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Some electromagnetic quantities in the black hole (BH) magnetosphere are discussed by considering the coexistence of the Blandford-Znajek process and the magnetic coupling process. These quantities are (i) flux of electromagnetic energy and angular momentum transferred between the BH and the disc, (ii) poloidal currents flowing on the 相似文献
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This paper reports the investigation results on directional growth of Al-Mg2Si eutectic alloy in the SZ2 unmanned spaceship. The analysis shows that microgravity has influence on the directional growth of Al-Mg2Si eutectic alloy. The eutectic colony in space-grown sample is larger than that in ground-grown sample, and the directional effect is not so good as that of terrestrial sample. But there is no obvious difference in the lamellar thickness between these samples, and lamellar interspacing in space sample is smaller than that grown on the ground. A simple discussion is done on the gravity effect on the directional growth of Al-Mg2Si eutectic alloy. 相似文献
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对不同组分的Ru(dpphen)2+3[简称Ru(Ⅱ)]与花生酸(AA)在纯水亚相上的混合单分子膜的相容性、分子间相互作用以及凝聚单分子膜的结构进行了研究. 成功地将这种功能单体分子膜转移到固体载片上,制备成混合LB膜. 紫外-可见光谱、发射光谱及小角X光衍射表明这种混合LB膜是一种稳定、均一、具有良好的层状结构, 并且在可见光范围内具有很强的吸收及发射峰的功能膜. 相似文献
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磁约束聚变堆及ITER实验包层模块设计研究进展 总被引:5,自引:0,他引:5
目前国际上代表性的磁约束聚变反应堆设计包括美国的ARIES系列和APEX系列、欧洲的PPCS系列、日本的SSTR系列、中国的FDS系列设计,以及国际合作的国际热核聚变实验堆等。这些设计研究涉及到聚变能科学技术发展的各个方面,包括聚变实验堆、商用示范堆和商用动力电站等的设计研究、相关物理和技术发展以及相关的能源技术与经济策略研究等。简要介绍了上述设计研究领域的现状和发展趋势。The uhimate goal of the fusion program is to develop large scale power plants for the production of electricity. At present, there are many representative designs of magnetic confinement fusion reactors in the world,e.g. ARIES and APEX in USA, PPCS in EU, SSTR in Japan, FDS in China, and International Thermonuclear Experimental Reactor (ITER). These studies cover many aspects on fusion experimental reactors, DEMO reactors, and commercial fusion power plants, including plasma physics, blanket technologies, material behavior, and technologies required to construct and operate such complex plants. The study status and development strategy in various countries are summarized and reviewed. 相似文献
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Quantum interference effects on the probe amplification without and with inversion in a four-level system
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A four-level system driven by two coherent fields is considered. It is shown that in the presence of an incoherent pump, the probe gain at a short wavelength can be achieved due to the quantum interference. Our density matrix calculation provides the conditions for probe amplification from different origins, including gain without population inversion on any state basis, gain with population inversion on the dressed-state basis, and gain with population inversion on the bare-state basis. Also, by controlling the Rabi frequency of the coupling field a total change from non-inversion to inversion can be achieved which does not depend on the intensity of the incoherent pump. 相似文献
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We report the dynamic crossover behavior in metallic glass nanoparticles(MGNs)with the size reduction based on the extensive molecular dynamics(MD)simulations combined with the activation-relaxation technique(ART).The fragile-to-strong transition of dynamics can be achieved by just modulating the characteristic size of MGNs.It can be attributed to the abnormal fast surface dynamics enhanced by the surface curvature.By determining the potential energy surface,we reveal the hierarchy-to-flat transition of potential energy landscape(PEL)in MGNs,and demonstrate the intrinsic flat potential landscape feature of the MGN with size smaller than a critical size.Our results provide an important piece of the puzzle about the size-modulated potential energy landscape and shed some lights on the unique properties of MGs in nanoscale. 相似文献