期刊文献+
共找到4,222篇文章
< 1 2 212 >
每页显示 20 50 100
Dynamic instability and catastrophe mechanisms of surrounding rock with rigid-flexible coupling supporting structure under bidirectional impact loading
1
作者 YANG Rong-zhou XU Ying +2 位作者 ZHANG Quan HE Man-chao YU Mei-lu 《Journal of Central South University》 2026年第1期224-256,共33页
Aiming at the problem of dynamic instability of hard-brittle jointed rock surrounding in deep tunnel/roadway engineering,combining with the support concepts of"coupling rigidity with flexibility"and"ove... Aiming at the problem of dynamic instability of hard-brittle jointed rock surrounding in deep tunnel/roadway engineering,combining with the support concepts of"coupling rigidity with flexibility"and"overcoming rigidity by flexibility",the prevention and control method with"rigid-flexible coupling(R-F-C)"was put forward.Through numerical simulation calculation,the impact damage process,acoustic emission(AE)evolution characteristics,and element stress/displacement evolution characteristics of unsupported surrounding rock structure model,rigid supporting surrounding rock structure model,and"R-F-C"supporting surrounding rock structure model under horizontal bidirectional impact loading were compared and analyzed.Based on the theory of stress wave propagation,the dynamic instability catastrophe mechanism of three kinds of supporting structure models induced by horizontal bidirectional impact loading was revealed.Based on the Mohr-Coulomb strength theory,the stress discrimination methods of dynamic catastrophe of surrounding rock induced by horizontal bidirectional impact loading under three kinds of supporting structures were proposed.Combined with the above numerical simulation study,the explosion impact physical and mechanical test of"R-F-C"surrounding rock supporting plate structure was further designed and carried out.Finally,combined with the"conceptual model of ball-cliff potential energy instability",the energy driving theory and energy transformation mechanism of impact-induced rockburst under three kinds of supporting structures were discussed deeply.The research results provided a scientific basis for further promoting the effective application of"R-F-C"supporting structure in the prevention and control of dynamic instability of deep tunnel/roadway surrounding rock. 展开更多
关键词 jointed surrounding rock rigid-flexible coupling(R-F-C)supporting structure stress wave propagation acoustic emission(AE) damage evolution impact instability catastrophe mechanism
在线阅读 下载PDF
Mediating Effect of Medical Coping Styles in Patients with Chronic Pain between Pain Degree and Pain Catastrophe
2
作者 Hui Qiang Yan Hua 《Journal of Clinical and Nursing Research》 2025年第11期409-419,共11页
Objective:To explore the relationship between pain degree and pain catastrophe and medical coping mode in patients with chronic pain.Methods:A visual analogue score scale,medical coping style questionnaire and pain ca... Objective:To explore the relationship between pain degree and pain catastrophe and medical coping mode in patients with chronic pain.Methods:A visual analogue score scale,medical coping style questionnaire and pain catastrophe scale were used to survey 200 patients in the pain department.Results:The average scores of pain degree of patients with chronic pain were(5.97±2.29),the average score of the total score of the Pain Catastrophe Scale was(21.21±11.56),and the average scores of facing,avoidance and surrender in the Medical Response Style Questionnaire were(17.93±3.4),(16.82±2.4),and(8.87±2.83),respectively.Pain degree was positively correlated with the yield dimension in pain catastrophe and medical coping(p<0.05).The yield dimension of medical coping was positively correlated with pain catastrophe(p<0.05).Medical coping methods played a partial mediating role between pain degree and pain catastrophe,and the mediating effect accounted for 21.59%of the total effect.Conclusion:The pain level of chronic pain patients can affect the level of pain catastrophe through medical coping,and clinical medical staff should guide patients to adopt positive coping methods to promote their healthy recovery. 展开更多
关键词 Chronic pain Degree of pain Medical responses Catastrophic pain Mediating effects
暂未订购
Wood Gasification in Catastrophes: Electricity Production from Light-Duty Vehicles
3
