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21.
青藏块体及其周边地震活动 总被引：1，自引：0，他引：1
本文从青藏块体及其周边地区地震活动幕的划分入手,分析各期地震活动的图象特征,寻求本区地震发生的时空规律,探讨本区的地震活动与印度板块运动的内在联系,从而对今后本区地震活动的大形势进行了预测。 相似文献
22.
大姚6级双震前的地震前兆特征 总被引：8，自引：2，他引：6
在连续形变观测资料中除了存在于整个时间域的短周期潮汐信息(固体潮)外，还有出现在某个时间段的长周期非潮汐信息．如何从时间或空间上认识和提取这些信息．成为认识地震过程和进行地震预报关键和迫切的问题之一。利用小波分析的时一频特性和奇异性检测特性，对大姚6级双震前的连续形变观测资料进行了处理，提取潮汐资料中的非潮汐信息。发现在地震前震中附近的形变台站都接收到了相同频段的异常信号．周期为几天到十几天，出现在各个台站的时间也大致相同。这些在震前具有一定时、空分布的信息有可能是地震前兆。 相似文献
23.
In this study, we determined the cytotoxicity and genotoxicity of carbamate insecticide carbaryl to flounder gill(FG) cells and its teratogenicity to zebrafish embryos. The cytotoxicity of carbaryl to FG cells was determined with methods including MTT and neutral red uptaking(NRU), lactate dehydrogenase(LDH) releasing and Hoechst 33342 and propidium idodide(PI) double staining. Moderate cytotoxicity in a concentration-dependent manner was observed. The 24 h-IC50 value of 53.48 ± 1.21, 59.13 ± 1.19 and 46.21 ± 1.24 mg L-1 carbaryl was obtained through MTT, NRU and LDH assays, respectively. Double fluorescence staining demonstrated that carbaryl induced the death of FG cells mainly through necrosis. There was no significant genotoxicity found in the FG cells exposed to the highest testing concentration of carbaryl(20 mg L-1, P 0.05) as was demonstrated by Comet assay. Zebrafish embryos exposed to carbaryl at concentrations ≥10 mg L-1 displayed moderate toxic effects on the survival, spontaneous movement, hatching, heart rates of the embryos and their development, which were evidenced by yolk and pericardial sac edemas, body length reduction and tail flexure in time- and concentration-dependent manners at specific stages. The 24 h-, 48 h- and 96 h-LC50 values of carbaryl to zebrafish embryos were 41.80 ± 1.10, 17.80 ± 1.04 and 14.46 ± 1.05 mg L-1, respectively. These results suggested that carbaryl is moderately toxic to FG cells cultured in vitro and zebrafish embryos, and the FG cells were similar to zebrafish embryos in their sensitivity to carbaryl as 24 h-IC50 and LC50 indicated. 相似文献
24.
Xiang-Jun Lai Yan Li National Astronomical Observatories/ Yunnan Observatory Chinese Academy of Sciences Kunming China Key Laboratory for the Structure Evolution of Celestial Objects China Graduate University of Chinese Academy of Sciences Beijing China. 《中国天文和天体物理学报》2011,(10)
Based on the turbulent convection model (TCM) of Li & Yang, we have studied the characteristics of turbulent convection in the envelopes of 2 and 5M⊙ stars at the red giant branch and asymptotic giant branch phases. The TCM has been successfully applied over the entire convective envelopes, including the convective unstable zone and the overshooting regions. We find that the convective motions become progressively stronger when the stellar models are located farther up along the Hayashi line. In the convect... 相似文献
25.
Pei-Sheng Chen Xiao-Hong Yang Hong-Guang Shan National Astronomical Observatories /Yunnan Observatory Key Laboratory for the Structure Evolution of Celestial Objects Chinese Academy of Sciences Kunming China 《中国天文和天体物理学报》2010,10(4)
We collected almost all Highly Processed Data Products(HPDP)of ISO SWS01 spectra for the Galactic visual carbon stars,infrared carbon stars,extreme carbon stars and carbon-rich proto-planetary nebulae(PPNs).Those infrared spectra are primarily analyzed and discussed.It is shown that either spectral shapes/peaks,or main molecular/dust features are evidenced to change in the sequence of visual carbon stars,infrared carbon stars,extreme carbon stars and carbon-rich PPNs.Statistically,in this sequence,continua are gradually changed from blue to red and locations of spectral peaks of continua are also gradually changed from short wavelengths to long wavelengths.In addition,in this sequence,intensifies of main molecular/dust features are also gradually changed from prominent in the short wavelengths to prominent in the long wavelengths.Furthermore,from 2MASS and IRAS photometric data,the sequence is also proved.Results in this paper strongly support the previous suggestion for the evolution sequence of carbon-rich objects in our Galaxy,that is the sequence of visual carbon stars→infrared carbon stars→extreme carbon stars→carbon-rich PPNs. 相似文献
26.
