δ^(13)C_(org) perturbations preserved by the interglacial Datangpo Formation in South China with implications for stratigraphic correlation and carbon cycle

Palaeoclimatic and palaeoenvironmental reconstructions of the Cryogenian Period have attracted attention in relation to the debated“Snowball Earth”hypothesis and the early evolution of metazoan life.The carbon cycle and redox conditions of the Sturtian-Marinoan non-glacial interval have been subjected to much controversy in the past decades because of the lack of a high-resolution stratigraphic correlation scheme.As one of the typical Sturtian-Marinoan interglacial deposits,the Datangpo Formation was widely distributed in South China with shales continuously deposited.The previous zircon dating data of the Datangpo Formation provide important ages for global constrain of the Sturtian-Marinoan non-glacial interval.Here we present a high-resolution straitigraphic study of the organic carbon isotopes of the Datangpo Formation from a drill core section in northern Guizhou Province.Based on measured episodicδ^(13)C_(org) perturbations,three positive shifts and three negative excursions are identified.Aδ^(13)C_(org)-based chemostratigraphic correlation scheme is proposed herein that works well for the Datangpo Formation regionally.Meanwhile,theδ^(13)C_(org) vertical gradients changed dynamically throughout the formation.This discovery implies that a significant ocean circulation overturn might have occurred in the upper Datangpo Formation,coinciding with the potential oxygenation.

The Jiao Tong University Spectroscopic Telescope Project

The Jiao Tong University Spectroscopic Telescope(JUST)is a 4.4-meter f/6.0 segmented-mirror telescope dedicated to spectroscopic observations.The JUST primary mirror is composed of 18 hexagonal segments,each with a diameter of 1.1 m.JUST provides two Nasmyth platforms for placing science instruments.One Nasmyth focus fits a field of view of 10′and the other has an extended field of view of 1.2°with correction optics.A tertiary mirror is used to switch between the two Nasmyth foci.JUST will be installed at a site at Lenghu in Qinghai Province,China,and will conduct spectroscopic observations with three types of instruments to explore the dark universe,trace the dynamic universe,and search for exoplanets:(1)a multi-fiber(2000 fibers)medium-resolution spectrometer(R=4000-5000)to spectroscopically map galaxies and large-scale structure;(2)an integral field unit(IFU)array of 500 optical fibers and/or a long-slit spectrograph dedicated to fast follow-ups of transient sources for multi-messenger astronomy;(3)a high-resolution spectrometer(R~100000)designed to identify Jupiter analogs and Earth-like planets,with the capability to characterize the atmospheres of hot exoplanets.

Formation and evolution of the South China Sea since the Late Mesozoic:A review

The existing genetic models of the South China Sea(SCS)include an extrusion model of the Indochina Peninsula,a back-arc extension model,and a subduction and dragging model of the Proto-South China Sea(PSCS).However,none of these models has been universally accepted because they do not fully match a large number of geological phenomena and facts.By examining the regional tectonics and integrating them with measured data for the SCS,in this study,a back-arc spreading-sinistral shear model is proposed.It is suggested that the SCS is a back-arc basin formed by northward subduction of the PSCS and its formation was triggered by left-lateral strike-slip motion due to the northward drift of the Philippine Sea Plate.The left-lateral strike-slip fault on the western margin caused by the Indo-Eurasian collision changed the direction of the Southwest Sub-basin's spreading axis from nearly E–W to NE–SW,and subduction retreat caused the spreading ridge to jump southward.This study summarizes the evolution of the SCS and adjacent regions since the Late Mesozoic.

