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The effects of nutrients on stream invertebrates:a regional estimation by generalized propensity score

Ecological Processes 2018年第1期7卷 218-230页

作者： Zutao Ouyang song s.qian Richard Becker Jiquan Chen Center for Global Change and Earth Observations Michigan State University1405 S.Harrison RoadEast LansingMI 48823USA Department of Environmental sciences University of Toledo2801 West Bancroft StreetToledoOH 43606USA

Introduction:The effects of nutrients on stream conditions within individual streams or small areas have been studied extensively,but the same effects over a large region have rarely been examined due to the difficulty of applying large-scale manipulative *** this study,we estimated the causal effects of nutrients within the Western United states on invertebrate richness,an important biological indicator of stream conditions,by using observational ***:We used the generalized propensity score method to avoid the common problem of statistical inference using observational data,i.e.,correlation established based on observational data does not imply a causal relationship because the effects of confounding factors are not properly ***:Our analysis showed a subsidy-stress relationship between nutrients and invertebrate taxon richness in the whole Western United states and in its *** magnitude of the relationship varies among these subecoregions,suggesting a varying nitrogen effect on macroinvertebrates due,in large part,to the varying natural and anthropogenic conditions from ecoregion to ***,our analysis confirmed that causal estimation results using regression can be sensitive to the imbalance of confounding ***:stratifying data into ecoregions with relatively homogeneous environmental conditions or adjusting data by generalized propensity score can improve the balance of confounding factors,thereby allowing more reliable causal inference of nutrient *** respond to the same nutrient levels differently across different site conditions.

关键词： Nutrient criteria Water quality Environmental management Ecoregion

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Unveiling a half-century mystery of molecular bases for three-line hybrid rice breeding system

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Journal of Integrative Plant Biology 2024年第1期66卷 3-6页

作者： Xiaoming Zheng qian qian state Key Laboratory of Crop Gene Resources and Breeding Chinese Academy of Agricultural SciencesBeijing 100081China Yazhouwan National Laboratory No.8 Huanjin RoadYazhou DistrictSanya 572024China

Rice(Oryza sativa L.)isa staplecropforhalf theworld's Ipopulation and an important contributor to world food *** discovery and application of cytoplasmic male sterility(CMs)and fertility restoration(Rf)genetic materials have allowed the production of three-line hybrid rice(Kim and Zhang,2018),successfully harnessing heterosis in *** major CMs and/or Rf systems are commonly used to produce three-line hybrid rice:Wild Abortive(CMs-WA),Boroll(CMs-BT),and Honglian(CMs-HL).Among these,the CMs-WA system is the most widely employed(sattari et al.,2007;Chen and Liu,2014;Huang et al.,2014).several Rf genes from different CMs systems have been cloned in rice,including Rf4 for CMs-WA(Tang et al.,2014),Rf1a and Rf1b for CMs-BT(Wang et al.,2006),Rf5,and Rf6 for CMs-HL(Huet al.,2012;Huang et al.,2015),and Rf19for CMs-FA(Jiang et al.,2022).A molecular mechanism and evolutionary model for the CMs-WA gene WA352c have also been reported(Luo et al.,2013;Tang et al.,2017).

关键词： breeding fertility Wild

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Global patterns and ecological drivers of taxonomic and phylogenetic endemism in angiosperm genera

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Plant Diversity 2024年第2期46卷 149-157页

作者： Hong qian Brent D.Mishler Jian Zhang shenhua qian Research and Collections Center Illinois State Museum1011 East Ash StreetSpringfieldIL 62703USA University and Jepson Herbaria Department of Integrative BiologyUniversity of CaliforniaBerkeleyCA 94720-2465USA Center for Global Change and Complex Ecosystems Zhejiang Tiantong Forest Ecosystem National Observation and Research StationSchool of Ecological and Environmental SciencesEast China Normal UniversityShanghai 200241China shanghai Institute of Pollution Control and Ecological security Shanghai 200092China Key Laboratory of the Three Gorges Reservoir Region's Eco-Environment Ministry of EducationChongqing UniversityChongqing 400045China

