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Variations of Laohugou Glacier No.12 in the western Qilian Mountains, China, from 1957 to 2015

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Journal of Mountain Science 2018年第1期15卷 25-32页

作者： LIU Yu-shuo qin Xiang CHEN Ji-zu LI Zhen-lin wanG Jing DU Wen-tao guo wan-qin State Key Laboratory of Cryospheric Science Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Qilian Shan Station of Glaciology and Ecologic Environment Northwest Institute of Eco-Environment and Resources Chinese Academy of Sciences Geomatics Center of Gansu Province Gansu Bureau of Surveying Mapping and Geoinformation

Glaciers were solid reservoirs and important water resources in western China,but they were retreating significantly in context of global warming.Laohugou Glacier No.12 was the largest valley glacier in Qilian Mountains.In this study,realtime kinematic(RTK)data,topographic map and World View-2 satellite imagery were used to measure changes in terminus,extent and volume of Laohugou Glacier No.12.Results showed that Laohugou Glacier No.12 was shrinking significantly since 1957.From1960 to 2015,the terminus reduction of Laohugou Glacier No.12 was 402.96 m(3.99%)in total,and glacier length decreased to 9.7 km from 10.1 km.Reduction of glacier area and volume were the most obvious.From 1957 to 2015,glacier area and volume decreased by 1.54 km^2(7.03%)and 0.1816 km^3,respectively.Reduction trend of terminus and area was slowing in 1950-1980s,even stable for a period in the mid-1980s,and then accelerated.Ice core analysis result and nearly meteorological station data shown an increasing trend of temperature in 1957-2015,it was a main reason of continuous retreating of Laohugou Glacier No.12.

关键词：冰河西方中国水资源上下文运动学 RTK 山谷

Glacier changes since the early 1960s, eastern Pamir, China

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Journal of Mountain Science 2016年第2期13卷 276-291页

作者： ZHANG Zhen XU Jun-li LIU Shi-yin guo wan-qin WEI Jun-feng FENG Tong State Key Laboratory of Cryospheric Sciences Cold and Arid Regions Environmental and Engineering Research Institute Chinese Academy of Sciences Lanzhou 730000 China University of Chinese Academy of Sciences Beijing 100049 China

Glaciers in the eastern Pamir are important for water resources and the social and economic development of the region.In the last 50 years,these glaciers have shrunk and lost ice mass due to climate change.In order to understand recent glacier dynamics in the region,a new inventory was compiled from Landsat TM/ETM+ images acquired in2009,free of clouds and with minimal snow cover on the glacierized mountains.The first glacier inventory of the area was also updated by digitizing glacier outlines from topographical maps that had been modified and verified using aerial photographs.Total glacier area decreased by 10.8%±1.1%,mainly attributed to an increase in air temperature,although precipitation,glacier size and topographic features also combined to affect the general shrinkage of the glaciers.The 19.3–21.4 km^3 estimated glacier mass loss has contributed to an increase in river runoff and water resources.

关键词：冰川面积帕米尔高原 Landsat 年代中国社会经济发展气候变化航空照片

Mass Loss from Glaciers in the Chinese Altai Mountains between 1959 and 2008 Revealed Based on Historical Maps, SRTM, and ASTER Images

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Journal of Mountain Science 2015年第2期12卷 330-343页

作者： WEI Jun-feng LIU Shi-yin XU Jun-li guo wan-qin BAO Wei-jia SHANGGUAN Dong-hui JIANG Zong-li State Key Laboratory of Cryospheric Sciences Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of Sciences University of Chinese Academy of Sciences Department of Geography University of Zürich Hunan Province Key Laboratory of Coal Resources Clean-Utilization and Mine Environment Protection Hunan University of Science and Technology

Mass loss of glaciers in the Chinese Altai was detected using geodetic methods based on topographical maps(1959), the Shuttle Radar Topography Mission(SRTM) Digital Elevation Model(DEM)(2000), and the Advanced Space-borne Thermal Emission and Reflection Radiometer(ASTER) stereo images(2008). The results indicate that a continued and accelerating shrinkage has occurred in the Chinese Altai Mountains during the last 50 years, with mass deficits of 0.43 ± 0.02 and0.54 ± 0.13 m a-1 water equivalent(w.e.) during the periods 1959-1999 and 1999-2008, respectively.Overall, the Chinese Altai Mountains have lost 7.06 ±0.44 km3 in ice volume(equivalent to-0.43 ± 0.03 m a-1 w.e.) from 1959-2008. The spatial heterogeneity in mass loss was potentially affected by comprehensive changes in temperature and precipitation, and had a substantial correlation withglacier size and topographic settings. Comparison shows that in the Chinese Altai Mountains glaciers have experienced a more rapid mass loss than those in the Tianshan and northwestern Tibetan Plateau(TP), and the mass balance of glaciers was slightly less negative relative to those in the Russian Altai, Himalaya, and southern TP.

