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1.
We present simulation results of the vortex dynamics in a trapped Bose-Einstein condensate in the presence of a rotating optical
lattice. Changing the potential amplitude and the relative rotation frequency between the condensate and the optical lattice,
we find a rich variety of dynamical phases of vortices. In particular, when the optical lattice rotates faster than the condensate,
the competition between the pinning force and the interactions by nucleated interstitial vortices leads to the melting of
vortex lattice, yielding a vortex liquid phase. 相似文献
2.
We study dynamics of quantized vortex lattice formation in a rotating Bose-Einstein condensate with a square blue-detuned
optical lattice by solving the Gross-Pitaevskii equation. This dynamics depends on the depth of the optical lattice. Vortices
tend to form a triangular lattice under the rotation, while an optical lattice likes to pin vortices at their peaks. Such
a competition of two effects makes this system more interesting and complicated. 相似文献
3.
大多数经济发达国家,都在大规模地推动电子商务的发展,并以此取代或改造传统的商务活动方式。基于此分析了目前B2B的现状及发展趋势,全面介绍了电子商务B2B的理论以及开发环境、技术支持、设计思路,并使用流行的VS.net、IIS以及SQL技术,设计并实现了B2B子系统。 相似文献
4.
N. Hashimoto A. Handa M. Nakagawa K. Obara H. Yano O. Ishikawa T. Hata 《Journal of Low Temperature Physics》2007,148(3-4):299-303
We have investigated the turbulence transition of the superfluid 4He flow generated by a vibrating wire. For a 1.2-kHz vibrating wire, we observed intermittent switchings between laminar and
turbulent flows. The switching rate decreases with increasing temperature above 100 mK, until no occurrence of the switchings
at 350 mK. For a 2.4-kHz vibrating wire, we find that the switching rate is much lower than that of the 1.2-kHz vibrating
wire even at low temperatures. This result indicates that a mechanism causing the switchings is influenced by the temperature
and the oscillation frequency of the superfluid flow. 相似文献
5.
M. B. Sobnack F. V. Kusmartsev J. C. H. Fung 《Journal of Low Temperature Physics》2007,148(5-6):869-873
We study the nucleation of vortices in a thin (thickness ≪ penetration depth) mesoscopic superconducting disc in an applied magnetic field perpendicular to the disc (i.e., parallel
to the axis of the disc). We write down an expression for the free energy of the system with an arbitrary number of vortices
and anti-vortices at finite (non-zero) temperatures. For a given applied field, we minimize the free energy to find the optimal
position of the vortices and anti-vortices (the configuration which minimizes the energy). We show that, whereas at zero temperature
anti-vortices do not nucleate, anti-vortices do penetrate the disc at finite temperatures. We also calculate the magnetization
of the disc as a function of the applied field and hence determine the different configurations possible in which a fixed
number of fluxoids can penetrate the disc. 相似文献
6.
Microscopic dissipation mechanism of quantized vortices in quantum fluid is studied numerically by solving the Gross-Pitaevskii
equation coupled with the Bogoliubov-de-Gennes equation for thermal excitations. At low temperatures, dissipation works at
smaller scales than the vortex core size, which supports the self-similar cascade process of quantized vortices at large scales
and the Kolmogorov energy spectrum of quantum turbulence. On the other hand, this dissipation spreads to larger scales at
high temperatures, and directly affects the vortex dynamics. This effect of dissipation at high temperatures is qualitatively
similar to the mutual friction in superfluid 4He. 相似文献
7.
首先对GridView和Repeater这两个控件在显示数据库数据时的性能进行实验,然后对实验结果进行分析,最后就GridView和Repeater控件的性能优劣性得出结论,从而为研究人员和开发人员基于性能选择使用这两个控件时提供依据,实验同时还测试SQL SERVR 2005数据库中用存储过程插入大批量数据时的性能。 相似文献
8.
We describe a finite element numerical approach to the full Hartree-Fock-Bogoliubov treatment of a vortex lattice in a rapidly rotating Bose–Einstein condensate. We study the system in the regime of high thermal or significant quantum fluctuations where we are presented with a very large nonlinear unsymmetric eigenvalue problem which is indefinite and which possesses low-lying excitations clustered arbitrarily close to zero, a problem that requires state-of-the-art numerical techniques. 相似文献
9.
本文介绍了振动计算中桩基刚度的弹性理论和Vs修正的实用计算方法.通过2种方法结合使用,可以确定增强地基刚度所需的桩数.弹性理论实用计算方法确定的桩基刚度,可认为是桩基杆件的弹簧常数,用于基础和桩基联合模型的动力分析. 相似文献
10.
卫开旗 《昆明冶金高等专科学校学报》2003,19(2):12-14,24
研究了锰含量对15MnV钢中钒化合物溶解析出的影响。用中途淬火.萃取物化学相分析等方法,测定了加热时钒化合物的溶解量,980—500℃等温过程中钒化合物的析出量.用应力松弛法测定了奥氏体中钒化合物的析出动力学.讨论了锰含量与[V][C]固溶度积的关系,得到了锰含量与奥氏体中析出温度--时间(PTT)曲线的关系,分析了锰含量对等温过程中钒化合物析出峰值温度、最大析出量的影响。 相似文献