Endemism of lineages lies at the core of understanding variation in community composition among geographic regions because it reflects how speciation,extinction,and dispersal have influenced current ***,we investigated geographic patterns and ecological drivers of taxonomic and phylogenetic endemism of angiosperm genera across the *** identify centers of paleo-endemism and neo-endemism of angiosperm genera,and show that they are mostly located in the southern Hemisphere in tropical and subtropical regions,particularly in Asia and *** categories of phylogenetic endemism centers can be differentiated using current climate *** climate,historical climate change,and geographic variables together explained~80%of global variation in taxonomic and phylogenetic endemism,while 42-46%,1%,and 15%were independently explained by these three types of variables,*** our findings show that past climate change,current climate,and geography act together in shaping endemism,which are consistent with the findings of previous studies that higher temperature and topographic heterogeneity promote *** study showed that many centers of phylogenetic endemism of angiosperms,including regions in Amazonia,Venezuela,and west-central tropical Africa that have not previously been identified as biodiversity hotspots,are missed by taxon-based measures of endemism,indicating the importance of including evolutionary history in biodiversity assessment.

关键词： Angiosperm Current climate Endemism Historical climate change Topographic heterogeneity

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Recent progress in MnBi2nTe3n+1 intrinsic magnetic topological insulators: crystal growth, magnetism and chemical disorder

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National science Review 2024年第2期11卷 65-80页

作者： Chaowei Hu Tiema qian Ni Ni Department of Physics and Astronomy and California Nano systems Institute University of California-Los Angeles

The search for magnetic topological materials has been at the forefront of condensed matter research for their potential to host exotic states such as axion insulators, magnetic Weyl semimetals, Chern insulators,etc. To date, the MnBi2nTe3n+1family is the only group of materials showcasing van der Waals-layered structures, intrinsic magnetism and non-trivial band topology without trivial bands at the Fermi level. The interplay between magnetism and band topology in this family has led to the proposal of various topological phenomena, including the quantum anomalous Hall effect, quantum spin Hall effect and quantum magnetoelectric effect. Among these, the quantum anomalous Hall effect has been experimentally observed at record-high temperatures, highlighting the unprecedented potential of this family of materials in fundamental science and technological innovation. In this paper, we provide a comprehensive review of the research progress in this intrinsic magnetic topological insulator family, with a focus on single-crystal growth, characterization of chemical disorder, manipulation of magnetism through chemical substitution and external pressure, and important questions that remain to be conclusively answered.

关键词： MnBi2Te4 magnetic topological insulator magnetism tuning antiferromagnetism ferromagnetism pressure chemical doping

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AFM probe with the U-shaped cross-sectional cantilever for measuring the ultra-low coefficient of friction of 10^(–6)

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Friction 2024年第8期12卷 1707-1715,F0004页

作者： Yushan CHEN Liang JIANG Linmao qian Tribology Research Institute State Key Laboratory of Traction PowerSouthwest Jiaotong UniversityChengdu 610031China

Accurately measuring the coefficient of friction(COF)is the fundamental prerequisite of superlubricity *** study aimed to reduce the COF measurement resolutionΔμof atomic force microscopy(AFM).Based on the theoretical model,a distinctive strategy was adopted to reduceΔμby optimizing the cantilever’s cross-section of the AFM probe,inspired by civil engineering.Δμcan be reduced by decreasing the width of the horizontal side wR and the wall thickness t and increasing the width of the vertical side ***,the I-shape demonstrates the highest reduction inΔμ,followed by the *** the processability,the AFM probe with the U-shaped cross-sectional cantilever was investigated further,and the dimensions are 35μm wR,3.5μm wH,0.5μm t,50μm l(cantilever length),and 23μm htip(tip height).The finite element analysis results confirm its *** being fabricated and calibrated,the AFM probe achieves the minimalΔμof 1.9×10^(–6)under the maximum normal force so ***,the friction detection capability of the fabricated AFM probe improves by 78 times compared to the commercial tipless-force modulation mode(TL-FM)AFM probe with the conventional solid rectangular cross-sectional *** study provides a powerful tool for measuring 10^(–6)COF.

