Correspondence Between Oscillations and Emitted Photon Closed-Orbits in Spontaneous Emission Rate of an Atom Near a Dielectric Slab

We study the oscillations in the spontaneous emission rate of an atom near a dielectric slab. The emission rate is calculated as a function of system size using quantum electrodynamics. It exhibits multi-periodic oscillations. Four frequencies of the oscillations are extracted by Fourier transforms. They agree with actions of photon closed-orbits going away and returning to the atom. These oscillations are explained as manifestations of quantum interference effects between the emitted photon wave near the atom and the returning photon waves travelling along various closed-orbits.     

等电聚焦分离与18O稳定同位素标记联用的磷酸化蛋白质组学定量方法研究

磷酸化蛋白质组学定量分析,要对磷酸化修饰富集技术和定量技术进行研究。基于此,本研究采用18O稳定同位素标记技术对胰蛋白酶酶解肽段混合物进行标记,并对其标记时间和标记后胰蛋白酶的变性条件进行优化。结果表明:在pH=4～5的KH2PO4缓冲体系中,37℃,标记反应持续19～24h,除了C-端肽之外,几乎所有的肽段都可达到100%标记;采用TCEP可以有效地抑制16O-18O回标现象。建立了与18O标记技术兼容性良好的IPG-IEF技术对磷酸化肽段进行选择性富集,富集后共从HepG2细胞中鉴定到491个磷酸化位点、362个磷酸化肽段和356个磷酸化蛋白,表明IPG-IEF在大规模磷酸化肽段分离富集中是有效的;最后与高准确度高灵敏度高分辨率的LTQ-FTICR质谱仪联用,建立了基于18O-IPG-IEF-LTQ-FTICR的磷酸化蛋白质组定量技术。实验结果表明,该技术可以实现磷酸化肽段的有效定性和定量。本研究为磷酸化蛋白质组学定量研究提供了实用技术。     

精确确定光路中四分之一波片光轴方位的新方法

为了准确安装四分之一波片,介绍了一种精确确定光路中四分之一波片光轴方位的新方法,并利用米勒矩阵理论分析了影响测量结果的误差因素.测试方法所用的主要理论有米勒矩阵理论、傅里叶分析方法和最小二乘法.该方法利用最小二乘法得到了最优傅里叶系数,利用消光比测试原理实现了检偏棱镜的精确安装,利用反馈环控制系统对步进电机的步进角进行了控制.误差分析表明该方法的测量误差与四分之一波片光轴方位角本身的大小有关.实验结果表明该方法的标准不确定度为0.03.     

Higher-Dimensional KdV Equations and Their Soliton Solutions

A (2+1)-dimensional KdV equation is obtained by use of Hirota method, which possesses N-soliton solution, specially its exact two-soliton solution is presented. By employing a proper algebraic transformation and the Riccati equation, a type of bell-shape soliton solutions are produced via regarding the variable in the Riccati equation as the independent variable. Finally, we extend the above (2+1)-dimensional KdV equation into (3+1)-dimensional equation, the two-soliton solutions are given.     

高斯型空间光孤子相互作用的数值研究

 通过数值模拟的方法,对高斯孤子在对数型饱和非线性介质中的相互作用进行了研究,考查了两光束间的相对振幅和相对相位对其相互作用的影响。结果表明：高斯孤子之间的相互作用敏感地依赖于两光束间的相对振幅和相对相位。在不同的振幅差异范围内,光束间的主要作用交替地表现为相互排斥和相互吸引,并由于高斯孤子的不稳定性,导致了光束在碰撞后以一种尺寸周期性变化的呼吸模式传输。随着相对相位的增大,两光束间始终持续地表现出强烈的排斥作用,直到相对相位增加到一个2π周期之后。而且碰撞之后,光束也都以呼吸模式进行传输,其分离的角度越大,呼吸就越明显。     

