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Spatiotemporal variation of rainy season span and precipitation recorded by lacustrine laminated pollen in the Tibetan Plateau during the past two millennia

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Science China Earth Sciences 2024年第3期67卷 789-801页

作者： Anning CUI Houyuan LU Juzhi HOU Xingqi LIU Deke XU Key Laboratory of Cenozoic Geology and environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Innovation Academy for Earth Science Chinese Academy of SciencesBeijing 100029China college of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China Group of Alpine Paleoecology and Human Adaptation State Key Laboratory of Tibetan Plateau Earth SystemResources and EnvironmentInstitute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China university of Chinese Academy of Sciences Beijing 100049China capital normal university college of resource environment and tourism Beijing 100048China

The quantitative reconstruction of the length of the rainy season and precipitation on the Tibetan Plateau(TP) is crucial for revealing the spatiotemporal evolution of the Westerlies and Asian summer monsoon, as well as its ecological and environmental effects. Accurately determining the start and end times of the rainy season on the Plateau remains challenging.This study determined the start and end times of the rainy season in different locations on the Plateau by identifying precipitation inflection points. We calculated the duration and precipitation amount of the rainy season and established a transfer function between the modern pollen assemblages and them. Then, we reconstructed the rainy season variations in Kusai Lake(northern TP) and Jiang Co(central TP) during the past two millennia. The results showed that, the rainy season precipitation in Kusai Lake recorded five periods of high precipitation: AD 580–680, 1000–1100, 1200–1450, 1550–1780, and 1920–present, corresponding to the stages with long rainy season. The rainy season precipitation sequence in Jiang Co recorded four periods of high precipitation: AD 80–500, 800–950, 1250–1450, and 1780–present, which is consistent with the long rainy season before AD 1000 but unclear afterward. Spatially, rainy season precipitation on the Plateau exhibited four patterns: “wet in both north and south” may be related to abnormally strong summer monsoons;“dry in both north and south” likely associated with weak Westerly wind and weak summer monsoon;“wet in the south and dry in the north” linked to strong summer monsoon and weak Westerly wind;and “dry in the south and wet in the north” connected to weak summer monsoon and strong Westerly wind. This study revealed the spatiotemporal evolution pattern of the rainy season onset and end, duration, and precipitation amount on the Plateau over the past two millennia. It provides natural background support for further understanding the coupling between Westerly wind and Asian summer monsoon.

关键词： Tibetan Plateau Past two millennia Rainy season length Rainy season precipitation Quantitative reconstruction

Automatic Extraction Method of 3D Feature Guidelines for Complex Cultural Relic Surfaces Based on Point Cloud

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Journal of Geodesy and Geoinformation Science 2024年第1期7卷 16-41页

作者： GENG Yuxin ZHONG Ruofei HUANG Yuqin SUN Haili college of resources environment and tourism Capital Normal UniversityBeijing 100048China Key Laboratory of 3-Dimensional Information Acquisition and Application Ministry of EducationBeijing 100048China Chinese Academy of Cultural Heritage Beijing 100029China

Cultural relics line graphic serves as a crucial form of traditional artifact information documentation,which is a simple and intuitive product with low cost of displaying compared with 3D models.Dimensionality reduction is undoubtedly necessary for line drawings.However,most existing methods for artifact drawing rely on the principles of orthographic projection that always cannot avoid angle occlusion and data overlapping while the surface of cultural relics is complex.Therefore,conformal mapping was introduced as a dimensionality reduction way to compensate for the limitation of orthographic projection.Based on the given criteria for assessing surface complexity,this paper proposed a three-dimensional feature guideline extraction method for complex cultural relic surfaces.A 2D and 3D combined factor that measured the importance of points on describing surface features,vertex weight,was designed.Then the selection threshold for feature guideline extraction was determined based on the differences between vertex weight and shape index distributions.The feasibility and stability were verified through experiments conducted on real cultural relic surface data.Results demonstrated the ability of the method to address the challenges associated with the automatic generation of line drawings for complex surfaces.The extraction method and the obtained results will be useful for line graphic drawing,displaying and propaganda of cultural relics.

