Characteristics of Raman spectra of natural clinochlore at 200 degrees C and 0.95-7.70 GPa

Variation of crystal structure of natural clinochlore with pressure was investigated by the approach of diamond anvil cell (DAC) and in situ micro-Raman spectroscopic measurement at 200 degrees C and up to 7.7 GPa. The 481 and 786 cm(-1) peaks shift towards high-frequency linearly with increasing pressure at 200 degrees C. The linear relations between Raman shift (N, cm(-1)) and pressure (P, GPa) for the two peaks are: N = 11.136P+482.6 (R2 = 0.987 4) and N = 5.055P+785.7 (R2 = 0.983 7), respectively. The 865 cm(-1) peak arising from the stretching mode of the Si-O(nb) shifts slightly because of the strong repulsion between T cations at the tetrahedral sites and M cations at the octahedral sites in the TOT layer. Raman shift of 481 cm(-1) and 786 means the shortening of the length of M-O(br) and Si-CO(br) bonds since the peaks are contributed by the stretching mode of the M-O(br) and Si-O(br) respectively. No phase transition of clinochlore under the experimental condition was found. The results indicate that chlorite minerals may be stable at least at a depth of 80-90 km in the cold subduction zones, and the fluid derived from chlorite dehydration may be an important fact for earthquake occurrence in the subduction zones.     

四种新型仲胺配合物的合成、表征及与ct-DNA相互作用的光谱研究

合成了新型仲胺类配体L(N,N’-二(4-甲基苄基)乙二胺)及其四种过渡金属的硝酸盐配合物,[ML2(H2O)2]2+.2NO3-(M=CuⅡ,CoⅡ,NiⅡ,ZnⅡ),利用元素分析、红外、1H NMR等对其结构进行了表征,其中用X-ray单晶衍射解析了Cu-L单晶结构,为波谱分析推测的分子结构进行了验证。通过紫外、荧光光谱研究了该四种金属配合物与小牛胸腺DNA的相互作用,结果表明配合物与DNA的作用方式均为静电结合,Cu-L,Co-L,Ni-L,Zn-L与DNA的结合常数分别为:1.67×103,2.5×103,1.35×103和9.85×102。     

The geometric phase of the quantum systems with slow but finite rate of the external time-dependent field

With the help of the time-dependent gauge transformation technique, we have studied the geometric phase of a spin-half particle in a rotating magnetic field. We have found that the slow but finite frequency of the rotating magnetic field will make the difference between the adiabatic geometric phase and the exact geometric phase. When the frequency is much smaller than the energy space and the adiabatic condition is perfectly guaranteed, the adiabatic approximation geometric phase is exactly consistent with the adiabatic geometric phase. A simple relation for the accuracy of the adiabatic approximation is given in terms of the changing rate of the frequency of the rotating magnetic field and the energy level space.     

直接荧光法和流动注射荧光法测定微量氨的研究

在碱性介质中 ,基于氨与邻苯二甲醛及 2 巯基乙醇反应生成强荧光性吲哚取代衍生物的体系建立测定水溶液中微量氨的直接荧光法和流动注射荧光法。曲通X 10 0 (TritonX 10 0 )对该体系具有良好的增稳作用。在λex=4 15nm ,λem=4 86nm下 ,用直接荧光法测定NH3含量在 0 2～ 1 0 μg·mL- 1 范围内 ,工作曲线的回归方程为ΔI =2 2 2 86 785 71cNH3(μg·mL- 1 ) (I即为Intensity) ,r=0 9995 ;NH3含量在 0 0 2～ 0 10 μg·mL- 1 范围内 ,工作曲线的回归方程为ΔI=- 2 7 4 2 9 2 371 4cNH3(μg·mL- 1 ) ,r=0 996 5。用流动注射法测定的工作曲线的回归方程为ΔI=1188cNH3(μg·mL- 1 ) ,r=0 9998,线性范围为 0～ 0 7μg·mL- 1 ,并对反应机理进行初步探讨。     

Facile controlled synthesis of micro/nanostructure MCrO4 (M = Ba, Pb) by using Gemini surfactant C12-PEG-C12 as a soft template

