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101.
StephenF. Lincoln 《Helvetica chimica acta》2005,88(3):523-545
A semi‐historical review of the establishment of the nature of metal aqua ions ranging from the alkali metal ions to the lanthanides and the mechanism of water exchange and ligand substitution on them is presented. 相似文献
102.
Robert L. Schiller Stephen F. Lincoln John H. Coates 《Journal of inclusion phenomena and macrocyclic chemistry》1987,5(1):59-63
Equilibrium and temperature-jump spectrophotometric studies show that the mono-cation of pyronine B (PB) is included by beta- and gamma-cyclodextrins (CD and CD) to form the labile complexes PB. CD, PB. CD and (PB)2. CD in water. The equilibrium, kinetic and structural aspects of these complexes and those formed by pyronine Y are discussed in conjunction with data characterizing the inclusion of other dyes by cyclodextrins. 相似文献
103.
Cusumano M Di Pietro ML Giannetto A Nicolò F Nordén B Lincoln P 《Inorganic chemistry》2004,43(7):2416-2421
Novel platinum(II) square planar coordination complexes, in which two heteroaromatic ligands are held by the metal in an unusual L-shaped geometry orthogonal to each other, have been synthesized, and their interaction with DNA was investigated with absorption and linear dichroism spectroscopy. As a rule, the ligand that is coplanar with the coordination square of Pt is found to be oriented perpendicular relative to the DNA helix axis when bound, suggestive of its intercalation between the base pairs of DNA. However, when this coplanar ligand is replaced by two pyridines, the opposite ligand, orthogonal to the coordination square, is instead preferentially intercalated. This behavior shows that these new complexes do indeed show some properties of true ambintercalators, i.e., compounds that can bind by intercalation of either of two distinct aromatic moieties. 相似文献
104.
Geoffrey J. Honan Stephen F. Lincoln Evan H. Williams 《Journal of solution chemistry》1978,7(6):443-451
The species UO2(DMSO)
5
2+
is shown from1H NMR studies to be the predominant dioxouranium(VI) species existing in dilute anhydrous acetonedimethyl sulfoxide (DMSO) solutions, and this result is compared with data reported for the analogous water-acetone-dimethyl sulfoxide system. Complete line-shape analyses of exchange-modified1H NMR line shapes indicate that the mechanism for DMSO exchange on UO2(DMSO)
5
2+
is probably of theD orI
D
type. A typical set of rate parameters arek
ex
(260°K) =273±14 sec–1, H
#=38.9±0.5 kJ-mole–1, and S
#=–47.5±1.8 J-oK–1-mole–1 for a solution in which [UO2(DMSO)5
2+], [DMSO], and [d
6 acetone] are, respectively, 0.01155, 0.0875, and 13.00 moles-dm–3. 相似文献
105.
Julia S. Lock Bruce L. May Philip Clements Stephen F. Lincoln Christopher J. Easton 《Journal of inclusion phenomena and macrocyclic chemistry》2004,50(1-2):13-18
E-4-(2-(4- tert - butylphenyl) ethen-1- yl)benzoate, E-1–, photoisomerizes to the Z-1– isomer and vice versa in the free state and in the binary complexes 2·E-1–, 2·Z-1–, 3·E-1– and 3·Z-1– where 2 is the urea-linked cyclodextrin N-(6
A
-deoxy--cyclodextrin-6
A
- yl)-N-(6
A
-deoxy--cyclodextrin-6
A
- yl)urea and 3 is N,N- bis(6
A
-deoxy--cyclodextrin-6
A
- yl)urea. In 2·E-1–and 3·E-1– the stilbene occupies both cyclodextrin (CD) components of 2 and 3, whereas in 2·Z-1– and 3·Z-1– it only occupies one CD component while the other CD component is unoccupied. 4- tert - Butylphenolate, 4–, and its carboxylate, 5–, and sulfonate, 6–, analogues form the ternary complex 2·Z-1–·4– and its analogues and also 3·Z-1–·4– and its analogues. These photoisomerize to 2·E-1–and 3·E-1– and either free 4–, 57– or 6– and thereby function as molecular devices. 相似文献
106.
