检索结果-南通市图书馆

Early-Holocene Paleo-Tropical Cyclone Activity Inferred from a Sedimentary Sequence in South Yellow Sea,East Asia

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Earth Science 2022年第3期33卷 789-801页

作者： Geng Liu xibin han Yanping Chen Jun Li Lehui Song Xin Zhou Bangqi Hu Liang Yi MNR Key Laboratory of Submarine Geosciences Second Institute of OceanographyMinistry of Natural ResourcesHangzhou 310012China Zhejiang Academy of Marine Sciences Second Institute of OceanographyMinistry of Natural ResourcesHangzhou 310012China MNR Key Laboratory of Marine Hydrocarbon Resources and Environmental Geology Qingdao Institute of Marine GeologyChina Geological SurveyQingdao 266071China School of Earth and Space Sciences University of Science and Technology of ChinaHefei 230026China Laboratory for Marine Mineral Resources Pilot National Laboratory for Marine Science and TechnologyQingdao 266071China State Key Laboratory of Marine Geology Tongji UniversityShanghai 200092China Wuhan Center China Geological SurveyWuhan 430205China

Although tropical cyclones play a critical role in global climate changes,their long-term variations in the past are not well *** this article,a sediment core from the South Yellow Sea was studied in order to reveal the influence of tropical cyclones on depositional *** the results of radiocarbon dating and sediment grain-size analysis,we show that the studied sequence was deposited during the Holocene and the sedimentary dynamics were stable and at a relatively low level,with a median grain-size range of 5.3-8.7μ*** is found that coarse particles were likely transported by highly dynamic depositional *** on the findings,a record of paleo-tropical cyclones was derived for the Early Holocene,and several intervals with a reduced influence of tropical cyclones were *** addition,it reveals a good agreement between the grain-size results and the changes in solar activity,monsoonal intensity,and the El Ni?o-Southern ***,it can be concluded that the influence of tropical cyclones on the sedimentary evolution of the muddy zone of the South Yellow Sea was substantial during the Early Holocene on centennial timescales,and that solar maxima may control the intensity of tropical cyclones via strengthening the walker circulation over the tropical Pacific.

关键词： the Yellow Sea Early Holocene tropical cyclone sedimentary process sediment grain size solar activity

Biomarker records of D5-6 columns in the eastern Antarctic Peninsula waters:responses of planktonic communities and bio-pump structures to sea ice global warming in the past centenary

在线全文

学校读者我要写书评

暂无评论

Advances in Polar Science 2021年第1期32卷 28-41页

作者： YANG Dan ZhanG Haisheng han Zhengbing han xibin ZhanG Yicheng CHEN Wensheng LIU Qian PAN Jianming FAN Gaojing LE Fengfeng LU Bing HUANG Jing Key Laboratory of Marine Ecosystem and Biogeochemistry Second Institute of OceanographyMinistry of Natural ResourcesHangzhou 310012China Key Laboratory of Submarine Geosciences Second Institute of OceanographyMinistry of Natural ResourcesHangzhou 310012China Zhuhai Central Station of Marine Environmental Monitoring State Oceanic AdministrationZhuhai 519015China Polar Research Institute of China Shanghai 200136China*

Molecular biomarkers(e.g.,isoprenoid glycerol dialkyl glycerol tetraethers(iGDGTs)and proxies,such as di-unsaturated to tri-unsaturated highly branched isoprenoids(D/T)ratio,total organic carbon,δ^(13)C and ice-rafted debris(IRD))were used to reconstruct the dominant phytoplankton(diatoms,dinoflagellates and coccolithophores),phytoplankton and zooplankton productivity,biological pump structure,and archaea assemblage(Euryarchaeota and Crenarchaeota)from a marine sediment core(D5-6)dated with^(210)Pb(1922–2012).We characterized the environmental response to sea ice variations/global warming off the eastern Antarctic *** results showed that(1)the biomarkers brassicasterol(average=519.79 ng·g^(-1)),dinosterol(average=129.68 ng·g^(-1))and C37 alkenones(average=40.53 ng·g^(-1))reconstructed phytoplankton(average=690.00 ng·g^(-1))and zooplankton(cholesterol average=669.25 ng·g^(-1))*** relative contribution to productivity by different phytoplankton groups was diatoms>dinoflagellates>*** is consistent with field surveys showing that diatoms dominate the phytoplankton in waters adjacent to the Antarctic Peninsula.(2)The relative abundances of different highly branched isoprenoids reflected the contributions of sea ice algae and open water phytoplankton(D/T=1.2–30.15).Phytoplankton productivity and sea ice showed a good linear relationship with a negative correlation,indicating that more open water during periods of warming and reduced sea ice cover led to an enhanced biological pump.(3)Over the past 100 years,phytoplankton productivity and zooplankton biomass *** trend was particularly evident in the last 50 years,corresponding to increased global warming,and showed a negative correlation with IRD and D/*** suggests that with decreasing sea ice coverage in a warming climate,diatom biomass greatly ***/diatom values and the ratio of C37 alkenones to total phytoplankton productivity decreased,indicati

