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Sedimentary and geochemical evidence of Eocene climate change in the Xining Basin, northeastern Tibetan Plateau

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Science China Earth Sciences 2018年第9期61卷 1292-1305页

作者： Abu Sadat Md SAYEM zhengtang GUO Haibin WU Chunxia ZHANG Fan YANG Guoqiao XIAO Zhilin HE Key Laboratory of Cenozoic Geology and Environment Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China University of Chinese Academy of Sciences Beijing 100049 China Department of Geological Sciences Jahangirnagar University Dhaka 1342 Bangladesh CAS Center for Excellence in Life and Paleoenvironment Bering 100044 China State Key Laboratory of Biogeology and Environmental Geology School of Earth Sciences China University of Geosciences Wuhan 430074 China

The northeastern Tibetan Plateau began to grow during the Eocene and it is important to understand the climatic history of Asia during this period of so-called ‘doubthouse' conditions. However, despite major advances in the last few decades,the evolutionary history and possible mechanisms of Eocene climate change in the northeastern Tibetan Plateau remain *** Xining Basin in the northeastern Tibetan Plateau contains a continuous sequence of Early to Late Eocene non-marine sediments which provides the opportunity to resolve long-term climate changes during this period. In this study, we report the results of analyses of lithofacies, sediment color and geochemistry of bulk samples collected from the Xijigou section of the Xining Basin. An abrupt lithofacies change between the Early(~52.40 Ma) and Late Eocene(~40–34 Ma) indicates a change in the depositional environment from a shallow lake to a playa lake in response to a significant climatic shift. During ~52.40 Ma,higher values of sediment redness(a*), redness/lightness(a*/L*) and higher modified Chemical Index of Weathering(CIW′)indicate a relatively warm and humid climate, while from ~40–34 Ma the lower values of a*, a*/L*and lower CIW′ imply subhumid to semi-arid climatic conditions. The paleoclimatic records indicate a long-term(~52.34 Ma) trend of decreasing chemical weathering, consistent with global climate change. An abrupt sharp excursion of the proxy records during ~42.40 Ma suggests a relatively brief warm interval, corresponding to the Middle Eocene Climatic Optimum(MECO). We suggest that global cooling substantially reduced humidity in inner Asia, resulting in sub-humid to semi-arid climatic conditions after 40 Ma in the Xining Basin, which may have been responsible for the long-term trend of decreasing chemical weathering during the Eocene.

关键词： Eocene Climate change Sediment color Chemical index of weathering Xining Basin Tibetan Plateau

Evidence of advancing spring xylem phenology in Chinese forests under global warming

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Science China Earth Sciences 2023年第10期66卷 2187-2199页

作者： Huihong XUE Feng SHI Fabio GENNARETTI Yongshuo H.FU Bin HE Xiuchen WU zhengtang GUO Key Laboratory of Cenozoic Geology and Environment Institute of Geology and GeophysicsChinese Academy of SciencesBeijing100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing100049China CAS Center for Excellence in Life and Paleoenvironment Beijing100044China Institut de Recherche sur les Forêts Groupe de Recherche enÉcologie de la MRC-AbitibiUniversitédu Québec en Abitibi-TémiscamingueAmosJ9T 2L8Canada College of Water Sciences Beijing Normal UniversityBeijing100875China Faculty of Geographical Science Beijing Normal UniversityBeijing100875China

Phenological responses of vegetation to the ongoing warming trend impact current and future primary ***,few studies focus on wood phenology because its observed data are much scarcer,which hinders the estimation and prediction of forest carbon budgets over large ***,we use a physiological process-based tree-ring growth model(Vaganov-Shashkin model)to investigate the spatial and temporal variations of spring xylem phenology(start of the growing season of xylem,SOS_(x))in tree-ring sites of China during 1962.2.16 *** model is calibrated on measured tree-ring width chronologies(70 tree-ring chronologies)and successfully validated with field observations of *** found that spring xylem phenology significantly advances during 1962.2.16 CE period under global warming,with the rate of advance quickly increasing after the 1990s to an average of 0.2. days per *** preseason daily mean temperature is the main climatic driver for spring xylem phenology as indicated by its significant correlations with SOS_(x)at most sites(71%).Warmer preseason allows heat requirements for tree growth to be reached more quickly,with increase of 1℃in temperature of preseason anticipates SOS_(x)by 6 to 7 days,which will benefit the radial growth of trees in the relatively cold-humid *** addition,the significant positive correlation between the simulated spring xylem phenology and remote sensing derived phenology highlights the primary and secondary growth may be governed by the same variable(temperature)and change in the same direction with global *** study provides the long-term perspective on the spring xylem phenology variations covering most of China.

