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Digital Communications and Networks 2024年第1期10卷 53-62页

作者： Zhipeng Cheng Minghui Liwang Ning Chen Lianfen Huang Nadra Guizani xiaojiang Du Department of Information and Communication Engineering Xiamen UniversityXiamen361005China School of Electrical and Computer Engineering University of Texas at ArlingtonArlingtonTX7619USA Department of Electrical and Computer Engineering Stevens Institute of TechnologyHobokenNJ07030USA

Unmanned Aerial Vehicles(UAvs)as aerial base stations to provide communication services for ground users is a flexible and cost-effective paradigm in B5G.Besides,dynamic resource allocation and multi-connectivity can be adopted to further harness the potentials of UAVs in improving communication capacity,in such situations such that the interference among users becomes a pivotal disincentive requiring effective solutions.To this end,we investigate the Joint UAV-User Association,Channel Allocation,and transmission Power Control(J-UACAPC)problem in a multi-connectivity-enabled UAV network with constrained backhaul links,where each UAV can determine the reusable channels and transmission power to serve the selected ground users.The goal was to mitigate co-channel interference while maximizing long-term system utility.The problem was modeled as a cooperative stochastic game with hybrid discrete-continuous action space.A Multi-Agent Hybrid Deep Reinforcement Learning(MAHDRL)algorithm was proposed to address this problem.Extensive simulation results demonstrated the effectiveness of the proposed algorithm and showed that it has a higher system utility than the baseline methods.

关键词： UAV-user association Multi-connectivity Resource allocation Power control Multi-agent deep reinforcement learning

Construction of phosphorus-doping with spontaneously developed selenium vacancies: Inducing superior ion-diffusion kinetics in hollow Cu_(2)Se@C nanospheres for efficient sodium storage

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Journal of Energy Chemistry 2023年第2期77卷 227-238,I0007页

作者： Xiaoqing Ma Yadong Li xiaojiang long Hong-chuan Luo Chunping Xu Guangzhao Wang Wenxi Zhao School of Chemistry and Chemical Engineering Yangtze Normal UniversityChongqing 408100China Sports Medicine Center Department of Orthopedic SurgerySouthwest Hospitalthe 3rd Military Medical UniversityChongqing 400038China School of Electronic Information Engineering Key Laboratory of Extraordinary Bond Engineering and Advanced Materials Technology of ChongqingYangtze Normal UniversityChongqing 408100China Postgraduate Admission Office of Graduate School Southwest UniversityChongqing 400715China Vanadium and Titanium Resource Comprehensive Utilization Key Laboratory of Sichuan Province Panzhihua 617000SichuanChina

Achieving high-efficiency sodium storage in metal selenides is still severely constrained in consideration of their inferior electronic conductivity and inadequate Na^(+)insertion pathways and active sites.Heteroatom doping accompanied by spontaneously developed lattice defects can effectively tune electronic structure of metal selenides,which give a strong effect to motivate fast charge transfer and Na^(+)accessibility.Herein,we finely designed and successfully constructed a fascinating phosphorus-doped Cu_(2)Se@C hollow nanosphere with abundant vacancy defects(Cu_(2)P_(x)Se_(1-x)@C)through a combination strategy of selenization of Cu_(2)O nanosphere template,self-polymerization of dopamine,and subsequent phosphorization treatment.Such exquisite composite possesses enriched active sites,superior conductivity,and sufficient Na^(+)insertion channel,which enable much faster Na^(+)diffusion rates and more remarkable pseudocapacitive features,Satisfyingly,the Cu_(2)P_(x)Se_(1-x)@C composites manifest the supernormal sodium-storage capabilities,that is,a reversible capacity of 403.7 mA h g^(-1) at 1.0 A g^(-1) over 100 cycles,and an ultrastable cyclic lifespan over 1000 cycles at 20.0 A g^(-1) with a high capacity-retention of about249.7 mA h g^(-1).The phase transformation of the Cu_(2)P_(x)Se_(1-x)@C involving the intercalation of Na^(+)into Cu_(2)Se and the following conversion of NaCuSe to Cu and Na2Se were further demonstrated through a series of ex-situ characterization methods.DFT results demonstrate that the coexistence of phosphorusdoping and vacancy defects within Cu_(2)Se results in the reduction of Na^(+)adsorption energy from-1.47to-1.56 eV improving the conductivity of Cu_(2)Se to further accelerate fast Na^(+)mobility.

