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Thermal History of Cambrian Burgess Shale-Type Deposits:New Insights from the Early Cambrian Chengjiang and Qingjiang Fossils of South China

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Journal of Earth Science 2024年第4期35卷 1215-1223页

作者： Yuheng Qiao Linhao Cui Guangyuan Xing Dongjing Fu Chao chang robert Gaines Xingliang Zhang State Key Laboratory of Continental Dynamics Shaanxi Key laboratory of Early Life and EnvironmentsDepartment of GeologyNorthwest UniversityXi’an710069China Department of Geology Pomona CollegeClaremontCA91711USA

Burgess Shale-type deposits provide a wealth of information on the early evolution of *** that are central to understanding the exceptional preservation of these biotas and the paleoenvironments they inhabited may be obscured by the post-depositional alteration due to metamorphism at depth and weathering near the Earth’s *** over 50 Cambrian BST biotas,the Chengjiang and Qingjiang deposits are well known for their richness of soft-bodied taxa,fidelity of preservation,and Early Cambrian *** alteration via weathering has been well-investigated,the thermal maturity of the units bearing the two biotas has not yet been *** we investigate peak metamorphic temperatures of the two deposits using two independent *** gradient analyses demonstrate that the most fossiliferous sections of the Chengjiang were buried at a maximum depth of∼8500 m in the Early Triassic,corresponding to∼300°C,while the type area of the Qingjiang biota was buried at a maximum depth of∼8700 m in the Early Jurassic,corresponding to∼240°*** geothermometer analyses of fossil carbonaceous material demonstrate that peak temperatures varied across localities with different burial *** two productive sections of the Chengjiang biota were thermally altered at a peak temperature of approximately 300°C,and the main locality of the Qingjiang biota experienced a peak temperature of 238±22°*** results from two independent methods are *** BST deposits for which thermal maturity has been documented,the Qingjiang biota is the least thermally mature,and therefore holds promise for enriching our understanding of BST deposits.

关键词： the Chengjiang Biota the Qingjiang Biota burial history Raman geothermometer thermal history Burgess Shale-type Lagerstätte

Ruthenium-lead oxide for acidic oxygen evolution reaction in proton exchange membrane water electrolysis

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Nano Research 2024年第10期17卷 8671-8677页

作者： Feng-Yang Chen chang Qiu Zhen-Yu wu Tae-Ung wi YZou Finfrock Haotian wang Department of Chemical and Biomolecular Engineering Rice UniversityHoustonTX 77005USA Structural Biology Center X-ray Science DivisionArgonne National LaboratoryLemontIL 60439USA Department of Materials Science and NanoEngineering Rice UniversityHoustonTX 77005USA Department of Chemistry Rice UniversityHoustonTX 77005USA

Developing an active and stable anode catalyst for the proton exchange membrane water electrolyzer(PEM-wE)is a critical objective to enhance the economic viability of green hydrogen ***,the expensive iridium-based electrocatalyst remains the sole practical material with industrial-level stability for the acidic oxygen evolution reaction(OER)at the ***-based catalysts have been proposed as more cost-effective alternatives with improved activity,though their stability requires *** current urgent goal is to reduce costs and noble metal loading of the OER catalyst while maintaining robust activity and *** this study,we design a Ru-based OER catalyst incorporating Pb as a supporting *** electrocatalyst exhibits an OER overpotential of 201 mV at 10 mA·cm^(-2),simultaneously reducing Ru noble metal loading by~40%.Normalization of the electrochemically active surface area unveils improved intrinsic activity compared to the pristine RuO_(2) *** a practical stability test in a PEM-wE setup,our developed catalyst sustains stable performance over 300 h without notable degradation,underscoring its potential for future applications as a reliable anodic catalyst.