West LC Wyness O May BL Clements P Lincoln SF Easton CJ 《Organic & biomolecular chemistry》2003,1(5):887-894
Complexation of the Brilliant Yellow tetraanion, 3(4-), by two new diazacoronand linked beta-cyclodextrin (beta CD) dimers 4,13-bis(2-(6A-deoxy-beta-cyclodextrin-6A-yl)aminooctylamidomethyl- and 4,13-bis(8-(6A-deoxy-beta-cyclodextrin-6A-yl)aminooctylamidomethyl)-4,13- diaza-1,7,10-trioxacyclopentadecane, 1 and 2, respectively, has been studied in aqueous solution. UV-visible spectrophotometric studies at 298.2 K, pH 10.0 and I = 0.10 mol dm-3 (NEt4ClO4) yielded complexation constants for the complexes 1 x 3(4-) and 2 x 3(4-), K1 = (1.08 +/- 0.01) x 10(5) and (6.21 +/- 0.08) x 10(3) dm3 mol-1, respectively. Similar studies at 298.2 K, pH 10.0 and I = 0.10 mol dm-3 (NaClO4) yielded K3 = (4.63 +/- 0.09) x 10(5) and (3.38 +/- 0.05) x 10(4) dm3 mol-1 for the complexation of 3(4-) by Na+ x 1 and Na+ x 2 to give Na+ x 1 x 3(4-) and Na+ x 2 x 3(4-), respectively. Potentiometric studies of the complexation of Na+ by 1 and 2 by the diazacoronand component of the linkers to give Na+ x 1 and Na+ x 2 yielded K2 = (2.00 +/- 0.05) x 10(3) and (1.8 +/- 0.05) x 10(3) dm3 mol-1, respectively, at 298.2 K and I = 0.10 mol dm-3(NEt4ClO4). For complexation of Na+ by 1 x 3(4-) and 2 x 3(4-) to give Na+ x 1 x 3(4-) and Na+ x 2 x 3(4-) K2K3/K1 = K4 = 8.6 x 10(2) and 9.8 x 10(3) dm3 mol-1, respectively. The pKaS of 1H4(4+) are 7.63 +/- 0.01, 6.84 +/- 0.02, 5.51 +/- 0.04 and 4.98 +/- 0.03, and those of 2H4(4+) are 8.67 +/- 0.02, 8.11 +/- 0.02, 6.06 +/- 0.02 and 5.14 +/- 0.05. The larger magnitude of K1 for 1 by comparison with K1 for 2 is attributed to the octamethylene linkers of 2 competing with 3(4-) for occupancy of the annuli of the beta CD entities while the competitive ability of the dimethylene linkers of 1 is less. A similar argument applies to the relative magnitudes of K3 for Na+ x 1 and Na+ x 2. Increased electrostatic attraction probably accounts for K3 > K1 for Na+ x 1 x 3(4-) and 1 x 3(4-) and for Na+ x 2 x 3(4-) and 2 x 3(4-). The lesser magnitudes of K2 and K4 for Na+ x 1 and Na+ x 1 x 3(4-) compared with those for Na+ x 2 and Na+ x 2 x 3(4-) are attributed to the octamethylene linkers of 2 producing a more hydrophobic environment for the diazacoronand than that produced by the dimethylene linkers of 1. 1H NMR spectroscopic studies and the syntheses of 1 and 2 are described. 相似文献
107.
Complexation of dodecyl‐substituted poly(acrylate) by linked β‐cyclodextrin dimers and trimers in aqueous solution 下载免费PDF全文
Duc‐Truc Pham Hanh‐Trang Nguyen Stephen F. Lincoln Jie Wang Xuhong Guo Christopher J. Easton Robert K. Prud'homme 《Journal of polymer science. Part A, Polymer chemistry》2015,53(10):1278-1286
Two‐dimensional NOESY 1H NMR, isothermal titration calorimetric (ITC), and rheological studies of host–guest complexation by β‐cyclodextrin, β‐CD, and the β‐CD groups of the linked β‐CD dimers, β‐CD2ur and β‐CD2su and trimers, β‐CD3bz and β‐CDen3bz, of the dodecyl, C12, substituents of the 3.0% substituted poly(acrylate), PAAC12, in aqueous solution are reported. Complexations by β‐CD, β‐CD2ur, β‐CD2su, β‐CD3bz, and β‐CDen3bz of the C12 substituents of PAAC12 in 0.2 wt % solution exhibit complexation constants 10?4K11 (298.2 K) = 0.83, 5.80, 4.40, 15.0, and 1.50 dm3 mol?1, respectively. (The corresponding ΔH11 and TΔS11 show a linear relationship.) The rheologically determined zero‐shear viscosities of 3.3 wt % aqueous solutions of PAAC12 alone and in the presence of β‐CD, β‐CD2ur, β‐CD2su, β‐CD3bz, and β‐CDen3bz (where the β‐CD groups and C12 substituents are equimolar) are 0.016, 0.03, 0.12, 0.25, 0.12, and 0.08 Pa s (298.2 K), respectively, and show PAAC12 to form interstrand cross‐links through complexation. © 2015 Wiley Periodicals, Inc. J. Polym. Sci., Part A: Polym. Chem. 2015 , 53, 1278–1286 相似文献
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