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21.
For couplings and mass ratios appropriate to molecules such as H2O, D2O, and CH2 large volumes of the classical vibrational phase space are found to be non-dissociating even well above threshold. Fully quantum calculations yield families of exceptionally long-lived quantum states corresponding to these trapped volumes. 相似文献
22.
Ingrid Daubechies 《Communications in Mathematical Physics》1984,94(4):523-535
We discuss the discrete spectrum of the operator $$H_K (c) = \left[ { - \hbar ^2 c^2 \Delta + m^2 c^4 } \right]^{{1 \mathord{\left/ {\vphantom {1 2}} \right. \kern-\nulldelimiterspace} 2}} - \sum\limits_{k = 1}^K {Z_k e^2 \left| {x - R_k } \right|^{ - 1} } $$ . More specifically, we study 1) the behaviour of the eigenvalues when the internuclear distances contract, 2) the existence of ac-independent lower bound forH K (c)?mc 2, 3) the nonrelativistic limit of the eigenvalues ofH K (c)?mc 2. 相似文献
23.
Ingrid Fischler Rosi Wagner Ernst A.Koerner Von Gustorf 《Journal of organometallic chemistry》1976,112(2):155-165
The photochemical reaction of the trinuclear complex Fe3(CO)10NSi(CH3)3 under hydrogen leads to substitution of the bridging carbonyl group by two hydrogens. The resulting complex H2Fe3(CO)9NSi(CH3)3 acts as a catalyst in the photochemical hydrogenation of olefins and dienes. 相似文献
24.
R. Furler Ingrid E. C. P. M. Licht J. K. L. Offenberg H. L. Polak 《Journal of Radioanalytical and Nuclear Chemistry》1975,25(2):255-260
Studies are reported to illustrate surface adsorption of144Ce,59Fe,234Th,233U,237Np,239Pu and241Am on a dextran gel made by crosslinkage of the polysaccharide dextran (Sephadex). Fixation of such elements was studied from
aqueous solution and was found to depend on pH, age of the tracer solution, hydrolytic behaviour of the adsorbed species,
concentration and the valency of the adsorbed element. 相似文献
25.
Siloxy substituted methyl cyclopropanecar?ylates are cleaved by bromine to afford α-bromo-γ-oxoester and, after treatment with triethylamine, good yields of α,β-unsaturated γ-oxoesters. 相似文献
26.
Using the Breit—Wigner definition of a resonance, we calculate both resonance positions and widths for a model non-separable hamiltonian, using a uniform semiclassical self-consistent-field (SCF) method. Excellent agreement with recent complex-coordinate quantum SCF calculations is obtained. 相似文献
27.
28.
Gottfried Mrkl Karl Gschwendner Ingrid Rtzer Peter Kreitmeier 《Helvetica chimica acta》2004,87(4):825-844
Tetrakis(diethyl phosphonate), Tetrakis(ethyl phenylphosphinate)‐, and Tetrakis(diphenylphosphine oxide)‐Substituted Phthalocyanines The title compounds 7, 9 , and 11 are obtained by tetramerization of diethyl (3,4‐dicyanophenyl)phosphonate ( 5 ), ethyl (3,4‐dicyanophenyl)phenylphosphinate ( 8 ), and 4‐(diphenylphosphinyl)benzene‐1,2‐dicarbonitrile ( 10 ). The 31P‐NMR spectra of the phthalocyanines 7, 9 , and 11 and of their metal complexes present five to eight signals confirming the formation of four constitutional isomers with the expected C4h, D2h, C2v, and Cs symmetry. In the FAB‐MS of the Zn, Cu, and Ni complexes of 7 and 9 , the peaks of dimeric phthalocyanines are observed. By gel‐permeation chromatography, the monomeric complex [Ni( 7 )] and a dimer [Ni( 7 )]2 can be separated. These dimers differ from the known phthalocyanine dimers, i.e., possibly the P(O)(OEt)2 and P(O)(Ph)(OEt) substituents in 7 and 9 are involved in complexation. The free phosphonic acid complex [Zn( 12 )] and [Cu( 12 )] are H2O‐soluble. In the FAB‐MS of [Zn( 12 )], only the peaks of the dimer are present; the ESI‐MS confirms the existence of the dimer and the metal‐free dimer. In the UV/VIS spectrum of [Zn( 12 )], the hypsochromic shift characteristic for the known type of dimers from 660–700 nm to 620–640 nm is observed. As in the FAB‐MS of [Zn( 12 )], the free phosphinic acid complex [Zn( 13 )] shows only the monomer, an ESI‐MS cannot be obtained for solubility problems. The UV/VIS spectrum of [Zn( 13 )] demonstrates the existence of the monomer as well as of the dimer. 相似文献
29.
The novel versatile cobalt(I) tris-carbene complex [(TIMEN(xyl))Co]Cl (1) (where TIMEN = (tris[2-(3-arylimidazol-2-ylidene)ethyl]amine) reacts with CO, one-electron oxidizers such as CH(2)Cl(2), and O(2) to yield the cobalt complexes [(TIMEN(xyl))Co(CO)]Cl (2), [(TIMEN(xyl))Co(Cl)]Cl (3), and peroxo species [(TIMEN(xyl))Co(O(2))](BPh(4)) (5). All new complexes were fully characterized by (1)H NMR, UV/vis, and IR spectroscopy as well as superconducting quantum interference device (SQUID) magnetization measurements and single-crystal X-ray crystallography. The nucleophilic character of the eta(2)-bound dioxygen ligand in 5 was confirmed by density functional theory (DFT) studies and allows for oxygen-transfer reactions with electron-deficient organic substrates, such as benzoyl chloride. 相似文献
30.
Zusammenfassung Die Reaktion von 2-Pyridylessigsäurederivaten (1a, 1b) mit Diketen (2) in sied. Eisessig liefert in 1-Stellung substit. 4-Methyl-2-chinolizinone.
Syntheses of heterocycles, CXXI: Quinolizines and indolizines. A synthesis of 4-methyl-2-quinolizinones
The reaction of 2-pyridylacetic acid derivatives (1a, 1b) with diketene (2), gives 4-methyl-2-quinolizinones.相似文献