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Molecular signatures of soil-derived dissolved organic matter constrained by mineral weathering

Fundamental Research 2023年第3期3卷 377-383页

作者： Ying-Hui Wang Peng Zhang Chen He Jian-Chun Yu Quan Shi randy a.dahlgren Robert G.M.Spencer Zhi-Bing Yang Jun-Jian Wang State Environmental Protection Key Laboratory of Integrated Surface Water-Groundwater Pollution Control School of Environmental Science and EngineeringSouthern University of Science and TechnologyShenzhen 518055China Guangdong Provincial Key Laboratory of Soil and Groundwater Pollution Control School of Environmental Science and EngineeringSouthern University of Science and TechnologyShenzhen 518055China State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan 430072China State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijing 102249China Shanghai Engineering Research Center of Hadal Science and Technology College of Marine SciencesShanghai Ocean UniversityShanghai 201306China Department of Land Air and Water ResourcesUniversity of California DavisDavis 95616United States Department of Earth Ocean and Atmospheric ScienceFlorida State UniversityTallahassee 32306United States

Dissolved organic matter(DOM)in soils drives biogeochemical cycling and soil functions in different directions depending on its molecular signature.Notably,there is a distinct paucity of information concerning how the molecular signatures of soil DOM vary with different degrees of weathering across wide geographic scales.Herein,we resolved the DOM molecular signatures from 22 diverse Chinese reference soils and linked them with soil organic matter and weathering-related mineralogical properties.The mixed-effects models revealed that the yields of DOM were determined by soil organic carbon content,whereas the molecular signature of DOM was primarily constrained by the weathering-related dimension.The soil weathering index showed a positive effect on the lability and a negative effect on the aromaticity of DOM.Specifically,DOM in highly weathered acidic soils featured more amino sugars,carbohydrates,and aliphatics,as well as less O-rich polyphenols and condensed aromatics,thereby conferring a higher DOM biolability and lower DOM aromaticity.This study highlights the dominance of the weathering-related dimension in constraining the molecular signatures and potential functions of DOM in soils across a wide geographic scale.

关键词： Soil organic matter Dissolved organic matter Chemical composition Molecular signature Mineral weathering

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Soil Biogeochemical Cycle Couplings Inferred from a Function-Taxon Network

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Research 2021年第1期2021卷 432-441页

作者： Bin Ma Erinne Stirling Yuanhui Liu Kankan Zhao Jizhong Zhou Brajesh K.Singh Caixian Tang randy a.dahlgren Jianming Xu Institute of Soil and Water Resources and Environmental Science College of Environmental and Resource SciencesZhejiang UniversityHangzhou 310058China Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment Zhejiang UniversityHangzhou 310058China Hangzhou Global Scientific and Technological Innovation Center Zhejiang UniversityHangzhou 310058China Acid Sulfate Soils Centre School of Biological SciencesThe University of AdelaideAdelaideSA 5005Australia Institute for Environmental Genomics Department of Microbiology and Plant Biologyand School of Civil Engineering and Environmental SciencesUniversity of OklahomaNormanOKUSA Global Centre for Land-Based Innovation Hawkesbury Institute for the EnvironmentWestern Sydney UniversityPenrithNSW 2750Australia Department of Animal Plant and Soil SciencesLa Trobe UniversityMelbourne CampusBundooraVIC 3086Australia Department of Land Air and Water ResourcesUniversity of CaliforniaDavis95616 CAUSA

Soil biogeochemical cycles and their interconnections play a critical role in regulating functions and services of environmental systems.However,the coupling of soil biogeochemical processes with their mediating microbes remains poorly understood.Here,we identified key microbial taxa regulating soil biogeochemical processes by exploring biomarker genes and taxa of contigs assembled from metagenomes of forest soils collected along a latitudinal transect(18°N to 48°N)in eastern China.Among environmental and soil factors,soil pH was a sensitive indicator for functional gene composition and diversity.A function-taxon bipartite network inferred from metagenomic contigs identified the microbial taxa regulating coupled biogeochemical cycles between carbon and phosphorus,nitrogen and sulfur,and nitrogen and iron.Our results provide novel evidence for the coupling of soil biogeochemical cycles,identify key regulating microbes,and demonstrate the efficacy of a new approach to investigate the processes and microbial taxa regulating soil ecosystem functions.

