Correlation between structure and hardness of magnetron sputtering deposited CNx films

Carbon nitride films are deposited on Si (001) substrates by reactive dc magnetron sputtering graphite in a pure N2 discharge. The structure of carbon nitride films has been probed using Fourier transformation infrared, near edge X-ray absorption fine structure (NEXAFS) and high resolution electron microscopy (HREM), and the hardness has been evaluated in nanoin-dentation experiments. FTIR spectra show that N atoms are bound to sp1, sp2, and sp3 hybridized C atoms. C1s NEXAFS spectra show that the intensity of π* resonance is the lowest for the film grown at substrate temperature TS = 350℃, with a turbostratic-like structure and high hardness, while it is the highest for the film grown at TS = 100℃, with an amorphous structure and low hardness. The correlation between the structure and hardness of carbon nitride films has been discussed.     

N,N‘-双水杨醛缩环己二胺指纹区拉曼光谱研究

采用633 nm激光器,检测了合成的N,N'-双水杨醛缩环己二胺产物在指纹区的拉曼光谱,并根据密度泛函理论对其拉曼光谱进行理论模拟.该分子拉曼光谱检测值和理论值比较表明:在位移800 cm-1,该物质有一特征峰,初步将其归属为C-N-C两碳原子围绕N原子的剪式振动和苯环碳骨架伸缩振动的协同振动,这是该物质多个原子的集体...     

An unexpected palladium migration from vinylic sp<Superscript>2</Superscript> carbon to allylic sp<Superscript>3</Superscript> carbon

A unique transformation to realize the allylic amination from vinylic bromides was described and an unexpected C–Pd migration was observed from sp² carbon to adjacent allylic sp³ carbon initiated from vinyl bromide. Various 3-aryl-2-bromopropenes and secondary amines were surveyed and the allyl amination products were obtained in moderate isolated yields. The primary amine was not fit for this transformation. Mechanistic studies indicate that this migration went through β-hydride elimination and reverse C=C bond insertion.     

吴茱萸次碱结构和振动光谱的密度泛函理论研究

采用密度泛函理论B3LYP和B3PW91方法对吴茱萸次碱的几何结构进行了全优化,得到吴茱萸次碱的平衡几何结构参数,结果表明,吴茱萸次碱是一个平面结构的分子.在相同水平上计算了吴茱萸次碱的红外和拉曼振动光谱,依据计算结果,对吴茱萸次碱分子的振动基频进行了理论指认和归属.在红外光谱中,所有振动模式均具有红外活性,最强的振动频率为1 729 cm-1,摩尔吸光系数为1 461 L/(mol·cm),归属于C21O22的伸缩振动.在拉曼光谱中,吴茱萸次碱的所有振动模式也表现出了拉曼活性,最强的吸收峰频率为1 630 cm-1,吸收强度为170.8km/mol,由C21O22键的伸缩振动吸收所贡献.该研究结果可为进一步探讨吴茱萸次碱的结构和生物活性关系提供理论参考.     

Chemical composition of decomposing stumps in successive rotation of Chinese fir （Cunninghamia lanceolata （Lamb.） Hook.） plantations

Decomposition of stumps in successive rotation of Chinese fir （Cunninghamia lanceolata （Lamb.） Hook.） plantations was studied using a chronosequenee approach. The results showed that decomposition rate constant of Chinese fir stump was 0.02695 as calculated from Olson＇s model. The N content of stump increased during the first two-year decomposition. When the dead stump C/N ratio was 463.2 ± 27.3, the stumps started to release N. The pattern of P release was similar to that for N. However, K content of stumps showed a consistent declining trend over time during the whole decomposition. ^13C nuclear magnetic resonance spectroscopy with cross polarization and magic-angle spinning （^13C CPMAS-NMR） was used to analyse organic carbon （C） components in decomposing stumps. The ^13C CPMAS-NMR spectra of stumps displayed that stump was dominated by cellulose and hemieellulose. The spectra also showed the accumulation of intensity in alkyl C, aromatic C, and earboxyl C spectral regions, which was expected as the labile cellulose and hemieellulose components in O-alkyl C spectral region were selectively decomposed first.     

