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India at crossroads for energy

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Geoscience Frontiers 2021年第6期12卷 356-360页

作者： Mu Ramkumar M.Santosh Manoj J.Mathew Numair A.Siddiqui Department of Geology Periyar UniversitySalem636011India School of earth Sciences and Resources China University of Geosciences(Beijing)Beijing100083China Department of earth Science University of AdelaideAdelaideSAAustralia Shale Gas Research Group Institute of Hydrocarbon RecoveryUniversiti Teknologi PETRONAS32610Seri IskandarMalaysia Department of Geosciences Universiti Teknologi PetronasTronohMalaysia

As one of the fastest growing economies and further larger consumer of energy in the world, there has been a paradigm shift in India’s energy demand. Here we evaluate the growth of Indian economy its, diversification of agriculture-based economy to industrial production, service and digital-technology based economy and deepening of income sources, although the dependence on foreign sources for energy demands has not markedly *** situation has placed India at the crossroads for energy sufficiency, especially under the highly fluid and changing geopolitical, strategic, environmental and economic scenarios of the World order. We attempt to understand the issue from geological perspective and address some of the impediments.

关键词： Economy Energy sources Technology Geological impediments India

Evaluation of temporal compositing algorithms for annual land cover classification using Landsat time series data

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International Journal of Digital earth 2023年第1期16卷 2574-2598页

作者： Xichen Meng Shuai Xie Lin Sun Liangyun Liu Yilong Han College of Geodesy and Geomatics Shandong University of Science and TechnologyQingdaoPeople’s Republic of China bKey Laboratory of Digital earth Science Aerospace Information Research InstituteChinese Academy of SciencesBeijingPeople’s Republic of China

In this paper, four widely used temporal compositing algorithms, ***, maximum NDVI, medoid, and weighted scoring-basedalgorithms, were evaluated for annual land cover classification usingmonthly Landsat time series data. Four study areas located in California,Texas, Kansas, and Minnesota, USA were selected for image compositingand land cover classification. Results indicated that images compositedusing weighted scoring-based algorithms have the best spatial fidelitycompared to other three algorithms. In addition, the weighted scoringbasedalgorithms have superior classification accuracy, followed bymedian, maximum NDVI, and medoid in descending order. However, themedian algorithm has a significant advantage in computational efficiencywhich was ~70 times that of weighted scoring-based algorithms, andwith overall classification accuracy just slightly lower (~0.13% onaverage) than weighted scoring-based algorithms. Therefore, werecommended the weighted scoring-based compositing algorithms forsmall area land cover mapping, and median compositing algorithm forthe land cover mapping of large area considering the balance betweencomputational complexity and classification accuracy. The findings of thisstudy provide insights into the performance difference between variouscompositing algorithms, and have potential uses for the selection ofpixel-based image compositing technique adopted for land covermapping based on Landsat time series data.

关键词： Temporal compositing spatial fidelity time series land cover classification Landsat

Exhumation and preservation of the Yangchuling porphyry W-Mo deposit in the Jiangnan tungsten ore belt， South China: Insights from (U-Th)/He and fission track dating

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Journal of earth Science 2023年

作者： Yue Sun Ying Wang Jianzhang Pang Samuel C.Boone Minting Wu Chongjian Shao Wei Liu Jiangxi DuChang JinDing Tungsten Co.， Ltd. School of Geography， earth and Atmospheric Sciences， The University of Melbourne，VIC State Key Laboratory of Nuclear Resources and Environment， School of earth Science， East China University of Technology institute of Geology，China earthquake Administration Department of earth Sciences， The University of Adelaide