Tectonic-thermal history and hydrocarbon potential of the Pearl River Mouth Basin,northern South China Sea:Insights from borehole apatite fission-track thermochronology

The Pearl River Mouth Basin(PRMB)is one of the most petroliferous basins on the northern margin of the South China Sea.Knowledge of the thermal history of the PRMB is significant for understanding its tectonic evolution and for unraveling its poorly studied source-rock maturation history.Our investigations in this study are based on apatite fission-track(AFT)thermochronology analysis of 12 cutting samples from 4 boreholes.Both AFT ages and length data suggested that the PRMB has experienced quite complicated thermal evolution.Thermal history modeling results unraveled four successive events of heating separated by three stages of cooling since the early Middle Eocene.The cooling events occurred approximately in the Late Eocene,early Oligocene,and the Late Miocene,possibly attributed to the Zhuqiong II Event,Nanhai Event,and Dongsha Event,respectively.The erosion amount during the first cooling stage is roughly estimated to be about 455-712 m,with an erosion rate of 0.08-0.12 mm/a.The second erosion-driven cooling is stronger than the first one,with an erosion amount of about 747-814 m and an erosion rate between about 0.13-0.21 mm/a.The erosion amount calculated related to the third cooling event varies from 800 m to 3419 m,which is speculative due to the possible influence of the magmatic activity.

基于工程参数变化趋势异常诊断的卡钻实时预警方法

川南工区是中石化重点页岩气勘探开发工区,该工区地层压力系数高、钻井地质条件苛刻,导致该工区钻井复杂、故障频发,其中卡钻故障最为突出,严重制约了川南页岩气的安全高效开发。现有卡钻识别技术存在监控信息综合利用能力差、风险预警不及时、主观性强等问题。本文通过分析钻井作业过程中卡钻故障的专家知识判断,确定了卡钻风险对应的关键表征参数,并研究了卡钻发生位点的关键表征参数的变化趋势,得到了相应的变化规律;在此基础上建立了基于工程参数变化趋势异常诊断的卡钻实时预警方法。选取WY-XX井为实例进行分析,软件预警结果与实际井下风险相吻合,验证了模型的准确性和可靠性,准确率达83%。

Optical system research of multi-object fiber spectroscopic survey telescope

In the first part of this paper,four different Cassegrain optical systems with their correctors are designed and studied for multi-object fiber slit spectroscopic survey.The aperture in 6.5 m and field of view 3°are taken for these optical systems.Assuming observation wavelength range is 0.365-0.95μm,the maximum zenith distance for observing is 60°,the maximum diameter of these lenses is 1.66 m,the altitude of the telescope site is 2500 m,two correctors are composed of 4-piece lenses and the other two are 5-piece lenses.The results obtained are:f-ratio about 3.7,the image quality for all four systems with EE80D≤0.60″,the linear diameter of the focal surface is about 1.2 m and 11 000 fibers can be set on it.Considering the limit of size of fused silica and optical glass,the maximum diameter for lens is about 1.7 m.Such a 6.5 m telescope is about the largest one if using the above correctors.Considering the multiobject spectroscopic survey is greatly important,we also studied some telescope optical systems having their aperture near or larger than 10 m used for the multi-object fiber spectroscopic survey.Such ideas are introduced in the last section of this paper.

Deep structural research of the South China Sea: Progresses and directions

The South China Sea(SCS)is the hotspot of geological scientific research and nature resource exploration and development due to the potential for enormous hydrocarbon resource development and a complex formation and evolution process.The SCS has experienced complex geological processes including continental lithospheric breakup,seafloor spreading and oceanic crust subduction,which leads debates for decades.However,there are still no clear answers regarding to the following aspects:the crustal and Moho structure,the structure of the continent-ocean transition zone,the formation and evolution process and geodynamic mechanism,and deep processes and their coupling relationships with the petroliferous basins in the SCS.Under the guidance of the“Deep-Earth”science and technology innovation strategy of the Ministry of Natural Resources,deep structural and comprehensive geological research are carried out in the SCS.Geophysical investigations such as long array-large volume deep reflection seismic,gravity,magnetism and ocean bottom seismometer are carried out.The authors proposed that joint gravitymagnetic-seismic inversion should be used to obtain deep crustal information in the SCS and construct high resolution deep structural sections in different regions of the SCS.This paper systematically interpreted the formation and evolution of the SCS and explored the coupling relationship between deep structure and evolution of Mesozoic-Cenozoic basins in the SCS.It is of great significance for promoting the geosystem scientific research and resource exploration of the SCS.

