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Erosion-induced recovery CO_(2) sink offset the horizontal soil organic carbon removal at the basin scale

Science China Earth Sciences 2024年第6期67卷 2019-2033页

作者： Lingxia WANG Xiaodong NIE Jiaqi LI yaojun liu Hui WANG Yazhe LI Zhongwu LI School of Geographic Science Hunan Normal UniversityChangsha 410081China Institute of Interdisciplinary Studies Hunan Normal University and Hunan Provincial Key Laboratory for Eco-environmental Changes and Carbon Sequestration of the Dongting Lake BasinChangsha 410081China College of Environmental Science and Engineering Hunan University and Key Laboratory of Environmental Biology and Pollution Control(Hunan University)Ministry of EducationChangsha 410082China

To improve soil carbon sequestration capacity,the full soil carbon cycle process needs to be understood and *** is essential to evaluate whether water erosion acts as a net source or sink of atmospheric CO_(2)at the basin scale,which encompasses the entire hydrological *** study introduced an approach that combined a spatially distributed sediment delivery model and biogeochemical model to estimate the lateral and vertical carbon fluxes by water erosion at the basin *** this coupling model to the Dongting Lake Basin,the results showed that the annual average amount of soil erosion during 1980-2020 was 1.33×10^(8)t,displaying a decreasing trend followed by a slight *** 12% of the soil organic carbon displacement was ultimately lost in the riverine systems,and the rest was deposited downhill within the *** average lateral soil organic carbon loss induced by erosion was 8.86×10^(11)g C in 1980 and 1.50×10^(11)g C in 2020,with a decline rate of 83%.A net land sink for atmospheric CO_(2)of 5.54×1011g C a^(-1)occurred during erosion,primarily through sediment burial and dynamic ***,ecological restoration projects and tillage practice policies are still significant in reducing erosion,which could improve the capacity of the carbon sink for recovery beyond the rate of horizontal carbon ***,our model enables the spatial explicit simulation of erosion-induced carbon fluxes using costeffective and easily accessible input data across large spatial scales and long ***,it offers a valuable tool for predicting the interactions between carbon dynamics,land use changes,and future climate.

关键词： Water erosion Sediment transfer Lateral soil carbon loss Land-atmosphere CO_(2) flux Dongting Lake Basin

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氮氧同位素解析堤垸地表水硝酸盐来源

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环境科学研究 2024年第2期37卷 326-335页

作者：杨忆凡刘窑军田亮聂小东彭博李忠武湖南师范大学地理科学学院湖南长沙410081

堤垸是滨湖、滨江低洼地带的一种重要景观,农业面源污染已成为其主要的环境问题之一.为解析堤垸地区地表水硝酸盐污染来源,以洞庭湖屈原垸平江河段为研究对象,采用稳定同位素及水化学分析方法定性识别污染来源,并结合MixSIAR模型量化不... 详细信息

堤垸是滨湖、滨江低洼地带的一种重要景观,农业面源污染已成为其主要的环境问题之一.为解析堤垸地区地表水硝酸盐污染来源,以洞庭湖屈原垸平江河段为研究对象,采用稳定同位素及水化学分析方法定性识别污染来源,并结合MixSIAR模型量化不同污染源的贡献率.结果表明:①硝态氮和氨氮是屈原垸平江河段地表水无机氮的主要赋存形态,时间上,硝态氮浓度在丰、枯水期间无显著差异(p>0.05),而丰水期氨氮浓度平均值高于枯水期;空间上,垸内硝态氮浓度显著低于垸外(p<0.01),而氨氮浓度显著高于垸外(p<0.01).②MixSIAR模型结果表明,化肥、土壤有机氮、水产养殖废水、粪肥和污水是研究区地表水硝酸盐的主要来源,对丰水期地表水中硝酸盐的贡献率分别为33.0%、32.6%、19.4%和11.7%,对枯水期的贡献率分别为26.7%、31.2%、21.5%和16.9%,而大气沉降对地表水中硝酸盐来源贡献较小,仅为3.5%.③研究区地表水硝酸盐转化过程主要以硝化作用为主,未发生明显的反硝化过程.研究显示,研究区地表水硝酸盐污染主要受农业面源污染的影响,污染物主要来源于土壤有机氮、化肥及水产养殖废水,硝酸盐污染防治应考虑化肥使用效率和水产养殖废水处理.

