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Promotion effects of salt-alkali on ammonia volatilization in a coastal soil

Pedosphere 2024年第1期34卷 191-199页

作者： Zhenqi SHI Dongli SHE yongchun PAN Yongqiu XIA College of Agricultural Science and Engineering Hohai UniversityNanjing 210098China Jiangsu Province Engineering Research Center for Agricultural Soil-Water Efficient Utilization Carbon Sequestration and Emission ReductionNanjing 210098China Key Laboratory of Soil and Sustainable Agriculture Institute of Soil ScienceChinese Academy of SciencesNanjing 210008China

Coastal ecosystems are highly susceptible to salt-related problems due to their formation process and geographical location. As such ecosystems are the most accessible land resources on Earth, clarifying and quantifying the effects of salt-alkali conditions on N concentration and ammonia(NH_(3)) volatilization are pivotal for promoting coastal agricultural productivity. The challenge in establishing this effect is to determine how salt-alkali conditions impact NH_(3) volatilization through direct or indirect interactions. An incubation experiment using a coastal soil from a paddy farmland, combined with the structural equation modeling(SEM) method, was conducted to reveal the net effects of salt-alkali on NH_(3) volatilization and the role of environmental and microbial factors in mutual interaction networks. The specific experimental design consisted of four salt treatments(S1, S2, S3, and S4: 1‰, 3‰, 8‰, and 15‰ NaCl by mass of soil, respectively), four alkaline treatments(A1, A2, A3, and A4: 0.5‰, 1‰, 3‰, and 8‰ NaHCO_(3)by mass of soil, respectively) and a control without NaCl or NaHCO_(3) addition(CK), and each treatment had three urea concentrations(N1, N2, and N3: 0.05, 0.10, and 0.15 g N kg^(-1) soil,respectively) and three replicates. At the N1, N2, and N3 levels, NH_(3)volatilization increased by 9.31%–34.98%, 3.07%–26.92%, and 2.99%–43.61% as the NaCl concentration increased from 1‰ to 15‰, respectively, compared with CK. With an increase in the NaHCO_(3)concentration from 0.5‰ to 8‰, NH_(3) volatilization increased by 8.36%–56.46%, 5.49%–30.10%, and 30.72%–73.18% at the N1, N2, and N3 levels, respectively, compared with CK. According to the SEM method, salinity and alkalinity had positive direct effects on NH_(3)volatilization, with standardized path coefficients of 0.40 and 0.19, *** the total effects(net positive and negative effects) in the SEM results, alkalinity had a greater influence than salinity(total standardized coefficien

关键词： alkalinity coastal ecosystem NH_(3)emission N-transforming microbe salinity structural equation modeling

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Health risks and sources of trace elements and black carbon in PM_(2.5)from 2019 to 2021 in Beijing

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Journal of Environmental Sciences 2024年第8期142卷 69-82页

作者： Chenjie Hua Wei Ma Feixue zheng Yusheng Zhang Jiali Xie Li Ma Boying Song Chao Yan Hongyan Li Zhen Liu Qian Liu Markku Kulmala yongchun Liu Aerosol and Haze Laboratory Advanced Innovation Center for Soft Matter Science and EngineeringBeijing University of Chemical TechnologyBeijing 100029China Institute for Atmospheric and Earth System Research Faculty of ScienceUniversity of HelsinkiHelsinki 00014Finland School of Environment and Safety Taiyuan University of Science and TechnologyTaiyuan 030024China State Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China

A comprehensive health risk assessment of PM_(2.5)is meaningful to understand the current status and directions regarding further improving air quality from the perspective of human *** this study,we evaluated the health risks of PM_(2.5)as well as highly toxic inorganic components,including heavy metals(HMs)and black carbon(BC)based on longterm observations in Beijing from 2019 to *** results showed that the relative risks of chronic obstructive pulmonary disease,lung cancer,acute lower respiratory tract infection,ischemic heart disease,and stroke decreased by 4.07%-9.30%in 2020 and 2.12%-6.70%in2021 compared with ***,they were still at high levels ranging from 1.26 to 1.77,in particular,stroke showed the highest value in *** had the highest hazard quotient(HQ,from 2.18 to 2.56)for adults from 2019 to 2021,while Ni,Cr,Pb,As,and BC showed high carcinogenic risks(CR>1.0×10^(-6))for *** HQ values of Mn and As and the CR values of Pb and As showed constant or slight upwards trends during our observations,which is in contrast to the downward trends of other HMs and PM_(2.5).Mn,Cr,and BC are crucial toxicants in PM_(2.5).A significant shrink of southern region sourcesof HMs and BCshrank suggests the increased importance of local ***,dust,and biomass burning are the major contributors to the non-carcinogenic risks,while traffic emissions and industry are the dominant contributors to the carcinogenic risks in Beijing.

