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Staring-imaging satellite pointing estimation based on sequential ISAR images

Chinese Journal of Aeronautics 2024年第8期37卷 261-276页

作者： Canyu wang Libing JIANG Weijun zhong Xiaoyuan REN Zhuang wang National Key Laboratory of Automatic Target Recognition National University of Defense TechnologyChangsha 410073China Xi’an Satellite Control Center Xi’an 710600China

Pointing estimation for spacecraft using Inverse Synthetic Aperture Radar(ISAR)images plays a significant role in space situational awareness and ***,feature extraction and cross-range scaling of ISAR images create bottlenecks that limit performances of current estimation ***,the emergence of staring imaging satellites,characterized by complex kinematic behaviors,presents a novel challenge to this *** address these issues,this article proposes a pointing estimation method based on Convolutional Neural Networks(CNNs)and a numerical optimization algorithm.A satellite’s main axis,which is extracted from ISAR images by a proposed Semantic Axis Region Regression Net(SARRN),is chosen for investigation in this article due to its unique ***,considering the kinematic characteristic of the staring satellite,an ISAR imaging model is established to bridge the target pointing and the extracted *** on the imaging model,pointing estimation and cross-range scaling can be described as a maximum likelihood estimation problem,and an iterative optimization algorithm modified by using the strategy of random sampling-consistency check and weighted least squares is proposed to solve this ***,the pointing of targets and the cross-range scaling factors of ISAR images are *** experiments based on actual satellite orbital parameters verify the effectiveness of the proposed *** work can improve the performance of satellite reconnaissance warning,while accurate cross-range scaling can provide a basis for subsequent data processes such as 3D reconstruction and attitude estimation.

关键词： Staring-imaging Agile satellite Inverse Synthetic Aperture Radar(ISAR) Pointing estimation Cross-range scaling

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A highly reduced Mo_(74) polyoxometalate featuring high proton conductivity accessed by building block strategy

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Science China Chemistry 2024年第3期67卷 862-868页

作者： Shi-yi Liu Xue-Xin Li Wei-Chao Chen Kui-Zhan Shao Xin-Long wang Chao Qin zhong-Min Su Key Laboratory of Polyoxometalate and Reticular Material Chemistry of Ministry of Education Department of ChemistryNortheast Normal UniversityChangchun 130024China State Key Laboratory of Supramolecular Structure and Materials Institute of Theoretical ChemistryCollege of ChemistryJilin UniversityChangchun 130021China

Highly reduced polyoxometalates(POMs) are predicted to be used as rather high energy density materials;however,it still suffers from the limited cluster species and reduction *** we demonstrate that it is possible to employ the building block strategy to generate a highly reduced polyoxomolybdate(C_(2)H_(8)N)_(14)(NH_(4))_(4)H_(14)[Mo_(48)-ⅤMo_(26)ⅥO_(202)(OH)_(12)(SO_(4))_(6)]·46H_(2)O(Mo_(74)).The fundamental Mo-based{Mo_x}(x=4,5,and 6) building blocks,which are templated by tetra-coordinated anions{MoO_(4)}or{SO_(4)},not only lay foundation for the formation of Mo_(74) featuring an unprecedented reduction ratio of 65%,but also give rise to SBBs-mediated(secondary building blocks) supramolecular dense packing interactions among the isolated Mo_(74) clusters that are favorable for proton ***,high proton conductivity(2.04×10^(-2)S cm^(-1)) had been realized at 50℃ and 90% relative humidity,revealing one of the well-known POMs-based crystalline proton conducting *** result highlights that this building block approach possesses great potential in producing highly reduced POM systems that can achieve controllable reduced ratio and desirable properties.

关键词： polyoxometalate building block molybdenum highly reduced state proton conduction

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Pictorial review of hepatic echinococcosis:Ultrasound imaging and differential diagnosis

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World Journal of Gastroenterology 2024年第37期30卷 4115-4131页

作者： yi Tao yi-Fei wang Jun wang Shuang Long Barnabas C Seyler Xiao-Fei zhong Qiang Lu Department of Medical Ultrasound West China Hospital of Sichuan UniversityChengdu 610041Sichuan ProvinceChina Department of Radiology Gaoping District People’s HospitalNanchong 637100Sichuan ProvinceChina Shude International Chengdu Shude High SchoolChengdu 610066Sichuan ProvinceChina Department of Environment Sichuan UniversityChengdu 610065Sichuan ProvinceChina

