Two new species of Vestrogothia (Phosphatocopina, Crustacea) of Orsten-type preservation from the Upper Cambrian in western Hunan, South China     

ZHANG HuaQiao  & DONG XiPing  School of Earth  Space Sciences  Peking University  Beijing  China  State Key Laboratory of Palaeobiology  Stratigraphy  Nanjing Institute of Geology  Palaeontology  Chinese Academy of Sciences  Nanjing 《中国科学D辑(英文版)》2009,(6)

Although fossils of Orsten-type preservation represented by Skaracarida and Phosphatocopina were first reported from the Middle and Upper Cambrian in western Hunan, South China in 2005, diversified phosphatocopine species have never been appropriately described and elucidated in terms of their evolutionary relationships. Here, we described two new species of Phosphatocopina, Vestrogothia anterispinata sp. nov. and V. bispinata sp. nov. The evolutionary relationship among all the valid species of Phosphatoco...  相似文献   

Performance of A Combination Process of UV/H2O2/Micro‐Aeration for Oxidation of Dichloroacetic Acid in Drinking Water     

WenHai Chu  N. Y. Gao  Y. Deng 《洁净——土壤、空气、水》2009,37(3):233-238

The decomposition of dichloroacetic acid (DCAA) in water using a UV/H₂O₂/micro‐aeration process was investigated in this paper. DCAA cannot be removed by UV radiation, H₂O₂ oxidation or micro‐aeration alone, while UV/H₂O₂/micro‐aeration combination processes have proved effective and can degrade this compound completely. With initial concentrations of about 110 μg/L, more than 95.1% of DCAA can be removed in 180 min under UV intensity of 1048.7 μW/cm², H₂O₂ dosage of 30 mg/L and micro‐aeration flow rate of 2 L/min. However, more than 30 μg/L of DCAA was left after 180 min by UV/H₂O₂ combination process without micro‐aeration with the same UV intensity and H₂O₂ dosage. The effects of applied UV radiation intensity, H₂O₂ dose, initial DCAA concentration and pH on the degradation of DCAA have been examined in this study. Degradation mechanisms of DCAA with hydroxyl radical oxidation have been discussed. The removal rate of DCAA was sensitive to operational parameters. There was a linear relationship between rate constant k and UV intensity and initial H₂O₂ concentration, which indicated that a higher removal capacity can be achieved by improvement of both factors. A newly found nitrogenous disinfection by‐product (N‐DBP)‐DCAcAm, which has the potential to form DCAA, was easier to remove than DCAA by UV/H₂O₂ and UV/H₂O₂/micro‐aeration processes. Finally, a preliminary cost comparison revealed that the UV/H₂O₂/micro‐aeration process was more cost‐effective than the UV/H₂O₂ process in the removal of DCAA from drinking water.  相似文献   

结构性粘土研究进展   总被引：9，自引：0，他引：9  

刘恩龙  沈珠江  范文 《岩土力学》2005,26(Z1):1-8

通过对结构性粘土的研究,可以掌握天然土受荷过程中的变形破坏过程,从而为考虑土结构性的结构物的设计、地基加固等提供依据。近年来随着高、深和大型建筑的兴建,结构性粘土的研究变得尤为重要。从结构性粘土的微观变形机理、结构性土样的制备、土工特性和数学模型等几个方面,介绍了国内外学者的研究进展,认为进行原位测试、结构性土样的制备及细观结构参数的量测方法、考虑细观结构的数值方法和建立考虑微观变形机理的宏观本构模型是进行结构性土研究的发展方向。  相似文献   

松辽盆地徐家围子断陷深层天然气同位素倒转现象研究   总被引：15，自引：0，他引：15       下载免费PDF全文

黄海平 《地球科学》2000,25(6):617-623

天然气的同位素组成受源岩有机质类型、热演化程度和成藏后的次生变化等多种因素的影响, 其单体烃同位素分布特征是区分各种因素影响程度的地球化学指纹.天然气单体烃同位素通常有随碳数增加而变重的趋势, 而徐家围子深层天然气单体烃同位素倒转现象却比较普遍, 高地温和细菌氧化对于造成该区同位素倒转的可能性不大, 浅层油型气或无机气的混合作用没有充分的地质证据, 同层有机质中不同类型气的混合和盖层微渗漏造成的蒸发分馏作用可能是导致徐家围子断陷深层天然气同位素倒转的主要原因.   相似文献   

