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61.
Anthony J. Paine James McNulty 《Journal of polymer science. Part A, Polymer chemistry》1990,28(9):2569-2574
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In a search for more hydrocarbon solvent soluble derivatives of the parent ligand, 2,6-[Ph(2)P(O)CH(2)](2)C(5)H(3)NO (1a), a series of new ligands, 2,6-[R(2)P(O)CH(2)](2)C(5)H(3)NO [R = Bz (1b); Tol (1c); Et (1d); Pr (1e); Bu (1f); Pn (1g); Hx (1h); Hp (1i); and Oct (1j)] and 2,6-[RR'P(O)CH(2)](2)C(5)H(3)NO [R = Ph, R' = Bz (2a); R = Ph, R' = Me (2b); R = Ph, R' = Hx (2c); R = Ph, R' = Oct (2d)], have been prepared by either Arbusov or Grignard substitutions on 2,6-bis(chloromethyl)pyridine followed by N-oxidation. The new ligands have been characterized by spectroscopic methods, and their coordination chemistry with selected lanthanide ions has been surveyed. Several 1:1 and 2:1 ligand/metal complexes have been isolated, and single-crystal X-ray diffraction analyses for Nd(2a)(NO(3))(3), Er(2a)(NO(3))(3), Yb(1d)(NO(3))(3), and [Nd(1c)(2)](NO(3))(3) are described. The new structural data are discussed in relation to the structures of complexes formed by 1a. 相似文献
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Sylvie Pailloux Iris Binyamin Lorraine M. Deck Benjamin P. Hay Eileen N. Duesler Lev N. Zakharov W. Scott Kassel Arnold L. Rheingold Robert T. Paine 《Polyhedron》2009,28(18):3979-3984
The lanthanide coordination chemistry of the new ligand 2-hydroxy-2-(1-oxy-pyridin-2-yl)-N,N-diphenyl acetamide (5) has been examined. X-ray crystal structure determinations for the free ligand 5 and for one complex, [La(5)6] (NO3)3·7H2O, have been completed and the latter reveals an unexpected bidentate chelation mode for 5 that involves the amide carbonyl oxygen atom and the 2-hydroxy oxygen atom of each ligand. The six bidentate ligands generate an icosohedral inner coordination sphere. The N-oxide oxygen atom of each ligand also hydrogen bonds with a 2-hydroxyl hydrogen atom in a neighboring ligand molecule in the same molecular unit. 相似文献
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Troy A. Lowe Martin R. L. Paine David L. Marshall Larry A. Hick Jenny A. Boge Philip J. Barker Stephen J. Blanksby 《Journal of mass spectrometry : JMS》2010,45(5):486-495
Hindered amine light stabilisers (HALS) are the most effective antioxidants currently available for polymer systems in post‐production, in‐service applications, yet the mechanism of their action is still not fully understood. Structural characterisation of HALS in polymer matrices, particularly the identification of structural modifications brought about by oxidative conditions, is critical to aid mechanistic understanding of the prophylactic effects of these molecules. In this work, electrospray ionisation tandem mass spectrometry (ESI‐MS/MS) was applied to the analysis of a suite of commercially available 2,2,6,6‐tetramethylpiperidine‐based HALS. Fragmentation mechanisms for the [M + H]+ ions are proposed, which provide a rationale for the product ions observed in the MS/MS and MS3 mass spectra of N‐H, N‐CH3, N‐C(O)CH3 and N‐OR containing HALS (where R is an alkyl substituent). A common product ion at m/z 123 was identified for the group of antioxidants containing N‐H, N‐CH3 or N‐C(O)CH3 functionality, and this product ion was employed in precursor ion scans on a triple quadrupole mass spectrometer to identify the HALS species present in a crude extract from of a polyester‐based coil coating. Using MS/MS, two degradation products were unambiguously identified. This technique provides a simple and selective approach to monitoring HALS structures within complex matrices. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
68.
Five copper complexes [(L(1))(2)Cu(H(2)O)](ClO(4))(2) (1), [(L(1))Cu(H(2)O)(3)](ClO(4))(2) (1a), [(L(3))(2)Cu(H(2)O)](ClO(4))(2) (2), [(L(5))(2)Cu(H(2)O)](ClO(4))(2) (3) and [(L(6))(2)Cu](ClO(4)) (4) (where L(1) = 1,10-phenanthroline, L(3) = 1,10-phenanthroline-5,6-dione, L(5) = 1,10-phenanthrolinefuroxan and L(6) = 2,9-dimethyl-1,10-phenanthrolinefuroxan), and in situ prepared copper complexes of 2,9-dimethyl-1,10-phenanthroline (L(2)) or 2,9-dimethyl-1,10-phenanthrolinedione (L(4)) were used for aerial oxidation of primary alcohols to the corresponding aldehydes under ambient conditions. The copper catalysts have been found to catalyze a series of primary alcohols including one secondary alcohol with moderate turnover numbers and selectivity towards primary alcohols. Copper(ii) complexes 1 (or 1a) and 2 were found to be the better catalysts among all other systems explored in this study. A copper(ii)-superoxo species is implicated to initiate the oxidation reaction. Structural and electronic factors of 1,10-phenanthroline-based ligands affecting the catalytic results for aerial oxidation of alcohols are discussed. 相似文献
69.
The compound 2,6-bis(N-tert-butylacetamide)pyridine (2) was obtained via a Ritter synthesis, and oxidation with oxone provided the title pyridine-N-oxide (3). The compounds were characterized by spectroscopic methods, and the molecular structure of the N-oxide was determined by single-crystal X-ray diffraction methods. The coordination chemistry with Eu(NO3)3 was examined by using 1:1 and 2:1 ligand/Eu ratios, and a single-crystal X-ray analysis for Eu(3)(NO3)3(H2O) was completed. The ligand 3 is found to chelate in a tridentate fashion on the Eu(III). 相似文献
70.
Formation of a layered framework structure based upon 4-methyl-2,6-bis(methylphosphonic acid) phenol
Gan XM Binyamin I Pailloux S Duesler EN Paine RT 《Dalton transactions (Cambridge, England : 2003)》2006,(32):3912-3917
The trifunctional ligands, [(HO)2P(O)CH2]2C6H2(R)OH, (5-H4)(R = CH3, Br) were prepared in good yield via an Arbusov reaction between P(OEt)3 and the respective 4-R-2,6-bis(chloromethyl)phenols followed by acidic aqueous hydrolysis and they were spectroscopically characterized by IR and NMR techniques. The ligand 5-H4-CH3 readily dissolves lanthanide hydroxide residues and it forms a crystalline complex from aqueous LaCl3 solutions. This complex was characterized by single crystal X-ray diffraction methods and found to adopt a complex 2-D lamellar network in the bc plane. The La(III) inner coordination sphere is seven coordinate formed by oxygen atoms from two water molecules and five phosphonate oxygen atoms from three different ligands. The phenolic oxygen atom is not involved in the ligand binding to La(III). 相似文献