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All-optical control of exciton flow in a colloidal quantum well complex
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作者 Junhong Yu Manoj Sharma +3 位作者 Ashma Sharma Savas Delikanli Hilmi Volkan Demir Cuong Dang 《Light: Science & Applications》 SCIE EI CAS CSCD 2020年第1期1749-1756,共8页
Excitonics,an alternative to romising for processing information since semiconductor electronics is rapidly approaching the end of Moore’s law.Currently,the development of excitonic devices,where exciton flow is cont... Excitonics,an alternative to romising for processing information since semiconductor electronics is rapidly approaching the end of Moore’s law.Currently,the development of excitonic devices,where exciton flow is controlled,is mainly focused on electric-field modulation or exciton polaritons in high-Q cavities.Here,we show an alloptical strategy to manipulate the exciton flow in a binary colloidal quantum well complex through mediation of the Förster resonance energy transfer(FRET)by stimulated emission.In the spontaneous emission regime,FRET naturally occurs between a donor and an acceptor.In contrast,upon stronger excitation,the ultrafast consumption of excitons by stimulated emission effectively engineers the excitonic flow from the donors to the acceptors.Specifically,the acceptors’stimulated emission significantly accelerates the exciton flow,while the donors’stimulated emission almost stops this process.On this basis,a FRET-coupled rate equation model is derived to understand the controllable exciton flow using the density of the excited donors and the unexcited acceptors.The results will provide an effective alloptical route for realizing excitonic devices under room temperature operation. 展开更多
关键词 process FLOW QUANTUM
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基于图对比学习的再入院预测模型
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作者 姜超英 李倩 +2 位作者 刘宁 刘磊 崔立真 《计算机应用》 北大核心 2025年第6期1784-1792,共9页
针对疾病间的共同作用与再入院情况的关系的挖掘不足以及相关模型泛化能力较弱的问题,提出一种基于图对比学习的再入院预测模型HealthGraph。首先,利用数据集中的疾病共现信息构建疾病编码图,以充分挖掘疾病之间的关联信息;其次,提出一... 针对疾病间的共同作用与再入院情况的关系的挖掘不足以及相关模型泛化能力较弱的问题,提出一种基于图对比学习的再入院预测模型HealthGraph。首先,利用数据集中的疾病共现信息构建疾病编码图,以充分挖掘疾病之间的关联信息;其次,提出一种以图对比学习的思想为指导的患者数据增强方法,通过图采样器自适应地捕捉与任务相关的拓扑结构,构造新视图,提升数据丰富度,从而提高模型的泛化性能;最后,结合初始疾病编码图嵌入和新视图嵌入进行再入院预测。在真实数据集MIMIC-Ⅲ上构建呼吸系统疾病和循环系统疾病这2个数据集并进行大量实验。结果表明,相较于反转时间注意力模型(RETAIN)和阶段感知神经网络模型(StageNet),所提模型在准确率和F1指标上提升了1个百分点左右。此外,2组消融实验结果验证了所提模型在提高再入院预测的准确性和泛化性中的有效性。 展开更多
关键词 电子健康记录 再入院预测 图对比学习 数据增强 图神经网络
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解释纠偏框架:一种基于标准解释的归因分数生成方法
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作者 邢钟毓 梁嘉旋 +3 位作者 余国先 王峻 郭茂祖 崔立真 《计算机学报》 北大核心 2025年第4期949-970,共22页
模型可解释性研究面临一个关键挑战:对于同一数据集,不同模型尽管能达到相似的预测性能,但受训练过程中随机因素等变量影响,其输入特征的重要性评分(归因分数解释)存在显著不一致,这降低了解释的可信度。针对此问题,本文首先从理论上探... 模型可解释性研究面临一个关键挑战:对于同一数据集,不同模型尽管能达到相似的预测性能,但受训练过程中随机因素等变量影响,其输入特征的重要性评分(归因分数解释)存在显著不一致,这降低了解释的可信度。针对此问题,本文首先从理论上探讨了解释不一致与模型不确定性因素之间的联系,证明了归因解释中的SHAP(SHapley Additive exPlanation)方法在相似预测模型中的不确定性上界。在此基础上,我们通过实验深入研究了模型集合中模型训练随机因素等变量对特征归因方法的影响,发现模型不确定导致的解释不确定性普遍存在,而SHAP方法由于其上界的影响不确定性较低。据此,我们提出了一种基于不同模型的标准解释生成稳定归因分数解释的纠偏框架ASGM(Attribution Score Generation Method),以减少归因分数解释的不一致,提升模型解释的稳定性和可信度。该框架通过检测少量抽样模型解释与大量模型生成标准解释之间的差异,利用校正偏差的深度学习模型,生成代表规格不足集或罗生门效应集的归因分数解释,并能预测规格不足集解释间的不确定性。实验结果表明,ASGM可以生成受模型(尤其是随机因素)影响较小的解释,生成解释的质量高于对模型集合解释排名的均值,接近标准解释。此外,与标准解释相比,ASGM在罗生门效应集上的计算时间减少了20%~30%,在规格不足集上减少了17%~48%,这些结果验证了ASGM可有效提升解释稳定性和可信度。 展开更多
