区域滑坡灾害风险评估——以长江三峡库区秭归县为例     

彭令  牛瑞卿  赵艳南  邓清禄 《吉林大学学报(地球科学版)》2013,43(3):891-901

以滑坡灾害突出的三峡库区秭归县为研究区。在深入分析滑坡孕灾环境、诱发因素、滑坡编录和承灾体信息的基础上,利用Logistic回归模型和统计分析方法相结合进行了滑坡危险性评价。通过滑坡灾害致灾强度与承灾体抗灾能力分析了人口、建筑物、生命线工程和土地资源的易损性。采用成本价值核算法对各类承灾体进行了价值核算,最后通过风险模型预测了研究区内未来10年滑坡灾害的生命与经济风险。生命和经济高风险区分别占整个研究区面积的1.11%和2.71%,主要分布在集镇和学校、企事业单位等人口密集区以及交通建设用地等经济价值大的地区;中风险区分别占13.21%和20.66%,主要分布于农村居民生活居住和耕地活动区;低风险区分别占85.68%和76.63%,则分布在经过地质灾害治理和人类活动较为稀少的未利用地及林地等区域。通过实地调查分析与对比验证,发现预测结果与实际灾情较吻合。研究表明,集镇和学校、企事业单位等人口集中区和交通建设用地区是今后减灾防灾部署工作的重中之重。  相似文献   

Sorption of heavy metals from aqueous solution by dehydrated powders of aquatic plants   总被引：1，自引：0，他引：1  

P. Y. Deng  W. Liu  B. Q. Zeng  Y. K. Qiu  L. S. Li 《International Journal of Environmental Science and Technology》2013,10(3):559-566

Ruppia maritima and Echinodorus amazonicus were prepared in a dehydrated powder form. The characteristics and mechanisms of adsorption of heavy metals were studied under various pH values, reaction times, and heavy metal ion concentrations. The results showed that under different pH and reaction time conditions, heavy metal adsorption was lead > cadmium > zinc > copper. The adsorption of lead increased linearly with the lead concentration. For cadmium, zinc and copper, the adsorption was saturated when metal ion concentration exceeded 200 mg/L. When a Freundlich model was applied, R ² values for the heavy metal adsorption by the aquatic plants mostly exceeded 0.9. The adsorption of heavy metal ions by these two aquatic plant powders was better explained by the Lagergren second-order equation than the first-order equation. From the Fourier Transform Infrared spectra, there was an adsorption peak at 2,115 cm^?1 for R. maritima. The peak shape did not change with metal affiliation except there was a shift of peak wavelength before adsorption. The results indicate that the mechanism of heavy metal adsorption by the two species is not simply on the mono-molecular layer level, and that intra-particulate dispersal is the dominant process. Heavy metal pollution does not affect the basic chemical components, and major substances involved in heavy metal adsorption including carbohydrates, cell wall pectin, and protein functional groups.  相似文献   

Numerical modeling of borehole-to-surface logging technology based on incomplete Cholesky conjugate gradient     

Rui Deng  Yu Zhang  Yanming Huang  Fanshun Meng 《Arabian Journal of Geosciences》2013,6(7):2237-2243

For vertical line source, the total potential is divided into normal potential and abnormal one to eliminate singularity in this paper. Normal potential produced in homogeneous half-space is calculated by analytic method. While for abnormal potential produced by underground anomalous body, the finite difference method is used based on differential equation of abnormal potential. Further, the total potential is calculated and the forward is realized. Accordingly, incomplete Cholesky conjugate gradient that is introduced in this paper gives the analytical solution of equation, it converges more quickly while requiring less memory. It is an initiation to introduce a dipping bed model to indicate potential distribution produced by underground anomalous body.  相似文献   

基于植被指数和土地表面温度的干旱监测模型   总被引：79，自引：4，他引：79  

王鹏新  WAN Zheng-ming  龚健雅  李小文  王锦地 《地球科学进展》2003,18(4):527-533

干旱是一种周期性发生的自然现象,其发生过程中有关参数如地表覆盖度、温度和土壤表层含水量等可以通过遥感的途径进行定量反演,而这些参数客观地反映了地表的综合特征。综述了运用遥感反演产品---土地表面温度和归一化植被指数在干旱监测中的应用前景和进展,分析了距平植被指数、条件植被指数、条件温度指数和归一化温度指数等干旱监测方法的优缺点,在前人研究的基础上,提出了条件植被温度指数的干旱监测模型,探讨了其应用前景。  相似文献   