作者 Baxter L.M.Williams Henri Croft +8 位作者 James Hunt Josh Viloria Nathan Sherman James Oliver Brody Green Alexey Turchin Juan B.Garcia Martinez Joshua M.Pearce David Denkenberger 《Energy Engineering》 2025年第4期1265-1285,共21页
Following global catastrophic infrastructure loss(GCIL),traditional electricity networks would be damaged and unavailable for energy supply,necessitating alternative solutions to sustain critical services.These altern... Following global catastrophic infrastructure loss(GCIL),traditional electricity networks would be damaged and unavailable for energy supply,necessitating alternative solutions to sustain critical services.These alternative solutions would need to run without damaged infrastructure and would likely need to be located at the point of use,such as decentralized electricity generation from wood gas.This study explores the feasibility of using modified light duty vehicles to self-sustain electricity generation by producing wood chips for wood gasification.A 2004 Ford Falcon Fairmont was modified to power a woodchipper and an electrical generator.The vehicle successfully produced wood chips suitable for gasification with an energy return on investment(EROI)of 3.7 and sustained a stable output of 20 kW electrical power.Scalability analyses suggest such solutions could provide electricity to the critical water sanitation sector,equivalent to 4%of global electricity demand,if production of woodchippers was increased postcatastrophe.Future research could investigate the long-term durability of modified vehicles and alternative electricity generation,and quantify the scalability of wood gasification in GCIL scenarios.This work provides a foundation for developing resilient,decentralized energy systems to ensure the continuity of critical services during catastrophic events,leveraging existing vehicle infrastructure to enhance disaster preparedness. 展开更多
关键词 Global catastrophic infrastructure loss decentralized energy systems wood gasification energy resilience
在线阅读 下载PDF
新滩滑坡成功预报四十周年
4
作者 张国栋 杨恩彬 +6 位作者 李铮 卢书强 黄海峰 易庆林 左清军 张亚鑫 段淑远 《工程地质学报》 北大核心 2026年第1期168-181,共14页
1985年6月12日凌晨3点45分左右发生了震惊中外的新滩滑坡,滑坡成功预报,无一人伤亡,被誉为世界滑坡预报史上的奇迹,对滑坡地质灾害防灾减灾具有重要意义。基于地质调查和监测成果,结合滑坡内外动力作用因素,分析了崩塌加载和降雨作用下... 1985年6月12日凌晨3点45分左右发生了震惊中外的新滩滑坡,滑坡成功预报,无一人伤亡,被誉为世界滑坡预报史上的奇迹,对滑坡地质灾害防灾减灾具有重要意义。基于地质调查和监测成果,结合滑坡内外动力作用因素,分析了崩塌加载和降雨作用下新滩滑坡的成灾过程和灾变力学机制,总结了新滩滑坡变形规律、临滑特征及成功预报的过程和经验,指出了目前滑坡预警预测预报研究存在的问题与不足,随着大数据和人工智能技术的快速发展,多技术协同监测及多源数据融合、数据驱动和机制驱动的滑坡预警预测预报研究成为重要的发展方向。针对崩塌加载型堆积体滑坡,应在早期判识和风险研判、高山峡谷区高速滑坡碎屑流的演化机制及防控等方面进一步研究。研究成果为崩塌堆积加载型滑坡防灾减灾能力提升提供参考。 展开更多
关键词 新滩滑坡 复活型滑坡 灾变机制 滑坡监测 滑坡预报
在线阅读 下载PDF
Landslide Prediction Based on Wavelet Analysis and Cusp Catastrophe 被引量:7
5
作者 李长冬 唐辉明 +2 位作者 胡新丽 李东明 胡斌 《Journal of Earth Science》 SCIE CAS CSCD 2009年第6期971-977,共7页
During the monitoring engineering of landslides, the monitoring data of accumulated displacement are usually affected by the external factors. Therefore, the displacement curve always has step-like character, which br... During the monitoring engineering of landslides, the monitoring data of accumulated displacement are usually affected by the external factors. Therefore, the displacement curve always has step-like character, which brings some difficulties to the accurate prediction of landslides. In order to solve this problem, based on the wavelet analysis and cusp catastrophe, a new kind of analysis method is proposed in this article. First, Fourier transform method can be used to extract the frequency component of the curve of monitoring displacement. Second, the wavelet transform was adopted to inspect the breakpoints of signals, which can be used to analyze the cause of the occurrence of the step-like character in the curve of landslide monitoring. Based on the cusp catastrophe theory, a nonlinear dynamic model was established to conduct the simulation calculation of time forecasting of landslides. According to a case study of landslide, the periodical rainfall and reservoir level fluctuation are the main factors leading to the step-like changes in the curve of monitoring displacement. In addition, the results of simulation calculation are in agreement with the fact of local failure of landslides. This method can provide a new analysis way for the time prediction of landslides. 展开更多
关键词 LANDSLIDE PREDICTION step-like curve wavelet analysis cusp catastrophe.
