Development of Dispersive Liquid-Liquid Microextraction Based on Solidification of Floating Organic Drop for the Sensitive Determination of Trace Copper in Water and Beverage Samples by Flame Atomic Absorption Spectrometry

Chunxia Wu,Bin Zhao,Qiuhua Wu,Chun Wang,Zhi Wang,Yingli Li 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.3

A dispersive liquid-liquid microextraction based on solidification of floating organic droplet (DLLME-SFO)has been developed as a new approach for the extraction of trace copper in water and beverage samples followed by the determination with flame atomic absorption spectrometry. In the DLLME-SFO, 8-hydroxy quinoline, 1-dodecanol, and methanol were used as chelating agent, extraction solvent and dispersive solvent,respectively. The experimental parameters related to the DLLME-SFO such as the type and volume of the extraction and dispersive solvent, extraction time, sample volume, the concentration of chelating agent and salt addition were investigated and optimized. Under the optimum conditions, the enrichment factor for copper was 122. The method was linear in the range from 0.5 to 300 ng mL^(−1) of copper in the samples with a correlation coefficient (r) of 0.9996 and a limit of detection of 0.1 ng mL^(−1). The method was applied to the determination of copper in water and beverage samples. The recoveries for the spiked water and beverage samples at the copper concentration levels of 5.0 and 10.0 ng mL^(−1) were in the range between 92.0% and 108.0%. The relative standard deviations (RSD) varied from 3.0% to 5.6%.

The Design of the Multi-Scale Data Fusion Algorithm Based on Time Series Analysis

Chunxia Wang 보안공학연구지원센터 2016 International Journal of Database Theory and Appli Vol.9 No.12

Time series is an indicator at different times on different values, arranged in chronological sequence. The basic idea of the multi-scale analysis by orthogonal transformation, and it is such as wavelet transform signal decomposition analysis on different scales. The timing analysis method is achieved through the model method. The process parameters of the dynamic data time-domain analysis method is a parametric model to fit the observed data, and then use this model to analyze the observational data and produce data system. The paper presents the design of the multi-scale data fusion algorithm based on time series analysis. Finally, the advantages of the new algorithm are elaborated from the estimation accuracy and simulation demonstrated the effectiveness of the new algorithm.

Routing Protocol of Cognitive Ad Hoc Network

Chunxia Wang 보안공학연구지원센터 2015 International Journal of Future Generation Communi Vol.8 No.5

This paper proposes a priori cross layer routing protocol CLC-DSDV routing protocol in cognitive Ad Hoc network, the protocol will combine channel management mechanism and DSDV routing protocol in Ad Hoc network, and aiming at the existing problem of multi channel DSDV-MC routing protocol such as primary user interference, routing load imbalance, routing reconfiguration have been improved, in order to achieve the effective use of wireless spectrum of cognitive Ad Hoc networks. Concrete improvements on the routing protocol are described: joining the node load considerations in the routing process; through the information of the global routing table of each node for distribution in channel allocation; channel allocation information embedded in routing newspaper information and broadcasting timely; starting routing update packets to ensure compliance with the neighbor node information synchronization at the channel switching time. The simulation of the routing protocol based on NS2, the simulation results show that the CLC-DSDV routing protocol can effectively improve the utilization of licensed spectrum rate, throughput, delay, packet loss rate, routing load and other aspects can be more outstanding than the original multi channel routing protocol DSDV-MC.

Based on the Ant Colony Algorithm is a Distributed Intrusion Detection Method

Yiran Wang,Chunxia Wang 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.4

This paper analyzes the present situation of the current network security problems and points out the research and development of intrusion detection system has very important significance on the basis of comparative analysis of the traditional static security model and PPDR dynamic security model, and according to this model, using ant colony algorithm is a distributed computing network intrusion of metrics, the determination of index contrast and invasion route, increase the accuracy of testing operation and calculation results show that the effectiveness of the solution and the convergence speed. For distributed network intrusion is put forward a new kind of means.

Comparative transcriptome analysis of salt-sensitive and salt-tolerant maize reveals potential mechanisms to enhance salt resistance

Mingquan Wang,Yufeng Wang,Yifei Zhang,Chunxia Li,Shichen Gong,Shuqin Yan,Guoliang Li,Guanghui Hu,Honglei Ren,Jianfei Yang,Tao Yu,Kejun Yang 한국유전학회 2019 Genes & Genomics Vol.41 No.7

Background Salt stress is a devastating environmental stress that causes plant growth inhibition and yield reduction. Objective The identification of salt-tolerant genes brings hope for the generation of salinity-tolerant crop plants through molecular breeding. Methods In this study, one salt-sensitive and one salt-tolerant maize inbred line were screened from 242 maize inbred lines. Reactive oxygen species (ROS)-related enzyme activities were detected and salt-responsive comparative transcriptome analysis was performed for control and 220 mM NaCl treated maize leaves. Results Salt-tolerant maize inbred line (L87) showed higher ROS-related enzyme (SOD, POD, APX and CAT) activities and accumulated relatively lower levels of ROS under salt stress. Of the total DEGs, 1856 upregulated DEGs were specific to L87, including stress tolerance-related members of the 70kDa family of heat shock proteins (Hsp70s) and aquaporins. The DEGs involved in the abscisic acid (ABA), ethylene, jasmonic acid (JA) and salicylic acid (SA) signal transduction pathways may determine the difference in salt tolerance between the two varieties, especially one central component SnRK2, that positively regulates ABA signaling and was only upregulated in L87. Analysis of DEGs related to ROS scavenging showed that some peroxidase (POD), glutathione S-transferase (GST), catalase (CAT) and superoxide dismutase (SOD) genes specific to L87 probably enhanced its salt tolerance. The analysis of differentially expressed transcription factors (TFs) suggested that WRKY TFs could contribute to the difference in salt tolerance between the two maize lines. Conclusion Compared with Salt-sensitive maize inbred line (L29), L87 exhibits specific regulatory mechanisms related to salt tolerance, including plant hormone interactions, ROS scavenging and the regulation of TFs. Our study identifies new candidate genes that may regulate maize tolerance to salt stress and provides useful information for breeding maize with high salt resistance.

