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The estimate of sea ice resources quantity in the Bohai Sea based on NOAA/AVHRR data

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Acta Oceanologica Sinica 2012年第1期31卷 33-40页

作者： yuan shuai GU Wei XU Yingjun WANG Ping HUANG Shuqing LE Zhangyan CONG Jianou State Key Laboratory of Earth Surface Processes and Resource Ecology Beijing Normal UniversityBeijing 100875China Academy of Disaster Reduction and Emergency Management Ministry of Civil Affairs and Ministry of EducationBeijing 100875China National Marine Environmental Monitoring Center State Oceanic AdministrationDalian 116023China Meteorological Department of Langfang Hebei 065000China

The research on sea ice resources is the academic base of sea ice exploitation in the Bohai Sea. According to the ice-water spectrum differences and the correlation between ice thickness and albedo, this paper comes up with a sea ice thickness inversion model based on the NOAA/AVHRR data. And then a sea ice resources quantity （SIQ） time series of Bohai Sea is established from 1987 to 2009. The results indicate that the average error of inversion sea ice thickness is below 30%. The maximum sea ice resources quantity is about 6×109 m3 and the minimum is 1.3×109 m3. And a preliminary analysis has been made on the errors of the estimate of sea ice resources quantity （SIQ）.

关键词： sea ice in the Bohai Sea sea ice resources quantity NOAA/AVHRR error analysis

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一种非等阶积分的求积元孔压单元（英文）

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2018年第7期19卷 521-533页

作者： shuai yuan Hong-zhi ZHONG Institute of Geotechnical Engineering School of Highway Chang 'an University Xi 'an 710064 China Department of Civil Engineering Tsinghua University Beijing 100084 China

目的:在对土体固结问题进行求解时,如果对孔压和位移采用等阶积分,当时间步长取值很小时,得到的孔压结果会出现数值振荡,导致精度降低。本文提出一种非等阶积分的求积元孔压单元,致力于减小孔压振荡,提高单元稳定性和计算精度。创新点:1... 详细信息

目的:在对土体固结问题进行求解时,如果对孔压和位移采用等阶积分,当时间步长取值很小时,得到的孔压结果会出现数值振荡,导致精度降低。本文提出一种非等阶积分的求积元孔压单元,致力于减小孔压振荡,提高单元稳定性和计算精度。创新点:1.建立了一种对于孔压和位移采用不同阶积分的求积元复合单元;2.有效降低了小时间步长引起的孔压振荡。方法:1.通过求积元法对弱形式控制方程进行数值积分,并对比奥固结方程中的位移项和孔压项采用不等阶积分;2.通过拉格朗日插值获得位移点上的孔压和孔压点上的位移值;3.通过一维及二维问题的数值算例,验证所建立方法的有效性。结论:1.通过采用复合求积元单元,大大降低了孔压的数值振荡;2.应用复合求积单元时,采用二阶精度的Crank-Nicolson积分格式不会产生随时间的孔压振荡;3.本文所建立的单元可以大大提高固结问题求解的数值计算精度和计算效率。

关键词：弱形式求积元法不等阶积分孔压振荡固结分析

Solvothermal Synthesis of TiO2/Bi2WOs Heterojunction Photocatalyst with Optimized Interface Structure and Enabled Photocatalytic Performance

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Chinese Journal of Chemistry 2017年第2期35卷 183-188页

作者： Linpeng Jiang Shujie Wang Liyi Shi Yin Zhao Zhuyi Wang Meihong Zhang shuai yuan Research Center of Nanoscience and Nanotechnology Shanghai University Shanghai 200444 China

TiO2/Bi2WO6 （TB） heterojunction photocatalyst was successfully synthesized and characterized by XRD, SEM, TEM, UV-Vis and photoluminescence measurement. The heterojunction interface structure of TB heterojunction photocatalyst was optimized via adjusting the ethylene glycol/water （EG/W） ratio. Based on XRD, SEM and TEM, the crystal size of Bi2WO6 reduced from 14.6 nm to 8.8 nm, and the interface structure between Bi2WO6 nanosheets and TiO2 particle significantly changed with increasing EG concentration. Furthermore, the photoeatalytic activity and the related mechanism of TB heterojunction photocatalyst were systematically discussed. Among them, TBEG/w sample shows the highest normalized apparent rate constant, which is attributed to its highest electron-hole pairs separation ability driven by optimized heterojunction interface between two semiconductors.

