CH3Br和CH3I分子价轨道电子动量分布的理论计算

基于Hartree-Fock和密度泛函理论,用几种不同水平的基组对CH3Br和CH3I分子价轨道电子动量分布进行了计算,并与Minchinton等人的实验和理论进行了比较.得到的计算结果有很大的改善,与Minchinton等人的实验符合较好.对CH3Br分子,计算结果的改善主要是使用了有极化、弥散函数的大基组.对于CH3I分子,则主要是来自考虑了相对论效应的LANL2DZ基组.     

萘分子最高占据轨道和次最高占据轨道的电子动量谱学研究

利用高分辨率的第三代电子动量谱仪研究了萘(C10H8)分子的最高占据轨道1au和次最高占据轨道2b3u的电子动量谱,给出了外价轨道的电离能谱信息.实验在非共面对称几何条件下完成,入射电子的能量为1500eV加结合能.通过Hartree-Fock和密度泛函方法计算得到了萘分子1au和2b3u轨道的动量谱,理论与实验结果在低动量区(p<0.25a.u.)以外符合很好,低动量区的上翘现象应缘于扭曲波效应,将在下一步实验中证实这一推断.     

CH3CN分子价壳层轨道电子动量分布的理论研究

采用密度泛函理论DFT-B3LYP方法,选用6-31G,6-311++G,6-311++G(d,p)和AUG-cc-pVTZ基组以及HF方法选用AUG-cc-pVTZ基组对CH3CN分子价壳层轨道电子动量分布进行了研究。理论计算与前人实验结果和利用Snyder和Basch波函数以及HF方法选用431G基组计算得到的理论的动量分布进行了比较。总体而言,除DFT-B3LYP/631G外,采用的其它几种计算均较前人理论计算与实验结果符合更好。对外价轨道7a1,1e和6a1,轨道电子的弥散效应很明显,而轨道的极化效应不明显,且7a1和6a1轨道的电子关联效应比较显著。对内价轨道,不同基组计算结果之间差别很小,表明内价壳层轨道极化和弥散效应很弱。     

Electrostatic effect on electron transfer between cytochrome b5 and cytochrome c

The binding and electron transfer between wild type, E44A, E56A, E44/56A, E44/48/56A/D60Aand F35Y variants of cytochrome b5 and cytochrome c were studied. When mixed with cytochrome c, the cytochrome b5E44/48/56A/D60A did not show the typical UV-vis difference spectrum of absorption, indicating that the alteration ofthe surface electrostatic potential obviously influenced the spectrum. The electron transfer rates of wild type cytochromeb5, its variants and cytochrome e at different temperature and ionic strength exhibited an order of F35Y > wild type >E56A > E44A > E44/48/56A/D60A. The enthalpy and entropy of the reaction did not change obviously, suggestingthat the mutation did not significantly disturb the electron transfer conformation. The investigation of electron transfer rateconstants at different ionic strength demonstrated that electrostatic interaction obviously affected the electron transfer pro-cess. The significant difference of Cyt b5 F35Y and E44/48/56A/D60A from the wild type protein further confirmed thegreat importance of the electrostatic interaction in the protein electron transfer.     

Nd(Fe1-xCox)9Si2Cy化合物的穆斯堡尔谱研究

利用真空熔炼法制备了 Ba Cd11结构的 Nd(Fe1-x Cox) 9Si2 Cy 化合物 ,X射线衍射的结果表明 C原子加入后 ,单胞体积膨胀 .室温下测量了样品的穆斯堡尔谱 ,发现随着 Co含量的增加 ,化合物中 Fe的平均超精细场先增大后减小 .而 C原子的加入 ,则使 Fe的平均超精细增加 ,同质异能移减小     

Preparation, characterization and photodegradation of methylene blue based on TiO2 microparticles modified with thiophene substituents

The new microparticles,2-formylthiophene(FT)/TiO2 and(E)-1,2-bis(5-formyl-2-thienyl) ethylene(EBFTE)/TiO2 were synthesized with a silane coupling agent.The prepared TiO2 composites were characterized using Ultraviolet-Vis absorption(UV-Vis),X-ray diffraction(XRD),scanning electron microscope(SEM) and thermogravimetric analyzer(TGA).Methylene blue was used as a model material to examine the photocatalytic activities of the prepared catalysts under both Ultraviolet-Vis(UV) and visible(Vis) light.The enhanced photocatalytic activities were observed in the presence of(FT)/TiO2 and EBFTE/TiO2 under Vis light.It suggests that FT or EBFTE plays a block or active role in the photodegradation mechanisms under UV and Vis light irradiation,respectively.     

