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31.
C. Schmitt A. Guessous J.P. Bocquet H.-G. Clerc R. Brissot D. Engelhardt H.R. Faust F. Gönnenwein M. Mutterer H. Nifenecker J. Pannicke CH. Ristori J.P. Theobald 《Nuclear Physics A》1984,430(1):21-60
At the recoil spectrometer “Lohengrin” of the Institut Laue-Langevin in Grenoble, the yields of the light fission products from the thermal-neutron-induced fission of 239Pu were measured as a function of A, Z, the kinetic energy E and the ionic charge states q. The nuclear charge and mass distributions summed over all ionic charge states were determined for different light fissionproduct kinetic energies between 93 and 112 MeV. The proton odd-even effect which was measured to be (11.6 ± 0.6)% causes considerable fine structure in the yields. The average kinetic energy of even-Z elements in the light fission-product group is 0.3 ± 0.1 MeV larger than for odd-Z elements. The neutron odd-even effect is (6.5 ± 0.7)%. The comparison with previously published data 1) for thermal-neutron-induced fission of 235U reveals a correlation between the proton odd-even effect in the yield and in the kinetic energy of the elements. The dependence of the proton odd-even effect on the fragmentation is very similar for 235U and 239Pu when it is considered as a function of the nuclear charge of the heavy fission products. The isobaric variances σz2. for thermal-neutron fission of 235U and 239Pu coincide at all kinetic energies if the influence of the proton odd-even effect is averaged out. This supports the hypothesis that the magnitude of σz2 is determined only by quantum-mechanical zero-point fluctuations. The influence of the spherical shells Z = 50 and N = 82 on the fragmentation is discussed. 相似文献
32.
Inhaltsübersicht. Es ist gelungen, ein durch BeO stabilisiertes Bariumoxoiridat der Zusammensetzung BaIr0,67Be0,33O3 in der Kristallform eines kubischen Perowskits mit kleiner Elementarzelle erstmals darzustellen. Raumgruppe O1h–Pm3m, a = 4,1009 Å, Z = 1. Ir5+ und Be2 + besetzen die Oktaederposition des Perowskits statistisch. BaIr0,67Be0,33O3: A Stabilized Cubic Form of BaIrO3 For the first time it was possible to prepare a new barium-oxoiridate of the formula BaIr0,67Be0,33O3, stabilized by BeO. It crystallizes in a small cubic unit cell of the perovskite type. Space group O1h–Pm3m; a = 4.1009 Å; Z = 1. Ir5+ and Be2+ occupy the octahedra positions of the perovskite structure statistically. 相似文献
33.
The problem of determining the shape of an obstacle from far-field measurements is considered. It is well known that linear
sampling methods have been widely used for shape reconstructions obtained via the singular system of an ill conditioned discretized
far-field operator. For our reconstructions we assume that the far-field data are noisy and we employ a novel regularization
method that does not require determination of a regularization parameter. 相似文献
34.
Choi YO Ryu HJ Kim HR Song YS Kim C Lee W Choe H Leem CH Jang YJ 《Experimental & molecular medicine》2006,38(2):180-189
In adipocytes, insulin stimulates glucose transport primarily by promoting the translocation of GLUT4 to the plasma membrane. Requirements for Ca(2+)/calmodulin during insulin-stimulated GLUT4 translocation have been demonstrated; however, the mechanism of action of Ca(2+) in this process is unknown. Recently, myosin II, whose function in non-muscle cells is primarily regulated by phosphorylation of its regulatory light chain by the Ca(2+)/calmodulin-dependent myosin light chain kinase (MLCK), was implicated in insulin-stimulated GLUT4 translocation. The present studies in 3T3-F442A adipocytes demonstrate the novel finding that insulin significantly increases phosphorylation of the myosin II RLC in a Ca(2+)-dependent manner. In addition, ML-7, a selective inhibitor of MLCK, as well as inhibitors of myosin II, such as blebbistatin and 2,3-butanedione monoxime, block insulin-stimulated GLUT4 translocation and subsequent glucose transport. Our studies suggest that MLCK may be a regulatory target of Ca(2+)/calmodulin and may play an important role in insulin-stimulated glucose transport in adipocytes. 相似文献
35.
