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131.
Rosa Sparaco Ewa Kdzierska Agnieszka A. Kaczor Anna Bielenica Elisa Magli Beatrice Severino Angela Corvino Ewa Gibua-Tarowska Jolanta H. Kotliska Giorgia Andreozzi Paolo Luciano Elisa Perissutti Francesco Frecentese Marcello Casertano Anna Leniak Magdalena Bujalska-Zadrony Magorzata Ozibo Raffaele Capasso Vincenzo Santagada Giuseppe Caliendo Ferdinando Fiorino 《Molecules (Basel, Switzerland)》2022,27(19)
A new series of 5-norbornene-2-carboxamide derivatives was prepared and their affinities to the 5-HT1A, 5-HT2A, and 5-HT2C receptors were evaluated and compared to a previously synthesized series of derivatives characterized by exo-N-hydroxy-5-norbornene-2,3-dicarboximidenucleus, in order to identify selective ligands for the above-mentioned subtype receptors. Arylpiperazines represents one of the most important classes of 5-HT1AR ligands, and recent research concerning new derivatives has been focused on the modification of one or more portions of such pharmacophore. The combination of structural elements (heterocyclic nucleus, propyl chain and 4-substituted piperazine), known to be critical to the affinity to 5-HT1A receptors, and the proper selection of substituents led to compounds with high specificity and affinity towards serotoninergic receptors. The most active compounds were selected for further in vivo assays to determine their functional activity. Finally, to rationalize the obtained results, molecular docking studies were performed. The results of the pharmacological studies showed that Norbo-4 and Norbo-18 were the most active and promising derivatives for the serotonin receptor considered in this study. 相似文献
132.
This contribution aims at analysing the current understanding about the influence of Al distribution, zeolite topology, ligands/reagents and oxidation state on ions mobility in Cu-zeolites, and its relevance toward reactivity of the metal sites. The concept of Cu mobilization has been originally observed in the presence of ammonia, favouring the activation of oxygen by formation of NH3 oxo-bridged complexes in zeolites and opening a new perspective about the chemistry in single-site zeolite-based catalysts, in particular in the context of the NH3-mediated Selective Catalytic Reduction of NOx (NH3-SCR) processes. A different mobility of bare Cu+/Cu2+ ions has been documented too, showing for Cu+ a better mobilization than for Cu2+ also in absence of ligands. These concepts can have important consequences for the formation of Cu-oxo species, active and selective in other relevant reactions, such as the direct conversion of methane to methanol. Here, assessing the structure, the formation pathways and reactivity of Cu-oxo mono- or multimeric moieties still represents a challenging playground for chemical scientists. Translating the knowledge about Cu ions mobility and redox properties acquired in the context of NH3-SCR reaction into the field of direct conversion of methane to methanol can have important implications for a better understanding of transition metal ions redox properties in zeolites and for an improved design of catalysts and catalytic processes.The mobility of Cu ions in zeolites is influenced by oxidation state, ligands, zeolite topology and chemical composition. The known and possible implications for catalytic activity of Cu-zeolites are discussed. 相似文献
133.
Mussardo P Corda E González-Ruiz V Rajesh J Girotti S Martín MA Olives AI 《Analytical and bioanalytical chemistry》2011,400(2):321-327
The interaction between DNA and several newly synthesized derivatives of the natural anticancer compound luotonin A has been
studied. The results from our work reveal an effective and selective alkaloid/double-stranded DNA (ds-DNA) interaction. In
the presence of increasing amounts of ds-DNA, a noticeable fluorescence quenching of the luotonin A derivatives under study
was observed. However, this effect did not take place when single-stranded DNA (ss-DNA) was employed. The association constant
alkaloids/ds-DNA was calculated by quantitation of such a quenching effect. The influence of other quenchers, namely Co2+ and Br− on the native fluorescence of luotonin A and derivatives was also studied, and a remarkable quenching effect was observed
for both ions. We have also investigated how by binding DNA the alkaloids could get protected from the external Co2+ and Br− quenchers. The Stern–Volmer constants (K
SV) for Co2+ and Br− quenching effect on the studied alkaloids were considerably reduced (10–50%) after incubation of the compounds in the presence
of DNA with regard to the K
SV values in absence of DNA. An increase in the fluorescence anisotropy values of luotonins was also produced only in the presence
of ds-DNA but not in the case of ss-DNA. To better characterize the nature of that interaction, viscosimetry assays and ethidium
bromide displacement studies were conducted. With regard to DNA reference solutions, the viscosity of solutions containing
DNA and luotonin A derivatives was reduced or not significantly increased. It was also observed that the studied compounds
were unable to displace the intercalating agent ethidium bromide. All of these results, together with the obtained association
constants values (K
ass = 2.2 × 102 – 1.3 × 103), support that neither covalent nor intercalating interactions luotonin A derivatives/ds-DNA are produced, leading to the
conclusion that these alkaloids bind ds-DNA through the minor groove. The specific changes in the fluorescence behavior of
luotonin A and derivatives distinguishing between ss-DNA and ds-DNA binding, lead us to propose these compounds as attractive
turn-off probes to detect DNA hybridization. 相似文献
134.
