A ca. 2.2Ga Acidic Magmatic Event at the Northern Margin of the Yangtze Craton: Evidence from U‐Pb Dating and Hf Isotope Analysis of Zircons from the Kongling Complex     

XU Daliang  WEI Yunxu  PENG Lianhong  DENG Xin  HU Kun  LIU Hao 《《地质学报》英文版》2018,92(2):872-873

正Objective The Yangtze craton experienced Paleoproterozoic collisional orogeny at ca.1.95–2.0 Ga and post-orogenic extensional events at ca.1.85 Ga related to amalgamation of the Columbia(Nuna)supercontinent(Zhao and Cawood,2012).A ca.2.15 Ga suprasubduction zone ophiolitic mélange was recongized in the ArcheanPaleoproterozoic Kongling Complex of the northern  相似文献   

A New 40Ar-39Ar Dating Result of Volcanic Activities in the Mid-Late Miocene in the Liuhe Region, Nanjing City     

WU Kungang  WU Zhonghai  ZHAO Xitao  ZHOU Chunjing  YANG Xiaodong  GAO Kun 《《地质学报》英文版》2018,92(5):2041-2042

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Isolation,Identification, and Quantitative Determination of Saponin in Apostichopus japonicus by HPLC-DAD     

LIU Guiying  WANG Xuda  GE Kun  WU Jinhao  WANG Zhaohui  DU Jing  SONG Lun  ZHOU Zunchun 《中国海洋大学学报(英文版)》2022,21(2):473-478

Apostichopus japonicus is an important invertebrate that is widely used as a tonic food in Asian countries.The purpose of this study is to purify and identify a class of compound,the saponins,from the body wall of A.japonicus,and to establish a new me-thod to determine the quantity of saponins in the sea cucumber.In this study,the saponins of A.japonicus,cladoloside A(CA),were ob-tained from 80%ethanol extract by column chromatography for the first time and were characterized using the spectral method.The resulting purified saponins were then profiled using ¹HNMR,¹³CNMR,and ESI-MS,which revealed the CA molecular formula of C₅₃H₈₂O₂ and contained a triterpenoid backbone,a methylglucopyranosyl moiety,a quinovopyranosyl,and two xylopyranosyls.A me-thod for the quantitative determination of CA,comprising microwave-assisted extraction,high-performance liquid chromatography,and diode array detector method,was established.Extraction efficiency was optimized by changing microwave power,extraction sol-vent,volume,time,and temperature.Results showed that under the optimum conditions(extraction time of 10 min,temperature of 45℃,and solvent of 25 mL 70%ethanol under 400 W),the detection limit of CA was 0.0015 mg mL^?1,and the recoveries of CA from samples at spiking levels of 10,20,and 50μg g^?1 ranged from 90.1%-104%.The proposed method was successfully applied to ana-lyze the saponins in different tissues of A.japonicus collected in different seasons.The method developed in this study can provide quantitative technical support for the quality control of A.japonicus.  相似文献   

Influence of Wave Direction on the Dynamic Response of A Submarine Equipment Launch and Recovery System     

JIN Yong-ping  XIE Kun  LIU Guang-ping  WAN Bu-yan  PENG You-duo 《中国海洋工程》2022,36(1):144-154

A launch and recovery system for a seafloor drill was studied using a dynamic model that considered the influences of seawater resistance and the elastic deformation of the cable based on the lumped mass method. The influence of wave direction angle on heave, roll, and pitch motions of the ship was analyzed, and those motion characteristics were then used to assess the tension response of the armored umbilical cable at the lifting point under different wave direction angles. By analyzing the dif...  相似文献   

Variable Stars in the 50BiN Open Cluster Survey. Ⅲ. NGC 884     

Lin-Hong Wang  Qian-Heng Nie  Kun Wang  Xiao-Dian Chen  Chun-Guang Zhang  Li-Cai Deng  Xiao-Bin Zhang  Tian-Lu Chen 《天文和天体物理学研究(英文版)》2024,(2):38-47

Open clusters are the basic building blocks that serve as a laboratory for the study of young stellar populations in the Milky Way.Variable stars in open clusters provide a unique way to accurately probe the internal structure,temporal and dynamical evolutionary stages of individual stars and the host cluster.The most powerful tool for such studies is time-domain photometric observations.This paper follows the route of our previous work,concentrating on a photometric search for variable stars in...  相似文献   

Method development for estimating soil organic carbon content in an alpine region using soil moisture data     

Qi LUO  Kun YANG  Yingying CHEN  Xu ZHOU 《中国科学:地球科学(英文版)》2020,63(4):591-601

The high soil organic carbon(SOC) content in alpine meadow can significantly change soil hydrothermal properties and further affect the soil temperature and moisture as well as the surface water and energy budget. Therefore, this study first introduces a parameterization scheme to describe the effect of SOC content on soil hydraulic and thermal parameters in a land surface model(LSM), and then the SOC content is estimated by minimizing the difference between observed and simulated surface-layer soil moisture. The accuracy of the estimated SOC content was evaluated using in situ observation data at a soil moisture and temperature-measuring network in Naqu, central Tibetan Plateau. Sensitivity experiments show that the optimum time window for stabilizing the estimation results cannot be shorter than three years. In the experimental area, the estimated SOC content can generally reflect the spatial distribution of the measurements, with a root mean square error of 0.099 m^3 m^-3, a mean bias of 0.043 m^3 m^-3, and a correlation coefficient of 0.695. The estimated SOC content is not sensitive to the temporal frequency of the soil moisture data input. Even if the temporal frequency is as low as that of current soil moisture products derived from passive microwave satellites, the estimation result is still stable. Therefore, by combining a high-quality satellite soil moisture product and a parameter optimization method, it is possible to obtain grid-scale effective parameter values, such as SOC content,for an LSM and improve the simulation ability of the LSM.  相似文献   