关键词： Phosphorus-doping Selenium vacancies Hollow Cu_(2)Se@C nanospheres Anode Sodium storage

Spatiotemporal variations of parameters of internal solitary waves in the northern South China Sea

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Journal of Oceanology and Limnology 2024年第2期42卷 421-438页

作者： Yu’ang LIU Yifei JIANG xiaojiang ZHANG Zhiyuan WANG Yu CAO Huizan WANG College of Meteorology and Oceanography National University of Defense TechnologyChangsha 410000China

The dynamic parameters for internal solitary waves(ISWs)derived from the extended Korteweg-de Vries(eKdV)equation play an important role in the understanding and prediction of ISWs.The spatiotemporal variations of the dynamic parameters of the ISWs in the northern South China Sea(SCS)were studied based on the reanalysis of long-term temperature and salinity datasets.The results for spectrum analysis show that there are definite geographical differences for the periodic variation of the parameters:in shallow water,all parameters vary with a wave period of one year,while in deep water wave components of the parameters at other frequencies exist.Using wavelet analysis,the wavelet power spectral densities in deep water exhibited an inter-annual variation pattern.For example,the wave component of the dispersion coefficient with a wave period of about half a year reached its power peak once every two years.Based on previous work,this inter-annual variation pattern was deduced to be caused by dynamic processes.In further work on the regulatory mechanisms,empirical orthogonal function(EOF)decomposition was performed.It was found that the modes of the dispersion coefficient have different geographical distributions,explaining the reason why the wave components in different frequencies appeared in different locations.The numerical simulation results confirm that the variations in the parameters of the ISWs derived from the eKdV equation could affect the waveforms significantly because of changes in the polarity of the ISWs.Therefore,the periodic variations of the dynamic parameters are related to the geographical location because of dynamic processes operating.

关键词： internal solitary waves(ISWs) dynamic parameters eKdV equation spatiotemporal variation polarity empirical orthogonal function(EOF)decomposition

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典型稀土材料催化氧化挥发性有机物研究进展

中国稀土学报 2024年第3期42卷 419-433页

作者：赵永昌田时泓张潇潇龙璐璐姚小江重庆交通大学河海学院重庆400074 中国科学院重庆绿色智能技术研究院大气环境研究中心中国科学院大学重庆学院资源与环境学院重庆400714

挥发性有机物(volatile organic compounds,VOCs)是参与臭氧、二次气溶胶形成的重要前体物,其生物毒性、光化学污染性受到人们的广泛关注,催化氧化是防治VOCs污染的主要技术。稀土材料由于富含表面晶格缺陷、良好的高温稳定性、VOCs亲... 详细信息

挥发性有机物(volatile organic compounds,VOCs)是参与臭氧、二次气溶胶形成的重要前体物,其生物毒性、光化学污染性受到人们的广泛关注,催化氧化是防治VOCs污染的主要技术。稀土材料由于富含表面晶格缺陷、良好的高温稳定性、VOCs亲和力和储释氧能力,在VOCs催化氧化方面受到重点关注。本文就典型稀土材料用于VOCs的热催化、光催化以及光热催化处理开展评述,阐述VOCs的来源、危害和催化氧化机制,探讨不同典型稀土材料的制备方法、结构特征、化学状态用于催化氧化VOCs的效果,明晰了稀土材料的优势并分析了目前面临的难题,以期为稀土材料在VOCs治理中的应用及推广提供参考。

关键词：稀土材料挥发性有机物热催化光催化光热催化

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轨道交通运营数字化应急预案关键技术研究

现代信息科技 2024年第3期8卷 143-148,153页

作者：何靓俊彭逸月沈龙贺龙肖小江金华市轨道交通集团有限公司浙江金华322015 上海宝信软件股份有限公司上海201900

针对轨道交通网络化运营下日益增长的运营安全保障与应急管理压力,通过分析和调研轨道交通的应急痛点以及日常运营中遇到的棘手问题,对轨道交通数字化应急预案的功能和场景进行了研究和设计,并提出了建设过程中的难点和痛点,从而有效地... 详细信息

针对轨道交通网络化运营下日益增长的运营安全保障与应急管理压力,通过分析和调研轨道交通的应急痛点以及日常运营中遇到的棘手问题,对轨道交通数字化应急预案的功能和场景进行了研究和设计,并提出了建设过程中的难点和痛点,从而有效地完善城市轨道交通运营突发事件处置工作机制,提升应急处置效率,保障地铁安全、稳定的运营。

