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Comparison and Analysis between Two Types of Sounding Data of China
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作者 陈哲 臧海佳 《Agricultural Science & Technology》 CAS 2009年第6期175-177,共3页
The upper air weather forecast data used in current business and research and digital data of the recently finished upper air meteorological monthly report were comparatively analyzed in complete data and quality cond... The upper air weather forecast data used in current business and research and digital data of the recently finished upper air meteorological monthly report were comparatively analyzed in complete data and quality condition of data, and sounding curve change caused by the difference of complete data was also compared, which evaluated advantages and disadvantages of two types of data. 展开更多
关键词 sounding Coded messages for upper-level data Monthly tables of sounding
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The Earth Summit Mission-2022:Successful ozone soundings contribute to source identification in the north Mt.Qomolangma region 被引量:2
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作者 Jinqiang Zhang Chunxiang Ye +11 位作者 Yuejian Xuan Zhixuan Bai Weili Lin Dan Li Lingkun Ran Baofeng Jiao YaomingMa Weiqiang Ma Nan Yao Yunshu Zeng Daren Lv Tong Zhu 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2024年第2期412-421,共10页
As part of“The Earth Summit Mission-2022”during the second Tibetan Plateau Scientific Expedition and Research(STEP)in April and May 2022,we conducted the ozone sounding experiment(an ozonesonde mated to a radiosonde... As part of“The Earth Summit Mission-2022”during the second Tibetan Plateau Scientific Expedition and Research(STEP)in April and May 2022,we conducted the ozone sounding experiment(an ozonesonde mated to a radiosonde)at Mt.Qomolangma Base Camp(MQBC;86.85°E,28.14°N;5200 m),a location at an extremely high altitude.A total of ten sounding profiles were obtained between April 30 and May 06,2022,of which seven profiles were above35 km in altitude,with a maximum detection altitude up to 39.0 km.This study presents the temporal variation and vertical distributions of atmospheric temperature,humidity,and ozone during the MQBC campaign.The averaged ozone concentration was high(68.3 ppbv)at the surface and then increased smoothly until peaking(~110 ppbv)in the middle troposphere(approximately 10 km),and afterward,the ozone concentration increased rapidly from the upper troposphere to a maximum of~10 ppmv at~30 km.The enhanced ozone concentration in the middle troposphere was associated with the blocking high pressure,and transport from the southern flank of the Himalayas occurred during the campaign period.The average total ozone column was 291.9±21.4 DU for the seven profiles exceeding 35km in altitude.The ozonesonde measurements were also compared with the vertical ozone profiles retrieved from the space-borne ozone products from the Microwave Limb Sounder(MLS)onboard the Aura satellite and the Atmospheric Infrared Sounder(AIRS)onboard the Aqua satellite. 展开更多