关键词： point cloud conformal parameterization vertex weight surface mesh cultural relics feature extraction

氮添加对内蒙古草原植物地上和地下碳氮磷化学计量学特征的影响

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Journal of Plant Ecology 2024年第1期17卷 57-67页

作者： Ziqi Wang Jie Wang Honghui Wu Tian Yang Yixin An Yunlong Zhang Jianlin Bian Ying Li Haiyan Ren Ariuntsetseg Lkhagva Xu Wang Qiang Yu School of Grassland Science Beijing Forestry UniversityBeijing 100083China National Hulunber Grassland Ecosystem Observation and Research Station Institute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural SciencesBeijing 100081China Ministry of Agriculture Key Laboratory of Crop Nutrition and Fertilization Institute of Agricultural Resources and Regional PlanningChinese Academy of Agricultural SciencesBeijing 100081China Department of Biology University of Western OntarioLondonONCanada college of Grassland Science and Technology China Agricultural UniversityBeijing 100083China college of resource environment and tourism Capital Normal UniversityBeijing 100048China college of Agro-grassland Science Nanjing Agricultural UniversityNanjing 210095China Department of Biology School of Arts and SciencesNational University of MongoliaUlaanbaatar 14200Mongolia

氮沉降对生态系统功能和过程具有显著影响。已有研究表明氮添加会影响植物叶片C:N:P化学计量特征。然而,氮添加对植物根系C:N:P化学计量特征影响的研究罕有报道。本论文的主要目的是对比氮添加对草原植物群落地上和地下C:N:P化学计量特... 详细信息

氮沉降对生态系统功能和过程具有显著影响。已有研究表明氮添加会影响植物叶片C:N:P化学计量特征。然而,氮添加对植物根系C:N:P化学计量特征影响的研究罕有报道。本论文的主要目的是对比氮添加对草原植物群落地上和地下C:N:P化学计量特征的影响。我们在内蒙古锡林郭勒草原开展了一个7年的氮添加实验,该实验包括6个处理,分别是对照:control;N1:0.4 mol·m-2 N;N2:0.8 mol·m^(-2) N;N3:1.6 mol·m^(-2) N;N4:2.8 mol·m^(-2) N;N5:4 mol·m^(-2) N,每个处理6次重复。我们测量并分析了植物地上、地下生物量和C:N:P化学计量特征。研究结果表明,氮添加会导致植物群落地上部分碳浓度降低,氮浓度和磷浓度升高,C:N和C:P比值降低,N:P升高,而且地上碳、氮、磷库均因施氮而增加。然而,氮添加对0-10,10-30,30-50和50-100 cm 4个土层的地下部分碳、氮、磷浓度、比例、库和化学计量特征没有显著影响。综上所述,氮添加会显著改变植物群落地上部分C:N:P化学计量特征,进而影响草地生态系统的功能和过程,但对地下C:N:P化学计量特征几乎没有影响。

关键词：氮沉降 C:N:P 化学计量草地生态系统群落地下

Modeling of acute cadmium toxicity in solution to barley root elongation using biotic ligand model theory

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Journal of environmental Sciences 2016年第4期28卷 112-118页

作者： Xuedong Wang Mingyan Wu Jingxing Ma Xiaolin Chen Luo Hua The Key Lab of resource environment and GIS College of Resource Environment and TourismCapital Normal University

Protons（H^＋）as well as different major and trace elements may inhibit cadmium（Cd）uptake in aquatic organisms and thus alleviate Cd toxicity.However,little is known about such interactions in soil organisms.In this study,the independent effects of the cations calcium（Ca^2＋）,magnesium（Mg^2＋）,potassium（K^＋）,H^＋ and zinc（Zn^2＋）on Cd toxicity were investigated with 5-day long barley root elongation tests in nutrient solutions.The tested concentrations of selected cations and trace metal ions were based on the ranges that occur naturally in soil pore water.The toxicity of Cd decreased with increasing activity of Ca^2＋,Mg^2＋,H^＋and Zn^2＋,but not K^＋.Accordingly,conditional binding constants were obtained for the binding of Cd^2＋,Ca^2＋,Mg^2＋,H^＋,and Zn^2＋ with the binding ligand：log K（CdBL）5.19,logK（CaBL）2.87,logK（MgBL）2.98,logK（HBL）5.13 and logK（ZnBL）5.42,respectively.Furthermore,it was calculated that on average 29% of the biotic ligand sites needed to be occupied by Cd to induce a 50% decrease in root elongation.Using the estimated constants,a biotic ligand model was successfully developed to predict the Cd toxicity to barley root elongation as a function of solution characteristics.The feasibility and accuracy of its application for predicting Cd toxicity in soils were discussed.

