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Flow-field analysis of a continuous gas-solid separation fluidized bed equipped with a moving scraper

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Particuology 2021年第4期19卷 45-55页

作者： Bo Lv Xiaowei Deng Chaojun Fang Xiangnan Zhu College of Chemistry and Chemical Engineering Henan Polytechnic UniversityJiaozuo 454000China Henan Key Laboratory for Green and Efficient Mining&Comprehensive Utilization of Mineral Resources Henan Polytechnic UniversityJiaozuo 454000China School of Chemical&Environmental Engineering Shandong University of Science&TechnologyQingdao 266590China

Continuous gas-solid separation fluidized beds are one of the most widely used practical operation units for the dry separation of coal in China,particularly in Northwest China,and they can effectively promote the efficient and clean utilization of raw *** a continuous gas-solid separation fluidized bed,the bed flow field is the concrete manifestation of the fluidization ***,the complexity of the flow field increases under the action of a moving *** this study,a combination of computational fluid dynamics(CFD)simulations and experimental measurements was used to study the changes in the flow field of a fluidized *** results showed that when the scraper moved,the local flow field(mainly characterized by the movement of medium particles)near the scraper was affected not only by the common airflow or bubbles,but also by the lateral driving force of the *** the scraper speed was v_(l)<6.0 cm/s,it reduced the frequency of the formation of large bubbles and alleviated the random fluctuation of the nearby particle collision stress signals,which improved the fluidization stability of the ***,the movement of the scraper affected the global flow *** flow field shifted to the right near the scraper,with the direction of the scraper movement,while the flow field exhibited a leftward trend on the surface of the bed,accompanied by some vortices,in the middle and lower parts of the ***,the critical height of the area,directly affected by the scraper,increased from 52 to 54 mm with an increase in its operating speed from v_(l)=2.96 cm/s to v_(l)=4.44 cm/s,*** provides a theoretical basis for further understanding the hydrodynamic characteristics of fluidized beds.

关键词： simulation analysis Moving scraper Flow-field Particle collision pressure Hydrodynamic characteristics

Na-doping-induced modification of the Cu_(2)ZnSn(S,Se)_(4)/CdS heterojunction towards efficient solar cells

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Journal of Energy Chemistry 2021年第6期30卷 618-626,I0015页

作者： Yali Sun Hongling Guo Pengfei Qiu Shengli Zhang Siyu Wang Li Wu Jianping Ao Yi Zhang Institute of Photoelectronic Thin Film Devices and Technology and Tianjin Key Laboratory of Thin Film Devices and Technology Nankai UniversityTianjin 300350China College of Physics Science and Technology Hebei UniversityBaoding 071002HebeiChina The MOE Key Laboratory of Weak-Light Nonlinear Photonics School of PhysicsNankai UniversityTianjin 300071China

It is very important to understand why a small amount of alkali metal doping in Cu_(2)ZnSn(S,Se)_(4)(CZTSSe)solar cells can improve the conversion *** this work,Na-doped CZTSSe is prepared by a simple solution method,and then the effects on the surface properties of the absorber layer,the buffer layer growth,and the modifications of the solar cell performance induced by the Na doping are *** surface of the absorber layer is more Cu-depletion and less roughness due to the Na *** addition,the contact angle of the surface increases because of Na *** a consequence,the thickness of the CdS buffer layer is significantly reduced and the optical losses in the CdS buffer layer are *** difference of quasi-Fermi levels(EFn-EFp) increases with a small amount of Na doping in the CZTSSe solar cell,so that open circuit voltage(VOC) increased *** work offers new insights into the effects of Na doping on CZTSSe via a solution-based approach and provides a deeper understanding of the origin of the efficiency improvement of Na-doped CZTSSe thin film solar cells.