关键词 Ozone soundings Mt.Qomolangma Vertical ozone structure Ozone source Satellite data
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Study on the detection of abnormal sounding data based on LS-SVM 被引量:3
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作者 HUANG Xianyuan ZHAI Guojun +1 位作者 SUI Lifen CHAI Hongzhou 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2010年第6期115-120,共6页
A new method of detecting abnormal sounding data based on LS-SVM is presented.The theorem proves that the trend surface filter is the especial result of LS-SVM.In order to depict the relationship of trend surface filt... A new method of detecting abnormal sounding data based on LS-SVM is presented.The theorem proves that the trend surface filter is the especial result of LS-SVM.In order to depict the relationship of trend surface filter and LS-SVM,a contrast is given.The example shows that abnormal sounding data could be detected effectively by LS-SVM when the training samples and kernel function are reasonable. 展开更多
关键词 LS-SVM trend surface filter kernel function abnormal sounding data
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The movement age of hidden fault and analysis on width of its effect zone from shallow seismic sounding and drilling data
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作者 YANG Xiao-ping LI De-qing +3 位作者 ZHAO Cheng-bin LIU Bao-jin SUN Zhen-guo ZHAO Jing-yao 《Acta Seismologica Sinica(English Edition)》 CSCD 2004年第z1期94-102,共9页
Field experimental seismic sounding permitted us to obtain optimal shallow seismic reflection sounding parameters.In process of data processing,we obtained a high-qualitative shallow seismic reflection sounding profil... Field experimental seismic sounding permitted us to obtain optimal shallow seismic reflection sounding parameters.In process of data processing,we obtained a high-qualitative shallow seismic reflection sounding profile by using the techniques such as filtering,edition surgical blanking,prediction deconvolution,fitting static correlation of first arrival time,and velocity analysis.Comprehensive analysis on the information of reflection wave groups along the seismic sounding profile and the stratigraphic and neogeochronological data obtained from many drills near the sounding line reveals that the upper termination of the detected fault zone is located at depth of 75~80 m,in the Middle Pleistocene deposits dated to be about 220 ka BP.The continuity,discontinuity,increasing and decreasing amount of reflection wave groups and change of their configurations,in combination with geological columns of drills,permitted us to know that the width of upper termination of the fault zone is 100 m.It can be inferred from the variation of number of reflection wave groups along the profile that the scarp of hidden fault is 200 m wide and the fault is a synsedimentary active fault in the Early Pleistocene and the early stage of Middle Pleistocene.No tectonic movement,which offset the covering deposits,had occurred since the late stage of Middle Pleistocene. 展开更多
