South Central University for Nationalities is a national university located in Hubei province's capital Wuhan, directly under the State Ethnic Affairs Commission of PRC. It is a comprehensive university founded in 1951 and the former name was South Central College for Nationalities . In March 2002, the school adopted the current name. As one of the six national higher education institutes for ethnic groups in China, SCUN is committed to innovation in higher education for ethnic groups and thus has achieved a rapid and comprehensive development. Everyone in SCUN, led by a wise and united leadership, is making great effort for the comprehensive development of the school to improve its teaching and learning conditions, enhance its education quality, construct a harmonious campus and ultimately make SCUN an outstanding university for ethnic groups with its own distinguishing features. SCUN is well on its way to a better future. Wikipedia.
Liu H.,South-Central University for Nationalities |
Wang J.,South-Central University for Nationalities
Electrochimica Acta | Year: 2013
ZnCo2O4 nanorods are first synthesized via hydrothermal method. X-ray diffraction, scanning electron microscopy, and transmission electron microscopy are used to study the structure and shape of the obtained powders. The data indicates that the as-synthesized ZnCo 2O4 nanorods range from 150 to 200 nm in length and from 15 to 22 nm in diameter. It is the first time that two cathode peaks have been simultaneously observed on the initial cyclic voltammogram curve. A synthesis mechanism of nanorods and charge-discharge mechanism have also been supposed. EIS data shows that the ZnCo2O4 nanorods have lower surface layer resistance (∼192 Ω), which can improve electrochemical activity. The clearer plateaus are seen at ∼0.5 V for the first discharge curve and at ∼0.05 V for all the discharge curves, respectively. The initial discharge capacity is 1509 mAh g-1. After 50 cycles, the capacity is 767.15 mAh g-1. The obtained ZnCo2O4 nanorods show a great prospect for application in the anode materials of lithium ion batteries.
Liu B.,South-Central University for Nationalities |
Zhang Z.,South-Central University for Nationalities
RSC Advances | Year: 2013
In this study, prepared silica supported sulfonic acid was used as a heterogeneous catalyst for the production of 5-ethoxymethylfurfural (EMF) from fructose based carbohydrates and the synthesis of ethyl d-glucopyranoside from glucose based carbohydrates in ethanol. EMF was obtained in a high yield of 83.8% from 5-hydroxymethylfurfural (HMF) after 10 h, and a 63.1% yield was obtained from fructose at 100°C for 24 h. Temperature experiments demonstrated that a higher reaction temperature (in the case of 120°C) resulted in side reactions such as polymerization of HMF and alcoholysis of HMF into ethyl levulinates. When di- and poly-saccharides (sucrose and inulin) were used, the fructose moieties in sucrose and inulin were also successfully converted into EMF. However, the silica supported sulfonic acid catalyst was inert for the production of EMF from aldose based carbohydrates such as glucose and cellobiose. Ethyl d-glucopyranoside was formed in a high yield of 91.7% from glucose. More importantly, the catalyst could be reused several times without losing its catalytic activity with an average EMF yield of around 60% from a one-pot reaction of fructose. This work provides a good outlook for the conversion of carbohydrates into fine chemicals and biofuel additive. This journal is © The Royal Society of Chemistry 2013.
Zhou T.,South-Central University for Nationalities |
Hu J.,South-Central University for Nationalities
Environmental Science and Technology | Year: 2010
Highly crystalline metastable bismuth titanate (Bi20TiO 32) nanosheets are prepared via a simple green wet chemical route for the first time. The Bi20TiO32 photocatalysts were characterized by transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), energy dispersive spectrum analysis (EDS), X-ray diffraction (XRD), N2 adsorption-desorption (BET), and UV-vis diffuse reflectance spectroscopy (DRS). Inspiringly, Bi20TiO32 nanosheets showed high photocatalytic activity for the degradation of nonbiodegradable azo dye under simulated sunlight and visible-light irradiation. The experimental results showed that the photocatalytic activity of the Bi 20TiO32 nanosheets was superior to the commercial Degussa P25 TiO2, and demonstrated that the morphology and crystal structure have a distinct effect on the photocatalytic activity. The reasons for the high photocatalytic activity and the formation mechanism of Bi20TiO 32 nanosheets are also discussed. © 2010 American Chemical Society.