Cross-sectional rainfall observation on the central-western Tibetan Plateau in the warm season:System design and preliminary results     

Kun YANG  Yingying CHEN  Lazhu  Changhui ZHAN  Xiaoyan LING  Xu ZHOU  Yaozhi JIANG  Xiangnan YAO  Hui LU  Xiaogang MA  Lin OUYANG  Weihao PAN  Yanghang REN  Changkun SHAO  Jiaxin TIAN  Yan WANG  Hua YANG  Siyu YUE  Ke ZHANG  Dingchi ZHAO  Long ZHAO  Jianhong ZHOU  Mijun ZOU 《中国科学:地球科学(英文版)》2023,(5):1015-1030

The central and western Tibetan Plateau(CWTP)is characterized by harsh environment and strong interactions among the spheres of earth as well as significant changes in climate and water cycles over the past four decades.The lack of precipitation observations is a bottleneck for the study of land surface processes in this region.Over the past six years,we have designed and established two observation transects across the south-north and the west-east in this region to obtain hourly rainfall data ...  相似文献   

综合航空物探方法在金矿勘查中的应用研究--以新疆康古尔塔格地区金矿勘查为例     

吴其 《地质科技情报》1999,18(4)

通过对新疆康古尔塔格地区Ⅵ号和Ⅷ号金矿进行的试验研究,结合测区的地质与地貌的实际情况,确立了空中和地面地球物理测量条件,建立了本区寻找金矿的综合地质-地球物理标志;应用综合找矿标志,圈出了该区金矿远景区10个,经地面查证发现了其中含金矿化蚀变带5处,并确认该区石炭系苦水组地层为新的含矿层.  相似文献   

Improving Airgun Signal Detection with Small-Aperture Seismic Array in Yunnan   总被引：1，自引：1，他引：0  

WANG Weijun  ZHOU Qingyun  KOU Huadong  LIU Guiping  ZHU Hongbo  YAN Kun 《中国地震研究》2019,33(2):248-264

Repeating airgun sources are eco-friendly sources for monitoring the changes in the physical properties of subsurface mediums, but their signals decay quickly and are buried in the noises soon after traveling short distances. Stacking waveforms from different airgun shots recorded by a single seismic station (shot stacking) is the most popular technique to detect weak signals from noisy backgrounds, and has been widely used to process the data of Fixed Airgun Signal Transmission Stations (FASTS) in China. However, shot stacking sacrifices the time resolution in monitoring to recover a qualified airgun signal by stacking many shots at distance stations, and also suffers from persistent local noises. In this paper, we carried out several small-aperture seismic array experiments around the Binchuan FAST Station (BCFASTS) in Yunnan Province,China, and applied the array technique to improve airgun signal detection. The results show that seismic array processing combining with shot stacking can suppress seismic noises more efficiently, and provide better signal-to-noise ratio (SNR) and coherent airgun signals with less airgun shots. This work suggests that the array technique is a feasible and promising tool in FAST to increase the time resolution and reduce noise interference on routine monitoring.  相似文献   

A 3D Geological Model Constrained by Gravity and Magnetic Inversion and its Exploration Implications for the World-class Zhuxi Tungsten Deposit, South China     

YAN Jiayong  Lü Qingtian  QI Guang  FU Guangming  ZHANG Kun  LAN Xueyi  GUO Xin  WEI Jin  LUO Fan  WANG Hao  WANG Xu 《《地质学报》英文版》2020,94(6):1940-1959

The Zhuxi tungsten deposit in Jiangxi Province, South China, contains a total W reserve of about 2.86 Mt at an average grade of 0.54 wt% WO3, representing the largest W deposit in the world. Numerous studies on the metallogeny of the deposit have included its timing, the ore-controlling structures and sedimentary host rocks and their implications for mineral exploration. However, the deep nappe structural style of Taqian–Fuchun metallogenic belt that hosts the W deposit, and the spatial shape and scale of deeply concealed intrusions and their sedimentary host rocks are still poorly defined, which seriously restricts the discovery of new deposits at depth and in surrounding areas of the W deposit. Modern 3D geological modeling is an important tool for the exploration of concealed orebodies, especially in brownfield environments. There are obvious density contrast and weak magnetic contrast in the ore-controlling strata and granite at the periphery of the deposit, which lays a physical foundation for solving the 3D spatial problems of the ore-controlling geological body in the deep part of the study area through gravity and magnetic modeling. Gravity data (1:50000) and aeromagnetic data (1:50000) from the latest geophysical surveys of 2016–2018 have been used, firstly, to carry out a potential field separation to obtain residual anomalies for gravity and magnetic interactive inversion. Then, on the basis of the analysis of the relationship between physical properties and lithology, under the constraints of surface geology and borehole data, human–computer interactive gravity and magnetic inversion for 18 cross-sections were completed. Finally, the 3D geological model of the Zhuxi tungsten deposit and its periphery have been established through these 18 sections, and the spatial shape of the intrusions and strata with a depth of 5 km underground were obtained, initially realizing “transparency” for ore-controlling bodies. According the analysis of the geophysical, geochemical, and geological characteristics of the Zhuxi tungsten deposit, we discern three principles for prospecting and prediction in the research area, and propose five new?exploration?targets in?its?periphery.  相似文献