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Formation time of the big mantle wedge beneath eastern China and a new lithospheric thinning mechanism of the North China craton—Geodynamic effects of deep recycled carbon

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Science China Earth Sciences 2018年第7期61卷 853-868页

作者： Shuguang LI Yang Wang State Key Laboratory of Geological Processes and Mineral Resources China University of Geosciences CAS Key Laboratory of Crust-Mantle Materials and Environments School of Earth and Space Sciences University of Science and Technology of China

High-resolution P wave tomography shows that the subducting Pacific slab is stagnant in the mantle transition zone and forms a big mantle wedge beneath eastern China. The Mg isotopic investigation of large numbers of mantle-derived volcanic rocks from eastern China has revealed that carbonates carried by the subducted slab have been recycled into the upper mantle and formed carbonated peridotite overlying the mantle transition zone, which becomes the sources of various basalts. These basalts display light Mg isotopic compositions(δ26 Mg = –0.60‰ to –0.30‰) and relatively low87 Sr/86 Sr ratios(0.70314–0.70564) with ages ranging from 106 Ma to Quaternary, suggesting that their mantle source had been hybridized by recycled magnesite with minor dolomite and their initial melting occurred at 300-360 km in depth. Therefore, the carbonate metasomatism of their mantle source should have occurred at the depth larger than 360 km, which means that the subducted slab should be stagnant in the mantle transition zone forming the big mantle wedge before 106 Ma. This timing supports the rollback model of subducting slab to form the big mantle wedge. Based on high P-T experiment results, when carbonated silicate melts produced by partial melting of carbonated peridotite was raising and reached the bottom(180–120 km in depth) of cratonic lithosphere in North China, the carbonated silicate melts should have 25–18 wt% CO2 contents, with lower Si O2 and Al2 O3 contents, and higher Ca O/Al2 O3 values, similar to those of nephelinites and basanites, and have higher εNdvalues(2 to 6). The carbonatited silicate melts migrated upward and metasomatized the overlying lithospheric mantle, resulting in carbonated peridotite in the bottom of continental lithosphere beneath eastern China. As the craton lithospheric geotherm intersects the solidus of carbonated peridotite at 130 km in depth, the carbonated peridotite in the bottom of cratonic lithosphere should be partially melted, thus its physical characters are similar to the asthenosphere an

关键词：形成时间再循环碳酸盐中国东方北方机制融化过程

A Large-Scale Cross-Sectional Study on Mental Health Status Among Children and Adolescents - Jiangsu Province, China, 2022

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China CDC weekly 2023年第32期5卷 710-714页

作者： Xin wang Yan wang Xiyan Zhang Wenyi yang Jie yang Department of Child and Adolescent Health Promotion Jiangsu Provincial Center for Disease Control and PreventionNanjing CityJiangsu ProvinceChina

What is already known about this topic?The prevalence of mental health disorders among children and youth in China stands at 17.5%,a figure that has been gradually escalating over recent years.This surge has led to substantial psychological distress and financial strain for both families and the wider society.What is added by this report?This study boasts an expansive geographical scope by covering the Jiangsu Province extensively and utilizing a substantial sample size.An investigation was conducted on the prevalence and risk factors,which included family type and health behaviors,of depressive,anxiety,and stress symptoms.What are the implications for public health practice?The mental health status of children and adolescents should be of great concern to the government.Therefore,it is important that public health measures are implemented to mitigate the development of depressive symptoms.These measures may include regular screening procedures and the implementation of proven interventions.