电子束辐照对氟掺杂二氧化锡导电玻璃的影响

运用XRD分析氟掺杂二氧化锡导电玻璃导电面SnO2的晶型,发现其属于四方晶系,晶粒尺寸为32.35nm。运用XPS分析氟掺杂二氧化锡导电玻璃导电面的元素组成主要是Sn和O,未能检测出F。进一步研究表明,电子束辐照前后Sn所处的化学状态相同(以Sn4+的形式存在),O以2种化学状态存在,分别对应氧充足和氧缺乏状态,且随着电子束辐照注量的增加,会有少量的氧失去而使氧充足状态的O1s逐渐减少。     

AM1 andab initio studies on the internal reorganization energy of self-exchange electron transfer reactions of several quinone derivatives

The semiempirical AM1 method, ab initio (HF/3-21G, 6-31G, 6-31G(d), 6-31+G(d)) and DFT (B3LYP/6-31G(d), 6-31+G(d)) methods were used to optimize the geometry of DDQ and its anion radical . Nelsen’s model was used to calculate the internal reorganization energy ?i of self-exchange electron transfer (ET) reactions. The calculated l _i results of by AM1 and B3LYP/ 6-31G(d), 6-31+G(d) methods are close to each other and consistent with the reported values; while those from Hartree-Fock methods are too large because of not considering the effect of electron correlation. The structure and ET behavior of couple were studied by AM1 and DFT (B3LYP/6-31G(d), 6-31+ G(d, p)) methods, and those of (n = 1—7) were studied by AM1 method for the first time. The results indicate that the values of the heat of formation of MQ_n increases with the increasing of the length of the isoamylene substituent chains. It also shows that the length of substituent has little effect on the bond lengths, bond angles of ring A, ring B and the dihedral angles of ring B, but it has considerable effect on the dihedral angles between the plane of ring A and oxygen atoms. The calculated l _i results of and (n = 1—7) indicate that not only the changes of high frequency vibrations, corresponding to the changes of bond lengths and bond angles, contribute to l _i of (n = 1—7), but also do those of the low frequency vibrations, corresponding to the changes of dihedral angles of MQ_n and . The contribution from the change of low frequency vibrations between the plane of ring A and oxygen atoms to the l _i values of (n = 1—7) is greater than 1.60 kJ/mol; in addition, the contribution from the changes of the low frequency vibrations of the isoamylene substituent to the l _i values of and is about 2 kJ/mol.     

不同动量比对T型管冷热流体掺混及管道热疲劳的影响

为探究主支管流体不同动量比对T型管道内冷热流体掺混过程及管道热疲劳程度的影响,通过对T型管内不同主支管流体动量比工况下冷热流体的掺混过程进行大涡模拟（LES）,计算得到管道壁面及管道内流体的温度波动情况,并使用同一套T型管网格模型进行了流固耦合计算,得到了动量比对T型管道热应力及热疲劳寿命的影响规律。计算结果表明,当动量比变化使得T型管内流体的搅混流型发生变化时,动量比对管道热疲劳的影响明显,其中,搅混流型为偏转流时,管道的热疲劳现象相较于搅混流型为壁面流的热疲劳现象得到明显的改善,预测热疲劳寿命从8.81×10^-4年提高到5.40×10¹⁵年。因此,随着主支管流体动量比的降低,流体搅混流型从壁面流转变为偏转流,管道的热疲劳寿命得到明显提高。     

AlCl3水溶液的激光诱导击穿光谱特性研究

利用自建的液相射流单脉冲激光诱导击穿光谱(LIBS)实验装置,系统地研究了激光能量、ICCD探测延时和ICCD门宽等实验参数对AlCl_3水溶液LIBS特性的影响,确定了将LIBS用于AlCl_3水溶液中Al元素定量分析时的最佳实验条件.     

