Si衬底上异质外延金刚石的初始阶段原子H的作用及其界面结构

用高分辨率电子能量损失谱方法研究了原子 Ｈ 与被 Ｃ２ Ｈ２ 吸附的 Ｓｉ（１００） 界面的相互作用．结果显示,在 Ｓｉ（１００） 界面上, Ｓｉ— Ｓｉ 二聚化键和 Ｃ２ Ｈ２ 中的 Ｃ— Ｃ 键被 Ｈ 原子打开,它们分别形成 Ｓｉ— Ｈ, Ｃ— Ｈ 键．用 Ａ Ｍ１ 量子化学方法,计算了 Ｃ２ Ｈ２ 和 Ｃ２ Ｈ４ 在 Ｓｉ（１００） 上的吸附结构,指出了 Ｃ２ Ｈ２ 在 Ｓｉ（１００） 上的吸附位置,进一步讨论了金刚石在 Ｓｉ 异质外延初始阶段的形核机制．计算结果显示：在原子 Ｈ 的作用下,可以显著地降低反应的活化能,有利于 Ｃ Ｈ３ 的产生和 Ｃ Ｈ３ 向 Ｓｉ 衬底的键连．计算结果与实验相符合．     

一类新颖含C60复合材料的合成及其光限制效应的研究

报道了在Ｃ６０与ＮＨ２（ＣＨ２）３Ｓｉ（ＯＣ２Ｈ５）３中的胺基反应生成Ｃ６０－ＮＨ２（ＣＨ２）３Ｓｉ（ＯＣ２Ｈ５）３物质后引入ｒ－缩水甘油醚基丙基三甲氧基硅烷「ＣＨ２ＯＣＨＣＨ２ＯＣＨ２ＣＨ２ＣＨ２Ｓｉ（ＯＣＨ３）３，３－Ｇｌｙｃｉｄｏｘｙｐｒｏｐｌｔｒｉｍｅｔｈｏｘｙｓｉｌａｎｅ，简称ＫＨ５６０」与二甲基二乙氧基硅烷「（ＣＨ３）２Ｓｉ（ＯＣ２Ｈ５）２，Ｄｉｅｔｈｏｘｙｄｉｍｅｔｈｙｌｓｉｌａｎｅ     

乙胺分子的多光子电离过程质谱研究

报道了乙胺分子在４４０～４７５ｎｍ波长范围内多光子电离（ＭＰＩ）质谱（ＭＳ）研究结果。碎片离子主要由母体离子碎裂模式产生。母体离子ＣＨ３ＣＨ２Ｎ＋·Ｈ２由经３ｓ里德堡态的（２＋２）共振多光子电离产生后，大部分发生β键断裂，形成ＣＨ２＝Ｎ＋Ｈ２离子，还有一部分再吸收一个光子，通过Ｃ－Ｈ（ＣＨ２）键的断裂产生了ＣＨ３ＣＨ＝Ｎ＋Ｈ２离子。ＣＨ３ＣＨ＝Ｎ＋Ｈ２和ＣＨ２＝Ｎ＋Ｈ２离子最容易发生的碎裂过程是脱去氢分子，分别产生Ｃ２Ｈ４Ｎ＋（分子式）离子和ＣＨ≡Ｎ＋Ｈ离子。     

束—气条件下He（2^3S）＋CH2Cl2碰撞传能反应的动力学研究

本文在束－气条件下研究了亚稳态原子Ｈｅ（２＾３Ｓ）与ＣＨ２Ｃｌ２间的传能反应，测得了由该反应产生的ＣＨ（Ａ＾２△－Ｘ＾２П），ＣＨ（Ｂ＾２∑＾－Ｘ＾２П）ＣＨ（Ｃ＾２∑＾＋－Ｘ＾２П）和Ｈ原子（Ｂａｌｍｅｒ系）的化学发光光谱。通过对ＣＨ（Ａ，Ｂ）的光谱进行计算机模拟，推测出初手的ＣＨ（Ａ＾２△，ｖ＾１＝０－２）态振动分布为Ｎｏ：Ｎ１：Ｎ２＝１００：４０±５：１９±２，ＣＨ（Ａ＾２△，ｖ＾１＝０－０     

SinSem分子簇的SCC—DV—Xa方法的计算研究

本文应用ＳＣＣ－ＤＶ－Ｘａ方法计算了（ＲＳｉ）４Ｓｅ６，（ＲＳｉ）２Ｓｅ３和Ｒ４Ｓｉ３Ｓｅ４（Ｒ＝ＣＨ３，Ｃ２Ｈ５，Ｐｈ）等分子簇的结合能，轨道能级，电荷分布，状态密度，分析了簇的稳定性，ＮＭＲ化学位移，紫外可见吸收和催化性能等，结果与实验相符。     

