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Enhanced catalytic performance for direct synthesis of dimethyl ether from syngas over a La_2O_3 modified Cu-ZrO_2/γ-Al_2O_3 hybrid catalyst

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Journal of Natural Gas Chemistry 2012年第3期21卷 360-365页

作者： Zhuo li jianqing li Cheng Yang Jinhu Wu Key Laboratory of Biofuels Qingdao Institute of Bioenergy and Bioprocess Technology Chinese Academy of Sciences Qingdao 266101 Shandong China Graduate School of Chinese Academy of Sciences Beijing 100039 China

A series of hybrid catalysts were made by physically mixing Cu-ZrO2 and γ-A12O3, for former it was modified with different loadings of La2O3 prepared by co-precipitation method. The catalysts were characterized by BET, XRD, N2O-adsorption, EXAFS, H2-TPR, NH3-TPD techniques and evaluated in the synthesis of dimethyl ether from syngas. The results show that La2O3 promoted catalysts displayed a significantly better catalytic performance compared with Cu-ZrO2#y-A12O3 catalyst in CO conversion and DME selectivity, and the optimum catalytic activity was obtained when the content of La2O3 was 12 wt%. The characterizations reveal that high copper dispersion, facile reducibility of copper particles and appropriate amount of acidic sites are responsible for the superior catalytic performance.

关键词： dimethyl ether syngas hybrid catalyst Cu-ZrO2 La2O3

Autonomous navigation to quasi-periodic orbits near translunar libration points

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Chinese Journal of Aeronautics 2013年第5期26卷 1259-1268页

作者： Jing Wuxing Qian Yingjing Gao Changsheng li jianqing Department of Aerospace Engineering Harbin Institute of Technology

libration-point missions have been very useful and successful. Due to the unstable natures of most of these orbits, the long-time stationkeeping demands frequent maneuvers and precise orbit determinations. Earth-based tracking will have to undertake much more responsibilities with the increasing number of libration missions. An autonomous navigation system could offer a better way to decrease the need for Earth-based tracking. Nevertheless, when an autonomous navigation system is applied, there are three important factors affecting autonomous navigation accuracy, i.e., the accuracy of initial conditions, the accuracy of measurements, and the accuracy of onboard dynamics for propagation. This paper focuses on analyzing the influence from the third factor and finding an appropriate navigation dynamics, which can satisfy the requirement of estimation accuracy but not cause too much burden for onboard computation. When considering the restricted three-body model and the bicircular restricted four-body model as navigation dynamics, the astrin- gency is not shown during the simulations. Meanwhile, when considering the influences of the Sun＇s direct and indirect perturbations and the eccentricity of the Moon＇s orbit, a new navigation dynamic model with the standard ephemerides is proposed. The simulation shows the feasibility of the proposed model.

关键词： Autonomous navigation Extended Kalman filters libration points Multi-body dynamics Quasi-periodic orbit

Design and passive analysis of a novel softness display device

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High Technology Letters 2007年第3期13卷 239-243页

作者：吴涓 Song Aiguo li jianqing School of Instrument Science and Engineering Southeast University Nanjing 210096 P.R. China

Simulating the softness property of object is quite a challenge in virtual reality system. A novel softness display system was developed based on the principle of deformable length of elastic element control （DLEEC）. In the system, the equivalent stiffness of the device is adjustable, and is inversely proportional to the third power of the deformable length of elastic beam. PD position control is employed to guarantee the accurate softness display. The softness of the virtual objects in large scale can be felt with the softness display device. Compared with other haptic devices, the device is passive and exert the react force only when the operator ＂actively touch＂ the virtual objects. The stability of the softness display system was analyzed. It was theoretical proved that the system satisfied the criteria of wide impedance range ＂Z-width＂, and the performance was superior to an active system. The experimental results were presented.

关键词： softness display elastic beam virtual reality passive

A Reliable Routing Algorithm with Network Coding in Internet of Vehicles

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China Communications 2017年第5期14卷 174-184页

作者： Zhen Wang jianqing li Manlin Fang Yang li Botao Feng Faculty of Information Technology Macao University of Science and Technology College of Electronic Science and Technology Shenzhen University

The intelligent vehicle network uses advanced information technology to establish an efficient integrated vehicle transport system, which has received great attention in industry and academia, lnternet of Vehicles （loV） in an urban environment is operated in a wireless environment with high bit error rate and interference. In addition, the wireless link between vehicles is likely to be lost. All of this makes it an important challenge to provide reliable mobile routing in an urban traffic environment. In this paper, a reliable routing algorithm with network coding （RR_ NC） is proposed to solve the above problems. A routing node sequence is discovered in IoV from source to destination by multi-metric ant colony optimization algorithm （MACO）, and then clusters are formed around every node in the sequence. By adding linear encoding into the transmission of data between vehicle＇s clusters, the RR_NC provides much more reliable transmission and can recover the original message in the event of disorder and loss of message. Simulations are taken under different scenarios, and the results prove that this novel algorithm can deliver the information more reliably between vehicles in real-time with lower data loss and communication overhead.

