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Characterization of size-resolved effective density of atmospheric particles in an urban atmosphere in Southern China

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Journal of Environmental Sciences 2024年第7期141卷 194-204页

作者： tingting xie Liming Cao Jinyi Zheng Peng Xuan Xiaofeng Huang Laboratory of Atmospheric Observation Supersite School of Environment and EnergyPeking University Shenzhen Graduate SchoolShenzhen 518055China

Effective density(ρ_(eff))is one of the most important physical properties of atmospheric particles,providing important references in exploring the emissions and aging processes of fresh particles.In this study,a combined system of differential mobility analyzer,centrifugal particle mass analyzer,and condensation particle counter was used to periodically measure theρ_(eff)of atmospheric particles in Shenzhen from Oct.2021 to Jan.2022.Results showed that theρ_(eff)of particles with various size presented a bimodal distribution,which could be divided into main density(ρ_(m),main peak,corresponding to relatively dense particles after aging)and sub density(ρ_(s),sub peak,corresponding to fresh particles).The occurrence frequencies ofρ_(s)of particles with diameters of 50 and 80 nm were less than 20%,but were as high as about 40%of that with diameters from 120 to 350 nm.Theρ_(m)showed increasing trend with the size of particles,whileρ_(s)decreased as the increasing of the size of particles.Theρ_(eff)on pollution day varied significantly with chemical compositions.The increasing of the proportion of sulfate could promote the increasing ofρ_(eff),while black carbon and organic matter caused opposite effects,which may be related to various factors,including the difference of the material density and morphology of various chemical components.Theρ_(eff)of 50,80 and 120 nm particles decreased considerably during the new particle formation event,indicating that organic condensation was an important contributor to new particle growth.

关键词： DMA-CPMA-CPC Effective density Main/sub density Size distribution

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Evaluation of the applicability of multiple drought indices in the core zone of “westerlies-dominated climatic regime”

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Science China Earth Sciences 2023年第7期66卷 1504-1520页

作者： Huiwen GUO Wei HUANG tingting xie Shuai MA Key Laboratory of Western China’s Environmental Systems(Ministry of Education) College of Earth and Environmental SciencesLanzhou UniversityLanzhou 730000China

Drought indices are frequently used to measure the intensity,start and end of droughts.However,the performances of these indices depend on regions and the type of droughts.Therefore,it is necessary to evaluate whether these indices are applicable for a given region.This study evaluated the ability of the self-calibrating Palmer Drought Severity Index(sc PDSI),the Standardized Precipitation Evapotranspiration Index(SPEI),and the Standardized Moisture Anomaly Index(SZI) to describe the dry-wet conditions and drought events in the core zone of the “westerlies-dominated climatic regime”.The results showed that the 12-month SZI(SZI12) and SPEI(SPEI12) have good correlations with precipitation and PET respectively,while the sc PDSI can capture the changes in precipitation and soil moisture.In Xinjiang region of China,the SZI12 and sc PDSI showed that this region gradually became wetter during 1961–2014,which was consistent with increased precipitation,decreased PET,and improved vegetation.However,the SPEI12 showed significant drying due to the strong influence of the PET,suggesting that this index exaggerated the drought conditions in this region.Precipitation in Kazakhstan and the southern Central Asian regions has increased slightly over the past 50 years,but the PET has greatly increased,altogether,all three indices suggested a drying trend in Central Asia.The evaluation of the ability of these drought indices to identify typical drought events in Xinjiang region of China suggested that the sc PDSI can better detect the typical drought events compared with the SZI12.In conclusion,the sc PDSI is the most suitable index for characterizing the long-term trend of hydroclimate conditions and drought events in the core zone of the “westerlies-dominated climatic regime”.This study provides a theoretical basis for the rational utilization and improvement of the drought index,which is critical for monitoring,attributing,and predicting of drought events in arid areas.

关键词： Drought index Applicability of the drought index Hydroclimate conditions Potential evapotranspiration Drought events

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Increased water vapor supply in winter and spring leading to the arid Central Asian wetting in last 6000 years

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Science China Earth Sciences 2022年第7期65卷 1353-1367页

作者： Xu ZHANG Bo LIU Shengqian CHEN Zhenhao FU tingting xie Fahu CHEN Key Laboratory of Western China's Environmental SystemsMinistry of Education College of Earth and Environmental SciencesLanzhou UniversityLanzhou 730000China Alpine Paleoecology and Human Adaption Group(ALPHA) State Key Laboratory of Tibetan Plateau Earth SystemResources and Environment(TPESRE)Institute of Tibetan Plateau ResearchChinese Academy of ScienceBeijing 100101China

