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Integration of maximum crop response with machine learning regression model to timely estimate crop yield 被引量:1
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作者 Qiming Zhou Ali Ismaeel 《Geo-Spatial Information Science》 SCIE EI CSCD 2021年第3期474-483,共10页
Timely and reliable estimation of regional crop yield is a vital component of food security assessment, especially in developing regions. The traditional crop forecasting methods need ample time and labor to collect a... Timely and reliable estimation of regional crop yield is a vital component of food security assessment, especially in developing regions. The traditional crop forecasting methods need ample time and labor to collect and process field data to release official yield reports. Satellite remote sensing data is considered a cost-effective and accurate way of predicting crop yield at pixel-level. In this study, maximum Enhanced Vegetation Index (EVI) during the crop-growing season was integrated with Machine Learning Regression (MLR) models to estimate wheat and rice yields in Pakistan’s Punjab province. Five MLR models were compared using a fivefold cross-validation method for their predictive accuracy. The study results revealed that the regression model based on the Gaussian process outperformed over other models. The best performing model attained coefficient of determination (R^(2)), Root Mean Square Error (RMSE, t/ ha), and Mean Absolute Error (MAE, t/ha) of 0.75, 0.281, and 0.236 for wheat;0.68, 0.112, and 0.091 for rice, respectively. The proposed method made it feasible to predict wheat and rice 6- 8 weeks before the harvest. The early prediction of crop yield and its spatial distribution in the region can help formulate efficient agricultural policies for sustainable social, environmental, and economic progress. 展开更多
关键词 Machine learning remote sensing crop yield timely forecast
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Quorum systems for intrusion-tolerance based on trusted timely computing base
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作者 Hua Zhou Xiangru Meng Li Zhang Xiangdong Qiao 《Journal of Systems Engineering and Electronics》 SCIE EI CSCD 2010年第1期168-174,共7页
Quorum systems have been used to solve the problem of data consistency in distributed fault-tolerance systems. But when intrusions occur, traditional quorum systems have some disadvantages. For example, synchronous qu... Quorum systems have been used to solve the problem of data consistency in distributed fault-tolerance systems. But when intrusions occur, traditional quorum systems have some disadvantages. For example, synchronous quorum systems are subject to DOS attacks, while asynchronous quorum systems need a larger system size (at least 3f+1 for generic data, and f fewer for self-verifying data). In order to solve the problems above, an intrusion-tolerance quorum system (ITQS) of hybrid time model based on trust timely computing base is presented (TTCB). The TTCB is a trust secure real-time component inside the server with a well defined interface and separated from the operation system. It is in the synchronous communication environment while the application layer in the server deals with read-write requests and executes update-copy protocols asynchronously. The architectural hybridization of synchrony and asynchrony can achieve the data consistency and availability correctly. We also build two kinds of ITQSes based on TTCB, i.e., the symmetrical and the asymmetrical TTCB quorum systems. In the performance evaluations, we show that TTCB quorum systems are of smaller size, lower load and higher availability. 展开更多
关键词 network security intrusion-tolerance quorum system trusted timely computing base (TTCB) CONSISTENCY availability.
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Determinants of Delay in Malaria Prompt Diagnosis and Timely Treatment among Under-Five Children in Shashogo Woreda, Hadiya Zone, Southern Ethiopia: A Case Control Study
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作者 Ermias Abera Turuse Kassahun Alemu Gelaye Teresa Kisi Beyen 《Health》 2014年第10期950-959,共10页
