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35篇 您的检索式:作者名="LING Hongfei"
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1Re-Os isotopes and PGE geochemistry of black shales and intercalated Ni-Mo polymetallic sulfide bed from the Lower Cambrian Niutitang Formation, South China显示文摘The Lower Cambrian Niutitang Formation consists of a thick black shale sequence with a regionally distributed conformable Ni Mo polymetallic sulfide horizon and a chert bed at its basal strata on theYangtze Platform, South China. In this paper, we discuss all available data on Re Os isotopes and Platinum Group Element (PGE) distribution pattern of the Ni Mo polymetallic sulfide ore and its host rocks (black shales, cherts, and phosphorites) from Guizhou and Hunan provinces. Our results show that the black shales and the Ni Mo sulfide ore have a high initial 187 Os/ 188 Os ratio of 0.78~0.86, indicating that the Early Cambrian ocean across the Yangtze Platform had a highly radiogenic Os value. This ratio is slightly lower than but still similar to present day seawater, possibly as a result of high continental weathering at that time. The Ni Mo sulfide ore yields a Re Os isochron of 537±10 Ma (MSWD=11.9), possibly representing the depositional age of the Niutitang Formation. The chondrite normalized PGE pattern, Pt anomaly (Pt/Pt *), Pt/Pd, Ir/Pd, Au/Ir and Re/Mo ratios of the Ni Mo sulfide ore and its host rocks from South China indicate a varying source contribution of the PGE and other metals for different rocks. It is suggested that the cherts and Ni Mo sulfide ore may have a significant proportion of PGE and probably other metals deriving from submarine hydrothermal fluids with a mantle signature.JIANG Shaoyong*, YANG Jinghong, LING Hongfei, FENG Hongzhen, CHEN Yongquan and CHEN Jianhua(State Key Laboratory for Mineral Deposits Research, Department of Earth Sciences, Nanjing University, Nanjing 210093, China) 2003Progress in Natural Science:Materials International2003,13,10:78
2Hf isotopic composition of zircons from the Huashan-Guposhan intrusive complex and their mafic enclaves in northeastern Guangxi:Implication for petrogenesis显示文摘High precision zircon U-Pb dating indicates that main intrusive bodies (Tong'an,Niumiao,Huashan,Lisong),and a mafic microgranular enclave in the Huashan-Guposhan complex were formed at 160-163 Ma.The εHf(t) values of zircons from the Huashan granite vary from -2.8 to +0.3 and those from the Lisong granite vary from -2.3 to +0.3,which are obviously different with those values (+2.6 to +7.4) of the mafic enclaves from the Lisong granite.These Hf isotopic data indicate that the mafic enclaves and host granites were crystallized from different sources of magmas,providing evidence for mafic-felsic magma mixing processes.The highest εHf(t) value of zircons from the mafic enclaves is up to +7.4,indicating that the mafic magma was originated from a relatively depleted mantle source.Studies on regional geology and the contemporaneous mafic and alkaline rocks in this area indicate that the mafic magma was not originated from reworking of basaltic juvenile crust,but from partial melting of the mantle.However,it remains to be resolved whether the mafic magma was derived from partial melting of the asthenosphere or the lithospheric mantle.The Huashan granite and the Lisong granite were formed from hybrid magma of mantle-derived and crust-derived magmas,and the mafic enclaves are considered as remains of mantle-derived magma during mixing processes.The εHf(t) values of zircons from the Niumiao diorite vary from -1.1 to +2.1,and those from the Tong'an quartz monzonite vary from -1.7 to +1.7.These values are lower than those from the mafic enclaves,suggesting that the diorite and monzonite were formed from different source-derived magmas with the mafic enclaves.The εHf(t) values for the Niumiao diorite and the Tong'an monzonite are only slightly higher than those for the Hushan granite and the Lisong granite.Abundant mafic enclaves also occur in the Niumiao diorite and in the Tong'an monzonite.Thus,we suggest that the Niumiao diorite and the Tong'an monzonite were probably also formed from the same hybrid magma as the granites but come through less degree of fractional crystallization and crustal contamination.The strong mantle-derived and crust-derived magma mixing caused by an intense crustal extension and thinning in the Mid-Late Jurassic may be the major mechanism for generating the diorites and granites in southeastern Hunan and northeastern Guangxi belt in South China.ZHAO KuiDong JIANG ShaoYong ZHU JinChu LI Liang DAI BaoZhang JIANG YaoHui LING HongFei 2010Chinese Science Bulletin2010,55,6:24
