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181.
Marija Dodig 《Numerical Linear Algebra with Applications》2011,18(3):283-297
In this paper the pole placement problem for singular systems via state feedback is studied. We give a complete solution to this problem for systems without row minimal indices. As a corollary, the eigenvalue assignment problem is solved for singular systems in the case they are regularizable. Copyright © 2009 John Wiley & Sons, Ltd. 相似文献
182.
Zoran Marković Jelena Đorović Milan Dekić Milanka Radulović Svetlana Marković Marija Ilić 《Chemical Papers》2013,67(11):1453-1461
Antioxidant activity of erodiol was examined at the M05-2X/6-311+G(d,p) level of theory in the gas and aqueous phases. The structure and energy of radicals and anions of the most stable erodiol rotamer were analyzed. To estimate antioxidant potential of erodiol, different molecular properties were examined: bond dissociation enthalpy, proton affinity together with electron transfer energy, and ionization potential followed by proton dissociation enthalpy. It was found that hydrogen atom transfer is the prevailing mechanism of erodiol behavior in gas; whereas single electron transfer followed by proton transfer and sequential proton loss electron transfer mechanisms represent the thermodynamically preferred reaction paths in water. 相似文献
183.
[structure: see text] Oligonucleotides with a novel, 2'-O-[2-[2-(N,N-dimethylamino)ethoxy]ethyl] (2'-O-DMAEOE) modification have been synthesized. This modification, a cationic analogue of the 2'-O-(2-methoxyethyl) (2'-O-MOE) modification, exhibits high binding affinity to target RNA (but not to DNA) and exceptional resistance to nuclease degradation. Analysis of the crystal structure of a self-complementary oligonucleotide containing a single 2'-O-DMAEOE modification explains the importance of charge factors and gauche effects on the observed antisense properties. 2'-O-DMAEOE modified oligonucleotides are ideal candidates for antisense drugs. 相似文献
184.
Janković Bojan Ž. Janković Marija M. Marinović-Cincović Milena M. Todorović Dragana J. Sarap Nataša B. 《Journal of Thermal Analysis and Calorimetry》2018,133(1):481-487
Journal of Thermal Analysis and Calorimetry - Kaolins are used in a multiplicity of industries because of unique physical and chemical properties. Relationships between thermal and radioactivity... 相似文献
185.
186.
Aleksandar Višnjevac Marija Luić Renata Kobetić Dubravka Gembarovski Biserka Žinić 《Polyhedron》2009,28(6):1057-1064
The synthesis, as well as chemical and structural characterization, of 1-(p-toluenesulfonyl)cytosine (1) and its dinuclear complexes of the composition Pd2(1-TosC?–N3,N4)4 (3) and Pd2(1-TosC?–N3,N4)2DMSO2Cl2 (4) by means of ESI-MS, IR, 1H NMR and X-ray single crystal analysis are described. Ligand 1 exists in the preferred aminooxo tautomeric form, while both dinuclear complexes reveal the presence of the iminooxo form of the ligand, where 1-TosC? stands for the anion of the cytosine derivative of 1, bridging two palladium atoms. Complex 3 has a paddlewheel structure with two square-planar coordination spheres, consisting of four N atoms each, mutually parallel and perpendicular to the interpalladium vector. Complex 4 is characterized by two mutually parallel square-planar coordination spheres consisting of two nitrogens, sulfur from the solvent molecule and a chloride. A feasible chemical route for the formation of 3 and 4 via the kinetically favoured mononuclear complex Pd(1-TosC–N3)2Cl2 (2) is proposed, based on the IR, 1H NMR, mass spectrometry, elemental analysis and X-ray structure analysis data. 相似文献
187.