关键词： electrocatalysis oxygen evolution reaction water splitting proton exchange membrane water electrolyzer

Atom-referenced and stabilized soliton microcomb

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Science China(Physics,Mechanics & Astronomy) 2024年第2期67卷 2-8页

作者： Rui Niu Shuai wan Tian-Peng Hua wei-Qiang wang Zheng-Yu wang Jin Li Zhu-Bo wang Ming Li Zhen Shen Yu robert Sun Shui-Ming Hu Brent ELittle Sai Tak Chu wei Zhao Guang-Can Guo chang-Ling Zou Yun-Feng Xiao wen-Fu Zhang Chun-Hua Dong State Key Laboratory of Transient Optics and Photonics Xi’an Institute of Optics and Precision MechanicsChinese Academy of SciencesXi’an 710119China CAS Key Laboratory of Quantum Information University of Science and Technology of ChinaHefei 230026China CAS Center for Excellence in Quantum Information and Quantum Physics University of Science and Technology of ChinaHefei 230026China University of Chinese Academy of Sciences Beijing 100049China Department of Chemical Physics University of Science and Technology of ChinaHefei 230026China Department of Physics and Materials Science City University of Hong KongHong Kong 999077China State Key Laboratory for Mesoscopic Physics and Frontiers Science Center for Nano-optoelectronics School of PhysicsPeking UniversityBeijing 100871China

For the applications of the frequency comb in microresonators,it is essential to obtain a fully frequency-stabilized microcomb laser *** this study,we present a system for generating a fully atom-referenced stabilized soliton *** pump light around 1560.48 nm is locked to an ultra-low-expansion(ULE)*** pump light is then frequency-doubled and referenced to the atomic transition *** repetition rate of the soliton microcomb is injection-locked to an atomic-clockstabilized radio frequency(RF)source,leading to mHz stabilization at 1 *** a result,all comb lines have been frequencystabilized based on the atomic reference and the ULE cavity,achieving a very high precision of approximately 18 Hz at 1 s,corresponding to the frequency stability of 9.5×10^(-14).Our approach provides a fully stabilized microcomb experiment scheme with no requirement of f-2f technique,which could be easily implemented and generalized to various photonic platforms,thus paving the way towards the ultraprecise optical sources for high precision spectroscopy.

关键词： microcavity frequency comb dissipative Kerr solitons fully stabilized microcomb

REACHING PAST LUNAR LIMITS

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Beijing Review 2024年第31期67卷 20-21页

作者： robert walker Jingshi Academyat Beijing Normal University Green Templeton College University of Oxford

Chaqg'e is the Chinese moon *** after'her,the chang'e-6 lunar module returned to Earth this June carrying 1,935.3 grams of rocks and dust from the far side of the moon.A world first,the unique samples-more viscous and... 详细信息

关键词： analysis. globally REACH

Aiming Far Beyond the Moon

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China Today 2024年第8期73卷 38-40页

作者： robert wALKER Green Templeton College University of Oxford Beijing Normal University Royal Society of Arts Academy of Social Sciences in the U.K.

Understanding the importance that the third plenary session of the 20th Central Committee of the Communist Party of China(CPC)attached to science and technological ***’E is the Chinese moon *** after her,the chang’e... 详细信息

关键词： development. attached Beyond

Bone morphogenetic protein signaling：a promising target for white matter protection in perinatal brain injury

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Neural Regeneration Research 2018年第7期13卷 1183-1184页

作者： Jill chang robert w.Dettman Maria L.V.Dizon Department of Pediatrics Feinberg School of Medicine Northwestern University Chicago IL USA Stanley Manne Research Institute Chicago IL USA

Prematurely born newborns,as well as those born at term,may suffer from several types of brain injury including hypoxic-ischemic injury,intracranial hemorrhage,both intraventricular and parenchymal,and injury that is the consequence of intrauterine growth restriction（IUGR）.Injury of all types can impact the motor and cognitive abilities of *** mechanisms leading to disability are not completely understood.