3SHRIMP U-Pb zircon dating for lamprophyre from Liaodong Peninsula: Constraints on the initial time of Mesozoic lithosphere thinning beneath eastern China显示文摘It is undebated fact that the lithospheric mantle beneath eastern China was considerably thinned during the Mesozoic time. However, it has no adequate evidence for the exact timing when the lithosphere thinning started. The Liaodong Peninsula is located in the eastern segment of the North China Craton and is one of the important domains to explore the event of lithosphere thinning. SHRIMP U-Pb zircon dating and geochemical study were carried out for the lamprophyre dike swarm that intruded into the magnesite ore-beds in the Dashiqiao Formation of Paleoproterozoic Liaohe Group at the Huaziyu magnesite ore district, Liaodong Peninsula. The results indicate that these lampro- phyre dikes were intruded in late Jurassic (155±4 Ma) and show some geochemical characteristics of potassic magmas. It is now accepted that the lithosphere thinning took place in the late Mesozoic, and the peak thinning stage occurred in early Cretaceous (130―120 Ma). Considering the potassic mafic magmatism marking the onset of the lithospheric thin- ning, we therefore suggest that the studied late Jurassic potassic lamprophyre dike swarm could imply that the late Jurassic is the time that lithosphere thinning started.JIANG Yaohui JIANG Shaoyong ZHAO Kuidong NI Pei LING Hongfei LIU Dunyi 2005Chinese Science Bulletin2005,50,22:22
4SHRIMP zircon U-Pb ages and tectonic implications for Indosinian granitoids of southern Zhuguangshan granitic composite, South China显示文摘The large southern Zhuguangshan granitic batholith composite consists of granites with ages varying from the Caledonian through Indosinian to Yanshanian. Based on K-Ar dating data, the ages of the major parts of this composite were previously regarded as Yanshanian. In this study, the SHRIMP zircon U-Pb dating method has been adopted for six plutons, Ledong, Longhuashan, Dawozi, Zhaidi, Baiyun and Jiangnan, in the southern Zhuguangshan composite, in which the four plutons other than Baiyun and Jiangnan were previously regarded as Yanshanian granites. Magmatic zircons from these six plutons, dated by this study, have yielded ages of 239±5 Ma (MSWD = 2.5), 239±5 Ma (MSWD = 2.5), 239±2 Ma (MSWD = 1.7), 239±4 Ma (MSWD = 3.2), 231±2 Ma (MSWD = 0.81) and 231±3 Ma (MSWD = 1.8), respectively. The results indicate that these plutons were formed by early Indosinian magmatism. Geochemical characteristics suggest that these granites were formed in an extensional tectonic environment. Therefore, the Indosinian period granites in the southern Zhuguangshan composite were formed by partial melting of the Paleo-Mesoproterozoic crustal components during the collapse of thickened lithosphere after the collision between the South China and Indosinian plates.DENG Ping REN JiShun LING HongFei SHEN WeiZhou SUN LiQiang ZHU Ba TAN ZhengZhong 2012Chinese Science Bulletin2012,57,13:19
5Pb-Pb isotope dating of black shales from the Lower Cambrian Niutitang Formation, Guizhou Province, South China显示文摘The Lower Cambrian black shales of the Niutitang Formation and their lateral equivalents occur widely on the Yangtze Platform, South China. In this study, we examine two sections of the Niutitang Formation in Guizhou Province. We employ a stepwise acid leaching technique to obtain Pb isotope compositions of the black shales. At the Zhongnan section, the black shales display large Pb isotope variations, with 206 Pb/ 204 Pb of 20.5396~33.5709, and 207 Pb/ 204 Pb of 15.8407~16.5782. In contrast, Pb isotope data show a relatively limited range in 206 Pb/ 204 Pb (18.2797~18.5972) and 207 Pb/ 204 Pb (15.6813~15.7159) at the Zhijin section. Data for all acid leached black shale samples