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111.
Masaru Matsuoka Akihiro Iwamoto Takeshi Ouchi Hiroshi Yoshioka Kazumi Nakatsu 《Journal of heterocyclic chemistry》1993,30(1):173-176
The structure of 1,4-dithiines obtained from orthodihalogeno heterocycles with thiocarbonyl compounds was determined by X-ray structure analysis of the intermolecular charge-transfer complex between 5,7,12,14-tetramethoxydibenzo[b,i]thianthrene and TCNQ. The formation of the thiazole ring has already been reported but the products were confirmed to be 1,4-dithiines by X-ray structure analysis and the previously reported results. 相似文献
112.
Yuko Uchio Yukio Isozaki Tsutomu Ota Atsushi Utsunomiya Mikhail M. Buslov Shigenori Maruyama 《Proceedings of the Japan Academy. Series B, Physical and biological sciences》2004,80(9):422
The Baratal limestone in the Gorny Altai Mountains, southern Siberia, occurs as large allochthonous blocks within a Cambrian accretionary complex that developed around the Siberia craton. Before the final accretion to Siberia in the Cambrian, the terrigenous clastic-free Baratal limestone was deposited directly upon a basaltic basement with a geochemical signature identical to that of modern oceanic plateau. The Baratal limestone with 598 ± 25 Ma (Early Vendian) Pb-Pb isochron age consists of three distinct facies; 1) massive lime mudstone with ooids and stromatolites, 2) bedded lime mudstone, and 3) limestone conglomerate/breccia dominated by ooid-bearing lime mudstone clasts. The first represents a shallow marine environment on top of an ancient oceanic plateau, while the latter two represent the deeper slope to bottom-of-slope facies of a plateau. The Vendian Baratal limestone provides the oldest example of a reconstructed shallow marine carbonate buildup complex developed on a plateau/seamount in a mid-ocean. 相似文献
113.
Katsuo Ohkata Yoshihiko Ohyama Yuko Watanabe Kin-ya Akiba 《Tetrahedron letters》1984,25(40):4561-4564
Substituents at 5-position of 5-amino-3-methyl- and 3-p-chlorophenyl-5-methylisothiazoles (7 and 8) were silylated and then lithiated to couple with aromatic nitriles in order to afford the adducts (4 and 5) via 1,3-silyl group shift. Desilylation of 5 with TBAF gave solely non-ring-transformed product (3-α-form). By using the pure sample of 3-α-form, the reversible ring-trans- formation (bond switch) was observed for the first time. 相似文献
114.
Hamada T Sato YT Yoshikawa K Nagasaki T 《Langmuir : the ACS journal of surfaces and colloids》2005,21(17):7626-7628
A photosensitive amphiphilic molecule can switch the shape of an assembled vesicle as determined by microscopic observation. Photoisomerization induces a change in membrane fluctuation behavior or a morphological transition between ellipsoid and bud shapes, depending on the asymmetrical degree of the initial shape. The mechanism of this reversible photoswitching in the vesicle morphology is interpreted in terms of a change in the effective cross-sectional area of the photosensitive molecule. 相似文献
115.
Yuko?Ogihara Richard?L.?SmithJr.Email author Hiroshi?Inomata Kunio?Arai 《Cellulose (London, England)》2005,12(6):595-606
Direct observations of the heating of microcrystalline cellulose (230 DP) in water at temperatures up to 410 °C and at pressures
up to 700 MPa were made with a batch-type microreactor. Cellulose particles were found to dissolve with water over temperatures
ranging from 315 to 355 °C at high pressures. Dissolution temperatures depended on water density and decreased from about
350 °C at a water density of 560 kg/m3 to a minimum of around 320 °C at a water density of 850 kg/m3. At densities greater than 850 kg/m3, the dissolution temperatures increased and reached a value of about 347 °C at 980 kg/m3. The cellulose dissolution temperatures were independent of heating rates for values ranging from 10 to 17 °C/s. The low
dependence of dissolution temperatures on the heating rates is strong evidence for simultaneous dissolution and reaction of
the cellulose. Different phenomena occurred depending on water density. At low densities, particles turned transparent and
seemed to dissolve into the aqueous phase from the surface. From 670 to 850 kg/m3, the cellulose particles visibly swelled just before completely collapsing and dissolving into the aqueous phase. The swelling
probably increased water accessibility and particle surface area and thus lead to the lower dissolution temperatures observed.
From 850 to 1000 kg/m3, the particles required longer times to dissolve and many fine brown-like particles were generated as the particles dissolved.
FT-IR spectra of the residues were analyzed. Residues formed from heating cellulose at high densities still retained some
cellulose character whereas those as low densities had little cellulose character, especially in the O–H stretching vibration
region. 相似文献
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Retro-allylation of homoallyl alcohol by rhodium catalysis occurs to generate allylrhodium species. This allylrhodium reacts with aldehydes to give the corresponding secondary alcohols in situ. Isomerization of these alcohols proceeds in the same pots to furnish the corresponding saturated ketones in good yields. [reaction: see text] 相似文献