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71.
Chung Fang Yongqi Wang Kolumban Hutter 《Archive of Applied Mechanics (Ingenieur Archiv)》2006,76(3-4):119-131
In the present study a variational principle is proposed for the revised Goodman–Cowin theory with internal length for cohesionless granular materials (Fang et al. in Continuum Mech Thermodyn in press). The balance equations of the internal variables employed in the theory in equilibrium states, the equilibrium expressions of the constitutive variables and the corresponding natural boundary conditions are derived by use of the proposed variational principle for both cases of compressible and incompressible grains. It is demonstrated that the derived results coincide with those obtained by use of the thermodynamic analysis. The current work serves as a supplementary variational verification of the constitutive theory proposed in Fang et al. (in Continuum Mech Thermodyn in press). 相似文献
72.
G. Sciarra K. Hutter G. A. Maugin 《Archive of Applied Mechanics (Ingenieur Archiv)》2003,73(3-4):199-224
Summary In this paper, we present a micro-structured model for describing global deformations of heterogeneous mixtures. In particular, for a saturated solid-fluid mixture, we regard the solid volume fraction as a microstructural parameter so as to enlarge the space of admissible deformations with respect to the classical theory of mixtures. According to the variational approach, the governing equations are obtained as the stationarity of a suitable action functional. The micro-structured model is then forced to establish a second-gradient mixture theory, by introducing among the considered state parameters a suitable internal constraint. Finally, we determine under which (integrability) conditions the additional balance laws, typically employed to close the theory of porous media endowed with the volume fraction, can fit the variational framework.
The authors wish to thank Prof. Francesco dell'Isola from University of Rome La Sapienza for his constructive criticism about the variational approach to continuum mechanics and the interpretation of the volume-fraction balance law. 相似文献
73.
Structural information is extracted from the all-particle (non-Born-Oppenheimer) wave function by calculating radial and angular densities derived from n-particle densities. As a result, one- and two-dimensional motifs of classical molecular structure can be recognized in quantum mechanics. Numerical examples are presented for three- (H(-), Ps(-), H(2)(+)), four- (Ps(2), H(2)), and five-particle (H(2)D(+)) systems. 相似文献
74.
Henkelis JJ Ronson TK Harding LP Hardie MJ 《Chemical communications (Cambridge, England)》2011,47(23):6560-6562
Crystalline M(3)L(2) complexes with either single cage or triply interlocking [2]catenane chiral structures are formed the self-assembly of host-like ligands with transition metals. 相似文献
75.
76.
On the thermodynamic consistency of the equivalence principle in continuum damage mechanics 总被引:1,自引:0,他引:1
We consider theories of continuum damage mechanics involving damage effect variables of different tensorial ranks. It turns out that orthotropic damage together with the use of Lemaitre's equivalence principle for the elastic part does not allow thermodynamic potentials such as the free enthalpy to exist. As the existence of these potentials is, however, a strict thermodynamic requirement, a theory employing orthotropic damage in this way is inconsistent. We show that the use of a rank-4 damage effect variable allows a consistent use of the equivalence principle. 相似文献
77.
Tanya M RamondGustavo E Davico Fredrik HellbergFredrik Svedberg Peter SalénPatrick Söderqvist W.Carl Lineberger 《Journal of Molecular Spectroscopy》2002,216(1):1-14
The 364-nm negative ion photoelectron spectra of XO and OXO molecules (X=Ni, Pd, and Pt) are reported. The spectra yield the electron affinities (EAs): EA(NiO)=1.455±0.005 eV; EA(PdO)=1.672±0.005 eV; EA(PtO)=2.172±0.005 eV; EA(ONiO)=3.043±0.005 eV; EA(OPdO)=3.086±0.005 eV; EA(OPtO)=2.677±0.005 eV. In addition, for the diatomics, transitions from the anion X?2Π3/2 and X?′2Π1/2 states into neutral X?3Σ−, 3Π, and for NiO and PdO, 1Π, are assigned. Several states have been reassigned from those in the existing literature. Anion 2Π3/2-2Π1/2 spin-orbit splittings are measured, as are neutral 3Π2-3Π1 spin-orbit splittings: the XO 3Π 2-3Π1 splittings increase from 405±30 cm−1 (NiO) to 805±30 cm−1 (PdO) to 3580±40 cm−1 (PtO). A bond length shortening of 0.03±0.01 Å is measured upon electron detachment from NiO−, resulting in an anion bond length of 1.66±0.01 Å. The bond length does not change upon electron detachment from PdO− using 3.4-eV photons. The Pt-O bond length decreases by 0.035±0.010 Å in the 3Π1←2Π3/2 transition. The spectrum of OPtO displays a significantly more extended vibrational progression than those of ONiO or OPdO, and the O-Pt bond length is found to decrease by 0.07±0.01 Å upon electron detachment. The spectra support the view that the Ni-O bond is largely ionic, the Pd-O bond is somewhat less so, and the Pt-O bond displays a substantial covalent character. 相似文献
78.
M. Grasserbauer G. Friedbacher H. Hutter G. Stingeder 《Fresenius' Journal of Analytical Chemistry》1993,346(6-9):594-603
Summary The rapid progress in high technology constantly poses new challenges for Analytical Chemistry and prompts the development of new techniques and procedures. The influence is particularly strong in surface and interface analysis, which is developing at a rapid pace. This paper discusses some of the frontier areas like high-resolution depth-distribution analysis of trace elements, quantitative depth distribution analysis of ultra thin-layer systems, quantitative trace element analysis in monolayers, 3-dimensional stereometric analysis, molecular analysis, in-situ atomic resolution analysis of surfaces (chemical nanoscopy). Methodological approaches are discussed as well as results obtained mainly with solid state mass spectrometry and atomic force microscopy.Abbreviations and acronyms AES
Auger Electron Spectrometry
- AEM
Analytical Electron Microscopy
- AFM
Atomic Force Microscopy
- BSE
Back Scattered Electrons
- EPMA
Electron Probe Micro Analysis
- LRI-SNMS
Laser Resonance Ionization Sputtered Neutrals Mass Spectrometry
- SE
Secondary Electrons
- SEM
Scanning Electron Microscopy
- SIMS
Secondary Ion Mass Spectrometry
- STM
Scanning Tunneling Microscopy
- TEM
Transmission Electron Microscopy
- TOF-MS
Time-of-Flight Mass Spectrometer
- TXRF
Total Reflection X-Ray Spectrometry
- XPS
X-Ray Photoelectron Spectroscopy
Dedicated to Professor Dr. Wilhelm Fresenius on the occasion of his 80th birthday 相似文献
79.
K. Hutter Rolf Jeltsch 《Zeitschrift für Angewandte Mathematik und Physik (ZAMP)》1992,43(6):1085-1086
80.