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1.
2.
N. N. Zatsepina I. F. Tupitsyn A. I. Belyashova N. S. Kolodina A. A. Kane G. N. Sudakova 《Chemistry of Heterocyclic Compounds》1979,15(3):322-327
The chemical shifts of the methyl protons (
) in the PMR spectra and the integral intensities (A1/2) of the band of the symmetrical CH stretching vibration of the methyl group in the IR spectra were measured for an extensive series of methyl derivatives of aromatic and heteroaromatic compounds including 3-, 4-, 5-, and 6-substituted 1- and 2-methylnaphthalenes, 4-, 5-, 6-, and 7-substituted 2-methylquinolines, and 5- and 6-substituted 2-methylbenzothiazoles, as well as a number of two- and three-ring systems that do not contain substituents. The changes in the chemical shifts are interpreted with allowance for two principal contributions: the contribution from the ring currents and the contribution from the changes in the electron densities (q) on the H and C atoms of the methyl group. The fact of the existence of a linear relationship between the corrected (for the ring current)
values and the calculated (by the CNDO/2 method) electron charges qC and qH (the latter plays the dominant role) indicates that the electronic effects of the substituent make the principal contribution to the changes in the shielding constants of the protons of the methyl group in most of the investigated compounds. Similarly, the charges on the H and C atoms of the methyl group convey the trend of the integral intensities of the IR bands, thereby confirming the primarily electronic nature of the effects of structural factors on the A1/2 values.See [2] for communication 2.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 390–396, March, 1979. 相似文献
3.
I. F. Tupitsyn Yu. V. Puzanov A. Yu. Shibaev A. A. Kane S. A. Egorov 《Chemistry of Heterocyclic Compounds》1989,25(12):1342-1348
The intensities of the absorption bands of the CH stretching vibrations in the IR spectra of solutions of cyclopropane, aziridine, oxirane, and thiirane in CCl4 were measured. Quantum-mechanical calculations of these intensities were performed.Translated from Khimiya Geterotsikhlicheskikh Soedinenii, No. 12, pp. 1612–1619, December, 1989. 相似文献
4.
I. F. Tupitsyn N. N. Zatsepina A. I. Belyashova A. A. Kane 《Chemistry of Heterocyclic Compounds》1986,22(5):557-564
The kinetics of acid deuterium exchange in benzazoles carrying electron-donor substituents in the 5-, 6-, or 7-positions have been studied. Mass spectrometric studies have shown that exchange in 5-methoxy-1, 2-dimethylbenzimidazole takes place exclusively at one position in the benzene ring, in 5-chloro-, 7-chloro-,5-methoxy-2-methylbenzothiazole and 6-methoxy-2-methylbenzoxazole simultaneously in two positions, and in 6-methoxy-2-methylbenzothiazole the hydrogen at all three possible positions is exchangeable. Using quantum chemical reactivity indices (CNDO/2) in dynamic and state approximations, the orientational features of the reaction have been ascertained. The lack of agreement between the reactivities of the most reactive sites to exchange in heteroaromatic bicycles of similar structure and electrophilic localization energies is explained by differences in the energy profile of the reaction.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 679–687, May, 1986. 相似文献
5.
By means of the multichannel Hartree-Fock-Dirac method, the parameters β and α2 of the angular distribution of Auger electrons and the parameter β2 of their spin polarization are calculated for sodium, krypton, xenon, barium, mercury, and excited argon. Relevant Coulomb
matrix elements are determined by using orthogonal multielectron initial-and final-state wave functions for intermediate-type
coupling in a relativistic approximation. Exchange interaction is taken into account in all calculations. A comparison of
the results of calculations performed in the frozen-core approximation and those obtained with orthogonal initial-and final-state
wave functions reveals that the relaxation of core orbital processes has only a slight effect on the anisotropy parameters
of the angular distribution. The resulting values of the parameters β, α2, and β2 are compared with the results of different calculations. 相似文献
6.
