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131.
Gabriel J. Summers M. Patrick Ndawuni Carol A. Summers 《Journal of polymer science. Part A, Polymer chemistry》2001,39(12):2058-2067
The quantitative synthesis of tertiary amine-functionalized polymers by atom transfer radical polymerization is reported. Tertiary amine-functionalized polystyrene was prepared with the adduct of 1-(bromoethyl)benzene with 1-(4-dimethyl-aminophenyl)-1-phenylethylene as an initiator in the atom transfer radical polymerization of styrene in the presence of a copper (I) bromide/2,2′-bipyridyl catalyst system. The polymerization proceeded via a controlled free-radical polymerization process to afford quantitative yields of the corresponding tertiary amine-functionalized polystyrene with predictable number-average molecular weights (1600–4400), narrow molecular weight distributions (1.09–1.31), and an initiator efficiency of 0.95. The polymerization process was monitored by gas chromatographic analysis. The tertiary amine-functionalized polymers were characterized by thin-layer chromatography, size exclusion chromatography, potentiometry, and spectroscopy. All experimental evidence was consistent with quantitative functionalization via the 1,1-diphenylethylene derivative. Polymerization kinetic measurements showed that the polymerization reaction followed first-order-rate kinetics with respect to monomer consumption and that the number-average molecular weight increased linearly with monomer conversion. © 2001 John Wiley & Sons, Inc. J Polym Sci A Part A: Polym Chem 39: 2058–2067, 2001 相似文献
132.
Zhengjie Pi J. P. Kennedy 《Journal of polymer science. Part A, Polymer chemistry》2001,39(10):1675-1680
The cationic grafting of isobutylene, styrene, α-methylstyrene, and β-pinene from a poly(vinyl chloride) (PVC) backbone was investigated. Grafting-from was induced by Et2AlCl in 1,2-dichloroethane and methylene dichloride solutions from 20 to −70 °C. The effects of temperature and proton trap [2,6-di-tert-butylpyridine (DtBP)] on grafting-from efficiency (Geff), extent of grafting, branch length (molecular weight), and number of branches per PVC molecule were determined. Reducing the temperature invariably increased the Geff and the molecular weight of polyisobutylene, polystyrene, poly(α-methylstyrene), and poly(β-pinene) branches attached to PVC. The magnitude of the effects was different with the various olefins and depended on the reaction conditions. The effect of DtBP was examined in the 5 × 10−4–4 × 10−3 mol/L range. By increasing the DtBP concentration the Geff increased; however, the number-average molecular weight of the grafted branches decreased. The lengths of the grafted branches can be controlled, and Geff's close to 100% were obtained. The fact that the proton trap reduced the molecular weights of grafted branches suggests that besides proton scavenging, DtBP may also abstract protons from the growing carbenium ion site. © 2001 John Wiley & Sons, Inc. J Polym Sci A: Polym Chem 39: 1675–1680, 2001 相似文献
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Two novel tetrahedral silicon‐centered cyano functionalized silanes, namely bis(4‐cyanophenylethynyl)dimethylsilane ( CN-1 ) and bis(4‐cyanophenylethynyl) diphenylsilane ( CN-2 ), have been synthesized and well characterized. They demonstrated unusual aggregation‐induced emission enhancement (AIEE) properties in the H‐type aggregation state with nanoparticle aggregate formation. Further study shows that the 4‐cyanophenylethynyl unit is the structure base to induce the AIEE phenomenon and the silicon core may enhance the AIEE effect. By single‐crystal analysis, the twisted tetrahedral conformation of silicon core and restricted intramolecular motions are speculated as the AIEE mechanism for these unusual H‐type aggregates of CN-1 and CN-2 . Moreover, both CN-1 and CN-2 show an obvious fluorescent quenching response to 2,4,6‐trinitrotoluene (TNT) in THF solution, making them promising candidates in the application of explosive detection. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
136.
Two novel salicylaldoxime‐functionalized poly(ethylene glycol)‐bridged dicationic ionic liquids ([salox‐PEG1000‐DIL][BF4] and [salox‐PEG1000‐DIL][PF6]) were prepared and characterized. [salox‐PEG1000‐DIL][BF4] was found to be an efficient and recyclable ligand for palladium‐catalyzed Suzuki–Miyaura reaction in water. The catalytic system could be easily recovered and reused for at least five runs only with slight decrease in its activity. Copyright © 2013 John Wiley & Sons, Ltd. 相似文献
137.
