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Dielectric Constant Calculation of Poly(vinylidene fluoride)Based on Finite Field and Density Functional Theory

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Chinese Journal of Polymer Science 2024年第5期42卷 655-662,I0009页

作者： Yong-Zhi Lin Lu-Kun Feng ya-dong Li Chao-fan Chang Cai-Zhen Zhu Ming-Liang Wang Jian Xu College of Chemistry and Environmental Engineering Shenzhen UniversityShenzhen518055China Chengdu Institute of Organic Chemistry Chinese Academy of SciencesChengdu610041China

In this study,we proposed a novel method that integrates density functional theory(DFT)with the finite field method to accurately estimate the polarizability and dielectric constant of *** approach effectively accounts for the influence of electronic and geometric conformation changed on the dielectric *** validated our method using polyethylene(PE)and polytetrafluoroethylene(PTFE)as benchmark materials,and found that it reliably predicted their dielectric ***,we explored the impact of conformation variations in poly(vinylidene fluoride)(PVDF)on its dielectric constant and *** resulting dielectric constants ofα-andγ-PVDF(3.0)showed excellent agreement with crystalline PVDF in *** findings illuminate the relationship between PVDF’s structural properties and its electrical behavior,offering valuable insights for material design and applications.

关键词： Dielectric constant PVDF Finite field DFT

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Game theory based finite-time formation control using artificial potentials for tethered space net robot

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Chinese Journal of Aeronautics 2024年第8期37卷 358-372页

作者： Yifeng MA Yizhai ZHANG Panfeng HUANG ya LIU fan ZHANG The Research Center for Intelligent Robotics School of AstronauticsNorthwestern Polytechnical UniversityXi’an 710072China School of Electronic Information and Electrical Engineering Shanghai Jiao Tong UniversityShanghai 200240China

The Tethered Space Net Robot(TSNR)is an innovative solution for active space debris capture and *** large envelope and simple capture method make it an attractive option for this ***,capturing maneuverable debris with the flexible and elastic underactuated net poses significant *** address this,a novel formation control method for the TSNR is proposed through the integration of differential game theory and robust adaptive control in this ***,the trajectory of the TSNR is obtained through the solution of a real-time feedback pursuit-evasion game with a dynamic target,where the primary condition is to ensure the stability of the ***,to minimize tracking errors and maintain a specific configuration,a robust adaptive formation control scheme with Artificial Potential Field(APF)based on a Finite-Time Convergent Extended State Observer(FTCESO)is *** proposed control method has a key advantage in suppressing complex oscillations by a new adaptive law,thus precisely maintaining the ***,numerical simulations are performed to demonstrate the effectiveness of the proposed scheme.

关键词： Game theory Formation control Artificial potential field Relative distance constraint Tethered space net robot(TSNR)

Laryngopharyngeal reflux disease:Updated examination of mechanisms,pathophysiology,treatment,and association with gastroesophageal reflux disease

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World Journal of Gastroenterology 2024年第16期30卷 2209-2219页

作者： Na Cui Ting Dai yang Liu ya-Yu Wang Jia-Yu Lin Qing-fan Zheng dong-dong Zhu Xue-Wei Zhu Department of Otorhinolaryngology Head and Neck Surgery China-Japan Union Hospital of Jilin UniversityChangchun 130033Jilin ProvinceChina Department of Ultrasound China-Japan Union Hospital of Jilin UniversityChangchun 130033Jilin ProvinceChina Department of Gastroenterology China-Japan Union Hospital of Jilin UniversityChangchun 130033Jilin ProvinceChina

Laryngopharyngeal reflux disease(LPRD)is an inflammatory condition in the laryngopharynx and upper aerodigestive tract mucosa caused by reflux of stomach contents beyond the *** commonly presents with symptoms such as hoarseness,cough,sore throat,a feeling of throat obstruction,excessive throat *** complex condition is thought to involve both reflux and reflex mechanisms,but a clear understanding of its molecular mechanisms is still ***,there is no standardized diagnosis or treatment *** strategies for LPRD mainly include lifestyle modifications,proton pump inhibitors and endoscopic *** paper seeks to provide a comprehensive overview of the existing literature regarding the mechanisms,pathophysiology and treatment of *** also provide an in-depth exploration of the association between LPRD and gastroesophageal reflux disease.