Elisa Frederico Seneme Daiane Carla dos Santos Evelyn Marcela Rodrigues Silva Yollanda Edwirges Moreira Franco Giovanna Barbarini Longato 《Molecules (Basel, Switzerland)》2021,26(19)
Natural products have been used by humanity for many centuries to treat various illnesses and with the advancement of technology, it became possible to isolate the substances responsible for the beneficial effects of these products, as well as to understand their mechanisms. In this context, myristicin, a substance of natural origin, has shown several promising activities in a large number of in vitro and in vivo studies carried out. This molecule is found in plants such as nutmeg, parsley, carrots, peppers, and several species endemic to the Asian continent. The purpose of this review article is to discuss data published in the last 10 years at Pubmed, Lilacs and Scielo databases, reporting beneficial effects, toxicity and promising data of myristicin for its future use in medicine. From 94 articles found in the literature, 68 were included. Exclusion criteria took into account articles whose tested extracts did not have myristicin as one of the major compounds. 相似文献
135.
Jaime Rodríguez André Ferraz Raquel F. P. Nogueira Irene Ferrer Elisa Esposito Nelson Durán 《Applied biochemistry and biotechnology》1997,62(2-3):233-242
The lignin biodegradation process has an important role in the carbon cycle of the biosphere. The study of this natural process
has developed mainly with the use of basidiomycetes in laboratory investigations. This has been a logical approach since most
of the microorganisms involved in lignocellulosic degradation belong to this class of fungi. However, other microorganisms
such as ascomycetes and also some bacteria, are involved in the lignin decaying process. This work focuses on lignin biodegradation
by a microorganism belonging to the ascomycete class,Chrysonilia sitophila. Lignin peroxidase production and characterization, mechanisms of lignin degradation (lignin model compounds and lignin in
wood matrix) and biosynthesis of veratryl alcohol are outstanding. Applications of C.sitophila for effluent treatment, wood biodegradation and single-cell protein production are also discussed. 相似文献
136.
Three series of compounds characterized by biphenylic structure were synthesized in order to develop new scaffolds able to induce β-sheet folding in the peptides. Microwave flash heating was used in order to shorten reaction times and to enhance the obtained yields. Simulated annealing molecular dynamics simulations demonstrated that some of the compounds were capable of adopting a 15-membered intramolecularly hydrogen-bonded conformation, which supports an antiparallel β-sheet structure. 相似文献
137.
Tom Wagner Elisa Lopez‐Capel David Manning 《Rapid communications in mass spectrometry : RCM》2008,22(11):1625-1625
138.
Elisa Udeschini Brinis 《Annali di Matematica Pura ed Applicata》1969,81(1):45-59
Sunto Si deducono da un principio variazionale le equazioni gravitazionali per gli spazi vuoti, in forma spinoriale, valendosi dell’azione
gravitazionale einsteiniana e assumendo come variabili base le componenti dello spin-tensore fondamentale. Per particolari
variazioni, si ottengono le identità contratte del Bianchi, in forma spinoriale.
Summary In this paper, gravitational field equations for empty-space, in spinor form, are derived from a variational principle by making use of the einsteinian gravitational Action and by assuming as basic variables describing the field the components of the fundamental spin-tensor. With an appropriate variation, the contracted Bianchi identities, in spinor form, are deduced.相似文献
139.
140.
J. Solla-Gullón Elvira Gómez Elisa Vallés Antonio Aldaz Juan M. Feliu 《Journal of nanoparticle research》2010,12(4):1149-1159
PtCo nanoparticles with homogeneous size (around 3–4 nm) have been synthesized in a water-in-oil microemulsion of water/polyethylenglycol–dodecylether (BRIJ®30)/n-heptane. X-ray diffraction study revealed the formation of a cubic phase with a gradual decrease of the cell parameter with increasing cobalt incorporation in the crystalline lattice of platinum. In relation to their magnetic properties, the PtCo nanoparticles present a superparamagnetic behaviour even after annealing, although higher permeability was induced by the thermal treatment. Finally, the electrocatalytic activity of the particles towards oxalic acid oxidation in H2SO4 was evaluated. The Pt74Co26 nanoparticles showed the highest reactivity for this reaction. 相似文献