乙胺分子的多光子电主过程质谱研究

报道了乙胺分子在４４０－４７５ｎｍ波长范围内多光子电离（ＭＰＩ）质谱（ＭＳ）研究结果。碎片离子主要由母体离子碎裂模式产生。母体离子ＣＨ３ＣＨ２ＮＨ２由经３ｓ里德堡态的（２＋２）共振多光子电离产生后，大部分发生β键断裂，形成ＣＨ２＝Ｎ＋Ｈ２离离子，还有一部分再吸收一个光子，通过Ｃ－Ｈ（ＣＨ２）键的断裂产生了ＣＨ３ＣＨ－ＮＨ２离子。ＣＨ３ＣＨ＝ＮＨ２和ＣＨ２＝ＮＨ２离子最容易发生的碎裂过程是脱去氢分子     

氟原子与氯溴代甲烷反应的光谱及动力学研究

本文报导了氯原子与三种含氢氯溴代甲烷（ＣＨ２ＢｒＣｌ，ＣＨＢｒＣｌ２，ＣＨＢｒ２Ｃｌ）反应的光谱及动力学研究结果，观察了这些反应的可见化学发光（３００－９００ｎｍ）和染料Ｒ６Ｇ波段（５６５－６１０ｎｍ）的激光诱导荧光，观测到ＨＦ基电子态振动泛频跃迁和Ｂｒ２（Ａ，Ｂ），ＢｒＦ（Ｂ）分子电子激发态跃迁的发射谱以及ＢｒＦ（Ｘ），ＣＨＦ（Ｘ）的基电子态的激发谱，计算机模拟光谱求出了Ｂｒ２（Ｂ），ＢｒＦ（Ｘ     

H2O＋Cl→HCl＋OH反应中D同位素的动力学效应的理论研究

根据传统过渡态，变分过渡理论计算了Ｈ２Ｏ＋Ｃｌ→ＨＣｌ＋ＯＨ（Ｒ１）反应中Ｄ代替的同位素动力学效应（ＫＩＥ）得到了ＨＯＤ＋Ｃｌ→ＤＣｌ＋ＯＨ（Ｒ２），ＤＯＨ＋Ｃｌ→ＨＣｌ＋ＯＤ（Ｒ３）反应不同的ＫＩＥ值，对ＫＩＥ进行了分解，讨论了平动（ｔｒａｒｓ）转动（ｒｏｔ）振动（ｖｉｂ）等各种因素的作用，在反应Ｒ２中，由于ＨＯＤ中ＯＤ键直接参与反应，Ｄ同位素的ＫＥ很大，对Ｒ２的ＫＩＥ分解表明，振动对ＫＩＥ贡献     

芳香氮化物-CHCl3系列复合物密度泛函法研究

报道对芳香氮化物吡咯（Ｃ４Ｈ５Ｎ）、苯（Ｃ６Ｈ５ＮＨ２）、对位氯代吡啶（Ｃ５Ｈ４ＮＣｌ）、吡啶（Ｃ５Ｈ５Ｎ）及吡咯负离子（Ｃ４Ｈ４Ｎ＾－）与三氯甲烷（ＣＨＣｌ３）形成的系列弱作用复合物的理论计算结果。把复合物看作是一个超分子在密度泛函Ｂ３ＬＹＰ／６－３１１Ｇ（ｄ,ｐ）的水平上进行计算,探讨该系列复合物的稳定性规律、电荷转移及主要几何参数变化等规律,计算结果表明：此类芳香氮化物与三氯甲（ＣＨ３ｌ３）     

(NH_2CH_2COOH)_2CdCl_2晶体的拉曼光谱的研究

（ＮＨ２ＣＨ２ＣＯＯＨ）２ＣｄＣｌ２晶体的拉曼光谱的研究刘建军吴粤郑吉民扈士芬蓝国祥（南开大学天津３０００７１）ＲａｍａｎＳｐｅｃｔｒａｏｆ（ＮＨ２ＣＨ２ＣＯＯＨ）２ＣｄＣｌ２ＣｒｙｓｔａｌｓＬｉｕＪｉａｎｊｕｎ，ＷｕＹｕｅ，ＺｈｅｎｇＪｉｍｉｎ，Ｈ...     

