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671.
An innovative approach which combines high order compact schemes, Immersed Boundary Method and an efficient domain decomposition
method is used to perform high fidelity Direct Numerical Simulations (DNS) of four spatially evolving turbulent flows, one
generated by a regular grid and three generated by fractal square grids. The main results which we have been able to obtain
from these simulations are the following: the vorticity field appears more clustered when generated by fractal square grids
compared to a regular grid; fractal square grids generate higher vorticities and turbulence intensities than a regular grid;
the flow holds clear geometrical imprints of the fractal grids far downstream, a property which could be used in the future
for flow design, management and passive control; the DNS obtained with fractal grids confirmed the existence of two turbulent
regions, one where the turbulence progressively amplifies closer to the grid (the production region) followed by one where
the turbulence decays; the energy spectra of fluctuating turbulent velocities at various locations in the production region
of the flow provide some information on how the turbulence is generated at the smallest scales first near the grid where the
smallest wakes are dominant, followed by progressively smaller turbulent frequencies further downstream where progressively
larger wakes interact. 相似文献
672.
673.
Karagiannis EE Kefalidis CE Petrakopoulou I Tsipis CA 《Journal of computational chemistry》2011,32(7):1241-1261
The structural, electronic, bonding, magnetic, and optical properties of bimetallic [Cu(n)Ru(m)](+/0/-) (n + m ≤ 3; n, m = 0-3) clusters were computed in the framework of the density functional theory (DFT) and time-dependent DFT (TD-DFT) using the full-range PBE0 nonlocal hybrid GGA functional combined with the Def2-QZVPP basis sets. Several low-lying states have been investigated and the stability of the ground state spinomers was estimated with respect to all possible fragmentation schemes. Molecular orbital and population analysis schemes along with computed electronic parameters illustrated the details of the bonding mechanisms in the [Cu(n Ru(m)](+/0/-) clusters. The TD-DFT computed UV-visible absorption spectra of the bimetallic clusters have been fully analyzed and assignments of all principal electronic transitions were made and interpreted in terms of contribution from specific molecular orbital excitations. 相似文献
674.
Christos Anastopoulos Nicolas Kerschen Stathes Paganis 《The European Physical Journal C - Particles and Fields》2011,71(9):1746
A data-driven method for simultaneously extracting a potential Higgs → ZZ(∗) → 4e, 4μ, 2e2μ signal and its dominant backgrounds, is presented. The method relies on a combined fit of the 2-lepton, Z(∗), and 4-lepton invariant masses. The fit is assisted by normalization of the Z+X backgrounds in data control regions. The
Higgs discovery potential for the next few years of LHC running is presented. The demonstrated high sensitivity of the method
makes it ideal for the search performed by the ATLAS and CMS experiments. 相似文献
675.
We report here on the formation of hybrid compound block copolymer micelles encapsulating gold nanoparticles, utilizing a direct and general preparation method. The giant hybrid compound micelles are structured with micelles of PS‐b‐P2VP with gold nanoparticles in their P2VP core and PI‐b‐PS chains as the outer part of the compound micelles. The gold nanoparticles were produced using gold ion‐loaded PS‐b‐P2VP micelles as a nanoreactor, in a PS selective solvent (toluene), by the subsequent reduction of gold ions. The synthesis of the gold nanoparticles was monitored by UV‐vis spectroscopy. The gold containing micelles were then encapsulated in larger micelles of PI‐b‐PS copolymer, by successive utilization of toluene and heptane with the intermediate evaporation of toluene. The nanoassembly of the compound materials comprised a PI corona and a PS compound core, with P2VP/Au0 domains, and was characterized using UV‐vis spectroscopy, dynamic light scattering and transmission electron microscopy.
676.
We study the conditions under which and how an imposed cluster of fixed colloidal particles at prescribed positions triggers crystal nucleation from a metastable colloidal fluid. Dynamical density functional theory of freezing and Brownian dynamics simulations are applied to a two-dimensional colloidal system with dipolar interactions. The externally imposed nucleation clusters involve colloidal particles either on a rhombic lattice or along two linear arrays separated by a gap. Crystal growth occurs after the peaks of the nucleation cluster have first relaxed to a cutout of the stable bulk crystal. 相似文献
677.
678.
Dr. Sebastian Dengler Dr. Ryan T. Howard Dr. Vasily Morozov Dr. Christos Tsiamantas Wei-En Huang Prof. Zhiwei Liu Dr. Christopher Dobrzanski Prof. Vojislava Pophristic Dr. Sophie Brameyer Céline Douat Prof. Hiroaki Suga Prof. Ivan Huc 《Angewandte Chemie (International ed. in English)》2023,62(46):e202308408
Expanding the chemical diversity of peptide macrocycle libraries for display selection is desirable to improve their potential to bind biomolecular targets. We now have implemented a considerable expansion through a large aromatic helical foldamer inclusion. A foldamer was first identified that undergoes flexizyme-mediated tRNA acylation and that is capable of initiating ribosomal translation with yields sufficiently high to perform an mRNA display selection of macrocyclic foldamer–peptide hybrids. A hybrid macrocyclic nanomolar binder to the C-lobe of the E6AP HECT domain was selected that showed a highly converged peptide sequence. A crystal structure and molecular dynamics simulations revealed that both the peptide and foldamer are helical in an intriguing reciprocal stapling fashion. The strong residue convergence could be rationalized based on their involvement in specific interactions with the target protein. The foldamer stabilizes the peptide helix through stapling and through contacts with key residues. These results altogether represent a significant extension of the chemical space amenable to display selection and highlight possible benefits of inserting an aromatic foldamer into a peptide macrocycle for the purpose of protein recognition. 相似文献
679.
680.
Zoë Adams Christos Bechlivanidis Magda Osman John O'Hagan Dzhordzhio Naldzhiev 《Photochemistry and photobiology》2023,99(5):1299-1309
The COVID-19 pandemic increased sales of portable UV-C devices as a means of inactivating the SARS-CoV-2 virus. Research suggests that excessive UV-C exposure to the eyes and skin can lead to side-effects, primarily photokeratitis and erythema, but these findings are limited to case studies. This study explores self-reported side-effects of UV-C devices by collating five waves of UK consumer survey data from April 2020–December 2021 (N = 26 864). 30%–46% of owners report a side-effect after using a device claiming to emit UV-C. However, detailed analysis of Wave 4 data (N = 309) highlights inconsistencies between reported and plausible side-effect(s) associated with skin or eye exposure from UV-C devices. Alternative explanations are considered, namely that the reported side-effect(s) were psychosomatic or misattributed to direct exposure of UV-C radiation. Data regarding awareness of warnings about device side-effect(s) supports the misattribution explanation. For risk assessment purposes, limited reliable information about specific irritation or injury to the eye and skin was found from self-reporting surveys. To optimize future data collection, we recommend addressing recall errors by: reducing the period under investigation, supplementing responses with empirical measures, and incentivizing respondents to provide accurate information about the make and model of the UV-C device. 相似文献