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151.
Dynameric solid films may be generated via the adequate imine-bond connection between bis(pyridine-2,6-diimine) core centres, coordinated with different metal cations and diaminoPEG connectors. The adequate selection of metal cations leads to cross-linked metallo-dynameric films, allowing the fine modulation of their colour and mechanical property. The coordination of the metal cations and bis(pyridine-2,6-diimine), results in the formation of interlocked structures, leading to the most probably formation of interweaved structures with better mechanical properties than those formed in the absence of the metallic cations. Removal and addition of metal cations from solid films can be achieved via tris(2-aminoethyl)amine (TREN) complexing agent, which strongly binds the metal cations, followed by subsequent insertion of other metallic cations. It allows a ligand-modulated dynamic release of the metal cations from the solid films, together with colour transfer and change of mechanical strength at the interfaces between various solid films. 相似文献
152.
Fundamental physical considerations indicate that the scaling of devices that use electron charge as the information carrier
will limit within the next one to two decades. The Nanoelectronics Research Initiative (NRI), a joint industry-government
program, has been developed to fund university research seeking devices that utilize alternative physical information carriers
or non-equilibrium switching mechanisms to continue the historical cost and performance trends of information technology.
Three research centers have been established to pursue five research vectors that have been identified as critical to the
effort to replace the electronic switch. A brief history and rationale for NRI is given and the projects currently underway
are described in the context of the five research vectors. 相似文献
153.
Th. I. Pirtea und G. Mihail 《Fresenius' Journal of Analytical Chemistry》1958,159(3):205-208
Zusammenfassung Es wird eine neue mikrogewichtsanalytische Bestimmungsmethode für Beryllium beschrieben, bei der das Beryllium in Form der komplexen Verbindung [Co(NH3)6][(H2O)2 Be2(CO3)2(OH)3]. 3H2O gewogen wird.Das vorgeschlagene Verfahren ist einfach und in der kurzen Zeit von 30–90 min leicht durchführbar.Das Verfahren ist auch zur Bestimmung von Beryllium in Gegenwart von Eisen, Aluminium und Magnesium geeignet, wenn man die Begleitmetalle mittels ÄDTA (Natriumsalz der Äthylendiamintetraessigsäure) maskiert. 相似文献
154.
155.
Mihail Megan Bogdan Sasu Adina Luminia Sasu 《Integral Equations and Operator Theory》2002,44(1):71-78
The problem of nonuniform exponential dichotomy of evolution operators in Banach spaces is considered. Connections between this concept and admissibility of the pair (C
0,C
0) are established. Generalizations to the nonuniform case of some results of Van Min, Räbiger and Schnaubelt ([MRS]) are obtained. It is shown that an implication from the uniform case is not true for nonuniform exponential dichotomy. The results are applicable for general time-varying linear equations with unbounded coefficients in Banach spaces. 相似文献
156.
Jan Pelant Mihail G. Tkachenko Vladimir V. Tkachuk Richard G. Wilson 《Proceedings of the American Mathematical Society》2003,131(10):3257-3265
We prove in ZFC that there exists a Tychonoff pseudocompact scattered AP-space of uncountable tightness. We give some sufficient and necessary conditions for a -space to be AP as well as a characterization of AP-property in linearly ordered topological spaces.
157.
Mihail N. Kolountzakis Szilá rd Gy. Ré vé sz 《Proceedings of the American Mathematical Society》2003,131(11):3423-3430
We study the following question posed by Turán. Suppose is a convex body in Euclidean space which is symmetric in and with value at the origin; which one has the largest integral? It is probably the case that the extremal function is the indicator of the half-body convolved with itself and properly scaled, but this has been proved only for a small class of domains so far. We add to this class of known Turán domains the class of all spectral convex domains. These are all convex domains which have an orthogonal basis of exponentials , . As a corollary we obtain that all convex domains which tile space by translation are Turán domains.
We also give a new proof that the Euclidean ball is a Turán domain.
158.
The migration of two-dimensional Pb clusters on Cu(1 1 1) surface is studied in the framework of three-dimensional (3D) continuum space tight binding (TB) computational model. Monte Carlo simulations based on many-body TB interactions reveal significant influence of cluster-substrate misfit on diffusion behavior of two-dimensional (2D) clusters. The analysis of pair distribution function (PDF) demonstrates that cluster lattice constant depends on the number of atoms N for 1 < N < 10. The observed effect is more pronounced for heteroepitaxial than homoepitaxial systems. It can be explained in the framework of model accounting for enhanced charge transfer in heteroepitaxy and strong influence of surface potential on cluster atomic arrangement. The variation of lattice constant leads to variable misfit which affects the island migration behavior. The results are discussed in a physical model that implies cluster diffusion with size dependent cluster-substrate misfit. 相似文献
159.
Anhydrous Amorphous Calcium Oxalate Nanoparticles from Ionic Liquids: Stable Crystallization Intermediates in the Formation of Whewellite
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Aaron Gehl Dr. Michael Dietzsch Dr. Mihail Mondeshki Sven Bach Dr. Tobias Häger Dr. Martin Panthöfer Dr. Bastian Barton Dr. Ute Kolb Prof. Dr. Wolfgang Tremel 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(50):18192-18201
The mechanisms by which amorphous intermediates transform into crystalline materials are not well understood. To test the viability and the limits of the classical crystallization, new model systems for crystallization are needed. With a view to elucidating the formation of an amorphous precursor and its subsequent crystallization, the crystallization of calcium oxalate, a biomineral widely occurring in plants, is investigated. Amorphous calcium oxalate (ACO) precipitated from an aqueous solution is described as a hydrated metastable phase, as often observed during low‐temperature inorganic synthesis and biomineralization. In the presence of water, ACO rapidly transforms into hydrated whewellite (monohydrate, CaC2O4 ? H2O, COM). The problem of fast crystallization kinetics is circumvented by synthesizing anhydrous ACO from a pure ionic liquid (IL‐ACO) for the first time. IL‐ACO is stable in the absence of water at ambient temperature. It is obtained as well‐defined, non‐agglomerated particles with diameters of 15–20 nm. When exposed to water, it crystallizes to give (hydrated) COM through a dissolution/recrystallization mechanism. 相似文献
160.
gota Simon Tatiana Tozar Adriana Smarandache Mihai Boni Alexandru Stoicu Alan Dowson Jack J. W. A. van Loon Mihail Lucian Pascu 《Molecules (Basel, Switzerland)》2022,27(5)
Pharmaceuticals carried into space are subjected to different gravitational conditions. Hypergravity is encountered in the first stage, during spacecraft launching. The stability of medicines represents a critical element of space missions, especially long-duration ones. Therefore, stability studies should be envisaged before the implementation of drugs for future deep space travel, where the available pharmaceuticals would be limited and restocking from Earth would be impossible. Multipurpose drugs should be proposed for this reason, such as phenothiazine derivatives that can be transformed by optical methods into antimicrobial agents. Within this preliminary study, promethazine and thioridazine aqueous solutions were exposed to UV laser radiation that modified their structures and generated a mixture of photoproducts efficient against particular bacteria. Subsequently, they were subjected to 20 g in the European Space Agency’s Large Diameter Centrifuge. The aim was to evaluate the impact of hypergravity on the physico-chemical and spectral properties of unirradiated and laser-irradiated medicine solutions through pH assay, UV-Vis/FTIR absorption spectroscopy, and thin-layer chromatography. The results revealed no substantial alterations in centrifuged samples when compared to uncentrifuged ones. Due to their stability after high-g episodes, laser-exposed phenothiazines could be considered for future space missions. 相似文献