Direct observation of the ultrafast energy transfer in a porphyrin and ruthenium dyad

The luminescence dynamics of a polypyridyl ruthenium II [Ru（phen）2（ip）]2＋ and 5,10,15,20- tetraphenylporphyrin （H2TPP） dyad have been measured by using time-resolved fluorescence spectroscopy. The transient luminescent spectra of the dyad show an ultrafast energy transfer within 300 ps after pho- toexcitation of the [Ru（phen）2（ip）]2＋ at 453 am. However, no energy transfer has been observed as the excitation wavelength is 400 nm, corresponding to the absorption peak of H2TPP. The origin of the energy transfer from [Ru（phen）2（ip）]2＋ to H2TPP has been analyzed according to the FSrster energy-transfer theory.     

KAl(MoO4)2晶体中掺杂Cr3+的能谱和g因子的理论计算*

采用强场方案和三角基，通过对角化三角畸变的立方晶场下的d3 完全能量矩阵，计算出了KAl(MoO4)2:Cr3+ 的能谱和波函数。使用对角化完全能量矩阵所获得的波函数，进一步计算了KAl(MoO4)2:Cr3+ 的基态g 因子。计算结果与光谱，EPR谱实验数据很好地符合。研究表明,利用对角化完全能量矩阵获得的波函数对 g 因子所作的计算为整个理论计算及波函数的归属提供了重要判据,充分体现了将能谱和g 因子作统一计算的重要性和必要性.     

Initial stages in the Sm-Si(111) interface formation

The initial stages in the formation of the Sm-Si(111) interface have been studied by thermal desorption, atomic beam modulation, and low-energy-electron-diffraction spectroscopy. The structure of adsorbed films and samarium silicide films, as well as the Sm atom desorption kinetics have been investigated within a broad range of surface coverages and temperatures. The activation energy of desorption from the thermally most stable 3×2 submonolayer structure, as well as the binding energy of a single samarium atom with the substrate, have been measured. The temperature of the onset of silicide decomposition and the activation energy of this process have been determined. It is shown that the Sm-Si(111) interface forms by a mechanism close to that of Stransky-Krastanov. Fiz. Tverd. Tela (St. Petersburg) 40, 371–378 (February 1998)     

Pressure Effects on Spectra of Tunable Laser Crystal GSGG:Cr3+Ⅱ:Energy Spectra at Normal Pressure, Low and Room Temperatures

With the strong-field scheme and trigonal bases, the complete d3 energy matrix in a trigonally distorted cubic-field has been constructed. By diagonalizing this matrix, the normal-pressure energy spectra and wavefunctions of GSGG:Cr3+ at 70 K and 300 K have been calculated without the electron-phonon interaction (EPI), respectively. Further, the contributions to energy spectra from EPI at two temperatures have also been calculated, where temperatureindependent terms of EPI are found to be dominant. The sum of aforementioned two parts gives rise to the total energy spectrum. The calculated results are in good agreement with all the optical-spectral experimental data and the experimental results of g||(R1) and g⊥(R1). It is found that the contribution from EPI to R1 line of GSGG:Cr3+ with taking into account spin-orbit interaction (Hso) and trigonal field (Vtrig) is much larger than the one with neglecting Hso and Vtrig, and accordingly it is essential for the calculation of the EPI effect to take first into account Hso and Vtrig. The admixture of base-wavefunctions, |t32 2E) and |t22(3T1)e4T2 ), the average energy separation △＝ E[t22 (3T1)e4T2]-E[t32 2E] and their variations with temperature have been calculated and discussed.     

Mg2Ni分子的结构和势能函数

采用密度泛函B3LYP方法在6-311+g(d,p)基组水平上对MgNi、Mg2和Mg2Ni分子的各种可能的结构进行优化,得到了它们的几何构型、平衡核间距、离解能和谐振频率.采用最小二乘法拟合MgNi和Mg2分子的Murrell-Sorbie势能函数,在此基础上导出光谱数据和力常数.通过多体项展式理论导出Mg2Ni分子的解析势能函数,并绘出了Mg2Ni分子的等值势能面,其等值势能面正确地反应了基态Mg2Ni分子的平衡构型特征.     

Precise determination of the 2s(1/2)-2p(1/2) splitting in very heavy lithiumlike ions utilizing dielectronic recombination

The 2s(1/2)-2p(1/2) energy splittings DeltaE(L) of the lithiumlike ions 19779Au76+, 20882Pb79+, and 23892U89+ have been measured at the Experimental Storage Ring, utilizing low energy dielectronic recombination. The resonance energies in total 41 different 1s(2) 2p(1/2)nl(j(')) (n > or =20) autoionizing Rydberg states populated in the dielectronic capture process have been determined. The 2s(1/2)-->2p(1/2) excitation energies have been obtained by extrapolation of these resonance energies to the associated series limits n--> infinity. The combined analysis of the experimental data for all three ions yields DeltaE(L)=216.134(96) eV for Au76+, 230.650(81) eV for Pb79+, and 280.516(99) eV for U89+.     

