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71.
稳态锁模产生4ps激光脉冲 总被引:1,自引:0,他引:1
首次利用GaAs光电导开关,控制Nd:YLF激光器腔内Q值,实现稳态锁模,获得脉宽和能量稳定性极高的4ps激光脉冲。 相似文献
72.
用Q-YAG激光的三次谐波(355nm)与调谐的Rh·6G染料激光在β-BaB2O4(BBO)晶体中和频,获得217.3~221.4nm连续调谐输出,和频输出的最大能量为250μJ,转换效率为11%.我们还讨论了获取最大和频输出能量的一些实验条件. 相似文献
73.
Zi‐Cai Li Tzon‐Tzer Lu Hung‐Tsai Huang Alexander H.‐D. Cheng 《Numerical Methods for Partial Differential Equations》2007,23(1):93-144
In this article we survey the Trefftz method (TM), the collocation method (CM), and the collocation Trefftz method (CTM). We also review the coupling techniques for the interzonal conditions, which include the indirect Trefftz method, the original Trefftz method, the penalty plus hybrid Trefftz method, and the direct Trefftz method. Other boundary methods are also briefly described. Key issues in these algorithms, including the error analysis, are addressed. New numerical results are reported. Comparisons among TMs and other numerical methods are made. It is concluded that the CTM is the simplest algorithm and provides the most accurate solution with the best numerical stability. © 2006 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2007 相似文献
74.
工件带到达时间的两阶段柔性流水作业的近似算法 总被引:1,自引:0,他引:1
研究了工件带到时间的两阶段柔性流水作业的排序问题,基于求解流水作业和平行机问题的算法思想,提出两个相应的近似算法H(R)和H(MR(?)),证明了这两个算法的最坏情况性能比分别为3-1/m和2/5-1/m,讨论了界的紧性,并利用数值模拟以分析算法与最优值的近似性能比. 相似文献
75.
In this paper we investigate the distribution of the Heisenberg evolution of the number operator in the stochastic limit of
the quantum electromagnetic field without dipole approximation. We prove that in this case the usual Poisson statistics of
the free fields has to be replaced by a hypergeometric series whose coefficients we compute explicitly. The physical effects
of the new statistics should manifest themselves in situation which are not yet in the relativistic regime, but in which the
dipole approximation is no longer valid.
The text was submitted by the authors in English. 相似文献
76.
The method of demodulation with two parallel matched fiber Bragg gratings( FBGs)system is introduced to enlarge the range of strain that can be detected by the FBG sensor system. 相似文献
77.
The strategy of expert system for high performance liquid chromatography was discussed, the attentions are mainly placed on the knowledge base for selection of column system, separation modes and detection modes in the analysis of amino acids, peptides and proteins. 相似文献
78.
Meihua Lu H. Gong T. Song Jian-Ping Wang Hong-Wei Zhang T.J. Zhou 《Journal of magnetism and magnetic materials》2006
We present a simple way to synthesize FePt and ZnO (wide-band-gap semiconductor) nanoparticle composites. The FePt nanoparticles were fabricated using the method reported by Sun et al. By controlling the heating rate, 3 nm FePt nanoparticles were synthesized. Well-dispersed FePt and ZnO nanoparticle composites were prepared by further adding zinc acetate and oleyl amine into the 3 nm FePt nanoparticle dispersion. By controlling the molar ratio of the FePt and zinc acetate, FePt and ZnO nanoparticle composites with different FePt particle fractions were obtained. The intensity of photo luminescence spectra of the nanoparticle composites increases very much with decreasing FePt particle fraction, whereas the peak position shifts a little. After annealing at 550 °C for half an hour, the nanoparticle composites become magnetically hard or semi-hard with coercivity much dependent on the FePt particle volume fraction. The coercivity of the composites increases with annealing temperature. The composites hold the promise of applications in new generation recording and/or optical devices. 相似文献
79.
Y.-Q. Peng J.-H. Yang F.-P. Lu 《Applied Physics A: Materials Science & Processing》2006,83(2):305-311
Under the assumption of Gaussian energy distributions of the lowest unoccupied molecular orbital (LUMO) and the highest occupied
molecular orbital (HOMO), analytical expressions of generalized Einstein relation for electron and hole transport in doped
organic semiconductor thin films are developed. Numerical calculations show that, although traditional Einstein relation still
holds for low carrier concentrations, that is, the diffusion-coefficient-to-mobility ratio in units of kBT/q, with kB the Boltzmann’s constant, T the temperature and q the elementary charge, equals 1. But when the electron (hole) concentration
is high, the diffusion-coefficient-to-mobility ratio for electrons (holes) changes strongly with the electron (hole) concentration,
the doping level, the mean energy of LUMOs (HOMOs) of the dopant ELd (EHd) and the host EL (EH), as well as their variances. Dopants with ELd<EL (EHd>EH) affect the diffusion-coefficient-to-mobility ratio mainly in the range of low and middle carrier concentrations, while those
with ELd>EL (EHd<EH) have significant effect only in the range of high carrier concentrations. It was found that there can be a maximum in the
dependence of the diffusion-coefficient-to-mobility ratio on the quasi-Fermi energy or carrier concentration exist, for appropriate
values of the doping level, the mean energy and variance of LUMO or HOMO states of the dopant.
PACS 71.20.Rv; 72.90.+y; 73.50.-h 相似文献
80.
Kai Wang Huan-yu Li Jian-ping Li Zhi-gang Zhang Ning Zhang Lu Chai Qing-yue Wang 《Optics Communications》2006,265(2):369-372
Recently, the semiconductor saturable absorber mirror (SESAM) has become a key component of passive mode-locked solid-state lasers. Here we present a simple method based on the reflection Z-scan technique to measure the key optical parameters of SESAM such as saturation fluence and modulation depth. The experimental results demonstrate that our method is able to perform with a high accuracy of 10−4 and a dynamic range of over four orders of magnitude. 相似文献