维普中文期刊产品整合服务
6篇 您的检索式:作者名="Lejun Yu"
    题名 作者 年代 出处 被引量
1Geochronology and significance of volcanic rocks in the Ning-Wu Basin of China显示文摘The Ning-Wu(Nanjing-Wuhu) Basin is one of the most important volcanic basins in the Middle-Lower Yangtze River Valley,eastern China.It consists of four volcanic units,i.e.,the Longwangshan,Dawangshan,Gushan,and Niangniangshan Formations.Their LA-ICP MS U-Pb zircon ages are 134.8±1.8,132.2±1.6,129.5±0.8,and 126.8±0.6 Ma,respectively.Results of this study indicate that all volcanic rocks in the Ning-Wu Basin were formed in the Early Cretaceous from 135 to 127 Ma,lasting 8-10 m.y.No Jurassic volcanic activities occurred in any of the volcanic basins of the Middle-Lower Yangtze River Valley,including the Ning-Wu Basin.These new chronological results provide significant evidence for further study of this region to improve our understanding of Mesozoic tectonic,magmatic,and metallogenic processes of eastern China.ZHOU TaoFa FAN Yu YUAN Feng ZHANG LeJun QIAN Bin MA Liang YANG XiFei David R COOKE 2011Science China Earth Sciences2011,54,2:33
2Characterization of VOC emissions from construction machinery and river ships in the Pearl River Delta of China显示文摘Speciated characterization of Volatile Organic Compounds (VOCs),including oxygenated VOCs (OVOCs),from construction machinery and river ships in China is currently lacking.In this regard,we conducted field measurement on speciated VOC (including OVOC) emissions from six construction machinery and five river ships in the Pearl River Delta (PRD) region to identify VOC emission characteristics.We noticed that OVOC emissions from construction machinery and ships accounted for more than 50%of the total VOC emissions,followed by alkenes,aromatics and alkanes.Formaldehyde and acetaldehyde were the most emission species,accounting for 61.8%-83.2%of OVOCs.For construction machinery,the fuel-based emission factors of roller,grader and pile driver were 3.12,3.12 and 7.36 g/kg,respectively.With the rigorous restraint by the national emission standards,VOC emissions of construction machinery had decreased considerably,especially during stageⅢ.Ozone formation potential was also significantly reduced due to the significant decrease in emissions of OVOCs and alkenes with higher reactivity.For river ships,the fuel-based emission factors of cargo ships and speedboat were 1.46 and 0.44 g/kg,respectively.VOC emissions from construction machinery and river ships in Guangdong Province in 2017 were 8851.0 and 4361.0 ton,respectively.This study filled the knowledge gaps of reactive gas emissions from different kinds of non-road mobile sources over the PRD,and more importantly,highlighted the necessity in adding OVOC measurement to give a complete and accurate depiction of reactive gas emissions from non-road mobile sources.Richao Wang Zibing Yuan Junyu Zheng Cheng Li Zhijiong Huang Wenshi Li Yan Xie Yiran Wang Kaiyang Yu Lejun Duan 2020Journal of Environmental Sciences2020,32,10:5
3Preparations,Characterizations and Applications of Chitosan-based Nanoparticles显示文摘Chitosan is a natural polysaccharide prepared by the N-deacetylation of chitin. In this paper we have reviewed the methods of preparation of chitosan-based nanoparticles and their pharmaceutical applications. There are five methods of their prepa-rations:emulsion cross-linking,emulsion-droplet coalescence,ionic gelation,reverse micellar method and chemically modified chi-tosan method. Chitosan nanoparticles are used as carriers for low molecular weight drug,vaccines and DNA. Releasing characteris-tics,biodistribution and applications are also summarized.LIU Chenguang TAN Yulong LIU Chengsheng CHEN Xiguang YU Lejun 2007Journal of Ocean University of China2007,6,3:3