关键词： PM_(2.5) Heavy metals Black carbon Health risk Source apportionment

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从月球背面到深邃宇宙——2018年太空探索主要进展评述

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科技导报 2019年第3期37卷 35-39页

作者：郑永春中国科学院国家天文台北京100101

2018年,人类在太空探索方面取得重要进展。中国"嫦娥四号"探测器成功登陆月球背面,着陆点位于南极艾特肯盆地的冯·卡门撞击坑,实现人类航天器首次登陆月球背面;之后,中国探月工程将在完成月球采样返回后,朝着建设月球科研站的方向前进... 详细信息

2018年,人类在太空探索方面取得重要进展。中国"嫦娥四号"探测器成功登陆月球背面,着陆点位于南极艾特肯盆地的冯·卡门撞击坑,实现人类航天器首次登陆月球背面;之后,中国探月工程将在完成月球采样返回后,朝着建设月球科研站的方向前进。在火星探测方面,重点是回答火星上是否曾经有过适宜生命生存的环境及其持续时间,而中国的火星探测器已在研制中,将于下一发射窗口发射升空。在引力波探测方面,中国启动以地面观测为主的阿里原初引力波探测计划以及以空间观测为主的天琴计划和太极计划,有望在这一领域做出重要贡献。多信使探测宇宙、寻找太阳系外的宜居行星是天文和天体物理领域的研究前沿和热点领域,正在酝酿新的突破。

关键词：月球背面火星生命引力波多信使宜居行星

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A guidance strategy for rendezvous and docking to the space station in the Earth-Moon NRHO orbit

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中国空间科学技术（中英文） 2024年第4期44卷 29-39页

作者： XIE yongchun CHEN Changqing LI Xiangyu LI Zhenyu Beijing Institute of Control Engineering Beijing 100094China School of Aerospace Engineering Beijing Institute of TechnologyBeijing 100081China

With the development of space technology,it is possible to build a space station in Earth-Moon space as a transit for Earth-Moon round-trip and entering in the deep *** and docking is one of the key technologies for building an Earth-Moon space station.A guidance strategy for rendezvous and docking from the Earth orbit to the space station in the Earth-Moon NRHO orbit is proposed in this paper,which is suitable for engineering ***,the rendezvous and docking process is divided into three sections,i.e.,the large-range orbit transfer section,far-range guidance section,and close-range approaching *** suitable terminal of large-range orbit transfer is selected according to the eigenvalue of NRHO orbit state transition *** two-impulse guidance method based on the relative motion equation in the three-body problem is adopted for the far-range guidance *** impulse time and amplitude are solved with the optimization *** linear constant three-body relative motion equation is proposed for the close-range approaching section,and the rendezvous and docking is completed by a two-stage linear ***,a simulation analysis is carried out,and the simulation results show that the adopted dynamics equations and the designed guidance law are effective,and the three flight phases are naturally connected to accomplish the rendezvous and docking mission from the Earth orbit to the space station on the Earth-Moon NRHO.

关键词： Earth-Moon space station rendezvous and docking NRHO orbit relative motion guidance strategy

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Effect of oxide interactions on chromium speciation transformation during simulated municipal solid waste incineration

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Journal of Environmental Sciences 2024年第8期142卷 11-20页

作者： Guodong Zhao Chong Tian Peidong Wu Xuguang Zhang Zhikang Wang Xiaoxiang Chen Zhuo Xiong yongchun Zhao Junying Zhang State Key Laboratory of Coal Combustion School of Energy and Power EngineeringHuazhong University of Science and TechnologyWuhan 430074China School of Power and Mechanical Engineering Wuhan UniversityWuhan 430072China National Environmental Protection Engineering Technology Center for Trace Elements Pollution Control and Low Carbon Utilization of Coal Huazhong University of Science and TechnologyWuhan 430074China School of Environmental Engineering Wuhan Textile UniversityWuhan 430200China

