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双束分步激光光解方法的建立及应用
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作者 蔡喜臣 韩镇辉 +1 位作者 姚思德 林念芸 《辐射研究与辐射工艺学报》 CAS CSCD 北大核心 2002年第3期166-170,共5页
建立了双束激光激发分子的方法 ,即通过第一束激光把分子激发到激发三线态 ,以第二束共振激光再把三线态分子激发到更高的激发态 ,甚至使其电离的方法。利用这种研究方法对二苯甲酮分子进行了研究 ,结果发现 ,高激发三线态的二苯甲酮分... 建立了双束激光激发分子的方法 ,即通过第一束激光把分子激发到激发三线态 ,以第二束共振激光再把三线态分子激发到更高的激发态 ,甚至使其电离的方法。利用这种研究方法对二苯甲酮分子进行了研究 ,结果发现 ,高激发三线态的二苯甲酮分子与异丙醇分子进行的抽氢反应要比低激发三线态分子快得多 ,这为研究处于高激发态分子的电子转移反应提供了新的途径。同时 。 展开更多
关键词 双束分步激光光解方法 激发三线态 二苯甲酮 电子转移 激光分子
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高效薄层析进行农药吸附态光解的研究 被引量:8
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作者 岳永德 《环境科学》 CAS CSSCI CSCD 北大核心 1995年第4期16-18,66,共4页
研究了绿麦隆和消草醚2种除草剂在硅胶G高效薄层上的光稳定性,提出应用高效薄层析技术作为农药吸附态光解的一种试验方法。在高效薄层上直接点样,同一薄层上包括照光、黑暗对照和定量曲线样品,原始剂量400—800ng·1&... 研究了绿麦隆和消草醚2种除草剂在硅胶G高效薄层上的光稳定性,提出应用高效薄层析技术作为农药吸附态光解的一种试验方法。在高效薄层上直接点样,同一薄层上包括照光、黑暗对照和定量曲线样品,原始剂量400—800ng·1×5mm斑点-1,照光后直接展开和扫描定量测定,最低检测量可达20ng·斑点-1。本方法无须对样品进行提取、净化等处理,具有快速高效、重复性好,且可直观光解产物等优点。 展开更多
关键词 高效薄层析 农药 光解方法 吸附
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探索更短的时间
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《发现.图形科普》 2001年第4期42-42,共1页
关键词 化学反应 过渡态 毫秒时间尺度 闪光光解方法 微秒时间尺度 分子运动 光脉冲
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Linearity optimization of edge filter demodulators in FBG_s 被引量:2
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作者 LI Dong-sheng SUI Qing-mei CAO Yu-qiang 《Optoelectronics Letters》 EI 2008年第3期193-195,共3页
A kind of electric circuit is improved to optimize the linearity of edge filter demodulators in FBG .By using a logarithm amplifier and an extraction operation, the linear range of optimized edge filter demodulators h... A kind of electric circuit is improved to optimize the linearity of edge filter demodulators in FBG .By using a logarithm amplifier and an extraction operation, the linear range of optimized edge filter demodulators has been broadened effectively, and the requirement of optical filter's linear range has been reduced. Theoretical analyses and the simulation results indi-cated that the linear range of optimized edge fdter demodulator's covers the whole transition region of the edge filter, while a strict linearity of the optical filter is not necessary. 展开更多
关键词 光纤 解调器 线性分析 分析方法
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Soliton Solutions for Nonisospectral AKNS Equation by Hirota's Method 被引量:1
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作者 BI Jin-Bo SUN Ye-Peng CHEN Deng-Yuan 《Communications in Theoretical Physics》 SCIE CAS CSCD 2006年第3期398-400,共3页
Bilinear form of the nonisospectral AKNS equation is given. The N-soliton solutions are obtained through Hirota's method.
关键词 nonisospectral AKNS equation soliton solutions Hirota's method
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N-Soliton Solutions of(2+1)-Dimensional Non-isospectral AKNS System
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作者 ZHANG Xiao-Xian SUN Ye-Peng 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第11期1181-1184,共4页
The bilinear form of the (2+1)-dimensional non-isospectral AKNS system is derived. Its N-soliton solutions are obtained by using the Hirota method. As a reduction, a (2+1)-dimensional non-isospectral Schrodinger... The bilinear form of the (2+1)-dimensional non-isospectral AKNS system is derived. Its N-soliton solutions are obtained by using the Hirota method. As a reduction, a (2+1)-dimensional non-isospectral Schrodinger equation and its N-soliton solutions are constructed. 展开更多
关键词 non-isospectral AKNS system Hirota method N-soliton solution non-isospectral Schrodinger equation
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Pseudo-spectral Approximations for a Class of the Kdv-Burgers Type Equation
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作者 ZHANGRui-feng YANGHui 《Chinese Quarterly Journal of Mathematics》 CSCD 2004年第3期267-272,共6页
In this paper, the pseudo-spectral approximations for a class of the Kdv-Burgers type equation is presented. Convergence and stability of the approximation have been proved by Sobolev's inequalities and the bounde... In this paper, the pseudo-spectral approximations for a class of the Kdv-Burgers type equation is presented. Convergence and stability of the approximation have been proved by Sobolev's inequalities and the bounded extensive method of the nonlinear function. Finally, the numerical examples are proposed. 展开更多
关键词 Kdv-Burgers equation pseudo-spectral scheme numerical experiments
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Decomposition Method for Complex 3D Problems in Electron Optics
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作者 Valentin Ivanov 《Journal of Physical Science and Application》 2015年第2期96-100,共5页
The decomposition method was successfully used in solving of 3D problems with complex geometry shape in electron optics for the FDM (Finite Difference Method) and FEM (Finite Element Method) mostly to implement fa... The decomposition method was successfully used in solving of 3D problems with complex geometry shape in electron optics for the FDM (Finite Difference Method) and FEM (Finite Element Method) mostly to implement fast and robust parallel algorithms and computer codes. We suggest a new version of similar approach for the BEM (Boundary Element Method) based on the alternating method by Schwartz. This approach substantially reduce the dimension of dense global matrix of algebraic system produced by BEM algorithm to solve a complex problem on as single CPU (Central Processor Unit) desktop computer. New algorithm is iterative one, but exponential convergence for the Schwatlz's algorithm creates the fast numerical procedures. We describe the results of numerical simulation for a multi electrode ion transport system. The algorithms were implemented in the computer code "POISSON-3". 展开更多
关键词 Electron optics decomposition method numerical-analytical technique boundary element method.