Background: Ensuring prompt diagnosis and timely malaria treatment will prevent most cases of uncomplicated malaria from progressing to severe and fatal illness. To avoid this progression, treatment must begin as soon... Background: Ensuring prompt diagnosis and timely malaria treatment will prevent most cases of uncomplicated malaria from progressing to severe and fatal illness. To avoid this progression, treatment must begin as soon as possible, generally within 24 hours after symptoms onset. The reason why mothers/caretakers delay in malaria prompt diagnosis and timely treatment for under-five is not well studied in the study area as well as in Ethiopia. Objective: To assess determinants of delay in malaria prompt diagnosis and timely treatment among under-five children in Shashogo Woreda, Hadiya Zone, Southern Ethiopia, 2013. Methods: An unmatched case control study was conducted from March 25-April 25, 2013. A total sample size of 302 with 151 cases and 151 controls were selected by systematic random sampling techniques. Cases were under-five children who had clinical malaria and sought treatment after 24 hours of symptoms onset, and controls were under-five children who had clinical malaria and sought treatment within 24 hours of symptoms onset. Both bivariate and multivariate logistic regressions were done to identify determinant of delay in malaria prompt diagnosis and timely treatment. Results: A total of 151 mothers/caretakers of cases and 151 mothers/caretakers of controls were interviewed. Illiterate mothers (AOR = 7.14;95%CI: 1.10, 46.39), monthly income ≤500 ETB (AOR = 5.49;95%CI: 2.09, 14.45), females sex (AOR = 3.45;95%CI: 1.62, 7.34), distance from health facility >5 km (AOR = 4.31;95%CI: 1.22, 15.23), absence of history of child death (AOR = 4.21;95%CI: 1.514, 11.68), side effects of antimalarial drugs (AOR = 2.91;95%CI: 1.15, 7.33) and khat chewing (AOR = 2.38;95%CI: 1.28, 5.79) were determinants of delay in malaria prompt diagnosis and timely treatment of under-five children. Conclusion: Mother’s education, monthly income, distance from health facility, absence of history of child death, complained about side effects of drugs and khat chewing were predictors of delay of prompt diagnosis and timely malaria treatment. Effective malaria control programs revision would be required to avoid delay of prompt diagnosis and timely treatment for under-five children. 展开更多
关键词 PROMPT DIAGNOSIS timely TREATMENT Children
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TIME伤口床准备联合封闭式负压引流用于食管肿瘤术后颈部吻合瘘护理
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作者 李艳 周林荣 +4 位作者 龚兰娟 叶春燕 关雪红 李桃 李翠 《医学理论与实践》 2025年第16期2841-2843,共3页
目的:在食管肿瘤术后并发颈部吻合瘘患者护理中给予TIME伤口床准备联合封闭式负压引流的干预方式,就其护理效果进行分析。方法:选取2020年7月—2023年6月我科26例食管癌术后并发吻合口瘘患者为研究对象,采用随机数字表法将患者分为观察... 目的:在食管肿瘤术后并发颈部吻合瘘患者护理中给予TIME伤口床准备联合封闭式负压引流的干预方式,就其护理效果进行分析。方法:选取2020年7月—2023年6月我科26例食管癌术后并发吻合口瘘患者为研究对象,采用随机数字表法将患者分为观察组和对照组。观察组应用TIME伤口床准备联合封闭式负压引流治疗,对照组采用常规伤口换药处理,对比两组护理成效。结果:观察组术后15d内换药次数少于对照组,颈部切口愈合时间、经口进食流质时间以及术后住院时间明显短于对照组,同时观察组的6个月内吻合口狭窄发生率、6个月并发症发生率明显低于对照组(P<0.05);干预后,两组患者的QLQ-OES18各维度评分均较干预前降低,且观察组的各维度评分均低于对照组(P<0.05);观察组的护理总有效率显著高于对照组(P<0.05)。结论:TIME伤口床准备联合封闭式负压引流应用于食管肿瘤术后并发颈部吻合瘘护理中效果显著,可以有效缩短治疗时间,提高生活质量,改善预后,建议在临床上推广应用。 展开更多
关键词 食管肿瘤术后 颈部吻合瘘 TIME伤口床准备 封闭式负压引流 护理效果
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The Pathological Complexity of Stroke and Rational Treatment Principles of Chinese Herbal Medicine
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作者 Guanyuan Jin Louis Lei Jin Belinda Jie He 《Chinese Medicine and Natural Products》 2025年第1期1-22,共22页
This paper first analyzes the complexity of pathological processes involved in acute hemorrhagic or ischemic stroke,including primary and secondary brain injury manifestations and mechanisms,potential transformations ... This paper first analyzes the complexity of pathological processes involved in acute hemorrhagic or ischemic stroke,including primary and secondary brain injury manifestations and mechanisms,potential transformations between hemorrhage and infarction,and the impact of postbrain injury inflammation on disease progression.Based on decades of extensive clinical and pharmacological research on the usage of Chinese herbal medicine(CHM)monomers or formulas that promote blood circulation and remove blood stasis(such as Angong Niuhuang Wan,Buyang Huanwu Tang,Dahuoluo Wan,and Dushen Tang)for stroke treatment,it proposes that tonifying qi,promoting blood circulation,removing blood stasis,and detoxifying are rational treatment principles of CHM.These principles correspond to the following Western medical implications:tonifying qi corresponds to neuroprotection effects,promoting blood circulation corresponds to anticoagulation and thrombolysis,removing blood stasis addresses hematoma absorption and cerebral edema reduction,and detoxifying corresponds to anti-inflammatory actions.This paper further proposes from a systems medicine perspective that acute stroke is a complex