关键词： measures utilizing Jiangsu

Prototethyan orogenesis in southwest Yunnan and Southeast Asia

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Science China Earth Sciences 2022年第10期65卷 1921-1947页

作者： Yuejun wang Xianghong LU Xin QIAN Sainan WU Yuzhi ZHANG Yang Wang Guangdong Key Lab of Geodynamics and Geohazards School of Earth Sciences and EngineeringSun Yat-sen UniversityZhuhai 519082China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 519082China

The Prototethyan Ocean has been suggested as an Early Paleozoic Ocean developed at the Gondwana northern margin. However, its spatial pattern, subduction style and closure time in SW Yunnan and SE Asia still remain unknown. The Prototethyan evolution in SW Yunnan and SE Asia and its internal connection with the South China Kwangsian(Ordo-Silurian)intracontinental orogenesis are also poorly constrained. By summarizing and analyzing the Early Paleozoic geological records in the Sibumasu and Indochina blocks, the eastern South China and SW Japan, this paper proposes the existence of a giant OrdoSilurian igneous belt along the Gondwana northern margin. A preliminary limitation has been obtained regarding the source nature and migration pattern of the igneous belt. Our data allow us to propose a model of the Early Paleozoic Andean-type active continental margin along the East Gondwana northern margin. This is the foundation to determine the southward subduction of the southern branch of the eastern Prototethyan Ocean underneath the Sibumasu and Indochina blocks along the YunxianMenghai(SW Yunnan)-Thailand Peninsula and the Tam Ky-Phouc Son suture in Central Vietnam, respectively, and the eastward linkage with the Early Paleozoic Osaka subduction zone in SW Japan across the peripheral Sanya area. These data synthetically indicate an easterly-diachronous and propagating Andean-type Cambrian(Furongian)-Silurian(Llandovery) orogenesis along the Gondwana northern margin from Nepal, NW India, South Tibet, Qiangtang to Central Vietnam across South Indochina and Sibumasu. This paper reconstructs the Early Paleozoic locations of the Sibumasu and Indochina fragments, as well as SW Japan and South China continent in the Gondwana northern margin, and proposes the far-field effect on the South China Kwangsian intra-continental orogenesis from the subduction of the Early Paleozoic Prototethyan southern branch.

关键词： Igneous rocks Sedimentary sequence Early Paleozoic Prototethyan southern branch ocean Andean-type orogenesis SW Yunnan and SE Asia

Investigation on environment monitoring system for a combination of hydroponics and aquaculture in greenhouse

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Information Processing in Agriculture 2022年第1期9卷 123-134页

作者： Shanhong Zhang Yu Guo Shuai Li Zhixin Ke Huajian Zhao Jinqi yang Yang Wang Daoliang Li Liang wang Wenhua yang Zhili Zhang National Innovation Center for Digital Fishery China Agricultural UniversityBeijing 100083China College of Information and Electrical Engineering China Agricultural UniversityBeijing 100083China Beijing Zhong Nong Tianlu Micro-nano Bubble Water Science and Technology Co. LtdChina

This work develops a distributed environmental monitoring system for the combination of hydroponics and aquaculture based on the internet of things technology,which mainly includes the information perception layer,the information transmission layer and the sys-tem architecture.The system has employed multiple sensors terminal to real-time acqui-sition,including air and water temperatures,dissolved oxygen etc.LoRa protocol is suitable for sending small data and the 4G was employed to collect data and send to the cloud plat-form.Java is used to develop background applications,to access cloud platforms and local data processing.Based on the collection and processing of environmental data and cloud service platform,the mobile application program client and remote login desktop have been developed.It has been implemented and tested in Tongzhou,Beijing for 3 months in 2020.The results showed the proposed monitoring system stability for overall operation and accuracy data transmission,which can support the actual hydroponics and aquacul-ture production management.After analysis of monitoring data collected from the devel-oped monitoring system,indoor air and water temperature have the obvious correlation with atmospheric pressure(0.7 and 0.9)and outdoor temperature(1.0 and 0.9),respectively.

