PdH2和YH2分子结构与分子光谱

使用钯和钇原子相对论有效原子实势SDD和密度泛函理论B3LYP方法对PdH2和YH2分子结构与分子光谱进行理论研究.结果表明PdH2分子基态为角形C2v结构,基态电子态为1A1,平衡几何为RPd-H=0.169 3 nm,∠HPdH=29.3°,YH2分子基态为角形C2v结构,基态电子态为2A1,平衡几何为RY-H=0.196 2 nm,∠HYH=114.3°.同时计算给出各种稳定结构的振动频率,红外强度,拉曼活性与退极化率和偶极矩.     

RuH2分子结构与分子光谱

使用钌原子相对论有效原子实势LanL2dz和密度泛函理论B3LYP方法对RuH2分子结构与分子光谱进行理论研究,结果表明RuH2分子基态为角形C2v结构,基态电子态为3A2,平衡几何为R Ru-H=0.157 4 nm,∠HRuH=74.73°,同时计算给出各种稳定结构的振动频率、红外强度、拉曼活性、退极化率和偶极矩.     

具有Hollandite结构的八面体分子筛MnO_2的合成及表征

：以KMnO4和MnSO4为原料，在酸性介质中，首先得到无定形的MnO2再将无定形的MnO2进行热处理，得到的样品通过XRD分析及SEM对表面形貌的观察，证明形成了具有Hollandite结构的MnO2。     

Molecular evolution of FOXP2, a gene involved in speech and language

Language is a uniquely human trait likely to have been a prerequisite for the development of human culture. The ability to develop articulate speech relies on capabilities, such as fine control of the larynx and mouth, that are absent in chimpanzees and other great apes. FOXP2 is the first gene relevant to the human ability to develop language. A point mutation in FOXP2 co-segregates with a disorder in a family in which half of the members have severe articulation difficulties accompanied by linguistic and grammatical impairment. This gene is disrupted by translocation in an unrelated individual who has a similar disorder. Thus, two functional copies of FOXP2 seem to be required for acquisition of normal spoken language. We sequenced the complementary DNAs that encode the FOXP2 protein in the chimpanzee, gorilla, orang-utan, rhesus macaque and mouse, and compared them with the human cDNA. We also investigated intraspecific variation of the human FOXP2 gene. Here we show that human FOXP2 contains changes in amino-acid coding and a pattern of nucleotide polymorphism, which strongly suggest that this gene has been the target of selection during recent human evolution.     

Al H_2的分子反应动力学研究

基于多体展式方法所导出的AlH2 (X2 A1)分析势能函数 ,用准经典的Monte Carlo轨迹方法对Al(2 Pu) H2 (X1Σ g) (υ =0 ,j=0 ) AlH(υ′ ,j′) H(2 Sg)的分子反应动力学过程进行了计算 ,研究了该反应的反应阈能、反应截面、产物散射角分布和微观反应机理 .     

CH3N和CH2NH分子结构与分子光谱

在B3LYP/6-311 G**理论水平上对CH3N和CH2NH的分子结构和分子光谱进行理论研究,得到CH3N基态具有C3v对称性,电子态为3A1;CH2NH分子基态具有Cs对称性,电子态为1A′,3A″、5A″和5B2态为激发态,稳定性依次降低.同时得到基态振动光谱与拉曼光谱.     

O_2-O_2,O_2-N_2和O-N_2分子相互作用势模型

利用Tang Toennies(TT)势模型,计算了O2-O2,O2-N2,和O-N2相互作用势,得到了重要的的相互作用势的参数Rm和ε,并在此基础上计算了O2-O2系统的输运系数.其结果与文献值符合较好,说明TT势模型对于计算氧分子系统是可行的.     

广义Efimov-共振暗态技术制备稳态分子~(41)K_2~(87)Rb_2

通过广义暗态方法形成稳定分子凝聚物~(41)K_2~(87)Rb_2,即Efimov-共振辅助条件下的激发绝热通道,在此过程中,双通道随量子化学反应间的相长干涉可以进一步提高分子制备的产率.进一步研究表明,初始粒子数的布居不平衡也会对该条件下的原子-分子转化率产生重要影响.     

Al+H2的分子反应动力学研究

基于多体展式方法所导出的ＡｌＨ２（Ｘ＾２Ａ１）分析势能函数，用准经典的Ｍｏｎｔｅ－Ｃａｒｌｏ轨迹方法对Ａｌ（＾２Ｐｕ）＋Ｈ２（Ｘ＾１∑＾＋ｇ）（ｕ＝０，ｊ＝０）→ＡｌＨ（ｕ′，ｙ′）＋Ｈ（＾２Ｓｇ）的分子反应动力学过程进行了计算，研究了该反应的反应阈有，反应截面、产物散射角分布和微观反应机理。     

PdH2,YH2和PdYH2分子结构性质的理论研究

在相对论有效原子实势(RECP)近似和密度泛函(B3LYP)方法基础上,对氢化物PdH2、YH2和PdYH2分子的结构进行了优化,得到PdH2和YH2分子基态为C2v构型,电子态分别为X^1A1和X^2A1,PdYH2分子基电子态为X^2A^1,属Cs构型,PdH2、YH2和PdYH2分子基态离解能分别为0．5537、0．9066和1．0302eV．最后计算了分子最高占据轨道与最低空轨道之间的能级间隙,分析了分子的化学活性。     

超临界CO_2体系黏度分子动力学研究

由于具有较低的临界温度以及适中的临界压力,超临界CO2成为最为常见的超临界流体,被广泛应用到超临界萃取和制冷等领域.充实超临界CO2体系的基础物性数据,对于进一步利用超临界CO2具有积极意义.运用平衡分子动力学方法,以Lammps免费开放源代码模拟平台为基本框架,自行编译针对超临界CO2特性的脚本文件,对超临界CO2体系的黏度物性进行计算,并将计算结果与成熟的物性数据库进行对比.结果表明,所编译脚本文件计算值与相关数据误差在0.5%以内,说明使用该方法用来获得超临界CO2黏度是可行的.     