Zhu R.,South-Central University for Nationalities
International Journal of Distributed Sensor Networks | Year: 2012
Event query processing is a very important issue in wireless sensor networks (WSNs). In order to detect event early and provide monitoring information and event query timely in WSNs, an efficient intelligent collaborative event query (ICEQ) algorithm is proposed, in which sensor nodes that are near to the boundary of events are selected to accomplish complex event monitoring and query processing through intelligent collaboration. ICEQ will select range-nearest neighbors as the basic components of surrounding nodes. Then it will identify the gaps between the surrounding nodes and try to select the nearest neighbor collaborative nodes for enclosing the event in the node selection phase, which can avoid redundant sensor nodes to join surrounding nodes via identifying a set of association surrounding nodes between the nearest sensor nodes and the query events. Detailed experimental results and comparisons with existed algorithm show that the proposed ICEQ algorithm can achieve better performance in terms of query-processing time, average number of selected collaborative nodes, and query message consumption. © 2012 Rongbo Zhu.
You Z.Z.,South-Central University for Nationalities |
Hua G.J.,South-Central University for Nationalities
Journal of Alloys and Compounds | Year: 2012
Thin films of transparent conducting gallium-doped zinc oxide (GZO) were deposited by magnetron sputtering technique onto glass substrates. The films were characterized by various methods to understand their microstructural, optical and electrical characteristics. The effects of substrate temperature on the physical properties of the films were investigated. The results show that the GZO films are polycrystalline in nature having a hexagonal wurtzite type crystal structure with a preferred grain orientation in the (0 0 2) direction. The substrate temperature significantly affects the crystal structure and optoelectrical properties of the films. The GZO film grown at the substrate temperature of 670 K has the largest crystal grain, the lowest resistivity and the highest figure of merit. Meanwhile, the optical constants, dielectric function and dissipation factor of the films were determined using the methods of Manifacier and Swanepoel. The dispersion behavior of the refractive index was studied in terms of the single-oscillator Wemple-DiDomenico (W-D) model, and the oscillator parameters of the films were achieved. Furthermore, the optical energy gaps were calculated by W-D model and Tauc's relation, respectively, and the values obtained from W-D model are in agreement with those determined from the Tauc's relation. © 2012 Elsevier B.V. All rights reserved.
Xinli H.,South-Central University for Nationalities
Electronic Library | Year: 2015
Purpose - The purpose of this paper is to examine the effectiveness of information technology in reducing corruption in China. Meanwhile this paper explores whether electronic monitoring systems (EMS) can be evaluated in terms of the DeLone and McLean information systems (IS) success model. Design/methodology/approach - The status of the EMS in five cities is first proposed, and then a model of e-government system success is designed to evaluate the EMS. Data are obtained from 387 civil servants in the supervision agencies. Then the effectiveness of EMS in reducing corruption is deeply assessed, and the DeLone and McLean IS success model is validated. Findings - The findings show that the application ofEMShas a positive effect on reducing corruption. IT thus has the potential to reduce corruption, but the institution and the people are more important. Originality/value - Although many theories about reducing corruption have been proposed, the EMS application in reducing corruption has seldom been addressed. This study is the first, to the author's knowledge, to examine EMS and corruption reduction from the point of view of the IS success model. © Emerald Group Publishing Limited.
Liu H.,South-Central University for Nationalities
Journal of Electronic Materials | Year: 2014
In this work, nanosize MgFe2O4 spinel with quasispherical shape was prepared as anode material for lithium ion batteries by the hydroxide coprecipitation method. The crystal structure, composition, and morphology of the as-prepared powders were characterized by means of x-ray diffraction (XRD) analysis, x-ray photoelectron spectroscopy, and scanning electron microscopy (SEM), respectively. The XRD and SEM data revealed that the material as-prepared at 900°C was of high crystallinity and quasispherical with diameter of about 100 nm. A reaction mechanism is proposed. Theelectrochemical properties were evaluated by cyclic voltammetry and galvanostatic charge-discharge studies. The sample calcined at 900°C delivered a higher initial discharge capacity (1200 mAh g-1) and better cyclability. The enhanced electrochemical behavior was ascribed to the nanosize and the better crystallinity of the spherical powder. All the results suggest that nanosize quasispherical MgFe2O4 is a promising candidate anode material for lithium ion batteries. © 2014 TMS.
