检索结果-南通市图书馆

MADRL-based UAV swarm non-cooperative game under incomplete information

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2024年第6期37卷 293-306页

作者： Ershen WANG Fan LIU Chen HONG Jing GUO Lin ZHAO jian xue Ning HE School of Electronic and Information Engineering Shenyang Aerospace UniversityShenyang 110136China College of Robotics Beijing Union UniversityBeijing 100101China School of Engineering Science University of Chinese Academy of SciencesBeijing 100049China College of Smart City Beijing Union UniversityBeijing 100101China

Unmanned Aerial Vehicles(UAVs)play increasing important role in modern *** this paper,considering the incomplete observation information of individual UAV in complex combat environment,we put forward an UAV swarm non-cooperative game model based on Multi-Agent Deep Reinforcement Learning(MADRL),where the state space and action space are constructed to adapt the real features of UAV swarm air-to-air *** multi-agent particle environment is employed to generate an UAV combat scene with continuous observation *** recently popular MADRL methods are compared extensively in the UAV swarm noncooperative game model,the results indicate that the performance of Multi-Agent Soft Actor-Critic(MASAC)is better than that of other MADRL methods by a large *** swarm employing MASAC can learn more effective policies,and obtain much higher hit rate and win *** under different swarm sizes and UAV physical parameters are also performed,which implies that MASAC owns a well generalization ***,the practicability and convergence of MASAC are addressed by investigating the loss value of Q-value networks with respect to individual UAV,the results demonstrate that MASAC is of good practicability and the Nash equilibrium of the UAV swarm non-cooperative game under incomplete information can be reached.

关键词： UAV swarm Reinforcement learning Deep learning Multi-agent Non-cooperative game Nash equilibrium

Ni-Catalyzed Enantioselective Difunctionalization of Alkynes to Azepine Derivatives Bearing a Quaternary Center and an Unprotected Imine

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2024年第8期42卷 873-878页

作者： jian Long Zhiwu Lu Xiao-Lin Li Peng xue Wen-Bo Liu Engineering Research Center of Organosilicon Compounds&Materials(Ministry of Education)and College of Chemistry and Molecular Sciences Wuhan UniversityWuhanHubei430072 China

Comprehensive Summary,The azepine ring is a prominent structural scaffold in biologically significant molecules. In this study, we present a Ni(II)-catalyzed asymmetric difunctionalization of alkynes, involving intermolecular regioselective arylation and intramolecular nitrile addition, enabling the synthesis of enantioenriched azepine derivatives. This reaction simultaneously installs an all-carbon quaternary stereocenter and introduces an unprotected imine functionality, showing great promise for subsequent transformations. The reaction exhibits good tolerance toward various functional groups, resulting in high yields and enantioselectivities. The synthetic utility of this methodology is further demonstrated through gram-scale synthesis and product derivatization. This research offers an efficient approach to the synthesis of seven-membered nitrogen heterocycles.

关键词： Nickel Asymmetric catalysis N-Heterocycles Alkyne functionalization Quaternary centers

Multicomponent Reaction in Ionic Liquid: A Novel and Green Synthesis of 1, 4-Dihydropyridine Derivatives

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2006年第2期17卷 150-152页

作者： Xin Ying ZHANG Yan Zhen LI xue Sen FAN Gui Rong QU xue Yuan hu jian Ji WANG College of Chemistry and Environmental Science Henan Key Laboratory for Environmental Pollution Control Henan Normal University Xinxiang 453007

An efficient and green method for the synthesis of 1, 4-dihydropyridine derivatives mediated in an ionic liquid, [bmim][BF4], through a four-component condensation process of aldehydes, 1, 3-dione, Meldrum＇s acid and... 详细信息

关键词： 1,4-Dihydropyridines ionic liquids multicomponent reaction green chemistry.

Synthetic Control of Thorium Metal-Organic Frameworks for Sequencing and Sensing of Radioiodine Species

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemistry 2024年第1期42卷 20-28,I0004页

作者： Yu Ju Zi-jian Li xue Wang Jie Qiu Yiuhon Chan Zhi-hui Zhang Mingyang He jian Lin jiangsu Key Laboratory of Advanced Catalytic Materials and Technology Changzhou UniversityNo.21Gehu Middle RoadChangzhouJiangsu 213164China Schoolof Nuclear Science and Technology Xi'an Jiaotong UniversityNo.28West Xianning RoadXianShaanxi 710049China Key Laboratoryof Interfacial Physics and Technology Shanghai Institute of Applied PhysicsChinese Academy of Sciences2019JiaLuoRoadShanghai 201800China

