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31.
Smith AB Risatti CA Atasoylu O Bennett CS Liu J Cheng H TenDyke K Xu Q 《Journal of the American Chemical Society》2011,133(35):14042-14053
The design, synthesis, and biological evaluation of two diminutive forms of (+)-spongistatin 1, in conjunction with the development of a potentially general design strategy to simplify highly flexible macrocyclic molecules while maintaining biological activity, have been achieved. Examination of the solution conformations of (+)-spongistatin 1 revealed a common conformational preference along the western perimeter comprising the ABEF rings. Exploiting the hypothesis that the small-molecule recognition/binding domains are likely to comprise the conformationally less mobile portions of a ligand led to the design of analogues, incorporating tethers (blue) in place of the CD and the ABCD components of the (+)-spongistatin 1 macrolide, such that the conformation of the retained (+)-spongistatin 1 skeleton would mimic the assigned solution conformations of the natural product. The observed nanomolar cytotoxicity and microtubule destabilizing activity of the ABEF analogue provide support for both the assigned solution conformation of (+)-spongistatin 1 and the validity of the design strategy. 相似文献
32.
Michael J. Patrick Chia-Yuan Chen David H. Frakes Onur Dur Kerem Pekkan 《Experiments in fluids》2011,50(4):887-904
In hemodynamics, the inherent intermittency of two-phase cellular-level flow has received little attention. Unsteadiness is
reported and quantified for the first time in the literature using a combination of fluorescent dye labeling, time-resolved
scanning confocal microscopy, and micro-particle image velocimetry (μPIV). The near-wall red blood cell (RBC) motion of physiologic
high-hematocrit blood in a rectangular microchannel was investigated under pressure-driven flow. Intermittent flow was associated
with (1) the stretching of RBCs as they passed through RBC clusters with twisting motions; (2) external flow through local
obstacles; and (3) transitionary rouleaux formations. Velocity profiles are presented for these cases. Unsteady flow clustered
in local regions. Extra-cellular fluid flow generated by individual RBCs was examined using submicron fluorescent microspheres.
The capabilities of confocal μPIV post-processing were verified using synthetic raw PIV data for validation. Cellular interactions
and oscillating velocity profiles are presented, and 3D data are made available for computational model validation. 相似文献
33.
A. Dilek Azaz Selma Celen Hilmi Namli Onur Turhan Raif Kurtaran Canan Kazak N. Burcu Arslan 《Transition Metal Chemistry》2007,32(7):884-888
A complex of NiII with 2,6-diacetylpyridinedihydrazone (L) towards nickel(II) has been prepared and characterized by means of elemental analyses,
IR, electronic spectra and single crystal X-ray analyses. [NiL2](NO3) was crystallized in the tetragonal space group P-4 21 c. The complex exhibits the expected coordination sphere with six
nitrogen atoms coordinated to the central NiII with a deformation from pseudo-octahedral geometry. Antimicrobial activities of the ligand and its complex were investigated. 相似文献
34.
We introduce a "double direct templating" method for obtaining hollow microspheres with periodically nanostructured walls. Silica or polystyrene colloids are dispersed in a self-assembled hexagonal lyotropic liquid crystal containing precursors for ZnS. The semiconductor ZnS mineralizes on the surface of the colloid, expressing a pore morphology that is a copy of the structure of the liquid crystal. After etching of the sacrificial colloids, hollow capsules with templated and uniform mesoporous shells are obtained. 相似文献
35.
36.
Dağlı Özge Köse Dursun Ali İçten Okan Avcı Gülçin Alp Şahin Onur 《Journal of Thermal Analysis and Calorimetry》2019,136(4):1467-1480
Journal of Thermal Analysis and Calorimetry - The coumarilate (coum?) and 1,10-phenanthroline (phen) mixed ligand complexes of Co(II) (1), Ni(II) (2) Cu(II) (3) and Zn(II) (4) were... 相似文献
37.
We demonstrate a technique for characterizing two-photon quantum states based on joint temporal correlation measurements using time-resolved single-photon detection by femtosecond up-conversion. We measure for the first time the joint temporal density of a two-photon entangled state, showing clearly the time anticorrelation of the coincident-frequency entangled photon pair generated by ultrafast spontaneous parametric down-conversion under extended phase-matching conditions. The new technique enables us to manipulate the frequency entanglement by varying the down-conversion pump bandwidth to produce a nearly unentangled two-photon state that is expected to yield a heralded single-photon state with a purity of 0.88. The time-domain correlation technique complements existing frequency-domain measurement methods for a more complete characterization of photonic entanglement. 相似文献
38.
The decolorisation process of a synthetic textile dye, direct violet 51, was investigated in an aqueous solution using an electrochemical method in a batch electrochemical cell. Graphite electrodes were used as the anode and cathode for the decolorisation process. The parameters such as applied current, initial pH, solution conductivity, interfering ions, and effect of electrodes were optimised. It was found that the dye with an initial concentration of 20 mg L?1 could be removed after 50 min using a current of 100 mA with colour removal of up to 94 %. The UV-VIS spectra of the dye were analysed prior to and after treatment and these confirmed that the conjugated systems were decomposed at a current of 100 mA. The optimised method was successfully applied to real wastewater samples. 相似文献
39.
40.
1-Bromo-1-fluoro-[1a,2,7,7a]-tetrahydro-1H-cyclopropa[b]naphthalene (19) has been prepared by the addition of bromofluorocarbene to 1,4-dihydronaphthalene (18). Treatment of a solution of 19 in dry ether with MeLi afforded the tricyclic hydrocarbon 17, resulting from the intramolecular C-H insertion of carbene 16, and two dimerization products, the head-to-head 20 and head-to-tail 21 allene dimers, confirming the formation of title cycloallene 15 as a reactive intermediate. B3LYP/6-31G(d) calculation predicts the activation barriers for insertion product 17 and allene product 15 as 3.70 and 9.52 kcal/mol, respectively. This prediction was in good agreement with our experimental results. 相似文献