检索结果-南通市图书馆

Site testing at Muztagh-ata site Ⅱ:seeing statistics

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2020年第6期20卷 175-184页

作者： jing Xu Ali Esamdin jin-Xin Hao jin-min bai Ji Yang Xu Zhou Yong-Qiang Yao jin-Liang Hou Guang-Xin Pu Guo-Jie Feng Chun-Hai bai Peng Wei Shu-Guo Ma Abudusaimaitijiang Yisikandee Le-Tian Wang Xuan Zhang Liang ming Lu Ma jin-Zhong Liu Zi-Huang Cao Yong-Heng Zhao Lu Feng Jian-Rong Shi Hua-Lin Chen Chong Pei Xiao-Jun Jiang Jian-Feng Wang Jian-Feng Tian Yan-Jie Xue jing-Yao Hu Yun-Ying Jiang Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Yun nan Observatories Chin ese Academy of Scie ncesKun ming 650000China Purple Mountain Observatory Chinese Academy of SciencesNanjing 21000&China Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China Nanjing Institute of Astronomical Optics&Technology Chinese Academy of SciencesNanjing 210008China

In this article,we present a detailed analysis of the statistical properties of seeing for the Muztaghata site which is a candidate site for hosting the future Chinese Large Optical/infrared Telescope(LOT)*** measurements were obtained with differential image motion monitors(DIMMs)from April2017 to November 2018 at different heights during different *** median seeings at 11 m and6 m are very close but significantly different from that on the *** mainly analyzed the seeing at11 m monthly and hourly,having found that the best season for observing was from late autumn to early winter and seeing tended to improve during the night only in *** analysis of the dependence on temperature inversion,wind speed and direction also was made and the best meteorological conditions for seeing are given.

关键词： site testing seeing

Site testing campaign for the Large Optical/infrared Telescope of China:overview

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2020年第6期20卷 81-95页

作者： Lu Feng jin-Xin Hao Zi-Huang Cao jin-min bai Ji Yang Xu Zhou Yong-Qiang Yao jin-Liang Hou Yong-Heng Zhao Yu Liu Teng-Fei Song Li-Yong Liu Jia Yin Hua-Lin Chen Chong Pei Ali Esamdin Lu Ma Chun-Hai bai Peng Wei jing Xu Guang-Xin Pu Guo-Jie Feng Xuan Zhang Liang ming Abudusaimaitijiang Yisikandee Jian-Rong Shi Jian Li Yuan Tian Zheng Wang Xia Wang Xiao-Jun Jiang Jian-Feng Wang Jian-Feng Tian Yan-Jie Xue Jian-Sheng Chen jing-Yao Hu Zhi-Xia Shen Yun-Ying Jiang National Astronomical Observatories Chinese Academy of SciencesBeijing 100101China Yunnan Observatories Chinese Academy of SciencesKunming 650216China Xinjiang Astronomical Observatory Chinese Academy of SciencesUrumqi 830011China Shanghai Astronomical Observatory Chinese Academy of SciencesShanghai 200030China Nanjing Institute of Astronomical Optics&Technology Chinese Academy of SciencesNanjing 210042China Purple Mountain Observatory Chinese Academy of SciencesNanjing 210033China University of Chinese Academy of Sciences Beijing 100049China

The Large Optical/infrared Telescope(LOT)is a ground-based 12 m diameter optical/infrared telescope which is proposed to be built in the western part of China in the next *** on satellite remote sensing data,along with geographical,logistical and political considerations,three candidate sites were chosen for ground-based astronomical performance *** sites include:Ali in Tibet,Daocheng in Sichuan and Muztagh-ata in *** until now,all three sites have continuously collected data for two *** this paper,we will introduce this site testing campaign,and present its monitoring results obtained during the period between March 2017 and March 2019.

关键词： techniques telescope-site testing

在线全文

学校读者我要写书评

暂无评论

面向航拍路面裂缝检测的AC-YOLO

计算机工程与应用 2025年第01期61卷 153-164页

作者：白锋马庆禄赵敏重庆交通大学土木工程学院重庆交通大学交通运输学院重庆大学自动化学院

针对当前道路巡检智能化程度不足以及效率低等现状，为提高利用无人机道路巡检检测效率与检测精度，在YOLOv8s的基础上针对无人机航拍场景提出改进模型AC-YOLO，在主干网络引入动态大卷积核注意机制LSK-attention来扩展模型的感受野，... 详细信息