关键词： TiO2/Bi2WO6 heterojunction interface structure carriers separation photocatalytic

Theoretical mean-variance relationship of IP network traffic based on ON/OFF model

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Science in China(Series F) 2009年第4期52卷 645-655页

作者： JIN Yi ZHOU Gang JIANG DongChen yuan shuai WANG LiLi CAO JianTing State Key Laboratory of Software Development Environment Beihang University Beijing 100191 China School of Computer Science & Engineering Beihang University Beijing 100191 China National Digital Switching System Engineering & Technological Research Center Zhengzhou 450002 China

Mean-variance relationship （MVR）, nowadays agreed in power law form, is an important function. It is currently used by traffic matrix estimation as a basic statistical assumption. Because all the existing papers obtain MVR only through empirical ways, they cannot provide theoretical support to power law MVR or the definition of its power exponent. Furthermore, because of the lack of theoretical model, all traffic matrix estimation methods based on MVR have not been theoretically supported yet. By observing both our laboratory and campus network for more than one year, we find that such an empirical MVR is not sufficient to describe actual network traffic. In this paper, we derive a theoretical MVR from ON/OFF model. Then we prove that current empirical power law MVR is generally reasonable by the fact that it is an approximate form of theoretical MVR under specific precondition, which can theoretically support those traffic matrix estimation algorithms of using MVR. Through verifying our MVR by actual observation and public DECPKT traces, we verify that our theoretical MVR is valid and more capable of describing actual network traffic than power law MVR.

关键词： traffic matrix mean-variance relationship self-similar

Unsupervised Interpolation Recovery Method for Spectrum Anomaly Detection and Localization

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Space(Science & Technology) 2023年第1期3卷 560-571页

作者： Yishi Huang shuai yuan Naijin Liu Qing Li Wenyu Liang Lei Liu Shaanxi Aerospace Flight Vehicle Design Key Laboratory School of AstronauticsNorthwestern Polytechnical UniversityXi'anChina Qian Xuesen Laboratory of Space Technology China Academy of Space TechnologyBeijingChina Department of Electrical and Computer Engineering National University of SingaporeSingaporeSingapore

With the growing efficiency of the use of unlicensed spectrum,the challenge of ensuring spectrum security has become increasingly *** managers aim to accurately and efficiently detect and recognize anomaly behaviors in the *** this study,we propose a novel framework for spectrum anomaly detection and localization by spectrum interpolation *** interpolation recovery refers to the recovery of the rest of the spectrum distribution based on a part of the spectrum distribution,which is achieved through a masked autoencoder(MAE)model with a core of multi-head self-attention(MHSA)*** spectrum interpolation recovery method restores the region where the masked abnormal signals are present,yielding anomaly-free results,with the difference between the restored and the masked representing the anomaly *** proposed method has been demonstrated to effectively reduce model-induced over-recovery of anomalous signals and dilute large-scale generation errors caused by anomalies,thereby improving the detection and localization performance of anomaly signals,and improving the area under the receiver operating characteristic curve(AUC)and the area under the precision-recall curve(AUPRC)by 0.0382(3.68%)and 0.1992(68.90%),*** a designed dataset containing 3 variables of interference-to-signal ratio(ISR),signal-to-noise ratio(SNR),and anomaly type,the total recall of anomaly detection and localization at a 5%false alarm rate reached 0.8799 and 0.5536,***,a comparative study among different methods demonstrates the effectiveness and rationality of the proposed method.

关键词： interpolation spectrum thereby

An open conformation determined by a structural switch for 2A protease from coxsackievirus A16

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Protein & Cell 2013年第10期4卷 782-792页

作者： Yao Sun Xiangxi Wang shuai yuan Minghao Dang Xuemei Li Xuejun CZhang Zihe Rao National Laboratory of Biomacromolecules Institute of BiophysicsChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

Coxsackievirus A16 belongs to the family Picornaviridae,and is a major agent of hand-foot-and-mouth disease that infects mostly children,and to date no vaccines or antivi-ral therapies are available.2A protease of enterovirus is a nonstructural protein and possesses both self-cleavage activity and the ability to cleave the eukaryotic translation initiation factor *** we present the crystal structure of coxsackievirus A162A protease,which interestingly forms hexamers in crystal as well as in *** structure shows an open conformation,with its active site accessible,ready for substrate binding and cleav-age *** conjunction with a previously reported“closed”state structure of human rhinovirus 2,we were able to develop a detailed hypothesis for the conforma-tional conversion triggered by two“switcher”residues Glu88 and Tyr89 located within the bll2-cII *** recognition assays revealed that amino acid residues P1′,P2 and P4 are essential for substrate specificity,which was verifi ed by our substrate binding *** addition,we compared the in vitro cleavage effi ciency of 2A pro-teases from coxsackievirus A16 and enterovirus 71 upon the same substrates by fl uorescence resonance energy transfer(FRET),and observed higher protease activity of enterovirus 71 compared to that of coxsackievirus *** conclusion,our study shows an open conformation of coxsackievirus A162A protease and the underlying mechanisms for conformational conversion and substrate specifi *** new insights should facilitate the future rational design of effi cient 2A protease inhibitors.

