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131.
Katarína Kráľová František Šeršeň Matúš Peško Karel Waisser Lenka Kubicová 《Chemical Papers》2014,68(1):46-52
5-Bromo-(Br-PBA) and 3,5-dibromo-2-hydroxy-N-phenylbenzamides (Br2-PBA) inhibited photosynthetic electron transport (PET) and their inhibitory efficiency depended on the compound lipophilicity as well as on the electronic properties of the R substituent in the N-phenyl moiety. Br-PBA showed higher PET inhibiting activity than Br2-PBA with the same R substituent. The most effective inhibitors in the tested series were the derivatives with R = 3-F (Br-PBA; IC50 = 4.3 μmol dm?3) and R = 3-Cl (Br2-PBA; IC50 = 8.6 μmol dm?3). Bilinear dependence of the PET inhibiting activity on the lipophilicity of the compounds as well as on the Hammett constant, σ, of the R substituent was observed for both investigated series. Using EPR spectroscopy it was found that the site of action of the tested compounds in the photosynthetic apparatus is situated on the donor side of PS 2, in D· or in the Z·/D· intermediates. Interaction of the studied compounds with chlorophyll a and aromatic amino acids present in the pigment-protein complexes mainly in photosystem 2 was documented by fluorescence spectroscopy. 相似文献
132.
Łukasz Wiśniewski Katarína Vaňková Pavel Ačai Milan Polakovič 《Chemical Papers》2014,68(12):1649-1655
Galacto-oligosaccharides are typically produced by an enzymatic reaction when the post-reaction mixture contains considerable amounts of lactose and glucose and a smaller amount of galactose. In order to develop a process of chromatographic removal of saccharide impurities, adsorption equilibria and kinetics of these di- and monosaccharides were investigated for Diaion UBK 530, an industrialgrade strong cation-exchanger in the Na+ form. Frontal chromatographic experiments were carried out in the temperature range of 30–70°C and a broad interval of saccharide concentrations up to 350 g L?1. Breakthrough curves were described using the equilibrium-dispersive model with the linear adsorption isotherm. Both the distribution and the axial dispersion coefficient values depended on the saccharide molecule type and size. No significant effect of temperature or concentration on the distribution coefficient was observed. The apparent dispersion coefficients of all saccharides exhibited some decrease with the temperature, which was caused by the decrease of the intraparticle mass transfer resistance. An analysis showed that both the intraparticle mass transfer and the axial dispersion had a significant influence on the front dispersion. 相似文献
133.
Sandra Mller Stefan Barwe Justus Masa Daniela Wintrich Sabine Seisel Helmut Baltruschat Wolfgang Schuhmann 《Angewandte Chemie (International ed. in English)》2020,59(4):1585-1589
Carbon corrosion at high anodic potentials is a major source of instability, especially in acidic electrolytes and impairs the long‐term functionality of electrodes. In‐depth investigation of carbon corrosion in alkaline environment by means of differential electrochemical mass spectrometry (DEMS) is prevented by the conversion of CO2 into CO32?. We report the adaptation of a DEMS system for online CO2 detection as the product of carbon corrosion in alkaline electrolytes. A new cell design allows for in situ acidification of the electrolyte to release initially dissolved CO32? as CO2 in front of the DEMS membrane and its subsequent detection by mass spectrometry. DEMS studies of a carbon‐supported nickel boride (NixB/C) catalyst and Vulcan XC 72 at high anodic potentials suggest protection of carbon in the presence of highly active oxygen evolution electrocatalysts. Most importantly, carbon corrosion is decreased in alkaline solution. 相似文献
134.
Daniela Mazzier Soumen De Barbara Wicher Victor Maurizot Ivan Huc 《Angewandte Chemie (International ed. in English)》2020,59(4):1606-1610
A hydrogen‐bonding interface between helical aromatic oligoamide foldamers has been designed to promote the folding of a helix‐turn‐helix motif with a head‐to‐tail arrangement of two helices of opposite handedness. This design complements an earlier helix‐turn‐helix motif with a head‐to‐head arrangement of two helices of identical handedness interface. The two motifs were shown to have comparable stability and were combined in a unimolecular tetra‐helix fold constituting the largest abiotic tertiary structure to date. 相似文献
135.
Elisa Roda Fabrizio De Luca Carlo Alessandro Locatelli Daniela Ratto Carmine Di Iorio Elena Savino Maria Grazia Bottone Paola Rossi 《Molecules (Basel, Switzerland)》2020,25(22)
Bioactive metabolites isolated from medicinal mushrooms (MM) used as supportive treatment in conventional oncology have recently gained interest. Acting as anticancer agents, they interfere with tumor cells and microenvironment (TME), disturbing cancer development/progression. Nonetheless, their action mechanisms still need to be elucidated. Recently, using a 4T1 triple-negative mouse BC model, we demonstrated that supplementation with Micotherapy U-Care, a MM blend, produced a striking reduction of lung metastases density/number, paralleled by decreased inflammation and oxidative stress both in TME and metastases, together with QoL amelioration. We hypothesized that these effects could be due to either a direct anticancer effect and/or to a secondary/indirect impact of Micotherapy U-Care on systemic inflammation/immunomodulation. To address this question, we presently focused on apoptosis/proliferation, investigating specific molecules, i.e., PARP1, p53, BAX, Bcl2, and PCNA, whose critical role in BC is well recognized. We revealed that Micotherapy U-Care is effective to influence balance between cell death and proliferation, which appeared strictly interconnected and inversely related (p53/Bax vs. Bcl2/PARP1/PCNA expression trends). MM blend displayed a direct effect, with different efficacy extent on cancer cells and TME, forcing tumor cells to apoptosis. Yet again, this study supports the potential of MM extracts, as adjuvant supplement in the TNBC management. 相似文献
136.
