检索结果-南通市图书馆

Palaeoenvironmental setting of lacustrine stromatolites in the Miocene Wudaoliang Group, northern Tibetan Plateau

在线全文

学校读者我要写书评

暂无评论

Journal of Palaeogeography 2019年第3期8卷 270-284页

作者： Ling-Qi Zeng Hai-Sheng Yi Guo-Qing Xia klaus simon Christine Heim Gernot Arp Institute of Sedimentary Geology Chengdu University of Technology Chengdu 610059 Sichuan Province China State Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Chengdu 610059 Sichuan Province China Geoscie nee Center Georg-August-Universitat Gottingen GoldschmidtstraBe 3 37077 Gottingen Germany

Lacustrine stromatolites were widespread in the Miocene Wudaoliang Group(stromatolites of the Wudaoliang Group), northern Tibetan Plateau;but only at one location nearby the Wudaoliang Town, they occurred intensively in thick, laterally traceable beds(Wudaoliang stromatolites). Although deposited in lacustrine environment, the lack of fossils in these rocks hampers determining whether the stromatolites formed in freshwater or saline *** address this problem, and in an attempt to identify criteria to distinguish differences of freshwater and saline conditions, we studied the laminae microfabrics, stable carbon and oxygen isotope ratios, rare earth element patterns and biomarkers of the stromatolites. These stromatolites can be divided into fenestral stromatolites and agglutinated stromatolites. The fabric of fenestral stromatolites is formed by microcrystalline carbonate enclosing spar-cemented, angular crystal traces. Essentially, this fabric is interpreted as pseudomorph after former formed evaporite crystals. Faecal pel ets identical to that of the present-day brine shrimp Artemia, lack of other eukaryotic fossils,and stable isotopic signals point to a shal ow, evaporation-dominated hypersaline lake setting. Covariation of carbon and oxygen isotopes indicates hydrological y closed conditions of the Miocene lake on northern Tibetan ***, if compared to other lacustrine carbonates of the Wudaoliang Group, the high δ13 C values of the investigated Wudaoliang stromatolites reveal an additional photosynthetic effect during the deposition of the ***, although no direct evidence is available from field observations and microfabrics, a positive europium anomaly of Wudaoliang stromatolites indicates that a palaeo-hydrothermal inflow system had existed in the outcrop *** new results favour a hypersaline lake setting subject to hot spring inflow for the Wudaoliang stromatolites, in contrast to earlier interpretations suggesti

关键词： Lacustrine stromatolites Miocene Wudaoliang Group Hypersaline lake Hydrothermal Northern Tibetan plateau

Isotope and REE Characterization of Groundwater Aquifers within the Aquifer Storage and Recovery Programme in Sukhothai (N.-Thailand)

在线全文

学校读者我要写书评

暂无评论

Journal of Water Resource and Protection 2016年第6期8卷 665-686页

作者： Manussawee Hengsuwan Monthon Yongprawat klaus simon Bent T. Hansen Department of Groundwater Resources Bangkok Thailand Geoscience Center Georg-August-University of G&#246ttingen G&#246ttingen Germany Thailand Institute of Nuclear Technology Nakornnayok Thailand

Aquifer Storage and Recovery (ASR) was a pilot project for solving flood and drought problem in the northern part of Chao Phraya River basin, Thailand. This part of Thailand always faces flooding in rainy season and drought during dry season every year. The overexploitation of groundwater during dry season leads to continuously decline of water level in this area. In this project, the excessive surface water during rainy season was stored by injection of this treated surface water through recharge wells into the underground aquifers. This would serve to raise the water level, which can be extracted for use during the dry season. To assess the efficiency of the ASR process some tracers are required. The aim of this study is to prove the suitability of natural tracers to follow up the artificial recharge process;emphasis will be placed on Strontium (Sr) isotopic composition. The results showed that the change in 87Sr/86Sr ratios could be observed during an artificial recharge due to the different isotopic fingerprint of surface water and groundwater. However, the flow direction of the injected water cannot be clearly interpreted because of the limited number of monitoring wells, small distance between each monitoring well and the short duration of injection.

