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Chinese Geographical Science 2023年第3期33卷 503-511页

作者： YAN Guangxuan WANG Jieqi LUO Tingting CHEN Weiwei SHAO Yun LI Chunxi Key Laboratory for Yellow River and Huai River Water Environment and Pollution Control(Ministry of Education) School of EnvironmentHenan Normal UniversityXinxiang 453007China College of life Sciences Henan Normal UniversityXinxiang 453007China Northeast Institute of Geography and Agroecology Chinese Academy of SciencesChangchun 130102China

Globally,agricultural soils are considered as one of the most important sources of greenhouse gas(GHG)emissions.No-tillage(NT),one of the most admired ways of climate-smart agriculture,has been deemed to have co-benefit to mitigation of GHG emissions and sustainability for crop yield,however,the effect of NT on GHG emissions is controversial.This study analyzed the overall effects of NT on GHG emissions,as well as the moderators that significantly influenced the overall effects,of the wheat-based rotation cropping systems in China through meta-analysis.The results showed that the overall effect size of NT on methane(CH4)uptake,nitrous oxide(N2O)emission,and global warming potential(GWP)was 0.70(95%Confidence Interval(CI):0.21–1.19),-0.27(95%CI:-0.72–0.18),and-0.39(95%CI:-1.01–0.23),respectively.In temperate climate zones with alkaline soils,the nitrogen application rate of 120–240 kg/ha,NT could significantly reduce GHG emissions and GWP.However,the mitigation effect will be weakened along with NT duration,except for proper straw addition.Overall,NT has the potential to reduce GHG emissions from wheat-based rotation systems in China,but it is necessary to implement NT depending on local conditions,soil characteristics,and field management.

关键词： Wheat soil rotation

Dynamic time prediction for electric vehicle charging based on charging pattern recognition

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Frontiers of Information Technology & Electronic Engineering 2023年第2期24卷 299-313页

作者： chunxi li Yingying FU Xiangke CUI Quanbo GE Logistics Engineering College Shanghai Maritime UniversityShanghai200135China School of Economics and Management Beijing Jiaotong UniversityBeijing102603China School of Automation Nanjing University of Information Science and TechnologyNanjing210044China Jiangsu Collaborative Innovation Center of Atmospheric Environment and Equipment Technology(CICAEET) Nanjing University of Information Science and TechnologyNanjing210044China Jiangsu Key Laboratory of Big Data Analysis Technology(B-DAT) Nanjing University of Information Science and TechnologyNanjing210044China

Overcharging is an important safety issue in the charging process of electric vehicle power batteries,and can easily lead to accelerated battery aging and serious safety accidents.It is necessary to accurately predict the vehicle’s charging time to effectively prevent the battery from overcharging.Due to the complex structure of the battery pack and various charging modes,the traditional charging time prediction method often encounters modeling difficulties and low accuracy.In response to the above problems,data drivers and machine learning theories are applied.On the basis of fully considering the different electric vehicle battery management system(BMS)charging modes,a charging time prediction method with charging mode recognition is proposed.First,an intelligent algorithm based on dynamic weighted density peak clustering(DWDPC)and random forest fusion is proposed to classify vehicle charging modes.Then,on the basis of an improved simplified particle swarm optimization(ISPSO)algorithm,a high-performance charging time prediction method is constructed by fully integrating long short-term memory(LSTM)and a strong tracking filter.Finally,the data run by the actual engineering system are verified for the proposed charging time prediction algorithm.Experimental results show that the new method can effectively distinguish the charging modes of different vehicles,identify the charging characteristics of different electric vehicles,and achieve high prediction accuracy.