Wei Z.,South-Central University for Nationalities
Physics Letters, Section A: General, Atomic and Solid State Physics | Year: 2011
Based on Sprott D system, a simple three-dimensional autonomous system with no equilibria is reported. The remarkable particularity of the system is that there exists a constant controller, which can adjust the type of chaotic attractors. It is demonstrated to be chaotic in the sense of having a positive largest Lyapunov exponent and fractional dimension. To further understand the complex dynamics of the system, some basic properties such as Lyapunov exponents, bifurcation diagram, Poincaré mapping and period-doubling route to chaos are analyzed with careful numerical simulations. © 2011 Elsevier B.V. All rights reserved.
Zhu R.,South-Central University for Nationalities
Journal of Network and Computer Applications | Year: 2011
To provide high quality of service (QoS) for delay sensitive real-time traffic in wireless local area network-based (WLAN) mesh networks is a challenging task. In particular for real-time flows subject to multiple hops, mobility and time-varying channel, the performance of real-time flows will be degraded greatly. Efficient allocation and management of resources, such as transmission rate and throughput, is a crucial element and an attractive and efficient way for interconnecting access points (APs) to form an efficient multihop WLAN mesh network supporting QoS. Considering that IEEE 802.11 WLAN physical layers (PHYs) provide multiple transmission rates by employing different modulations and channel coding schemes, it is an important issue how to select the transmission rate so that the performance is improved, since each link generally has different characteristics with other links. In order to support real-time traffic, an efficient intelligent rate control algorithm is proposed in this paper, which aims to improve the system performance by adaptively adjusting the transmission rate to the current channel status. Based on the learning the local information of each node, the proposed algorithm can achieve accurate channel estimation without any extra implementation effort and modifications to the current 802.11 standard. And each node is able to select the optimized transmission rate, so that the system performance can be improved obviously. The proposed scheme also offers an appealing combination of the allocation of transmission rate and the current link condition. Based on the basic relationship between them, the intelligent rate control algorithm maximizes the throughput with periodic learning of channel variation and system status. Theoretical analysis proves that the proposed algorithm is quickly convergent. Detailed simulation and numerical results show the proposed rate control algorithm closely approximates the ideal case with the perfect knowledge about the channel. Compared with the existed schemes, the proposed algorithm can also significantly improve the system performance in terms of packet loss rate, end-to-end delay and throughput. © 2010 Elsevier Ltd. All rights reserved.
Zhang Z.,South-Central University for Nationalities |
Deng K.,South-Central University for Nationalities
ACS Catalysis | Year: 2015
Catalytic synthesis of value-added chemicals from renewable biomass or biomass-derived platform chemicals is an important way to reduce current dependence on fossil-fuel resources. In recent years, 2,5-furandicarboxylic acid (FDCA) has received significant attention due to its wide application in many fields, particularly as a substitute of petrochemical-derived terephthalic acid in the synthesis of useful polymers. Therefore, much effort has been devoted to the catalytic synthesis of FDCA. In this critical review, we will provide an overview of concise and up-to-date methods for the synthesis of FDCA from HMF oxidation or directly from carbohydrates by one-pot reaction, giving special attention to catalytic systems, mechanistic insight, reaction pathway, and catalyst stability. In addition, the one-pot oxidative conversion of carbohydrates into FDCA and the one-pot synthesis of FDCA derivatives are also discussed. It is anticipated that the chemistry detailed in this review will guide researchers to develop effective catalysts for the economical and environmentally friendly synthesis of FDCA in large-scale. © 2015 American Chemical Society.