河北省卢龙Ms 3．9地震与体应变异常特征     

关晓明  柴慈滨  纪延辉  王玉莹 《地震地磁观测与研究》2009,30(2):106-111

通过提取2008年3月11日河北省卢龙Ms 3．9地震前锦州地震台体应变短临异常信息,探讨了震前震源区附近的应力状态及异常形态特征。  相似文献   

厦门海关缉私艇码头选址的地质条件     

蔡爱智 《福建地质》2000,19(1):52-56

按照厦门市规划局的安排,厦门海关缉私艇码头位于小学路北端,该处正是ＹｕｎＤｏｎｇ海堤南端的外侧,从海图上便可清楚看出该海域是一片高程在理论基准面零点以上的礁石群区。应用Ｋｌｅｉｎ－５１０型海底剖面仪探研结果获得证实,若不另选码头地址,必然带来巨大的经济损失和一系列问题。为此,我们提出另寻适合般只吃水和工作要求的码头地点。市政府采纳了这一建议,自原地向ＮＷ方向延伸３００ｍ的次航道东侧。五年多来,新码  相似文献   

灰色关联度在地震预报中的应用     

王成亮  柴文生  梁东洲  韩银美  孙素芳 《华北地震科学》2000,18(4):48-52

根据灰色系统理论中的关联度统计量,使用计算机,计算了河北北部和南部地下水观测资料,对关联度在地震预报中的应用进行了分析和研究。  相似文献   

The Relation Between Distribution of Damming Landslides and Tibetan Plateau Upheaval     

Chai Hejun  Liu Hanchao  Zhang Zhuoyuan 《地学前缘》2000,(Z1)

THE RELATION BETWEEN DISTRIBUTION OF DAMMING LANDSLIDES AND TIBETAN PLATEAU UPHEAVAL  相似文献   

Ca2+对罗非鱼嗅电图的影响     

陈荣  柴敏娟 《台湾海峡》2000,19(3):364-366

将４种不同浓度的Ｃａ＾２＋溶液灌注罗非鱼嗅上皮,观测其对罗非鱼嗅电图（ｅｌｅｃｔｒｏｏｌｔａｃｔｏｇｒａｍ,简称ＥＯＧ）电位幅值的影响,结果表明：Ｃａ＾２＋对罗非鱼ＥＯＧ具双重效应,在一定浓度范围（１～４ｍｍｏｌ／ｄｍ＾３）内,随着Ｃａ＾２＋对ＥＯＧ的效应由抑制逐渐转向促进,表现为反应的增大与Ｃａ＾２＋浓度的提高呈正相关。但当Ｃａ＾２＋浓度进一步提高到８ｍｍｏｌ／ｄｍ＾３时,ＥＯＧ反映减小,呈现抑制效应,本文探讨了Ｃａ＾２＋影响ＥＯＧ的可能机制。  相似文献   

利用强震震源机制解资料反演中国大陆及其邻区的形变场模型     

李长军  任金卫  周琳  秦姗兰  柴旭超 《中国地震研究》2015,29(2):146-157

搜集了1900-2013年间发生在中国大陆及其邻区的震源机制解资料,详细整理了其中的70个7级及以上大震的震源参数、地表破裂带和地表位移资料。根据资料的完整程度将地震分成三类：A类存在地表破裂和地表位移观测资料;B类存在地表破裂资料,但缺少地表位移观测数据;C类缺少地表破裂带和地表位移观测资料。对B类和C类缺少地表位移观测数据的地震,利用三角形模型模拟其位移分布。再根据地表位移分布及地震破裂带与本文使用网格模型之间的位置关系将地震分段。最后,利用分段前、后的地震数据和改进的双三次样条方法反演研究区域的形变场模型。结果表明：①大震资料的分段处理改进了地震数据的反演结果,提高了反演模型的合理性和空间一致性;在喜马拉雅断裂带,形变场具有更好的连续性,其变形特征与地质等数据的反演结果基本吻合;塔里木盆地和阿尔金断裂的形变量减小,与该区域较低的地震活动性一致;戈壁—阿尔泰的变形从SE的挤压和ＮＥ的拉张调整到NE的挤压和NW的拉张;鄂尔多斯西缘的拉张分量明显减小。②113年的地震资料解释了印度板块向欧亚板块运动总速率的30～50%,存在20mm/a左右的速度亏损,该亏损量可能包括断层蠕动、褶皱等非震形变,未监测到或者缺失的地震,及以弹性应变能形式存在通过潜在地震释放的应变。  相似文献   

Assessment and analysis of microwave emissivity and transmissivity of a deciduous forest towards the estimate of vegetation biomass     

ZhongJun Zhang  XianChuan Yu  ShaoJie Zhao  LinNa Chai 《中国科学:地球科学(英文版)》2014,57(3):534-541

Forests play an important role in the global carbon cycle and have a potential impact on global climatic change.Monitoring forest biomass is of considerable importance in understanding the hydrological cycle.Because of the problem of dense forest cover,no reliable method with which to retrieve soil moisture in forest areas from the microwave emission signature has been established.All of these issues relate to the microwave emissivity and transmissivity characteristics of a forest.The microwave emission contribution received by a sensor above a forest canopy comes from both the soil surface and the vegetation layer.To analyze the relationship of forest biomass and forest emission and transmissivity,a high-order emission model,the matrix-doubling model,which consists of both soil and vegetation models,was developed and then validated for a young deciduous forest stand in a field experiment.To simulate the emissivity and transmissivity of a deciduous forest in the L and X bands using the matrix-doubling model,the parameters of components of deciduous trees when the leaf area index varies from 1 to10 were generated by an L-system and a forest growth model.The emissivity and transmissivity of a forest and the relationships of these parameters to forest biomass are presented and analyzed in this paper.Emissivity in the L band when the leaf area index is less than 6 and at viewing angles less than 40°,and transmissivity in the L band are the most sensitive parameters in deciduous forest biomass estimation.  相似文献   