关键词： global warming phytoplankton productivity zooplankton productivity archaea iGDGTs sea ice proxy D/T eastern Antarctic Peninsula

Application o f 210 Pb, Carbon and Nitrogen Isotope in Tracing of Changes and Burial Effect of Endogenous and Terrigenous Organic Matter in the Bering Sea over the Past 100 Years

在线全文

学校读者我要写书评

暂无评论

Meteorological and Environmental Research 2017年第5期8卷 111-117页

作者： Zhang Haisheng Chen Jianfang han Zhengbing han xibin Xu Xudan Fan Gaojing Lu Bing Second Institute of Oceanography State Oceanic AdministrationHangzhou 310012China Key Laboratory of Marine Ecosystem and Biogeochemistry State Oceanic AdministrationHangzhou 310012China Key Laboratory of Submarine Geosciences State Oceanic AdministrationHangzhou 310012China

By using the multi-tube sediment samples collected from NB01 station in the Bering Sea during the period of the fourth Chinese Arctic research expedition in 2010,as well as the dating technique of radioisotope ^(210)Pb in sedimentary strata,based on the exponential decay trend of ^(210)Pb exwith the column sample depth,relative stable modern sedimentary environment in the investigation area was reflected. The results show that the deposition rate of modern marine sediment S was 0. 27 cm/a,and correlation coefficient R was 0. 96( n = 17),while time span was 107 a(1903-2010). Meanwhile,carbon,nitrogen and isotopes were used to trace the sources of materials in the Bering Sea. It is found that the content of organic carbon and nitrogen in the column samples from NB01 station in the Bering Sea was 1. 18%-1. 80% and 0. 16%-0. 28% respectively,and C/N ratio ranged from 5. 13 to 8. 31. Total organic carbon( TOC) and total organic nitrogen( TON) were preserved well in sedimentary strata and had good consistency,showing that sources of organic matter were consistent. Moreover,their changes positively correlated with^(210)Pb. Organic carbon isotope( δ13 C) ranged from-22. 45‰ to-21. 82‰,and its changing trend was similar to that of C/N ratio; organic nitrogen isotope(δ15 N) varied from 7. 53‰ to 8. 54‰,indicating that organic matter was mainly from remaining marine organisms after being decomposed,into which a certain quantity of terrigenous materials were mixed. In the 100 years,the overall trend of terrigenous materials became increasingly obvious,showing that the input and burial of organic carbon from seas and land in the Bering Sea were changing. According to the burial rate of surface sediment and content of organic carbon,the apparent burial flux of sedimentary organic carbon in the column sample from NB01 station in the Bering Sea was estimated,about 1 450 mmol C/( m^2·a). It is suggested that the high burial flux of sedimentary organic carbon in the regions was mainl

关键词： The Arctic The Bering Sea 210Pb Deposition rate Organic carbon and nitrogen isotope Sources of materials

国家中小学智慧教育平台赋能农村义务教育高质量发展

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

中国电化教育 2023年第8期 7-17页

作者：杜江韩锡斌宜宾学院教育学部四川宜宾644000 清华大学教育研究院北京100084

教育数字化转型已成为化解人民日益增长的优质教育需求与不平衡不充分的教育发展之间矛盾的重要突破口。作为国家教育数字化战略行动的重要抓手,国家中小学智慧教育平台的建设和应用,为加速推进农村义务教育优质均衡发展和城乡一体化提... 详细信息

教育数字化转型已成为化解人民日益增长的优质教育需求与不平衡不充分的教育发展之间矛盾的重要突破口。作为国家教育数字化战略行动的重要抓手,国家中小学智慧教育平台的建设和应用,为加速推进农村义务教育优质均衡发展和城乡一体化提供了新的机遇。该文通过文献研究、理论分析和经验总结等方法,在明晰农村义务教育基本情况,分析农村义务教育信息化研究与实践状况,梳理国家中小学智慧教育平台建设成就与优势的基础上,以创新扩散理论和扩展的技术接受和使用统一理论为分析框架,构建了国家中小学智慧教育平台赋能农村义务教育发展的框架,讨论了平台赋能农村义务教育发展的关键路径。

