维普中文期刊产品整合服务
5篇 您的检索式:作者名="Zejun DAI"
    题名 作者 年代 出处 被引量
1An infectious disease of ducks caused by a newly emerged Tembusu virus strain in mainland China显示文摘Pixi Yan Youshu Zhao Xu Zhang Dawei Xu Xiaoguang Dai Qiaoyang Teng Liping Yan Jiewen Zhou Xiwen Ji Shumei Zhang Guangqing Liu Yanjun Zhou Yoshihiro Kawaoka Guangzhi Tong Zejun Li 2011Virology2011,,1:5
2大熊猫保护区的生态系统服务价值显示文摘文章简介全球生态系统服务价值估计每年为125万亿美元,相似的国家和区域层面的评估也显示生态系统服务价值足以支撑我们的生活。所有的生态系统服务价值评估都肯定了生物多样性的重要作用.魏辅文 Robert Costanza Qiang Dai Natalie Stoeckl Xiaodong Gu Stephen Farber Yonggang Nie Ida Kubiszewski Yibo Hu Ronald Swaisgood Xuyu Yang Michael Bruford Youping Chen Alexey Voinov Dunwu Qi Megan Owen Li Yan Daniel C.Kenny Zejun Zhang Rong Hou Shiwei Jiang Hongbo Liu Xiangjiang Zhan Li Zhang Biao Yang Lianjun Zhao Xiaoguang Zheng Wenliang Zhou Yali Wen Heran Gao Wen Zhang 2019科学新闻2019,0,2:1
3A Recombination Clustering Technique for Forecasting of Tropical Cyclone Tracks Based on the CMA-TRAMS Ensemble Prediction System显示文摘Despite marked improvements in tropical cyclone(TC) track ensemble forecasting,forecasters still have difficulty in making quick decisions when facing multiple potential predictions,so it is demanding to develop post-processing techniques reducing the uncertainty in TC track forecasts,and one of such techniques is the cluster-based methods.To improve the effect and efficiency of the previous cluster-based methods,this study adopts recombination clustering(RC) by optimizing the use of limited TC variables and constructing better features that can accurately capture the good TC track forecasts from the ensemble prediction system(EPS) of the China Meteorological Administration Tropical Regional Atmosphere Model for the South China Sea(CMA-TRAMS).The RC technique is further optimized by constraining the number of clusters using the absolute track bias between the ensemble mean(EM) and ensemble spread(ES).Finally,the RC-based deterministic and weighted probabilistic forecasts are compared with the TC track forecasts from traditional methods.It is found that(1) for deterministic TC track forecasts,the RC-based TC track forecasts outperform all other methods at 12–72-h lead times;compared with the skillful EM(118.6 km),the improvements introduced by the use of RC reach up to 10.8%(8.1 km),10.2%(13.7 km),and 8.7%(20.5 km) at forecast times of 24,48,and 72 h,respectively.(2) For probabilistic TC track forecasts,RC yields significantly more accurate and discriminative forecasts than traditional equal-weight track forecasts,by increasing the weight of the best cluster,with a decrease of 4.1% in brier score(BS) and an increase of 1.4% in area under the relative operating characteristic curve(AUC).(3) In particular,for cases with recurved tracks,such as typhoons Saudel(2017) and Bavi(2008),RC significantly reduces track errors relative to EM by 56.0%(125.5 km) and 77.7%(192.2 km),respectively.Our results demonstrate that the RC technique not only improves TC track forecasts but also helps to unravel skillful ensemble members,and is likely useful for feature construction in machine learning.Jinqing LIU Xubin ZHANG Zejun DAI Hui ZHOU Zhaoli YANG 2023Journal of Meteorological Research2023,37,6:0
4Need of a paradigm shift to conserve endangered species in China’s national park system显示文摘CHINAS EVOLVING NATIONAL PARK DESIGNATIONS AND SINGLE LARGE PROTECTED AREA OR SEVERAL SMALL PROTECTED AREAS(SLOSS)DEBATE As of 2021,the International Union for Conservation of Nature estimated that there are over 6,000 national parks(NPs)in more than 100 countries,most of which are strongly focused on endangered species.1 Over the past 6 years,China has invested US$20million in developing the Giant Panda National Park(GPNP)and a furtherUS$16million in establishing theNortheast China Tiger and Leopard National Park(NCTLNP).Biao Yang Qiang Dai Yu Xu Christina D.Buesching Xiaodong Gu Zhisong Yang Zejun Zhang Fuwen Wei 2023The Innovation2023,4,4:0
5Analysis of force and leakage in water hydraulic motor's piston pairs显示文摘The positive pressure between pistonwall and piston hole of inner curve water hydraulic motor’s piston pairs is analyzed.The flow field of the piston pairs is numerically calculated and analyzed by the use of computational fluid dynamics method.The pressure and velocity distribution of flow field at different clearance is analyzed in the paper.The results show that when the clearance is 4-8 μm,with the increase of clearance,the negative pressure and the velocity of piston chamber decrease significantly,the velocity and leakage flow of the clearance increase.However,when the clearance is 10 μm,the negative pressure and the velocity of plunger chamber increase suddenly.By comprehensive analysis,the cylinder annular clearance should be controlled to be near 8 μm.王志强 DAI Zejun LI Xinglin HE Wen GAO Dianrong 2022High Technology Letters2022,28,3:0
返回顶部 每页显示:
共1页 首页 上一页 第1页 下一页 末页 /1 跳转

网站首页 | 关于我们 | 联系我们 | 产品服务 | 客服中心 | 广告服务 | 版权声明 | 网站联盟 | 友情链接 | 售卡网点

版权所有© 渝B2-20050021-1 渝公网安备 50019002500403号 违法和不良信息举报中心

互联网出版许可证 新出网证(渝)字10号 全国400电话 - 免长途话费