A smoothing Newton-type method for generalized nonlinear complementarity problem

By using a new type of smoothing function, we first reformulate the generalized nonlinear complementarity problem over a polyhedral cone as a smoothing system of equations, and then develop a smoothing Newton-type method for solving it. For the proposed method, we obtain its global convergence under milder conditions, and we further establish its local superlinear (quadratic) convergence rate under the BD-regular assumption. Preliminary numerical experiments are also reported in this paper.     

分子动力学模拟和自由能计算研究孕酮和孕酮受体蛋白的结合模式

孕酮在确立和维持妊娠中起到了关键的作用. 为了研究孕酮和孕酮受体蛋白的结合模式，进行了3.5纳秒的分子动力学模拟，用 MM-PBSA\GBSA方法计算了结合自由能. 自由能分解和丙氨酸扫描两种方法说明，残基 Leu718, Met756, Met759, Phe778 和 Tyr890 对于结合抑制剂作用明显，这些残基的主要作用能是范德瓦尔斯作用能. 这一研究结果可以指导孕酮受体蛋白抑制剂的优化     

偏心环形开放台球中粒子逃逸动力学的分形性质

二维台球体系因为能够体现混沌现象的基本特征且数值运算相对简单,从而成为研究微观体系混沌动力学的理想模型,近年来一直广受关注.本文研究非同心的环形开放台球中粒子逃逸的混沌动力学性质,它体现了与初条件密切相关的奇异性.采用简化的盒计数 (box-counting)算法,计算了分形维数,结果定量地反映了粒子逃逸前与环壁碰撞次数随粒子入射角变化的函数关系.其中,特别关注环形台球的偏心率对体系混沌性质的影响.     

化学教学目标设计的反思与对策

教学目标的设计是教学设计的核心内容,教学目标一经确定,就成为教师选择教学策略、安排和组织学习活动以及实施教学评价的重要依据。本文以教学设计的有关理论为指导,结合当前化学教学目标设计中存在的一些现象,对如何理解化学三维目标,依据什么来设计目标,如何设计目标才能更好地发挥对教学过程的导向作用进行了分析和探讨。     

中学化学教科书中实验安全教育内容编排的思考

随着课程改革对化学探究实验的重视,实验安全教育的重要性日益显现。通过对我国现行3个版本义务教育初中化学课程标准实验教科书及美国初中主流化学教科书《化学反应》中的化学实验安全教育内容的比较研究,发现我国教科书中实验安全教育内容相对薄弱。建议以教科书为载体显化实验安全教育内容、教科书中增加实验安全标志、处理好安全教育与主动探究的关系,把安全作为实验评价指标,充分发挥评价的导向功能。     

烯/炔基有机共轭分子双光子吸收特性的理论研究-溶剂效应

The present work concerns the study of solvent effects on the geometrical structures, as well as one- and two-photon absorption (TPA) processes, for two series of alkyne and alkene π-bridging molecules, within the framework of the polarization continuum model. Particular emphasis was put on the characterization of solvent effects on the molecular geometrical structures and geometric distortion, which were measured by the bond-length-alternation parameter. The π centres in the compounds are seen to play a decisive role in increasing the TPA cross section and nonlinear optical properties. All studied molecules have relatively strong TPA characteristics, while the alkyne π-bridging ones yield larger TPA cross sections.     

A new nanobiosensor for glucose with high sensitivity and selectivity in serum based on fluorescence resonance Energy transfer (FRET) between CdTe quantum dots and Au nanoparticles