关键词 模型不确定性 可解释人工智能 规格不足集 罗生门效应集 SHAP方法
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土壤重金属污染的环境影响评价与管理策略研究 被引量:1
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作者 何小霞 《皮革制作与环保科技》 2025年第18期173-175,共3页
环境影响评价工作的落实可以为土壤重金属污染治理提供更多的信息参考和数据支持,是保障土壤重金属污染治理科学性、规范性和有效性的重要基础。本文主要从土壤重金属污染环境影响评价流程出发分析环境影响评价的要点及管理策略,希望通... 环境影响评价工作的落实可以为土壤重金属污染治理提供更多的信息参考和数据支持,是保障土壤重金属污染治理科学性、规范性和有效性的重要基础。本文主要从土壤重金属污染环境影响评价流程出发分析环境影响评价的要点及管理策略,希望通过本文的探讨和分析可以为相关工作人员提供参考与借鉴,以提高环境影响评价的质量和水平,有效解决土壤重金属污染问题。 展开更多
关键词 土壤重金属污染 环境影响评价 管理策略 环境保护
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土壤污染防治及修复策略思考 被引量:1
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作者 朱麟 《皮革制作与环保科技》 2025年第2期193-195,共3页
随着经济的发展,人们越来越关注环境保护,尤其是土壤污染的防治与修复工作,更是成为社会关注的焦点。本文主要从土壤污染防治和土壤污染修复两个方面进行论述,以期为相关单位提供参考与借鉴,从而提高土壤污染防治与修复的效果,更好地维... 随着经济的发展,人们越来越关注环境保护,尤其是土壤污染的防治与修复工作,更是成为社会关注的焦点。本文主要从土壤污染防治和土壤污染修复两个方面进行论述,以期为相关单位提供参考与借鉴,从而提高土壤污染防治与修复的效果,更好地维护生态平衡,降低土壤对人体健康的危害。 展开更多
关键词 土壤污染 防治 修复 环境保护
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V–Ti‑Based Solid Solution Alloys for Solid‑State Hydrogen Storage 被引量:2
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作者 Shaoyang Shen Yongan Li +3 位作者 Liuzhang Ouyang Lan Zhang Min Zhu Zongwen Liu 《Nano-Micro Letters》 2025年第7期453-482,共30页
This review details the advancement in the development of V–Ti-based hydrogen storage materials for using in metal hydride(MH)tanks to supply hydrogen to fuel cells at relatively ambient temperatures and pressures.V... This review details the advancement in the development of V–Ti-based hydrogen storage materials for using in metal hydride(MH)tanks to supply hydrogen to fuel cells at relatively ambient temperatures and pressures.V–Tibased solid solution alloys are excellent hydrogen storage materials among many metal hydrides due to their high reversible hydrogen storage capacity which is over 2 wt%at ambient temperature.The preparation methods,structure characteristics,improvement methods of hydrogen storage performance,and attenuation mechanism are systematically summarized and discussed.The relationships between hydrogen storage properties and alloy compositions as well as phase structures are discussed emphatically.For large-scale applications on MH tanks,it is necessary to develop low-cost and high-performance V–Ti-based solid solution alloys with high reversible hydrogen storage capacity,good cyclic durability,and excellent activation performance. 展开更多
关键词 Hydrogen storage V-Ti-based solid solution alloys Metal hydride tank Hydrogen storage properties Cyclic stability
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生态环境治理背景下关于大气污染防治管理策略的思考
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作者 孙丽丽 《皮革制作与环保科技》 2025年第7期119-120,144,共3页
