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141.
Nobuhiro Kihara Hidefumi Tochigi Takeshi Endo 《Journal of polymer science. Part A, Polymer chemistry》1995,33(7):1005-1010
5-(Methacryloyloxy)methyl-1,3-oxathiolane-2-thione ( 3 ) was synthesized from glycidyl methacrylate (GMA) and carbon disulfide in the presence of lithium bromide in 93% yield. The radical polymerization of 3 in DMSO initiated by AIBN at 60°C afforded corresponding polymethacrylate 4 quantitatively. Copolymerization of 3 with MMA was also carried out. 5-Phenoxymethyl-1,3-oxathiolane-2-thione ( 6 ), model dithiocarbonate, reacts with benzylamine at room temperature to afford O-(1-mercapto-3-phenoxy-2-propyl)N-benzyl-thiocarbamate ( 7 ) and 1,1′-dithiobis[3-phenoxy-2-(benzylaminothiocarbonyloxy)-propane] ( 8 ) in 89% and 7% yield, respectively. Polymer 4 reacted with butylamine or dipropylamine to afford a corresponding polymethacrylate bearing thiol group, which immediately turned to insoluble gel by facile auto-oxidation of the thiol group. © 1995 John Wiley & Sons, Inc. 相似文献
142.
Hidefumi Hirai Tsuneaki Tanabe Hideomi Koinuma 《Journal of polymer science. Part A, Polymer chemistry》1979,17(3):843-857
Methyl methacrylate (MMA) and styrene (St) copolymerize in the presence of zinc chloride at 3°C under photoirradiation. The contents of methyl methacrylate in the copolymers obtained at a [ZnCl2]/[MMA] molar ratio of 0.4 are systematically larger than 53 mole %, which is the limiting value at a small feed ratio of methyl methacrylate. The resulting copolymers are confirmed as the sole products and not the mixtures by thin layer chromatography. The effect of dilution of the monomer feed mixture with toluene on copolymer composition suggests that it depends chiefly on the feed concentration of styrene and hardly at all on monomer feed ratios. Copolymerizations are also conducted in the presence of stannic chloride at ?17°C under photoirradiation and in the presence of ethylaluminium sesquichloride at 0°C with spontaneous initiation. The contents of methyl methacrylate in both copolymers obtained at feed ratios lower than 60 mole % almost correspond to the 1:1 alternating copolymer and increase systematically with higher feed ratios. The systematic deviations of copolymer composition obtained in the presence of metal halides are reasonably interpreted by the participation of the binary molecular complex composed of metal halide and methyl methacrylate in the polymerization of the ternary molecular complex composed of metal halide, methyl methacrylate, and styrene. 相似文献
143.
Cao B Nikawa H Nakahodo T Tsuchiya T Maeda Y Akasaka T Sawa H Slanina Z Mizorogi N Nagase S 《Journal of the American Chemical Society》2008,130(3):983-989
Thermal and photochemical reactions of La2@C78 with 2-admantane-2,3-[3H]-diazirine are investigated. Four isomers of the monoadduct (La2@C78Ad) synthesized by the photoreaction are isolated by HPLC and characterized by mass, UV-vis-NIR absorption, cyclic voltammogram and differential pulse voltammogram spectroscopy, proton and 13C NMR spectroscopic analysis, single-crystal X-ray diffraction analysis, and theoretical approaches. The addition reactions occur at both the [5,6] and [6,6] positions. X-ray and theoretical studies indicate that one of the monoadduct isomers has an open structure with two La atoms on the C3 axis of the D3h cage of La2@C78. 相似文献
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148.
Yuki Miyazawa Makoto Sugimoto Ayumi Tanaka-Oda Hidefumi Makabe 《Tetrahedron letters》2019,60(36):151039
Syntheses of (+)-goniopypyrone and (+)-goniotriol isolated from Goniothalamus giganteus were achieved. The key steps involve Pd-catalyzed carbonylation for lactone ring formation and diastereoselective reduction of ynone using the (R)-CBS catalyst and borane dimethyl sulfide complex. 相似文献
149.
Yutaka Maeda Prof. Dr. Satoru Sato Koji Inada Hidefumi Nikawa Michio Yamada Dr. Naomi Mizorogi Dr. Tadashi Hasegawa Prof. Dr. Takahiro Tsuchiya Dr. Takeshi Akasaka Prof. Dr. Tatsuhisa Kato Prof. Dr. Zdenek Slanina Dr. Shigeru Nagase Prof. Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(7):2193-2197
The first regioselective functionalization of La@C82 by two different groups has been performed. Bis‐adducts of La@C82 with Cp* and adamantylidene were synthesized by using two different routes and characterized. Spectroscopic analysis and theoretical calculations reveal that the addition position is controlled by the charge density and p‐orbital axis vector value of the fullerene cage. 相似文献
150.
Makoto Komiyama Hidefumi Hirai 《Journal of polymer science. Part A, Polymer chemistry》1976,14(2):307-318
The alternating copolymerization of methyl methacrylate with styrene with the use of stannic chloride was kinetically examined at ?20°C in 1,2-dichloroethane both under photoirradiation and with radical initiator (2:1 tri-n-butylboron-benzoyl peroxide system). At conversions lower than 7%, the conversion increases linearly to the polymerization time, whereas the degree of polymerization is constant irrespective of the polymerization time. The alternating copolymerizations are 1.5 order and the 1.0 order reactions with respect to the ternary molecular complex composed of stannic chloride, methyl methacrylate, and styrene, under photoirradiation and with initiator, respectively. The linear dependences of the rates upon the 0.5 order of the intensity of the incident light and upon the 1.0 order of the concentration of tri-n-butylboron indicate a bimolecular termination. The rate normalized by the 1.5 order of the concentration of the coordinated methyl methacrylate and the rate normalized by the concentration of the coordinated methyl methacrylate are proportional to the 1.5 and 1.0 orders of the charged concentration of styrene, for the copolymerizations under photoirradiation and with initiator, respectively. The kinetic results in the 1,2-dichloroethane solution are quite consistent with those in the toluene solution. The alternating copolymerization mechanism, in which the ternary molecular complex predominantly homopolymerizes as a monomer unit, is confirmed. 相似文献