Two suggested configurations for the Chinese space telescope

China will establish a 2-meter space-based astronomical telescope. Its main science goals are performing a sky survey for research about dark matter and dark energy, and high resolution observations. Some experts suggest that this space telescope should be installed inside the Chinese space station. In accord with this suggestion we put forward our first configuration, i.e., to adopt a coude system for this telescope. This coude system comes from the Chinese 2.16 m telescope＇s coude system, which includes a relay mirror so that excellent image quality can be obtained. In our second configuration, we suggest that the whole space telescope fly freely as an independent satellite outside the space station. When it needs servicing, for example, changing in- struments, refilling refrigerant or propellant, etc., this space telescope can fly near or even dock with the core space station. Although some space stations have had accom- panying satellites, the one we propose is a space telescope that will be much larger than other accompanying satellites in terms of weight and volume. On the basis of the second configuration, we also put forward the following idea： the space station can be composed of several large independent modules if necessary.

Mineral Evaluations for Small Scale Miners:A Case for Zimbabwe and South Africa

Since the establishment of geological surveys in Southern Africa a lots of geological information has been systematically stored.Due to the vast amounts of data generated one of the main functions of

The Survey of Ermia mangshanensis Resource in South China Tiger Nature Reserve

In 2007,one living Ermia mangshanensis was found in the Shapingpian area at the junction of South China Tiger Nature Reserve in North Guangdong and Hunan Mangshan National Nature Reserve.To learn more about Ermia mangshanensis resource,the researchers in South China Tiger Nature Reserve in North Guangdong and Hunan Mangshan National Nature Reserve conducted field survey of Ermia mangshanensis in the Shapingpian area during the period 2010- 2012.The results show that there is Ermia mangshanensis in the Shapingpian area of South China Tiger Nature Reserve at the elevation of 800- 1200 m,and the population number is estimated at 48- 80.

清中晚期江南十番与南北戏曲曲艺环流考论

清中晚期是全国戏剧戏曲等艺术形式发生深刻转变的重要时期。兴起于民间、晚明已趋活跃的江南十番得到明清文人诸多描述,呈现出独特的艺术特征,且与戏剧演出有着千丝万缕的关系。江南十番从演出人才、演出曲目到伎艺传承等诸多方面与北京宫廷等演出场域形成南北环流。在戏曲曲艺生态共同体的视角下,对江南及宫廷等南北十番演出情况的考述,深入探考南北曲艺环流下的地方曲艺发展形态,重新审视清代戏曲曲艺生态场域及历史进程,显然具有重要的价值和意义。

南亚季风环流与臭氧时空分布变化关系的特征分析

利用2005年1月至2017年12月搭载在美国环境监测Aura卫星上的臭氧监测仪(Ozone Monitoring Instrument,OMI)数据和NCEP气象资料,在夏季风环流指数定义方法的基础上,重新定义了南亚区域冬季风环流指数,并分别计算了南亚夏季风和冬季风环流指数.结合冬夏两季环流的强弱变化采用相关分析、合成分析和奇异值分解(Singular Value Decomposition,SVD)等方法,探讨了环流异常形势下臭氧的时空变化特征.结果表明:(1)南亚夏季纬向环流与经向环流的强度变化存在一致性,冬季经向环流与纬向环流的强度变化差异较大.(2)南亚臭氧柱总量的季节变化明显,且近13年来臭氧柱总量整体呈上升趋势.(3)夏季(冬季)风环流指数与对流层中低(中高)层和平流层中低层臭氧的相关性显著,但夏季平流层和对流层的相关趋势相反.(4)夏季风环流增强对应青藏高原-伊朗高原上空及南侧区域的上升运动增强,对臭氧的输送作用是造成对流层臭氧分布呈现差异的原因.(5)冬季风环流强弱期的垂直上升和下沉运动中心的移动,以及南北向、东西向气流交汇区的差异是造成臭氧分布不同的原因.

