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
For better understanding of the sexual behaviours that are high-risk in terms of HIV infection, a random sample of 200 people aged above 20 and below 60 years, from a population of 23,700, was selected in the provincial city of Nagano and surveyed by visitation. The responses of 156 people (a rate of response of 78%) were collected and the results were statistically analyzed. The methods employed in conducting a survey on sexual behaviour were also evaluated. The number of sexual partners is an indicator of high-risk sexual behaviour for HIV infection. The data reveals that 65.3% of the men and 37% of the women had two or more partners in the past, with 37.5% of the men and 12.5% of the women having two or more partners in the last 5 years, and 19.1% of the men and 4.2% of the women having two or more partners in the last year, revealing that a higher percentage of men than women have multiple partners. Comparison by age group reveals that young men and women in their 20s have the highest percentage of multiple partners. For both men and women first sexual intercourse before the age of 18, for men self-employment, being a craftsmen or in agriculture, and for women, higher education, were all factors in having greater numbers of partners. In conducting a survey on sexual behaviour the following should be kept in mind. 1) The psychological background of the respondent; Sex counseling skills are required on the part of the interviewer when taking a survey on sex since it is a very private and personal topic for people. Respondents have a tendency to be those who are open-minded about sex and are active in life, and these factors can exaggerate the survey results. 2) Conduct of a survey on sexual behaviour; The survey should be taken only after the purpose of the survey has been fully explained to the respondents and trust has been established. In principle, therefore, mailing of a letter of request and the actual questions should not be the method utilized prior to the collection of responses. 相似文献
A strontium tantalum sulfide, SrTa2S5, has a hexagonal structure with lattice constants of a =3.32 and c=24.1 Å. With decreasing temperature the electrical resistivity decreases monotonically and exhibits an abrupt superconducting transition at 3.16 K (midpoint). The diamagnetic susceptibility is observed below Tc. The magnetic susceptibility is nearly independent of temperature above Tc and shows Pauli paramagnetism. 相似文献
When we select No students from N applicants on the basis of a composite score of subtests, it is important to evaluate the contribution of each subtest. The swap-rate, which is defined as the proportion of the applicants who actually pass the examination but would fail if the j-th subtest were not included in the component to rank the applicants, is one of the measures of the contribution of the j-th subtest.
In this article, first, we derive the characteristics and limiting properties of the population swap-rate. Next, using the properties of the order statistics and the extended hypergeometric distribution, we derive an approximation to the asymptotic variance of the sample swap-rate when the number of applicants is large. Finally, we propose the use of our analytic approximation to the variance of the sample swap-rate in the real data problem and show that it is very efficient.
A development of 170GHz/500kW level gyrotron was carried out as R&D work of ITER. The oscillation mode is TE31,8. In a short pulse experiment, the maximum power of 750kW was achieved at 85kV/40A. The efficiency was 22%. In the depressed collector operation, 500kW/36%/50ms was obtained. The maximum efficiency of 40% was obtained at PRF=470kW whereas the power decrease by the electron trapping was observed. Pulse extension was done up to 10s at PRF=170kW with the depressed collector operation. The power was limited by the temperature increase of the output window. 相似文献
In this paper, we describe two kinds of characteristic nonlinear dynamics in two-component Bose–Einstein condensates. For two overlapping components, we analyzed the collective modes and a variety of nonlinear mode couplings, which were then confirmed by numerical simulation of the time-dependent Gross–Pitaevskii equations. Next, we consider the nonlinear dynamics of two condensates after abruptly turning on the intercomponent coupling strength. For strong intercomponent interactions the out-of-phase density wave of the condensates became unstable, leading to mugtiple domain formation. 相似文献
Multilayer piezoelectric actuators when driven under high frequency, generate significant heat, which influences the reliability and other piezoelectric properties. In this paper, heat generation in various types of multilayer PZT-based actuators was studied. Experimental results showed that heat generation is mainly caused by ferroelectric hysteresis loss in the stress-free state. A simplified analytic method was established to evaluate the temperature rise, which is useful for the design of multilayer and other high-power actuators. 相似文献
In infants and children requiring prolonged, multiple central venous (CV) catheterizations, the superior (SVC) and inferior vena cava may become thrombosed or stenotic, making CV access a difficult problem. Use of the iliac vein may be an acceptable alternative. We report a patient with thrombosis of the SVC in whom the external iliac vein was accessed through a retroperitoneal approach for placement of an implantable port. This technique is easy to perform, and there are no special materials or patient positioning required. 相似文献