加强大气污染防治管理、优化管理措施是实现可持续发展的重要基础。本文也将目光集中于大气污染防治管理,主要从大气污染的来源、危害以及生态环境治理背景下的大气污染防治管理策略三个方面展开论述。希望本文的探讨和分析,可以为相关... 加强大气污染防治管理、优化管理措施是实现可持续发展的重要基础。本文也将目光集中于大气污染防治管理,主要从大气污染的来源、危害以及生态环境治理背景下的大气污染防治管理策略三个方面展开论述。希望本文的探讨和分析,可以为相关单位提供更多的参考与借鉴,对大气污染防治管理策略做出有效的优化和调整,以提升大气污染防治管理能力和管理效果。 展开更多
关键词 大气污染防治管理 生态环境治理 可持续发展 环境保护
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Advanced bioprinting strategies for fabrication of biomimetic tissues and organs
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作者 Wei Long Ng Cian Vyas +2 位作者 Boyang Huang Wai Yee Yeong Paulo Bartolo 《International Journal of Extreme Manufacturing》 2025年第6期198-245,共48页
Bioprinting is a revolutionary technology within the field of tissue engineering that enables the precise fabrication of three-dimensional(3D)tissue constructs.It combines the principles of engineering and biology to ... Bioprinting is a revolutionary technology within the field of tissue engineering that enables the precise fabrication of three-dimensional(3D)tissue constructs.It combines the principles of engineering and biology to create structures that closely mimic the complexity of native human tissues,facilitating advancements in regenerative medicine and personalized healthcare.This review paper systematically explores the challenges and design requirements in the fabrication of 3D biomimetic tissue constructs,emphasizing the need for advanced bioprinting strategies.Achieving biomimicry involves creating 3D anatomically relevant structures,biomimetic microenvironments,and vascularization.The focus is on overcoming existing bottlenecks through advancements in both fabrication techniques and bio-inks.Future directions in bioprinting are outlined,including multi-modal bioprinting systems,in-situ bioprinting,and the integration of machine learning into bioprinting processes.The critical role of bio-inks and printing methodologies in influencing cell viability is highlighted,providing insights into strategies for enhancing cellular functionality throughout the bioprinting process.Furthermore,the paper addresses post-fabrication considerations,particularly in accelerating tissue maturation,as a pivotal component for advancing the clinical applicability of bioprinted tissues.By navigating through the challenges,innovations,and prospects of advanced bioprinting strategies,this review highlights the transformative impact on tissue engineering.Pushing the boundaries of technological capabilities,these strategies hold the promise of groundbreaking advancements in regenerative medicine and personalized healthcare.Ultimately,the integration of these advanced techniques into bioprinting processes will pave the way for the development of more highly biomimetic and functional bioprinted tissues. 展开更多
关键词 3D bioprinting BIOFABRICATION bio-inks machine learning multi-modal bioprinting tissue engineering
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An eigen-based theory for developing numerical methods for structural dynamics
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作者 Huang Chiu-Li Chang Shuenn-Yih Chang Karen 《Earthquake Engineering and Engineering Vibration》 2025年第2期333-356,共24页