Chromium released during municipal solid waste incineration(MSWI)is toxic and *** removal of chromium from simulated MSWI flue gas by four sorbents(CaO,bamboo charcoal(BC),powdered activated carbon(PAC),and Al_(2)O_(3))and the effects of four oxides(SiO_(2),Al_(2)O_(3),Fe_(2)O_(3),and CaO)on chromium speciation transformationwere *** results showed that the removal rates of total Cr by the four sorbents were Al_(2)O_(3)

关键词： Cr(Ⅵ)reduction Cr(Ⅲ)oxidation Alkali oxides Acidic oxides Municipal solid waste incineration

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Study on the spatial and temporal evolutionary characteristics of ozone concentration and the impact of human activities in China in 2019

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Acta Geochimica 2024年第05期43卷 985-995页

作者： yongchun Wang Wang Zhang Yu'an Liu Yazhu Wang Yuting Fu Zhaohui Feng Lingqing Wang School of Geography South China Normal University College of Urban and Environmental Sciences Hunan University of Technology Nanjing Institute of Geography and Limnology Chinese Academy of Sciences Institute of Geographical Sciences and Natural Resources Research Chinese Academy of Sciences

Ozone （O3） pollution has a profound impact on human health,vegetation development,and the ecological environment,making it a critical focus of global academic *** recent years,O3pollution in China has been on a steady rise,with ozone emerging as the sole conventional pollutant to consistently increase in concentration without any *** study conducted a quantitative analysis of O3concentrations across 367 Chinese cities in 2019,examining spatial autocorrelation and local clustering of O3levels,and investigated the diverse relationships between human activity factors and *** seasonal fluctuation of O3exhibited the“M-type”pattern,with peak concentrations in winter and the lowest levels in *** center of O3pollution migrated southeastward,with the area of highest concentration progressively shifting south along the eastern ***,O3concentration showed a strong positive correlation with population density,road freight volume,and industrial emissions,suggesting that human activities,vehicle emissions,and industrial operations are significant contributors to *** results provide comprehensive information on the characteristics,causes,and occurrence mechanism of O3in Chinese cities that can be utilized by global government departments to formulate strategies to prevent and control O3pollution.

关键词： Human activities Ozone concentration Spatial heterogeneity Urban agglomerations

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中华钙果的形态解剖观察

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贵州农业科学 2012年第12期40卷 165-167页

作者：郑永春迟丽华吉林农业科技学院吉林吉林132101

为给中华钙果的科学开发和综合利用提供依据,对中华钙果的根、茎叶、花、果实进行解剖显微镜观察。结果表明:1)根结构中有发达的韧皮部和木栓层、次生韧皮部,不仅适应性强,而且有很强的输导能力。2)茎为初生结构,由厚角细胞组成,维管束... 详细信息

为给中华钙果的科学开发和综合利用提供依据,对中华钙果的根、茎叶、花、果实进行解剖显微镜观察。结果表明:1)根结构中有发达的韧皮部和木栓层、次生韧皮部,不仅适应性强,而且有很强的输导能力。2)茎为初生结构,由厚角细胞组成,维管束类型是无限外韧维管束。3)叶内有比较厚的角质层和发达的栅栏组织,叶肉组织细胞排列紧凑,叶绿体含量高。4)果皮细胞内有内含物质,果肉细胞为薄壁细胞,果肉厚,维管束的输导组织较发达,且在北方地区适应性较强,有较高的生态、经济效益。

关键词：中华钙果石蜡切片形态解剖

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Contact Stress Reliability Analysis Model for Cylindrical Gear with Circular Arc Tooth Trace Based on an Improved Metamodel

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Computer Modeling in Engineering & Sciences 2024年第7期140卷 593-619页

作者： Qi Zhang Zhixin Chen Yang Wu Guoqi Xiang Guang Wen Xuegang Zhang yongchun Xie Guangchun Yang School of Intelligent Manufacturing&Automobile Chengdu Industrial Vocational Technical CollegeChengdu610218China School of Intelligent Manufacturing Panzhihua UniversityPanzhihua617000China School of Electrical Engineering Chengdu Industry and Trade CollegeChengdu601165China School of Mechanical Engineering Sichuan UniversityChengdu601165China Chengdu Technological University Chengdu611730China