关键词： soil forest Soil

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基于地理加权回归模型评估土地利用对地表水质的影响

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环境科学学报 2015年第5期35卷 1571-1580页

作者：陈强朱慧敏何溶 randy a.dahlgren 张明华梅琨温州医科大学浙南水科学研究院浙江省流域水环境与健康风险重点实验室温州325035 加州大学戴维斯分校农业与环境科学学院陆地、大气与水资源系美国戴维斯CA95616

针对传统线性回归模型大多忽视空间数据局部变化特征这一缺陷,引入地理加权回归模型(GWR)用于评估土地利用对地表水质的影响,分析了不同子流域内两者关系出现空间变化的规律并阐释了原因.同时,对比了GWR模型与普通最小二乘模型(OLS)的校... 详细信息

针对传统线性回归模型大多忽视空间数据局部变化特征这一缺陷,引入地理加权回归模型(GWR)用于评估土地利用对地表水质的影响,分析了不同子流域内两者关系出现空间变化的规律并阐释了原因.同时,对比了GWR模型与普通最小二乘模型(OLS)的校正R2、Akaike信息准则(AICc)及残差的空间自相关指数(Moran's I),验证了GWR模型在预测精度和处理空间自相关过程中是否优于OLS模型.结果表明,同一土地利用类型对水质的影响随空间位置的改变而发生方向或大小的变化.以温瑞塘河流域总氮(TN)与农用地的关系为例,从GWR模型局部回归系数的方向分析,两者关系表现为农村正、城区负的现象,从大小分析,旧城区TN与农用地回归系数的绝对值高于其它区域;在溶解氧(DO)与人口密度所构建的GWR模型中,两者关系在整个研究区域内均表现为负值,与OLS结果吻合,从回归系数的大小分析,人口密度对DO的作用在郊区及农村更为显著.针对此类关系出现空间变化的原因分析表明,相邻子流域土地利用百分比的改变及水体主要污染源的不同,是导致土地利用对水质作用发生变化的根本因素.最后,对比所构建的80个GWR与OLS模型校正R2、AICc指标,验证了GWR作为一种局部统计模型,其预测精度优于OLS等传统全局模型且更能反映实际空间特征.

关键词：地理加权回归土地利用水质 OLS 温瑞塘河

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土地利用方式对流域氮输入输出关系的影响--以加州San Joaquin流域为例

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地理科学进展 2010年第9期29卷 1081-1086页

作者：韩震罗燏辀王中根 randy a.dahlgren 浙江大学生命科学学学院杭州310058 加州大学戴维斯分校陆地空气与水资源学院戴维斯95616 加州大学戴维斯分校陆地空气与水资源学院戴维斯 95616 中国科学院地理科学与资源研究所陆地水循环及地表过程重点实验室北京100101 加州大学戴维斯分校陆地空气与水资源学院戴维斯95616

土地利用方式影响流域氮输入的空间分布和氮素的迁移输出过程,与非点源污染的防治密切相关。本文利用加州San Joaquin流域数据,考虑不同土地利用方式的影响,在GIS平台上分析了流域氮输入与输出的关系及其空间分布。本文提出了一个新的指... 详细信息

土地利用方式影响流域氮输入的空间分布和氮素的迁移输出过程,与非点源污染的防治密切相关。本文利用加州San Joaquin流域数据,考虑不同土地利用方式的影响,在GIS平台上分析了流域氮输入与输出的关系及其空间分布。本文提出了一个新的指标(F=CN/(L/Q))来衡量河流氮输出的变化趋势,该指标综合考虑了田间产流和河道输移两个过程的影响因子,能够描述土地利用类型对流域氮素迁移转化的影响。在实例研究中,通过该指标能够指示出研究区氮素流失的高风险区,为流域土地利用规划和非点源污染防治提供了重要的科学依据。

关键词：土地利用流域氮平衡河流氮输出 San Joaquin流域

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Changes in profile distribution and chemical properties of natural nanoparticles in paddy soils as affected by long-term rice cultivation

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Pedosphere 2021年第5期31卷 659-669页

作者： Dan HUANG Xinyu ZHU Baile XU Yan HE Mingkui ZHANG Fei LIU Zhenghua LIAN randy Adahlgren Philip CBROOKES Jianming XU Institute of Soil and Water Resources and Environmental Science College of Environmental and Resource SciencesZhejiang UniversityHangzhou 310058(China) Zhejiang Provincial Key Laboratory of Agricultural Resources and Environment Hangzhou 310058(China) Department of Land Air and Water ResourcesUniversity of California-DavisDavis CA 95616(USA)