关键词： Tree-ring Xylem Phenology Vaganov-Shashkin model China

幼龄大鼠颅骨缺损后硬脑膜相关促成骨基因的表达情况

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医学理论与实践 2024年第14期37卷 2341-2344,2349页

作者：李烨李政堂王勇张中奇邵国张春阳内蒙古科技大学包头医学院内蒙古包头市014010 内蒙古科技大学包头第一附属医院神经外科包头医学院神经外科疾病研究所(转化医学) 内蒙古自治区骨组织再生与损伤修复中心深圳市龙岗区第三人民医院转化医学中心

目的:通过建立大鼠幼鼠颅骨缺损模型(2.m、5mm),探讨硬脑膜在颅骨缺损中促进骨修复的作用,并观察不同大小颅骨缺损中硬脑膜促成骨基因表达差异,为在临床治疗小儿颅骨缺损中补充理论基础。方法:选取60只10日龄SD大鼠随机分为3组,在顶骨... 详细信息

目的:通过建立大鼠幼鼠颅骨缺损模型(2.m、5mm),探讨硬脑膜在颅骨缺损中促进骨修复的作用,并观察不同大小颅骨缺损中硬脑膜促成骨基因表达差异,为在临床治疗小儿颅骨缺损中补充理论基础。方法:选取60只10日龄SD大鼠随机分为3组,在顶骨中心制造颅骨缺损,分别是2.m缺损组、5mm缺损组、未缺损对照组(其中2.m缺损组、5mm缺损组为实验组),每组2.只。对照组暴露颅骨后不做处理。将每组大鼠随机分为两部分,分别在术后1周、术后6周取材。采用Western-blot、RT-qPCR检测不同时期颅骨缺损处硬脑膜中骨形态蛋白2.Bmp2.、Runt相关转录因子2.Runx2.、成纤维细胞生长因子受体2.FGFR2.的蛋白表达情况及mRNA表达情况。结果:(1)术后1周时,实验组Bmp2.Runx2.FGFR2.达量均高于未缺损对照组,其中2.m颅骨缺损组的Bmp2.Runx2.白表达量显著高于5mm缺损组,FGFR2.白表达量低于5mm缺损组(P2.Runx2.白表达量均高于未缺损对照组,其中5mm缺损组Bmp2.Runx2.达量高于2.m缺损组(P2.m缺损组的FGFR2.白表达量与对照组无明显差异(P>0.05),但5mm缺损组的FGFR2.白表达量高于未缺损对照组和2.m缺损组(P2.Runx2.Bmp2.FGFR2.mRNA表达水平情况:表达趋势同Western blot结果表达趋势相似。结论:(1)颅骨缺损后,未成熟硬脑膜促成骨因子表达增加;(2.硬脑膜中不同促成骨因子在不同大小的颅骨缺损中表达量存在差异。

关键词：未成熟硬脑膜颅骨缺损促成骨能力骨再生

Carbon isotopic compositions of pore and matrix carbonates in carbonate nodules, and origin of carbonate formation

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Chinese Science Bulletin 2010年第26期55卷 2926-2929页

作者： LIU Lian YIN QiuZhen WU HaiBin GUO zhengtang Key Laboratory of Cenozoic Geology and Environment Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China Graduate University of the Chinese Academy of Sciences Beijing 100049 China Institut d'Astronomie et de Geophysique G. Lemaitre Universite catholique de Louvain Chemin du Cyclotron 2 1348 Louvain-la-Neuve Bel gium

Carbon isotopes of pedogenic carbonate are often used to study paleoenvironments, but the existence of detrital carbonate changes the carbon isotopic composition. To develop an experimental method to determine existence of detrital carbonate in carbonate nodules, and to avoid it during isotope analysis, 2. pedogenic carbonate nodules in Miocene loess from the Loess Plateau of China were studied through micromorphology and carbon isotope analysis. The difference in carbon isotopic composition between matrix carbonate (B) and pore carbonate (A) (δ 13C(B-A)) ranges from 0.2.‰ to 0.44‰ in nodules containing detrital carbonate and -0.16‰ to 0.13‰ in nodules where detrital carbonate is absent. The latter is within measurement error, but the former is beyond it. Here we propose an isotopic approach to determine if nodules contain detrital carbonate: if δ 13C(B-A) is within the measurement error, the nodules do not contain detrital carbonate, and vice versa. We suggest that it is better to analyze pore carbonate instead of matrix carbonate when using carbon isotope of carbonate nodules to reconstruct paleoenvironments.