A. A. Kaminskii V. V. Balashov E. A. Cheshev Yu. L. Kopylov A. L. Koromyslov O. N. Krokhin V. B. Kravchenko K. V. Lopukhin I. M. Tupitsyn V. V. Shemet 《Bulletin of the Lebedev Physics Institute》2016,43(12):371-374
The effect of sintering aids of SiO2, ZrO2, B2O3, and MgO oxides on the optimum sintering temperature, ceramics grain growth, total volume of residual pores, and optical quality of obtained ceramics is studied. The best combinations of sintering aids are found; as a result, YAG:Nd (1 at%) samples of ceramics of high optical quality are obtained. An original method for characterizing laser properties of ceramics is developed. Comparative measurements of main laser characteristics of the obtained ceramics and ceramics of the Konoshima Chemical Corp. Ltd wellknown in the world practice, are performed. 相似文献
7.
Volotka AV Glazov DA Andreev OV Shabaev VM Tupitsyn II Plunien G 《Physical review letters》2012,108(7):073001
A rigorous evaluation of the two-photon exchange corrections to the hyperfine structure in lithiumlike heavy ions is presented. As a result, the theoretical accuracy of the specific difference between the hyperfine splitting values of H- and Li-like Bi ions is significantly improved. This opens a possibility for the stringent test of the many-electron QED effects on a few percent level in the strongest electromagnetic field presently available in experiments. 相似文献
8.
Draganić I Crespo López-Urrutia JR DuBois R Fritzsche S Shabaev VM Orts RS Tupitsyn II Zou Y Ullrich J 《Physical review letters》2003,91(18):183001
We present the results of an experimental study of magnetic dipole (M1) transitions in highly charged argon ions (Ar X, Ar XI, Ar XIV, Ar XV) in the visible spectral range using an electron beam ion trap. Their wavelengths were determined with, for highly charged ions, unprecedented accuracy up to the sub-ppm level and compared with theoretical calculations. The QED contributions, calculated in this Letter, are found to be 4 orders of magnitude larger than the experimental error and are absolutely indispensable to bring theory and experiment to a good agreement. This method shows great potential for the study of QED effects in relativistic few-electron systems. 相似文献
9.
N. N. Zatsepina V. A. Zyryanov A. V. Kirova V. L. Rusinov I. Ya. Postovskii I. F. Tupitsyn 《Chemistry of Heterocyclic Compounds》1978,14(1):104-107
The rate constants for basic deuterium exchange of the methyl group (kD) in 2-phenyl-5-methyl-tetrazole (I) and 1-aryl-5-methyltetrazole (II) and its derivatives with a polar substituent (R) in the phenyl ring were measured. The increased CH acidity of II as compared with I [kD(II)/kD(I)20] is in agreement with the calculated and experimental values regarding the character of the electron-density distribution in the molecules. The effect of R on the rate of deuterium exchange of the methyl group correlates with the ° constants (=3.0, r = 0.997). The results of measurement of the kinetic isotope effect during deuterium (tritium) exchange in II (kD/kT1.8) are discussed in connection with the peculiarities of the stepwise reaction mechanism.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No.1, pp. 127–130, January, 1978. 相似文献
10.
Contributions of the superposition of configurations ns 25d 8+ns5d 8 n′s (n=1–5, n′=6–10) and ns 25d 6+ns5d 6 n′s (n=1–6, n′=7–10) to parameters a 5d 01 , a 5d 12 , and a 5d 10 of the hyperfine structure in the spectrum of the osmium atom OsI are calculated. It is shown that the nonzero contribution is made only to a 5d 10 . The effect of the spatial distribution of nuclear charge on the parameters of the hyperfine structure in the spectra of 187Os and 189Os isotopes and on the hyperfine anomaly for the 5d 76s levels in the spectrum of these isotopes is estimated. 相似文献