The feasibility of using a problem-dependent method to solve systems of second order ODEs is corroborated by an eigen-based theory and a methodology to develop such a numerical method is constructed.The key steps of t... The feasibility of using a problem-dependent method to solve systems of second order ODEs is corroborated by an eigen-based theory and a methodology to develop such a numerical method is constructed.The key steps of this methodology are to decouple a system of ODEs of second order into a set of uncoupled ODEs of second order;next,an eigen-dependent method is proposed to approximate the solution of each uncoupled ODE of second order.It is vital to transform all eigen-dependent methods to a problem-dependent method to bypass an Eigen analysis.The development of an eigen-dependent method plays a key role in this methodology so that slow eigenmodes can be accurately integrated while there is no instability or excessive amplitude growth in fast eigenmodes.This can explain why a problem-dependent method can simultaneously combine the explicitness of each step and A-stability.Consequently,huge computational efforts can be saved for solving nonlinear stiff problems.A new family of problem-dependent methods is developed in this work so that the feasibility of the proposed methodology can be affirmed.It has almost the same performance as that of the HHT-αmethod.However,it can save more than 99.5%of CPU demand in approximating a solution for a system of 1000 nonlinear second order ODEs. 展开更多
关键词 an eigen-based theory unconditional stability accuracy eigen-dependent method structure-dependent method nonlinear dynamics
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Unraveling the Morphological and Energetic Properties of 2PACz Self-Assembled Monolayers Fabricated With Upscaling Deposition Methods
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作者 Silvia Mariotti Ilhem Nadia Rabehi +13 位作者 Congyang Zhang Xiaomin Huo Jiahao Zhang Penghui Ji Tianhao Wu Tongtong Li Shuai Yuan Xiaomin Liu Ting Guo Chenfeng Ding Hengyuan Wang Annalisa Bruno Luis K.Ono Yabing Qi 《Energy & Environmental Materials》 2025年第2期291-304,共14页
Self-assembled monolayers(SAMs)are widely used as hole transport materials in inverted perovskite solar cells,offering low parasitic absorption and suitability for semitransparent and tandem solar cells.While SAMs hav... Self-assembled monolayers(SAMs)are widely used as hole transport materials in inverted perovskite solar cells,offering low parasitic absorption and suitability for semitransparent and tandem solar cells.While SAMs have shown to be promising in small-area devices(≤1 cm^(2)),their application in larger areas has been limited by a lack of knowledge regarding alternative deposition methods beyond the common spin-coating approach.Here,we compare spin-coating and upscalable methods such as thermal evaporation and spray-coating for[2-(9H-carbazol-9-yl)ethyl]phosphonic acid(2PACz),one of the most common carbazole-based SAMs.The impact of these deposition methods on the device performance is investigated,revealing that the spray-coating technique yields higher device performance.Furthermore,our work provides guidelines for the deposition of SAM materials for the fabrication of perovskite solar modules.In addition,we provide an extensive characterization of 2PACz films focusing on thermal evaporation and spray-coating methods,which allow for thicker 2PACz deposition.It is found that the optimal 2PACz deposition conditions corresponding to the highest device performances do not always correlate with the monolayer characteristics. 展开更多
