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21.
The velocity field in breaking water waves is considered in this paper. A numerical simulation describes in detail the transition from a primary overturning and consequent rebounding jets into a bore front, where the vorticity in the coherent large‐scale eddy structures devolves into turbulence. Spatial changes in the frequency spectra of the kinetic energy and the enstrophy are associated with the production, transport and dissipation of the Reynolds stress and the various wave and turbulent mixing length scales. Mean velocity fields and the wave and kinetic energy in a surf zone are evaluated. Fourier and wavelet spectral analysis is applied to study both the surface elevation and energy changes, and the distinction that must be made between spilling and plunging breakers is clarified in this paper. Copyright © 2002 John Wiley & Sons, Ltd. 相似文献
22.
Velocity and metastable state population distributions of neodymium atoms produced by laser ablation
H. Wang H. Ohba M. Saeki M. Miyabe T. Shibata H. Miyatake H. Iimura 《Applied physics. B, Lasers and optics》2005,81(8):1127-1133
Laser-induced fluorescence spectroscopy has been employed to characterize the plume produced in nanosecond laser ablation
of metallic neodymium. The kinetic-energy distributions of the neutral and ionized atoms in the plume under both vacuum and
gas environments have been investigated. The population distribution of metastable levels in the ablated atoms was also derived.
The results show that some metastable states are more heavily populated than predicted by a Boltzmann-type distribution. These
investigations provide preliminary data for the design of a new type of resonance photo-ionization laser ion source as well
as for high-resolution laser spectroscopy of refractory elements.
PACS 52.38.Mf; 33.50.Dq; 42.62.Fi 相似文献
23.
24.
S. Saeki J. C. Holste D. C. Bonner 《Journal of Polymer Science.Polymer Physics》1983,21(10):2049-2056
The segment fraction Ψ1 activity coefficients, a1/Ψ1, of solvents have been determined by the piezoelectric sorption method for 0.1 ≤ Ψ1 ≤ 0.5 in binary solutions of chlorinated methanes [carbon tetrachloride (CCl4), chloroform (CHCl3), and dichloromethane (CH2Cl2)] with aromatic hydrocarbons (benzene and toluene) in poly(methyl methacrylate), poly(methyl acrylate), poly(ethyl methacrylate), and poly(n-butyl acrylate) at 23.5°C. The present results for toluene in PMMA agree with previously published values obtained by gas-liquid chromatography. For CCl4 and the aromatic hydrocarbons, the polymer–solvent interaction parameter χ is positive and constant, while for the polar solvents (CHCl3 and CH2Cl2), χ is negative and increases with increasing Ψ1. The effect of the polymer side chains on vapor sorption in nonpolar and polar solvent systems is discussed in terms of the χ parameter. 相似文献
25.
Summary In order to investigate physical properties of semicrystalline high polymer, such as collagen or gelatin, over a wide temperature
range, the phase change which might occur in this range is first of all required to elucidate. For this purpose, experiments
seeking for the temperature dependence of linear thermal expansion, retractive stress, complex dynamic elasticity moduli,
and equilibrium stress, the time rate of change of stress at constant temperatures, differential thermal analysis, and wide-angle
X-ray diffraction analysis were performed on dried steer Achilles tendon fiber and gelatin film.
The following conclusions were obtained. Tendon fiber consists of three regions of different structure: amorphous region having
a second order phase transition point at 120 °C, less oriented unstable crystalline region having widely distributed melting
temperatures over the range between 80–100° and 180 °C, and stable crystalline region having sharply distributed melting temperatures
around 200 °C. Gelatin also consists of the same three regions, and the stable crystalline region is stabilized further by
the higher degree of cross-linking having bonds of ionic nature and possesses its melting temperatures around 220 °C.
With 13 figures in 18 details and 1 table
Dedicated to Prof. Dr. R. Hilsch for his 60th birthday. 相似文献
Zusammenfassung Um physikalische Eigenschaften teilkristalliner Hochpolymerer wie Kollagen oder Gelatine zu untersuchen, wurde über einen weiten Temperaturbereich der Phasenwechsel, der in diesem Bereich eintritt, untersucht. Zu diesem Zweck wurde die Temperatur abh?ngigkeit der linearen thermischen Ausdehnung, die Zugkraft, der komplexe Elastizit?tsmodul, der Gleichgewichtszug, die Geschwindigkeit der ?nderung des Zugs bei konstanter Temperatur, ‘differential-thermoanalytische Daten und Weitwinkel-R?ntgenstreuung an getrockneter Stier-Achilles-Sehne und Gelatinefilm durchgeführt. Es ergaben sich folgende Schlüsse: Fasern der Sehnen bestehen aus drei Bereichen verschiedener Struktur: amorphen Bereichen, die einen Phasenübergang zweiter Ordnung bei 120 °C zeigen, weniger orientierten instabilen kristallinen Bereichen mit weit verteilten Schmelztemperaturen im Bereich zwischen 80–100 und 180 °C und stabilen kristallinen Bereichen mit scharf verteilten Schmelztemperaturen um 200° herum. Auch Gelatine besteht aus denselben drei Anteilen, und die stabilen kristallinen Bezirke sind au?erdem durch einen h?heren Grad von Vernetzung mit Bindungen ionischer Natur stabilisiert und besitzen Schmelztemperaturen um 220 °C.