The Yangchuling porphyry W-Mo deposit (YPWD)， located in the Jiangnan porphyry-skarn tungsten ore belt， is one of the most important and large-scale porphyry W-Mo deposits in South China. While previous zircon U-Pb and molybdenite Re-Os data suggest that Yangchuling W-Mo ore bodies formed almost simultaneously with granodiorite and monzogranitic porphyry at ～150-144 Ma， their post emplacement history remains poorly understood， making their preservation status at depth uncertain. In this paper， new zircon and apatite (U-Th)/He and apatite fission track (ZHe， AHe and AFT， respectively) data of one hornfels and five intrusive rocks from a 1，000-meter borehole are presented. These， together with new inverse thermal history models and previous geochronological data， help elucidate the post-diagenetic exhumation history and preservation status of the Yangchuling porphyry W-Mo deposit. In general， ZHe and AHe ages decrease gradually from the near surface downwards and have relatively little intra-sample variation， ranging from 133 to 73 Ma and 67 to 25 Ma， respectively. All four granodiorites yield similar AFT ages that range from 63 to 55 Ma with mean track lengths varying from 12.2 ± 0.7 to 12.6 ± 0.5 μm. Thermal history modelling indicates that the Yangchuling ore district experienced slow， monotonic cooling since the Cretaceous. Age-depth relationships are interpreted as recording ～3.7 ± 0.8 km of Cretaceous-recent exhumation in response to regional extension throughout South China thought to have been driven by subduction retreat of the Paleo-Pacific Plate. Comparison of estimated net exhumation and previous metallogenic depth of ～4-5 km suggests that W-Mo ore bodies could still exist at depths of up to ～1.3 ± 0.8 km relative to earth surface in the YPWD region. Preservation of the YPWD is attributed to the limited amount of regional denudation during the Late Cretaceous and Cenozoic.

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Detecting abrupt change in land cover in the eastern Hindu Kush region using Landsat time series(1988-2020)

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Journal of Mountain Science 2022年第6期19卷 1699-1716页

作者： Saeed A.KHAN Kim A.VANSELOW Oliver SASS Cyrus SAMIMI Department of earth Sciences University of Bayreuth95447 BayreuthGermany institute of Geography Friedrich-Alexander-University of Erlangen-Nürnberg91058 ErlangenGermany Bayreuth Centre of Ecology and Environmental Research University of Bayreuth95448 BayreuthGermany

Land cover change in the semi-arid environment of the eastern Hindu Kush region is driven by anthropogenic activities and environmental change impacts. Natural hazards, such as floods presumably influenced by climatic change, cause abrupt change of land cover. So far, little research has been conducted to investigate the spatiotemporal aspects of this abrupt change in the valleys. In order to explore the abrupt change in land cover and floods as its possible drivers in the eastern Hindu Kush, a semi-arid mountain region characterized by complex terrain, vegetation variation, and precipitation seasonality, we analyzed long-term Landsat image time series from 1988 to 2020 using Breaks For Additive Seasonal and Trend(BFAST). Overall, BFAST effectively detected abrupt change by using Landsat-derived Modified Soil Adjusted Vegetation Index(MSAVI). The results of our study indicate that approximately 95% of the study area experienced at least one abrupt change during 1988-2020. The years 1991, 1995, 1998, 2007, and 2016 were detected as the peak years, with the peaks occurring in different seasons. The annual trend of abrupt change is decreasing for the study area. The seasonality of abrupt change at the catchment level shows an increasing trend in the spring season for the southern catchments of Panjkora and Swat. The spatial distribution patterns show that abrupt change is primarily concentrated in the floodplains indicating that flooding is the primary driver of the land cover change in the region. We also demonstrated the accurate detection of past flood events(2015) based on the two case examples of Ayun, Rumbur, and Kalash valleys. The detection of the flood events was verified by fieldwork and historical high-resolution Google earth imagery. Finally, our study provides an example of applying Landsat time series in a dry mountain region to detect abrupt changes in land cover and analyze impact of natural hazards such as floods.

关键词： Land cover change Floods Natural hazards BFAST Chitral Pakistan

Microstructural evolution and aging behavior of Mg-4.5Y-2.5Nd-1.0Gd-0.5Zr alloys with different Zn additions

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Rare Metals 2021年第8期40卷 2188-2196页

作者： Zheng Tian Qiang Yang Kai Guan Zhan-Yi Cao Jian Meng Key Laboratory of Automobile Materials of Ministry of Education Department of Materials Science and EngineeringJilin UniversityChangchun130025China State Key Laboratory of Rare earth Resources Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun130022China