关键词： Monitoring system Hydroponics Aquaculture Greenhouse Internet of things Greenhouse environment

Corrosion resistance and electrical conductivity of V/Ce conversion coating on magnesium alloy AZ31B

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矿物冶金与材料学报：英文版 2023年第4期30卷 653-659页

作者： Jinxiao yang Xudong wang Yiren Cai Xiuyu yang Institute of Advanced Materials and Technology University of Science and Technology BeijingBeijing 100083China NAURA Technology Group Co. LtdBeijing 100176China

A V/Ce conversion coating was deposited in the surface of AZ31B magnesium alloy in a solution containing vanadate and cerium nitrate.The coating composition and morphology were examined.The conversion coating appears to consist of a thin and cracked coating with a scattering of spherical particles.The corrosion behavior of the substrate and conversion coating was studied by potentiodynamic polarization and electrochemical impedance spectroscopy (EIS).Compared with AZ31B magnesium alloy,the corrosion current density of the conversion coating is decreased by two orders of magnitude.The total impedance of the V/Ce conversion coating rise to 1.6×10^(3)Ω·cm^(2)in contrast with2.2×10^(2)Ω·cm^(2)of the bare AZ31B.In addition,the electrical conductivity of the coating was assessed by conductivity meter and Mott-Schottky measurement.The results reveal a high dependence of the conductivity of the coating on the semiconductor properties of the phase compositions.

关键词： AZ31B magnesium alloy conversion coating conductivity corrosion resistance

N-doped carbon nanotube encapsulated nZVI as a high-performance bifunctional catalyst for oxidative desulfurization

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Particuology 2023年第10期81卷 109-118页

作者： Ge Zhang Fan yang wang yang Yongfeng Li State Key Laboratory of Heavy Oil Processing China University of PetroleumBeijingChina Beijing NAURA Vacuum Technology Co. LtdBeijingChina

Great efforts have been made to remove sulfur from fossil fuels to protect the environment.We proposed synthesis of high efficiency oxidation desulfurization(ODS)catalysts by encapsulating nano zero valent iron(nZVI)in self-catalyzed carbon nanotubes.The synthetic strategy features facile hydrothermal and pyrolysis process.The specific surface area,pore structure,and microstructure of the catalysts were characterized by series techniques,and the catalytic ability was evaluated by the reduction of sulfur after oxidation and reflux-extraction.The optimized nZVI@CNT catalyst exhibits outstanding catalytic performance(within 120 min,the oxidative removal rate of DBT reached 96%)and enhanced stability(a 80%retention of initial performance after six cycles.),revealing the effective optimization and modulation between carbon nanotubes and iron particles.This excellent ODS activity originated from the defects of N-doped nanotubes as well as excellent particle dispersion and material transport capacity,which excites highly active free radicals with the assistance of H_(2)O_(2).In addition,the unique two-dimensional tube channel and mesoporous structure promoted the diffusion and transfer of reactants and electrons,leading to high density of active sites.The different experimental conditions confirmed that the material is a bifunctional catalyst integrating adsorption and catalysis.This work provides an creative ideas for the rational design and synthesis of advanced ODS catalysts for fuel oil.

关键词： Carbon nanotubes Oxidative desulfurization Dispersion Nanoscale zero valent iron

Deep Underground Energy Storage:Aiming for Carbon Neutrality and Its Challenges

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Engineering 2023年第10期29卷 11-14页

作者： Chunhe yang Tongtao wang State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil MechanicsChinese Academy of SciencesWuhan 430071China

1.Definition of deep underground energy storage Deep underground energy storage(DUES)is an important strategic practice for ensuring China’s energy supply,its national defense,and the realization of China’s strategic goals of achieving a carbon peak and carbon neutrality(CPCN).In 2021,China’s oil and natural gas consumption reached 712 million tonnes and 372.6 billion cubic meters,respectively,while its external dependence reached about 72%and 45%.China’s reserves only met about 30%of the requirements for a safe supply and peak shaving.

