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991.
992.
Gold nanoparticles functionalized with self-assembled films of ferrocenylhexanethiol and mercaptoundecanoic acid (MUA) were used for the determination of ascorbic acid (AA). The modified nanoparticles (mNPs) were prepared by a combination of the modified Schifrin’s and the place-exchange methods. Well-organized films were obtained due to electrostatic attraction between the carboxy groups of MUA and cationic surface of poly(diallyldimethylammonium chloride). The mNP films are highly stable and can be exploited to fabricate an enzyme-less sensor for AA whose function is based on the highly electrocatalytic activity of ferrocene in the mNPs towards AA. The sensor was characterized by cyclic voltammetry and chronoamperometry. Under optimal conditions, the response current towards AA is proportional to its concentration in the range from 8.0 μM to 6.0 mM, with a detection limit of 0.14 μM (at a signal-to-noise ratio of 3). This work represents a simple controlled test-bed for fundamental studies on the use of self-assembled mNPs for sensor applications.  相似文献   
993.
A theoretical investigation of the H2O + HCNO reaction, which is carried out by means of CCSD(T)/6‐311G(d,p)//B3LYP/6‐311G(d,p)+ZPVE computational method to determine a set of reasonable pathways, there are seven product pathways, P i with i = 1 , 2 , …, 7 are involved. It is shown that P 1 (H2O + NCOH), P 2 (CO + NH2 + OH), P 4 (HCN + HO2 + H), and P 6 (CO + NH2OH) are the major product channels; and P 7 (HOC + H2 + NO) is the minor product channels, whereas the other channels for P 3 (HNO + HCOH) and P 5 (HNO + H2CO) are very minor, the minor product channels. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011  相似文献   
994.
A series of novel pyrazole amides J1 , J2 , J3 , J4 , J5 , J6 , J7 , J8 , J9 , J10 , J11 , J12 , J13 , J14 , J15 containing an α‐aminophosphonate moiety were synthesized and subsequently characterized by spectral (IR, 1H‐, 13C‐, 31P‐, and 19F‐NMR) data and elemental analysis. The racemic sample of J1 was further separated into its enantiomers under normal‐phase condition on two immobilized polysaccharide‐based chiral stationary phases (Chiralpak IA and Chiralpak IC). The synthesized compounds revealed certain degree of antiviral activity in the bioassay. The title compounds ( J3 , J10 , and J12 ) showed some curative activities (39.9%, 41.8%, 50.1%, respectively) against tobacco mosaic virus at 0.5 mg/mL. J. Heterocyclic Chem., 00 , 00 (2011).  相似文献   
995.
996.
1 引 言 对于一阶常微分方程 y'=f(t,y).(1) 的数值解法,目前常用的主要有两类方法:单步法和线性多步法(Linear Multistep Methods,LMM).  相似文献   
997.
Ir(ppy)2(VPHD) (ppy=2-phenyl pyridine, VPHD=6-(4-vinylphenyl)-2,4-hexanedione) was copolymerized with methyl methacrylate (MMA). The copolymer had high quantum yield of 52.3±0.5% in dilute ethyl acetate solution, and the yield increased around 45% than that of the iridium monomer. The maximum emission peaks for the copolymers shifted from 515 to 489 nm while the iridium complex content was less than 0.005 mol% in the feed. The blue emission at 489 nm and the green emission at 520 nm were analyzed by Lorenz function. They are attributed to 1MLCT and 3MLCT emissions, respectively.  相似文献   
998.
An oxidative rearrangement of cyclic tertiary a-hydroxy allylsilanes has been carried out in refluxing ClCH2CH2Cl with pyridinium chlorochromate(PCC).The reaction provides a convenient method to synthesize cyclicβ-silylenones in modest to excellent yields.  相似文献   
999.
1000.
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