Microstructures and mechanical properties of Mg-4.5 Y-2.5 Nd-1.0 Gd-0.5 Zr-xZn(x=0,0.5,1.0,and 1.5;wt%)alloys under as-cast and peak-aged states were investigated in this *** results indicate that the intermetallic phase components are closely dependent on Zn *** as-cast state,the dominant eutectic phase is Mg5 RE in the alloys with 0 wt%and 0.5 wt%Zn additions while Mg5 RE,18 R-and 14 H-LPSO(long period stacking ordered)phases in the alloys with 1.0 wt%and1.5 wt%Zn *** solution and peak-aging,the highest strength and hardness were obtained on the alloy with 0.5 wt%Zn *** electron microscopy(TEM)characterizations revealed that there are denser and finer precipitates on basal(β’)and prismatic(γ’)planes,***,the excellent mechanical performance of the alloy with 0.5 wt%Zn addition is mainly due to precipitation strengthening and grain boundary strengthening.

关键词： Magnesium alloy Intermetallic phase Precipitates Mechanical property

The M5.0 Suining-Tongnan (China) earthquake of 31 January 2010:A destructive earthquake occurring in sedimentary cover

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Chinese Science Bulletin 2011年第6期56卷 521-525页

作者： LUO Yan NI SiDao ZENG XiangFang XIE Jun CHEN Yong LONG Feng institute of earthquake Science China Earthquake Administration Beijing 100036 China institute of Geodesy and Geophysics Chinese Academy of Sciences Wuhan 430077 China Menghcheng National Geophysical Observatory School of Earth and Space Sciences University of Science of China Hefei 230026 China

Usually, only crystalline basement is strong enough to store the massive strain energy that can be released in a damaging earthquake. By contrast, sedimentary cover is weak, because of its relatively high porosity and fluids. Therefore, it generally cannot accumulate enough energy for strong earthquakes. On January 31, 2010, a M5.0 earthquake occurred near the border of Suining and Tongnan in China. It excited strong short-period Rayleigh waves Rg, indicative of its shallow focal depth. The focal depth is constrained to less than 4 km, most probably in the range of 1-3 km, by modeling amplitude dependence on the frequency and waveforms of teleseismic depth phases (pP, sP). Because the local Mesozoic sedimentary cover is about 6 km thick, this earthquake should have occurred in the sedimentary cover. Though some shallow earthquakes with magnitudes up to M4 occur in Paleozoic sediments, this earthquake is the first M5 event studied in Mesozoic sedimentary cover. This event provides a rare opportunity to study seismogenic processes of damaging earthquakes in sedimentary basins.

关键词：沉积盖层地震发生破坏性地震中国边境遂宁震源深度结晶基底强烈地震

A Review of RGB-D Camera Calibration Methods

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Journal of Geodesy and Geoinformation Science 2021年第4期4卷 11-33页

作者： Chenyang ZHANG Teng HUANG Yueqian SHEN School of Civil Engineering and Architecture Changzhou Institute of TechnologyChangzhou 213032China School of earth Science and Engineering Hohai UniversityNanjing 211100China

RGB-D camera is a new type of sensor,which can obtain the depth and texture information in an unknown 3D scene simultaneously,and they have been applied in various fields *** fact,when implementing such kinds of applications using RGB-D camera,it is necessary to calibrate it *** the best of our knowledge,at present,there is no existing a systemic summary related to RGB-D camera calibration ***,a systemic review of RGB-D camera calibration is concluded as ***,the mechanism of obtained measurement and the related principle of RGB-D camera calibration methods are ***,as some specific applications need to fuse depth and color information,the calibration methods of relative pose between depth camera and RGB camera are introduced in Section *** the depth correction models within RGB-D cameras are summarized and compared respectively in Section ***,considering that the angle of the view field of RGB-D camera is smaller and limited to some specific applications,we discuss the calibration models of relative pose among multiple RGB-D cameras in Section *** last,the direction and trend of RGB-D camera calibration are prospected and concluded.