Exploring the physiochemical properties and expanding the applications of actinide-containing materials is paramount to address the escalating challenge of radioactive waste ***,unlocking the full potential of these materials is largely crippled by the radiotoxicity of the *** report here two porous and luminescent thorium-based metal-organic frameworks(Th-BITD-1 and Th-BITD-2)that serve as a bifunctional platform for sequencing and sensing of radioiodine,a much more radioactive fission product discharged during the nuclear fuel *** particular,Th-BITD-1 displays better iodine uptake performance than Th-BITD-2 via the solution-based process and vapor diffusion with the maximum adsorption capacities of 831 and 1099 mg/g,*** thermore,Th-BITD-1 can function as a highly sensitive luminescence sensor for iodate with a quenching constant(Ksv)of 6.6(5)×10^(3) M^(-1)and a detection limit of 2.02μM,respectively,outperforming 2.96(6)×10^(3)M^(-1)and 10.5μM of ***,a positive correlation between the sensing efficacy and the iodate adsorption capacity has been *** work highlights the opportunity in designing novel actinide-based MOFs for their potential applications in radiological fields,e.g.,radionuclide separation and detection.

关键词： Thorium Metal-organic frameworks Adsorption Detection lodine Actinides Radiochemistry Luminescence

Mechanistic insight into Cr(Ⅵ)retention by Si-containing ferrihydrite

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Journal of Environmental Sciences 2024年第5期139卷 217-225页

作者： Ying hu Qiang xue Honghan Chen huaming Guo Kenneth C.Carroll Song Wang MOE Key Laboratory of Groundwater Circulation and Environmental Evolution School of Water Resources and EnvironmentChina University of Geosciences(Beijing)Beijing 100083China Beijing Key Laboratory of Water Resources and Environmental Engineering School of Water Resources and EnvironmentChina University of GeosciencesBeijing 100083China State Key Laboratory of Biogeology and Environmental Geology China University of GeosciencesBeijing 100083China Plant&Environmental Science New Mexico State UniversityNM 88003USA Institute of Theoretical Chemistry College of ChemistryJilin UniversityChangchun 130023China

Hexavalent chromium[Cr(Ⅵ)]causes serious harm to the environment due to its high toxicity,solubility,and ***(Fh)are the main adsorbent and trapping agent of Cr(Ⅵ)in soils and aquifers,and they usually coexist with silicate(Si),forming Si-containing ferrihydrite(Si-Fh)***,the mechanism of Cr(Ⅵ)retention by Si-Fh mixtures is poorly *** this study,the behaviors and mechanisms of Cr(Ⅵ)adsorption onto Si-Fh with different Si/Fe molar ratios was *** electron microscope,Fourier transform infrared spectroscopy,X-ray diffraction,X-ray photoelectron spectroscopy,and other techniques were used to characterize Si-Fh and Cr(Ⅵ)-loading of *** results show that specific surface area of Si-Fh increases gradually with increasing Si/Fe ratios,but Cr(Ⅵ)adsorption on Si-Fh decreases with increasing Si/Fe *** is because with an increase in Si/Fe molar ratio,the point of zero charge of Si-Fh gradually decreases and electrostatic repulsion between Si-Fh and Cr(Ⅵ)***,the complexation of Cr(Ⅵ)is enhanced due to the increase in adsorbed hydroxyl(A-OH-)on Si-Fh with increasing Si/Fe molar ratio,which partly counteracts the effect of the electrostatic ***,the increase in the electrostatic repulsion has a greater impact on adsorption than the additional complexation with *** functional theory calculation further supports this observation,showing the increases in electron variation of bonding atoms and reaction energies of inner spherical complexes with the increase in Si/Fe ratio.

关键词： Hexavalent chromium Ferrihydrite Si/Fe ratio Cr(Ⅵ)Adsorption

Quantifying the agreement and accuracy characteristics of four satellite-based LULC products for cropland classification in China

在线全文

学校读者我要写书评

暂无评论

Journal of Integrative Agriculture 2024年第1期23卷 283-297页

作者： Jie xue Xianglin Zhang Songchao Chen Bifeng hu Nan Wang Zhou Shi Department of Land Management Zhejiang UniversityHangzhou 310058China Institute of Applied Remote Sensing and Information Technology College of Environmental and Resource SciencesZhejiang UniversityHangzhou 310058China ZJU-Hangzhou Global Scientific and Technological Innovation Center Zhejiang UniversityHangzhou 311215China Department of Land Resource Management School of Public Finance and Public AdministrationJiangxi University of Finance and EconomicsNanchang 330013China Key Laboratory of Data Science in Finance and Economics Jiangxi University of Finance and EconomicsNanchang 330013China Key Laboratory of Spectroscopy Sensing Ministry of Agriculture and Rural AffairsHangzhou 310058China