disease requiring individualized CHM treatment with timely modifications rather than a one-sizefits-all approach.CHM monomers or formulas for promoting blood circulation and removing blood stasis,which have various effects such as lowering blood pressure,hemostasis,anticoagulation,antiplatelet,anti-inflammatory,promoting fibrinolysis,and edema reduction,must align with disease progression and be applied within appropriate therapeutic time windows to ensure efficacy and safety.Finally,this paper suggests that a combined use of acupuncture and CHM can potentially synergistically leverage their respective therapeutic strengths.Additionally,acupuncture shows clear benefits in the acute phase of intracerebral hemorrhage(ICH),such as stimulating the vagus nerve to enhance cerebral blood flow,reducing inflammation,as well as triggering hemostatic effects.By applying these rational treatment principles in an integrated approach,better CHM treatment outcomes and higher efficacy of stroke management may be attained. 展开更多
关键词 stroke-chinese herbal medicine tonifying qi promoting blood circulation removing blood stasis detoxifying anti-inflammatory therapeutic time windows treatment with timely modification
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基于VMD-T2V-Transformer的太阳辐射预测
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作者 胡雅彬 史加荣 +1 位作者 陈应瑞 雍龙泉 《太阳能学报》 北大核心 2025年第7期778-784,共7页
太阳辐射的不确定性导致太阳能发电具有明显的随机性和不稳定性。针对此问题,该文结合变分模态分解(VMD)、Time2Vec(T2V)和Transformer,提出一种用于太阳辐射预测的VMD-T2V-Transformer模型。首先利用VMD将太阳辐射序列分解为若干子序列... 太阳辐射的不确定性导致太阳能发电具有明显的随机性和不稳定性。针对此问题,该文结合变分模态分解(VMD)、Time2Vec(T2V)和Transformer,提出一种用于太阳辐射预测的VMD-T2V-Transformer模型。首先利用VMD将太阳辐射序列分解为若干子序列;接着采用T2V对分解后的每个子序列进行时间特征嵌入;然后对嵌入时间特征后的子序列建立Transformer预测模型;最后将各模型的预测结果进行叠加,得到最终预测值。实验结果表明:该文所提模型优于其他主流模型,RMSE和MAE至少降低13.81%和16.44%。 展开更多
关键词 太阳辐射 太阳能发电 变分模态分解 Time2Vec TRANSFORMER
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IoT Empowered Early Warning of Transmission Line Galloping Based on Integrated Optical Fiber Sensing and Weather Forecast Time Series Data 被引量:1
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作者 Zhe Li Yun Liang +1 位作者 Jinyu Wang Yang Gao 《Computers, Materials & Continua》 SCIE EI 2025年第1期1171-1192,共22页
Iced transmission line galloping poses a significant threat to the safety and reliability of power systems,leading directly to line tripping,disconnections,and power outages.Existing early warning methods of iced tran... Iced transmission line galloping poses a significant threat to the safety and reliability of power systems,leading directly to line tripping,disconnections,and power outages.Existing early warning methods of iced transmission line galloping suffer from issues such as reliance on a single data source,neglect of irregular time series,and lack of attention-based closed-loop feedback,resulting in high rates of missed and false alarms.To address these challenges,we propose an Internet of Things(IoT)empowered early warning method of transmission line galloping that integrates time series data from optical fiber sensing and weather forecast.Initially,the method applies a primary adaptive weighted fusion to the IoT empowered optical fiber real-time sensing data and weather forecast data,followed by a secondary fusion based on a Back Propagation(BP)neural network,and uses the K-medoids algorithm for clustering the fused data.Furthermore,an adaptive irregular time series perception adjustment module is introduced into the traditional Gated Recurrent Unit(GRU)network,and closed-loop feedback based on attentionmechanism is employed to update network parameters through gradient feedback of the loss function,enabling closed-loop training and time series data prediction of the GRU network model.Subsequently,considering various types of prediction data and the duration of icing,an iced transmission line galloping risk coefficient is established,and warnings are categorized based on this coefficient.Finally,using an IoT-driven realistic dataset of iced transmission line galloping,the effectiveness of the proposed method is validated through multi-dimensional simulation scenarios. 展开更多
关键词 Optical fiber sensing multi-source data fusion early warning of galloping time series data IOT adaptive weighted learning irregular time series perception closed-loop attention mechanism
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时间嵌入和注意力机制的超短期风速预测混合模型研究
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作者 田建辉 黄国勇 +1 位作者 邓为权 刘发炳 《太阳能学报》 北大核心 2025年第10期746-752,共7页
