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High-responsivity solar-blind photodetector based on MOCVD-grown Si-dopedβ-Ga_(2)O_(3)thin film

Chinese Physics B 2021年第5期30卷 595-601页

作者： Yu-Song Zhi Wei-Yu Jiang Zeng Liu Yuan-Yuan Liu Xu-Long Chu Jia-Hang Liu Shan Li Zu-Yong Yan Yue-Hui Wang Pei-Gang Li Zhen-Ping Wu Wei-Hua Tang Laboratory of Information Functional Materials and Devices School of Science&State Key Laboratory of Information Photonics and Optical CommunicationsBeijing University of Posts and TelecommunicationsBeijing 100876China Center of Materials Science and Optoelectronics Engineering University of Chinese Academy of SciencesBeijing 100049China The Engineering Research Center for Semiconductor Integrated Technology Institute of SemiconductorsChinese Academy of SciencesBeijing 100083China China Aerospace System Simulation Technology Co. Ltd.(Beijing)Beijing 100195China College of Electronic and Optical Engineering&College of Microelectronics Nanjing University of Posts and TelecommunicationsNanjing 210023China

Si-dopedβ-Ga_(2)O_(3)films are fabricated through metal-organic chemical vapor deposition(MOCVD).Solar-blind ultraviolet(UV)photodetector(PD)based on the films is fabricated by standard photolithography,and the photodetection properties are *** results show that the photocurrent increases to 11.2 mA under 200μW·cm^(-2)254 nm illumination and±20 V bias,leading to photo-responsivity as high as 788 A·W^(-1).The Si-dopedβ-Ga2O3-based PD is promised to perform solar-blind photodetection with high performance.

关键词： Si-dopedβ-Ga_(2)O_(3) metal-organic chemical vapor deposition(MOCVD) solar-blind high responsivity

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A homogenization method for nonlinear inhomogeneous elastic materials

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Virtual Reality & Intelligent Hardware 2021年第2期3卷 156-170页

作者： Jing ZHAO Fei ZHU Liyou XU Yong TANG Sheng LI College of Information Science and Engineering Yanshan UniversityQinhuangdaoHebei 066004China The Key Laboratory for Computer Virtual Technology and System Integration of Hebei Province QinhuangdaoHebei 066004China School of Electronics Engineering and Computer Science Peking UniversityBeijing 100871China Beijing Engineering Research Center for Virtual Simulation and Visualization Beijing 100871China

Background Fast simulation techniques are strongly favored in computer graphics,especially for the nonlinear inhomogeneous elastic *** homogenization theory is a perfect match to simulate inhomogeneous deformable objects with its coarse discretization,as it reveals how to extract information at a fine scale and to perform efficient computation with much less *** existing homogenization method is not applicable for ubiquitous nonlinear materials with the limited input deformation *** In this paper,we have proposed a homogenization method for the efficient simulation of nonlinear inhomogeneous elastic *** approach allows for a faithful approximation of fine,heterogeneous nonlinear materials with very coarse *** analysis provides the basis of a linear deformation space and modal derivatives extend the space to a nonlinear regime;based on this,we exploited modal derivatives as the input characteristic deformations for *** also present a simple elastic material model that is nonlinear and anisotropic to represent the homogenized *** nonlinearity of material deformations can be represented properly with this *** material properties for the coarsened model were solved via a constrained optimization that minimizes the weighted sum of the strain energy deviations for all input deformation *** arbitrary number of bases can be used as inputs for homogenization,and greater weights are placed on the more important low-frequency *** Based on the experimental results,this study illustrates that the homogenized material properties obtained from our method approximate the original nonlinear material behavior much better than the existing homogenization method with linear displacements,and saves orders of magnitude of computational *** The proposed homogenization method for nonlinear inhomogeneous elastic materials is capable of capturing the nonlinear dynamics of the

关键词： Physical-based simulation Homogenization theory Heterogeneous material Modal basis

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Design and Experimental Validation of Sealing Assembly for Lunar Regolith Volatile Extraction Heating Furnace

Design and Experimental Validation of Sealing Assembly for L...