关键词：碳同位素组成碳酸盐结核核基质中国黄土高原碳同位素分析起源测量误差同位素方法

Eolian origin of the Miocene loess-soil sequence at Qin'an,China:Evidence of quartz morphology and quartz grain-size

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Chinese Science Bulletin 2006年第1期51卷 117-120页

作者： LIU Jinfeng GUO zhengtang QIAO Yansong HAO Qingzheng YUAN Baoyin Institute of Geology and Geophysics Chinese Academy of Sciences Beijing 100029 China SKLLQG Institute of Earth Environment Chinese Academy of Sciences Xi'an 710075 China Institute of Geomechanics Chinese Academy of Geological Sciences Beijing 100081 China

Recent study revealed that the so-called Neogene Gansu System in the westernLoess Plateau contains loess-soil sequences of Miocene age. A most complete sequence (QA-I) covers atime interval from ～2. to ～6.2.Ma BP, consisting of more than 2.0 visually definable paleosolsinterbedded with loess layers. A loess-soil sequence of late Miocene-Pliocene age, synchronous withthe Hipparian Red Clay in the eastern Loess Plateau, was also recognized, and extends the Miocenesequences into the Pliocene, ～3.5 Ma BP. Recently, Miocene eolian deposits were also reported fromthe high terraces near Xining.

关键词：石英形态尺寸中新世黄土

案例式教学法在中医老年医学研究生教学中的应用

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中国病案 2024年第9期25卷 86-89页

作者：赵智茹龙霖梓刘征堂谭令贾凡中国中医科学院西苑医院老年病研究所北京市100091 中山大学附属第八医院广东省深圳市518033

目的探讨案例式教学法在中医老年医学研究生中的教学效果,为提高教学质量提供参考依据。方法以2.2.年9月16日-2.2.年10月15日期间在某三甲医院老年病科学习的100名专业型研究生为研究对象,随机分为对照组和实验组,对照组(n=50)采用传统... 详细信息

目的探讨案例式教学法在中医老年医学研究生中的教学效果,为提高教学质量提供参考依据。方法以2.2.年9月16日-2.2.年10月15日期间在某三甲医院老年病科学习的100名专业型研究生为研究对象,随机分为对照组和实验组,对照组(n=50)采用传统教学方法,实验组(n=50)采用案例式教学法。通过使用考试成绩和问卷调查相结合的方式,比较2.学生的中医老年病学理论成绩、实践操作成绩、学生的自我评价、对教学法的评价和对教师的评价方面的差异,对2.教学模式的教学效果进行评价。结果实验组理论成绩和实践技能操作成绩分别为(85.78±6.08)分和(89.12.6.40)分,高于对照组,差异有统计学意义;学生的自我评价方面,实验组调查问卷各项结果均显著优于对照组,差异有统计学意义;对教学法的评价方面,实验组在教学引起好奇心、教学文本内容符合兴趣、教学能加深对老年病的理解和掌握、能从中学到一些意料之外的知识、努力得到肯定、教学有关于如何运用理论知识的说明方面的调查问卷分数均显著高于对照组,差异有统计学意义,在文本内容比想象中困难、讨论难度太大、教学模式增加了学习负担方面实验组的调查问卷分数均显著低于对照组,差异均有统计学意义;对教师的评价方面,实验组在教学开始前教师能适当引导学生收集资料、教学过程中教师能进行有针对性的引导、教学过程中教师能深入了解学生想法、教学过程中教师能补充讲解最新进展、整体上教师的角色扮演是称职的方面的调查问卷分数均显著高于对照组,差异均有统计学意义;实验组在教学过程中教师没有过多表达他自己的意见调查问卷分数显著低于对照组,差异有统计学意义。结论案例式教学法在中医老年医学研究生临床教学中应用,可提高学生的理论成绩和操作成绩,提高学生对自我及带教老师的满意度,引起学生的好奇心及培养创新性思维,加深学生对中医老年病学的理解和掌握,这种带教模式值得进一步研究和推广。

关键词：案例式教学法中医老年病中医老年医学研究生临床带教教学效果

基于队列多重随机对照试验的中医药临床评价创新方法及适用性评价方法的探索构建

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中华中医药杂志 2024年第1期39卷 272-278页