from the two sections yield a Pb Pb isochron age of 531±24 Ma. This age may represent the sedimentary age of the black shales. The initial Pb isotope composition of the black shales falls near the upper crust evolution curve in a Zartman Pb Pb evolution diagram. Hence, it is likely that the Pb in the black shales may have been derived from an upper continental crustal source.CHEN Yongquan, JIANG Shaoyong*, LING Hongfei, FENG Hongzhen, YANG Jinghong and CHEN Jianhua (State Key Laboratory for Mineral Deposits Research, Department of Earth Sciences, Nanjing University, Nanjing 210093, China) 2003Progress in Natural Science:Materials International2003,13,10:19
6A Study of Sr, Nd and O Isotopes of the K-rich Melanocratic Dykes in the Late Mesozoic Gold Field in the Jiaodong Peninsula显示文摘Geologic, petrographic and petrochemical studies of the lateMesozoic K-rich melanocratic dykes, including lamprophyres, andesite porphyrites and dacite-porphyry in the gold field system in the Jiaodong Peninsula, China, have shown that these dykes are characterized by rich potassium and alkali but poor titanium. They belong to an ultra-high potassic, shoshonitic and high potassic calc-alkaline rock series. The parental magma has relatively high initial strontium ratios ((87Sr/86Sr)i-0.70895-0.71140) and low (143Nd/144Nd)i ratios (varying from 0.51135 to 0.51231); and its δ18OsMow. whole rock values vary from +5.8‰ to +10.6‰ with a mean of +7.1‰. These features suggest that the source region of the magma is an enriched mantle wedge transformed from a continental lithosphere mantle which has experienced me tasomatism by mantle-derived fluids with H2O-dominated fluids that were provided during the underthrusting of an ocean crust. The initial magma was generated by low-degree partial melting of the enriched mantle in its mature stage in the back-arc spreading environment. The evolution of magmas is associated with two trends, i.e., fractional crystallization and mixing with or intensive contamination by palaeo-crust materials or metamorphic rocks. The former process is evident in the gold field system of quartz-vein type, whereas the latter is dominated in the gold field system of the altered-rock type. This conclusion is very important for more detailed study of petrogenesis and mineralization through the crust-mantle interaction (exchange) in the Mesozoic in this region.SUN Jinggui, HU Shouxi, LIU Jianmin, SHEN Kun and LING Hongfei Earth Science Institute, Jilin University, Changchun 130062 State Key Laboratory of Research on Metallogenesis of Endogenic Ore Deposits,Nanjing University, Nanjing 210093 Institute of Geology and Geophysics, Chinese Academy of Sciences, Beijing 100101 Shandong Institute and Laboratory of Geological Sciences, Jinan 250013 2001Acta Geologica Sinica(English Edition)2001,75,4:14
7Geochemical Characteristics and Genesis of the Luxi-Xianrenzhang Diabase Dikes in Xiazhuang Uranium Orefield, Northern Guangdong Province显示文摘The Luxi-Xianrenzhang diabase dikes were emplaced into the eastern part of the Guidong composite granitoids in northern Guangdong Province at the end of the Early Cretaceous. They show tholeiitic features, enrichment in large ion lithophile elements, slight enrichment in light rare earth elements, depletion in Zr and Hf, and basically no depletion in Nb and Ta and no Eu anomaly. They are similar to intraplate basalt in terms of trace element characteristics. They have high εNd(t) values (3.6–4.9), initial 87Sr/86Sr ratios (0.70530–0.70641) and δ18O values and Dupal anomaly of Pb isotope compositions. Their Sr-Nd, Pb-Sr, Pb-Nd and Pb-Pb isotopes plot between DMM and EMII, with Pb similar to EMII, Nd relatively close to DMM and Sr in between. This profile suggests that the diabase dikes studied were derived from partial melting of a mantle source that had been subjected to metasomatism by fluids originated from a subduction zone under a tectonic environment of crustal extension and lithosphere thinning in the late Yanshanian.LING Hongfei SHEN Weizhou DENG Ping JIANG Shaoyong JIANG Yaohui YE Haimin PU Wei TAN Zhengzhong 2005Acta Geologica Sinica(English Edition)2005,79,4:13
