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来宾市强对流天气X波段双偏振雷达特征分析 被引量:1
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作者 许云杰 欧晔 +3 位作者 梁依玲 张靖 潘佳彦 李泳竺 《气象研究与应用》 2025年第2期43-49,共7页
利用地面、高空、雷达、卫星云图等资料,对2024年4月3日夜间来宾市的混合性强对流天气过程进行分析。结果表明:(1)60 dBZ以上强回波、中低层弱回波区、55 dBZ回波伸展至-20℃层高度以上,VIL达60 kg∙m^(-2)以上以及S波段雷达回波中的TBSS... 利用地面、高空、雷达、卫星云图等资料,对2024年4月3日夜间来宾市的混合性强对流天气过程进行分析。结果表明:(1)60 dBZ以上强回波、中低层弱回波区、55 dBZ回波伸展至-20℃层高度以上,VIL达60 kg∙m^(-2)以上以及S波段雷达回波中的TBSS、X波段雷达回波中的V型缺口,均对冰雹生成有较好的提示作用。(2)S波段雷达5 km以下的强回波,X波段双偏振雷达大的Z_(DR)、K_(DP)对短时强降水生成有提示作用。(3)低仰角大风区、中层径向辐合、回波质心快速下降以及中气旋的存在对雷暴大风的出现有指示意义。(4)S波段雷达订正X波段雷达的衰减回波,X波段雷达则弥补S波段在静锥区的观测盲区,两者优势互补,可有效提升强对流天气的监测能力。 展开更多
关键词 强对流 冰雹 双偏振 X波段雷达
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2种作物降水适宜度评价模型在广西甘蔗的适用性比较
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作者 刘武 匡昭敏 +3 位作者 张蕾 程俊淇 欧晔 赖嘉良 《甘蔗糖业》 2025年第2期11-21,共11页
针对侯英雨等的模型(模型Ⅰ)和魏瑞江等的模型(模型Ⅱ)2种作物降水适宜度模型在广西甘蔗的适用性进行分析比较,并使用不同降水类型、不同降水时间尺度作为输入参数,以选出相对较好的输入降水类型和降水时间尺度。利用广西91个国家气象... 针对侯英雨等的模型(模型Ⅰ)和魏瑞江等的模型(模型Ⅱ)2种作物降水适宜度模型在广西甘蔗的适用性进行分析比较,并使用不同降水类型、不同降水时间尺度作为输入参数,以选出相对较好的输入降水类型和降水时间尺度。利用广西91个国家气象观测站1981~2023年逐日气象资料计算甘蔗降水适宜度,使用主产市农业气象观测站的甘蔗观测资料进行验证,选取适宜的模型和降水类型分析广西甘蔗降水适宜度时空分布特征。结果表明:对比输入10、30日时间尺度降水量,模型Ⅱ适宜度与茎伸长的平均相关系数比模型Ⅰ分别高0.06、0.12,而模型Ⅰ在超出作物需水量上、下限时出现适宜度为0的跳跃现象,模型Ⅱ相对优于模型Ⅰ;2种模型的输入降水类型的相关度从高到低均为有效降水>观测降水>可利用降水;2种模型的输入降水时间尺度的相关度从高到低排序均为30日>10日;模型Ⅱ与茎伸长的相关性显著且用于作物适宜度的时空分析时差异明显,可应用于作物适宜度和长势分析。 展开更多
关键词 降水适宜度 模型 甘蔗 评价 比较
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来宾市2023年“4·19”极端大风成因和预报偏差分析
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作者 许云杰 翟丽萍 +3 位作者 李生艳 梁振清 欧晔 程俊淇 《山地气象学报》 2025年第2期46-55,共10页
【目的】分析广西暖区飑线的形成机理,为提升雷暴大风的预报预警服务质量提供参考。【方法】2023年4月19日来宾市出现一次范围广、极端性强的全市性雷暴大风天气过程,最大风速达34.1 m·s^(-1),打破来宾历史记录。利用常规观测、雷... 【目的】分析广西暖区飑线的形成机理,为提升雷暴大风的预报预警服务质量提供参考。【方法】2023年4月19日来宾市出现一次范围广、极端性强的全市性雷暴大风天气过程,最大风速达34.1 m·s^(-1),打破来宾历史记录。利用常规观测、雷达、卫星及ERA5再分析资料和数值模式等资料,对此次天气过程进行天气学诊断分析。【结果】(1)此次为暖区雷暴大风过程,初始阶段由多单体风暴造成,后通过自组织发展形成飑线继续南移影响造成全市性雷暴大风天气。(2)过程发生在上干冷下暖湿的不稳定层结中,低层暖平流增强热力不稳定,大的CAPE和DCAPE、强的风垂直切变和中高层干区等提供有利的环境条件,地面辐合线、干线触发对流,冷池发展与对流单体自组织的正反馈作用促使飑线形成和维持。(3)来宾大范围大风主要出现在飑线的发展—强盛期,飑线阶段移动速度快、存在速度模糊、显著中层径向辐合、中气旋和风暴顶的辐散以及对流顶高、回波质心、VIL的快速下降均对极端大风的出现有指示意义。(4)主客观短期预报均对此次过程漏报,主要是对风暴能够通过自组织发展形成飑线继续南下影响考虑不足所导致。【结论】在短时临近预报中加强实况和中尺度对流回波的演变分析,及时发布预报预警信息,能够弥补短期预报的不足。 展开更多
关键词 暖区飑线 极端大风 云顶坍塌 对流自组织过程
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A Black-Box Speech Adversarial Attack Method Based on Enhanced Neural Predictors in Industrial IoT
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作者 Yun Zhang Zhenhua Yu +2 位作者 Xufei Hu Xuya Cong ou ye 《Computers, Materials & Continua》 2025年第9期5403-5426,共24页
Devices in Industrial Internet of Things are vulnerable to voice adversarial attacks.Studying adversarial speech samples is crucial for enhancing the security of automatic speech recognition systems in Industrial Inte... Devices in Industrial Internet of Things are vulnerable to voice adversarial attacks.Studying adversarial speech samples is crucial for enhancing the security of automatic speech recognition systems in Industrial Internet of Things devices.Current black-box attack methods often face challenges such as complex search processes and excessive perturbation generation.To address these issues,this paper proposes a black-box voice adversarial attack method based on enhanced neural predictors.This method searches for minimal perturbations in the perturbation space,employing an optimization process guided by a self-attention neural predictor to identify the optimal perturbation direction.This direction is then applied to the original sample to generate adversarial samples.To improve