关键词：轨道交通数字化预案应急处置

Doping effect of rare earth metal ions Sm^(3+),Nd^(3+)and Ce^(4+)on denitration performance of MnO_(x) catalyst in low temperature NH_(3)-SCR reaction

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稀土学报:英文版 2023年第9期41卷 1323-1335,I0002页

作者： Jing Rong Wanxia Zhao Wen Luo Keke Kang Lulu long Yang Chen xiaojiang Yao Research Center for Atmospheric Environment Key Laboratory of Reservoir Aquatic Environment of CASChongqing Institute of Green and Intelligent TechnologyChinese Academy of SciencesChongqing 400714China College of Resources and Environment Chongqing SchoolUniversity of Chinese Academy of Sciences(UCAS Chongqing)Chongqing 400714China Chongqing Key Laboratory of Catalysis and New Environmental Materials College of Environment and ResourcesChongqing Technology and Business UniversityChongqing400067China

The MnXO_(x) catalysts(i.e.,MnSmO_(x),MnNdO_(x),MnCeO_(x)) were prepared by reverse co-precipitation method and used for NH_(3)-SCR reaction.It is found that MnCeO_(x) catalyst presents the best low tempe rature catalytic activity(higher than 90% NO_(x) conversion in the te mperature range from 125 to 225℃)and excellent H_(2)O+SO_(2) resistance.In order to explore the reason for this result,the characterization of X-ray diffraction(XRD),Raman spectroscopy,Brunauer-Emmett-Teller(BET),H_(2)-temperature programmed reduction(H_(2)-TPR),NH_(3)-temperature programmed desorption(NH_(3)-TPD),X-ray photoelectron spectroscopy(XPS) and in situ diffuse reflaxions infrared Fourier transformations spectroscopy(DRIFTS) were conducted.The obtained results suggest that MnCeO_(x) catalyst shows the largest amount of acid sites and the best reducibility among these MnXO_(x) catalysts.Besides,Ce^(4+) doping inhibits the crystallization of MnO_(x) catalyst and shows the largest specific surface area.Finally,in situ DRIFTS experiments reveal that NH_(3)-SCR reaction over MnCeO_(x) catalyst follows both Langmuir-Hinshelwood(LH) and Eley-Rideal(E-R) mechanisms,which is through "fast SCR" reaction.

关键词： Low temperature NH_(3)-SCR reaction MnO_(x)catalyst Rare earth Doping effect

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干热岩超高温防衰退水泥浆体系及应用

钻井液与完井液 2024年第1期41卷 92-97页

作者：肖京男李小江周仕明魏浩光杨红歧中石化石油工程技术研究院有限公司北京102200

干热岩长期高温导致水泥石强度衰退,易造成套管挤毁或窜流,严重影响钻井的安全。针对200℃以上常规加砂水泥石强度衰退难题,基于硅铝键结合增强效应,通过优化水泥物相组成,开发了超高温增强材料SCKL,可以满足210~300℃下固井要求,不仅... 详细信息

干热岩长期高温导致水泥石强度衰退,易造成套管挤毁或窜流,严重影响钻井的安全。针对200℃以上常规加砂水泥石强度衰退难题,基于硅铝键结合增强效应,通过优化水泥物相组成,开发了超高温增强材料SCKL,可以满足210~300℃下固井要求,不仅抑制了水泥石强度衰退,且促进了水泥石强度长期发育,300℃、48 h的抗压强度为18.2 MPa,30 d抗压强度高达23.2 MPa,探索了超高温增强材料对水泥石微观结构的影响,揭示了超高温水泥石微观作用机制。研选了温度广谱型缓凝剂,开发了大温差防衰退水泥浆体系,可以满足干热岩100℃温差下安全固井需求,并在青海共和盆地成功应用5口井,固井质量均为优质,为干热岩井筒水泥环密封完整性提供了安全保障。

关键词：干热岩固井强度衰退超高温

小江河滩表土磁化率与Cu、Cd相关性差异及原因

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环境科学与技术 2024年第2期47卷 137-142页

作者：罗淘源苏怀龙佳云南师范大学地理学部云南昆明650500

磁化率与重金属元素之间的相关性是利用磁化率评估区域重金属污染的前提。文章通过测定东川小江河谷30个河滩表土样品的磁化率与Cu、Cd元素发现,小江河滩表土磁化率(低频)平均值为218.46×10-8m3/kg,频率磁化率百分数为0.87%;Cu、Cd平... 详细信息

