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871.
Aubert B Bona M Boutigny D Karyotakis Y Lees JP Poireau V Prudent X Tisserand V Zghiche A Garra Tico J Grauges E Lopez L Palano A Eigen G Ofte I Stugu B Sun L Abrams GS Battaglia M Brown DN Button-Shafer J Cahn RN Groysman Y Jacobsen RG Kadyk JA Kerth LT Kolomensky YG Kukartsev G Lopes Pegna D Lynch G Mir LM Orimoto TJ Pripstein M Roe NA Ronan MT Tackmann K Wenzel WA Del Amo Sanchez P Hawkes CM Watson AT Held T Koch H Lewandowski B Pelizaeus M Schroeder T Steinke M Boyd JT Burke JP 《Physical review letters》2007,99(8):081801
We report a measurement of the time-dependent CP-asymmetry parameters S and C in color-suppressed B{0}-->D{(*)0}h{0} decays, where h{0} is a pi{0}, eta, or omega meson, and the decays to one of the CP eigenstates K+K-, K{S}{0}pi{0}, or K{S}{0}omega. The data sample consists of 383 x 10{6} Upsilon(4S)-->BB decays collected with the BABAR detector at the PEP-II asymmetric-energy B factory at SLAC. The results are S=-0.56+/-0.23+/-0.05 and C=-0.23+/-0.16+/-0.04, where the first error is statistical and the second is systematic. 相似文献
872.
Aubert B Bona M Boutigny D Karyotakis Y Lees JP Poireau V Prudent X Tisserand V Zghiche A Garra Tico J Grauges E Lopez L Palano A Eigen G Stugu B Sun L Abrams GS Battaglia M Brown DN Button-Shafer J Cahn RN Groysman Y Jacobsen RG Kadyk JA Kerth LT Kolomensky YG Kukartsev G Lopes Pegna D Lynch G Mir LM Orimoto TJ Ronan MT Tackmann K Wenzel WA del Amo Sanchez P Hawkes CM Watson AT Held T Koch H Lewandowski B Pelizaeus M Schroeder T Steinke M Walker D Asgeirsson DJ Cuhadar-Donszelmann T Fulsom BG 《Physical review letters》2007,99(7):071801
We present updated measurements of CP-violating asymmetries in the decays B0-->D*(+/-)D(-/+) and B0-->D+D- using (383+/-4) x 10(6)B(B) pairs collected by the BABAR detector at the SLAC PEP-II B factory. We determine the time-integrated CP asymmetry A(D*(+/-)D(-/+))=0.12+/-0.06+/-0.02, and the time-dependent asymmetry parameters to be C(D*+D-)=0.18+/-0.15+/-0.04, S(D*+D-)=-0.79+/-0.21+/-0.06, C(D*-D+)=0.23+/-0.15+/-0.04, S(D*-D+)=-0.44+/-0.22+/-0.06, C(D+D-)=0.11+/-0.22+/-0.07, and S(D+D-)=-0.54+/-0.34+/-0.06, where the first uncertainty is statistical and the second is systematic. 相似文献
873.
Steurer W Apfolter A Koch M Ernst WE Holst B Søndergård E Manson JR 《Physical review letters》2007,99(3):035503
The boson peak is an excess in the phonon density of states compared to the Debye model that appears in almost all glasses. It has been repeatedly measured in the bulk by a variety of methods, but its origin is still highly debated. Here we present first experimental evidence of the boson peak on the v-SiO2 surface. The measurements were obtained by helium atom scattering. The boson peak appears as a dispersionless mode of approximately 4 meV in the recorded time-of-flight spectra. It is clearly identified as an excess contribution to the low energy Debye-like region in the surface phonon spectral density which is extracted from the time-of-flight spectra using a straightforward theoretical model. 相似文献
874.
875.
876.