With 13 figures in 18 details and 1 table
Dedicated to Prof. Dr. R. Hilsch for his 60th birthday. 相似文献
26.
Masakatsu Saeki Masami Nakada Nobuyuki M. Masaki Zenko Yoshida Kazutoyo Endo Yoshitaka Minai Toshiyuki Yamashita Hiroshi Mutoh Masaaki Magara 《Hyperfine Interactions》1994,92(1):1177-1181
Experiments on the57Fe Mössbauer effect in frozen solutions were carried out in order to demonstrate the capabilities of a cryostat which was developed for the emission Mössbauer spectroscopy of237Np. We confirmed the existence of an aliovalent state of57Fe in the temperature range from 5.5 to 35 K. However, the relative amounts of Fe(II) and Fe(III) in the frozen matrix were almost constant for the temperature range from 5.5 to 150 K. The design, operation and capabilities of the cryostat are also described. 相似文献
27.
Hiroshi Nozaki Masanobu Saeki Mitsuko Onoda Yoshito Onoda 《Journal of solid state chemistry》1983,46(1):132-137
The phase relations of the ternary system V1?xTixS1.57 are presented on the basis of X-ray diffractometry. The site distribution of Ti and V atoms in the structure is clarified through an NMR absorption study at room temperature. The phase relations and the site distribution of Ti and V, which appear to be closely related to each other, are discussed in terms of the metal-metal interaction of the face-shared octahedra in the metal-deficient distorted NiAs structure. 相似文献
28.
29.
Vapor sorption isotherms in binary solutions of polyisobutylene (PIB), (Mη = 4.7 × 106 g/mol) in hydrocarbons (cyclopentane; cyclohexane; n-heptane; 2,2-dimethyl butane; and 2,2,4-trimethyl pentane) and chlorinated methanes [carbon tetrachloride (CCI4) and chloroform (CHCI3)] have been determined at 23.5°C using the piezoelectric sorption method. The polymer-solvent interaction parameter χ obtained agrees with previously published values determined by using gas-liquid chromatography and a quartz-helix vapor sorption apparatus. The Flory theory of corresponding-states has been applied to the experimental results through the χ parameter and affords a good prediction of the concentration dependence of χ for solutions of chloroform, carbon tetrachloride, n-heptane, and 2,2-dimethyl butane in PIB. The experimental values of \documentclass{article}\pagestyle{empty}\begin{document}$ [\partial (a_1 /\psi _1 )/\partial a_1 ]_{T,P} $\end{document} for the PIB solutions are constant over the measured concentration range, for example \documentclass{article}\pagestyle{empty}\begin{document}$ [\partial (a_1 /\psi _1 )/\partial a_1 ]_{T,P} $\end{document} = ?4.1 for CCI4, ?3.65 for CHCI3, ?3.0 for 2,2-dimethyl butane and n-heptane, ?2.7 for 2,2,4-trimethyl pentane, ?2.7 for cyclohexane, and ?1.7 for cyclopentane, where a1 is the solvent activity and ψ1 is the solvent segment fraction. The correlations between the values of \documentclass{article}\pagestyle{empty}\begin{document}$ [\partial (a_1 /\psi _1 )/\partial a_1 ]_{T,P} $\end{document} and the theories of Guggenheim, Miller, Huggins, and Flory are discussed. 相似文献
30.
Mizuhiko Saeki 《Physica A》2010,389(18):3720-1903
The non-equilibrium thermo-field dynamics proposed by Arimitsu and Umezawa are generalized to the case of a non-bilinear unperturbed Hamiltonian which includes not only a bilinear part but also a non-bilinear part with momentum mixing. The forms of the quasi-particle operators for a semi-free boson field are derived. The form of the two-point Green’s function for the semi-free boson field is evaluated. A form of the admittance for a boson system interacting with its heat reservoir, which includes effects of the initial correlation and memory, is derived using the TCLE method formulated in terms of generalized non-equilibrium thermo-field dynamics. The expressions of the zeroth-order, first-order and second-order parts of the admittance in powers of the boson-boson interaction, are derived. 相似文献