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Photolysis and Rate Constant of 2,3-butanedione with OH Radicals in the Aqueous Phase under Tropospheric Conditions
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作者 L. E1 Maimouni A. Ait Taleb A. E1 Hammadi 《Journal of Environmental Science and Engineering》 2011年第4期440-445,共6页
Photolysis rate (J1) and reaction rate constants (kl) for the biacetyl (butane-2,3-dione) were evaluated in aqueous phase using a continuous photolysis system with a conventional Xe-Hg arc lamp as a light source... Photolysis rate (J1) and reaction rate constants (kl) for the biacetyl (butane-2,3-dione) were evaluated in aqueous phase using a continuous photolysis system with a conventional Xe-Hg arc lamp as a light source. The OH radicals was generated by H2OE/UV process and biacetyl (CH3C(O)C(O)CH3) concentrations were monitored using 2,4-DNPH derivatization method. 2,3-butanedione molecule is widely present in the atmosphere, it have been detected in hydrometeors (fogs, rain, and clouds) and at a significant yield (up to 10μmolar). The measurements were performed at 294 K and with free pH values. Our results lead to the following obtained values: J1= 3×10^-4 S^-1 and k1 = (6.17±0.95)×10^8 M^-1·s^-1.The uncertainty listed above is ±15%. 展开更多
关键词 PHOTOLYSIS OH radicals 2 3-butanedione atmospheric photochemistry
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A second order finite difference-spectral method for space fractional diffusion equations 被引量:4
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作者 HUANG JianFei NIE NingMing TANG YiFa 《Science China Mathematics》 SCIE 2014年第6期1303-1317,共15页
A high order finite difference-spectral method is derived for solving space fractional diffusion equations,by combining the second order finite difference method in time and the spectral Galerkin method in space.The s... A high order finite difference-spectral method is derived for solving space fractional diffusion equations,by combining the second order finite difference method in time and the spectral Galerkin method in space.The stability and error estimates of the temporal semidiscrete scheme are rigorously discussed,and the convergence order of the proposed method is proved to be O(τ2+Nα-m)in L2-norm,whereτ,N,αand m are the time step size,polynomial degree,fractional derivative index and regularity of the exact solution,respectively.Numerical experiments are carried out to demonstrate the theoretical analysis. 展开更多
关键词 space fractional diffusion equation Crank-Nicolson scheme spectral method STABILITY conver-gence
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The Expansion of a Wedge of Gas into Vacuum with Small Angle in Two-Dimensional Isothermal Flow 被引量:1
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作者 Ju GE Wancheng SHENG 《Chinese Annals of Mathematics,Series B》 SCIE CSCD 2016年第3期395-404,共10页
In this paper, the authors consider the expansion problem of a wedge of gas into vacuum for the two-dimensional Euler equations in isothermal flow. By the bootstrapping argument, they prove the global existence of the... In this paper, the authors consider the expansion problem of a wedge of gas into vacuum for the two-dimensional Euler equations in isothermal flow. By the bootstrapping argument, they prove the global existence of the smooth solution through the direct method in the case 0 〈 θ 〈 -θ=arctan 1/(√2+√5), where θ is the half angle of the wedge. Furthermore, they get the uniform C^1,1 estimates of the solution to the expansion problem. 展开更多
关键词 Hyperbolic partial differential equation 2D Riemann problem Rarefaction wave Isothermal flow
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Direct visualization of the charge transfer in conjugated polymers 被引量:1
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作者 LI Yan LI YuanZuo +1 位作者 DONG Bin YANG ZhiLin 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2011年第6期1119-1123,共5页
Ion-induced charge-transfer states in conjugated polyelectrolytes were experimentally investigated by Justin M.Hodgkiss and his co-workers [J Am Chem Soc,2009,131(25):8913].In this work,charged and neutral conjugated ... Ion-induced charge-transfer states in conjugated polyelectrolytes were experimentally investigated by Justin M.Hodgkiss and his co-workers [J Am Chem Soc,2009,131(25):8913].In this work,charged and neutral conjugated polyelectrolytes were further studied with quantum chemistry methods.The calculation result shows that the absorption spectra are roughly in visible and ultraviolet light regions,and the two absorption peaks are located in the wavelength span 300-400 nm for charged polyelectrolytes.However,in neutral conjugated polyelectrolytes,the peaks of the absorption spectra showed a blue shift compared with those of the charged polyelectrolytes.Charge transfer (CT) properties of the studied compounds were also investigated with both the three-dimensional real-space analysis method of transition and charge difference densities,and the two-dimensional real-space analysis method of transition density matrices based on the simulated absorption spectra.The calculation results revealed the charge transfer in conjugated polyelectrolytes on the excitation states. 展开更多
关键词 conjugated polyelectrolytes charger transfer charge difference density
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