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991.
Assist. Prof. Dr. Sumbal Saba Caio R. Dos Santos Bruno R. Zavarise Aline A. S. Naujorks Marcelo S. Franco Alex R. Schneider Marcos R. Scheide Dr. Ricardo F. Affeldt Assoc. Prof. Dr. Jamal Rafique Prof. Dr. Antonio L. Braga 《Chemistry (Weinheim an der Bergstrasse, Germany)》2020,26(20):4461-4466
Herein, a greener approach to the eosin Y-Na2 catalyzed, C(sp2)−H bond azo coupling of imidazoheteroarene with aryl diazonium salts is described, under acid free conditions. This direct photoredox process resulted in the corresponding azo products in good to excellent yields. Besides, this new approach could also be applicable to anilines, which is a poorly reactive substrate by other methods. The main features of this reaction are that it provides high yields and is gram-scalable and applicable to biologically relevant imidazoheteroarenes and -anilines. 相似文献
992.
Jing Zhang Dr. Astrid Schaly Dr. Jean-Claude Chambron Dr. Bruno Vincent Nathalie Zorn Dr. Emmanuelle Leize-Wagner Marion Jean Dr. Nicolas Vanthuyne 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(7):e202103759
Chiral gold(I) acetylide trinuclear complexes 1 – 3 based on the cyclotribenzylene platform and terminal PR3 ligands (R=Ph, Et, and Cy, respectively), were characterized and their light emission studied. They exhibited long-lived blue phosphorescence in CHCl3 and a weak fluorescence in the UV. In MeOH/CHCl3 mixtures of >1:1 volume ratio, 1 and 2 exhibited a new emission band at ca. 540 nm that developed at the expense of the UV emission. DLS studies demonstrated the presence of molecular aggregates of Ø 30–80 nm. The green emission observed in MeOH-rich solvent mixtures was therefore induced by aggregation, and could originate from Au⋅⋅⋅Au interactions. The AIE spectrum of 3 was observed only in solutions containing 99 % of MeOH, and correlated with its solid state emission. The AIE profiles of the enantiomers of 1 differed from that of rac- 1 , suggesting that the latter is a true racemate. 相似文献
993.
994.
995.
Rango Bruno J. Serralunga Fernando J. Piovan Marcelo T. Ballaben Jorge S. Rosales Marta B. 《Meccanica》2019,54(1-2):33-46
Meccanica - The present paper explores two approaches which, based on the measurement of the two first natural frequencies, allow the identification of the tension force in cables with insulators.... 相似文献
996.
Beatriz Rivas‐Murias Juan M. Asensio Nicolas Mille Benito Rodríguez‐Gonzlez Pier‐Francesco Fazzini Julian Carrey Bruno Chaudret Vernica Salgueirio 《Angewandte Chemie (International ed. in English)》2020,59(36):15537-15542
Magnetically induced catalysis can be promoted taking advantage of optimal heating properties from the magnetic nanoparticles to be employed. However, when unprotected, these heating agents that are usually air‐sensitive, get sintered under the harsh catalytic conditions. In this context, we present, to the best of our knowledge, the first example of air‐stable magnetic nanoparticles that: 1) show excellent performance as heating agents in the CO2 methanation catalyzed by Ni/SiRAlOx, with CH4 yields above 95 %, and 2) do not sinter under reaction conditions. To attain both characteristics we demonstrate, first the exchange‐coupled magnetic approach as an alternative and effective way to tune the magnetic response and heating efficiency, and second, the chemical stability of cuboctahedron‐shaped core–shell hard CoFe2O4–soft Fe3O4 nanoparticles. 相似文献
997.
