LaNi_5的硫化物中毒及其再生的表面研究

本文概括了氢气中的硫化物(如H_2S,SO_2和CS_2)对LaNi_5的表面中毒和再生。 AES,XPS的分析表明,三种硫化物的中毒性质不同:H_2S中毒产生La_2S_3和NiS这样的表面化合物;SO_2和CS_2中毒分别发生化学吸附和物理吸附。此外,从Ni(2P_(3/2))谱峰强度变化,表明了在LaNi_5表面上活性镍的表面催化性质。纯氢循环法再生CS_2和SO_2中毒是有效的,但对H_2S中毒无效。试验结果对解释稀土金属间氢化物的表面中毒机理和再生机理非常有用。     

BaB_2O_4低温相单晶体的生长及其相关体系相图的研究

本文用差热分析和X射线衍射等方法研究了BaO-Na_2O-B_2O_3三元系的两个截面:BaB_2O_4-Na_2B_2O_4和BaB_2O_4-Na_2O赝二元系的相平衡关系。BaB_2O_4-Na_2B_2O_4属共晶体系,其共晶温度为826±3℃。在BaB_2O_4-Na_2O体系中发现一个新化合物BaB_2O_4·Na_2O,该化合物在846±3℃同成分熔化。BaB_2O_4·Na_2O对BaB_2O_4和Na_2O均为共晶体系,其共晶温度分别为755±3℃和573±3℃。并根据所得的结果,分别以15mol％Na_2O和13mol％Na_2B_2O_4为助熔剂,用提拉法培养出2×4×6mm~3和2×4×8mm~3的低温相BaB_2O_4单晶体。     

金属锡表面吸附氢同位素的量子力学计算

根据原子分子反应静力学与群论,确定了H2、D2和T2的基电子状态为1∑+g(D∞v),SnH、SnD和SnT的基电子状态为2∑+( C∞v).应用基函数SDD**和6-311G**,密度泛函B3P86方法,计算了氢同位素分子及其锡化物的结构、能量E、定容热容Cv和熵S.H2 (D2, T2) ,SnH(D , T)和SnH2(D2, T2)的基电子状态分别为1∑+g(D∞h ),2∑+(C∞v)和3B1(C2v).H2、D2和T2的离解能为4.591 8 eV,SnH(D, T)分子的离解能为2.714 7 eV,SnH2(D2, T2)分子的离解能为4.833 9 eV.用总能量中的电子和振动能量近似代表SnHn、SnDn和SnTn(n=1,2)分子处于固态时的能量,用总熵中的电子和振动熵近似代表SnH、 SnD和SnT分子处于固态时的熵,从而计算了锡与H2、D2和T2反应过程的△Hf°,△Sf°,△Gf°和平衡压力, 并导出他们与温度的函数关系.X     

"电源的电动势和内阻的测定"实验的误差分析

1 实验原理。由闭合电路的欧姆定律E=U Ir，测出两组路端电压和电流，即有E=U1 I1r，E=U2 I2r，可得E=（U1I2-U2I1）/（I2-I1），r=(U2-U1)/(I1-I2).需要测定的物理量为U和I．     

基于香豆酰肼的高选择性的铜离子荧光探针

设计合成了含有香豆酰肼官能团的铜离子荧光探针,N,N-二乙基氨基香豆素-3-酰肼吡啶醛(XB),该探针在水溶液中[V(CH3CN):V(H2O)=1:1]对铜离子识别和检测具有较高的灵敏度和选择性。碱金属和碱土金属离子K+、Na+、Mg2+、Ca2+以及过渡金属离子Cr3+、Mn2+、Fe3+、Co2+、Ni2+、Zn2+、Cd2+、Hg2+和Ag+等对Cu2+离子的识别无显著影响。光谱滴定和ESI-MS谱表明Cu2+离子与XB以1:2的化学计量比形成配合物。     

BH~+离子基态及激发态的势能曲线和跃迁性质的研究

利用高精度的多组态相互作用及Davidson修正方法 (MRCI+Q),采用ACV5Z-DK全电子基组计算了BH~+离子的前4个离解通道B~+(~1S_g)+H(~2S_g),B~+(~3Pu)+H(~2S_g),B(~2P_u)+H~+(~1Sg)和B~+(~1Pu)+H(~2Sg)的9个Λ—S态的势能曲线.X~2Σ~+,A~2Π和B~2Σ~+态的光谱常数和已有实验值符合得很好,其中b~4Σ~+,3~2Σ~+,3~2Π和4~2Σ~+态的光谱常数为首次报道,3~2Π和4~2Σ~+态具有双势阱结构.预测了A~2Π和B~2Σ~+态的辐射寿命:τ(A~2Π)=239.2 ns和τ(B~2Σ~+)=431.2 ns.最后在考虑自旋轨道耦合效应下讨论了B~2Σ~+与A~2Π态的势能曲线的相交对激光冷却BH~+离子的影响.     

