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A finite-time fuzzy adaptive output-feedback fault-tolerant control for underactuated wheeled mobile robots systems

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Journal of Automation and Intelligence 2024年第2期3卷 111-118页

作者： Pingfan liu Shaocheng tong The Electrical Engineering College Liaoning University of TechnologyJinzhouLiaoning121001China College of Science Liaoning University of TechnologyJinzhouLiaoning121001China

This paper investigates the adaptive fuzzy finite-time output-feedback fault-tolerant control (FTC) problemfor a class of nonlinear underactuated wheeled mobile robots (UWMRs) system with intermittent actuatorfaults. The UWMR system includes unknown nonlinear dynamics and immeasurable states. Fuzzy logic systems(FLSs) are utilized to work out immeasurable functions. Furthermore, with the support of the backsteppingcontrol technique and adaptive fuzzy state observer, a fuzzy adaptive finite-time output-feedback FTC scheme isdeveloped under the intermittent actuator faults. It is testifying the scheme can ensure the controlled nonlinearUWMRs is stable and the estimation errors are convergent. Finally, the comparison results and simulationvalidate the effectiveness of the proposed fuzzy adaptive finite-time FTC approach.

关键词： Underactuated wheeled mobile robots system Finite-time Fuzzy adaptive fault-tolerant control Output-feedback Intermittent actuator faults

Effect of Three-High Rotary Piercing Process on Microstructure,Texture and Mechanical Properties of Magnesium Alloy Seamless Tube

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Acta Metallurgica Sinica(English Letters) 2024年第6期37卷 953-968页

作者： xiaofeng Ding Zehao Wu tong Li Jianxun Chen Yuanhua Shuang Baosheng liu Heavy Machinery Engineering Research Center of Education Ministry Taiyuan University of Science and TechnologyTaiyuan030024China College of Materials Science and Engineering Taiyuan University of Science and TechnologyTaiyuan030024China

Mg alloy seamless tubes(MASTs)were prepared through three-high rotary piercing process,effect of billet temperature,feed angle and plug advance on microstructure,texture and mechanical properties of tubes were *** effect on the deformation mechanism and improving mechanical properties mechanism of this process for MASTs were *** results show that the grain size could be refined to 11.3-31.1%of the initial grain size and the microstructure was more uniform due to the accumulation of *** formation of high strain gradient at the grain boundary activated the non-basal *** piercing process could change the grain orientation of as-extruded billet and eliminate the initial basal texture to produce new favorable *** the process could accelerate the continuous dynamic recrystallization *** piercing,yield strength of pierced tubes decreased by 6.7%,ultimate tensile strength(UTS)and elongation increased by 32.4 and 45%,respectively,at optimal *** plate-shapedβ_(1)-Mg_(17)Al_(12) orientation transformed from basal plates to prismatic plates,facilitating the increase in UTS and *** decrease size of nanoscale precipitates could reduce the cracking *** critical resolved shear stress ratios of pyramidal(10−11)slip and(11−22)slip to basal slip for the sample including prismatic plates both decreased compared to that including basal *** could enhance the ductility of tube ***,grain boundary sliding could contribute to a better ductility via coordinating deformation and reducing stress concentration during piercing process.

关键词： Mg alloy tube Rotary piercing Microstructure Texture Mechanical properties

Rotational Doppler effect of composite vortex beams with tailored OAM spectra

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Photonics Research 2024年第8期12卷 1665-1672页

作者： YUTIAN LIANG RUIJIAN LI JIE ZHAO xiNGYUAN LU tong liu ZHENGLIANG liu YUAN REN CHENGLIANG ZHAO Department of Aerospace Science and Technology Space Engineering UniversityBeijing 101416China School of Physical Science and Technology Soochow UniversitySuzhou 215006China Department of Basic Course Space Engineering UniversityBeijing 101416China

