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Ginette Ratovo Jean‐Pierre Souchard Pascale Urizzi Yvon Coulais Franoise Nepveu Etienne Hollande 《应用有机金属化学》2004,18(1):1-8
Pancreatic cancer has an extremely poor prognosis, due, in part, to lack of methods for early diagnosis. The present study was designed to evaluate the potential of labeling low‐density lipoprotein (LDL) with a radionuclide using a lipid chelating agent, bis(stearylamide) of diethylenetriaminepentaacetic acid (L), to detect pancreatic tumors by gamma‐scintigraphy. Previous studies indicated that the difficulty of visualization of pancreatic tumors was due to their poor vascularization. This study compares the ability of two radiotracers, 111In–L–LDL and 153Gd–L–LDL to target highly vascularized rat pancreatic tumors (AR4‐2J) implanted in nude mice. Biodistribution studies showed that the tumor uptake of 111In–L–LDL and 153Gd–L–LDL tracers was twofold and fivefold higher respectively than with the controls (111In citrate and 153Gd citrate respectively). These tracers would thus be suitable for scintigraphic imaging. We show here that LDL could be employed as a delivery system for tracers such as 111In or 153Gd when these two radionuclides are complexed by a lipid‐chelating anchor, and that 111In–L–LDL and 153Gd–L–LDL enabled better visualization of the pancreatic tumor tissues, with a better result with 153Gd–L–LDL. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
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Pascale F Catti M Damin A Orlando R Saunders VR Dovesi R 《The journal of physical chemistry. B》2005,109(39):18522-18527
The vibrational spectrum of Ca3Fe2Si3O12 andradite is calculated at the Gamma point by using the periodic ab initio CRYSTAL program that adopts an all-electron Gaussian-type basis set and the B3LYP Hamiltonian. The full set of frequencies (17 IR active, 25 Raman active, and 55 inactive modes) is calculated. The effect of the basis set on the calculated frequencies is discussed. The modes are characterized by direct inspection of the eigenvectors and isotopic substitution. The present calculations permit us to clarify some of the assignment problems raised by experiments. The mean absolute differences of the various modes with respect to the available experimental IR and Raman data are as small as 9 and 5 cm(-1), respectively. 相似文献
5.
Pascale F Ugliengo P Civalleri B Orlando R D'Arco P Dovesi R 《The Journal of chemical physics》2004,121(2):1005-1013
The structure of the Si-free katoite hydrogarnet (116 atoms in the unit cell) has been investigated at the periodic ab initio quantum mechanical level with the CRYSTAL program, by using a Gaussian type basis set and both the HF and the hybrid B3-LYP Hamiltonians. The structure has been fully optimized at various pressures in the 0-46 GPa range; the modifications of the structure, and in particular of the (OH)4 group, as a function of pressure are analyzed. At the B3-LYP level and P greater than 15 GPa, a O-H...O interaction of increasing strength appears, with important modifications in the local geometry of the tetrahedral site. The calculated omega01(O-H) fundamental vibrational frequency at zero pressure is in excellent agreement with experiment (3674 and 3663 cm(-1), respectively); the omega01(O-H) stretching frequency remains essentially constant in the 0-15 GPa interval, whereas it dramatically decreases at higher pressures with a corresponding anharmonicity increase, as a consequence of the formation of a strong hydrogen bond. The hydration energy of grossular and the formation energy of Si-free katoite have also been computed, and the B3-LYP results are in quite good agreement with experiment. 相似文献
6.
