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A Case Study on the Rapid Rain-to-Snow Transition in Late Spring 2018 over Northern China:Effects of Return Flows and Topography

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Journal of Meteorological Research 2022年第1期36卷 107-127页

作者： Wenlong ZHANG Xiaopeng CUI Bolong DUAN Bo YU Runxia GUO Haiwen LIU Institute of Urban Meteorology China Meteorological AdministrationBeijing 100089 key laboratory of Cloud-Precipitation Physics and Severe Storms Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029 Lanzhou Central Meteorological Observatory Lanzhou 730020 Beijing Weather Forecast Center Beijing 100089 Department of Aviation Meteorology Civil Aviation University of ChinaTianjin 300300 University of Chinese Academy of Sciences Beijing 100049

Phase changes in the precipitation processes of early winter and late spring in midlatitude regions represent challenges when forecasting the timing and magnitude of *** 4 April 2018,a heavy snow process occurred in Beijing and northwestern Hebei Province,becoming the most delayed occurrence of heavy spring snow ever recorded over Beijing in the last 30 *** paper uses observational and numerical simulation data to investigate the causes for the rapid rain-to-snow(RRTS)phase transition during this *** following results are obtained.(1)Return flows(RFs),an interesting type of easterly wind,including those at 1000,925,and 800 hPa,played an important role in this heavy snow process and presented a characteristic"sandwich"*** RFs,complex topography,and snow particles that dominated the clouds,were the three key factors for the RRTS transition.(2)The RRTS transition in the plains was directly related to the RF at 925 hPa,which brought about advective cooling initiated approximately 4-6 h before the onset of ***,the RF played a role of diabatic cooling when snow particles began to fall at the onset of precipitation.(3)The RRTS transition in the northern part of the Taihang Mountains was closely related to the relatively high altitude that led to a lower surface temperature owing to the vertical temperature lapse *** immediately before and after the onset of precipitation,the snow particles in clouds entrained the middle-level cold air downward,causing the melting layer(from surface to the 0℃-isotherm level)to become very thin;and thus the snow particles did not have adequate time to melt before falling to the ground.(4)The rapid RRTS over the Yanqing mountainous area in the northwest of Beijing could have involved all the three concurrent mechanisms:the advective cooling of RF,the melting cooling of cloud snow particles,and the high-altitude *** with that in the plain area with less urbanization the duration

关键词： midlatitude heavy snow return flow phase transition Bohai Sea cold pool complex terrain numerical simulation

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Design and Synthesis of Tb^(3+)-doped KGW Crystal for the Exploration of Scintillation Performance with X-ray Imaging

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Chinese Journal of Structural Chemistry 2021年第8期40卷 1023-1030,969页

作者： XU Hui XU Wei-Wei XU Liu-Wei WANG Zhi-Lin WANG Shuai-Hua SU Qing ZHANG Bi-Sheng ZENG Qing-You WU Shao-Fan College of Chemistry Fuzhou UniversityFuzhou 350108China key laboratory of Optoelectronic Materials Chemistry and Physics Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient DevicesFujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China Fujian Communications Planning&Design Institute Company Fuzhou 350004China Fujian Luhai Engineering Investigation&Designing Company Fuzhou 350000China

X-ray scintillators have been widely used in many fields owing to their strong penetrating ability,including security inspection,medical imaging,nuclear cameras,high energy physics and so *** explore new scintillation materials,we designed and synthesized KGW:Tb bulk scintillation crystals with monoclinic phase *** explored the fluorescence performance of KGW:Tb by testing the photoluminescence spectrum and fluorescence decay curve and observed strong green light emission in the visible light range at room ***,our crystal has a high stability under X-ray irradiation,a good sensitivity response and an appreciable light output(3424 ph/MeV)that is approximately twenty times more than ***,we used a 0.98 mm thickness polished crystal sheet for X-ray imaging applications and observed excellent ***,KGW:Tb crystal may be an important direction for X-ray scintillation detection.

关键词： KGW X-ray scintillators light yield high stability X-ray imaging

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Research Advancements in key Technologies for Space-Based Situational Awareness

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Space(Science & Technology) 2022年第1期2022卷 176-206页

作者： Beichao Wang Shuang Li Jinzhen Mu Xiaolong Hao Wenshan Zhu Jiaqian Hu Advanced Space Technology laboratory College of AstronauticsNanjing University of Aeronautics and AstronauticsNanjing 211106China

The space environment has become highly congested due to the increasing space debris,seriously threatening the safety of orbiting ***-based situational awareness,as a comprehensive capability of threat knowledge,analysis,and decision-making,is of significant importance to ensure space security and maintain normal *** space situational awareness systems have been designed and *** acquisition,target recognition,and monitoring constituting key technologies make major contributions,and various advanced algorithms are explored as technical ***,comprehensive reviews of these technologies and specific algorithms rarely *** disadvantages the future development of space situational ***,this paper further reviews and analyzes research advancements in key technologies for space situational awareness,emphasizing target recognition and *** mature and emerging methods are presented for these technologies while discussing application advantages and ***,the research prospects of multiagent and synergetic constellation technologies are expected for future situational *** paper indicates the future directions of the key technologies,aiming to provide references for space-based situational awareness to realize space sustainability.

