电荷调控下Ti3C2O2和V2CO2吸附CH4的第一性原理计算

本文采用第一性原理计算首先研究了Ti3C2O2和V2CO2与CH4气体分子之间的相互作用,发现Ti3C2O2和V2CO2对CH4的吸附较弱属于物理吸附,不适宜用作探测CH4。在此基础上研究了电荷调控下CH4气体分子与Ti3C2O2和V2CO2之间的相互作用。结果表明：随着体系电荷态的增加,Ti3C2O2和V2CO2对CH4气体分子的吸附作用逐渐增加变为化学吸附。当体系电荷态大于或等于-2时,CH4气体分子在Ti3C2O2和V2CO2表面可以被有效捕获。撤去电荷后,Ti3C2O2、V2CO2与CH4气体分子之间的吸附恢复至物理吸附,CH4气体分子易脱附。因此,通过调控Ti3C2O2和V2CO2的电荷态,可以简单地实现CH4的捕获与释放。Ti3C2O2和V2CO2有望成为CH4探测或捕获材料。     

铕、铽四元配合物的合成及其发光性能

以对苯二甲酸(p-PA)、苯甲酸(BA)、邻(间、对)甲基苯甲酸[o(m、p)-MBA]和1,10-邻菲啰啉(phen)为配体,合成了4种Eu(Ⅲ)和4种Tb(Ⅲ)的四元配合物。通过EDTA配位滴定分析和元素分析,确定了各配合物的组成。利用红外光谱分析对配合物的结构进行了初步表征,在配合物中羧基氧原子和1,10-邻菲啰啉中的氮原子均参与了配位。在室温条件下,测定了各固体配合物的激发和发射光谱,结果表明:4种铕的四元配合物中,苯甲酸配合物在614 nm最强发射峰的荧光强度强于3种甲基取代苯甲酸配合物的荧光强度;4种铽的四元配合物中,以对甲基苯甲酸为配体的配合物在545 nm最佳发射峰和490 nm次强发射峰的荧光强度较高。     

BaCl2:Eu和BaCl2·2H2O:Eu微晶的发光特性

本文研究了用还原气氛法在箱式炉内制得的BaCl2:Eu2+微晶及进一步处理后得到的BaCl2·2H2O:Eu2+微晶的发光特性,包括发射光谱、激发光谱、热释光、光激励发光(存贮效应)及其温度依赖,就这些特性对BaCl2:Eu与BaCl2·2H2O:Eu进行了比较.根据发光光谱与激发光谱分析了它们具有良好光致发光特性的原因,讨论了这两种材料在热释光性能及光激励发光(存贮效应)上的明显不同,并对BaCl2·2H2O:Eu2+中Eu2+发光的增强提出了可能的解释.     

显微激光拉曼定量分析CO_2气体碳同位素组成方法研究

制备了一系列不同比例的~(12)CO_2/N_2和~(13)CO_2/N_2混合物,对样品进行显微激光拉曼测试分析后发现气体拉曼特征峰峰面积比与其摩尔分数比成正比例关系,拟合方程的斜率被认为是拉曼量化因子F_(12CO_2)和F_(13CO_2)。用气相组分中只含有~(12)CO_2和N_2的流体包裹体验证了当F_(12CO_2),为1.163 49时,根据气体的拉曼特征峰峰面积比能估算出其摩尔分数比。由线性拟合后的方程斜率得出F_(13CO_2)和F_(12CO_2)分别为1.610 86和1.163 49,它们的比率F_(13CO_2)/F_(12CO_2)是1.3845。在确定稳定同位素分子的拉曼参数和实验条件基础上,CO_2气体碳同位素摩尔分数比C_(12)/C_(13)可根据A_(12Co_2)/A_(13CO_2)(拉曼峰峰面积比)和F_(13CO_2)/F_(12CO_2)的乘积求出。此外,用已知摩尔分数比(C_(12)/C_(13))的人造包裹体验证了此方法具有一定的可行性,可以建立起定量分析CO_2气体碳同位素激光拉曼测试方法。     

应用特雷纳法和吉尔法求解脱硫脱硝中化学反应动力学方程

应用特雷纳法和吉尔法求解脱硫脱硝中一类化学反应动力学方程,均得到了满意的结果.分别讨论了NO-NO₂-N₂,NO-NO₂-N₂-O₂和NO-NO₂-N₂-O₂-H₂O系统,指出了各种系统脱除NO_x的途径.同时,讨论了加入CO₂及SO₂后,脱除NO_x和SO₂的情况.     