Systematic studies on the genesis,properties,and distribution of natural nanoparticles(NNPs)in soil remain scarce.This study examined a soil chronosequence of continuous paddy field land use for periods ranging from 0 to 1000 years to determine how NNPs in soil changed at the early stages of soil genesis in eastern China.Soil samples were collected from coastal reclaimed paddy fields that were cultivated for 0,50,100,300,700,and 1000 years.Natural nanoparticles were isolated and characterized along with bulk soil samples(<2-mm fraction)for selected physical and chemical properties.The NNP content increased with increasing soil cultivation age at 60 g m^(-2) year-1,which was related to decreasing soil electrical conductivity(172-1297μS cm^(-1))and NNP zeta potentials(from -22 to -36 mV)with increasing soil cultivation age.Changes in several NNP properties,such as pedogenic iron oxide and total organic carbon contents,were consistent with those of the bulk soils across the soil chronosequence.Notably,changes in NNP iron oxide content were obvious and illustrated active chemical weathering,pedogenesis,and potential impacts on the microbial community.Redundancy analysis demonstrated that the soil cultivation age was the most important factor affecting NNP properties,contributing 60.7% of the total variation.Cluster and principal component analysis(PCA)revealed splitting of NNP samples into age groups of 50-300 and 700-1000 years,indicating rapid evolution of NNP properties,after an initial period of desalinization(approximately 50 years).Overall,this study provides new insights into NNP evolution in soil during pedogenesis and predicting their influences on agriculture and ecological risks over millennial-scale rice cultivation.

关键词： natural nanoparticle evolution soil chronosequence soil cultivation age soil genesis soil nanoparticles

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Magnetic effervescent tablets containing ionic liquids as a non-conventional extraction and dispersive agent for determination of pyrethroids in milk

Magnetic effervescent tablets containing ionic liquids as a ...

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中国营养学会第十次特殊营养学术会议

作者： Peipei Zhou Man Gao Jingang Qu Zhanen Zhang randy a.dahlgren Yanyan Li Wei Liu Hong Huang Xuedong Wang Key Laboratory of Watershed Sciences and Health of Zhejiang Province College of Public Health and Management Wenzhou Medical University College of Environmental Sciences and Engineering Suzhou University of Science and Technology

Previously reported magnetic effervescent tablet microextraction procedures have a series of drawbacks, such as slow effervescence, not practicable for field processing, rapid moisture absorption, and poor tablet storage characteristics. To address these shortcomings, we developed a novel magnetic effervescent tablet containing ionic liquid microextraction(MET-ILM) for determination of pyrethroids in dairy milk. The MET-ILM method contains only NaCO as an alkali source(no acidic source) in the FeO magnetic tablet. The CO-forming reaction is initiated in the acidic solution containing the analytes, and thus the prepared tablet can be stored for long time periods without deterioration. Because the ionic liquids(ILs) are added to the tablet, the combined action of ILs(extractant) and magnetic nanoparticles(sorbent) greatly increase the extraction efficiency. Given the simple apparatus required(a centrifuge tube, a magnet and magnetic tablets prepared in advance), the method is very feasible for use in the field. The optimized MET-ILM procedure consisted of a 0.1866 g effervescent tablet(8-mm-diameter ×2-mm-thickness), 2:1 HCl:NaCO, 60 μL [CMIM]PF as extraction solvent, 2-min water-bath at 60℃, and 2% NaCl. Under optimized conditions, LODs for five pyrethroids ranged from 0.024 to0.075 μg kg with extraction recoveries between 78.3 and 101.8%. The RSDs were less than 4.8% for intra-day repeatability precision, and no greater than 6.3% for inter-day reproducibility precision. Overall, this simple method provides a rapid, sensitive, and environmentally benign technique for pyrethroid extraction, and therefore it has great prospects for application in food and environmental detection of trace pesticides under field conditions.

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Non-Linear Matrix Completion

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Journal of Data Analysis and Information Processing 2024年第1期12卷 115-137页

作者： Fengrui Zhang randy C. Paffenroth David Worth Worcester Polytechnic Institute Worcester MA USA

Current methods for predicting missing values in datasets often rely on simplistic approaches such as taking median value of attributes, limiting their applicability. Real-world observations can be diverse, taking stock price as example, ranging from prices post-IPO to values before a company’s collapse, or instances where certain data points are missing due to stock suspension. In this paper, we propose a novel approach using Nonlinear Matrix Completion (NIMC) and Deep Matrix Completion (DIMC) to predict associations, and conduct experiment on financial data between dates and stocks. Our method leverages various types of stock observations to capture latent factors explaining the observed date-stock associations. Notably, our approach is nonlinear, making it suitable for datasets with nonlinear structures, such as the Russell 3000. Unlike traditional methods that may suffer from information loss, NIMC and DIMC maintain nearly complete information, especially in high-dimensional parameters. We compared our approach with state-of-the-art linear methods, including Inductive Matrix Completion, Nonlinear Inductive Matrix Completion, and Deep Inductive Matrix Completion. Our findings show that the nonlinear matrix completion method is particularly effective for handling nonlinear structured data, as exemplified by the Russell 3000. Additionally, we validate the information loss of the three methods across different dimensionalities.

