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The developmental trend of labrum and median eyes of Orsten-type preserved Phosphatocopina (Crustacea)

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Science china earth sciences 2010年第1期53卷 18-26页

作者： liu zheng 1,2.& dong xiping 1,2.1 school of earth and space sciences,peking university,beijing 100871,china 2 State Key Laboratory of Palaeobiology and Stratigraphy,Nanjing Institute of Geology and Palaeontology,Chinese Academy of sciences,Nanjing 210008,china 1. school of earth and space sciences Peking University Beijing 100871 China2. State Key Laboratory of Palaeobiology and Stratigraphy Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences Nanjing 210008 China

The Phosphatocopina (Crustacea,Arthropoda) is an important group of 'Orsten-type' preserved *** is resolved as the sister-group of *** we study the labrum,the median eyes,and the inner lamella of Phosphatocopina based on the selected specimens respectively from western Hunan,South china,and *** labrum characters of different species exhibit interspecific *** ratio of labrum length/shield length is significant to the reconstruction of the ontogeny of *** labrum characters should be introduced to the diagnosis of *** the earliest growth stage,the median eyes were inconspicuous,almost as flat as the other area of the ***,with the growth of the individuals they became *** were two obviously concave structures on the ventral side of the hypostome in later stages,which were the positions where the median eyes should have been *** addition,the two modes of preservation of the inner lamella,i.e.,that of shrinking and that of bulging up,are interpreted as the preservational artifact herein.

关键词： Phosphatocopina Crustacea Orsten-type preservation morphology ontogeny Cambrian South china Sweden

New hybrid algorithm for land surface temperature retrieval from multiple-band thermal infrared image without atmospheric and emissivity data inputs

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International Journal of Digital earth 2020年第12期13卷 1430-1453页

作者： Huazhong Ren Jiaji dong Rongyuan liu Yitong zheng Jinxin Guo Shanshan Chen Jing Nie Yan Zhao Institute of Remote Sensing and Geographic Information System School of Earth and Space SciencesPeking UniversityBeijingPeople’s Republic of China china Aero Geophysical Survey and Remote Sensing Center for Natural Resources BeijingPeople’s Republic of China china Translation Telecommunications and Information Center BeijingPeople’s Republic of China

Land surface temperature(LST)retrieval from thermal infrared(TIR)remote sensing image requires atmospheric and land surface emissivity(LSE)data that are sometimes *** overcome this problem,a hybrid algorithm is developed to retrieve LST without atmospheric correction and LSE data input,by combining the split-window(SW)and temperature–emissivity separation(TES)*** SW algorithm is used to estimate surface-emitting radiance in adjacent TIR bands,and such radiance is applied to the TES algorithm to retrieve LST and *** hybrid algorithm is implemented on five TIR bands of the Advanced spaceborne Thermal Emission and Reflection Radiometer(ASTER).Analysis shows that the hybrid algorithm can estimate LST and LSE with an error of 0.5–1.5 K and 0.007–0.020,***,the LST error of the hybrid algorithm is equivalent to that of the original ASTER TES algorithm,involving 1%–2%uncertainty in atmospheric *** hybrid algorithm is validated using ground-measured LST at six sites and ASTER LST products,indicating that the temperature difference between the ASTER TES algorithm and the hybrid algorithm is 1.4 K and about 2.5–3.5 K compared to the ground ***,the hybrid algorithm is applied to at two places.

关键词： Land surface temperature and emissivity TES algorithm split-window algorithm hybrid algorithm

Methane formation from CaCO_3 reduction catalyzed by high pressure

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Chinese Chemical Letters 2008年第4期19卷 475-478页

作者： Jin Yang Chen Lu Jiang Jin Jun Ping dong Hai Fei zheng Gui Yang liu school of Environmental and Chemical Engineering Shanghai UniversityShanghai 201800China school of sciences Shanghai UniversityShanghai 200436China school of the earth and space sciences Peking UniversityBeijing 100871China

Under high pressures of several giga-pascals using hydrothermal diamond anvil cell,methane generated directly from CaCO3 reduction in gold-lined chamber is in situ measured by Raman spectroscopy at the temperature of 550℃ Fhe reducing agents include FeO,SiO and natural fayalite（Fe2SiO4）,and the resource of hydrogen are water and natural serpentine（Mg3Si2O5（OH）4）. The study demonstrates the existence of abiogenic formation of methane under high pressures in the earth＇s interior and that the application of high pressure to catalyze multicomponent reactions is a very promising method.

