检索结果-南通市图书馆

Impacts of Upper Tropospheric Cooling upon the Late Spring Drought in East Asia Simulated by a Regional Climate Model

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2008年第4期25卷 555-562页

作者：辛晓歌 zhaoxin li 宇如聪周天军 State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 Graduate University of Chinese Academy of Sciences Beijing 100049 Laboratoire de Mdteorologie Dynamique IPSL/CNRS Universite Pierre et Marie Curie Paris France National Climate Center China Meteorological Administration Beijing 100081 State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences China Meteorological Administration Beijing 100081

Responses of late spring （21 April 20 May） rainfall to the upper tropospheric cooling over East Asia are investigated with a regional climate model based on Laboratoire de M6t6orologie Dynamique Zoom （LMDZ4-RCM）. A control experiment is performed with two runs driven by the mean ERA-40 data during 1958-1977 and 1981 2000, respectively. The model reproduces the major decadal-scale circulation changes in late spring over East Asia, including a cooling in the upper troposphere and an anomalous meridional cell. Accordingly, the precipitation decrease is also captured in the southeast of the upper-level cooling region. To quantify the role of the upper-level cooling in the drought mechanism, a sensitivity experiment is further conducted with the cooling imposed in the upper troposphere. It is demonstrated that the upper-level cooling can generate the anomalous meridional cell and consequently the drought to the southeast of the cooling center. Therefore, upper tropospheric cooling should have played a dominant role in the observed late spring drought over Southeast China in recent decades.

关键词： Southeast China spring drought inter-decadal variability regional climate modeling

One-step fabrication superhydrophobic sand filter for capillary-driven separation of water-in-oil emulsions

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Chemical Engineering 2021年第5期34卷 70-75页

作者： Bao Wang Chaolang Chen zhaoxin li Jianfeng Wu Xianglou liu Jiadao Wang Northeast Petroleum University Daqing 163318China Sate Key Laboratory of Tribology Tsinghua UniversityBeijing 100084China

The efficient separation of water-in-oil emulsion is of significance in environment and energy filed,and it has become a world-wide challenge.Herein,we have presented a one-step,facile and low-cost approach to prepare superhydrophobic sands for efficient separation of water-in-oil emulsion.The as-prepared sand layers possessed a water contact angle higher than 151°,demonstrating their superior superhydrophobic property.Besides,the as-prepared sand layers could separate water-in-emulsions with separation efficiency up to 99.7%,which is superior to both traditional and superwettable filtration membranes.The effect of thickness of sand layer on separation performance was also investigated.The results showed that the filtration flux decreased with the increased of filtration thickness while the separation efficiency increased.The as-prepared sand layer proposed by this study is a processing candidate for separating water-in-oil emulsion in practical industry.Additionally,the as-prepared superhydrophobic sand fabrication method also provides an alternative for desert water storage.

关键词： Separation Filtration Superhydrophobic sand Preparation Emulsion

在线全文

学校读者我要写书评

暂无评论

钢筋混凝土结构不同加固方法分析

工程建设（维泽科技） 2024年第8期7卷 47-49页

作者：李赵鑫新疆工程学院土木工程学院新疆乌鲁木齐830000

钢筋混凝土结构是建筑结构领域内应用最为广泛的结构形式,而随着结构使用年限的增加和外界环境的侵蚀,其承载能力会有所下降,为了使结构满足使用年限内的承载力要求,必须对结构进行加固。文中首先详细介绍了现存钢筋混凝土结构的加固方... 详细信息

钢筋混凝土结构是建筑结构领域内应用最为广泛的结构形式,而随着结构使用年限的增加和外界环境的侵蚀,其承载能力会有所下降,为了使结构满足使用年限内的承载力要求,必须对结构进行加固。文中首先详细介绍了现存钢筋混凝土结构的加固方法,包括传统加固方法、粘贴纤维增强复合材料加固方法、预应力加固技术、高性能水泥基复合材料加固技术和钢筋混凝土结构体系加固技术。之后根据不同加固方法的特点给出了与之相匹配的应用场景,最终分析了发展加固技术的必要性,以期为今后的加固工程提供参考。