磁化率与重金属元素之间的相关性是利用磁化率评估区域重金属污染的前提。文章通过测定东川小江河谷30个河滩表土样品的磁化率与Cu、Cd元素发现,小江河滩表土磁化率(低频)平均值为218.46×10-8m3/kg,频率磁化率百分数为0.87%;Cu、Cd平均含量分别为130.86 mg/kg和0.18 mg/kg。磁化率与Cu、Cd元素含量均在P<0.01级别上呈正相关,但磁化率与Cu的相关性(R=0.624)明显高于Cd(R=0.495)。X射线衍射鉴定和电子显微观察显示河滩表土的主要载磁物质(对表土磁化率值起主要贡献的物质)为粒径10~200μm的多畴磁铁矿。载磁物质的Cu、Cd元素测定结果显示,载磁物质Cu平均含量为420.95 mg/kg,高出所在表土样品平均值3倍以上,而Cd的平均含量为0.16 mg/kg,低于其所在表土样品的平均值。研究结果表明,载磁物质与Cu元素存在着同源(伴生)排放关系,而与Cd元素存在此类关系的概率较低,这可能是小江河滩表土磁化率与Cu相关性高于Cd的主要原因。

关键词：磁化率载磁物质磁学监测 Cu、Cd元素

基于中断时间序列模型对河北省扩大免疫规划前后风疹防控效果评价分析

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华南预防医学 2024年第2期50卷 99-103页

作者：周然雷子龙邹显东马晓江曾娟董辉河北省疾病预防控制中心公共卫生信息所河北石家庄050021 华中科技大学同济医学院第二临床学院河北省卫生健康委项目办

目的了解河北省扩大免疫规划前后风疹发病率的变化情况,对其预防效果给予短期和长期评价。方法采集2004—2022年河北省风疹报告发病情况,通过中断时间序列建立多元线性回归模型。依据求得斜率和系数对扩大免疫规划前后效果给予评价。结... 详细信息

目的了解河北省扩大免疫规划前后风疹发病率的变化情况,对其预防效果给予短期和长期评价。方法采集2004—2022年河北省风疹报告发病情况,通过中断时间序列建立多元线性回归模型。依据求得斜率和系数对扩大免疫规划前后效果给予评价。结果2004—2022年共报告风疹25690例,报告年平均发病率为1.925/10万,占丙类传染病报告发病数的1.00%。中断时间序列回归模型分析结果表明2004—2008年扩大免疫规划前风疹报告发病率呈上升趋势(β_(1)=0.0043,P<0.05);2009年为扩大免疫规划后第1年,短期干预效果良好,报告发病率较免疫前有所下降;2009—2022年进入扩大免疫规划后阶段报告发病率下降(β_(3)=-0.0056,P<0.05);扩大免疫规划后报告发病率整体呈下降趋势(β_(1)+β_(3)=-0.0013)。报告年平均发病率由扩大免疫规划前的3.938/10万下降到扩大免疫规划后的1.206/10万。结论使用中断时间序列回归模型对风疹实施扩大免疫规划前后效果评价,可外推至其他传染病或疾病的免疫与治疗效果评价。可为专业人员提供新的方法和思路。

关键词：中断时间序列免疫规划防控效果评价

Elastic and thermodynamic properties of TiC from first-principles calculations

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Science China(Physics,Mechanics & Astronomy) 2011年第12期54卷 2196-2201页

作者： LI YanHong WANG WanFeng ZHU Bo XU Ming ZHU Jun HAO YanJun LI WeiHu long xiaojiang College of Physical Science and Technology Sichuan University Chengdu 610064 China Institute of Atomic and Molecular Physics Sichuan University Chengdu 610065 China

Using the pseudopotential plane-wave method, we investigate the elastic constants and thermodynamic properties of the rocksalt structure Titanium Carbide (TiC). The obtained lattice parameters, bulk modulus and elastic constants are in very good agreement with the available experimental data and other theoretical results. The thermodynamic properties of the cubic TiC are predicted by using the quasi-harmonic Debye model. The normalized volume V/V 0 , bulk modulus B, thermal expansion , heat capacity C V , Grüneisen parameter and Debye temperature dependence on the pressure and temperature are obtained successfully. At low temperature and low pressure, thermal expansion coefficient increases rapidly with temperature. At high temperature and high pressure, the increasing trend becomes tender. At low temperatures, C V is proportional to T 3 , and C V tends to the Dulong-Petit limit at higher temperatures.

关键词：热力学性质弹性常数第一原理计算 TiC 温度依赖性体积弹性模量赝势平面波方法热膨胀系数