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A Finite and Instantaneous Screw Based Approach for Topology Design and Kinematic Analysis of 5-Axis Parallel Kinematic Machines

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Chinese Journal of Mechanical Engineering 2018年第2期31卷 66-75页

作者： Tao Sun Shuo-Fei Yang Tian Huang jian S.dai Key Laboratory of Mechanism Theory and Equipment Design of Ministry of Education Tianjin University School of Engineering The University of Warwick Centre for Robotics Research School of Natural Sciences and Mathematics King’s College London University of London

Unifying the models for topology design and kinematic analysis has long been a desire for the research of parallel kinematic machines(PKMs). This requires that analytical description, formulation and operation for both finite and instantaneous motions are performed by the same mathematical tool. Based upon finite and instantaneous screw theory, a unified and systematic approach for topology design and kinematic analysis of PKMs is proposed in this paper. Using the derivative mapping between finite and instantaneous screws built in the authors’ previous work, the finite and instantaneous motions of PKMs are analytically described by the simple and non?redundant screws in quasi?vector and vector forms. And topological and parametric models of PKMs are algebraically formulated and related. These related topological and parametric models are ready to do type synthesis and kinematic analysis of PKMs under the unified framework of screw theory. In order to show the validity of the proposed approach, a kind of two?translational and three?rotational(2T3R)5?axis PKMs is taken as example. Numerous new structures of the 2T3R PKMs are synthe?sized as the results of topology design, and their Jacobian matrix is obtained easily for parameter optimization and performance evaluation. Some of the synthesized PKMs have outstanding capabilities in terms of large workspaces and flexible orientations, and have great potential for industrial applications of machining and manufacture. Among them, METROM PKM is a typical example which has attracted a lot of attention from global companies and already been developed as commercial products. The approach is a general and unified approach that can be used in the innovative design of different kinds of PKMs.

关键词： Innovative design Parallel kinematic machines Screw theory Finite screw Instantaneous screw

Efficient extraction of phenol from wastewater by ionic micro-emulsion method:Anionic and cationic

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Chinese Journal of Chemical Engineering 2023年第6期58卷 137-145页

作者： Chaobo Zhang Xiaoyong Yang jian dai Wenxia Liu Hang Yang Zhishan Bai State Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process School of Mechanical and Power EngineeringEast China University of Science and TechnologyShanghai 200237China

Phenolic wastewater is one of the priorities in the field of wastewater treatment,which poses a serious threat to the human health and nature *** this paper,cationic cetyltrimethylammonium bromide(CTAB)and anionic sodium oleate(Na OL)microemulsions were utilized to extract phenol from the *** optimal extraction factors were investigated by exploring the effects of microemulsion composition ratio and extraction conditions on the phenol extraction ***,the enhanced extraction mechanism of phenol by cations microemulsions is illustrated by studying the extraction process of cationic and anionic microemulsions in the extraction of *** optimum components were obtained:surfactant concentration of 0.2 mol·L^(-1),isoamyl alcohol volume of 30%,internal aqueous phase concentration of CTAB microemulsion of 0.05 mol·L^(-1),and internal aqueous phase concentration of Na OL microemulsion of 0.09 mol·L^(-1).The extraction efficiencies were 96.44%and 82.0%when using CTAB and Na OL microemulsions under optimal conditions(water-emulsion ratio of 5,contact time of 9 min,extraction temperature of 298.15 K,and p H of 9),confirming the enhanced extraction of phenol by CTAB cationic *** was analyzed that the enhanced extraction of CTAB microemulsion was due to the electrostatic adsorption of cations with phenol root ions.