关键词： Sr-Isotope Rare Earth Elements (REE) Aquifer Storage and Recovery (ASR) Thailand

Garnets in leucogranites from the southern margin of North China Craton:Element and Oxygen isotope date

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Garnets in leucogranites from the southern margin of North C...

Niobium-tantalum fractionation during slab subduction: Implications for the formation of continental crust

中国矿物岩石地球化学学会第13届学术年会

作者： Gerhard Wrner Andreas Kronz klaus simon Geowissenschaftliches Zentrum Gttingen Abt.GeochemieGoldschmidtstr.137077 GttingenGermany

＜正＞The late Jurassic Jingshan leucogranite is located in the south-eastern margin of the North China Craton and contains abundant *** this study,four types of garnets are found according to their occurrences in the Jingshan leucogranite:（a） Garnets in biotite -rich restite（GrtⅠ）;（b） xenocrystic garnets in leucogranite associated petrographically with abundant mafic minerals（GrtⅡ）;（c） clustered garnet- xenocrysts with complex zoning in leucogranite（GrtⅢ）;（d） small（＜100μm） euhedral phenocrystic garnets in aplite and granite（GrtⅣ）.GrtⅠusually shows euhedral morphology,whereas GrtⅡor GrtⅢoften occur together with GrtⅣin intergrowths.

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Niobium-tantalum fractionation during slab subduction: Impli...

Niobium-tantalum Fractionation During Slab Subduction: Implications for the Formation of Continental Crust

2006年全国岩石学与地球动力学研讨会

作者： Jochen Hoefs klaus simon Albrecht W.Hofmann Geowissenschaftliches Zentrum der Universitt Gttingen Goldschmittstrasse 1 D-37077 GttingenGermany Geowissenschaftliches Zentrum der Universitt Gttingen Goldschmittstrasse 1 D-37077 GttingenGermany Max-Planck Institut fuer Chemie Postfach 3060 D-55020 MainzGermany

关键词：

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

Niobium-tantalum Fractionation During Slab Subduction: Impli...

193nm ArF准分子激光系统对LA-ICP-MS分析中不同基体的剥蚀行为和剥蚀速率探究

中国矿物岩石地球化学学会第11届学术年会

作者： Jochen Hoefs klaus simon Albrecht W．Hofmann Geowissenschaftliches Zentrum der Universitt Gttingen Goldschmittstrasse 1D-37077 GttingenGermany Geowissenschaftliches Zentrum der Universitt Gttingen Goldschmittstrasse 1D-37077 GttingenGermany Max-Planck Institute fuer Chemie Postfach 3060D-55020 MainzGermany

＜正＞Compared with the oceanic crust, knowledge about the formation of the continental crust （CC） is relatively poor. Although melting of subducted slabs in the early history of the Earth has been considered as the major way that shaped the chemical characteristics of the CC by most geologists, as the CC shares many characteristics with modern adakites, some geologists argued that Archean TTG was formed in the same way as modern arcs rather than slab melting, whereas others proposed that melting at the bottom of the thickened oceanic crust was more important. Recently, the debate is mainly focused on the unique subchondritic Nb/Ta value of the CC, and particularly, how Nb and Ta fractionated from each other and consequently how, in detail, the CC was built.

关键词： niobium-tantalum fractionation slab subduction formation of continental crust

来源： cnki会议评论

在线全文

cnki会议

学校读者我要写书评

暂无评论

岩矿测试 2017年第5期36卷 451-459页

作者：吴石头许春雪 klaus simon 肖益林王亚平 Geowissenschaftliches Zentrum Gttingen Universitt 国家地质实验测试中心北京100037 中国科学技术大学地球和空间科学学院合肥安徽230026

探究LA-ICP-MS分析中不同基体的剥蚀行为和剥蚀速率,可为激光参数设定、基体匹配选择、数据质量保证等方面提供重要参考。本文研究了193 nm ArF准分子激光系统对人工合成/地质样品玻璃、常见矿物和粉末压片的剥蚀行为,同时探究了激光参... 详细信息

