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181.
Boguslaw Buszewski Pawel Olszowy Tomasz Ligor Malgorzata Szultka Jacek Nowaczyk Maciej Jaworski Marek Jackowski 《Analytical and bioanalytical chemistry》2010,397(1):173-179
Five adrenolytic drugs have been analyzed by liquid chromatography–mass spectrometry (LC–MS). Samples were prepared by solid-phase
microextraction (SPME) using polypyrrole fibers coated on stainless steel support as an adsorbent for the drugs. Adsorption
efficiencies were 95% and were close for all the drugs investigated. Relative standard deviations (RSD), calculated for samples
prepared in standard solutions, were in the range 2.5–13%, however RSD values for the drugs in human plasma were 2.5–4.5%.
Using LC–MS the limit of detection (LOD) and the limit of quantification (LOQ) were in the ranges 0.11–0.18 and 0.39–0.54 ng mL−1, respectively, for the five drugs. 相似文献
182.
The stable benzylazido-boronate ester 1 is presented as an example of a dual-functional linker that allows the synthetically valuable boronate motif to be clicked onto other molecules under mild conditions. The utility of the azido-boronate motif as a modular building block is demonstrated in the rapid synthesis of drug-like structures employing sequential catalytic azide-alkyne cycloaddition and Suzuki coupling reactions. 相似文献
183.
In the present work we outline the implications of a quantum-classical approach for modeling two-photon absorption of organic chromophores in solution. The approach joins many-photon absorption dynamic simulations with quantum chemical first principles calculations of corresponding excitation energies and transition matrix elements. Among a number of conclusions of the study, we highlight three: (i) The use of either short- or long-pulse excitation is demonstrated to switch the absorptive capacity of the nonlinear medium owing to enhancement of the nonlinear stepwise processes; (ii) The two-photon cross section strongly depends on the way in which the dephasing rate decays when the laser frequency is tuned off-resonant with the corresponding molecular transition; (iii) The results of the pulse propagation simulations based on electronic structure data obtained with a new Coulomb attenuated functional is shown to be in much better agreement with the experimental results than those based on data received with traditional density functionals. 相似文献
184.
185.
186.
We have explored the thermoluminescence (TL) properties of a few series of liquid crystal unsymmetrical and symmetrical azomethines and poly(azomethines) with different shapes. Rod-, bent- and star-shaped compounds were investigated as thermoluminescent detectors. All of the investigated compounds, except ASB3, AG2 and PAZ2, exhibited mesomorphic behavior. The thermoluminescence studies have shown that molecular structure of the compound along with shape influenced the TL properties of azomethines and poly(azomethines). Thermoluminescence intensity (I), temperature of maximum TL (T), activation energy values (E) and frequency factor (s) were detected. For the first time, to the best of our knowledge, thermoluminescence properties of liquid crystalline azomethines and polyazomethines were described and compared in this article. 相似文献
187.
Interpolation of Vector-Valued Real Analytic Functions 总被引:2,自引:0,他引:2
Let Rd be an open domain. The sequentially complete DF-spacesE are characterized such that for each (some) discrete sequence(zn) , a sequence of natural numbers (kn) and any family the infinite system of equations
has an E-valued real analytic solution f. 相似文献
188.
The following results are presented: 1) a characterization through the Liouville property of those Stein manifoldsU such that every germ of holomorphic functions on xU can be developed locally as a vector-valued Taylor series in the first variable with values inH(U); 2) ifT
is a surjective convolution operator on the space of scalar-valued real analytic functions, one can find a solutionu of the equationT
u=f which depends holomorphically on the parameterz wheneverf depends in the same manner. These results are obtained as an application of a thorough study of vector-valued real analytic maps by means of the modern functional analytic tools. In particular, we give a tensor product representation and a characterization of those Fréchet spaces or LB-spacesE for whichE-valued real analytic functions defined via composition with functionals and via suitably convergent Taylor series are the same. 相似文献
189.
Silvia Zamponi Anna M. Kijak André J. Sommer Roberto Marassi Pawel J. Kulesza James A. Cox 《Journal of Solid State Electrochemistry》2002,6(8):528-533
The inclusion of a generation-4 polyamidoamine (G4-PAMAM) dendrimer in a silica sol-gel yielded a solid electrolyte that
was used to encapsulate Prussian Blue (PB), iron(III) hexacyanoferrate(II), and cobalt hexacyanoferrate. The PB was synthesized
in the doped silica by sequential immersion of a monolith in 0.1 M K4Fe(CN)6, water, and 0.1 M FeCl3. Inclusion of G4-PAMAM resulted in a nanoporous anion-exchange material with a capacity of 10.1 mmol g–1, which is about four times greater than the capacity of silica alone. Relative to its G0 counterpart, the G4-PAMAM doped
silica increased the rate of formation of PB by a factor of ca. 20. The solid state voltammetry of PB in the doped silica
had the usual features for this compound. At 0.1 V vs. a Ag quasi-reference electrode, a reversible reduction was seen; the
relationship between current and scan rate was that for a surface-confined redox couple. The quasi-reversible oxidation of
PB was observed at 0.85 V. Inclusion of G4-PAMAM increased the lifetime of silica as a solid electrolyte from a few days to
at least three months. Raman microprobe mapping analysis demonstrated that PB was homogeneously distributed across the entire
width (ca. 1 mm) of the G4-doped monolith with 20-h immersions.
Electronic Publication 相似文献
190.
Double-proton transfer in adenine-thymine and guanine-cytosine base pairs. A post-Hartree-Fock ab initio study 总被引:2,自引:0,他引:2
Gorb L Podolyan Y Dziekonski P Sokalski WA Leszczynski J 《Journal of the American Chemical Society》2004,126(32):10119-10129
The results of a comprehensive study on the double-proton transfer in Adenine-Thymine (AT) and Guanine-Cytosine (GC) base pairs at room temperature in gas phase and with the inclusion of environmental effects are obtained. The double-proton-transfer process has been investigated in the AT and GC base pairs at the B3LYP/6-31G(d) and MP2/6-31G(d) levels of theory. It has been predicted that the hydrogen-bonded bases possess nonplanar geometries due to sp3 hybridization of nitrogen atoms and because of the soft intermolecular vibrations in the molecular complexes. An analysis of the energetic parameters of the local minima suggests that rare AT base pair conformation is not populated due to the shallowness of this minimum, which completely disappears from the Gibbs free energy surface. The stabilization of canonic or rare forms of the DNA bases by water molecules and metal cations has been predicted by calculating the optimal configuration of charges (using differential product/transition state stabilization approach) followed by calculations of the interactions between the base pair and a water/sodium cation. 相似文献