关键词： awareness directions maintain

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Scintillation Properties of Ce^(3+)/Tb^(3+) Co-doped Oxyfluoride Glass with the Exploration of Imaging Application

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Chinese Journal of Structural Chemistry 2021年第10期40卷 1337-1345页

作者： CHEN Da-Yi LI Yan WU Yi-Heng WANG Zhi-Lin WANG Shuai-Hua SU Qing ZHANG Bi-Sheng ZENG Qing-You WU Shao-Fan University of Chinese Academy of Sciences Chinese Academy of SciencesBeijing 100039China key laboratory of Optoelectronic Materials Chemistry and Physics Collaborative Innovation Center for Optoelectronic Semiconductors and Efficient DevicesFujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China College of Chemistry Fuzhou UniversityFuzhou 350108China Fujian Luhai Engineering Investigation&Designing Company Fuzhou 350007China

Scintillator is a material that converts high-energy rays into visible light, and has great applications in high-energy physics, medical imaging, and security inspections. As a type of scintillator, scintillation glass has the advantages of low cost, high stability, controllable shape, and ability to be prepared on a large scale. In this paper, a traditional fusion quenching method was used to prepare a cerium-terbium co-doped glass. The green characteristic light of Tb ion was observed at 543 nm. Moreover, through the doping sensitization of Ce ions, the luminescence of Tb was successfully enhanced. The material has high X-ray response sensitivity, complete stability and strong X-ray emission intensity. We use a simple X-ray imaging platform for imaging, and the results show that our glass has a spatial resolution of 7.0 lp/mm.

关键词： scintillators light yield glass X-ray imaging luminescence

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Simulation of future land-use scenarios in the Three Gorges Reservoir Region under the effects of multiple factors

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Journal of Geographical Sciences 2018年第12期28卷 1907-1932页

作者：邵景安党永峰王威张仕超 College of Geography and Tourism Chongqing Normal University key laboratory of Surface Process and Environment Remote Sensing in the Three Gorges Reservoir Area Academy of Forestry Inventory and Planning State Forestry Administration

Model simulation and scenario change analysis are the core contents of the future land-use change（LUC） study. In this paper, land use status data of the Three Gorges Reservoir Region（TGRR） in 1990 was used as base data. The relationship between driving factors and land-use change was analyzed by using binary logistic stepwise regression analysis, based on which land use in 2010 was simulated by CLUE-S model. After the inspection and determination of main parameters impacting on driving factors of land use in the TGRR, land use of this region in 2030 was simulated based on four scenarios, including natural growth, food security, migration-related construction and ecological conservation. The results were shown as follows：（1） The areas under ROC curves of land-use types（LUTs） were both greater than 0.8 under the analysis and inspection of binary logistic model. These LUTs include paddy field, dryland, woodland, grassland, construction land and water area. Therefore, it has a strong interpretation ability of driving factors on land use, which can be used in the estimation of land use probability distribution.（2） The Kappa coefficients, verified from the result of land-use simulation in 2010, were shown of paddy field 0.9, dryland 0.95, woodland 0.97, grassland 0.84, construction land 0.85 and water area 0.77. So the results of simulation could meet the needs of future simulation and prediction.（3） The results of multi-scenario simulation showed a spatial competitive relationship between different LUTs, and an influence on food security, migration-related construction and ecological conservation in the TGRR, including some land use actions such as the large-scale conversion from paddy field to dryland, the occupation on cultivated land, woodland and grassland for rapid expansion of construction land, the reclamation of woodland and grassland into cultivated land, returning steep sloping farmland back into woodland and grassland. Therefore, it is necessary to balance the

关键词： land use CLUE-S model driving factor scenario simulation Three Gorges Reservoir Region

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Improved PBFT protocol based on phase voting and threshold signature

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Journal of Southeast University(English Edition) 2022年第3期38卷 213-218页

作者： Chen Liquan Hu Jie Gu Pengpeng School of Cyber Science and Engineering Southeast UniversityNanjing 210096China Purple Mountain Laboratories for Network and Communication security Nanjing 211111China

The communication complexity of the practical byzantine fault tolerance(PBFT)protocol is reduced with the threshold signature technique applied to the consensus process by phase voting PBFT(PV-PBFT).As most communication occurs between the primary node and replica nodes in PV-PVFT,consistency verification is accomplished through threshold signatures,multi-PV,and multiple *** view replacement protocol introduces node weights to influence the election of a primary node,reducing the probability of the same node being elected primary multiple *** experimental results of consensus algorithms show that compared to PBFT,the communication overhead of PV-PBFT decreases by approximately 90% with nearly one-time improvement in the throughput relative and approximately 2/3 consensus latency,lower than that of the scalable hierarchical byzantine fault *** communication complexity of the PBFT is O(N^(2)),whereas that of PV-PBFT is only O(N),which implies the significant improvement of the operational efficiency of the blockchain system.

