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151.
152.
Strong magnetic fields were generated using a fast pulsed power generator, to investigate the interaction of plasma flows
with magnetic fields and magnetized background plasmas. The inductive loads used in these experiments were designed using
a filament and a finite element modeling approaches. Magnetic fields up to 2 MG (200 T) were measured by using the Faraday
rotation technique. 相似文献
153.
J. Martinez Alfaro 《Celestial Mechanics and Dynamical Astronomy》1984,33(4):375-383
Some of the properties of the oblate planet problem are derived. We use the technique of blowing up the singularity to study the collision orbits. We define some families of them in terms of their asymptotic behavior. 相似文献
154.
155.
Maxime Lion Béatrice Ledésert Frédéric Skoczylas Philippe Recourt Thierry Dubois 《地学学报》2004,16(6):351-357
Many poromechanical studies of rocks give little regard to the micropetrographic observation of their constituents. The aim of this study is to show how such a detailed study can help understand and provide more precision on the poromechanical behaviour of the material. The rock studied here is an oolitic limestone. Micropetrography reveals the nature of the constituents (calcite, mostly in the form of fine‐grained micrite), their abundance, their organization (micrite organized in ooids linked by a calcitic cement, small‐sized highly connected isotropic porosity, scarce unconnected porosity) and the structure of the rock (global isotropy, small heterogeneities due to sedimentological phenomena, no microcracks). Micropetrography completes the information obtained by poromechanics in that it allows the observation of elements deduced from macroscopical tests. The aim of this paper is to show the effect of microporosity on permeability and flow in a rock where microporous grains are in contact with each other. 相似文献
156.
Peter Martinez 《Astrophysics and Space Science》1989,155(2):iii-iii
Publisher's announcement 相似文献
157.
The aim of this study was to investigate the potential application of the beta-d-glucuronidase (GLUase) activity measurement for the routine detection and quantification of E. coli in marine bathing waters. GLUase activity was measured as the rate of hydrolysis of 4-methylumbelliferyl-beta-d-glucuronide. Culturable E. coli were quantified by the most probable number (MPN) microplate method. Both methods were applied to a large set of seawater samples. Significant correlation was found between the log of GLUase activity and the log of culturable E. coli. The mean coefficient of variation (CV) of the GLUase activity was less than 15% at concentrations around the current standards of International regulations whereas the CV of the microplate method was around 30%. When samples were stored at 4 degrees C and 20 degrees C, the mean CV of the GLUase activity remained below 15% up to 6 hours after sample collection whereas the range of variation of the microplate method varied between 10 and 50%. We concluded that the GLUase activity is an operational, reproducible, simple, very rapid and low cost method for the real-time enumeration of E. coli in bathing waters and should be preferred to the microplate method. The GLUase activity method should be routinely applied to the rapid enumeration of E. coli in recreational waters and recommendations for its application were suggested to water quality managers. 相似文献
158.
The new target of the Rosetta mission is comet 67P/Churyumov-Gerasimenko (hereafter 67P/C-G). In order to support the planning of the mission, in particular the strategy during the mapping and landing phases, we have performed numerical simulations of the rotational evolution of a comet in the orbit of 67P/C-G. In these simulations, the currently known observational constraints have been taken into account and a large set of initial conditions were considered. For most of the simulations, we observe that the sublimation-induced torques produce significant changes in the rotational parameters of a 67P/C-G-like comet. Typical rates of change for the spin period from the rendezvous up to the end of the nominal mission range from 0.001 to depending on different circumstances as described in the text. At perihelion, rates of change of the orientation of the angular momentum vector amount to about 0.01-. These simulations suggest that a specific strategy should be defined in order to monitor likely variations of the rotational parameters. As an example we show a possible optimized schedule for observations with the OSIRIS instrument to determine the rotational parameters of comet 67P/C-G and their possible evolution. 相似文献
159.
Twenty granodioritic rocks and one amphibolitic enclave of the “basement” of the Suomussalmi-Kuhmo Archaean (2.65 Ga) greenstone belts (central-eastern Finland), have been chosen together with one greenstone sample for Rb-Sr and Sm-Nd geochronological and isotopic studies.The granitoïd rocks are subdivided into three groups: two generations of grey gneisses and a post-belt augen gneiss. The Rb-Sr ages of the first and second generation of grey gneisses are 2.86 ± 0.09 and 2.62 ± 0.07 Ga, respectively. These results are corroborated by Sm-Nd data. The post-belt augen gneiss gives an age of 2.51 ± 0.11 Ga. The results show that the two generations of grey gneisses, the greenstone belts and the post-greenstone augen gneiss, were developed over a period > 350 Ma. The two generations of grey gneisses show identical ISr values (0.7023 ± 8 and 0.7024 ± 6) which contrast with that of the augen gneiss (0.7049 ± 8). The low ISr and the near-chondritic ?TCHUR values indicate that the grey gneisses cannot derived from much older continental materials. Trace element studies suggest that these grey gneisses have had a multi-stage development. The augen gneiss with a moderately high ISr is likely to be derived from a granodiorite originated by partial melting of older sialic crust. The more probable parent rock seems to be the first generation grey gneisses. The ISr and average Rb/Sr values preclude the greenstone belt and the second generation of grey gneisses as the protolith. 相似文献
160.
A Laser-induced Fluorescence Instrument for Detecting Tropospheric OH and HO2: Characteristics and Calibration 总被引:1,自引:0,他引:1