原文传递
Mitotic Catastrophe的研究进展 被引量:2
6
作者 张博 周平坤 《细胞生物学杂志》 CSCD 2007年第6期849-852,共4页
细胞死亡是多细胞生物生命过程中重要的生理或病理现象,可分为坏死和程序性细胞死亡,而后者根据死亡细胞的形态学和发生机制的不同又可分为凋亡、自吞噬和mitotic catastrophe,其中mitotic catastrophe是近年来才被揭示报道,是指细胞在... 细胞死亡是多细胞生物生命过程中重要的生理或病理现象,可分为坏死和程序性细胞死亡,而后者根据死亡细胞的形态学和发生机制的不同又可分为凋亡、自吞噬和mitotic catastrophe,其中mitotic catastrophe是近年来才被揭示报道,是指细胞在有丝分裂过程中死亡的现象,是一种发生在细胞有丝分裂期由于异常的细胞分裂而导致的细胞死亡,它常常伴随着细胞有丝分裂检查点的异常和基因或纺锤体结构的损伤而发生。现对mitotic catastrophe及相关的调控机制进行综述。 展开更多
关键词 MITOTIC catastrophe DNA损伤 细胞周期检查点 纺锤体
在线阅读 下载PDF
CUSP CATASTROPHE MODEL OF INSTABILITY OF PILLAR IN ASYMMETRIC MINING 被引量:19
7
作者 李江腾 曹平 《应用数学和力学》 EI CSCD 北大核心 2005年第8期1003-1008,共6页
关键词 矿柱 稳定性 势能 尖点突变 非对称开采
在线阅读 下载PDF
白龙江流域溃决型泥石流灾变过程
8
作者 张宁 常鸣 +3 位作者 李宏杰 周康驰 尹道龙 刘洋 《水土保持通报》 北大核心 2026年第1期403-413,424,共12页
[目的]揭示白龙江流域溃决型泥石流的演化机理,阐明其灾变过程,为溃决型泥石流预警和防治提供技术支撑。[方法]以甘肃省陇南市汉王镇甘家沟为研究区,通过室内遥感解译与野外实地考察,获取物源、地形与降雨特征,结合区域地质构造、地震... [目的]揭示白龙江流域溃决型泥石流的演化机理,阐明其灾变过程,为溃决型泥石流预警和防治提供技术支撑。[方法]以甘肃省陇南市汉王镇甘家沟为研究区,通过室内遥感解译与野外实地考察,获取物源、地形与降雨特征,结合区域地质构造、地震活动等成灾条件,系统分析溃决型泥石流的运动特征,并结合数值仿真平台OpenLISEM,对主沟、支沟及级联溃决3种溃决模式进行模拟与对比分析。[结果](1)甘家沟物源丰富,存在大量崩滑体,主要触发因素为暴雨,崩滑体堵塞沟道后极易形成溃决型泥石流。(2)溃决型泥石流演化过程可分为“崩滑体失稳—沟道堵塞—堰塞坝形成与溃决—流量放大致灾”4个阶段,其灾变过程是重力势能快速转化为动能与流体整体冲压力的耦合作用结果。(3)模拟结果显示,主沟溃决型泥石流冲出距离达1342.06 m,堆积面积1.38 km^(2),最大堆积厚度达21.64 m,轻微堵塞白龙江;支沟溃决型泥石流规模相对较小,堆积面积1.03 km^(2),最大堆积厚度15.37 m,未对白龙江造成堵塞;级联溃决型泥石流规模最大,冲出距离1365.64 m,堆积面积1.92 km^(2),最大堆积厚度28.2 m,严重堵塞白龙江并形成堰塞湖,有极大可能产生溃决洪水,对下游居民区构成严重威胁。[结论](1)甘家沟具备陡峻地形、物源丰富、降雨集中和地震频繁等不利条件,是溃决型泥石流高发区。(2)溃决型泥石流普遍经历堵塞—蓄水—溃决阶段,灾害破坏力显著高于一般暴雨型泥石流。(3)不同溃决模式在规模、堆积范围及危害程度上存在差异,其中级联溃决风险最大。 展开更多
关键词 级联溃决型泥石流 灾变机理 数值仿真 堰塞体 白龙江流域
在线阅读 下载PDF
基于尖点突变理论的岩溶山体稳定性分析
9
作者 赵瑞欣 蒲峻驰 +3 位作者 李滨 易连兴 张东 张秀钰 《重庆大学学报》 北大核心 2026年第1期94-105,共12页
为研究岩溶地区山体稳定性变化规律,考虑岩溶山体后缘管道、滑面管道劣化以及水对结构面的弱化作用,以岩溶山体平面滑动为例建立了岩溶管道未贯通与岩溶管道贯通2种地质模型及相应的力学模型。基于尖点突变理论,推导出岩溶管道流作用下... 为研究岩溶地区山体稳定性变化规律,考虑岩溶山体后缘管道、滑面管道劣化以及水对结构面的弱化作用,以岩溶山体平面滑动为例建立了岩溶管道未贯通与岩溶管道贯通2种地质模型及相应的力学模型。基于尖点突变理论,推导出岩溶管道流作用下岩溶山体稳定性系数(FOS)与岩溶山体临界稳定性系数(FOS^(*)),提出岩溶地区山体突变失稳的能量准则。结果表明,平衡点与临界失稳点的位移大小关系可表征山体是否失稳;岩溶管道未贯通时FOS、FOS^(*)的计算公式中比贯通时多1项关于刚度系数k的因子,即岩溶管道对山体稳定性有一定影响;岩溶山体稳定性系数与刚度系数k,管道劣化系数m有关,是影响山体稳定性的重要因素;通过鸡尾山滑坡实例研究证明,基于尖点突变理论的能量准则能更好地验证滑面结构复杂的岩溶山体稳定性,可对极限平衡法所得结果进行补充验证。 展开更多
关键词 岩土工程 山体稳定性 尖点突变理论 岩溶管道 水锤作用力 能量准则
在线阅读 下载PDF
Avoidance method for medium-to-long-range air-to-air missile based on the kan-λ-ppo algorithm
10
作者 Shijie Deng Yingxin Kou +4 位作者 You Li An Xu Bincheng Wen Juntao Zhang Ling Ma 《Defence Technology(防务技术)》 2026年第2期352-366,共15页
