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121.
A. N. Veselkov L. N. Dymant S. F. Baranovskii P. A. Bolotin O. S. Zav'yalova D. A. Veselkov H. Parkes D. Davies 《Journal of Structural Chemistry》1995,36(1):69-75
This paper presents the results of a proton magnetic resonance study (500 MHz) of self-association of actinomycin D (AMD)
antibiotic in an aqueous solution. The equailibrium constants and thermo-dynamic parameters (ΔH, ΔS) of molecular association
as well as the limiting values of proton chemical shifts of associate molecules were determined from the concentration and
temperature dependences of1H NMR chemical shifts of AMD. The results were analyzed using dimeric and infinite-dimensional cooperative models of molecular
self-association. The value of the cooperativity parameter indicates that AMD self-association is anticooperative, i.e., formation
of aggregates larger than dimers is energetically unfavorable. The values of induced proton chemical shifts were used to determine
the most probable mutual orientation of chromophores in AMD structure.
Sevastopol State Technical University. Berkbeck College, London University. Translated fromZhurnal Struktumoi Khimii, Vol. 36, No. 1, pp. 81–88, January–February, 1995.
Translated by L. Smolina 相似文献
122.
M. A. Mikhaleva B. M. Bolotin E. S. Serebryakova R. U. Safina T. A. Kizner E. G. Sklyarova 《Chemistry of Heterocyclic Compounds》1992,28(3):316-320
Analogs of known mesogenic 2,5-diarylpyrimidines, 5-[p-alkyl(alkoxy)phenyl]-2-(o-hydroxy-p-alkoxyphenyl)pyrimidines (I), have been synthesized that have a wider mesogenic phase temperature range. Pyrimidines I show smectic C and A phases but not the nematic phase.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 377–381, March, 1992. 相似文献
123.
L.-M. Balevi
ius A. Bolotin D. Shatkovskaya 《International journal of quantum chemistry》1990,38(2):225-229
The dependence of the long-wave absorption-band intensity on the structural peculiarities of a number of polymethine dyes has been investigated using the PPP method. It has been shown that the analyzed dependence is caused by the electronic properties of the substitutes. 相似文献
124.
P. P. Pipiraite A. B. Bolotin B. N. Gorbunov 《Theoretical and Experimental Chemistry》1991,27(2):152-156
Heats of reaction describing the mechanism of antioxidant action of phenols in polyolefins have been calculated by the MNDO quantum-chemical method. It has been shown that reactions producing substituted quinones will proceed the most readily. The influence of substituents on the heat of reaction has been investigated.Vilnius University. Materials, Tambov. Translated from Teoreticheskaya i 8ksperimentaI'naya Khimiya, Vol. 27, No. 2, pp. 165–170, March–April, 1991. Original article submitted February 16, 1990. 相似文献
125.
M. V. Loseva B. M. Bolotin G. A. Bogdanova B. M. Krasovitskii 《Chemistry of Heterocyclic Compounds》1972,8(5):557-561
Nitro-substituted 2-phenyl- and 2-(2-tosylaminophenyl)-4H-3,1-benzoxazin-4-ones were synthesized. The UV, IR, and luminescence spectra were studied. The position of the nitro group affects the strength of the intramolecular hydrogen bond (IHB). The luminescence properties of nitro-substituted 2-(2-tosylaminophenyl)-4H-3,1-benzoxazin-4-ones are associated with the strength of the IHB. The luminescence maximum is shifted to the short-wave region as the IHB becomes stronger.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 5, pp. 616–621, May, 1972. 相似文献
126.
Precessions of the 2 1 + states in198Pt and192Os have been measured in the enhanced transient hyperfine magnetic field acting on these nuclei as they recoiled through thin polarized cobalt foils. Two separate targets consisting of contiguous layers of198Pt and192Os electrodeposited on ~1 μm and ~4 μm Co foils were employed. The levels of interest were Coulomb excited by 80 MeV32S and 220 MeV58Ni beams and the precessions of the 2 1 + →0 1 + γ-ray angular distributions in both nuclides were measured simultaneously. The results of these studies are compared with recently reported similar studies in which ions of188Os and194Pt recoiled through thin polarized Fe foils. It is concluded that (i) the transient field acting on Pt in Fe is singularly anomalous, and (ii) the recent contention that the g-factors of the 2 1 + states in the event Pt isotopes may be substantially lower than had been reported in the literature cannot be sustained. This transient field discontinuity is examined in terms of possible molecular orbital electron vacancy sharing between Pt and Fe. 相似文献
127.