Nadège Handké Thomas Trimaille Elsa Luciani Marion Rollet Thierry Delair Bernard Verrier Denis Bertin Didier Gigmes 《Journal of polymer science. Part A, Polymer chemistry》2011,49(6):1341-1350
Poly(N‐acryloxysuccinimide) (PNAS) and poly(N‐acryloxysuccinimide‐co‐N‐vinylpyrrolidone) (P(NAS‐co‐NVP)) of adjustable molecular weights and narrow polydispersities were prepared by nitroxide‐mediated polymerization (NMP) in N,N‐dimethylformamide in the presence of free SG1 (N‐tert‐butyl‐N‐1‐diethylphosphono‐(2,2‐dimethylpropyl) nitroxide), with MAMA‐SG1 (N‐(2‐methylpropyl)‐N‐(1‐diethylphosphono‐2,2‐dimethylpropyl)‐O‐(2‐carboxylprop‐2‐yl)hydroxylamine) alkoxyamine as initiator. The reactivity ratios of NAS and NVP were determined to be rNAS = 0.12 and rNVP = 0, indicating a strong alternating tendency for the P(NAS‐co‐NVP) copolymer. NAS/NVP copolymerization was then performed from a SG1‐functionalized poly(D ,L ‐lactide) (PLA‐SG1) macro‐alkoxyamine as initiator, leading to the corresponding PLA‐b‐P(NAS‐co‐NVP) block copolymer, with similar NAS and NVP reactivity ratios as mentioned above. The copolymer was used as a surface modifier for the PLA diafiltration and nanoprecipitation processes to achieve nanoparticles in the range of 450 and 150 nm, respectively. The presence of the functional/hydrophilic P(NAS‐co‐NVP) block, and particularly the N‐succinimidyl (NS) ester moieties at the particle surface, was evidenced by ethanolamine derivatization and zeta potential measurements. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
138.
FAN Jing ZHU GuiFen WANG HaiBo & WANG JianJi Henan Key Laboratory for Environmental Pollution Control Key Laboratory for Yellow Huai River Water Environmental Pollution Control Ministry of Education School of Chemical Environmental Sciences Henan Normal University Xinxiang China 《中国科学B辑(英文版)》2011,(6)
Trace of Pb(Ⅱ) has been on-line separated and enriched from environmental samples and wastewater by using the self-made alizarin violet functionalized silica gel micro-column coupling with a sequential injection sampling technology. The determination is based on the color reaction of Pb(Ⅱ) with iodide and crystal violet to form an ionic association complex in the presence of polyvinyl alcohol and hydrochloric acid. The use of the microcolumn can prevent the interference of most familiar metal ions, and ther... 相似文献
139.
Ping Zhao Dina Shpasser Moris S. Eisen 《Journal of polymer science. Part A, Polymer chemistry》2012,50(3):523-533
Introduction of functional groups into polyolefins has the potential of broadening their end use. An attractive method for preparing polyolefins containing functional groups is the copolymerization of the olefins with α‐olefins containing a functional group. Copolymerizations of propylene with 10‐undecen‐1‐ol, containing a hydroxyl group protected by either TIBA or TBDMSCl, 11‐chloro‐1‐undecene, 5‐bromopent‐1‐ene and N‐allyl‐2,2,2‐trifluoroacetamide were performed using three organometallic catalysts: the metallocene rac‐Et(Ind)2ZrCl2 and two new benzamidinate catalysts [3‐C5H4NC(NSiCH3)2]2TiCl2 and [(m‐OMe‐C6H4NC(NSiCH3)2]2ZrCl2. 10‐Undecene‐1‐ol protected “in situ” with TIBA and N‐(dec‐9‐enyl)‐2,2,2‐trifluoroacetamide gave copolymers with similar polar monomer incorporation percentages and molecular weights 17%; 28,900 g/mol for the protected 10‐undecene‐1‐ol, and 15%; 27,100 g/mol for N‐(dec‐9‐enyl)‐2,2,2‐trifluoroacetamide. 11‐Chloro‐1‐undecene gave copolymers with up to 22% incorporation for 0.12 M of the comonomer in the reaction feed. The obtained copolymers were characterized by NMR, DSC, and GPC. Membranes were prepared from two copolymers containing the hydroxyl groups (6 and 10%) and one copolymer containing chlorine groups (7%). The membranes prepared could be wetted in contrast to polypropylene membranes which do not contain functional groups. In addition, it was observed that for both type of membranes prepared from the different copolymers containing the hydroxyl groups, the flux was significantly greater than for the membrane prepared from the copolymer containing a chlorine groups. © 2011 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2011 相似文献
140.
Inside Back Cover: SrB5O7F3 Functionalized with [B5O9F3]6− Chromophores: Accelerating the Rational Design of Deep‐Ultraviolet Nonlinear Optical Materials (Angew. Chem. Int. Ed. 21/2018)
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