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Synthesis of a kind of geminal imidazolium ionic liquid with long aliphatic chains

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Chinese Chemical Letters 2007年第1期18卷 48-50页

作者： Yun Sheng Ding Min zha jun zhang Seng Shan Wang Department of Polymer Materials and Engineering School of Chemical Engineering Hefei University of Technology Hefei 230009 China CAS Key Laboratory of Engineering Plastics Joint Laboratory of Polymer Science and Materials Institute of Chemistry Chinese Academy of Sciences Beijing 100080 China

A novel geminal imidazolium ionic liquid with long hydrocarbon group, 1,4-bis （3-tetradecylimidazolium- 1-yl） butane bromide was synthesized and an efficient synthesized method was introduced detailedly. Its structu... 详细信息

关键词： Geminai imidazolium ionic liquid Long aliphatic chain Physicochemicai properties

Rangeland Grasshoppers in Relation to Soils in the Qinghai Lake Region, China

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Pedosphere 2007年第1期17卷 84-89页

作者： NI Shao-Xiang WANG Jie-Chen JIANG Jian-jun zha Yong College of Geographical Science Nanjing Normal University Nanjing 210097 （China） Department of Urban and Resources Science Nanjing UniversityNanjing 910093 （China）

The relationship between rangeland grasshopper density and soil type as well as topsoil moisture content was analyzed with in situ soil data collected in the Qinghai Lake region of China. Grasshoppers were confined mainly to the areas with light chestnut soil or chestnut soil, and very few were found in areas with subalpine meadow soil. Grasshoppers were almost absent from other types of soil, such as aeolian soil. In addition, analysis of 14 soil samples collected in the study area revealed that a soil moisture content between 18 and 32 g kg-1 coincided spatially with a higher density of grasshoppers, with the grasshopper density averaging 15 head m-2. In areas with a soil moisture content above 42 g kg-1 or below 10 g kg-1, grasshopper density dropped to less than 5 head m-2. These indicated that for the study area, soils with very high or very low moisture contents were not conducive to the survival of grasshoppers.

关键词： Qinghai Lake rangeland grasshopper soil type soil moisture

Unpinning the spiral waves by using parameter waves

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Chinese Physics B 2021年第5期30卷 682-686页

作者： Lu peng jun Tang School of Materials and Physics China University of Mining and TechnologyXuzhou 221116China

The spiral waves anchored to heterogeneous areas are more difficult to control and eliminate than freely rotating ones in homogenous *** eliminate pinned spiral waves,the resistant force should be provided to resist the pinning *** than advection field,we introduce parametric wave to play the role of providing resistant *** is found that the parametric wave with large enough amplitude and proper frequency can unpin and eliminate the spiral wave *** capability of parametric wave in providing resistant force is dependent on its amplitude and frequency *** the basis of parametric wave,the dependence of pinning force on the size and level of heterogeneity is further confirmed.

关键词： pinned spiral wave heterogeneity pinning force

Electrochemical synthesis ofα,α-dihaloacetophenones from terminal alkyne derivatives

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Chinese Chemical Letters 2020年第7期31卷 1855-1858页

作者： Zhibin Li Qi Sun peng Qian Kangfei Hu Zhenggen zha Zhiyong Wang Hefei National Laboratory for Physical Sciences at Microscale CAS Key Laboratory of Soft Matter Chemistry&Center for Excellence in Molecular Synthesis of Chinese Academy of SciencesCollaborative Innovation Center of Suzhou Nano Science and Technology&School of Chemistry and Materials ScienceUniversity of Science and Technology of ChinaHefei 230026China

By virtue of electrochemistry,a series ofα,α-dihaloacetophenones were easily obtained with good to excellent *** electrochemical procedure was taken in a divided cell with constant current in aqueous *** reaction can be carried out smoothly at room temperature under metal and oxidant free condition,which provides an eco-friendly synthesis for theα,α-dihaloacetophenone derivatives.

关键词： Electrochemistry Alkyne derivatives α,α-Dihaloacetophenones Divided cell Oxidant free

Numerical Simulation of the Vortex-Induced Vibration of A Curved Flexible Riser in Shear Flow

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China Ocean Engineering 2018年第3期32卷 301-311页

作者： ZHU Hong-jun LIN peng-zhi State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum University State Key Laboratory of Hydraulics and Mountain River Engineering Sichuan University

A series of fully three-dimensional(3 D) numerical simulations of flow past a free-to-oscillate curved flexible riser in shear flow were conducted at Reynolds number of 185–1015. The numerical results obtained by the two-way fluid–structure interaction(FSI) simulations are in good agreement with the experimental results reported in the earlier study. It is further found that the frequency transition is out of phase not only in the inline(IL) and crossflow(CF) directions but also along the span direction. The mode competition leads to the non-zero nodes of the rootmean-square(RMS) amplitude and the relatively chaotic trajectories. The fluid–structure interaction is to some extent reflected by the transverse velocity of the ambient fluid, which reaches the maximum value when the riser reaches the equilibrium position. Moreover, the local maximum transverse velocities occur at the peak CF amplitudes, and the values are relatively large when the vibration is in the resonance regions. The 3 D vortex columns are shed nearly parallel to the axis of the curved flexible riser. As the local Reynolds number increases from 0 at the bottom of the riser to the maximum value at the top, the wake undergoes a transition from a two-dimensional structure to a 3 D one. More irregular small-scale vortices appeared at the wake region of the riser, undergoing large amplitude responses.