Gemini surfactants, double sodium α-sulfonic polyethylene glycol laurate (abbreviated C₁₂-PEG-C₁₂), were prepared and applied as soft templates in the controlled synthesis of BaCrO₄ and PbCrO₄ micro/nanocrystals. The template effects were investigated by adjusting the length of the spacer, using PEG400 and PEG4000, of the Gemini surfactant. The results indicated that the size and morphology of BaCrO₄ and PbCrO₄ micro/nanocrystals varied with the change in spacer length of C₁₂-PEG-C₁₂, suggesting that the different lengths of the polyethylene glycol group spacers in the Gemini surfactants played a key role in determining the size and shape of the MCrO₄ micro/nanoparticles. The dynamic process of the formation of the novel morphology BaCrO₄ crystals showed that the morphology grew from a round-bar polyhedron, to regular polyhedron, to approximate octahedron to a uniform pistachio nut shape. The growth mechanism of the BaCrO₄ micro/nanocrystals was explained that C₁₂-PEG-C₁₂ had a greater interfacial adsorption and would effectively control the shape evolution during the crystal growth, while PbCrO₄ could be explained that the Gemini surfactants can undergo liquid-crystalline phase transitions with long channels providing a soft template effect and derived the nanorods formation. Room temperature fluorescence spectra were studied and these showed that the pistachio-shaped BaCrO₄ microcrystals and PbCrO₄ nanorods possess photoactive luminescence properties with emission peaks at 470 and 549 nm, respectively.     

Fluorescent Triphenyl Substituted Maleimide Derivatives: Synthesis,Spectroscopy and Quantum Chemical Calculations

In this paper we describe a semi-empirical quantum method for predicting the wavelength of maximum fluorescence excitation and emission for several known and new maleimide derivatives. All new maleimides, containing a N-Benzyl attachment, were successfully synthesised via a tandem Suzuki reaction with aryl boronic acids containing either an electron donating, electron withdrawing functional groups. Absorption and emission spectra calculated using the semi-empirical AM1 method with excited state ZINDO calculations proved more reliable than either Hartree-Fock Configuration interaction or time dependent density functional methods. Calculated absorption and emission wavelengths were compared with 26 experimental spectra from known or newly synthesised maleimides and found to have provide reasonable predictions, with an average deviation of less the 6% for absorption maxima and less than 4% for emission peaks. The described method provides a strong benchmark for the accuracy that can be expected from theoretical predictions of fluorescence spectra.     

On the synchronization of a hyperchaotic system based on adaptive method

This Letter researches the adaptive synchronization of a hyperchaotic system. Based on Lyapunov method, a general adaptive method via a driving vector and an original adaptive method via a single driving variable are presented to achieve the chaos synchronization. Especially, the latter makes the structure of adaptive controller simple and has more practical value compared with the former. Some typical numerical examples are included to demonstrate the effectiveness of the method proposed.     

Soliton switching and propagation in two-core nonlinear fiber coupler with high order coupling coefficient

We use the variational approach (VA) and the split-step Fourier transforms (SSFT) to study the transmission and switching characteristics inside the fiber nonlinear directional coupler (NDLC). The results, based on the VA, indicate that the second-order coupling coefficient dispersion and initiative chirp all reduce the coupling length, and the second-order coupling coefficient dispersion makes the switching characteristics become sharper and threshold power become bigger under the case of not having initiative chirp. The outcomes, based on the SSFT, indicate that the first order intermodal dispersion coefficient make optical pulses splitting in the propagation of fundamental solitons, and the second-order coupling coefficient dispersion reduces the coupling length, sharpens the switching characteristics and increases the switching threshold power, the results agrees well with those from the VA.     

Multi-objective optimization of inverse planning for accurate radiotherapy

The multi-objective optimization of inverse planning based on the Pareto solution set, according to the multi-objective character of inverse planning in accurate radiotherapy, was studied in this paper. Firstly,the clinical requirements of a treatment plan were transformed into a multi-objective optimization problem with multiple constraints. Then, the fast and elitist multi-objective Non-dominated Sorting Genetic Algorithm (NSGA-Ⅱ)was introduced to optimize the problem. A clinical example was tested using this method. The results show that an obtained set of non-dominated solutions were uniformly distributed and the corresponding dose distribution of each solution not only approached the expected dose distribution, but also met the dosevolume constraints. It was indicated that the clinical requirements were better satisfied using the method and the planner could select the optimal treatment plan from the non-dominated solution set.     

PERTURBATION FINITE ELEMENT METHOD FOR SOLVING GEOMETRICALLY NONLINEAR PROBLEMS OF AXISYMMETRICAL SHELL

In analysing the geometrically nonlinear problem of an axisymmetrical thin-walled shell, the paper combines the perturbation method with the finite element method by introducing the former into the variational equation to obtain a series of linear equations of different orders and then solving the equations with the latter. It is well-known that the finite element method can be used to deal with difficult problems as in the case of structures with complicated shapes or boundary conditions, and the perturbation method can change the nonlinear problems into linear ones. Evidently the combination of the two methods will give an efficient solution to many difficult nonlinear problems and clear away some obstacles resulted from using any of the two methods solely. The paper derives all the formulas concerning an axisym-metric shell of large deformation by means of the perturbation finite element method and gives two numerical examples,the results of which show good convergence characteristics.