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403.
Experimental study of poromechanical behavior of saturated claystone under triaxial compression 总被引:1,自引:1,他引:0
This paper presents experimental results of drained and undrained triaxial compression tests of saturated Meuse–Haute/Marne claystone. The emphasis is to study the evolution of pore pressure with growth of microcracks and the effect of pore pressure on mechanical behavior. Basic mechanical responses are first investigated through drained triaxial compression tests, showing nonlinear stress strain relations, volumetric dilatancy and pressure sensitivity. In undrained triaxial compression tests, the pore pressure exhibits a transition from increase to decrease due to the transition from volumetric compressibility to dilatancy caused by the growth of microcracks. The failure surfaces, determined by total stress and Terzaghi’s effective stress under undrained condition, are compared with the one under drained condition. 相似文献
404.
405.
The Seasonal Variabilities in the Concentration of Atmospheric Aerosols over Qingdao, China 总被引:2,自引:0,他引:2
SHENG Lifang FU Ying QIU Mingyan GAO Huiwang 《中国海洋大学学报(英文版)》2005,4(4):383-390
Mass concentrations of Total Suspended Particles (TSP) and size-segregated particles were obtained from July 2001 to June 2002 in Qingdao to characterize the seasonal variations of atmospheric aerosols and to show the impact of dust events on the air quality in Qingdao. Data on size-segregated aerosols show that 73.74% of the TSP mass concentration is contributed by particles with diameters less than 11 μm. Particles with diameters less than 1.1μm have a higher concentration during the winter. In spring, larger particles tend to have higher mass concentrations. Bimodal particle size distributions have been observed, with maxima around 4.7-7 μand 0.43-0.65 μm in the winter season, and 7-11 μm and 0.65-1.1 μm in the autumn season. Measurements made during the dust events in March 2002 show high concentrations of particles in the size range 2.1-7μm. 相似文献
406.
GPS Solutions - Carrier phase ambiguity resolution over long baselines is challenging in BDS data processing. This is partially due to the variations of the hardware biases in BDS code signals and... 相似文献
407.
On October 24, 1991, a white-light flare was observed both from space and from the ground. A multi-waveband spectral analysis shows that the peak time of the continuum emission coincides well with that of a radio burst at 2840 MHz and with the hard X-ray emission. Three semi-empirical models, corresponding to the pre-flare condition and to the peak time of continuum emission both with and without non-thermal excitation and ionization of hydrogen by an electron beam, have been obtained. The results indicate that there is fast heating both in the chromosphere and the photosphere. Some evidence is given that this WLF is very likely a result of bombardment by an electron beam. By taking into account non-thermal effects, the chromospheric temperature of the semi-empirical model is significantly reduced. 相似文献
408.
A systematic method is presented to construct a mapping model for a near-conservative system, based on that of Hadjidemetriou for a Hamiltonian system [1]. The mapping we constructed preserves the basic features of the actual system. We apply this method to the forced oscillating system and to the 3 : 1 resonant grain motion in the presence of Poynting-Robertson drag.Supported by the National Natural Science Foundation of China. 相似文献
409.
INTRODUCTIONFromthe1990’s,thescallop,C.farreri,culturedinthenorthernChinaSea,deterioratedinsize,healthandoutputbecauseofhighstockingdensities,shortageofnaturalfoodanddiseases.Massmortalityof50%-90%occurredinJiaozhouBay,Qingdao,andSishiliwanBay,Yantai,fromJulyto… 相似文献
410.
Li Zhixiong Zhang Guomin Fu Zhengxiang and Zhang YongxianState Seismological Bureau Beijing China Center for Analysis Prediction SSB Beijing China 《中国地震研究》1996,(4)
In this paper,characteristics of spatial and temporal variation of linear fitting goodness before some moderately strong earthquakes(Ms≥5.0)in the eastern part of China(east of longitude 180)are studied according to the famous Gutenberg-Richter's relation expressed as lgN=a-bM,by using the moderate and small events that occurred in and around the source area.The results show that the linear goodness of fitting varies abnormally prior to these moderately strong earthquakes.In the early stage of the earthquake preparatory process,distribution of the energy released through small events in and around the source area is isostatic and the fitting goodness approximates 1,while the distribution of the energy turns to be isostatic before moderately strong earthquakes,leading to the obvious decrease of the linear goodness of fitting.This phenomenon could be a medium term anomaly and a medium term criterion for moderately strong earthquake prediction. 相似文献