FELWI—自由电子激光的一个新方向

30多年前Stanford大学的博土生J.M.Madey提出～([1])自由电子激光(FEL),时至今日这一直是一个不断取得重要进展～([2])的科学领域。由短波长(高增益)自由电子激光途径发展第四代光源又是该领域最重要的方向,在分子环境科学、分子反应动力学、纳米科技和生命科学等许多科学和技术领域具有广泛诱人的应用前     

关于张弛振动的普遍方程式 f(x,) g(x)=O的周期解之唯一性定理

§1 序言远在廿一年前,Norman Levinson与 Oliver K.Smith([1])首创地研究了张弛振动的普遍方程式 (1) 的周期解,給出了(1)的周期解之存在与唯一性定理。可是,不但唯一性定理的条件应用起来不大方便,而且1957年Z.Mikolajska([2])列举反例說明該定理是錯誤的(但她沒有加以修正,本文§4将陈述其修正形式)。直到1954年,Antonio DeCastro([3])公布了一个存在与唯一性定理,虽然其条件較便于掌握,似定理仍是     

蛋白质异戊二烯化关键酶GGPPS结合小分子筛选模型的构建

蛋白质的基本翻译后修饰包括磷酸化、糖基化、乙酰化、棕榈酸化等~([1]),而异戊二烯化修饰是蛋白质的基本翻译后修饰之一,属于蛋白质的脂质修饰~([2]).甲羟戊酸途径中的关键分支酶——香叶基香叶基焦磷酸合成酶(Geranylgeranyl diphosphate synthase,GGPPS)能够催化法尼基焦磷酸盐(Farnesyl diphosphate,FPP)生成香叶基香叶基焦磷酸盐(Geranylgeranyl diphosphate,GGPP),介导蛋白质异戊二烯化的平衡~([3]).导致包括胰岛素抵抗~([4])、胰岛功能失调~([5])、生殖代谢异常~([6])等各种疾病的发生.GGPPS作为调节蛋白质异戊二烯化的重要靶点,因其在调节机体能量代谢稳态中的重要作用,促使构建筛选模型得到靶向GGPPS的小分子治疗药物,具有重要实践意义.实现EGFP荧光标记GGPPS原核蛋白的纯化以及表达,结合微量热泳动技术进行GGPPS结合天然化合物小分子的筛选模型构建.根据筛选模型对于检测蛋白稳定荧光的要求,分别构建含有GGPPS和EGFP基因的重组pET28a质粒以及对照质粒pET28a-EGFP.筛选高水平分泌表达GGPPS-EGFP-His蛋白的菌株,并对该菌株的目的基因整合位置及拷贝数进行测序.将含有目的基因的重组质粒的BL-21菌株大规模培养,表达的目的蛋白上带有His标签,利用镍(Ni)柱的亲和层析原理纯化获得重组蛋白GGPPS-EGFP-His,测定蛋白浓度留存.随后基于微量热泳动技术进行小分子结合筛选.重组GGPPS蛋白与梯度浓度化合物小分子在红外激光作用下发生热泳动,通过中心区域荧光检测可得出GGPPS与小分子化合物的结合状况.重组表达质粒GGPPS-EGFP-His经电泳及测序鉴定构建正确.纯化获得的重组蛋白纯度约为80%,在微量热泳动实验中,经GGPPS底物小分子法尼基焦磷酸(Farnesyl pyrophosphate,FPP)浓度梯度测试呈现良好结合.重组蛋白GGPPS-EGFP-His能够在微量热泳动技术下显示与小分子底物FPP的结合,该系统的构建对于筛选出GGPPS结合天然化合物小分子以及靶向GGPPS的小分子治疗药物具有重要意义.     

改善量子点背光LCD四周发蓝的方法研究

正引言量子点通常是指尺寸小于100 nm的纳米粒子,并由IIB-ⅥA(如:CdSe)或IIIA-VA(如:InAs)元素组成,可吸收某波段的光并被激发放射出其它波段的光~([1-2])。量子点由于其特有的量子效应特性,被广泛用于生物检测荧光标记~([3])、太阳能电池研究~([4])、半导体器件研究~([5])等。     

稳定能与更变能的对比

为了描述分子结构对其力能性质的影响,近三十年内提出了稳定能E_s~([1])、共振能E_(r e)~([2])、超稳定能E_(e s)~([3])、自由基改组能E_r~([4])等四种概念。以烯丙基自由基CH_2 CH CH_2为例、它们分别为E_s(CH_2 CHCH_2)=D(C_2H_5-H)-D(CH_2 CHCH_2-H),(1) E_(r e)(CH_2 CHCH_2)=D(CH_3-H)-D(CH_2 CHCH_2-H),(2)     

可见光驱动的Bi_2S_3@ZIF-8核壳结构构筑与催化机理研究

正随着工业化和城市化的发展,水中污染物(有机染料等)的排放和处理问题日趋严峻。利用廉价、绿色的光催化技术对污染物进行降解,符合当今"绿色化学"和"可持续发展"的环保理念,因而开发高效、稳定和价廉的可见光驱动的光催化材料成为关键所在~([1-4])。硫化铋(Bi_2S_3),是一种窄带隙(1.3～1.7eV)半导体,无毒、对可见光有较强的吸收,具有担当高效可见光催化材料的有利条件~([5-7])。迄今为止,国内外研究者已报道了不同形貌(如:纳米线、纳米管等)     

