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141.
Gericke M Doliška A Stana J Liebert T Heinze T Stana-Kleinschek K 《Macromolecular bioscience》2011,11(4):549-556
In the present study, blood-compatible PET surfaces were prepared by coating with anticoagulant cellulose sulfates that were synthesized homogeneously in ionic liquids. The adsorption behavior of polysaccharides on PET films was investigated using QCM-D. It was demonstrated that pre-coating with different amino-group-containing polysaccharides improves the affinity toward cellulose sulfate. Moreover, the effect of different degrees of sulfation on the adsorption process was evaluated. Based on these results, several layer-by-layer coated PET foils were prepared that showed significantly improved blood compatibility compared to the initial untreated material. 相似文献
142.
Tim Dinges Rolf-Dieter Hoffmann Leo van Wüllen Paul Henry Hellmut Eckert Rainer Pöttgen 《Journal of Solid State Electrochemistry》2011,15(2):237-243
The lithium-rich silicide Li4Pt3Si was synthesised from the elements by high-temperature synthesis in a sealed niobium ampoule. Its structure was refined
on the basis of single-crystal X-ray diffraction data: R32, a = 693.7(2), c = 1627.1(4) pm, wR2 = 0.0762, 525 F2 values and 21 variables. The striking structural motifs of the Li4Pt3Si structure are silicon atoms with a slightly distorted trigonal prismatic platinum coordination with short Si–Pt distances
(238–246 pm). Always two trigonal prisms are condensed via a common Pt3 triangle, and these double units built up a three-dimensional network by condensation via common corners. The channels left
by this prismatic network are filled by two crystallographically independent lithium sites in a 3:1 ratio. The single crystal
X-ray data were fully confirmed by neutron powder diffraction and 7Li magic-angle spinning (MAS)–nuclear magnetic resonance (NMR) results. The two distinct lithium sites are well differentiated
by their 7Li isotropic chemical shift and nuclear electric quadrupolar interaction parameters. MAS-NMR spectra reveal signal coalescence
effects above 300 K, indicating chemical exchange between the lithium sites on the millisecond timescale. The spectra can
be simulated with a simple two-site exchange model. From the resulting temperature-dependent correlation times, an activation
energy of 50 kJ/mol is extracted. 相似文献
143.
Tim J. Causon Markus Himmelsbach Wolfgang Buchberger Christian W. Klampfl 《Electrophoresis》2013,34(6):944-949
Polyimides (PIs) are a group of widely used synthetic materials that service a variety of different purposes including microelectronics, insulating films and aerospace applications. Depending on the requirements (defined by the particular final product), the actual composition of PIs may show substantial chemical variation. To study this variation in chemical structure, CE‐MS can be employed for the determination of PI composition following chemical degradation of the polymer sample. PI is chemically decomposed to corresponding aromatic diamine and carboxylic acid components using an alkali fusion reaction. Solid polymer samples are fused in a potassium hydroxide melt yielding reaction products that are diluted in acid and can be immediately analysed by CE coupled to a Q/TOF‐MS with quantification performed using conventional UV detection. This approach involves a simple and rapid sample preparation yielding both qualitative and quantitative information regarding the chemical composition of the polymer. Application of the CE‐MS approach is shown for a range of commercially available PI and poly(amide–imide) materials and the results are used to infer the respective chemical compositions. 相似文献
144.
Dendrimers are three dimensional nanosized synthetic molecules that have internal cavities and numerous surface groups. In recent times they have received increased attention in sensing applications. For dendrimers to be used as sensors, they most commonly require functionalization at their surface. This is because the surface is generally the first point of contact between the dendrimer and the outside world, hence surface functionalization serves to selectively home in on the target analyte. Further, sensor signals may be transmitted through surface functionalities e.g. fluorochromic molecules. It is therefore important to document surface functionalization approaches. Dendrimers with amine surface groups have the advantage of being able to be conjugated to other molecules via an amide linkage, which is one of the most fundamental and widespread chemical bonds in nature. In this paper we demonstrate the properties of dendrimers that make them so applicable to sensing. We review several methods for functionalizing dendrimers via an amide linkage, as well as present a review of surface functionalized polyamidoamine, polyamine, and polypeptide dendrimers that have been employed for biological, chemical and molecular sensing. 相似文献
145.
146.
Characterization of polymer materials by scattering techniques,with applications to block copolymers
Tim Lodge 《Mikrochimica acta》1994,116(1-3):1-31
The application of six techniques—static and dynamic light scattering, small-angle neutron and X-ray scattering, neutron and X-ray reflectivity—to the characterization of polymer materials is summarized. Emphasis is placed on the similarities and differences among the various techniques, and on recent advances in experimental practice. Twelve examples from the recent literature are described, most of which concern block copolymers. A brief introduction to block copolymer properties is also provided. 相似文献
147.
148.
Dr. Roland Frach Patrick Kibies Saraphina Böttcher Tim Pongratz Steven Strohfeldt Simon Kurrmann Dr. Joerg Koehler Martin Hofmann Prof. Dr. Werner Kremer Prof. Dr. Hans Robert Kalbitzer Prof. Dr. Oliver Reiser Prof. Dr. Dominik Horinek Prof. Dr. Stefan M. Kast 《Angewandte Chemie (International ed. in English)》2016,55(39):11713-11713
149.
The conformational preferences of ethanolamine and its hydrochloride in solution were estimated by comparing experimental NMR vicinal proton-proton coupling constants to semiemprical coupling constants for each staggered rotamer, derived by the Haasnoot-Altona method. Strong gauche preferences are observed for both ethanolamine and its hydrochloride over a wide range of solvent polarities. Concentration was not observed to significantly affect the position of the conformer equilibria. 相似文献
150.