关键词：阿尔泰山 ASTER SRTM 立体图像物质平衡中国冰川历史地图

Glacier change in the western Nyainqentanglha Range,Tibetan Plateau using historical maps and Landsat imagery:1970-2014

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Journal of Mountain Science 2016年第8期13卷 1358-1374页

作者： WU Kun-peng LIU Shi-yin guo wan-qin WEI Jun-feng XU Jun-li BAO Wei-jia YAO Xiao-jun State Key Laboratory of Cryospheric Sciences Cold and Arid Regions Environmental and Engineering Research InstituteChinese Academy of ScienceLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China

Glaciers in the western Nyainqentanglha Range are an important source of water for social and economic development. Changes in their area were derived from two Chinese glacier inventories; one from the 1970 1:50,000 scale Chinese Topographic Maps series and the other from Landsat TM/ETM+ images acquired in 2009. Analyses also included boundaries from 2000 and 2014 Landsat TM/ETM+ images. A continuing and accelerating shrinkage of glaciers occurred here from 1970 to 2014, with glacier area decreasing by 244.38 ± 29.48 km^2(27.4% ± 3.3%)or 0.62% ± 0.08% a^(–1). While this is consistent with a changing climate, local topographic parameters, such as altitude, slope, aspect and debris cover, are also important influences. Recession is manifested by a rise in the elevation of the glacier terminus. The shrinkage of glaciers with NE, N and NW orientations exceeded that of other aspects, and glaciers with SE and S orientations experienced less shrinkage. Changes in the average positive difference of glaciation(PDG) show that the western Nyainqentanglha Range has unfavorable conditions for glacier maintenance which is being exacerbated by a warming climate since 1970.

关键词：念青唐古拉山脉 Landsat 冰川变化西方历史地图青藏高原意象图像边界

Light People:Prof.Kei May Lau,newly elected US NAE member in Hong Kong,talks about future of photonics and women in science

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Light(Science & Applications) 2024年第4期13卷 602-608页

作者： Yating wan Chenzi guo Electrical and Computer Engineering the ComputerElectrical and Mathematical Sciences and Engineering DivisionKing Abdullah University of Science and Technology23955-6900 ThuwalSaudi Arabia Changchun Institute of Optics Fine Mechanics and PhysicsChinese Academy of SciencesChangchunChina

Editorial Photonics technology remains a driving force in today’s scientific landscape,marked by continuous innovation and crossdisciplinary relevance.In an enlighting conversation with Light:Science&Applications,Prof.Kei May Lau,a pioneer in photonics research,shares her deep insights on the evolution of technologies of LEDs,lasers,challenges of hetero-epitaxy,and the future of micro-LEDs and quantum dot lasers.Recently honored as a member of the US National Academy of Engineering(NAE)for her significant contributions to photonics and electronics using III-V semiconductors on silicon,Prof.Lau stands out as the sole Hong Kong scholar inducted into the NAE this year,joining 114 new and 21 international members.In this exclusive Light People interview,Prof.Lau shares her journey as a pioneering woman in engineering,her commitment to mentorship and academia,and her perspective on advancing female representation in science.The summary provided is distilled from Prof.Lau’s thoughtful responses during the interview.For a deeper exploration of Prof.Lau’s experiences and advice,the full interview is available in the Supplementary material.

关键词： interview lighting driving

Harnessing data using symbolic regression methods for discovering novel paradigms in physics

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Science China(Physics,Mechanics & Astronomy) 2024年第6期67卷 1-11页

作者： Jianyang guo wan-Jian Yin College of Energy Soochow Institute for Energy and Materials Innovations(SIEMIS)Jiangsu Provincial Key Laboratory for Advanced Carbon Materials and Wearable Energy TechnologiesSoochow UniversitySuzhou 215006China Shanghai Qi Zhi Institute Shanghai 200232China Light Industry Institute of Electrochemical Power Sources Soochow UniversitySuzhou 215006China

In recent years,machine-learning methods have profoundly impacted research in the interdisciplinary fields of physics.However,most machine-learning models lack interpretability,and physicists doubt the credibility of their conclusions because they cannot be combined with prior physical knowledge.Therefore,this review focuses on symbolic regression,which is an interpretable machine-learning method.First,the relevant concepts of machine learning are introduced in conjunction with induction.Next,we provide an overview of symbolic regression methods.Subsequently,the recent directions for the application of symbolic regression methods in different subfields of physics are outlined,and an overview of the ways in which the applications of symbolic regression have evolved in the realm of physics is provided.The major aim of this review is to introduce the basic principles of symbolic regression and explain its applications in the field of physics.