基于多齿菲咯啉配体的Cu(Ⅰ)和Ru(Ⅱ)光敏剂研究

正基于过渡金属配合物的光敏剂因其优越的光物理性能和电化学性能而受到了广泛的关注~([1])。这些化合物已成功用于各种光子应用,例如染料敏化太阳能电池(DSSC)~([2]),有机发光二极管(OLED)~([3])以及光氧化还原催化~([4]。Ru(Ⅱ)聚吡啶配合物因其高化学稳定性、对可见光的强吸收性以及可调节的氧化还原性,在合成化学和催化剂设计等领域有着广泛的应用~([1])。但钌是稀有的贵金属(在地壳中仅为0.001×10~(–6)),这限制了Ru(Ⅱ)光敏剂在太阳能转化中的应用。     

带有逐段常值变量的一阶中立型泛函微分方程的全局吸引性

研究了带有逐段常值变量的一阶中立型微分方程(y(t) py(t 13) )′=qy([t 12 ]) ,建立了零解全局吸引的充分条件     

一类二阶泛函微分方程解的振动性质

本文的目的是讨论二阶泛函微分方程(r(t)x′(t))′ f((t,x_t,X′t)=0 (1)解的振动性质。本丈推广了Yoshiyuki Hin9([1])和Taro Yoshizawa([2])的某些结论,应用Liapunov第二方法,给出了这个方程振动的充分条件。     

锁阳的一个新寄主植物:盐爪爪

正锁阳(Cynomorium songaricum Rupr.)为中国锁阳科全寄生植物,具有补肾阳、益精血、润肠通便的作用,主治肾阳不足、精血亏虚、腰膝酸软、阳痿滑精、肠燥便秘等~([1]).锁阳的寄主有白刺属(Nitraria L.)~([2])、红砂属(Reaumuria L.)~([2])、霸王(Sarcozygium xanthoxylon Bunge)~([3])及多裂骆驼蓬(Peganum multisectum(Maxim.)Bobr)等~([4]).甘肃省河西地区常见的白刺属锁阳寄主植物有小果白刺     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Features of Women's language

Language is a means of verbal communication. People use language to communicate with each other. In the society, no two speakers are exactly alike in the way of speaking. Some differences are due to age, gender, statue and personality. Above all, gender is one of the obvious reasons. The writer of this paper tries to describe the features of women＇s language from these perspectives： pronunciation, intonation, diction, subjects, grammar and discourse. From the discussion of the features of women＇s language, more attention should be paid to language use in social context. What＇s more, the linguistic phenomena in a speaking community can be understood more thoroughly.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.     

Achieving Unusual States of Matter Under High Pressure

正The periodicity of the elements and the non-reactivity of the inner-shell electrons are two related principles of chemistry,rooted in the atomic shell structure.Within compounds,Group I elements,for example,invariably assume the+1 oxidation state,and their chemical properties differ completely from those of the p-block elements.These general rules govern our understanding of chemical structures and reactions.Using first principles calcula-     

Exchange-Correlation and Electronic Excitation Energies from Pairing Matrix Fluctuations

We have developed an adiabatic connection to formulate the ground-state exchange-correlation energy in terms of pairing matrix linear fluctuations.This formulation of the exchange-correlation energy opens a new channel for density functional approximations based on the many-body perturbation theory.We illustrate the potential of such approaches with an approximation based on the particle-particle Random Phase Approximation(pp-RPA).This re-     

Density Functional Theory for the Response of Periodic Systems to Electric Fields Based on the Vector Potential Approach

正The electronic and nuclear(structural/vibrational)response of 1D-3D nanoscale systems to electric fields gives rise to a host of optical,mechanical,spectral,etc.properties that are of high theoretical and applied interest.Due to the computational difficulty of treating such large systems it is convenient to model them as infinite and periodic(at least,in first approximation).The fundamental theoretical/computational problem in doing so is that     

On the Thermodynamic Limit for Responses to Static Electromagnetic Fields

For molecular systems,the quantum-mechanical treatment of their responses to static electromagnetic fields usually employs a scalar-potential treatment of the electric field and a vector-potential treatment of the magnetic field.Although the potential for each field separately is associated with the choice of an(unphysical)origin,the precise choice of the origin for the electrostatic field has little consequences for the results.This is different for the     

An affordable accurate evaluation of the binding conformations predicted by molecular docking studies in bio-system

Franck-Condon factors bridge the gap between theoretical modeling and experimental observations for molecular electronic spectroscopy and electron transfer.Under the displaced harmonic oscillator approximation,multidimensional Franck-Condon factors are decomposed into a product of many one-dimensional(1D)Franck-Condon(FC)factors,and each 1D-FC factor is associated with one Huang-Rhys factor that determines the leading contribution of     

Call for Papers

<正>"The Journal of Shanghai Normal University:Mathematics"is published by Shanghai Normal University as regular issues of The Journal of Shanghai Normal University each year from 2014 in English.The editors-in-chief of the issues are professors Yuhao Cong and Maoan Han.The Journal of Shanghai Normal University was started in 1958 with