提出一种基于无人机搭载测风的超短期风速预测混合模型,该模型首先融合Time2Vec时间嵌入层对复杂非线性时间信息进行表征,其次采用宽深度卷积神经网络(WDCNN),能够在风速特征准确提取的同时进一步降低高频噪声的影响,在准确特征表征的... 提出一种基于无人机搭载测风的超短期风速预测混合模型,该模型首先融合Time2Vec时间嵌入层对复杂非线性时间信息进行表征,其次采用宽深度卷积神经网络(WDCNN),能够在风速特征准确提取的同时进一步降低高频噪声的影响,在准确特征表征的基础上,结合双向门控单元(BiGRU)与注意力机制实现短期风速的准确预测。使用无人机搭载在5~25 m获取的风速数据进行验证,所提混合模型在各高度层上对风速预测的准确性均优于对比方法,在风速波动性最大的25 m高度层,该模型风速预测的E_(MAE)、E_(RMSE)和E_(MSE)分别为0.1455、0.4124和0.1700 m/s,相较于对比模型分别降低45%、25%和43%以上。 展开更多
关键词 风电 风速 神经网络 时间序列 Time2Vec 注意力机制 无人机搭载测风
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基于DEMATEL和TOPSIS的低空安防系统方案多属性评价方法 被引量:1
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作者 施玮 吴坚 《科学技术与工程》 北大核心 2025年第14期6109-6117,共9页
针对低空经济发展涉及的安全管理问题,在总结低空经济相关技术路线原理及落地方案的运行经验,分析低空安防普适性的4个建设方案:雷达与通感一体技术融合方案、广播式自动相关监视技术方案、远程识别技术方案和基于TDOA(time difference ... 针对低空经济发展涉及的安全管理问题,在总结低空经济相关技术路线原理及落地方案的运行经验,分析低空安防普适性的4个建设方案:雷达与通感一体技术融合方案、广播式自动相关监视技术方案、远程识别技术方案和基于TDOA(time difference of arrival)无线电技术的多源融合方案的基础上,构建无人飞行器探测技术评价指标体系,并建立了一种基于决策试验评估实验室(decision-making trial and evaluation laboratory, DEMATEL)和优劣解距离法(technique for order preference by similarity to an ideal solution, TOPSIS)的多属性评价方法。结果发现,以TDOA为基础的多源融合方案是构建城市低空安防体系的有效路径和普适性方案。研究表明,低空安防体系的建设是一个系统性工程,需要政府、企业和社会各方的共同努力,在技术、数据、运营等多个层面进行整合,以适应未来低空经济的发展需求。 展开更多
关键词 低空经济 低空安防系统 多属性评价方法 TDOA(time difference of arrival)技术 无人机管控
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基于Time2Vec-BiGRU-SA深度学习模型的碳价格预测
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作者 杨楠 毕贵红 +3 位作者 李玉洪 孔凡文 骆钊 王瑞 《电力科学与工程》 2025年第9期1-12,共12页
碳交易价格预测对政策制定与市场稳态的维护至关重要,但碳价时间序列的非线性、非平稳性等特征给其精准预测带来困难。为此,提出基于时序特征向量映射模块、双向门控循环单元和自注意力机制融合的深度学习模型。模型集成3个分支:直接处... 碳交易价格预测对政策制定与市场稳态的维护至关重要,但碳价时间序列的非线性、非平稳性等特征给其精准预测带来困难。为此,提出基于时序特征向量映射模块、双向门控循环单元和自注意力机制融合的深度学习模型。模型集成3个分支:直接处理原始碳价时间序列;构建碳价序列多尺度分量矩阵;基于灰色关联度分析与极端随机树方法筛选出与碳价相关的关键变量。各分支均利用时序特征向量映射模块编码时间信息。双向门控循环单元捕捉双向长时依赖。自注意力机制模型加权特征进行综合集成。实证研究显示,该模型单步及多步预测精度高,均优于基准模型,模型具有优越性与稳健性。 展开更多
关键词 深度学习 碳市场价格 多变量时间序列预测 多分支输入 Time2Vec
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Assessing ground stability of a vertical backfilled stope considering creep behaviors of surrounding rocks 被引量:2
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作者 Ruofan Wang Lang Liu +4 位作者 Mengbo Zhu Huafu Qiu Bingbing Tu Huisheng Qu Hao Cui 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第1期187-199,共13页
Backfill is often employed in mining operations for ground support,with its positive impact on ground stability acknowledged in many underground mines.However,existing studies have predominantly focused only on the st... Backfill is often employed in mining operations for ground support,with its positive impact on ground stability acknowledged in many underground mines.However,existing studies have predominantly focused only on the stress development within the backfill material,leaving the influence of stope backfilling on stress distribution in surrounding rock mass and ground stability largely unexplored.Therefore,this paper presents numerical models in FLAC3D to investigate,for the first time,the time-dependent stress redistribution around a vertical backfilled stope and its implications on ground stability,considering the creep of surrounding rock mass.Using the Soft Soil constitutive model,the compressibility of backfill under large pressure was captured.It is found that the creep deformation of rock mass exercises compression on backfill and results in a less void ratio and increased modulus for fill material.The compacted backfill conversely influenced the stress distribution and ground stability of rock mass which was a combined effect of wall creep and compressibility of backfill.With the increase of time or/and creep deformation,the minimum principal stress in the rocks surrounding the backfilled stope increased towards the pre-mining stress state,while the deviatoric stress reduces leading to an increased factor of safety and improved ground stability.This improvement effect of backfill on ground stability increased with the increase of mine depth and stope height,while it is also more pronounced for the narrow stope,the backfill with a smaller compression index,and the soft rocks with a smaller viscosity coefficient.Furthermore,the results emphasize the importance of minimizing empty time and backfilling extracted stope as soon as possible for ground control.Reduction of filling gap height enhances the local stability around the roof of stope. 展开更多
关键词 Ground stability Time dependency CREEP Surrounding rocks Backfilled stope
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Evaluating the effectiveness of ultrasound-assisted wound debridement in managing diabetic foot ulcers:A systematic review and meta-analysis 被引量:2
