丁二酰化壳寡糖镧配合物的合成及与牛血清白蛋白的相互作用

运用紫外和荧光光谱研究丁二酰化壳寡糖镧配合物与牛血清白蛋白(BSA)的相互作用.结果表明:随稀土配合物浓度的增加,BSA的紫外光谱表现增色效应并伴有蓝移;稀土配合物可有规律地猝灭BSA的内源荧光,猝灭方式为静态猝灭,并计算了结合常数和结合位点数.     

杜康酒香气成分的GC/MS分析

采用液液萃取法提取杜康酒中的香气成分,通过气相色谱-质谱联用(GC-MS)技术对杜康酒中的香气成分进行分析鉴定,共检测到了39种香气成分.其中酯类22种,酸类8种,醇类6种,烷类物质2种.含量较高的物质有己酸乙酯、乳酸乙酯、已酸、乙酸、丁酸乙酯等物质,     

Origin对物理实验数据处理重要性的分析

与传统的数据处理方法相比,利用Origin数据分析软件不仅能够得到精确的结果,而且能有效减小实验误差,提高物理实验教学的效果。     

Evolution of geometrical structures,stabilities and electronic properties of neutral and anionic Li n Cu λ (n = 1–9, λ = 0, −1) clusters: compare with pure lithium clusters

The structural evolution, stabilities, and electronic properties of copper-doped lithium Li _n Cu^λ (n?=?1–9, λ?=?0, ?1) clusters have been systematically investigated using a density functional method at PW91PW91 level. Extensive searches for ground-state structures were carried out, and the results showed the copper tends to occupy the most highly coordinated position and form the largest probable number of bonds with lithium atoms. By calculating the binding energies per atom, fragmentation energies and the HOMO-LOMO gaps, we found LiCu, Li₇Cu, LiCu^?, Li₂Cu^? and Li₈Cu^? clusters have the stronger relative stability and enhanced chemical stability. The content and pattern of frontier MOs for the most stable doped isomers were analysed to investigate the bond nature of interaction among Li and Cu atoms. The results show some σ-type and π-type bonds are formed among them, and with small admixture of the Cu d characters. To achieve a deep insight into the electron localization and reliable electronic structure information, the natural population analysis and electron localization function were performed and discussed.     

SOI多环级联光学谐振腔滤波器

利用MEMS工艺制备了基于SOI的小尺寸、高集成光波导多环级联谐振腔滤波器,理论分析了多环级联微环腔的光场传输特性与光谱响应特性,实验验证并得到了不同级联环数与谐振谱线滚降垂直度的关系。研究表明:当波导宽度为450 nm、半径为5μm时,单环、双环和十环滤波器响应谱线的-3 dB带宽分别为0.313,0.279,0.239 nm,相应结果与理论吻合,即随着级联环数的增多,谐振谱线顶端趋于平坦,滚降垂直度增高。设计制备了环形与跑道形两种级联谐振腔滤波器,研究了相应的透射谱特性。     

Isotopic mass effects for low-energy channeling in a silicon crystal

Monte Carlo (MC) simulations have been used to study the low-energy channeling of ¹⁰B and ¹¹B ions along the [100] axis in Si crystal. MC simulations show that the critical angle Ψ_C ≈ 15.3(keV/E)^1/2 (in degrees) for the channeling of isotopic ¹⁰B ions and Ψ_C=14.5(keV/E)^1/2 (in degrees) for the channeling of isotopic ¹¹B ions, where E is the incident energy. This means that (Ψ_{C for 10B ions}/Ψ_{C for 11B ions})≈ (15.3/14.5)≈ (11/10)^1/2.     

一种修正的拟Grünwald插值在Orlicz空间内的逼近度

修正了以第二类Chebyshev多项式的零点为插值结点组的拟Grünwald插值多项式,使之转化为积分形式,并利用不等式技巧和Hardy-Littlewood极大函数的方法,研究了此积分型拟Grünwald插值算子在带权Orlicz空间内的逼近问题,得出了意义相对广泛的逼近度估计的结果.     

No Spin-Localization Phase Transition in the Spin-Boson Model without Local Field

We explore the spin-boson model in a special case, i.e., with zero local field. In contrast to previous studies, we find no possibility for quantum phase transition （QPT） happening between the localized and delocalized phases, and the behavior of the model can be fully characterized by the even or odd parity as well as the parity breaking, instead of the QPT, owned by the ground state of the system. The parity breaking mentioned in our case is completely different from the spontaneously broken symmetry relevant to the conventionally defined QPT in previous studies. Our analytical treatment about the eigensolution of the ground state of the model presents for the first time a rigorous proof of no- degeneracy for the ground state of the model, which is independent of the bath type, the degrees of freedom of the bath and the calculation precision. We argue that the QPT mentioned previously appears due to incorrect employment of the ground state of the model and/or unreasonable treatment of the infrared divergence existing in the spectral functions for Ohmic and sub-Ohmic dissipations.     

Use of simulated infrared spectra to test N2-Ar pair potentials and dipole moment surfaces

Infrared spectra of the ¹⁴N₂-Ar van der Waals complex have been simulated by performing exact quantum mechanical calculations using two recent potential energy surfaces, one having a modified Morse-Morse-spline-van der Waals form and the other an exchange-Coulomb (XC) modelform. Frequencies and intensities have been calculated for some 10⁵ spectral transitions amongst the bound states of the complex, and simulations of the mid-infrared (2290-2370 cm^-1) spectrum of the complex at 77 K constructed from superpositions of lines, each of which has been assigned a Lorentzian lineshape with a linewidth appropriate to the experimental conditions. The roles of the various terms in the effective dipole moment surface proposed by Ayllon et al. (1990, Molecular Physics, 71, 1043) have also been examined, and a modification made which yields improved agreement with the experimental mid-infrared spectrum obtained by McKellar (1988, Journal of Chemical Physics, 88, 4190). Based upon the present calculations, the 48 most intense bands of the simulated spectrum of the ¹⁴N₂-Ar van der Waals complex have been given vibrational assignments. The spectrum simulated from the modified Morse-type potential surface, when employed together with the present modified dipole moment surface, shows distinctly better agreement with experiment than does the spectrum simulated from either the XC or the earlier empirical potential energy surface. Far-infrared spectra have also been simulated at 5 K and at 77 K using an appropriate effective dipole surface, and compared with the calculation of Ayllon et al.     

具有n个小时滞脉冲系统的周期解

本文考虑有n个小时滞的脉冲系统,利用隐函数存在性定理证明了该系统时滞 充分小时,系统的周期解存在性,推广了已有的相关结论.