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41.
Peter J. Chen Morton E. Gurtin 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1970,21(2):232-241
Zusammenfassung Vor kurzem haben Gurtin und Pipkin eine allgemeine nichtlineare Theorie der Wärmeleitung entwickelt, die vollständig mit den Gesetzen der Thermodynamik vereinbar ist und in welcher Wärmestörungen sich mit endlicher Geschwindigkeit ausbreiten. Wir erweitern hier diese Theorie auf verformbare Körper.Zuerst beschreiben wir die Einschränkungen, die die Gesetze der Thermodynamik den stoffgleichungen auferlegen. Dann wenden wir uns dem Studium der Wellenfortpflanzung in diesen Stoffen zu und zeigen, dass zwei Fortpflanzungsgeschwindigkeiten für Beschleunigungswellen existieren: Die erste Schallgeschwindigkeit hat mechanischen Charakter und liegt in der Nähe der isothermen und isentropen Schallgeschwindigkeit. Die zweite Schallgeschwindigkeit ist mit einer hauptsächlich thermalen Welle verbunden. 相似文献
42.
A consitutive theory for polymetric liquids based on the transient network concept is developed, following Wiegel and Jongschaap. The Phan-Thien-Tanner equation is shown to follow from the general theory with two critical assumption, one of these is quasi-equilibrium of the internal structure, which preludes consistency of application in ”fast flows“. The Marrucci model can be made consistent with the general format with a small change in the kinetic equation that can be deduced from asymptotic behaviour and leaves the steady viscometric behavior unchanged. The simplest genaral formulation requires the linear viscoelastic spectrum and two parameters; the latter cannot be determined uniquely from steady viscometric flow data. 相似文献
43.
Morton JJ Tyryshkin AM Ardavan A Porfyrakis K Lyon SA Briggs GA 《Physical review letters》2005,95(20):200501
Systematic errors in spin rotation operations using simple rf pulses place severe limitations on the usefulness of the pulsed magnetic resonance methods in quantum computing applications. In particular, the fidelity of quantum logic operations performed on electron spin qubits falls well below the threshold for the application of quantum algorithms. Using three independent techniques, we demonstrate the use of composite pulses to improve this fidelity by several orders of magnitude. The observed high-fidelity operations are limited by pulse phase errors, but nevertheless fall within the limits required for the application of quantum error correction. 相似文献
44.
Let G be a group with a set of operators such that Z(G) is -admissible. Central -automorphisms occur in the Krull-Remak-Schmidt Theorem. We discuss the existence of a central -endomorphism of G that is not an automorphism.2000 Mathematics Subject Classification: 20E36 相似文献
45.
S. N. Liddick P. F. Mantica R. V.F. Janssens B. A. Brown M. P. Carpenter A. D. Davies M. Honma M. Horoi T. Mizusaki A. C. Morton W. F. Mueller T. Otsuka J. Pavan H. Schatz A. Stolz S. L. Tabor B. E. Tomlin M. Wiedeking 《The European physical journal. Special topics》2007,150(1):135-136
We have utilized the selective process of β decay to
populate low-energy excited states in the neutron-rich 22Ti,
23V, 24Cr, and 25Mn nuclei. The goal was to systematically
track the monopole shift of the νf5/2 single-particle
level with increased occupancy of the πf7/2 orbital.
The β-decay properties of the parent nuclides, along
with the low-energy structure of the daughters, are
presented and compared with the results of shell model calculations
employing the GXPF1 interaction. 相似文献
46.
By employing Senanayake's oxathiazolidine-2-oxide reagent, a collection of sulfinamides was prepared and provided the first examples of sulfinamides promoting the allylation of benzaldehyde and N-benzoylhydrazones with allyltrichlorosilane. The optimum sulfinamide-derived Lewis base promoter displays comparable activity to the best sulfinyl-based Lewis bases reported. The use of bis-sulfoxides is also discussed. 相似文献
47.
48.
Morton E. Gurtin Terrance D. Ralston 《International Journal of Solids and Structures》1974,10(9):933-943
This paper establishes the convergence of the continuous-time Galerkin technique as applied to quasi-static, linear viscoelasticity. 相似文献
49.
Sarah R. Dennison Leslie H.G. Morton Andrea J. Shorrocks Frederick Harris David A. Phoenix 《Colloids and surfaces. B, Biointerfaces》2009,68(2):225-230
Aurein 2.5 (GLFDIVKKVVGAFGSL-NH2) is an uncharacterised antimicrobial peptide. At an air/water interface, it exhibited strong surface activity (maximal surface pressure 25 mN m−1) and molecular areas consistent with the adoption of α-helical structure orientated either perpendicular (1.72 nm2 molecule−1) or parallel (3.6 nm2 molecule−1) to the interface. Aurein 2.5 was strongly antibacterial, exhibiting a minimum inhibitory concentration (MIC) of 30 μM against Bacillus subtilis and Escherichia coli. The peptide induced maximal surface pressure changes of 9 mN m−1 and 5 mN m−1, respectively, in monolayers mimicking membranes of these organisms whilst compression isotherm analysis of these monolayers showed ΔGMix > 0, indicating destabilisation by Aurein 2.5. These combined data suggested that toxicity of the peptide to these organisms may involve membrane invasion via the use of oblique orientated α-helical structure. The peptide induced strong, comparable maximal surface changes in monolayers of DOPG (7.5 mN m−1) and DOPE monolayers (6 mN m−1) suggesting that the membrane interactions of Aurein 2.5 were driven by amphiphilicity rather than electrostatic interaction. Based on these data, it was suggested that the differing ability of Aurein 2.5 to insert into membranes of B. subtilis and E. coli was probably related to membrane-based factors such as differences in lipid packing characteristics. The peptide was active against both sessile E. coli and Staphylococcus aureus with an MIC of 125 μM. The broad-spectrum antibacterial activity and non-specific modes of membrane action used by Aurein 2.5 suggested use as an anti-biofilm agent such as in the decontamination of medical devices. 相似文献
50.
Innus Mohammad JiYoung Mun Amber Onorato Martha D. Morton Abdullah I. Saleh Michael B. Smith 《Tetrahedron letters》2017,58(44):4162-4165
When compared to a long-straight chain terminal alkyne, a long chain terminal alkyne with a distal isopropyl unit (isobranched) isomerizes about two times faster when treated with strong base under identical conditions, and appears to follow pseudo first order kinetics. In both cases, equilibration to a 95–97:5–3 mixture of terminal:internal alkyne accompanies isomerization. The difference in rate may be due to an unusual folding of both long-chain alkynes, bringing the distal substituent close to the carbon-carbon-triple bond moiety. The distal isopropyl moiety may provide unanticipated steric hindrance that disrupts such folding, making the propargylic proton more available for reaction with base. 相似文献