Seit mehr als 20 Jahren wird an der Technischen Universität Dresden Forschung und Ausbildung auf dem Gebiet der Anwendung kernphysikalischer Meßverfahren in der Betriebsmeßtechnik, der Analysenmeßtechnik und der Tracertechnik betrieben. Es wird ein Überblick über die wesentlichen Forschungsarbeiten auf diesem Gebiet gegeben. 相似文献
877.
unter Verwendung des Meßkopfes und der Zentrale des ächengewichtsmeßgerätes VA-T-70 A wurden Untersuchungen über die Leistungsfähigkeit des β-Rückstreuverfahrens hinsichtlich der quantitativen Analyse von Zweistoffsystemen durchgeführt. Die Messungen erfolgten an Prüfligen, die aus Metallpulvergemischen hergestellt waren. Es wurden 9 verschiedene Zweistoffsysteme untersucht. Die Ordnungszahldifferenzen der beiden Komponenten lagen zwischen 1 und 48. Es erfolgate die Bestimmung der Meßempfindlichkeit und des mittleren Meßfehlers bei verschiedenen Meßbedingungen. 相似文献
878.
Hooff GP Meesters RJ van Kampen JJ van Huizen NA Koch B Al Hadithy AF van Gelder T Osterhaus AD Gruters RA Luider TM 《Analytical and bioanalytical chemistry》2011,400(10):3473-3479
The neuraminidase inhibitor oseltamivir (Tamiflu®) is currently the first-line therapy for patients with influenza virus infection. Common analysis of the prodrug and its active metabolite oseltamivircarboxylate is determined via extraction from plasma. Compared with these assays, dried blood spot (DBS) analysis provides several advantages, including a minimum sample volume required for the measurement of drugs in whole blood. Samples can easily be obtained via a simple, non-invasive finger or heel prick. Mainly, these characteristics make DBS an ideal tool for pediatrics and to measure multiple time points such as those needed in therapeutic drug monitoring or pharmacokinetic studies. Additionally, DBS sample preparation, stability, and storage are usually most convenient. In the present work, we developed and fully validated a DBS assay for the simultaneous determination of oseltamivir and oseltamivircarboxylate concentrations in human whole blood. We demonstrate the simplicity of DBS sample preparation, and a fast, accurate and reproducible analysis using ultra high-performance liquid chromatography coupled to a triple quadrupole mass spectrometer. A thorough validation on the basis of the most recent FDA guidelines for bioanalytical method validation showed that the method is selective, precise, and accurate (≤15% RSD), and sensitive over the relevant clinical range of 5–1,500 ng/mL for oseltamivir and 20–1,500 ng/mL for the oseltamivircarboxylate metabolite. As a proof of concept, oseltamivir and oseltamivircarboxylate levels were determined in DBS obtained from healthy volunteers who received a single oral dose of Tamiflu®. 相似文献
879.
High‐resolution structural data of protein inhibitor complexes are the key to rational drug design. Synchrotron radiation allows for atomic resolutions but is frequently accompanied by radiation damage to protein complexes. In this study a human aldose reductase mutant complexed with a bromine‐substituted inhibitor was determined to atomic resolution [Protein Data Bank (PDB) code 3onc ]. Though the radiation dose was moderate, a selective disruption of a bromine–inhibitor bond during the experiment was observed while the protein appears unaffected. A covalent bond to bromine is cleaved and the displaced atom is not scattered throughout the crystal but can most likely be assigned as a bromide to an additional difference electron density peak observed in the structure. The bromide relocates to an adjacent unoccupied site where promising interactions to protein residues stabilize its position. These findings were verified by a second similar structure determined with considerably higher radiation dose (PDB code 3onb ). 相似文献
880.
Umut Aygül Dr. Heiko Peisert Johannes Frisch Dr. Antje Vollmer Prof. Norbert Koch Prof. Thomas Chassé 《Chemphyschem》2011,12(12):2345-2351
We report on the electronic structure of poly[2,6‐(4,4‐bis‐ (2‐ethylhexyl)‐4H‐cyclopenta[2,1‐b;3,4‐b′]dithiophene)‐alt‐4,7(2,1,3‐benzothiadiazole)] (PCPDTBT), a promising low‐band‐gap donor material for efficient bulk heterojunction organic solar cells. Electronic properties of interfaces formed between PCPDTBT and prototypical electrodes [Au, indium‐tin‐oxide and poly(ethylene‐dioxythiophene): poly(styrenesulfonate)], obtained from X‐ray photoemission spectroscopy and ultraviolet photoemission spectroscopy, are evaluated. The formation of interface dipoles is observed, and their consequences for device performance are discussed. For the system PCPDTBT/Au chemical interactions occur, which may affect in particular the charge extraction at the corresponding interface. 相似文献