Echinococcosis is a zoonotic disease caused by parasites belonging to the genus Echinococcus that primarily affect the *** western plateau and pastoral areas of China are high-risk regions for hepatic cystic echinococcosis and hepatic alveolar echinococcosis(HAE).The high late mortality rate associated with HAE underscores the critical need for early diagnosis to improve cure rates and mitigate the disease burden in endemic ***,the World Health Orga-nization recommends ultrasonography as the preferred initial screening method for hepatic ***,distinguishing between specific types of lesions,such as those of hepatic cystic echinococcosis and HAE,and other focal liver lesions is *** address this issue,contrast-enhanced ultrasound is recommended as a tool to differentiate solid and cysto-solid hepatic echino-coccosis from other focal liver lesions,significantly enhancing diagnostic *** this comprehensive review,we discuss the progression of hepatic echinococcosis and detail the imaging features of various types of echinococcosis using conventional,contrast-enhanced,and intraoperative ultrasound *** objective is to provide robust imaging evidence and guidance for early diagnosis,clinical decision making,and postoperative follow-up in regions with high disease prevalence.

关键词： Echinococcosis Zoonotic disease Ultrasound Contrast-enhanced ultrasound Diagnosis

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Selective sintering of magnesia-calcia materials by utilizing hot spots during induction sintering process

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Journal of Iron and Steel Research International 2024年第8期31卷 1914-1922页

作者： Yun-jie Dong Zhou-fu wang Hao Liu Yan Ma Xi-tang wang Nian yi zhong-feng Xia Yu-xuan Zhu Cheng-ji Deng Ling Zhang The State Key Laboratory of Refractories and Metallurgy Wuhan University of Science and TechnologyWuhan 430081HubeiChina School of Materials and Metallurgy University of Science and Technology LiaoningAnshan 110325LiaoningChina

Magnesia-calcia refractories are widely used in the production process of clean steel due to their excellent high-tem-perature stability,slag resistance and ability to purify molten ***,there are still problems such as difficult sintering and easy ***-calcia materials with various calcium oxide contents were prepared by using induction sintering,and the sintering property combined with the hydration resistance of the materials was *** experimental results showed that the magnesia-calcia materials prepared under induction field had higher density,microhardness and hydration *** particular,the relative density of induction sintered magnesia-calcia materials with 50 mo1%CaO was greater than 98%,and the average grain size of CaO was 4.56μm,which was much larger than that of traditional sintered *** order to clarify the densification and microstructure evolution mechanism of the magnesia-calcia materials,the changes in temperature and magnetic field throughout the sintering process were analyzed by using finite element *** results showed that the larger heating rate and higher sintering temperature under the induction sintering mode were beneficial to the rapid *** addition,the hot spots generated within the material due to the difference in high-temperature electric conductivity between MgO and CaO were the critical factor to realize selective sintering in MgO-CaO system,which provides a novel pathway to solve the problem of difficult sintering and control the microstructure of high-temperature composite material used in the field of high-purity steel smelting.

关键词： Magnesia-calcia material Induction sintering Hot spot Selective sintering Density Microstructure control Hydration resistance

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Ore Geology,H-O-C Isotopes and 40Ar-39Ar Dating of the Wutonggou Iron Deposit,Eastern Tianshan,NW China:Implications for the Source,Timing,and Genesis of Hydrothermal Mineralization in a Sedimentary Iron Deposit

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Journal of Earth Science 2024年第4期35卷 1170-1185页

作者： Chun-Long wang yi-Tian wang State Key Laboratory of Geological Processes and Mineral Resources Collaborative Innovation Center for Exploration of Strategic Mineral ResourcesSchool of Earth ResourcesChina University of GeosciencesWuhan430074China MNR Key Laboratory of Metallogeny and Mineral Assessment Institute of Mineral ResourcesChinese Academy of Geological SciencesBeijing100037China