关键词： CaCO3 reduction High pressure Methane Raman spectroscopy

A Review of Atmospheric Electricity Research in china from 2.19 to 2022

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Advances in Atmospheric sciences 2023年第8期40卷 1457-1484页

作者： Weitao LYU dong zheng Yang ZHANG Wen YAO Rubin JIANG Shanfeng YUAN dongxia liu Fanchao LYU Baoyou ZHU Gaopeng LU Qilin ZHANG Yongbo TAN Xuejuan WANG Yakun liu Shaodong CHEN Lyuwen CHEN Qingyong LI Yijun ZHANG State Key Laboratory of Severe Weather Chinese Academy of Meteorological SciencesBeijing 100081China Laboratory of Lightning Physics and Protection Engineering Chinese Academy of Meteorological SciencesBeijing 100081China Key Laboratory of Middle Atmosphere and Global Environment Observation Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Key Laboratory of Transportation Meteorology of china Meteorological Administration Nanjing Joint Institute for Atmospheric SciencesNanjing 210041China Chinese Academy of sciences Key Laboratory of Geospace Environment School of Earth and Space SciencesUniversity of Science and Technology of ChinaHefei 230026China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD) Nanjing University of Information Science&TechnologyNanjing 210044China Department of Electrical Engineering Shanghai Jiao Tong UniversityShanghai 200030China Institute of Tropical and Marine Meteorology China Meteorological AdministrationGuangzhou 510641China beijing Key Lab of Transportation Data Analysis and Mining Beijing Jiaotong UniversityBeijing 100044China Department of Atmospheric and Oceanic sciences and Institute of Atmospheric sciences Fudan UniversityShanghai 200438China

Atmospheric electricity is composed of a series of electric phenomena in the *** advances in atmospheric electricity research conducted in china have been achieved in recent *** this paper,the research progress on atmospheric electricity achieved in china during 2.19-22 is reviewed focusing on the following aspects:(1)lightning detection and location techniques,(2)thunderstorm electricity,(3)lightning forecasting methods and techniques,(4)physical processes of lightning discharge,(5)high energy emissions and effects of thunderstorms on the upper atmosphere,and(6)the effect of aerosol on lightning.

关键词： atmospheric electricity thunderstorm lightning lightning detection lightning physics

寒武纪化石胚胎 Markuelia 的肌肉组织

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北京大学学报（自然科学版） 2021年第2期57卷 390-394页

作者：刘腾段佰川刘建波董熙平北京大学地球与空间科学学院北京100871 自然资源部第一海洋研究所海洋地质与成矿作用重点实验室青岛266061

利用同步加速器辐射X射线断层显微技术(SRXTM),研究湖南省王村化石库的化石胚胎Markuelia hunanensis。所研究的标本保存了头部和尾部表皮下的栅栏状结构,对这些结构进行三维重建后,发现栅栏结构为环形,呈两侧对称状排列。将头部和尾部... 详细信息

利用同步加速器辐射X射线断层显微技术(SRXTM),研究湖南省王村化石库的化石胚胎Markuelia hunanensis。所研究的标本保存了头部和尾部表皮下的栅栏状结构,对这些结构进行三维重建后,发现栅栏结构为环形,呈两侧对称状排列。将头部和尾部的栅栏结构分别解释为可能的咽部和尾刺基部的肌肉组织。对可能的肌肉组织结构的进一步研究表明,Markuelia hunanensis最早的胚后阶段可能是小型底栖动物,生活在泥砂缝隙之间,并且可能是活跃的捕食者。

关键词：化石胚胎软组织解剖学肌肉组织 Markuelia 寒武纪

陕西汉南毕机沟钒钛磁铁矿锆石U-Pb年代学及其意义

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地球学报 2017年第4期38卷 505-512页

作者：陈龙耀崔建军刘晓春曲玮李淼郑光高李东东张海峰刘林中国地质科学院地质力学研究所北京100081 北京大学地球科学与空间学院北京100871 陕西省地质矿产勘查开发总公司第二分公司陕西汉中723000 陕西省矿产资源勘查与综合利用重点实验室陕西西安710054

毕机沟钒钛磁铁矿位于扬子板块北缘汉南杂岩的西北部,是基性-超基性杂岩体分异演化的产物。矿区范围出露的岩石主要包括橄长岩、辉长岩、辉长闪长岩和闪长岩,具有明显岩相分带和韵律旋回特征。目前,已发现的多个钒钛磁铁矿体均位于基性... 详细信息