search efficiency,a pruning strategy is designed to discard samples below a threshold in the early search stages,reducing the number of searches.Additionally,a dynamic factor based on feedback from querying the automatic speech recognition system is introduced to adaptively adjust the search step size,further accelerating the search process.To validate the performance of the proposed method,experiments are conducted on the LibriSpeech dataset.Compared with the mainstream methods,the proposed method improves the signal-to-noise ratio by 0.8 dB,increases sample similarity by 0.43%,and reduces the average number of queries by 7%.Experimental results demonstrate that the proposed method offers better attack effectiveness and stealthiness. 展开更多
关键词 Speech recognition adversarial attack self attention pruning strategy
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风化淋积型稀土矿山原地浸取工艺中精细化注液管理方法研究
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作者 罗果 侯春明 +1 位作者 欧烨 梁伟 《世界有色金属》 2025年第6期205-207,共3页
风化淋积型稀土矿山原地浸取工艺的基本原理是利用浸矿剂阳离子化学性质更活泼的特性,在特定环境下将吸附于硅酸盐粘土矿物表面的稀土离子交换浸出,从浸矿剂注入采区到浸出液回收,整个交换浸出过程属于“不可视”状态,导致无法精确控制... 风化淋积型稀土矿山原地浸取工艺的基本原理是利用浸矿剂阳离子化学性质更活泼的特性,在特定环境下将吸附于硅酸盐粘土矿物表面的稀土离子交换浸出,从浸矿剂注入采区到浸出液回收,整个交换浸出过程属于“不可视”状态,导致无法精确控制交换过程和浸矿剂的用量。浸矿剂用量的不确定性不仅影响到开采经济效益,过量使用还会加重对环境的影响,加大治理成本。本文以硫酸铵为浸矿剂,从生产各环节的技术、管理要求分析,探讨适用于风化淋积型稀土矿山注液生产过程中的精细化管理方法,以达到降本增效、降低环境破坏的目的。 展开更多
关键词 风化淋积型稀土矿山 原地浸取 硫酸铵 注液管理
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长江三角洲近3年秋冬季典型霾天气成因研究 被引量:4
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作者 邓欣柔 欧晔 +2 位作者 李云丹 李贤灏 康娜 《环境科学与技术》 CAS CSCD 北大核心 2020年第3期1-9,共9页
针对2016-2018年3年长三角地区冬季的3次典型霾污染过程,利用颗粒物质量浓度资料、地面天气图、地面气象要素观测资料,结合逆温层、混合层资料以及后向轨迹进行分析研究,深入探讨霾的形成及发展机制。结果表明:2016年12月14-21日、2018... 针对2016-2018年3年长三角地区冬季的3次典型霾污染过程,利用颗粒物质量浓度资料、地面天气图、地面气象要素观测资料,结合逆温层、混合层资料以及后向轨迹进行分析研究,深入探讨霾的形成及发展机制。结果表明:2016年12月14-21日、2018年1月16-24日、2019年1月11-17日3个霾天气过程期间,长三角地区维持较稳定的地表温度、较高的相对湿度、较小的风速值。期间长三角地区混合层高度的降低压制大气长距离水平输送,且均出现逆温层。2016年12月霾过程主要受来自境外西北地区及国内北部地区的长距离输送气团的影响;2018年1月霾过程主要受国内西北地区以及长三角地区气团的影响;2019年1月霾污染过程主要受来自山东半岛的海洋性气团的影响,较前2次霾过程此次污染程度较小。 展开更多
关键词 霾污染 颗粒物PM2.5、PM10质量浓度 逆温层 混合层高度 HYSPLIT后向轨迹模式
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Social Robot Detection Method with Improved Graph Neural Networks 被引量:2
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作者 Zhenhua Yu Liangxue Bai +1 位作者 ou ye Xuya Cong 《Computers, Materials & Continua》 SCIE EI 2024年第2期1773-1795,共23页
Social robot accounts controlled by artificial intelligence or humans are active in social networks,bringing negative impacts to network security and social life.Existing social robot detection methods based on graph ... Social robot accounts controlled by artificial intelligence or humans are active in social networks,bringing negative impacts to network security and social life.Existing social robot detection methods based on graph neural networks suffer from the problem of many social network nodes and complex relationships,which makes it difficult to accurately describe the difference between the topological relations of nodes,resulting in low detection accuracy of social robots.This paper proposes a social robot detection method with the use of an improved neural network.First,social relationship subgraphs are constructed by leveraging the user’s social network to disentangle intricate social relationships effectively.Then,a linear modulated graph attention residual network model is devised to extract the node and network topology features of the social relation subgraph,thereby generating comprehensive social relation subgraph features,and the feature-wise linear modulation module of the model