This study addresses the maneuver evasion problem for medium-to-long-range air-to-air missiles by proposing a KAN-λ-PPO-based evasion algorithm.The algorithm introduces Kolmogorov-Arnold Networks(KAN)to mitigate the ... This study addresses the maneuver evasion problem for medium-to-long-range air-to-air missiles by proposing a KAN-λ-PPO-based evasion algorithm.The algorithm introduces Kolmogorov-Arnold Networks(KAN)to mitigate the catastrophic forgetting issue of Multilayer Perceptrons(MLP)in continual learning,while incorporatingλ-return to resolve sparse reward challenges in evasion scenarios.First,we model the evasion problem withλ-return and present the KAN-λ-PPO algorithm.Subsequently,we establish game environments based on the segmented ballistic characteristics of medium and long range missiles.During training,a joint reward function is designed by combining the miss distance and positional advantages to train the agent.Experiments evaluate four dimensions:(1)Performance comparison between KAN and MLP in value function approximation;(2)Catastrophic forgetting mitigation of KAN-λ-PPO in dual-task scenarios;(3)Continual learning capabilities across multiple evasion scenarios;(4)Quantitative analysis of agent strategy evolution and positional advantages.Empirical results demonstrate that KAN improves value function approximation accuracy by an order of magnitude compared with traditional MLP architectures.In continual learning tasks,the KAN-λ-PPO scheme exhibits significant knowledge retention,achieving performance improvements of 32.7% and 8.6%over MLP baselines in Task1→2 and Task2→3 transitions,respectively.Furthermore,the learned maneuver strategies outperform High-G Barrel Rolls(HGB)and S-maneuver tactics in securing positional advantages while accomplishing evasion. 展开更多
关键词 Missile evasion Kolmogorov-Arnold networks Catastrophic forgetting λ-return PPO
在线阅读 下载PDF
Neuro-Symbolic Graph Learning for Causal Inference and Continual Learning in Mental-Health Risk Assessment
11
作者 Monalisa Jena Noman Khan +1 位作者 Mi Young Lee Seungmin Rho 《Computer Modeling in Engineering & Sciences》 2026年第1期1311-1338,共28页
Mental-health risk detection seeks early signs of distress from social media posts and clinical transcripts to enable timely intervention before crises.When such risks go undetected,consequences can escalate to self-h... Mental-health risk detection seeks early signs of distress from social media posts and clinical transcripts to enable timely intervention before crises.When such risks go undetected,consequences can escalate to self-harm,long-term disability,reduced productivity,and significant societal and economic burden.Despite recent advances,detecting risk from online text remains challenging due to heterogeneous language,evolving semantics,and the sequential emergence of new datasets.Effective solutions must encode clinically meaningful cues,reason about causal relations,and adapt to new domains without forgetting prior knowledge.To address these challenges,this paper presents a Continual Neuro-Symbolic Graph