关键词： Phenol-containing wastewater Phenol recovery Microemulsion extraction Ionic microemulsion Mechanism analysis

Repeater jamming suppression method for pulse Doppler fuze based on identity recognition and chaotic encryption

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Defence Technology（防务技术） 2021年第3期17卷 1002-1012页

作者： jian dai Xin-hong Hao Qiang Liu Xiao-peng Yan Ping Li Science and Technology on Electromechanical Dynamic Control Laboratory School of Mechatronical EngineeringBeijing Institute of TechnologyBeijing 100081China Ordnance Science Institute of China Beijing 100089China

Pulse Doppler(PD) fuze is widely used in current battlefield. However, with the threat of repeater jamming, especially digital radio frequency memory technology, the deficiency in the anti-repeater jamming of a traditional PD fuze increasingly emerges. Therefore, a repeater jamming suppression method for a PD fuze based on identity(ID) recognition and chaotic encryption is proposed. Every fuze has its own ID which is encrypted with different chaotic binary sequences in every pulse period of the transmitted signal. The thumbtack-shaped ambiguity function shows a good resolution and distance cutoff characteristic. The ability of anti-repeater jamming is emphatically analyzed, and the results at different signal-to-noise ratio(SNR) show a strong anti-repeater jamming ability and range resolution that the proposed method possesses. Furthermore, the anti-repeater jamming ability is influenced by processing gain, bit error rate(BER) and correlation function. The simulation result validates the theoretical analysis, it shows the proposed method can significantly improve the anti-repeater jamming ability of a PD fuze.

关键词： Pulse Doppler fuze ID Chaotic binary code Encryption Repeater jamming

Adaptive target and jamming recognition for the pulse doppler radar fuze based on a time-frequency joint feature and an online-updated naive bayesian classifier with minimal risk

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Defence Technology（防务技术） 2022年第3期18卷 457-466页

作者： jian dai Xin-hong Hao Ze Li Ping Li Xiao-peng Yan Science and Technology on Electromechanical Dynamic Control Laboratory School of Mechatronical EngineeringBeijing Institute of TechnologyBeijing100081China

This paper considers the problem of target and jamming recognition for the pulse Doppler radar fuze(PDRF).To solve the problem,the matched filter outputs of the PDRF under the action of target and jamming are ***,the frequency entropy and peak-to-peak ratio are extracted from the matched filter output of the PDRF,and the time-frequency joint feature is *** on the time-frequency joint feature,the naive Bayesian classifier(NBC)with minimal risk is established for target and jamming *** improve the adaptability of the proposed method in complex environments,an online update process that adaptively modifies the classifier in the duration of the work of the PDRF is *** experiments show that the PDRF can maintain high recognition accuracy when the signal-to-noise ratio(SNR)decreases and the jamming-to-signal ratio(JSR)***,the applicable analysis shows that he ONBCMR method has low computational complexity and can fully meet the real-time requirements of PDRF.

关键词： Pulse Doppler radar fuze(PDRF) Target and jamming recognition Time-frequency joint feature Online-update naive Bayesian classifier minimal risk(ONBCMR)

Electrochemically promoted decarboxylative borylation of alkyl N-hydroxyphthalimide esters

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Chinese Chemical Letters 2022年第3期33卷 1555-1558页

作者： jian-Jun dai Xin-Xin Teng Wen Fang Jun Xu Hua-jian Xu School of Food and Biological Engineering Hefei University of TechnologyHefei 230009China Anhui Province Key Laboratory of Advance Catalytic Materials and Reaction Engineering Hefei University of TechnologyHefei 230009China

An electrochemically promoted decarboxylative borylation reaction is reported. The reaction proceeds under mild conditions in an undivided cell without use of transition metal-or photo-catalysts. The key feature of the reaction is the compatibility of diboron reagents with the electrochemical conditions. This reaction exhibits broad substrate scope, good functional group tolerability, and easy scalability.