关键词 2PACz EVAPORATION Perovskite solar cells Self-assembled monolayer Spray-coating
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Integrated seismo-geodetic observatory network for monitoring the Lembang Fault,West Java,Indonesia
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作者 Nuraini Rahma Hanifa Endra Gunawan +22 位作者 Dini Nurfiani Achmad Fakhrus Shomim Faiz Muttaqy Aang Gunawan Sutyawan Lina Handayani Deasy Arisa Rian Amukti Muhammad Hanif Yayat Sudrajat Dannie Hidayat Iwan Hermawan Agus Men Riyanto Eko Yulianto Adrin Tohari Qori'atu Zahro Atin Nur Aulia Juniator Tulius Sri Widiyantoro Rachmah Ida Cecep Pratama Ridwan Suhud Putri Natari Ratna Titi Anggono 《Earth and Planetary Physics》 2025年第5期1087-1097,共11页
The Lembang Fault is a major geological feature in West Java that borders the northern edge of Bandung(one of Indonesia’s largest cities).It lies just south of the active Tangkuban Perahu Volcano,exhibiting clear geo... The Lembang Fault is a major geological feature in West Java that borders the northern edge of Bandung(one of Indonesia’s largest cities).It lies just south of the active Tangkuban Perahu Volcano,exhibiting clear geomorphic signs of recent activity,and has been scientifically confirmed as active through geological and geophysical studies.In this work,we describe an Integrated along the Lembang Fault,which can be used for geodynamic research in Indonesia.We discuss the design of a seismic and Global Navigation Satellite System(GNSS)array sensor network for continuous monitoring,and report the status of monitoring stations that periodically collect highly accurate,continuous seismographic and GNSS readings,transmitting these data to a central server in Bandung for post-processing.Solutions from the array data are used to provide precise measurements of the deformation of the Earth’s surface over large distances,allowing for spatio-temporal tracking of tectonic movement,and resulting in a better understanding of seismic events in the region.In this study,our investigation revealed a significant compression rate of an estimated 13 microstrain/yr along the Lembang Fault,whereas the strain rate is much smaller farther south of the fault.This study presents the design of a seismo-geodetic observatory network that can be implemented in earthquake-prone regions for mitigation purposes,with particular utility for studying other active faults that also traverse populated areas in Indonesia. 展开更多
关键词 Lembang Fault seismo-geodetic observatory EARTHQUAKE disaster risk reduction
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Carbothermal shock fabrication of CoO-Cu_(2)O nanocomposites on N-doped porous carbon for enhanced hydrolysis of ammonia borane
