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121.
Nomiya K Togashi Y Kasahara Y Aoki S Seki H Noguchi M Yoshida S 《Inorganic chemistry》2011,50(19):9606-9619
Four novel multifunctional polyoxometalate (POM)-based inorganic-organic hybrid compounds, [α(2)-P(2)W(17)O(61){(RGe)}](7-) (Ge-1, R(1) = HOOC(CH(2))(2(-)) and Ge-2, R(2) = H(2)C═CHCH(2(-))) and [α(2)-P(2)W(17)O(61){(RSi)(2)O}](6-) (Si-1, R(1) and Si-2, R(2)), were prepared by incorporating organic chains having terminal functional groups (carboxylic acid and allyl groups) into monolacunary site of Dawson polyoxoanion [α(2)-P(2)W(17)O(61)](10-). In these POMs, new modification of the terminal functional groups was attained by introducing organogermyl and organosilyl groups. Dimethylammonium salts of the organogermyl complexes, (Me(2)NH(2))(7)[α(2)-P(2)W(17)O(61)(R(1)Ge)]·H(2)O MeN-Ge-1 and (Me(2)NH(2))(7)[α(2)-P(2)W(17)O(61)(R(2)Ge)]·4H(2)O MeN-Ge-2, were obtained as analytically pure crystals, in 22.8% and 55.3% yields, respectively, by stoichiometric reactions of [α(2)-P(2)W(17)O(61)](10-) with separately prepared Cl(3)GeC(2)H(4)COOH in water, and H(2)C═CHCH(2)GeCl(3) in a solvent mixture of water/acetonitrile. Synthesis and X-ray structure analysis of the Dawson POM-based organogermyl complexes were first successful. Dimethylammonium salts of the corresponding organosilyl complexes, (Me(2)NH(2))(6)[α(2)-P(2)W(17)O(61){(R(1)Si)(2)O}]·4H(2)O MeN-Si-1 and (Me(2)NH(2))(6)[α(2)-P(2)W(17)O(61){(R(2)Si)(2)O}]·6H(2)O MeN-Si-2, were also obtained as analytically pure crystalline crystals, in 17.1% and 63.5% yields, respectively, by stoichiometric reactions of [α(2)-P(2)W(17)O(61)](10-) with NaOOC(CH(2))(2)Si(OH)(2)(ONa) and H(2)C═CHCH(2)Si(OEt)(3). These complexes were characterized by elemental analysis, thermogravimetric and differential thermal analyses (TG/DTA), FTIR, solid-state ((31)P) and solution ((31)P, (1)H, and (13)C) NMR, and X-ray crystallography. 相似文献
122.
Ellagic Acid Suppresses ApoB Secretion and Enhances ApoA-1 Secretion from Human Hepatoma Cells,HepG2
Ayana Ieda Maki Wada Yuuki Moriyasu Yuuko Okuno Nobuhiro Zaima Tatsuya Moriyama 《Molecules (Basel, Switzerland)》2021,26(13)
The effect of ellagic acid (EA), a naturally occurring polyphenolic compound, on the secretion of apolipoproteins from human hepatocytes, HepG2, was investigated. The levels of apoB and apoA-1 secreted in the cell culture medium were determined by sandwich ELISA. EA did not affect cell viability at the tested concentrations (up to 50 µM). EA suppressed the secretion of apoB and enhanced that of apoA-1 from HepG2 cells. However, cellular apoB levels were increased, suggesting that EA inhibited the trafficking of apoB during the process of secretion. In contrast, the increase in the cellular levels of apoA-1 was consistent with its secreted levels. These results indicate that EA inhibits the secretion of apoB from hepatocytes and increases the secretion of apoA-1. Both of these effects are beneficial for lipoprotein metabolism in the prevention of lifestyle-related diseases. The detailed mechanism underlying these effects of EA on lipoprotein metabolism should be elucidated in the future, but this naturally occurring polyphenolic compound might be antihyperlipidemic. Based on these results, EA is suggested as a candidate food-derived compound for the prevention of hyperlipidemia. 相似文献
123.