KM Clauwaert Van Bocxlaer JF HJ Major JA Claereboudt WE Lambert Van den Eeckhout EM Van Peteghem CH De Leenheer AP 《Rapid communications in mass spectrometry : RCM》1999,13(14):1540-1545
This paper describes the investigation of the potential of a quadrupole orthogonal acceleration time-of-flight mass spectrometer (Q-TOF) equipped with an atmospheric pressure ionisation interface for quantitative measurements of small molecules separated by reversed phase liquid chromatography. To this end, the detection limits and linear dynamic range in particular were studied in an LC/MS/MS experiment using 3,4-methylenedioxymethamphetamine standards and 3,4-methylenedioxyethylamphetamine for internal standardisation. In a second phase, the experiment was repeated with real biological extracts (whole blood, serum, and vitreous humour). A calibration for 3,4-methylenedioxymethamphetamine and its metabolite 3,4-methylenedioxyamphetamine was prepared in each of these matrices again using 3,4-methylenedioxyethylamphetamine as internal standard. The resulting quantitative data were compared with those obtained by liquid chromatography with fluorescence detection for the same extracts. The Q-TOF results revealed excellent sensitivity and a linear dynamic range of nearly four decades (2-10 000 pg on-column, r(2) = 0.9998, 1/x weighting). Furthermore, all the calibration curves prepared in biological material were superimposable, LC/MS/MS and LC-fluorescence, and the quantitative results for actual samples compared very favourably. It was concluded that the Q-TOF achieves a linear dynamic range for quantitative LC/MS/MS work exceeding that of fluorescence detection and at much better absolute sensitivity. Copyright 1999 John Wiley & Sons, Ltd. 相似文献
36.
P. A. Kumar Swathi Pisupati V. G. K. M. Pisipati CH. Srinivasu P. Narayana Murty 《Liquid crystals》2002,29(7):967-977
A systematic kinetic study leading to the crystallization process from the kinetophases (which occur prior to crystal phase) smectic B, crystal G and smectic F is performed on representative compounds of the homologous series p-phenylbenzylidene-p'-alkylanilines (PBnA) and p-n-alkoxybenzylidene-p'-alkylanilines (nO.m) these compounds are p-phenylbenzylidene-p'-nonylaniline (PB9A), p-phenylbenzylidene-p'-tetradecylaniline (PB14A), p-n-pentadecyloxybenzylidene p'-tetradecylaniline (15O.14) and p-n-octadecyloxybenzylidene-p'-nonylaniline (18O.9). The molecular mechanism and dimensionality in crystal growth from the kineto phases are computed from the Avrami equation, while the characteristic crystalline time (t*) at each crystallization temperature is deduced from the individual plots of log t vs. ΔH. The low magnitudes of the dimensionality parameter n infers the occurrence of diffusion-controlled transformations leading to the formation of plates or needles of finite size possessing impinged edges. The degree of variation in the value of n at each crystallization temperature also reveals the existence of an independent nucleation mechanism for any individual member of the series. The influence of the terminal alkyl chain lengths on the rate of crystallization is determined from a comparative study with the reported analogous compounds. 相似文献
37.
The magnetic moments of the 12+ isomers in 192, 196, 198, 200, 206Pb and of the isomer in 205Pb have been measured using the PAD technique. The results for the g-factors are: g(192) = ?0.173(2), g(196) = ?0.1600(15), g(198) = ?0.1552(15), g(200) = ?0.1512(15), g(206) = ?0.1496(18), and g(205) = ?0.148(5). As all states have a rather pure configuration, the values reflect directly the orbital. They show a decrease towards the more neutron-deficient isotopes attributed to the reduced core polarisation as a result of decreasing occupation of the neutron shell. The measured systematics are discussed regarding core polarisation, mesonic corrections, and small admixtures of core-excited states to the wave function. 相似文献
38.
We introduce two numerical schemes for solving a system of ordinary differential equations which characterizes several kinds of linear reactions and diffusion from biochemistry, physiology, etc. The methods consist of sequential applications of the simple exact solver for a reversible reaction. We provide absolute stability and convergence of the proposed explicit methods. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
39.
Min Su KimKwang Gug Yim Dong-Yul LeeJin Soo Kim Jong Su KimJeong-Sik Son Jae-Young Leem 《Applied Surface Science》2011,257(21):9019-9023
Sol-gel spin-coated ZnO thin films are cooled with different rates after the pre-heat treatment. Atomic force microscopy (AFM), X-ray diffraction (XRD), Raman, and photoluminescence (PL) were carried out to investigate the effects of the cooling rate during pre-heat treatment on structural and optical properties of the ZnO thin films. The ZnO thin films cooled slowly exhibit mountain chain structure while the ones cooled rapidly have smooth surface. The ZnO thin films cooled rapidly have higher c-axis orientation compared to the ones cooled slowly. The narrower and the higher near-band-edge emission (NBE) peaks are observed in the ZnO thin films cooled rapidly. 相似文献