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121.
Based on the extended Huygens–Fresnel integral and the second-order moments of the Wigner distribution function, an analytical formulae for the propagation factors (M2-factors) of coherent and partially coherent one-dimensional Hermite–Gaussian beams in a turbulent atmosphere are derived. Evolution properties of the M2-factor of the Hermite–Gaussian beam in a turbulent atmosphere are studied numerically in detail. Our results show that the M2-factor of the Hermite–Gaussian beam increases upon propagation in a turbulent atmosphere. The M2-factor of the Hermite–Gaussian beam with larger beam order (or lower coherence) increases slower that of the Hermite–Gaussian beam with smaller beam order (or higher coherence) in a turbulent atmosphere, which means that the Hermite–Gaussian beam with a larger beam order and lower coherence is less affected by a turbulent atmosphere. Our results will be useful in long-distance free-space optical communications.  相似文献   
122.
123.
This article summarizes my research over 40 years. The main theme of my work is nitrogen metabolism of amino acids, though later I focused on protein turnover in the cell. In the first years of my research work, I was busy dissecting the pathways involved in the metabolism of certain amino acids and their related enzymes. Then I became interested in the physiology and regulation of matabolism of these amino acids. For that, I used primary cultured hepatocytes, which contain many liver-specific enzymes. However, this play field was very rough around 1970 and hence I had to smooth them (differentiated) first. We discovered a specific growth factor (hepatocyte growth factor, HGF) in rat platelets. Exceptionally, I also worked on branched chain amino acids (valine, leucine and isoleucine). These amino acids are not efficiently metabolized in the liver, so I had to consider the physiology of extrahepatic tissues as well. Finally, I came across a huge protease complex, the proteasome. Whether these players, small amino acid metabolizing enzymes and the huge protease complex, danced well in harmony on my playground or not, I still do not know.  相似文献   
124.
1.IntroductionInthepastfe\\'ycarsltllcil1tcnsity-momentsmethodandtheM2factorhavebeenre-vea1edtobeveryuscfulrotlcscribethepropagationlawandthebeamqualityofastaticlightbeam[l~Jj.Rccent1y,1ncji:1sctal.generalizedtheintensitymomentsmethodfortheSCLQ(speetral1y`"el1-centcrcdandlocallyquasi-monochromatic)pulsedlightboms[5j.Itisapparentthatthosercsu]tsubtainedinreferenceL5]areon1yvalidfortheso-calledquasi-monochromaticlightbeamsandarenotvalidforgeneralpolychromaticpulsedlightbeams,esPeciallyaredono…  相似文献   
125.
Huey-Wen Lin 《中国物理 C》2009,33(12):1238-1243
In this proceeding, I review the attempts to calculate the Nucleon resonance (including Roper as first radially excited state of nucleon and other excited states) using lattice quantum chromodynamics (QCD). The latest preliminary results from Hadron Spectrum Collaboration (HSC) with mπ≈ 380 MeV are reported. The Sachs electric form factor of the proton and neutron and their transition with the Roper at large Q2 are also updated in this work.  相似文献   
126.
徐海磊  沈建其  陈一新 《物理学报》2003,52(6):1372-1378
利用Lewis-Riesenfeld不变量理论和与不变量有关的幺正变换方法研究了双阱结构含时量子 输运的微扰论.获得了双阱内含时薛定谔方程的精确解的完备集,在此基础上,把双阱与左 右热库的相互作用作为微挠,获得了双阱结构一阶近似下的输运方程,并在绝热近似下提供 了一种用于研究量子输运过程中几何相因子(Berry相因子)的方法. 关键词: 含时量子输运 输运方程 不变量 几何相因子  相似文献   
127.
保偏反射膜温度特性对BGOCT灵敏度影响的理论研究   总被引:4,自引:1,他引:4  
采用琼斯矩阵方法对保偏膜反射相移温度特性对块状光学电流互感器(BGOCT)灵敏度的影响作了理论研究,结果表明,当温度从5.3℃变化到39℃时,表征系统灵敏度的归一化尺度因子会在一定范围内变化.表明镀制于光学玻璃电流传感头上的保偏膜反射相移温度特性影响光学电流传感器的稳定性.因此,在实际系统设计中对光学玻璃电流传感头应采取必要的温度控制或补偿措施.  相似文献   
128.
The g-factor of the 27 isomer state of 152Dy has been measured using the Time-Integral Perturbed Angular Distribution (TIPAD) method. The high-spin states of 152Dy have been populated by 141Pr(16O,p4n)152Dy reaction at E = 115 MeV from the AVF cyclotron at CYRIC. The paramagnetic correction factor of Dy ions in Pr has been determined to be 4.2(5) by the Time-Differential Perturbed Angular Distribution (TDPAD) measurement of the 21 state of 152Dy. As a result, the g-factor of the 27 isomer state of 152Dy has been obtained to be +0.09(5). This shows the smaller value than the expected one of +0.39 deduced from a fully aligned configuration of π(h 11/2 2) ⊗ ν(f 7/2 2 h 9/2 i 13/2).  相似文献   
129.
The safety most important factor profile is one of the the plasma discharge. For limiter configuration, people usually use the following cylindrical approximation formula to calculate it q(r)=5r^2BT/RIp where r is the minor radius of the plasma toms, R is the major radius (in m) , BT is the toroidal magnetic field (in T), Ip is the total toroidal current(in MA).  相似文献   
130.
Transient saturation absorption spectroscopy in GaAs thin films was investigated using femtosecond pump and supercontinuum probe technique at excitation densities higher than 1×10^{19}cm^{-3}. The Coulomb enhancement factor of the electron-hole plasma results in a spectrum hole at the pump wavelength. Two distinct transmission peaks at two sides of the pump wavelength are observed, arising from the bleaching of transitions from the heavy- and light-hole bands to the conduction band. The dynamic process of the transient saturation absorption is fitted using a bi-exponential function. The fast decay process is dominated by the carrier-phonon scattering and the slow process may be attributed to the electron-hole recombination.  相似文献   
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