关键词： intelligent transportation system (ITS) internet of vehicles (IoV) routing cluster network coding mobility

Neighborhood Modularization‑based Artificial Bee Colony Algorithm for Disassembly Planning with Operation Attributes

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Chinese Journal of Mechanical Engineering 2022年第6期35卷 165-177页

作者： Hongfei Guo linsheng Zhang Yaping Ren Leilei Meng Zhongwei Zhou jianqing li GBA and B&R International Joint Research Center for Smart Logistics School of Intelligent Systems Science and EngineeringInstitute of Physical InternetJinan University(Zhuhai Campus)Zhuhai 519070China School of Computer Science Liaocheng UniversityLiaocheng 252059China Faculty of Information Technology Macao University of Science and TechnologyMacao 999078China

The recycling and remanufacturing of end-of-life products are significant for environmental protection and resource *** is an essential process of remanufacturing end-of-life *** disassembly plans help improve disassembly efficiency and reduce disassembly *** paper studies a disassembly planning problem with operation attributes,in which an integrated decision of the disassembly sequence,disassembly directions,and disassembly tools are ***,a mathematical model is formulated with the objective of minimizing the penalty cost caused by the changing of operation ***,a neighborhood modularization-based artificial bee colony algorithm is developed,which contains a modular optimized ***,two case studies with different scales and complexities are used to verify the performance of the proposed approach,and experimental results show that the proposed algorithm outperforms the two existing methods within an acceptable computational time.

关键词： End-of-life products Disassembly planning Artificial bee colony Neighborhood modularization

Secrecy rate analysis of dual-hop AF relay wiretap channel

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High Technology Letters 2014年第4期20卷 390-394页

作者：丁飞 Song Aiguo li jianqing Wu Zhenyang School of Information Science and Engineering Southeast University Research and Development Center China Mobile Group Jiangsu Co.Ltd School of Instrument Science and Engineering Southeast University

An amplify-and-forward(AF) dual-hop relay is proposed for secure communication within Wyner s wiretap *** on an information-theoretic formulation,the average secrecy rate is characterized when two legitimate partners communicate over a quasi-static fading *** analysis and simulation results show that both cooperative strategies of average power scaling(APS) and instantaneous power scaling(IPS) are proved to be able to achieve information-theoretic security,and eavesdropper is unable to decode any information.

关键词： secrecy rate information-theoretic security amplify-and-forward (AF) dual-hop relay wiretap channel

Design method and machine learning application of acoustic holographic computational metamaterials

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Science China(Technological Sciences) 2022年第1期65卷 238-243页

作者： LV ZengYao li jianqing HOU ZeWei DING YuanShuai XU WangDong PEI YongMao Department of Engineering Mechanics/Center for Flexible Electronics Technology Applied Mechanics LaboratoryTsinghua UniversityBeijing 100084China State Key Laboratory for Turbulence and Complex Systems Department of Mechanics and Engineering ScienceCollege of EngineeringPeking UniversityBeijing 100871China

Acoustic holographic method has been used in imaging,particle manipulation,material preparation and other *** acoustics,it is important to design the implementation of any acoustic wave formation surface[1-5].Traditio... 详细信息

关键词： holographic method acoustics

Mesozoic–Cenozoic Volcanic Cycle and Volcanic Reservoirs in East China

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Journal of Earth Science 2021年第4期32卷 742-765页

作者： Guangfu Xing jianqing li Zheng Duan Mingxuan Cao Minggang Yu Pingli Chu Rong Chen Wuhan Center of China Geological Survey Wuhan 430205China Nanjing Center of China Geological Survey Nanjing 210016China

There are widespread Mesozoic–Cenozoic terrestrial volcanic activities in East China,and they produced favorable geologic factors for the volcanic *** reveal the spatio-temporal evolution of regional volcanisms and their tectonic setting,we subdivide Mesozoic–Cenozoic volcanic activities into 6 volcanic cycles(Ⅰ–Ⅵ),and summarize the temporal-spatial distribution,rock association and tectonic setting of each *** Cycle I forms a post-orogenic intraplate bimodal volcanic *** cyclesⅡandⅢinclude arc volcanic associations formed in compressional and extensional subduction environments,*** CycleⅣcontains a post-orogenic arc bimodal *** CycleⅤis a basaltic association of tholeiite series under initial rift setting,and the CycleⅥis basaltic association of alkaline series under typical rift *** volcanic strata between each cycle are bounded by regional *** above 6 volcanic cycles correspond to 6 sequential stages of tectonic evolutions from the Early Jurassic post-orogeny,the Mid-Jurassic–Cretaceous subduction of the paleo-Pacific Plate to the Cenozoic marginal *** to the geological characteristics of volcanic reservoirs in different volcanic cycles,it is put forward that the CycleⅤis the major formation period of volcanic reservoirs in East China and should be the focus of exploration,and that the volcanic reservoirs of the CycleⅣare also worthy of attention.

关键词： volcanic reservoir tectonic evolution volcanic cycle Mesozoic-Cenozoic East China

同方期刊数据库

Numerical studies on pair production in ultra-intense laser interaction with a thin solid-foil

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Plasma Science and Technology 2018年第8期20卷 11-15页

作者： Yunxian TIAN Xiaolin JIN Xiaoliang GU Weizhong YAN jianqing li Bin li National Key Laboratory of Science and Technology on Vacuum Electronics School of Physical ElectronicsUniversity of Electronic Science and Technology of ChinaChengdu 610054People＇s Republic of China Shanghai Aerospace Electronics Co. LtdChina Academy of Aerospace Electronics TechnologyShanghai 201821People＇s Republic of China

A theoretical and numerical model of photon and electron–positron pair production in strong-field quantum electrodynamics（QED） is described. Two processes are contained in our QED theoretical model, one is photon emission in the interaction of ultra-intense laser with relativistic electron（or positron）, and the other is pair production by a gamma-ray photon interacting with the laser *** model has been included in a PIC/MCC simulation code named BUMBLEBEE 1 D, which is used to simulate the laser plasma interaction. Using this code, the evolutions of electron–positron pair and gamma-ray photon production in ultra-intense laser interaction with aluminum foil target are simulated and analyzed. The simulation results revealed that more positrons are moved in the opposite direction to the incident direction of the laser under the charge separation field.

关键词： QED ultra-intense laser gamma ray photon electron-positron pair