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Carbon Isotope Features of the Sugetbrak Section in the Aksu-Wushi Area, Northwest China: Implications for the Precambrian/Cambrian Stratigraphic Correlations

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Acta Geologica Sinica(English Edition) 2014年第5期88卷 1535-1546页

作者： YAO Chunyan DING Haifeng ma dongsheng LI Guoxiang Nanjing Center China Geological Survey Institute of Remote Sensing and Digital Earth Chinese Academy of Sciences State Key Laboratory for Mineral Deposits Research Nanjing University Nanjing Institute of Geology and Palaeontology Chinese Academy of Sciences

The upper Qigeblaq Formation （Fm） dolostones and the Yurtus Fm phosphatic cherts, black shales, limestones, and dolostones are widely distributed in the Precambrian/Cambrian transitional succession of the Aksu-Wushi area. Negative δ13C excursion above the Yurtus Fm/ Qigeblaq Fm boundary was determined in this study. The pronounced negative carbon isotope excursion occurs in the phosphatic chert layers at the bottom of the Cambrian Yurtus Fm, below which the first appearance of the Asteridium- Heh＇osphaeridium-Comasphaeridium （AHC） acritarch assemblage zone. The δ13C curve of the lower part of the Yurtus Fm in the Aksu-Wushi area was found to be correlated with the early Cambrian δ13C curves of the Zhujiaqing Fm （Daibu Member）, the lower part of the Yanjiahe Fm on the Yangtze Platform in China, the lower Tal Fm in India, the Sukharikha Fm in Siberia, and the upper part of the Tsagaan Oloom Fm in Mongolia through biostigraphy. The lower part of the Yurtus Fm in the Tarim Basin is at the Nemakit-Daldynian stage, and the Precambrian/Cambrian boundary of the Aksu-Wushi area may be located in the phosphatic chert unit which just below the first appearance AHC acritarch assemblage zone. The negative δ13C excursion （N1） across the Precambrian/Cambrian boundary in the studied section may have resulted from oceanic overturning and sea level rise.

关键词： Carbon isotope Stratigraphic correlation Precambrian/Cambrian boundary Northwest China

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Multivariate rational regression and its application in semiconductor device modeling

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Journal of Semiconductors 2018年第9期39卷 67-73页

作者： Yuxi Hong dongsheng ma Zuochang Ye Institute of Microelectronics Tsinghua University

Physics equation-based semiconductor device modeling is accurate but time and money *** need for studying new material and devices is increasing so that there has to be an efficient and accurate device modeling method. In this paper, two methods based on multivariate rational regression（MRR） for device modeling are proposed. They are single-pole MRR and double-pole MRR. The two MRR methods are proved to be powerful in nonlinear curve fitting and have good numerical stability. Two methods are compared with OLS and LASSO by fitting the SMIC 40 nm MOS-FET I–V characteristic curve and the normalized mean square error of Single-pole MRR is 3.02 × 10^-8 which is 4 magnitudes less than an ordinary least square. The I–V characteristics of CNT-FET and performance indicators（noise factor, gain, power） of a low noise amplifier are also modeled by using MRR methods. The results show MRR methods are very powerful methods for semiconductor device modeling and have a strong nonlinear curve fitting ability.

关键词： multivariate rational regression MRR semiconductor device modeling vector fitting

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Early Cambrian carbon isotope stratigraphy in the Tarim Basin and a correlation with the Yangtze Platform

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Chinese Journal Of Geochemistry 2011年第3期30卷 382-390页

作者： YAO Chunyan ma dongsheng DING Haifeng ZHANG Xiaoyong State Key Laboratory for Mineral Deposits Research Nanjing 210093 China Jiangsu Environment Monitoring Center Nanjing 210036 China

