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J. A. Paixo F. V. Nascimento A. Matos Beja M. Ramos Silva 《Acta Crystallographica. Section C, Structural Chemistry》2000,56(2):168-170
In the title compound, Na+·C14H11O2?, the diphenylacetate ions have a conformation where the two phenyl rings and the carboxylate group are oriented like the blades of a propeller, each ion having a well defined helicity. The crystal structure of the title compound is achiral, although non‐centrosymmetric (space group ); thus, ions with both (+) and (?) helicities are present in the crystal. Each Na+ ion is coordinated by four carboxylate O atoms at distances in the range 2.207 (2)–2.467 (3) Å to form cubes of Na and O atoms which are linked via the carboxylate C atoms into a columnar structure along the rotoinversion axis. 相似文献
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Teresa M.V.D. Pinho e Melo Ana L. CardosoAntónio M.d'A. Rocha Gonsalves Richard C. StorrJoão Costa Pessoa José A. PaixãoAna M. Beja Manuela Ramos Silva 《Tetrahedron letters》2003,44(34):6409-6412
A phosphorus ylide bearing a 10-phenylsulfonylisoborneol unit reacted with ketenes, generated in situ from acid chlorides and triethylamine, to give allenic compounds. The reaction with methylketene led to asymmetric induction with the selective synthesis of an allene with axial chirality corresponding to an S configuration. The structure of the chiral allene 10-phenylsulfonylisobornyl penta-2,3-dienoate was determined by X-ray crystallography. Chirooptical studies of the chiral allene derivatives were done. 相似文献
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Handzy DO Bauer W Daffin FC Gaff SJ Gelbke CK Glasmacher T Gualtieri E Hannuschke S Huang MJ Kunde GJ Lacey R Li T Lisa MA Llope WJ Lynch WG Martin L Montoya CP Pak R Peaslee GF Pratt S Schwarz C Stone N Tsang MB Vander Molen AM Westfall GD Yee J Yennello SJ 《Physical review letters》1995,75(16):2916-2919
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M. Ramos Silva A. Matos Beja J. A. Paixo J. Martin‐Gil 《Acta Crystallographica. Section C, Structural Chemistry》2005,61(8):m380-m382
The title compound, [Cu4Cl8(C4H9NO2)4], crystallizes in the centrosymmetric space group P21/c with a unit cell containing two tetranuclear copper(II) complexes sited on crystallographic inversion centres. The coordination geometry around the central Cu atoms is square pyramidal, with four O atoms in the basal plane and a Cl atom in the apical position. The lateral CuCl4 groups are flattened tetrahedral. The bridging dimethylglycine molecules are present in the dipolar zwitterionic form. The tetranuclear copper complexes exist as isolated entities since only intramolecular hydrogen bonds are found. 相似文献
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V. H. Rodrigues J. A. Paixão M. M. R. R. Costa A. Matos Beja 《Acta Crystallographica. Section C, Structural Chemistry》2001,57(2):213-215
The title compound, C5H12NO2+·C2HO4−·C5H11NO2 or HC2O4−·(HBET·BET)+ [BET is trimethylglycine (betaine); IUPAC name: 1-carboxy-N,N,N-trimethylmethanaminium hydroxide inner salt], contains pairs of betaine molecules bridged by an H atom, forming dimers linked by a strong hydrogen bond. The hydrogen oxalate anions have a rather unusual star conformation, with an internal torsion angle of 70.1 (4)°. The betaine–betainium dimers are anchored between two zigzag chains of hydrogen oxalate molecules hydrogen bonded head-to-tail running parallel to the b axis. An extended network of C—H⃛O interactions links the anionic chains to the cationic dimers. 相似文献