Nanchang Hangkong University

About: Nanchang Hangkong University is a education organization based out in Nanchang, China. It is known for research contribution in the topics: Microstructure & Alloy. The organization has 7004 authors who have published 5270 publications receiving 62162 citations. The organization is also known as: Nanchang Aviation University.

Atomic-Level and Modulated Interfaces of Photocatalyst Heterostructure Constructed by External Defect-Induced Strategy: A Critical Review.

Abstract: Despite the existence of numerous photocatalyst heterostructures, their separation efficiency and charge flow precision remain low due to the poor study on interfacial properties. The photocatalysts with confined defects can effectively control the photogenerated carrier migration, but the metastability of such defects considerably decreases the photocatalyst stability. Meanwhile, the introduction of defective region can increase the coordinative unsaturation and delocalize local electrons to promote their interactions with the molecules/ions in that region. The selective growth of modulated heterogeneous interface by defect-induced strategy may not only increase the stability of defective structures, but also enhance the migration of interfacial charges. Using this method, photocatalytic heterostructures with low contact resistances and intimate interfaces are constructed to achieve the optimal charge migration in terms of efficiency and accuracy. In this work, the point, linear, and planar heterogeneous interfaces and related defect engineering techniques are discussed. Particularly, it is focused on the external, defect-induced interfacial heterogeneities with various spatial and dimensional configurations, which exhibit modulated and controllable interfacial properties. Furthermore, the main aspects of fabricating photocatalyst heterostructures by the defect-induced strategy, including the i) controllable generation of defects, ii) advanced characterization methods, and iii) elaborate construction of the minimal interface, are described.

Development of an open-path incoherent broadband cavity-enhanced spectroscopy based instrument for simultaneous measurement of HONO and NO2 in ambient air

Abstract: We report on the development of an optical instrument based on incoherent broadband cavity-enhanced absorption spectroscopy (IBBCEAS) for simultaneous open-path measurements of nitrous acid (HONO) and nitrogen dioxide (NO2) in ambient air using a UV light emitting diode operating at ∼366 nm. Detection limits of ∼430 pptv for HONO and ∼1 ppbv for NO2 were achieved with an optimum acquisition time of 90 s, determined by an Allan variance analysis. Based on a 1.85 m long high optical finesse open-path cavity, the effective optical path length of 2.8 km was realized in aerosol-free samples or in an urban environment at modest aerosol levels. Such a kilometer long optical absorption is comparable to that achieved in the well established differential optical absorption spectroscopy (DOAS) technology while keeping the instrument very compact. Open-path detection configuration allows one to avoid absorption cell wall losses and sampling induced artifacts. The demonstrated sensitivity and specificity shows high potential of this cost-effective and compact infrastructure for future field applications with high spatial resolution.

A g-C3N4@Au@SrAl2O4:Eu2+,Dy3+ composite as an efficient plasmonic photocatalyst for round-the-clock environmental purification and hydrogen evolution

Abstract: Here, we demonstrate a g-C3N4@Au@SrAl2O4:Eu2+,Dy3+ composite as a novel efficient self-luminous visible-light plasmonic photocatalyst for photocatalytic degradation of organic pollutants and hydrogen evolution from water around the clock. The g-C3N4@Au@SrAl2O4:Eu2+,Dy3+ composite was prepared by integrating a g-C3N4@Au plasmonic photocatalyst composite with a SrAl2O4:Eu2+,Dy3+ long-afterglow phosphor through a simple Pechini-type sol–gel method followed by a mechanical mixing and high-temperature calcination process. Owing to the synergistic effect of surface plasmon resonance of the Au nanoparticles in g-C3N4 and long-lasting phosphorescence of the SrAl2O4:Eu2+,Dy3+ phosphor, the prepared g-C3N4@Au@SrAl2O4:Eu2+,Dy3+ composite shows a continuous and efficient photocatalytic activity for photocatalytic degradation of organic pollutants and hydrogen evolution from water in a sunless environment. The current research study could provide a new strategy for designing a highly efficient composite photocatalyst for solar environmental purification and hydrogen energy production around the clock.

A remote cancelable palmprint authentication protocol based on multi-directional two-dimensional PalmPhasor-fusion

Abstract: Biometric template security and privacy issues are critical in biometric authentication systems and require special attention. However, remote biometric authentication systems demand wider array of measures for maximum protection. This paper proposes a remote cancelable palmprint authentication protocol based on multi-directional two-dimensional PalmPhasor-fusion. The main contribution is three-fold. First, with a transposition direction selection mechanism, multi-directional two-dimensional PalmPhasor MTDPP improves the accuracy performance of two-dimensional PalmPhasor. Second, we provide the theoretical analysis of the effect of transposition on the accuracy performance of two-dimensional PalmPhasor, and hence establish an effective transposition direction range for the proposed MTDPP. Third, according to our analysis, the existing remote palmprint authentication system does not satisfy non-invertibility criterion of secure template protection and is vulnerable to interception. Besides, secret message embedding as a countermeasure for database attacks deteriorates accuracy performance and causes inconvenience in updating authenticator. The proposed protocol uses multi-directional two-dimensional PalmPhasor-fusion, one-time random number encrypted with asymmetric cryptography and encrypted hash codes of MTDPP to address the problems. Copyright © 2013 John Wiley & Sons, Ltd.

A simple two-step electrochemical synthesis of graphene sheets film on the ITO electrode as supercapacitors

Abstract: In this study, a simple and controllable two-step electrochemical process is described for the synthesis of graphene sheets (GS) film on a cleaned indium tin oxide (ITO) sheet electrode. Namely, the main procedures involve the electrophoretic deposition (EPD) of graphene oxide (GO) film onto ITO electrode and the subsequent in situ electrochemical reduction (ECR) of GO to generate GS film. X-ray photoelectron spectroscopy (XPS) measurement demonstrates that most of the oxygen-containing functional groups in GO film have been removed after ECR. By electrochemical measurements, the maximum specific capacitance of the prepared GS film electrode was calculated to be 156 F g−1, besides, the capacitance retention of the material remained 78% after 400 times of cycling, showing a promising prospect as supercapacitor materials.