拐子湖地区近40a气候变化特征分析   总被引：4，自引：1，他引：4  

许延强  邓红  段志钟  刘文英 《内蒙古气象》2013,(2):21-22,41

利用1971—2010年拐子湖气象站地面气象观测资料,分析了近40a拐子湖气候变化基本特征。结果表明:近40a来拐子湖地区气温变化的总趋势是升高的,其中春、夏、秋三季的温度上升尤为明显;年降水量不是很稳定;相对湿度变化不大;1971—2000年年蒸发量变化较小,但2000年以后下降非常明显;大风日数呈明显的下降趋势;沙尘暴天气也呈下降趋势。  相似文献   

Phase asynchrony of hemispheric flare activity revisited: empirical mode decomposition and wavelet transform analyses     

L. H. Deng  N. Gai  Y. K. Tang  C. L. Xu  W. J. Huang 《Astrophysics and Space Science》2013,343(1):27-32

The phase relation of flare index in the northern and southern hemispheres in the time interval of January 1966 to December 2008 is investigated. It is found that, (1) the flare index in the northern hemisphere begin six months earlier than that in the southern one, which should lead to phase asynchrony between them but with a slight effect; (2) the main periods of the flare activity in the two hemispheres slightly differ from each other, which should also lead to phase asynchrony between them; (3) the low-frequency modes of the flare activity can be used to study the varying relationship of long-term solar activities and the high-frequency modes can be considered as the stochastic component that is amplitude modulated.  相似文献   

The effect of f(T) gravity on an interplanetary clock and its time transfer link   总被引：1，自引：0，他引：1  

Xue-Mei Deng  Yi Xie 《天文和天体物理学研究(英文版)》2013,(10):1225-1230

As an extension of the"teleparallel"equivalent of general relativity,f(T)gravity is proposed to explain some puzzling cosmological behaviors,such as accelerating expansion of the Universe.Given the fact that modified gravity also has impacts on the Solar System,we might test it during future interplanetary missions with ultrastable clocks.In this work,we investigate the effects of f(T)gravity on the dynamics of the clock and its time transfer link.Under these influences,theΛ-term and theα-term of f(T)gravity play important roles.Here,Λis the cosmological constant andαrepresents a model parameter in f(T)gravity that determines the divergence from teleparallel gravity at the first order approximation.We find that the signal of f(T)gravity in the time transfer is much more difficult to detect with the current state of development for clocks than those effects on dynamics of an interplanetary spacecraft with a bounded orbit with parameters 0.5 au≤a≤5.5 au and 0≤e≤0.1.  相似文献   

Moon night sky brightness simulation for the Xinglong station     

Song Yao  Hao-Tong Zhang  Hai-Long Yuan  Yong-Heng Zhao  Yi-Qiao Dong  Zhong-Rui Bai  Li-Cai Deng  Ya-Juan Lei 《天文和天体物理学研究(英文版)》2013,(10):1255-1268

Using a sky brightness monitor at the Xinglong station of National Astronomical Observatories,Chinese Academy of Sciences,we collected data from22 dark clear nights and 90 moon nights.We first measured the sky brightness variation with time for dark nights and found a clear correlation between sky brightness and human activity.Then with a modified sky brightness model of moon nights and data from these nights,we derived the typical value for several important parameters in the model.With these results,we calculated the sky brightness distribution under a given moon condition for the Xinglong station.Furthermore,we simulated the sky brightness distribution of a moon night for a telescope with a 5 field of view(such as LAMOST).These simulations will be helpful for determining the limiting magnitude and exposure time,as well as planning the survey for LAMOST during moon nights.  相似文献   

Environmental dependence of other properties of main galaxies at fixed luminosity     

Xin-Fa Deng  Yong Xin  Cheng-Hong Luo  Ping Wu 《Astrophysics》2011,54(3):355-362

  相似文献   

基于Camera Link总线的CCD高速图像采集技术   总被引：1，自引：0，他引：1  

程祖桥  邓辉  王锋  梁波  季凯帆  王传军  许骏 《天文研究与技术》2011,(4)

现代天文学研究越来越依赖于高质量的天文观测结果。针对天文实测的需要,对基于Camera Link总线的CCD高速图像采集技术进行了系统调研,分析对比了Camera Link总线技术及其优缺点,对基于Camera link接口的高速CCD采集技术进行了深入的研究,着重讨论了单缓存与双缓存高速采集技术和实现机制。经实际测试,所实现的技术稳定、可靠,CPU负载低,采集速度达到了厂家给出的CCD相机的最高采集速度,可以满足天文大数据量采集与准实时观测的需要。  相似文献