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排序方式: 共有210条查询结果,搜索用时 31 毫秒
81.
82.
Ambika Prasad JenaMoshiour Rahaman Abhijit Mookerjee 《Physica B: Condensed Matter》2011,406(20):3810-3815
In this communication we propose a method for the study of disorder-order transitions in FexAl1−x binary alloys. We turn to our earlier development [1] of a combination of the recursion method introduced by Haydock et al. [2] and our augmented space approach [3] with the orbital peeling technique proposed by Burke [4] to determine the small energy differences required in obtaining the pair energies which go as input to the generalized perturbation technique [5] of studying disorder-order transitions. 相似文献
83.
84.
Numerical Algorithms - In this article, we introduce a new type of split monotone Yosida inclusion problem in the setting of infinite-dimensional Hilbert spaces. To calculate the approximate... 相似文献
85.
Rupali Gangopadhyay Mijanur Rahaman Molla 《Journal of Polymer Science.Polymer Physics》2011,49(11):792-800
Chemical polymerization of pyrrole within aqueous polyvinyl alcohol (PVA) solution gives rise to a nanodispersion with unique stability and monodispersity. The nanodispersion has shown uniform distribution of perfectly spherical ~110 nm polypyrrole particles (from transmission electron microscopy and dynamic light scattering) with high doping level (from UV‐Vis analysis) and sufficient electrical conductivity (10?3 S/cm). The dispersion with optimum stability and conductivity was subjected to viscoelastic studies. The viscosity of the system was adjusted by dilution with water and shear thinning (under steady shear) was generally observed. Dynamic mechanical studies have shown that the dispersion behaves like a semidiluted polymeric solution that roughly follows the Zimm model of viscoelasticity. This behavior accounts for its unique stability and miscibility with water at any proportion without precipitation. On drying or leaving the sample for 7 days, Fe3+ induced partial crosslinking of PVA chains takes place via –OH groups, although complete gelling does not occur. The dispersion forms flexible and uniform films on glass and metal surfaces that does not dissolve after complete drying; this observation combined with shear thinning encourages its application as ink or paint. © 2011 Wiley Periodicals, Inc. J Polym Sci Part B: Polym Phys, 2011 相似文献
86.
Ramij Rahaman 《Physics letters. A》2011,375(24):2291-2295
In this Letter we analyze the (im)possibility of the exact cloning of orthogonal three-qubit CAT states under local operation and classical communication (LOCC) with the help of a restricted entangled state. We also classify the three-qubit CAT states that can (not) be cloned under LOCC restrictions and extend the results to the n-qubit case. 相似文献
87.
Quantum mechanical estimation of Abraham hydrogen bond parameters using 1:1 donor–acceptor complexes
Obaidur Rahaman Douglas J. Doren Dominic M. Di Toro 《Journal of Physical Organic Chemistry》2014,27(10):783-793
Hydrogen bond donor strength () and acceptor strength () have been successfully used in models of many environmental and chemical systems, and a number of computational methods have been developed to predict them. In this work, a quantum chemical Møller–Plesset perturbation (MP2) method is applied to estimate the binding free energies (ΔGhbond) of several 1:1 hydrogen‐bonded complexes. A correlation between the binding free energies and hydrogen bond strength is established. This relationship can be used to develop an accurate computational model for predicting and using binding free energies. The accuracy of the method in predicting Abraham (root mean squared deviation (RMSD) = 0.0693) and (RMSD = 0.0677) are comparable to the empirical, fragment‐based ABSOLV method (RMSD = 0.1144 and 0.1281 for and , respectively). The binding free energy has been decomposed into its thermodynamic components, and it is demonstrated that the linear relationships in the dataset and the existence of magic point can be attributed to a constant entropy of reaction. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
88.
Nd3+-doped precursor glass in the K2O–SiO2–Y2O3–Al2O3 (KSYA) system was prepared by the melt-quench technique. The transparent Y3Al5O12 (YAG) glass–ceramics were derived from this glass by a controlled crystallization process at 750 °C for 5–100 h. The formation of YAG crystal phase, size and morphology with progress of heat-treatment was examined by X-ray diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM) and Fourier transformed infrared reflectance spectroscopy (FT-IRRS). The crystallite sizes obtained from XRD are found to increase with heat-treatment time and vary in the range 25–40 nm. The measured photoluminescence spectra have exhibited emission transitions of 4F3/2 → 4IJ (J = 9/2, 11/2 and 13/2) from Nd3+ ions upon excitation at 829 nm. It is observed that the photoluminescence intensity and excited state lifetime of Nd3+ ions decrease with increase in heat-treatment time. The present study indicates that the incorporation of Nd3+ ions into YAG crystal lattice enhance the fluorescence performance of the glass–ceramic nanocomposites. 相似文献
89.
A practical synthesis of spiro-naphthyridinone derivatives is described by the combination of the Claisen rearrangement and ring-closing metathesis/ring-closing enyne metathesis process. The RCM or RCEM proceeded smoothly in the presence of Grubbs' first generation catalyst at room temperature under a nitrogen atmosphere. 相似文献
90.
Mubasher Jamil Peter K. F. Kuhfittig Farook Rahaman Sk. A. Rakib 《The European Physical Journal C - Particles and Fields》2010,67(3-4):513-520
It is generally agreed that the acceleration of the Universe can best be explained by the presence of dark or phantom energy. The equation of state of the latter shows that the null energy condition is violated. Such a violation is the primary ingredient for sustaining traversable wormholes. This paper discusses wormholes supported by a more general form called polytropic phantom energy. Its equation of state results in significant generalizations of the phantom-energy and, in some cases, the generalized Chaplygin-gas wormhole models, both of which continue to receive considerable attention from researchers. Several specific solutions are explored, namely, a constant redshift function, a particular choice of the shape function, and an isotropic-pressure model with various shape functions. Some of the wormhole spacetimes are asymptotically flat, but most are not. 相似文献