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201.
Regis de A. Farani Wagner M. Teles Carlos B. Pinheiro Kasslio J. Guedes Klaus Krambrock Maria Irene Yoshida Luiz Fernando C. de Oliveira Flvia C. Machado 《Inorganica chimica acta》2008,361(7):2045-2050
The synthesis and structural characterization of the 2-D Cu(II) coordination polymer namely {[Cu2(BPP)4(NCS)4]}n, where BPP is the nitrogen ligand 1,3-bis(4-pyridyl)propane, are described. Single crystal diffraction analysis shows that the asymmetric unit consists on two crystallographically independent Cu(II) ions that adopt a distorted octahedral geometry. Each Cu(II) center is coordinated by four nitrogen atoms from different BPP ligands and by other two nitrogen atoms from isothiocyanate groups. The BPP ligands link the metal centers generating an undulated two-dimensional net of (4, 4) topology. Two sets of two-dimensional sheets interlock each other in the same plane, giving rise to a twofold parallel interpenetrating network. EPR spectra indicate no magnetic coupling of the two individual Cu2+ centers. 相似文献
202.
Aspergillus niger pectinase, together with κ-carrageenan, could be precipitated in the presence of 0.2% KCl and re-dissolved by ten-fold dilution of the salt. The free as well as this reversibly-soluble (rs) enzyme were evaluated for hydrolysis of polygalacturonic acid, chitosan and chitin. The rs-enzyme showed 92%, 80% and 74% activity (as compared to the corresponding amount of enzyme when present as a free enzyme) towards the three substrates, respectively. There was no significant change in the pH and temperature optima of the rs-enzyme. This preparation could be reused six times without loss of any detectable polygalacturonase activity. This biocatalyst design was found to be efficient for the hydrolysis of polygalacturonic acid, chitosan and chitin. 相似文献
203.
Production and characterization of a transgenic bread wheat line over-expressing a low-molecular-weight glutenin subunit gene 总被引:5,自引:0,他引:5
Masci S. D'Ovidio R. Scossa F. Patacchini C. Lafiandra D. Anderson O.D. Blechl A.E. 《Molecular breeding : new strategies in plant improvement》2003,12(3):209-222
The end-use properties, and thus the value, of wheat flours are determined to a large extent by the proteins that make up the polymeric network called gluten. Low molecular weight glutenin subunits (LMW-GS) are important components of gluten structure. Their relative amounts and/or the presence of specific components can influence dough visco-elasticity, a property that is correlated with the end-use properties of wheat flour. For these reasons, manipulation of gluten dough strength and elasticity is important. We are pursuing this goal by transforming the bread wheat cultivar Bobwhite with a LMW-GS gene driven by its own promoter. Particle bombardment of immature embryos produced several transgenic lines, one of which over-expressed the LMW-GS transgene. Southern blots confirmed that the transgene was integrated into the wheat genome, although segregation analyses showed that its expression was sometimes poorly transmitted to progeny. We have determined that the transgene-encoded LMW-GS accumulates to very high levels in seeds of this line, and that it is incorporated into the glutenin polymer, nearly doubling its overall amount. However, SDS sedimentation test values were lower from the transgenic material compared to a non transgenic flour. These results suggest that the widely accepted correlation between the amount of the glutenin polymers and flour technological properties might not be valid, depending on the components of the polymer. 相似文献
204.
β-Imino carbonyl enolato metal(II) complexes of general formula [M((RCO)(R′CO)CC(R″)NH)2] (M = Mn, Fe, Co, Ni, Cu, Zn, Pd, R = R′ = Me, R″ = CCl3; M = Cu, Pd, R = R′ = Me, R″ = PhCO; R = Me, R′ = Ph, R″ = PhCO; R = R′ = Ph, R″ = PhCO) are easily synthesized by the reaction of metal(II) acetates with the proper β-enaminodiones in 1/2 molar ratio in ethanol at room temperature. In all the cases the trifunctional NOO β-imino carbonyl enolate ligand acts as bidentate to give ML2 complexes, whose structure depends on the metal center and on the nature of the substituent R″ at the imino carbon. With R″ = CCl3 an O,O coordination is observed for all the metal centers but one, in fact palladium(II) exhibits an N,O coordination through the imino nitrogen and one keto oxygen. By contrast with R″ = PhCO the ligand is always coordinated through the imino nitrogen and one keto oxygen atom. 相似文献
205.
Five new complexes [Cu2(L1)I2]∞ (1), [Cu(L2)I]2 (2), {[Cu2(L2)I2](CH3CN)3}∞ (3), [Cu2(L3)I2]∞ (4) and {[Cu(L3)I](CH3CN)}2 (5) have been obtained by reacting three structurally related ligands, 2,3-bis(n-propylthiomethyl)quinoxaline (L1), 2,3-bis(tert-butylthiomethyl)quinoxaline (L2) and 2,3-bis[(o-aminophenyl)thiomethyl]quinoxaline (L3) with CuI, respectively, at different temperatures. Single crystal X-ray analyses show that 1, 3, 4 possess 1D chain structures, while 2 and 5 are discrete dinuclear molecules. It is interesting that the reactions of CuI with L1 at room temperature and 0 °C, respectively, only afforded same structure of 1 (1a and 1b), while using L2 (or L3) instead, two different frameworks 2 and 3 (or 4 and 5) have been obtained. The structural changes mainly resulted from the different conformations that L2 or L3 adopted at different temperatures. Our research indicates that terminal groups of ligands take an essential role in the framework formation, and the reaction temperature also has important effect on the construction of such Cu(I) coordination architectures. Furthermore, the influence of hydrogen bonds on the conformation of ligands and the supramolecular structures of these complexes have also been explored. The luminescence properties of complexes 1, 2, and 4 have been studied in solid state at room temperature. 相似文献
206.