Ab initio study of neutral (TiO2)n clusters and their interactions with water and transition metal atoms

We have systematically investigated the growth behavior and stability of small stoichiometric (TiO(2))(n) (n = 1-10) clusters as well as their structural, electronic and magnetic properties by using the first-principles plane wave pseudopotential method within density functional theory. In order to find out the ground state geometries, a large number of initial cluster structures for each n has been searched via total energy calculations. Generally, the ground state structures for the case of n = 1-9 clusters have at least one monovalent O atom, which only binds to a single Ti atom. However, the most stable structure of the n = 10 cluster does not have any monovalent O atom. On the other hand, Ti atoms are at least fourfold coordinated for the ground state structures for n ≥ 4 clusters. Our calculations have revealed that clusters prefer to form three-dimensional structures. Furthermore, all these stoichiometric clusters have nonmagnetic ground state. The formation energy and the highest occupied molecular orbital (HOMO)-lowest unoccupied molecular orbital (LUMO) gap for the most stable structure of (TiO(2))(n) clusters for each n have also been calculated. The formation energy and hence the stability increases as the cluster size grows. In addition, the interactions between the ground state structure of the (TiO(2))(n) cluster and a single water molecule have been studied. The binding energy (E(b)) of the H(2)O molecule exhibits an oscillatory behavior with the size of the clusters. A single water molecule preferably binds to the cluster Ti atom through its oxygen atom, resulting an average binding energy of 1.1 eV. We have also reported the interaction of the selected clusters (n = 3, 4, 10) with multiple water molecules. We have found that additional water molecules lead to a decrease in the binding energy of these molecules to the (TiO(2))(n) clusters. Finally, the adsorption of transition metal (TM) atoms (V, Co and Pt) on the n = 10 cluster has been investigated for possible functionalization. All these elements interact strongly with this cluster, and a permanent magnetic moment is induced upon adsorption of Co and V atoms. We have observed gap localized TM states leading to significant HOMO-LUMO gap narrowing, which is essential to achieve visible light response for the efficient use of TiO(2) based materials. In this way, electronic and optical as well as magnetic properties of TiO(2) materials can be modulated by using the appropriate adsorbate atoms.     

基态TiH2分子的结构与分析势能函数

用密度泛函理论的B3lyp方法,Ti原子采用相对论有效实势(LanL2DZ)收缩价基函数,氢原子采用6-311 g**全电子基函数,对TiH2体系的结构进行优化计算.得到TiH2分子最稳态为C2v构型,电子状态为(C2v(X)3A2),平衡核间距,RTi-H=0.1789 nm,键角∠HTiH =123.365°,离解能:De=5.54216 eV.基态简正振动频υ(A1)=485.4150 cm-1,υ(B2)=1507.6533 cm-1,υ(A1)=1580.2361 cm-1.由微观过程的可逆性原理分析了分子的可能离解极限,并用多体项展式理论方法分别导出基态TiH2分子的势能函数,其等值势能面图准确地再现了TiH2分子的结构特征和离解能.由此讨论了TiH2分子反应的势能面静态特征.     

过氧硝酸分解势能面的理论研究

使用密度泛函理论B3LYP/6-311+ G(2d,2p)研究了过氧硝酸的最低能量结构．采用耦合簇方法CCSD(T)/aug-cc-pVDZ首次分别扫描了过氧硝酸沿氧-氮和氧-氧键的分解势能面．计算结果表明在氧-氮势能面上,当O3—N4键长是2.82 ?时,对应的疏松过渡态的能垒是25.6 kcal/mol;在氧$-$氧键的势能面上,当O2—O3键长是2.35 ?时,对应的疏松过渡态的能垒是37.4 kcal/mol．这表明过氧硝酸更容易分解为HO₂和NO₂．     

Measurements of charge transfer efficiency in a proton-irradiated swept charge device

Charged Coupled Devices (CCDs) have been successfully used in several low energy X-ray astronomical satellites over the past two decades. Their high energy resolution and high spatial resolution make them a perfect tool for low energy astronomy, such as observing the formation of galaxy clusters and the environment around black holes. The Low Energy X-ray Telescope (LE) group is developing a Swept Charge Device (SCD) for the Hard X-ray Modulation Telescope (HXMT) satellite. A SCD is a special low energy X-ray CCD, which can be read out a thousand times faster than traditional CCDs, simultaneously keeping excellent energy resolution. A test method for measuring the charge transfer efficiency (CTE) of a prototype SCD has been set up. Studies of the charge transfer inefficiency (CTI) with a proton-irradiated SCD have been performed at a range of operating temperatures. The SCD is irradiated by 3×10⁸cm^-2 10 MeV protons.