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High mixing effectiveness lobed nozzles and mixing mechanisms

Science China(Technological Sciences) 2015年第7期58卷 1218-1233页

作者： SHENG ZhiQiang CHEN ShiChun WU Zhe huang PeiLin School of Aeronautic Science and Engineering Beijing University of Aeronautics and Astronautics

For a circular lobed nozzle with the exit plane displaced from the center body,adding a central plug at exit or replacing the nozzle with an alternating-lobe nozzle can improve the mixing *** this study,numerical investigations of jet mixing in the lobed nozzles with a central plug and alternating-lobe nozzles in pumping operation were *** effects of the central plugs with the wake ranging from attached to separated flow on the mixing were analyzed,along with the mechanism of improving the mixing performance in a"sword"alternating-lobe *** simulation results reveal that the large-scale mixing rate,which is dominated by streamwise vortices,is related to the intensity of the attainable heat and mass transfer in the streamwise *** effects of the streamwise vortices on the normal vortex ring are virtually a manifestation of the heat and mass transfer/mixing process of the streamwise *** simulation results also show that the central plug with the attached rear-flow performs better in improving the mixing effectiveness and pumping performance;on the contrary,if the rear-flow is separated,more pressure loss will be *** particular,a completely separated flow over the rear of the central plug will severely degrade the attainable heat and mass transfer in the streamwise *** the sword alternating-lobe nozzle,wider sword deep troughs help to increase the flux of the secondary stream around the core region and delay the confluence of the primary stream in the region between the deep and shallow ***,the mixing is improved in the middle and posterior *** to the lobed nozzle with a central plug,the improved sword alternating-lobe nozzle can achieve a higher mixing effectiveness with much less pressure loss,which is preferred in situations when the power loss of the engine is restricted.

关键词： jet mixing lobed nozzle mixing effectiveness streamwise vortices heat and mass transfer

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A recursive model for static empty container allocation

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Frontiers of Computer Science 2011年第4期5卷 486-495页

作者： Zijian GUO Wenyuan WANG Guolei TANG Jun huang Faculty of Infrastructure Engineering Dalian University of Technology Dalian 116023 China Transport Planning and Research Institute Ministry of Communications Beijing 100028 China

Backlogged empty containers have gradually turned into a serious burden to shipping networks. Empty container allocation has become an urgent settlement issue for the container shipping industry on a global scale. Therefore, this paper proposes an improved immune algorithm based recursive model for optimizing static empty container allocation which integrates with the global maritime container shipping network. This model minimizes the operating and capital costs during container shipping considering 0-1 mixed-integer programming. So an immune algorithm procedure based on a special two- dimensional chromosome encoding is proposed. Finally, computational experiments are performed to optimize a 10-port static empty container shipping system. The results indicate that the proposed recursive model for static empty container allocation is effective in making an optimal strategy for empty container allocation.

关键词： immune algorithm shipping network emptycontainer allocation

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Agent-based Collaborative Design Framework Supporting Synchronization and Asynchronization on Internet

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High Technology Letters 2001年第1期7卷 59-62页

作者：李旭东 huang Kezheng Province Key CAD Lab. Shandong University of Technology

On the basis of analysis of the research issues and requirement of collaborative design, we propose the overall framework of agent based collaborative design on Internet. Then, we describe the implementation of synchronous and asynchronous collaborative design process based on standardized design activities under the overall framework. In order to realize design message passing, the DMP Protocol is proposed as well in this paper and described in detail.

关键词： Collaborative design process Agent Synchronous Asynchronous Internet

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Research progress in performance improvement strategies and sulfur conversion mechanisms of Li-S batteries based on Fe series nanomaterials

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Nano Research 2024年第9期17卷 8045-8067页

作者： Ziyang huang Zhenghua Wang Lei Zhou Jun Pu Key Laboratory of Functional Molecular Solids(Ministry of Education) College of Chemistry and Materials ScienceAnhui Provincial Engineering Laboratory for New-Energy Vehicle Battery Energy-Storage MaterialsAnhui Normal UniversityWuhu 241000China School of Energy and Power Engineering Jiangsu UniversityZhenjiang 212013China Department of Electrical Engineering Eindhoven University of TechnologyEindhoven MB 5600The Netherlands

Lithium-sulfur(Li-S)batteries hold the potential to revolutionize energy storage due to the high theoretical capacity and energy ***,the commercialization process is seriously hindered by the rapid capacity decay and low utilization of sulfur,caused by the inevitable slow dynamics and the“shuttle effect”.The incorporation of metal-based electrocatalysts into sulfur cathodes shows promise in promoting the conversion of lithium polysulfides(LiPSs),reducing the“shuttle effect”,and enhancing cell kinetics and cycle *** these,Fe-based materials,characterized by environmental friendliness,low cost,abundant reserves,and high activity,are extensively used in sulfur cathode *** article reviews the advancements of Fe-based materials in enhancing Li-S batteries in recent *** from single/multi-component Fe-based metal compounds and single/bimetallic atoms,the influence of different Fe coordination environments on the conversion mechanism of LiPSs is *** is hoped that this review and the proposed prospects can further stimulate the development and application of the Fe element in Li-S batteries in the future.