毕机沟钒钛磁铁矿位于扬子板块北缘汉南杂岩的西北部,是基性-超基性杂岩体分异演化的产物。矿区范围出露的岩石主要包括橄长岩、辉长岩、辉长闪长岩和闪长岩,具有明显岩相分带和韵律旋回特征。目前,已发现的多个钒钛磁铁矿体均位于基性岩-超基性杂岩体的辉长岩相带内。本次研究对毕机沟矿区的含矿辉长岩和穿切含矿辉长岩的花岗岩脉进行了原位微区LA-MC-ICPMS锆石U-Pb定年,获得两者的侵位时间分别为(783±4)Ma(MSWD=0.09)和(759±4)Ma(MSWD=1.50),结果表明毕机沟钒钛磁铁矿的成矿时代大约为783 Ma,但不晚于759 Ma。结合前人区域成果资料,毕机沟含钒钛磁铁矿的基性-超基性杂岩体与该区新元古代大规模具岛弧性质的基性-超基性杂岩体的形成时代相近,我们认为毕机沟钒-钛磁铁矿可能形成于活动型大陆边缘环境。

关键词：毕机沟汉南基性-超基性杂岩体钒钛磁铁矿锆石U-Pb年龄

The nearest neutron star candidate in a binary revealed by optical time-domain surveys

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Science china(Physics,Mechanics & Astronomy) 2023年第12期66卷 184-202页

作者： Ling-Lin zheng Mouyuan Sun Wei-Min Gu Tuan Yi Zhi-Xiang Zhang Pei Wang Junfeng Wang Jianfeng Wu Shan-Shan Weng Song Wang Sen-Yu Qi Jia Zhang Chun-Qian Li Jian-Rong Shi Yong Shao Xiang-dong Li Jin-Bo Fu Fan Yang Zhongrui Bai Yu Bai Haotong Zhang Jifeng liu Department of Astronomy Xiamen UniversityXiamen 361005China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Institute for Frontiers in Astronomy and Astrophysics Beijing Normal UniversityBeijing 102206China Department of Physics Institute of Theoretical PhysicsNanjing Normal UniversityNanjing 210023China Yunnan Observatories Chinese Academy of SciencesKunming 650216China College of Astronomy and space Science University of Chinese Academy of SciencesBeijing 100049China school of Astronomy and space Science Nanjing UniversityNanjing 210023China Key Laboratory of Modern Astronomy and Astrophysics Nanjing UniversityNanjing 210023China

The near-earth(within~100 pc)supernova explosions in the past several million years can cause the global deposition of radioactive elements(e.g.,60Fe)on *** remnants of such supernovae are too old to be easily *** is therefore of great interest to search for million-year-old near-earth neutron stars or black holes,the products of ***,neutron stars and black holes are challenging to find even in our Solar neighbourhood if they are not radio pulsars or X-ray/γ-ray *** we report the discovery of one of the nearest(127.7±0.3 pc)neutron star candidates in a detached single-lined spectroscopic binary LAMOST J235456.73+335625.9(hereafter J2354).Utilizing the time-resolved ground-based spectroscopy and space photometry,we find that J2354 hosts an unseen compact object with M_(inv)being 1.4-1.6 M_(⊙).The follow-up Swift ultraviolet(UV)and X-ray observations suggest that the UV and X-ray emission is produced by the visible star rather than the compact ***,J2354 probably harbours a neutron star rather than a hot ultramassive white ***-hour exceptionally sensitive radio follow-up observations with Five-hundred-meter Aperture Spherical radio Telescope fail to reveal any pulsating radio signals at the 6σflux upper limit of 12.5μ***,the neutron star candidate in J2354 can only be revealed via our time-resolved ***,the distance between J2354 and our earth can be as close as~50 pc around 2.5 million years(Myrs)ago,as revealed by the Gaia *** discovery demonstrates a promising way to unveil the hidden near-earth neutron stars in binaries by exploring the optical time domain,thereby facilitating understanding of the metal-enrichment history in our Solar neighbourhood.