Learning(CNSGL)framework that unifies symbolic reasoning,causal inference,and continual learning within a single architecture.Each post is represented as a symbolic graph linking clinically relevant tags to textual content,enriched with causal edges derived from directional Point-wise Mutual Information(PMI).A two-layer Graph Convolutional Network(GCN)encodes these graphs,and a Transformer-based attention pooler aggregates node embeddings while providing interpretable tag-level importances.Continual adaptation across datasets is achieved through the Multi-Head Freeze(MH-Freeze)strategy,which freezes a shared encoder and incrementally trains lightweight task-specific heads(small classifiers attached to the shared embedding).Experimental evaluations across six diverse mental-health datasets ranging from Reddit discourse to clinical interviews,demonstrate that MH-Freeze consistently outperforms existing continual-learning baselines in both discriminative accuracy and calibration reliability.Across six datasets,MH-Freeze achieves up to 0.925 accuracy and 0.923 F1-Score,with AUPRC≥0.934 and AUROC≥0.942,consistently surpassing all continual-learning baselines.The results confirm the framework’s ability to preserve prior knowledge,adapt to domain shifts,and maintain causal interpretability,establishing CNSGL as a promising step toward robust,explainable,and lifelong mental-health risk assessment. 展开更多
关键词 Catastrophic forgetting causal inference continual learning deep learning graph convolutional network mental health monitoring transformer
在线阅读 下载PDF
Support Vector-Guided Class-Incremental Learning:Discriminative Replay with Dual-Alignment Distillation
12
作者 Moyi Zhang Yixin Wang Yu Cheng 《Computers, Materials & Continua》 2026年第3期2040-2061,共22页
Modern intelligent systems,such as autonomous vehicles and face recognition,must continuously adapt to new scenarios while preserving their ability to handle previously encountered situations.However,when neural netwo... Modern intelligent systems,such as autonomous vehicles and face recognition,must continuously adapt to new scenarios while preserving their ability to handle previously encountered situations.However,when neural networks learn new classes sequentially,they suffer from catastrophic forgetting—the tendency to lose knowledge of earlier classes.This challenge,which lies at the core of class-incremental learning,severely limits the deployment of continual learning systems in real-world applications with streaming data.Existing approaches,including rehearsalbased methods and knowledge distillation techniques,have attempted to address this issue but often struggle to effectively preserve decision boundaries and discriminative features under limited memory constraints.To