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Elevation of basal lacustrine sediments along the mid-lower reaches of the Yangtze River and its implications for the reconstruction of Holocene water levels

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Science China Earth Sciences 2024年第9期67卷 2924-2936页

作者： Shuchun YAO Chunhai LI Bin xue Nanjing Institute of Geography and Limnology Chinese Academy of SciencesNanjing 210008China University of Chinese Academy of Sciences Beijing 100049China

The middle and lower reaches of the Yangtze River,a primary region for freshwater lakes in China,have undergone significant transformations throughout the *** changes,driven by factors such as sea-level rise,climate change,and human activities,have led to the progressive elevation of water levels in this *** a result,a floodplain has emerged,characterized by the formation of numerous shallow lakes along the river ***,the pattern of water-level changes in the main channel of the Yangtze River during the Holocene remains *** gap in knowledge poses challenges for understanding sediment transport dynamics,the interactions between the river and its adjacent lakes,and the prevention and control of flood disasters in the Yangtze River *** shed light on these issues,our study compiled data on the surface elevation and water depth of 81 lakes in the mid-lower reaches of the Yangtze River ***,we analyzed historical water-level records from the 1900s to the 1970s at eight gauging stations from Shashi to Jiangyin along the river’s main *** findings reveal that,particularly along the Jingjiang section,the basal elevation of most lakes is lower than the Yangtze River’s water level during the dry ***,the water level of the main stream exceeds that of both the floodplain and the lakes enclosed by the Jingjiang *** the tidal reach,especially within the Taihu Lake basin,the basal elevation of lakes typically falls below sea ***,lakes located along the section from Chenglingji to Wuhu exhibit basal elevations that correspond with the Yangtze River’s annual average and dry season water *** the widespread presence of lakes along the middle and lower reaches of the Yangtze River,our study introduces a new proxy for reconstructing the mean water level of the mid-lower Yangtze River in the *** analyzing sediments from Nanyi Lake and Chenyao Lake in the lower Yangtze River,we a

关键词： Middle and lower Yangtze River Holocene Water level Floodplain lakes Basal sediment elevation

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刮板输送机的安装及操作维护保养分析

现代工业经济和信息化 2020年第4期10卷 107-109页

作者：薛霄飞阳煤集团开元公司山西寿阳045400

刮板输送机是矿井开采过程中运送煤炭物料的重要部件,在井下巷道长距离运输过程中直接与煤炭进行接触,在煤矿恶劣的作业环境中会受到各种形式的破坏损耗。为确保刮板输送机的连续运转生产,应重视对刮板输送机在安装以及日常维护保养方... 详细信息

刮板输送机是矿井开采过程中运送煤炭物料的重要部件,在井下巷道长距离运输过程中直接与煤炭进行接触,在煤矿恶劣的作业环境中会受到各种形式的破坏损耗。为确保刮板输送机的连续运转生产,应重视对刮板输送机在安装以及日常维护保养方面的工作。通过分析刮板输送机在安装、维护保养方面的相关技术要点,得出刮板输送机全过程生产周期的关键节点,要求一线作业人员严格按照规范及规程开展刮板输送机的管理工作,为煤矿企业日常管理刮板输送机提供依据。

关键词：刮板输送机安装维护保养

Sample Generation for Security Region Boundary Identification Based on Topological Features of Historical Operation Data

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Journal of Modern Power Systems and Clean Energy 2024年第4期12卷 1087-1095页

作者： Xiaokang Wu Wei Xu Feng xue College of Energy and Electrical Engineering Hohai UniversityNanjingChina NARI Group Corporation NanjingChina State Grid Electric Power Research Institute NanjingChina

Since the scale and uncertainty of the power sys-tem have been rapidly increasing,the computation efficiency of constructing the security region boundary(SRB)has become a prominent *** on the topological features of histori-cal operation data,a sample generation method for SRB identi-fication is proposed to generate evenly distributed samples,which cover dominant security *** boundary sample pair(BSP)composed of a secure sample and an unsecure sam-ple is defined to describe the feature of *** resolution,sampling,and span indices are designed to evaluate the cover-age degree of existing BSPs on the SRB and generate samples closer to the *** on the feature of flat distribution of BSPs over the SRB,the principal component analysis(PCA)is adopted to calculate the tangent vectors and normal vectors of ***,the sample distribution can be expanded along the tangent vector and corrected along the normal vector to cover different security ***,a sample set is randomly gen-erated based on the IEEE standard example and another new sample set is generated by the proposed *** results in-dicate that the new sample set is closer to the SRB and covers different security modes with a small calculation time cost.