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作者 Rui Yang Geng Chen +5 位作者 Qing-Yun Pan Yao Yao Yan-Fen Li Hai-Ting Chen Chang-Jiang Lei Xia Liang 《World Journal of Diabetes》 2025年第2期246-256,共11页
BACKGROUND Diabetic foot ulcers(DFUs)present a significant clinical challenge due to their high prevalence and profound impact on morbidity.Ultrasound-assisted wound debridement(UAWD)has emerged as a potential therape... BACKGROUND Diabetic foot ulcers(DFUs)present a significant clinical challenge due to their high prevalence and profound impact on morbidity.Ultrasound-assisted wound debridement(UAWD)has emerged as a potential therapeutic modality to improve healing outcomes in DFU management.AIM To evaluate the efficacy of UAWD in treating DFUs on wound closure rates,treatment duration,and quality of life outcomes.METHODS This systematic review and meta-analysis followed PRISMA guidelines,systematically searching PubMed,Embase,Web of Science,and the Cochrane Library with no date restrictions.Randomized controlled trials(RCTs)that evaluated the efficacy of UAWD in DFU treatment were included.Data were independently extracted by two reviewers,with discrepancies resolved through consensus or third-party consultation.The risk of bias was assessed using the Cochrane tool.χ2 and I2 statistics assessed heterogeneity,informing the use of fixed or random-effects models for meta-analysis,supplemented by sensitivity analysis and publication bias assessment through funnel plots and Egger's test.RESULTS From 1255 articles,seven RCTs met the inclusion criteria.The studies demonstrated that UAWD significantly reduced DFU healing time(standardized mean difference=-0.78,95%CI:-0.97 to-0.60,P<0.001)and increased healing rates(odds ratio=9.96,95%CI:5.99 to 16.56,P<0.001)compared to standard care.Sensitivity analysis confirmed the stability of these results,and no significant publication bias was detected.CONCLUSION UAWD is a promising adjunctive treatment for DFUs,significantly reducing healing times and increasing healing rates.These findings advocate for the integration of UAWD into standard DFU care protocols. 展开更多
关键词 Diabetic foot ulcers Ultrasound-assisted wound debridement Healing time Healing rates META-ANALYSIS
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基于不同前处理方法结合全二维气相色谱飞行时间质谱解析红星二锅头白酒的风味成分 被引量:2
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作者 于立娟 田红云 +3 位作者 单群 孟士皓 冯思雨 邹弯 《食品与发酵工业》 北大核心 2025年第8期332-340,I0021-I0047,共36页
采用顶空固相微萃取(headspace solid-phase microextraction,HS-SPME)和液液萃取(liquid-liquid extraction,LLE)结合全二维气相色谱飞行时间质谱(comprehensive two-dimensional gas chromatography time of flight mass spectrometry... 采用顶空固相微萃取(headspace solid-phase microextraction,HS-SPME)和液液萃取(liquid-liquid extraction,LLE)结合全二维气相色谱飞行时间质谱(comprehensive two-dimensional gas chromatography time of flight mass spectrometry,GC×GC-TOF-MS)以及香气活度值(odour active value,OAV),对红星二锅头白酒的挥发性成分进行全面解析。研究发现,HS-SPME、LLE分别定性出928、802种挥发性化合物,共计定性出1304种挥发性化合物,共同定性出426种挥发性化合物。基于HS-SPME数据,通过香气数据库筛选出具有香气特征的382种香气化合物,其中酯类相对百分含量占比最高,其次是醇类、酸类和醛类。计算得到了49种香气化合物OAV>1,其中酯类(辛酸乙酯、异戊酸乙酯等)和萜烯类(β-大马酮)对白酒风味的贡献最大,醛类(异戊醛、己醛等)和含硫类(二甲基三硫)其次,醇类(1-辛烯-3-醇)和含氮类(2,3,5-三甲基吡嗪)也有一定风味贡献。该研究丰富了红星二锅头白酒的风味研究,也为下一步生产研究及调控提供了理论和数据支撑。 展开更多
关键词 红星二锅头白酒 全二维气相色谱飞行时间质谱(comprehensive two-dimensional gas chromatography time of flight mass spectrometry GC×GC-TOF-MS) 挥发性化合物 顶空固相微萃取(headspace solid-phase microextraction HS-SPME) 液液萃取(liquid-liquid extraction LLE)
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Coastal ozone dynamics and formation regime in Eastern China:Integrating trend decomposition and machine learning techniques 被引量:1
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作者 Lei Tong Zhuoliang Gu +8 位作者 Xuchu Zhu Cenyan Huang Baoye Hu Yasheng Shi Yang Meng Jie Zheng Mengmeng He Jun He Hang Xiao 《Journal of Environmental Sciences》 2025年第9期597-612,共16页
Machine-learning is a robust technique for understanding pollution characteristics of surface ozone,which are at high levels in urban China.This study introduced an innovative approach combining trend decomposition wi... Machine-learning is a robust technique for understanding pollution characteristics of surface ozone,which are at high levels in urban China.This study introduced an innovative approach combining trend decomposition with Random Forest algorithm to investigate ozone dynamics and formation regimes in a coastal area of China.During the period of 2017–2022,significant inter-annual fluctuations emerged,with peaks in mid-2017 attributed to volatile organic compounds(VOCs),and