overcome these limitations,we propose a support vector-guided framework for class-incremental learning.The framework integrates an enhanced feature extractor with a Support Vector Machine classifier,which generates boundary-critical support vectors to guide both replay and distillation.Building on this architecture,we design a joint feature retention strategy that combines boundary proximity with feature diversity,and a Support Vector Distillation Loss that enforces dual alignment in decision and semantic spaces.In addition,triple attention modules are incorporated into the feature extractor to enhance representation power.Extensive experiments on CIFAR-100 and Tiny-ImageNet demonstrate effective improvements.On CIFAR-100 and Tiny-ImageNet with 5 tasks,our method achieves 71.68%and 58.61%average accuracy,outperforming strong baselines by 3.34%and 2.05%.These advantages are consistently observed across different task splits,highlighting the robustness and generalization of the proposed approach.Beyond benchmark evaluations,the framework also shows potential in few-shot and resource-constrained applications such as edge computing and mobile robotics. 展开更多
关键词 Class-incremental learning catastrophic forgetting support vector machine knowledge distillation
在线阅读 下载PDF
Influenceof native pores on the size distribution and predictability of rock failure
13
作者 Lichang Wang Qi Hao +4 位作者 Yuchen Zhong Xiling Liu Qin Xie Xiaoran Tian Feifei Qin 《Journal of Rock Mechanics and Geotechnical Engineering》 2026年第2期1447-1459,共13页
This study examines how native pore structures and loading conditions influencethe fracture size distribution and the predictability of catastrophic failure in rocks.Four lithologies with distinct pore characteristics... This study examines how native pore structures and loading conditions influencethe fracture size distribution and the predictability of catastrophic failure in rocks.Four lithologies with distinct pore characteristics,i.e.granite,limestone,red sandstone,and marble,were tested under uniaxial compression and Brazilian splitting.Nuclear magnetic resonance(NMR)was used to characterize pore structures,while acoustic emission(AE)monitoring captured the temporal evolution of microcracking.The relationships among pore properties,AE b-values,and failure predictability were systematically evaluated.Results show that the overall b-value is primarily controlled by native pore size rather than loading condition.Rocks with larger pores display higher b-value and greater temporal variability,whereas those with smaller pores exhibit lower and more stable b-value.To assess failure predictability,the AE count rate was incorporated into an inverse power law model.The model demonstrates higher predictive accuracy