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41.
42.
Achille M. Bivigou-Koumba Eckhard Görnitz André Laschewsky Peter Müller-Buschbaum Christine M. Papadakis 《Colloid and polymer science》2010,288(5):499-517
Several series of symmetrical triblock copolymers were synthesized by the reversible addition fragmentation chain transfer
method. They consist of a long block of poly(N-isopropylacrylamide) as hydrophilic, thermoresponsive middle block, which is end-capped by two small strongly hydrophobic
blocks made from five different vinyl polymers. The association of the amphiphilic polymers was studied in dilute and concentrated
aqueous solution. The polymer micelles found at low concentrations form hydrogels at high concentrations, typically above
30–35 wt.%. Hydrogel formation and the thermosensitive rheological behavior were studied exemplarily for copolymers with hydrophobic
blocks of polystyrene, poly(2-ethylhexyl acrylate), and poly(n-octadecyl acrylate). All systems exhibited a cloud point around 30 °C. Heating beyond the cloud point initially favors hydrogel
formation but continued heating results in macroscopic phase separation. The rheological behavior suggests that the copolymers
associate into flower-like micelles, with only a small share of polymers that bridge the micelles and act as physical cross-linkers,
even at high concentrations. 相似文献
43.
44.
The title redox couple, in noncoordinating perchlorate medium, has been used to probe the electrochemical behavior of different IrO2-based electrodes; pure oxide electrodes, as well as IrO2-SnO2 mixtures, have been investigated. The obtained results show that the electrode material strongly affects the electrochemical response. A tentative explanation, based on the different point of zero charge of the considered oxides, is presented. 相似文献
45.
Roberto Centore Antonio Roviello Angela Tuzi Barbara Panunzi 《Acta Crystallographica. Section C, Structural Chemistry》2002,58(1):m26-m28
The title compounds, {5‐(dimethylamino)‐2‐[N‐(4‐methoxyphenyl)iminomethyl]phenyl}[N‐(4‐methoxyphenyl)‐4‐nitrosalicylaldiminato]palladium(II), [Pd(C14H11N2O4)(C16H17N2O)], (I), and [4‐(diethylamino)‐N‐(4‐methoxyphenyl)salicylaldiminato]{2‐[N‐(4‐methoxyphenyl)iminomethyl]‐5‐nitrophenyl}palladium(II) dichloromethane hemisolvate, [Pd(C14H11N2O3)(C18H21N2O2)]·0.5CH2Cl2, (II), both contain push–pull chromophores coordinated to Pd in a square‐planar arrangement. In both compounds, the five‐membered orthopalladated ring is essentially planar, while the coordinated six‐membered ring is not. Deviations from a coplanar arrangement of the phenylene rings of the coordinated Schiff bases are observed in both (I) and (II) as a result of intramolecular steric interactions. 相似文献
46.
Augusto De Renzi Achille Panunzi Michaelangelo Scalone Aldo Vitagliano 《Journal of organometallic chemistry》1980,192(1):129-132
Amination of PtII-allene complexes of the type cis[PtCl2(Me2CCCHR)(PPh3)] gives the new four-membered C, N chelate aminoalkenyl complexes [Me2(PPh3)Cl]. These undergo ready insertion of carbon monoxide into the CPt σ-bond; the resulting acyl complexes are oxidized by hydrogen peroxide to aminoacidato complexes, and the free unsaturated β-aminoacids can be recovered in good yield by ligand displacement. 相似文献
47.
Rosita Diana Ugo Caruso Francesco Silvio Gentile Luigi Di Costanzo Barbara Panunzi 《Molecules (Basel, Switzerland)》2021,26(23)
In the field of optical sensors, small molecules responsive to metal cations are of current interest. Probes displaying aggregation-induced emission (AIE) can solve the problems due to the aggregation-caused quenching (ACQ) molecules, scarcely emissive as aggregates in aqueous media and in tissues. The addition of a metal cation to an AIE ligand dissolved in solution can cause a “turn-on” of the fluorescence emission. Half-cruciform-shaped molecules can be a winning strategy to build specific AIE probes. Herein, we report the synthesis and characterization of a novel L-shaped fluorophore containing a benzofuran core condensed with 3-hydroxy-2-naphthaldehyde crossed with a nitrobenzene moiety. The novel AIE probe produces a fast colorimetric and fluorescence response toward zinc (II) in both in neutral and basic conditions. Acting as a tridentate ligand, it produces a complex with enhanced and red-shifted emission in the DR/NIR spectral range. The AIE nature of both compounds was examined on the basis of X-ray crystallography and DFT analysis. 相似文献
48.
By reaction with aromatic Grignard reagents in the presence of low valent nickel species at low temperature, the 1,2-unsaturated furanoid glycal (1) undergoes coupling reaction to produce 2,3-unsaturated products (1a,b) as pure stereoisomers. When these reaction conditions are applied to protected 1,2-unsaturated pyranoid glycals (2, 3, 4), both cross-coupling and elimination reactions occur to give conjugated diene-alcohol derivatives (2a; 3a,b; 4a,b, respectively), in moderate yield. 相似文献
49.
Fabio Borbone Ugo Caruso Antonella De Maria Michela Fusco Barbara Panunzi Antonio Roviello 《Macromolecular Symposia》2004,218(1):313-322
A series of new metal containing polymers for second order nonlinear optics have been prepared by grafting Cu (II) and Pd (II) chromophoric complexes on a preformed (4-vinylpyridine-styrene) copolymeric backbone. The metallated polymers have been chemically and physically characterized. They show high glass transition temperatures, high thermal stability and good solubility. Their properties have been compared with analogous metallated poly(4-vinylpyridine) samples: variations in the polymeric backbone, as well as in ligands, metal, and metallation ratio, allow to tune their properties. 相似文献
50.
Gian Paolo Boldrini Achille Umani-Ronchi Mauro Panunzio 《Journal of organometallic chemistry》1979,171(1):85-88
The tetraethylammonium undecacarbonylhydridotriferrate [(C2H5)4N+ HFe3(CO)11?] (I): which can be easily prepared in a two-step sequence from iron pentacarbonyl, triethylamine and tetraethylammonium chloride, selectively reduces nitroarenes to amines and α, β-unsaturated carbonyl compounds to the corresponding saturated compounds both in good yield. I reacts with some organic halides to give dehalogenated products. 相似文献