Paleoclimate reconstructions show that the arid Central Asia(ACA)is characterized by a wetting trend from the midHolocene(MH)to the Preindustrial period(PI),which has been acknowledged to be a result of increased mean precipitation.However,a systemic understanding of its governing dynamics remains elusive.Based on model outputs from 13 climate models from the Paleoclimate Model Intercomparison Project phase 4(PMIP4)and proxy records from ACA,here we show that increase in mean precipitation in ACA can be attributed to changes in water vapor source and its transport intensity in winter(December,January,and February)and spring(March,April,and May).In particular,the increase in water vapor supply in winter is associated with the southerly wind anomaly over the northwestern Indian Ocean and Central Asia,caused by an overall weakening of the Asian winter monsoon.This is conducive to water vapor transport from the upwind regions(e.g.,Mediterranean)to ACA.Meanwhile,water vapor supply from the eastern Iceland is also enhanced due to a negative North Atlantic Oscillation-like(NAO-like)atmospheric circulation pattern caused by sea ice expansion in the North Atlantic.In spring,evaporation over land and inland lakes is enhanced by increased insolation in the Northern Hemisphere,which increases atmospheric humidity that fuels midlatitude westerlies to enhance ACA precipitation.In addition,weakened atmospheric subsidence over ACA in winter and spring also contributes to the increased precipitation.Overall,our results indicate that paleoclimate modeling is of great importance for disentangling governing dynamics accounting for reconstructed climate phenomena that might be a synergic consequence of several processes operating in different seasons.

关键词： Arid Central Asia Precipitation Mid-Holocene Paleoclimate simulation

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Discussion of the“warming and wetting”trend and its future variation in the drylands of Northwest China under global warming

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Science China Earth Sciences 2023年第6期66卷 1241-1257页

作者： Fahu CHEN tingting xie Yujie YANG Shengqian CHEN Feng CHEN Wei HUANG Jie CHEN Group of Alpine Paleoecology and Human Adaptation(ALPHA) State Key Laboratory of Tibetan Plateau Earth SystemEnvironment and Resources(TPESER)Institute of Tibetan Plateau Research(ITPCAS)Chinese Academy of Sciences(CAS)Beijing 100101China Key Laboratory of Western China’s Environmental Systems(Ministry of Education) College of Earth and Environmental SciencesLanzhou UniversityLanzhou 730000China Yunnan Key Laboratory of International Rivers and Transboundary Eco-Security Institute of International Rivers and Eco-SecurityYunnan UniversityKunming 650500China Key Laboratory of Tree-Ring Physical and Chemical Research of the Chinese Meteorological Administration Xinjiang Laboratory of Tree-Ring EcologyInstitute of Desert MeteorologyChinese Meteorological AdministrationUrumqi 830002China College of Atmospheric Sciences Lanzhou UniversityLanzhou 730000China

Since Shi et al.proposed that the climate in the drylands of Northwest China experienced a significant transition from a“warming and drying”trend to a“warming and wetting”trend in the 1980s,researchers have conducted numerous studies on the variations in precipitation and humidity in the region and even in arid Central Asia.In particular,the process of the“warming and wetting”trend by using obtained measurement data received much attention.However,there remain uncertainties about whether the“warming and wetting”trend has paused and what its future variations may be.In this study,we examined the spatiotemporal variations in temperature,precipitation,the aridity index(AI),vegetation,and runoff during 1950-2019.The results showed that the climate in the drylands of Northwest China and the northern Tibetan Plateau is persistently warming and wetting since the 1980s,with an acceleration since the 1990s.The precipitation/humidity variations in North China,which are mainly influenced by summer monsoon,are generally opposite to those in the drylands of Northwest China.This reverse change is mainly controlled by an anomalous anticyclone over Mongolia,which leads to an anomalous easterly wind,reduced water vapor output,and increased precipitation in the drylands of Northwest China.While it also causes an anomalous descending motion,increased water vapor divergence,and decreased precipitation in North China.Precipitation is the primary controlling factor of humidity,which ultimately forms the spatiotemporal pattern of the“westerlies-dominated climatic regime”of antiphase precipitation/humidity variations between the drylands of Northwest China and monsoonal region of North China.The primary reasons behind the debate of the“warming and wetting”trend in Northwest China were due to the use of different time series lengths,regional ranges,and humidity indices in previous analyses.Since the EC-Earth3 has a good performance for simulating precipitation and humidity in Northwest and North China.By using its simulated results,we fo

关键词： The drylands of Northwest China “Warming and wetting”transition Sustained“warming and wetting” Westerliesdominated climatic regime Moderate warming

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An integrative bioinformatics pipeline shows that honeybee-associated microbiomes are driven primarily by pollen composition

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Insect Science 2023年第2期30卷 555-568页

