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31.
Hanna Mouaziz Sebastian Braconnot Frédéric Ginot Abdelhamid Elaissari 《Colloid and polymer science》2009,287(3):287-297
Aminodextran containing submicron magnetic latex particles were prepared in two steps: (a) transformation of oil-in-water
magnetic emulsion into structured magnetic latex particles via combination of seed and miniemulsion-like polymerization process
and (b) immobilization (adsorption and chemical grafting) of prepared aminodextran onto negatively charged seed magnetic latex
particles. The elaborated magnetic latex particles were characterized in terms of particle size, size distribution, morphology,
surface charge density, chemical composition, magnetic properties, and also colloidal stability. The results showed that the
morphology of the prepared seed magnetic latex is core–shell like and the cationic latex particles are hydrophilic and of
high colloidal stability, irrespective of the aminodextran immobilization process. 相似文献
32.
Heydari-Gorji A Belmabkhout Y Sayari A 《Langmuir : the ACS journal of surfaces and colloids》2011,27(20):12411-12416
Poly(ethyleneimine) (PEI) supported on pore-expanded MCM-41 whose surface is covered with a layer of long-alkyl chains was found to be a more efficient CO(2) adsorbent than PEI supported on the corresponding calcined silica and all PEI-impregnated materials reported in the literature. The layer of surface alkyl chains plays an important role in enhancing the dispersion of PEI, thus decreasing the diffusion resistance. It was also found that at low temperature, adsorbents with relatively low PEI contents are more efficient than their highly loaded counterparts because of the increased adsorption rate. Extensive CO(2) adsorption-desorption cycling showed that the use of humidified feed and purge gases affords materials with enhanced stability, despite limited loss due to amine evaporation. 相似文献
33.
Adsorption of CO2, N2, CH4 and H2 on triamine-grafted pore-expanded MCM-41 mesoporous silica (TRI-PE-MCM-41) was investigated at room temperature in a wide
range of pressure (up to 25 bar) using gravimetric measurements. The material was found to exhibit high affinity toward CO2 in comparison to the other species over the whole range of pressure. Column-breakthrough dynamic measurements of CO2-containing mixtures showed very high selectivity toward CO2 over N2, CH4 and H2 at CO2 concentrations within the range of 5 to 50%. These conditions are suitable for effective removal of CO2 at room temperature from syngas, flue gas and biogas using temperature swing (TS) or temperature-pressure swing (TPS) regeneration
mode. Moreover, TRI-PE-MCM-41 was found to be highly stable over hundreds of adsorption-desorption cycles using TPS as regeneration
mode. 相似文献
34.
Hnaien M Lagarde F Bausells J Errachid A Jaffrezic-Renault N 《Analytical and bioanalytical chemistry》2011,400(4):1083-1092
Trichloroethylene (TCE), a suspected human carcinogen, is one of the most common volatile groundwater contaminants. Many different
methodologies have already been developed for the determination of TCE and its degradation products in water, but most of
them are costly, time-consuming and require well-trained operators. In this work, a fast, sensitive and miniaturised whole
cell conductometric biosensor was developed for the determination of trichloroethylene. The biosensor assembly was prepared
by immobilising Pseudomonas putida F1 bacteria (PpF1) at the surface of gold interdigitated microelectrodes through a three-dimensional alkanethiol self-assembly
monolayer/carbon nanotube architecture functionalised with Pseudomonas antibodies. The biosensor response was linear from 0.07 to 100 μM of TCE (9–13,100 μg L−1). No significant loss of the enzymatic activity was observed after 5 weeks of storage at 4 °C in the M457 pH 7 defined medium
(two or three measurements per week). Ninety-two per cent of the initial signal still remained after 7 weeks. The biosensor
response to TCE was not significantly affected by cis-1,2-dichloroethylene and vinyl chloride and, in a limited way, by phenol. Toluene was the major interference found. The bacterial
biosensor was successfully applied to the determination of TCE in spiked groundwater samples and in six water samples collected
in an urban industrial site contaminated with TCE. Gas chromatography–mass spectrometric analysis of these samples confirmed
the biosensor measurements. 相似文献
35.
