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排序方式: 共有315条查询结果,搜索用时 31 毫秒
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Chantal Degrand L. Roullier Larry L. Miller Baruch Zinger 《Journal of Electroanalytical Chemistry》1984,178(1):101-111
Chemically modified carbon electrodes are prepared which hold polymeric layers of anthraquinone or dopamine units on the surface. In each case only those quinonoid units nearest the carbon are electroactive in neutral solution. Other units can be activated by one-electron redox shuttles dissolved in the solution phase which help propagate the redox process through the film. Cobalticinium dicarboxylic acid and methyl viologen are used to catalyze reductive reactions and ferrocene carboxylic acid catalyzes the oxidative propagation. 相似文献
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Lazerges M Perrot H Rabehagasoa N Antoine E Compere C 《Chemical communications (Cambridge, England)》2005,(48):6020-6022
Supramolecular polymerizations of 45- and 70- base DNAs on the surface of an in-situ time-resolved 27 MHz quartz crystal microbalance biosensor. 相似文献
36.
Dubois MP Gondran C Renaudet O Dumy P Driguez H Fort S Cosnier S 《Chemical communications (Cambridge, England)》2005,(34):4318-4320
Direct detection of peanut agglutinin/lactose interactions was realized by an electrochemical approach based on a polypyrrole coated electrode displaying pendant carbohydrates. 相似文献
37.
Ab initio calculations using 6-311G**, cc-pVDZ, and aug-cc-pVDZ, with (MP2, QCISD, CCSD(T)) and without (UHF) electron correlation, and density functional methods (BHandHLYP and B3LYP) predict that cyclization of the 5-aza-5-hexenoyl and (E)-6-aza-5-hexenoyl radicals proceed to afford the 5-exo products. At the CCSD(T)/cc-pVDZ//BHandHLYP/cc-pVDZ level of theory, energy barriers (deltaE(double dagger)) of 36.1 and 47.0 kJ mol(-1) were calculated for the 5-exo and 6-endo pathways for the cyclization of the 5-aza-5-hexenoyl radical. On the other hand, at the same level of theory, deltaE(double dagger) of 38.9 and 45.4 kJ mol(-1) were obtained for the 5-exo and 6-endo cyclization modes of (E)-6-aza-5-hexenoyl radical, with exothermicities of about 27 and 110 kJ mol(-1) calculated for the exo and endo modes, respectively. Under suitable experimental conditions, the 6-endo cyclization product is likely to dominate. Analysis of the molecular orbitals involved in these ring-closure reactions indicate that both reactions at nitrogen are assisted by dual orbital interactions involving simultaneous SOMO-pi* and LP-pi* overlap in the transitions states. Interestingly, the (Z)-6-aza-5-hexenoyl radical, that cannot benefit from these dual orbital effects is predicted to ring-close exclusively in the 5-exo fashion. 相似文献
38.
Laser processing for bio-microfluidics applications (part I) 总被引:1,自引:0,他引:1
Khan Malek CG 《Analytical and bioanalytical chemistry》2006,385(8):1351-1361
This paper reviews applications of laser-based techniques to the fabrication of microfluidic devices for biochips and addresses
some of the challenges associated with the manufacture of these devices. Special emphasis is placed on the use of lasers for
the rapid prototyping and production of biochips in particular for applications in which silicon is not the preferred material
base. Part I of this review addresses applications and devices using UV lasers for laser ablation and surface treatment of
microchannels, in particular in polymers. 相似文献
39.
Jean-Loïc Rose Alain Lalande Olivier Bouchot El-Bey Bourennane Paul M. Walker Patricia Ugolini Chantal Revol-Muller Raymond Cartier François Brunotte 《Magnetic resonance imaging》2010
Magnetic resonance imaging (MRI) is particularly well adapted to the evaluation of aortic distensibility. The calculation of this parameter, based on the change in vessel cross-sectional area per unit change in blood pressure, requires precise delineation of the aortic wall on a series of cine-MR images. Firstly, the study consisted in validating a new automatic method to assess aortic elasticity. Secondly, aortic distensibility was studied for the ascending and descending thoracic aortas in 26 healthy subjects. Two homogeneous groups were available to evaluate the influence of sex and age (with an age limit value of 35 years). The automatic postprocessing method proved to be robust and reliable enough to automatically determine aortic distensibility, even on artefacted images. In the 26 healthy volunteers, a marked decrease in distensibility appears with age, although this decrease is only significant for the ascending aorta (8.97±2.69 10−3 mmHg−1 vs. 5.97±2.02 10−3 mmHg−1). Women have a higher aortic distensibility than men but only significantly at the level of the descending aorta (7.20±1.61 10−3 mmHg−1 vs. 5.05±2.40 10−3 mmHg−1). Through our automatic contouring method, the aortic distensibility from routine cine-MRI has been studied on a healthy subject population providing reference values of aortic stiffness. The aortic distensibility calculation shows that age and sex are causes of aortic stiffness variations in healthy subjects. 相似文献
40.
Disorder in colloid crystals was induced by doping them with a different number of large or small guest particles, which had a different deviation in size from the host colloids. The change in optical properties of the guest-host colloid crystals was assessed by using optical transmission spectroscopy while the variation in crystal structure was examined using scanning electron microscopy (SEM). The disruption in the crystalline lattices depended on the relative deviation in sizes of the guest and host particles and the concentration of the guest colloids. In parallel with experiments, the packing of spheres in guest-host crystals was modeled with a simulated annealing algorithm. A good correlation was found between the changes in crystal structure observed by SEM imaging and the simulated sphere packing. The experimental and simulated changes in the transmission spectra of guest-host colloid crystals were in good agreement. 相似文献