关键词： vortex-induced vibration flexible riser shear flow fluid–structure interaction computational fluid dynamics

Reliability and Availability Models of Belt Drive Systems Considering Failure Dependence

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Chinese Journal of Mechanical Engineering 2019年第2期32卷 133-144页

作者： peng Gao Liyang Xie jun Pan School of Mechanical Engineering Liaoning Shihua University School of Mechanical Engineering and Automation Zhejiang Sci-Tech University School of Mechanical Engineering and Automation Northeastern University

Conventional reliability models of belt drive systems in the failure mode of fatigue are mainly based on the static stress strength interference model and its extended models, which cannot consider dynamic factors in the operational duration and be used for further availability analysis. In this paper, time-dependent reliability models, failure rate models and availability models of belt drive systems are developed based on the system dynamic equations with the dynamic stress and the material property degradation taken into account. In the proposed models, dynamic failure dependence and imperfect maintenance are taken into consideration. Furthermore, the issue of time scale inconsistency between system failure rate and system availability is proposed and addressed in the proposed system availability models. Besides, Monte Carlo simulations are carried out to validate the established models. The results from the proposed models and those from the Monte Carlo simulations show a consistency. Furthermore, the case studies show that the failure dependence, imperfect maintenance and the time scale inconsistency have significant influences on system availability. The independence assumption about the belt drive systems results in underestimations of both reliability and availability. Moreover, the neglect of the time scale inconsistency causes the underestimate of the system availability. Meanwhile, these influences show obvious time-dependent characteristics.

关键词： Availability Reliability Belt drive Failure dependence Time scale inconsistency

Density-based rough set model for hesitant node clustering in overlapping community detection

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Journal of Systems Engineering and Electronics 2014年第6期25卷 1089-1097页

作者： jun Wang Jiaxu peng Ou Liu School of Economics and Management Beihang University School of Accounting and Finance The Hong Kong Polytechnic University

Overlapping community detection in a network is a challenging issue which attracts lots of attention in recent years.A notion of hesitant node（HN） is proposed. An HN contacts with multiple communities while the communications are not strong or even accidental, thus the HN holds an implicit community ***, HNs are not rare in the real world network. It is important to identify them because they can be efficient hubs which form the overlapping portions of communities or simple attached nodes to some communities. Current approaches have difficulties in identifying and clustering HNs. A density-based rough set model（DBRSM） is proposed by combining the virtue of densitybased algorithms and rough set models. It incorporates the macro perspective of the community structure of the whole network and the micro perspective of the local information held by HNs, which would facilitate the further ＂growth＂ of HNs in community. We offer a theoretical support for this model from the point of strength of the trust path. The experiments on the real-world and synthetic datasets show the practical significance of analyzing and clustering the HNs based on DBRSM. Besides, the clustering based on DBRSM promotes the modularity optimization.

关键词： density-based rough set model(DBRSM) overlapping community detection rough set hesitant node(HN) trust path

A Sensor Redeployment Algorithm Based on Virtual Forces for Underwater Sensor Networks

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Chinese Journal of Electronics 2018年第2期27卷 413-421页

作者： JIANG peng WANG Xingmin LIU jun College of Automation Hangzhou Dianzi University

Practical underwater sensor networks redeployment algorithm needs to fully consider limited node resources, node move time and other characteristics in real environment. A Redeployment based on virtual forces(RBVF) algorithm is proposed. The non-persistent carrier sense multiple access protocol is introduced to solve communication conflicts between nodes during redeployment process. Based on existing study on three-dimensional space node deployment, the threshold value is determined to divide the attractive and repulsion forces. The speed of the node is considered. Simulation results indicate that the RBVF algorithm can achieve better coverage and less total move distance when moving nodes are not considered in virtual forces *** flow force is introduced, and a Virtual forces redeployment based on energy consuming(VFRBEC) algorithm is proposed, where different energy consumptions in different directions are used to modify node displacement. Simulation results indicate that the VFRBEC algorithm can achieve the same coverage performance with the RBVF algorithm with less energy and is better than the redeployment based on combined virtual forces algorithm in terms of both coverage and energy consumption performances.

关键词： Underwater sensor networks Virtual forces Node redeployment Water flow force

An improved differential evolution algorithm for learning high-fidelity quantum controls

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Science Bulletin 2019年第19期64卷 1402-1408页

作者： Xiaodong Yang jun Li Xinhua peng CAS Key Laboratory of Microscale Magnetic Resonance and Department of Modern Physics University of Science and Technology of ChinaHefei230026China Shenzhen Institute for Quantum Science and Engineering and Department of Physics Southern University of Science and TechnologyShenzhen518055China Center for Quantum Computing Peng Cheng LaboratoryShenzhen518055China Shenzhen Key Laboratory of Quantum Science and Engineering Southern University of Science and TechnologyShenzhen518055China Synergetic Innovation Centre of Quantum Information&Quantum Physics University of Science and Technology of ChinaHefei230026China

Precisely and efficiently designing control pulses for the preparation of quantum states and quantum gates are the fundamental tasks for quantum ***-based optimal control methods are the routine to design such ***,the gradient information is often difficult to calculate or measure,especially when the system is not well calibrated or in the presence of various ***-free evolutionary algorithm is an alternative choice to accomplish this task but usually with ***,we design an efficient mutation rule by using the information of the current and the former individuals *** leads to our improved differential evolution algorithm,called da *** demonstrate its performance,we numerically benchmark the pulse optimization for quantum states and quantum gates preparations on small-scale NMR *** numerical comparisons with conventional differential evolution algorithms show that da DE has great advantages on the convergence speed and robustness to several uncertainties including pulse imperfections and measurement errors.

关键词： Control pulses searching Differential evolution Quantum states and gates preparation Pulse imperfections Random measurement errors