The Wutonggou iron deposit is located in the well-known iron metallogenic belt in the eastern Tianshan,NW China,and has been regarded as a sedimentary iron *** hydrothermal overprinting could play indispensable roles in the formation of high-grade iron ores in sedimentary iron deposits,previous studies mainly focused on sedimentary-related iron mineralization,while the nature and contribution of hydrothermal fluids are poorly ***,an integrated study of ore geology,H-O-C isotopes and^(40)Ar-^(39)Ar dating,is conducted on the Wutonggou deposit,in order to reveal the features,source,and timing of hydrothermal *** studied deposit includes two mining sections namely the Jianshan and ***δ^(18)O values of early magnetite from the Jianshan section range from+3.0‰to+5.8‰that nearly consistent with classic magmatic magnetite,while increase to 6.3‰-8.0‰in the late *** from the two sections shows comparable H-O isotopic compositions and identical fractionation trends,and is plotted in or periphery to the primary magmatic water *** from the two sections are broadly similar in carbon and oxygen isotopic compositions,and siderite from the Wutonggou section is plotted in the same ***,comparable stable isotopic compositions and evolution trends indicate similar magmatic fluids contributed hydrothermal iron mineralization in the two mining ***,water-rock interactions of varying degrees generated distinct mineralization styles in the Jianshan and Wutonggou sections,and caused the isotopic fractionation in late *** extracted from a hydrothermal siderite ore yielded a^(40)Ar-^(39)Ar plateau age of 299.5±2.0 Ma,indicates the timing of hydrothermal iron mineralization is corresponding to the emplacement of vicinity *** together,the hydrothermal mineralization in the Wutonggou iron deposit was the product of remobilization and upgrading of early sedimentary iron ores,a

关键词： iron deposits H-O-C isotopes 40Ar-39Ar dating sedimentary iron deposits Wutonggou iron deposit eastern Tianshan

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Unconditionally stable Crank-Nicolson algorithm with enhanced absorption for rotationally symmetric multi-scale problems in anisotropic magnetized plasma

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Journal of Systems Engineering and Electronics 2024年第1期35卷 65-73页

作者： WEN yi wang Junxiang XU Hongbing School of Automatic Engineering University of Electronic Science and Technology of ChinaChengdu 611731China Beijing Institute of Aerospace Systems Engineering Beijing 100076China

Large calculation error can be formed by directly employing the conventional Yee’s grid to curve *** order to alleviate such condition,unconditionally stable CrankNicolson Douglas-Gunn(CNDG)algorithm with is proposed for rotationally symmetric multi-scale problems in anisotropic magnetized *** the CNDG algorithm,an alternative scheme for the simulation of anisotropic plasma is proposed in body-of-revolution *** perfectly matched layer(CPML)formulation is proposed to efficiently solve the open region *** example is carried out for the illustration of effectiveness including the efficiency,resources,and *** the results,it can be concluded that the proposed scheme shows considerable performance during the simulation.

关键词： anisotropic magnetized plasma body-of-revolution(BOR) Crank-Nicolson Douglas-Gunn(CNDG) finite-difference time-domain(FDTD) perfectly matched layer(PML) rotationally symmetric multi-scale problems

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Enhanced visible light absorption of Bi_(2)WO_(6)/SiO_(2) with abundant adsorbed oxygen for the degradation of organic pollutant

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Particuology 2024年第5期88卷 210-217页

作者： Yuanting Wu Xiaoying wang Wenlong zhong Shan Zhang School of Material Science and Engineering Shaanxi University of Science and TechnologyXi'an 710021China

Heterogeneous photocatalysts exhibit high catalytic efficiency in the degradation of pollutants,but their stability and repeatability is not very good and requires high structural *** by nanosizing the pure Bi_(2)WO_(6)(BWO)photocatalyst without constructing a heterojunction,there is a significant improvement in its performance,with an enhancement effect of about 2.3 times(99.43%).The high photocatalytic degradation efficiency of the material can be attributed to the enhanced light absorption effect brought by the three-dimensional inverse-opal structure SiO_(2)(IS)and the abundant surface adsorbed oxygen generated after the formation of Si–O–W *** addition,the introduction of IS greatly increases the surface area of nanostructured BWO,which accelerates the charge transfer process,while the adsorbed oxygen promotes the participation of·O^(2−) in the photocatalytic reaction,thereby accelerating the consumption of photo-generated electrons and ultimately improving the separation of charge ***,the matched photonic bandgap further improves the absorption and utilization of light of the *** this work,we constructs Si–O–W bonds to obtain inverse-opal SiO_(2)/Bi_(2)WO_(6) with uniformly growth of pure phase nano BWO,which provides a feasible strategy for the preparation of high-performance pure-phase photocatalysts.