can better learn the differences between the nodes.Next,user text content and behavioral gene sequences are extracted to construct social behavioral features combined with the social relationship subgraph features.Finally,social robots can be more accurately identified by combining user behavioral and relationship features.By carrying out experimental studies based on the publicly available datasets TwiBot-20 and Cresci-15,the suggested method’s detection accuracies can achieve 86.73%and 97.86%,respectively.Compared with the existing mainstream approaches,the accuracy of the proposed method is 2.2%and 1.35%higher on the two datasets.The results show that the method proposed in this paper can effectively detect social robots and maintain a healthy ecological environment of social networks. 展开更多
关键词 Social robot detection social relationship subgraph graph attention network feature linear modulation behavioral gene sequences
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A Video Captioning Method by Semantic Topic-Guided Generation
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作者 ou ye Xinli Wei +2 位作者 Zhenhua Yu Yan Fu Ying Yang 《Computers, Materials & Continua》 SCIE EI 2024年第1期1071-1093,共23页
In the video captioning methods based on an encoder-decoder,limited visual features are extracted by an encoder,and a natural sentence of the video content is generated using a decoder.However,this kind ofmethod is de... In the video captioning methods based on an encoder-decoder,limited visual features are extracted by an encoder,and a natural sentence of the video content is generated using a decoder.However,this kind ofmethod is dependent on a single video input source and few visual labels,and there is a problem with semantic alignment between video contents and generated natural sentences,which are not suitable for accurately comprehending and describing the video contents.To address this issue,this paper proposes a video captioning method by semantic topic-guided generation.First,a 3D convolutional neural network is utilized to extract the spatiotemporal features of videos during the encoding.Then,the semantic topics of video data are extracted using the visual labels retrieved from similar video data.In the decoding,a decoder is constructed by combining a novel Enhance-TopK sampling algorithm with a Generative Pre-trained Transformer-2 deep neural network,which decreases the influence of“deviation”in the semantic mapping process between videos and texts by jointly decoding a baseline and semantic topics of video contents.During this process,the designed Enhance-TopK sampling algorithm can alleviate a long-tail problem by dynamically adjusting the probability distribution of the predicted words.Finally,the experiments are conducted on two publicly used Microsoft Research Video Description andMicrosoft Research-Video to Text datasets.The experimental results demonstrate that the proposed method outperforms several state-of-art approaches.Specifically,the performance indicators Bilingual Evaluation Understudy,Metric for Evaluation of Translation with Explicit Ordering,Recall Oriented Understudy for Gisting Evaluation-longest common subsequence,and Consensus-based Image Description Evaluation of the proposed method are improved by 1.2%,0.1%,0.3%,and 2.4% on the Microsoft Research Video Description dataset,and 0.1%,1.0%,0.1%,and 2.8% on the Microsoft Research-Video to Text dataset,respectively,compared with the existing video captioning methods.As a result,the proposed method can generate video captioning that is more closely aligned with human natural language expression habits. 展开更多