探究LA-ICP-MS分析中不同基体的剥蚀行为和剥蚀速率,可为激光参数设定、基体匹配选择、数据质量保证等方面提供重要参考。本文研究了193 nm ArF准分子激光系统对人工合成/地质样品玻璃、常见矿物和粉末压片的剥蚀行为,同时探究了激光参数(束斑直径、能量密度和剥蚀频率)对剥蚀速率的影响情况。从剥蚀坑形貌可知,193nm ArF激光对玻璃和绝大多数矿物的剥蚀行为良好,但对石英相对较差,这可能与石英内含有微观包裹体,剥蚀过程中局部受热不均有关。粉末压片的剥蚀行为呈现出不可控,可通过提高粉末压片的压制压力或降低粉末颗粒的粒径来改善剥蚀行为;当剥蚀深度大于1.5倍束斑直径时,剥蚀速率随剥蚀深度的增加而逐渐减小,剥蚀深度最多可达束斑直径的两倍左右(RESOlution M-50型号激光系统,3.0 J/cm2激光能量密度);剥蚀速率随激光能量密度的增加而增大,但基本不受剥蚀频率(2~20 Hz)影响。不同基体具有特征的剥蚀速率,本文报道了43种基体的剥蚀速率参数,总体而言,NIST系列玻璃的剥蚀速率大于地质样品玻璃,碳酸盐矿物和硫化物矿物大于硅酸岩矿物,粉末压片大于玻璃和常见矿物。

关键词： 193nm ArF激光剥蚀行为剥蚀速率能量密度

CGSG系列标准物质元素分馏效应及主量微量元素单元内均匀性探究

在线全文

学校读者我要写书评

暂无评论

岩矿测试 2016年第6期35卷 612-620页

作者：吴石头王亚平詹秀春 Andreas Kronz klaus simon 许春雪田欢 Geowissenschaftliches Zentrum G?ttingen Universit?t 国家地质实验测试中心北京100037 中国地质大学(武汉)地球科学学院湖北武汉430074

探究CGSG系列标准物质(CGSG-1、CGSG-2、CGSG-4、CGSG-5)的元素分馏效应及均匀性问题有助于开展其质量评估和应用推广。本文采用电子探针(EMPA)和激光剥蚀电感耦合等离子体质谱(LA-ICP-MS)研究了CGSG标准物质中的元素分馏效应、主量和... 详细信息

探究CGSG系列标准物质(CGSG-1、CGSG-2、CGSG-4、CGSG-5)的元素分馏效应及均匀性问题有助于开展其质量评估和应用推广。本文采用电子探针(EMPA)和激光剥蚀电感耦合等离子体质谱(LA-ICP-MS)研究了CGSG标准物质中的元素分馏效应、主量和微量元素单元内均匀性,并报道了主量和微量元素分析数据。结果表明,在50μm激光束斑下,CGSG系列标准物质的元素分馏效应可忽略不计。EMPA均匀性指数结果显示,CGSG标准物质主量元素的单元内均匀性满足要求;以MPI-DING标准物质为参照,LA-ICP-MS测试CGSG标准物质中的大多数微量元素的单元内均匀性良好。与已报道的数据相比,本文报道的EMPA主量元素数据偏差在2%以内;LA-ICP-MS主量元素数据偏差在5%以内,微量元素数据基本匹配,少数元素由于分析不确定度较大等原因,如Cr、Ge、Cd、As、Tl等与已报道数据偏差较大。总体上,本文报道的分析数据可为CGSG定值数据库提供进一步的补充。

关键词： CGSG标准物质元素分馏均匀性检验电子探针激光剥蚀电感耦合等离子体质谱

Niobium-tantalum Fractionation During Slab Subduction:Implications for the Formation of Continental Crust

