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排序方式: 共有652条查询结果,搜索用时 343 毫秒
561.
Ushida N Kondo T Tasaka S Park IG Song JS Hara T Homma Y Tsuzuki Y Fujioka G Fukushima H Takahashi Y Tatsumi S Yokoyama C Fujiwara K Taruma K Bahk SY Kim CO Park JN Bailey DC Conetti S Mercure P Trischuk J Turcotte M Aoki S Chiba K Fuchi H Hoshino K Kodama K Matsui R Miyanishi M Nakamura M Nakazawa K Niu K Niwa K Ohashi M Sasaki H Tomita Y Torii N Yamakawa O Yanagisawa Y Aubrecht GJ Dunlea J Errede S Gauthier A Gutzwiller MJ Kuramata S Oleynik G Reay NW Reibel K Sidwell RA Stanton NR Moriyama K 《Physical review letters》1986,56(17):1771-1774
562.
Ushida N Kondo T Tasaka S Park IG Song JS Hara T Homma Y Tsuzuki Y Fujioka G Fukushima H Takahashi Y Tatsumi S Yokoyama C Fujiwara K Taruma K Bahk SY Kim CO Park JN Bailey DC Conetti S Mercure P Trischuk J Turcotte M Aoki S Chiba K Fuchi H Hoshino K Kodama K Matsui R Miyanishi M Nakamura M Nakazawa K Niu K Niwa K Ohashi M Sasaki H Tomita Y Torii N Yamakawa O Yanagisawa Y Aubrecht GJ Dunlea J Errede S Gauthier A Gutzwiller MJ Kuramata S Oleynik G Reay NW Reibel K Sidwell RA Stanton NR Moriyama K 《Physical review letters》1986,56(17):1767-1770
563.
T Katagi H Kataoka K Takahashi T Fujioka M Kunitomo Y Yamaguchi M Fujiwara T Inoi 《Chemical & pharmaceutical bulletin》1992,40(9):2419-2422
Novel oximes were prepared from the corresponding aldehyde or ketone in the usual way, and a number of oxime esters, O-lauroyl, O-2-pyridinecarbonyl, O-nicotinoyl, and O-isonicotinoyl oximes were synthesized by 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDCI)-4-dimethylaminopyridine (DMAP) method or a mixed anhydride method, in our search for potent anti-inflammatory compounds. The anti-inflammatory activity of these compounds was assessed by the carrageenan-induced paw edema assay in rats. The oximes (4, 5, and 13), O-lauroyloxime 1L, O-nicotinoyloximes (1N, 2N, 3N, and 4N), O-isonicotinoyloxime 1I, and O-2-pyridinecarbonyloxime 7P showed higher anti-inflammatory potency than aspirin, a prostaglandin cyclooxygenase inhibitor. 相似文献
564.
Eiji Ihara Shinsuke Tanaka Kenzo Inoue 《Journal of polymer science. Part A, Polymer chemistry》2002,40(23):4302-4315
Molybdenum chloride (MoCl5 or 1a ) and tungsten chloride (WCl6 or 1b )/phenyllithium (PhLi)/triisobutylaluminum (iBu3Al) systems were found to be quite effective for controlling the anionic polymerization of methyl methacrylate (MMA), affording high molecular weight poly(methyl methacrylate)s (PMMAs; number‐average molecular weight > 100,000) with narrow molecular weight distributions (weight‐average molecular weight/number‐average molecular weight < 1.25) quantitatively at 0 °C for 1 h in toluene. Matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS) analyses of PMMAs obtained with the 1a and 1b /organolithium (RM; n‐butyllithium, PhLi)/iBu3Al systems revealed that the initiation of MMA with the systems occurred by a nucleophilic attack of H? to the monomer. In addition, the MALDI‐TOF MS analyses indicated that the presence of iBu3Al was responsible for the controlled polymerization by improving the uniformity of the polymerization with respect to initiation and termination and by preventing a backbiting reaction. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 4302–4315, 2002 相似文献
565.