in late-2019 influenced by air temperature.Multifaceted periodicities(daily,weekly,holiday,and yearly)in ozone were revealed,elucidating substantial influences of daily and yearly components on ozone periodicity.A VOC-sensitive ozone formation regime was identified,characterized by lower VOCs/NO_(x) ratios(average=0.88)and significant positive correlations between ozone and VOCs.This interplay manifested in elevated ozone duringweekends,holidays,and pandemic lockdowns.Key variables influencing ozone across diverse timescaleswere uncovered,with solar radiation and temperature driving daily and yearly ozone variations,respectively.Precursor substances,particularly VOCs,significantly shaped weekly/holiday patterns and long-term trends of ozone.Specifically,acetone,ethane,hexanal,and toluene had a notable impact on the multi-year ozone trend,emphasizing the urgency of VOC regulation.Furthermore,our observations indicated that NO_(x) primarily drived the stochastic variations in ozone,a distinguishing characteristic of regions with heavy traffic.This research provides novel insights into ozone dynamics in coastal urban areas and highlights the importance of integrating statistical and machinelearning methods in atmospheric pollution studies,with implications for targeted mitigation strategies beyond this specific region and pollutant. 展开更多
关键词 Time series decomposition Random forest VOC-sensitive Long-term trend Port area
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Actuator fault diagnosis and severity identification of turbofan engines for steady-state and dynamic conditions 被引量:1
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作者 Yuzhi CHEN Weigang ZHANG +4 位作者 Zhiwen ZHAO Elias TSOUTSANIS Areti MALKOGIANNI Yanhua MA Linfeng GOU 《Chinese Journal of Aeronautics》 2025年第1期427-443,共17页
Actuator faults can be critical in turbofan engines as they can lead to stall,surge,loss of thrust and failure of speed control.Thus,fault diagnosis of gas turbine actuators has attracted considerable attention,from b... Actuator faults can be critical in turbofan engines as they can lead to stall,surge,loss of thrust and failure of speed control.Thus,fault diagnosis of gas turbine actuators has attracted considerable attention,from both academia and industry.However,the extensive literature that exists on this topic does not address identifying the severity of actuator faults and focuses mainly on actuator fault detection and isolation.In addition,previous studies of actuator fault identification have not dealt with multiple concurrent faults in real time,especially when these are accompanied by sudden failures under dynamic conditions.This study develops component-level models for fault identification in four typical actuators used in high-bypass ratio turbofan engines under both dynamic and steady-state conditions and these are then integrated with the engine performance model developed by the authors.The research results reported here present a novel method of quantifying actuator faults using dynamic effect compensation.The maximum error for each actuator is less than0.06%and 0.07%,with average computational time of less than 0.0058 s and 0.0086 s for steady-state and transient cases,respectively.These results confirm that the proposed method can accurately and efficiently identify concurrent actuator fault for an engine operating under either transient or steady-state conditions,even in the case of a sudden malfunction.The research results emonstrate the potential benefit to emergency response capabilities by introducing this method of monitoring the health of aero engines. 展开更多
关键词 Turbofan engines Actuators Real time systems Fault identification Steady-state conditions Dynamic conditions
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A dual⁃parameter method for seismic resilience assessment of buildings 被引量:1
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作者 LI Shuang HU Binbin +1 位作者 LIU Wen ZHAI Changhai 《Journal of Southeast University(English Edition)》 2025年第1期1-11,共11页