Carbon isotope chemostratigraphy has been used worldwide for stratigraphic *** this study,δ13Ccarb values are estimated for the Early Cambrian Sugaitebulake section in the Tarim Basin,Xinjiang Autonomous Region,*** a result,one positive and two negative carbon isotope excursions in the studied section were *** δ13Ccarb values reached the maximum negative excursion(N1:-12.39‰) at the basal of the Yuertusi For-mation,and then increased to *** P1,δ13Ccarb values sharply decreased to about-7.06‰(N2) in the studied *** pattern of δ13Ccarb in the Early Cambrian is comparable to the synchronous records of other sections,such as the Laolin section,the Xiaotan section and the Anjiahe section of the Yangtze *** is concluded that the Early Cambrian Yuertusi Formation from the Tarim Basin is within the Nemakit-Daldynian stage,and the lower strata of the Yuertusi Formation may belong to the Zhujiaqing Formation(Meishucun Formation) of the Yangtze *** Ediacaran/Cambrian boundary of the Tarim Block should be located in cherts and phosphorites suc-cessions at the basal of the Yuertusi *** δ13Ccarb negative excursion N1 is just across the PC/C boundary,and may be related to certain biomass extinction due to anoxic sedimentary environment,transgression and/or the oceanic *** second δ13Ccarb negative excursion N2 may account for the sea-level falling in the Early Cam-brian.

关键词：塔里木盆地碳同位素同位素地层学早寒武世扬子地台新疆维吾尔自治区化学地层学塔里木地块

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Trace elements and stable isotopic geochemistry of an Early Cambrian chert-phosphorite unit from the lower Yurtus Formation of the Sugetbrak section in the Tarim Basin

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Science China Earth Sciences 2014年第3期57卷 454-464页

作者： YAO ChunYan ma dongsheng DING HaiFeng ZHANG XiaoYong HUANG Hui School of Earth Sciences and Engineering State Key Laboratory for Mineral Deposits Research Nanjing University Nanjing Center China Geological Survey Institute of Remote Sensing and Digital Earth Chinese Academy of Sciences Jiangsu Environment Monitoring Center Guangdong Provincial Key Laboratory of Geological Processes and Mineral Resource Exploration Department of Earth Sciences Sun Yat-sen University

A chert-phosphorite unit from the Sugetbrak section in the Tarim Basin was analyzed for rare earth elements(Ce,Eu),redox sensitive proxies,and carbon isotopic compositions(??13C carb and??13C org)in the lower Yurtus Formation of the Early Cambrian *** sensitive element ratios(Th/U,V/Cr,Ni/Co,and V/Sc)were employed to determine the palaeoenvironmental conditions during this *** ratios indicated that the depositional environment of the chert-phosphorite-black shale unit ranged from suboxic to *** Ce and positive Eu anomalies in the chert-phosphorite assemblages of the studied Yurtus Formation indicated the existence of a redox-stratified ocean,similar to that of South *** or upward expansion of the deep water-mass probably reached the shallow marine zone after the formation of the Yurtus *** characteristics of the negative Ce anomaly may be due to phosphoritic inheritance from the Ce-depleted signature of the overlying water *** hydrothermal inputs and reduced detrital supplies of the deep water caused by the upwelling affected certain redox sensitive elements in the sedimentary basin.??13C carb and??13C org negative excursions in the Yurtus chert-phosphorite unit may be related to a transgression phase when episodic basinal upwelling moved12C-and P-rich waters from the pelagic basin floor to the continental *** carbon isotopic compositions in the Yurtus chert-phosphorite assemblages may have suffered from diagenetic alteration,they can be used to probe diagenetic ***-proxy geochemical studies indicated that the??13C carb values of the Yurtus chert-phosphorite assemblages might be considered reflections of a predominantly suboxic environment that was subsequently affected by hydrothermal inputs due to the upwelling.

