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排序方式: 共有117条查询结果,搜索用时 15 毫秒
71.
Dr. Simona Bettini Dr. Rosanna Pagano Dr. Paola Semeraro Michela Ottolini Luca Salvatore Fabio Marzo Prof. Nicola Lovergine Dr. Gabriele Giancane Prof. Ludovico Valli 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(62):14123-14132
Many strategies have been adopted to improve the photoinduced features of zinc oxide nanostructures for different application fields. In this work, zinc oxide has been synthesised and decorated by plasmonic metal nanoparticles to enhance its photocatalytic activity in the visible range. Furthermore, an insulating layer of SiO2 has been grown between the surface of zinc oxide nanoflakes and silver nanoparticles. A synthetic procedure that allows the accurate modulation of the insulating layer thickness in the range 5–40 nm has been developed. Evidences highlight the crucial role of the SiO2 layer in dramatically increasing photocatalytic water oxidation promoted by the nanostructure under both UV and visible illumination. An ideal thickness value of about 10 nm has been demonstrated to guarantee the plasmon-induced resonance energy-transfer process and to quench the Förster resonance energy-transfer mechanism; thus, optimising the local surface plasmon resonance effect and water oxidation properties. 相似文献
72.
S. Anuradha Jabasingh C. Valli Nachiyar 《Journal of Thermal Analysis and Calorimetry》2012,109(1):193-202
The present study deals with the immobilization of Aspergillus nidulans SU04 cellulase onto modified activated carbon (MAC). The effect of contact time, cellulase concentration, MAC dosage, and temperature for maximum immobilization percentage and immobilization capacity is investigated. The equilibrium nature of immobilization is described by Langmuir and Freundlich isotherms. The kinetic data were tested using the pseudo first order. The activation energy of immobilization was evaluated to be 11.78?J?mol?1. Results of the thermodynamic investigation indicate the spontaneity (?G <0), slightly endothermic (?H >0), and irreversible (?S >0) nature of the sorption process. Entropy and enthalpy were found to be 41.32 J?mol?1?mg?1 and 10.99?kJ?mol?1, respectively. The Gibbs free energy was found to be ?22.79?kJ?mol?1. At 80?rpm, 323?K, 2?h, 5?mg of MAC, immobilization capacity was 4.935?mg cellulase per mg of MAC from an initial cellulase concentration of 16?mg?ml?1 with retention of 70% of native cellulase activity up to 10 cycles of batch hydrolysis experiments. The diffusion studies that were carried out revealed the reaction rate as ??mol?min?1. At optimized conditions, immobilized cellulase had a higher Michaelis?CMenten constant, K m of 1.52?mmol and a lower reaction rate, V max of 42.2???mol?min?1, compared with the free cellulase, the K m and V max values of which were 0.52?mmol and 18.9???mol?min?1, respectively, indicating the affinity of cellulase for MAC matrix. 相似文献
73.
Zanoni G Valli M Bendjeddou L Porta A Bruno P Vidari G 《The Journal of organic chemistry》2010,75(23):8311-8314
Endogenous nitro-fatty acids, acting as partial agonist of PPARγ, are able to lower the insulin and glucose levels without the side effects associated with common antidiabetic drugs. (E)-12-Nitrooctadec-12-enoic acid, a potent activator of this peroxisome receptor, was synthesized in a very efficient sequence via a Henry-retro-Claisen ring fragmentation, followed by a novel enzymatic cleavage of methyl esters. The latter method was then applied in the last step of the synthesis of a few labile natural products, such as prostaglandins, isoprostanes, and phytoprostanes. 相似文献
74.
Santi M. Mandal Ludovico Migliolo Octavio L. Franco 《Journal of the American Society for Mass Spectrometry》2012,23(11):1939-1948
Several methods have been proposed for determining the binding affinity of antimicrobial peptides (AMPs) to bacterial cells. Here the utilization of MALDI-TOF-MS was proposed as a reliable and efficient method for high throughput AMP screening. The major advantage of the technique consists of finding AMPs that are selective and specific to a wide range of Gram-negative and -positive bacteria, providing a simple reliable screening tool to determine the potential candidates for broad spectrum antimicrobial drugs. As a prototype, amp-1 and -2 were used, showing highest activity toward Gram-negative and -positive membranes respectively. In addition, in silico molecular docking studies with both peptides were carried out for the membranes. In silico results indicated that both peptides presented affinity for DPPG and DPPE phospholipids, constructed in order to emulate an in vivo membrane bilayer. As a result, amp-1 showed a higher complementary surface for Gram-negative while amp-2 showed higher affinity to Gram-positive membranes, corroborating MS analyses. In summary, results here obtained suggested that in vitro methodology using MALDI-TOF-MS in addition to theoretical studies may be able to improve AMP screening quality. 相似文献
75.
