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Liu S.-Q.,Suzhou University of Science and Technology
Environmental Chemistry Letters | Year: 2012

Photocatalytic degradation of organic pollutants using suspended and dispersed semiconductor nano-photocatalysts in wastewater holds unique advantages, including high activity, low cost, solar utilization, and complete mineralization. But the recovery and reuse of photocatalysts are difficult because the fine particles are easily discharged in waters. Immobilization of photocatalysts on supports such as glass and zeolite results in decreased activities due to the low specific area and slow mass transfer. Furthermore, a large amount of the photocatalysts will result in colored contamination. Therefore, it is necessary to develop photocatalysts with a separation function for the reusable and cyclic application. In order to take advantage of the high activity and enable the semiconductor nano-photocatalysts to be reused, the concept of magnetic photocatalysts with separation function was raised. We review the photocatalytic principle, structure, and application of the magnetic semiconductor catalysts. © 2011 Springer-Verlag.

Zhang Y.,Suzhou University of Science and Technology | Zhou Y.,Suzhou University of Science and Technology
Nonlinear Dynamics | Year: 2013

The fractional Pfaffian variational problems and the fractional Noether theory are studied under a fractional model presented by El-Nabulsi. Firstly, the fractional action-like Pfaffian variational problem is presented, the El-Nabulsi-Pfaff-Birkhoff-d'Alembert fractional principle is established, then the El-Nabulsi-Birkhoff fractional equations are derived; secondly, the definitions and criteria of the fractional Noether symmetric transformations are given, which are based on the invariance of El-Nabulsi-Pfaffian action under the infinitesimal transformations of group, then the inner relationship between a fractional Noether symmetry and a fractional conserved quantity is established; finally, two examples are given to illustrate the application of the results. © 2013 Springer Science+Business Media Dordrecht.

Zhang J.,Suzhou University of Science and Technology | Yu S.-H.,Suzhou University of Science and Technology
Nanoscale | Year: 2014

Hydrothermal treatment of 3-aminopropyltrimethoxysilane (APTMS) in the presence of sodium citrate generates a suspension of highly fluorescent silicon nanocrystals that fluoresces blue under UV irradiation. The photoluminescent quantum yield of the as-prepared silicon nanocrystals was calculated to be 21.6%, with quinine sulfate as the standard reference. Only mercuric ions (Hg2+) can readily prevent the fluorescence of the silicon nanocrystals, indicating a remarkably high selectivity towards Hg2+ over other metal ions. The optimized sensor system shows a sensitive detection range from 50 nM to 1 μM and a detection limit of 50 nM. The quenching mechanism was explained in terms of optical absorption spectra and time-resolved fluorescence decay spectra. Due to the strong interaction of Hg2+ with the thiol group, the fluorescence can be fully recovered by biothiols such as cysteine and glutathione, therefore, a regenerative strategy has been proposed and successfully applied to detect Hg2+ by the same sensor for at least five cycles. Endowed with relatively high sensitivity and selectivity, the present sensor holds the potential to be applied for mercuric assay in water. © the Partner Organisations 2014.

Cong H.-P.,Suzhou University of Science and Technology | Cong H.-P.,Hefei University of Technology | Chen J.-F.,Suzhou University of Science and Technology | Yu S.-H.,Suzhou University of Science and Technology
Chemical Society Reviews | Year: 2014

Due to the outstanding physicochemical properties arising from its truly two-dimensional (2D) planar structure with a single-atom thickness, graphene exhibits great potential for use in sensors, catalysts, electrodes, and in biological applications, etc. With further developments in the theoretical understanding and assembly techniques, graphene should enable great changes both in scientific research and practical industrial applications. By the look of development, it is of fundamental and practical significance to translate the novel physical and chemical properties of individual graphene nanosheets into the macroscale by the assembly of graphene building blocks into macroscopic architectures with structural specialities and functional novelties. The combined features of a 2D planar structure and abundant functional groups of graphene oxide (GO) should provide great possibilities for the assembly of GO nanosheets into macroscopic architectures with different macroscaled shapes through various assembly techniques under different bonding interactions. Moreover, macroscopic graphene frameworks can be used as ideal scaffolds for the incorporation of functional materials to offset the shortage of pure graphene in the specific desired functionality. The advantages of light weight, supra-flexibility, large surface area, tough mechanical strength, and high electrical conductivity guarantee graphene-based architectures wide application fields. This critical review mainly addresses recent advances in the design and fabrication of graphene-based macroscopic assemblies and architectures and their potential applications. Herein, we first provide overviews of the functional macroscopic graphene materials from three aspects, i.e., 1D graphene fibers/ribbons, 2D graphene films/papers, 3D network-structured graphene monoliths, and their composite counterparts with either polymers or nano-objects. Then, we present the promising potential applications of graphene-based macroscopic assemblies in the fields of electronic and optoelectronic devices, sensors, electrochemical energy devices, and in water treatment. Last, the personal conclusions and perspectives for this intriguing field are given. © 2014 the Partner Organisations.

Huang W.,Suzhou University of Science and Technology | Gao Y.,Suzhou University of Science and Technology
Catalysis Science and Technology | Year: 2014

Surface chemistry and catalysis over oxide nanocrystals with well-defined morphologies are emerging as a hot topic, and the relevant progress on CeO2 nanocrystals is critically reviewed. CeO2 nanocrystals expose morphology-dependent crystal planes on their surfaces, and CeO2 nanocrystal and metal/CeO2 nanocrystal catalysts exhibit morphology-dependent surface chemistry and catalysis. A comprehensive analysis of the published literature nicely correlates the surface chemistry and catalysis of CeO2 nanocrystal and metal/CeO2 nanocrystal catalysts with the surface composition/structure and oxygen vacancy structure of exposed CeO2 crystal planes. A concept of morphology engineering of oxide nanocrystals not only for the optimization of the catalytic performance but also for the fundamental understanding of the structure-activity relation and catalytic reaction mechanism is discussed. This journal is © the Partner Organisations 2014.

