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351.
Gandham Munikumari Ramaiah Konakanchi Venkata Bharat Nishtala Gondru Ramesh Laxma Reddy Kotha K. B. Chandrasekhar 《合成通讯》2019,49(1):146-158
Substituted heterocyclic (isatin) appended thiosemicarbazone ligands (L1–L3) are synthesized by condensation of substituted isatin molecule with N(4)-phenyl-3-thiosemicarbazide in good yields. The palladium(II) complexes are synthesized from ligands (L1–L3) and PdCl2, with a general formula [PdCl(X-C15H10N4OS)] where X?=?5-chloro (1), 5-bromo (2), and 5-nitro (3). Both analytical and spectroscopic methods have been used for the analysis and characterization of the synthesized compounds. The antimicrobial activity results observed that complexes, 1 and 2 have registered potent antibacterial activity against B. subtilis and K. pneumoniae and also complex 2 has shown good antifungal activity against the micro organisms. The antioxidant activity analysis revealed that the complex 3 showed significant activity with IC50 values 7.24?±?0.09?µM. Moreover, the in vitro antiproliferative activity results suggested that complex 3 exhibited high activity against HeLa cell line compared with the standard with the IC50 value 16.52?±?1.08?µM. The docking results correlate well. 相似文献
352.
Debabrata Dhara Shubhajit Das Swapan K. Pati David Scheschkewitz Vadapalli Chandrasekhar Anukul Jana 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2019,131(43):15511-15515
An NHC‐coordinated diphosphene is employed as ligand for the synthesis of a hydrocarbon‐soluble monomeric AuI hydride, which readily adds CO2 at room temperature yielding the corresponding AuI formate. The reversible reaction can be expedited by the addition of NHC, which induces β‐hydride shift and the removal of CO2 from equilibrium through the formation of an NHC‐CO2 adduct. The AuI formate is alternatively formed by dehydrogenative coupling of the AuI hydride with formic acid (HCO2H), thus in total establishing a reaction sequence for the AuI hydride mediated dehydrogenation of HCO2H as chemical hydrogen storage material. 相似文献
353.
Chandrasekhar Mandala Prasad Gandavaram Syam Venkataramaiah Chintha Naga Raju Chamarthi Seshaiah Kalluru Rajendra Wudayagiri 《Molecular diversity》2019,23(3):723-738
Molecular Diversity - A series of new urea/thiourea derivatives 3a–j were synthesized by simple addition reaction of functionalized phenyl isocyanates/isothiocyanates 2a–j with... 相似文献
354.
Gowthaman Swaminathan Chandrakumar Palanisamy Gowrisankar Chidambaram Gaëlle Henri Chandrasekhar Udayagiri 《Composite Interfaces》2018,25(2):151-168
This paper investigated the application of ZnO nanowires (ZnO NW) to enhance the interfacial strength of glass/epoxy composites. ZnO NW were grown on glass fibers by hydrothermal method, tensile properties of bare and ZnO NW coated fibers were measured by single fiber tensile testing, wettability of fiber with resin was studied by contact angle measurements and finally the interfacial strength and mechanisms were determined by single fiber fragmentation testing of glass/epoxy composites. The surface coverage of ZnO NW on glass fibers was fairly uniform without formation of major clusters. The coating of ZnO NW slightly reduced the tensile strength and improved the tensile modulus of fibers. Wettability tests showed reduction in contact angles for ZnO NW coated fibers because of enhanced wetting and infiltration of epoxy resin into nanowires. In fragmentation testing of microcomposites, smaller and concentrated interfacial debonding zones for ZnO NW coated fibers indicated good stress transfer and strong interfacial adhesion. A new form of crossed and closely spaced stress patterns were observed for nanowires of high aspect ratios. The interfacial strength of ZnO NW coated fibers increased by at least 109% and by 430% on average, which was attributed to the increased surface area and mechanical interlocking provided by ZnO NW. 相似文献
355.
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357.
We calculate the thermal conductance G(T) of diffusive Andreev interferometers, which are hybrid loops with one superconducting arm and one normal-metal arm. The presence of the superconductor suppresses G(T); however, unlike a conventional superconductor, G(T)/G(T)(N) does not vanish as the temperature T-->0, but saturates at a finite value that depends on the resistance of the normal-superconducting interfaces, and their distance from the path of the temperature gradient. The reduction of G(T) is determined primarily by the suppression of the density of states in the proximity-coupled normal metal along the path of the temperature gradient. G(T) is also a strongly nonlinear function of the thermal current, as found in recent experiments. 相似文献
358.
