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A four-band index for both liquid and solid water and its applications in the Aral Sea Basin

Science China Earth Sciences 2024年第3期67卷 769-788页

作者： Bing YUE Xi CHEN Saibo LI zhengping du John WILSON Junhui YANG Yimen JIAO Shuangyan HUANG Chenghu ZHOU Xinjiang Institute of Ecology and Geography Chinese Academy of SciencesUrumqi 830011China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China Institute of Geographical Sciences and Natural Resources Research Chinese Academy of SciencesBeijing 100101China Spatial Sciences Institute University of Southern CaliforniaLos AngelesCA 90089-0374USA

Various investigations have been conducted to analyze the water-coverage area of the Aral Sea and the Aral Sea Basin(ASB). However, the investigations incorporated considerable uncertainty and the used water indices had misclassification problem, which made different research groups present different results. Thus we first ascertain the boundaries of the ASB, the Syr and Amu river basins as well as their upper, middle and lower reaches. Then a four-band index for both liquid and solid water(ILSW) is proposed to address the misclassification problems of the classic water indices. ILSW is calculated by using the reflectance values of the green, red, near infrared, and thermal infrared bands, which combines the normalized difference water index(NDWI) and land surface temperature(LST) together. Validation results show that the ILSW water index has the highest accuracy by far in the Aral Sea Basin. Our results indicate that annual average decline of the water-coverage area was 963 km^(2) in the southern Aral Sea, whereas the northern Aral Sea has experienced little change. In the meanwhile, permanent ice and snow in upper reach of ASB has retreated considerably. Annual retreating rates of the permanent ice and snow were respectively 6233and 3841 km^(2) in upper reaches of Amu river basin(UARB) and Syr river basin(USRB). One of major reasons is that climate has become warmer in ASB. The climate change has caused serious water deficit problem. The water deficit had an increasing trend since the 1990s and its increasing rates was 3.778 billion m^(3) yearly on average. The total water deficit was 76.967 billion m^(3) on average in the whole area of ASB in the 2010s. However, up reaches of Syr river basin(USRB), a component area of ASB, had water surplus of 25.461 billion m^(3). These conclusions are useful for setting out a sustainable development strategy in ASB.

关键词： Aral Sea Basin Syr river basin Amu river basin Water indices Water-coverage area Water deficit Climate change

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HASM quantum machine learning

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Science China Earth Sciences 2023年第9期66卷 1937-1945页

作者： Tianxiang YUE Chenchen WU Yi LIU zhengping du Na ZHAO Yimeng JIAO Zhe XU Wenjiao SHI State Key Laboratory of Resources and Environment Information System Institute of Geographical Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China Yanqi Lake Beijing Institute of Mathematical Sciences and Applications Beijing 101408China College of Resources and Environment University of Chinese Academy of SciencesBeijing 101499China College of Land Resources and Environment Jiangxi Agricultural UniversityNanchang 330045China

The miniaturization of transistors led to advances in computers mainly to speed up their computation.Such miniaturization has approached its fundamental limits.However,many practices require better computational resources than the capabilities of existing computers.Fortunately,the development of quantum computing brings light to solve this problem.We briefly review the history of quantum computing and highlight some of its advanced achievements.Based on current studies,the Quantum Computing Advantage(QCA)seems indisputable.The challenge is how to actualize the practical quantum advantage(PQA).It is clear that machine learning can help with this task.The method used for high accuracy surface modelling(HASM)incorporates reinforced machine learning.It can be transformed into a large sparse linear system and combined with the Harrow-Hassidim-Lloyd(HHL)quantum algorithm to support quantum machine learning.HASM has been successfully used with classical computers to conduct spatial interpolation,upscaling,downscaling,data fusion and model-data assimilation of ecoenvironmental surfaces.Furthermore,a training experiment on a supercomputer indicates that our HASM-HHL quantum computing approach has a similar accuracy to classical HASM and can realize exponential acceleration over the classical algorithms.A universal platform for hybrid classical-quantum computing would be an obvious next step along with further work to improve the approach because of the many known limitations of the HHL algorithm.In addition,HASM quantum machine learning might be improved by:(1)considerably reducing the number of gates required for operating HASM-HHL;(2)evaluating cost and benchmark problems of quantum machine learning;(3)comparing the performance of the quantum and classical algorithms to clarify their advantages and disadvantages in terms of accuracy and computational speed;and(4)the algorithms would be added to a cloud platform to support applications and gather active feedback from users of the algorithms.

