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排序方式: 共有332条查询结果,搜索用时 15 毫秒
1.
Cyrille Ospel 《Journal of Pure and Applied Algebra》2002,173(3):315-337
For a commutative algebra the shuffle product is a morphism of complexes. We generalize this result to the quantum shuffle product, associated to a class of non-commutative algebras (for example all the Hopf algebras). As a first application we show that the Hochschild-Serre identity is the dual statement of our result. In particular, we extend this identity to Hopf algebras. Secondly, we clarify the construction of a class of quasi-Hopf algebras. 相似文献
2.
Grandjean C Boutonnier A Guerreiro C Fournier JM Mulard LA 《The Journal of organic chemistry》2005,70(18):7123-7132
[reaction: see text] The nature of a linker used for preparing glycoconjugate vaccines is of utmost importance as it may lead to immunogenic biomolecules. We report the conjugation of carbohydrate haptens to protein carriers leading to potential vaccines using the traceless Staudinger ligation. The ligation relies on the selective transfer of a phosphane substituent to an azide to form a native amide bond in the final product upon release of an oxidized phosphane byproduct. We designed new phosphino-functionalized cross-linkers suitable for protein carrier derivatization. We evaluated their utility in preparing conjugates using both synthetic and purified bacterial carbohydrates. The use of a borane-protected phosphane which is deprotected at the time of the ligation reaction led to the best results observed thus far in terms of stability toward oxidation and reactivity. 相似文献
3.
Cyrille Ceugniet Ltitia Lepetit Nancy Lauth De Viguerie Henry Jammes Nicole Peyrot Monique Rivire 《Journal of chromatography. A》1998,810(1-2):237-240
A high-performance liquid chromatographic (HPLC) procedure was developed to allow the rapid separation, in a single run, of a mixture of the main retinal isomers (all-trans, 13-cis, 9-cis), all-trans-retinol, and of the two major photooxygenated photoproducts (5,8-peroxyretinal and 5,6-epoxyretinal). The mixture was separated by HPLC on an octadecyl (ODS) column with 16% (v/v) diethyl ether in hexane as mobile phase and anthracene as the internal standard. A commercial type cosmetic formulation containing 0.05% all-trans-retinal was analyzed successfully for this analyte. 相似文献
4.
In this paper, the synthesis of a crosslinkable co-polymer containing new push-pull arylethynyl zinc porphyrins is described. The synthesis of porphyrin chromophores, analogous to Therien's porphyrin (J. Am. Chem. Soc.1996, 118, 1497-1503) functionalized with a methacrylic polymerizable group and a carboxylic acid crosslinking group was achieved with a new synthetic procedure leading to a higher overall yield compared to what was previously reported in the literature for similar and simpler structures. Radical copolymerization of the porphyrin chromophore with glycidyl methacrylate has then been carried out with success. This work opens a perspective on the possibility to integrate porphyrinic chromophore with high first-order molecular quadratic hyperpolarizability coefficient in opto-electronic devices. 相似文献
5.
Monnereau C Gomez J Blart E Odobel F Wallin S Fallberg A Hammarström L 《Inorganic chemistry》2005,44(13):4806-4817
A series of six new dyads consisting of a zinc or magnesium porphyrin appended to a platinum terpyridine acetylide complex via a para-phenylene bisacetylene spacer are described. Different substituents on the 4' position of the terpyridinyl ligand were explored (OC7H15, PO3Et2, and H). The ground-state electronic properties of the dyads are studied by electronic absorption spectroscopy and electrochemistry, and they indicate some electronic interactions between the porphyrin subunit and the platinum complex. The photophysical properties of these dyads were investigated by steady-state, time-resolved, and femtosecond transient absorption spectroscopy in N,N-dimethylformamide solution. Excitation of the porphyrin unit leads to a very rapid electron transfer (2-20 ps) to the nearby platinum complex followed by an ultrafast charge recombination, thus preventing any observation of the charge separated state. The variation in the rate of the photoinduced electron transfer in the series of dyads is consistent with Marcus theory. The results underscore the potential of the para-phenylene bisacetylene bridge to mediate a rapid electron transfer over a long donor-acceptor distance. 相似文献
6.
Benturquia N Couderc F Sauvinet V Orset C Parrot S Bayle C Renaud B Denoroy L 《Electrophoresis》2005,26(6):1071-1079
Serotonin or 5-hydroxytryptamine (5-HT) is a major neurotransmitter in the central nervous system. In this work, a method for analyzing 5-HT in brain microdialysis samples using a commercially available capillary electrophoresis (CE) system has been developed. A pH-mediated in-capillary preconcentration of samples was performed, and after separation by capillary zone electrophoresis, native fluorescence of 5-HT was detected by a 266 nm solid-state laser. The separation conditions for the analysis of 5-HT in standard solutions and microdialysates have been optimized, and this method has been validated on both pharmacological and analytical bases. Separation of 5-HT was performed using a 80 mmol/L citrate buffer, pH 2.5, containing 20 mmol/L hydroxypropyl-beta-cyclodextrin (HP-beta-CD) and +30 kV voltage. The detection limit was 2.5 x 10(-10) mol/L. This method allows the in vivo brain monitoring of 5-HT using a simple, accurate CE measurement in underivatized microdialysis samples. 相似文献
7.
