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Size-selective pH-operated megagates on mesoporous silica materials.
Xue, Min,Cao, Dennis,Stoddart, J Fraser,Zink, Jeffrey I RSC Pub 2012 Nanoscale Vol.4 No.23
<P>pH-responsive megagates have been fabricated around mesoporous silica material SBA-15 in order to mechanize the mesopores. These megagates remain closed in neutral conditions, but open at pH 5. The capping components of the megagates were designed to be capable of controlling pores up to 6.5 nm in diameter. Selectivity of payloads with different sizes can be achieved through the use of different capping components. The operation of the megagates was demonstrated by time-resolved fluorescence spectroscopy which is capable of monitoring the release of both the payload and the cap. This study opens up new possibilities in the field of controllable release.</P>
P2PCloud-W: A Novel P2PCloud Workflow Management Architecture Based on Petri Net
Xuemin Zhang,Zenggang Xiong,Gangwei Wang,Conghuan Ye,Xu Fang 보안공학연구지원센터 2015 International Journal of Grid and Distributed Comp Vol.8 No.2
IaaS model in the Cloud Computing provides infrastructure services to users. However, the provider of such centralized Cloud requires notable investments to maintain the infrastructures. P2P Cloud, whose infrastructures are provided by multiple volunteer nodes in the P2P network, gives a low cost option to the provision of Cloud Computing. P2PCloud workflow is used to handle tasks with control and data dependencies, and plays an important role in P2PCloud environment. It is essential to design an appropriate model to satisfy the distributed and heterogeneous workflow systems that must be flexible, reusable, dynamic feature in higher level. In this paper, An architecture of a P2PCloud system firstly is proposed, and then a P2PCloud-W(P2PCloud workflow system) framework is proposed, which is a novel hybrid decentralized workflow management system facilitating both Cloud and P2P technologies. Finally, a P2PCloud-W case is analyzed using Petri Net.
The Study of Services Management Based on the Network Environment
Xuemin Zhang,Zenggang Xiong,Guangwei Wang,Conghuan Ye,Fang Xu 보안공학연구지원센터 2015 International Journal of Smart Home Vol.9 No.5
Service-Oriented Architecture (SOA) constructs applications by publishing services in an open network environment. In network environment individual service changes highly dynamically, it is required the system based on services to adapt to this change. But the current service management in network environment doesn’t have a good, unified management mode, management mechanism, service and quality control system, and lacks of theoretical foundation to express formal service system. In this paper, a service management framework is designed. A mechanism and method based on strategy and dynamic network environment service management are proposed. The method can effectively solve the problem of dynamic service management in network environment, and is widely used in dynamic service management based on Web services.
Effect of serrated trailing-edge blades on aerodynamic noise of an axial fan
Xuemin Ye,Nan Zheng,Ruixing Zhang,Chunxi Li 대한기계학회 2022 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.36 No.6
A bionic geometric modification inspired by the trailing-edge serrations of owl wings provides a new approach for controlling the aerodynamic noise of rotary fluid machinery. The effect of different serrated trailing-edges (STEs) on aerodynamic performance and noise of a single-stage variable-pitch axial fan was numerically investigated using steady Reynolds averaged Navier-Stokes and large eddy simulation model, respectively. Results show that STEs could improve fan efficiency at the design and low flow rates, and significantly reduce the noise in the middle- and low-frequency as well as suppress the pressure pulsation of airflow. STEs split large-scale vortices into small ones by intensifying the turbulent flow mixing. STEs with appropriate serration parameters improve the spanwise distribution of the vortex, reduce the span dimension of wake vortices, and induce wake vortices distribution to be more uniform. The innovation of this paper is that a novel blade with partial serrations is presented for the realization of the apparent noise reduction and more preferred aerodynamic performance of the axial fan by improving serration parameters and rearranging the region of the serration.
Xuemin Zhong,Hongqi Liu,Xinyong Mao,Bin Li 한국정밀공학회 2019 International Journal of Precision Engineering and Vol.20 No.10
This paper proposes a new method to identify the squareness errors of machine tools and gives an optimal method to improve the volumetric compensation accuracy based on the identified squareness errors. The volumetric error model based on screw theory is proposed and the effects of the squareness errors on the volumetric errors have been analyzed to clarify the possibility of improving volumetric error compensation by proper and accurate squareness errors. Then the identification method of the squareness errors is deduced in theory considering a 3-axis horizontal machine tool. With the identified squareness errors, an optimal method to improve volumetric error compensation in machine tools has been proposed. Experiments have verified that the 3 identified squareness errors are in accordance with the measured squareness errors within the accuracy range. Moreover, compared with the traditional measurement of squareness errors not considering the PDGEs, the proposed method is more effective and shows error compensation improvement in the volumetric error compensation process.