作者： Douglas Chesters Xiuwei Liu Karen L.Bell Michael C.Orr tingting xie Qingsong Zhou Chaodong Zhu Key Laboratory ofZoological Systematics andEvolution Institute ofZoologyChinese Academy of SciencesBejingChina International College University of Chinese Academy of SciencesBejingChina Institute of Agro-Products Processing Yunnan Province Academy of Agricultural ScienceKunmingChina School of Biological Sciences University of Western AustraliaCrawleyWAAustralia cSIRO Health&Biosecurity FloreatWAAustralia College of Life Sciences Anhui Normal UniversityWuhuAnhui ProvinceChina State Key Laboratory of Integrated Pest Management Institute of ZoologyChinese Academy of SciencesBeijingChina College of Biological Sciences University of Chinese Academy of SciencesBeijingChina

The microbiomes associated with bee nests influence colony health through various mechanisms,although it is not yet clear how honeybee congeners differ in microbiome assembly processes,in particular the degrees to which floral visitations and the environment contribute to different aspects of diversity.We used DNA metabarcoding to sequence bacterial 16S rRNA from honey and stored pollen from nests of 4 honeybee species(Apis cerana,A.dorsata,A.florea,and A.laboriosa)sampled throughout Yunnan,China,a global biodiversity hotspot.We developed a computational pipeline integrating multiple databases for quantifying key facets of diversity,including compositional,taxonomic,phylogenetic,and functional ones.Further,we assessed candidate drivers of observed microbiome dissimilarity,particularly differences in floral visitations,habitat disturbance,and other key environmental variables.Analyses revealed that microbiome alpha diversity was broadly equivalent across the study sites and between bee species,apart from functional diversity which was very low in nests of the reclusive A.laboriosa.Turnover in microbiome composition across Yunnan was driven predominantly by pollen composition.Human disturbance negatively impacted both compositional and phylogenetic alpha diversity of nest microbiomes,but did not correlate with microbial turnover.We herein make progress in understanding microbiome diversity associated with key pollinators in a biodiversity hotspot,and provide a model for the use of a comprehensive informatics framework in assessing pattern and drivers of diversity,which enables the inclusion of explanatory variables both subtly and fundamentally different and enables elucidation of emergent or unexpected drivers.

关键词： Apis biodiversity hotspot honeybee informatics metabarcoding microbiome

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国家重点生态功能区如何实现环境保护与经济发展的平衡

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世界经济 2024年第5期 34-63页

作者：谢婷婷中央财经大学经济学院北京市102206

寻求环境保护与经济发展的平衡是经济学关注的重点问题。本文构建了简单的理论模型,提出实现环境保护与经济发展双赢的逻辑条件,并以国家重点生态功能区政策为准自然实验,采用双重差分法进行检验。研究发现:国家重点生态功能区政策显著... 详细信息

寻求环境保护与经济发展的平衡是经济学关注的重点问题。本文构建了简单的理论模型,提出实现环境保护与经济发展双赢的逻辑条件,并以国家重点生态功能区政策为准自然实验,采用双重差分法进行检验。研究发现:国家重点生态功能区政策显著促进了县域人均GDP和植被覆盖率。机制分析表明,空间利用效率提升、产业结构转型和中央转移支付是推动国家重点生态功能区县实现环境保护与经济发展协同的重要路径。该政策效应具有异质性,主要由生态环境保护的机会成本、经济发展方式的转型成本和中央转移支付的补偿效果综合决定。总之,本文的分析有助于县域在环境保护和经济发展方面寻找交集,探寻绿色高质量发展之路。

关键词：绿水青山就是金山银山国家重点生态功能区绿色高质量发展

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Changes in climate regimes over China based on a high-resolution dataset

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Science Bulletin 2019年第6期64卷 377-379页

作者： Wei Huang Jingjing Yan Chang Liu tingting xie Key Laboratory of Western China’s Environmental Systems (Ministry of Education) College of Earth and Environmental Sciences Lanzhou University Central Asia Center for Atmospheric Science Research China Meteorological Administration Department of Geosciences University of Arkansas

During the 20th century the global climate has been shifted towards warmer and drier regimes, mainly due to anthropogenic warming [1,2]. Climate changes can notably disrupt the environment and ecosystems. To evaluate the impacts of climate change on ecoregions, the Kdppen-Trewartha (K-T) climate classification [3] is widely used because it was constructed on the basis of surface vegetation. The K-T classification system combines temperature, precipitation, and their seasonality into a single metric. Six major climate types and several sub-climate types are defined (A: tropical, B: dry, C: subtropical, D: temperate, E: subpolar, F: polar). Each K-T climate type is consistent with certain prevalent plant species. Definitions and criteria of K-T climate types were outlined by Feng et al.[4].

