Analytical study of ground motion caused by seismic wave propagation across faulted rock masses          下载免费PDF全文

J.C. Li  N.N. Li  S.B. Chai  H.B. Li 《国际地质力学数值与分析法杂志》2018,42(1):95-109

Studying seismic wave propagation across rock masses and the induced ground motion is an important topic, which receives considerable attention in design and construction of underground cavern/tunnel constructions and mining activities. The current study investigates wave propagation across a rock mass with one fault and the induced ground motion using a recursive approach. The rocks beside the fault are assumed as viscoelastic media with seismic quality factors, Q_p and Q_s. Two kinds of interactions between stress waves and a discontinuity and between stress waves and a free surface are analyzed, respectively. As the result of the wave superposition, the mathematical expressions for induced ground vibration are deduced. The proposed approach is then compared with the existing analysis for special cases. Finally, parametric studies are carried out, which includes the influences of fault stiffness, incident angle, and frequency of incident waves on the peak particle velocities of the ground motions.  相似文献   

Petroleum Hydrocarbon Distribution Features in Water and Sediment off Fujian Shore   总被引：1，自引：0，他引：1  

王宪  徐鲁荣  李文权  李凌云  钱爱红 《中国海洋湖沼学报》2003,21(2):187-192

This study on the distribution features of petroleum hydrocarbon in water and sedi-ment off the Fujian shore using data obtained from the baseline research on oceanic contamination in Fujian showed that:during the research preiod,petroleum hydrocarbon concentrations in water varied from 5.77μg/L to 37.28μg/L,averaged 14.48 μg/L;was lower in the wet seasson than in the dry season;and was highest in the Minjiang Estuary and Jiulong Estuary in both seasons ,The petorleum hydrocarbon concentrations in shore sediment varied from 14.48 mg/kg to 784.36 mg/kg,averaged 133.3 mg/kg ,and was closely related to sediment types (granularity).  相似文献   

宁夏香山-天景山弧形断裂带新活动特征及1709年中卫南71/2级地震形变带   总被引：5，自引：1，他引：4       下载免费PDF全文

张维岐  焦德成  柴炽章  宋方敏  汪一鹏 《地震地质》1988,10(3):12

本文根据野外地质填图和水系位移测量结果,论述了香山-天景山弧形断裂带新生代有两个不同活动性质的阶段,即早期阶段的强烈挤压和晚期阶段的左旋走滑兼挤压。分析、讨论了不同活动阶段的时间界限和转变原因。指出了1709年中卫南71/_2级地震形变带的表现形式、延伸范围  相似文献   

Occurrence and evolution of the Xiaotangshan hot spring in Beijing, China   总被引：1，自引：0，他引：1  

Zhou Haiyan  Zhou Xun  Chai Rui  Yu Lan  Liu Chunhui  Li Liangping 《Environmental Geology》2008,53(7):1483-1489

Thermal groundwater occurs in bedrock aquifers consisting of the dolomite of the Wumishan Group of the Jixianin System and the Cambrian carbonate in the Xiaotangshan geothermal field near the northern margin of the North China Plain, China. The hot water in the geothermal field of basin-type discharges partly in the form of the Xiaotangshan hot spring under natural conditions. The hot water has TDS of less than 600 mg/L and is of Na·Ca-HCO₃ type. The geothermal water receives recharge from precipitation in the mountain area with elevation of about 500 m above sea level to the north of the spring. Thermal groundwater flows slowly south and southeast through a deep circulation with a residence time of 224 years estimated with the Ra–Rn method. The Xiaotangshan hot spring dried up in the middle of the 1980s owing to the increasing withdrawal of the hot water in the geothermal field in the past decades. The water level of the geothermal system still falls continually at an annual average rate of about 2 m, although water temperature changes very little, indicating that the recharge of such a geothermal system of basin-type is limited. Over-exploitation has a dramatic impact on the geothermal system, and reduction in exploitation and reinjection are required for the sustainable usage of the hot water.  相似文献   

水中荧光计及其在海洋现场探测中的应用     

夏达英  王振先  夏荣环  辛海英 《海洋科学进展》1997,(2)

本文描述了近几年来我们首次研制成功的３种类型的水中荧光计系统及其应用测量结果：１．用于水体混合扩散实验研究的水中荧光计，对罗丹明Ｂ浓度测量范围为１×１０－６～１×１０－１０ｇ／ｃｍ３；２．拖曳荧光计系统，能在２～８０ｍ水深内进行水平拖曳平稳地工作，拖曳速度为０～８ｋｎ，除检测罗丹明Ｂ外，还可检测无机悬浮物质的含量，检测范围为２～２０００ｍｇ／ｄｍ３；３．用于测量海中浮游植物体内叶绿素ａ浓度的水中荧光计，测量范围为１×１０－６～１×１０－９ｇ／ｃｍ３。用荧光法测量海中物质是近代新发展的一种简便、快速、灵敏度高、用途极其广泛的测量技术，有着重要的应用价值。  相似文献   

A nitrate and silicate budget in the equatorial Pacific Ocean: a coupled physical–biological model study     

M. -S. Jiang  F. Chai  R. C. Dugdale  F. P. Wilkerson  T. -H. Peng  R. T. Barber   《Deep Sea Research Part II: Topical Studies in Oceanography》2003,50(22-26):2971