关键词： neutron stars binary stars stellar evolution

甚低频台站信号对地球内辐射带和槽区能量电子的散射效应分析

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物理学报 2021年第14期70卷 399-409页

作者：刘阳希子项正郭建广顾旭东付松周若贤花漫朱琪易娟倪彬彬武汉大学电子信息学院武汉430072 中国气象局国家空间天气监测预警中心北京100081 中国科学院比较行星学卓越创新中心合肥230026

人工地面甚低频台站发射的10-30 kHz信号主要在地球-低电离层波导传播,部分能量会泄露进入内磁层,进而会影响近地空间中高能电子的动态变化过程.本文详细研究了NWC,NAA和DHO38三个人工甚低频台站信号对内辐射带和槽区高能电子的散射作用... 详细信息

人工地面甚低频台站发射的10-30 kHz信号主要在地球-低电离层波导传播,部分能量会泄露进入内磁层,进而会影响近地空间中高能电子的动态变化过程.本文详细研究了NWC,NAA和DHO38三个人工甚低频台站信号对内辐射带和槽区高能电子的散射作用.基于准线性理论,分别计算了三个甚低频台站信号单独和共同作用时对高能电子的弹跳平均投掷角扩散系数,并进一步利用Fokker-Planck扩散方程模拟内辐射带及槽区的高能电子在200 d内的动态演化过程.结果表明,在低L-shell(L≤1.8),NWC台站信号对电子的损失占主导作用,可以使能量在100 keV附近、投掷角小于60°的电子出现明显损失;在较高的L-shell(2.2≤L≤2.7),主要是NAA和DHO38台站信号占主导作用,可以使能量小于20 keV、投掷角小于70°的电子通量显著下降;三个甚低频台站信号对高投掷角(>80°)的电子均无显著影响.

关键词：地球辐射带人工甚低频台站信号波粒相互作用电子投掷角扩散系数

新疆和田地区大理岩型和田玉的形成及致色因素探讨

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岩石矿物学杂志 2018年第6期37卷 1011-1026页

作者：韩冬刘喜锋刘琰张勇郑奋买托乎提.阿不都瓦衣提张红清文茈燊自然资源部珠宝玉石首饰管理中心北京100013 华南理工大学广州学院广东广州510800 中国地质科学院地质研究所北京100037 中国地质大学(北京)珠宝学院北京100037 新疆维吾尔自治区和田地区质检局新疆和田848000 北京大学地球科学与空间学院北京100871

采集阿拉玛斯和田玉山料和喀拉喀什河(墨玉河)的和田玉样品,利用显微镜和背散射图像、电子探针等研究手段,结合以往全岩数据对和田玉的形成和致色因素进行了综合分析。研究发现,除透闪石以外,和田玉中还含有大量的绿帘石、透辉石、绿泥... 详细信息

采集阿拉玛斯和田玉山料和喀拉喀什河(墨玉河)的和田玉样品,利用显微镜和背散射图像、电子探针等研究手段,结合以往全岩数据对和田玉的形成和致色因素进行了综合分析。研究发现,除透闪石以外,和田玉中还含有大量的绿帘石、透辉石、绿泥石、锆石、磷灰石、尖晶石、石榴石、重晶石、阳起石、闪锌矿、磁黄铁矿、石墨、方解石和氢氧化铁等多种副矿物; Cr、Ni含量(100×10-6)及Mg/(Mg+Fe2+)-Si投点显示这些样品均属于大理岩型软玉(和田玉)。全岩及其微区成分分析结果显示,从白玉(TFe_2O_3=0. 33%～1. 42%)、青白玉(TFe_2O_3=0. 43%～0. 96%)至青玉(TFe_2O_3=0. 77%～3. 97%),TFe_2O_3含量逐渐增加,而且所有样品的Cr和Ni含量都分别低于60×10-6和20×10-6,说明从白玉、青白玉至青玉,颜色的加深与透闪石中铁元素含量逐渐增加有关。墨玉的颜色主要与透闪石集合体中的石墨和Fe(OH)3等细脉大量出现有关。为深入研究和田玉的致色因素,同时采集了加拿大的碧玉样品进行对比,发现同样主要为透闪石组成的加拿大碧玉,除Fe外,还含有大量的Cr元素(1 400×10-6～5 100×10-6),碧玉的颜色鲜艳与透闪石C位中含有0. 01～0. 03 a. p. f. u.的Cr有关,而和田玉中Cr含量较低,在C位中几乎为0。通过野外观察和岩相学分析认为,含和田玉的镁质矽卡岩的形成经历了接触变质、接触交代变质和硫化物阶段,主要通过交代镁质大理岩、透辉石、绿帘石等矿物形成,而和田玉的主要形成机制是多期次的细粒透闪石交代粗粒透闪石。

关键词：和田玉透闪石新疆致色因素和田地区