LaNi5的硫化物中毒及其再生的表面研究

本文概括了氢气中的硫化物(如H₂S,SO₂和CS₂)对LaNi₅的表面中毒和再生。AES,XPS的分析表明,三种硫化物的中毒性质不同:H₂S中毒产生La₂S₃和NiS这样的表面化合物;SO₂和CS₂中毒分别发生化学吸附和物理吸附。此外,从Ni(2P_3/2)谱峰强度变化,表明了在LaNi关键词：     

HF~+离子在旋轨耦合作用下电子态的特性

采用多组态准简并微扰理论对旋轨耦合作用下HF+离子的基态X2Πi和第一激发态A2Σ+的性质进行了研究,得到了电子态X2Π3/2和2Π1/2的垂直跃迁能v[2Π1/2(v=0)→X2Π3/2(v=0)]=285.176 cm-1,以及电子态X2Π3/2和2Π1/2的势能曲线;采用Murrell-Sorbie函数和最小二乘法拟合得到了这两个分裂电子态的解析势能函数;并在此基础上推导出了电子态X2Π3/2,2Π1/2和A2Σ+的光谱常数,而且首次给出了分裂电子态X2Π3/2和2Π1/2的解析势能函数和光谱数据.     

LB膜的XPS光谱及其电致发光

采用X射线光电子能谱 (XPS)和UV Vis光谱研究了 2个以 8 氨基喹啉为亲水头基的两亲配体 ;2 长链烷基丙二酸二 (8 氨基喹啉 )酰胺 (H2 A) (H2 A1 2 :长链烷基为十二烷基 ;H2 A1 6 :十六烷基 )在气 /水界面与Cu2 离子的配位作用。配位后H2 A1 2 和H2 A1 6 单分子膜的崩溃压分别由 12 5和 15 6mN·m- 1 增加至 2 8 0和33 8mN·m- 1 。从含Cu2 离子亚相表面组装的LB膜出现了Cu2 离子的特征XPS峰 ,Cu2p为 935和 95 5eV ,XPS表明H2 A与Cu2 的配位比为 1∶1。H2 A的LB膜可以用作电致发光 (EL)器件的空穴传输材料 ,三层EL器件ITO/TPD/LB膜 /Alq3/Al(LB膜分别为 15层H2 A1 2 和 15层H2 A1 6 )的驱动电压分别为 6 5和 7 5V ,最大亮度分别为 6 2 1和 2 0 1cd·m- 2 。     

掺铕的氟氯化锶型磷光体的发光

MeFX:Eu~(2 )(Me=Sr,Ba;X=Cl,Br)型的化合物是一种高效率的磷光体。由5d—4f带谱以及4f—4f线谱组成的发射,其相对强度强烈地依赖于基质晶格和温度。 1.实验方法和结果 在氧化物中,Eu~(2 )的发光是由5d—4f带谱发射组成的[1]。在一些氟化物中,4f—4f的线谱发射已被发现[2—4]。本文论述MeFX:Eu~(2 )(Me=Sr,Ba,X=Cl,Br)型化合物的发光。用原材料SrF_2,SrCl_2,BaF_2,BaCl_2·2H_2O,SrBr_2·6H_2O和BaBr_2·2H_2O的直接混合物,在     

