾晶  耿金培  方绍庆  粟智平  张京萱  许红岩  王颖  鲁闽  尹伟力  孟广校 《中国海洋湖沼学报》2010,28(6):1221-1226

We investigated the developmental expression pattern of AmphiCaM in cephalochordate amphioxus (Branchiostoma belcheri tsingtauense). We cultured and sampled the animals at different developmental stages (eggs and larvae), and used in-situ hybridization and northern blotting to document the spatial and temporal changes in AmphiCaM expression. The alimentary tract dominates the development from the late neurula stage to the adult stage. AmphiCaM expression increased significantly in the alimentary tract during the late neurula stage and remained elevated in the adults. Our results indicate that AmphiCaM is involved in the differentiation of the alimentary tract in amphioxus; and furthermore, provide an insight into the change in function of CaM genes during evolution.  相似文献   

Comparison of nonlinear and linear PCA on surface wind, surface height, and SST in the South China Sea     

陈海英  尹宝树  方国洪  王永刚 《中国海洋湖沼学报》2010,28(5):981-989

We compared nonlinear principal component analysis (NLPCA) with linear principal component analysis (LPCA) with the data of sea surface wind anomalies (SWA), surface height anomalies (SSHA), and sea surface temperature anomalies (SSTA), taken in the South China Sea (SCS) between 1993 and 2003. The SCS monthly data for SWA, SSHA and SSTA (i.e., the anomalies with climatological seasonal cycle removed) were pre-filtered by LPCA, with only three leading modes retained. The first three modes of SWA, SSHA, and SSTA of LPCA explained 86%, 71%, and 94% of the total variance in the original data, respectively. Thus, the three associated time coefficient functions (TCFs) were used as the input data for NLPCA network. The NLPCA was made based on feed-forward neural network models. Compared with classical linear PCA, the first NLPCA mode could explain more variance than linear PCA for the above data. The nonlinearity of SWA and SSHA were stronger in most areas of the SCS. The first mode of the NLPCA on the SWA and SSHA accounted for 67.26% of the variance versus 54.7%, and 60.24% versus 50.43%, respectively for the first LPCA mode. Conversely, the nonlinear SSTA, localized in the northern SCS and southern continental shelf region, resulted in little improvement in the explanation of the variance for the first NLPCA.  相似文献   

中国地质灾害总体特征与形势分析     

曲雪妍  李媛  杨旭东  房浩  尹春荣 《中国地质灾害与防治学报》2016,27(4):109-113

我国地质灾害总体特征为灾害数量多、分布广、损失重,多发生在汛期的5~8月,地质灾害年内高发时段由南向北逐渐推移。滑坡崩塌泥石流高易发区主要分布在西南山地区、秦岭大巴山区和黄土高原等地区。近年来,极端气候事件增多、地震活跃等因素增加了地质灾害预警预报的难度,总体来看,未来5年,我国地质灾害仍将处于高发期,面临的防灾减灾形势更加严峻。  相似文献   

寻找隐伏地震断层     

Wasow.  L 续春荣 《地震科技情报》1995,(1):32-33

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厦门花岗石风化壳工程地质带及风化岩石的工程地质特征     

任国林  尹子良等 《福建地质》1990,9(2):100-110

本文对厦门花岗岩风化壳进行了系统地分带，共分为新鲜岩石带、微风化带、强风化带、不均匀风化岩土带及残积土带。阐述了各带工程地质特征，并进行了定量分带的探讨。本文用点荷载强度、弹性波速度及回弹锤试验结果进行了单指标和多指标的综合评判。根据大量现场和室内测试的研究资料，作者详细论述了各风化带的组构、物理力学性质及其变化规律。并建立了风化岩石点荷载强度指数Is（50）与弹性波纵波速度Vp、弹性波纵速度Vp与极限抗压强度R及点荷载强度指数Is（50）与极限抗压强度R之间的关系式。  相似文献   

化学光谱法测定微量金的摄谱电极之改进     

尹沙林 《湖南地质》2001,20(4):302-302

化学光谱法测定微量金已实用多年。一般使用杯形下电极、锥形上电极，本实验在前人基础上将上电极改为凹形电极，与锥形上电极摄谱相比较的优点是：（）使用凹形上电极避免了炽热的锥形电极头像进入光栏孔。样品含量低于μ时摄谱11g曝光时间控制为。上下电极有效对齐，避免了摄谱激发因瞬时电势差极大而引起的溅弧现8 s象，所以光谱背景浅。×110－3μ的金在线处也能看到清晰谱线。g2 675.95 （）凹形对电极摄谱，增大工作电流，延长曝光时间，从而提高弧焰的温度，使蒸发出2来的金得以充分激发。另外，上下电极都存在一个气室，对金的…  相似文献   

THE DEPENDENCE OF WIND STRESS ON SEA STATE     

尹宝树  王涛 《中国海洋湖沼学报》1996,14(3):234-242

Based on up to date literature, this paper details the evolution of wave dependence of wind stress.Some typical models of the dependence of wind stress on waves are described in detail. Although there isno universally accepted theory and model, recent studies indicate that the wind strees strongly dependson the development state of sea waves, i. e., young seas are rougher than mature seas, in other words, thewind stress decreases with increasing wave age.  相似文献   

国际国内地震信息网络技术扫描     

续春荣 《地壳构造与地壳应力》2005,(4):10-18

随着信息网络技术的不断发展，国际上地震信息网络的发展已从INTERNET的初始发展阶段，（即建立网站、发布信息、局部资源共享的阶段），朝着全球信息化的方向发展。2003年12月在瑞士召开的RSIS会议（信息社会中科学的作用）强调让全世界所有的人都能自由地利用网络得到所需要的信息。尽管发达国家与第三世界国家存在着“科技鸿沟”问题，但站在地球这个共同家园的角度，全球信息化是一个正确的方向。  相似文献   

全球IPv6的发展现状     

雷震洲  续春荣 《地壳构造与地壳应力》2005,(4):25-28

20世纪90年代，移动通信和互联网技术突飞猛进，全球互联网用户数突破了5亿，目前已近7亿。无论在技术还是在发展速度上，互联网获得的巨大成功是不争的事实。然而在新世纪初，互联网在前进的道路上面临着一系列的挑战。  相似文献