电子相互作用对准一维有机铁磁体的铁磁基态的影响

提出了一种基于极化子的准一维有机高聚物铁磁体模型．在这种模型中，依靠极化子而不是有机自由基来提供未配对电子．利用 Ｐｅｉｅｒｌｓ Ｈｕｂｂａｒｄ 哈密顿量，考虑强电声耦合，允许完全的格子松驰过程，建立了一套自洽迭代方程，计算了格点上的电子相互作用和格点间的电子相互作用对有机铁磁体的铁磁基态的影响     

共振光电子及俄歇电子出电势谱复合分析管的研制和应用

一、引言共振光电子出现电势谱(RPAPS)的主要特点是对杂质元素的分辨率均优于同样条件下的软x射线出现电势谱(SXAPS)并与二次离子谱仪(SIMS)相妣美,因此它是一种对表面杂质分析相当灵敏的有用的出现电势谱。俄歇电子出现电势谱是芯能级谱中灵敏度最离的一种出现电势谱,而三极式结构的俄歇电子出现电势谱又最适于各种场合和各种类型材料的分析,     

中性导体在磁场中旋转时电磁场能量及角动量守恒研究

从能量和角动量角度对均匀磁场中旋转运动的中性导体进行研究，具体论证了中性导体在均匀磁场中旋转时，其电磁场的能量和角动量是守恒的，认为能流密度s＝c^2g在守恒中起着传输的作用．     

Adsorption and reaction of CO and O2 on the Ag/Pt(110) surface studied by photoemission electron microscopy

The Ag/Pt(110) model catalyst was prepared by evaporating silver on Pt(110). Adsorption and reaction of CO and O₂ on Ag/Pt(110) surface were studied in situ by photoemission electron microscopy (PEEM) during the pressure range of 10^-5——10^-2 Pa at 480 K. The Ag/Pt(110) surface consisted of Pt(110), AgPt interface and Ag area after annealing at 500 K. The dosing pressure of CO and O₂ had a larger influence on their adsorption on the Ag area than on the Pt(110) and AgPt interface. Small Pt clusters formed on the Ag area and AgPt interface, which had a stronger ability to adsorb CO than Pt(110) terrace. The existence of Ag had an obvious influence on the kinetic of CO oxidation on Pt(110). No pattern was observed on the AgPt interface under the same condition when the formation of reaction-diffusion waves occurred on Pt(110).     

外加电场下激光诱导Al等离子体特性的实验研究

由Q-Nd∶YAG脉冲激光(波长1.06μm,脉宽10 ns)烧蚀Al靶产生等离子体.观测了在低气压和直流电场条件下的Al等离子体发射光谱.研究了激光功率密度和直流电场对各谱线强度的影响,分析了等离子体电子温度与激光能量之间的变化规律.结果表明,直流电场对铝原子谱线和离子谱线强度有显著的增强作用,铝等离子体的电子温度随激光功率密度持续增长.     

2-(2,4-二氯-5-氟-苯甲酰基)-3-(4-氯苯基)-4-( 1,2,4-三唑-1-基)-5-苯基氨基噻吩的合成、晶体结构及光谱特性

测定了合成的标题化合物的晶体结构并对其光谱特性进行了分析．晶体为单斜晶系,P2(1)/c空间群,晶胞参数为：a=1．4665(3)nm,b=0．75437(15)nm,c=2．2891(5)nm,β=105．98(3)^*,V=2．4345(8)nm^-3,Z=4,Dc=1．484g/cm^3．     

水吸附硼氮纳米管电子结构的第一性原理研究

本文采用第一性原理研究了无电场存在时各种极性分子吸附硼氮纳米管(BNNT)的电子结构性质。结果表明：随吸附水分子数目增加BNNT的DOS向低能端移动;BNNT CH4电子结构变化不明显。DOS、Mulliken电荷分布、HOMO/LUMO及其能隙分析一致表明：各种吸附体系中BNNT 3H2O的场发射性能最佳。     

Nb2O5纳米纤维的尺寸与物相调控研究

采用静电纺丝技术制备不同晶体结构的Nb2O5纳米纤维,利用SEM和XRD技术对产物的形貌和结构进行表征.结果表明:所得Nb2O5纳米纤维晶化良好、尺寸分布均匀、长径比高且连续性好.通过调整静电纺丝的电压,可对纳米纤维的直径进行调控.调整退火温度和退火气氛,可分别获得伪六方、正交、单斜和正交/单斜混合相的纳米纤维.     

Assembly of gold nanoparticles with H10TTPR （3a, 4, 5, 8, 9, 9a, 10, 11-octa-hydro-2H,3H-1,6,7,12-tetrathia-perylene） as the rigid cross-linker

Gold nanoparticles were assembled with the rigid cross-linker, H10TTPR. The assembly process was studied with the UV-vis spectroscopy and TEM. By adjusting the amount of H10TTPR added to the gold nanoparticle solution,the aggregate form of gold nanoparticles could be controlled.