There recently has been increasing interest in the research and application of the rotational Doppler effect(RDE),which paves a promising way to detect rotating objects *** order to obtain more information about the rotating object from the rotational Doppler signal,composite vortex beams by coaxial superposition of orbital angular momentum(OAM)modes are often used as the probe ***,to the best of our knowledge,the RDE of composite vortex beams with arbitrary OAM spectra has not yet been comprehensively *** this paper,the correspondence between the OAM spectrum of a probe beam and the frequency spectrum of a rotational Doppler signal is theoretically *** is explicitly revealed that the RDE frequency spectrum of scattered light is related to the product of two autocorrelation functions:one from the OAM spectrum of probe beam and the other from the spiral spectrum of rotating *** the basis of this relation,one can regulate the RDE frequency spectrum on demand via tailoring the OAM spectrum of the probe *** a proof of concept we design a special composite vortex beam to eliminate the broadening of the RDE spectrum induced by *** findings are of practical value in applications such as remote sensing and optical metrology.

关键词： OAM composite rotating

Dealloyed TiCuMn efficiently catalyze the NO reduction and Zn-NO batteries

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Frontiers of Chemical Science and Engineering 2024年第9期18卷 51-59页

作者： Lang Zhang tong Hou Weijia liu Yeyu Wu Tianran Wei Junyang Ding Qian liu Jun Luo xijun liu State Key Laboratory of Featured Metal Materials and Life-Cycle Safety for Composite Structures MOE Key Laboratory of New Processing Technology for Nonferrous Metals and MaterialsSchool of ResourcesEnvironment and MaterialsGuangxi UniversityNanning 530004China Education Department of Guangxi Zhuang Autonomous Region Key Laboratory of Applied Analytical ChemistryGuangxi Collaborative Innovation Center for Chemistry and Engineering of Forest ProductsGuangxi Key Laboratory of Chemistry and Engineering of Forest ProductsKey Laboratory of Chemistry and Engineering of Forest ProductsState Ethnic Affairs CommissionSchool of Chemistry and Chemical EngineeringGuangxi Minzu UniversityNanning 530006China Institute for New Energy Materials&Low-Carbon Technologies School of Materials Science and EngineeringTianjin University of TechnologyTianjin 300384China Institute for Advanced Study Chengdu UniversityChengdu 610106China ShenSi Lab Shenzhen Institute for Advanced StudyUniversity of Electronic Science and Technology of ChinaShenzhen 518110China

Electrocatalytic NO reduction reaction offers a sustainable route to achieving environmental protection and NH3 production targets as *** this work,a class of dealloyed Ti_(60)Cu_(33)Mn_(7)ribbons with enough nanoparticles for the high-efficient NO reduction reaction to NH_(3)is fabricated,reaching an excellent Faradaic efficiency of 93.2%at–0.5 V vs reversible hydrogen electrode and a high NH3 synthesis rate of 717.4μmol·h^(-1)·mgcat.-1 at–0.6 V vs reversible hydrogen *** formed nanoparticles on the surface of the catalyst could facilitate the exposure of active sites and the transportation of various reactive ions and ***,the Mn content in the TiCuMn ribbons modulates the chemical and physical properties of its surface,such as modifying the electronic structure of the Cu species,optimizing the adsorption energy of N^(*)atoms,decreasing the strength of the NO adsorption,and eliminating the thermodynamic energy barrier,thus improving the NO reduction reaction catalytic ***,a Zn-NO battery was fabricated using the catalyst and Zn plates,generating an NH3 yield of 129.1µmol·h^(-1)·cm^(-2)while offering a peak power density of 1.45 mW·cm^(-2).

