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971.
Z. G. Chrelashvili M. V. Mavrov A. V. Dolidze A. P. Voronkov E. P. Serebryakov 《Russian Chemical Bulletin》1993,42(4):734-736
Two syntheses of 7E,9Z-dodecadienyl acetate from 1,3-butadiyne were carried out using either 2E,4Z-heptadienyl acetate or 1-bromo-3E,5Z-octadiene as the key intermediates. The latter underwent organocopper cross-coupling with the respective complementary Grignard reagents (prepared from the corresponding 1-tert-butoxy--chlorohydrins) as alkylating agents.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 4, pp. 766–768, April, 1993. 相似文献
972.
The kinetics of Tl(III) acetate oxidation of semicarbazones of benzaldehyde and substituted benzaldehydes have been investigated
in aqueous (90%) acetic acid. Electron-releasing substituents in the phenyl ring enhance the rate of the reaction, whereas
electron-withdrawing substituents retard the rate. The rho value of −1 favours electron-deficient transition state. To account
for the major product of the reaction,viz respective benzaldehyde, a suitable scheme involving N-thallated intermediate has been proposed 相似文献
973.
In this article we determine the miscibility of azobenzene derivative (poly(4‐(N‐(2‐methacryloyloxyethyl)‐N‐ethylamino)‐4′‐nitroazobenzene)90‐co‐(methyl methacrylate)10)/poly(vinyl acetate) (PVAc) and azobenzene derivative/poly(vinyl chloride) (PVC) blends using Fourier Transform infrared (FT‐IR) spectroscopy. With this method we can clearly identify the exact interactions responsible for miscibility. In the azobenzene derivative 50:50PVAc blend new peaks were evident at 2960, 2890, 1237 and 959 cm?1, these peaks depict miscible interactions. These wavenumbers indicate that the miscible interactions occurring are from the C? H stretching band, the vinyl acetate C?O, conjugated to the ester carbonyl, the cis‐transformation N?N stretch frequency and the acetate ester weak doublet. The azobenzene derivative 80:20PVC blend display peaks identical in profile to the blend homopolymers, indicating no miscible interactions. However, this could be due to overlapping of peaks within the same wavenumber region, making resolution difficult. This research demonstrates FT‐IR can deduce favorable interactions for miscibility and therefore numerous miscible blends can successfully be calculated if possessing the same groups responsible for miscibility. This paves the way for a new generation of designer optical materials with the desired properties. Copyright © 2003 John Wiley & Sons, Ltd. 相似文献
974.
975.
Dong?Heng-ShanEmail author Wang?Dong-Dong Jin?Chi-Qiong 《Journal of chemical crystallography》2005,35(11):897-901
(4E)-5-(3-Chlorophenyl)-N-(4-chlorophenyl)-2-diazo-3-oxopent-4-enoic acid amide (5) was synthesized from p-chloroaniline to N-(4-chlorophenyl)-2-diazo-3-oxo-butyramide (4) with 3-chlorobenzaldehyde. The yielded product 5 was investigated with X-ray crystallographic, NMR, MS, and IR techniques. Compound 5 (C17H11Cl2N3O2, Formula wt = 360.19), crystallizes in the monoclinic space group P21/c with unit cell parameters a = 10.516(2), b = 17.996(4), c = 8.902(2) Å, α = 90.00, β = 105.36(3), γ = 90.00°. V = 1624.5(6) Å3, Z = 4, D x = 1.473 Mg m?3. The final R was 0.0511. 相似文献
976.
977.
2-Acetoxy-3-(3-methoxy-4-acetoxy-5-chlorophenyl)-propenoic acid 2 was synthesized from the azlactone of 5-chlorovanillin and its structure confirmed by X-ray crystallography and nuclear magnetic resonance methods. Compound 2 crystallized with a molecule of acetic acid in the P-1(#2) space group (Z = 2) and with cell dimensions a = 6.303(2), b = 9.779(1), c = 15.528(3) Å, = 101.46(2), = 100.71(2) and = 90.21(2)°. This study reveals the formation of an -acetoxy propenoic acid with a trans extended side acid side chain conformation. The 1H and 13C NMR spectral values of 2 also show the existence of the enolic ester in solution. 相似文献
978.
Anelise M. Regiani Elisabete Frollini Guilherme A. Marson Guilherme M. Arantes Omar A. El Seoud 《Journal of polymer science. Part A, Polymer chemistry》1999,37(9):1357-1363
Commercially available cellulose (Avicell PH101) was successfully acylated under homogeneous solution conditions by the following procedure: 2.0 g of cellulose were stirred with 75 mL of N,N‐dimethylacetamide for 1 h at 150°C, 3.5 g of LiCl were added, the temperature was raised to 170°C, ca. 18.5 mL of the solvent were distilled and the suspension was cooled to room temperature and stirred overnight. The temperature of the clear cellulose solution was raised to 110°C, kept at that temperature for 1 h, an acid anhydride was added and the solution stirred at 110°C for additional 4 h. Acetates, propionates, butyrates, and acetate/propionate mixed ester were prepared with excellent control of the degree of substitution, DS, 1 to 3 for acetates, 2 and 3 for propionates and butyrates, and 3 for acetate/propionate. The degree of polymerization of cellulose is negligibly affected under these reaction conditions. The distribution of the acetyl moiety among the three OH groups of the anhydroglucose unit shows a preference for the C6 position. © 1999 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 37: 1357–1363, 1999 相似文献
979.
Critical temperatures for polystyrene/methyl acetate (PS/MA) and polystyrene/ethyl formate (PS/EF) solutions were measured at positive (PS/MA, PS/EF) and negative (PS/MA) pressure. The results confirm that solvent quality is sensitive to pressure; some solvents, designated Θ, at Pnominal ∼ 0, undergo a Θ-to-poor transition at negative pressure, and others, nominally designated “poor,” show a poor-to-Θ transition at positive pressure. Thus, any dichotomous division into sets of “poor” and “Θ” solvents is inaccurate, unless it accounts for the effects of pressure and other variables on solvent quality. © 1997 John Wiley & Sons, Inc. J Polym Sci B: Polym Phys 35 : 1251–1259, 1997 相似文献
980.
A new method of synthesis of acetic acid in water has been developed from the carboxylation of methane with carbon monoxide using lanthanide catalysts. Ytterbium(III) acetate has been found to be the most active catalyst among the compounds of the lanthanide series in the carboxylation reaction of methane with carbon monoxide. Sodium hypochlorite or hydrogen peroxide was used as the oxidant in this reaction. Sodium hypochlorite exhibited more favorable activity than hydrogen peroxide in the reaction. The catalytic activity was improved by the addition of transition-metal salts such as manganese(II) acetate. The best result has been found at a ratio of manganese(II) acetate to ytterbium(III) acetate of 1:10. The optimum reaction conditions (reaction temperature, 40 °C; time, 20 h; methane, 20 atm; carbon monoxide, 5 atm) have been obtained. © 1998 John Wiley & Sons, Ltd. 相似文献