Development of Dispersive Liquid-Liquid Microextraction Based on Solidification of Floating Organic Drop for the Sensitive Determination of Trace Copper in Water and Beverage Samples by Flame Atomic Absorption Spectrometry

Wu, Chunxia,Zhao, Bin,Li, Yingli,Wu, Qiuhua,Wang, Chun,Wang, Zhi Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.3

A dispersive liquid-liquid microextraction based on solidification of floating organic droplet (DLLME-SFO) has been developed as a new approach for the extraction of trace copper in water and beverage samples followed by the determination with flame atomic absorption spectrometry. In the DLLME-SFO, 8-hydroxy quinoline, 1-dodecanol, and methanol were used as chelating agent, extraction solvent and dispersive solvent, respectively. The experimental parameters related to the DLLME-SFO such as the type and volume of the extraction and dispersive solvent, extraction time, sample volume, the concentration of chelating agent and salt addition were investigated and optimized. Under the optimum conditions, the enrichment factor for copper was 122. The method was linear in the range from 0.5 to $300\;ng\;mL^{-1}$ of copper in the samples with a correlation coefficient (r) of 0.9996 and a limit of detection of $0.1\;ng\;mL^{-1}$. The method was applied to the determination of copper in water and beverage samples. The recoveries for the spiked water and beverage samples at the copper concentration levels of 5.0 and $10.0\;ng\;mL^{-1}$ were in the range between 92.0% and 108.0%. The relative standard deviations (RSD) varied from 3.0% to 5.6%.

Dynamic characteristic parameters identification analysis of a parallel manipulator with flexible links

Chunxia Zhu,Jing Wang,Zhiwen Chen,Bo Liu 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.12

This paper presents dynamic parameters identification analysis of a 3-TPT parallel manipulator with flexible links by means of simulationand experiment. The 3-TPT mechanism is described in detail, and the dynamic equations of the regarded mechanism are derivedanalytically based on the Newton’s second law. The dynamic simulation model of parallel manipulator with flexible links is built by theintegration method of virtual prototyping (VP) and finite element analysis (FEA), which forms the flexible multi-body system of parallelmanipulator. Frequency response curves are obtained by applied force on the simulation model, and the stiffness and damping ratio areidentified, respectively, from the simulation results. The strategy has been experimentally tested on an actual 3-TPT parallel manipulator. The compared results show that the errors are very small and reasonable scope, so it is feasible for the integration method used as referenceand basis for dynamic characteristic. Therefore, the integration simulation method provides a theoretical foundation and referencefor dynamic optimal design of parallel manipulator. These analyses and results provide valuable insight into the design and control of theparallel manipulator with flexible links.

Serological and molecular epidemiology of Japanese encephalitis virus infections in swine herds in China, 2006–2012

Chunxia Chai,Qiao Wang,Sanjie Cao,Qin Zhao,Yiping Wen,Xiaobo Huang,Xintian Wen,Qiguai Yan,Xiaoping Ma,Rui Wu 대한수의학회 2018 Journal of Veterinary Science Vol.19 No.1

Japanese encephalitis virus (JEV) is a mosquito-borne, zoonotic flavivirus causing viral encephalitis in humans and reproductive disorder in swine. JEV is prevalent throughout China in human; however, spatiotemporal analysis of JEV in Chinese swine herds has not been reported previously. Herein, we present serological and molecular epidemiological results and estimates of prevalence of JEV infections among swine herds in various regions of China. The results suggest that JEV infections are widespread and genotype I and III strains co-exist in the same regions. Therefore, there is an urgent need to monitor JEV infection status among swine herds in China.

Preparation of Nano-Convex and Nano-Concave-Patterned Polyimide Surfaces and their Nano-Tribological Behavior

Chunxia Wu,XIAOLIANG ZHANG,HONGWEI CHE,JINGBO MU,Guangshuo Wang,Zhixiao Zhang,Guohua Cui 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2017 NANO Vol.12 No.4

In this work, nano-convex-patterned polyimide surface (notated as 1-sample) and nano-concavepatterned polyimide surface (notated as 2-sample) were prepared by self-assembly and etching. Atomic force microscope (AFM) with a colloidal probe was used to examine the adhesion and nano-tribological behavior of the 1-sample and 2-sample. Results suggest that the 1-sample and 2-sample can decrease the surface friction and adhesive forces because of the decreased contact area between the contacting pairs. The friction forces of the 1-sample and 2-sample increased with the increase in sliding velocity and applied load. Moreover, the nano-concave pattern is more effective in reducing the adhesive force than the nano-convex pattern because of its higher surface roughness. However, the nano-convex patterning is more effective in reducing the friction force than the nano-concave patterning because of the smaller area of contact between the 2-sample and the colloidal probe.

Ding projective modules with respect to a semidualizing module

Chunxia Zhang,Limin Wang,Zhongkui Liu 대한수학회 2014 대한수학회보 Vol.51 No.2

In this paper, we introduce and discuss the notion of DC- projective modules over commutative rings, where C is a semidualizing module. This extends Gillespie and Ding, Mao’s notion of Ding projective modules. The properties of DC-projective dimensions are also given.