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141.
Valentina Noemi Madia Walter Toscanelli Daniela De Vita Marta De Angelis Antonella Messore Davide Ialongo Luigi Scipione Valeria Tudino Felicia Diodata DAuria Roberto Di Santo Stefania Garzoli Annarita Stringaro Marisa Colone Magda Marchetti Fabiana Superti Lucia Nencioni Roberta Costi 《Molecules (Basel, Switzerland)》2022,27(12)
Influenza viruses are transmitted from human to human via airborne droplets and can be transferred through contaminated environmental surfaces. Some works have demonstrated the efficacy of essential oils (EOs) as antimicrobial and antiviral agents, but most of them examined the liquid phases, which are generally toxic for oral applications. In our study, we describe the antiviral activity of Citrus bergamia, Melaleuca alternifolia, Illicium verum and Eucalyptus globulus vapor EOs against influenza virus type A. In the vapor phase, C. bergamia and M. alternifolia strongly reduced viral cytopathic effect without exerting any cytotoxicity. The E. globulus vapor EO reduced viral infection by 78% with no cytotoxicity, while I. verum was not effective. Furthermore, we characterized the EOs and their vapor phase by the head-space gas chromatography–mass spectrometry technique, observing that the major component found in each liquid EO is the same one of the corresponding vapor phases, with the exception of M. alternifolia. To deepen the mechanism of action, the morphological integrity of virus particles was checked by negative staining transmission electron microscopy, showing that they interfere with the lipid bilayer of the viral envelope, leading to the decomposition of membranes. We speculated that the most abundant components of the vapor EOs might directly interfere with influenza virus envelope structures or mask viral structures important for early steps of viral infection. 相似文献
142.
Zoi S. Metaxa Athanasia K. Tolkou Stefania Efstathiou Abbas Rahdar Evangelos P. Favvas Athanasios C. Mitropoulos George Z. Kyzas 《Molecules (Basel, Switzerland)》2021,26(5)
This review is an update about the addition of nanomaterials in cementitious composites in order to improve their performance. The most common used nanomaterials for cementitious materials are carbon nanotubes, nanocellulose, nanographene, graphene oxide, nanosilica and nanoTiO2. All these nanomaterials can improve the physical, mechanical, thermal and electrical properties of cementitious composites, for example increase their compressive and tensile strength, accelerate hydration, decrease porosity and enhance fire resistance. Cement based materials have a very complex nanostructure consisting of hydration products, crystals, unhydrated cement particles and nanoporosity where traditional reinforcement, which is at the macro and micro scale, is not effective. Nanomaterials can reinforce the nanoscale, which wasn’t possible heretofore, enhancing the performance of the cementitious matrix. 相似文献
143.
Felipe L. Oliveira Dr. Stefania P. de Souza Dr. Jonathan Bassut Prof. Heiddy M. Álvarez Prof. Yunier Garcia-Basabe Prof. Rodrigo O. M. Alves de Souza Prof. Pierre M. Esteves Prof. Raoni S. B. Gonçalves 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(69):15863-15870
Sustainability in chemistry heavily relies on heterogeneous catalysis. Enzymes, the main catalyst for biochemical reactions in nature, are an elegant choice to catalyze reactions due to their high activity and selectivity, although they usually suffer from lack of robustness. To overcome this drawback, enzyme-decorated nanoporous heterogeneous catalysts were developed. Three different approaches for Candida antarctica lipase B (CAL-B) immobilization on a covalent organic framework (PPF-2) were employed: physical adsorption on the surface, covalent attachment of the enzyme in functional groups on the surface and covalent attachment into a linker added post-synthesis. The influence of the immobilization strategy on the enzyme uptake, specific activity, thermal stability, and the possibility of its use through multiple cycles was explored. High specific activities were observed for PPF-2-supported CAL-B in the esterification of oleic acid with ethanol, ranging from 58 to 283 U mg−1, which was 2.6 to 12.7 times greater than the observed for the commercial Novozyme 435. 相似文献
144.
145.
Stefania Fioravanti Alberto MorrealeLucio Pellacani Paolo A. Tardella 《Tetrahedron letters》2003,44(15):3031-3034
The synthesis of a new chiral nosyloxycarbamate derived from Helmchen's auxiliary is described. Reactions performed with this aminating reagent successfully give the formation of diastereomeric allylic carbamates or diastereomeric aziridines starting from different kinds of olefins. 相似文献
146.