针对当前道路巡检智能化程度不足以及效率低等现状，为提高利用无人机道路巡检检测效率与检测精度，在YOLOv8s的基础上针对无人机航拍场景提出改进模型AC-YOLO，在主干网络引入动态大卷积核注意机制LSK-attention来扩展模型的感受野，提高对路面裂缝范围检测的准确性。在颈部结构设计多尺度特征融合策略，融入BiFPN网络，改善对细小裂缝的检测。替换损失函数为WIoUv3，优化梯度分配策略，使模型更加关注裂缝主体。在数据集UAV-PDD2023上进行实验验证，改进后AC-YOLO精准度达到0.895，较原模型提高0.128,mAP50达到0.791，提高0.071,F1得分提高0.051，模型大小减小8.5%,FPS达到了129，提高4%。同时采用不同任务验证了模型泛化性能，实验结果证明AC-YOLO具有更强的检测性能，能有效应用于无人机视角下的路面裂缝检测。

关键词：道路巡检裂缝检测航拍裂缝增强感知特征融合

同方期刊数据库

Two Efficient Parameterized Boundaries for Vee's Asian Option Pricing PDE

在线全文

学校读者我要写书评

暂无评论

Acta Mathematicae Applicatae Sinica 2012年第4期28卷 643-652页

作者： bai-min YU School of International Trade and Economics University of International Business and Economics

In this paper, we derive two general parameterized boundaries of finite difference scheme for VeSe~＇s PDE which is used to price both fixed and floating strike Asian options. Using these two boundaries, we can deal with all kinds of situations, especially, some extreme cases, like overhigh volatility, very small volatility, etc, under which the Asian option is usually mispriced in many existing numerical methods. Numerical results show that our boundaries are pretty efficient.

关键词： Asian option Vecer's PDE finite difference parameterized boundaries sensitivity

Homogenous strength-toughness match for 20Mn2SiCrMoV bainitic large-size parts via processing of VC particles and quenching control

在线全文

学校读者我要写书评

暂无评论

Rare Metals 2023年第10期42卷 3485-3496页

作者： Yu Tian Zhun-Li Tan jin-Zhou Zhang Zheng-Yuan Yuan min Zhang Bing-Zhe bai Material Science&Engineering Research Center School of MechanicalElectronic and Control EngineeringBeijing Jiaotong UniversityBeijing100044China Key Laboratory of Advanced Materials of ministry of Education School of Materials Science and EngineeringTsinghua UniversityBeijing100084China

The problem of insufficient hardenability in general large-size parts always occurs in product manufacturing because of their large size,*** is restricted mainly by its own alloy composition with micro-alloy and key quenching and partitioning(Q&P) *** relationship between the cooling rate and properties of small samples was analyzed as the basis of the initial cooling rate at different positions corresponding to large-size parts combined with controlled austenization temperature in this *** as-treated micro structure after a fast cooling rate is mainly composed of lath bainite,martensite,and retained austenite(RA),while bainite and RA after a slow cooling *** showed that cooling control via decreasing spray intensity,meeting higher strength at the surface,and good strength and toughness match can be obtained both at the surface and in the ***-treated large ring part has~1330 MPa tensile strength and~95 J impact energy at the surface,and meantime,~1191 MPa tensile strength and~70 J impact energy in the center,which narrows the property difference.

关键词： Large-size parts Property homogeneity Cooling control bainite VC

Preparation of SO_4^(2-)/TiO_2-La_2O_3 solid superacid and its catalytic activities in acetalation and ketalation

在线全文

学校读者我要写书评

暂无评论

Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2006年第7期7卷 553-558页

作者： YANG Shui-jin bai Ai-min SUN Ju-tang Department of Chemistry and Environmental Engineering Hubei Normal University Huangshi 435002 China College of Chemistry and Molecular Sciences Wuhan University Wuhan 430072 China

SO4^2- / TiO2-La2O3, a novel solid superacid, was prepared and its catalytic activities at different synthetic conditions are discussed with esterification of n-butanoic acid and n-butyl alcohol as probing reaction. The optimum conditions have also been found, mole ratio of n（La^3＋）：n（Ti^4＋） is 1：34, the soaked consistency of H2SO4 is 0.8 tool/L, the soaked time of HESO4 is 24 h, the calcining temperature is 480 ℃, the calcining time is 3 h. Then it was applied in the catalytic synthesis often important ketals and acetals as catalyst and revealed high catalytic activity. Under these conditions on which the molar ratio of aldehyde/ketone to glycol is l： 1.5, the mass ratio of the catalyst used in the reactants is 0.5%, and the reaction time is 1.0 h, the yields of ketals and acetals can reach 41.4%-95.8%.