Nasser Eddine Mouhoub Abdelhamid Benhocine Hocine Belouadah 《Applied Mathematical Modelling》2011,35(9):4575-4588
A project is an enterprise consisting of several activities which are to be carried out in some specific order. The activities and the order in which they need to be carried out can be represented by a PERT network. The PERT technique is a traditional, well-known approach to the expert of project management. When networks are used, it often becomes necessary to draw dummy activities. Since the computation of project completion time is proportional to the number of arcs, including dummy arcs, it is desirable to draw a network with as few dummy activities as possible.In this paper, we propose a new method for constructing, for a given project scheduling problem, a PERT network having as small as possible the number of dummy arcs by using some results on line graphs. This algorithm deals with the existence of transitive arcs. The paper contains illustrative examples, proofs of some theoretical results as well as a comparative study with a similar algorithm known in the literature. Computational results showed the superiority of our algorithm. 相似文献
36.
Pyrazolo[4,3‐d]pyrimidines, pyrazolo[4,3‐d]triazolino[4,3‐a]pyrimidines, 3‐(2‐thiazolyl)thiophenes, thiazolo[3,2‐a]pyridine and pyrazolo[1,5‐a]pyrimidines were synthesized from 2‐[4‐(3‐oxobenzo[f]‐2H‐chromen‐2‐yl)‐1,3‐thiazol‐2‐yl]ethanenitrile. The newly synthesized compounds were elucidated by elemental analysis, spectral data, chemical transformation and alternative synthesis route whenever possible. 相似文献
37.
Abdelhamid Khaled 《Mathematische Annalen》1993,295(1):685-701
Sans résumé
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38.
Abdelhamid Benchakroun Jean-Pierre Dussault Abdelatif Mansouri 《Mathematical Methods of Operations Research》1995,41(1):25-55
In this paper, we analyze the mixed penalty methods introduced in the classic book of Fiacco and McCormick usingtwo distinct penalty parametersr, t. The two penalty coefficients induce a two-parameter differentiable trajectory. We analyze the numerical behaviour of an extrapolation strategy that follows the path of the two-parameter trajectory. We show also how to remove the ill-conditioning by suitable transformations of the equations. In the resulting theory, we show that function values as well as distances to the optimum are both governed by the same behaviour as interior methods (two-step superlinearly convergent, with limiting exponent 4/3).Research partially supported by NSERC grant OGP0036512.Research partially supported by NSERC grant OGP0005491. 相似文献
39.
Athar Ata Joe Ackerman Abdelhamid Bayoud Parvataneni Radhika 《Helvetica chimica acta》2004,87(3):592-597
From the methanolic extract of Cladiella sp., collected from the Andaman Island, India, a new sesquiterpene, cladidiol ( 2 ), and three known diterpenes, cladiellaperoxide ( 3 ), (6E)‐2α,9α‐epoxyeunicella‐6,11(12)‐dien‐3β‐ol ( 4 ), and polyanthellin A ( 5 ) were isolated. The structures of these compounds were established by extensive spectroscopic studies. Compound 2 exhibited modest acetylcholinesterase‐inhibition activity, and compounds 3 – 5 showed antibacterial activities against Streptococcus pyogenes, Escherichia coli, and Pseudomonas aeruginosa. 相似文献
40.
Bahgat E. Elanadouli Abdou O. Abdelhamid Ahmad S. Shawali 《Journal of heterocyclic chemistry》1984,21(4):1087-1091
The polarographic behaviour of a series of 2-amino-4-phenyl-5-arylazothiazoles has been investigated at a dropping mercury electrode. Each of the compounds studied exhibits one wave which was shown to correspond to the reductive cleavage of the azo linkage by a 4e irreversible step. On the basis of the polarographic data, it was concluded that the compounds exist only in one tautomeric form, namely the aminoazo structure 1 . The results of E1/2 — σX correlations and HMO calculations of bonding energies of the various possible tautomeric forms 1–3 indicate that the aminoazo form 1 is the most stable structure of the compounds examined. 相似文献