SiO2分子体系的反应动力学研究

基于多体项展式理论方法导出的SiO2分子基态( )的分析势能函数,用准经典的 Monte-Carlo轨线法对Si (3Pg) + OO' ( ) 和O (1Dg) + SiO' ( )体系的分子反应动力学过程进行了计算．结果表明Si (3Pg) + OO' ( )体系生成络合物是一个阈能比较小的反应,而生成离解产物则是一个有比较大的阈能反应,其阈能值约为200kJ.mol-1, 说明主要以生成络合物为主;O (1Dg) + SiO' ( )体系没有络合物生成,生成离解产物O (1Dg)+ SiO' ( )→O + O' + Si的反应截面比非反应碰撞产物O (1Dg) + SiO' ( )→Si + OO'的反应截面要大约两个数量级,在低能区是有阈能的反应,其阈能值约为120kJ.mol-1．     

野桑蚕Ras 2基因的cDNA分子克隆及其特征

基于家蚕(Bombyx mori)Ras2基因的cDNA序列设计引物,利用逆转录聚合酶链式反应(RT-PCR)克隆了野桑蚕(Bombyx mandarina)Ras2基因,得到的cDNA序列长631bp,含有一个603bp的完整开放阅读框,由2个外显子和1个内含子组成,编码一个由200个氨基酸残基组成的蛋白质.该蛋白质的等电点为6.33,分子量为22.866kD.其氨基酸序列与其他昆虫Ras2氨基酸序列的同源性较高,且具有它们Ras2基因的典型特征.组织表达谱表明,该基因mRNA在野桑蚕的表皮、马氏管、中肠、脂肪体、丝腺中均有不同程度的表达.     

Molecular cloning of cDNA encoding human interleukin-2 receptor

The human interleukin-2 (IL-2) receptor was purified by affinity chromatography using the anti-Tac monoclonal antibody, and its N-terminal amino acid sequence was determined. Complementary DNA clones were isolated and sequenced to reveal the primary structure of the IL-2 receptor precursor, which has 272 amino acid residues. The receptor is separated into two domains by a putative 19-residue transmembrane region. Two mRNAs (1.4 and 3.5 kilobases) hybridizing to the cDNA clone were found in human T cells bearing the IL-2 receptor. The cDNA directed synthesis of the IL-2 receptor in COS cells.     

p.q.度量分子格中的拓扑

分子格Ｌ上的一个ｐｑ度量可自然诱导出Ｌ上一个余拓扑ηｄ和一个拓扑τｄ。证明了在拓扑分子格（Ｌ,ηｄ）中,每个分子皆有一个由τｄ－开元组成的远域基;在拓扑空间（Ｌ,τｄ）中,每个分子皆有一个由ηｄ－闭元组成的重域基,这里Ｌ是Ｆｕｚｚｙ格;若（Ｌ,ｄ）是ｐ度量Ｆｕｚｚｙ格,则τｄ′＝τｄ。     

Molecular manipulation using a tunnelling microscope

In a very short time the scanning tunnelling microscope has become an important tool in surface science, and physics in general. Its primary use has been to obtain atomic-resolution images of surfaces, but recently, efforts have been made to use it to manipulate materials as well as image them. One may now reasonably ask if it is possible to move and alter matter predictably on an atomic scale. Here we report the accomplishment of the smallest yet, purposeful, spatially localized changes in matter, effected on a graphite surface. We believe that the changes result from the pinning of individual organic molecules to the graphite. The reverse manipulation, the removal of pinned molecules, has also been demonstrated. Finally, we have evidence that we can remove a portion of a pinned molecule, effectively performing transformations on single molecules using the tunnelling microscope.     

氰基胍分子结构的研究

通过硫脲与氯乙酸反应制备了氰基胍,由红外光谱分析得出产物有氰基胍的特征峰并用四圆衍射仪测得了其结构。结果表明,该晶体属单斜晶系,空间群为C2/c,晶体学参数为:a=1.4978(2)nm,b=0.4497(1)nm,c=1.3109(2)nm;α=90°,β=115.37(1)°,γ=90°;V=0.7978(2)nm~3,Z=8,D_C=1.400g·cm~(-3),μ=1.04cm~(-1),F(000)=352;最终偏离因子R=0.0387,ωR=0.1075.     

NO2分子Faraday效应磁强计

采用Faraday光谱方法,系统研究了交流(Zeeman调制)、直流(光强调制)磁场下,NO2气体分子的光谱信号随外加磁场的变化关系.实验结果与理论分析表明,NO2分子的光谱信号与外加磁场呈线性关系,由此提出了一种NO2分子Faraday效应磁强计,预期可以测量5×10-3～100 mT,DC-1 MHz范围内的磁场,并具有良好的线性度.