关键词： Bi_(2)WO_(6) SiO_(2) inverse-opal structure Photocatalysis Adsorbed oxygen

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Two polyoxovanadoborates with over 100 nuclei assembled from a {V_(14)Co_(12)B_(72)} cluster

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Science China Chemistry 2024年第8期67卷 2578-2585页

作者： Shuang-Xue Wu Yu-Jiao Dong Yang Yang Chao Qin Chun-yi Sun Wei Guan Xin-Long wang zhong-Min Su Key Laboratory of Polyoxometalate and Reticular Material Chemistry of Ministry of Education Northeast Normal UniversityChangchun 130024China School of Chemistry and Environmental Engineering Changchun University of Science and TechnologyChangchun 130013China Key Laboratory of Advanced Materials of Tropical Island Resources Hainan UniversityHaikou 570228China

Combining theoretical prediction and experimental exploration, the first sandwich-type polyoxovanadoborate(POVB) with an odd number of nuclei, [V_(11)B_(26)O_(73)(OH)_(10)]^(8-)(1), was discovered under hydrothermal conditions. Density-functional theory(DFT)gives a rationalization for the existence of this structure and the structural feature is consistent with the {V_NB_(2N+X)}(X = 2, 4, 6, 8)general formula. Excitingly, when Co and 1,10-phenanthroline(phen) are introduced into the synthesis of vanadoborates system,a 100-nuclei [Co_6(phen)_(10)(H_(2)O)_8][V_(14)Co_(12)B_(72)O_(144)(OH)_(20)]·28H_(2)O(2) and a 102-nuclei [Co_6(phen)_(14)(H_(2)O)_(4)][V_(14)Co_(12)B_(72)O_(144)(OH)_(20)]·23H_(2)O(3) with the same core structure of [V_(14)Co_(12)B_(72)]^(12-)are obtained. The vase-shaped [V_(14)Co_(12)B_(72)] polyanion is a multilayered sandwich-type structure containing seven distinct structural layers and is the largest known POVB. Furthermore, 2demonstrates exceptional thermal and chemical stability and serves as an efficient and stable catalyst for the photoreduction of carbon dioxide.

关键词： boronate metallic materials polyoxovanadoborates density functional theory photocatalysis CO_(2)reduction

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Dynamic COVID Zero Strategy triggered a significant increase of chlorine-based disinfectant

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Frontiers of Environmental Science & Engineering 2024年第8期18卷 73-80页

作者： Xuhao wang Mai Su Chunyan wang yi Liu School of Environment Tsinghua UniversityBeijing 100084China

Chlorine-based disinfectants(CBDs)have been widely used to prevent and control the spread of the COVID-19,which may lead to the formation of carcinogenic *** China,strict disinfection strategies by local governments/communities or volunteering by residents have been implemented to meet the Dynamic COVID Zero(DCZ)***,the amount of CBDs used has not been *** author proposed an urban-scale disinfectant consumption estimation(ALICE)model to quantify weekly CBD *** results show that the CBD consumption for the urban region of Beijing during the DCZ strategy was 3704.0 t(0.43 kg/(cap-yr)),equivalent to a monthly increase of 15 g/cap(70.5%)in CBD consumption compared with that in *** to the scenario analysis,a stricter strategy with a shorter response time toward new cases will decrease the total CBD consumption by 1.2% compared with the baseline estimation.A more precise prevention strategy with a smaller delineation of risk area and a less stringent strategy with a longer response time will lower the total CBD consumption by 0.42% and 0.35%,***,the more precise prevention strategy will reduce CBD consumption of close off and lockdown area(COLD area)by 16.9%,and the stricter strategy will reduce this consumption by 37.7%.This study highlights the impact of pandemic prevention and control strategies on chlorine-based disinfectant consumption and some implications for future environmental pollution and risk assessments.

关键词： COVID-19 Dynamic COVID Zero Strategy Disinfectants consumption Bottom-up approach Scenario analysis

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Some Convergence Properties for Weighted Sums of Martingale Difference Random Vectors

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Acta Mathematica Sinica,English Series 2024年第4期40卷 1127-1142页

作者： yi WU Xue Jun wang School of Big Data and Artificial Intelligence Chizhou UniversityChizhou 247000P.R.China School of Big Data and Statistics Anhui UniversityHefei 230601P.R.China

Let{X_(ni),F_(ni);1≤i≤n,n≥1}be an array of R^(d)martingale difference random vectors and{A_(ni),1≤i≤n,n≥1}be an array of m×d matrices of real *** this paper,the Marcinkiewicz-Zygmund type weak law of large numb... 详细信息

关键词： Martingale difference random vectors weighted sums Marcinkiewicz–Zygmund type weak law of large numbers complete convergence strong law of large numbers multivariate simple linear regression model

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