for high-porosity rocks.The average predicted failure time(t_(p))decreases monotonically with porosity:under uniaxial compression,t_(p)for granite,marble,limestone,and sandstone are 2.32,1.82,1.42,and 0.03,respectively;under Brazilian splitting,3.54,3.30,0.10,and 0.03.Among the four rock types,sandstone with the highest porosity exhibits the smallest discrepancy between predicted and actual failure time,whereas granite with the lowest porosity shows the largest.As porosity decreases,prediction accuracy progressively declines for limestone and marble.Overall,the findings indicate that native pore heterogeneity governs both fracture scaling behavior and failure predictability,and that these effects are largely independent of the loading conditions examined in this study. 展开更多
关键词 Rock deformation test Acoustic emission(AE) B-VALUE Inverse power law model Predictability of catastrophic failure
在线阅读 下载PDF
克服人工神经网络灾难性遗忘的连续学习算法研究
14
作者 于达 董晓飞 +2 位作者 曹峰 查富生 孙立宁 《信息通信技术与政策》 2026年第1期75-83,共9页
传统的人工神经网络训练通常聚焦于封闭、静态的独立同分布数据,并在完成离线训练后执行单一任务。然而,当数据分布随环境不断变化时,模型会忘记在先前任务中学到的知识,即发生“灾难性遗忘”。连续学习作为一个新的学习范式,旨在赋予... 传统的人工神经网络训练通常聚焦于封闭、静态的独立同分布数据,并在完成离线训练后执行单一任务。然而,当数据分布随环境不断变化时,模型会忘记在先前任务中学到的知识,即发生“灾难性遗忘”。连续学习作为一个新的学习范式,旨在赋予模型从分布不断变化的数据流中持续学习、累计和巩固知识的能力,使得人工神经网络达到“稳定性-可塑性”平衡,进而克服灾难性遗忘。通过深入分析当前连续学习算法的主要特点,搭建真实机器人实物验证平台,在机器人实物抓取场景下验证连续学习算法的有效性。试验结果表明,将对比相关性保留回放算法应用到机器人实物抓取任务,抓取任务的平均准确率提高26.67%,能更好地帮助机器人执行目标任务。 展开更多
关键词 人工智能 人工神经网络 连续学习 灾难性遗忘
在线阅读 下载PDF
早期肺癌术后患者负性信息注意偏向在内感受性与疼痛灾难化间的中介作用
15
作者 边冠军 魏诗瑜 +2 位作者 王颖 常青 张春梅 《护理学杂志》 北大核心 2026年第4期91-94,100,共5页
目的 探讨早期肺癌术后患者负性信息注意偏向在内感受性与疼痛灾难化间的中介作用,为术后实施精准心理干预提供依据。方法 采用方便抽样法,于2025年6-8月选取268例早期肺癌术后3个月内门诊复查及日间病房患者为研究对象。使用一般资料... 目的 探讨早期肺癌术后患者负性信息注意偏向在内感受性与疼痛灾难化间的中介作用,为术后实施精准心理干预提供依据。方法 采用方便抽样法,于2025年6-8月选取268例早期肺癌术后3个月内门诊复查及日间病房患者为研究对象。使用一般资料调查表、中文版疼痛灾难化量表、多维内感受意识评估问卷第2版、中文版负性信息注意量表对患者进行调查,构建并检验中介模型。结果 早期肺癌术后患者疼痛灾难化得分为(32.99±5.05)分,内感受性得分为(112.98±14.64)分,负性信息注意偏向得分为(30.04±7.22)分。早期肺癌术后患者疼痛灾难化与内感受性和负性信息注意偏向呈正相关,内感受性和负性信息注意偏向呈正相关(均P<0.05)。负性信息注意偏向在内感受性与疼痛灾难化间起部分中介作用,中介效应占总效应的18.87%。结论 早期肺癌术后患者疼痛灾难化处于中等偏高水平。临床实践中应重视该人群的心理认知状态,尤其需警惕高内感受性与负性注意偏向协同作用对疼痛灾难化的潜在放大效应。医护人员可采取“注意调控+认知重构”双靶点干预策略,以降低疼痛灾难化风险,预防慢性术后疼痛综合征。 展开更多
关键词 肺癌 疼痛灾难化 负性信息注意偏向 内感受性 认知-情感加工 中介效应 肿瘤护理
暂未订购
洞庭湖流域水库调控对1954年特大洪水的防洪效果评估
16
作者 钟家淦 谷黄河 +2 位作者 戴明龙 陈玺 余之光 《水力发电学报》 北大核心 2026年第1期31-43,共13页
为评估洞庭湖流域四水水系现状水利工程体系对历史极端洪水的调控能力,本研究构建了耦合水库调度模块的VIC-WUR分布式水文模型,模拟并对比了1954年全流域特大洪水在有、无水库调控两种情景下的洪水过程。结果表明:四水水系水库群对洪水... 为评估洞庭湖流域四水水系现状水利工程体系对历史极端洪水的调控能力,本研究构建了耦合水库调度模块的VIC-WUR分布式水文模型,模拟并对比了1954年全流域特大洪水在有、无水库调控两种情景下的洪水过程。结果表明:四水水系水库群对洪水过程削峰作用显著,削峰率最高达62.5%(澧水皂市水库),洪峰滞后时间最长达177小时;调控效果空间分异显著,受库容规模、地理位置及协同调度共同控制,澧水皂市与江垭水库联动使其平均削峰率提升至56.6%。本研究定量揭示了水库群对极端洪水的时空调控规律,可为长江中游洪水风险管理与水库群协同调度决策提供关键科学依据。 展开更多
关键词 水库调控 防洪效果 VIC-WUR模型 1954年特大洪水 洞庭湖四水水系
在线阅读 下载PDF