关键词： Laryngopharyngeal reflux Gastroesophageal reflux Head neck surgery Laryngitis Otolaryngology

Type Synthesis of Self-Alignment Parallel Ankle Rehabilitation Robot with Suitable Passive Degrees of Freedom

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Chinese Journal of Mechanical Engineering 2024年第1期37卷 160-175页

作者： ya Liu Wenjuan Lu Dabao fan Weijian Tan Bo Hu Daxing Zeng School of Mechanical Engineering Yanshan UniversityQinhuangdao 066004China School of Mechanical Engineering Dongguan University of TechnologyDongguan 523808China dongguan Engineering Technology Research Center for Parallel Robot Dongguan 523808China The DGUT Innovation Center of Robotics and Intelligent Equipment Dongguan 523808China

The current parallel ankle rehabilitation robot(ARR)suffers from the problem of difficult real-time alignment of the human-robot joint center of rotation,which may lead to secondary injuries to the *** study investigates type synthesis of a parallel self-alignment ankle rehabilitation robot(PSAARR)based on the kinematic characteristics of ankle joint rotation center drift from the perspective of introducing"suitable passive degrees of freedom(DOF)"with a suitable number and ***,the self-alignment principle of parallel ARR was proposed by deriving conditions for transforming a human-robot closed chain(HRCC)formed by an ARR and human body into a kinematic suitable constrained system and introducing conditions of"decoupled"and"less limb".Second,the relationship between the self-alignment principle and actuation wrenches(twists)of PSAARR was analyzed with the velocity Jacobian matrix as a"bridge".Subsequently,the type synthesis conditions of PSAARR were ***,a PSAARR synthesis method was proposed based on the screw theory and type of PSAARR synthesis ***,an HRCC kinematic model was established to verify the self-alignment capability of the *** this study,93 types of PSAARR limb structures were synthesized and the self-alignment capability of a human-robot joint axis was verified through kinematic analysis,which provides a theoretical basis for the design of such an ARR.

关键词： Ankle rehabilitation robot Self-alignment Parallel mechanism Type synthesis Screw theory

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Traditional Chinese medicine:an important broad-spectrum anti-coronavirus treatment strategy on COVID-19 background?

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Traditional Medicine Research 2022年第3期7卷 1-18页

作者： Run-dong Chai ya-dong fan Qi-yao Li Huan-Tian Cui Hai-Zhao Liu Ying Wang Bo-yang Gong Lu Han Shuai Zhang Yu-Hong Bian Jun Kang Yu Wang Tianjin University of Traditional Chinese Medicine Tianjin 300193China School of life Sciences Shandong UniversityQingdao 266071China School of life Sciences Tianjin UniversityTianjin 300072China

Coronaviruses exist widely in nature,can cause cross-species transmission,and pose serious threats to human and animal *** the past 20 years,coronaviruses have led to three major epidemics that have caused global panic,including severe acute respiratory syndrome,Middle East respiratory syndrome,and coronavirus *** present,coronavirus disease 19 not only spreads rapidly,but also mutates easily to escape host immune response,becoming more *** present,there are no effective specific therapeutic drugs or *** targeting severe acute respiratory syndrome coronavirus 2 and the host cell defense system that have been developed based on the structure and replication cycle of coronaviruses have a certain broad-spectrum antiviral effect;however,their efficacy still needs to be demonstrated in further clinical *** Chinese medicine has an indispensable role in the ongoing response to coronavirus ***-virus treatment with traditional Chinese medicine has advantages such as broad-spectrum application,low toxicity and side effects,low susceptibility to drug resistance,and overall comprehensive ***,researches on effective components and mechanisms of action of the anti-viral effects of traditional Chinese medicine have increasingly gained *** present paper examines coronaviruses,specifically summarizing the genomes,replication mechanisms,and mutant ***,the therapeutic effects and mechanisms of action of modern broad-spectrum anti-coronavirus drugs and traditional Chinese medicine are *** considering the virus and the targets in the host comprehensively,in addition to the beneficial multi-target and multi-path antiviral effects of traditional Chinese medicines,this paper could guide the development of treatment strategies for broad-spectrum anti-coronavirus traditional Chinese medicines,and could facilitate the modernization and globalization of traditional Chinese medic

关键词： COVID-19 SARS-CoV-2 traditional Chinese medicine broad-spectrum antivirals

Local search yields a PTAS for fixed-dimensional k-means problem with penalties

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Journal of the Operations Research Society of China 2024年第2期12卷 351-362页

作者： fan Yuan Da-Chuan Xu dong-Lei Du dong-Mei Zhang Beijing Institute for Scientific and Engineering Computing Beijing University of TechnologyBeijing 100124China Faculty of Management University of New BrunswickFrederictonNB E3B 9Y2Canada School of Computer Science and Technology Shandong Jianzhu UniversityJinan 250101ShandongChina

We study a problem called the k-means problem with penalties(k-MPWP),which is a natural generalization of the typical k-means *** this problem,we have a set D of client points in R^(d),a set F of possible centers in R^(d),and a penalty cost Pj>O for each point j∈*** are also given an integer k which is the size of the center point *** want to find a center point set S■F with size k,choose a penalized subset of clients P■D,and assign every client in D\P to its open *** goal is to minimize the sum of the squared distances between every point in D\P to its assigned centre point and the sum of the penalty costs for all clients in *** using the multi-swap local search technique and under the fixed-dimensional Euclidean space setting,we present a polynomial-time approximation scheme(PTAS)for the k-MPWP.