关键词： nitric oxide reduction NH3 electrosynthesis TiCuMn alloy Mn modulation Zn-NO battery

Ash removal from inferior coal via ammonium fluoride roasting and simultaneous yield of white carbon black

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International Journal of Mining Science and Technology 2024年第2期34卷 261-279页

作者： Xuqin Duan Shuaiyu Lu Yuxiao Fu Jiazhe Zhang tong liu Jian Ma School of Civil and Resource Engineering University of Science&Technology BeijingBeijing 100083China State Key Laboratory for Efficient Mining of Metal Mines University of Science&Technology BeijingBeijing 100083China China Coal Processing and Utilizaiton Association Beijing 100013China

The quality upgrading and deashing of inferior coal by chemical method still faces great *** dangers of strong acid,strong alkali,waste water and exhaust gas as well as high cost limit its industrial *** paper systematically investigates the ash reduction and desilicification of two typical inferior coal utilizing ammonium fluoride roasting *** the optimal conditions,for fat coal and gas coal,the deashing rates are 69.02%and 54.13%,and the desilicification rates are 92.64%and 90.27%,*** molar dosage of ammonium fluoride remains consistent for both coals;however,the gas coal,characterized by a lower ash and silica content(less than half that of the fat coal),achieves optimum deashing effect at a reduced time and *** majority of silicon in coal transforms into gaseous ammonium fluorosilicate,subsequently preparing nanoscale amorphous silica with a purity of 99.90%through ammonia *** of the fluorine in deashed coal are assigned in inorganic minerals,suggesting the possibility of further fluorine and ash removal via *** research provides a green and facile route to deash inferior coal and produce nano-scale white carbon black simultaneously.

关键词： Inferior coal Deashing treatment Silicon recycling Ammonium fluoride roasting White carbon black

Heterostructure of 2D MoSe_(2) nanosheets vertically grown on bowllike carbon for high-performance sodium storage

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Nano Research 2024年第5期17卷 4023-4030页

作者： Nianxiang Shi Guangzeng liu Baojuan xi Xuguang An Changhui Sun Shenglin xiong School of Chemistry and Chemistry Engineering Qilu Normal UniversityJinan 250200China School of Chemistry and Chemical Engineering Shandong UniversityJinan 250100China School of Mechanical Engineering Chengdu UniversityChengdu 610106China

Transition metal dichalcogenides are attractive anode materials for sodium ion batteries(SIBs)due to their high theoretical capacity and large interlayer ***,its practical application is hampered by the sluggish kinetics of Na^(+)insertion and structure collapse caused by Na^(+)insertion/***,the heterostructures of MoSe_(2) nanosheets vertically growing on bowl-like carbon(MoSe_(2)@C)are designed and prepared by a template method coupled with selenization treatment to boost storage sodium *** hollow and collapse could provide enough storage space for Na^(+)and alleviate the volume expansion during the charge/discharge ***_(2) nanosheets vertically grown on carbon could expose more active sites for adsorbing Na^(+)to enhance the utilization rate of electrode ***,building heterostructures by combining different phase components could facilitate Na^(+)diffusion and advance reaction *** from these merits,the bowl-like MoSe_(2)@C shows outstanding reversible capacity(356.8 mAh·g^(-1) after 1500 cycles at 1 A·g^(-1))and remarkable rate performance(249.9 mAh·g^(-1)10 A·g^(-1)).

关键词： MoSe_(2)nanosheets bowl-like carbon heterostructure sodium ion batteries

Extract lithium from clay-type lithium ore by mixed acid and its mechanism Author links open overlay panel

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Particuology 2024年第8期91卷 323-332页

作者： Wuchang Zhou Ruiqi xie xiong tong xian xie Yang liu Zhihui Zhao Faculty of Land Resource Engineering Kunming University of Science and TechnologyKunming650093China Technology Innovation Center for Comprehensive Utilization of Strategic Mineral Resources Ministry of Natural ResourcesChengdu610041China National&Regional Engineering Research Center for Green comprehensive Utilization of Tailing Resources from Metal Minerals Kunming650093China

