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971.
The large deviations theorem and ergodicity 总被引:2,自引:0,他引:2
Rongbao Gu 《Chaos, solitons, and fractals》2007,34(5):1387-1392
In this paper, some relationships between stochastic and topological properties of dynamical systems are studied. For a continuous map f from a compact metric space X into itself, we show that if f satisfies the large deviations theorem then it is topologically ergodic. Moreover, we introduce the topologically strong ergodicity, and prove that if f is a topologically strongly ergodic map satisfying the large deviations theorem then it is sensitively dependent on initial conditions. 相似文献
972.
973.
A polymer volume grating-based four-channel coarse wavelength division multiplexer (WDM) for inter- and intra-satellite optical communication application is reported for the first time. This compact four-channel WDM device working at 0.83, 1.06, 1.34 and 1.55 μm is designed to build a complete optical link between two satellites, where wavelengths of 0.83 and 1.55 μm are used for data stream channels, 1.06 and 1.34 μm are used for inter- and intra-satellite connection. It is for the first time reported that a WDM device can cover such a large wavelength range in a single substrate. For transverse electric (TE) wave, the channel efficiencies at 0.83, 1.06, 1.34 and 1.55 μm are 55%, 40%, 35% and 45%, respectively. Channel efficiencies for transverse magnetic (TM) waves are 20% lower than those of TE waves on average. Wavelength shifts due to Doppler effect, temperature variations and radiation effects in space can be adequately accommodated. 相似文献
974.
Lei ZHANG Gu JIN 《中国化学快报》2005,16(11):1495-1498
In this study, we developed a tailored capillary sorbent for bilirubin removal. For immobilized bioligand, capillaries were grafted with epoxy groups using RIGP. The HSA immobilized capillaries has a high affinity adsorption capacity (71.2 mg bilirubin/g polymer) and a shorter adsorption equilibrium time (about 60 min). 相似文献
975.
976.
The finite element method has been well established for numerically solving parabolic partial differential equations (PDEs). Also it is well known that a too large time step should not be chosen in order to obtain a stable and accurate numerical solution. In this article, accuracy analysis shows that a too small time step should not be chosen either for some time‐stepping schemes. Otherwise, the accuracy of the numerical solution cannot be improved or can even be worsened in some cases. Furthermore, the so‐called minimum time step criteria are established for the Crank‐Nicolson scheme, the Galerkin‐time scheme, and the backward‐difference scheme used in the temporal discretization. For the forward‐difference scheme, no minimum time step exists as far as the accuracy is concerned. In the accuracy analysis, no specific initial and boundary conditions are invoked so that such established criteria can be applied to the parabolic PDEs subject to any initial and boundary conditions. These minimum time step criteria are verified in a series of numerical experiments for a one‐dimensional transient field problem with a known analytical solution. The minimum time step criteria developed in this study are useful for choosing appropriate time steps in numerical simulations of practical engineering problems. © 2005 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2006 相似文献
977.
通过透射光谱、x射线激发发射光谱(XSL)的测试,研究了Bridgman法生长的几种不同+3价离子掺杂钨酸铅晶体的发光性能,并利用正电子湮没寿命谱(PAT)和x光电子能谱(XPS)的实验手段,对不同钨酸铅晶体的微观缺陷进行研究.实验表明,不同的+3价离子掺杂,对钨酸铅晶体发光性能的改善不同,并使得晶体中正电子俘获中心和低价氧的浓度发生不同变化.其中掺镧晶体的正电子俘获中心和低价氧浓度均上升,而掺钇和掺铋晶体的正电子俘获中心和低价氧浓度均下降,掺锑晶体则出现了正电子俘获中心浓度上升、低价氧浓度下降的情况.提
关键词:
钨酸铅晶体
+3价离子掺杂
正电子湮没寿命谱
x光电子能谱 相似文献
978.
Using potassium atoms cooled with a MOT, ground-state hyperfine coherent population trapped (CPT) states were prepared in a magnetic (B) field, and the behavior of CPT states was experimentally studied. We carefully measured the preparation of the CPT state as a function of time and the CPT signal as a function of laser power. The experimental CPT signal linewidth was approximately proportional to the square root of laser intensity in the range of parameters studied, and limits of this relation were explored theoretically. 相似文献
979.
980.
以金镍复合膜作催化剂,在96%的高氢气浓度下实现了碳纳米管的定向生长,并对其生长过 程进行了深入探讨.结果表明,高氢气浓度下碳纳米管生长的实现与本实验所选用的催化剂 ——金镍复合膜有密切关系.催化剂中金的参与,促进了碳在催化剂中的扩散,提高了碳在 催化剂中的活度.与催化剂中没有金的情况相比较,金的参与有利于镍吸收气氛中的碳,从 而使镍更容易达到碳饱和,有利于在高的氢气浓度下实现碳纳米管的定向生长.
关键词:
金镍复合膜
高氢气浓度
原子氢
碳活度 相似文献