关键词： Cu_(2)ZnSn(S,Se)_(4)solar cells Na doping Heterojunction Contact angles simulation analysis

Assessment and analysis of Carrying Capacity of 350 km/h EMUs Operating on Beijing-Shanghai Highspeed Railway

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Chinese Railways 2022年第2期 39-49页

作者： QU Siyuan SHI Junquan XU Ruihua Transport Department China Railway Shanghai Group Co Ltd. Collaborative Innovation Center on High-speed Rail Safety of Ministry of Education Nanjing Institute of Railway Technology College of Transportation Engineering Tongji University

This paper makes an analysis of the impact on the structure of the corridortype train working diagram by increasing the 350 km/h train pairs of Beijing-Shanghai High-speed Railway(HSR).According to the requirements of operation speed diversity,the multi-station receiving characteristics of cross-line trains and different train stopping schemes,this paper proposes a scheme of adding 350 km/h train pairs via computer analysis of carrying capability *** scheme is divided into three stages:(1)Initial stage:It is planned to increase trains running at 350 km/h,with 15~26 pairs of trains put into operation;(2)Rapid increase stage:27~142 pairs of 350 km/h trains are put into operation;(3)Full replacement stage:143~195 pairs of 350 km/h trains are put into operation,during which the number of cross-line trains under operation is controlled,the number of cross-line trains in each section is determined,the operation and connection scheme of cross-line trains is adjusted and the train stopping scheme is *** results of this study were used for the adjustment of the train working diagram in the third quarter of June 25,2021 to increase the number of 350 km/h train pairs from 19 to 30 on Beijing-Shanghai HSR.350 km/h trains are evenly arranged during 7:00—19:00 on the train working diagram and 300 km/h trains are arranged by making full use of every time and space,to improve the travelling speed on Beijing-Shanghai HSR as a whole.

关键词： Beijing-Shanghai HSR 350 km/h EMU train operation scheme train operation diagram carrying capacity assessment simulation analysis

The predicted effects of climate change on local species distributions around Beijing,China

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Journal of Forestry Research 2020年第5期31卷 1539-1550页

作者： Lichun Mo Jiakai Liu Hui Zhang Yi Xie School of Economies and Management Beijing Forestry UniversityBeijingPeople’s Republic of China School of Nature Conservation Beijing Forestry UniversityBeijingPeople’s Republic of China

To assist conservationists and policymakers in managing and protecting forests in Beijing from the effects of climate change,this study predicts changes for 2012–2112 in habitable areas of three tree species—Betula platyphylla,Quercus palustris,Platycladus orientalis,plus other mixed broadleaf species—in Beijing using a classification and regression tree niche model under the International Panel on Climate Change’s A2 and B2 emissions scenarios(SRES).The results show that climate change will increase annual average temperatures in the Beijing area by 2.0–4.7℃,and annual precipitation by 4.7–8.5 mm,depending on the emissions scenario *** changes result in shifts in the range of each of the *** suitable areas for distributions of *** and *** will decrease in the *** model points to significant shifts in the distributions of these species,withdrawing from their current ranges and pushing southward towards central *** of the ranges decline during the initial 2012–2040 period before shifting southward and ending up larger overall at the end of the 88-year *** mixed broadleaf forests expand their ranges *** *** forests,on the other hand,expand their range *** results indicate that climate change and its effects will accelerate significantly in Beijing over the next 88 *** stress is likely to be a major limiting factor on the distribution of forests and the most important factor affecting migration of species into and out of existing nature *** is a potential for the extinction of some ***,long-term vegetation monitoring and warning systems will be needed to protect local species from habitat loss and genetic swamping of native species by hybrids.