作者：吕健刘光宇赵晓晓刘征堂黄悦王慧婵付建华谢雁鸣中国中医科学院西苑医院国家药物临床试验机构北京100091 中国中医科学院西苑医院中药临床研究与评价重点实验室北京100091 中国中医科学院西苑医院国家中医心血管病临床医学研究中心北京100091 中国中医科学院中医临床基础医学研究所北京100700 中国中医科学院西苑医院老年病科北京100091

2.19年中国科协发布了2.个重大科学问题和工程技术难题,其中之一为“中医药临床疗效评价创新方法与技术”。《“十四五”中医药发展规划》提出要加强中医药临床疗效评价研究。中医药临床疗效评价创新方法与技术是一个亟待解决的关键问题... 详细信息

2.19年中国科协发布了2.个重大科学问题和工程技术难题,其中之一为“中医药临床疗效评价创新方法与技术”。《“十四五”中医药发展规划》提出要加强中医药临床疗效评价研究。中医药临床疗效评价创新方法与技术是一个亟待解决的关键问题。2.10年,BMJ杂志首次提出“队列多重随机对照试验(cmRCT)”,其作为新兴的实用性临床试验设计方法,具有招募效率高、人群代表性较好、节省资源等优势。文章通过梳理cmRCT相关研究,创新性融合倾向性评分匹配(PSM)、广义线性混合模型(GLMM),以处理混杂偏倚与重复测量问题,初步构建一套基于cmRCT的中医药临床评价方法;并构建了适用性评价的基本维度与要素,以期为中医药临床评价创新研究提供新的方法学参考。

关键词：队列多重随机对照试验适用性评价倾向性评分匹配法重复测量分析模型临床评价创新方法

Effects of substrate and transfer on CVD-grown graphene over sapphire-induced Cu films

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Science China Chemistry 2014年第6期57卷 895-901页

作者： HU BaoShan WEI ZiDong AGO Hiroki JIN Yan XIA MeiRong LUO zhengtang PAN QingJiang LIU YunLing School of Chemistry and Chemical Engineering Chongqing University Institute for Materials Chemistry and Engineering Kyushu University Department of Chemical and Biomolecular Engineering Hongkong University of Science and Technology Key Laboratory of Functional Inorganic Material Chemistry Ministry of EducationHeilongjiang University State Key Laboratory of Inorganic Synthesis and Preparative Chemistry College of ChemistryJilin University

We differentiated the effects of Cu films deposited on single crystalline a-,r-,and c-plane sapphire substrates upon graphene films synthesized with atmospheric pressure chemical vapor deposition(CVD).The data illustrate that the realization of high-crystalline Cu film is dependent not only on the crystallinity of underlying substrate,but also on the symmetric match of crystallographic geometry between metal film and *** also systematically investigated the effects of PMMA removal on the Raman ID/IG and IG/I2. values of transferred *** results reveal that different PMMA removal methods do not alter the ID/IG values;instead,the residue of PMMA increases the IG/I2. values and the thermal decomposition of PMMA leads to higher IG/I2. values than the removal of PMMA with *** effects of PMMA removal on variations of the Raman spectra are also discussed.

关键词： graphene CVD growth sapphire substrate crystallographic match transfer Raman spectrum

Synthesis of hexagonal boron nitrides by chemical vapor deposition and their use as single photon emitters

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Nano Materials Science 2021年第3期3卷 291-312页

作者： Hongwei Liu Chae Young You Jingwei Li Patrick Ryan Galligan Jiawen You Zhenjing Liu Yuting Cai zhengtang Luo Department of Chemical and Biological Engineering the Hong Kong University of Science and TechnologyClear Water BayKowloon999077Hong Kong

Two-dimensional(2.)hexagonal boron nitride(hBN),due to its extraordinary thermal,chemical,and optical properties,has arisen as an enticing material for the research community to explore for various applications,including the use of site defects in hBN as single photon emitters(SPEs).In this review,we systematically summarize recent advanced strategies towards the controllable synthesis of 2. hBN using chemical vapor deposition,towards a full control of the domain size,orientation,morphology,layer number,and stacking order,***,we review the underlying mechanisms for single photon emission(SPE)in hBN and methods to selectively generate and tune the ***(e.g.,carbon substituted defects)are discussed for the potential use as emission *** finally give an outlook of future challenges and opportunities on desirable hBN synthesis and further investigation of SPEs in hBN,targeting to utilize hBN as single photon emitters in an industrial scale.

关键词： hBN CVD Controllable synthesis Single photon emission