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1.
We have calculated total and differential cross-sections for 1s →ns (n = 2, 3, 4) electron impact excitation of hydrogen and hydrogenic ions at various energies in Coulomb-projected Born approximation.
Distortion due to static interactions, target polarization and exchange effects has been incorporated in the initial channel.
The present calculations have been compared with other theoretical and experimental results. 相似文献
2.
Analysis of a part of the meteorite which fell at Dergaon (India) on March 2, 16.40 local time (2001) is presented with the
help of FTIR, absorption and atomic spectra. The FTIR spectrum exhibits prominent absorption bands in the region 800–1100
cm−1, originating from the valence vibration of SiO4, a basic component of the silicate lattice. 相似文献
3.
The binuclear complex [Cu2(TS)(H2O)]·CH3OH, where TS denotes the binucleating ligand derived from the schiff base N,N′-bis(3-carboxylsalidene)trimethylenediamine, was obtained from the self-decomposition of mononuclear complex Na2CuTS·H2O. It crystallizes in the monoclinic system, space group P21/c. The lattice parameters are a=11.935(2)?,b=15.667(3)?,c=11.621(2)?,β=111.60(3)°,V=2020.2(7)?3, Z=4 with R=0.0467. The structure is made of binuclear units, in which two copper atoms are bridged by two phenolic oxygen atoms. The “inside”copper atom is coordinated by two nitrogens, two phenolic oxygens in a planar coordi-nation site, the copper atom deviates from the mean plane by 0.47?. The “outside” copper atom is five coordinated by two phenolic oxygen atoms、two equatorial carboxyl oxygen atoms and one axial water oxygen atom in a distorted tetragonal cone site, the copper atom is pulled out of the equatorial plane by 0.46?. 相似文献
4.
Andrea Posilicano 《Potential Analysis》1996,5(3):241-271
We prove a convergence theorem for sequences of Diffusion Processes corresponding to Dirichlet Forms of the kind
.We obtain convergence in total variation norm of the corresponding probability measures on the path space C(+;d) under hypotheses which, for example, are satisfied in the case of H
loc
1
(
d
)-convergence of the 's, but we can allow more singular situations as regards the approximating sequences. We use then these results to give a criterion of convergence for generalized Schrödinger operators in which the potential function should not necessarily exists as a measurable function. We obtain convergence not only in strong resolvent sense, but we also obtain convergence in the uniform operator topology up to sets of arbitrarily small Lebesgue measure. Applications to the problem of the approximation of ordinary Schrödinger operators by generalized ones corresponding to zero-range interactions are given. 相似文献
5.
Chun-Long?Chen Andrea?M.?Goforth Mark?D.?Smith William?R.?Gemmill Cheng-Yong?Su Hans-Conrad?zur?LoyeEmail author 《Journal of Cluster Science》2005,16(4):477-487
A new flexible ligand, 1,5-bis(8-oxaquinoline)-3-methylpentane (C5MeOQ), was synthesized and used in the preparation of the
new dinuclear copper(II) complex 1: [Cu2(μ-OMe)2(μ-C5MeOQ)(NO3)2]. Single crystal X-ray analysis revealed that complex 1 contains dinuclear Cu(II) units with bridging methoxo groups. The ligand, C5MeOQ, takes on a bent conformation in order to
connect to and complete the square planar coordination environment of both copper centers; and one of the two Cu(II) centers
adopts a distorted square planar configuration as a result of the ligand conformation. The magnetic properties of complex
1 were investigated by variable-temperature magnetic susceptibility measurements in the 100–300 K range. Interestingly, the
susceptibility data for complex 1 reveals that the compound is diamagnetic, suggesting the presence of very strong antiferromagnetic coupling interactions
between the adjacent Cu(II) centers. 相似文献
6.