青藏块体及周缘潜在震源与强震关系研究 总被引：7，自引：3，他引：4
利用1993－1999、1999－2001年青藏块体东北以及1991－2000年中国大陆GPS水平运动年速率资料，基于单一力源模型，反演获得了青藏块体及其周缘地区2000－2001年10次地震的震前资料反映的潜在震源参数，所得力源中心位置距实际震中的距离相对较小，其中2000年景泰5．9、2001年宁蒗5．8、昆仑8．1及格尔木3次5．7、5．8级地震均在50km左右；2000年兴海6．6、2001年年施甸5．9、永胜6．0级地震不到100km；2001年雅江6．0级地震最远（121km）。此外，1999－2001年青藏块体东北缘地区的反演结果表明，沿东昆仑构造带的昆仑山口－达日及库玛断裂向东至甘东南、甘青交界区域，可能仍存在潜在震源。 相似文献
27.
腾冲火山区地表垂直形变分析 总被引：11，自引：3，他引：8
对腾冲火山区1998～2000年的3期垂直形变资料进行了分析，进而利用相关资料得出与计算有关的参数，再用多元Mogi模型反演了岩浆房的位置和大小，所得出的结果与地震层析反演结果基本相似。分析反演结果，认为火山区可能存在多个岩浆房，并有岩脉相通。 相似文献
28.
WANG Zhimin XU Bei ZHOU Yaoqi XU Hehua HUANG Shaoying The Key Laboratory of Orogenic Belts Crustal Evolution 《《地质学报》英文版》2004,78(1):313-319
Continent subduction is one of the hot research problems in geoscience. New models presented here have been set up and two-dimensional numerical modeling research on the possibility of continental subduction has been made with the finite element software, ANSYS, based on documentary evidence and reasonable assumptions that the subduction of oceanic crust has occurred, the subduction of continental crust can take place and the process can be simplified to a discontinuous plane strain theory model. The modeling results show that it is completely possible for continental crust to be subducted to a depth of 120 km under certain circumstances and conditions. At the same time, the simulations of continental subduction under a single dynamical factor have also been made, including the pull force of the subducted oceanic lithosphere, the drag force connected with mantle convection and the push force of the mid-ocean ridge. These experiments show that the drag force connected with mantle convection is critical fo 相似文献
29.
Guo Liangqian Ying ShaofenFirst Crustal Deformation Monitoring Center CSB Tianjin China 《中国地震研究》1999,(3)
In this paper, the baseline variation and displacement vector was analyzed using the calculated results of GPS measurements carried out from 1995 to 1996 in North China. Based on these analytical results, we studied the recent tectonic activity. In general, the regional extension is dominant in the direction of proximately EW, but there is a difference in the SN direction. Extension is significant in the Shanxi fault-depression zone and Bohai region, while compression with strike-slip is characterized along the Yishui-Tancheng segment of the Tanlu fault zone. The baseline shortening zone is distributed along the Baotou-Zhangjiakou-Ninghe areas. It is a boundary zone of regional variation where many differences of crustal horizontal deformation are discovered between the southern part and the northern part of this zone. The baseline shortening zone in NE direction is distributed along the Jianchang-Tangshan-Gucheng area. It is consistent with the Tangshan-Xingtai seismic zone which indicates that tectoni 相似文献
30.
频谱分析法在核爆与地震识别中具有广泛的应用．但是频谱分析方法是稳态方法,即使采用Gabor变换,也因时-频窗口形状不变而分辨串较低．为提高时-频分辨率,本文将小波变换理论用于乌鲁木齐台记录的地震与核爆事件的分析,并提出了识别核爆和天然地震的小波包分量比判据．通过对加拿大黄刀地震台记录的印度地下核爆的分析,进一步验证了小波包分量比判据对核爆和地震的识别具有较高的识别效率．结果表明：对于地震信号,其小波包分量比U03/U1一般都大于1.0,而对于核爆信号,比值U03／U13一般都小于1.0. 相似文献