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941.
Simona Quartieri Gabriele Montagna Giovanna Vezzalini 《Journal of solid state chemistry》2011,184(6):1505-1516
The elastic behavior of H-ZSM-5 was investigated by in-situ synchrotron X-ray powder diffraction, using both silicone oil (s.o.) and (16:3:1) methanol:ethanol:water (m.e.w.) as “non-penetrating” and “penetrating” pressure transmitting media, respectively. From Pamb to 6.2 GPa the volume reduction observed in s.o. is 16.6%. This testifies that H-ZSM-5 is one of the most flexible microporous materials up to now compressed in s.o. Volume reduction observed in m.e.w. up to 7.6 GPa is 14.6%. A strong increase in the total electron number of the extraframework system, due to the penetration of water/alcohol molecules in the pores, is observed in m.e.w. This effect is the largest up to now observed in zeolites undergoing this phenomenon without cell volume expansion. The higher compressibility in s.o. than in m.e.w. can be ascribed to the penetration of the extra-water/alcohol molecules, which stiffen the structure and contrast the channel deformations. 相似文献
942.
Donor–acceptor conjugated copolymers incorporating tetrafluorobenzene as the π‐electron deficient unit 下载免费PDF全文
Andrea Nitti Federico Debattista Luigi Abbondanza Gabriele Bianchi Riccardo Po Dario Pasini 《Journal of polymer science. Part A, Polymer chemistry》2017,55(9):1601-1610
We present the synthesis and characterization of a new family of perfectly alternating conjugated polymers, obtained through different methodologies (Stille, Direct Arylation, and Horner–Wadsworth–Emmons polymerizations). The polymers comprise either 2,5‐dialkoxybenzene or benzodithiophene electron rich units, and 1,2,4,5‐tetrafluorobenzene as the electron‐deficient unit, eventually separated by a vinylene bridge, if suitable monomers and HWE polymerization procedures are used. As shown by NMR spectroscopy, the introduction of the fluorinated aromatic units brings complications in the polymer stereodefinition in the HWE polymerization, and regiodefinition in the case of the Direct Arylation. The polymers show moderate degrees of polymerization (up to 10 repeating alternating units in the backbone), which are however significant enough to unravel interesting properties such as energy HOMO–LUMO gaps and aggregation behavior in solution at room temperature. In depth calculations fully confirmed the aggregation tendency, highlighting the key role of the benzodithiophene as the donor component when in combination with the tetrafluorobenzene unit. © 2017 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2017 , 55, 1601–1610 相似文献
943.
Design and fabrication of a shielded interdigital sensor for noninvasive In situ real‐time production monitoring of polymers 下载免费PDF全文
Yang Yang Gabriele Chiesura Thomas Vervust Joris Degrieck Jan Vanfleteren 《Journal of Polymer Science.Polymer Physics》2016,54(20):2028-2037
Interdigital sensors (IDS) have received great attention for production monitoring of polymers over the past decade. However, conventional IDS are limited by high noise to environment due to the dual side access of the sensor, low nominal capacitance, and sensitivity. In this study, a shielded IDS fabricated by flexible circuit board (FCB) technology is presented to overcome these challenges. Compared to conventional sensors, the environmental dependence of the new sensor is minimized by the copper shield. Furthermore, nominal capacitance of at least 350% higher, and an increase of sensitivity per unit area are achieved. To demonstrate the capabilities of the new IDS, a FCB comprising the proposed sensor is fabricated, attached to a mould, and successfully applied for in situ real‐time production monitoring of an epoxy resin. The resulting flexible sensor is noninvasive towards the fabricated parts, and measures the key stages along the production process. © 2016 Wiley Periodicals, Inc. J. Polym. Sci., Part B: Polym. Phys. 2016 , 54, 2028–2037 相似文献
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Jørgen M. Mollerup Martin P. BreilChristina Vogelpohl Gabriele Sadowski 《Fluid Phase Equilibria》2011,301(2):163-170
The chromatographic retention in hydrophobic and reversed phase chromatography and the solubility of proteins display some common features. The chromatographic retention, as well as the solubility, is modulated by the thermodynamic properties of the solute in the fluid phase. The retention measurements at linear conditions provide information of the solution properties of the protein at infinite dilution, and the solubility measurements produce the supplementary information about the solution properties at the saturation limit. This provides a useful approach to simultaneous correlation of the chromatographic retention and the solubility.The experimental data, used for the correlation, comprise retention measurements of lysozyme on different HIC adsorbents using an aqueous ammonium sulphate eluant, an aqueous ammonium sulphate eluant with an admixture of ethanol, as well as published solubility data.The chromatographic retention data and the corresponding solubility data have been correlated using a chemical potential model derived from Kirkwood's theory of solutions of charged macro-ions and zwitterions in electrolyte solutions. The model correlated the chromatographic retention factor and the solubility data within the precision of the measurements. The model was applied in a pH range from 4 to 11. It was demonstrated experimentally, as well as theoretically, that an admixture of ethanol to the aqueous eluant changes the thermodynamic retention factor on various adsorbents identically when compared to the thermodynamic retention factor in an ethanol free eluant. 相似文献
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Dr. Merle Arrowsmith Prof. Michael S. Hill Dr. Andrew L. Johnson Dr. Gabriele Kociok‐Köhn Dr. Mary F. Mahon 《Angewandte Chemie (International ed. in English)》2015,54(27):7882-7885
Sequential reactions between a 2,6‐diisopropylphenyl‐substituted β‐diketiminato magnesium n‐butyl derivative and P4 allow the highly discriminating synthesis of unusual [nBu2P4]2? and [nBu2P8]2? cluster dianions. 相似文献
950.
Gabriele Ciaramella 《Numerical Functional Analysis & Optimization》2016,37(8):938-965
In this article, the investigation of a class of quantum optimal control problems with L1 sparsity cost functionals is presented. The focus is on quantum systems modeled by Schrödinger-type equations with a bilinear control structure as it appears in many applications in nuclear magnetic resonance spectroscopy, quantum imaging, quantum computing, and in chemical and photochemical processes. In these problems, the choice of L1 control spaces promotes sparse optimal control functions that are conveniently produced by laboratory pulse shapers. The characterization of L1 quantum optimal controls and an efficient numerical semi-smooth Newton solution procedure are discussed. 相似文献