关键词： climate has been shifted change on ecoregions climate types

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土地供给约束、工业用地优化配置与企业效率——来自耕地保护政策的证据

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经济研究 2024年第5期59卷 190-208页

作者：谢婷婷张辉中央财经大学经济学院 100081 北京大学经济学院 100080

生产要素优化配置是提升宏观全要素生产率的重要途径。本文以耕地保有量指标管控政策为准自然实验,根据土壤属性预测耕地数量和空间位置解决了内生性问题,结合全国税收调查数据和国土统计数据,研究土地供给约束对企业全要素生产率的影... 详细信息

生产要素优化配置是提升宏观全要素生产率的重要途径。本文以耕地保有量指标管控政策为准自然实验,根据土壤属性预测耕地数量和空间位置解决了内生性问题,结合全国税收调查数据和国土统计数据,研究土地供给约束对企业全要素生产率的影响及机制。研究发现,土地供给约束显著减少了工业用地配置中“压低价格、过量供给和协议出让方式”的供地行为。土地供给收紧后,工业用地配置优化,促进了企业生产效率提升。异质性分析发现,在中心城区、非高技术行业及土地需求旺盛的地区,土地供给收紧后企业效率提升更大。在土地资源趋紧的现实背景下,本文为“腾笼换鸟,凤凰涅槃”及“亩产论英雄”等改革实践提供了学理上的回应。

关键词：耕地保护工业用地配置企业效率高质量发展

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联盟管理视域下美国推动“五眼联盟”转型的策略分析

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情报杂志 2024年第1期43卷 57-63,90页

作者：张衡谢婷婷华侨大学国际关系学院厦门361021

[研究目的]探究在新的历史时期,美国推动“五眼联盟”转型中使用的政策手段,为中国应对“五眼联盟”转型带来的问题提供参考。[研究方法]使用案例研究法,以“五眼联盟”相关的研究成果及与“五眼联盟”相关的政策文献、新闻报道等文献... 详细信息

[研究目的]探究在新的历史时期,美国推动“五眼联盟”转型中使用的政策手段,为中国应对“五眼联盟”转型带来的问题提供参考。[研究方法]使用案例研究法,以“五眼联盟”相关的研究成果及与“五眼联盟”相关的政策文献、新闻报道等文献材料作为案例进行阅读分析,从中总结归纳出美国在“五眼联盟”转型过程中采取的联盟管理措施。[研究结论]面对“五眼联盟”转型过程中的新联盟困境,美国从认知、权力、制度、利益四个层面采取措施进行了联盟管理。这些联盟管理的措施取得了良好的效果,使得“五眼联盟”在行动上基本保持一致,顺利地向针对中国的“大国竞争”联盟转型。

关键词：五眼联盟中美关系情报安全联盟政治联盟管理案例研究法

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Response of root traits of Reaumuria soongorica and Salsola passerina to facilitation

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Journal of Arid Land 2014年第5期6卷 628-636页

作者： HaiNa ZHANG PeiXi SU ShanJia LI ZiJuan ZHOU tingting xie Linze Inland River Basin Research Station Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of Sciences Key Laboratory of Land Surface Process and Climate Change in Cold and Arid Regions Chinese Academy of Sciences

C3 plant Reaumuria soongorica and C4 plant Salsola passerina are super xerophytes and coexist in a mixed community in either isolated or associated growth, and interspecific facilitation occurs in associated growth. In the present study, the root traits including root distribution, root length（RL）, root surface area（RSA）, root weight（RW） and specific root length（SRL） of both species in two growth forms were investigated to clarify their response to facilitation in associated growth. Six isolated plants of each species, as well as six associated plants similar in size and development were selected during the plant growing season, and their roots were excavated at 0–10, 10–20, 20–30, 30–40 and 40–50 cm soil depths at the end of the growing season. All the roots of each plant were separated into the two categories of fine roots（2 mm diameter） and coarse roots（≥2 mm diameter）. Root traits such as RL and RSA in the fine and coarse roots were obtained by the root analyzing system WinRHIZO. Most of the coarse roots in R. soongorica and S. passerina were distributed in the top 10 cm of the soil in both growth forms, whereas the fine roots of the two plant species were found mainly in the 10–20 and 20–30 cm soil depths in isolated growth, respectively. However, the fine roots of both species were mostly overlapped in 10–20 cm soil depth in associated growth. The root/canopy ratios of both species reduced, whereas the ratios of their fine roots to coarse roots in RL increased, and both species had an increased SRL in the fine roots in associated growth. In addition, there was the increase in RL of fine roots and content of root N for S. passerina in associated growth. Taken together, the root growth of S. passerina was facilitated for water and nutrient exploration under the interaction of the overlapped roots in both species in associated growth, and higher SRL allowed both species to more effectively adapt to the infertile soil in the desert ecosystem.

关键词： C3 plant C4 plant facilitation relationship root traits specific root length

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