关键词： Charging mode Charging time Random forest Long short-term memory(LSTM) Simplified particle swarm optimization(SPSO)

Mechanochemical synthesis of oxygenated alkynyl carbon materials with excellent Hg(Ⅱ) adsorption performance from CaC2 and carbonates

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Green Energy & Environment 2023年第1期8卷 275-282页

作者： Yingjie li Songping li Xinyi Xu Hong Meng Yingzhou Lu chunxi li State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing100029China Beijing Key Laboratory of Energy Environmental Catalysis Beijing University of Chemical TechnologyBeijing100029China College of Chemical Engineering Beijing University of Chemical TechnologyBeijing100029China Anhui Key Lab of Coal Clean Conversion and Utilization School of Chemistry and Chemical EngineeringAnhui University of TechnologyMaanshan243032China

Adsorptive removal of heavy metal ions from wastewater is very important,and the key is the development of efficient sorbents.In this work,oxygenated alkynyl carbon materials(OACMs)were synthesized via mechanochemical reaction of CaC_(2) and a carbonate(CaCO_(3),Na2CO_(3),or NaHCO_(3))at ambient temperature.The resultant OACMs are micro mesoporous carbon nanomaterials with high specific area(>648 m2 g^(-1)),highly crosslinked texture,and rich alkynyl and oxygenated groups.The OACMs exhibit excellent Hg(Ⅱ)adsorption due to the soft acid-soft base interaction between alkynyl and Hg(Ⅱ),and OACM-3 derived from CaC_(2) and NaHCO_(3) has the saturated Hg(Ⅱ)adsorbance of 483.9 mg g^(-1)along with good selectivity and recyclability.The adsorption is mainly chemisorption following the Langmuir mode.OACM-3 also shows high adsorbance for other heavy metal ions,e.g.256.6 mg g^(-1)for Pb(II),232.4 mg g^(-1)for Zn(II),and 198.7 mg g^(-1)for Cu(II).This work expands the mechnochemical reaction of CaC_(2)with carbonates and possibly other oxyanionic salts,provides a new synthesis approach for functional alkynyl carbon materials with excellent adsorption performance for heavy metal ions,as well as a feasible approach for CO2 resource utilization.

关键词： CaC_(2) Mechanochemistry Alkynyl carbon materials Hg(Ⅱ) Heavy metal Adsorption

A muon high-resolution pseudorange measurement method: Application to muon navigation in confined spaces

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Chinese Journal of Aeronautics 2024年第4期37卷 391-404页

作者： Haoyang li chunxi ZHANG Xingming FAN Longjie TIAN Tianqi li Yang PANG Yanqiang YANG Institute of Optics and Electronics School of Instrumentation Science and Optoelectronics EngineeringBeihang UniversityBeijing 100191China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China

Confined spaces such as polar regions, deep earth and deep ocean are crucial navigation scenarios where traditional navigation techniques have difficulty in obtaining external signals for positioning. The cosmic ray muons, which carry the spatial and energetic information, are easy to penetrate these confined spaces. Therefore, the unique muon characteristic provides a new perspective to estimate detector position, which can be considered using in confined spaces navigation.In this paper, a well-developed theory of muon navigation is established by combining a muon pseudorange measurement method. Moreover, an Equivalent Velocity Calculation Model(EVCM)and a Muon Sequence Matching Technology(MSMT) are proposed. The first model corrects flight pseudorange error caused by the relativistic energy loss and the second technology compensates the random error in pseudorange measurement. Further, a series of simulations are performed to analyze the muon events number which can be received by detector in different scenarios with the variations of zenith angle, detector area, varied detector plates gap, and muon flight distance.Meanwhile, the simulation results demonstrate that the muon navigation update rate every 10 minutes can reach 5.989 in confined spaces at 100 m, and further pseudorange error analysis indicates that the meter-level positioning accuracy can be acquired. Finally, we construct a muon coincidence measurement scheme and verify that the laws of the muon positioning system for high-energy muons are consistent with the simulation results.

