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991.
Haibel Elena Berendts Stefan Walter Dirk 《Journal of Thermal Analysis and Calorimetry》2018,133(1):261-269
Journal of Thermal Analysis and Calorimetry - The mechanism and kinetics of tungsten and copper oxides joint reduction by Mg + C combined reducer was studied at high heating rates... 相似文献
992.
993.
Probing Supramolecular Interactions between a Crown Ether Appended Zinc Phthalocyanine and an Ammonium Group Appended to a C60 Derivative 下载免费PDF全文
Marcus Lederer Dr. Uwe Hahn Jean‐Marc Strub Dr. Sarah Cianférani Dr. Alain Van Dorsselaer Dr. Jean‐François Nierengarten Prof. Dr. Tomas Torres Prof. Dr. Dirk M. Guldi 《Chemistry (Weinheim an der Bergstrasse, Germany)》2016,22(6):2051-2059
Self‐assembly driven by crown ether complexation of zinc phthalocyanines equipped with one 18‐crown‐6 moiety and fullerenes bearing an ammonium head group afforded a novel donor–acceptor hybrid. In reference experiments, fullerenes containing a Boc‐protected amine functionality have been probed. The circumvention of zinc phthalocyanine aggregation is important for the self‐assembly, which required the addition of pyridine. From absorption and fluorescence titration assays, which provided sound and unambiguous evidence for mutual interactions between the electron donor and the electron acceptor within the hybrids, association constants in the order of 8.0×105 m ?1 have been derived. The aforementioned is based on 1:1 stoichiometries, which have been independently confirmed by Job's plot measurements. In the excited state, which has been examined by transient absorption experiments, intermolecular charge separation evolves from the photoexcited zinc phthalocyanine to the fullerene subunit and leads to short‐lived charge‐separated states. Interestingly, photoexcitation of zinc phthalocyanine dimers/aggregates can also be followed by an intermolecular charge separation between vicinal phthalocyanines. These multicomponent supramolecular ensembles have also been shown by in‐depth electrospray ionization mass spectrometry (ESI‐MS) studies, giving rise to the formation and detection of a variety of non‐covalently linked species. 相似文献
994.
995.
Dr. Ben W. Greatrex Dr. Alison M. Daines Dr. Sarah Hook Dr. Dirk H. Lenz Dr. Warren McBurney Prof. Thomas Rades Dr. Phillip M. Rendle 《ChemistryOpen》2015,4(6):740-755
In an attempt to discover a new synthetic vaccine adjuvant, the glycosylation of hederagenin, gypsogenin, and oleanolic acid acceptors with di‐ and trisaccharide donors to generate a range of mimics of natural product QS‐21 was carried out. The saponins were formulated with phosphatidylcholine and cholesterol, and the structures analyzed by transmission electron microscopy. 3‐O‐(Manp(1→3)Glcp)hederagenin was found to produce numerous ring‐like micelles when formulated, while C‐28 choline ester derivatives preferred self‐assembly and did not interact with the liposomes. When alone and in the presence of cholesterol and phospholipid, the choline ester derivatives produced nanocrystalline rods or helical micelles. The effects of modifying sugar stereochemistry and the aglycone on the immunostimulatory effects of the saponins was then evaluated using the activation markers MHC class II and CD86 in murine bone marrow dendritic cells. The most active saponin, 3‐O‐(Manp(1→3)Glcp)hederagenin, was stimulatory at high concentrations in cell culture, but this did not translate to strong responses in vivo. 相似文献
996.
997.
Lydia KerschensteinerFlorian Löbermann Wolfgang Steglich Dirk Trauner 《Tetrahedron》2011,67(8):1536-1539
Crocipodin, an unusual benzotropolone pigment, has been isolated from the fruit bodies of the mushroom Leccinum crocipodium. Its structure was determined by spectroscopic methods, particularly 2D NMR spectroscopy. The structure was confirmed by total synthesis, starting from 4-bromocatechol and gallic acid. 相似文献
998.
Nikola Popović Dirk Praetorius Anja Schlömerkemper 《Continuum Mechanics and Thermodynamics》2007,19(1-2):81-109
The analysis of magnetoelastic phenomena is a field of active research. Formulae for the magnetic force in macroscopic systems
have been under discussion for some time. In Popović et al. (Continum. Mech. Thermodyn. 2007), we rigorously justify several
of the available formulae in the context of rigid bodies in two and three space dimensions. In the present, second part of
our study, we investigate these formulae in a series of numerical experiments in which the magnetic force is computed in dependence
on the geometries of the bodies as well as on the distance between them. In case the two bodies are in contact, i.e., in the
limit as their distance tends to zero, we focus especially on a formula obtained in a discrete-to-continuum approximation.
The aim of our study is to help clarify the question which force formula is the correct one in the sense that it describes
nature most accurately and to suggest adequate real-life experiments for a comparison with the provided numerical data.
相似文献
999.
Electronic Structure of the Positive Radical of 13C-Labeled Poly(3-Octylthienylene Vinylene) Polymer
Yun Ling Hanne Diliën Dirk Vanderzande Peter J. Adriaensens Sabine Van Doorslaer 《Applied magnetic resonance》2014,45(9):827-839
Poly(3-octylthienylene vinylene) (O-PTV) has a great potential as low-bandgap p-type semiconductor for photovoltaic applications. Here, the positive radical state (positive polaron) is induced chemically in the O-PTV polymer in which the vinylene sites are selectively 13C-labeled. Using multi-frequency continuous wave and pulsed electron paramagnetic resonance, the g tensor and maximum 1H and 13C hyperfine couplings are determined. A comparative density functional theory (DFT) analysis of PTV-like oligomers is performed. The experimental parameters suggest a larger localization of the positive polaron than follows from the DFT analysis. The counter anion may play a crucial role in localizing the polaron. 相似文献
1000.
Tim Brereton Ole Stenzel Björn Baumeier Denis Andrienko Volker Schmidt Dirk Kroese 《Methodology and Computing in Applied Probability》2014,16(2):465-484
A methodology is proposed that is suitable for efficient simulation of continuous-time Markov chains that are nearly-completely decomposable. For such Markov chains the effort to adequately explore the state space via Crude Monte Carlo (CMC) simulation can be extremely large. The purpose of this paper is to provide a fast alternative to the standard CMC algorithm, which we call Aggregate Monte Carlo (AMC). The idea of the AMC algorithm is to reduce the jumping back and forth of the Markov chain in small subregions of the state space. We accomplish this by aggregating such problem regions into single states. We discuss two methods to identify collections of states where the Markov chain may become ‘trapped’: the stochastic watershed segmentation from image analysis, and a graph-theoretic decomposition method. As a motivating application, we consider the problem of estimating the charge carrier mobility of disordered organic semiconductors, which contain low-energy regions in which the charge carrier can quickly become stuck. It is shown that the AMC estimator for the charge carrier mobility reduces computational costs by several orders of magnitude compared to the CMC estimator. 相似文献