关键词： SO4^2-/ TiO2-La2O3 Rare earth Solid superacid Catalysis

Constant-level spatio-temporal integrated search algorithm for repeating sun-synchronous orbit satellite images

在线全文

学校读者我要写书评

暂无评论

International Journal of Digital Earth 2021年第8期14卷 943-958页

作者： Yuqi bai Meng jin Department of Earth System Science Tsinghua UniversityBeijingPeople’s Republic of China

Metadata information and catalogue services are major ways of making satellite images findable and ***-temporal indexing is the key to ensuring efficient *** spatial information and temporal information are usually independently maintained and indexed,the image retrieval process has to include two search steps:a spatial query and a temporal *** most Earth Observation satellites are specially designed to have repeating sun-synchronous orbits(RSSO),this type of satellite data has a close correlation between its spatial coverage and temporal coverage *** this paper,an integrated spatiotemporal indexing mechanism is proposed for RSSO *** spatio-temporal Look-Up Table(st-LUT)that serves as the index reflects the coupled correlation between the spatial and temporal coverage information within one orbit revisiting *** retrieval algorithms are designed based on the *** this study,1,765,797 Landsat 8 scenes collected from 28 June 2013 to 31 December 2019 data are used to establish and validate the proposed indexing mechanism and search *** this new method only need to focus on the changes of the spatial and temporal coverage over the time in one orbit revisiting cycle,the spatial search space is limited to the fixed number of ***,the search algorithm is at a constant *** performance is not related to the volume of the images that need to search.

关键词： Earth observation data acquisition remote sensing spatial data infrastructure image retrieval

基于TCN-Bi-GRU和交叉注意Transformer的多模态情感识别

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

陕西科技大学学报 2025年第1期43卷 161-168页

作者：李嘉华陈景霞白义民陕西科技大学电子信息与人工智能学院陕西西安710021

多模态语音情感识别是近年来在自然语言处理和机器学习领域备受关注的研究方向之一,不同模态的数据存在异构性和不一致性,将不同模态信息有效地融合起来并学习到高效的表示形式是一个挑战.为此,本文提出了一种新的基于时序信息建模和交... 详细信息

多模态语音情感识别是近年来在自然语言处理和机器学习领域备受关注的研究方向之一,不同模态的数据存在异构性和不一致性,将不同模态信息有效地融合起来并学习到高效的表示形式是一个挑战.为此,本文提出了一种新的基于时序信息建模和交叉注意力的多模态语音情感识别模型.首先采用时间卷积网络(Time Convolutional Network,TCN)提取语音、文本和视频数据的深层时序特征,使用双向门控递归单元(Bidirectional Gated Recurrent Unit,Bi-GRU)捕捉序列数据的上下文信息,提高模型对序列数据的理解能力.然后基于交叉注意力机制和Transformer构建多模态融合网络,用于挖掘并捕获音频、文本和视觉特征之间交互的情感信息.此外,在训练过程中引入弹性网络正则化(Elastic Net Regularization)防止模型过拟合,最后完成情感识别任务.在IEMOCAP数据集上,针对快乐、悲伤、愤怒和中性四类情感的分类实验中,准确率分别为87.6%、84.1%、87.5%、71.5%,F1值分别为85.1%、84.3%、87.4%、71.4%.加权平均精度为80.75%,未加权平均精度为82.80%.结果表明,所提方法实现了较好的分类性能.

关键词：语音识别多模态情感识别时间卷积网络交叉注意力机制弹性网络

Optical multi-color monitoring of OJ 287 from 2006 to 2012

在线全文

学校读者我要写书评

暂无评论

Research in Astronomy and Astrophysics 2017年第8期17卷 57-68页

作者： Qian Guo Ding-Rong Xiong jin-ming bai Xu-Liang Fan Wei-min Yi Yunnan Observatories Chinese Academy of Sciences Kunming 650216 China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of Sciences Kunming 650216 China Center for Astronomical Mega-Science Chinese Academy of Sciences Beijing 100012 China University of Chinese Academy of Sciences Beijing 100049 China

We present our optical multi-color monitoring of the BL Lac object OJ 287 from January 2006to December 2012 in the V,R and I bands.A relatively active state in OJ 287 has been found over all monitored epochs,among which the variations of average magnitude in V/R/I bands were measured with ?V=1.956 mag,?R=2.067 mag and ?I=2.115 mag,*** reliable intraday variability is detected,but possible variability is detected on 16 *** relative variation amplitudes fall into the range between 1% and 8%,with the majority between 2% and 4%.No time lags have been detected,but strong correlations exist among light curves in the three *** bluer-when-brighter trend is dominant over intraday timescales,which supports the shock-in-jet *** combining with additional V/R band data obtained from SMARTS and the Steward Observatory,we also find a bluer-when-brighter trend over a long-term *** possible periods of 513,176,36,30,26,17 and 14 d are found in all time-series data sets from 2006 to *** explanations about these periods are given.

关键词： BL Lacertae objects individual(OJ 287)—galaxies active—galaxies photometry