关键词： Quantum computing Machine learning Eco-environmental surface High accuracy surface modelling Quantum computational advantage Practical quantum advantage

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An improved HASM method for dealing with large spatial data sets

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Science China Earth Sciences 2018年第8期61卷 1078-1087页

作者： Na ZHAO Tianxiang YUE Chuanfa CHEN Miaomiao ZHAO zhengping du State Key Laboratory of Resources and Environment Information System Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Beijing 100101 China Jiangsu Center for Collaborative Innovation in Geographic Information Resource Development and Application Nanjing 210023 China College of Resources and Environment University of Chinese Academy of Sciences Beijing 100101 China Geomatics College Shandong University of Science and Technology Qingdao 266510 China

Surface modeling with very large data sets is challenging. An efficient method for modeling massive data sets using the high accuracy surface modeling method(HASM) is proposed, and HASM_Big is developed to handle very large data sets. A large data set is defined here as a large spatial domain with high resolution leading to a linear equation with matrix dimensions of hundreds of thousands. An augmented system approach is employed to solve the equality-constrained least squares problem(LSE) produced in HASM_Big, and a block row action method is applied to solve the corresponding very large matrix equations.A matrix partitioning method is used to avoid information redundancy among each block and thereby accelerate the model.Experiments including numerical tests and real-world applications are used to compare the performances of HASM_Big with its previous version, HASM. Results show that the memory storage and computing speed of HASM_Big are better than those of HASM. It is found that the computational cost of HASM_Big is linearly scalable, even with massive data sets. In conclusion,HASM_Big provides a powerful tool for surface modeling, especially when there are millions or more computing grid cells.

关键词：空间数据数据集合表面建模线性方程高分辨率扩充系统数字测试应用程序

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Nonlinear uncertainty impact of geometric variations on aerodynamic performance of low-pressure turbine blades with ultra-high loading under extreme operational conditions

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Chinese Journal of Aeronautics 2024年第5期37卷 281-300页

作者： Xiaojing WANG zhengping ZOU Chao FU Pengcheng du School of Energy and Power Engineering Beihang UniversityBeijing 100191China National Key Laboratory of Science and Technology on Aero-Engine Aero-Thermodynamics Beihang UniversityBeijing 100191China Research Institute of Aero-Engine Beihang UniversityBeijing 100191China

Uncertainty impact of random geometric variations on the aerodynamic performance of low-pressure turbine blades is considerable,which is further amplified by the current ultra-high-lift design trend for weight reduction.Therefore,this uncertainty impact on ultra-highly loaded blades under extreme operational conditions near the margins with potential large-scale open separation is focused on in this study.It is demonstrated that this impact is significant,unfavourable,and nonlinear,which is clearly severer under extreme conditions.In addition to the overall attenuation and notable scattering of specific performance,the operational margins with open separation are also notably scattered with great risk of significant reduction.This scattering and nonlinearity are dominated by the variations in leading-edge thickness.The thinning of leading edge triggers local transition,enhancing downstream friction and reducing resistance to open separation,which is further exacerbated by operational deterioration.However,the opposite thickening yields less benefit,implying nonlinearity.This unfavourable impact highlights the need for robust aerodynamic design,where both a safer operational condition and a more robust blade are indispensable,i.e.,a compromise among performance,weight,and robustness.Besides the necessary limitation of loading levels,a mid-loaded design is recommended to reduce adverse pressure gradients in both the leading edge and rear region of the suction side,which helps to decrease the susceptibility of the transition and open separation to random perturbations.Similar improvements can also be achieved by appropriately thickening the leading edge.

