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31.
N. N. Andreychuk A. A. Frolov K. V. Rotmanov V. Ya. Vasiliev 《Journal of Radioanalytical and Nuclear Chemistry》1990,143(2):427-432
Plutonium(III) oxidation under high energy α-irradiation in nitric acid solutions has been studied relative to concentrations of both nitric acid (0.12–2.9 mol/l) and plutonium (1.4–10 mmol/l) using spectrophotometric techniques. Curium-244 has been used as the basic alpha-irradiation source. It has been stated that in solutions with nitric acid concentrations lower than 0.5 mol/l plutonium(III) does not oxidize completely. In the course of the process the formation of a plutonium(IV) peroxide complex is observed. Increase in the nitric acid concentration results in that in both the rate and degree of plutonium(III) oxidation. When cHNO 3 is higher than 0.5 mol/l the peroxide complex does not form and the process assumes an autocatalytic character. It has also been shown that plutonium(III) oxidation kinetics is significantly affected by nitrous acid, one of the nitrate ion radiolysis products. To describe plutonium chemical transformations under irradiation in nitric acid solutions, a kinetic scheme is proposed. The calculations have been carried out on a BESM-6 computer; a satisfactory agreement between the calculated and experimental data has been obtained. 相似文献
32.
Yu. A. Yuzhelevskii E. G. Kagan V. N. Frolov A. L. Klebanskii 《Chemistry of Heterocyclic Compounds》1968,4(1):24-28
The influence of the number of 3, 3, 3-trifluoropropyl(methyl)siloxane links (Φ/Φ) in the cyclotetrasiloxanes ΦmD4-m, where D represents the dimethylsiloxane link and m=0–4, on the rearrangement of these compounds in acetone solution under the action of sodium siloxanolate has been studied. The rearrangement takes place with the formation of a linear polysiloxane the degradation of which yields, in addition to the initial ring, cyclosiloxanes with a different structure. The rate of rearrangement of ΦmD4-m and of the formation of a linear polysiloxane rises with an increase in m from 0 to 3. The equilibrium concentration of the linear polysiloxane formed from ΦmD4-m is inversely proportional to m. Results have been obtained on the kinetics of the formation of the cyclosiloxanes ΦmDn, where m=0–5, n=0–5, and m+n=3–6, in the rearrangement of the rings ΦD3, Φ2D2, Φ3D, and Φ4. The reactivity of the siloxane links rises in the sequence ~ (CH3)2Si-O-Si(CH3)2 ~<~ (CF3CH2CH2)-(CH3) Si-O-Si(CH3)2 ~<(CF3CH2CH2) (CH3)Si-O-Si(CH3) (CH2CH2CF3) ~. Because of the negative inductive effect transferred through the siloxane links, the 3, 3, 3-trifluoropropyl groups strongly activate the siloxane ring with respect to nucleophiiic reagents. 相似文献
33.
S. N. Bolotin V. Yu. Frolov A. I. Shestavin A. I. Oflidi D. V. Kolechko V. T. Panyushkin 《Russian Journal of Inorganic Chemistry》2007,52(8):1211-1214
The influence of the conditions and the method of synthesis on the composition of copper(II) complexes with galactaric acid (H2Gala) has been studied. In aqueous and water-DMSO solutions, 1 : 1 complexes are formed. Depending on the procedure and conditions of the synthesis, CuGala · 4H2O, Cu(HGala)2 · 4H2O, and (CuOH)2Gala · 2H2O compounds have been obtained. The structure of the coordination environment of the metal ion has been identified by IR spectroscopy. 相似文献
34.
Steric and electronic structure of the methyl phenyl sulfide molecule was studied by nonempirical quantum-chemical methods. The calculations were performed by the B3LYP and MP2 procedures with account taken of electronic correlation using extended 6-311++G(3d,p) basis sets. The use of a balanced method and basis set allowed us to avoid discrepancy between the experimental and calculated data reported by other authors. The results confirmed coplanar orientation of the CÄSÄC fragment and the benzene ring, which follows from most experimental studies. 相似文献
35.
A A Frolov E I Zenkevich G P Gurinovich G A Kochubeyev 《Journal of photochemistry and photobiology. B, Biology》1990,7(1):43-56
On the basis of spectral fluorescence and polarization measurements and results obtained on the luminescence quenching of the membrane fluorescent probe 1,6-diphenyl-1,3,5-hexatriene (DPH) by incorporated chlorin e6 (chl e6) molecules, it is shown that the interaction of the water-soluble pigment with smaller unilamellar lipid vesicles occurs by a mechanism of partition between the aqueous and lipid phases (partition coefficient Kp = 6.7 x 10(3) and provides rigid fixing of chl e6 monomers at the boundary between the polar and non-polar parts of the lipid membrane. In terms of inductive resonance electronic excitation energy transfer between DPH and chl e6 (R0 = 36.2 A), we have analysed data on DPH fluorescence quenching under different conditions of chl e6 localization in the lipid bilayer and have concluded that the incorporation of the pigment molecules into the vesicles from the aqueous phase occurs mainly into the external monolayer. 相似文献
36.
B. A. Chapyzhnikov E. D. Malikova L. L. Kunin V. N. Samosyuk A. M. Vasserman E. V. Frolov Kh. N. Evganov 《Journal of Radioanalytical and Nuclear Chemistry》1973,17(1-2):275-290
Résumé On a étudié une méthode de séparation rapide des isotopes de courte période15O et13N dans les métaux alcalins et15O dans d'autres métaux pour déterminer l'oxygène et le carbone par activation γ à l'aide d'un microtron. 相似文献
37.
Calculations of three-electron atomic systems in Hylleraas coordinates require integrals involving all the interparticle distances r(ij), which have usually been evaluated by introducing series expansions. For integrals with the smallest powers of r(ij) these expansions do not converge at a satisfactory rate, leading some investigators to introduce convergence-acceleration procedures. This paper recommends the alternative of evaluating these integrals in closed form and presents stable explicit formulas for so doing. Some of the formulas are more compact versions of those in the literature; others have not been previously reported. It is also shown that finite-difference methods can be used with advantage to obtain additional low-order integrals. Sample integral values have been provided for test purposes. 相似文献
38.
I. I. Chuev S. M. Aldoshin E. G. Atovmyan D. B. Frolov A. N. Utenyshev 《Russian Chemical Bulletin》1996,45(4):851-855
N-Thenylidene- andN-(o-nitrobenzylidene)hydrazides of isonicotinic acid have been studied by X-ray structural analysis and IR spectroscopy. In the crystalline state, these molecules are linked through intermolecular N—H ... Npy hydrogen bonds. Carbonyl groups are not involved in intermolecular hydrogen bonds. However, it was found that the C=O group participates in an attractive interaction with the sulfur atom of the thiophene group. The energy of this interaction is comparable with the energies of intermolecular C=O ... H—N hydrogen bonds in amides.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 896–900, April, 1996. 相似文献
39.
40.
K. A. Frolov V. V. Dotsenko S. G. Krivokolysko 《Chemistry of Heterocyclic Compounds》2013,48(10):1555-1561