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G. La Penna S. Letardi V. Minicozzi S. Morante G.C. Rossi G. Salina 《The European physical journal. E, Soft matter》2001,5(3):259-274
In this paper we present the results of a large-scale numerical investigation of structural properties of a model of cell
membrane, simulated as a bilayer of flexible molecules in vacuum. The study was performed by carrying out extensive Molecular
Dynamics simulations, in the (NVE) micro-canonical ensemble, of two systems of different sizes ( 2×32 and 2×256 molecules), over a fairly large set of temperatures and densities, using
parallel platforms and more standard serial computers. Depending on the dimension of the system, the dynamics was followed
for physical times that go from few hundred picoseconds for the largest system to 5-10 nanoseconds for the smallest one. We
find that the bilayer remains stable even in the absence of water and neglecting Coulomb interactions in the whole range of
temperatures and densities we have investigated. The extension of the region of physical parameters that we have explored
has allowed us to study significant points in the phase diagram of the bilayer and to expose marked structural changes as
density and temperature are varied, which are interpreted as the system passing from a crystal to a gel phase.
Received 6 July 2000 and Received in final form 28 December 2000 相似文献
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Kazi A. Azam Mohitosh Bhowmick Golam Mohammad Golzar Hossain Shariff E. Kabir Kalipada Kundu Khalifa Mohammad Abdul Malik Salina Perven 《Journal of chemical crystallography》2001,31(1):63-68
Treatment of [Ru3(CO)10(-dppm)] (1) with the ditelluride Te2(C6H4OEt-4)2 in refluxing toluene afforded the new aryltellurol bridged complex [Ru2(CO)4(-TeC6H4OEt-4)2 (-dppm)] (2) together with three known complexes [Ru4(CO)8(-CO)(4-Te)2(-dppm)] (3), [Ru2(CO)6{-CH2PPh(C6H4)PPh}] (4), and [Ru2(CO)6{-C6H4PPh(CH2)PPh}] (5). All the four complexes were characterized by spectroscopic methods, including an X-ray structure determination for 5. Complex 5 crystallizes in the monoclinic space group P21/c with a = 13.650(2), b = 9.995(2), c = 18.929(3) Å, = 97.49(2)°, V = 2560.4(8) Å3, and Z = 4. In this complex the two ruthenium atoms are bridged by the phosphino-phosphide ligand C6H4PPh(CH2)PPh which is attached to one Ru by the C6H4 group and a P atom while to the other Ru by both the two P atoms. Both the ruthenium atoms show distorted octahedral geometry. The Ru—Ru bond length is 2.8719(7) Å. 相似文献
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A. R. Gataoullin M. S. Salina S. A. Bogdanova Yu. G. Galyametdinov 《Russian Journal of Applied Chemistry》2013,86(11):1656-1662
Dispersion of C60 fullerenes in water and ethanol in the presence of nonionic surfactants, ethylene oxide derivatives, was studied. It was found that the quality of the dispersion process and the stability of dispersions depend on the structure, degree of oxyethylation, and concentration of surfactants. The optimal conditions are found in which stable fullerene dispersions are obtained as ingredients of cosmetic preparations with antioxidant properties. 相似文献
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Shishir Ghosh Shariff E. Kabir Salina Pervin G. M. Golzar Hossain Daniel T. Haworth Sergey V. Lindeman Tasneem A. Siddiquee Dennis W. Bennett Herbert W. Roesky Prof. Dr. Dr. h.c. 《无机化学与普通化学杂志》2009,635(1):76-87
Reaction of [Mn2(CO)10] with 2‐mercapto‐1‐methylimidazole in the presence of Me3NO at 25 °C afforded two new dimanganese complexes [Mn2(CO)6(μ‐SN2C4H5)2] ( 1 ) and [Mn2(CO)7(μ‐SN2C4H5)2] ( 2 ). Compound 1 consists of two μ‐SN2C4H5 ligands, each bound through the sulfur atom to two Mn atoms and through the nitrogen atom to one Mn atom forming a four‐membered chelate ring. Compound 2 was found to consist of one μ‐SN2C4H5 ligand in a similar bonding mode to 1 but another μ‐SN2C4H5 ligand coordinates through the sulfur atom to one Mn atom and through the nitrogen atom to another Mn atom. Compound 1 was also obtained as the only product from the reaction of [Mn2(CO)8(NCMe)2] with 2‐mercapto‐1‐methylimidazole. In contrast, a similar reaction of [Re2(CO)8(NCMe)2] with 2‐mercapto‐1‐methylimidazole led to the formation of the di‐, tri‐, and tetranuclear complexes [Re3(CO)8(μ‐CO)(μ3‐SN2C4H5)2(μ‐H)] ( 3 ), [Re4(CO)12(μ‐SN2C4H5)4] ( 4 ), and [Re2(CO)6(μ‐SN2C4H5)2] ( 5 ). Compound 3 provides a unique example of a hydrido trirhenium compound. The reaction of [Cr(CO)3(NCMe)3] and [Mo(CO)3(NCMe)3] with 1 in refluxing THF afforded the mixed metal complexes [CrMn2(CO)8(μ‐CO)2(μ3‐SN2C4H5)2] ( 6 ) and [MoMn2(CO)8(μ‐CO)2(μ3‐SN2C4H5)2] ( 7 ), respectively, in which two Mn–M (M = Mo, Cr) bonds were formed. In contrast, a