Marta Jakubaszek Jeremie Rossier Johannes Karges Joachim Delasoie Bruno Goud Gilles Gasser Fabio Zobi 《Helvetica chimica acta》2019,102(7)
The current photosensitizers (PSs) for photodynamic therapy (PDT) lack selectivity for cancer cells. To tackle this drawback, in view of selective cancer delivery, we envisioned conjugating two ruthenium polypyridyl complexes to vitamin B12 (Cobalamin, Cbl) to take advantage of the solubility and active uptake of the latter. Ultimately, our results showed that the transcobalamin pathway is unlikely involved for the delivery of these ruthenium‐based PDT PSs, emphasizing the difficulty in successfully delivering metal complexes to cancer cells. 相似文献
998.
Tonka Vasileva Ilia Iliev Myriam Amari Veselin Bivolarski Marie-Sophie Bounaix Hervé Robert Sandrine Morel Philippe Rabier Iskra Ivanova Bruno Gabriel Catherine Fontagné-Faucher Valérie Gabriel 《Applied biochemistry and biotechnology》2012,168(3):718-730
Glycosyltransferase activity of 13 Leuconostoc mesenteroides strains isolated from Bulgarian fermented vegetables was investigated. All the strains displayed a mucoid phenotype on sucrose-containing agar media. Strains were characterized according to carbohydrate fermentation, species-specific multiple PCR using several primers, repetitive element-PCR fingerprinting using (GTG)5 primers and glycosyltransferase activity. Level of activity and cellular localization (soluble or cell-associated) were variable among strains. Precipitation of exopolysaccharides produced from sucrose by the soluble fractions from these strains allowed recovery of only glucans and further characterization by 1H and 13C NMR analysis and enzymatic digestion with dextranase revealed dextran production. However, levans could be detected in presence of raffinose as fructosyl donor. Both fructosyltransferase and glucosyltransferase encoding genes were detected by PCR and both active enzymes were detected after functional characterization by SDS-PAGE electrophoresis and in situ polymer production after incubation with sucrose. This work therefore showed that concomitant production of glucosyltransferase and fructosyltransferase is widespread in L. mesenteroides strains. 相似文献
999.
Using the matrix method, spin-dependent tunneling properties such as barrier transparency, the degree of resonance polarization, and tunneling lifetime of electrons are examined in the non-magnetic/diluted magnetic semiconductor heterostructure. The effects of the double δ-potential and the magnetic field are discussed on the transport properties of the electrons. The introduction of double δ-potential shifts the resonance peak of polarization to the higher energy value. Both height and position of the δ-potential influence the degree of resonance polarization in the considered heterostructure. The increasing magnetic field enhances the spin-polarization. 相似文献
1000.
Jieting Ding Prof. Shan Ji Hui Wang Prof. Dan J. L. Brett Prof. Bruno G. Pollet Prof. Rongfang Wang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2019,25(11):2868-2876
The development of alternative electrocatalysts exhibiting high activity in the oxygen reduction reaction (ORR) is vital for the deployment of large-scale clean energy devices, such as fuel cells and zinc–air batteries. N-doped carbon materials offer a promising platform for the design and synthesis of electrocatalysts due to their high ORR activity, high surface area, and tunable porosity. In this study, materials in which MnO nanoparticles are entrapped in N-doped mesoporous carbon (MnO/NC) were developed as electrocatalysts for the ORR, and their performances were evaluated in zinc–air batteries. The obtained carbon materials had large surface area and high electrocatalytic activity toward the ORR. The carbon compounds were fabricated by using NaCl as template in a one-pot process, which significantly simplifies the procedure for preparing mesoporous carbon materials and in turn reduces the total cost. A primary zinc–air battery based on this material exhibits an open-circuit voltage of 1.49 V, which is higher than that of conventional zinc–air batteries with Pt/C (Pt/C cell) as ORR catalyst (1.41 V). The assembled zinc–air battery delivered a peak power density of 168 mW cm−2 at a current density of about 200 mA cm−2, which is higher than that of an equivalent Pt/C cell (151 mW cm−2 at a current density of ca. 200 mA cm−2). The electrocatalytic data revealed that MnO/NC is a promising nonprecious-metal ORR catalyst for practical applications in metal–air batteries. 相似文献