Various land use and land cover(LULC)products have been produced over the past decade with the development of remote sensing *** the differences in LULC classification schemes,there is a lack of research on assessing the accuracy of their application to croplands in a unified ***,this study evaluated the spatial and area accuracies of cropland classification for four commonly used global LULC products(i.e.,MCD12Q1V6,GlobCover2009,FROM-GLC and GlobeLand30)based on the harmonised FAO criterion,and quantified the relationships between four factors(i.e.,slope,elevation,field size and crop system)and cropland classification *** validation results indicated that MCD12Q1 and GlobeLand30 performed well in cropland classification regarding spatial consistency,with overall accuracies of 94.90 and 93.52%,*** FROMGLC showed the worst performance,with an overall accuracy of 83.17%.Overlaying the cropland generated by the four global LULC products,we found the proportions of complete agreement and disagreement were 15.51 and 44.72% for the cropland classification,*** consistency was mainly observed in the Northeast China Plain,the huang-huai-Hai Plain and the northern part of the Middle-lower Yangtze Plain,*** contrast,low consistency was detected primarily on the eastern edge of the northern and semiarid region,the Yunnan-Guizhou Plateau and southern *** size was the most important factor for mapping *** area accuracy,compared with China Statistical Yearbook data at the provincial scale,the accuracies of different products in descending order were:GlobeLand30,FROM-GLC,MCD12Q1,and *** cropland classification schemes mainly caused large area deviations among the four products,and they also resulted in the different ranks of spatial accuracy and area accuracy among the four *** results can provide valuable suggestions for selecting cropland products at the national or provinc

关键词： global LULC products cropland mapping accuracy evaluation food security China

On the Quantum Cohomology of Blow-ups of Four-dimensional Quadrics

在线全文

学校读者我要写书评

暂无评论

Acta Mathematica Sinica,English Series 2024年第1期40卷 313-328页

作者： jian Xun hu hua Zhong KE Chang Zheng LI Lei SONG School of Mathematics Sun Yat-sen UniversityGuangzhou 510275P.R.China

We propose a conjecture relevant to Galkin’s lower bound conjecture,and verify it for the blow-ups of a four-dimensional quadric at a point or along a projective *** also show that Conjecture O holds in these two cases.

关键词： Quantum cohomology blow-up quadric hypersurface

Mitigated lattice distortion and oxygen loss of Li-rich layered cathode materials through anion/cation regulation by Ti^(4+)-substitution

在线全文

学校读者我要写书评

暂无评论

Chinese Chemical Letters 2024年第2期35卷 548-552页

作者： Kaicheng Zhang Yu Tian Xuanjin Chen Shan hu Zelang jian State Key Laboratory of Advanced Technology for Materials Synthesis and Processing School of Materials Science and EngineeringWuhan University of TechnologyWuhan 430070China

Lithium-rich layered cathode material(LLM)can meet the requirement of power lithium-ion energy storage devices due to the great energy ***,the de/intercalation of Li+will cause the irreversible loss of lattice oxygen and trigger transition metal(TM)ions migrate to Li+vacancies,resulting in capacity *** we brought Ti4+in substitution of TM ions in Li_(1.2)Mn_(0.54)Ni_(0.13)Co_(0.13)O_(2),which could stabilize structure and expand the layer spacing of ***,optimized Ti-substitution can regulate the anions and cations of LLM,enhance the interaction with lattice oxygen,increase Ni^(3+) and Co^(3+),and improve Mn^(4+) coordination,improving reversibility of oxygen redox activation,maintaining the stable framework and facilitating the Li^(+) ***,we found 5%Ti-substitution sample delivered a high discharge capacity of 244.2 mAh/g at 50 mA/g,an improved cycling stability to 87.3%after 100 cycles and enhanced rate *** Ti-substitution gives a new pathway to achieve high reversible cycle retention for LLMs.

关键词： Lithium-rich layered cathode material Ti-substitution Anion/cation regulation Structural stability Cycling stability

Review of Inductance Identification Methods Considering Inverter Nonlinearity for PMSM

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Electrical Engineering 2024年第2期10卷 1-15页

作者： Qiwei Wang Jiqing xue Gaolin Wang Yihua hu Dianguo Xu School of Electrical Engineering and Automation Harbin Institute of TechnologyHarbin 150000China Department of Engineering King’s College LondonLondon WC2R 2LSUK

Permanent magnet synchronous motors(PMSMs)are widely used in high-power-density and flexible control ***,the inductance changes significantly in real-time machine operations because of magnetic saturation and coupling ***,the identification of inductance is crucial for PMSM *** inductance identification methods are primarily based on the voltage source inverter(VSI),making inverter nonlinearity one of the main error sources in inductance *** improve the accuracy of inductance identification,it is necessary to compensate for the inverter nonlinearity *** this study,an overview of the PMSM inductance identification and the related inverter nonlinearity self-learning methods are presented.

关键词： Inductance identification inverter nonlinearity self-learning permanent magnet synchronous motor