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21.
JETP Letters - We demonstrate that the resonance recently observed by the CMS collaboration can be responsible for the deviation of the experimentally measured muon anomalous magnetic moment from... 相似文献
22.
S. K. Godunov 《Siberian Mathematical Journal》1989,30(1):54-63
Novosibirsk. Translated from Sibirskii Matematicheskii Zhurnal, Vol. 30, No. 1, pp. 70–81, January–February, 1989. 相似文献
23.
24.
25.
Experimental data (obtained by the authors and taken from the literature) on the structure and conformations of carbonyl molecules
in the ground and lower excited electronic states are presented. The structure of carbonyl fragments, the orientation of substituent
groups, the energy of the molecules in excited states, and the potential functions of the internal rotation and inversion
are considered. The structural similarities of the molecules are discussed.
M. V. Lomonosov Moscow State University, Chemical Faculty. Translated fromZhurnal Strukturnoi Khimii, Vol. 36, No. 2, pp. 269–285, March–April, 1995.
Translated by I. Izvekova 相似文献
26.
I. A. Godunov S. L. Lure N. N. Yakovlev V. A. Bataev 《Russian Journal of Physical Chemistry A, Focus on Chemistry》2007,81(1):47-57
A multipass cell with an optical path up to 120 m long was used to measure the vibronic absorption spectra of 2-methylpropanal-h1 (MPA-h1, (CH3)2CHCHO)) and 2-methylpropanal-d1 (MPA-d1, (CH3)2CHCDO)) over the frequency range 28200–31600 cm−1. The most intense spectral lines were assigned to transitions from vibrational levels of the cis and gauche MPA-h1 and MPA-d1 conformers in the ground electronic state (S
0) to vibrational levels of conformers 1 and 3 in the lowest singlet excited electronic state (S
1). According to our estimates, the origins (0
0
0
) of the 1
S
1) ← cis(S
0) and 3(S
1) ← cis(S
0) and also 1(S
1) ← gauche(S
0) and 3(S
1) ← gauche(S
0) electronic transitions were situated at 29147 and 29177, 29391 and 29417 cm−1, respectively, for MPA-h1 and at 29226 and 29240, 29480 and 29500 cm−1 for MPA-d1. The structure of conformers 1 and 3 in the S
1 state was shown to differ from the structure of the cis and gauche conformers in the S
0 state by the angle of rotation of the (CH3)2CH-isopropyl top and “pyramidal distortion” of the CCHO/CCDO carbonyl fragment. A series of fundamental frequencies of MPA
conformers in different electronic states were found. The potential functions of inversion were determined for the conformer
1-conformer 3 pairs of MPA-h1 and MPA-d1 from the experimental energy levels of inversion vibrations. The potential barriers to inversion and equilibrium displacements
of the CH/CD bond out of the CCO plane were found to be 735/675 cm−1 and ±34°/±32° for MPA-h1 and MPA-d1, respectively.
Original Russian Text ? I.A. Godunov, S.L. Lur’e, N.N. Yakovlev, V.A. Bataev, 2007, published in Zhurnal Fizicheskoi Khimii,
2007, Vol. 81, No. 1, pp. 52–62. 相似文献
27.
We propose an algorithm that transforms a real symplectic matrix with a stable structure to a block diagonal form composed of three main blocks. The two extreme blocks of the same size are associated respectively with the eigenvalues outside and inside the unit circle. Moreover, these eigenvalues are symmetric with respect to the unit circle. The central block is in turn composed of several diagonal blocks whose eigenvalues are on the unit circle and satisfy a modification of the Krein-Gelfand-Lidskii criterion. The proposed algorithm also gives a qualitative criterion for structural stability. 相似文献
28.
Vadim A. Bataev Eugeniy K. Dolgov Alexandr V. Abramenkov Vladimir I. Pupyshev Igor A. Godunov 《International journal of quantum chemistry》2002,88(4):414-425
The potential energy surface (PES) for the CHF2CHO molecule in the excited S1 state is calculated by the CASSCF method. The features of the 1‐ and 2‐D cross‐sections of PES are considered in comparison with those of the relative molecules. The vibrational frequencies are calculated in harmonic approximation and the vibrational energy levels for the inversion motion of the carbonyl fragment CCHaO and for the torsion motion of the CHF2‐top are calculated in anharmonic approximation by the 1‐ and 2‐D variational methods. The calculated data are compared with the experimental ones. The problems of the experimental data interpretation are considered. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002 相似文献
29.
Ekaterina V. Rastoltseva Vadim A. Bataev Alexander V. Abramenkov Vladimir I. Pupyshev Igor A. Godunov 《Journal of Molecular Structure》2010,939(1-3):14-21
Geometric parameters, harmonic and anharmonic vibrational frequencies, conformer energy differences and barriers to internal rotation were obtained for dicyclopropyl ketone (DCPK) in the ground electronic state through MP2, DFT, CCSD and CCSD(T) calculations. VFPA was used to improve the estimations of conformer energy differences and heights of barriers to internal rotation. The ab initio calculations demonstrated that there are three stable conformations of DCPK: the cis–cis, the cis–trans and the gauche–gauche. The energy of the gauche–gauche conformer is noticeably higher than the energy of the two other conformers, so this conformer was not found experimentally. To study the conformational dynamics of the DCPK molecule, one- and two-dimensional sections of the potential energy surface corresponding to the rotations of the cyclopropyl groups were calculated. These sections were used to calculate torsion transition energies and vibrational wave functions in anharmonic approach. It was found that there is a strong coupling of large-amplitude torsion motions in the area of the cis–cis and gauche–gauche conformers. 相似文献
30.
Sergey I. Bokarev Evgeny K. Dolgov Vadim A. Bataev Igor A. Godunov 《International journal of quantum chemistry》2009,109(3):569-585
Geometrical parameters of tetraatomic carbonyl molecules X2CO and XYCO (X, Y = H, F, Cl) in the ground (S0) and lowest excited singlet (S1) and triplet (T1) electronic states as well as values of barriers to inversion in S1 and T1 states and S1 ← S0 and T1 ← S0 adiabatic transition energies were systematically investigated by means of various quantum‐chemical techniques. The following methods were tested: HF, MP2, CIS, CISD, CCSD, EOM‐CCSD, CCSD(T), CR‐EOM‐CCSD(T), CASSCF, MR‐MP2, CASPT2, CASPT3, NEVPT2, MR‐CISD, and MR‐AQCC within cc‐pVTZ and cc‐pVQZ basis sets. The accuracy of quantum‐chemical methods was estimated in comparison with experimental data and rather accurate structures of excited electronic states were obtained. MP2 and CASPT2 methods appeared to be the most efficient and CCSD(T), CR‐EOM‐CCSD(T), and MR‐AQCC the most accurate. It was found that at equilibrium all the molecules under study are nonplanar in S1 and T1 electronic states with CO out‐of‐plane angle ranging from 34° (H2CO, S1) to 52° (F2CO, T1), and height of barrier to inversion varying from 300 (H2CO, S1) to 11,000 (F2CO, T1) cm?1. © 2008 Wiley Periodicals, Inc. Int J Quantum Chem, 2009 相似文献