关键词 shallow seismic reflection sounding drill geological data stratum dating hidden fault fault movement
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Shallow Discussion about the Application of L-band Sounding Seconds Data in the Artificial Precipitation
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作者 TIAN Guang-yuan, ZHANG Peng-liang Weather Modification Office in Liaoning Province, Shenyang 110016, China 《Meteorological and Environmental Research》 CAS 2011年第4期57-59,64,共4页
[Objective] The research aimed to discuss shallowly the application of L-band sounding seconds data in the artificial precipitation. [Method] The characteristics, getting manner and displaying method of L-band soundin... [Objective] The research aimed to discuss shallowly the application of L-band sounding seconds data in the artificial precipitation. [Method] The characteristics, getting manner and displaying method of L-band sounding seconds data were introduced briefly. Moreover, its application prospect in the artificial precipitation operation was analyzed initially. We aimed to improve its application rate in the artificial precipitation operation. [Result] L-band sounding seconds data had the great improvement in the time-space resolution and the space positioning accuracy aspects when compared with the previous sounding data, and the precision reached the second level. It could provide the high-precision data basis for the assimilation of artificial precipitation numerical model initial field, and improve the numerical model. Moreover, the sounding product could provide the accurate scientific basis for the selection of artificial precipitation operation tool, the determination of operation height and range, and guide the artificial precipitation operation, and improve the operation efficiency. [Conclusion] The research provided the analysis and reference basis for the command of artificial precipitation operation. 展开更多
关键词 L-BAND sounding data Seconds data Artificial precipitation China
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Analysis of Continuous Thunderstorm in One Week at Qingdao Airport Based on Sounding Data
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作者 Yuan LIU Xiaoxia HE +1 位作者 Xi LIU Jinghua ZHAO 《Meteorological and Environmental Research》 CAS 2023年第1期15-20,共6页
Continuous thunderstorm occurring at Qingdao Airport in China from August 7 to 13,2022 was analyzed based on sounding data.The weather was divided into thunderstorm gale,thunderstorm and heavy precipitation,and some p... Continuous thunderstorm occurring at Qingdao Airport in China from August 7 to 13,2022 was analyzed based on sounding data.The weather was divided into thunderstorm gale,thunderstorm and heavy precipitation,and some physical quantities and time variables which can effectively identify severe convective weather types were preliminarily