关键词： Cadmium Biotic ligand model （BLM） Toxicity Barley

二氧化碳浓度增加和气候变暖导致太白山林线树木生长与氮有效性关系减弱

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Journal of Plant Ecology 2024年第1期17卷 148-164页

作者： Lelong Yin Xiaohong Liu Xiaomin Zeng Ziyi Wang Guobao Xu Liangju Zhao Qiangqiang Lu Lingnan Zhang Xiaoyu Xing School of Geography and tourism Shaanxi Normal UniversityXi'an 710119China State Key Laboratory of Cryospheric Sciences Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China Shaanxi Key Laboratory of Earth Surface System and environmental Carrying Capacity College of Urban and Environmental SciencesNorthwest UniversityXi'an 710069China Key Laboratory of Soil resource&Biotech Applications Shaanxi Academy of SciencesXi'an Botanical Garden of Shaanxi Province(Institute of Botany of Shaanxi Province)Xi'an 710061China Qinling National Botanical Garden Xi'an 710061China

全球气候变暖、大气二氧化碳浓度(C_(a))升高和氮有效性正对全球森林生态系统产生深远影响,尤其是在高海拔林线地区。本研究结合树木生长指标和树轮稳定同位素指标,探讨了太白山林线树种太白红杉(Larix chinensis)对环境胁迫的生理生态... 详细信息

全球气候变暖、大气二氧化碳浓度(C_(a))升高和氮有效性正对全球森林生态系统产生深远影响,尤其是在高海拔林线地区。本研究结合树木生长指标和树轮稳定同位素指标,探讨了太白山林线树种太白红杉(Larix chinensis)对环境胁迫的生理生态响应。研究结果表明,近60年来太白红杉的生长速度显著增加,且该林线树木生长对春季温度特别敏感。太白红杉的潜在水分利用效率(iWUE)的持续上升与大气二氧化碳浓度升高和气候变暖紧密相关,共同促进了树木的生长。1851-1964年,树轮δ^(15)N随树木生长速度的加快逐渐增大;1964年之后转变为不显著的下降,打破了原有的碳-氮平衡。分析结果表明,自20世纪60年代以来气候变暖和iWUE的迅速增加已经取代氮有效性成为树木生长的主要驱动因子。随着树木持续加速生长,氮有效性在未来可能会显著下降甚至供不应求。本研究深入揭示了植物对生长环境变化响应的生理生态机制,这将提高我们预测未来高海拔地区森林生态系统演变的能力。

关键词：树轮稳定同位素高山林线植被气候变暖 CO_(2)肥化效应太白山

Advances in preparation,application in contaminant removal,and environmental risks of biochar-based catalysts:a review

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Biochar 2022年第1期4卷 327-357页

作者： Bowen Yang Jiawei Dai Yuan Zhao Jingwei Wu Caiya Ji Yuhu Zhang college of resource environment and tourism Capital Normal UniversityBeijing 100048China School of environmental and Safety Engineering Changzhou UniversityChangzhou 213164China

As a carbon-rich material produced by pyrolysis of biomass,biochar features low cost,large specific surface area,and widely available feedstocks based on the functional diversity and environmental-friendly properties,it has received increasing attention in the fields of pollutant removal due to three win-win effects of water remediation,carbon sequestration and reutilization of wastes.To design excellent biochar-based catalysts for environmental applications,one must understand recent advances in the catalysts for contaminant removal.This review focuses on the current application of biochar-based catalysts in redox systems,Fenton-like systems,sonocatalytic systems and photocatalytic systems.Besides in-depth discussion in effects of preparation conditions on physicochemical characteristics of biochars,the review supplements new preparation technologies of biochar and biochar-based catalysts.Most importantly,the advantages/shortcomings,catalysis mechanisms,as well as the pollutant removal ability of different types of biochar-based catalysts are discussed.The environmental risks of the catalyst applications are also elaborated on.Future research on biochar-based catalyst production and its environmental applications is discussed.The review provides a good overview of the current advances of biochar-based catalysts in pollutant control and the future research directions.

关键词： Biochar-based catalysts Sonocatalysts Fenton-like catalysts Photocatalysts Pollutant removal environmental risks

Dynamic evolution and trend prediction of multi-scale green innovation in China

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Geography and Sustainability 2023年第3期4卷 222-231页

作者： Xiaohua Xin Lachang Lyu Yanan Zhao college of resource environment and tourism Capital Normal UniversityBeijing 100048China Beijing Urban Innovation and Development Research Center Beijing 100048China