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2023 IEEE International Conference on Robotics and Biomimetics, ROBIO 2023

作者： Zhang, Hongan Tang, Junyue Wang, Yinchao Lu, Zixiao Wang, Bo Cao, Miaoyan Jiang, Shengyuan Yanshan University Mechanical Engineering Qinhuangdao China Harbin Institute of Technology State Key Laboratory of Robotics and System Harbin China Shenyang Aerospace University Mechatronics Institute Shenyang China Chinese Academy of Science National Center for Nanoscience and Technlogy Beijing China China Academy of Space Technology Beijing China

ISBN: (纸本)9798350325706

A lunar regolith in-situ analysis payload deploying a mass spectrometer is proposed to exactly detect the water ice of the South Pole of the moon for China future lunar exploration missions. In order to realize the goal, an airtight heating furnace for volatile extraction from lunar regolith is desired. In this paper, sealing methods for lunar regolith volatile in heating furnace to future proposed in-situ sampling and analysis of lunar samples were investigated based on power requirements, furnace closing accuracy requirements, dust tolerance and operation in the Lunar environment. Methods implemented include a balanced metal hollow ring seal, a double channel ferrule tab ring radial seal and a spring energized seal. Comparing the performance of sealing methods under the above conditions, a spring energized seal is selected as the heating furnace seal. The materials and structure of the seal are designed based on the rigidity requirements, leakage rate requirements and working environment requirements. In order to test the sealing performance of seals after repeated sealing in high and low temperature environments, a seal leak detection system was designed. The test results indicate that the seal can meet the sealing performance requirements after repeated sealing at various temperatures. © 2023 IEEE.

关键词： Dust tolerance Leakage rate Lunar environment Repeated sealing Spring energized seal

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Better Modeling the Hierarchical Structure of Language for Sentence Semantic Matching 2

Better Modeling the Hierarchical Structure of Language for S...

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2020 2nd International Conference on Artificial Intelligence Technologies and Application, ICAITA 2020

作者： Pei, Zhongmin Li, Changqun Xiong, Wei Luo, Zhangkai Science and Technology on Complex Electronic System Simulation Laboratory Space Engineering University Beijing100014 China

Sentence semantic matching requires understanding the semantic relationship between two sentences, which is widely used in various natural language tasks such as paraphrase identification, natural language inference and question answering. Usually, the underlying structure of sentence is not strictly sequential, this structure is hierarchical. This paper studies how to better model the hierarchical structure of sentence for semantic matching. Recent research suggests that BERT implicitly captures classical, tree-like structures. Based on this, this paper proposes to further enhance the strength of modeling hierarchical structure of language with an advanced variant of LSTM-Ordered Neurons LSTM(ON-LSTM), which introduces a syntax-oriented inductive bias to perform the composition of classical tree structure. Experimental results demonstrate that the proposed approach, which enhances hierarchical structure of language, significantly improves the performance of sentence semantic matching. © 2020 Published under licence by IOP Publishing Ltd.

关键词： Modeling languages

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Land surface modeling informed by earth observation data:toward understanding blue-green-white water fluxes in High Mountain Asia

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地球空间信息科学学报（英文版） 2024年第3期27卷 703-727页

作者： Pascal Buri Simone Fatichi Thomas E.Shaw Catriona L.Fyffe Evan S.Miles Michael J.McCarthy Marin Kneib Shaoting Ren Achille Jouberton Stefan Fugger Li Jia Jing Zhang Cong Shen Chaolei Zheng Massimo Menenti Francesca Pellicciotti Swiss Federal Institute for Forest Snow and Landscape Research WSLBirmensdorfSwitzerland Department of Civil and Environmental Engineering National University of SingaporeSingaporeSingapore Swiss Federal Institute for Forest Snow and Landscape Research WSLBirmensdorfSwitzerland Institute of Science and Technology Austria(ISTA) KlosterneuburgAustria Institute of Science and Technology Austria(ISTA) KlosterneuburgAustria Institute of Environmental Geosciences Université Grenoble AlpesGrenobleFrance Department of Atmospheric and Cryospheric Sciences University of InnsbruckInnsbruckAustria State Key Laboratory of Tibetan Plateau Earth System Environment and Resources(TPESER)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijingChina Swiss Federal Institute for Forest Snow and Landscape Research WSLBirmensdorfSwitzerland Institute of Environmental Engineering ETH ZurichZurichSwitzerland State Key Laboratory of Remote Sensing Science Aerospace Information Research InstituteChinese Academy of SciencesBeijingChina National Space Sciences Center Chinese Academy of SciencesBeijingChina State Key Laboratory of Remote Sensing Science Aerospace Information Research InstituteChinese Academy of SciencesBeijingChina Faculty of Civil Engineering and Geosciences Delft University of TechnologyDelftThe Netherlands