关键词：洞庭湖堤垸氮氧同位素硝酸盐源解析 MixSIAR模型

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应用线性方程组理论证明矩阵秩的性质

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中央民族大学学报（自然科学版） 2024年第2期33卷 62-68页

作者：张姗梅刘耀军太原师范学院数学与统计学院山西晋中030619 太原师范学院计算机科学与技术学院山西晋中030619

利用矩阵秩的定义证明矩阵秩的性质时,需要使用行列式的性质,证明过程较为复杂。线性方程组解的理论与矩阵秩的内在联系,使得用线性方程组解的理论证明矩阵秩的性质成为可能。应用线性方程组解的理论,可将矩阵秩的等式证明转化为线性方... 详细信息

利用矩阵秩的定义证明矩阵秩的性质时,需要使用行列式的性质,证明过程较为复杂。线性方程组解的理论与矩阵秩的内在联系,使得用线性方程组解的理论证明矩阵秩的性质成为可能。应用线性方程组解的理论,可将矩阵秩的等式证明转化为线性方程组解空间相等的证明;将矩阵秩的不等式的证明转化为解空间包含的证明。从行列式性质法的证明转化为集合间关系的证明,不仅简化了矩阵秩的性质的证明,而且证明过程便于理解。

关键词：线性方程组的解矩阵的秩线性空间的维数

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表层土壤结构对红壤坡耕地产流及产沙过程的影响

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土壤学报 2024年第2期61卷 434-444页

作者：张紫薇赵文俊李奇马一淳田亮杨广勇李忠武刘窑军湖南师范大学地理科学学院长沙410081 华中农业大学水土保持研究中心武汉430070

针对南方红壤区坡耕地水土流失严重与表层结构退化的现状,采用室内模拟降雨的方法,分析表层土壤结构和雨强对降雨再分配、坡面产流及产沙过程的影响。结果表明:(1)表层土壤结构显著改变降雨的再分配过程,深耕作层可以降低地表径流比例,... 详细信息

针对南方红壤区坡耕地水土流失严重与表层结构退化的现状,采用室内模拟降雨的方法,分析表层土壤结构和雨强对降雨再分配、坡面产流及产沙过程的影响。结果表明:(1)表层土壤结构显著改变降雨的再分配过程,深耕作层可以降低地表径流比例,增加壤中流比例,60和90 mm·h^(-1)雨强下,随耕作层深度增加,地表径流平均比例依次为70.5%,62.9%和56.8%,壤中流平均比例依次提升为7.1%,12.3%和18.1%;(2)土壤流失率随雨强增加而增大,90 mm·h^(-1)雨强下土壤流失率为60 mm·h^(-1)雨强下的4.4倍,土壤流失率随耕作层深度增加而显著减小,依次为36.8、21.1和13.1 g·m^(-2) min^(-1);(3)雨强和表层土壤结构显著影响坡面侵蚀形态的演变,随耕作深度增加坡面侵蚀由细沟侵蚀逐渐转变为面蚀。表层土壤结构显著改变坡耕地降雨-径流关系和侵蚀过程,合理增加耕作层深度,对降低地表侵蚀、促进土壤水分的深层下渗、增加土壤深层持水量具有积极作用。

关键词：土壤结构产流产沙壤中流红壤坡耕地

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Vitamin K alleviates bone calcium loss caused by Salmonella Enteritidis through carboxylation of osteocalcin

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Journal of Animal Science and Biotechnology 2021年第4期12卷 1572-1581页

作者： yaojun liu Rainer Mosenthin Lihong Zhao Jianyun Zhang Cheng Ji Qiugang Ma State Key Laboratory of Animal Nutrition College of Animal Science and TechnologyChina Agricultural UniversityBeijing 100193China Institute of Animal Science University of Hohenheim70593 StuttgartGermany