Alberto Valli 《Applied Mathematics Letters》2012,25(10):1410-1414
The aim of this note is to give a simple and direct proof of the existence and uniqueness of the solution to an electrostatics-like problem when the source (namely, the applied current density) is a current dipole. The result is obtained by using the classical duality method. 相似文献
76.
Vera Bernardoni Eleonora Cuccia Giulia Calzolai Massimo Chiari Franco Lucarelli Dario Massabò Silvia Nava Paolo Prati Gianluigi Valli Roberta Vecchi 《X射线光谱测定》2011,40(2):79-87
The knowledge of size‐segregated elemental concentrations in atmospheric particulate matter (PM) gives a useful contribution to the complete chemical characterisation; this information can be obtained by sampling with multi‐stage cascade impactors. In this work, samples were collected using a low‐pressure 12‐stage Small Deposit Impactor and a 13‐stage rotating Micro Orifice Uniform Deposit Impactor?. Both impactors collect the aerosol in an inhomogeneous geometry, which needs a special set‐up for X‐ray analysis. This work aims at setting up an energy dispersive X‐ray fluorescence (ED‐XRF) spectrometer to analyse quantitatively size‐segregated samples obtained by these impactors. The analysis of cascade impactor samples by ED‐XRF is not customary; therefore, as additional consistency test some samples were analysed also by particle‐induced X‐ray emission (PIXE), which is more frequently applied to size‐segregated samples characterised by small PM quantities. A very good agreement between ED‐XRF and PIXE results was obtained for all the detected elements in samples collected with both impactors. The good inter‐comparability proves that our methodology is reliable for analysing size‐segregated samples by ED‐XRF technique. The advantage of this approach is that ED‐XRF is cheaper, easier to use, and more widespread than PIXE, thus promoting an intensive use of multi‐stage impactors. Copyright © 2011 John Wiley & Sons, Ltd. 相似文献
77.
78.
Here we report the first documented synthesis of a periodic mesoporous organosilica (PMO), that contains a multiply bonded C60 moiety integrated into the silica channel walls of the material, dubbed C60-PMO. This is accomplished through the acid-catalyzed co-assembly, of C60(NHCH2CH2CH2Si(OEt)3)x and tetraethylorthosilicate (TEOS) with a polyethyleneoxide-polylpropyleneoxide-polyethyleneoxide triblock copolymer template. The percentage of C60 in the final material was estimated to be a minimum of 63 vol %, but potentially as high as 91 vol %. The effects of the synthesis conditions on the mesostructure of the resulting materials are examined. In particular, we demonstrate that the C60 is uniformly distributed throughout the entire sample by the use of energy dispersive X-ray fluorescence (EDX) analysis and an OsO4 label bonded to the C60. 相似文献
79.
Ludovico Nappa 《Annali dell'Universita di Ferrara》2008,54(1):95-106
This paper is concerned with the theory of non-heat-conducting microfluids. We consider a specialized microfluid continuum
theory in which the micromotions consist of the intrinsic rotations and stretch. First, we establish a representation of Galerkin
type for the solutions to the field equations. Then, we derive the fundamental solutions for the differential system governing
the motion in the case of steady vibrations.
相似文献
80.
The collective gyromagnetic ratio and moment of inertia of deformed odd-proton and oddneutron axially symmetric nuclei have been calculated in the cranking approximation using wave functions obtained with the Skyrme force SIII. Good agreement with experiment is found for gR. Our parameter-free cranking results are better than those of Prior, Boehm and Nilsson where effective charges were used. The cranking formula leads to better results than the projection method (in which one simply takes the expectation value of the relevant operator in the deformed HF ground state, neglecting corrections of relative order 1/〈J2〉. In particular, the cranking results follow nicely the exceptionally large/small gR for the odd-proton/neutron nuclei around mass 153–167. 相似文献