关键词：混凝土结构加固技术加固技术应用

Vehicle tracking by detection in UAV aerial video

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2019年第2期62卷 192-194页

作者： Shaohua liU Suqin WANG Wenhao SHI Haibo liU zhaoxin li Tianlu MAO School of Electronic Engineering University of Beijing Posts and Telecommunications Institute of Electronic and Information Engineering in Guangdong University of Electronic Science and Technology of China School of Control and Computer Engineering North China Electric Power University Beijing Key Lab of Mobile Computing and Pervasive Device Institute of Computing TechnologyChinese Academy of Sciences

With the maturity and popularity of UAV (unmanned aerial vehicle) technology [1–3], UAV video is becoming an effective supplement to the fixed monitoring video [4, 5]. In the aspect of traffic information acquisition, the advantages of UAV are obvious. UAV can fly not only between the buildings, but also on the freeway, and even into the tunnel, showing the unique flexibility and maneuverability. UAV can control its hovering position artificially and has a high angle shot to get more comprehensive and clearer video data.In some emergent situation, such as evacuation caused by typhoons and earthquakes, there are lots of countryside areas without fixed road monitoring cameras. UAV is undoubtedly the best choice to

关键词： UAV Vehicle tracking by detection in UAV aerial video

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

基于偏正结构表示的加工命名实体识别方法

计算机集成制造系统 2024年第3期30卷 958-967页

作者：王素琴王钰珏石敏朱登明李兆歆华北电力大学控制与计算机工程学院北京102206 中国农业科学院农业信息研究所北京100081

制造企业积累大量的零件加工经验多以文本形式存在,如何从文本中挖掘出高质量的零件加工知识是个尚待解决的问题。针对待识别实体存在的偏正结构特征,导致实体边界界定模糊的问题,提出一种多网络协调的中文命名实体识别方法。在BERT生... 详细信息

制造企业积累大量的零件加工经验多以文本形式存在,如何从文本中挖掘出高质量的零件加工知识是个尚待解决的问题。针对待识别实体存在的偏正结构特征,导致实体边界界定模糊的问题,提出一种多网络协调的中文命名实体识别方法。在BERT生成字向量的过程中,通过领域自适应方法,提高字向量对工艺实体的表征能力,同时,在BiLSTM-CRF模型中引入注意力机制和多门控制的混合专家网络捕获上下文特征与实体信息。实验表明,较于当前主流的命名实体识别模型,该文提出的方法对机械零件加工实体识别的F1值达到80.15%,取得优于其他模型的最好性能。

关键词：中文命名实体识别机械零件加工多门控制的混合专家网络领域自适应

Review of Chinese atmospheric science research over the past 70 years: Climate and climate change

在线全文

学校读者我要写书评

暂无评论

Science China Earth Sciences 2019年第10期62卷 1514-1550页

作者： Jianping HUANG Wen CHEN Zhiping WEN Guangjun ZHANG zhaoxin li Zhiyan ZUO Qingyun ZHAO College of Atmospheric Sciences Lanzhou UniversityLanzhou730000China Center for Monsoon System Research Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing100190China Department of Atmospheric and Oceanic Sciences Fudan UniversityShanghai200438China Scripps Institution of Oceanography University of CaliforniaSan Diego92093USA Laboratoire de Météorologie Dynamique CNRSSorbonne UniversitéParis75005France Chinese Academy of Meteorological Sciences Beijing100081China

Climate and climate change have always been a research focus of atmospheric sciences. This paper summaries research efforts, achievements and international contributions of the Chinese scientific community on climate and climate change over the past 70 years. The review is based on papers published officially in national or international scientific journals,and is organized to cover six aspects:(1) general climate studies;(2) impact of the Qinghai-Tibetan Plateau;(3) impact of the East Asian monsoon;(4) influences of teleconnection oscillation and westerlies;(5) climate dynamics and development of climate models;and(6) climate change. It is, however, to be noted that the present review can not be considered as an exhaustive one, since there is a huge body of literature in the field.