Fonseca GS Umpierre AP Fichtner PF Teixeira SR Dupont J 《Chemistry (Weinheim an der Bergstrasse, Germany)》2003,9(14):3263-3269
Stable transition-metal nanoparticles of the type [M(0)](n) are easily accessible through the reduction of Ir(I) or Rh(III) compounds dissolved in "dry" 1-n-butyl-3-methylimidazolium hexafluorophosphate ionic liquid by molecular hydrogen. The formation of these [M(0)](n) nanoparticles is straightforward; they are prepared in dry ionic liquid whereas the presence of the water causes the partial decomposition of ionic liquid with the formation of phosphates, HF and transition-metal fluorides. Transmission electron microscopy (TEM) observations and X-ray diffraction analysis (XRD) show the formation of [Ir(0)](n) and [Rh(0)](n) nanoparticles with 2.0-2.5 nm in diameter. The isolated [M(0)](n) nanoparticles can be redispersed in the ionic liquid, in acetone or used in solventless conditions for the liquid-liquid biphasic, homogeneous or heterogeneous hydrogenation of arenes under mild reaction conditions (75 degrees C and 4 atm). The recovered iridium nanoparticles can be reused several times without any significant loss in catalytic activity. Unprecedented total turnover numbers (TTO) of 3509 in 32 h, for arene hydrogenation by nanoparticles catalysts, have been achieved in the reduction of benzene by the [Ir(0)](n) in solventless conditions. Contrarily, the recovered Rh(0) nanoparticles show significant agglomeration into large particles with a loss of catalytic activity. The hydrogenation of arenes containing functional groups, such as anisole, by the [Ir(0)](n) nanoparticles occurs with concomitant hydrogenolysis of the C-O bond, suggesting that these nanoparticles behave as "heterogeneous catalysts" rather than "homogeneous catalysts". 相似文献
7.
Determination of ochratoxin A in domestic and imported beers in italy by immunoaffinity clean-up and liquid chromatography 总被引:4,自引:0,他引:4
A method first developed to quantify ochratoxin A in wine has been applied to the analysis of domestic and imported beers in Italy. The method uses commercial immunoaffinity columns for clean-up and high-performance liquid chromatography for quantification of the toxin. Beer was degassed, then diluted with a polyethylene glycol-sodium hydrogencarbonate solution and applied to an OchraTest immunoaffinity column. Ochratoxin A was eluted from the immunoaffinity column with methanol and quantified by reversed-phase HPLC with fluorometric detector. Average recoveries of ochratoxin A from blank beer spiked at levels from 0.04 to 1.0 ng/ml ranged from 93.8% to 100.4%, with relative standard deviations between 3.3% and 5.7%. The detection limit was 0.01 ng/ml based on a signal-to-noise ratio of 3:1. The analysis of 61 samples of domestic (10) and imported (51) beers showed ochratoxin A levels ranging from <0.01 to 0.135 ng/ml with an incidence of contamination of 50% and no substantial difference between strong and pale beers. 相似文献
8.
A new simple and efficient methodology for reductive sulfur extrusion from 2,1,3-benzothiadiazole compounds has been developed using NaBH4 in the presence of catalytic amounts of CoCl2·6H2O (1 mol %). This method is an efficient alternative for the generation of various 1,4-disubstituted-2,3-diaminobenzene derivatives from 4,7-disubstituted-2,1,3-benzothiadiazoles. The diamines can be easily converted into 4,7-disubstituted-quinoxaline compounds by simple reaction with glyoxal-sodium bisulfite. 相似文献
9.
Bonnet C Gadelle A Pécaut J Fries PH Delangle P 《Chemical communications (Cambridge, England)》2005,(5):625-627
The cyclodextrin derivative (hexakis (2-O-carboxymethyl-3,6-anhydro)-alpha-cyclodextrin) forms mono- and bimetallic complexes with lutetium(III) in aqueous solution; the X-ray structure of the binuclear complex [Lu2(ACX)(H2O)2] is the first example of a lanthanide-cyclodextrin inclusion complex. 相似文献
10.
H. Dupont Durst Luis Echegoyen George W. Gokel Angel Kaifer 《Tetrahedron letters》1982,23(43):4449-4452
The 13C spin-lattice relaxation times (T1's) of cryptands [2.1.1], [2.2.1] and [2.2.2] as well as those of the corresponding cryptate complexes with Li+, Na+, and K+ in CDCl3 and CH3OH:D2O (90:10) were measured and the results are interpreted in terms of molecular compression and desolvation effects. 相似文献