极端洪水下北江芦苞浅段江心洲演变特征分析
17
作者 朱政涛 王慧琳 +4 位作者 黄东 刘画眉 陈鑫池 余铖峥 江青蓉 《人民珠江》 2026年第1期42-52,共11页
2022年6月北江流域遭遇百年一遇特大洪水,对下游江心洲的形态与植被覆盖产生了显著影响。研究基于2022年多时相哨兵2号遥感影像及实测河道地形数据,结合归一化差分水体指数(Normalized Difference Water Index,NDWI)和归一化差分植被指... 2022年6月北江流域遭遇百年一遇特大洪水,对下游江心洲的形态与植被覆盖产生了显著影响。研究基于2022年多时相哨兵2号遥感影像及实测河道地形数据,结合归一化差分水体指数(Normalized Difference Water Index,NDWI)和归一化差分植被指数(Normalized Difference Vegetation Index,NDVI),分析了北江下游芦苞浅段5个江心洲的平面形态、断面地形、NDVI均值及植被覆盖的年内演变特征。结果表明:洪水期间各江心洲面积与周长均显著减小,其中未建土堤的中间洲、芦苞洲和太监洲面积减少幅度更大,分别达55.4%、69.0%和66.4%。河道断面地形显示洪水后主河槽以轻微淤积为主,江心洲高程未发生显著变化。建堤江心洲(邓塘洲、四姓洲)堤内植被受洪水影响较小,NDVI均值在洪水后仍保持较高水平,而江心洲堤外及未建堤江心洲植被面积普遍减少32.5%~74.4%。研究分析了特大洪水对北江下游芦苞浅段江心洲形态及植被覆盖的差异化影响,为区域河道治理与生态修复提供了科学依据。 展开更多
关键词 “22·6”特大洪水 遥感 NDWI NDVI 江心洲形态 植被覆盖 北江
在线阅读 下载PDF
高山峡谷区滑坡涌浪作用下库坝工程灾变响应研究进展
18
作者 吴昊 方建鹏 +2 位作者 高杨 郭雨秋 张亦尧 《中国地质灾害与防治学报》 2026年第1期18-27,共10页
我国西南高山峡谷区地质条件复杂、构造活动强烈且山地灾害活跃,滑坡地质灾害防治成为这一区域高坝大库工程安全与防灾减灾领域十分重要的研究课题。文章全面梳理了库区滑坡涌浪动力过程、滑坡-涌浪-溃坝灾害多物理场耦合分析方法、滑... 我国西南高山峡谷区地质条件复杂、构造活动强烈且山地灾害活跃,滑坡地质灾害防治成为这一区域高坝大库工程安全与防灾减灾领域十分重要的研究课题。文章全面梳理了库区滑坡涌浪动力过程、滑坡-涌浪-溃坝灾害多物理场耦合分析方法、滑坡涌浪作用下库坝工程灾变响应规律及巨灾形成条件等方面的研究进展,发现当前研究对高山峡谷区滑坡涌浪链式灾害演化过程及其对库坝工程的作用机制的认识不足。基于当前研究存在的局限性,凝炼未来研究应重点关注的3个问题:(1)建立考虑土–水界面质能传递的库区滑坡涌浪动力过程模型;(2)发展面向滑坡–涌浪–溃坝全过程的高效多物理场数值计算框架;(3)构建基于能量与强度双控制的库坝工程巨灾判据与风险评估体系。研究成果能弥补库区滑坡源特征与坝体灾变之间定量表征的空白,为高山峡谷区重大水电工程长期安全运行与流域防灾减灾提供理论支撑与技术保障。 展开更多
关键词 灾害链生机理 地质灾害 库区滑坡 库坝工程 灾变临界条件
在线阅读 下载PDF
超材料领域的持续学习:动态数据生成与模型性能评估
19
作者 陈祺东 徐国梁 +1 位作者 邓瑞翔 吴豪 《电子测量技术》 北大核心 2026年第2期89-98,共10页
数据集规模是影响深度学习模型性能的关键因素之一。由于深度学习模型性能高度依赖于数据集规模,实现特定精度所需的数据量通常难以预估。该问题在超材料智能设计中同样存在,成为制约建模精度和效率的重要因素。为此,提出一种动态数据... 数据集规模是影响深度学习模型性能的关键因素之一。由于深度学习模型性能高度依赖于数据集规模,实现特定精度所需的数据量通常难以预估。该问题在超材料智能设计中同样存在,成为制约建模精度和效率的重要因素。为此,提出一种动态数据生成与模型性能评估框架,以实现数据集规模与模型性能的动态监控。为提升模型动态评估效率并有效缓解灾难性遗忘现象,设计了一种持续学习策略,使模型在动态评估过程中仅需针对新数据进行学习,同时保持对已有知识的记忆。实验结果表明,基于该持续学习策略训练的模型预测平均准确率可达到93.28%,平均遗忘率为3.68%,充分验证了该模型在缓解灾难性遗忘问题方面的有效性。 展开更多
关键词 微波吸收超材料 数据生成 数据集规模 灾难性遗忘
原文传递
1990—2023年黄河三角洲生态系统韧性演变特征及其突变机制
20
作者 管青春 周旭 +1 位作者 刘黎明 任国平 《生态学报》 北大核心 2026年第2期721-741,共21页
在全球气候变化和人类活动的双重影响下,河口海岸生态系统韧性呈现出高脆弱性和复杂性,易发生转折性突变。早期预警信号和突变驱动机制研究对于提升河口海岸区域韧性及保障生态安全具有重要意义。以黄河三角洲为研究对象,基于生态系统... 在全球气候变化和人类活动的双重影响下,河口海岸生态系统韧性呈现出高脆弱性和复杂性,易发生转折性突变。早期预警信号和突变驱动机制研究对于提升河口海岸区域韧性及保障生态安全具有重要意义。以黄河三角洲为研究对象,基于生态系统服务和突变级数理论构建韧性评估体系,分析1990—2023年黄河三角洲生态系统韧性的时空演变特征,并结合Mann-Kendall突变检验和滑动t突变检验方法识别韧性突变预警信号,在此基础上,采用非线性回归方法探究韧性转变影响因素与突变驱动机制。研究发现:(1)黄河三角洲生态系统韧性在2008—2017年间发生了“V型”突变现象,其韧性能力在2011年降到最低,而后逐渐恢复并在2017年到达到新稳态;这种韧性突变可能通过“韧性持续小幅下降”阶段进行早期预警;(2)空间上,黄河三角洲韧性突变易发区主要位于东北部油田、港口及中部居民点,其次为北部和东南部的养殖池、盐田及中西部的农业用地,而沿海滩涂湿地及中北部、中东部的林草带韧性能力较高;(3)黄河三角洲生态韧性突变受人类活动与自然变化的共同驱动。耕地扩张和农渔业开发虽促进经济增长,但造成资源超载与污染加剧等压力,叠加林地、草地和滩涂湿地的不合理开发导致的生境退化问题,最终使韧性突破临界阈值。研究结果可为黄河三角洲及河口海岸区域生态系统韧性能力的提升和突变风险管理提供重要理论依据。 展开更多
关键词 黄河三角洲 生态系统服务 韧性评价 生态系统突变 早期预警信号
在线阅读 下载PDF
上一页 1 2 212 下一页 到第
使用帮助 返回顶部