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111.
T Courant VG Roullin C Cadiou M Callewaert MC Andry C Portefaix C Hoeffel MC de Goltstein M Port S Laurent LV Elst R Muller M Molinari F Chuburu 《Angewandte Chemie (International ed. in English)》2012,51(36):9119-9122
Do not tumble dry: Gadolinium-DOTA encapsulated into polysaccharide nanoparticles (GdDOTA?NPs) exhibited high relaxivity (r(1) =101.7?s(-1) mM(-1) per Gd(3+) ion at 37?°C and 20?MHz). This high relaxation rate is due to efficient Gd loading, reduced tumbling of the Gd complex, and the hydrogel nature of the nanoparticles. The efficacy of the nanoparticles as a T(1) /T(2) dual-mode contrast agent was studied in C6 cells. 相似文献
112.
113.
Thomas Courant Valrie Gaëlle Roullin Cyril Cadiou Maït Callewaert Marie Christine Andry Christophe Portefaix Christine Hoeffel Marie Christine deGoltstein Marc Port Sophie Laurent Luce Vander Elst Robert Muller Michaël Molinari Franoise Chuburu 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2012,124(36):9253-9256
114.
Primary photodamage sites and mitochondrial events after Foscan photosensitization of MCF-7 human breast cancer cells 总被引:4,自引:0,他引:4
Teiten MH Marchal S D'Hallewin MA Guillemin F Bezdetnaya L 《Photochemistry and photobiology》2003,78(1):9-14
To determine the initial photodamage sites of Foscan-mediated photodynamic treatment, we evaluated the enzymatic activities in selected organelles immediately after light exposure of MCF-7 cells. The measurements indicated that the enzymes located in the Golgi apparatus (uridine 5'-diphosphate galactosyl transferase) and in the endoplasmic reticulum (ER) (nicotinamide adenine dinucleotide [reduced] [NADH] cytochrome c [cyt c] reductase) are inactivated by the treatment, whereas mitochondrial marker enzymes (cyt c oxidase and dehydrogenases) were unaffected. This indicates that the ER and the Golgi apparatus are the primary intracellular sites damaged by Foscan-mediated PDT in MCF-7 cells. We further investigated whether the specific mitochondria events could be associated with Foscan photoinduced cell death. The dose response profiles of mitochondrial depolarization and cytochrome c release immediately after Foscan-based PDT were very different from that of overall cell death. By 24 h post-PDT the fluence dependency was strikingly similar for both mitochondrial alterations and cell death. Therefore, although mitochondria are not directly affected by the treatment, they can be strongly implicated in Foscan-mediated MCF-7 cell death by late and indirect mechanism. 相似文献
115.
The electrophilic ipso-reactions of a tBu-calix[6]arene that presents alternate O-methyl and O-2-methylen-N-methyl-imidazolyl groups (1) at the small rim have been studied. Whereas 1 underwent per-sulfonation in sulfuric acid, it selectively reacted with nitric acid to yield a tris-nitro derivative. The ipso-nitration occurred regioselectively on the calixarene anisol units. The reaction has been studied with various tBu-calixarenes (2-11) presenting alternate anisol and phenol ether units. The regioselectivity of the process appeared to be correlated to the presence of a protonable site on the O-substituent. It is proposed that the corresponding protonated heteroatom (N for the amines, O for the amides and the carboxylic acid), situated in the gamma or epsilon position of the phenoxy moieties, deactivates the corresponding aromatic ring by removing electron density through intramolecular hydrogen bonding. The high control operated by the O-substituents at the small rim even allowed the selective ipso-nitration of partially detertiobutylated calixarene 1(H3). Hence, these findings open new routes to a wide range of nonsymmetrically substituted calixarenes at the large rim. 相似文献
116.