关键词： RGB-D camera calibration relative pose depth correction multiple RGB-D cameras

Facile synthesis of Au embedded CuOx-CeO2 core/shell nanospheres as highly reactive and sinter-resistant catalysts for catalytic hydrogenation of p-nitrophenol

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Nano Research 2020年第8期13卷 2044-2055页

作者： Ke Wu Xin-Yu Wang Ling-Ling Guo Yue-Jiao Xu Liang Zhou Ze-Yu Lyu Kang-Yu Liu Rui Si Ya-Wen Zhang Ling-Dong Sun Chun-Hua Yan Beijing National Laboratory for Molecular Sciences State Key Laboratory of Rare Earth Materials Chemistry and ApplicationsPKU-HKU Joint Laboratory in Rare Earth Materials and Bioinorganic Chemistryand College of Chemistry and Molecular EngineeringPeking UniversityBeijing100871China Shanghai Synchrotron Radiation Facility Shanghai Institute of Applied PhysicsChinese Academy of SciencesShanghai201204China College of Chemistry and Chemical Engineering Lanzhou UniversityLanzhou730000China

Exploring cost-effective catalysts with high catalytic performance and long-term stability has always been a general concern for environment protection and energy ***,Au nanoparticles(NPs)embedded CuOx-CeO2 core/shell nanospheres(Au@CuOx-CeO2 CSNs)have been successfully prepared through a versatile one-pot method at ambient *** spontaneous auto-redox reaction between HAuCl4 and Ce(OH)3 in aqueous solution triggered the self-assembly growth of micro-/nanostructural Au@CuOx-CeO2 ***,the CuOx clusters in Au@CuOx-CeO2 CSNs are capable of improving the anti-sintering ability of Au NPs and providing synergistic catalysis *** a result,the confined Au NPs exhibited extraordinary thermal stability even at a harsh thermal condition up to 700℃.In addition,before and after the severe calcination process,Au@CuOx-CeO2 CSNs can exhibit enhanced catalytic activity and excellent recyclability towards the hydrogenation of p-nitrophenol compared to previously reported *** synergistic catalysis path between Au/CuOx/CeO2 triphasic interfaces was revealed by density functional theory(DFT)*** CuOx clusters around the embedded Au NPs can provide moderate adsorption strength of p-nitrophenol,while the adjacent CeO2-supported Au NPs can facilitate the hydrogen dissociation to form H*species,which contributes to achieve the efficient reduction of *** study opens up new possibilities for developing high-efficient and sintering-resistant micro-/nanostructural nanocatalysts by exploiting multiphasic systems.

关键词： core/shell nanostructure sinter-resistant catalysts triphasic interfaces catalysis p-nitrophenol reduction

Heterojunction synergistic catalysis of MXene-supported PrF_(3)nanosheets for the efficient hydrogen storage of AlH_(3)

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Nano Research 2023年第7期16卷 9546-9552页

作者： Long Liang Shaolei Zhao Chunli Wang Dongming Yin Shaohua Wang Qingshuang Wang Fei Liang Shouliang Li Limin Wang Yong Cheng State Key Laboratory of Rare earth Resource Utilization Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun 130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei 230026China National Engineering Research Center of Nonferrous Metals Materials and Products for New Energy GRINM Group Co.Ltd.Beijing 100088China GRIMAT Engineering institute Co. Ltd.Beijing 101407China College of life Science and Technology Changchun University of Science and TechnologyChangchun 130022China Henan Nayu New Material Co. Ltd.Xinxiang 453000China

Aluminum hydride is a promising chemical hydrogen storage material that can achieve dehydrogenation under mild conditions as well as high hydrogen storage ***,designing an efficient and cost-effective catalyst,especially a synergistic catalyst,for realizing low-temperature and high-efficiency hydrogen supply remains *** this study,the heterojunction synergistic catalyst of Ti_(3)C_(2)supported PrF_(3)nanosheets considerably improved the dehydrogenation kinetics of AlH_(3)at low temperatures and maintained a high hydrogen storage *** the synergistic catalyst,Pr produced a synergistic coupling interaction through its unique electronic *** sandwich structure with close contact between the two phases enhanced the interaction between species and the synergistic *** initial dehydrogenation temperature of the composite is reduced to 70.2℃,and the dehydrogenation capacity is 8.6 wt.%at 120℃ in 90 min under the kinetic test,which reached 93%of the theoretical hydrogen storage *** catalyst considerably reduced the activation energy of the dehydrogenation ***,the multielectron pairs on the surface of the catalyst promoted electron transfer and accelerated the reaction.

关键词： hydrogen storage aluminium hydride catalysis synergistic effect dehydrogenation