关键词： atomic force microscopy superlubricity coefficient of friction probe cantilever

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AFM probe for measuring~10^(−5)ultra-low friction coefficient:Design and application

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Friction 2024年第1期12卷 64-73页

作者： Yushan CHEN Liang JIANG Linmao qian Tribology Research Institute State Key Laboratory of Traction PowerSouthwest Jiaotong UniversityChengdu 610031China

superlubricity provides a novel approach to addressing friction and wear issues in mechanical ***,little is known regarding improving the atomic force microscope(AFM)friction coefficient measurement ***,this study established the theoretical formula for the AFM friction coefficient measurement and deduced the measurement ***,the formula was applied to the AFM probe with a rectangular cross-section *** measurement resolution is associated with the dimensional properties of the AFM probe,the mechanical properties of the cantilever material,the properties of the position-sensitive detector(PsD),and probably the anti-vibration performance of the *** is feasible to make the cantilever as short as possible and the tip as high as possible to improve the measurement *** AFM probe for measuring an ultra-low friction coefficient was designed and *** cantilever’s length,width,and thickness are 50,35,and 0.6μm,*** tip height is 23μ*** measurement resolution can reach 7.1×10^(−6) under the maximum normal ***,the AFM probe was applied to measure the superlubricity between graphene *** friction coefficient is 0.00139 under 853.08 *** work provides a promising method for measuring a~10^(−5) friction coefficient of superlubricity.

关键词： atomic force microscope(AFM) superlubricity friction coefficientμ probe

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Toward a rapid and convenient nanoplastic quantification method in laboratory-scale study based on fluorescence intensity

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Frontiers of Environmental science & Engineering 2024年第5期18卷 117-126页

作者： Ruiqi Yan sen Lin qian Ding Lei Zhang Xia Yu Wentao Zhao qian sui state Environmental Protection Key Laboratory of Environmental Risk Assessment and Control on Chemical Process School of Resources and Environmental EngineeringEast China University of Science and TechnologyShanghai200237China state Key Laboratory of Pollution Control and Resource Reuse College of Environmental Science and EngineeringTongji UniversityShanghai200092China shanghai Institute of Pollution Control and Ecological security Shanghai200092China

The thorough investigation of nanoplastics(NPs)in aqueous environments requires efficient and expeditious quantitative analytical methods that are sensitive to environmentally relevant NP concentrations and convenient to *** analysis-based quantitative methods have been acknowledged as effective and rapid approaches for quantifying NP concentrations in laboratory-scale ***,we compared three commonly used optical response indicators,namely fluorescence intensity(FI),ultraviolet absorbance,and turbidity,to assess their performance in quantifying ***,orthogonal experiments were conducted to evaluate the influence of various water quality parameters on the preferred indicator-based quantification *** results revealed that FI exhibits the highest correlation coefficient(>0.99)with NP ***,the limit of quantification(LOQ)for various types of NPs is exceptionally low,ranging from 0.0089 to 0.0584 mg/L in ultrapure water,well below environmentally relevant *** variations in water quality parameters such as pH,salinity,suspended solids(ss),and humic acid,a robust relationship between detectable FI and NP concentration was ***,an increased matrix,especially ss in water samples,results in an enhanced LOQ for ***,the quantitative method remains applicable in real water bodies,especially in drinking water,with NP LOQ as low as 0.0157–0.0711 mg/*** exceeds the previously reported detectable concentration for 100 nm NPs at 40µg/mL using surface-enhanced Raman *** study confirms the potential of FI as a reliable indicator for the rapid quantification of NPs in aqueous environments,offering substantial advantages in terms of both convenience and cost-effectiveness.

关键词： Nanoplastic quantification Fluorescence intensity Drinking water Limit of quantification(LOQ) Matrix effects

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The homogenous growth of Co-based coordination compound on graphene nanosheet for high-performance K-organic battery and its reaction mechanism

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Rare Metals 2024年第4期43卷 1622-1634页

作者： qian-qian Peng Yi-Ting Wang shuo Qi Yao Xiao Yong Wang shuang-qiang Chen school of Environmental and Chemical Engineering Shanghai UniversityShanghai200444China school of Chemistry and Materials Engineering Wenzhou UniversityWenzhou325035China

Metal coordination compounds(MCCs)are gaining popularity for potassium-ion batteries(PIBs)owing to their tuneable structure,multiple reaction sites,low cost and unique ***,they are generally subjected to intrinsic features of the sluggish ionic diffusion coefficient,low electronic conductivity and slow ***,a new MCC material of cobalt-1,3,5-trioxy-2,4,6-triamino-benzo(Co-TB)coordination compound was synthesized and homogenously grown on the surface of graphene nanosheets(GNs),forming a Co-TB@GNs composite with enhanced electronic conductivity and flexible *** from the overall enhanced conductivity,high surface area and abundant activated K-storage sites,Co-TB@GNs electrodes have exhibited superior cycling performance with high reversible capacities(312 mAh·g^(-1)after 100 cycles at 100 mA·g^(-1),224 mAh·g^(-1)after 500 cycles at 1 A·g^(-1))and better rate performances compared with the pure Co-TB compound when served as PIB's ***,multiple in-situ measurement techniques have jointly confirmed that the organic functional groups(C=O,C=N and C=C of benzene rings)and Co^(2+)in Co-TB are the main reversible K-storage sites,including in-situ Fourier transform infrared spectroscopy(FTIR)and X-ray diffraction(XRD),and partial capacity contribution is originated from GNs by the apparent K-storage behavior in the in-situ XRD pattern,proving the possibility of K-storage for metal-organic materials.