Mountains are important suppliers of freshwater to downstream areas,affecting large populations in particular in High Mountain Asia(HMA).Yet,the propagation of water from HMA headwaters to downstream areas is not fully understood,as interactions in the mountain water cycle between the cryo-,hydro-and biosphere remain *** review the definition of blue and green water fluxes as liquid water that contributes to runoff at the outlet of the selected domain(blue)and water lost to the atmosphere through vapor fluxes,that is evaporation from water,ground,and interception plus transpiration(green)and propose to add the term white water to account for the(often neglected)evaporation and sublimation from snow and *** provide an assessment of models that can simulate the cryo-hydro-biosphere continuum and the interactions between spheres in high mountain catchments,going beyond disciplinary *** surface models are uniquely able to account for such complexity,since they solve the coupled fluxes of water,energy,and carbon between the land surface and *** to the mechanistic nature of such models,specific variables can be compared systematically to independent remote sensing observations-providing vital insights into model accuracy and enabling the understanding of the complex watersheds of *** discuss recent developments in spaceborne earth observation products that have the potential to support catchment modeling in high mountain *** then present a pilot study application of the mechanistic land surface model Tethys & Chloris to a glacierized watershed in the Nepalese Himalayas and discuss the use of high-resolution earth observation data to constrain the meteorological forcing uncertainty and validate model *** use these insights to highlight the remaining challenges and future opportunities that remote sensing data presents for land surface modeling in HMA.

关键词： Land surface modeling remote sensing High Mountain Asia(HMA) blue-green water cryosphere-hydrosphere-biosphere continuum snow glaciers high mountain water cycle

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Design and modeling of satellite network structure for business scenarios

Design and modeling of satellite network structure for busin...

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2020 International Seminar on Artificial Intelligence, Networking and Information technology, AINIT 2020

作者： Ren, Lintao Pei, Zhongmin Xiong, Wei Luo, Zhangkai Science and Technology on Complex Electronic System Simulation Laboratory Space Engineering University Beijing101416 China

In view of the actual decentralized development of the satellite service constellation and the trend of space-ground integrated information network, based on the idea of clustering, methodology of complex network community structure, a business scenario-oriented satellite network structure is designed. On the one hand, it reflects the different separation and integration of satellite constellations in business scenarios. On the other hand, the "head node"mechanism is introduced to be responsible for the interaction between constellation in different business scenarios. The satellite network structure is modeled using the growth and priority connection mechanism, and through computational derivation and simulation validation, the scale-free characteristics of the satellite network are revealed. Finally, through the simulation experiments on different satellite network parameters, the effect of different parameters on the static geometry, network efficiency, etc., are obtained. The influence of the law of the network will provide theoretical and methodological reference for the design of satellite network structure. © Published under licence by IOP Publishing Ltd.

关键词： Complex networks

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Collaborative Filtering Recommendation Algorithm of Weaponry Based on Knowledge Graph

Collaborative Filtering Recommendation Algorithm of Weaponry...

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Information technology,Big Data and Artificial Intelligence (ICIBA), International Conference on IEEE International Conference on

作者： Xiao Li Desheng Liu Qing Chang Science and Technology on Complex Electronic System Simulation Laboratory Space Engineering University Beijing

ISBN: (纸本)9781665428781

Nowadays, modern warfare has changed from weapon-centric operations to network-centric system operations, which has led to the phenomenon of sea-level quantification of weaponry. It is an important research topic for combat commanders to select suitable weaponry from a large number of available resources when facing combat tasks. Recommendation technology is a solution to this problem, which can effectively solve the problem of information overload, so that combat commanders do not produce the phenomenon of “information loss”, in the shortest possible time to make the right decision. Therefore, this paper proposes a collaborative filtering recommendation algorithm for weaponry based on the knowledge graph and the idea of collaborative filtering. In this algorithm, the knowledge graph provides a clear data model with various association relationships, and the collaborative filtering algorithm can realize it without relying on professional experience, which can realize the recommendation process more actively, faster and more intelligently.

关键词： Weapons Collaborative filtering systems operation Conferences Filtering algorithms Big Data Information filters

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Researchment of mainlobe anti-jamming algorithms 6

Researchment of mainlobe anti-jamming algorithms

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6th Annual International Conference on Computer science and Applications, CSA 2020

作者： Luo, Zhangkai Pei, Zhongmin Li, Yinan Wang, Xinmin Zou, Bo Science and Technology on Complex Electronic System Simulation Laboratory Space Engineering University Beijing101400 China

Main lobe interferences usually cause the distortion and peak offset of main lobe and the heighten of side lobe level in adaptive beamformers. The block matrix algorithm utilized the direction vector which was determined by both the antenna arrays and the direction of interference to eliminate the main lobe interference. But this algorithms is sensitive to the error occurred in the interference arrive angle and would consume the array of degrees of freedom. In this paper a new algorithm is proposed which projects the receive signal into a space which is orthogonal to the signal subspace to achieve the goal. The space can get by three steps. Frist we obtain eigenvalues by the decomposition of the covariance matrix of the snapshots to evaluate the noise power. Then we get a new matrix by removing the noise from the covariance matrix of the snapshots. At last we get the target space by conducting the singular value decomposition to the new matrix. Performance is mainly assessed in terms of the beamforming gain and the signal to interference and noise (SINR) ratio. The computer simulation shows the effective of this method. © 2020 Institute of Physics Publishing. All rights reserved.