Zhang C.-L.,Suzhou University of Science and Technology | Yu S.-H.,Suzhou University of Science and Technology
Chemical Society Reviews | Year: 2014

Nanofibres can be fabricated by various methods and perhaps electrospinning is the most facile route. In past years, electrospinning has been used as a synthesis technique and the fibres have been prepared from a variety of starting materials and show various properties. Recently, incorporating functional nanoparticles (NPs) with electrospun fibres has emerged as one of most exciting research topics in the field of electrospinning. When NPs are incorporated, on the one hand the NPs endow the electrospun fibres/mats novel or better performance, on the other hand the electrospun fibres/mats could preserve the NPs from corrosion and/or oxidation, especially for NPs with anisotropic structures. More importantly, electrospinning shows potential applications in self-assembly of nanoscale building blocks for generating new functions, and has some obvious advantages that are not available by other self-assembly methods, i.e., the obtained free-standing hybrid mats are usually flexible and with large area, which is favourable for their commercial applications. In this critical review, we will focus on the fabrication and applications of NPs-electrospun fibre composites and give an overview on this emerging field combining nanoparticles and electrospinning. Firstly, two main strategies for producing NPs-electrospun fibres will be discussed, i.e., one is preparing the NPs-electrospun fibres after electrospinning process that is usually combined with other post-processing methods, and the other is fabricating the composite nanofibres during the electrospinning process. In particular, the NPs in the latter method will be classified and introduced to show the assembling effect of electrospinning on NPs with different anisotropic structures. The subsequent section describes the applications of these NPs-electrospun fibre mats and nanocomposites, and finally a conclusion and perspectives of the future research in this emerging field is given. © 2014 The Royal Society of Chemistry.

Wang F.,Suzhou University of Science and Technology | Cai Y.,Suzhou University of Science and Technology
Optics Express | Year: 2010

We present a detailed investigation of the second-order statistics of a twisted Gaussian Schell-model (TGSM) beam propagating in turbulent atmosphere. Based on the extended Huygens-Fresnel integral, analytical expressions for the second-order moments of the Wigner distribution function of a TGSM beam in turbulent atmosphere are derived. Evolution properties of the second-order statistics, such as the propagation factor, the effective radius of curvature (ERC) and the Rayleigh range, of a TGSM beam in turbulent atmosphere are explored in detail. Our results show that a TGSM beam is less affected by the turbulence than a GSM beam without twist phase. In turbulent atmosphere the Rayleigh range doesn't equal to the distance where the ERC takes a minimum value, which is much different from the result in free space. The second-order statistics are closely determined by the parameters of the turbulent atmosphere and the initial beam parameters. Our results will be useful in long-distance free-space optical communications. ©2010 Optical Society of America.

Yao H.-B.,Suzhou University of Science and Technology | Ge J.,Suzhou University of Science and Technology | Mao L.-B.,Suzhou University of Science and Technology | Yan Y.-X.,Suzhou University of Science and Technology | Yu S.-H.,Suzhou University of Science and Technology
Advanced Materials | Year: 2014

Rigid biological systems are increasingly becoming a source of inspiration for the fabrication of next generation advanced functional materials due to their diverse hierarchical structures and remarkable engineering properties. Among these rigid biomaterials, nacre, as the main constituent of the armor system of seashells, exhibiting a well-defined 'brick-and-mortar' architecture, excellent mechanical properties, and interesting iridescence, has become one of the most attractive models for novel artificial materials design. In this review, recent advances in nacre-inspired artificial carbonate nanocrystals and layered structural nanocomposites are presented. To clearly illustrate the inspiration of nacre, the basic principles relating to plate-like aragonite single-crystal growth and the contribution of hierarchical structure to outstanding properties in nacre are discussed. The inspiration of nacre for the synthesis of carbonate nanocrystals and the fabrication of layered structural nanocomposites is also discussed. Furthermore, the broad applications of these nacre inspired materials are emphasized. Finally, a brief summary of present nacre-inspired materials and challenges for the next generation of nacre-inspired materials is given. Artificial carbonate nanocrystals and layered structural nanocomposites: this review focuses on two kinds of nacre-inspired materials, including artificial carbonate nanocrystals and layered structural nanocomposites. An overview of the latest developments and advances in the synthesis, fabrication, and applications of nacre-inspired materials is presented. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Chen Y.,Suzhou University of Science and Technology | Cai Y.,Suzhou University of Science and Technology
Optics Letters | Year: 2014

We analyze the intensity of a Laguerre-Gaussian correlated Schell-model (LGCSM) beam focused by a thin lens near the focal region, and it is found that a controllable optical cage can be formed through varying the initial spatial coherence width. Furthermore, we carry out experimental measurement of the intensity of a focused LGCSM beam, and we observe that the optical cage is indeed formed in experiment. Our results will be useful for trapping particles or atoms. © 2014 Optical Society of America.

Zhang Y.,Suzhou University of Science and Technology
Chinese Physics B | Year: 2012

In this paper, we focus on studying the fractional variational principle and the differential equations of motion for a fractional mechanical system. A combined Riemann - Liouville fractional derivative operator is defined, and a fractional Hamilton principle under this definition is established. The fractional Lagrange equations and the fractional Hamilton canonical equations are derived from the fractional Hamilton principle. A number of special cases are given, showing the universality of our conclusions. At the end of the paper, an example is given to illustrate the application of the results. © 2012 Chinese Physical Society and IOP Publishing Ltd.

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