Abstract Transformation kinetics from hBN to cBN has been studied at 6 GPa with changing reaction temperature and content of catalyst mixed with hBN powder. At lower catalyst content (3–10 wt %), rate of transformation was extraordinary rapid between 1300 and 1350 C. At higher catalyst content (30–50 wt %), rate of transformation was decreased. Normal nucleation kinetics was observed at about 1500 C. The rapid transformation temperature region correlates characteristic behavior of the sintering process. 相似文献
124.
O. Adriani L. Bonechi M. Bongi R. D’Alessandro P. Papini D. A. Faus J. Velasco M. Haguenauer Y. Itow K. Masuda Y. Matsubara H. Matsumoto H. Menjo Y. Muraki T. Sako K. Kasahara T. Tamura K. Yoshida 《Czechoslovak Journal of Physics》2006,56(1):A107-A116
The LHCf experiment will be installed in 2007 on the LHC collider in the forward direction at ±140m from the ATLAS interaction point. The purpose of LHCf is to precisely measure the pion production cross section near zero degrees through the measurement of the photons produced in neutral pion decay. This measurement is crucial for the simulation of the showers induced in the atmosphere by very high energy cosmic rays; the 14 TeV energy available in the center of mass frame corresponds in fact to an equivalent energy of 1017 eV in the laboratory system. The paper focus on the proposed experiment and on the physics results that we expect from it. 相似文献
125.
126.
K. Kasahara 《Optical and Quantum Electronics》1992,24(8):783-800
Recent progress is reviewed in surface-normal optoelectronic devices primarily for use in optical switching and information processing. A type of optoelectronic integrated circuit (OEIC), the surface-normal two-dimensional array, is fabricated using these devices. This improves on first-generation OEICs by featuring large-scale integration in a small area, which results in a higher production yield. It also has structures which can easily be integrated with electronic circuits and can meet multichannel requirements. This approach supports optoelectronic progress towards optical information processing. 相似文献
127.
Triplet state sublevel spectroscopy using optical detection of magnetic resonance (ODMR) in zero magnetic field can be successfully
employed to study (i) the environment of tryptophan (Trp) residues in a protein by observing the position and structure of
phosphorescence spectra, zero field ODMR transitions and triplet state sublevel kinetics, (ii) the energy transfer among Trp
residues, and (iii) whether any cysteine (Cys) residue is within van der Waals distance of any Trp residue by studying the
complex of the protein with methylmercury(II) iodide (CH3HgI) which binds to Cys residues. These studies are particularly important where crystal structure study is not possible.
Study of the S1 state often gives ambiguous results since fluorescence is always broad and shows multi-exponential decay. Our results on
bacteriophage lysozyme T4 which contains three Trp residues at positions 126, 138 and 158 are presented. Measurements were
facilitated by the use of a mutated enzyme containing one or two Trp-Tyr substitutions. The results indicate that (i) Trp
126 and 158 are solvent exposed, whereas Trp 138 is buried in a hydrophobic environment, (ii)S ↔S non-radiative energy transfer takes place predominantly from Trp 126 to Trp 158, and (iii) only Trp-158 undergoes a heavy
atom perturbation, which affects selectively the z-sublevel (z is an out-of-plane axis of the indole plane) as a result of
CH3HgI binding to nearby Cys 97. We suggest that the Hg atom is located on the z-axis of Trp 158 in the complex. This interpretation
is based on our investigations on the effect of orientation of heavy atom perturbers in some naphthalene-crown ether metal
ion complexes. 相似文献
128.
129.
130.
Sanjib Ghosh Jeffry G. Weers Michael Petrin August H. Maki 《Chemical physics letters》1984,108(1):87-93
The temperature dependence of the individual spin—lattice relaxation rate constants (Wij) between the lowest triplet sublevels of naphthalene-h8 in a polycrystalline Shpol'skii matrix of n-pentane have been measured between 1.2 and 2.4 K in zero field. The total sublevel decay constants are evaluated and found to be independent of temperature. The Wij are found to be highly anisotropic, but the anisotropy pattern differs from that observed previously in a durene matrix. 相似文献