obtained.The results show that CAPE was sensitive to different types of weather,but the uncertainty was relatively large.Convective temperature T_(CON),temperature difference between 500 and 850 hPa,and vertical wind shear can distinguish thunderstorm gale,thunderstorm and heavy precipitation weather obviously.Besides,K index,Showalter index,θ_(se) difference between 500 and 850 hPa were also important basis to distinguish thunderstorm and heavy precipitation weather.Thunderstorm gale can be distinguished by the 24-hour variations of K index,and the difference of dew point between 500 and 850 hPa.The 24-hour variations of(T-T_(d))_(500) and vertical wind shear can be used to distinguish between heavy precipitation and thunderstorm weather;the 24-hour variation of stratification stability Δθ_(se) can distinguish the three kinds of weather well.For the wind field,the existence of vertical wind shear was required for strong convective weather,and the 24-hour increment of thunderstorm gale and thunderstorm was larger than that of heavy precipitation. 展开更多
关键词 THUNDERSTORM sounding data Qingdao Airport
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A New Infrared Atmospheric Sounding Interferometer Channel Selection and Assessment of Its Impact on Met Office NWP Forecasts 被引量:8
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作者 Young-Chan NOH Byung-Ju SOHN. +3 位作者 Yoonjae KIM Sangwon JOO William BELL Roger SAUNDERS 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2017年第11期1265-1281,共17页
A new set of Infrared Atmospheric Sounding Interferometer (IASI) channels was re-selected from 314 EUMETSAT channels. In selecting channels, we calculated the impact of the individually added channel on the improvem... A new set of Infrared Atmospheric Sounding Interferometer (IASI) channels was re-selected from 314 EUMETSAT channels. In selecting channels, we calculated the impact of the individually added channel on the improvement in the analysis outputs from a one-dimensional variational analysis (1D-Var) for the Unified Model (UM) data assimilation system at the Met Office, using the channel score index (CSI) as a figure of merit. Then, 200 channels were selected in order by counting each individual channel's CSI contribution. Compared with the operationally used 183 channels for the UM at the Met Office, the new set shares 149 channels, while the other 51 channels are new. Also examined is the selection from the entropy reduction method with the same 1D-Var approach, Results suggest that channel selection can be made in a more objective fashion using the proposed CSI method. This is because the most important channels can be selected across the whole IASI observation spectrum. In the experimental trial runs using the UM global assimilation system, the new channels had an overall neutral impact in terms of improvement in forecasts, as compared with results from the operational channels. However, upper-tropospheric moist biases shown in the control run with operational channels were significantly reduced in the experimental trial with the newly selected channels. The reduction of moist biases was mainly due to the additional water vapor channels, which are sensitive to the upper-tropospheric water vapor. 展开更多