Background:The present study aimed at evaluating the effect of vitamin K(VK)supplementation on bone health of laying hens challenged by Salmonella ***:A total of 8032-week-old double negative salmonella-free brown-egg laying hens were randomly assigned to 4 treatments with 20 replicates each(1 bird per replicate)according to a 2×2 factorial design with 2 dietary VK supplementation levels[0 mg/kg(VK0)vs 2 mg/kg VK(VK2)and 2 challenge treatments[Salmonella Enteritidis(SE)vs physiological saline solution(PS)].During the last 3 days of week 43 of age,birds of both VK treatments were either orally challenged with 1.0 mL suspension of 109 cfu/mL *** daily or received the same volume of ***:The laying rate,daily egg mass,tibia strength,CT,cOC and cOC/(cOC+ucOC)of VK2 treatment increased(P<0.05)in contrast to VK0,however,the medullary area and ucOC of VK2 treatment decreased(P<0.05)in contrast to ***,medullary area,serum Ca content of SE treatments increased(P<0.05)in contrast to PS *** both SE treatments,the decrease(P<0.05)in birds’tibia strength was associated with higher(P<0.05)Ca levels in *** is an interaction(P<0.05)between SE challenge and VK levels with regard to tibia strength and serum Ca *** week 42,serum CT was positively correlated with cOC(R=0.99,P=0.009);at week 44,tibia strength was positively correlated with BMD(R=0.95,P=0.045),but negatively correlated with medullary area(R=−0.98,P=0.018).Conclusions:VK(2 mg/kg)supplementation to diets of laying hens can enhance bone strength under challenge situations with Salmonella *** area has proven to be a sensitive biomarker for bone calcium loss caused by SE infection.

关键词： Calcium Laying hen Salmonella Enteritidis Vitamin K

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Advantages and disadvantages of terracing:A comprehensive review

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International Soil and Water Conservation Research 2021年第3期9卷 344-359页

作者： Chuxiong Deng Guangye Zhang yaojun liu Xiaodong Nie Zhongwu Li Junyu liu Damei Zhu College of Resources and Environmental Science Hunan Normal UniversityChangsha410082PR China College of Environmental Science and Engineering Hunan UniversityChangsha410081PR China

For thousands of years,terracing has been one of the most important systems for preventing soil erosion,conserving water,and increasing agricultural *** having a long history,the wide-ranging effects and mechanisms of terracing are poorly understood owing to large-scale spatial and temporal distribution patterns and the challenges related to assessing the ecosystem services of terraced ***,our study aims to review comprehensively the effect of terraces by describing the mechanisms behind terraced *** provide many ecosystem services,including the reduction of runoff and sediment by over 41.9%and 52%,respectively,and the improvement of grain yields and soil moisture content by 44.8%and 12.9%,*** addition,terracing can also contribute toward the conservation of plant biodiversity on a local ***,as terraces age,a number of disadvantages gradually emerge,including interference with water circulation and the development of serious environmental problems caused by poorly designed or mismanaged terraces,where the average runoff and soil loss can be 1—5 times that of well-managed *** understanding the complexity and multifaceted effects of terracing is vital for terrace construction and management,the negative effects of terracing are often not considered,and existing studies have several *** this context,this paper aims to describe both the benefits and disadvantages of terracing,investigate the gaps in current research,as well as discuss preventive and remedial measures so as to negate the possible bad impacts of terracing.

关键词： Ecosystem services Terraces Terrace abandonment Terrace management Soil and water loss

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一流学科建设和研究生教育的关系研究

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科教导刊 2024年第2期 1-4页

作者：李忠武谭长银孙艳艳刘窑军湖南师范大学地理科学学院湖南长沙410081

一流学科建设和研究生教育共同构成“双一流”建设的重要支撑。本课题基于“双一流”建设背景,探讨一流学科的深刻内涵和外延,阐明一流学科建设和研究生教育之间联动发展、相辅相成、互相成就的关系,并从师资力量、人才培养、科研成果... 详细信息

一流学科建设和研究生教育共同构成“双一流”建设的重要支撑。本课题基于“双一流”建设背景,探讨一流学科的深刻内涵和外延,阐明一流学科建设和研究生教育之间联动发展、相辅相成、互相成就的关系,并从师资力量、人才培养、科研成果等方面来深入探究一流学科与研究生教育之间的相互作用和相互促进。一流学科建设的核心任务和研究生教育高素质发展的基本目标密切符合,以此实现二者协同推进。

关键词：一流学科学科内涵研究生教育高质量发展相互关系

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Heteroatoms doped iron oxide-based catalyst prepared from zinc slag for efficient selective catalytic reduction of NO_(x) with NH_(3)

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International Journal of Coal Science & Technology 2024年第1期11卷 180-193页

作者： Jiale Liang yaojun Zhang Hao Chen Licai liu Panyang He Lei Wu College of Materials Science and Engineering Xi’an University of Architecture and TechnologyXi’an710055China School of Chemistry and Chemical Engineering Xi’an University of Architecture and TechnologyXi’an710055China School of Resources Engineering Xi’an University of Architecture and TechnologyXi’an710055China

