水液相环境下羟自由基诱导的苯丙氨酸分子损伤机理

在MP2/ SMD/6-311++g(3df, 2pd)//WB97X-D/SMD/6-311++G(d, p)理论水平上,研究了水液相环境下羟自由基诱导的苯丙氨酸分子的损伤机理。研究发现,羟自由基（水分子簇）抽取α-氢、β-氢、苯环-氢以及羟自由基与苯环加成均可致苯丙氨酸分子损伤。势能面计算表明,羟自由基（水分子簇）抽取α-氢和β-氢的最低能垒分别为68.4和89.3 kJ·mol^-1,羟自由基抽取苯环-氢的最低能垒为111.6 kJ·mol^-1,羟自由基加成到苯环不同位点碳的能垒大约在106.5~110.2 kJ·mol^-1,羟自由基（水分子簇）抽α-氢和β-氢是显著的放热反应。结果表明,羟自由基（水分子簇）抽取α-氢是苯丙氨酸分子损伤的主要途径。     

基于碳纳米薄膜/砷化镓范德华异质结的高性能自驱动光电探测器研究

基于碳纳米材料/体半导体范德华(vdW)异质结的光电器件可以同时实现碳纳米材料的超高载流子迁移率以及体半导体的优异光电性能,且具有结构简单、工艺简便、易于调控界面等优点.尤其是通过调控单壁碳纳米管(SWCNT)的直径/手性、费米能级等可以与体半导体形成能带匹配、具有原子级界面的新型混合维度vdW异质结.本文报道了一种基...     

A THEORETICAL INVESTIGATION ON THE WAVE FORCES ON THE MULTIPLE CYLINDERS IN SHALLOW WATER

The diffraction problem of two kinds of shallow water wave,cnoidal wave and solita.wave, around a group of cylinders is discussed. A Bessel corrdinate transformation (?)employed to uniform the coordinate system, and thus the boundary condition on eachcylinder＇s surface can be satisfied by determining the coefficients in the solution.Severalexamples are calculated for two kinds of incident wave and various arrangement of thecylinders,and the results are discussed and compared with the available experimental data.     

气相环境下丙氨酸Ca2+配合物的手性转变机理及水分子的催化作用

采用基于密度泛函理论的M06方法，研究了气相环境下2种稳定构型的丙氨酸（Ala）与Ca²⁺配合物的手性转变及水分子的催化。研究发现，Ala_1·Ca²⁺的手性转变有a和b 2个通道，a通道是α-氢只以羰基氧为桥迁移；b通道是α-氢迁移到羰基氧后，氨基上的质子在纸面内侧向α-碳迁移。Ala_2·Ca²⁺的手性转变有a、b、c、d 4个通道，a和b通道分别是羧基内质子迁移后，α-氢只以羰基氧为桥迁移和α-氢迁移到羰基氧接质子从氨基氮向α-碳迁移；c通道是钙与氮的配位键断裂后，α-氢向氨基氮迁移；d通道是钙与氮的配位键断裂后，Ala_2·Ca²⁺向Ala_1·Ca²⁺异构，再接Ala_1·Ca²⁺的手性转变。势能面计算表明，Ala_1·Ca²⁺手性转变的a通道具有优势，总包能垒为134.8 kJ·mol^－1，Ala_2·Ca²⁺手性转变的d通道具有优势，总包能垒为235.3 kJ·mol^－1；水分子的催化使能垒分别降至40.8和141.3 kJ·mol^－1。结果表明，Ca²⁺对Ala的手性转变具有催化作用，水分子对丙氨酸Ca²⁺配合物的手性转变具有极好的催化作用。     

A theoretical investigation on the wave forces on the multiple cylinders in shallow water

The diffraction problem of two kinds of shallow water wave, cnoidal wave and solita. wave, around a group of cylinders is discussed. A Bessel corrdinate transformation i. employed to uniform the coordinate system, and thus the boundary condition on each cylinder’s surface can be satisfied by determining the coefficients in the solution. Several examples are calculated for two kinds of incident wave and various arrangement of the cylinders, and the results are discussed and compared with the available experimental data.     

精确计算n-n重正化链图传播下n+n→２π0反应截面

采用中子n-反中子n与中性介子π⁰强相互作用的Lorentz不变耦合模型,对n-n重正化链图传播子作了有关物理分析及其严格解析计算,获得精确理论计算结果. 进而将此结果用于n+n→2π⁰反应的物理过程分析及其截面的计算研究中,并精确计算出n-n重正化链图传播下n+n→2π⁰反应微分截面. 还将此计算结果与n-n树图和重正化单圈链图传播下n+n→2π⁰反应微分截面作了对比分析,获得了有关辐射修正的重要信息. 此结果对于深 关键词： Lorentz不变耦合模型 重正化链图传播子 微分截面 辐射修正     

扶手椅型单壁碳纳米管孔径对缬氨酸分子旋光异构的限域影响

采用量子力学与分子力学组合的ONIOM方法,研究了扶手椅型单壁碳纳米管(SWCNT)孔径对缬氨酸(valine,Val)分子两种构象Val_1和Val_2旋光异构的限域影响。结构分析表明:扶手椅型SWCNT(5,5)的限域作用致Val分子骨架明显形变,同时SWCNT(5,5)也发生了明显形变。势能面研究表明:限域在SWCNT内的Val分子以氨基氮为质子转移桥梁的旋光异构反应通道具有优势;Val_1和Val_2限域在SWCNT(5,5)内,在优势通道上旋光异构决速步骤的内禀能垒分别为340.55和361.13kJ·mol~(-1),限域在SWCNT(6,6)内,在优势通道上旋光异构决速步骤的内禀能垒分别为302.80和293.11kJ·mol~(-1),限域在SWCNT(7,7)内,在优势通道上旋光异构决速步骤的内禀能垒为265.54kJ·mol~(-1)左右。计算结果表明:SWCNT(5,5)的限域作用及其固体溶剂效应对Val分子的旋光异构反应具有显著的阻碍作用,SWCNT(5,5)可以安全地储存光学纯Val。     

Gravitational Radiation of Binaries Coalescence into Intermediate Mass Black Holes

This paper discusses the gravitation waveforms of binaries coalescence into intermediate mass black holes(about 30 times of the solar mass).We focus on the non-spinning intermediate mass black hole located less than 100 Mpc from earth.By comparing two simulation waveforms(effective one body numerical relativity waveform(EOBNR),phenomenological waveform),we discuss the relationship between the effective distance and frequency;and through analyzing large amounts of data in event,we find that the phenomenological waveform is much smoother than EOBNR waveform,and has higher accuracy at the same effective distance.     

新型干涉条纹计数器的设计与应用

针对用迈克尔逊干涉仪测量激光波长实验需要人工记录干涉环改变数量问题,研制一种干涉条纹自动计数器。该计数器不仅能显示干涉条纹改变数量,还能显示不同光强对应信号强度。同时,准确度高、操作简便,能在不同背景光强环境和光源光强条件下使用。