V掺杂对类金刚石薄膜性能的影响

通过磁控溅射的方法,使用石墨靶、V靶复合拼接靶,以氩气作为辅助气体,成功制备了不同原子分数的V掺杂类金刚石薄膜。采用拉曼光谱仪、电子探针X射线显微分析仪、X射线光电子能谱仪、原子力显微镜、扫描电子显微镜、纳米压痕仪、薄膜应力仪、往复摩擦磨损试验机等设备研究了V掺杂对类金刚石薄膜微观结构、力学性能、摩擦学性能的影响。结果表明,V掺杂提高了类金刚石薄膜的力学性能,当薄膜中V的原子分数为54.28%时,薄膜的硬度和弹性模量分别为14.1 GPa和147.6 GPa。掺杂V后,薄膜中生成了V₂O₅,降低了薄膜的耐磨性能。这主要是因为V促进了sp³杂化C数量的增加,并且在摩擦过程中,薄膜中的sp³杂化C的数量进一步增加,导致其硬度升高,耐磨性能下降。     

β-Ga2O3的高压原位拉曼光谱

利用金刚石对顶砧（DAC）高压装置产生高压, 在0~23.4 GPa研究β相氧化镓（β-Ga₂O₃）晶体高压原位拉曼光谱. 根据高压拉曼光谱的实验数据, 给出了β-Ga₂O₃晶体拉曼振动频率与压力的关系, 并将外振动谱线144 cm^-1归属于平移模, 169 cm^-1归属于转动模. 在18 GPa附近, 发现两个新的拉曼峰232 cm^-1和483 cm^-1, 由这两个峰的强度随压力的升高逐渐增强可知, β-Ga₂O₃晶体发生了压力导致的结构相变.      

室温沉积碳氮薄膜的成键分析

在前文对碳氮薄膜结构研究的基础上,分析了室温沉积碳氮薄膜的成键状况。结果发现,氮、碳ＸＰＳ结合能之差随氮碳原子比的增加而线性地减小;碳、氮峰可以分解为若干个子峰,但与化合物Ｃ３Ｎ４难以建立明显的联系。红外吸收和喇曼散射显示出类似的结果。因此,应对碳氮薄膜的检测结果持更审慎的态度。     

指纹频域内木糖拉曼光谱的研究

为深入了解木糖分子在指纹区（1000～400 cm-1）的特征振动,利用拉曼光谱仪,检测木糖得到该频域内的拉曼光谱,并用密度泛函理论选用B3LYP/6-311＋G＊＊基组,计算了木糖分子在该频域内的拉曼光谱。结果表明：检测值和理论值有很好的一致性。并根据势能分布进行分析,对振动进行归属和指认,该频域内的振动为基本上可以归属于木糖分子的即弯曲振动、剪式振动、扭曲转动以及伸缩振动,其他振动类型所占比例较小。这些振动可以作为木糖指纹区的特征振动。     

Ab initio calculation of structure and Raman and Infrared spectra of Trifluoromethylthiosulphenyl Chloride

The molecular model of Trifluoromethylthiosulphenyl Chloride, CF₃SSCl, was presented.Ab initio method was used to calculate the structure and Raman and Infrared spectra. The results show that CF₃SSCl possess stereoscopic structure ofC ₁ symmetry with a torsional angle of 94.2°. The potential energy distribution and isotope replacement methods were applied to determine the vibrational assignment. The vibrational frequencies and corresponding modes of the molecule were obtained. The calculated vibrational frequencies are in good agreement with experiments. Supported by the National Natural Science Foundation of China Zou Xianwu: born in Apr, 1938, Professor     

