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排序方式: 共有790条查询结果,搜索用时 15 毫秒
781.
782.
Emmanuel Mousset Clément Trellu Hugo Olvera-Vargas Yoan Pechaud Florence Fourcade Mehmet A. Oturan 《Current Opinion in Electrochemistry》2021
When possible, the bioprocesses should be implemented to treat wastewater for their cost-effectiveness. However, many effluents are composed of biorecalcitrant organic pollutants, especially in industrial wastewaters. Advanced physico-chemical treatments are therefore needed to deal with these pollution levels. Electrochemical processes could be cost-effective solutions. However, the energy required to reach complete mineralization is often high. One promising combination would be to combine electrochemical processes that can remove xenobiotic compounds from effluent with biotechnologies that are able to mineralize the biodegradable fraction. Therefore, this review presents the most recent articles dealing with this combination, by mainly focusing on electrochemical advanced oxidation processes that demonstrated to have high removal efficiency for organic biorecalcitrant compounds. Additional and imperative information about the treatment strategy and the engineering aspects for the upscaling approach are also given. 相似文献
783.
A method of increasing the stability ofo/w emulsions and providing a potential additional barrier to drug release from the oil droplets is described. Diacryloyl derivatives of non-ionic block copolymers (poloxamers) have been used to stabilise isopropyl myristate in water emulsions. Cross-linking of these stabilisers at the oil-water interface produces a polymeric region which increases the stabilityo/w emulsions to centrifugation and of thew/o emulsions to creaming. 相似文献
784.
Depletion of high field strength elements (HFSE: Nb, Ta, Zr, Hf ) relative to other lithophile trace elements in arc magmas
and variations of Nb/Ta and Zr/Hf ratios in mantle-derived rocks can be addressed through studies of minerals, which concentrate
and fractionate these elements. The presence of rutile, a common accessory Ti-oxide phase in various mantle rocks, has often
been invoked to explain the Nb and Ta depletion in arc lavas because it has the highest HFSE abundances among the known mantle
minerals. In this study, we measure the concentrations of Nb, Ta, Zr and Hf (at > 200 ppm) in rutile of two metasomatized
mantle lherzolites using a Cameca SX-100 electron microprobe and obtain Nb/Ta ratios with an accuracy of about ± 5%. Mass
balance calculations indicate that ≤ 1−5% of Nb and Ta in the rocks reside in major minerals and that the balance is hosted
by accessory Ti-oxides. The Nb/Ta ratios vary significantly in nearby rutile grains in both peridotites (17–33, average 23;
12–37, average 21). Therefore, individual rutile grains may not be representative of the total grain population. However,
Nb/Ta ratios measured in the bulk rock lherzolites by solution ICP-MS (21 ± 0.3) are within the analytical error of the average
Nb/Ta values calculated for 5–7 rutile grains in both samples. These results emphasise that a representative grain selection
must be analysed in order to determine trace elements contents of bulk rocks from data on accessory phases. 相似文献
785.
The association constants for the interactions of 2-hydroxy-4-methoxyacetophenone, 2-hydroxy-5-methoxyacetophenone, 2-hydroxy-6-methoxyacetophenone, 3-hydroxy-4-methoxyacetophenone and 4-hydroxy-3-methoxyacetophenone with β-cyclodextrin in water were measured by (1)H NMR and by isothermal titration calorimetry. Very good agreement was obtained between the different methods. The errors associated with the NMR method for measuring mM binding affinities were estimated to be 10-30%, and by isothermal titration calorimetry, 10-20%. Rotating frame nuclear Overhauser effect spectroscopy studies show that the solution phase host-guest complexes formed by β-cyclodextrin with these hydroxymethoxyacetophenone derivatives are not structurally well defined but that the hydroxymethoxyacetophenone derivatives are mostly associated with the narrow primary hydroxyl rim. 相似文献
786.
O'Connell MA de Cuendias A Gayet F Shirley IM Mackenzie SR Haddleton DM Unwin PR 《Langmuir : the ACS journal of surfaces and colloids》2012,28(17):6902-6910
Evanescent wave cavity ring-down spectroscopy (EW-CRDS) has been employed to study the interfacial adsorption kinetics of coumarin-tagged macromolecules onto a range of functionalized planar surfaces. Such studies are valuable in designing polymers for complex systems where the degree of interaction between the polymer and surface needs to be tailored. Three tagged synthetic polymers with different functionalities are examined: poly(acrylic acid) (PAA), poly(3-sulfopropyl methacrylate, potassium salt) (PSPMA), and a mannose-modified glycopolymer. Adsorption transients at the silica/water interface are found to be characteristic for each polymer, and kinetics are deduced from the initial rates. The chemistry of the adsorption interfaces has been varied by, first, manipulation of silica surface chemistry via the bulk pH, followed by surfaces modified by poly(L-glutamic acid) (PGA) and cellulose, giving five chemically different surfaces. Complementary atomic force microscopy (AFM) imaging has been used for additional surface characterization of adsorbed layers and functionalized interfaces to allow adsorption rates to be interpreted more fully. Adsorption rates for PSPMA and the glycopolymer are seen to be highly surface sensitive, with significantly higher rates on cellulose-modified surfaces, whereas PAA shows a much smaller rate dependence on the nature of the adsorption surface. 相似文献
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