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By using a constituent quark model we compute the form factors relevant to semileptonic transitions of the B mesons into low-lying p-wave charmed mesons. We evaluate the q2 dependence of these form factors and compare them with other model calculations. The Isgur–Wise functions τ1/2 and τ3/2 are also obtained in the heavy quark limit of our results. PACS 13.25.Hw; 12.39.Hg; 12.39.Jh 相似文献
114.
Azimi Bahareh Maleki Homa Gigante Vito Bagherzadeh Roohollah Mezzetta Andrea Milazzo Mario Guazzelli Lorenzo Cinelli Patrizia Lazzeri Andrea Danti Serena 《Cellulose (London, England)》2022,29(6):3079-3129
Cellulose - Cellulose, a natural, renewable, and environment friendly biopolymer, has been considered as a sustainable feedstock in the near future. However, only 0.3% of cellulose is today... 相似文献
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Dr. Simone Ghinato Dr. Davide Territo Prof. Andrea Maranzana Prof. Vito Capriati Dr. Marco Blangetti Prof. Cristina Prandi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(8):2868-2874
We report that the nucleophilic acyl substitution reaction of aliphatic and (hetero)aromatic amides by organolithium reagents proceeds quickly (20 s reaction time), efficiently, and chemoselectively with a broad substrate scope in the environmentally responsible cyclopentyl methyl ether, at ambient temperature and under air, to provide ketones in up to 93 % yield with an effective suppression of the notorious over-addition reaction. Detailed DFT calculations and NMR investigations support the experimental results. The described methodology was proven to be amenable to scale-up and recyclability protocols. Contrasting classical procedures carried out under inert atmospheres, this work lays the foundation for a profound paradigm shift of the reactivity of carboxylic acid amides with organolithiums, with ketones being straightforwardly obtained by simply combining the reagents under aerobic conditions and with no need of using previously modified or pre-activated amides, as recommended. 相似文献
117.
Silvia Todros Chiara Venturato Arturo N. Natali Giuseppe Pace Vito Di Noto 《Journal of Polymer Science.Polymer Physics》2014,52(20):1337-1346
The effect of steam on the micro‐phase structure and mechanical properties of different block copolymers used in biomedical devices is investigated via FT‐IR, tensile tests and dynamic mechanical analysis (DMA). Steam sterilization, commonly performed on medical devices and simulated in this work, affects the copolymers' morphology, due to high temperature and humidity conditions. FT‐IR analysis reveals that steam induces a modification in the crystalline conformations of copolymers with a pre‐existing hydrogen bonding network, that is, thermoplastic polyurethanes (TPU) and poly(ether‐block‐amide) (PEBA), while it does not significantly affect the domain conformation in styrenic block copolymers (SEBS), due to weak interaction with water. As a consequence, relevant changes of the mechanical properties, closely related to the microdomain structure, are found for TPU and PEBA after sterilization, while SEBS mechanical behavior remains stable, as demonstrated by tensile tests and DMA results. For this reason, SEBS is suggested as the best choice in terms of durability in biomedical applications. © 2014 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2014 , 52, 1337–1346 相似文献
118.
Vito Fiandanese Giuseppe Marchese Francesco Naso 《Phosphorus, sulfur, and silicon and the related elements》2013,188(1-2):89-90
Abstract Synthetic, mechanistic, and stereochemical aspects of the reactions of cuprates with various systems are being investigated in these laboratories(1). The series of substrates includes several sulphonyl-activated compounds. 相似文献
119.
Mariaelena Ricca Vito Foderà Daniela Giacomazza Maurizio Leone Giuseppe Spadaro Clelia Dispenza 《Colloid and polymer science》2010,288(9):969-980
Poly(N-vinyl-2-pyrrolidone) (PVP) hydrogels have been synthesised from the aqueous solutions of the same linear polymer by two different
radiation sources: electron beams and UV rays. The present investigation couples conventional hydrogel characterisation techniques
with the study of the partition equilibria, fluorescence behaviour and release of two different molecular probes, 1-anilino-8-naphthalene
sulphonate (ANS) and Thioflavin T (ThT). The two probes have comparable molecular weight and different structural and optical
properties. The ‘chemical’ networks produced upon irradiation in different experimental conditions presented quite distinctive
mechanical spectra, yielded to different porous solids upon freeze-drying and showed specific rehydration ratios when ‘equilibrated’
in water. More interestingly, they offered ‘hydrophobic pockets’ to host the ANS molecules in a way that the probe is completely
occluded from water, making it fluoresce. Conversely, the generated PVP networks did not show any specific affinity towards
the hydrophilic ThT that was only barely untaken. 相似文献
120.
Marta Mameli M. Carla Aragoni Dr. Massimiliano Arca Dr. Claudia Caltagirone Dr. Francesco Demartin Prof. Giovanna Farruggia Dr. Greta De Filippo Francesco A. Devillanova Prof. Alessandra Garau Dr. Francesco Isaia Prof. Vito Lippolis Prof. Dr. Sergio Murgia Dr. Luca Prodi Prof. Dr. Anna Pintus Nelsi Zaccheroni Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(3):919-930
In spite of the fact that cadmium(II) has been recognized as a highly toxic element and that excessive exposure to this metal ion has been reported to have many adverse effects on human health, very few selective and specific fluorescent probes are available for imaging Cd2+ in living cells. Herein, we report the spectroscopic and photochemical characterization of 5‐(5‐chloro‐8‐hydroxyquinolinylmethyl)‐2,8‐dithia‐5‐aza‐2,6‐pyridinophane ( L ) as a fluorescent sensor for the selective imaging of Cd2+ in living cells. In particular, the response of L to Cd2+ was first assessed in aqueous solutions, sodium dodecyl sulfate micelles, and liposomes, and subsequently in living cells by fluorescence microscopy techniques. Cytofluorimetric analyses of leukemic HL‐60 cells loaded with L also allowed evaluation of the toxicity of the probe and the selective analysis of its intracellular fluorescence in the presence of Cd2+. Furthermore, the 1:1 complex species [Cd( L )H2O]2+ responsible for the OFF–ON chelation enhancement of fluorescence (CHEF) effect on L was structurally characterized; time‐dependent DFT calculations allowed the prediction of theoretical excitations, which were comparable with the experimental ones. 相似文献