8Timing of hydrothermal activity associated with the Douzhashan uranium-bearing granite and its significance for uranium mineralization in northeastern Guangxi, China显示文摘The Miaoershan uranium(U)ore field in northeastern Guangxi is one of the important granite-related U deposits in south China and is closely related to the Douzhashan U-bearing granite.The Douzhashan granite contains primary U-rich accessory minerals,including monazite(UO2=0.98-1.75 wt%)and xenotime(UO2=1.48-6.14 wt%).Primary monazite and xenotime yield chemical ages of 231±28 Ma and 230±38 Ma by electron microprobe analysis and U-Pb isotopic ages of 220±6 Ma and 211±7 Ma by laser ablation-inductively coupled-mass spectrometry respectively.These ages demonstrate that the Douzhashan granite formed during the period of Indosinian magmatic activity.Back scattered electron imaging shows that monazite and xenotime are commonly altered to assemblages of low-U synchisite and apatite,which was associated with loss of U to hydrothermal fluids.U-Th-Pb analyses of secondary apatite yielded a chemical age of 136±17 Ma,which corresponds to the timing of Cretaceous-Tertiary crustal extension in south China.We suggest that the heat and CO2required for mineralization was the result of Yanshanian crustal extension,and that this triggered the breakdown of U-rich accessory minerals in the Douzhashan U-bearing granite.Uranium remobilization from the Douzhashan granite provided materials for mineralization within the granite and/or surrounding country rocks.Therefore,a combination of Indosinian compression and Yanshanian extensional overprint produced the hydrothermal U deposits associated with the Douzhashan granite.HU Huan WANG RuCheng CHEN WeiFeng CHEN PeiRong LING HongFei LIU GuoNing 2013Chinese Science Bulletin2013,58,34:10
9The thermal history of the miarolitic granite at Xincun, Fujian Province, China显示文摘The thermal history of the late Mesozoic miarolitic granite has been studied based on zircon U-Pb dating, whole rock Rb-Sr dating and K-Ar dating of muscovite, biotite and K-feldspar from the same rock sample. From the beginning of zircon crystallization to the closure of K-Ar system of biotite, the granite body had a slow cooling rate (11.0℃/Ma) and an ascending rate (0.07 mm/a). From the end of this stage to the closure of K-Ar system of K-feldspar, the granite body increased its cooling rate (45℃/Ma) and ascending rate (0.36 mm/a). The thermal history of the Xincun granite with a slow cooling rate at the early stage and a fast cooling rate at the late stage may have been related to the fact that the Fujian coastal area had very high geothermal gradient in the late Mesozoic and evident decrease in geothermal gradient in the early Cenozoic.SHEN Weizhou LING Hongfei LI Huimin LI Wuxian WANG Dezi 2000Chinese Science Bulletin2000,45,21:9
10Estimate of influence of U-Th-K radiogenic heat on cooling process of granitic melt and its geological implications显示文摘The U-Th-^(40)K concentrations of granite are on 1―2 orders of magnitude greater than those of basal- tic-ultrabasic rocks. Radiogenic heat of a granitic melt has significant influence on the cool- ing-crystallization period of the melt. In this paper we derived a formula to calculate prolongation period (tA) of cooling-crystallization of a granitic melt caused by radiogenic heat. Calculation using this for- mula and radioactive element concentrations (U=5.31×10-6; Th=23.1×10-6; K=4.55%) for the biotite adamellite of the Jinjiling batholith shows that the tA of the adamellite is 1.4 times of the cooling period of the granitic melt without considering radiogenic heat from the initial temperature (Tm=960℃) to crystallization temperature (Tc=600℃) of the melt. It has been demonstrated that the radiogenic heat produced in a granitic melt is a key factor influencing the cooling-crystallization process of the granitic melt, and is likely one of the reasons for inconsistence between emplacement ages and crystallization ages of many Meso-Cenozoic granitoids.ZHANG BangTong WU JunQi LING HongFei CHEN PeiRong 2007Science China Earth Sciences2007,50,5:9
11Estimating Influence of Crystallizing Latent Heat on Cooling-Crystallizing Process of a Granitic Melt and Its Geological Implications显示文摘摘要:基于热电导率的理论,在我们导出的这份报纸估计凉爽结晶化的过程的延伸时期(tL ) 的一个公式一花岗石融化如下由结晶化的潜伏的热引起了:ZHANG Bangtong WU Junqi LING Hongfei CHEN Peirong 2008Acta Geologica Sinica(English Edition)2008,82,2:8