关键词 Hyperspectral IR sounding channel selection 1D-Vat data assimilation
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Reconstructing Sound Speed Profiles with Sea Surface Data 被引量:2
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作者 CHEN Cheng JIN Tao ZHOU Zhiquan 《Aerospace China》 2018年第4期38-43,共6页
Ocean sound speed profile(SSP) is the key factor affecting acoustic propagation. The acquisition of SSPsin real time with high precision is meaningful for underwater activities. By means of the remote sensing method, ... Ocean sound speed profile(SSP) is the key factor affecting acoustic propagation. The acquisition of SSPsin real time with high precision is meaningful for underwater activities. By means of the remote sensing method, thesea surface data could be obtained in near-real time. Typically, the subsurface fields are correlated with the sea surfaceparameters. Thus, the SSPs could be obtained by means of satellite remote sensing. In this paper, the history as wellas the current research over the reconstruction of subsurface fields by means of sea surface data is introduced. Thentwo methods to reconstruct the SSPs with sea surface data, including the linear regression method using the empiricalorthogonal function, and the self-organizing method based on the big data theory, are described in detail in the paper. 展开更多
关键词 sound Speed Profile(SSP) SEA surface data linear regression METHOD SELF-ORGANIZING METHOD
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Deep Learning-based Environmental Sound Classification Using Feature Fusion and Data Enhancement
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作者 Rashid Jahangir Muhammad Asif Nauman +3 位作者 Roobaea Alroobaea Jasem Almotiri Muhammad Mohsin Malik Sabah M.Alzahrani 《Computers, Materials & Continua》 SCIE EI 2023年第1期1069-1091,共23页
Environmental sound classification(ESC)involves the process of distinguishing an audio stream associated with numerous environmental sounds.Some common aspects such as the framework difference,overlapping of different... Environmental sound classification(ESC)involves the process of distinguishing an audio stream associated with numerous environmental sounds.Some common aspects such as the framework difference,overlapping of different sound events,and the presence of various sound sources during recording make the ESC task much more complicated and complex.This research is to propose a deep learning model to improve the recognition rate of environmental sounds and reduce the model training time under limited computation resources.In this research,the performance of transformer and convolutional neural networks(CNN)are investigated.Seven audio features,chromagram,Mel-spectrogram,tonnetz,Mel-Frequency Cepstral