关键词 Video captioning encoder-decoder semantic topic jointly decoding Enhance-TopK sampling
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A Sentence Retrieval Generation Network Guided Video Captioning
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作者 ou ye Mimi Wang +3 位作者 Zhenhua Yu Yan Fu Shun Yi Jun Deng 《Computers, Materials & Continua》 SCIE EI 2023年第6期5675-5696,共22页
Currently,the video captioning models based on an encoder-decoder mainly rely on a single video input source.The contents of video captioning are limited since few studies employed external corpus information to guide... Currently,the video captioning models based on an encoder-decoder mainly rely on a single video input source.The contents of video captioning are limited since few studies employed external corpus information to guide the generation of video captioning,which is not conducive to the accurate descrip-tion and understanding of video content.To address this issue,a novel video captioning method guided by a sentence retrieval generation network(ED-SRG)is proposed in this paper.First,a ResNeXt network model,an efficient convolutional network for online video understanding(ECO)model,and a long short-term memory(LSTM)network model are integrated to construct an encoder-decoder,which is utilized to extract the 2D features,3D features,and object features of video data respectively.These features are decoded to generate textual sentences that conform to video content for sentence retrieval.Then,a sentence-transformer network model is employed to retrieve different sentences in an external corpus that are semantically similar to the above textual sentences.The candidate sentences are screened out through similarity measurement.Finally,a novel GPT-2 network model is constructed based on GPT-2 network structure.The model introduces a designed random selector to randomly select predicted words with a high probability in the corpus,which is used to guide and generate textual sentences that are more in line with human natural language expressions.The proposed method in this paper is compared with several existing works by experiments.The results show that the indicators BLEU-4,CIDEr,ROUGE_L,and METEOR are improved by 3.1%,1.3%,0.3%,and 1.5%on a public dataset MSVD and 1.3%,0.5%,0.2%,1.9%on a public dataset MSR-VTT respectively.It can be seen that the proposed method in this paper can generate video captioning with richer semantics than several state-of-the-art approaches. 展开更多
关键词 Video captioning encoder-decoder sentence retrieval external corpus RS GPT-2 network model
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腹腔镜与开腹胰十二指肠切除术治疗远端胆管癌疗效分析 被引量:5
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作者 陈顺 吴子龙 +8 位作者 王方明 王俊 吕品 梁刚 田秉璋 周力学 欧晔 周芬 李林欢 《中华普通外科杂志》 CSCD 北大核心 2021年第9期653-657,共5页
目的:评估腹腔镜与开腹胰十二指肠切除术治疗远端胆管癌的近期疗效、根治性效果和远期生存情况。方法:回顾性分析湖南省人民医院2015年1月至2019年12月行胰十二指肠切除术治疗的200例远端胆管癌患者的临床资料,其中行腹腔镜胰十二指肠... 目的:评估腹腔镜与开腹胰十二指肠切除术治疗远端胆管癌的近期疗效、根治性效果和远期生存情况。方法:回顾性分析湖南省人民医院2015年1月至2019年12月行胰十二指肠切除术治疗的200例远端胆管癌患者的临床资料,其中行腹腔镜胰十二指肠切除术(LPD组)101例,开腹胰十二指肠切除术(OPD组)99例。比较两组手术时间、术中出血量、淋巴结清扫数目、R 0切除率、术后住院时间、术后并发症和随访总体生存率。结果:两组手术时间分别为(475.0±90.7)min和(444.8±63.3)min、术中出血量分别为(350.9±397.9)ml和(546.7±642.9)ml、术后住院时间分别为(11.5±4.7)d和(13.3±5.1)d,差异均有统计学意义(均P<0.05),淋巴结清扫数目分别为(14.8±3.0)枚和(15.4±2.4)枚、R 0切除率分别为93.1%和96.0%,差异均无统计学意义(均P>0.05),两组术后并发症除伤口感染外,余并发症发生率比较差异均无统计学意义(均P>0.05)。随访5~64个月,两组的1、3、5年的总体生存率(OS)分别为90.4%、41.3%、20.6%和94.3%、50.8%和24.7%,差异无统计学意义(P>0.05)。结论:LPD治疗远端胆管癌是安全可行的,在近期疗效、根治性效果和远期OS方面可取得与OPD相似的临床疗效。 展开更多
关键词 胰十二指肠切除术 腹腔镜 远端胆管癌
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