关键词： Ultra-highly loaded turbine blade Geometric variations Uncertainty analysis Operational margins Robust aerodynamic design Nonlinearity

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Development of a surface modeling method for mapping soil properties

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Journal of Geographical Sciences 2012年第4期22卷 752-760页

作者： SHI Wenjiao LIU Jiyuan du zhengping YUE Tianxiang Institute of Geographic Sciences and Natural Resources Research CASBeijing 100101China

High accuracy surface modeling （HASM） is a method which can be applied to soil property interpolation. In this paper, we present a method of HASM combined geographic information for soil property interpolation （HASM-SP） to improve the accuracy. Based on soil types, land use types and parent rocks, HASM-SP was applied to interpolate soil available P, Li, pH, alkali-hydrolyzable N, total K and Cr in a typical red soil hilly region. To evaluate the performance of HASM-SP, we compared its performance with that of ordinary kriging （OK）, ordinary kriging combined geographic information （OK-Geo） and stratified kriging （SK）. The results showed that the methods combined with geographic information including HASM-SP and OK-Geo obtained a lower estimation bias. HASM-SP also showed less MAEs and RMSEs when it was compared with the other three methods （OK-Geo, OK and SK）. Much more details were presented in the HASM-SP maps for soil properties due to the combination of different types of geographic information which gave abrupt boundary for the spatial varia- tion of soil properties. Therefore, HASM-SP can not only reduce prediction errors but also can be accordant with the distribution of geographic information, which make the spatial simula- tion of soil property more reasonable. HASM-SP has not only enriched the theory of high accuracy surface modeling of soil property, but also provided a scientific method for the ap- plication in resource management and environment planning.

关键词： high accuracy surface modeling （HASM） spatial interpolation accuracy geostatistics soil properties red soil hilly legion in South China

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Dark Localized Waves in Shallow Waters:Analysis within an Extended Boussinesq System

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Chinese Physics Letters 2024年第4期41卷 32-37页

作者： zhengping Yang Wei-Ping Zhong Milivoj Belic Department of Medical Science Shunde PolytechnicShunde 528300China Department of Electronic Engineering Shunde PolytechnicShunde 528300China Division of Arts and Sciences Texas A&M University at Qatar23874 DohaQatar

We study dark localized waves within a nonlinear system based on the Boussinesq approximation,describing the dynamics of shallow water waves.Employing symbolic calculus,we apply the Hirota bilinear method to transform an extended Boussinesq system into a bilinear form,and then use the multiple rogue wave method to obtain its dark rational solutions.Exploring the first-and second-order dark solutions,we examine the conditions under which these localized solutions exist and their spatiotemporal distributions.Through the selection of various parameters and by utilizing different visualization techniques(intensity distributions and contour plots),we explore the dynamical properties of dark solutions found:in particular,the first-and second-order dark rogue waves.We also explore the methods of their control.The findings presented here not only deepen the understanding of physical phenomena described by the(1+1)-dimensional Boussinesq equation,but also expand avenues for further research.Our method can be extended to other nonlinear systems,to conceivably obtain higher-order dark rogue waves.

关键词： Boussinesq bilinear nonlinear

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Compound Product of Hypermatrices

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Journal of Systems Science & Complexity 2024年第1期37卷 169-183页

作者： CHENG Daizhan MENG Min ZHANG Xiao JI zhengping Key Laboratory of Systems and Control Academy of Mathematics and Systems ScienceChinese Academy of SciencesBeijing 100190China Department of Control Science and Engineering School of Electronics and Information EngineeringTongji UniversityShanghai 201210China National Center for Mathematics and Interdisciplinary Sciences Chinese Academy of SciencesBeijing 100190China School of Mathematical Sciences University of Chinese Academy of SciencesBeijing 100149China.

The semi-tensor product(STP)of matrices is generalized to multidimensional arrays,called the compound product of hypermatrices.The product is first defined for three-dimensional hypermatrices with compatible orders and then extended to general cases.Three different types of hyperdeterminants are introduced and certain properties are revealed.The Lie groups and Lie algebras corresponding to the hypermatrix products are constructed.Finally,these results are applied to dynamical systems.

关键词： Compound semi-tensor product hyperdeterminants hypereigenvalues and hypereigenvectors hypergeneral linear groups hypermatrices.