12New index of ferromanganese crusts reflecting oceanic environmental oxidation显示文摘Ferromanganese crusts (hereinafter crusts) form in aerobic environment and the environmental oxida-tion degree is recorded by the redox sensitive element Co in the crusts. The ages of the layers from the surface to bottom of the crusts are determined, and main element contents at high resolution along the depth sections of three crusts from the Pacific Ocean are analyzed by an electron microprobe. Thus the variations of Co/(Fe+Mn) and Co/(Ni+Cu) with age/depth of the crust layers are obtained. By comparing the ratios of Co/(Fe+Mn) and Co/(Ni+Cu) with the δ 18O curves of the Pacific benthic foraminifera, we find that these two ratios can reflect the variation of the environmental oxidation state under which the crust layers deposit. The evolution of the oxidation degree reflected by the two indexes resembles the evo-lution of temperature since the Oligocene reflected by the δ 18O curves of the Pacific benthic foraminif-era. This suggests that the crust-forming environment after the Oligocene is controlled mainly by the oxygen-rich bottom water originated from the Antarctic bottom water (AABW). However it is not the case prior to the Oligocene. Furthermore it suggests that the environmental oxidation degree controls the formation of the crusts and the Co contents in the crusts. This explains why the Co contents in the crusts increase with time up to now.WU GuangHai ZHOU HuaiYang ZHANG HaiSheng LING HongFei MA WeiLin ZHAO HongQiao CHEN JianLin LIU JieHong 2007Science China Earth Sciences2007,50,3:7
13Granulite Genesis and Tectonic Evolution in Tongbai Area:Single Zircon Evaporation Ages and Nd Isotopic Geochemistry显示文摘INTRODUCTIONTongbaiareainCentralChinaisanimportantregionforstudyinggenesisrelationbetweenQinlingorogenicbeltandDabieorogenicb...Zhang Hongfei Gao Shan Zhang Li Zhong Zengqiu Ling Wenli Wang Linsen Faculty of Earth Sciences, China University of Geosciences, Wuhan 430074 1998Journal of Earth Science1998,17,3:6
14The Lanshantou Kyanite-bearing Eclogite with Coesite Inclusions in the Sulu Ultrahigh-Pressure Metamorphic Belt and Its PTt Path显示文摘Coesite inclusions are found in kyanite from the Lanshantoueclogite in the Sulu ultrahigh-pressure (UHP) metamorphic belt. This discovery extends the stable region of kyanite to over 2.4 GPa. As an important UHP metamorphic belt in China, the Sulu eclogite belt is the product of A-subduction induced by strong compression of the Yellow Sea terrane to the Jiaodong-northereastem Jiangsu terrane during the interaction of the Eurasian plate and Palaeo-Pacific plate in the Indosinian. It stretches about 350 km and contains over 1000 eclogite bodies. Most eclogites in this belt belong to Groups B and C in the classification of Coleman et al., and commonly contain kyanite, while the Lanshantou eclogite belongs to Group A and contains coesite. The MgO, CaO and FeO contents in garnet and pyroxene show regular variation from the core to the rim, which reveals the PTt paths of progressive metamorphism during the Early Mesozoic (240-200 Ma) and retrogressive metamorphism during the Late Mesozoic and Cenozoic exhumation.HU Shouxi, SUN Jinggui, LING Hongfei, YE Ying, Fang Changquan and ZHAO Yiying Department of Earth Sciences, Nanjing University, Nanjing 210008, Jiangsu Department of Earth Sciences, Zhejiang University, Hangzhou 310027, Zhejiang 2001Acta Geologica Sinica(English Edition)2001,75,4:5
15Neodymium isotopes distribution and transport in the central North Pacific deep water显示文摘Radiogenic Neodymium (Nd) isotopes in the central North Pacific deep water have been generally interpreted as reflecting Pacific arcs input according to previous studies,while little is known about the specific path and mode of radiogenic Nd from these arcs to deep water.In this study,Nd isotopic data from surface scrapings of 17 Fe-Mn crusts from the central North Pacific deep water (around 20°N) have been reported.Based on these data together with recently published data on dissolved Nd isotopes in seawater for this region,we propose that radiogenic Nd isotopes in North