关键词： Approximation algorithm k-means Local search Penalty

Linear-fitting-based recursive filtering for nonlinear systems under encoding-decoding mechanism

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Science China(Information Sciences) 2024年第5期67卷 183-196页

作者： Bo JIANG Hongli dong Zhiwei GAO Yuxuan SHEN fan yaNG Artificial Intelligence Energy Research Institute Northeast Petroleum University Heilongjiang Provincial Key Laboratory of Networking and Intelligent Control Sanya Offshore Oil & Gas Research Institute Northeast Petroleum University School of Electrical & Information Engineering Northeast Petroleum University

This paper deals with a recursive filtering problem for a class of discrete time-varying nonlinear networked systems with the encoding-decoding mechanism. The linear fitting method is introduced to handle the nonlinearity. An encoding-decoding mechanism is constructed to describe the data transmission process in wireless communication networks(WCNs). To be specific, the measurement outputs are mapped by a quantizer to unique codewords for transmission in WCNs. Then, the codewords are decoded by the decoder to recover the measurement outputs which are sent to the filter. The processing/encoding delay and network delay have been considered. Firstly, on the premise that the upper bound of the filtering error covariance is minimum, the appropriate filtering gain is calculated. Then, the mean square exponential boundedness of the filtering error is analyzed. Finally, two simulation examples are presented to verify the effectiveness of the proposed algorithm.

关键词： encoding-decoding mechanism uniform quantizer linear fitting networked systems recursive filtering

Rapid Energy Exchange between In Situ Formed Bromine Vacancies and CO_(2)Molecules Enhances CO_(2)Photoreduction

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Research 2024年第2期2023卷 763-771页

作者： Qin Ren Ye He Hong Wang yanjuan Sun fan dong Research Center for Environmental and Energy Catalysis Institute of Fundamental and Frontier SciencesUniversity of Electronic Science and Technology of ChinaChengdu 611731China School of Resources and Environment University of Electronic Science and Technology of ChinaChengdu 611731China

Photocatalytic reduction of CO_(2)into fuels provides a prospective tactic for regulating the global carbon balance utilizing renewable solar ***,CO_(2)molecules are difficult to activate and reduce due to the thermodynamic stability and chemical *** this work,we develop a novel strategy to promote the adsorption and activation of CO_(2)molecules via the rapid energy exchange between the photoinduced Br vacancies and CO_(2)*** in situ continuous wave-electron paramagnetic resonance(cw-EPR)and pulsed EPR technologies,we observe that the spin-spin relaxation time(T_(2))of BiOBr is decreased by 198 ns during the CO_(2)photoreduction reaction,which is further confirmed by the broadened EPR *** result reveals that there is an energy exchange interaction between in situ formed Br vacancies and CO_(2)molecules,which promotes the formation of high-energy CO_(2)molecules to facilitate the subsequent reduction *** addition,theoretical calculations indicate that the bended CO_(2)adsorption configuration on the surface of BiOBr with Br vacancies caused the decrease of the lowest unoccupied molecular orbital of the CO_(2)molecule,which makes it easier for CO_(2)molecules to acquire electrons and get *** situ diffuse reflectance infrared Fourier transform spectroscopy further shows that the activated CO_(2)molecules are favorably converted to key intermediates of COOH*,resulting in a CO generation rate of 9.1μmol g^(-1)h^(-1)and a selectivity of 100%.This study elucidates the underlying mechanism of CO_(2)activation at active sites and deepens the understanding of CO_(2)photoreduction reaction.

关键词： reaction. adsorption activation

Control of aluminum distribution in ZSM-5 zeolite for enhancement of its catalytic performance for propane aromatization

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Frontiers of Chemical Science and Engineering 2024年第8期18卷 15-24页

作者： Zhao Ma Dezhi Shi Sen Wang Mei dong Weibin fan State Key Laboratory of Coal Conversion Institute of Coal ChemistryChinese Academy of SciencesTaiyuan 030001China University of Chinese Academy of Sciences Beijing 100049China

Regulation of aluminum distribution in zeolite framework is an effective method for improving its catalytic performance for propane ***,we found that recrystallization and post-realuminization of ZSM-5 cannot only create hollow structures to enhance the diffusion ability,but also adjust the content and position of paired aluminum species in its *** characterizations results confirmed that increase of paired aluminum content and inducement of more aluminum atoms sited in the intersection cavity are beneficial to the formation of aromatic products in propane *** a result,the hollow-structured ZSM-5 zeolite with more paired aluminum(H-200-hollow)showed higher propane conversion and aromatics selectivity than other samples at the same *** catalytic performance of H-200-hollow can be further improved by ion-exchanging with a small amount of Ga(III)*** propane conversion and aromatics selectivity of Ga-200-hollow reached as high as 95%and 70%,respectively,at 540°C and 1 atm.

关键词： propane aromatization zeolite aluminum distribution recrystallization and post-realuminization