Mattia Mazza Cyrille Alliot Corinne Sinquin Sylvia Colliec-Jouault Pascal E. Reiller Sandrine Huclier-Markai 《Molecules (Basel, Switzerland)》2021,26(4)
(1) Background: Exopolysaccharide (EPS) derivatives, produced by Alteromonas infernus bacterium, showed anti-metastatic properties. They may represent a new class of ligands to be combined with theranostic radionuclides, such as 47Sc/44Sc. The goal of this work was to investigate the feasibility of such coupling. (2) Methods: EPSs, as well as heparin used as a drug reference, were characterized in terms of molar mass and dispersity using Asymmetrical Flow Field-Flow Fractionation coupled to Multi-Angle Light Scattering (AF4-MALS). The intrinsic viscosity of EPSs at different ionic strengths were measured in order to establish the conformation. To determine the stability constants of Sc with EPS and heparin, a Free-ion selective radiotracer extraction (FISRE) method has been used. (3) Results: AF4-MALS showed that radical depolymerization produces monodisperse EPSs, suitable for therapeutic use. EPS conformation exhibited a lower hydrodynamic volume for the highest ionic strengths. The resulting random-coiled conformation could affect the complexation with metal for high concentration. The LogK of Sc-EPS complexes have been determined and showing that they are comparable to the Sc-Hep. (4) Conclusions: EPSs are very promising to be coupled with the theranostic pair of scandium for Nuclear Medicine. 相似文献
8.
Walid Mabrouk Ridha Lafi Jean Franois Fauvarque Amor Hafiane Cyrille Sollogoub 《先进技术聚合物》2021,32(1):304-314
The purpose of this work is to study the desalination of brackish water using a new ion exchange membrane, made from sulfochlorated polyethersulfone (Cl‐PES), and crosslinked using aminated polyethersulfone (NH2‐PES) as a crosslinking reagent. This membrane, named ClNH2 membrane, has been obtained by reaction between Cl‐PES with 1.3 SO2Cl groups per monomer unit and 0.2 equivalent amount of NH2‐PES. ClNH2 membrane has been characterized in terms of contact angle, transport number, intrinsic conductivity, and water uptake (as a function of temperature). Electrodialysis performances of the newly synthetized membranes have been measured using an electrodialysis cell at a laboratory scale and compared to commercial membranes. All the experiments have been performed using synthetic brackish water solutions prepared from sodium chloride salts with different concentrations (varying from 0.5 to 5.0 g/L). The concentration of different water samples obtained has been found to be below the amount recommended by the World Health Organization (WHO) for drinking water. 相似文献
9.
Clément Ghiazza Vincent Debrauwer Dr. Cyrille Monnereau Lhoussain Khrouz Dr. Maurice Médebielle Dr. Thierry Billard Dr. Anis Tlili 《Angewandte Chemie (International ed. in English)》2018,57(36):11781-11785
The first visible‐light‐mediated synthesis of trifluoromethylselenolated arenes under metal‐free conditions is reported. The use of an organic photocatalyst enables the trifluoromethylselenolation of arene diazonium salts using the shelf‐stable reagent trifluoromethyl tolueneselenosulfonate at room temperature. The reaction does not require the presence of any additives and shows high functional‐group tolerance, covering a very broad range of starting materials. Mechanistic investigations, including EPR spectroscopy, luminescence investigations, and cyclic voltammetry allow rationalization of the reaction mechanism. 相似文献
10.
Cornard JP Lapouge C Dangleterre L Allet-Bodelot C 《The journal of physical chemistry. A》2008,112(48):12475-12484
Density functional theory (DFT) structure calculations and time-dependent DFT electronic excitation calculations have been performed on chlorogenic acid (H(3)CGA), a polyphenolic compound, used as a model molecule of humic substances. The different deprotonated forms of H(3)CGA have also been investigated. H(3)CGA is a multisite ligand that presents several metal complexing sites in competition, notably the carboxylic and catechol moieties. In low acidic aqueous medium, the complexation of Pb(II) has been followed by electronic absorption spectrometry. The formation of two complexes of stoichiometry metal:ligand 1:1 (log beta(1:1) = 3.39) and 2:1 (log beta(2:1) = 7.12) has been highlighted with use of chemometric methods. The theoretical spectrum of the 1:1 complex obtained by TD-DFT methodology shows the formation of a chelate [Pb(H(2)CGA)(H(2)O)(3)](+) with the metal fixation at the level of the carboxylate function. The second complexing site, the catechol moiety, is rapidly involved in the formation of the 2:1 complex from molar ratios [metal]/[ligand] higher than 0.1. The electronic transitions calculated for both free ligand and complexes involved the same molecular orbitals, and no ligand-metal or metal-ligand charge transfer is observed. 相似文献