关键词： Matrix Completion Data Pipeline Machine Learning

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连续纵向水质监测方法在温瑞塘河的应用

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中国环境监测 2013年第2期29卷 131-136页

作者：马小雪李军商栩 randy a.dahlgren 张明华温州医学院水域科学与环境生态研究所浙江温州325035 University of California LandAir and Water Resources DepartmentDavisCA95616USA 南京大学地理科学与海洋学院江苏南京210008

水质监测结果是水质评价与水污染防治的重要依据。针对常规定点水质监测方法无法完整再现水质指标的时空连续分布特征的问题,将船只搭载的水质实时监测设备与GPS同步形成基于GIS数据支撑的连续纵向水质监测方法。重点对水质监测仪及GPS... 详细信息

水质监测结果是水质评价与水污染防治的重要依据。针对常规定点水质监测方法无法完整再现水质指标的时空连续分布特征的问题,将船只搭载的水质实时监测设备与GPS同步形成基于GIS数据支撑的连续纵向水质监测方法。重点对水质监测仪及GPS空间数据集成问题进行了分析讨论,并在温瑞塘河流域进行了实验论证。结果表明,连续性纵向水质监测不但能进行连续时空水质监测,还能与GPS、GIS结合进行连续性时空分布特征的分析。

关键词：连续性水质监测 GPS GIS

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基于GIS栅格数据的城市河网水质综合评价模型构建

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环境与健康杂志 2015年第1期32卷 54-58,F0003页

作者：朱慧敏陈强王振峰任坤何溶 randy a.dahlgren 张明华温州医科大学水环境应用技术研究所浙南水科学研究院浙江温州325035 美国加州大学戴维斯分校陆地大气与水资源系

目的建立基于GIS栅格数据的城市河网水质综合评价模型。方法该文章利用温瑞塘河流域32个水质监测点2008年至2010年水质监测数据,采用一种基于GIS栅格的指数模型对城市河网水质进行多因子综合评价,并根据GB3838—2002《地表水环境质量标... 详细信息

目的建立基于GIS栅格数据的城市河网水质综合评价模型。方法该文章利用温瑞塘河流域32个水质监测点2008年至2010年水质监测数据,采用一种基于GIS栅格的指数模型对城市河网水质进行多因子综合评价,并根据GB3838—2002《地表水环境质量标准》对评价结果进行水质等级分类。通过对比分类结果与实际情况来探讨该种水质评价方法的评价效果以及栅格指数模型在温瑞塘河的适用性。结果温瑞塘河流域温州市区河网部分水质较差,大部分区域属于劣Ⅴ类水质,水质综合整治仍需加强;氨氮、总磷为温瑞塘河的主要污染物;塘河水质综合污染状况呈现城市重于郊区农村、旧城区重于新城区、支流重于干流的空间分布特征;GIS指数模型在温瑞塘河流域水质评价的结果与实际水质状况高度吻合。结论该方法具有可行性,适用于城市河网水质评价。

关键词：水质评价 GIS指数模型温瑞塘河

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加拿大央行打响了背离美联储的第一枪

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商业周刊（中文版） 2024年第9期 20-22页

作者： Erik Hertzberg randy Thanthong-Knight Jay Zhao-Murray 杨(译) 不详

加拿大央行行长蒂夫·麦克勒姆明确表示,尽管加元可能面临下行压力,但加拿大的利率政策不需要与美国亦步亦趋。加拿大央行行长蒂夫·麦克勒姆(Tiff Macklem)率先在七国集团(G-7)中降息,他对这一举措的信心,或有助于让其他央行放下心来,... 详细信息

加拿大央行行长蒂夫·麦克勒姆明确表示,尽管加元可能面临下行压力,但加拿大的利率政策不需要与美国亦步亦趋。加拿大央行行长蒂夫·麦克勒姆(Tiff Macklem)率先在七国集团(G-7)中降息,他对这一举措的信心,或有助于让其他央行放下心来,他们也可以在美联储之前降息。

关键词：七国集团克勒姆降息利率政策央行第一枪美联储加拿大

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