To quantify the seismic resilience of buildings,a method for evaluating functional loss from the component level to the overall building is proposed,and the dual-parameter seismic resilience assessment method based on... To quantify the seismic resilience of buildings,a method for evaluating functional loss from the component level to the overall building is proposed,and the dual-parameter seismic resilience assessment method based on postearthquake loss and recovery time is improved.A threelevel function tree model is established,which can consider the dynamic changes in weight coefficients of different category of components relative to their functional losses.Bayesian networks are utilized to quantify the impact of weather conditions,construction technology levels,and worker skill levels on component repair time.A method for determining the real-time functional recovery curve of buildings based on the component repair process is proposed.Taking a three-story teaching building as an example,the seismic resilience indices under basic earthquakes and rare earthquakes are calculated.The results show that the seismic resilience grade of the teaching building is comprehensively judged as GradeⅢ,and its resilience grade is more significantly affected by postearthquake loss.The proposed method can be used to predict the seismic resilience of buildings prior to earthquakes,identify weak components within buildings,and provide guidance for taking measures to enhance the seismic resilience of buildings. 展开更多
关键词 seismic resilience assessment dual-parameter method functional loss recovery time Bayesian networks
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A core-surface flow model derived from magnetic data of Macao Science Satellite-1 被引量:1
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作者 Jin Feng Li Yu Feng Lin +2 位作者 Hong Bo Yao Ju Yuan Xu Keke Zhang 《Earth and Planetary Physics》 2025年第3期577-585,共9页
The core-surface flow is crucial for understanding the dynamics of the Earth's outer core and geomagnetic secular variations.Conventional core flow models often use a single set of spherical harmonic coefficients ... The core-surface flow is crucial for understanding the dynamics of the Earth's outer core and geomagnetic secular variations.Conventional core flow models often use a single set of spherical harmonic coefficients to represent the flow both inside and outside the tangent cylinder,inherently imposing continuity across the tangent cylinder around the solid inner core.To address this limitation,we present a core-surface flow inversion framework based on physics-informed neural networks.This framework employs distinct neural network representations for the flow inside and outside the tangent cylinder,allowing for discontinuities as the flow crosses the tangent cylinder.Additionally,it incorporates secular acceleration data to constrain the temporal evolution of the core flow.Using this inversion framework,we derive a new core-surface flow model spanning 2001 to 2024 from a geomagnetic model,incorporating the latest magnetic data from Swarm satellites and Macao Science Satellite-1.The recovered model reveals persistent large-scale circulation linked to westward drift,significant temporal variations in the equatorial Pacific,and distinct jet-like structures at the poles.The inversion also reveals a large-scale wave pattern in equatorial azimuthal flow acceleration,corresponding to observed geomagnetic jerks and likely resulting from quasi-geostrophic magneto-Coriolis waves.Additionally,the framework infers small-scale magnetic fields at the core-mantle boundary,highlighting split flux concentrations and localized high-latitude patches. 展开更多
关键词 Macao Science Satellite-1 PINNs core-surface flow rapid time variations
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Accurate determination of reaction rate constants for lithium-ion batteries by characteristic time-decomposed overpotential 被引量:1
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作者 Yifu Chen Haitao Zhu +7 位作者 Mengyuan Zhou Maoyuan Li Ruoyu Xiong Shuaiyi Yang Shiyu Zhang Yun Zhang Jingying Xie Huamin Zhou 《Journal of Energy Chemistry》 2025年第7期608-618,共11页
The reaction rate constant is a crucial kinetic parameter that governs the charge and discharge performance of batteries,particularly in high-rate and thick-electrode applications.However,conventional estimation or fi... The reaction rate constant is a crucial kinetic parameter that governs the charge and discharge performance of batteries,particularly in high-rate and thick-electrode applications.However,conventional estimation or fitting methods often overestimate the charge transfer overpotential,leading to substantial errors in reaction rate constant measurements.These inaccuracies hinder the accurate prediction of voltage profiles and overall cell performance.In this study,we propose the characteristic time-decomposed overpotential(CTDO)method,which employs a single-layer particle electrode(SLPE)structure to eliminate interference overpotentials.By leveraging the distribution of relaxation