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41.
Pei‐Cheng Hsu Yu‐Sheng Chen Yeukuang Hwu J. H. Je G. Margaritondo Eng Soon Tok 《Journal of synchrotron radiation》2015,22(6):1524-1527
X‐ray irradiation is shown to trigger the deposition of Cu from solution, at room temperature, on a wide variety of insulating substrates: glass, passivated Si, TiN/Ti/SiO2/Si and photoresists like PMMA and SU‐8. The process is suitable for patterning and the products can be used as seeds for electroplating of thicker overlayers. 相似文献
42.
Growth mechanism of gold nanoparticles decorated on polystyrene spheres via self-regulated reduction
Chang-Pin Chang Chun-Chieh Tseng Jinn-Luh Ou Wen-Hwa Hwu Ming-Der Ger 《Colloid and polymer science》2010,288(4):395-403
Uniform polystyrene (PS) microspheres prepared for deposition of metallic nanoparticles were synthesized using the surfactant-free
emulsion polymerization based on styrene/potassium persulfate/water (St/KPS/H2O) system. Owing to the presence of sulfate groups, the PS microspheres can be utilized to reduce gold nanoparticles without
adding extra reducing agent into the mixture. The synthesis and characterization of metal-polystyrene nanocomposites are reported,
and a possible reduction mechanism is proposed: by heating the aqueous solution in the presence of metal ions and PS, the
sulfate chain end groups of the PS hydrolyzed and transformed to hydroxyl groups firstly. The hydroxyl groups function as
a reducing agent, and carboxylic groups provide a site to adsorb the gold nuclei. The Au nanoparticles grow in size with the
coalescence and dissolving of nuclei through the Ostwald ripening process. The PS microspheres and Au nanoparticles were characterized
by Fourier transform infrared spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, X-ray power
diffraction, and thermal gravimetric analysis. 相似文献
43.
Two new noncentrosymmetric (NCS) solids were isolated via high-temperature, salt-inclusion reactions, Cs(2)Cu(7)(P(2)O(7))(4).6CsCl (1, CU-9) and Cs(2)Cu(5)(P(2)O(7))(3).3CsCl (2, CU-11). These copper(II) phosphates exhibit novel open-framework structures conceptually templated by extended Cs-Cl salt. The latter resides cooperatively in the channels upon the formation of the NCS Cu-P-O frameworks, leading to the formation of fascinating salt lattices centered by the NaCl-type core. These new discoveries are significant for they may give rise to a new route for the templated synthesis of NCS solids. We are to show here the structural correlation of the newly discovered hybrid solids, and the role of the chlorine atoms in the "intergrowth" of covalent/ionic sublattices. 相似文献
44.
The addition of reactive carbanions to tricarbonyl(η4-1,3-diene)iron(0) complexes proceeded at ?78 °C to give putative tricarbonyl(η1,η2-but-3-en-1-y1)iron(0) anion complexes and at 25 °C to produce postulated tricarbonyl(η3-allyl)iron(O) anion complexes; trapping of reactive intermediates with dioxygen produced γ,δ-unsaturated acids and allylic alcohols, respectively. 相似文献
45.
Jih Ru Hwu Prof. Joseph Jen‐Tse Huang Dr. Fu‐Yuan Tsai Dr. Shwu‐Chen Tsay Dr. Ming‐Hua Hsu Dr. Kuo Chu Hwang Dr. Jia‐Cherng Horng Dr. Ja‐an Annie Ho Dr. Chun‐Cheng Lin Dr. 《Chemistry (Weinheim an der Bergstrasse, Germany)》2009,15(35):8742-8750
N‐Nitroso compounds containing benzene, fluorene or fluorenone rings were synthesized. Photolysis of these compounds with 312‐nm UV light provided the NO . species, the presence of which was corroborated by use of an EPR method and of 2‐phenyl‐4,4,5,5‐tetramethylimidazolin‐1‐oxyl 3‐oxide (PTIO) as a trapping agent. During irradiation of N‐methyl‐N‐nitroso‐9‐fluorenone carboxamide ( 14 c ) in the absence of PTIO, it underwent decomposition followed by recombination to give the heterocyclic nitric oxide radical 15 . Incorporation of intercalating moieties endowed the N‐nitroso compounds with DNA‐cleaving ability through single‐strand scission upon UV irradiation in a phosphate buffer (pH 5.0–8.0) under aerobic conditions. 相似文献
46.