关键词： Electrochemical Decarboxylation Borylation Alkyl boronic esters Redox active esters

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基于改进遗传算法的家庭用电调度优化方法

计算机科学 2024年第S1期51卷 1157-1162页

作者：黄飞李永福高杨夏磊廖庆龙戴健向洪国网重庆市电力公司电力科学研究院重庆401123 重庆邮电大学通信与信息工程学院重庆400065

用电高峰期的用电需求给电力系统带来了巨大压力,因此优化家庭用电调度变得尤为重要。针对用电高峰期用户端存在的用电经济性及舒适度不够的问题,提出了一种基于改进遗传算法的家庭用电调度优化方法。首先以分时电价为基础,建立综合考... 详细信息

用电高峰期的用电需求给电力系统带来了巨大压力,因此优化家庭用电调度变得尤为重要。针对用电高峰期用户端存在的用电经济性及舒适度不够的问题,提出了一种基于改进遗传算法的家庭用电调度优化方法。首先以分时电价为基础,建立综合考虑用电经济性与用户满意度的家用电器调度模型,然后对不同类型的电器采取不同的编码方式来替代传统遗传算法的单一编码,并用带惩罚函数的适应度函数来约束各个电器用电任务所需时长等,以对传统遗传算法进行改进和用电行为优化。结果表明,所提算法可有效地依据分时电价实现用电负荷调度优化,在满足用户用电舒适度情况下为用户提供经济性的用电方案,且复杂度较低,能有效解决用电高峰期的用电经济性和舒适度问题。

关键词：微电网调度需求响应家庭用电多约束条件混合编码遗传算法

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北京月坛街道公共服务设施空间分布研究

城市建筑空间 2024年第2期31卷 107-111页

作者：郭雨萌戴俭惠晓曦北京工业大学城建学部北京工业大学北京市历史建筑保护工程技术研究中心

存量更新背景下,公共服务设施面临诸多困境,摸清现状尤为重要。以北京月坛街道为研究对象,运用实地调研对基础教育、医疗卫生、社会福利、文化、体育5类设施行进数量及位置统计,确定各类公共服务设施的服务半径,并进行空间分布研究,为... 详细信息

存量更新背景下,公共服务设施面临诸多困境,摸清现状尤为重要。以北京月坛街道为研究对象,运用实地调研对基础教育、医疗卫生、社会福利、文化、体育5类设施行进数量及位置统计,确定各类公共服务设施的服务半径,并进行空间分布研究,为公共服务设施的更新规划提供依据。

关键词：城市更新公共服务设施空间分布

Ruptured azygos vein caused by blunt trauma on left chest

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Chinese Medical Journal 2012年第18期125卷 3355-3356页

作者： CAO jian-guo dai Ning-feng CHEN Chang-zhi Department of Cardiothoracic Surgery Cangnan County People'sHospital Affiliated Shanghai Renji Hospital Group Cangnan China Zhejiang 325804

Rupture of the azygos vein caused by blunt trauma is rare. According to the literature there are total of 21cases of azygos vein injury since 1978 although the actual occurrence number may be much higher.^1,2 Mostly, it is the result of traffic accidents. If the diagnosis and treatment is delayed, patients will be dying of bleeding and hemorrhagic shock. So far its mortality rate is about 40% for patients with ruptured azygos vein even if they underwent operation^3 We present a patient who had blunt trauma on his left chest, which caused right haemothorax due to ruptured azygos vein.

关键词： blunt trauma, ruptured azygos vein hemorrhagic shock

Iron-catalyzed selective oxidation of 5-hydroxylmethylfurfural in air:A facile synthesis of 2,5-diformylfuran at room temperature

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Chinese Chemical Letters 2015年第10期26卷 1265-1268页

作者： Chi Fang jian-Jun dai Hua-jian Xu Qing-Xiang Guo Yao Fu Anhui Province Key Laboratory of Biomass Clean Energy Department of Chemistry University of Science and Technology of China School of Medical Engineering Hefei University of Technology

An iron（Ⅲ）-catalyzed selective oxidation of 5-HMF to 2,5-DFF in air at room temperature was *** approach gives 2,5-DFF with good selectivity and yields. Additionally, a two-step process was developed for the oxidation of 2,5-DFF to 2,5-FDCA at remarkably high substrate concentrations. This work demonstrates unequivocally the great potential of iron as a cheap and earth-abundant catalyst for the development of new protocols for the conversion of biomass to value-added chemicals.

关键词： Iron Biomass Oxidation Platform molecules Sustainable chemistry