A novel assembled nanobiosensor QDs-ConA-beta-CDs-AuNPs was designed for the direct determination of glucose in serum with high sensitivity and selectivity. The sensing approach is based on fluorescence resonance energy transfer (FRET) between CdTe quantum dots (QDs) as an energy donor and gold nanoparticles (AuNPs) as an energy acceptor. The specific combination of concanavalin A (ConA)-conjugated QDs and thiolated beta-cyclodextrins (beta-SH-CDs)-modified AuNPs assembles a hyperefficient FRET nanobiosensor. In the presence of glucose, the AuNPs-beta-CDs segment of the nanobiosensor is displaced by glucose which competes with beta-CDs on the binding sites of ConA, resulting in the fluorescence recovery of the quenched QDs. Experimental results show that the increase in fluorescence intensity is proportional to the concentration of glucose within the range of 0.10-50 muM under the optimized experimental conditions. In addition, the nanobiosensor has high sensitivity with a detection limit as low as 50 nM, and has excellent selectivity for glucose over other sugars and most biological species present in serum. The nanobiosensor was applied directly to determine glucose in normal adult human serum, and the recovery and precision of the method were satisfactory. The unique combination of high sensitivity and good selectivity of this biosensor indicates its potential for the clinical determination of glucose directly and simply in serum, and provides the possibility to detect low levels of glucose in single cells or bacterial cultures. Moreover, the designed nanobiosensor achieves direct detection in biological samples, suggesting the use of nanobiotechnology-based assembled sensors for direct analytical applications in vivo or in vitro.     

Experimental and theoretical studies on bis[<Emphasis Type="Italic">μ</Emphasis>-2-methoxy-<Emphasis Type="Italic">N</Emphasis>′-(2-oxidobenzoyl)benzohydrazidato(3-)]dipyridinetricopper(II)

A novel homotrinuclear pyridine Schiff base copper(II) compound, [Cu₃(C₁₅H₁₁N₂O₄)₂(C₅H₅N)₂], has been synthesized and characterized by elemental analysis and X-ray single crystal deterimination. X-ray structural determination reveals that each copper(II) ion has a distorted square-planar geometry. The central copper ion is coordinated by two O and two N atoms from two Schiff base ligands, while each terminal copper ion is coordinated by one N and two O atoms of one Schiff base ligand and by one N atom of a pyridine molecule. Density funcational theory (DFT) method calculations of the structure, atomic charges distribution and natural bond orbital (NBO) analyses have been performed. The coordinate stabilization energies show that the trinuclear copper(II) compound is very stable.     

Recurrence spectra and dynamical simulation of Rydberg hydrogen atom near a metal surface

By using the closed-orbit theory including the effect of Coulomb scattering together with an electrical image potential approach, the recurrence spectra and the dynamical behaviours of the Rydberg hydrogen atom near a metal surface are presented. Theoretical analysis and numerical simulation reveal that the impacts of the image potential contributing to the recurrence spectrum are qualitatively analogous to that of the parallel electrical and magnetic fields on the Rydberg atom. The recurrence spectra are computed for a few selected scaled energies and the results demonstrate that the scaled energy dominates the dynamical properties of system. With the increase of the scaled energy e from small to large, the whole trend of spectral structure is from simple to complex,and then simple.     

Optical waveguides in LiNbO<Subscript>3</Subscript> and stoichiometric LiNbO<Subscript>3</Subscript> crystals by proton exchange

The formation of optical planar waveguides in LiNbO₃ and stoichiometric LiNbO₃ crystals by proton exchange was reported. The prism-coupling method was used to characterize the dark-line spectroscopy at the wavelength of 633 and 1539 nm, respectively. The mode optical near-field outputs from proton-exchanged LiNbO₃ and SLN waveguides at 633 nm were presented. The mode field from stoichiometric LiNbO₃ (SLN) waveguide is lighter and more uniform than that from LiNbO₃ waveguide, which means the quality of the waveguide in SLN crystal is better than that of the LiNbO₃ waveguide. For proton-exchanged LiNbO₃ waveguides, the evolution of the refractive index profile with annealing was presented. The disorder profiles of Nb atoms in proton-exchanged LiNbO₃ waveguides were obtained by Rutherford backscattering/channeling technique. It is shown that the longer the exchange time, the larger the displacement of Nb atoms. Supported by the National Natural Science Foundation of China (Grant No. 10475052) and the Scientific Research Start-up Financing of Qufu Normal University