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Summary In the salt (NMe4[MoO2(H2tart)2] · EtOH · 1.5 H2O (H4tart = R,R-(+)-tartaric acid) the tartrato-ligands are linked to molybdenum through a carboxyl oxygen and the vicinal deprotonated hydroxyl oxygen atom, with carboxyl oxygentrans to terminal oxygen of the MoO2
cis-dioxo core. The configuration about Mo is A. The C-C-C-C torsion angles of the ligands are almost 180°. This enables inter-ligand H-bonding from the uncoordinated hydroxyl groups. The five skeletal atoms from the uncoordinated section of a ligand are nearly co-planar. The probable strong preference fortrans coordination of carboxyl must limit the range of dissolved molybdenum(VI)-tartrate species. 相似文献
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Shi Xunqing Wang Zhiping John HL Pang Zhang Xueren Nie Jingxu 《Acta Mechanica Sinica》2002,18(3):274-287
In this study, a new unified creep constitutive relation and a modified energy-based fatigue model have been established respectively
to describe the creep flow and predict the fatigue life of Sn−Pb solders. It is found that the relation successfully elucidates
the creep mechanism related to current constitutive relations. The model can be used to describe the temperature and frequency
dependent low cycle fatigue behavior of the solder. The relation and the model are further employed in part II to develop
the numerical simulation approach for the long-term reliability assessment of the plastic ball grid array (BGA) assembly.
The project supported by the National Natural Science Foundation of China (59705008) 相似文献
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Surprising Antibacterial Activity and Selectivity of Hydrophilic Polyphosphoniums Featuring Sugar and Hydroxy Substituents 下载免费PDF全文
Tyler J. Cuthbert Benjamin Hisey Tristan D. Harrison Dr. John F. Trant Prof. Elizabeth R. Gillies Prof. Paul J. Ragogna 《Angewandte Chemie (International ed. in English)》2018,57(39):12707-12710
There is currently an urgent need for the development of new antibacterial agents to combat the spread of antibiotic‐resistant bacteria. We explored the synthesis and antibacterial activities of novel, sugar‐functionalized phosphonium polymers. While these compounds exhibited antibacterial activity, we unexpectedly found that the control polymer poly(tris(hydroxypropyl)vinylbenzylphosphonium chloride) showed very high activity against both Gram‐negative Escherichia coli and Gram‐positive Staphylococcus aureus and very low haemolytic activity against red blood cells. These results challenge the conventional wisdom in the field that lipophilic alkyl substituents are required for high antibacterial activity and opens prospects for new classes of antibacterial polymers. 相似文献
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Heather L. Cuthbert Andrew I. Wallbank Nicholas J. Taylor John F. Corrigan 《无机化学与普通化学杂志》2002,628(11):2483-2488
Reaction of lithium phenylselenothiolate, generated in situ from the reductive cleavage of PhSe‐SiMe3 with alkyl lithium reagents and insertion of elemental sulfur, with triphenylphosphine solubilized CuCl affords the molecular cluster complex [Cu20Se4 (μ3‐SePh)12(PPh3)6] ( 1 ). The analogous reaction with AgCl yields the extended structure [Ag(SePh)]∞ ( 2 ) in which an infinite layer of AgI atoms is capped on either side by μ4‐SePh ligands. 1: space group P¯1, a = 17.9510(6), b = 18.1712(7), c = 31.4311(11) Å, a = 78.098(2), β = 82.905(2), γ = 70.012(2)°. 2: space group C2/c, a = 5.8762(6), b = 7.2989(7), c = 29.124(2) Å, β = 95.790(3)°. 相似文献
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A new and convenient synthesis of benzo-fused 8-oxabicyclo[3.2.1]octane and 9-oxabicyclo[4.2.1]nonane derivatives are described. The reaction involved a TiCl(4)-mediated tandem carbonyl or imine addition followed by a Friedel-Crafts cyclization to provide these functionalized derivatives in good to excellent yields and high diastereoselectivity. 相似文献
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T. Cuthbert Day 《Fresenius' Journal of Analytical Chemistry》1889,28(1):620-621
Ohne Zusammenfassung 相似文献
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Daneshvar P Yazdanpanah M Cuthbert C Cole DE 《Rapid communications in mass spectrometry : RCM》2003,17(4):358-362
Enzymatic cyclization of homocysteine forms a reactive thiolactone that may play an important role in its cardiovascular toxicity, but reliable quantitation of the free thiolactone metabolite in physiological fluids has not been reported. We have therefore used a highly selective gas chromatography/mass spectrometry (GC/MS) technique combined with the sensitivity of negative chemical ionization (NCI) to develop a quantitative method for the detection of homocysteine thiolactone (HcyTL) in plasma. To improve accuracy the deuterated isomer d(4)-HcyTL was synthesized and added to plasma as internal standard. The plasma was then treated with silica solid-phase extraction and derivatized with heptafluorobutyric anhydride. The derivative was analyzed by GC/MS in NCI mode with methane as the reagent gas and quantified by analyzing for the HcyTL ion [M(-)[bond]HF] and its d(4)-HcyTL counterpart in single-ion monitoring mode. The calibration curve showed a dynamic linear range up to 40 nmol/L. Within-day precision (n = 20, nominal concentration 5.2 nmol/L) was 0.96% and between-day precision was 3.9%, with a detection limit of 1.7 nmol/L and quantification limit of 5.2 nmol/L. Two human plasma samples had HcyTL concentrations of 18 and 25 nmol/L. This facile method for quantitation of homocysteine thiolactone opens the way for more detailed clinical studies of its potential role in homocysteine-induced arteriosclerosis and vaso-occlusive disease. 相似文献
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Heather L. Cuthbert John E. Greedan Lachlan Cranswick 《Journal of solid state chemistry》2006,179(7):1938-1947
La5Re3CoO16 and La5Re3NiO16 were synthesized by solid-state reaction and studied by SQUID magnetometry, heat capacity and powder neutron diffraction measurements. These two compounds belong to a series of isostructural Re-based pillared perovskites [Chi et al. J. Solid State Chem. 170 (2003) 165]. Magnetic susceptibility measurements indicate apparent short-range ferri or ferromagnetic correlations and possible long-range antiferromagnetic order for La5Re3CoO16 at 35 K, and at 38 and 14 K for La5Re3NiO16. Heat capacity measurements of the Co compound show a lambda anomaly, typical of long-range magnetic order, at 32 K. In contrast, the Ni compound displays a broader, more symmetric feature at 12 K in the heat capacity data, indicative of short-range magnetic order. Low-temperature powder neutron diffraction revealed contrasting magnetic structures. While both show an ordering wave vector, k=(0,0,1/2), in La5Re3CoO16, the Co2+ and Re5+ moments are ordered ferrimagnetically within the corner-shared octahedral layers, while the layers themselves are coupled antiferromagnetically along the c-axis, as also found in La5Re3MnO16 and La5Re3FeO16. In the case of the Ni material, the Re5+ and Ni2+ moments in the perovskite layers couple ferromagnetically and are canted 30° away from the c-axis, angled 45° in the ab-plane. The layers then couple antiferromagnetically at low temperature, a unique magnetic structure for this series. The properties of the La5Re3MO16 series, with M=Mn, Fe, Co, Ni and Mg are also reviewed. 相似文献