在线全文

学校读者我要写书评

暂无评论

矿物岩石地球化学通报 2007年第Z1期26卷 61-62页

作者： Yilin Xiao Weidong Sun Jochen Hoefs klaus simon Zeming Zhang Shuguang Li Albrecht W. Hofmann CAS Key Laboratory of Crust-Mantle and Environments School of Earth and Space Sciences University of Science and Technology of China Hefei 230026 China Geowissenschaftliches Zentrum der Universit(a)t G(o)ttingen Geldschmittstrasse 1 D- 37077 G(o)ttingen Germany Key Laboratory of Isotope Geochronology and Geochemistry Guangzhou Institut of Geochemistry Chinese Academy of Sciences Wushan Guangzhou 510640China Max-Planck Institute fuer Chemie Postfach 3060 D-55020 Mainz Germany Geowissenschaftliches Zentrum der Universit(a)t G(o)ttingen Geldschmittstrasse 1 D- 37077 G(o)ttingen Germany Institute of Geology Chinese Academy of Geological Sciences Beijing 100037 China CAS Key Laboratory of Crust-Mantle and Environments School of Earth and Space Sciences University of Science and Technology of China Hefei 230026 China Max-Planck Institute fuer Chemie Postfach 3060 D-55020 Mainz Germany

　　Compared with the oceanic crust, knowledge about the formation of the continental crust (CC) is relatively poor. Although melting of subducted slabs in the early history of the Earth has been considered as the major way that shaped the chemical characteristics of the CC by most geologists, as the CC shares many characteristics with modern adakites, some geologists argued that Archean TTG was formed in the same way as modern arcs rather than slab melting, whereas others proposed that melting at the bottom of the thickened oceanic crust was more important. Recently,the debate is mainly focused on the unique subchondritic Nb/Ta value of the CC, and particularly, how Nb and Ta fractionated from each other and consequently how, in detail, the CC was built.……

关键词： niobium-tantalum fractionation slab subduction formation of continental crust

Piezo1 expression in chondrocytes controls endochondral ossification and osteoarthritis development

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Bone Research 2024年第1期12卷 199-214页

作者： Laura J.Brylka Assil-Ramin Alimy Miriam E.A.Tschaffon-Müller Shan Jiang Tobias Malte Ballhause Anke Baranowsky simon von Kroge Julian Delsmann Eva Pawlus Kian Eghbalian klaus Püschel Astrid Schoppa Melanie Haffner-Luntzer David J.Beech Frank Timo Beil Michael Amling Johannes Keller Anita Ignatius Timur A.Yorgan Tim Rolvien Thorsten Schinke Department of Osteology and Biomechanics University Medical Center Hamburg-Eppendorf20246 HamburgGermany Department of Trauma and Orthopedic Surgery University Medical Center Hamburg-Eppendorf20246 HamburgGermany Institute of Orthopedic Research and Biomechanics University Medical Center UlmBadenWürttemberg89081 UlmGermany Department Legal Medicine University Medical Center Hamburg-Eppendorf20246 HamburgGermany Leeds Institute of Cardiovascular and Metabolic Medicine School of MedicineUniversity of LeedsLS29JT LeedsUK

Piezo proteins are mechanically activated ion channels,which are required for mechanosensing functions in a variety of cell *** we and others have previously demonstrated that the expression of Piezo1 in osteoblast lineage cells is essential for boneanabolic processes,there was only suggestive evidence indicating a role of Piezo1 and/or Piezo2 in *** we addressed the question if and how chondrocyte expression of the mechanosensitive proteins Piezo1 or Piezo2 controls physiological endochondral ossification and pathological osteoarthritis(OA)*** with chondrocyte-specific inactivation of Piezo1(Piezo1^(Col2a1Cre)),but not of Piezo2,developed a near absence of trabecular bone below the chondrogenic growth plate ***,all Piezo1^(Col2a1Cre) animals displayed multiple fractures of rib bones at 7 days of age,which were located close to the growth *** skeletal growth was only mildly affected in these mice,OA pathologies were markedly less pronounced compared to littermate controls at 60 weeks of ***,when OA was induced by anterior cruciate ligament transection,only the chondrocyte inactivation of Piezo1,not of Piezo2,resulted in attenuated articular cartilage ***,osteophyte formation and maturation were also reduced in Piezo1^(Col2a1Cre) *** further observed increased Piezo1 protein abundance in cartilaginous zones of human ***,we identified Ptgs2 and Ccn2 as potentially relevant Piezo1 downstream genes in ***,our data do not only demonstrate that Piezo1 is a critical regulator of physiological and pathological endochondral ossification processes,but also suggest that Piezo1 antagonists may be established as a novel approach to limit osteophyte formation in OA.

关键词： Piezo1 markedly ossification