Coefficients(MFCCs),delta MFCCs,delta-delta MFCCs and spectral contrast,are extracted fromtheUrbanSound8K,ESC-50,and ESC-10,databases.Moreover,this research also employed three data enhancement methods,namely,white noise,pitch tuning,and time stretch to reduce the risk of overfitting issue due to the limited audio clips.The evaluation of various experiments demonstrates that the best performance was achieved by the proposed transformer model using seven audio features on enhanced database.For UrbanSound8K,ESC-50,and ESC-10,the highest attained accuracies are 0.98,0.94,and 0.97 respectively.The experimental results reveal that the proposed technique can achieve the best performance for ESC problems. 展开更多
关键词 Environmental sound classification convolutional neural network deep learning TRANSFORMER data augmentation
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黄海夏季温跃层适应性观测对声传播的影响
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作者 过武宏 范培勤 +2 位作者 刘敬一 孙雪海 笪良龙 《应用声学》 北大核心 2025年第4期1083-1090,共8页
针对黄海夏季冷水团引起的声速跃层预报准确性对水声传播的影响问题,设计了一套黄海夏季跃层的适应性观测方案,进行海上试验将获取的适应性观测信息融入数值预报背景场,从而验证适应性观测对跃层预报的有效性,进一步研究探讨适应性观测... 针对黄海夏季冷水团引起的声速跃层预报准确性对水声传播的影响问题,设计了一套黄海夏季跃层的适应性观测方案,进行海上试验将获取的适应性观测信息融入数值预报背景场,从而验证适应性观测对跃层预报的有效性,进一步研究探讨适应性观测对水声传播预报的影响。结果表明,适应性观测可有效提高黄海夏季温跃层的预报精度,减小声速剖面预报误差,提高了声传播预报水平:当频率为500 Hz时有明显改善,随着频率增加,改善效果逐渐变弱。该结论可为进一步开展海洋声学适应性观测、深入研究黄海夏季温跃层的声学效应提供物理和技术基础。 展开更多
关键词 温跃层 适应性观测 水声传播 数据同化
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北斗导航探空上升-下降段探空资料在华南区域数值模式同化应用试验
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作者 张诚忠 黄燕燕 +1 位作者 梁家豪 徐黄飞 《热带气象学报》 北大核心 2025年第1期16-25,共10页
为了解华南区域北斗导航往返探空资料的性能及其对华南区域模式预报的影响,以一个月北斗导航探空资料,分别与L波段观测资料和欧洲中心分析场进行比较分析。结果发现,北斗导航资料与L波段上升段资料之间的速度均方根误差<1 m·s^(... 为了解华南区域北斗导航往返探空资料的性能及其对华南区域模式预报的影响,以一个月北斗导航探空资料,分别与L波段观测资料和欧洲中心分析场进行比较分析。结果发现,北斗导航资料与L波段上升段资料之间的速度均方根误差<1 m·s^(-1),温度均方根误差<1°,相对湿度的均方根误差<10%。北斗导航探空资料与欧洲分析场标准差在对流层内U、V分量<2 m·s^(-1);温度比分析场偏低~1°;湿度在大气层中除了在400~200 hPa附近偏干5%外,其余偏湿5%~15%。对流层以上的各要素标准差均大于对流层。分别对一次空气影响过程、台风登陆过程进行同化对比试验发现,同化北斗导航探空资料试验与同化L波段资料试验的各级别降水TS互有高低,前者试验24 h台风路径预报有32%的提高,反映出与同化L波段单一的上升资料试验相比,北斗导航的往、返探空资料的同化对短期的降水预报、台风路径预报有着中性至正的改善作用。 展开更多
关键词 北斗导航探空 同化试验 个例研究 华南区域
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新型往返平漂式探空资料对长江中下游数值预报质量的影响
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作者 张鑫 王秋萍 +3 位作者 马旭林 张旭鹏 成巍 夏元彩 《大气科学》 北大核心 2025年第1期245-256,共12页
对于新型观测系统的建立,准确客观地评估其性能对系统的完善和发展具有重要的意义。我国新一代往返平漂式探空系统(Round-trip Drifting Sounding System,RDSS)创新性地突破了传统探空观测模式,通过一次释放实现“上升—平漂—下降”三... 对于新型观测系统的建立,准确客观地评估其性能对系统的完善和发展具有重要的意义。我国新一代往返平漂式探空系统(Round-trip Drifting Sounding System,RDSS)创新性地突破了传统探空观测模式,通过一次释放实现“上升—平漂—下降”三段式观测,拓展了现有探空观测的能力和范围。本文利用基于伴随模式的预报敏感性方法(Forecast Sensitivity to Observations,FSO),研究了长江中下游目标区数值预报质量对新型探空观测资料的敏感性。结果表明:试验时段内同化常规观测资料均能够不同程度地减小预报误差,提高预报质量,其中风场和温度观测的贡献最为显著。新型探空试验资料对长江中下游目标区预报具有显著正贡献,71.4%时次的预报误差有了进一步的减小。经向风和湿度观测对预报质量的改善最为明显。新型探空风场观测对预报误差的贡献具有明显的空间差异,预报误差减小的大值区主要分布在试验站本站及其附近区域;整层新型探空风场、温度、湿度观测对预报质量的正贡献比较显著,仅对流层中低层的纬向风观测对预报质量呈现弱的负贡献。 展开更多
关键词 数值预报 资料同化 预报敏感性 往返平漂式探空系统