Regional environmental risk assessment for the Nanjing Chemical Industry Park: an analysis based on information-diffusion theory   总被引：1，自引：1，他引：0  

Xiaojie Meng  Yan Zhang  Xiangyi Yu  Junhong Bai  Yingying Chai  Yating Li 《Stochastic Environmental Research and Risk Assessment (SERRA)》2014,28(8):2217-2233

A recent Chinese policy requires that all enterprises that store and use hazardous chemicals must become part of a chemical industry park. Although this reduces the environmental risk caused by the establishment of uncontrolled sites, it cannot eliminate the risk within the industrial park; on the contrary, it may exacerbate the risk. The storage and use of a wide range of hazardous chemicals in the industrial park increases both the complexity and the diversity of the environmental risk. Identification of the sources of risk will significantly affect the results of regional risk assessments. In this paper, we selected China’s Nanjing Chemical Industry Park as a case study. Based on an environmental risk assessment for every enterprise within the park, we calculated the maximum environmental risk values of each individual risk source and obtained the overall regional environmental risk values by using information-diffusion theory. The regional environmental risk value can be clustered according to the classification criteria described in this paper and depicted using a spatial partitioning map. The result can help administrative managers optimize the distribution of industrial areas and support the development of risk-prevention and -management measures.  相似文献   

Seasonal dynamics of physical and biological processes in the central California Current System: A modeling study   总被引：1，自引：0，他引：1  

Lin Guo  Fei Chai  Peng Xiu  Huijie Xue  Shivanesh Rao  Yuguang Liu  Francisco P. Chavez 《Ocean Dynamics》2014,64(8):1137-1152

A 3-D physical and biological model is used to study the seasonal dynamics of physical and biological processes in the central California Current System. Comparisons of model results with remote sensing and in situ observations along CalCOFI Line 67 indicate our model can capture the spatial variations of key variables (temperature, nutrients, chlorophyll, and so on) on annual mean and seasonal cycle. In the coastal upwelling system, it is the alongshore wind stress that upwells high nutrients to surface from 60 m and stimulates enhanced plankton biomass and productivity in the upwelling season. As a result, coastal species peak in the late upwelling period (May–July), and oceanic species reach the annual maxima in the oceanic period (August–October). The annual maximum occurs in the late upwelling period for new production and in the oceanic period for regenerated production. From the late upwelling period to the oceanic period, stratification is intensified while coastal upwelling becomes weaker. Correspondingly, the coastal ecosystem retreats from ～300 to ～100 km offshore with significant decline in chlorophyll and primary production, and the oceanic ecosystem moves onshore. During this transition, the decline in phytoplankton biomass is due to the grazing pressure by mesozooplankton in the 0–150 km domain, but is regulated by low growth rates in the 150–500 km offshore domain. Meanwhile, the growth rates of phytoplankton increase in the coastal waters due to deeper light penetration, while the decrease in offshore growth rates is caused by lower nitrate concentrations.  相似文献   

Dextral strike-slip of Sanguankou-Niushoushan fault zone and extension of arc tectonic belt in the northeastern margin of the Tibet Plateau   总被引：4，自引：0，他引：4  

QiYun Lei  PeiZhen Zhang  WenJun Zheng  ChiZhang Chai  WeiTao Wang  Peng Du  JingXing Yu 《中国科学:地球科学(英文版)》2016,59(5):1025-1040

The kinematic characteristics of the Sanguankou-Niushoushan fault(SGK-NSSF) are of great significance to the understanding of the extension of the arc tectonic belt in the northeastern margin of the Tibet Plateau. Using field surveys and various data collection methods, including large-scale geological mapping, measurement of typical topographies, and dating of sedimentary strata, it was determined that the SGK-NSSF exhibits obvious dextral strike-slip characteristics and thus is not a sinistral strike-slip fault, as believed by previous researchers. The results of this study show that the geological boundaries for the Paleozoic, Mesozoic, and Cenozoic eras were all dextrally dislocated by the fault, with the faulted displacements being similar. The maximum strike-slip displacement of the fault, after elimination of topographic effects, was found to be 961±6 m. The Sanguankou fault at the northern section exhibits obvious characteristics of more recent activities, with a series of small gullies having undergone synchronized dextral writhing after traversing the fault. The average horizontal slip rate of the fault since the late Quaternary was determined to be approximately 0.35 mm/a. The pre-existing fold structures formed during the late Pliocene were dislocated by the fault and became ex situ, indicating that dextral strike-slip of the fault could not have occurred prior to the late Pliocene. The maximum displacements and average slip rates were used to estimate the onset time of the dextral strike-slip activities of the fault as being after 2.7 Ma. In this study, the understanding of previous researchers concerning the extension in the northeastern margin of the Tibet Plateau was combined with analyses of the successive relationships between fold deformations and fault activities. This led to the finding that the extension in the northeastern margin of the Tibet Plateau reached the vicinity of the SGK-NSSF during the late Pliocene(~2.7 Ma), causing regional uplift and fold deformations of the strata there. During the early Quaternary, the northeastern compression of the Tibet Plateau and the counterclockwise rotation of the Ordos block collectively resulted in the dextral strike-slip activities of the SGK-NSSF. This then formed the foremost margin of the arc tectonic belt extension in the northeastern margin of the Tibet Plateau.  相似文献