关键词： Covariance matrix

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A Study on the Assessment and Integration of Multi-Source Evapotranspiration Products over the Tibetan Plateau

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Advances in Atmospheric sciences 2024年第3期41卷 435-448页

作者： Ming CHENG Lei ZHONG Yaoming MA Han MA Yaoxin CHANG Peizhen LI Meilin CHENG Xian WANG Nan GE School of Earth and Space Sciences University of Science and Technology of ChinaHefei 230026China CAS Center for Excellence in Comparative Planetology Hefei 230026China Jiangsu Collaborative Innovation Center for Climate Change Nanjing 210023China Frontiers Science Center for Planetary Exploration and Emerging Technologies University of Science and Technology of ChinaHefei 230026China Land-Atmosphere Interaction and its Climatic Effects Group State Key Laboratory of Tibetan Plateau Earth SystemResources and Environment(TPESRE)Institute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China College of Atmospheric Science Lanzhou UniversityLanzhou 730000China National Observation and Research Station for Qomolongma Special Atmospheric Processes and Environmental Changes Dingri 858200China Kathmandu Center of Research and Education Chinese Academy of SciencesBeijing 100101China China-Pakistan Joint Research Center on Earth Sciences Chinese Academy of SciencesIslamabad 45320Pakistan

Evapotranspiration(ET)is a crucial variable in the terrestrial water,carbon,and energy *** present,a large number of multi source ET products *** to sparse observations,however,great challenges exist in the evaluation and integration of ET products in remote and complex areas such as the Tibetan Plateau(TP).In this paper,the applicability of the multiple collocation(MC)method over the TP is evaluated for the first time,and the uncertainty of multisource ET products(based on reanalysis,remote sensing,and land surface models)is further analyzed,which provides a theoretical basis for ET data *** results show that 1)ET uncertainties quantified via the MC method are lower in RS-based ET products(5.95 vs.7.06 mm month^(-1))than in LSM ET products(10.22 vs.17.97 mm month^(-1))and reanalysis ET estimates(7.27 vs.12.26 mm month-1).2)A multisource evapotranspiration(MET)dataset is generated at a monthly temporal scale with a spatial resolution of 0.25°across the TP during *** has better performance than any individual product.3)Based on the fusion product,the total ET amount over the TP and its patterns of spatiotemporal variability are clearly *** annual total ET over the entire TP is approximately 380.60 ***,an increasing trend of 1.59±0.85 mm yr^(-1)over the TP is shown during *** study provides a basis for future studies on water and energy cycles and water resource management over the TP and surrounding regions.

关键词： evapotranspiration data fusion multiple collocation the Tibetan Plateau

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Ontology-Based BERT Model for Automated Information Extraction from Geological Hazard Reports

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Journal of Earth science 2023年第5期34卷 1390-1405页

作者： Kai Ma Miao Tian Yongjian Tan Qinjun Qiu Zhong Xie Rong Huang Hubei Key Laboratory of Intelligent Vision Based Monitoring for Hydroelectric Engineering China Three Gorges UniversityYichang 443002China College of Computer and Information Technology China Three Gorges UniversityYichang 443002China Hubei Engineering Technology Research Center for Farmland Environment Monitoring China Three Gorges UniversityYichang 443002China School of Computer Science China University of GeosciencesWuhan 430074China Key Laboratory of Urban Land Resources Monitoring and Simulation Ministry of Natural ResourcesShenzhen 518034China Beijing Key Laboratory of Urban Spatial Information Engineering Beijing 100045China College of Economics and Management China Three Gorges UniversityYichang 443002China

Geological knowledge can provide support for knowledge discovery, knowledge inference and mineralization predictions of geological big data. Entity identification and relationship extraction from geological data description text are the key links for constructing knowledge graphs. Given the lack of publicly annotated datasets in the geology domain, this paper illustrates the construction process of geological entity datasets, defines the types of entities and interconceptual relationships by using the geological entity concept system, and completes the construction of the geological corpus. To address the shortcomings of existing language models(such as Word2vec and Glove) that cannot solve polysemous words and have a poor ability to fuse contexts, we propose a geological named entity recognition and relationship extraction model jointly with Bidirectional Encoder Representation from Transformers(BERT) pretrained language model. To effectively represent the text features, we construct a BERT-bidirectional gated recurrent unit network(BiGRU)-conditional random field(CRF)-based architecture to extract the named entities and the BERT-BiGRU-Attention-based architecture to extract the entity relations. The results show that the F1-score of the BERT-BiGRU-CRF named entity recognition model is 0.91 and the F1-score of the BERT-BiGRU-Attention relationship extraction model is 0.84, which are significant performance improvements when compared to classic language models(e.g., word2vec and Embedding from Language Models(ELMo)).

关键词： ontology BERT model name entity recognition relation extraction knowledge graph

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