A roasting-leaching test was carried out for the efficient utilization of clay-type lithium ore in the central region of Yunnan *** test used the mixed acid of sulfuric acid and phosphoric acid as the leaching *** the conditions of roasting temperature of 600℃,roasting time of 1 h,liquid-solid ratio of 5:1,volume ratio of H_(2)SO_(4)solution to H_(3)PO_(4)solution of 45:5,leaching time of 2 h and leaching temperature of 80℃,the leaching rate of lithium was as high as 97.83%.The leaching mechanism was studied by SEM,pore property analysis,XRD and *** was found that the morphology of the ore changed obviously after roasting and leaching,and a certain degree of collapse and fragmentation occurred,which provided favorable spatial conditions for the leaching of *** porosity,total intrusion volume and total pore area also increased after roasting and leaching,thus promoting the leaching of Li^(+).The results showed that chemical reaction taken placed during the roasting and *** phase of the sample changed from chlorite,kaolinite and diaspore(boehmite)mainly to corundum,hematite,periclase and quartz after ***,after leaching,no new phase was produced in the ore sample,and no S and P elements were found on the surface of the ore sample,indicating that the leaching mechanism of lithium might be the ion exchange between H^(+)and Li^(+).

关键词： Clay-type lithium ore Lithium extraction Roasting Leaching

Realizing the purification and grain refinement of Mg-Gd-Y alloy by one-step flux refining

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Journal of Materials Science & Technology 2024年第6期173卷 202-217页

作者： xin tong Guohua Wu Ming Sun Qiman Wang Liang Zhang Wencai liu National Engineering Research Center of Light Alloy Net Forming and State Key Laboratory of Metal Matrix Composites School of Materials Science and EngineeringShanghai Jiao Tong UniversityShanghai 200240China School of Materials and Chemistry University of Shanghai for Science and TechnologyShanghai 200093China

In the conventional melt preparation of magnesium rare-earth(Mg-RE)alloys,the repeated heating/cooling process involved in grain refinement and flux refining usually prolongs the preparation period and aggravates melt *** this work,the purification and grain refinement of Mg-9Gd-3Y(GW93)alloy was simultaneously realized by one-step refining at 740℃ by using a self-developed compound *** results show that,only after holding for 10 min,the inclusion content of the alloy is reduced by 81%to 0.29%,while the grain size is reduced by 84%to 119μm.A physical model depicting the interactions between compound flux and alloy melt was proposed based on thermodynamic calculation and microstructure *** grain refinement mechanism has been analyzed by considering the presence of Zr particle(Zr_(p))and Zr solute(Zr_(s)).In addition,the generated RECl_(3) was found to be readily absorbed by the flux,decreasing the surface tension and promoting the purification efficacy of the flux,which plays an important role in the promoted elongation of the as-cast Mg-9Gd-3Y-0.5Zr(GW93K)*** work presents a unique prospect in simplifying the melt preparation of Mg-RE alloy with a promoted quality.

关键词： Mg-Gd-Y-Zr alloy Purification Grain refinement Compound flux Settling behavior

Mismatch loss analysis of solar array output power on stratospheric airship during flight

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Chinese Journal of Aeronautics 2024年第2期37卷 371-384页

作者： Siyu liu Kangwen SUN Haoquan LIANG xinzhe JI tong ZOU Chuan SHAN School of Aeronautic Science and Engineering Beihang UniversityBeijing 100191China Yunnan Innovation Institute Beihang UniversityKunming 650233China Institute of Unmanned System Beihang UniversityBeijing 100191China

Stratospheric airships are long-endurance aerostats and have broad *** of the energy required for their operation is obtained from solar radiation,which makes accurate calculation of the energy output from the solar array crucial to the design and flight planning of the ***,the status of each photovoltaic module in the solar array may differ due to the airship curvature,resulting in mismatch losses and lowered output power,which has not been widely *** this paper,an irradiation model and a thermal model are established based on the actual arrangement of the *** output power model is established considering the non-uniform radiation in the *** mismatch losses of the array are analyzed under different flight *** output power of the solar array is decreased by up to 31.6%compared to the ideal ***,the proportion of mismatch losses increases with latitude,but the maximum mismatch loss power occurs at ***,an array reconfiguration method is proposed based on the irradiance dispersion index and position dispersion *** reconfigured array increases output power by 11.5%and can maintain energy balance in continuous *** results can be used to correct the overestimation of the output power during the airship design or to guide the configuration of the solar array.

关键词： Stratospheric airship Solar panels Solar energy Non-uniform irradiation Mismatch loss assessment Reconfiguration