Shuichi Ohuchida Nobuyuki Hamanaka Shinsuke Hashimoto Masaki Hayashi 《Tetrahedron letters》1982,23(28):2883-2886
The synthesis of thromboxane A2 (TXA) analogue, 9α,11α-thia-TXA2 methyl ester , in which the oxygen atom in the oxetane ring of TXA2 was replaced by a sulfur atom, is described. 相似文献
566.
An asymmetric synthesis of chiral 1,4- and 1,5-diols has been developed from the ene acetals 1a and 1c, prepared from the corresponding aldehydes and chiral C(2)-symmetric diols, involving remote asymmetric induction as a key step. In the first step, treatment of 1 with I(coll)(2)ClO(4) in the presence of an alcohol afforded the macrocyclic acetals (3-5 and 7) in a highly stereoselective manner. Subsequent nucleophilic substitution of iodide followed by a Grignard reaction with complete retention of stereochemistry and a final deprotection of the diphenylethylene or diphenylpropylene unit successfully gave optically active 1,4- and 1,5-diols in good yields. 相似文献
567.
The thermolysis of pivaloyl- and adamantoyltris(trimethylsilyl)germane in the presence of 2,3-dimethyl- and 2,3-diphenyl-1,3-butadiene gave the respective adducts derived from [2+4] cycloaddition of the germenes with butadienes in good yields. 相似文献
568.
Substituent-control exciton in J-aggregates of protonated water-insoluble porphyrins 总被引:2,自引:0,他引:2
A series of protonated porphyrin J-aggregates of various water-insoluble tetraphenylporphyrin derivatives was prepared by aggregation at the liquid-liquid or gas-liquid interface. Using atomic force microscopy, we observed microcrystalline porphyrin J-aggregates. The J-aggregates have two strong exciton bands corresponding to the B (Soret)- and Q-bands of the protonated porphyrin. Interestingly, the excitation energy of the lower exciton (denoted by S1) markedly depends on the meso-substituents, whereas that of the higher exciton (denoted by S2) does not depend on them. These results indicate that the nature of the exciton coupling of the S1 transition dipole moment can be systematically changed by the substituents. 相似文献
569.
Kita Y Iio K Kawaguchi K Fukuda N Takeda Y Ueno H Okunaka R Higuchi K Tsujino T Fujioka H Akai S 《Chemistry (Weinheim an der Bergstrasse, Germany)》2000,6(21):3897-3905
A linear approach to the total synthesis of racemic fredericamycin A (1) through the oxidative intramolecular [4 + 2] cycloaddition of a (phenylthio)acetylene-cobalt complex is described, which is applicable for the asymmetric total synthesis of naturally occuring 1. The highlight of this work is the aromatic Pummerer-type reaction with 1-ethoxyvinyl chloroacetate, which effects the introduction of the oxygen functional group to the internal B-ring of the highly functionalized, congested polyaromatic ABC-ring moiety. 相似文献
570.
E Ohsugi T Fujioka H Harada M Nakamura R Maeda 《Chemical & pharmaceutical bulletin》1989,37(5):1268-1278
6,7-Dichloro-2,3-dihydro-2-benzo[b]furancarboxylic acid derivatives having a 3,3-N,S-disubstituted-2-propenoyl group at the 5-position were prepared by alkylation of 5-(thiocarbamoyl)acetyl derivatives of the 2,3-dihydro-2-benzo[b]furancarboxylic acid ester or by acetal exchange reaction of 5-[3,3-bis(alkylthio)-2-propenoyl] derivatives. Synthesis of 5-[4 and/or 5-(di)substituted-4-thiazolin-2-ylidene]acetyl-2,3- dihydro-2-benzo[b]furancarboxylic acids was also achieved by the reaction of 2-halo-1-methoxyethyl isothiocyanate with the 5-acetyl derivative in the presence of base or through sulfide contraction of 2-[[6,7-dichloro-2-methoxycarbonyl-2,3-dihydrobenzo[b]furan-5-yl) carbonyl)-methylthio]thiazolium bromide. Some of the compounds which were synthesized showed potent natriuretic activities in rats and mice. The structure-activity relationship is also discussed. 相似文献