The control of syndepositional faulting on the Eogene sedimentary basin fills of the Dongying and Zhanhua sags, Bohai Bay Basin

CopyrightbyScienceinChinaPress2004Theconfigurationandpredictionofdepositionalsystemsinasedimentarybasinhavelongbeenoneofthemajortasksofbasinanalysisandsedimentarygeologicalresearch.Intermsofsequencestratigraphy,originallyestablishedinstudyoftectonicallytablecontinentalmargins,thesealevelchangehasbeenusedtoeffectivelyinterpretandpredictthedistributionandevolutionofdepositionalsystemsinthesebasins[1,2].Butintectonicallyactivebasins,tectonismmaycontrolpredominatelythearchitectureandevolutionofth…     

消光—小角散射法遥感气溶胶谱分布的实验研究

本文主要论述了采用一台多波长光度计进行消光—小角前向散射的综合探测,并从实验数据反演了北京大气柱气溶胶谱分布,结合天气条件,初步讨论了谱分布的特点。     

冬季台湾海峡210Po和210Pb的分布特征及颗粒物的输出

~(210) Po and ~(210) Pb are increasingly used to constrain particle dynamics in the open oceans, however they are less used in coastal waters. Here, distributions and partitions of ~(210) Po and ~(210) Pb were examined in the Taiwan Strait, as well as their application to quantify particle sinking. Activity concentrations of dissolved ~(210) Po and ~(210) Pb(0.6 μm)ranged from 1.21 to 7.63 dpm/(100 L) and from 1.07 to 6.33 dpm/(100 L), respectively. Activity concentrations of particulate ~(210) Po and ~(210) Pb varied from 1.96 to 36.74 dpm/(100 L) and from 3.11 to 38.06 dpm/(100 L). Overall,particulate ~(210) Po and ~(210) Pb accounted for the majority of the bulk ~(210) Po and ~(210) Pb. 210 Po either in dissolved or particulate phases showed similar spatial patterns to 210 Pb, indicating similar mechanisms for controlling the distributions of ~(210) Po and ~(210) Pb in the Taiwan Strait. The different fractionation coefficients indicated that particles in the Zhemin Coastal Current(ZCC) inclined to absorb 210 Po prior to 210 Pb while they showed an opposite effect in the Taiwan Warm Current(TWC). Based on the disequilibria between ~(210) Po and ~(210) Pb, the sinking fluxes of total particulate matter(TPM) were estimated to range from –0.22 to 3.84 g/(m2·d), showing an overall comparable spatial distribution to previous reported sediment accumulation rates. However, our sinking fluxes were lower than the sedimentation rates, indicating a sediment resuspension in winter and horizontal transport of particulate matter from the Taiwan Strait to the East China Sea.     

Earth fissures in Jiangsu Province,China and geological investigation of Hetang earth fissure

Earth fissures are a geohazard in Jiangsu Province, China. They can be caused by earthquakes and active faults, underground mining, groundwater extraction and landslides. In order to establish a provincial rehabilitation plan in Jiangsu, a range of monitoring programs, surveys, geological investigations and modeling have been implemented or planned. One of the focuses of the project is the land subsidence and earth fissures caused by excessive groundwater withdrawal in Suzhou, Wuxi and Changzhou (Su-Xi-Chang) area, southern Jiangsu Province. Hetang earth fissure within the Su-Xi-Chang area was first reported in 1995 and a series of investigation has been conducted since then. The site investigations and geophysical survey in 1997 have recognized the causative factor as the excessive groundwater drawdown coupled by the underlying bedrock ridge. An open trench excavation in 2007 and a plane strain analysis suggest that Hetang earth fissures may have cracked from the bedrock ridge to ground surface. Geological drilling in 2007 has further confirmed the existence and configuration of the ridge and extracted soil samples for laboratory tests to obtain soil parameters for numerical analyses and modeling of land subsidence and earth fissures in the Su-Xi-Chang area, Jiangsu, China. The laboratory tests are currently in progress and the result of numerical analyses and modeling is expected to be presented in the near future.     

扬子地区晚奥陶世碳酸盐台地淹没事件及其地质意义

碳酸盐岩台地广泛发育及其淹没事件是扬子地区晚奥陶世地层的重要特征之一.基于岩石学、沉积学特征和古生物资料等对扬子地区晚奥陶世碳酸盐岩台地沉积演化、淹没事件及其油气地质意义进行了分析.结果表明:扬子地区晚奥陶世沉积演化分为宝塔一临湘期碳酸盐台地沉积和五峰期深水、浅水陆棚沉积两个阶段;淹没事件开始于五峰初期,主要受控于构造...     

Growth inhibition to three red tide microalgae by extracts of Ulva pertusa

1 INTRODUCTION In recent decades, red tides that induced by in- creasing eutrophication occur frequently in coastal areas worldwide. This has caused serious problems in marine environment, aquaculture industries and human health (Qi et al., 1993; Horner e…     

文登市农村集体建设用地情况的调查

2006年12月至2007年4月，文登市国土资源局结合国土资源部、世界银行“农村集体建设用地管理利用政策研究”项目，从农村集体建设用地流转、农民宅基地管理、小城镇建设用地以及农村集体建设用地整理等4个方面人手，对农村集体建设用地管理开展全面调查。并对调查结果进行了分析研究，提出了文登市农村集体建设用地管理利用的思路。     

地震应变变化的理论量级与最大传递距离关系

为了与实际观测资料对比 ,用线弹性理论位错公式算出了各种断层的地震应变变化并进行了全面、系统的分析 ,归纳了一些特点 ,阐明了理论应变变化量级与其最大传递距离的关系。分析表明 :对于一定震级的地震 ,当断层出露地面、倾角为 4 5°、并且为倾滑运动时 ,一定量级的应变变化传递的距离最长 ;其中一个主应变传递得最远 ,其次为体应变 ,再其次为最大剪应变 ,另一个主应变的最大传递距离最短 ;泊松比和断层的长宽比的变化对应变传递距离的影响极小 ,可以忽略     

New Variable Stars Discovered as By-product of the Beijing Astronomical Observatory Supernova Survey

The Beijing Astronomical Observatory (BAO) 0.6 m telescope has been used for nearby supernova survey in more than 3000 fields, covering a total area of 235 deg2. More than 260000 CCD images have been collected since April 1996, with 45 supernovae discovered. We searched for variables in about 90000 images taken during 1996-1998. For the fields in which long period variables (LPVs) were discovered, we reduced further images taken from 1999 to 2000, for the period estimation. Among the 280000 stars selected from the survey fields, i.e., brighter than 18 mag, we discovered seven new LPVs and reconfirmed three known LPVs. Additionally, we found 146 variable star candidates, and reconfirmed about 20 previously known or suspected objects.