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Wang X.,Shandong University | Yu L.,Shandong University | Jiao J.,Shandong University | Zhang H.,Guangxi Agricultural Vocational Technical College | And 2 more authors.
Journal of Molecular Liquids | Year: 2012

A series of novel COOH-functionalized imidazolium-based surface active ionic liquids (SAILs), N-alkyl-N′-carboxymethyl imidazolium bromide ([N-C n, N′-CO 2H-Im]Br, n = 10, 12, 14), was synthesized. Their aggregation behavior in aqueous solution was investigated by surface tension and steady-state fluorescence measurements. From surface tension data, a group of micellization parameters was obtained. Compared with 1-alkyl-3-methylimidazolium bromide ([C nmim]Br) bearing the same hydrocarbon chain, [N-C n, N′-CO 2H-Im]Br exhibits considerably lower critical micelle concentration (cmc) and surface tension at cmc (γ cmc), higher adsorption efficiency (pC 20) and effectiveness of surface tension reduction (π cmc), indicating the incorporation of carboxyl group favors micelle formation. The average aggregation number (N agg) values of [N-C n, N′-CO 2H-Im]Br, determined by fluorescence quenching method, are slightly different from those of [C nmim]Br. The effect of temperature on the aggregation behavior of [N-C 12, N′-CO 2H-Im]Br was also studied. It is found that there exists a minimum cmc at nearly 38 °C, which is higher than that of [C 12mim]Br. © 2012 Elsevier B.V. All rights reserved. Source


Jiao J.,Shandong University | Dong B.,Shandong University | Zhang H.,Guangxi Agricultural Vocational Technical College | Zhao Y.,Shandong University | And 3 more authors.
Journal of Physical Chemistry B | Year: 2012

Halogen-free, low-cost alkyl sulfate-based surface active ionic liquids (SAILs), 1-butyl-3-methylimidazolium dodecyl sulfate ([C4mim][C 12SO4]), and N-butyl-N-methylpyrrolidinium dodecyl sulfate ([C4MP][C12SO4]) were easily synthesized through ion exchange reaction. The aggregation behaviors of [C 4mim][C12SO4] and [C4MP][C 12SO4] in aqueous solution were investigated by surface tension, electric conductivity, and static fluorescence quenching. Both [C 4mim][C12SO4] and [C4MP][C 12SO4] have rather lower cmc, γcmc values and higher pC20, πcmc values than those reported for the traditional ionic surfactant, sodium dodecyl sulfate (SDS), and imidazolium-based SAIL, 1-dodecyl-3-methylimidazolium bromide ([C 12mim]Br), with the same hydrocarbon chain length. The thermodynamic parameters evaluated from electric conductivity measurements show that the micelle formation of [C4mim][C12SO4] and [C4MP][C12SO4] is entropy-driven in the temperature range investigated. Lower average aggregation number indicates that the micelles of two SAILs present much looser structure. It is found that both the nature and the ring type of counterions can affect the aggregation behavior in aqueous solution. 1H NMR results of [C4mim][C 12SO4] were used to further verify the mechanism of micelle formation. Hydration ability and steric hindrance of the imidazolium or pyrrolidinium counterion as well as the cooperative hydrophobic interaction of longer alkyl chain of [C12SO4] anion and comparatively shorter alkyl chain of [C4mim] or [C4MP] cation are proposed to play critical roles in the aggregation of [C4mim][C 12SO4] and [C4MP][C12SO 4]. © 2011 American Chemical Society. Source


Lou B.H.,Guangxi Citrus Research Institute | Deng C.L.,Guangxi Citrus Research Institute | Song Y.Q.,Guangxi Citrus Research Institute | Zhao X.L.,Guangxi Agricultural Vocational Technical College | And 2 more authors.
Journal of Plant Pathology | Year: 2013

In September 2010, erumpent, callus-like lesions with water- soaked margins, the typical citrus canker (CC) symptoms, were observed on leaves of Nanfeng tangerine [Citrus reticulata Blanco var. kinokuni (Tanaka) H.H. Hu] in Guangxi Province (China). Seven leaf samples of Nanfeng tangerine showing symptoms of CC were collected from three different groves. Pathogen isolations were done using Luria-Bertani medium, and yellow mucoid, Xanthomonas-like isolates were selected. Pathogenicity tests were carried out on Nanfeng tangerine, navel orange (C. sinensis), Mexican lime (C. aurantifolia), and Eureka lemon (C. limon). Four attached leaves of each one-year-old citrus cultivar were inoculated with each of seven isolated Xanthomonas-like strains and two previously identified X. citri subsp. citri pathotype A (Xcc-A) strains at 1 × 107 CFU/ml. After 21 days, all inoculated bacterial isolates induced clear-cut CC symptoms on each of the four tested citrus species and were successfully re-isolated from the symptomatic leaves of inoculated plants. The 16S rDNA and 16S/23S intergenic transcribed spacer (ITS) of the seven isolates were amplified with primer sets fD1/rP1 (1) and 1493f/23r (2), respectively, cloned and sequenced. Consensus sequences of 1469 bp 16S rDNA (accession No. KC820706) and 545 bp 16S/23S ITS (KC820707) were obtained. BLAST analysis showed both 16S rDNA and 16S/23S ITS from this study had the highest sequence identity (99.9% and 100%, respectively) with those of Xcc strain 306 (AE008923). These results confirmed that the pathogen inducing typical CC symptoms on Nanfeng tangerine was Xcc-A. To our knowledge, this is the first formal report of Xcc-A on Nanfeng tangerine in China. Source


Jiao J.,Shandong University | Zhang H.,Guangxi Agricultural Vocational Technical College | Yu L.,Shandong University | Wang X.,Shandong University | Wang R.,Shandong University
Colloids and Surfaces A: Physicochemical and Engineering Aspects | Year: 2012

Multi-walled carbon nanotubes (MWCNTs) could be well dispersed in the aqueous solution of 1-hexadecyl-3-methylimidazolium bromide ([C 16mim]Br), an amphiphilic ionic liquid, because of hydrophobic interaction. [C 16mim]Br could self-assemble and form hemimicelles on the surfaces of MWCNTs. MWCNTs became positively charged due to the adsorption of C 16mim + and negatively charged Au nanoparticles (Au NPs) could be easily attached to the surfaces of MWCNTs by electrostatic interaction. In the UV-vis region, disappearance of characteristic adsorption peaks of MWCNTs and Au NPs indicates that Au NPs are completely attached to the MWCNTs in aqueous solution. Transmission electron microscope (TEM) images show Au NPs are uniformly deposited on the walls of MWCNTs. Both X-ray powder diffraction (XRD) and X-ray photoelectron spectroscopy (XPS) patterns illustrate the existence of high purity Au NPs in MWCNTs-Au NPs hybrids. In this work, amphiphilic ionic liquid has been used to disperse MWCNTs and subsequently MWCNTs-Au NPs hybrids have been prepared by a very simple strategy. © 2012 Elsevier B.V. Source


Yu S.,Guangxi Agricultural Vocational Technical College | Huang X.,Guangxi Agricultural Vocational Technical College
WIT Transactions on Information and Communication Technologies | Year: 2014

The network security is becoming more and more important in today's society. Network security defence system is an important part of information security assurance and by using new methods to improve the real-time performance and adaptability has become a hot spot. This paper introduces the basic principle of the neural network based on T-S model discusses its application in network security defence system, and analyzes the security hidden danger existing in the current network system. In the end, from the three aspects, that is, computer network hardware, software, network management, it proposed the "trinity" of the computer network security protection system construction ideas. © 2014 WIT Press. Source

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