C60材料红外和拉曼特性

采用自制的专利设备成功地制备了全碳分子材料Ｃ６０，分析了红外，拉曼光谱图，发现在５２７，５７６，１１８７，１４３０ｃｍ＾－１处的４个Ｃ６０的红外特性吸收峰，进行了理论计算，结果与实验基本吻合，由红外测试数值计算得出的力常数结果表明，Ｃ６０内部原子间作用力的类型为Ｃ－Ｃ键和弱Ｃ＝Ｃ键。     

Algebraic approach to stretching vibrational spectrum of H2S

The stretching vibrational spectra of H₂S have been calculated by using the algebraic model, and the local mode characteristics have been analyzed. Within the vibrational quantav= 5, the standard deviation is 1.71 cm⁻¹, which is better than that from the local model HCAO model calculation.     

Modulation structure stability of heat-treated Co/C and CoN/CN soft X-ray multilayers

Modulation structure stability of Co/C and CoN/CN soft X ray multilayers has been investigated by X ray diffraction and Raman spectroscopy. The graphitization of the amorphous carbon layers in Co/C multilayers causes a period expansion of 12% at annealing temperatures below 400℃. An enormous period expansion (～40%) induced by the crystallization and agglomeration of Co layers has been observed at 500℃. While the period expansion of CoN/CN multilayers is only 4% at 400℃. The interface pattern of the CoN/CN multilayers still exists even if they were annealed at 700℃. The relatively good thermal stability of CoN/CN multilayers can be attributed to the suppression of the formation of the sp 3 bonding and, at annealing temperatures higher than the phase transition temperature of 420℃ (from hcp to fcc), the coexistence of hcp and fcc Co structures through doping nitrogen.     

反应等离子体制备碳锥及其表征

利用等离子体增强热丝化学气相沉积系统,用CH4、H2和NH3为反应气体,分别在沉积有钛膜和碳膜的Si片衬底上制备了锥形碳结构,采用场发射扫描电子显微镜(FESEM)、X射线能谱仪(EDX)和显微Raman光谱仪对其形貌和结构进行了表征.SEM结果表明在沉积有碳膜的Si片衬底上易形成碳锥,EDX谱和Raman谱进一步表明形成的碳锥为碳氮结构,由sp3 C-N、sp2 C和sp2 C=N键形成.根据溅射机制和扩散机制,分析了碳锥的形成.同时,还对碳锥Raman谱的荧光背景进行了分析,结果表明由于氮的掺杂,使得碳锥由非极性的碳材料变成为极性碳材料.     

High density methane inclusions in Puguang Gasfield: Discovery and a T-P genetic study

Based on measurement of homogenization temperature of inclusions and Raman spectral analysis, high density methane inclusions were discovered in the Triassic reservoirs of Puguang Gasfield. The methane inclusions show a homogenization temperature Th = -117.5― -118.1℃, a corresponding density of 0.3455―0.3477 g/cm3, and a Raman scatter peak v1 shift varying between 2911―2910 cm-1, which signifies a very high density of methane inclusions. The salt water inclusions paragenetic with methane inclusions show a homogenization temperature Th=170―180℃. Based on the composition of methane inclusions as determined by Raman spectra, PVTsim software was used to simulate the trapping pressure for high density methane inclusions in geologic history, and the trapping pressure was found to be as high as 153―160 MPa. Even though Puguang Gasfield is currently a gas pool of normal pressure, and the fluid pressure for the gas pool ranges between 56―65 MPa. However, data from this study indicates that remarkable overpressure may be generated at the stage of mass production of gas cracked from oils in Cretaceous, as high density methane inclusions constitute key evidence for overpressure in gas pool in geologic history. Meanwhile, discovery of small amounts of H2S, CO2 or heavy hydrocarbon in part of the high density methane inclusions indicates that the geochemical environment for trapping of inclusions may be related to formation of H2S. Therefore, the observation results can help to explore the thermochemical sulfate reduction （TSR） conditions for oil cracking and H2S formation.     