关键词： blockchain practical byzantine fault tolerance(PBFT) threshold signature phase voting

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Flooding attack and defence in Ad hoc networks

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Journal of Systems Engineering and Electronics 2006年第2期17卷 410-416页

作者： Yi Ping Hou Yafei Zhong Yiping Zhang Shiyong Dai Zhoulin School of Information security Engineering Shanghai Jiaotong Univ. Shanghai 200030 P. R. China Dept. of Computing and Information Technology Fudan Univ. Shanghai 200433 P. R. China Graduate School of Engineering Kochi University of Technology Rochi 782-8502 Japan.

Mobile ad hoc networks are particularly vulnerable to denial of service （DOS） attacks launched through compromised nodes or intruders. In this paper, we present a new DOS attack and its defense in ad hoc networks. The new DOS attack, called AA hoc Flooding Attack（AHFA）, is that intruder broadcasts mass Route Request packets to exhaust the communication bandwidth and node resource so that the valid communication can not be kept. After analyzed AM hoc Flooding Attack, we develop Flooding Attack Prevention （FAP）, a genetic defense against the AM hoc Flooding Attack. When the intruder broadcasts exceeding packets of Route Request, the immediate neighbors of the intruder record the rate of Route Request. Once the threshold is exceeded, nodes deny any future request packets from the intruder. The results of our implementation show FAP can prevent the AM hoe Flooding attack efficiently.

关键词： computer networks security mobile Ad hoe networks routing protocol denial of service Ad hoc flooding attack.

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A Scalable Design of RSA Crypto-coprocessor

A Scalable Design of RSA Crypto-coprocessor

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2006 8th International Conference on Solid-State and Integrated Circuit Technology

作者： Yehua Gu Xiaoyang Zeng Jun Han Yongxin Ma Jia Zhao State key Lab of ASIC ＆ System Fudan University

ISBN: (纸本)1424401607

＜正＞A scalable design of RSA Crypto-coprocessor is presented in this paper,which supports variable keys up to 4096- *** analyzing and improving the modified multiple-word Montgomery multiplication algorithm,its pipeline architecture is optimized and critical path is greatly ***, its performance is much higher compared with previous work. Therefore,the proposed design is very suitable to the low-cost and high-performance RSA cryptosystem and can be easily implemented in VLSI technology.

关键词： Partitioning algorithms Pipelines Very large scale integration Algorithm design and analysis Clocks Application specific integrated circuits Delay public key cryptography Internet security

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Building an IPv6 address generation and traceback system with NIDTGA in Address Driven Network

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Science China(Information Sciences) 2015年第12期58卷 14-27页

作者： LIU Ying REN Gang WU JianPing ZHANG ShengLin HE Lin JIA YiHao Institute for Network Sciences and Cyberspace Tsinghua University Tsinghua National laboratory for Information Science and Technology Department of Computer Science and Technology Tsinghua University

In the design and construction process of Next Generation Internet, it is important to identify the source of each IP packet forwarding accurately, especially for the support of precise fine-grained management,control, traceability and improving the trustworthiness of the Internet. This paper designed a scalable Network Identity(NID) scheme for the Internet users, proposed NIDTGA(Network Identity and Time Generated Address), an IPv6 address generation algorithm embedded NID and time information, then designed and implemented an IPv6 address generation and traceback system based on NIDTGA. The design of NIDTGA, which reflects the length, time and owner attributes of the IP address, can be a good support to ADN(Address Driven Network). At the same time, by embedding the key elements of user identity and time in the IPv6 address,and by taking into account both the traceability and privacy, NIDTGA can provide a technical basis for the establishment of the network trust mechanism, and achieve the traceability of security event.

关键词： network identity IPv6 Address Driven Network IP traceback IP address generation

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Engineering thermotolerant plants: a solution to protecting crop production threatened by global warming

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Science Bulletin 2015年第15期60卷 1366-1367页

作者： Jianmin Wan National key Facility for Crop Gene Resources and Genetic Improvement Institute of Crop Science Chinese Academy of Agricultural Sciences

The effects of global warming are the environmental and social changes caused directly or indirectly by human emissions of greenhouse *** of climate change have already been evidenced by observed glacier retreat,chang... 详细信息

关键词：作物生产全球变暖开花植物耐热性威胁保护温室气体排放量非生物胁迫

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