关键词： Clustering analysis principal component analysis(PCA) sample generation security region boundary(SRB)

Open-Shell Oligomers and Polymers: Theory, Characterization Methods, Molecular Design, and Applications

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Chinese Journal of Polymer Science 2024年第4期42卷 417-436页

作者： xue-Qing Wang Cheng Song Ting Lei Key Laboratory of Polymer Chemistry and Physics(Ministry of Education) School of Materials Science and EngineeringPeking UniversityBeijing100871China

Open-shell oligomers and polymers have exhibited intriguing electronic and magnetic properties, making them highly desirable for a wide range of applications, including ambipolar organic field-effect transistors (OFETs), photodetectors, organic thermoelectrics, and spintronics. Although open-shell ground states have been observed in certain small molecules and doped organic semiconductors, the exploration of open-shell ground-state conjugated polymers is still limited, and the strategies for designing these polymers remain obscure. This review aims to briefly introduce the theory and characterization methods of open-shell conjugated polymers, along with an overview of recent progress and applications. The objective is to stimulate further advancements and investigations in this promising area by shedding light on the potential of open-shell conjugated polymers and the challenges that lie ahead.

关键词： Conjugated polymers Open-shell molecules High-spin ground state Donor-acceptor(D-A)polymers Optoelectronic and magnetic properties

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浅壁煤层注水防片帮技术实践

江西煤炭科技 2021年第4期 17-18,24页

作者：薛霄飞华阳新材料科技集团开元煤炭有限责任公司山西晋中045400

为解决煤层开采过程中煤壁片帮问题,综合运用理论分析、试验研究等方法对浅壁注水工艺进行了可行性分析,并在开元煤炭有限责任公司9714工作面进行了现场实践。结果表明:浅壁注水能够在工作面前方形成一层抗剪强度较高的粘结层,可提高煤... 详细信息

为解决煤层开采过程中煤壁片帮问题,综合运用理论分析、试验研究等方法对浅壁注水工艺进行了可行性分析,并在开元煤炭有限责任公司9714工作面进行了现场实践。结果表明:浅壁注水能够在工作面前方形成一层抗剪强度较高的粘结层,可提高煤壁的整体性与稳定性;当煤体含水率在2%~12%区间内时,内聚力和抗剪强度两项力学性能指标随着含水率的增加而逐渐递增,煤体抗压强度则与含水率呈反比关系;煤层浅壁注水工艺实施后煤壁片帮冒顶事故较过去降低了80%,片帮深度和影响范围也大幅缩减。

关键词：煤壁片帮浅壁注水黏结层内聚力

Classification,biosynthesis,and biological functions of triterpene esters in plants

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Plant Communications 2024年第4期5卷 67-93页

作者： Jia Liu xue Yin Chengxi Kou Ramesha Thimmappa Xin Hua Zheyong xue Key Laboratory of Saline-alkali Vegetation Ecology Restoration(Northeast Forestry University) Ministry of EducationHarbin 150040China Heilongjiang Key Laboratory of Plant Bioactive Substance Biosynthesis and Utilization Northeast Forestry UniversityHarbin 150040China Amity Institute of Genome Engineering Amity UniversityNoidaUP India 201313India State Key Laboratory for Quality Ensurance and Sustainable Use of Dao-di Herbs Beijing 100700P.R.China