Upconversion Fluorescence of Er_2O_3 Doped BaF_2-TeO_2 and PbF_1-TeO_2 Oxyhalide Tellurite Glasses

ＵｐｃｏｎｖｅｒｓｉｏｎＦｌｕｏｒｅｓｃｅｎｃｅｏｆＥｒ_２Ｏ_３ＤｏｐｅｄＢａＦ_２－ＴｅＯ_２ａｎｄＰｂＦ_１－ＴｅＯ_２ＯｘｙｈａｌｉｄｅＴｅｌｌｕｒｉｔｅＧｌａｓｓｅｓ￥ＨＵＬｉｎ；ＪＩＡＮＧＺｈｏｎｇｈｏｎｇ；ＨＵＷｅｎｔａｏ；ＳＯＮＧＸｉｕｙｕ...     

新型FED荧光粉MSi2N2O2∶Eu2+(M=Sr,Ba)的发光性能

采用高温固相法合成了一系列新型绿色FED(Field Emission Display)荧光粉MSi2N2O2∶Eu2+(M=Sr,Ba),研究了该荧光粉在不同电压和电流密度下的发光特性.在电子束激发下,SrSi2N2O2:Eu2+的发射主峰位于541 nm,属于黄绿光发射;BaSi2N2O2∶Eu2+的发射主峰位于4...     

THE 82S1/2→62D EXCITATION TRANSFER OF RUBIDIUM ATOMS INDUCED BY COLLISIONS WITH GROUND-STATE RUBIDIUM AND HYDROGEN MOLECULES

The processes of excitation transfer from the 8²S_1/2 state to the 6²D state of rubidium in Rb(8²S_1/2)-Rb(5²S_1/2) and Rb(8²S_1/2)-H₂ collisions have been studied experimentally. During irradiating the Rb vapor, mixed with H₂, by two light beams for selective stepwise excitation, the Rb 8²S_1/2→5²P_3/2 direct fluorescence and the Rb 6²D_3/2→5²P_1/2 sensitized fluorescence have been measured as a function of H₂ gas pressure. The measurements yielded the cross-sections σ(8²S_1/2→6²D) and σ^*(8²S_1/2→6²D) of Rb 8²S_1/2→6²D excitation tranfer induced by collisions with 5²S_1/2 atom and H₂ molecules respectively. The results are discussed in detail.     

含硫双Schiff碱型配体的合成与表征

用桥联水杨醛OHC-C6H4O-R-OC6H4-CHO[R=-(CH2)2-，-(CH2)3-，-CH2CH2OCH2CH2-，-(CH2CH2O)2CH2CH2-]与肼基二硫代甲酸酯(H2NNH-CSSCH3)反应，合成了四个含硫双Sehiff碱，并进行了元素分析和IR,1HNMR、MS的表征，确定了其结构。     

Mechanical anisotropy and electronic properties of X2N2 (XH2 ): first-principles calculations*

The mechanical anisotropy, structural properties, electronic band structures and thermal properties of C₂ N₂ (CH₂ ), Si₂ N₂ (SiH₂ ) and Ge₂ N₂ (GeH₂ ) are detailed and investigated in this work. The novel silicon nitride phase Si₂ N₂ (SiH₂ ) and germanium nitride phase Ge₂ N₂ (GeH₂ ) in the Cmc 2₁ structure are proposed in this work. The novel proposed Si₂ N₂ (SiH₂ ) and Ge₂ N₂ (GeH₂ ) are both mechanically and dynamically stable. The electronic band calculation of the HSE06 hybrid functional shows that C₂ N₂ (CH₂ ), Si₂ N₂ (SiH₂ ) and Ge₂ N₂ (GeH₂ ) are all wide band gap semiconductor materials, and C₂ N₂ (CH₂ ) and Si₂ N₂ (SiH₂ ) are direct band gap semiconductor materials, while Ge₂ N₂ (GeH₂ ) is a quasi-direct band gap semiconductor material, the band gap of C₂ N₂ (CH₂ ), Si₂ N₂ (SiH₂ ) and Ge₂ N₂ (GeH₂ ) are 5.634 eV, 3.013 eV, and 2.377 eV, respectively. The three-dimensional and plane distributions of Young’s modulus, shear modulus and Poisson’s ratio of C₂ N₂ (CH₂ ), Si₂ N₂ (SiH₂ ) and Ge₂ N₂ (GeH₂ ) show that these materials have different degrees of mechanical anisotropy. The order of Young’s modulus of Si₂ N₂ (SiH₂ ) and Ge₂ N₂ (GeH₂ ) in different directions is different from that of C₂ N₂ (CH₂ ). When the tensile axis is in a particular direction, the order of the Young’s modulus of Si₂ N₂ (SiH₂ ): E _[110] <E _[120] <E _[111] <E _[101] <E _[010] =E _[100] <E _[011] <E _[001], and the order of the Young’s modulus of Ge₂ N₂ (GeH₂ ): E _[110] <E _[111] <E _[101] <E _[120] <E _[100] <E _[010] <E _[011] <E _[001] .     