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作者 Jun-Rui Zhang Yun-Qi Jia +9 位作者 Fei Chu Nuo Lei Jia-Peng Bi Hai-Ying Qin Mi-Li Liu Yu-Xiao Jia Lan Zhang Lin Jiang Liu-Zhang Ouyang Xue-Zhang Xiao 《Rare Metals》 2025年第8期5486-5497,共12页
The high hydrogen desorption density(19.6 wt%)of ammonia borane(AB)makes it one of the most promising chemical hydrogen storage materials.Developing cost-effective catalysts is the key for accelerating the hydrolysis ... The high hydrogen desorption density(19.6 wt%)of ammonia borane(AB)makes it one of the most promising chemical hydrogen storage materials.Developing cost-effective catalysts is the key for accelerating the hydrolysis of AB.Herein,we present a straightforward synthesis method for the Cu_(2)O decorated CoO catalyst derived from ZIF-67 precursors using carbothermal shock(~1 s)in air.The obtained results demonstrate that a small amount of Cu_(2)O doping into CoO synergistically enhances AB hydrolysis,resulting in an almost fivefold increase in turnover frequency(TOF=97 molH_(2)molCoO-1min-1at 298 K).Further studies indicated that the incorporation of Cu_(2)O alters the electronic distribution of the surface of catalysts,introducing more oxygen vacancies and increasing the pyridinic nitrogen content.The increased oxygen vacancies effectively enhanced the adsorption and activation ability of active sites for reactants(H_(2)O and AB),while the targeting effect of pyridinic nitrogen enhances the dispersion of the catalyst.Theoretical analysis reveals that CoO plays a key role in the dissociation of H_(2)O,while minor doping with Cu_(2)O substantially reduces the dissociation energy barrier of AB.This research provides a novel strategy for the design and efficient preparation of AB hydrolysis catalysts for efficient hydrogen production. 展开更多
关键词 HYDROLYSIS Ammonia borane Hydrogen generation Copper doping Cobalt monoxide
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Forecasting strong subsequent earthquakes in Japan using an improved version of NESTORE machine learning algorithm
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作者 S.Gentili G.D.Chiappetta +2 位作者 G.Petrillo P.Brondi J.Zhuang 《Geoscience Frontiers》 2025年第3期205-222,共18页
In this study,the advanced machine learning algorithm NESTORE(Next Strong Related Earthquake)was applied to the Japan Meteorological Agency catalog(1973-2024).It calculates the probability that the aftershocks will re... In this study,the advanced machine learning algorithm NESTORE(Next Strong Related Earthquake)was applied to the Japan Meteorological Agency catalog(1973-2024).It calculates the probability that the aftershocks will reach or exceed a magnitude equal to the magnitude of the mainshock minus one and classifies the clusters as type A or type B,depending on whether this condition is met or not.It has been shown useful in the tests in Italy,western Slovenia,Greece,and California.Due to Japan’s high and complex seismic activity,new algorithms were developed to complement NESTORE:a hybrid cluster identification method,which uses both ETAS-based stochastic declustering and