关键词： redox sensitive element ratios carbon isotope sedimentary environment Early Cambrian Tarim Basin

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Statistically modeling I-V characteristics of CNT-FET with LASSO

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Journal of Semiconductors 2017年第8期38卷 28-31页

作者： dongsheng ma Zuochang Ye Yan Wang Institute of Microelectronics Tsinghua University

With the advent ofinternet of things （lOT）, the need for studying new material and devices for various applications is increasing. Traditionally we build compact models for transistors on the basis of physics. But physi- cal models are expensive and need a very long time to adjust for non-ideal effects. As the vision for the application of many novel devices is not certain or the manufacture process is not mature, deriving generalized accurate physi- cal models for such devices is very strenuous, whereas statistical modeling is becoming a potential method because of its data oriented property and fast implementation. In this paper, one classical statistical regression method, LASSO, is used to model the I-V characteristics of CNT-FET and a pseudo-PMOS inverter simulation based on the trained model is implemented in Cadence. The normalized relative mean square prediction error of the trained model versus experiment sample data and the simulation results show that the model is acceptable for digital circuit static simulation. And such modeling methodology can extend to general devices.

关键词： statistical learning compact model CNT-FET I-V characteristics LASSO machine learning

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Petrogenetic differences between the Middle-Late Jurassic Cu-Pb-Zn-bearing and W-bearing granites in the Nanling Range,South China： A case study of the Tongshanling and Weijia deposits in southern Hunan Province

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Science China Earth Sciences 2017年第7期60卷 1220-1236页

作者： HUANG XuDong LU JianJun Stanislas SIZARET WANG RuCheng ma dongsheng ZHANG RongQing ZHAO Xu WU JinWei State Key Laboratory for Mineral Deposits Research School of Earth Sciences and Engineering Nanjing University Nanjing 210023 China Institut des Sciences de la Terre d'Orleans UMR 7327-CNRS/Université d'Orleans/BRGM Orleans 45071 France Chinese Academy of Sciences Key Laboratory of Mineralogy and Metallogeny Guangzhou Institute of Geochemistry Chinese Academy of Sciences Guangzhou 510640 China

The Middle-Late Jurassic Cu-Pb-Zn-bearing and W-bearing granites in the Nanling Range have distinctly different mineralogical and geochemical signatures. The Cu-Pb-Zn-bearing granites are dominated by metaluminous amphibole-bearing granodiorites, which have higher CaO/(Na2O+K2O) ratios, light/heavy rare earth element(LREE/HREE) ratios, and δEu values,lower Rb/Sr ratios, and weak Ba, Sr, P, and Ti depletions, exhibiting low degrees of fractionation. The W-bearing granites are highly differentiated and peraluminous, and they have lower CaO/(Na2O+K2O) ratios, LREE/HREE ratios, and δEu values,higher Rb/Sr ratios, and strong Ba, Sr, P, and Ti depletions. The Cu-Pb-Zn-bearing granites were formed predominantly between155.2 and 167.0 ma with a peak value of 160.6 ma, whereas the W-bearing granites were formed mainly from 151.1 to 161.8ma with a peak value of 155.5 ma. There is a time gap of about 5 ma between the two different types of ore-bearing *** on detailed geochronological and geochemical studies of both the Tongshanling Cu-Pb-Zn-bearing and Weijia W-bearing granites in southern Hunan Province and combined with the other Middle-Late Jurassic Cu-Pb-Zn-bearing and W-bearing granites in the Nanling Range, a genetic model of the two different types of ore-bearing granites has been proposed. Asthenosphere upwelling and basaltic magma underplating were induced by the subduction of the palaeo-Pacific plate. The underplated basaltic magmas provided heat to cause a partial melting of the mafic amphibolitic basement in the lower crust, resulting in the formation of Cu-Pb-Zn mineralization related granodioritic magmas. With the development of basaltic magma underplating,the muscovite-rich metasedimentary basement in the upper-middle crust was partially melted to generate W-bearing granitic magmas. The compositional difference of granite sources accounted for the metallogenic specialization, and the non-simultaneous partial melting of one source followed by the other

关键词： Cu-Pb-Zn-bearing granites W-bearing granites Petrogenesis Middle-Late Jurassic Nanling Range