Simonpietro Agnello Roberto Boscaino Marco Cannas Andrea Cannizzo Franco M. Gelardi Stefania Grandi Maurizio Leone 《Radiation measurements》2004,38(4-6):645-648
We report an experimental investigation of the emission spectra of a 1000 mol ppm sol–gel Ge-doped silica by fine tuning the excitation energy in the ultraviolet (UV) range, around 5 eV, and in the vacuum-UV range, around 7.3 eV, at room temperature and at 10 K. The sample is characterized by a blue (centered at 3.2 eV) and an UV (centered at 4.3 eV) bands. We have found that the ratio between the area of the blue and the UV bands depends on the temperature and on the excitation energy in both the vacuum-UV and the UV range. At both temperatures the spectral features of the blue and the UV bands are weakly affected when the excitation is varied in the vacuum-UV. At variance, under UV excitation the peaks of the bands are shifted and also their widths are changed. These results are interpreted in terms of distinct excitation channels of the luminescence that are influenced in a different way by the structural inhomogeneity of point defects. 相似文献
147.
148.
Summary Linear systems represent the computational kernel of many models that describe problems arising in the field of social, economic
as well as technical and scientific disciplines. Therefore, much effort has been devoted to the development of methods, algorithms
and software for the solution of linear systems. Finite precision computer arithmetics makes rounding error analysis and perturbation
theory a fundamental issue in this framework (Higham 1996). Indeed, Interval Arithmetics was firstly introduced to deal with
the solution of problems with computers (Moore 1979, Rump 1983), since a floating point number actually corresponds to an
interval of real numbers. On the other hand, in many applications data are affected by uncertainty (Jerrell 1995, Marino &
Palumbo 2002), that is, they are only known to lie within certain intervals. Thus, bounding the solution set of interval linear
systems plays a crucial role in many problems. In this work, we focus on the state of the art of theory and methods for bounding
the solution set of interval linear systems. We start from basic properties and main results obtained in the last years, then
we give an overview on existing methods. 相似文献
149.
Euro Solari Stefania De Angelis Mario Latronico Carlo Floriani Angiola Chiesi-Villa Corrado Rizzoli 《Journal of Cluster Science》1996,7(4):553-566
The function of the solvent in the self-assembling mode of [CuCl] with tetrahydrothiophene is reported. Copper(l) chloride has been used in the form of [CuCOCl]
n
, which is slightly soluble in the most common solvents, and to allow an homogeneous phase reaction. The reaction of [CuCOCl]
n
with THT gave [(CuCl)2(THT)3]
x
,1, in CH3OH, [(CuCl)(THT)2]
x
,2 in THF [(CuCl)(THT)]
x
,3, in CH2Cl2, and [(CuCl)3(THT)2]
x
,4, in DME. Compound1 consists of polymeric chains of centrosymmetric Cu2Cl2 dinuclear units bridged by THIT molecules running parallel to the [101] axis. In the structure of2 we found polymeric layers generated from the [(CuCl)(THT)] asymmetric unit by the center of symmetry and by the twofold axis. In compound3 the structure consists of layers generated through the center of symmetry by the [(Cu2Cl2)(THT)2] asymmetric unit, while4 consists of layers generated through the center of symmetry by the [(Cu3Cl3)(THT)2] asymmetric unit. Crystallographic details are as [ollows:2 is monoclinic, space group P21/c.a=9.657(3) A,b=6.441(2) A,c=11.459(3) A,\=111.96(2)°,V=661.0(4) A3. andR=0.075;3 is monoclinic, space group P21/n,a=19.327(7) A,b=6.703(2) A,c=10.116(3) A,ß=103.04(3)°,V=1276.7(7) A3 andR=0.043:4 is triclinic, space group Pl,a=12.513(2) A,b=6.698(1) A,c=9.651(1) A,=91.98(1)°,\=107.86(1)°,=74.59(1)°,V=741.2(2) A3, andR=0.044. 相似文献
150.
Trifluoromethyl aldimines derived from α-amino esters have proven to be very good starting materials to obtain the title compounds. A Ag2O-catalyzed Mannich-type/cyclization cascade reaction starting from suitable α-isocyano acetates leads to enantiopure valuable trans-carboxylic trifluoromethyl substituted 2-imidazolines by a highly stereoselective addition without the need to add organocatalysts. 相似文献