关键词： coxsackievirus A16 2A protease crystal structure switcher

Unsupervised Spectrum Anomaly Detection Method for Unauthorized Bands

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Space(Science & Technology) 2022年第1期2022卷 462-471页

作者： Yu Tian Haihua Liao Jing Xu Ya Wang shuai yuan Naijin Liu Qian Xuesen Laboratory of Space Technology China Academy of Space TechnologyBeijingChina

With the rapid development of wireless communication,spectrum plays increasingly important role in both military and civilian *** anomaly detection aims at detecting emerging anomaly signals and spectrum usage behavior in the environment,which is indispensable to secure safety and improve spectrum ***,spectrum anomaly detection faces many difficulties,especially for unauthorized frequency *** unauthorized bands,the composition of spectrum is complex and the anomaly usage patterns are unknown in *** this paper,a Variational Autoencoder-(VAE-)based method is proposed for spectrum anomaly detection in unauthorized *** of all,we theoretically prove that the anomalies in unauthorized bands will introduce Background Noise Enhancement(BNE)effect and Anomaly Signal Disappearance(ASD)effects after VAE ***,we introduce a novel anomaly metric termed as percentile(PER)score,which focuses on capturing the distribution variation of reconstruction error caused by ASD and *** order to verify the effectiveness of our method,we developed an ISM Anomaly Detection(IAD)*** proposed PER score achieves superior performance against different type of *** QPSK type anomaly,our method increases the recall rate from 80%to 93%while keeping a false alarm rate of 5%.The proposed method is beneficial to broadband spectrum sensing and massive spectrum data *** code will be released at git@***:QXSLAB/vae_ism_***.

关键词： bands authorized false

Microorganisms and Metabolically Biogeochemical Processes in Subglacial Ecosystems

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Journal of Earth Science 2024年

作者： shuai yuan Tao Wang Yongqin Liu Center for Pan-third Pole Environment， Lanzhou University Department of Ecology and Environment of Gansu Province State Key Laboratory of Tibetan Plateau Earth System， Environment and Resource (TPESER)， Institute of Tibetan Plateau Research， Chinese Academy of Sciences College of Resources and Environment， University of Chinese Academy of Sciences

Subglacial ecosystems are important components in cryosphere， considering to be cold， dark， anoxic， oligotrophic habitats for cold-adapted microorganisms， which is important in global scale. The energy source for life survival is constrained in a subglacial environment. Thus， the metabolism processes， depending on chemical energy synthesis， are essential for the microbes， mainly chemolithoautotrophs， to survive in subglacial environments. The chemolithoautotrophs obtain energy from diverse minerals and dissolved ions stored in subglacial sediments and meltwater， which induce the chemical weathering of subglacial sediments and enhance the biogeochemical cycle. Unraveling the metabolism mechanisms of subglacial microbes helps to understand the biogeochemical processes and evaluate the influence on in situ and proglacial environments in global scale. Moreover， the study of subglacial microorganisms can guide the life exploration on ice-covered extraterrestial planets: Mars， Europa and Enceladus. This Review summarizes current knowledge of the environmental conditions， the microbial composition and the major biogeochemical cycle processes of subglacial environments. Furthermore， the review concludes the environment conditions on 3 ice-covered planets， which indicate the possibility of cold-adapted life existing on ice-covered extraterrestial planets.

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Influence of defect density on the ZnO nanostructures of dye-sensitized solar cells

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Advances in Manufacturing 2013年第4期1卷 340-345页

作者： Yan-Yan Lou shuai yuan Yin Zhao Zhu-Yi Wang Li-Yi Shi Research Center of Nanoscience and Nanotechnology Shanghai University Laboratory for Microstructures Shanghai University

The relationship between bilayer nanostructure, defect density and dye-sensitized solar cell （DSCC） per- formances was investigated. By adjusting bilayer nano- structures, defect density of ZnO nanodendrite-nanorods structure was decreased comparing to that of nanoflower- nanorods structure. The performances of DSCC based on ZnO nanodendrites-nanorods structure and nanoflower- nanorods structure were studied by Raman spectrum, room temperature photoluminescence, dye loading, photocurrent density-voltage characteristic and open-circuit voltage decay （OCVD） technique. The device with nanodendrite- nanorods structure has lower charge recombination rate and prolonged electron lifetime due to its microstructure feature.

关键词： ZnO Bilayer Nanostructure -Nanodendrite-nanorods defect ~ Dye-sensitized solarcells