关键词： Muon navigation Cosmic ray muons Muon detection technology Muon transmission technology Pseudorange measurement

Scalable and quantitative contention generation for performance evaluation on OLTP databases

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Frontiers of Computer Science 2023年第2期17卷 15-31页

作者： chunxi ZHANG Yuming li Rong ZHANG Weining QIAN Aoying ZHOU School of Data Science and Engineering East China Normal UniversityShanghai 200062China

Massive scale of transactions with critical requirements become popular for emerging businesses,especially in E-commerce.One of the most representative applications is the promotional event running on Alibaba's platform on some special dates,widely expected by global customers.Although we have achieved significant progress in improving the scalability of transactional database systems(OLTP),the presence of contention operations in workloads is still one of the fundamental obstacles to performance improving.The reason is that the overhead of managing conflict transactions with concurrency control mechanisms is proportional to the amount of contentions.As a consequence,generating contented workloads is urgent to evaluate performance of modern OLTP database systems.Though we have kinds of standard benchmarks which provide some ways in simulating contentions,e.g.,skew distribution control of transactions,they can not control the generation of contention quantitatively;even worse,the simulation effectiveness of these methods is affected by the scale of data.So in this paper we design a scalable quantitative contention generation method with fine contention granularity control.We conduct a comprehensive set of experiments on popular opensourced DBMSs compared with the latest contention simulation method to demonstrate the effectiveness of our generation work.

关键词： high contention OLTP database performance evaluation database benchmarking

Modeling of pyridine synthesis process in a coupled fluidized bed reactor

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Particuology 2023年第4期75卷 69-81页

作者： Shuaishuai Zhou Jing li Congzhen Qiao Mengxi liu chunxi Lu Yan Bai College of Chemistry and Chemical Engineering Henan UniversityKaifeng475000China Nanomaterial Engineering Research Center Henan University.Kaifeng475000China Department of State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing102249China

To obtain the optimal operating conditions of a coupled reactor for pyridine synthesis,reactor modeling process is carried out in this paper.During the modeling process,the flow hydrodynamics,heat transfer behavior,inter-phase mass transfer behavior and reaction kinetics were taken into consideration consequently.Further,a regression program based on least square method was proposed to regress the model parameters.The prediction results agreed well with the experimental results with an average deviation of 5.9%.Finally,by setting suitable aim function,the optimal operating conditions of the coupled reactor for pyridine synthesis were determined.

关键词： Reactor modeling Pyridine synthesis Inter-phase mass transfer Optimal operating conditions

Heat transfer characterization and improvement in an external catalyst cooler fluidized bed

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Particuology 2021年第3期19卷 103-112页

作者： Jiantao li Xiuying Yao Lu liu Xudong Zhong chunxi Lu State Key Laboratory of Heavy Oil China University of Petroleum(Beijing)Beijing 102249China Luoyang R&D Center of Technology SINOPEC Engineering(Group)Co.Ltd.Luoyang 471003China

Gas-solid fluidized beds have been widely used in heat transfer processes,and so there have been many studies focused on increasing heat transfer in such units.In the present work,a pilot scale cold mode experimental rig was constructed to assess the effects of hydrodynamics on bed-to-wall heat transfer and to investigate various means of enhancing heat transfer in a dense gas-solid fluidized bed with external solid circulation.The experimental results show that heat transfer in the dense region played a dominant role in total bed-to-wall heat transfer,accounting for more than 88%of the total heat transfer load.Heat transfer could be lowered as a result of solids bypass that occurred because of external solids circulation,but this effect was weakened by the radial mixing of particles.The heat transfer characteristics identified in this study indicate that a specially designed baffle can be used to enhance bed-to-wall heat transfer.After installing such baffles in the fluidized bed test structure,a 70%increase in the total heat transfer coefficient was obtained.

关键词： Gas-solid fluidized bed Heat transfer Hydrodynamics Baffles Intensification

Alkynyl carbon materials as novel and efficient sorbents for the adsorption of mercury(Ⅱ) from wastewater

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Journal of Environmental Sciences 2018年第6期30卷 169-176页

作者： Yingjie li Wenfeng li Qingnan liu Hong Meng Yingzhou Lu chunxi li State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical Technology College of Chemical Engineering Beijing University of Chemical Technology