deterministic graph-based selection,and REPENESE(RElevant features,class imbalance PErcentage,NEighbour detection,SElection),an algorithm for detecting outliers in skewed class distributions,which takes in account if one class has a larger number of samples with respect to the other(class imbalance).Trained with data from 1973 to 2004(7 type A and 43 type B clusters)and tested from 2005 to 2023(4 type A and 27 type B clusters),the method correctly forecasted 75%of A clusters and 96%of B clusters,achieving a precision of 0.75 and an accuracy of 0.94 six hours after the mainshock.It accurately classified the 2011 Tōhoku event cluster.Near-real-time forecasting was applied to the sequence after the April 17,2024 M6.6 earthquake in Shikoku,correctly classifying it as a“Type B cluster”.These results highlight the potential for the forecasting of strong aftershocks in regions with high seismicity and class imbalance,as evidenced by the high recall,precision and accuracy values achieved in the test phase. 展开更多
关键词 Machine learning Cluster identification ETASS trong aftershock JAPAN Outliers detection
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动态应变场下相移光栅光谱特性及实验研究 被引量:2
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作者 王正方 王静 隋青美 《光谱学与光谱分析》 SCIE EI CAS CSCD 北大核心 2016年第12期4113-4119,共7页
光纤传感技术以其抗电磁干扰、高精度、易组网等优势在航空航天及地下工程领域的声发射传感中得到了广泛应用。针对光纤光栅声发射监测系统,目前研究侧重于均匀光纤光栅的动态应变场传感特性,基于相移光纤光栅(phase-shifted fiber Bra... 光纤传感技术以其抗电磁干扰、高精度、易组网等优势在航空航天及地下工程领域的声发射传感中得到了广泛应用。针对光纤光栅声发射监测系统,目前研究侧重于均匀光纤光栅的动态应变场传感特性,基于相移光纤光栅(phase-shifted fiber Bragg grating,PS-FBG)这一新型光纤光栅器件,重点研究声发射激励产生的动态应变场下相移光纤光栅的光谱特性变化规律。首先利用传输矩阵理论,建立PS-FBG的动态应变传感模型,利用指数衰减的余弦函数模拟声发射激励产生的动态应变场。通过数值仿真,详细研究PSFBG光谱对动态应变场幅度、采样时刻、衰减系数、声发射频率及波长的响应特性。结果表明,PS-FBG反射谱形状随声发射频率与采样时刻呈现周期性变化,具体表现为透射窗口所对波长产生周期性漂移,而带宽变化不明显;随着动态应变场幅值越大,PS-FBG反射谱的谐振峰向两侧逐渐增多,透射窗口所对波长漂移很小;一定范围内衰减系数对PS-FBG光谱影响较大;而当声发射波长为0.1~2 L时,对PS-FBG光谱产生较大影响,此时光谱畸变较严重,在此范围外,光谱形状不发生明显变化。最后,搭建连续信号激励下的动态应变场实验平台,分析不同幅度a与频率f变化下PS-FBG的光谱特性,实验结果与仿真结果较好吻合。表明PS-FBG光谱对不同声发射激励产生的动态应变场响应不同,呈现一定规律性,该研究为基于相移光纤光栅传感技术的声发射传感提供理论指导。 展开更多
关键词 相移光纤光栅 动态应变场 声发射传感
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印刷环节挥发性有机物无组织排放特征测定研究 被引量:8
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作者 宋梦龄 唐文婷 +3 位作者 张巍 宋捷 沈晓波 修光利 《环境污染与防治》 CAS CSCD 北大核心 2022年第2期225-229,共5页
对使用溶剂型油墨的凹版印刷设备和使用水性油墨的柔版印刷设备无组织排放的挥发性有机物(VOCs)浓度进行了实际监测,并采用计算流体动力学模拟无组织排放VOCs的收集效率。结果表明:(1)使用溶剂型油墨的凹版连续印刷过程非甲烷总烃(NMHC... 对使用溶剂型油墨的凹版印刷设备和使用水性油墨的柔版印刷设备无组织排放的挥发性有机物(VOCs)浓度进行了实际监测,并采用计算流体动力学模拟无组织排放VOCs的收集效率。结果表明:(1)使用溶剂型油墨的凹版连续印刷过程非甲烷总烃(NMHC)最高均值达到5975.67 mg/m^(3),约为使用水性油墨的柔版印刷(191.67 mg/m^(3))的31.2倍。虽然使用水性油墨可明显降低NMHC的排放,但其操作空间的浓度依然存在超过《工作场所有害因素职业接触限值第1部分:化学有害因素》(GBZ 2.1—2019)的现象。(2)印刷车间应该设置专门的调墨室,能缓解印刷车间内挥发性污染气体浓度的波动。(3)计算流体动力学模拟显示,设置合理的集气罩可有效降低VOCs的无组织排放,收集效率为70%~75%。 展开更多
关键词 印刷 挥发性有机物 无组织排放 计算流体动力学模拟
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低温制备N-Fe共掺杂TiO_2-SiO_2可见光催化复合薄膜 被引量:2
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作者 卜彦强 马德伟 +11 位作者 宋琨 曹鸿涛 吴爱国 王立平 陈亮 金亦君 徐裕 张莉 梁凌燕 张洪亮 高俊华 诸葛飞 《材料科学与工程学报》 CAS CSCD 北大核心 2018年第6期921-926,共6页