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Sensitivity studies of a high accuracy surface modeling method

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Science China Earth Sciences 2014年第10期57卷 2386-2396页

作者： ZHAO Na YUE TianXiang ZHAO MingWei du zhengping FAN ZeMeng CHEN ChuanFa State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources Research Chinese Academy of Sciences Geomatics College Shandong University of Science and Technology

The sensitivities of the initial value and the sampling information to the accuracy of a high accuracy surface modeling(HASM) are investigated and the implementations of this new modeling method are modified and enhanced. Based on the fundamental theorem of surface theory, HASM is developed to correct the error produced in geographical information system and ecological modeling process. However, the earlier version of HASM is theoretically incomplete and its initial value must be produced by other surface modeling methods, such as spline, which limit its promotion. In other words, we must use other interpolators to drive HASM. According to the fundamental theorem of surface theory, we modify HASM, namely HASM.MOD, by adding another important nonlinear equation to make it independent of other methods and, at the same time, have a complete and solid theory foundation. Two mathematic surfaces and monthly mean temperature of 1951–2010 are used to validate the effectiveness of the new method. Experiments show that the modified version of HASM is insensitive to the selection of initial value which is particular important for HASM. We analyze the sensitivities of sampling error and sampling ratio to the simulation accuracy of HASM.MOD. It is found that sampling information plays an important role in the simulation accuracy of HASM.MOD. Another feature of the modified version of HASM is that it is theoretically perfect as it considers the third equation of the surface theory which reflects the local warping of the surface. The modified HASM may be useful with a wide range of spatial interpolation as it would no longer rely on other interpolation methods.

关键词：建模方法曲面建模敏感性高精度地理信息系统表面建模非线性方程初始值

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A fundamental theorem for eco-environmental surface modelling and its applications

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Science China Earth Sciences 2020年第8期63卷 1092-1112页

作者： Tianxiang YUE Na ZHAO Yu LIU Yifu WANG Bin ZHANG zhengping du Zemeng FAN Wenjiao SHI Chuanfa CHEN Mingwei ZHAO dunjiang SONG Shihai WANG Yinjun SONG Changqing YAN Qiquan LI Xiaofang SUN Lili ZHANG Yongzhong TIAN Wei WANG Ying’an WANG Shengnan MA Hongsheng HUANG Yimin LU Qing WANG Chenliang WANG Yuzhu WANG Ming LU Wei ZHOU Yi LIU Xiaozhe YIN Zong WANG Zhengyi BAO Miaomiao ZHAO Yapeng ZHAO Yimeng JIAO Ufra NASEER Bin FAN Saibo LI Yang YANG John PWILSON State Key L aboratory of Resources and Environment Information System Institute of Geographical Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China College of Resources and Environment University of Chinese Academy of SciencesBeijing 100049China College of Land Resources and Environment Jiangxi Agricultural UniversityNanchang 330045China College of Geomatics Shandong University of Science and TechnologyQingdao 266590China College of Forestry Beijing Forestry UniversityBeijing 100083China School of Land and Resources China West Normal UniversityNanchong 637002China College of Geographical Information and Tourism Chuzhou UniversityChuzhou 239000China Institutes of Science and Development Chinese Academy of SciencesBeijing 100190China Department of Information Engineering Shandong University of Science and TechnologyTai'an 271019China College of Resources Sichuan Agricultural UniversityChengdu 611130China College of Geography and Tourism Qufu Normal UniversityRizhao 276828China Aerospace Information Research Institute Chinese Academy of SciencesBeijing 100101China School of Geographical Science Southwest UniversityChongqing 400715China National Disaster Reduction Center of China Ministry of Emergency ManagementBeijing 100721China Department for Population Data China Population and Development Research CenterBeijing 100081China Department for Industrial Standard China Standardization AdministrationBeijing 100088China The Academy of Digital China Fuzhou UniversityFuzhou 350002China National Institute of Environmental Health Chinese Center for Disease Control and PreventionBeijing 100021China School of Information Engineering China University of GeoscienceBeijing 100083China Qian Xuesen Laboratory of Space Technology Beijing 100094China College of Architecture and Urban Planning Chongqing Jiaotong UniversityChongqing 400074China Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application Nanjing