Paolo Aschieri Marija Dimitrijević Frank Meyer Stefan Schraml Julius Wess 《Letters in Mathematical Physics》2006,78(1):61-71
Gauge theories on a space-time that is deformed by the Moyal–Weyl product are constructed by twisting the coproduct for gauge transformations. This way a deformed Leibniz rule is obtained, which is used to construct gauge invariant quantities. The connection will be enveloping algebra valued in a particular representation of the Lie algebra. This gives rise to additional fields, which couple only weakly via the deformation parameter θ and reduce in the commutative limit to free fields. Consistent field equations that lead to conservation laws are derived and some properties of such theories are discussed. 相似文献
188.
Makogon O Flyunt R Tobien T Naumov S Bonifacić M 《The journal of physical chemistry. A》2008,112(26):5908-5916
Using pulse radiolysis and steady-state gamma-radiolysis techniques, it has been established that, in air-saturated aqueous solutions, peroxyl radicals CH 2HalOO (*) (Hal = halogen) derived from CH 2Cl 2 and CH 2Br 2 react with dimethyl selenide (Me 2Se), with k on the order of 7 x 10 (7) M (-1) s (-1), to form HCO 2H, CH 2O, CO 2, and CO as final products. An overall two-electron oxidation process leads directly to dimethyl selenoxide (Me 2SeO), along with oxyl radical CH 2HalO (*). The latter subsequently oxidizes another Me 2Se molecule by a much faster one-electron transfer mechanism, leading to the formation of equal yields of CH 2O and the dimer radical cation (Me 2Se) 2 (*+). In absolute terms, these yields amount to 18% and 28% of the CH 2ClO (*) and CH 2BrO (*) yields, respectively, at 1 mM Me 2Se. In competition, CH 2HalO (*) rearranges into (*)CH(OH)Hal. These C-centered radicals react further via two pathways: (a) Addition of an oxygen molecule leads to the corresponding peroxyl radicals, that is, species prone to decomposition into H (+)/O 2 (*-) and formylhalide, HC(O)Hal, which further degrades mostly to H (+)/Hal (-) and CO. (b) Elimination of HHal yields the formyl radical H-C(*)=O with a rate constant of about 6 x 10 (5) s (-1) for Hal = Cl. In an air-saturated solution, the predominant reaction pathway of the H-C(*)=O radical is addition of oxygen. The formylperoxyl radical HC(O)OO (*) thus formed reacts with Me 2Se via an overall two-electron transfer mechanism, giving additional Me 2SeO and formyloxyl radicals HC(O)O(*). The latter rearrange via a 1,2 H-atom shift into (*)C(O)OH, which reacts with O2 to give CO2 and O2(*)(-). The minor fraction of H-C(*)=O undergoes hydration, with an estimated rate constant of k approximately 2 x 10(5) s(-1). The resulting HC(*)(OH)2 radical, upon reaction with O2, yields HCO 2H and H (+)/O2(*-). Some of the conclusions about the reactions of halogenated alkoxyl radicals are supported by quantum chemical calculations [B3LYP/6-31G(d,p)] taking into account the influence of water as a dielectric continuum [by the self-consistent reaction field polarized continuum model (SCRF=PCM) technique]. Based on detailed product studies, mechanisms are proposed for the free-radical degradation of CH 2Cl 2 and CH 2Br 2 in the presence of oxygen and an electron donor (namely, Me 2Se in this study), and properties of the reactive intermediates are discussed. 相似文献
189.
190.
Nedić M Wassermann TN Xue Z Zielke P Suhm MA 《Physical chemistry chemical physics : PCCP》2008,10(39):5953-5956
Spontaneous Raman scattering in supersonic jet expansions is used to prove that the mixed dimer of ethanol and water (corresponding to a volume fraction of 79% ethanol in the liquid) prefers ethanol in a gauche conformation as the hydrogen bond acceptor. This represents a particularly simple case of adaptive aggregation. Furthermore, it is shown experimentally that the isolated cold trimer built from one ethanol and two waters (corresponding to 64% ethanol in the liquid) has a significantly negative excess enthalpy, in line with the thermodynamic bulk observation at room temperature. 相似文献