The effect of the nature of an ion exchanger and a plasticizer on the selectivity of ion-selective electrodes for cations of primary-tertiary amines and quaternary ammonium bases was studied. The increments of methylene and ionic groups in the logarithms of selectivity coefficients were calculated. It was demonstrated that the effect of the membrane composition on the selectivity coefficient was governed by changes in the increments of corresponding groups. The maximum change in selectivity, which may attain three orders of magnitude, was observed for pairs of primary-quaternary alkylammonium cations. It was shown that the effect of the nature of the cation exchanger on selectivity coefficients was comparable with that of the plasticizer nature. 相似文献
128.
Feynman diagrammatic technique was used for the calculation of Hartree-Fock and correlation energies, relativistic corrections, dipole matrix element. The whole energy of atomic system was defined as a polen-electron Green function. Breit operator was used for the calculation of relativistic corrections. The Feynman diagrammatic technique was developed for 〈HB>. Analytical expressions for the contributions from diagrams were received. The calculations were carried out for the terms of such configurations as 1s2 2sn1 2pn2 (2 ≧n1≧ 0, 6≧ n2 ≧ 0). Numerical results are presented for the energies of the terms in the form $$E = E_0 Z^2 + \Delta {\rm E}_2 + \frac{1}{Z}\Delta {\rm E}_3 + \frac{{\alpha ^2 }}{4}(E_0^r + \Delta {\rm E}_1^r Z^3 )$$ and for fine structure of the terms in the form $$\begin{gathered} \left\langle {1s^2 2s^{n_1 } 2p^{n_2 } LSJ|H_B |1s^2 2s^{n_1 \prime } 2p^{n_2 \prime } L\prime S\prime J} \right\rangle = \hfill \\ = ( - 1)^{\alpha + S\prime + J} \left\{ {\begin{array}{*{20}c} {L S J} \\ {S\prime L\prime 1} \\ \end{array} } \right\}\frac{{\alpha ^2 }}{4}(Z - A)^3 [E^{(0)} (Z - B) + \varepsilon _{co} ] + \hfill \\ + ( - 1)^{L + S\prime + J} \left\{ {\begin{array}{*{20}c} {L S J} \\ {S\prime L\prime 2} \\ \end{array} } \right\}\frac{{\alpha ^2 }}{4}(Z - A)^3 \varepsilon _{cc} . \hfill \\ \end{gathered} $$ Dipole matrix elements are necessary for calculations of oscillator strengths and transition probabilities. For dipole matrix elements two members of expansion by 1/Z have been obtained. Numerical results were presented in the form P(a,a′) = a/Z(1+τ/Z). 相似文献
129.
E. V. Gordeev V. K. Dolganov S. P. Krylova B. M. Bolotin 《Russian Physics Journal》1987,30(8):677-681
The liquid crystal 50B7A in the smectic A and nematic phases was studied by the method of polarization luminescence. The order parameters P2 and P4 were determined from the experimental values of the luminescence spectrum both neglecting and taking into account relaxation processes in the liquid crystal. The orientational distribution function of the molecules in the ground and excited states are constructed. The orientational relaxation time (10–9 sec for the nematic and smectic A phases) is calculated. The results obtained are compared with calculation of the rotational relaxation time determined from the coefficient of diffusion for the related compound EBBA.Translated from Izvestiya Vysshikh Uchebnykh Zavedenii, Fizika, No. 8, pp. 39–43, August, 1987. 相似文献
130.
M. V. Il’in D. S. Bolotin M. Ya. Demakova M. S. Avdontseva 《Russian Journal of General Chemistry》2016,86(4):806-809
A series of para-substituted aromatic aminonitrones p-RC6H4C(NH2)=N+(Me)O– (R = NMe2, H, Br, Cl, CF3) have been prepared. Acidity constants of the conjugate acids RC6H4C(NH2)N+(Me)OH at 25°C in a EtOH–H2O mixture (5: 95) have been determined by potentiometric titration. A linear correlation between log (kR/kH) and σpara values has been revealed, and a ρ298(σpara) parameter has been determined as of 0.635. 相似文献