We propose a fundamental theorem for eco-environmental surface modelling(FTEEM) in order to apply it into the fields of ecology and environmental science more easily after the fundamental theorem for Earth’s surface system modeling(FTESM). The Beijing-Tianjin-Hebei(BTH) region is taken as a case area to conduct empirical studies of algorithms for spatial upscaling, spatial downscaling, spatial interpolation, data fusion and model-data assimilation, which are based on high accuracy surface modelling(HASM), corresponding with corollaries of FTEEM. The case studies demonstrate how eco-environmental surface modelling is substantially improved when both extrinsic and intrinsic information are used along with an appropriate method of HASM. Compared with classic algorithms, the HASM-based algorithm for spatial upscaling reduced the root-meansquare error of the BTH elevation surface by 9 m. The HASM-based algorithm for spatial downscaling reduced the relative error of future scenarios of annual mean temperature by 16%. The HASM-based algorithm for spatial interpolation reduced the relative error of change trend of annual mean precipitation by 0.2%. The HASM-based algorithm for data fusion reduced the relative error of change trend of annual mean temperature by 70%. The HASM-based algorithm for model-data assimilation reduced the relative error of carbon stocks by 40%. We propose five theoretical challenges and three application problems of HASM that need to be addressed to improve FTEEM.

关键词： HASM FTEEM Spatial upscaling Spatial downscaling Spatial interpolation Data fusion Model-data assimilation Model coupling

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Controlling of coordination state of Ru_(x)N_(y) clusters for efficient oxygen reduction electrocatalysis

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Nano Research 2024年第3期17卷 1035-1041页

作者： Weiyang Fu Yihuan Yu Tongtong Liu Yinliang Cao zhengping Zhang Feng Wang State Key Laboratory of Chemical Resource Engineering Beijing Key Laboratory of Electrochemical Process and Technology for MaterialsBeijing University of Chemical TechnologyBeijing 100029China Beijing Advanced Innovation Center for Soft Matter Science and Engineering Beijing University of Chemical TechnologyBeijing 100029China Zhejiang Tianneng Hydrogen Energy Technology Co. Ltd.Huzhou 313100China

Ruthenium(Ru)is an attractive potential alternative to platinum as an electrocatalyst for the oxygen reduction reaction(ORR),in virtue of its high catalytic selectivity and relatively low price.In this work,a series of well-dispersed nitrogen-coordinated Ru-clusters on carbon black(Ru_(x)N_(y)/C)were prepared by pyrolyzing different Ru-containing sandwich compounds as the Ru sources.The higher thermal stability of these complexed sandwich precursors(bis(1,2,3,4,5-pentamethylcyclopentadienyl)Ru(II)monomer,dichloro(p-cymene)Ru(II)dimer,and chloro(1,2,3,4,5-pentamethylcyclopentadienyl)Ru(II)tetramer)affords the control of coordinated state for the resulting Ru-clusters,in comparison of that derived from ruthenium chlorides.After the pyrolysis treatment,the Ru coordinated state in Ru_(x)N_(y)/C,with the Ru–N and Ru–Ru bonds,still showed the structural inheritance from the Ru(II)monomer,dimer,and tetramer,but using ruthenium chlorides as the Ru source resulted in the nanoscale Ru agglomerations.The ORR testing exhibited that the Ru_(x)N_(y)/C sample derived from the Ru(II)tetramer(Ru_(x)N_(y)/C-T)presents the higher catalytic activity than the other obtained samples in either alkaline or acidic electrolytes.Even in the acidic electrolyte,Ru_(x)N_(y)/C-T shows the comparable ORR activity to that of Pt/C catalysts,and it shows the superior tolerance against methanol and CO.The X-ray absorption spectroscopy and density functional theory calculations demonstrate that these tetra-nuclear Ru-clusters could be the most active site due to their broadened d-orbital bands and lower energy d-band center than those of other subnano species and nanocrystals,and their favorable Yeager-type adsorption of O_(2)-molecules is also contributed to promoting O–O bond cleavage and accelerating the ORR process.

关键词： ruthenium clusters coordination environment sandwich compounds electrocatalysis oxygen reduction reaction

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