4An integrated rice panicle phenotyping method based on X-ray and RGB scanning and deep learning显示文摘Rice panicle phenotyping is required in rice breeding for high yield and grain quality.To fully evaluate spikelet and kernel traits without threshing and hulling,using X-ray and RGB scanning,we developed an integrated rice panicle phenotyping system and a corresponding image analysis pipeline.We compared five methods of counting spikelets and found that Faster R-CNN achieved high accuracy(R~2 of 0.99)and speed.Faster R-CNN was also applied to indica and japonica classification and achieved 91%accuracy.The proposed integrated panicle phenotyping method offers benefit for rice functional genetics and breeding.Lejun Yu Jiawei Shi Chenglong Huang Lingfeng Duan Di Wu Debao Fu Changyin Wu Lizhong Xiong Wanneng Yang Qian Liu 2021The Crop Journal2021,9,1:1
5Panicle-3D: A low-cost 3D-modeling method for rice panicles based on deep learning, shape from silhouette, and supervoxel clustering显示文摘Self-occlusions are common in rice canopy images and strongly influence the calculation accuracies of panicle traits. Such interference can be largely eliminated if panicles are phenotyped at the 3 D level.Research on 3 D panicle phenotyping has been limited. Given that existing 3 D modeling techniques do not focus on specified parts of a target object, an efficient method for panicle modeling of large numbers of rice plants is lacking. This paper presents an automatic and nondestructive method for 3 D panicle modeling. The proposed method integrates shoot rice reconstruction with shape from silhouette, 2 D panicle segmentation with a deep convolutional neural network, and 3 D panicle segmentation with ray tracing and supervoxel clustering. A multiview imaging system was built to acquire image sequences of rice canopies with an efficiency of approximately 4 min per rice plant. The execution time of panicle modeling per rice plant using 90 images was approximately 26 min. The outputs of the algorithm for a single rice plant are a shoot rice model, surface shoot rice model, panicle model, and surface panicle model, all represented by a list of spatial coordinates. The efficiency and performance were evaluated and compared with the classical structure-from-motion algorithm. The results demonstrated that the proposed method is well qualified to recover the 3 D shapes of rice panicles from multiview images and is readily adaptable to rice plants of diverse accessions and growth stages. The proposed algorithm is superior to the structure-from-motion method in terms of texture preservation and computational efficiency. The sample images and implementation of the algorithm are available online. This automatic, cost-efficient, and nondestructive method of 3 D panicle modeling may be applied to high-throughput 3 D phenotyping of large rice populations.Dan Wu Lejun Yu Junli Ye Ruifang Zhai Lingfeng Duan Lingbo Liu Nai Wu Zedong Geng Jingbo Fu Chenglong Huang Shangbin Chen Qian Liu Wanneng Yang 2022The Crop Journal2022,10,5:1
6Co- and post-seismic slip analysis of the 2017 M_(W)7.3 Sarpol Zahab earthquake using Sentinel-1 data显示文摘The M_(w)7.3 Sarpol Zahab earthquake that occurred in the Zagros Fold-Thrust Belt(ZFTB) of Iran on November 12,2017 is the largest earthquake instrumentally recorded in the region.This earthquake provides an opportunity to investigate the slip behaviour and frictional properties of the fault,which is significant for assessing future seismic potential.In this study,we use Sentinel-1 images to map the coand post-seismic deformation to invert for the fault slip.The result indicates that most of the coseismic slip is buried in the depth range of 11-17 km,and the maximum slip is about 3.8 m at a depth of 15 km.The coseismic slip induces an increase of Coulomb stress in the unruptured area of the seismogenic fault plane,driving the afterslip.Based on the stress-driven afterslip,we obtain a frictional parameter of(ab)=(0.001-0.002) for the updip afterslip zone and(a-b)=0.0002 for the downdip afterslip zone in the framework of rate-and-state friction.The constitutive parameter(a-b) of the fault is very small,suggesting that the fault segments are close to velocity-neutral and may experience coseismic rupture.Lejun Lu Yu Zhou 2022Geodesy and Geodynamics2022,13,2:1
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