关键词： In Bone morphogenetic protein signaling:a promising target for white matter protection in perinatal brain injury

早寒武纪清江丝菌牵出硫酸盐还原菌与地球环境协同演化历史

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Science Bulletin 2024年第10期69卷 1486-1494页

作者：崔琳浩朱珂磊李瑞云常超吴来源刘伟傅东静刘沛余邱浩唐国强李秋立 robert R.Gaines 陶昕王寅李金华张兴亮 State Key Laboratory of Continental Dynamics Shaanxi Key Laboratory of Early Life and EnvironmentsDepartment of GeologyNorthwest UniversityXi’an 710069China Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China State Key Laboratory of Lithospheric Evolution Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Department of Geology Pomona CollegeClaremont CA 91711USA State Key Laboratory of Microbial Metabolism School of Life Sciences and BiotechnologyShanghai Jiao Tong UniversityShanghai 200240China

Sulfate reduction is an essential metabolism that maintains biogeochemical cycles in marine and terrestrial *** reducers are exclusively prokaryotic,phylogenetically diverse,and may have evolved early in Earth’s ***,their origin is elusive and unequivocal fossils are *** we report a new microfossil,Qingjiangonema cambria,from518-million-year-old black shales that yield the Qingjiang *** is a long filamentous form comprising hundreds of cells filled by equimorphic and equidimensional pyrite microcrystals with a light sulfur isotope *** lines of evidence indicate Qingjiangonema was a sulfate-reducing bacterium that exhibits similar patterns of cell organization to filamentous forms within the phylum Desulfobacterota,including the sulfate-reducing Desulfonema and sulfide-oxidizing cable *** analyses confirm separate,independent origins of multicellularity in Desulfonema and in cable *** clock analyses infer that the Desulfobacterota,which encompass a majority of sulfate-reducing taxa,diverged~2.41 billion years ago during the Paleoproterozoic Great Oxygenation Event,while cable bacteria diverged~0.56 billion years ago during or immediately after the Neoproterozoic Oxygenation *** together,we interpret Qingjiangonema as a multicellular sulfate-reducing microfossil and propose that cable bacteria evolved from a multicellular filamentous sulfate-reducing *** infer that the diversification of the Desulfobacterota and the origin of cable bacteria may have been responses to oxygenation events in Earth’s history.

关键词： Cambrian Qingjiangonema Sulfate-reducing bacteria Cable bacteria Qingjiang biota Black shale

Structural and optical verification of residual strain effect in single crystalline CdTe nanowires

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Nano Research 2014年第2期7卷 228-235页

作者： Liubing Huang Siyuan Lu Paichun chang Karan Banerjee robert Hellwarth Jia Grace Lu Department of Physics and Astronomy Department of Electrical Engineering University of Southern California Los Angeles CA90089 USA IBM Thomas.I. watson Research Center 1101 Kitchawan Road Yorktown Heights NY 10598 USA

Single crystalline CdTe nanowires have been synthesized using Au-catalyzed chemical vapor deposition. X-ray diffraction reveals the existence of non- negligible inhomogeneous compressive strain in the nanowires along the 〈111〉 growth direction. The effect of the strain on the electronic structure is manifested by the blue-shifted and broadened photoluminescence spectra involving shallow donor/acceptor states. Such residual strain is of great importance for a better understanding of the optical and electrical behaviors of various semiconductor nanomaterials as well as for device design and applications.

关键词： CdTe nanowire single crystalline chemical vapor deposition residual strain photoluminescence

Geographic Spread of Currency Trading:The Renminbi and Other Emerging Market Currencies

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China & world Economy 2019年第5期27卷 25-36页

作者： Yin-wong Cheung robert N McCauley chang Shu Department of Economics and Finance City University of Hong KongChina Monetary and Economic Department Bank for International Settlements(BIS) Bloomberg USA

This paper studies the ongoing diffusion of renminbi (RMB) trading across the globe, the first of such research of an international currency. It analyses the distribution in offshore RMB trading in 2013 and 2016 using comprehensive data from the Triennial Central Bank Survey of foreign exchange markets. In 2013, Asian centers favored by the policy of RMB internationalization had disproportionate shares in global RMB trading. Over the following three years, RMB trading seemed to converge to the spatial pattern of all currencies, with a half-life of seven to eight years. The previously most traded emerging market currency, the Mexican peso, shows a similar pattern, although it is converging to the global norm more slowly. Three other emerging market currencies show a qualitatively similar evolution in the geography of their offshore trading. Overall, the RMB's internationalization is tracing an arc from the influence of administrative measures to the working of market forces.

关键词： foreign exchange turnover international currency international financial center renminbi internationalization