Although there is currently no unified standard theoretical formula for calculating the contact stress of cylindrical gears with a circular arc tooth trace(referred to as CATT gear),a mathematical model for determining the contact stress of CATT gear is essential for studying how parameters affect its contact stress and building the contact stress limit state equation for contact stress reliability *** this study,a mathematical relationship between design parameters and contact stress is formulated using the *** enhance the model’s accuracy,we propose a new hybrid algorithm that merges the genetic algorithm with the Quantum Particle Swarm optimization algorithm,leveraging the strengths of ***,the“parental inheritance+self-learning”optimization model is used to fine-tune the KrigingMetamodel’s *** this,amathematicalmodel for calculating the contact stress of Variable Hyperbolic Circular-Arc-Tooth-Trace(VH-CATT)gears using the optimized Kriging model was *** then examined how different gear parameters affect the VH-CATT gears’contact *** simulation results show:(1)Improvements in R2,RMSE,and RMAE.R2 rose from0.9852 to 0.9974(a 1.22%increase),nearing 1,suggesting the optimized Kriging Metamodel’s global error is ***,RMSE dropped from3.9210 to 1.6492,a decline of 57.94%.The global error of the GA-IQPSO-Kriging algorithm was also reduced,with RMAE decreasing by 58.69%from 0.1823 to 0.0753,showing the algorithm’s enhanced *** a comparison of ten experimental groups selected randomly,the GA-IQPSO-Kriging and FEM-based contact analysis methods were used to measure contact *** revealed a maximum error of 12.11667 MPA,which represents 2.85%of the real value.(2)Several factors,including the pressure angle,tooth width,modulus,and tooth line radius,are inversely related to contact *** descending order of their impact on the contact stress is:tooth line radius>modulus

关键词： CATT gear contact stress finite element method metamodel hybrid algorithm influencing factors

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An increment of diversity method for cell state trajectory inference of time-series scRNA-seq data

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Fundamental Research 2024年第4期4卷 770-776页

作者： Yan Hong Hanshuang Li Chunshen Long Pengfei Liang Jian Zhou yongchun Zuo State Key Laboratory of Reproductive Regulation and Breeding of Grassland Livestock Institutes of Biomedical SciencesCollege of Life SciencesInner Mongolia UniversityHohhot010020China

The increasing emergence of the time-series single-cell RNA sequencing(scRNA-seq)data,inferring developmental trajectory by connecting transcriptome similar cell states(i.e.,cell types or clusters)has become a major *** existing computational methods are designed for individual cells and do not take into account the available time series *** present IDTI based on the Increment of Diversity for Trajectory Inference,which combines time series information and the minimum increment of diversity method to infer cell state trajectory of time-series scRNA-seq *** apply IDTI to simulated and three real diverse tissue development datasets,and compare it with six other commonly used trajectory inference methods in terms of topology similarity and branching *** results have shown that the IDTI method accurately constructs the cell state trajectory without the requirement of starting *** the performance test,we further demonstrate that IDTI has the advantages of high accuracy and strong robustness.

关键词： Increment of diversity Time-series scRNA-seq data Cell state trajectory inference Topology similarity Branching accuracy

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火星地下冰川:新发现的意义

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科技导报 2018年第6期36卷 17-20页

作者：郑永春赵伟方中国科学院国家天文台北京100101 北京航空航天大学北京100191

火星上是否有水以及水的储藏位置和规模,不仅是一个科学问题,更与未来载人登陆火星和火星移民密切相关。作为太阳系中与地球最为相似的行星,火星表面同样覆盖了厚厚的沉积物,但这些沉积物之下究竟有什么,对人类来说一直是个谜。近期,科... 详细信息

火星上是否有水以及水的储藏位置和规模,不仅是一个科学问题,更与未来载人登陆火星和火星移民密切相关。作为太阳系中与地球最为相似的行星,火星表面同样覆盖了厚厚的沉积物,但这些沉积物之下究竟有什么,对人类来说一直是个谜。近期,科学家发现,火星中纬度地区的地下储藏着大量纯净的水冰。本文评论火星地下冰川这一发现的意义,讨论了科学家究竟发现了什么、如何证明观测到的物质确实是地下冰层、这些冰层是如何形成的、冰层所记录的历史等相关问题,并展望了未来火星探测中如何利用这些水冰资源。

关键词：断崖水冰地下冰层光谱分析

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