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结合不均衡样本生成及BOA-DRSN的扬声器异常声分类 被引量:1
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作者 周静雷 李振业 +1 位作者 路昌 李丽敏 《西安工程大学学报》 2025年第4期37-45,共9页
扬声器生产过程中,其正常数据与故障数据比例可能会严重失调,从而导致样本分布不均匀,进而影响故障诊断模型的准确率及可靠性。因此,文中根据样本生成扩增和优化深度学习网络的理念提出了一种新的扬声器异常声分类方法。首先,考虑到原... 扬声器生产过程中,其正常数据与故障数据比例可能会严重失调,从而导致样本分布不均匀,进而影响故障诊断模型的准确率及可靠性。因此,文中根据样本生成扩增和优化深度学习网络的理念提出了一种新的扬声器异常声分类方法。首先,考虑到原始数据特征过于复杂而导致生成样本的质量较差,对扬声器异常声响应信号进行变分模态分解(variational mode decomposition,VMD)突出原始样本的局部特征;其次,从扩增样本角度出发提升模型故障诊断精度,使用最小二乘生成对抗网络(least squares generative adversarial networks,LSGAN)进行对抗训练,生成具有真实样本特征的虚拟样本;最后,选用蝴蝶优化算法(butterfly optimization algorithm,BOA)在大规模权重空间中高效寻优以加速模型收敛,利用深度残差收缩网络(deep residual shrinkage network,DRSN)模型进行扬声器异常声分类,从而提升在样本不均衡情况下的分类准确率及诊断稳定性。实验结果表明:该方法能有效降低误判率,在样本不均衡情况下有效提高故障诊断准确率以及分类诊断的稳定性,其分类平均准确率可达0.9912。 展开更多
关键词 故障诊断 数据不均衡 异常声分类 深度残差收缩网络(DRSN) 蝴蝶优化算法(BOA) 最小二乘生成对抗网络(LSGAN)
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思茅站风廓线雷达的测风资料评估 被引量:1
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作者 尹涵 徐安伦 +3 位作者 王飞 马芳 张亚东 杨蕊静 《云南大学学报(自然科学版)》 北大核心 2025年第1期88-98,共11页
利用同址气球探空数据对2023年1—6月思茅站风廓线雷达资料进行了质量评估,并结合多普勒天气雷达、自动气象站资料,分析了不同强对流天气过境时两者的测风差异特征,进一步检验了思茅站风廓线雷达资料的准确性和可用性.结果表明:①思茅... 利用同址气球探空数据对2023年1—6月思茅站风廓线雷达资料进行了质量评估,并结合多普勒天气雷达、自动气象站资料,分析了不同强对流天气过境时两者的测风差异特征,进一步检验了思茅站风廓线雷达资料的准确性和可用性.结果表明:①思茅站风廓线雷达具有较强的探测能力,近地面至对流层中层数据获取率在80%以上,有效探测高度约5 km;②风廓线雷达和同址气球探空的风垂直廓线整体呈现较为一致的趋势,思茅站风廓线雷达资料有良好的可靠性;③风廓线雷达V风测风质量优于U风.U风和V风同时满足相关系数大于0.6.均方根误差小于6.5 m/s的层次与雷达的有效探测高度相对应;④在不同强对流天气下,思茅站风廓线雷达数据仍具有准确性和可用性,一些中小尺度系统在风羽图上都有很好的展示. 展开更多
关键词 风廓线雷达 气球探空 垂直廓线 资料评估 思茅
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基于经验正交函数和贝叶斯神经网络的水下声场预报研究
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作者 蒋方冰 吴金荣 +2 位作者 侯倩男 张祚祥 莫亚枭 《哈尔滨工程大学学报》 北大核心 2025年第8期1508-1515,共8页
在水下声场预报中,数据驱动模型的预报精度主要取决于训练样本数对样本空间的覆盖程度。针对现有方法多局限于单一水文环境、且水文样本数量不足导致精度下降的问题,本文提出一种基于经验正交函数和贝叶斯神经网络的水下声场预报方法。... 在水下声场预报中,数据驱动模型的预报精度主要取决于训练样本数对样本空间的覆盖程度。针对现有方法多局限于单一水文环境、且水文样本数量不足导致精度下降的问题,本文提出一种基于经验正交函数和贝叶斯神经网络的水下声场预报方法。利用经验正交函数有效降低声速剖面输入维度,并通过其系数组合生成覆盖多样化水文环境的样本集;进而借助具有强泛化能力的贝叶斯神经网络在部分数据空间内学习有效特征,预报变化水文条件下的声传播损失,并给出置信区间。结果表明:相较于传统神经网络,该方法在训练集范围内的预报误差更小,对未知数据的适应能力更强,且通过概率建模可实现端到端的不确定性量化,提升了数据驱动模型在复杂水文条件下的鲁棒性与可靠性。 展开更多
关键词 经验正交函数 数据驱动模型 贝叶斯神经网络 声速剖面 水声传播损失 声场预报 不确定性量化 置信区间
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基于双重随机增强与分层Transformer的城市环境声检测方法
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作者 付予哲 王玫 +1 位作者 阚瑞祥 仇洪冰 《现代电子技术》 北大核心 2025年第19期115-121,共7页
城市声学场景的复杂性和多样性使传统的声音识别方法在处理城市环境声时存在局限性,亟需解决检测能力与计算复杂度之间的平衡问题。为此文中提出一种新型的城市环境声检测方法,旨在提高模型在处理城市环境声分类任务的能力,同时降低对... 城市声学场景的复杂性和多样性使传统的声音识别方法在处理城市环境声时存在局限性,亟需解决检测能力与计算复杂度之间的平衡问题。为此文中提出一种新型的城市环境声检测方法,旨在提高模型在处理城市环境声分类任务的能力,同时降低对计算资源的依赖。首先,引入一种双重随机组合数据增强策略,通过随机组合不同的增强技术生成多样化的音频样本,以丰富训练数据并增强模型的泛化能力;随后,提出一种新型的具有分层结构的音频Transformer,该模型引入了窗口注意力机制和耦合简单注意力的标记语义模块,有效提升了声音分类能力。实验结果表明,所提方法仅需之前Transformer的32%的参数量和15%的训练时间;在UrbanSound8K中准确率为91.2%,在AudioSet中mAP为0.476,在ESC-50中准确率为97.2%。显著提升了城市环境声检测的性能。 展开更多
关键词 城市环境声检测 声音分类 深度学习 TRANSFORMER 数据增强 注意力机制
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ERA5计算的北京夏季对流参数与探空资料对比