THE SCREENING EFFECT OF PHONON MODES IN HIGH-Tc OXIDE SUPERCONDUCTOR

This paper presents three different kinds of infrared (IR) spectra of oxide materials. The first one is the IR reflection spectra of Ti₂Ba₂Ca₂Cu₃O₁₀ superconducting film at the incident angles 7°, 12° and 30°. The second one is the IR spectra of nonsuperconducting ceramic materials YBa₂Cu₃O₆ and PrBa₂Cu₃O₇. The third one is the IR spectra of superconductor YBa₂Cu₃O_7-δ and of its film with the c-axis perpendicular to the film plane, as well as the changes in the spectra of these materials after annealing at different temperatures. It is found that in the spectra of high-T_c oxide superconductor, only the phonon modes along c-axis can be observed while the modes in a-b plane are absent. But in the spectra of nonsuperconductors the modes in a-b plane can be observed, particularly in the absorption spectra of the semiconductor YBa₂Cu₃O₆, all eleven allowed IR active modes have been detected. We suggest that the above experimental phenomena may result from the fact that the phonon modes vibrating in the a-b plane of the high-T_c oxide superconducting materials are almost screened by the free carriers which can move only in a-b plane.     

悬浮二维晶体材料反射光谱和光致发光光谱的周期性振荡现象

研究了在二氧化硅/硅衬底上制备的悬浮石墨烯以及二硫化钼的反射光谱以及悬浮二硫化钼的光致发光光谱.研究发现:悬浮多层石墨烯的反射光谱表现出明显的振荡现象,并且该振荡具有一定的周期性;振荡周期的大小不依赖于悬浮多层石墨烯的层数,而是随着衬底上沉孔深度(空气层厚度)的增加而减小.利用多重光学干涉模型可以解释这种振荡现象以及振荡周期随沉孔深度改变的变化趋势.该模型计算结果表明,只有当沉孔深度达到微米量级时这种振荡现象才会显著出现;并且可由振荡周期定量地确定出沉孔深度.对于悬浮的二硫化钼样品,其反射光谱和光致发光光谱也出现了类似的振荡现象.这表明这种振荡现象是在各种衬底上悬浮二维材料反射光谱和光致发光光谱的一种普遍性结果,也预示悬浮二维材料器件的电致发光光谱也会出现类似的振荡现象,对悬浮二维晶体材料的物理性质和器件性能研究具有一定的参考价值.     

Vibrational modes in ZnAl2S4 and CdIn2S4 crystals

Infrared reflectivity spectra and Raman scattering of the ZnAl₂S₄ and CdIn₂S₄ crystals have been investigated. Reflectivity spectra contours were calculated and phonon parameters and dielectric constants were determined. Effective charges for the Zn, Cd, In and S ions of these materials were determined.     

全氟羧酸钕2,2’-联吡啶配合物的合成及其光学特性

合成了一系列全氟羧酸钕2,2’-联吡啶配合物:Nd(CF3COO)3.Dipy,Nd(C2F5COO)3.Dipy和Nd(C3F7COO)3.Dipy,并通过红外光谱、元素分析、热分析、紫外可见近红外吸收光谱和荧光光谱对其进行了表征。配合物的分解温度都高于260℃,最大失重温度超过340℃,说明它们具有良好的热稳定性。全氟羧酸的碳链长度和钕离子配位结构的差异,引起配合物的吸收跃迁强度的变化。根据紫外可见近红外吸收图谱,计算获得了Judd-Ofelt参数和受激辐射跃迁特性。配合物的受激发射面积分别为:3.63×10-20,2.36×10-20和1.49×10-20 cm2,可以和文献报道的无机材料媲美,它们将是非常有潜力的液体激光介质。     

羧酸型聚芴/二氧化钛杂化材料的制备及其荧光猝灭行为

通过Suzuki偶合反应合成了聚[9,9-二辛基芴-9,9-双(丙酸基)芴](PF8COOH),并采用溶胶-凝胶法制备了羧酸型聚芴/二氧化钛(TiO₂)杂化材料。通过核磁共振氢谱(¹H NMR)、凝胶渗透色谱(GPC)、紫外-可见吸收光谱(UV-Vis)、X射线衍射(XRD)和荧光发射光谱对聚合物及其杂化材料进行了表征,并研究了杂化材料的荧光猝灭行为。结果表明,所合成的PF8COOH数均分子量为19 600,PF8COOH的紫外-可见吸收和荧光发射光谱较聚(9,9-二辛基芴)(PF8)均发生红移。通过溶胶-凝胶法制得了PF8COOH/TiO₂杂化材料,其中TiO₂主要为金红石型。杂化材料出现明显的荧光猝灭现象,TiO₂含量越大则杂化材料的荧光猝灭现象越明显。羧基的引入可使聚芴与TiO₂之间的相互作用增强,电子更容易从聚芴向TiO₂转移,因而PF8COOH/TiO₂杂化材料的荧光猝灭现象比PF8/TiO₂杂化材料更明显。     

