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101.
Thermodynamics of rate-independent plasticity 总被引:1,自引:0,他引:1
G. Puglisi 《Journal of the mechanics and physics of solids》2005,53(3):655-679
102.
Rendiconti del Circolo Matematico di Palermo Series 1 - 相似文献
103.
XPS has been utilized to study the compositional changes which occur in glass after electron beam irradiation. In the bombarded surfaces a reduction in Na and O signals is observed, while Ca signal shows negligible variations. Two O1s signals, assigned to bridging and non-bridging oxygen were found. Irradiation causes a decrease of these two types of oxygen. This is at variance with Lineweaver's mechanism which accounts for the decrease of the non-bridging oxygens only. After irradiation a second component in the Si2p line is found. It has been attributed to the formation of SiSi bonds induced by oxygen outgassing. The formation of these bonds leads to a more compact structure and this might explain the observed density change in irradiated glass. 相似文献
104.
Summary Nanocapsule preparative procedures are able to change the availability of drugs from delivery devices. In particular, the
influence of the organic solvent, used in the interfacial polymerisation process, on the shape, mean particle size, size distribution
and type of colloidal suspension was investigated. The organic solvents employed in the preparation of PECA nanocapsules were
ethanol, acetone or acetonitrile. A non-ionic surfactant (Pluronic F68) was used during the preparation process. The amount
of monomer represented another variable, capable of influencing the final carrier properties of PECA nanocapsules. The presence
of ethanol achieved the formation of both nanoparticles and nanocapsules. However, the presence of acetone or acetonitrile
achieved not only a highly homogeneous size colloidal system, but also the formation of only one type of PECA nanosphere (nanocapsule).
The different amount of monomer led to the formation of nanocapsules with a wall thickness proportional to the initial concentration
of the polymerising agent.
Paper presented at the I International Conference on Scaling Concepts and Complex Fluids, Copanello, Italy, July 4–8, 1994. 相似文献
105.
Given a string x = x[1..n] on an alphabet of size α, and a threshold p
min
≥ 1, we describe four variants of an algorithm PSY1 that, using a suffix array, computes all the complete nonextendible repeats
in x of length p ≥ p
min
. The basic algorithm PSY1–1 and its simple extension PSY1–2 are fast on strings that occur in biological, natural language
and other applications (not highly periodic strings), while PSY1–3 guarantees Θ(n) worst-case execution time. The final variant, PSY1–4, also achieves Θ(n) processing time and, over the complete range of strings tested, is the fastest of the four. The space requirement of all
four algorithms is about 5n bytes, but all make use of the “longest common prefix” (LCP) array, whose construction requires about 6n bytes. The four algorithms are faster in applications and use less space than a recently-proposed algorithm (Narisawa in
Proceedings of 18th Annual Symposium on Combinatorial Pattern Matching, pp. 340–351, 2007) that produces equivalent output.
The suffix array is not explicitly used by algorithms PSY1, but may be required for postprocessing; in this case, storage
requirements rise to 9n bytes. We also describe two variants of a fast Θ(n)-time algorithm PSY2 for computing all complete supernonextendible repeats in x. 相似文献
106.
Rendiconti del Circolo Matematico di Palermo Series 1 - 相似文献
107.
Rizzarelli P Puglisi C Montaudo G 《Rapid communications in mass spectrometry : RCM》2006,20(11):1683-1694
Matrix-assisted laser desorption/ionization time-of-flight/time-of-flight tandem mass spectrometry (MALDI-TOF/TOF-MS/MS) was employed to analyze four poly(butylene adipate) (PBAd) oligomers and to investigate their fragmentation pathways as a continuation of our work on the MALDI-TOF/TOF-MS/MS study of synthetic polymers. MALDI-TOF/TOF-MS/MS analysis was performed on oligomers terminated by carboxyl and hydroxyl groups, methyl adipate and hydroxyl groups, dihydroxyl groups, and dicarboxyl groups. The sodium adducts of these oligomers were selected as precursor ions. Different end groups do not influence the fragmentation of sodiated polyester oligomers and similar series of product ions were observed in all the MALDI-TOF/TOF-MS/MS spectra. According to the structures of the most abundant product ions identified in the present work, three fragmentation pathways have been proposed to occur most frequently in PBAd: beta-hydrogen-transfer rearrangement, leading to the selective cleavage of the --O--CH(2)-- bonds; --CH(2)--CH(2)-- (beta--beta) bond cleavage in the adipate moiety; and ester bond scission. 相似文献
108.
We report what is to our knowledge the first laboratory experiment that shows the use of a pyramid wavefront sensor to cophase and align segmented mirrors having three degrees of freedom per segment, i.e., piston, tip, and tilt. In the laboratory the iterative alignment procedure reached a wavefront residual error of about 10 nm. The residual error was equally distributed between piston, tip, and tilt. These results demonstrate that the pyramid can successfully simultaneously sense the piston, tip, and tilt of a segmented mirror. This last feature makes this technique very attractive in phasing and aligning astronomical segmented telescopes such as extremely large telescopes currently under extensive studies. 相似文献
109.
The nonequilibrium fluctuations of power flux in a fluidized granular media have been recently measured in an experiment [Phys. Rev. Lett. 92, 164301 (2004)], which was announced to be a verification of the fluctuation relation (FR) by Gallavotti and Cohen. An effective temperature was also identified and proposed to be a useful probe for such nonequilibrium systems. We explain these results in terms of a two-temperature Poisson process. Within this model, supported by independent molecular dynamics simulations, power flux fluctuations do not satisfy the FR and the nature of the effective temperature is clarified. In the pursuit of a hypothetical global quantity fulfilling the FR, this points to the need of considering candidates other than the power flux. 相似文献
110.
G.?FaraciEmail author S.?Gibilisco P.?Russo A. R.?Pennisi G.?Compagnini S.?Battiato R.?Puglisi S.?La Rosa 《The European Physical Journal B - Condensed Matter and Complex Systems》2005,46(4):457-461
Using a pulsed microplasma source, clusters were produced through the ablation
of a Si cathode and successive supersonic expansion.
The Si cluster beam was deposited onto different substrates and the partial oxidation of the cluster
surface avoided the growth of large agglomerates, preserving their nanocrystalline morphology.
Micro-Raman spectroscopy was used for an accurate size diagnosis of the deposited nanoparticles. The size of the Si dots ranges between 2 and about 15 nm. The Si dots appear to have a Si oxide shell, as confirmed also by structural and compositional analysis through transmission electron microscopy and atomic force microscopy. Double Raman peaks were attributed to small Si agglomerates having a thin substoichiometric Si-O interface. 相似文献