含ME4(M＝Mo,W;E＝S,Se)单元簇合物的合成和红外谱表征

合成了一系列单立方烷Ｍ－Ｆｅ－Ｓｅ和Ｍ－Ｃｕ（Ａｇ）－Ｓ（Ｓｅ）簇合物,并用ＵＶ,ＩＲ和Ｘ－光衍射等方法对上述簇合物进行了分析。     

BaO-Li2O-B2O3三元系中BaB2O4-Li2B2O4和BaB2O4-Li2O截面相平衡关系的研究

本文用X射线和差热分析方法对BaO-Li₂O-B₂O₃三元系中的两个截面:BaB₂O₄-Li₂B₂O₄和BaB₂O₄-Li₂O作了研究。在BaB₂O₄-Li₂B₂O₄赝二元系中发现了一个新的化合物4BaB₂O₄·Li₂B₂O₄。化合物在930±3℃由包晶反应形成,并与Li₂B₂O₄形成共晶反应。共晶温度为797±3℃,共晶点组分为79mol％Li₂B₂O₄。在BaB₂O₄-Li₂O截面中也存在化合物4BaB₂O₄·Li₂B₂O₄,其包晶反应温度从930±3℃随Li₂O含量增加下降到908±3℃。在组分60mol％Li₂O处形成另一个新的化合物2BaB₂O₄·3Li₂O。该化合物在630±3℃也是由包晶反应形成,并与Li₂O和Li₂CO₃分别形成共晶反应,共晶温度分别为400±3℃和612±3℃。在BaB₂O₄-Li₂B₂O₄和BaB₂O₄-Li₂O体系中都没有观察到固溶体。用计算机程序分别对化合物4BaB₂O₄·Li₂B₂O₄和2BaB₂O₄·3Li₂O的X射线粉末衍射图案进行了指标化,其结果:4BaB₂O₄·Li₂B₂O₄的空间群为Pmma,a=13.033?,b=14.630?,c=4.247?,每个单胞包含两个化合式单位;2BaB₂O₄·3Li₂O的空间群为Pmmm,a=4.814?,b=9.897?,c=11.523?,每个单胞也含有两个化合式单位。 关键词：     

苯丙氨酸桥联金属双卟啉的诱导圆二色光谱研究

本文报道了邻位和对位桥联苯丙氨酸锌双卟啉的合成，考查了双卟啉的分子结构对诱导圆二色性的影响。结果表明，两个卟啉环之间的π－π堆积和手性激子偶合作用是影响此类双卟啉圆二色光谱的主要因素。     

Synthesis of ternary compound in H-S-Se system at high pressures

The chemical reaction products of elemental sulfur (S), selenium (Se), and molecular hydrogen (H₂) at high pressures and room temperature are probed by Raman spectroscopy. Two known compounds H₂S and H₂Se can be synthesized after laser heating at pressures lower than 1 GPa. Under further compression at room temperature, an H₂S-H₂Se and an H₂S-H₂Se-H₂ van der Waals compounds are synthesized at 4 GPa and 6 GPa, respectively. The later is of guest-host structure and can be identified as (H₂S)_x(H₂Se)_(2-x)H₂. It can be maintained up to 37 GPa at least, and the stability of its H₂Se molecules is extended:the H-Se stretching mode can be detected at least to 36 GPa but disappears at 22 GPa in (H₂Se)₂H₂. The pressure dependence of S-H and Se-H stretching modes of this ternary compound is in line with that of (H₂S)₂H₂ and (H₂Se)₂H₂, respectively. However, its hydrogen subsystem only shows the relevance to (H₂S)₂H₂, indicating that this ternary compound can be viewed as H₂Se-replaced partial H₂S of (H₂S)₂H₂.     