EPR diagnostics of laser materials based on ZnSe crystals doped with transition elements

The electron paramagnetic resonance (EPR) spectra observed in laser materials based on zinc selenide (ZnSe) crystals doped with transition elements have been analyzed and identified. It has been shown that, in addition to working impurities (Cr²⁺, Co²⁺, or Fe²⁺), the diffusion layer exhibits EPR spectra of accompanying impurities due to the diffusion of transition elements (chromium, cobalt, or iron) used in the preparation of active materials for quantum electronics (lasers, switches) operating in the mid-infrared range. EPR diagnostics of these impurities can be used in the development of appropriate regimes for minimizing concentrations of accompanying impurities that adversely affect the performance characteristics of laser materials. It has been found that, during the diffusion of transition metals, ions of the accompanying impurity Mn²⁺, which is characterized by extremely informative EPR spectra, are embedded in the crystal lattice. It has been proposed to use these ions as ideal markers to control, on the electronic level, the crystal structure of the active diffusion layer.     

基于低温光声光谱技术的高Tc超导材料Bi2Sr2CaCu2O8

在光声光谱技术基础上,将不同仪器组装成一套系统,并成功测量出碳黑的光声光谱。利用低温检测系统测定高温超导材料Bi2Sr2CaCu2O8在室温和液氮温度下的光声光谱,发现室温时在598nm和695nm有峰值,液氮温度时在466nm出现峰值。以吸收系数近似为1的碳黑为参照,利用归一化方法得到了Bi2Sr2CaCu2O8相对吸收系数谱图,并进行了初步的探讨,得到了该超导材料的一些信息,为利用低温光声光谱技术,研究超导材料的超导特性提供了一种可行的途径。     

Interpretation of Mn2+ EPR spectra in disordered Materials

It is interesting to be able to estimate the values of the zero-field splitting parametersD andE appearing in the spin Hamiltonian of the Mn²⁺ ion in disordered materials, such as glass and polycrystalline samples. Since the electronic spin of the Mn²⁺ ion is 5/2 (>1/2), it is able to interact with the crystalline electric field of the environment to provide information on its surroundings. The present work attemps to interpret the intensities and positions of both the allowed and hyperfine forbidden EPR lines of the Mn²⁺ ion in disordered materials. First, a discussion is presented of the analytical expressions for the intensities and positions of the EPR lines in a monocrystal, which are then exploited by averaging to describe the expected behavior in disordered materials in order to estimate the values of the parametersD andE. The discussion is thereafter generalized to use computer simulations to generate Mn²⁺ EPR spectra in glassy and polycrystalline media. The effects of distribution ofD andE parameters and expected singularities in Mn²⁺ EPR spectra on the resulting EPR spectra in disordered materials are considered. Some published results are included to illustrate the application of the techniques described in this paper.     

Synthesis and characterization of TiO2/MoO3/carbon clusters composite material

Nano-sized TiO₂/MoO₃/carbon clusters composite material has been successfully obtained by the calcinations of a TiO(acac)₂/MoO₂(acac)₂/epoxy resin complex under an oxygen atmosphere. The compositions of the resulting composite materials were determined using inductively coupled plasma (ICP) spectroscopy, elemental analysis and surface characterization by X-ray diffraction (XRD) and transmission electron microscopy (TEM). The ultraviolet–visible (UV–Vis), X-ray photoelectron spectra (XPS) and electron spin resonance (ESR) spectra of the composites were also measured. ESR spectra of the composite materials suggest that they have visible light-responsive catalytic ability with an electron transfer process of carbon clusters → MoO₃ → carbon clusters → TiO₂.     

二氧化碲(TeO2)晶体的Raman光谱研究

利用激光显微高温Raman光谱仪 ,测定了TeO2 晶体的常温Raman光谱及高温熔体法生长TeO2 晶体固 液边界层的高温Raman光谱。通过分析 ,指认了TeO2 晶体的常温Raman谱图 2 0 0～ 80 0cm- 1 谱峰的振动模式 ,解析了高温Raman谱图各谱峰的展宽、频移 ,提出了熔体可能的结构基团 ,从而为研究功能性晶体材料生长机理提供了一定依据。