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921.
922.
923.
The wavelet threshold estimator of a regression function for the random design is constructed. The optimal uniform convergence rate of the estimator in a ball of Besov Space Bsp, q is proved under general assumptions. The adaptive wavelet threshold estimator with near-optimal convergence rate in a wide range of Besov scale is also constructed. 相似文献
924.
The strongE andL dependence of the effective elastic channel potentials is shown to be an implicit radial kinetic energy (ε) dependence. It is also shown that this effective potential satisfies the dispersion relation inε variable at the strong absorption radius. Further, the experimental data for both elastic and fusion channels are consistent
with thisL-dependence of the corresponding effective potentials. The effective transfer channel potentials derived using CRC code FRESCO
are shown to exhibit strong energy dependence as a result of couplings. The energy dependence of effective transfer strength
for16O+208Pb and16O+232Th systems is determined using the experimental transfer angular distributions. 相似文献
925.
926.
Tb,Tm:YVO4晶体的激光性能分析 总被引:1,自引:1,他引:0
Tm:YVO4和Tb,Tm:YVO4晶体中激活离子之间或激活离子与敏化离子间的交叉弛豫、与无辐射跃迁及激光上能级的辐射跃迁的几率是相近的,对这种双掺离子晶体的激光阈值理论估算式中必须同时考虑离子间交叉弛豫。从激活离子能级跃迁速率方程和激光、抽运光传输方程推导出端面抽运的包含交叉弛豫几率等光学参量的激光阈值的理论估算式。用这些方程讨论了Tm:YVO4和Tb,Tm:YVO4的1.5μm和1.9μm波长的激光性能,并论述了Tb3 离子的作用。结果表明。Tb3 离子的的掺入,增加1.5μm波段激光的强度,降低阈值能量,但对1.9μm波长激光有负面作用。 相似文献
927.
We investigate the spin correlations in top quark pair production near the threshold at the e e- linear collider. Comparing with the results above the threshold region, we find that near the threshold region the off-diagonal basis, the optimized decomposition of the top quark spins above the threshold region, does not exist, and the beamline basis is the optimal basis, in which there are the dominant spin components: the up-down (UD) component for e-Le scattering and the down-up (DU) component for e-Re scattering can make up more than 50% of the total cross section,respectively. 相似文献
928.
Our theoretical analysis showed that the overall intracavity frequency-doubled actively Q-switched solid state laser performance
is affected by both pulse repetition rate and energy transfer up-conversion effect. The energy transfer up-conversion effect
increased greatly and seriously degraded the laser performance especially when operating at high pumping power and low pulse
repetition rate. The curves generated by numerical computation of the presented model can be used to predict the laser performance.
We concluded that the pulse lengthening effect also appears with the influence of energy transfer up-conversion and is not
related to the repetition rate. From the analysis, we found that the frequency doubling coefficient that Liu and Kim chose
in their experiment was just the optimized value. Considering the effect of excited state absorption of saturable absorber
into passively Q-switched intracavity frequency doubled solid state laser, the second threshold condition for this model is
derived. A simple and very clear formula is obtained. 相似文献
929.
930.
Chang Seoul Yong‐Tae Kim Chi‐Kyung Baek 《Journal of Polymer Science.Polymer Physics》2003,41(13):1572-1577
For conductive carbon nanotube (CN)/polymer composite fibers to be obtained, CNs were incorporated into poly(vinylidene fluoride) (PVDF) in dimethylformamide (DMF) solutions and electrospun to form CN/PVDF fiber mats. The thinnest fiber was 70 nm thick. The percolation threshold for the insulator‐to‐conductor transition was 0.003 wt % CN for CN/PVDF/DMF solutions, 0.015 wt % CN for CN/PVDF spin‐coated films, and 0.04 wt % CN for CN/PVDF electrospun fiber mats. © 2003 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys 41: 1572–1577, 2003 相似文献