Pressure-tuning resonance between the vibron and the libron in crystalline methylene halides

Abstract

The high-pressure Raman spectra of crystalline methylene halides (CH2Cl2, CH2ClI, CH2Br2, CH2BrI and CH2I2) have been measured to study the resonance phenomena between the vibron and the libron. The pressure-tuning resonances were observed around 4 3 and 2 5 kbar for CH2Br2 and CH2BrI, and their vibron-libron coupling constants were determined to be 10.3 and 4 cm^?1, respectively. The same resonance was not observed for CH2ClI; the libron just passes through the vibron mode without mutual interaction. From these results, including more CH2Cl2 and CH2I2, we investigate the dominant factors to determine the possibility of observing pressure-tuning of the vibron-libron resonance and present a systematic explanation of new phenomenon in methylene halides.     

金属-糖胺配合物的合成,光谱表征及催化酯类水解的动力学研究

合成了4种新的糖胺 金属配合物,分别为[Ni(HL) (H2 O) 2 ]2 Cl2 ·CH3OH·2H2 O ,[Cu(HL) ]2 Cl2 ·CH3CH2 OH·3H2 O ,[Zn(HL) ]2 Cl2 ·H2 O ,[Co(HL) (H2 O) (OH) ]2 Cl2 ·CH3OH·2H2 O (HLN ,N′ 二βD 葡萄糖基乙二胺) ,并用元素分析、红外、紫外、核磁共振氢谱对其结构进行了表征。结果表明,Ni(Ⅱ) ,Co(Ⅲ)配合物为八面体构型,而Cu(Ⅱ) ,Zn(Ⅱ)配合物为四面体构型。最后研究了其对对硝基苯吡啶甲酸酯(PNPP)催化水解的催化速率常数。     

杂多阴离子柱撑水滑石层柱相互作用的光电子能谱研究

本文用Ｘ－光电子能谱仪对二十二种同多和杂多阴离子柱撑水滑石层和柱中元素电子结合能的化学位移进行了研究。同时通过ＩＲ，ＸＲＤ的分析，对ＸＰＳ结果的讨论提供了一定的补充，探讨了同层不同柱，同性不同层的ＰＯＭ－ＬＤＨＳ的层柱相互作用机理。     

金属羰基化合物（CpFe（CO）2）2与金属氧化物表面作用的傅里叶变…

用漫反射红外光谱和光声红外光谱研究了金属羰基化合物（ＣｐＦｅ（ＣＯ）２）２Ｃｐ＝η＾５－Ｃ５Ｈ５与酸性，中性和碱性Ａｌ２Ｏ３及ＴｉＯ２的相互作用，结果表明，在Ａｌ２Ｏ３表面生成的洗生物种类及浓度与Ａｌ２Ｏ３的酸碱度明显相关，在酸性Ａｌ２Ｏ３表面，主要存在衍生物（ＣｐＦｅ（ＣＯ）２Ｆｅ－Ｈ－Ｆｅ（ＣＯ２Ｃｐ）＾＋及少量的ＣｐＦｅ（ＣＯ）２（－Ｏ－）；在中性Ａｌ２Ｏ３表面存在的ＣｐＦｅ（ＣＯ）２（－Ｏ     

拓扑相MoS2电子结构及光学性质的第一性原理研究

基于密度泛函理论的第一性原理对二维拓扑相1T′-MoS₂和2M-MoS₂的电子结构、有效质量和光学性质进行研究,并将其与二维H-MoS₂进行对比分析.研究表明,电子有效质量大小关系为：2M-MoS₂22,空穴有效质量大小关系为：T′-MoS₂<2M-MoS₂2,但2M-MoS₂的空穴有效质量和T′-MoS₂相差不大,二者均适用于高性能电子器件.由于拓扑相1T′-MoS₂和2M-MoS₂均存在能带反转,导致带间相关性以及导带和价带的波函数重叠增强,进而光电流响应增强,二者的光学性质均优于H-MoS₂. 2M-MoS₂具有较大的吸收系数和光电导率,2M-MoS₂对红外光和紫外光有着优...     

Au_(38)团簇上小分子H_2O和O_2共同吸附的第一性原理研究

利用密度泛函理论(DFT)计算的方法,对O_2,H_2O单独吸附和共吸附在Au_(38)团簇上的吸附性质进行了结构,能量和电子分析.计算结果表明,O_2倾向于吸附在edge位,H_2O则倾向于吸附在top位.Au(100)表面较之Au(111)表面更有利于O_2,H_2O的吸附,这与实验结果相符合.H_2O和O_2共吸附研究表明,H_2O的存在促进了O_2的吸附.Mulliken和分态密度(PDOS)分析得出:在共吸附中,H_2O将部分电子转移给了O_2,促进了O_2的活化与解离,并生成了类似H_2O_2的中间态,从而为催化氧化反应提供了O活性物种.