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131.
Inside Back Cover: Light‐Controlled Interconversion between a Self‐Assembled Triangle and a Rhombicuboctahedral Sphere (Angew. Chem. Int. Ed. 1/2016) 下载免费PDF全文
132.
Dr. Yining Jiang Dr. Carine Clavaguéra Dr. Suvasthika Indrajith Prof. Chantal Houée-Levin Dr. Giel Berden Prof. Dr. Jos Oomens Dr. Debora Scuderi 《Chemphyschem》2023,24(23):e202300830
OH⋅-induced oxidation products of DNA nucleosides and nucleotides have been structurally characterized by collision-induced dissociation tandem mass spectrometry (CID-MS2) and Infrared Multiple Photon Dissociation (IRMPD) spectroscopy. CID-MS2 results have shown that the addition of one oxygen atom occurs on the nucleobase moiety. The gas-phase geometries of +16 mass increment products of 2’-deoxyadenosine (dA(O)H+), 2’-deoxyadenosine 5’-monophosphate (dAMP(O)H+), 2’-deoxycytidine (dC(O)H+), and 2’-deoxycytidine 5’-monophosphate (dCMP(O)H+) are extensively investigated by IRMPD spectroscopy and quantum-chemical calculations. We show that a carbonyl group is formed at the C8 position after oxidation of 2’-deoxyadenosine and its monophosphate derivative. For 2’-deoxycytidine and its monophosphate derivative, the oxygen atom is added to the C5 position to form a C−OH group. IRMPD spectroscopy has been employed for the first time to provide direct structural information on oxidative lesions in DNA model systems. 相似文献
133.
Martino DM Reyna D Estenoz DA Trakhtenberg S Warner JC 《The journal of physical chemistry. A》2008,112(21):4786-4792
Here, we report a sensitization study on a family of water-soluble photopolymers based on thymine. The goal of this study was to determine whether the presence of sensitizer molecules would promote photocrosslinking/immobilization of the polymers using low-energy irradiation (520 nm) as compared to the UV irradiation (approximately 280 nm) necessary for the standard photoinduced process to take place. With the aid of Eosin Y Spirit Soluble (EY) as a sensitizer, water-soluble polystyrene copolymers of vinylbenzylthymine-vinylbenzyltriethylammonium chloride (VBT-VBA) were immobilized after exposure to visible irradiation. By exciting the sensitizer molecule in the presence of VBT copolymers at a wavelength where absorption by the latter does not occur, the triplet state of the sensitizer is generated in high yields, and consequently, polymer photocross-linking takes place. UV-vis spectroscopy has been used to study the effect of irradiation dose, copolymer composition, and sensitizer concentration on the photoreactivity of VBT polymers. These studies demonstrate the feasibility of using Eosin Y as a sensitizer to achieve the thymine photodimer formation, resulting in immobilization of VBT-VBA-EY films on PET substrate. This provides complementary information on photoinduced immobilization of VBT-VBA films that are crucial for developing new classes of environmentally benign materials and new energy-saving methods. 相似文献
134.
This communication reports the first example of polymerization initiated from specific domains on proteins. Streptavidin was coupled with a biotinylated initiator for atom transfer radical polymerization (ATRP) and exposed to an aqueous solution of CuBr/2,2'-bipyridine and monomer. N-Isopropylacrylamide (NIPAAm) and poly(ethylene glycol) methyl ether methacrylate (PEGMA) were readily initiated by the modified streptavidin and polymerized from the protein at room temperature. Formation of streptavidin-polymer conjugates was confirmed by size exclusion chromatography (SEC) and gel electrophoresis. Polymer identity and biotinylation was verified using 1H NMR spectroscopy, gel permeation chromatography (GPC), and surface plasmon resonance (SPR) after dissociation of the biotin-streptavidin complex. This general approach is likely to be extended to other proteins and monomers and promises to enable easy synthesis and purification of a variety of polymer-protein conjugates. 相似文献
135.
Dr. Subhadeep Saha Dr. Yen-Ting Chen Dr. Sudhakar Ganta Markus Gilles Björn Holzapfel Dr. Pascal Lill Prof. Dr. Heinz Rehage Prof. Dr. Christos Gatsogiannis Prof. Dr. Guido H. Clever 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(5):e202103406
Metallo-supramolecular self-assembly has yielded a plethora of discrete nanosystems, many of which show competence in capturing guests and catalyzing chemical reactions. However, the potential of low-molecular bottom-up self-assemblies in the development of structured inorganic materials has rarely been methodically explored so far. Herein, we present a new type of metallo-supramolecular surfactant with the ability to stabilize non-aqueous emulsions for a significant period. The molecular design of the surfactant is based on a heteroleptic coordination cage ( CGA-3 ; CGA =Cage-based Gemini Amphiphile), assembled from two pairs of organic building blocks, grouped around two Pd(II) cations. Shape-complementarity between the differently functionalized components generates discrete amphiphiles with a tailor-made polarity profile, able to stabilize non-aqueous emulsions, such as hexadecane-in-DMSO. These emulsions were used as a medium for the synthesis of spherical metal oxide microcapsules (titanium oxide, zirconium oxide, and niobium oxide) from soluble, water-sensitive alkoxide precursors by allowing a controlled dosage of water to the liquid-liquid phase boundary. Synthesized materials were analyzed by a combination of electron microscopic techniques. In situ liquid cell transmission electron microscopy (LC-TEM) was utilized for the first time to visualize the dynamics of the emulsion-templated formation of hollow inorganic titanium oxide and zirconium oxide microspheres. 相似文献
136.
Effect of hexyl substituent groups on photophysical and electrochemical properties of the poly[(9,9‐Dioctyluorene)−2,7‐diyl‐alt‐(4,7‐bis (3‐Hexylthien‐5‐Yl)−2,1,3‐Benzothiadiazole)−2′,2″‐diyl] 下载免费PDF全文
Daniel J. da Silva Herick G. Takimoto Karine C. C. Weber dos Santos Jarem R. Garcia Debora T. Balogh Shu Hui Wang 《Journal of Polymer Science.Polymer Physics》2016,54(19):1975-1982
The effect of the presence of hexyl group in thiophene on the photophysical and electrochemical properties of poly[(9,9‐dioctyluorene)?2,7‐diyl‐alt‐(4,7‐bis(3‐hexylthien‐5‐yl)?2,1,3‐benzothiadiazole)?2′,2″‐diyl] (F8TBT) is investigated. The copolymers present electron donor–acceptor architecture and are synthesized by Suzuki coupling reaction. The UV/Vis spectra show absorption maximum in the wavelength range of blue and orange, which are associated with different segments of the polymer backbone. Addition of hexyl substituent groups has a positive effect on the molar absorptivity and increases the emission and absorption intensities due to fluorene and thiophene‐benzothiadiazole‐thiophene (TBT) units, although an increment in the bandgap is observed. Cyclic voltammetry study of the polymer films reveal irreversible reduction and oxidation processes of the TBT units in the polymer chain and the HOMO and LUMO energy levels suggest ambipolar character for the polymers, while the electrochemical bandgaps are consistent with the absorbance measurements. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 1975–1982 相似文献
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139.
Valentin Clever Aparecido da Silva Jefferson Lins Kobelnik Marcelo Ribeiro Clovis Augusto 《Journal of Thermal Analysis and Calorimetry》2019,136(2):471-481
Journal of Thermal Analysis and Calorimetry - Studying thermal behavior is very important for monitoring the quality of polymers on an industrial scale. Commercial geomembranes are materials with... 相似文献
140.