采用溶胶-凝胶结合低温(<100℃)热水后处理法,在塑料衬底上制得N-Fe共掺杂锐钛矿TiO_2-SiO_2复合薄膜。采用多种技术手段对薄膜样品进行了表征,并考察了薄膜样品在可见光下对罗丹明B的降解能力。研究结果表明,有机衬底上形成了锐钛矿... 采用溶胶-凝胶结合低温(<100℃)热水后处理法,在塑料衬底上制得N-Fe共掺杂锐钛矿TiO_2-SiO_2复合薄膜。采用多种技术手段对薄膜样品进行了表征,并考察了薄膜样品在可见光下对罗丹明B的降解能力。研究结果表明,有机衬底上形成了锐钛矿TiO_2纳米晶弥散分布的复合薄膜,薄膜具有较高的可见光催化效率,150min后对罗丹明B的降解效率达到77.4%,其中矿化率达61%。 展开更多
关键词 锐钛矿TIO2 TiO2-SiO2复合薄膜 低温热水处理 可见光光催化
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面向应急通信的多无人机协同信道建模研究 被引量:9
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作者 白露 孙铭然 +2 位作者 黄子蔚 冯涛 程翔 《通信学报》 EI CSCD 北大核心 2023年第7期38-50,共13页
为了更好地进行应急通信的系统设计和技术研发,从而大力提升我国的安全风险防范和应急处置能力,面向应急通信场景开展了多无人机协同信道建模研究。首先,构建了城市地震和郊区暴雪两大典型应急环境中多无人机协同救援通信场景信道数据集... 为了更好地进行应急通信的系统设计和技术研发,从而大力提升我国的安全风险防范和应急处置能力,面向应急通信场景开展了多无人机协同信道建模研究。首先,构建了城市地震和郊区暴雪两大典型应急环境中多无人机协同救援通信场景信道数据集,并据此对多无人机协同应急通信信道参数及其统计特性进行深度分析。其次,针对多无人机协同应急通信提出了一种更加通用的基于随机统计建模的信道模型,计算了多无人机协同应急通信下的信道冲激响应,并联合建模了多无人机高速移动和协同通信带来的协同时间-空间非平稳特性。最后,经过仿真实验,充分分析了多无人机协同应急通信在城市地震和郊区暴雪场景下的信道特性,为多无人机协同应急通信的实际实施起到了一定的指导作用。同时,所提信道模型的统计特性与在城市地震和郊区暴雪场景下的信道数据的统计特性拟合良好,验证了所提模型的有效性。 展开更多
关键词 应急通信 多无人机协同通信 射线追踪 几何随机信道模型 协同时间-空间非平稳特性
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基于评论文本图表示学习的推荐算法 被引量:1
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作者 杨粟森 刘勇 张举勇 《计算机工程》 CAS CSCD 北大核心 2021年第11期69-76,共8页
基于卷积或循环神经网络的推荐系统主要捕捉评论文本中相邻词之间的局部和连续依赖关系,对长期、全局、非连续的依赖关系的捕捉能力有限。针对该问题,提出一种基于评论文本图表示学习的推荐算法RGP。将每个用户或项目的评论文本表示成图... 基于卷积或循环神经网络的推荐系统主要捕捉评论文本中相邻词之间的局部和连续依赖关系,对长期、全局、非连续的依赖关系的捕捉能力有限。针对该问题,提出一种基于评论文本图表示学习的推荐算法RGP。将每个用户或项目的评论文本表示成图,图的节点为评论文本的词,图的边为词与词的连接关系。针对图中的每个节点,使用基于连接关系的图注意力网络加权融合其邻点信息,利用基于交互关系的注意力机制对节点重新赋权,并加权融合图中所有节点的表征从而得到整个图的表征。在此基础上,将基于用户和项目ID的嵌入表征及其评论图表征耦合输入并采用因子分解机进行评分预测,以得到最终的推荐结果。实验结果表明,与NARRE、DAML等算法相比,RGP算法可有效提高推荐精度。 展开更多
关键词 推荐算法 评论文本 图神经网络 注意力机制 因子分解机
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基于深度学习的船舶机械微小故障快速诊断方法 被引量:10
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作者 宫文峰 陈辉 WANG Danwei 《计算机集成制造系统》 EI CSCD 北大核心 2022年第9期2852-2864,共13页
微小故障的快速诊断是预防和减少重大显著性故障发生的关键。近年来,基于卷积神经网络(CNN)的智能诊断方法已成为船舶机械领域研究的热点。然而,现行的基于图像处理框架的2D-CNN算法在处理多传感器、多通道故障数据时存在检测时间长、... 微小故障的快速诊断是预防和减少重大显著性故障发生的关键。近年来,基于卷积神经网络(CNN)的智能诊断方法已成为船舶机械领域研究的热点。然而,现行的基于图像处理框架的2D-CNN算法在处理多传感器、多通道故障数据时存在检测时间长、数据融合效率低的不足。为此,提出一种改进的1DCNN-GAP的深度学习新算法,用于船舶旋转机械的故障快速诊断。该方法首先引入1D-CNN处理多传感器数据融合问题,然后设计了一维全局均值池化层(1D-GAP)改进全连接层结构,减少传统CNN的模型参数量和诊断时间。通过将提出的方法用于滚动轴承在1马力、2马力和3马力多种负载工况下的2通道振动传感器故障监测数据进行诊断,诊断精确率分别为99.84%、99.51%和99.33%。通过与主流的SVM、KNN、DNN和2DCNN-FC算法进行对比验证,结果表明,所提方法具备更加优越的诊断性能,更适用于多传感器监测环境下微小故障的快速诊断。 展开更多
关键词 故障诊断 一维卷积神经网络 多通道数据融合 船舶机械 滚动轴承 深度学习
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基于感知图像信息的无人机信道路径损耗预测 被引量:2
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作者 孙铭然 黄子蔚 +3 位作者 白露 程翔 张洪广 冯涛 《模式识别与人工智能》 EI CSCD 北大核心 2023年第11期987-996,共10页
为了更好地促进6G无人机对地通信技术的应用和发展,完善无人机对地通信系统设计理论基础及满足6G通信的安全性和有效性的需求,开展6G无人机对地通信场景下基于感知图像信息的信道路径损耗预测研究.首先,基于感知数据仿真平台AirSim和无... 为了更好地促进6G无人机对地通信技术的应用和发展,完善无人机对地通信系统设计理论基础及满足6G通信的安全性和有效性的需求,开展6G无人机对地通信场景下基于感知图像信息的信道路径损耗预测研究.首先,基于感知数据仿真平台AirSim和无线信道仿真软件Wireless InSite,构建动态无人机对地通信场景下的混合通信与感知智能融合数据集,为探索物理空间和电磁空间的映射关系提供重要的数据支撑.然后,基于构建的数据集,建立物理空间的感知图像信息与电磁空间的路径损耗信息之间的映射关系,实现6G无人机对地通信场景下的实时路径损耗预测.最后,通过仿真测试,将模型预测结果和测试集进行对比,验证模型的准确性. 展开更多
关键词 通信与感知融合 路径损耗预测 联觉机理 无人机通信
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