similar treatment of [W(CO)3(NCMe)3] with 1 yielded two W‐Mn complexes [Mn2W(CO)8(μ‐CO)2(μ3‐SN2C4H5)2] ( 8 ) and [Mn2W(CO)7(μ‐CO)2(SN2C4H5)(μ3‐SN2C4H5)2] ( 9 ). Treatment of 1 with [Fe3(CO)12] at 70‐75 °C afforded the trinuclear mixed‐metal complex [FeMn2(CO)8(μ‐CO)(μ3‐SN2C4H5)2] ( 10 ) and the diiron side product [Fe2(CO)6(μ‐S2N2C4H5)2] ( 11 ). Compounds 6 ‐ 10 have a bent open structure of three metal atoms linked by two metal‐metal bonds and all, except 9 and 10 , contain a noncrystallographic two‐fold axis of symmetry. Compound 9 is structurally similar to 8 , but it contains a SN2C4H6 ligand, mono coordinated through the exocyclic sulfur atom to the W atom and a Mn–Mn bond instead of a Mn–W bond. Compound 11 comprises two bridging S2N2C4H5 ligands, which arise from the coupling of 2‐mercapto‐1‐methylimidazole with sulfur. 相似文献
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Masahiro Yoshida Salina EasminMohammad Al-Amin Yuuki HiraiKozo Shishido 《Tetrahedron》2011,67(18):3194-3200
The electrophilic cyclizations of N-substituted propargylic aziridines are described. 3-Iodopyrroles having a variety of substituents at the 2- and 3-positions were synthesized by reacting propargylic aziridines with iodine. Whereas N-tosyl-substituted substrates require a platinum catalyst to promote the reaction, the iodine-promoted cycloisomerizations proceed when N-benzyl-substituted substrates are employed. 相似文献
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Trifilenkov AS Kobak VV Salina MA Kusovkova JA Ilyin AP Khvat AV Tkachenko SE Ivachtchenko AV 《Journal of combinatorial chemistry》2006,8(4):469-479
In this work, we explored several original combinatorial derivatization patterns for the 3,4-dihydro-2H-1,4-benzothiazine scaffold. The synthesis begins with commercially available 4-chloro- and 4-fluoro-3-nitrobenzoates and employs a sequence of moderate and high-yielding reactions that display a relatively high substituent tolerance. Simple manual techniques for parallel reactions were coupled with easy workup and purification procedures to give high-purity final products. The developed approach was easily adaptable for parallel synthesis of more than 2600 novel 2H-benzo[1,4]thiazine-6-carboxylic acid amides, which were efficiently prepared in a semiautomatic fashion using special CombiSyn synthesizers. 相似文献
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Zal?U’yun?Wan?MahmoodEmail author Che?Abd.?Rahim?Mohamed Abdul?Kadir?Ishak Nita?Salina?Abu?Bakar Kamaruzzaman?Ishak 《Journal of Radioanalytical and Nuclear Chemistry》2011,289(3):953-959
Marine sediment cores were collected from two stations at East Malaysia coastal waters on June 2004. Activity concentrations
of 210Pb in sediment core were ranged from 11 Bqkg−1 to 84 Bqkg−1 dry wt. for SR 01 and 4 Bqkg−1 to 66 Bqkg−1 dry wt. for SB 03. Meanwhile, activity concentrations of 226Ra in sediment core were varied significantly depending on the sampling location of SR 01 and SB 03 with ranged 17–26 Bqkg−1 dry wt. and 8–11 Bqkg−1 dry wt., respectively. The activity ratios of 210Pb/226Ra were no significantly different at all sampling stations with an average of 1.78. Refer to the entire results; the activities
of 210Pb and 226Ra were higher at station SR 01 than station SB 03, but contrast with ratio of 210Pb/226Ra. The reasons of different 210Pb and 226Ra activity concentration and distribution of their ratios were strictly related to their half lives, environment origin,
potential sources and behavior. 相似文献
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Massimiliano Lucci Valerio Campanari Davide Cassi Vittorio Merlo Francesco Romeo Gaetano Salina Matteo Cirillo 《Entropy (Basel, Switzerland)》2022,24(11)
Measurements indicating that planar networks of superconductive islands connected by Josephson junctions display long-range quantum coherence are reported. The networks consist of superconducting islands connected by Josephson junctions and have a tree-like topological structure containing no loops. Enhancements of superconductive gaps over specific branches of the networks and sharp increases in pair currents are the main signatures of the coherent states. In order to unambiguously attribute the observed effects to branches being embedded in the networks, comparisons with geometrically equivalent—but isolated—counterparts are reported. Tuning the Josephson coupling energy by an external magnetic field generates increases in the Josephson currents, along the above-mentioned specific branches, which follow a functional dependence typical of phase transitions. Results are presented for double comb and star geometry networks, and in both cases, the observed effects provide positive quantitative evidence of the predictions of existing theoretical models. 相似文献