关键词： underground realization strategic

Urbanization strengthens the edge effects on species diversity and composition of woody plants in remnant forests

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Forest Ecosystems 2022年第5期9卷 657-665页

作者： Zijin wang Jingyi yang College of Forestry Guizhou UniversityGuiyang550025China

Background:Urban remnant forests are embedded in urban areas and are threatened directly and indirectly by urbanization.The direct effects(e.g.,loss of area)have been well studied.However,knowledge about the indirect influence of urbanization through edge effects on the biodiversity in remnant forests is limited.Methods:In this study,we surveyed woody plant species in 72 plots in nine remnant forest patches in Guiyang,China.We examined the influences of urbanization and edge effects on the species diversity and composition of woody plants in remnant forests.We compared alpha diversities and quantified compositional dissimilarities in interior and edge sites at different levels of urbanization.We also measured the niche width of the recorded plant species and assessed whether high levels of urbanization and edge effects increased the number of generalist species.Results and conclusions:The Shannon index,the Simpson index and the Pielou index of adult trees were lowest in the edge habitat under high levels of urbanization.Significant differences in the Shannon index and the Simpson index of sapling/seedling were detected between interior and edge sites under low urbanization.The edge effects on the species composition of adult trees were intensified by high levels of urbanization.Woody plant species with wide niche widths were more abundant at edge sites under high levels of urbanization.Therefore,we recommend that urban expansion surrounding remnant patches should be strictly controlled to alleviate edge effects on biodiversity.

关键词： Remnant forest Urbanization Edge effect Species diversity and composition Niche width Guiyang

Characterization of Regional Combustion Efficiency usingΔXCO:ΔXCO_(2)Observed by a Portable Fourier-Transform Spectrometer at an Urban Site in Beijing

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Advances in Atmospheric Sciences 2022年第8期39卷 1299-1315页

作者： Ke CHE Yi LIU Zhaonan CAI Dongxu yang Haibo wang Denghui JI yang yang Pucai wang Key Laboratory of Middle Atmosphere and Global Environment Observation Institute of Atmospheric PhysicsChinese Academy of ScienceBeijing 100029China Carbon Neutrality Research Center Institute of Atmospheric PhysicsChinese Academy of ScienceBeijing 100029China University of Chinese Academy of Science Beijing 100049China

Measurements of column-averaged dry-air mole fractions of carbon dioxide and carbon monoxide,CO_(2)(XCO_(2))and CO(XCO),were performed throughout 2019 at an urban site in Beijing using a compact Fourier Transform Spectrometer(FTS)EM27/SUN.This data set is used to assess the characteristics of combustion-related CO_(2)emissions of urban Beijing by analyzing the correlated daily anomalies of XCO and XCO_(2)(e.g.,ΔXCO andΔXCO_(2)).The EM27/SUN measurements were calibrated to a 125HR-FTS at the Xianghe station by an extra EM27/SUN instrument transferred between two sites.The ratio ofΔXCO overΔXCO_(2)(ΔXCO:ΔXCO_(2))is used to estimate the combustion efficiency in the Beijing region.A high correlation coefficient(0.86)betweenΔXCO andΔXCO_(2)is observed.The CO:CO_(2)emission ratio estimated from inventories is higher than the observedΔXCO:ΔXCO_(2)(10.46±0.11 ppb ppm^(−1))by 42.54%-101.15%,indicating an underestimation in combustion efficiency in the inventories.DailyΔXCO:ΔXCO_(2)are influenced by transportation governed by weather conditions,except for days in summer when the correlation is low due to the terrestrial biotic activity.By convolving the column footprint[ppm(μmol m-2 s-1)-1]generated by the Weather Research and Forecasting-X-Stochastic Time-Inverted Lagrangian Transport models(WRF-X-STILT)with two fossil-fuel emission inventories(the Multi-resolution Emission Inventory for China(MEIC)and the Peking University(PKU)inventory),the observed enhancements of CO_(2)and CO were used to evaluate the regional emissions.The CO_(2)emissions appear to be underestimated by 11%and 49%for the MEIC and PKU inventories,respectively,while CO emissions were overestimated by MEIC(30%)and PKU(35%)in the Beijing area.

关键词： FTS remote sensing ΔXCO:ΔXCO_(2) combustion efficiency megacity