A coupled physical–biological model was developed to simulate the low-silicate, high-nitrate, and low-chlorophyll (LSHNLC) conditions in the equatorial Pacific Ocean and used to compute a detailed budget in the Wyrtki box (5°N–5°S, 180–90°W) for the major sources and cycling of nitrogen and silicon in the equatorial Pacific. With the incorporation of biogenic silicon dissolution, NH₄ regeneration from organic nitrogen and nitrification of ammonia in the model, we show that silicon recycling in the upper ocean is less efficient than nitrogen. As the major source of nutrients to the equatorial Pacific, the Equatorial Undercurrent provides slightly less Si(OH)₄ than NO₃ to the upwelling zone, which is defined as 2.5°N–2.5°S. As a result, the equatorial upwelling supplies less Si(OH)₄ than NO₃ into the euphotic zone in the Wyrtki box, having a Si/N supply ratio of about 0.85 (2.5 vs. 2.96 mmolm⁻² day⁻¹). More Si(OH)₄ than NO₃ is taken up with a Si/N ratio of 1.17 (2.72 vs. 2.33 mmolm⁻² day⁻¹) within the euphotic zone. The difference between upwelling supply and biological uptake is balanced by nutrient regeneration and horizontal advection. Excluding regeneration, the net silicate and nitrate uptakes are nearly equal (1.76 vs. 1.84 mmolm⁻² day⁻¹). However, biogenic silica export production is slightly higher than organic nitrogen (1.74 vs. 1.59 mmolm⁻² day⁻¹) following a 1.1 Si/N ratio. In the central equatorial Pacific, low silicate concentrations limit diatom growth; therefore non-diatom new production accounts for most of the new production. Higher silicate supply in the east maintains elevated diatom growth rates and new production associated with diatoms dominate upwelling zone. In contrast, the new production associated with small phytoplankton is nearly constant or decreases eastward along the equator. The total new production has a higher rate in the east than in the west, following the pattern of surface silicate. This suggests that silicate regulates the diatom production, total new production, and thereby carbon cycle in this area. The modeled mean primary production is 48.4 mmolCm⁻² day⁻¹, representing the lower end of direct field measurements, while new production is 15.0 mmolCm⁻² day⁻¹, which compares well with previous estimates.  相似文献   

厦门港浮游植物对磷酸盐吸收速率的研究   总被引：12，自引：1，他引：12  

洪华生  戴民汉  黄邦钦  李文权 《海洋与湖沼》1994,25(1):54-59

用无载体32P同位素示踪测定海水中浮游植物和细菌吸收磷酸盐速率的方法，对厦门港浮游植物和细菌进行了研究。结果表明，厦门港海水中吸收磷酸盐的主体是浮游植物（几乎占100％），平均吸收速率为4．28×10－5μmol／（L·s），并且存在着晚秋＜冬＜初春的季节变化，培养实验的结果表明吸收速率的季节变化主要是由于种类更替和温度效应所致。  相似文献   

Research on the spectral analysis and test method of period signals in monthly mean sea level     

Ma Jirui  Tian Suzhen  Zheng Wenzhen  Chai Xinmin 《海洋学报(英文版)》1995,14(2):181-190

Ｒｅｓｅａｒｃｈｏｎｔｈｅｓｐｅｃｔｒａｌａｎａｌｙｓｉｓａｎｄｔｅｓｔｍｅｔｈｏｄｏｆｐｅｒｉｏｄｓｉｇｎａｌｓｉｎｍｏｎｔｈｌｙｍｅａｎｓｅａｌｅｖｅｌ￥ＭａＪｉｒｕｉ；ＴｉａｎＳｕｚｈｅｎ；ＺｈｅｎｇＷｅｎｚｈｅｎａｎｄＣｈａｉＸｉｎｍｉｎ（Ｒ...  相似文献   

Effects of light, temperature and nutrients on photosynthesis of Biddulphia regia     

Li Wenquan  Zheng Airong  Wang Xian  Chen Qinghua 《海洋学报(英文版)》1996,15(1):127-131

Ｅｆｆｅｃｔｓｏｆｌｉｇｈｔ，ｔｅｍｐｅｒａｔｕｒｅａｎｄｎｕｔｒｉｅｎｔｓｏｎｐｈｏｔｏｓｙｎｔｈｅｓｉｓｏｆＢｉｄｄｕｌｐｈｉａｒｅｇｉａＩＮＴＲＯＤＵＣＴＩＯＮＬｉｇｈｔ，ｔｅｍｐｅｒａｔｕｒｅａｎｄｎｕｔｒｉｅｎｔｓａｒｅｉｍｐｏｒｔａｎｔｅ...  相似文献   

Several significant hydrographic characteristics and their formation mechanism in the South China Sea during the spring and summer of 1998   总被引：1，自引：1，他引：1  

Xu Jianping  Chai Fei  Liu Zenghong  Zhu Bokang 《海洋学报(英文版)》2003,22(4):491-502

INTRODUCTIONTheSCSisthelargestmarginseainthewestoftheNorthPacificOcean .Theprevailingwindinwinterisnortheast,whileinsummeritissouthwest .Itisstilluncertainthathowthecirculationandtemperature -salinityfieldassociatewiththemonsoonforcingandaccompanywithseveralkindsofvariationsbeforeorafterthesummermonsoonburst .DuringSECMEXin 1 998,twointensiveobservationperiods (IOP)havebeencarriedoutntheSCS (Fig 1 ) :IOP1 ,from 1 0Aprilto 5May ;IOP2 ,from 1 2JunetoJuly 6 ,inordertounderstandthe…  相似文献