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301.
302.
Yamamoto Y Saigoku T Nishiyama H Ohgai T Itoh K 《Organic & biomolecular chemistry》2005,3(9):1768-1775
In the presence of catalytic amounts of Cp*RuCl(cod), the partially intramolecular cyclotrimerizations of various C-alkynylglycosides and C-diynylglycosides proceeded at ambient temperature to afford C-arylglycosides. 相似文献
303.
Yamamoto Y Kinpara K Saigoku T Nishiyama H Itoh K 《Organic & biomolecular chemistry》2004,2(9):1287-1294
In the presence of a catalytic amount of Cp*RuCl(cod), 1,6- and 1,7-diynes connected by an amide or an ester tether underwent cycloaddition with terminal alkynes at room temperature to give rise to cycloadducts in 40-93% yields with 63 : 37-83 : 17 regioisomer ratios. 相似文献
304.
Kiyoshi Endo Tomoaki Sugita 《Journal of polymer science. Part A, Polymer chemistry》2004,42(12):2904-2910
Copolymerization of styrene (St) and St‐terminated poly(ethylene oxide) macromonomer (SEOM) with CpTiCl3/methylaluminoxane (MAO) catalyst in toluene was investigated. The copolymerization of St and SEOM proceeded easily to give a graft copolymer consisting of syndiotactic polystyrene as the main chain and hydrophilic poly(ethylene oxide) as the side chain. A number of side chains in the graft copolymer could be controlled by the amount of SEOM in the feed. The reactivity of SEOM was determined from copolymerization of St and SEOM with the CpTiCl3/MAO catalyst, and the reactivity of SEOM depended on the molecular weight of SEOM. The thermal properties of the graft copolymer such as the melting temperature were influenced by the introduction of SEOM. © 2004 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 42: 2904–2910, 2004 相似文献
305.
Tomoaki Ono 《代数通讯》2013,41(5):1897-1907
Let R p ? R′ ? R be a tower of Noetherian semi-local rings of prime characteristic p. When R has locally p-bases over R′ which consist of countably infinite elements, we show the existence of a countably infinite subset {? i } i?? of R such that {? i } i?? is p-independent over R′, R′[? i ] i?? is Noetherian, and R = R′[? i ] i?? + ? ′ l R for all l ? ?, where ?′ is the Jacobson radical of R′. Moreover, we consider the existence of p-bases in the case of a tower of semi-local affine k-algebras. 相似文献
306.
307.
Nanostructured molecular film containing the (micro-hydroxo)bis(micro-carboxylato) diruthenium(III) units, [RuIII2(micro-OH)(micro-CH3COO)2(HBpz3)2]+ ({RuIII2(micro-OH)}), was prepared by an in situ conversion of its micro-oxo precursor, [RuIII2(micro-O)(micro-CH3COO)2(HBpz3)2] ({RuIII2(micro-O)}), in a Nafion membrane matrix, where HBpz3 is hydrotris(1-pyrazolyl)borate. The conversion procedure results in fine nanoparticle aggregates of the {RuIII2(micro-OH)} units in the Nafion membrane (Nf-{RuIII2(micro-OH)}), where an average particle size (4.1 +/- 2.3 nm) is close to the Nafion's cluster dimension of approximately 4 nm. Chemically modified electrodes by using the Nafion molecular membrane films (Nf-{RuIII2(micro-OH)}-MMFEs) were further developed on ITO/glass and glassy carbon electrode (GCE) surfaces, and a selective reduction of nitrosonium ion (NO+), presumably through reaction of a {RuIIRuIII(micro-OH)} mixed-valence state with HNO2, was demonstrated without interference by molecular oxygen in an acidic aqueous solution. The Nf-{RuIII2(micro-OH)}-MMFEs are stable even in a physiological condition (pH 7), where the naked {RuIII2(-OH)} complex is readily transformed into its deprotonated {RuIII2(micro-O)} form, demonstrating an unusual stabilizing effects for the {RuIII2(micro-OH)} unit by the Nafion cluster environment. 相似文献
308.
Nemoto T Fukuyama T Yamamoto E Tamura S Fukuda T Matsumoto T Akimoto Y Hamada Y 《Organic letters》2007,9(5):927-930
[reaction: see text] Asymmetric allylic amination of allylic carbonates prepared from racemic Morita-Baylis-Hillman adducts proceeded in the presence of Pd catalyst, chiral diaminophosphine oxide (DIAPHOX), and BSA, affording the corresponding chiral aza-Morita-Baylis-Hillman adduct derivatives in excellent yield with up to 99% ee. The cyclic reaction products could be converted into various synthetically useful compounds such as chiral cyclic beta-amino acids. 相似文献
309.
Acid-free, aminoborane-mediated Ugi-type reaction leading to general utilization of secondary amines
A variety of secondary amines have become utilized in the Ugi reaction by using aminoborane 1 as an iminium ion generator. Aldehydes, secondary amines, and isocyanides are coupled in the presence of 1 at room temperature, giving the corresponding alpha-amino amides in good yields. The nonacidic reaction conditions are beneficial for unique chemoselectivity, where the aldimine functionality is left intact in the present Ugi-type reaction. 相似文献
310.
Iizuka K Wato T Miseki Y Saito K Kudo A 《Journal of the American Chemical Society》2011,133(51):20863-20868
Ag cocatalyst-loaded ALa(4)Ti(4)O(15) (A = Ca, Sr, and Ba) photocatalysts with 3.79-3.85 eV of band gaps and layered perovskite structures showed activities for CO(2) reduction to form CO and HCOOH by bubbling CO(2) gas into the aqueous suspension of the photocatalyst powder without any sacrificial reagents. Ag cocatalyst-loaded BaLa(4)Ti(4)O(15) was the most active photocatalyst. A liquid-phase chemical reduction method was better than impregnation and in situ photodeposition methods for the loading of the Ag cocatalyst. The Ag cocatalyst prepared by the liquid-phase chemical reduction method was loaded as fine particles with the size smaller than 10 nm on the edge of the BaLa(4)Ti(4)O(15) photocatalyst powder with a plate shape during the CO(2) reduction. CO was the main reduction product rather than H(2) even in an aqueous medium on the optimized Ag/BaLa(4)Ti(4)O(15) photocatalyst. Evolution of O(2) in a stoichiometric ratio (H(2)+CO:O(2) = 2:1 in a molar ratio) indicated that water was consumed as a reducing reagent (an electron donor) for the CO(2) reduction. Thus, an uphill reaction of CO(2) reduction accompanied with water oxidation was achieved using the Ag/BaLa(4)Ti(4)O(15) photocatalyst. 相似文献