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61.
The quest for higher peak focused intensities and better temporal contrast drives one to improve the design of all possible stages of the chirped pulse amplification (CPA) system. In this paper, we have analyzed the role of dispersion and spectral profile on the temporal shape and contrast ratio of the output pulse of a CPA system. The simulations indicate that an initial sech2 or a Gaussian pulse in the CPA system is best for a good contrast ratio. Incorporating a four-grating based pulse compressor in the CPA system improves the contrast as well as provides the flexibility to compensate the dispersion upto the fourth order. The simulations also detail the effect of spectral profile tailoring on the contrast ratio and peak power. 相似文献
62.
63.
基于Hanbury Brown-Twiss(HBT)实验,我们借助于两个单光子计数模块,一个50/50分束器和一个快速计数卡(FastCom-P7888)研究了不同光场的二阶相干度。我们首先制备了脉冲相干光,连续相干光以及单原子发出的单光子源,并测量这几种不同光场的二阶相干度g(2)(τ)。我们通过测量俘获在磁光阱(MOT)和远失谐偶极阱(FORT)中的单原子在近共振连续激光激发下所辐射的荧光的二阶相干度,分别得到了g(2)(τ=0)=0.08和g(2)(τ=0)=0.09,借助于实验中产生的脉冲光与单原子,接下来我们将进行触发式单光子源的实验研究。 相似文献
64.
《Analytical letters》2012,45(16):1311-1325
Abstract Electrochemical caracteristics of 2-mercaptopyridine-5-carboxylic acid and its methylic ester have been determined using recent polarographic techniques. Measurements have been carried out as a function of parameters such as frequency, others surimposed signals and as a function of concentration and pH. Results are compared to those obtained for selectively methylated on sulfur or nitrogen atoms derivatives. Interpretations of the data are given. The optimal conditions for a quantitative determination by D.C. and differential pulse polarography are fixed. 相似文献
65.
We study the propagation of anisotropic sound and shock waves in dipolar Bose-Einstein condensate in three dimensions (3D) as well as in quasi-two (2D, disk shape) and quasi-one (1D, cigar shape) dimensions using the mean-field approach. In 3D, the propagation of sound and shock waves are distinct in directions parallel and perpendicular to dipole axis with the appearance of instability above a critical value corresponding to attraction. Similar instability appears in 1D and not in 2D. The numerical anisotropic Mach angle agrees with theoretical prediction. The numerical sound velocity in all cases agrees with that calculated from Bogoliubov theory. A movie of the anisotropic wave propagation in a dipolar condensate is made available as supplementary material. 相似文献
66.
《Analytical letters》2012,45(9):1683-1698
For the first time, a simple differential pulse voltammetry methodology for direct determination of benserazide in presence of levodopa in tablets was developed without any redox mediator, modified electrodes, or the aplication of mathematic deconvolution of signals. Benserazide was studied by differential pulse voltammetry using glassy carbon electrode in aqueous media. The drug exhibited a main well-defined oxidation signal in a broad pH range (2–10), and two poorly resolved signals at higher potentials. We have found that levodopa does not interfere on the electrochemical response of benserazide at pH 6.0. Thus, at this pH value, the developed analytical method exhibited adequate repeatability and reproducibility (RSD < 2%), recoveries >98.5%, which permitted its successful application to both the assay and the uniformity content of benserazide. Also, hydrolytic degradation studies of benserazide were carried out by differential pulse voltammetry. 相似文献
67.
Saied Saeed Hosseiny Davarani Hamid Reza Moazami Ali Reza Keshtkar Mohammad Hossein Banitaba Saeed Nojavan 《Analytica chimica acta》2013
A novel method for the selective electromembrane extraction (EME) of U6+ prior to fluorometric determination has been proposed. The effect of extraction conditions including supported liquid membrane (SLM) composition, extraction time and extraction voltage were investigated. An SLM composition of 1% di-2-ethyl hexyl phosphonic acid in nitrophenyl octyl ether (NPOE) showed good selectivity, recovery and enrichment factor. The best performance was achieved at an extraction potential of 80 volts and an extraction time of 14 minutes Under the optimized conditions, a linear range from 1 to 1000 ng mL−1 and LOD of 0.1 ng mL−1 were obtained for the determination of U6+. The EME method showed good performance in sample cleanup and the reduction of the interfering effects of Mn2+, Zn2+, Cd2+, Ni2+, Fe3+, Co2+, Cu2+, Cl− and PO43− ions during fluorometric determination of uranium in real water samples. The recoveries above 54% and enrichment factors above 64.7 were obtained by the proposed method for real sample analysis. 相似文献
68.
69.
In this paper, we investigate a generalized nonautonomous nonlinear equation which describes the ultrashort optical pulse propagating in a nonlinear inhomogeneous fiber. By virtue of the generalized Darboux transformation, the first- and second-order rogue-wave solutions for the generalized nonautonomous nonlinear equation are obtained, under some variable–coefficient constraints. Properties of the first- and second-order rogue waves are graphically presented and analyzed: When the coefficients are all chosen as the constants, we can observe the some functions, the shapes of wave crests and troughs for the first- and second-order rogue waves change. Oscillating behaviors of the first- and second-order rogue waves are observed when the coefficients are the trigonometric functions. 相似文献
70.
刘宝林 《原子与分子物理学报》2015,32(6):119-124
运用数学解析法导出了关于拉曼增益与自陡峭综合效应的光脉冲传输方程,在此基础上引入洛伦兹模型将拉曼增益整合到非线性系数中来研究光脉冲中拉曼增益对自陡峭效应的作用,重点分析了高斯脉冲在各向同性光纤中传播时,拉曼增益对其自陡峭效应具体影响方式,结果表明拉曼增益会减弱自陡峭中后沿偏移程度,减小脉冲展宽,但不会影响其峰值大小. 相似文献