Pacific Intermediate Water (NPIW 300-800 m) from the western Pacific margin is an important source for the central North Pacific deep water,while the surface water of this area has little influence on dominating deep water Nd isotopes.Such a view emphasizes the role of vertical mixing and advection of the marginal ocean currents in balancing Nd isotopes in central North Pacific deep water,and helps to understand oceanic Nd cycling.Moreover,the values of Nd from surface scrapings of Fe-Mn crusts are relatively homogenous,with an average value of about-3.4,which is higher than that of modern seawater (~-3.9).This difference over short time scales reflects the quick evolution of Nd isotopes in central North Pacific deep water.EN TianYu LING HongFei HU Rong 2011Chinese Science Bulletin2011,56,21:4
16Sm-Nd isotopic compositions of Cambrian-Ordovician strata at the Jinggangshan area in Jiangxi Province: Tectonic implications显示文摘Whole-rock Sm-Nd isotopes were investigated for Cambrian-Ordovician strata from the Jinggangshan area between the Yangtze Block and Cathysia Block in South China. These strata were deposited as a greatly thick unit of muddy-sandy laminas with intercalated carbonate and organic carbon-bearing layers. They have low εNd(t) values of –13.9 to –7.9 and old Nd model ages of 1842 to 2375 Ma. In tDM-tStr diagram, they are far away from the concordant line but fall within the evolution zone of the Proterozoic crust of South China. This indicates that the Cambrian-Ordovician strata are mainly composed of mat- ters eroded from ancient Paleoproterozoic crust that may mainly consist of continental-derived detrital sediments with high maturity in the Cathysia Block. However, the Ordovician Jueshangou Formation and Dui’ershi Formation have εNd(t) values of –10.5 and –7.9 at the higher end of the above range and Nd model ages of 1842 to 2059 Ma at the lower end of the above range. This suggests involvement of more detritus that were eroded from the relatively juvenile crust from Late Paleoproterozoic to the Early Neoproterozoic. All the Nd model ages for the Cambrian-Ordovician sedimentary rocks in the Cathysia Block and the southeastern margin of the Yangtze Block are older than 1800 Ma, suggesting that no material from the Early Paleozoic depleted mantle-derived magmas was involved in these regions.SHEN WeiZhou LING HongFei SHU LiangShu ZHANG FangRong XIANG Lei 2009Chinese Science Bulletin2009,54,10:4
17Isotopic compositions of small shelly fossil Anabarites from Lower Cambrian in Yangtze Platform of South China: Implications for palaeocean temperature显示文摘Anabarites belong to small shelly fossils (SSF), which occur widely in the Lower Cambrian strata of Yangtze Platform in South China. They are phosphate shell in composition and represent the earliest stage of the Cambrian bioradiation of Bilateria, the so-called 'Cambrian Explosion'. In this study, we attempted to separate Anabarites fossils from Lower Cambrian dolostones, and we obtained samples of both the fossils (SSF) and the granular phosphates (GP). Isotopic analyses were performed on samples of SSF, GP, and matrix dolostone (DH-23). The results showed that the δ30Si values of the quartz filling in fossils celoms, and the siliceous materials in granular phosphates are -0.6‰ and -0.7‰, which is different from normal sedimentary siliceous rocks from the Lower Cambrian strata (0—0.7‰) as reported by Li et al., but is consistent with the data for siliceous rocks and cherts of submarine hydrothermal origin. It is likely that a later hydrothermal replacement could have taken place in the SSF-bearing sedimentary rocks. The oxygen isotope values of the phosphate of SSF and GP are 16.8‰ and 17.0‰, respectively. These are significantly higher than the Neoproterozoic phosphate ores (10.9‰—13.9‰) as reported by Ling et al., hence, late diagenesis and hydrothermal replacement may not have caused a significant change in the oxygen isotope compositions of the small shelly fossils, and the calculated temperatures (25.4—26.3℃) for palaeo-seawater using a SSF phosphate oxygen isotope thermometer are therefore considered here as the upper limit of seawater temperature in the Early Cambrian ocean of the Yangtze Platform.Chen Yongquan Jiang Shaoyong Ling Hongfei Yang Jlnghong Wan Defan 2007Progress in Natural Science:Materials International2007,17,10:4