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Carbon and sulfur isotopic compositions of Early Cambrian black shales, NW Hunan, China: Implications for the Paleoceanographic sedimentary environment

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Chinese Journal Of Geochemistry 2011年第3期30卷 332-345页

作者： ma dongsheng CAO Shuanglin PAN Jiayong XIA Fei YAO Chunyan DING Haifeng State Key Laboratory for Mineral Deposit Research Nanjing University Nanjing 210093 China Department of Geoscience and Resource Information East China Institute of Technology Fuzhou 344000 China

In order to better understand the paleoceanographic sedimentary environment of the Lower Cambrian black shales extensively distributed in South China, outcropped along the present southern margin of the Yangtze Platform with a width of ca. 200-400 km and a length of more than 1500 km, we present new paired δ13C data on carbonates (δ13Ccarb) and associated organic carbon (δ13Corg) and δ34Spy data on sedimentary pyrite in black shales from three sections (Ganziping, Shancha and Xiaohekou) located in NW Hunan, China. In these sections, a total of 82 Lower Cambrian black shale samples have δ13Ccarb values ranging from -4.0‰ to 1.7‰ with an average value of -2.1‰, and δ13Corg values between -34.9‰ and -28.8‰, averaging -31.9‰. The ?34Spy values of 16 separated sedi-mentary pyrite samples from the black shales vary between +10.2‰ and +28.7‰ with an average value of +19.5‰, presenting a small isotope fractionation between seawater sulfate and sedimentary sulfide. The model calculation based on credible data from the paired analyses for δ13Ccarb and δ13Corg of 11 black shale samples shows a high CO2 concentration in the Early Cambrian atmosphere, about 20 times higher than pre-industrial revolution values, consis-tent with previous global predictions. The small sulfur isotope fractionation between seawater sulfate and sedimen-tary sulfide in black shales, only 15.5‰ on average, implies a low sulfate level in the Early Cambrian seawater around 1 mmol. In combination with a high degree of pyritization (DOP) in the black shales, it is suggested that sul-fidic deep-ocean water could have lingered up to the earliest Cambrian in this area. The black shale deposition is envisaged in a stratified marine basin, with a surface euphotic and oxygenated water layer and sulfidic deeper water, controlled by a continental margin rift.

关键词：硫同位素组成黑色页岩沉积环境中国南方古海洋学碳酸盐岩早寒武世湖南

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Ultrathin ternary PtNiGa nanowires for enhanced oxygen reduction reaction

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Chinese Chemical Letters 2024年第2期35卷 599-603页

作者： Giday Fisseha Yiping Hu Yanan Yu Shaojie Lu dongsheng ma Pei Nian Zheng Wang Qin Yue Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaChengdu 610054China State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering School of Chemistry and Chemical EngineeringNingxia UniversityYinchuan 750021China

Achieving high activity and durability for the oxygen reduction reaction(ORR)with an ultra-low amount of platinum is significant to promote the widespread application of proton exchange membrane fuel cells(PEMFCs).Here we report a new ultrathin(∼1 nm)ternary PtNiGa alloy nanowires(PtNiGa NWs)electrocatalyst,in which the presence of gallium(Ga)enhances the oxidation resistance of platinum(Pt)and nickel(Ni)and suppresses the dissolution of *** mass and specific activities of PtNiGa NWs are about 11.2 and 7.6 times higher than those of commercial Pt/C catalysts for ***,the mass activity of PtNiGa/C NWs nanocatalyst decreased only by 12.8%and largely retained its electrochemical surface area(ECSA)after 10,000 potential cycles,compared with 38%loss of ECSA for commercial Pt/C ***,this work provides a general guideline for preparing ternary alloy electrocatalysts and enhancing the activity and stability of the cathode ORR reaction of PEMFCs.