Xuemin Xiao,Fei Tian,Yujun Yan,Zhilin Wu,Zhansheng Wu,Giancarlo Cravotto 한국화학공학회 2015 Korean Journal of Chemical Engineering Vol.32 No.6
Coal-based activated carbon (CAC) was prepared from coal produced in Xinjiang of China by microwave activation. CAC was characterized and used as an adsorbent for phenanthrene adsorption. The effects of temperature, adsorption time, CAC amount, initial concentration and pH value of solution on phenanthrene adsorption were studied. The adsorption rate of phenanthrene onto CAC was obtained nearly 100% with initial concentration of 100 mg/L and CAC dosage of 0.3 g at 25 oC. Phenanthrene adsorption was well described with the Langmuir isotherm. The pseudosecond- order model was found to more effectively explain the adsorption kinetics of phenanthrene. The lower temperature was favorable to the adsorption rate and equilibrium adsorption capacity of phenanthrene onto CAC. The thermodynamic parameters ΔHθ, ΔSθ and ΔGθ computed for phenanthrene adsorption onto CAC demonstrate the process was spontaneous, radiative, and entropically driven. Thus, CAC prepared by microwave activation could be effective for removing phenanthrene.
Mobility Management in Mobile Hotspots with Heterogeneous Multihop Wireless Links
Sangheon Pack,Xuemin Shen,Mark, J.W.,Jianping Pan Institute of Electrical and Electronics Engineers 2007 IEEE communications magazine Vol.45 No.9
<P>In this article we study two representative mobility management schemes for mobile hotspots with heterogeneous multihop wireless links: the NEMO basic support protocol at the network layer and the SIP-based network mobility support protocol at the application layer. We evaluate their salient features and quantify their handoff latency. It is shown that the SIP-based network mobility support protocol can easily be deployed and reduce the tunneling overhead incurred in the NEMO basic support protocol. However, it increases handoff latency due to longer message length. We also discuss several open research issues for seamless mobility support in mobile hotspots.</P>
Kongshu Deng,Xuemin Zhang,Junsheng Yang,Huangong Wang 대한기계학회 2014 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.28 No.9
This study aims to investigate the deformation characteristics under variable stiffness for the propelling mechanism of Earth pressurebalance shield machines in mixed ground. In terms of hyperstatic compatibility, a mechanical model for the driving mechanism in compositestrata is first constructed. Based on the method of regarding spatial deformation difference as measuring effect on rectifying deviationin thrust system, the deforming difference trunk for the propelling mechanism is subsequently discovered in mixed face ground. Applying deformation difference trunk to the thrust mechanism of a tunneling machine in engineering applications, the characteristics ofdeformation in thrust mechanism that affect the thrust system correction are finally discussed. Results could provide a theoretical foundationand support for the design of a new pushing mechanism in tunneling machines.
Yuqing Zhang,Xuemin Xu,Yuyuan Zhang,Jianfa Li 한국생물공학회 2011 Biotechnology and Bioprocess Engineering Vol.16 No.5
Fuel ethanol is one of the most important alternative fuels used as a substitute for fossil fuel. Lignocellulose is the most abundant biomass resource for the production of fuel ethanol. However, the hydrolysis of lignocellulose requires high enzyme loading. In order to strengthen the process of enzyme hydrolysis of lignocellulose,surfactant-polyethylene glycol (PEG) was applied to the catalysis of lignocellulose into fermentable sugars. The effect of PEG on both the enzymatic hydrolysis and adsorption of cellulose were investigated. The addition of surfactant obviously facilitated enzymatic hydrolysis. In particular, upon addition of PEG4000, the enzyme catalytic efficiency increased by 51.06%. Meanwhile,the adsorption quantity of cellulase decreased by 11.25%. In addition, the mechanism of the effect of PEG on enzymatic hydrolysis and cellulase adsorption is discussed.