Triterpene esters comprise a class of secondary metabolites that are synthesized by decorating triterpene skeletons with a series of oxidation,glycosylation,and acylation *** triterpene esters with important bioactivities have been isolated and identified,including those with applications in the pesticide,pharmaceutical,and cosmetic *** also play essential roles in plant defense against pests,dis-eases,physical damage(as part of the cuticle),and regulation of root ***,there has been no recent summary of the biosynthetic pathways and biological functions of plant triterpene ***,we classify triterpene esters intofive categories based on their skeletons andfind that C-3 oxidation may have a significant effect on triterpenoid *** acid and aromatic moieties are common li-gands present in triterpene *** further analyze triterpene ester synthesis-related acyltransferases(TEsACTs)in the triterpene biosynthetic *** an evolutionary classification of BAHD acyltrans-ferases(BAHD-ATs)and serine carboxypeptidase-like acyltransferases(SCPL-ATs)in Arabidopsis thaliana and Oryza sativa,we classify 18 TEsACTs with identified functions from 11 *** the triterpene-skel-eton-related TEsACTs belong to BAHD-AT clades IIIa and I,and the only identified TEsACT from the SCPL-AT family belongs to the CP-I *** comprehensive review of the biosynthetic pathways and bioactivities of triterpene esters provides a foundation for further study of their bioactivities and applica-tions in industry,agricultural production,and human health.

关键词： triterpene esters acyltransferases classification biosynthesis biological functions

农村地区学前教育教师资源配置问题与优化路径——基于陕西省X市农村学前教师资源现状的调查分析

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教育研究 2015年第3期36卷 103-111页

作者：赖昀薛肖飞杨如安西南大学西南民族教育与心理研究中心西南大学教育学部

面对学前教育普及化趋势,农村地区学前教育学校迎来巨大挑战,教师资源的配置是其中一个突出问题。基于陕西省X市农村学前教师资源现状的调研,发现学前教育教师数量缺口巨大且结构失调,教师质量参差不齐,相关主体对教师资源配置认识不足... 详细信息

面对学前教育普及化趋势,农村地区学前教育学校迎来巨大挑战,教师资源的配置是其中一个突出问题。基于陕西省X市农村学前教师资源现状的调研,发现学前教育教师数量缺口巨大且结构失调,教师质量参差不齐,相关主体对教师资源配置认识不足,导致学前教育教师资源配置质量不高,影响学前教育教学质量。加强学前教育教师资源的合理配置,应拓宽学前教育教师资源的补充渠道,采用多途径提高农村学前教育师资质量,增强相关主体对学前教育的正确认识,构建学前教育高效循环监督机制等。

关键词：农村地区教师资源配置学前教育

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新建地方本科院校大学生就业问题研究

创新创业理论研究与实践 2018年第9期1卷 124-125页

作者：薛肖飞宜宾学院四川宜宾644000

随着地方经济社会转型发展,新建地方本科院校大学生就业将面临新的严峻挑战。就业质量不高、专业优势不凸显、自主创业艰难等问题将持续存在。通过确立鲜明的人才培养方向,调整优化专业结构,提升大学生的应用创新能力和竞争优势,适应地... 详细信息

随着地方经济社会转型发展,新建地方本科院校大学生就业将面临新的严峻挑战。就业质量不高、专业优势不凸显、自主创业艰难等问题将持续存在。通过确立鲜明的人才培养方向,调整优化专业结构,提升大学生的应用创新能力和竞争优势,适应地方社会经济转型发展的人才需求。

关键词：新建地方本科院校大学生就业问题地方经济社会转型发展人才需求导向应用型人才培养

Effects of microenvironment and biological behavior on the paracrine function of stem cells

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Genes & Diseases 2024年第1期11卷 135-147页

作者： Zhixin xue Yunjun Liao Ye Li The Department of Plastic and Cosmetic Surgery Nanfang HospitalSouthern Medical UniversityGuangzhouGuangdong 510515China

Mesenchymal stem cells(MSCs),the most well-studied cell type in the field of stem cell therapy,have multi-lineage differentiation and self-renewal ***-based thera-pies have been used to treat diverse diseases because of their ability to potently repair tissue and locally restore *** increasing body of evidence demonstrates that paracrine func-tion is central to the effects of MsC-based *** factors,cytokines,chemokines,extracellular matrix components,and extracellular vehicles all contribute to the beneficial ef-fects of MSCs on tissue regeneration and *** paracrine substances secreted by MSCs change depending on the tissue microenvironment and biological *** this review,we discuss the bioactive substances secreted by MsCs depending on the microenvironment and biological behavior and their regulatory mechanisms,which explain their potential to treat human diseases,to provide new ideas for further research and clinical cell-free therapy.

关键词： Bioactive behavior Mesenchymal stem cells Microenvironment Paracrine Secretome