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21.
Salts of the monooxomolybdenum(IV,V) areneselenolates having intramolecular NH...Se hydrogen bonds, [Mo(IV)O(Se-2-RCONHC6H4)4]2- (R = t-Bu, CH3, CF3) and [Mo(V)O(Se-2-t-BuCONHC6H4)4]-, were synthesized and characterized by 1H nuclear magnetic resonance (NMR), 77Se NMR, electron spin resonance (ESR), UV-visible spectra, X-ray analysis, and electrochemical measurements. 77Se-1H correlated spectroscopy (COSY) indicated a significant correlation between amide 1H and selenolate 77Se atoms through an NH...Se hydrogen bond with 1J(77Se-1H) = 5.4 Hz coupling. The hydrogen bonds contribute to the positive shift in the Mo(V)/Mo(IV) redox potential. In the crystal structure of (PPh4)2[Mo(IV)O(Se-2-CH3CONHC6H4)4], an NH...O=Mo hydrogen bond was found. Ab inito calculations support the presence of intramolecular NH...O=Mo and NH...Se hydrogen bonds.  相似文献   
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The line-cell (or line-seru) conversion is an innovation of assembly system applied widely in the electronics industry. Its essence is tearing out an assembly line and adopting a mini-assembly unit, called seru (or Japanese style assembly cell). In this paper, we develop a multi-objective optimization model to investigate two line-cell conversion performances: the total throughput time (TTPT) and the total labor hours (TLH). We analyze the bi-objective model to find out its mathematical characteristics such as solution space, combinatorial complexity and non-convex properties, and others. Owing to the difficulties of the model, a non-dominated sorting genetic algorithm that can solve large size problems in a reasonable time is developed. To verify the reliability of the algorithm, solutions are compared with those obtained from the enumeration method. We find that the proposed genetic algorithm is useful and can get reliable solutions in most cases.  相似文献   
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The root of Strobilanthes cusia BREMEK. (Acanthaceae), popularly known as Da-Ching-Yeh, has been commonly used in traditional Chinese medicine. It is used to treat influenza, epidemic cerebrospinal meningitis, encephalitis B, viral pneumonia, mumps, and severe acute respiratory syndrome (SARS). In this study, we found a new lignan glycoside (6) and two new phenylethanoid glycosides (7, 8) together with five known compounds as chemical constituents of Strobilanthes cusia root. Some samples were examined for anti-herpes simplex virus type-1 (HSV-1) activity. Among the tested samples, lupeol showed anti-HSV-1 activity (EC(50): 11.7 microM) and showed 100% inhibition of virus plaque formation at 58.7 microM.  相似文献   
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Polymers derived from 2-[2-(perfluoroalkyl)ethyl]-2-oxazolines have been prepared in very good yields with molecular weights up to 50000. The polymers are crystalline with melting temperatures (Tm's) varying from 180 to 232°C depending on the length and type of the perfluorinated side chain, have good thermal stability and are soluble in fluorinated solvents. They are effective as modifiers of surfaces of hydrophilic polymers, such as nylon-6,6, and give acceptable complement activation parameters. Factor C3a (μg/ml) released is 5.3 in contrast to positive control value of 45.2 (activated sepharose) and negative control = 4.8. A 1:1 mixture of 2-octyl-2-oxazoline and 2-[2-(perfluorohexyl)ethyl]-2-oxazoline copolymerize to give a block copolymer that exhibits two separate Tm's. The partially perfluorinated polymers also form stable monolayers at air-water interface.  相似文献   
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The current study investigated the effect of noise on sleep in subjects' own houses using recorded traffic noises. A railway noise and two kinds of road traffic noise differing in level-fluctuations were used as stimuli. Subjects were exposed all night to the artificially controlled stimuli for 10 days through a portable compact disc (CD) player. The effect of noise on sleep was judged in three ways, namely whether the subject had switched off the CD player, a self-declaration of the subject based on a questionnaire, and the amount of arm movement of the subject during the night as measured by an actigraph. The results of the analysis of the self-declaration data showed that the thresholds where sleep disturbance began were 40-45 dB in for road traffic noise and about 35 dB for railway noise, which corresponded to 50-55 dB in LA,Fmax of each train noise event. The results of the analysis of the actigraphy data showed a rapid increase in the incidence of mid-sleep awakening at sound pressure levels higher than 50 dB, for railway noise. However, neither of the road traffic noises showed such a tendency, as long as the sound pressure level was less than 55 dB, .  相似文献   
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A new fluorescent probe for Mn2+ ion, (6E)-N-((E)-1,2-diphenyl-2-(pyridin-2-ylimino)ethylidene)pyridin-2-amine (L), has been synthesized from benzil and 2-amino pyridine and characterized. In 1:1 (v/v) CH3CN:H2O (pH 4.0, universal buffer) L exhibits fluorescent intensity with emission peak at λmax 360 nm on excitation with photons of 310 nm. Fluorescent intensity of L increases distinguishingly on interaction with Mn2+ ion compared to metal ions—Na+, K+, Ca2+, Mg2+, Ba2+, Fe2+, Co2+, Ni2+, Cu2+, Zn2+, Cd2+, Hg2+, Pb2+ and Ag+ individually or all together. The enhancement in fluorescent intensity is due to snapping of photoinduced electron transfer (PET) prevailed in free L. Fluorescence and UV/visible spectral data analysis shows that binding stoichiometry between Mn2+ and L is 1:1 with log β?≈?3.0. Both L and its Mn2+ complex were optimised using density functional theory (DFT) and vibrational frequency calculations confirm that both are at local minima on the potential energy surfaces.  相似文献   
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L-proline, one of abundant amino acids, can be utilized as a biobased feedstock for the synthesis of an amino alcohol, L-prolinol, which serves as chiral auxiliary in a variety of asymmetric synthesis. Herein we examined selective hydrogenation of L-proline into L-prolinol over M−MoOx/Al2O3 (M=Pt, Rh, Pd, and Ru) in aqueous H3PO4 solution. Pt-MoOx/Al2O3 exhibited high activity among the catalysts, affording L-prolinol in 75 % selectivity and >99.9 % enantiomeric excess, while Pt/Al2O3 was inactive. Mo species were highly dispersed as a polyoxo cluster on both Pt nanoparticles and Al2O3 support, and participated concertedly with Pt nanoparticles in the hydrogenation. Activated carboxyl group of L-proline by MoOx species on Pt nanoparticle are readily hydrogenated with dissociative hydrogen formed on the same Pt nanoparticle with MoOx species, giving an effective route for the hydrogenation of L-proline. Pt-MoOx/Al2O3 could be identified as an active and reusable catalyst due to no loss of its original activity.  相似文献   
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