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991.
Three-dimensional ab initio dipole moment surfaces and stretching vibrational band intensities of the XH3 molecules 总被引:1,自引:0,他引:1 下载免费PDF全文
Stretching vibrational band intensities of XH3 (X=N, Sb) molecules are investigated employing three-dimensional dipole moment surfaces combined with the local mode Hamiltonian model.The dipole moment surfaces of NH3 and SbH3 are calculated with the density functional theory and at the correlated MP2 level,respectively. The calculated band intensities are in good agreement with the available experimental data. The contribution to the band intensities from the different terms in the polynomial expansion of the dipole moments of four group V hydrides (NH3, PH3,AsH3 and SbH3) are discussed. It is concluded that the breakdown of the bond dipole approximation must be considered. The intensity “borrowing” effect due to the wave function mixing among the stretching vibrational states is found to be less significant for the molecules that reach the local mode limit. 相似文献
992.
甲醇在纳米TiO2作用下进行光催化氧化反应的机理研究 总被引:7,自引:0,他引:7
以纳米TiO2 为催化剂 ,以主波长为 36 4nm的汞灯为光源 ,用气相色谱法分别考察了 0 .1mol/L的甲醇、甲醛和甲酸水溶液进行光催化氧化反应的动力学规律 .Langmuir Hinshelwood方程进行核算结果证明 ,该组反应均为零级反应 .用TEM、XRD、SSA和XPS对催化剂进行表征 .根据XPS的检测结果提出了甲醇光催化氧化的反应机理 .TiO2 光激发活化时间约为 30~ 6 0min ,生成物及剩余反应物浓度随时间变化的曲线表明 ,该反应速率为HCH2 OH 相似文献
993.
994.
Xie Ping Ding 《Journal of Mathematical Analysis and Applications》2002,266(1):21-37
Some new generalized G-KKM and generalized S-KKM theorems are proved under the noncompact setting of generalized convex spaces. As applications, some new minimax inequalities, saddle point theorems, a coincidence theorem, and a fixed point theorem are given in generalized convex spaces. These theorems improve and generalize many important known results in recent literature. 相似文献
995.
996.
Li S Wang D Wang K Akamatsu T Ma Z Han J 《The Journal of the Acoustical Society of America》2007,121(6):3938-3946
Acoustic signals from wild Neophocaena phocaenoides sunameri were recorded in the waters off Liao-dong-wan Bay located in Bohai Sea, China. Signal analysis shows that N. p. sunameri produced "typical" phocoenid clicks. The peak frequencies f(p) of clicks ranged from 113 to 131 kHz with an average of 121+/-3.78 kHz (n=71). The 3 dB bandwidths delta f ranged from 10.9 to 25.0 kHz with an average of 17.5+/-3.30 kHz. The signal durations delta t ranged from 56 to 109 micros with an average 80+/-11.49 micros. The number of cycles N(c) ranged from 7 to 13 with an average of 9+/-1.48. With increasing peak frequency there was a faint tendency of decrease in bandwidth, which implies a nonconstant value of f(p)/delta f. On occasion there were some click trains with faint click energy presenting below 70 kHz, however, it was possibly introduced by interference effect from multiple pulses structures. The acoustic parameters of the clicks were compared between the investigated population and a riverine population of finless porpoise. 相似文献
997.
In order to achieve a higher lateral resolution required for ultraprecision measurement of microstructural workpieces, phase-only pupil filtering differential confocal microscopy (PFDCM), a new approach is proposed based on the differential confocal microscopy (DCM), which uses a three-zone phase-only pupil filter with lateral super-resolution capability obtained through optimized design to change the distribution of DCM three-dimensional point spread function, so that the DCM lateral resolution is therefore significantly improved while its axial resolution is slightly improved. Preliminary experimental comparison and analyses indicate that, the lateral and axial resolutions of PFDCM are better than 0.2 μm and 2 nm, respectively, when wavelength of incidence laser beam , numerical aperture of measuring lens NA=0.85, and lateral spot size with a three-zone phase-only pupil filter GT=0.65. It is therefore concluded that PFDCM is a new approach to further improvement of lateral resolution in laser probe measurement systems. 相似文献
998.
Jue Wei Xiao-Feng Xu Yue Ding Zhi-Hui Kang Yun Jiang Jin-Yue Gao 《Optics and Lasers in Engineering》2007,45(3):419
A method employing an isosceles prism and a right-angle one is developed for loss measurement in planar waveguides. During the measuring process, the isosceles prism is fixed and the right-angle prism fixed on the waveguide slides by following the waveguide. Only by adjusting the gap thickness we can realize the loss measurement in planar waveguides. The method is demonstrated with an Ag/Na ion-exchanged waveguide fabricated on BK7 glass from AgNO3 melt diluted with NaNO3 (mass ratio 1:9), with the condition of 4 h and . The experimental results show that the method has the advantages on convenient operation, accurate results and no required end polishing. 相似文献
999.
1,5-Dinitroaryl-1,4-pentadien-3-ones were synthesized with ultrasound irradiation in the presence of K(2)CO(3) as catalyst. The reaction mechanism and the factors influencing the product were also discussed. The present procedure is more convenient with shorter reaction time and higher yields compared with conventional methods. 相似文献
1000.
I. K. Bensafa P. Achenbach M. Ases Antelo C. Ayerbe D. Baumann R. Böhm D. Bosnar E. Burtin X. Defaÿ N. D'Hose M. Ding M. O. Distler L. Doria H. Fonvieille J. M. Friedrich J. Friedrich J. García Llongo P. Janssens G. Jover Mañas M. Kohl G. Laveissière M. Lloyd M. Makek J. Marroncle H. Merkel P. Merle U. Müller L. Nungesser B. Pasquini R. Pérez Benito J. Pochodzalla M. Potokar G. Rosner S. Sánchez Majos M. Seimetz S. Širca T. Spitzenberg G. Tamas R. Van de Vyver L. Van Hoorebeke Th. Walcher M. Weis 《The European Physical Journal A - Hadrons and Nuclei》2007,32(1):69-75
The beam-helicity asymmetry has been measured simultaneously for the reactions
p→epγ and
p→epπ
0 in the Δ(1232)-resonance region at Q
2 = 0.35(GeV/c)2. The experiment was performed at MAMI with a longitudinally polarized beam and an out-of-plane detection of the proton. The
results are compared with calculations based on dispersion relations for virtual Compton scattering and with the MAID model
for pion electroproduction. There is an overall good agreement between experiment and theoretical calculations. The remaining
discrepancies may be ascribed to an imperfect parametrization of some γ
(*)
N→πN multipoles, mainly contributing to the non-resonant background. The beam-helicity asymmetry in both channels (γ and π
0) shows a good sensitivity to these multipoles and should allow future improvement in their parametrization. 相似文献