979 resultados para 150-905
Resumo:
This paper reports that the transmission of O6+ ions with energy of 150keV through capillaries in an uncoated Al2O3 membrane was measured, and agreements with previously reported results in general angular distribution of the transmitted ions and the transmission fractions as a function of the tilt angle well fitted to Gaussian-like functions were observed. Due to using an uncoated capillary membrane, our c is larger than that using a gold-coated one with a smaller value of E-p/q, which suggests a larger equilibrium charge Q(infinity) in our experiment. The observed special width variation with time and a larger width than that using a smaller E-p/q were qualitatively explained by using mean-field classical transport theory based on a classical-trajectory Monte Carlo simulation.
Resumo:
对北京春季6种物候的计算得出其代表性指标—山桃始花期,并分析物候对气温变化的响应模式。根据气温变化态势,将历史时期气温和物候资料划分为4个时间段,并采用u检验论证时间段间具有显著性差异,分析物候期对气温变化的响应模式和机制,得出:物候期的提前与推迟对温度的增高与降低的响应是非线性的,在同等增、降温幅度下,因降温而导致的物候期推迟幅度较因增温而导致物候期提前幅度小;平均气温增高1℃,北京春季物候期提前2.8~3.6d。并估算了未来北京春季物候变化趋势。
Resumo:
We have resolved the solid-liquid phase transition of carbon at pressures around 150GPa. High-pressure samples of different temperatures were created by laser-driven shock compression of graphite and varying the initial density from 1.30g/cm3 to 2.25g/cm3. In this way, temperatures from 5700K to 14,500K could be achieved for relatively constant pressure according to hydrodynamic simulations. From measuring the elastic X-ray scattering intensity of vanadium K-alpha radiation at 4.95keVat a scattering angle of 126°, which is very sensitive to the solid-liquid transition, we can determine whether the sample had transitioned to the fluid phase. We find that samples of initial density 1.3g/cm3 and 1.85g/cm3 are liquid in the compressed states, whereas samples close to the ideal graphite crystal density of 2.25g/cm3 remain solid, probably in a diamond-like state.
Resumo:
Se presentaron los resultados de la modificación y adaptaciones de la red pelágica 124/1800 para la captura del recurso Vinciguerria.
Resumo:
Collection : Théâtre contemporain illustré ; 156e et 157e livraisons
Resumo:
Collection : Théâtre contemporain illustré ; 156e et 157e livraisons