Soo Hyun Kim Young Joo Song Hyo Geun Koo Jung In Poong Cheal Kim Sung-Jin Kim Youngmee Kim 《Inorganica chimica acta》2009,362(11):4119-202
Five polymeric metal(II)-benzoate complexes of formula [Mn(O2CPh)2(CH3OH)2(bpa)]n (1-Mn), [Co(O2CPh)2(H2O)(bpa)1.5]n (2-Co), [Ni(O2CPh)2(H2O)(bpa)1.5]n (3-Ni), [Cu(O2CPh)2(CH3OH)2(bpa)]n (4-Cu), and [Cd(O2CPh)2(bpa)1.5]n (6-Cd) have been synthesized and characterized (bpa = 1,2-bis(4-pyridyl)ethane). They showed two kinds of structures: parallelogram-like two-dimensional sheets for Co, Ni, and Cd, and one-dimensional chains for Mn, Cu, and Zn. Since similar structures provide similar coordination geometries, the structures depend on the coordination geometries of metal ions. The compounds 1-Mn, 2-Co, 4-Cu, 5-Zn, and 6-Cd have catalyzed efficiently the transesterification of a variety of esters, while 3-Ni has displayed a very slow conversion. The reactivity of catalyst 6-Cd containing Cd ion, well known as an inert metal ion for the ligand substitution, was found to be comparable to that of 5-Zn. The reactivities of the compounds used in this study are in the order of 5-Zn > 6-Cd > 1-Mn > 4-Cu > 2-Co ? 3-Ni, indicating that the non-redox metal-containing compounds (5-Zn and 6-Cd) show better activity than the redox-active metal-containing compounds (1-Mn, 4-Cu, 2-Co, and 3-Ni). 相似文献
207.
Jing Xu 《Inorganica chimica acta》2009,362(11):4002-4008
Three new coordination polymers {[Cu(HL)(H2O)]·H2O}n (1), [Ag(H2L)]n (2), and {[Co(HL)(phen)(H2O)]·8H2O}n (3) [H3L = 5-(1H-imidazol-4-ylmethyl)aminoisophthalic acid, phen = 1,10-phenanthroline] have been synthesized under hydrothermal conditions. The results of X-ray diffraction analysis revealed that complex 1 displays (3, 3)-connected 2D network with (4, 82) topology, while complexes 2 and 3 have infinite 1D chain structure, in which one of the two carboxylic groups of H2L−/HL2− is uncoordinated. The 2D layers of 1 or the 1D chains of 2 and 3 are further linked together by hydrogen bonds and π-π interactions to form 3D supramolecular frameworks. Moreover, the electrochemical properties of complexes 1 and 2 have been studied by modified glassy carbon electrodes of 1 (Cu-GCE) and 2 (Ag-GCE), and the results indicate that the Cu-GCE and Ag-GCE show one-electron redox peaks. In addition, both Cu-GCE and Ag-GCE have good electrocatalytic activities toward the reduction of H2O2 in phosphate buffer (pH 5.5) solution. 相似文献
208.
The tetragonal-pyramidal VO2+ complexes [VO{(RSC-S)N-NX}2] (1-6) were synthesised by the reactions of VO(OCHMe2)3 with the dithiocarbazate ligands RSC(S)-NH-NX, where X = cyclo-pentyl, cyclo-hexyl or 4-Me2N-C6H4-CH, and R = CH3 or CH2C6H5. The compounds were characterised by elemental analysis, IR- and mass spectrometries, and in cases of compounds 1, 3, 4 and 5, by X-ray diffraction. The chiral compound 4 (X = cyclo-hexyl, R = CH2C6H5) crystallises in the C configuration. In compound 5, the VO moiety is disordered (83.3:16.7%) with respect to the plane spanned by the four equatorial ligand functions. 相似文献
209.
Hirihattaya Phetmung Sukanya Wongsawat David J. Harding 《Inorganica chimica acta》2009,362(7):2435-3544
A metal organic-inorganic coordination framework formulated as {[Cu(4,4′-bipy)(H2O)3(SO4)] · 2H2O}n (1) (where 4,4′-bipy = 4,4′-bipyridine) has been successfully prepared by microwave synthesis. The title complex has been characterized by single crystal X-ray crystallography, FT-IR spectroscopy and thermal analysis. Complex (1) is an one-dimensional (1D) polymer in which 4,4′-bipy acts as a bridging ligand supporting the formation of infinite [Cu(4,4′-bipy)(H2O)3(SO4)] chains. The packing diagram shows that a 3D network is formed via hydrogen bonds. The infrared spectra and thermographic data are consistent with the chemical formula. 相似文献
210.
Four one-dimensional coordination polymers, [Ln(H2O)4(HTDA)(H2TDA)] · H2O [Ln = Sm (1) and Eu (2)]; (H3TDA = 1H-[1,2,3]-triazole-4,5-dicarboxylic acid), [Ln(H2O)4(HTDA)] · (H2TDA) · H2O [Ln = Tb (3) and Dy (4)] were prepared and characterized by IR, elemental analysis, PXRD and single-crystal X-ray diffraction. The powder and single-crystal X-ray crystallographic studies of 1-4 reveal that all compounds are one-dimensional zigzag chain structures. Luminescent studies reveal that they are potential luminescent materials. Moreover, in solution, the emission intensity of 2 increases upon the addition of Ca2+ ions, while introduction of other metal ions leads to either unchanged or decreased intensity, which indicates that 2 may be applied as a promising Ca2+-ion-selective luminescent probe. The basic magnetic properties of 1-4 were also studied. 相似文献