Excessive emissions of nitrogen oxides from flue gas have imposed various detrimental impacts on environment,and the development of deNO_(x) catalysts with low-cost and high performance is an urgent *** oxide-based material has been explored for promising deNO_(x) ***,the unsatisfactory low-temperature activity limits their practical *** this study,a series of excellent low-temperature denitrification catalysts(Ha-FeO_(x)/yZS)were prepared by acid treatment of zinc slag,and the mass ratios of Fe to impure ions was regulated by adjusting the acid ***-FeO_(x)/yZS showed high denitrification performance(>90%)in the range of 180–300℃,and the optimal NO conversion and N2 selectivity were higher than 95%at 250℃.Among them,the Ha-FeO_(x)/2ZS synthesized with 2 mol/L HNO3 exhibited the widest temperature window(175–350℃).The excellent denitrification performance of Ha-FeO_(x)/yZS was mainly attributed to the strong interaction between Fe and impurity ions to inhibit the growth of crystals,making Ha-FeO_(x)/yZS with amorphous structure,nice fine particles,large specific surface area,more surface acid sites and high chemisorbed *** in-situ DRIFT experiments confirmed that the SCR reaction on the Ha-FeO_(x)/yZS followed both Langmuir-Hinshelwood(L-H)mechanism and Eley-Rideal(E-R)*** present work proposed a high value-added method for the preparation of cost-effective catalysts from zinc slag,which showed a promising application prospect in NO_(x) removal by selective catalytic reduction with ammonia.

关键词： Flue gas NO_(x)removal Zinc slag-derived catalyst NH_(3)-SCR Catalysis activity

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Assembly process and source tracking of microbial communities in sediments of Dongting Lake

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Soil Ecology Letters 2023年第4期5卷 101-110页

作者： Wenfei Liao Di Tong Xiaodong Nie yaojun liu Fengwei Ran Shanshan Liao Jia Chen Aoqi Zeng Zhongwu Li School of Geographical Sciences Hunan Normal UniversityChangsha 410081China Institute of Soil and Water Resources and Environmental Science College of Environmental and Resource SciencesZhejiang UniversityHangzhou 310058China College of Environmental Science and Engineering Hunan University and Key Laboratory of Environmental Biology and Pollution Control(Hunan University)Ministry of EducationChangsha 410082China

●Soil erosion resulted in homogenization of bacterial communities in the watershed.●Microbial community heterogeneity among erosion sites made soil tracing possible.●Assembly process results showed that the tracking results can achieve high precision.●Dryland was the main source of sediment deposition based on the result of *** source tracing can accurately provide a theoretical basis for controlling soil erosion effectively,by identifying the most serious types of land *** sediment tracing methods are based on physical,chemical,biological,and composite fingerprinting,which have not included *** high-throughput sequencing becomes more prevalent,microorganisms can provide more information than what we ***,whether the microorganism can also be used as a special fingerprint factor for sediment source identification during soil erosion,we have tested it by using microbial source tracking tool FEAST to quantify the microbe contribution from five types of eroded land(including dryland,urban,paddy field,forest and grassland)to the depositional areas(Niubitan)in the Yuanjiang *** source microbial community in the erosive area was heterogeneous,and assembly process analysis further demonstrated that the source tracking results could reach higher *** results of FEAST showed that dryland(35.50%),urban(17.21%),paddy field(8.14%),and forest(1.07%)were the major contributors to *** results follow the general soil erosion rules and prove its *** together,a new perspective is provided by these results for tracing sediment sources in erosion-sedimentary systems.

关键词： assembly processes soil erosion land types microbial source tracking FEAST

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Homogeneous Polynomial Lyapunov Functional for Stability Analysis of Systems with Delays

Homogeneous Polynomial Lyapunov Functional for Stability Ana...

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第30届中国控制与决策会议

作者： Xingwen liu yaojun liu IEEE College of Electrical and Information Engineering Southwest Minzu University Department of Finance Sichuan university Jincheng College

This paper addresses the stability problem of dynamic systems with delays. A new type of Lyapunov functional is proposed and an asymptotic stability criterion is established. A numerical example shows that the present... 详细信息

关键词： Delays Homogeneous Polynomial Lyapunov functional Kronecker Product Stability

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