关键词： machine learning genetic programming symbolic regression

Recent Advances in Mechanistic Understanding of Metal-Free Carbon Thermocatalysis and Electrocatalysis with Model Molecules

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Nano-Micro Letters 2024年第7期16卷 74-97页

作者： Wei guo Linhui Yu Ling Tang Yan wan Yangming Lin CAS Key Laboratory of Design and Assembly of Functional Nanostructures Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002People’s Republic of China Xiamen Key Laboratory of Rare Earth Photoelectric Functional Materials Xiamen Institute of Rare Earth MaterialsHaixi InstituteChinese Academy of SciencesXiamen 361021People’s Republic of China State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002People’s Republic of China Institute of Urban Environment Chinese Academy of SciencesXiamen 361021People’s Republic of China

Metal-free carbon,as the most representative heterogeneous metal-free catalysts,have received considerable interests in electro-and thermo-catalytic reac-tions due to their impressive performance and sustainability.Over the past decade,well-designed carbon catalysts with tunable structures and heteroatom groups coupled with various characterization techniques have proposed numerous reaction mechanisms.However,active sites,key intermediate species,precise structure-activity relationships and dynamic evolution processes of carbon catalysts are still rife with controversies due to the monotony and limitation of used experimental methods.In this Review,we sum-marize the extensive efforts on model catalysts since the 2000s,particularly in the past decade,to overcome the influences of material and structure limitations in metal-free carbon catalysis.Using both nanomolecule model and bulk model,the real contribution of each alien species,defect and edge configuration to a series of fundamentally important reactions,such as thermocatalytic reactions,electrocatalytic reactions,were systematically studied.Combined with in situ techniques,isotope labeling and size control,the detailed reaction mechanisms,the precise 2D structure-activity relationships and the rate-determining steps were revealed at a molecular level.Furthermore,the outlook of model carbon catalysis has also been proposed in this work.

关键词： Metal-free carbon catalysts Model catalyst Electrocatalysis Active site Reaction mechanisms

Vibration Control of A Flexible Marine Riser System Subject to Input Dead Zone and Extraneous Disturbances

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China Ocean Engineering 2024年第2期38卷 271-284页

作者： ZHOU Li wanG guo-rong wan Min School of Mechatronic Engineering Southwest Petroleum UniversityChengdu 610500China Energy Equipment Institute Southwest Petroleum UniversityChengdu 610500China National Key Laboratory of Oil and Gas Reservoir Geology and Exploitation Southwest Petroleum UniversityChengdu 610500China

An observer-based adaptive backstepping boundary control is proposed for vibration control of flexible offshore riser systems with unknown nonlinear input dead zone and uncertain environmental disturbances.The control algorithm can update the control law online through real-time data to make the controller adapt to the environment and improve the control precision.Specifically,based on the adaptive backstepping framework,virtual control laws and Lyapunov functions are designed for each subsystem.Three direction interference observers are designed to track the timevarying boundary disturbance.On this basis,the inverse of the dead zone and linear state transformation are used to compensate for the original system and eliminate the adverse effects of the dead zone.In addition,the stability of the closed-loop system is proven by Lyapunov stability theory.All the system states are bounded,and the vibration offset of the riser converges to a small area of the initial position.Finally,four examples of flexible marine risers are simulated in MATLAB to verify the effectiveness of the proposed controller.

关键词： adaptive backstepping control disturbance observer flexible marine riser input dead zone vibration control

An effective catalyst carrier SiO_(2):Enhancing catalytic and combustion properties of CuFe_(2)O_(4)on energetic components

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Defence Technology（防务技术） 2024年第2期32卷 383-392页

作者： Li Ding Chong wan Suhang Chen Zhao qin Kangzhen Xu School of Chemical Engineering/Xi'an Key Laboratory of Special Energy Materials Northwest UniversityXi'an710069China Xi’an Modern Chemistry Research Institute Xi'an710065China

To enhance the catalytic activity of copper ferrite(CuFe_(2)O_(4))nanoparticle and promote its application as combustion catalyst,a low-cost silicon dioxide(SiO_(2))carrier was employed to construct a novel CuFe_(2)O_(4)/SiO_(2)binary composites via solvothermal method.The phase structure,morphology and catalytic activity of CuFe_(2)O_(4)/SiO_(2)composites were studied firstly,and thermal decomposition,combustion and safety performance of ammonium perchlorate(AP)and 1,3,5-trinitroperhydro-1,3,5-triazine(RDX)with it affecting were then systematically analyzed.The results show that CuFe_(2)O_(4)/SiO_(2)composite can remarkably either advance the decomposition peak temperature of AP and RDX,or reduce the apparent activation energy at their main decomposition zone.Moreover,the flame propagation rate of RDX was promoted by about 2.73 times with SiO_(2)content of 3 wt%,and safety property of energetic component was also improved greatly,in which depressing the electrostatic discharge sensitivity of pure RDX by about 1.89 times.In addition,the effective range of SiO_(2)carrier content in the binary catalyst is found to be 3 to 5 wt%.Therefore,SiO_(2)opens a new insight on the design of combustion catalyst carrier and will promote the application of CuFe_(2)O_(4)catalyst in solid propellant.

关键词： Copper ferrite Silicon dioxide Combustion catalyst Thermal decomposition Laser ignition