关键词： Metal coordination compounds Potassiumion battery Cobalt coordination compound K-storage mechanism

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Perfluorinated iodine alkanes promote the differentiation of mouse embryonic stem cells by regulating estrogen receptor signaling

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Journal of Environmental sciences 2024年第3期137卷 443-454页

作者： Zhihua Ren Xiaoxi Yang Tingting Ku qian s.Liu Jiefeng Liang Qunfang Zhou Francesco Faiola Guibin Jiang state Key Laboratory of Environmental Chemistry and Ecotoxicology Research Center for Eco-Environmental SciencesChinese Academy of SciencesBeijing 100085China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China College of Environment and Resource Research Center of Environment and HealthShanxi UniversityTaiyuan 030006China College of sino-Danish University of Chinese Academy of SciencesBeijing 100049China

Investigating the development toxicity of perfuorinated iodine alkanes(PFIs)is critical,given their estrogenic effects through binding with estrogen receptors(ERs).In the present study,two PFIs,including dodecafuoro-1,6-diiodohexane(PFHx DI)and tridecafuorohexyl iodide(PFHx I),with binding preference to ERαand ERβ,respectively,were selected to evaluate their effects on proliferation and differentiation of the mouse embryonic stem cells(m EsCs).The results revealed that,similar to E_(2),50μmol/L PFHx DI accelerated the cell proliferation of the m *** PFI stimulation at the exposure concentrations of 2–50μmol/L promoted the differentiation of the m EsCs as characterized by the upregulation of differentiation-related biomarkers(i.e.,Otx2 and Dnmt3β)and downregulation of pluripotency genes(i.e.,Oct4,Nanog,sox2,Prdm14 and Rex1).Comparatively,PFHx DI exhibited higher induction effect on the differentiation of the m EsCs than did PFHx *** tests on ER signaling indicated that both PFI compounds induced exposure concentration-dependent expressions of ER signaling-related biomarkers(i.e.,ERα,ERβand Caveolin-1)in the m EsCs,and the downstream ER responsive genes(i.e.,c-fos,c-myc and c-jun)well responded to PFHx I *** role of ER in PFI-induced effects on the m EsCs was further validated by the antagonistic experiments using an ER inhibitor(ICI).The findings demonstrated that PFIs triggered ER signaling,and perturbed the differentiation program of the m EsCs,causing the potential health risk during early stage of development.

关键词： Perfuorinated iodine alkanes(PFIs) Embryonic stem cells(EsCs) Developmental toxicity Cell differentiation Estrogen receptor-related signaling

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Fairness in machine learning: definition, testing,debugging, and application

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science China(Information sciences) 2024年第9期67卷 41-61页

作者： Xuanqi GAO Chao sHEN Weipeng JIANG Chenhao LIN qian LI qian WANG Qi LI Xiaohong GUAN Faculty of Electronic and Information Engineering Xi'an Jiaotong University school of Cyber science and Engineering Wuhan University Institute for Network sciences and Cyberspace Tsinghua University

In recent years, artificial intelligence technology has been widely used in many fields, such as computer vision, natural language processing and autonomous driving. Machine learning algorithms, as the core technique of AI, have significantly facilitated people's lives. However, underlying fairness issues in machine learning systems can pose risks to individual fairness and social security. studying fairness definitions, sources of problems, and testing and debugging methods of fairness can help ensure the fairness of machine learning systems and promote the wide application of artificial intelligence technology in various fields. This paper introduces relevant definitions of machine learning fairness and analyzes the sources of fairness problems. Besides, it provides guidance on fairness testing and debugging methods and summarizes popular datasets. This paper also discusses the technical advancements in machine learning fairness and highlights future challenges in this area.

关键词： artificial intelligence security machine learning security machine learning fairness model testing model debugging

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