关键词： Climate change Classification and regression tree Plant distribution Scenario A2 and B2 simulation analysis

An in-depth review of theory of the TOPSIS method:An experimental analysis

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Journal of Management Analytics 2020年第2期7卷 281-300页

作者： Yakup Celikbilek Fatih Tuysuz Department of Management Information Systems Istanbul Gelisim UniversityIstanbulTurkey Department of Industrial Engineering Istanbul University-CerrahpaşaIstanbulTurkey

Decision-making is an important part of daily and business life for both individuals and *** the multi-criteria decision-making methods provide decision makers the necessary tools,they have differences in terms of the assumptions and fundamental ***,selecting the right decision-making method is at least as important as making the ***(Technique for Order Performance by Similarity to Ideal Solution)method,which is one of the most widely used multi-criteria decision-making methods,has gained attention of researchers and thus various improved versions of the method have been *** study considers the conventional TOPSIS method and experimentally displays the underlying reasons of the lacks of the conventional TOPSIS method by using a simulation *** experimental analysis based on simulation with an application is used to reveal theoretical fundamentals of the TOPSIS method to better understand it and contribute to its improvement.

关键词： TOPSIS Multiple criteria analysis simulation analysis Euclidean distance n-dimensionality

Design and experiment of the comb-brush harvesting machine with variable spacing for oil-tea camellia fruit

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International Journal of Agricultural and Biological Engineering 2021年第1期14卷 172-177页

作者： Xiaoqiang Du Tengfei Shen Lijun Zhao Guofeng Zhang Anguo Hu Shenggao Fang Yongqing Cao Xiaohua Yao School of Mechanical Engineering&Automation Zhejiang Sci-Tech UniversityHangzhou 310018China Zhejiang Province Key Laboratory of Transplanting Equipment and Technology Hangzhou 310018China College of Intelligent and Manufacturing Engineering Chongqing University of Arts and SciencesChongqing 402160China Yongkang Valid Technology Co. Ltd.Yongkang 321300ZhejiangChina Dongfanghong Forest Farm Jinhua 321000ZhejiangChina Research Institute of Subtropical Forestry Chinese Academy of ForestryHangzhou 311400China

Oil-tea camellia tree is an important oil plant in China that has long flexible *** most challenging feature for the mechanized harvest of oil-tea fruits is that its flower and fruit grow *** order to improve the harvesting efficiency and avoid damaging the flower bud,a hand-held fruit harvesting machine with a variable spacing comb brush was *** harvesting machine can generate three kinds of actuation to detach fruit when it *** main actuation results from the brushing of multiple comb *** other two kinds of actuation result from the beating of comb fingers on the fruits and the *** finger spacing of the comb brush can be adjusted consequently through moving the spacing adjusting ***,when the finger spacing is smaller than the diameter of the oil-tea fruit,the fruit is brushed off,but the flower bud and leaf pass through the finger *** the finger spacing is bigger than the fruit diameter,the fruit stuck between the fingers is loosened to ensure the continuous operation of the *** was used as the material of the brush finger to avoid damage,which can also reduce the overall *** dynamic simulation of the harvesting machine was carried out with ADAMS,and the acceleration of the front end of the comb finger and the variation of the finger spacing were *** prototype of the harvesting machine was built and tested in the *** experiment results showed that when the speed of the comb finger drive shaft was 480 r/min,the average harvesting percentage of oil-tea fruit was 80%,and the flower bud was seldom detached,which met the working requirements of oil-tea fruit harvesting.

关键词： oil-tea camellia fruit harvesting machine variable spacing comb brush simulation analysis

System dynamics model of the support-surrounding rock system in fully mechanized mining with large mining height face and its application

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International Journal of Mining Science and Technology 2013年第6期23卷 879-884页

作者： Yuan Yong Tu Shihao Zhang Xiaogang Li Bo School of Mines China University of Mining&Technology Key Laboratory of Deep Coal Resource Mining Ministry of Education China University of Mining&Technology