Numerous studies deal with spatial analysis of green innovation(GI).However,researchers have paid limited attention to analyzing the multi-scale evolution patterns and predicting trends of GI in China.This paper seeks to address this research gap by examining the multi-scale distribution and evolutionary characteristics of GI activities based on the data from 337 cities in China during 2000-2019.We used scale variance and the two-stage nested Theil decomposition method to examine the spatial distribution and inequalities of GI in China at multiple scales,including regional,provincial,and prefectural.Additionally,we utilized the Markov chain and spatial Markov chain to explore the dynamic evolution of GI in China and predict its long-term development.The findings indicate that GI in China has a multi-scale effect and is highly sensitive to changes in spatial scale,with significant spatial differences of GI decreasing in each scale.Furthermore,the spatiotemporal evolution of GI is influenced by both geospatial patterns and spatial scales,exhibiting the“club convergence”effect and a tendency to transfer to higher levels of proximity.This effect is more pronounced on a larger scale,but it is increasingly challenging to transfer to higher levels.The study also indicates a steady and sustained growth of GI in China,which concentrates on higher levels over time.These results contribute to a more precise understanding of the scale at which GI develops and provide a scientific basis and policy suggestions for optimizing the spatial structure of GI and promoting its development in China.

关键词： Green innovation Spatial pattern Trend prediction Multi-scale China

The Middle-aged and Knowledge Workers: Demographic and Economic Changes in the Pearl River Delta, China

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Chinese Geographical Science 2022年第2期32卷 268-284页

作者： FENG Pengfei Anna GROWE SHEN Yuming college of resources Environment&TourismCapital Normal UniversityBeijing 100048China Institute of Geography Heidelberg UniversityBerliner Strafie 48D-69120 HeidelbergGermany

Demographic and economic development can be seen as two sides of one coin in the process of regional development.This article deals with how economic and demographic changes influence the settlement structure and development of the Pearl River Delta(PRD)and lead to regionalization processes within the large agglomerations.The aim of the study was to understand the interrelation between the three aspects:economic change,demographic change and change of spatial structures.Based on population age and occupational data,spatial changes in demographic structure and economic activities from 2000 to 2010 were analyzed.It was found that the demographic and economic change reflected changing spatial patterns between the urban centers and the hinterland in the PRD.Two processes were apparent during the studied period in the hinterlands and the high-density areas of the PRD.On one hand,the hinterlands in the PRD attracted more manufacturing activities,while the inner high-density areas experienced a decrease in manufacturing,associated with an increase in young labor in regions where workplaces that only required limited education expanded.On the other hand,specialization in knowledge-intensive business services increased in the inner high-density areas,which also saw an increased share in the older population.This finding suggests that increasing knowledge-intensive work correlates with higher age structures due to the longer formal education required and also the benefits knowledge workers accrue through experience and gained knowledge over time.Therefore,based on a transformation process,we tentatively conclude that the populations in high-density areas in the PRD became more middle-aged and were represented by more knowledge workers.

关键词： manufacturing knowledge-intensive business services(KIBS) economic change demographic change Pearl River Delta

Relationship between the variation of water quality in rivers and the characteristics of watershed at Miyun, Beijing, China

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Chinese Journal Of Geochemistry 2009年第1期28卷 112-118页

作者： WANG Xiaoyan college of resource Environment ＆ Tourism Capital Normal University Beijing 100048 China

Based on the characteristics of land use and drainage network of the upper watershed of the Miyun Reservoir, Beijing, 26 monitoring and sampling sites were selected in different sub-catchments. Temporal and spatial variations in nutrient loss were dealt with in this paper in terms of the monitoring data on the water quality of the main tributaries flowing into the Miyun Reservoir. In combination with the monitoring data on water quality, the impacts of watershed characteristics including land-use type, landscape pattern, and drainage density were assessed. The concentrations of nutrients in the rainy season are higher than those in other seasons, and the concentrations of NO3--N are linearly related to those of total N which is the main form of nitrogen present in the river water. The concentrations of nitrogen become higher toward the reservoir along the main rivers. The seasonal variation of nitrogen in the watershed affected by intensive human activities is very obvious; in the watershed with steady or low water flow, the seasonal variation of nitrogen is less obvious. Forest land and grassland can trap and filter nitrogen effectively. Land-use pattern also has important impacts on the loss of nitrogen. The concentrations of nitrogen and phosphorus in the water bodies show great temporal and spatial variations. On a temporal scale, the concentrations of TN and TP in the rainy reason are higher than those in other seasons. On a spatial scale, the concentrations of TN and NO3--N in the Qingshui River and Chaohe River are highest all the time. The spatial variation of TP is distinct, being obvious at sampling sites near villages. The form of nitrogen and phosphorus loss varies in different hydrological seasons. Dissolved nitrogen and phosphorus are the main forms in streams in non-rainy seasons, the dissolved nitrogen and total nitrogen decrease in percentage in the rainy season. Particulate nitrogen and phosphorus are the main forms in some rivers. The concentrations of TN and NO3--N from orchards and villages a

关键词：坡度黄土坡面养分流失影响实验地球化学