关键词：教育数字化转型国家中小学智慧教育平台农村义务教育框架构建关键路径

在线全文

学校读者我要写书评

暂无评论

信息时代职业教育混合教学要素及其关系

电化教育研究 2022年第2期43卷 19-25,41页

作者：王雯韩锡斌中国教育科学研究院北京100088 清华大学教育研究院北京100084

职业教育“三教”(即教师、教材、教法)改革是职业教育深化内涵建设的切入点和突破口,但教学是个多要素的复杂系统,教学系统内部的矛盾性和信息时代外部环境的变化,都要求对教学系统各要素及其关系进行整体化认识。综合已有理论和相关... 详细信息

职业教育“三教”(即教师、教材、教法)改革是职业教育深化内涵建设的切入点和突破口,但教学是个多要素的复杂系统,教学系统内部的矛盾性和信息时代外部环境的变化,都要求对教学系统各要素及其关系进行整体化认识。综合已有理论和相关研究成果,阐明了信息时代职业教育混合教学具有七个要素,包括学生、教师两个主体要素,教学目标、教学内容、教学方法、教学反馈四个过程要素,教学环境一个环境要素。与基础教育和高等教育相同的是,这些要素的内涵在信息时代混合教学中向虚实融合方向拓展;不同的是,这些要素蕴含着职业教育“校企合作、产教融合、工学结合”的显著特征,七个要素间存在既相互支撑又相互约束的辩证关系。应以信息时代技术技能人才培养目标作为职业教育“三教”改革的出发点,立足“互联网+职业教育”的工学环境,面向职教学生的特点和学习需要,提升教师信息化“双师”教学能力,建设活页式、工作手册式、融媒体教材,选择恰当的混合教法,以数据化绩效考核的教学反馈连通教学改革的闭环,实现教学系统的有效运转与行动优化。

关键词：职业教育混合教学教学要素信息时代 “三教”改革

Distribution and Sources of Polycyclic Aromatic Hydrocarbons in the Sediment Cores M2 from the Prydz Bay and Implications for Sedimentary Environment

在线全文

学校读者我要写书评

暂无评论

Meteorological and Environmental Research 2019年第4期10卷 15-22页

作者： Yang Dan han xibin Zhang Haisheng Zhang Yicheng Xu Xudan Zhang Huijuan Key Laboratory of Marine Ecosystem and Biogeochemistry Second Institute of Oceanography Ministry of Natural Resources Hangzhou 310012 China Key Laboratory of Submarine Geosciences Second Institute of Oceanography Ministry of Natural Resources Hangzhou 310012 China

In this study, the polycyclic aromatic hydrocarbons (PAHs) from the sediment cores M2 in the Pryza Bay of the Antarctica were quantitatively measured using GC-MS analysis, and it is found that the PAHs mainly included bicyclic naphthalene compounds, tricyclic phenanthrene and fluorine series (dibenzofuran and dibenzothiophene), and tetracyclic fluoranthene, pyrene and chrysene series. The results showed that the phenanthrene series with low molecular weight (tricyclic compounds) had a relatively higher content than the series with high molecular weight (tetracyclic compounds). The fluoranthene/(fluoranthene and pyrene) ratio of M2 varied from 0.46 to 0.54. Integrated with the content of 1,7-dimethylphenanthrene and terrigenous chrysene, it is inferred that PAHs in the sediments from the Pryzd Bay were originated from a mixed source of the products of petroleum, refined products and coal combustion, natural source and terrigenous higher plants. Complete methyl dibenzothiophene and dimethyldibenzothiophene series compounds were detected in the sediment cores, which are closely associated with a reducing environment. The ratio of dibenzothiophene to dibenzofuran was between 0.46 and 3.21, mostly greater than 0.7. Combined with the oxidation/reduction index (Pr/Ph) ranging from 0.45 to 0.61 for the sediment cores, it is indicated that these compounds were formed in a normal reducing environment. Geochemical parameters of PAHs such as TNR-1 (0.53-1.57), MPI (0.24-1.21), MDR (1.83-5.57), and MDBI (0.41-0.93), and maturity parameters such as C 29 /C 29 (+), C 31 22S/C 31 (22S+22R), C 32 22S/C 32 (22S+22R) and Ts/(Tm+Ts) were all indicative of high maturity. However, all the above parameters were significantly deviated from those of modern sediments and modern organisms, which undoubtedly shows the input of exogenous mature organic matter.