夏季青藏高原O_3低值与南亚高压东西振荡的关系

利用O3监测仪(Ozone Monitoring Instrument,OMI)卫星O3廓线资料和NCEP/NCAR再分析资料,研究了2006年夏季南亚高压偏西型和偏东型条件下青藏高原地区O3垂直结构和变化特征差异。结果表明,夏季南亚高压东西振荡与青藏高原O3分布存在密切的关系,在西(东)部型南亚高压条件下,夏季青藏高原地区大气、对流层和平流层O3柱总量低值中心均偏西(东),位于青藏高原西(东)部,尤其是在南亚高压最强的对流层顶附近,O3低值中心位于南亚高压中心。在西部型南亚高压条件下,低纬度地区含低浓度O3的空气不易到达高原上空,青藏高原上空的O3低值较弱。在东部型南亚高压条件下,从低纬度经中南半岛西北方向孟加拉湾带来的低纬地区低浓度O3,在青藏高原上空堆积,形成O3低值中心。因此,南亚高压东西振荡是影响青藏高原上空O3低值中心变化的重要因素之一,该研究对理解南亚高压东西振荡机制及提高我国气候预测具有一定的指导意义。

中国江南音乐风格二胡作品演奏特点述要

文章以"实践·特点·要领"的论述模式,分别从学习并体验江南音乐的亲历实践、在南北音乐风格比较中把握江南音乐风格二胡作品演奏的一般特点、江南音乐风格二胡作品演奏和学习的五个要领这三个方面展开论述。其演奏要领中梳理阐述了音律、润腔、技术技巧特征与句法等特点,发现并提出演奏中技术技巧相互之间组合的规律,注重与地方语言、人文内涵相关的音乐声腔及风格,以"性格化"、"拟人化"把握作品并提取信息等。进而阐述在演奏中建立"用中国音乐文化诠释二胡作品"的表演美学观念。

论诸宫调与南戏的关系

诸宫调兴起于北宋中期,兴盛于金元之际,对南北曲影响极大。南戏的形成与诸宫调有着密切的联系。在音乐结构方面,南戏基本上承袭了诸宫调的常用曲式:一曲独用、一曲带尾在表演形式方面,二者也有许多相似或相同之处,如某些表演程序和主要伴奏乐器。

南海东部电缆地层测试仪器井下遇卡原因分析与应用

近几年南海东部电缆地层测试仪器在井下作业的遇卡频率越来越高,由此导致的时间损失在一定程度上提高了作业成本,针对该问题,对造成仪器遇卡的主控因素进行分析,认为影响仪器遇卡的原因主要为地质因素、环境因素及综合因素;其中,地质因素包括作业区块、层位及岩性等;环境因素包括井眼尺寸、井斜及泥浆密度等;综合因素包括仪器所在渗透段的位置、仪器外径与井眼尺寸相对大小以及测点井斜、压差等。将该研究成果实际应用于现场作业中,取得了较好的效果,对于提前判断仪器下井作业的风险点并采取相应的措施具有重要意义。

南方GPS软件中的独立网平差方法探讨

探讨了几种常用的GPS独立网平差方法,并结合工程应用说明这些方法在南方GPS软件中的实现。

南水北调东线一期工程蔺家坝泵站安全监测设计

安全监测对水工建筑物的安全运行越来越重要,由于南水北调东线泵站工程的重要性,其安全监测系统必须与之相适应。文章对南水北调东线一期工程蔺家坝泵站安全监测设计作了全面介绍,明确整体设计思想,突出主要监测项目及测点布置,以全面反映土基上大型泵站工程的安全监测设计特点。

“广东音乐”旋法特征探究

广东音乐以句首弱起、装饰音(帽头花)、音型与节奏的重复、音阶进行和模进为主要特征的创作手法。源于粤剧过场音乐和唱腔的广东音乐因时代的不同、社会背景的不同和社会需求的不同,曾吸收和融合了江南丝竹的元素和思维,并借鉴了西洋音乐中的音调与技法,使之成为一种风格独特的地方乐种。

从笙磬、颂磬看古代中国音乐文化

运用文化语言学的理论方法,利用历史文献、考古出土文物,阐释古文献里编磬中笙磬、颂磐的观念,并分析其所承载的音乐文化。古磬最初是单一的特磬,逐步发展为编磬,西周、春秋战国时期成为祭祀活动中的庙堂之乐;战国时期,不晚于汉朝进一步成为雅颂之声的载体,至今仍是佛教寺庙祭祀活动中不可或缺的法器和宗教乐器。