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81.
Vadapalli Chandrasekhar Viswanathan Baskar Ramamoorthy Boomishankar Selvarajan Nagendran 《Phosphorus, sulfur, and silicon and the related elements》2013,188(4-5):699-701
The reactions of n-butyl stannonic acid with(PhO) 2 P(O)H leads to the formation of a hexameric tin cage [{(n-BuSn) 3 (PhO) 3 O} 2 {HPO 3 } 4 ].This reaction involves an in situ P─O bond cleavage and the generation of a [HPO 3 ] 2? ion. A direct reaction of six equivalents of n-BuSnO(OH) acid with six equivalents of C 6 H 5 OH and four equivalents of H 3 PO 3 also leads to the formation of same cage structure. A tetranuclear organooxotin cage[(PhCH 2 ) 2 Sn 2 O(O 2 P(OH)-t-Bu) 4 ] 2 has been assembled by debenzylation involving the reaction of (PhCH 2 ) 2 SnCl 2 ,(PhCH 2 ) 2 SnO·H 2 O or (PhCH 2 ) 3 SnCl with two equivalents of t-BuP(O)OH 2 . A half-cage intermediate [(PhCH 2 ) 2 Sn 2 O(O 2 P(OH)-t-Bu) 4 ] has been detected. New organotin cations of the type [n-Bu 2 Sn(H 2 O) 4 ] 2+[2,5-Me 2 -C 6 H 3 SO 3 ]? 2 and {[n-Bu 2 Sn(H 2 O) 3 LSn(H 2 O) 3 (n-Bu) 2 ] 2+[1,5-(SO 3 ) 2 -C 10 H 6 ] 2?} have been obtained in the reactions of n-Bu 2 SnO or (n-Bu 3 Sn) 3 O with 2,5-dimethyl sulfonic acid and 1,5-naphthalene disulfonic acid respectively. These organotin cations form interesting supramolecular structures in the solid state as a result of O─H─···O hydrogen bonding. 相似文献
82.
Efficient syntheses of pheromone components of Aproaerema modicella starting from a common intermediate 7-octyn-1-ol is described. 相似文献
83.
84.
The efficient deprotection of several acetals, dithioacetals, and tetrahydropyranyl (THP) ethers under ambient conditions, using chloral hydrate in hexane, is described. Excellent yields were realized for a wide range of both aliphatic and aromatic substrates. The method is characterized by mild conditions (room temperatures or below), simple workup, and the ready availability of chloral hydrate. High chemoselectivity was also observed in the deprotection, acetonides, esters, and amides being unaffected under the reaction conditions. Products were generally purified chromatographically and identified spectrally. These results constitute a novel addition to current methodology involving a widely employed deprotection tactic in organic synthesis. It seems likely that the mechanism of the reaction involves adsorption of the substrate on the surface of the sparingly soluble chloral hydrate. 相似文献
85.
Pankaj Kalita;Joydeb Goura;Juan Manuel Herrera Martínez;Enrique Colacio;Vadapalli Chandrasekhar; 《欧洲无机化学杂志》2019,2019(2):212-220
A family of four dinuclear complexes, [NHEt3]2[Ln2(µ-NO3)2(NO3)2(HL)2] [Ln = GdIII (1), TbIII (2), HoIII (3), DyIII (4)], were synthesized by the reaction of an enolizable multidentate Schiff base ligand H3L (H3L = N′-(2-hydroxy-3-methoxy-5-nitrobenzylidene)-2-(hydroxyimino)propanehydrazide) with hydrated lanthanide nitrates in the presence of NEt3. The molecular structure of complexes 1–4 was confirmed by single-crystal XRD analysis. All of the centrosymmetric complexes are dianionic, isostructural and each of the LnIII centers is nine-coordinate and adopts a muffin like coordination geometry as indicated by SHAPE analysis. The dynamic magnetization studies revealed that the compounds 2 and 4 are field-induced single-molecule magnets with effective energy barriers,Ueff = 34(2) K (for 2) and 80(3) K (for 4) and pre-exponential factors, τo = 1.1 × 10–8 s (for 2) and 1.15 × 10–7 s (for 4). 相似文献
86.
Ramprasad Regar;Kundan Singh Mehra;Rohit Bhowal;Jeyaraman Sankar; 《European journal of organic chemistry》2019,2019(36):6278-6284
Three new symmetrically para-phenylethynylene-substituted terrylene diimide derivatives namely, TDI-Ph, TDI-PhCN and TDI-PhNMe2 were synthesized to study the electronic effects on the structure and properties. The solid-state single-crystal structures for TDI-Ph and TDI-PhCN as well as for the precursor TDI-Br4 are presented. The X-ray diffraction studies revealed twisting in the bay-area of terrylene core, which improved the solubility as well, despite of having some of the shortest intermolecular Br···Br and C-H···O interactions in TDI-Br4. All the compounds exhibited near infra-red absorption and emission except for TDI-PhNMe2; especially TDI-PhNMe2 showed interesting broad absorption ranging from 300 to 970 nm. Further, the effects of electron-donating and accepting unit on electrochemical and optical properties have been investigated. 相似文献
87.
Suvankar Bera;K. Chandrasekhar;Satadru Chatterjee;Sunil Kumar Killi;Debabrata Sarkar;Biswadip Banerji; 《European journal of organic chemistry》2019,2019(24):3877-3881
Here in we report, rhodium(III)-catalyzed decarboxylative acylation of arenes using α-oxocarboxylic acids as acyl surrogate. In this strategy, O–NHAc group act as an autocleavable oxidizing directing group (ODGauto), thus giving rise to ortho-acylated phenols in moderate to good yields. Mechanistic studies provided strong support for a kinetically relevant C–H bond activation. According to the best of our knowledge, this is the first report of Rhodium catalyzed decarboxylative acylation. 相似文献
88.
Atanu Dey;Sourav Das;María A. Palacios;Enrique Colacio;Vadapalli Chandrasekhar; 《欧洲无机化学杂志》2018,2018(15):1633-1633
89.
Prathama S. Mainkar Chirumarry Sridhar Ambadi Sudhakar Srivari Chandrasekhar 《Helvetica chimica acta》2013,96(1):99-108
The synthesis of bolaamphiphiles from unusual β‐amino acids or an alcohol and C12 or C20 spacers is described. Unusual β‐amino acids such as a sugar amino acid, an AZT‐derived amino acid, a norbornene amino acid, and an AZT‐derived amino alcohol were coupled with spacers under standard conditions to get the novel bolaamphiphiles 5 – 8 (Scheme 1), 12 and 13 (Scheme 2), and 17 and 20 (Scheme 3). Some of these compounds, on precipitation from MeOH/H2O, self‐assembled into organized molecular structures. 相似文献
90.