18Late Cenozoic history of deep water circulation in the western North Pacific: Evidence from Nd isotopes of ferromanganese crusts显示文摘尽管有它在调整全球气候的重要性,在西方的诺思太平洋的过去深的海洋发行量仍然是糟糕理解。铁锰合金外壳的 Nd 同位素被证明了是一个好代理监视 paleoceanic 发行量变化。在这研究,迟了的新生代 Nd 同位素的记录从在玛丽安娜弧附近,但是在不同的水深度定位的二个铁锰合金外壳被恢复(MKD13:1530 m, MDD53:2700 m ) ,并且他们为在这个区域的 paleocirculation 变化的含意被探索。从对早晚中新世, MDD53 的 Nd 同位素的作文留下了马厩,和他们被最不放射产生的签名(到 5.0 的 Nd 4.0 ) 也在中新世的诺思太平洋与类似的水深度的外壳相比描绘。后来,它的 Nd 价值的突然的增加发生在上新世。相反, MKD13 的 Nd 同位素与时间变得更放射产生在中新世并且此后是几乎不变的。更浅的外壳 MKD13 的 Nd 的不断的增加作为反映印度尼西亚的航道的进步闭合在被解释中新世,当从南部的太平洋采购的深西方的边界水流可能在一样期间统治了更深的外壳 MDD53 的 Nd 同位素时,预定间隔。在上新世的 MKD13 的 Nd 同位素的变化的缺乏显示在在印第安人之间的更浅的水和最后的限制里的 Nd 来源没有变化,太平洋从那以后可能仅仅发生了。因此,到在上新世的 MDD53 的更放射产生的 Nd 同位素的观察大移动不应该在垂直输入从变化被结果从对更深的水更浅。相反,沿着学习的水深度范围(2700 m ) 的深南部的部件电流的减少的通风可能在上新世继续了。HU Rong CHEN TianYu LING HongFei 2012Chinese Science Bulletin2012,57,31:3
19The Marine Redox Change and Nitrogen Cycle in the Early Cryogenian Interglacial Time: Evidence from Nitrogen Isotopes and Mo Contents of the Basal Datangpo Formation, Northeastern Guizhou, South China显示文摘Cryogenian Datangpo Formation was deposited during the interglacial time between the Sturtian and Marinoan ice ages. We studied nitrogen isotope compositions and contents of Mo of the black shales from the basal Datangpo Formation in northeastern Guizhou, South China, for an attempt to reconstruct the marine redox change and nitrogen cycle during the interglacial time. Based on lithostratigraphy as well as geochemical profiles, the basal black shales can be divided into four intervals: Interval 1 has the lowest δ^(15)N value(+5.0‰); in interval 2, δ^(15)N values vary between +6.4‰ and +7.4‰(the first peak); interval 3 records stable values of δ^(15)N around +6‰; and interval 4 is characterized by its higher δ^(15)N values, between +6.7‰ and +7.8‰(the second peak). The values of enrichment factor of Mo decrease from 56.8 to 2.6 with the ascending stratigraphic trend. It indicated that immediately after the Sturtian glaciations, the marine seawater above the transitional zone between the shelf to slope of the southern margin of the Yangtze Platform was stratified, with shallow seawater being oxic but deep water being sulfidic. Subsequently, high denitrification rates prevailed in expanded suboxic areas in spite of a short emergence of an oxic condition in the surface seawater, and the deep seawaters were still anoxic or even euxinic.Wei Wei Dan Wang Da Li Hongfei Ling Xi Chen Guangyi Wei Feifei Zhang Xiangkun Zhu Bin Yan 2016Journal of Earth Science2016,27,2:3
20Crystal phase-controlled growth of PtCu and PtCo alloys on 4H Au nanoribbons for electrocatalytic ethanol oxidation reaction显示文摘Crystal phase can greatly affect the physicochemical properties and applications of nanomaterials.However,it stil remains a great challenge to synthesize nanostructures with the same composition and morphology but different phases in order to explore the phase-dependent properties and applications.Herein,we report the crystal phase-controlled synthesis of PtCu alloy shells on 4H Au nanoribbons(NRBs),referred to as 4H-Au NRBs,to form the 4H-Au@PtCu core-shell NRBs.By tuning the thickness of PtCu,4H-PtCu and face-centered cubic(cc)phase PICu(cc-PtCu)alloy shells are successtully grown on the 4H-Au NRB cores.This thickness-dependent phase-controlled growth strategy can also be used to grow PtCo alloys with 4H or fcc phase on 4H-Au NRBs.Significantly,when used as electrocatalysts for the ethanol oxidation reaction(EOR)in alkaline media,the 4H-Au@4H-PtCu NRBs show much better EOR performance than the 4H-Au@fcc-PtCu NRBs,and both of them possess superior performance compared to the commercial Pt black.Our study provides a strategy on phase-contolled synthesis of nanomaterials used for crystal phase-dependent applications.Jie Wang Jian Zhang Guigao Liu Chongyi Ling Bo Chen Jingtao Huang Xiaozhi Liu Bing Li An-Liang Wang Zhaoning Hu Ming Zhou Ye Chen Hongfei Cheng Jiawei Liu Zhanxi Fan Nailiang Yang Chaoliang Tan Lin Gu Jinlan Wang Hua Zhang 2020Nano Research2020,13,7:2
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