西南极利文斯顿岛晚三叠世遗迹化石及其环境意义          下载免费PDF全文

邓希光  郑祥身  刘小汉  杨式溥 《地质科学》2000,35(4):422-431

西南极利文斯顿岛晚三叠世迈尔斯陡崖组形成于海底浊积扇中扇的上、下部分,发育着许多海相遗迹化石.在采集到的样品中鉴定共有15个遗迹属、16个遗迹种,其中有10个可以鉴定到遗迹种、两个比较种,4个只鉴定到遗迹属,未鉴定到遗迹种;并建立了1个新遗迹属及新遗迹种是文献中从未发现的.除新遗迹属种外,其余14个遗迹属,15个遗迹种都曾经在深海相浊积岩内发现过,Belorhaphe、Glockerichnus、Lophoctenium、Rhabdoglyphus、Paleodictyon、Sublorenzinia、Spirophycus、Strobilorhaphe、Tuberculichnus、Cochlichnus等属于浊流前产生在深海相泥岩内的高度分异的雕画迹(Graphoglyptida),它们产于泥岩却保存为上覆砂岩底面的铸型凸起.Fucusopsis和Neonereites却产生在砂岩内代表浊流后形成的沉积后遗迹组合.这些遗迹化石属深水的Nereites遗迹相,为研究区的沉积环境增添了可靠依据.  相似文献   

微细浸染型金矿深源矿质和流体地球化学示踪研究     

Г·Н·卡曼宁  B·H·贡恰罗夫  H·A·戈利亚契夫 《地质与资源》2000,9(2):97-99，104

在宏观和微观地质特征研究基础上,运用硅同位素动力学分馏原理,结合硅质阴极发光分析,论证了微细浸染型金矿的成矿硅质、矿质和流体主要直接来源于上地幔分异或深部循环的超临界流体,并认为这种深部因素可能对形成大型和超大型矿床发挥了重要作用.这对该类型金矿的成因研究及找矿开辟了新的思路.  相似文献   

天祝-古浪5.4级地震前震源区应力场的短临变化特征   总被引：1，自引：0，他引：1  

荣代潞  张元生  李亚荣 《高原地震》2000,(2)

利用矩张量反演方法反演了 1996年 6月 1日天祝 -古浪 5 .4级地震序列的震源机制 ,并与该区小震综合断层面解进行了比较。在此基础上讨论了该地震前后震源区应力场的变化特征。  相似文献   

Significance of ichnofossils to genetic stratigraphy--Examples from the Cretaceous of Alberta, Canada   总被引：1，自引：0，他引：1  

S. George Pemberton  James A. MacEachern  Murray K. Gingras  ZHANG Jianping 《中国科学D辑(英文版)》2000,43(5)

Trace fossils represent both sedimentological and paleontological entities, representing a unique blending of potential environmental indicators in the rock record. Trace fossils and trace fossil suites can be employed effectively to aid in the recognition of various discontinuity types and to assist in their genetic interpretation. Ichnology may be employed to resolve surfaces of stratigraphic significance in two main ways: 1) through the identification of discontinuities using substrate-controlled ichnofacies, and 2) through careful analysis of vertical softground (penecontemporaneous) ichnologic successions (analogous to facies successions). Ichnological analysis is a valuable tool in genetic stratigraphic studies. Integrating the data derived from substrate-controlled ichnofacies with paleoecological data from vertical ichnologic successions greatly enhances the recognition and interpretation of a wide variety of stratigraphic surfaces. When this is coupled with conventional facies analysis and sequence stratigraphy, a powerful approach to the interpretation of the rock record is generated.  相似文献   

辽宁锦州古生物化石和花岗岩国家地质公园地质遗迹特征及其地质背景     

张立军  姬书安  王磊  王梦易 《地球学报》2021,42(5):701-714

本文在系统收集、整理阜新—义县盆地和医巫闾山地区的地质学、古生物学、地貌学和年代地质学资料的基础上,对辽宁锦州古生物化石和花岗岩国家地质公园的地质遗迹景观资源进行了系统总结.进一步的研究揭示了阜新—义县盆地和医巫闾山同属于医巫闾山变质核杂岩系统,阜新—义县盆地的发育、热河生物群兴起与医巫闾山的形成密切相关.这一结论为整...  相似文献   

遗迹化石在层序地层学研究中的应用   总被引：2，自引：0，他引：2  

施振生  杨威  郭长敏  胡斌 《地层学杂志》2008,32(1):79-84

以济阳坳陷古近系沙河街组和塔里木盆地志留系为例,探讨了遗迹化石与层序地层学的关系,表现在3个方面:1)层序界面的识别层序界面位置发育有特征性的受基底控制的遗迹相,且界面上下遗迹组合类型发生变化;2)准层序界面的识别较深水环境中,界面上下生物扰动强度明显差异,界面之下扰动强度较大,扰动指数可达到3,而界面之上几乎没有生物扰动,且在同一准层序内部,由下至上,扰动强度逐渐增大;3)旋回层序的识别:在潮控滨线环境中,单个准层序内部,由下至上,高能环境的Skolithos遗迹组合逐渐变为中低能环境的Planolites-Palaeophycus遗迹组合和低能环境的Cochlichnus-Planolites遗迹组合,由下至上呈现旋回性变化特征。  相似文献