A Bregman-Split-Based Compressive Sensing Method for Dynamic Harmonic Estimation

In order to overcome the spectral interference of the conventional Fourier transform in the International Electrotechnical Commission framework, this paper introduces a Bregman-split-based compressive sensing (BSCS) method to estimate the Taylor–Fourier coefficients in a multi-frequency dynamic phasor model. Considering the DDC component estimation, this paper transforms the phasor problem into a compressive sensing model based on the regularity and sparsity of the dynamic harmonic signal distribution. It then derives an optimized hybrid regularization algorithm with the Bregman split method to reconstruct the dynamic phasor estimation. The accuracy of the model was verified by using the cross entropy to measure the distribution differences of values. Composite tests derived from the dynamic phasor test conditions were then used to verify the potentialities of the BSCS method. Simulation results show that the algorithm can alleviate the impact of dynamic signals on phasor estimation and significantly improve the estimation accuracy, which provides a theoretical basis for P-class phasor measurement units (PMUs).     

不同采收期滇龙胆的红外光谱鉴别研究

采收是中药生产的重要环节,采收时间直接影响中药质量和产量,是中医临床安全有效用药的前提,开展中药适时采收期的研究具有重要意义和应用价值。采用傅里叶变换红外光谱法对72份不同采收期的滇龙胆进行鉴别研究,用TQ8.0软件对原始光谱进行一阶导数(first derivative,FD)、二阶导数(second derivative,SD)、标准正态变量(standard normal variate,SNV)、多元散射校正(multiplicative scatter correction,MSC)和平滑(savitaky-golay filter,SG)预处理,样品按3∶1分为校正集和预测集,同时建立主成分分析(principal component analysis,PCA)和偏最小二乘判别分析(partial least square discriminant analysis,PLS-DA)模型。结果显示,选取1 800~600cm~(-1)波段范围的光谱,去除光谱噪音;SNV结合二阶导数光谱和SG(15,3)平滑,预处理结果满意。主成分分析表明,前三个主成分方差贡献率为92.47%,5月、9月和10月份采收的样品差异较小。偏最小二乘判别分析建立判别模型,决定系数R2和校正均方根误差(RMSEE)分别为0.967 8和0.086 0,可对18个预测集样品进行准确分类。红外光谱法结合主成分分析、偏最小二乘判别分析对不同采收期滇龙胆的分类和判别效果较好,为不同采收期的中药鉴别提供理论依据。     

基于快速傅里叶变换和汉克耳变换的逆阿贝尔变换

激光等离子体实验中的轴对称的Ｘ光的体发射强度及光学全息干涉的测量,需要采用逆阿贝尔（Ａｂｅｌ）变换。用快速傅里叶变换（ＦＦＴ）和汉克耳（Ｈａｎｋｅｌ）变换的算法数值求解逆阿贝尔变换,具有精度高、可在频域内滤波的特点。     

高精度非线性格式WCNS的分析研究与其应用

首先将Fourier方法推广于高维方向研究了五阶精度WCNS的特性,并与其他高阶格式进行比较。分析结果表明WCNS的高精度特性普遍接近甚至好于迎风偏置五阶显式格式EUW-5与Pade′标准格式。然后开展了WCNS的应用研究,采用高效率的WCNS-E-5数值模拟了含强激波的高维复杂流场。算例包括二维高超声速边界层对自由流扰动波的吸收问题以及三维球头绕流问题。计算结果反映出WCNS-E-5对激波等间断的良好捕捉能力,图像清晰光滑,数据准确可靠。     

Soliton solution and interaction property for a coupled modified Korteweg-de Vries （mKdV） system

Hirota＇s bilinear direct method is applied to constructing soliton solutions to a special coupled modified Korteweg- de Vries （mKdV） system. Some physical properties such as the spatiotemporal evolution, waveform structure, interactive phenomena of solitons are discussed, especially in the two-soliton case. It is found that different interactive behaviours of solitary waves take place under different parameter conditions of overtaking collision in this system. It is verified that the elastic interaction phenomena exist in this （1＋1）-dimensional integrable coupled model.