Emanuela Colombo Rosaria Pascente Daniela Triolo Claudia Bassani Anthea De Angelis Francesca Ruffini Linda Ottoboni Giancarlo Comi Gianvito Martino Cinthia Farina 《Molecules (Basel, Switzerland)》2020,25(22)
Astrocytes greatly participate to inflammatory and neurotoxic reactions occurring in neurodegenerative diseases and are valuable pharmacological targets to support neuroprotection. Here we used human astrocytes generated from reprogrammed fibroblasts as a cellular model to study the effect of the compound Laquinimod and its active metabolite de-Laquinimod on astrocyte functions and the astrocyte–neuron interaction. We show that human iAstrocytes expressed the receptor for the inflammatory mediator IL1 and responded to it via nuclear translocation of NFκB, an event that did not occur if cells were treated with Laquinimod, indicating a direct anti-inflammatory activity of the drug on the human astrocyte. Similarly, while exposure to IL1 downregulated glial glutamate transporters GLAST and GLT1, treatment with Laquinimod supported maintenance of physiological levels of these proteins despite the inflammatory milieu. Laquinimod also induced nuclear translocation of the aryl hydrocarbon receptor (AHR), suggesting that drug action was mediated by activation of the AHR pathway. However, the drug was effective despite AHR inhibition via CH223191, indicating that AHR signaling in the astrocyte is dispensable for drug responses. Finally, in vitro experiments with rat spinal neurons showed that laquinimod did not exert neuroprotection directly on the neuron but dampened astrocyte-induced neurodegeneration. Our findings indicate that fibroblast-derived human astrocytes represent a suitable model to study astrocyte–neuron crosstalk and demonstrate indirect, partial neuroprotective efficacy for laquinimod. 相似文献
137.
Dr. Shantanu Ganesh Kulkarni Kristýna Jelínková Dr. Marek Nečas Dr. Zdeňka Prucková Dr. Michal Rouchal Dr. Lenka Dastychová Dr. Petr Kulhánek Dr. Robert Vícha 《Chemphyschem》2020,21(18):2084-2095
Stilbene derivatives are well-recognised substructures of molecular switches based on photochemically and/or thermally induced (E)/(Z) isomerisation. We combined a stilbene motif with two benzimidazolium arms to prepare new sorts of supramolecular building blocks and examined their binding properties towards cucurbit[n]urils (n=7, 8) and cyclodextrins (β-CD, γ-CD) in water. Based on the 1H NMR data and molecular dynamics simulations, we found that two distinct complexes with different stoichiometry, i. e., guest@β-CD and guest@β-CD2, coexist in equilibrium in a water solution of the (Z)-stilbene-based guests. We also demonstrated that the bis(benzimidazolio)stilbene guests can be transformed from the (E) into the (Z) form via UV irradiation and back via thermal treatment in DMSO. 相似文献
138.
Daniela Metro Mattia Papa Luigi Manasseri Teresa Gervasi Luca Campone Vito Pellizzeri 《Natural product research》2020,34(16):2255-2261
Abstract Breakfast habits affect the nutritional status and health of people, in particular children and adolescents. This is the second part a previous study about the adherence to the Mediterranean diet in a Sicilian (Italy) student population. The investigation analysed both normal weight and overweight subjects in order to understand how eating habits, number of meals and daily calorie intakes could affect their body mass indexes (BMI). The aim of this second part was to analyse the breakfast nutritional profiles of this student population. The results highlighted that breakfast was regularly consumed by a percentage ranging from a maximum of 84% (in normal subjects) to a minimum value of 57.4% (in overweight/obese students). Milk, yoghurt, sugar, bread/rusk and tea contributed as main foods to the breakfast composition. The results highlighted that subjects who consumed breakfast showed lower BMI values with significant differences between normal and overweight/obese students. 相似文献
139.
140.
Three types of industrial poly (ester urethane) elastomers were studied by Curie–point pyrolysis–gas chromatography/Fourier–Transform infrared spectrometry (Py–GC/FTIR) with a maximum pyrolysis temperature of 973 K. The samples chosen were the Urepans 600 and 641 from Bayer and Elastollan C 78 A from BASF/Elastogran. The poly(ester urethane) elastomers are composed of three units: a polyesterdiol, a short chain diol and a diisocyanate. Py–GC/FTIR allows a rapid and unambiguous identification of the polymer chains by key fragments. 相似文献