三种六元杂环化合物的吸收光谱的密度泛函理论计算

利用Gaussian98密度泛函理论(DFT)计算程序B3LYP方法,在6-31G(d,p)水平上对三种六元杂环化合物,进行几何构型优化及其振动分析。在此基础上,用单激发组态相互作用(CIS)方法计算了分子轨道组合系数和三种物质的吸收光谱。计算结果表明:三种化合物分子内部HOMO到LU-MO电子跃迁,哒嗪的电子是由杂原子N向C原子转移,而吡嗪和嘧啶电子转移方向刚好相反;计算所得光谱数据与实验结果吻合较好。     

Chemical leaching of an Indian bituminous coal and characterization of the products by vibrational spectroscopic techniques

High volatile bituminous coal was demineralized by a chemical method. The vibrations of the "aromatics" structure of graphite, crystalline or non-crystalline, were observed in the spectra at the 1600 cm-1 region. The band at 1477 cm-1 is assigned as V_R band, the band at 1392 cm-1 as V_L band and the band at 1540 cm-1 as G_R band. Graphite structure remains after chemical leaching liberates oxygenated functional groups and mineral groups. The silicate bands between 1010 and 1100 cm-1 are active in the infrared (IR) spectrum but inactive in the Raman spectrum. Absorption arising from C-H stretching in alkenes occurs in the region of 3000 to 2840 cm-1. Raman bands because of symmetric stretch of water molecules were also observed in the spectrum at 3250 cm-1 and 3450 cm-1. Scanning electron microscopy analysis revealed the presence of a graphite layer on the surface. Leaching of the sample with hydrofluoric acid decreases the mineral phase and increases the carbon content. The ash content is reduced by 84.5wt% with leaching from its initial value by mainly removing aluminum and silicate containing minerals.     

Ionization process of collision of Ne(3P0,2) with CO under molecular beam condition

The ionization of CO with metastable Ne( 3P 0,2) in a molecular beam was studied by measuring the emission spectra of CO +(A 2Π i -X 2Σ +). The nascent vibrational and rotational distributions of CO +(A) were calculated by spectral simulation and the results are discussed     

Temperature dependence of surface enhanced Raman scattering on C<Subscript>70</Subscript>

The temperature dependence of surface enhanced Raman scattering of the C70 molecule is reported. The Raman scattering of C70 molecules adsorbed on the surface of a silver mirror was measured at different temperatures. The experimental results indicate that the relative intensities of the Raman features vary with the temperature of the sample. When the temperature decreases from room temperature to 0℃, the relative intensifies of certain Raman bands decrease abruptly. If we like the strongest band 1565cm^-1 as a standard value 100, the greatest decrease approaches to 43%. However, with the further decrease in the temperature these relative intensities increase and resume the value at room temperature. And such a temperature dependence is reversible. Our results show that the adsorption state of the C70 molecules on the silver surface around 0℃ changes greatly with the temperature, resulting in a decrease in relative intensities for some main Raman features of C70 molecule. When the temperature is lower than 0℃, the adsorption state changes continually and more slowly. Synchronously, eight new Raman features, which have not ever been reported in fiterature, are observed in our experiment and this enriches the basic information of the vibrational modes for C70 molecule.     

Raman and infrared spectroscopic investigation of some hydrous LnTPPTS complexes (Ln=La,Sm)

The Raman and IR spectra of LnTPPTS·10H₂O [Ln=La,Sm, TPPTS=P(m-C₆H₄SO₃) ₃ ³⁻ ] complexes are reported. Based on the observed Raman and IR characteristic frequencies, a vibrational assignments has been made for these complexes. Coordination induces a lengthening of the S−O bonds and a shortening of the C−S bond. The C−S stretching frequencies should therefore increase while the position of the should move to a lower wavenumber. Vibrational modes of metal-oxygen polyhedron V _(La-O) at 146, 168,253 cm⁻¹ are the structural charactrization for coordinate bond of LnTPPTS complexes. Chen Zhenhua: Born in 1938, Professor