关键词： Antarctica Sediment core Polycyclic aromatic hydrocarbons Material source Sedimentary environment

基于增量学习算法的混合课程学生成绩预测模型研究

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

电化教育研究 2021年第7期42卷 83-90页

作者：罗杨洋韩锡斌清华大学教育研究院北京100084

基于在线学习行为预测学生成绩可以辅助教师动态掌握学情,制定差异化的教学策略,然而在混合课程中仅仅依据在线数据对学生成绩进行预测难度很大,尚处于探索中。文章选取某高校2018秋季学期和2020春季学期的“高活跃型混合课程”学生在... 详细信息

基于在线学习行为预测学生成绩可以辅助教师动态掌握学情,制定差异化的教学策略,然而在混合课程中仅仅依据在线数据对学生成绩进行预测难度很大,尚处于探索中。文章选取某高校2018秋季学期和2020春季学期的“高活跃型混合课程”学生在线行为数据,采用增量学习的随机森林算法构建学生成绩预测模型,研究发现:(1)增量学习随机森林算法在混合课程样本最多的数据集中,获得预测结果准确率最高(75.1%);(2)相较于批量学习随机森林算法,增量学习算法在数据样本量较多的数据集中预测结果准确率更高;(3)当样本数量达到一定规模后,预测结果准确率波动减小、稳定性增强。本研究采用增量学习随机森林算法预测混合课程中的学生成绩,不仅取得了较好的预测准确率,而且解决了新增数据后模型的稳定性问题,将有助于模型的迭代优化,提高模型的通用性,以及可持续追踪学生在不同学期的学习行为特征。

关键词：学生成绩预测混合课程增量学习算法随机森林算法机器学习

在线全文

学校读者我要写书评

暂无评论

高校教师信息化教学能力培训迁移的分析框架

中国电化教育 2018年第4期 17-25页

作者：姜蔺韩锡斌清华大学教育研究院北京100084

对在职教师而言,教师培训是促进教师专业发展的一种有效途径,教师培训的有效性直接影响教师信息化教学能力的提升效果及专业发展水平。大多数教师培训研究更多关注培训结束时教师的学习结果和主观感受,然而教师培训后是否能够真正学以致... 详细信息

对在职教师而言,教师培训是促进教师专业发展的一种有效途径,教师培训的有效性直接影响教师信息化教学能力的提升效果及专业发展水平。大多数教师培训研究更多关注培训结束时教师的学习结果和主观感受,然而教师培训后是否能够真正学以致用,即培训迁移问题尚有待深入研究。该文借鉴企业人力资源管理领域的研究成果,系统梳理了培训迁移的概念、过程、影响因素以及效果评价,并综述了高校教师信息化教学能力培训迁移的研究现状。文章进一步界定了高校教师信息化教学能力培训迁移过程的范围,并从培训迁移的过程、影响因素、培训效果评价三个方面提出了高校教师信息化教学能力培训迁移的分析框架,其中培训迁移的过程不仅要包括学习结束后的教学应用阶段,还要包括培训学习阶段这一前提且贯穿教学应用过程的阶段;影响因素方面主要包括教师特征、培训干预、学校环境三部分;培训效果评价方面主要包括培训学习结果评价与教学应用结果评价;在分析框架中,迁移动机既是培训学习阶段与教学应用阶段的中间结果,又是影响因素与教学应用阶段的中间环节。

关键词：教师信息化教学能力教师培训培训迁移文献综述

高校教师教学大数据技术行为意向影响因素研究——基于清华“学堂在线”的调查

在线全文

学校读者我要写书评

暂无评论

远程教育杂志 2017年第6期35卷 76-86页

作者：方旭韩锡斌兰州大学高等教育研究所甘肃兰州730000 清华大学教育研究院北京100084

目前,教育大数据技术已成为教育技术领域的研究热点之一,国内外均对教育大数据的含义、应用等问题进行了探讨。而在教育大数据的构成方面,教学大数据首当其冲,国内外相关研究较多的集中于教育大数据的探讨,而对于教学大数据仍有待进一... 详细信息

目前,教育大数据技术已成为教育技术领域的研究热点之一,国内外均对教育大数据的含义、应用等问题进行了探讨。而在教育大数据的构成方面,教学大数据首当其冲,国内外相关研究较多的集中于教育大数据的探讨,而对于教学大数据仍有待进一步深入全面的探讨。因此,对教学大数据作深入研究具有重要的实践意义。已有研究表明,大数据技术如何"落地",是有待解决的问题。针对目前关于教师教学大数据技术行为意向影响因素的研究还很少,还缺乏深入的理论分析和实证研究。为此,在构建高校教师教学大数据技术行为意向影响因素模型的基础上,进行了实证分析,对教师教学大数据技术行为意向的影响因素进行了研究。研究结果表明:有用性感知和情绪两个变量与教师教学大数据的行为意向正相关,社群影响和绩效感知两个变量与有用性感知正相关,促成条件与易用性感知正相关(p<0.05);所构建的模型具有良好的解释力,对行为意向的解释度为73.3%;教师具有了一定的行为意向,而社群影响、易用性感知以及促成条件等方面的感知程度还很低。

关键词：教育大数据教学大数据行为意向影响因素实证研究