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作者 杨艺亚 何娜 +2 位作者 俞小鼎 占俊杰 徐路扬 《应用气象学报》 北大核心 2025年第6期705-718,共14页
为评估ERA5再分析资料在北京夏季强对流天气中的适用性,利用2009—2023年6—8月ERA5再分析资料和北京市观象台14:00(北京时)加密探空资料及台站观测资料计算对流参数,对比二者表征的对流热力、水汽、风切变和特性层厚度等特征的差异。... 为评估ERA5再分析资料在北京夏季强对流天气中的适用性,利用2009—2023年6—8月ERA5再分析资料和北京市观象台14:00(北京时)加密探空资料及台站观测资料计算对流参数,对比二者表征的对流热力、水汽、风切变和特性层厚度等特征的差异。结果表明:ERA5再分析资料对对流层中低层各层温度、抬升指数表征性能较好,对抬升凝结高度的表征不稳定,ERA5再分析资料高估大多数不超过2000 J·kg^(-1)的对流有效位能,但明显低估大于2000 J·kg^(-1)的对流有效位能。ERA5再分析资料能较好描述地面到对流层中层(0~6 km和0~8 km)的垂直风切变,但低估地面到低层(0~1 km和0~3 km)的垂直风切变。ERA5再分析资料对地面和对流层低层露点描述较为准确,但对对流层中层水汽和整层水汽含量估计偏大。在与冰雹相关的特性层高度厚度上,ERA5再分析资料与探空资料非常接近。3次典型强对流过程的分析表明:基于ERA5再分析资料的对流参数高估强降水发生概率,低估雷暴大风发生概率;ERA5再分析资料对0~1 km垂直风切变的估计极不可靠,导致其很难准确估计强龙卷潜势。 展开更多
关键词 ERA5再分析资料 探空 强对流 适用性
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可解释机器学习与物理规律融合的热物性显式预测方法——以气相声速为例
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作者 彭夏尧 杨震 段远源 《计量学报》 北大核心 2025年第4期467-474,共8页
提出了一种热物理规律指导的人工智能探索方法,利用计算机代替执行规律探索和公式提出过程。以基础热物性参数气相声速为例,针对截断维里方程在气相高压区的固有局限性,使用符号回归对表征多分子作用的众多高阶维里系数项进行总结归纳,... 提出了一种热物理规律指导的人工智能探索方法,利用计算机代替执行规律探索和公式提出过程。以基础热物性参数气相声速为例,针对截断维里方程在气相高压区的固有局限性,使用符号回归对表征多分子作用的众多高阶维里系数项进行总结归纳,形成了通用性的显式预测模型。模型预测28种物质的气相声速的均方根相对偏差仅为0.29%,且在近临界压力处的预测偏差显著低于现有的模型。研究结果有望形成一种新的热物性预测模型探索方法,也是对机器学习黑箱模型进行物理意义解释的一个尝试。 展开更多
关键词 热物性计量 气相声速 声学维里方程 数据驱动 可解释机器学习 符号回归
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基于同化探空资料的腾格里沙漠一次强降水过程分析
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作者 王雨恬 隆霄 +2 位作者 王号 陈佑奥 马星星 《干旱区研究》 北大核心 2025年第10期1802-1812,共11页
降水是干旱半干旱地区土壤水分的主要来源,降水的准确预测对该地区水资源的有效利用和减灾防灾有指导意义。干旱与半干旱地区观测数据稀疏,且再分析资料在沙漠地区存在较大误差,共同导致了数值模式对该地区降水模拟能力的不足。为此,本... 降水是干旱半干旱地区土壤水分的主要来源,降水的准确预测对该地区水资源的有效利用和减灾防灾有指导意义。干旱与半干旱地区观测数据稀疏,且再分析资料在沙漠地区存在较大误差,共同导致了数值模式对该地区降水模拟能力的不足。为此,本文选取一次发生在腾格里沙漠的降水过程,通过同化探空资料来优化模式初始场中的降水大尺度背景场,并分析此方法对此次降水过程模拟效果的影响。结果表明:两次试验模拟的降水分布特征总体一致,与GPM观测结果相比都存在一定的偏差,同化探空资料后初始场中200hPa南亚高压、500hPa高空槽和高空急流等大尺度环流背景均有所增强,中尺度暖低压和水汽输送特征也得到一定程度的加强,为降水的形成和发展提供了更有利的条件。降水的TS及ETS评分有明显提高(分别提高了约0.1和0.08),降水最强时刻中尺度系统的动力和热力结构均有不同程度的增强,这些结果对改进沙漠地区降水预报提供了有益的科学参考。 展开更多
关键词 强降水过程 探空资料 数值模拟 同化 腾格里沙漠
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端到端KAN卷积在房颤心音识别中的应用
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作者 邓洪 陈燕 +4 位作者 杨宏波 赵峰 蒋永卓 郭涛 王威廉 《计算机科学》 北大核心 2025年第9期62-70,共9页
房颤作为一种严重的心律失常疾病,及早诊断至关重要。房颤的传统检查方法是由心脏科医生借助心电图、超声心动图等设备做出诊断结论。为了缓解传统诊断方法检查成本高、过多依赖临床经验和便捷性不足等问题,创新性地应用Kolmogo-rov-Arn... 房颤作为一种严重的心律失常疾病,及早诊断至关重要。房颤的传统检查方法是由心脏科医生借助心电图、超声心动图等设备做出诊断结论。为了缓解传统诊断方法检查成本高、过多依赖临床经验和便捷性不足等问题,创新性地应用Kolmogo-rov-Arnold Network(KAN)来构建房颤心音分析模型。文中探索了KAN卷积在房颤心音识别中的应用,引入了具有灵活线性激活函数和优异参数效率的KAN卷积架构,提出了一种基于KAN卷积的端到端房颤心音识别模型。为提高信号的可用性,首先对心音信号进行预处理,包括心音分割、心音信号的质量评估和数据清洗;然后利用KAN的卷积层、池化层等自动学习;最后采用KAN卷积分类器进行识别研究。在特征提取阶段引入了KAN卷积的自注意力机制和焦点调制,以高效提取信号特征;在分类器阶段研究了KAN卷积的瓶颈结构和正则化手段,以提升模型的识别能力。该模型在中国人民解放军总医院第一医学中心的心音信号数据集上进行了正常和房颤的识别测试,准确率为97.86%,灵敏度为98.18%,特异度为97.43%,F_(β)值为98.06%。实验结果表明,KAN卷积模型在辅助诊断房颤信号上具有显著的优势。 展开更多
关键词 房颤 KAN卷积 心音识别 端到端 数据清洗
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