关键词： Ultrathin nanowires Gallium Oxygen reduction reaction Ternary alloy Durability

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High-entropy alloy nanoparticles as a promising electrocatalyst to enhance activity and durability for oxygen reduction

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Nano Research 2022年第9期15卷 7868-7876页

作者： Yanan Yu Fanjie Xia Chengjie Wang Jinsong Wu Xianbiao Fu dongsheng ma Bencai Lin Jiaao Wang Qin Yue Yijin Kang Institute of Fundamental and Frontier Sciences University of Electronic Science and Technology of ChinaChengdu 610054China State Key Laboratory of Advanced Technology for materials Synthesis and Processing Nanostructure Research CenterWuhan University of TechnologyWuhan 430070China Jiangsu Province Cultivation base for State Key Laboratory of Photovoltaic Science and Technology Changzhou UniversityChangzhou 213164China Department of Chemistry and the Oden Institute for Computational Engineering and Sciences The University of Texas at AustinTX 78712USA

Developing efficient platinum-based electrocatalysts with super durability for the oxygen reduction reaction(ORR)is highly desirable to promote the large-scale commercialization of fuel *** progress has been made in this aspect,the electrochemical kinetics and stability of platinum-based catalysts are still far from the requirements of the practical ***,PtPdFeCoNi high-entropy alloy(HEA)nanoparticles were demonstrated via a high-temperature injection *** HEA nanocatalyst exhibits outstanding catalytic activity and stability towards ORR due to the high entropy,lattice distortion,and sluggish diffusion effects of HEA,and the HEA nanoparticles delivered a mass activity of 1.23 A/mgPt and a specific activity of 1.80 ma/cmPt 2,which enhanced by 6.2 and 4.9 times,respectively,compared with the values of the commercial Pt/C *** importantly,the high durability of PtPdFeCoNi HEA/C was evidenced by only 6 mV negativeshifted half-wave potential after 50,000 cycles of accelerated durability test(ADT).

关键词： high-entropy alloy oxygen reduction reaction electrocatalyst high durability

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Re–Os and Pb isotope features of pyrite in the Shihangli graphite deposit:implications of coal-generated graphite mineralization in central Hunan,South China

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Acta Geochimica 2023年第5期42卷 895-911页

作者： Yong Zhang dongsheng ma Jian-Feng Gao Jiayong Pan Xupeng Lv Guoqi Liu Fujun Zhong Xiaotian Zhang Ying Liu State Key Laboratory of Nuclear Resources and Environment East China University of TechnologyNanchang 330013China School of Earth Sciences and Engineering Nanjing UniversityNanjing 210046China State Key Laboratory of Ore Deposit Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China Yunnan Institute of Geological Survey Kunming 650032China

The coal metamorphism in Central Hunan pro-vides valuable information about hydrothermal activity and water/rock *** how to collect age data on hydrothermal fluid systems is necessary for understanding the history and genetic mechanisms of large-scale coal-generated graphite *** Shihangli graphite deposit,formed by significant siliceous hydrothermal alteration,is the most distinctive in Central ***–Os dating of pyrite from the Shihangli graphite deposit demonstrates that the coal-generated graphite mineraliza-tion age is-127.6±3.8 *** on in-situ mineral analysis,the hydrothermal pyrite in the Shihangli graphite deposit is mostly enriched in Sb,As,Au,W,Ag,Cu,Pb,and *** on the pyrite Re–Os isochron,the initial(^(187)Os/^(188)Os)values of pyrite were 1.03±0.24 and the Os(t)values varied from 571.8 to *** from the Shihangli graphite deposit comprises a Pb isotope composition similar to that of the madiyi Formation bulk rock and stibnite from the Xikuangshan Sb *** on the Re–Os,Sr,S,and Pb isotopic compositions of sul-fides in the graphite and Sb deposits in Central Hunan,the madiyi Formation was likely the primary source of ore-forming elements(Sb,Au,and As).The Re–Os and Pb isotope compositions of pyrite most likely reflect when large-scale fluid migration and coal-generated graphite mineralization occurred in Central Hunan.

关键词： Pyrite Re–Os Pb isotope Graphite Central Hunan

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