《Journal of Coordination Chemistry》2012,65(23):3874-3892
AbstractThis analysis highlights the design, spectroscopic characterization and quantum mechanical calculation of some new dioxomolybdenum(VI) complexes of some dibasic tetradentate Schiff bases. Ligands were derived from mono 5-bromosalicylaldehyde-orthophenylenediamine (BrSal-OPD) and different 2-hydroxyketone derivatives. The characterization was performed by elemental analysis, FTIR, electronic, 1H NMR and mass spectra, magnetic and molar conductance studies. Structure of the ligands and complexes were designed depending on experimental data and computational studies. According to all data, distorted octahedral geometry was proposed where oxygen atoms are in cis position. Prepared complexes exhibit moderate antimicrobial properties when evaluated against some pathogenic bacteria and fungi. Pharmacokinetic parameters were calculated to search their biological action, for example, absorption, distribution, metabolism, excretion, and toxicity. 相似文献
7.
8.
Wan-Feng Zhang Xiao-Ping Xia Takahashi Eiichi Li Li Qing Yang Yan-Qiang Zhang Ya-Nan Yang Ming-Liang Liu Chunkit Lai 《Surface and interface analysis : SIA》2020,52(5):224-233
Secondary ion mass spectrometry (SIMS) has a wide range of applications in Earth Science research, thanks to its high precision and sensitivity, and its capacity in direct insitu micromeasurement. The technique is operated in ultra-high vacuum (UHV) conditions, especially for the measurement of volatiles such as hydrogen, or the water content in nominally anhydrous minerals (NAMs). To minimize the water background and obtain accurate and precise water contents in NAMs (eg, olivine) critical parameters such as presputtering time, field aperture (FA), dynamic transfer on/off, and primary beam current intensity were investigated for a CAMECA IMS 1280-HR system. When the chamber vacuum reaches approximately 2 × 10−9 mbar, we set the DTOS OFF, raster size to 50 μm and primary beam current to 5 nA, and used 2000 μm FA and 170-second presputtering time. Consequently, an approximately 1.2 ppmw water background and 3.6 ppmw limit of detection (LOD) were yielded, from analyzing the San Carlos olivine. Meanwhile, the water content and homogeneity of a range of olivine minerals were characterized for potential use as reference materials for SIMS water content measurement. Olivine water content calibration curve was also established by comparing the Fourier transform infrared (FTIR) results with the SIMS-measured 16O1H−/16O− ratios. Accuracy and precision of water content measurement were estimated to be better than approximately 10% in this study. 相似文献
9.
用XRD、IR和TPR等技术研究了钙钛矿型复合氧化物的晶体结构及其反应性能.整个组成范围内,LaNi_(i-x)Mn_xO_3(0.0≤x≤1.0)体系都生成单一钙钛矿相;x=0.0,0.6≤X≤1.0时为菱形晶系,0.2≤x≤0.5为立方晶系.IR和TPR研究表明,晶体结构对B—O键合作用存在较大影响.CO微反考察表明,本体系的催化活性与晶系存在密切关系,晶体对称性越高,反应活性越低.说明钙钛矿型复合氧化物的催化活性与体系活性中心的B—O键合作用能力有关. 相似文献
10.
Tar produced during biomass steam reforming is a complex mixture of single to multiple ring aromatic compounds and it is necessary to eliminate them in order to prevent any condensation-polymerisation problem. Tar steam reforming leads to additional hydrogen that improves gas production. Previous works have shown that olivine was active in tar removal during biomass gasification and the iron distribution into the mineral different phases has a real influence on its efficiency. A Fe/olivine catalytic system has been designed to study tar steam reforming. This work presents the Fe/olivine catalyst characterizations (XRD, Mössbauer, TPR) and compares the Fe/olivine and olivine reactivity in toluene steam reforming, a tar model molecule. At 850 °C, an important conversion (95%) was observed for Fe/olivine during 7 h. The strong interaction between iron and olivine, and the equilibrium between Fe0/FeII/FeIII seem to be responsible of the catalyst activity and stability in toluene steam reforming. 相似文献