Amy F Enriquez H Soukiassian P Storino PF Chabal YJ Mayne AJ Dujardin G Hwu YK Brylinski C 《Physical review letters》2001,86(19):4342-4345
The atomic scale oxidation of the alpha-SiC(0001)-(3 x 3) surface is investigated by atom-resolved scanning tunneling microscopy, core level synchrotron radiation based photoemission spectroscopy, and infrared absorption spectroscopy. The results reveal that the initial oxidation takes place through the relaxation of lower layers, away from the surface dangling bond, in sharp contrast to silicon oxidation. 相似文献
47.
An isotactic chain end unsaturated polypropylene was prepared by the homogeneous metallocene catalyst Et(Ind)2ZrCl2 with MAO. Herein, the chain end unsaturated polypropylene proceeded the hydroboration reaction to prepare borane‐containing polypropylene. The borane‐containing polypropylene could be transformed to hydroxyl‐terminated polypropylene, PPOH. And then the polypropylene‐nylon 6 diblock copolymer, PP‐b‐NY6, was synthesized from telechelic PPOH by converting this prepolymer with toluene diisocyanate and using the resulting materials as macroactivators for anionic caprolactam polymerization. Meanwhile, this investigation used borane‐containing polypropylene and oxygen to produce free radicals at the chain end on the polypropylene. Experimental results indicate that the free radical is an effective initiator for the polymerization of methyl methacrylate to produce diblock PP‐b‐PMMA. The block copolymers are characterized by IR, NMR, and DSC analyses. The diblock copolymer is a good compatibilizer for polymer blends. 相似文献
48.
The classical solution for an isotropic elastic wedge loaded by uniform tractions on the sides of the wedge becomes infinite everywhere in the wedge when the wedge angle 2 equals , 2 or 2* where tan 2* = 2*. When the wedge is loaded by a concentrated couple at the wedge apex the solution also becomes infinite at 2 = 2*. A similar situation occurs when the wedge is anisotropic except that 2* is governed by a different equation and depends on material properties. Solutions which do not become infinite everywhere in the wedge are available for isotropic elastic wedges. In this paper we present solutions for the anisotropic elastic wedge at critical wedge angles. The main feature of the solutions obtained here is that they are in a real form even though Stroh's complex formalism is employed. 相似文献
49.
Razia Noreen Chia-Chi Chien Hsiang-Hsin Chen Vladimir Bobroff Michel Moenner Sophie Javerzat Yeukuang Hwu Cyril Petibois 《Analytical and bioanalytical chemistry》2013,405(27):8729-8736
Evidence has recently emerged that solid and diffuse tumors produce a specific extracellular matrix (ECM) for division and diffusion, also developing a specific interface with microvasculature. This ECM is mainly composed of collagens and their scaffolding appears to drive tumor growth. Although collagens are not easily analyzable by UV-fluorescence means, FTIR imaging has appeared as a valuable tool to characterize collagen contents in tissues, specially the brain, where ECM is normally devoid of collagen proteins. Here, we used FTIR imaging to characterize collagen content changes in growing glioma tumors. We could determine that C6-derived solid tumors presented high content of triple helix after 8–11 days of growth (typical of collagen fibrils formation; 8/8 tumor samples; 91 % of total variance), and further turned to larger α-helix (days 12–15; 9/10 of tumors; 94 % of variance) and β-turns (day 18–21; 7/8 tumors; 97 % of variance) contents, which suggest the incorporation of non-fibrillar collagen types in ECM, a sign of more and more organized collagen scaffold along tumor progression. The growth of tumors was also associated to the level of collagen produced (P?<?0.05). This study thus confirms that collagen scaffolding is a major event accompanying the angiogenic shift and faster tumor growth in solid glioma phenotypes. 相似文献
50.