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121.
Isanu Nagata Kazuhiro Tamura Kaoru Tada Fumihiro Nishikawa 《Journal of solution chemistry》2000,29(9):815-835
An association model is presented to describe vapor–liquid equilibria,liquid–liquid equilibria, and excess enthalpies of binary and ternary liquid solutionscontaining alcohols, aniline, and/or acetonitrile using the concepts of linearself-association of associated components and of solvation between unlike molecules.Calculated results also show that the model works well in representing thethermodynamic properties for alcohol + aniline, alcohol + acetonitrile, andalcohol + alcohol mixtures. 相似文献
122.
The effect of the surface magnetic anisotropy on the critical behavior at surfaces is studied by using the 1/n expansion technique. Several surface critical exponents are obtained for the anisotropic special transition at arbitrary spatial dimensions. 相似文献
123.
Kaoru Nakamura Masato Higaki Kazutoshi Ushio Shinzaburo Oka Atsuyoshi Ohno 《Tetrahedron letters》1985,26(35):4213-4216
Ketones in β-keto esters are reduced asymmetrically by immobilized bakers' yeast. The configuration and the enantiomer excess of the products are dramatically changed by the entrapment of yeast cells in dense polyurethane matrices. 相似文献
124.
125.
Argon arc plasma induced a powerful and stepwise oxidation reaction including conversion of methyl group to carboxyl group, oxidative cleavage of carbon-carbon bond, and oxidative deamination. Main active species were considered to be hydroxyl radicals by decomposition of water molecules. 相似文献
126.
Tsubaki K Tanima D Nuruzzaman M Kusumoto T Fuji K Kawabata T 《The Journal of organic chemistry》2005,70(12):4609-4616
Various types of chiral host molecules 2-7 based on a phenolphthalein skeleton and two crown ethers were prepared for use in visual enantiomeric recognition, and we examined their enantioselective coloration in complexation with chiral amino acid derivatives 9-22 in methanol solution. Methyl-substituted host (S,S,S,S)-3 showed particularly prominent enantiomer selectivity for the alanine amide derivatives 11 and 12. A combination of methyl-substituted host (S,S,S,S)-3 with guest (R)-11 or (R)-12 developed a purple color, whereas no color development was observed with (S)-11 or (S)-12. On the other hand, phenyl-substituted host (S,S,S,S)-6 showed deeper coloration with a wide range of (S)-beta-amino alcohols compared to that seen with host (S,S,S,S)-6 and the corresponding (R)-beta-amino alcohols at 0 degrees C. Furthermore, absorbance inversion temperatures (AIT) were observed within the range of 0-50 degrees C in many cases. 相似文献
127.
Kaoru Ikeda 《Letters in Mathematical Physics》1991,23(2):121-126
We consider the Hamiltonian systems on the Poisson structure of GL() which is introduced from the quantum group GL
q
() by the so-called quasi-classical limit of GL
q
(). Furthermore, we show that the Toda lattice hierarchy is a Hamiltonian system of this structure. 相似文献
128.
An alternative synthetic route to 1,4,5-trisubstituted imidazoles from α-imino ketone, which can be prepared from imidoyl chlorides and aromatic aldehydes via N-heterocycle carbene-catalyzed aroylation was developed. This methodology consists of simple transformations, allowing a rapid access to imidazole derivatives with various aryl substituents at the desired positions. 相似文献
129.
Hitoshi Kamauchi Masahiro Noji Kaoru Kinoshita Toshikatsu Takanami Kiyotaka Koyama 《Tetrahedron》2018,74(23):2846-2856
The unprecedented tetracyclic coumarin derivatives 1 and 2 and the coumarin dimers 3–5 were isolated from chemically engineered extracts (coumarin dimerization of natural extract) of the marine-derived fungus Eurotium rubrum. The structures of these compounds were established using NMR, MS and IR methods. The absolute configuration of 1 was determined by ECD calculations. The unprecedented tetracyclic coumarin skeleton was generated by domino-Knoevenagel-Diels-Alder reactions. Compounds 1–5 showed tyrosinase inhibitory activity (IC50?=?1.7, 1.2, 4.9, 1.8 and 2.9?μM, respectively). The isolated coumarin derivatives 1–5 were not observed by HPLC analysis in crude extracts of E. rubrum, suggesting that chemically engineered extract generated these new coumarin derivatives with tyrosinase inhibitory activity. 相似文献
130.
Yamamoto A Nakamura K Furukawa K Konishi Y Ogino T Higashiura K Yago H Okamoto K Otsuka M 《Chemical & pharmaceutical bulletin》2002,50(1):47-52
To find new tachykinin NK1 receptor antagonists from natural sources, we examined the tachykinin antagonist activity in the extracts of approximately 200 species of plants by the use of isolated guinea pig ileum. As a result, we discovered a novel and potent NK1 receptor antagonist in the extract of dried flowers of Matricaria chamomilla L. (chamomile). The structure of the antagonist was established as N1,N5,N10,N14-tetrakis[3-(4-hydroxyphenyl)-2-propenoyl]-1,5,10,14-tetraazatetradecane (tetracoumaroyl spermine, 1a). The Ki values of 1a, estimated from the inhibitory action on the substance P (SP)-induced contraction of the guinea pig ileum and the inhibition of the binding of [3H][Sar9, Met(O2)11]SP to human NK1 receptors, were 21.9 nM and 3.3 nM, respectively. 1a is the first potent NK1 receptor antagonist from natural sources and it has a unique structure of a polyacylated spermine. 1a was concentrated in pollen of Matricaria chamomilla L. and was also found in the extracts of flowers of other four species of Compositae. In addition, we found N1,N5,N10-tris[3-(4-hydroxyphenyl)-2-propenoyl]-1,5,10,14-tetraazatetradecane (2) as a new compound in the extract of flowers of Matricaria chamomilla L., which did not exhibit any tachykinin antagonist activity. A number of related compounds were synthesized, and the structure-activity relationship was studied. 相似文献