关键词： Li-S batteries Fe-based nanomaterials shuttle effect reaction kinetics

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Practical constrained least-square algorithm for moving source location using TDOA and FDOA measurements

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Journal of Systems Engineering and Electronics 2012年第4期23卷 488-494页

作者： Huagang Yu Gaoming huang Jun Gao Bo Yan College of Electronic Engineering Naval University of Engineering Wuhan 430033 P. R. China Marine Communication Technology Institute Beijing 100841 P. R. China

By utilizing the time difference of arrival （TDOA） and frequency difference of arrival （FDOA） measurements of signals received at a number of receivers, a constrained least-square （CLS） algorithm for estimating the position and velocity of a moving source is proposed. By utilizing the Lagrange multipliers technique, the known relation between the intermediate variables and the source location coordinates could be exploited to constrain the solution. And without requiring apriori knowledge of TDOA and FDOA measurement noises, the proposed algorithm can satisfy the demand of practical applications. Additionally, on basis of con- volute and polynomial rooting operations, the Lagrange multipliers can be obtained efficiently and robustly allowing real-time imple- mentation and global convergence. Simulation results show that the proposed estimator achieves remarkably better performance than the two-step weighted least square （WLS） approach especially for higher measurement noise level.

关键词： source localization constrained least-square(CLS),time difference of arrival (TDOA) frequency difference of arrival(FDOA) Lagrange multiplier.

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A flight experimental platform for synchrophasing control based on a small propeller UAV

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Science China(Technological Sciences) 2018年第12期61卷 1915-1924页

作者： CAO YunFei huang XiangHua SHENG Long WANG ZhiPeng College of Energy and Power Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China JiangSu Province Key Laboratory of Aerospace Power System Nanjing 210016 China

Turboprop engine has the advantages of high efficiency and high thrust, but it has not been widely used in the civil field because of the noise excited by the low speed propellers. Propeller synchrophasing control is an active noise control method without increasing the weight of the airframe, which can attenuate the noise level in the cabin by controlling the relative phase among multiple propellers. It is generally accepted that altitude and airspeed have a great influence on the noise reduction effect of propeller synchrophasing, but there is no theoretical research about how these two factors affect the noise level. Therefore, flight experiment is considered to be a credible way. However, flight experiments of propeller synchrophasing control in turboprop aircraft have been accomplished in few countries due to enormous cost and inconvenience. An experimental platform of synchrophasing control based on a two-propeller small unmanned air vehicle(UAV) is proposed which can carry out the flight experiment research in a low-cost way. The phase angle sensor, the FOC-based scheme of motor driving, the all-slave synchrophasing control and the coordination between speed and phase difference control are presented in the UAV platform to meet its synchrophasing control precision requirement, experimental results prove that all of them can significantly enhance the performance of synchrophasing control. Noise characteristics of propellers are studied in the flight experiments, the noise predicted by the noise model is highly consistent with the actual measured noise, which verifies that the noise characteristics of small UAV accord with propeller signature theory. Based on the noise model, propeller synchrophasing has a steady effect to minimizing noise in the UAV platform. These show that the UAV platform is a feasible solution for propeller synchrophasing research.

关键词： propeller synchrophasing noise reduction small UAV flight experimental platform low cost

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Multi-feature-Based Subjective-Sentence Classification Method for Chinese Micro-blogs

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Chinese Journal of Electronics 2017年第6期26卷 1111-1117页

作者： ZHANG Yangsen ZHANG Yaorong JIANG Yuru huang gaijuan Beijing Information and Technology University

The accurate classification of subjective and objective sentences is important in the preparation for micro-blog sentiment analysis. Since a single feature type cannot provide enough subjective information for classification, we propose a Support vector machine(SVM)-based classification model for Chinese micro-blogs using multiple features. We extracted the subjective features from the Part of speech(POS) and the dependency relationship between words, and constructed a 3-POS subjective pattern set and a dependency template set. We fused these two types of features and used an SVM-based model to classify Chinese micro-blog text. The experimental results showed that the performance of the classification model improved remarkably when using multiple features.