For the first time, a series of alkynyl carbon materials（ACMs） were prepared via the mechanochemical reaction of CaC2 with six polyhalogenated precursors, namely CCl4,C2Cl6, C2Cl4, C6Cl6, C6Br6, and C14H4Br10（ACM-1, ACM-2, ACM-3, ACM-4, ACM-5, and ACM-6,respectively） and used for the adsorptive removal of mercury from aqueous solutions.Based on preliminary investigations, the adsorption of mercury on ACM-5 was studied in depth. Specifically, the effect of p H on mercury adsorptivity, adsorption kinetics,thermodynamics, isotherms, and recyclability was studied. The adsorptivity of mercury on ACMs was found to be closely related to the hydrocarbon precursor, specific surface area of sorbent, and the alkynyl content. ACM-5 showed the best performance and is among the best raw carbonaceous sorbents reported so far, with a Langmuir saturated adsorption capacity of 191.9 mg g-1. The promising mercury adsorption performance mainly arises from the strong Lewis soft acid–soft base interactions between the alkynyl groups and mercury ions. The adsorption isotherms could be satisfactorily correlated with the Langmuir equation. The results show that the ACMs can be used as efficient sorbents for the removal of mercury and may also be useful for the adsorption of other heavy metals.

关键词： Alkynyl carbon materials Mercury adsorption Chemisorption Kinetics Thermodynamics

论格日勒其木格·黑鹤的“重返草原”主题书写

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民族文学研究 2022年第2期40卷 108-114页

作者：李春喜泉州幼儿师范高等专科学校

“重返草原”是蒙古族作家格日勒其木格·黑鹤在其动物文学作品中着力表现的一个主题。他借助“草原—城市—草原”的地理空间转换,在重返草原的呼吁和期盼中传达勇敢、平等、自由的生命观,追寻信任、爱、忠诚等美好人性,缅怀古老的民... 详细信息

“重返草原”是蒙古族作家格日勒其木格·黑鹤在其动物文学作品中着力表现的一个主题。他借助“草原—城市—草原”的地理空间转换,在重返草原的呼吁和期盼中传达勇敢、平等、自由的生命观,追寻信任、爱、忠诚等美好人性,缅怀古老的民族传统文化,更是借重返草原的隐喻和精神家园的建构、人类生存的哲思,从多方面拓展了文学审美的视域,表现出独特的叙事价值。

关键词：黑鹤动物文学重返草原

Spongy acetylenic carbon material prepared by ball milling CaC2 and chlorinated rubber—Its mercury adsorption and electrochemical property

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Chinese Journal of Chemical Engineering 2019年第8期27卷 1988-1995页

作者： Xuebing Xu Wenfeng li Luyan Xia Yingzhou Lu Hong Meng chunxi li State Key Laboratory of Chemical Resource Engineering Beijing University of Chemical TechnologyBeijing 100029China College of Chemical Engineering Beijing University of Chemical TechnologyBeijing 100029China Beijing Key Laboratory of Energy Environmental Catalysis Beijing University of Chemical TechnologyBeijing 100029China

Design and preparation of novel advanced carbon materials with unique architecture and functional groups is of great significance.Herein,a spongy acetylenic carbon material(SACM) was prepared through mechanochemical reaction of CaC2 and chlorinated rubber in a planetary ball mill at ambient temperature.Its composition and structure were characterized,and its electrochemical properties and adsorption performance for Hg^2+ were studied.The SACM is composed of submicron spongy aggregates with high carbon content(81.8%) and specific area(503.9 m^2·g^-1),rich porosity and acetylenic groups.The SACM exhibits excellent adsorption for Hg2+with saturated adsorption amount being 157.1 mg·g^-1,which is superior to conventional carbon materials.Further,it exhibits good electrochemical performance with low equivalent series resistance(0.50 Ω),excellent cycling stability and ideal double layer capacitive behavior.This paper provides a novel and universal synthesis method of spongy carbon materials,and better results can be expected through tuning the pore structure,graphitization degree,and heteroatoms of the target carbon materials.

关键词： Acetylenic carbon material Calcium carbide Mechanochemical reaction Heavy metal adsorption