Sophie Laurent Luce VanderElst Sylvain Houz Nathalie Gurit RobertN. Muller 《Helvetica chimica acta》2000,83(2):394-406
Four derivatives of diethylenetriaminepentaacetic acid (=3,6,9‐tris(carboxymethyl)‐3,6,9‐triazaundecanedioic acid (H5dtpa)), potential contrast agents for magnetic resonance imaging (MRI), carrying benzyl groups at various positions of the parent structure were synthesized and characterized by a thorough multinuclear NMR study, i.e., the (S)‐ and (R)‐stereoisomers 1a and 1b of 4‐benzyl‐3,6,9‐tris(carboxymethyl)‐3,6,9‐triazaundecanedioic acid (H5[(S)‐(4‐Bz)dtpa] and H5[(R)‐(4‐Bz)dtpa], the diamide derivative N,N″‐bis[(benzylcarbamoyl)methyl]diethylenetriamine‐N,N′,N″‐triacetic acid (=3,9‐bis[2‐(benzylamino)‐2‐oxoethyl]‐6‐(carboxymethyl)‐3,6,9‐triazaundecanedioic acid; H3[dtpa(BzA)2]; 2 ), and the diester derivative N,N″‐bis{[(benzyloxy)carbonyl]methyl}diethylenetriamine‐N,N′,N″‐triacetic acid (=3,9‐bis[2‐(benzyloxy)‐2‐oxoethyl]‐6‐(carboxymethyl)‐3,6,9‐triazaundecanedioic acid; H3[dtpa(BzE)2]; 3 ). From the 17O‐NMR chemical shift of H2O induced by their dysprosium complexes with ligands 1 – 3 , it was concluded that only one H2O molecule is contained in the first coordination sphere of these lanthanide complexes. The rotational correlation times (τR) of the complexes were estimated from the 2H‐NMR longitudinal relaxation rate of the deuterated diamagnetic lanthanum complexes. The exchange time of the coordinated H2O molecule (τM) was studied through the temperature dependence of the 17O‐NMR transverse relaxation rate. As compared to [Gd(dtpa)]2−, the H2O‐exchange rate is faster for [Gd{(S)‐(4‐Bz)dtpa}]2− and [Gd{(R)‐(4‐Bz)dtpa}]2−‐, slower for [Gd{dtpa(BzA)2}], and almost identical for [Gd{dtpa(BzE)2}]. The analysis of the 1H‐relaxivity of the gadolinium complexes recorded from 0.02 to 300 MHz established that i) the relaxivity of [Gd{dtpa(BzE)2}] is similar to that of [Gd(dtpa)]2−, ii) the slightly slower molecular rotation of [Gd{dtpa(BzA)2}] induces a mild enhancement of its relaxivity, and iii) the marked increase of relaxivity of [Gd{(S)‐(4‐Bz)dtpa}]2− and [Gd{(R)‐(4‐Bz)dtpa}]2− mainly results from an apparently shorter distance between the gadolinium ion and the H2O protons of the coordinated H2O molecule. 相似文献
117.
In the present work a modular pathway towards the synthesis of a new versatile MRI contrast agent is reported and its physico-chemical properties are described. Two different functional groups were attached on two arms of the gadolinium 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetate (DOTA) in order to get a platform able to bind one probe designed to target specific biological marker and a fluorescent molecule likely to be used for optical imaging. The nuclear magnetic relaxation dispersion (NMRD) profile, the oxygen-17 relaxometric NMR study and stability assessment versus transmetalation of the Gd-complex show that this new contrast agent has a relaxivity and transmetalation stability similar to Gd–DOTA. 相似文献
118.
Sophie Nocquet-Thibault Corinne MinardPascal Retailleau Kevin CariouRobert H. Dodd 《Tetrahedron》2014
The combination of (diacetoxyiodo)benzene and iron(III) chloride in ethanol allows the efficient regioselective ethoxychlorination of a broad range of enamides. Mechanistic studies tend to rule out the involvement of free radical species and point towards the implication of a mixed [chloro(ethoxy)iodo]benzene intermediate. 相似文献
119.
Max Kronenwerth Kenan A. J. Bozhüyük Dr. Astrid S. Kahnt Prof. Dr. Dieter Steinhilber Dr. Sophie Gaudriault Marcel Kaiser Prof. Dr. Helge B. Bode 《Chemistry (Weinheim an der Bergstrasse, Germany)》2014,20(52):17478-17487
Six new lipodepsipeptides and an additional linear derivative named taxlllaids A–G ( 1 – 7 ) have been identified in the entomopathogenic bacterium Xenorhabdus indica. The structures of the main compounds have been solved by detailed NMR spectroscopic analysis and the structures of minor derivatives were elucidated by a combination of labelling experiments and detailed MS experiments. The absolute configuration of the taxlllaids was deduced by using the advanced Marfey method and analysis of the biosynthesis gene cluster showing the presence of epimerisation domains, which was subsequently proved to be correct by solid‐phase peptide synthesis of all taxlllaids. The exchange of a single amino acid in the adenylation domain was shown to be responsible for substrate promiscuity of the third A domain, resulting in the incorporation of leucine, phenylalanine or tyrosine. Bioactivity testing revealed the taxlllaids to be weakly active against Plasmodium falciparum and against a number of eukaryotic cell lines. 相似文献
120.
Miriana Kfoury Lizette Auezova Sophie Fourmentin Hélène Greige-Gerges 《Journal of inclusion phenomena and macrocyclic chemistry》2014,80(1-2):51-60
In this study, we investigated the inclusion complexation of 2-hydroxypropyl-β-cyclodextrin (HP-β-CD) and eight monoterpenes (eucalyptol, geraniol, limonene, linalool, α-pinene, β-pinene, pulegone, and thymol) in aqueous solution and solid state. The formation constants (K f) of inclusion complexes were determined using fluorescence spectroscopy and static headspace gas chromatography. The results indicated the formation of 1:1 inclusion complexes between HP-β-CD and all studied guests. A linear relationship was found between K f values and the hydrophobic character of the monoterpenes expressed as logP. Solid complexes were prepared by the freeze-drying method in a 1:1 (HP-β-CD:monoterpene) molar ratio. Physicochemical characterization of solid inclusion complexes was carried out using Fourier transform infrared spectroscopy and differential scanning calorimetry. Finally, the encapsulation efficiency (EE%) of HP-β-CD was determined using HPLC analysis. Noticeable difference in the EE% was observed between monoterpene hydrocarbons and oxygenated monoterpenes. These results suggested that complexation with HP-β-CD could be a promising strategy to enlarge the application of monoterpenes in cosmetic, pharmaceutical and food industries. 相似文献