关键词： Micro-blog sentiment analysis Subjective and objective classification Support vector machine(SVM) 3-POS subjective pattern set Dependency template set

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Quantum state tomography for generic pure states

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Science China(Physics,Mechanics & Astronomy) 2018年第11期61卷 1-7页

作者： ShiLin huang JianXin Chen YouNing Li Bei Zeng Institute for Interdisciplinary Information Sciences Tsinghua University Beijing 100084 China Aliyun Quantum Laboratory Hangzhou 310000 China Department of Physics and Collaborative Innovation Center of Quantum Matter Tsinghua University Beijing 100084 China Department of Mathematics & Statistics University of Guelph Guelph NIG2W1 Canada Institute for Quantum Computing University of Waterloo Waterloo N2L3G1 Canada

We examine the problem of whether a multipartite pure quantum state can be uniquely determined by its reduced density *** show that a generic pure state in three party Hilbert space HA■HB■HC, where dim(HA) = 2 and dim(HB) = dim(HC), can be uniquely determined by its reduced states on subsystems HA■HB and HA■HC. Then, we generalize the conclusion to the case that dim(H_1) > 2. As a corollary, we show that a generic N-qudit pure quantum state is uniquely determined by only two of its[(N+1)/2]-particle reduced density matrices. Furthermore,our results indicate a method to uniquely determine a generic N-qudit pure state of dimension D = d^N with only O(D) local measurements, which is an improvement compared to the previous known approach that uses O(D log^2 D) or O(D log D) local measurements.

关键词： state reconstruction quantum tomography foundations of quantum mechanics measurement theory

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Study of testability measurement method for equipment based on Bayesian network model

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Journal of Systems Engineering and Electronics 2009年第5期20卷 1017-1023页

作者： Lian Guangyao huang Kaoli Chen Jianhui Wei Zhonglin Ordnance Engineering Coll. Shijiazhuang 050003 P. R. China

To analyze and evaluate the testability design of equipment, a testability analysis method based on Bayesian network inference model is proposed in the paper. The model can adequately apply testability information and many uncertainty information of design and maintenance process, so it can analyze testability by and large from Bayesian inference. The detailed procedure to analyze and evaluate testability for equipments by Bayesian network is given in the paper. Its modeling process is simple, its formulation is visual, and the analysis results are more reliable than others. Examples prove that the analysis method based on Bayesian network inference can be applied to testability analysis and evaluation for complex equipments.

关键词： design for testability testability analysis and evaluation uncertainty information Bayesian network

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Low-resistance, high-force, and large-ROM fabric-based soft elbow exosuits with adaptive mechanism and composite bellows

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Science China(Technological Sciences) 2023年第1期66卷 24-32页

作者： huang WeiCheng FENG Miao YANG DeZhi GU GuoYing Robotics Institute School of Mechanical EngineeringShanghai Jiao Tong UniversityShanghai 200240China State Key Laboratory of Mechanical System and Vibration Shanghai Jiao Tong UniversityShanghai 200240China Meta Robotics Institute Shanghai Jiao TongUniversityShanghai 200240China

Due to the lightweight and compliance, fabric-based pneumatic exosuits are promising in the assistance and rehabilitation of elbow impairments. However, existing elbow exosuits generally suffer from remarkable mechanical resistance on the flexion of the elbow, thus limiting the output force, range of motion(ROM), and comfortability. To address these challenges, we develop a fabric-based soft elbow exosuit with an adaptive mechanism and composite bellows in this work. With the elbow kinesiology considered, the adaptive mechanism is fabricated by sewing the interface of the exosuit into spring-like triangle pleats, following the profile of the elbow to elongate or contract when the elbow flexes or extends. The composite bellows are implemented by further sealing a single blade of bellows into two branches to enhance the output force. Based on these structural features, we characterize the mechanical performance of different soft elbow exosuits: exosuit with normal bellows-NB, exosuit with adaptive mechanism and normal bellows-AMNB, exosuit with adaptive mechanism and composite bellows-AMCB. Experimental results demonstrate that by comparing with NB, the mechanical resistance of AMNB and AMCB decreases by 80.6% and 78.6%, respectively;on the other hand, the output torque of AMNB and AMCB increases to 120.3% and 207.0%, respectively, at50 k Pa when the joint angle is 120°. By wearing these exosuits on a wooden arm model(1.25 kg), we further verify that AMCB can cover a full ROM of 0°–130° at the elbow with 500 g weight. Finally, the application on a health volunteer with AMCB shows that when the volunteer flexes the elbow to lift a weight of 500 g, the s EMG activity of the biceps and triceps is markedly reduced.

关键词： wearable robots rehabilitation robots soft robot applications soft actuators design

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