关键词： Climate of China Qinghai-Tibetan Plateau East Asian Monsoon Climate change

在线全文

学校读者我要写书评

暂无评论

一种带高光处理的无缝纹理映射方法

图学学报 2024年第1期45卷 148-158页

作者：石敏王炳祺李兆歆朱登明华北电力大学控制与计算机工程学院北京102206 中国农业科学院农业信息研究所北京100081 中国科学院计算技术研究所前瞻研究实验室北京100190 太仓中科信息技术研究院江苏太仓215400

纹理映射作为三维重建的重要步骤,直接关系到生成模型的视觉效果。传统的纹理映射方法通常使用简单的混合方法来获取表面纹理。通过将模型表面投影到每个纹理图像上来获取相应的纹理区域,然后将它们混合在一起以获取表面纹理。然而,由... 详细信息

纹理映射作为三维重建的重要步骤,直接关系到生成模型的视觉效果。传统的纹理映射方法通常使用简单的混合方法来获取表面纹理。通过将模型表面投影到每个纹理图像上来获取相应的纹理区域,然后将它们混合在一起以获取表面纹理。然而,由于相机位姿的不准确性,纹理映射结果存在明显的模糊和鬼影等问题。此外,在高光环境下获取的纹理图像很容易包含高光区域,最终导致纹理颜色的丢失,降低纹理的真实性。为了解决这些问题,提出了一种无缝纹理映射方法,可以有效消除高光反射。通过衡量纹理图像的质量,为每个模型表面选择最佳的纹理图像,并利用色度一致性约束优化的相机位姿以消除明显的纹理错位。针对高光问题,提出了一个高光处理模块,使用多视图图像信息并基于双色反射模型定位和处理高光纹理。最后,对纹理图进行纹理颜色一致性调整,以处理纹理之间的颜色差异。实验结果表明,与现有方法相比,提出的算法可以有效消除高光反射的影响,从而获得更好的纹理映射结果。

关键词：三维重建纹理映射高光处理纹理渲染位姿校正

在线全文

学校读者我要写书评

暂无评论

河蟹池塘微孔增氧高效生态养殖技术

安徽农学通报 2024年第9期30卷 54-57页

作者：李兆新淮南市毛集社会发展综合实验区农业发展局安徽淮南232000

微孔增氧养殖技术能有效提高池水中的溶氧水平,适当加大池塘养殖密度,提高养殖产量,增加经济效益。为提高河蟹养殖品质及产量,本文结合河蟹养殖实践,对河蟹池塘微孔增氧高效生态养殖技术要点进行总结分析,包括池塘选择与改造管理、河蟹... 详细信息

微孔增氧养殖技术能有效提高池水中的溶氧水平,适当加大池塘养殖密度,提高养殖产量,增加经济效益。为提高河蟹养殖品质及产量,本文结合河蟹养殖实践,对河蟹池塘微孔增氧高效生态养殖技术要点进行总结分析,包括池塘选择与改造管理、河蟹苗投放、池塘管理以及河蟹捕捞等;应用效果分析表明,池塘微孔增氧养殖技术综合利润较常规养殖方式增加明显。可结合实际情况推广池塘微孔增氧养殖模式。

关键词：河蟹池塘微孔增氧生态养殖溶解氧养殖效益

维普期刊数据库博看期刊

在线全文

学校读者我要写书评

暂无评论

稻虾共育高效生态种养技术

安徽农学通报 2024年第10期30卷 15-18页

作者：李兆新淮南市毛集社会发展综合实验区农业发展局安徽淮南232000

稻虾共育是一种立体高效的新型种养模式。本文结合生产实践,从稻田选择、虾沟开挖、防逃设施固定、虾苗田管理、成虾场管理、日常管理以及成虾捕捞和亲虾留存方面,总结分析了稻虾共育高效生态种养技术要点,并分别从生态效益、经济效益... 详细信息

稻虾共育是一种立体高效的新型种养模式。本文结合生产实践,从稻田选择、虾沟开挖、防逃设施固定、虾苗田管理、成虾场管理、日常管理以及成虾捕捞和亲虾留存方面,总结分析了稻虾共育高效生态种养技术要点,并分别从生态效益、经济效益和综合效益3个方面探讨了稻虾共育的生态效益、经济效益和综合效益,为该技术的进一步推广应用提供参考。

关键词：稻虾共育生态种养绿色农业稻田改造种养管理