times(DRT),our method effectively isolates the characteristic time of the charge transfer process,enabling a more precise determination of the reaction rate constant.Simulation results indicate that our approach reduces measurement errors to below 2%,closely aligning with theoretical values.Furthermore,experimental validation demonstrates an 80% reduction in error compared to the conventional galvanostatic intermittent titration technique(GITT)method.Overall,this study provides a novel voltage-based approach for determining the reaction rate constant,enhancing the applicability of theoretical analysis in electrode structural design and facilitating rapid battery optimization. 展开更多
关键词 Kinetic parameter determination Decomposed overpotentials Charge transfer overpotential Characteristic time Single-layer particle
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The RhSPL4-RhPRR5L module positively regulates flowering time in rose(Rosa hybrida) 被引量:1
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作者 Ziwei Huang Guoqin Liu +10 位作者 Rui Chen Hao Zhang Dan Wang Daliang Li Yixin Zhang Huijun Yan Kaixue Tang Junping Gao Nan Ma Weikun Jing Xiaofeng Zhou 《Horticultural Plant Journal》 2025年第5期1930-1942,共13页
The proper flowering time of rose(Rosa hybrida)is vital for the market value of this horticultural crop,but the mechanism regulating this trait is largely unclear.Here,we found that the transcription factor SQUAMOSA P... The proper flowering time of rose(Rosa hybrida)is vital for the market value of this horticultural crop,but the mechanism regulating this trait is largely unclear.Here,we found that the transcription factor SQUAMOSA PROMOTER BINDING PROTEIN-LIKE4(RhSPL4)positively regulates flowering time in rose.Transient silencing or overexpression transgenic rose plants of RhSPL4 exhibited delayed or early flowering,respectively.Analysis of transcriptome data from transgenic lines overexpressing RhSPL4 compared to the wild type indicated that differentially expressed genes were significantly enriched in the circadian rhythm pathway.Among the proteins encoded by these genes,RhSPL4 binds to the promoter of PSEUDO-RESPONSE REGULATOR 5-LIKE(RhPRR5L),as revealed in yeast one-hybrid,dual-Luciferase/Renilla luciferase reporter,chromatin immunoprecipitation-quantitative PCR and electrophoretic mobility shift assay.Furthermore,RhSPL4 specifically binds to the478 to441 bp region of the RhPRR5L promoter and activates its transcription.The silencing of RhPRR5L delayed flowering time in rose,resembling the phenotype of RhSPL4-silenced plants.Together,these results indicate that the RhSPL4-RhPRR5L module positively regulates flowering time in rose,laying the foundation for the genetic improvement of flowering time in this important horticultural crop. 展开更多
关键词 SQUAMOSA PROMOTER BINDING PROTEIN-LIKE 4 Flowering time Circadian clock PSEUDO-RESPONSE REGULATORS Rosa hybrida
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Integrated Optical True Time Delay Phased Array Antenna Systems 被引量:1
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作者 Qi Zihang Yang Linhui +1 位作者 Zhao Wenyu Li Xiuping 《China Communications》 2025年第5期152-172,共21页
The integrated optical true time delay phased array antenna system has the advantages of high bandwidth,small size,low loss and strong antiinterference capability,etc.The high integration of the optically controlled p... The integrated optical true time delay phased array antenna system has the advantages of high bandwidth,small size,low loss and strong antiinterference capability,etc.The high integration of the optically controlled phased array antenna system is a necessary trend for the future development of the phased array,and it is also a major focus and difficulty in the current research of integrated microwave photonics.This paper firstly introduces the basic principle and development history of optical true time delay phased array antenna system based on microwave photonics,and briefly introduces the main implementation methods and integration platform of optical true time delay.Then,the application and development prospect of optical true time delay technology in beam control of phased array antenna system are mainly presented.Finally,according to the current research progress,the possible research directions of integrated optically controlled phased array antenna systems in the future are proposed. 展开更多
关键词 microwave photonics optical switch optical true time delay phased array antenna siliconbased integration
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