Chandrasekhar V Azhakar R Zacchini S Bickley JF Steiner A 《Inorganic chemistry》2005,44(13):4608-4615
Neutral trinuclear metal complexes L2Cd3 x 2H2O, L2Mn3 x MeOH, and L2Zn3 x MeOH were isolated in the reaction between the phosphorus-centered achiral tris(hydrazone) P(S)[N(Me)N=CHC6H(4)-o-OH]3 (LH3) and the corresponding divalent metal ions. The trinuclear complexes contain two equivalent terminal metal ions (M(t)) and a central metal ion (M(c)). The ligand encapsulates M(t) in a facial N3O3 coordination environment. From the coordination sphere of the two terminal metal ions a pair of phenolic oxygen atoms further coordinate to the central metal ion. The coordination requirements of M(c) are completed by the solvents of coordination. The achiral trianionic tripodal ligand (L)3- induces chirality in the metal complexes. This results in a delta (clockwise) or lambda (anticlockwise) configuration for the terminal metal ions. The enantiomeric complexes 2-4 (delta-delta or lambda-lambda) crystallize as racemic compounds. The supramolecular structures of 2-4 reveal chiral recognition in the solid-state; every molecule with the delta-delta configuration interacts stereospecifically, through C-H...S=P bonds, with two lambda-lambda molecules to generate a one-dimensional polymeric chain. Photophysical studies of the diamagnetic trinuclear complexes reveal that the tricadmium complex is luminescent in the solid state as well as in solution. In contrast LH3 and L2Zn3 x MeOH are nonluminescent. 相似文献
359.
Chandrasekhar V Athimoolam A Srivatsan SG Sundaram PS Verma S Steiner A Zacchini S Butcher R 《Inorganic chemistry》2002,41(20):5162-5173
A multi-pyrazolyl cyclotriphosphazene containing polymerizable group N(3)P(3)(3,5-Me(2)Pz)(5)(O-C(6)H(4)-p-C(6)H(4)-p-CH=CH(2)) (2) has been prepared from the corresponding chloro derivative N(3)P(3)Cl(5)(O-C(6)H(4)-p-C(6)H(4)-p-CH=CH(2)) (1). The X-ray structures of 1 and 2 have been determined. Compound 2 undergoes ready metalation with CuCl(2) to afford N(3)P(3)(3,5-Me(2)Pz)(5)(O-C(6)H(4)-p-C(6)H(4)-p-CH=CH(2)).CuCl(2) (3). Model compound N(3)P(3)(3,5-Me(2)Pz)(5)(O-C(6)H(4)-p-CHO).CuCl(2) (6) has been prepared and characterized by spectroscopy and X-ray crystallography. In this compound, the coordination around copper is distorted trigonal bipyramidal, and the cyclotriphosphazene coordinates in a non-gem N(3) mode. Compound 2 has been copolymerized with divinylbenzene to afford cross-linked multisite coordinating polymer CPPL which is readily metalated with CuCl(2) to afford copper-containing polymer CPPL-Cu. The coordination environment around copper in CPPL-Cu has been evaluated by obtaining its EPR, optical, and IR spectra and comparing them with those of model compounds 3 and 6. The utility of CPPL-Cu as a heterogeneous catalyst has been demonstrated in the phosphate ester hydrolysis involving three model phosphate esters: p-nitrophenyl phosphate (pNPP), bis(p-nitrophenyl) phosphate (bNPP), and 2-(hydroxypropyl)-p-nitrophenyl phosphate (hNPP). In all of these reactions, a significant rate enhancement of ester hydrolysis is observed. Detailed kinetic analyses to evaluate Michaelis-Menten parameters have also been carried out along with experiments to elucidate the effect of pH, solvent, and temperature on the rate of hydrolysis. Recycling experiments on the hydrolysis of pNPP with CPPL-Cu shows that it can be recycled several times over without affecting the rates. 相似文献
360.
The polymer-supported synthesis of isoxazolines is described via nitrile oxide intermediates, starting from primary nitroalkanes in a one-pot process. 相似文献