Fully mechanized mining with large mining height(FMMLMH)is widely used in thick coal seam mining face for its higher recovery ratio,especially where the thickness is less than 7.0 ***,because of the great mining height and intense rock pressure,the coal wall rib spalling,roof falling and the instability of support occur more likely in FMMLMH working face,and the above three types of disasters interact with each other with complicated *** order to get the relationship between each two of coal wall,roof,floor and support,and reduce the occurrence probability of the three types of disasters,we established the system dynamics(SD)model of the support-surrounding rock system which is composed of"coal wall-roof-floor-support"(CW-R-F-S)in a FMMLMH working face based on the condition of No.15104 working face in Sijiazhuang coal *** the software of Vensim,we also simulated the interaction process between each two factors of roof,floor,coal wall and the *** results show that the SD model of"CW-R-F-S"system can reveal the complicated and interactive relationship clearly between the support and surrounding rock in the FMMLMH working *** increasing the advancing speed of working face,the support resistance or the length of support guard,or by decreasing the tipto-face distance,the stability of"CW-R-F-S"system will be higher and the happening probability of the disasters such as coal wall rib spalling,roof falling or the instability of support will be *** research findings have been testified in field application in No.15104 working face,which can provide a new approach for researching the interaction relationship of support and surrounding rock.

关键词： FMMLMH Support-surrounding rock system SD model Disaster control simulation analysis

Characteristic analysis of Off-Axis Meta-Lens

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Optics and Photonics Journal 2023年第6期13卷 87-96页

作者： Jingaowa Hu Yang Liu Shangnan Zhao Lingjie Wang Haokun Ye Jianping Zhang Xin Zhang Changchun Institute of Optics Fine Mechanics and Physics Chinese Academy of Sciences Changchun China University of Chinese Academy of Sciences Beijing China

Meta-lens are a new type of planar optical element that can flexibly manipulate the phase, polarization and amplitude of the beam, and are currently receiving a great deal of attention as they are easier to process and manufacture. Off-axis meta-lens are a special type of meta-lens with a certain degree of dispersion that can be used as a beam-splitting element, providing a unique and feasible way to realize micro-miniature instruments. We analyze the effects of different numerical apertures and off-axis angles on the spectral resolution, focusing efficiency and simulation results of off-axis meta-lens to provide ideas for subsequent research and application of off-axis meta-lens. A number of off-axis meta-lens with parameters NA = 0.408 α = 13°, NA = 0.18 α = 13° and NA = 0.408 α = 20° were simulated through Lumerical software. The results show that the off-axis angle is related to the resolution;the larger the angle, the better the spectral resolution but the lower the focusing efficiency;when the numerical aperture is smaller, the smaller the coverage of the phase distribution, which will lead to a larger deviation between simulation and theory. The designer needs to balance the numerical aperture, off-axis angle and other parameters reasonably according to the requirements in order to achieve the desired effect. The findings of this study have important reference values for the theoretical analysis of off-axis meta-lens and the design of parameters in practical applications. .

关键词： Meta-Lens Off-Axis Meta-Lens simulation analysis

Control algorithm and energy management strategy for extended range electric tractors

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International Journal of Agricultural and Biological Engineering 2017年第5期10卷 35-44页

作者： Xu Liyou Zhang Junjiang Liu Mengnan Zhou Zhili Liu Chengqiang College of Vehicle and Traffic Engineering Henan University of Science and TechnologyLuoyang 471003China Shandong Shifeng Group Co. Ltd.Liaocheng 252800China

It is difficult to make full use of the electrical energy of the power battery for extended-range electric tractors because the battery’s state of charge may be relatively high at the end of the running *** address this situation,this paper aimed to study the control parameter adjustment in relation to the power battery’s electrical consumption and the diesel engine’s fuel consumption energy management *** on the AVL-Cruise simulation platform,the vehicle model of the tractor was established,and the control module of AVL-Cruise was used to compile the energy management *** order to verify the superiority of the proposed strategy,the contrast strategy was employed in terms of the diesel engine start and stop control plus fixed point energy management strategy(FPEMS).The applicability of the proposed strategy was tested through continuous transfer operation and the small area deep loosening *** simulation results show that the proposed strategy was of good *** with the FPEMS,the fuel consumption reduced significantly,and the electrical consumption of the power battery increased obviously.

关键词： extended-range electric tractor parameter adjustment energy management strategy simulation analysis