检索结果-南通市图书馆

Atomistic study on the microscopic mechanism of grain boundary embrittlement induced by small dense helium bubbles in iron

引用

Nuclear Science and Techniques 2024年第3期35卷 84-95页

作者： Lei Peng Yong-Jie Sun Jing-Yi Shi Yi-Fei Liu Shang-Ming Chen Liu-Liu Li State key laboratory of Particle detection and Electronics University of Science and Technology of ChinaHefei 230026China School of Nuclear Science and technology University of Science and Technology of ChinaHefei 230027China Science and technology on Reactor system Design technology laboratory Nuclear Power Institute of ChinaChengdu 610213China

The helium bubbles induced by 14 MeV neutron irradiation can cause intergranular fractures in reduced activation ferritic martensitic steel,which is a candidate structural material for fusion *** order to elucidate the susceptibility of different grain boundaries(GBs)to helium-induced embrittlement,the tensile fracture processes of 10 types of GBs with and without helium bubbles in body-centered cubic(bcc)iron at the relevant service temperature of 600 K were investigated via molecular dynamics *** results indicate that in the absence of helium bubbles,the GBs studied here can be classified into two distinct categories:brittle GBs and ductile *** atomic scale analysis shows that the plastic deformation of ductile GB at high temperatures originates from complex plastic deformation mechanisms,including the Bain/Burgers path phase transition and deformation twinning,in which the Bain path phase transition is the most dominant plastic deformation ***,the presence of helium bubbles severely inhibits the plastic deformation channels of the GBs,resulting in a significant decrease in elongation at *** bubble-decorated GBs,the ultimate tensile strength increases with the increase in the misorientation ***,the coherent twin boundary∑3{112}was found to maintain relatively high fracture strength and maximum failure strain under the influence of helium bubbles.

关键词： Helium bubble Grain boundary Embrittlement Reduced activation ferritic martensitic steel Molecular dynamics Bain path

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Prediction of Pediatric Sepsis Using a Deep Encoding Network with Cross Features

引用

Journal of Shanghai Jiaotong university(Science) 2024年第1期29卷 131-140页

作者：陈潇张瑞汤心溢钱娟 University of Chinese Academy of Sciences Beijing 100084China Shanghai Institute of Technical Physics of the Chinese Academy of Sciences Key Laboratory of Infrared Detection and Imaging TechnologyShanghai 200083China Shanghai Children's Medical Center Shanghai Jiao Tong University School of MedicineShanghai 200127China

Sepsis poses a serious threat to health of children in pediatric intensive care *** mortality from pediatric sepsis can be effectively reduced through in-time diagnosis and therapeutic *** bacilliculture detection method is too time-consuming to receive timely *** this research,we propose a new framework:a deep encoding network with cross features(CF-DEN)that enables accurate early detection of *** features are automatically constructed via the gradient boosting decision tree and distilled into the deep encoding network(DEN)we *** DEN is aimed at learning sufficiently effective representation from clinical test *** layer of the DEN fltrates the features involved in computation at current layer via attention mechanism and outputs the current prediction which is additive layer by layer to obtain the embedding feature at last *** framework takes the advantage of tree-based method and neural network method to extract effective representation from small clinical dataset and obtain accurate prediction in order to prompt patient to get timely *** evaluate the performance of the framework on the dataset collected from Shanghai Children's Medical *** with common machine learning methods,our method achieves the increase on F1-score by 16.06%on the test set.

关键词： pediatric sepsis gradient boosting decision tree cross feature neural network deep encoding network with cross features(CF-DEN)

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Electrically tunable phase-change metasurface for dynamic infrared thermal camouflage

引用

Photonics Research 2024年第2期12卷 292-300页

作者： YUFENG XIONG YUNZHENG WANG CHAO FENG YAOLAN TIAN LIANG GAO JUN-LEI WANG ZHUANG ZHUO XIAN ZHAO Center for Optics Research and Engineering Key Laboratory of Laser&Infrared SystemMinistry of EducationShandong UniversityQingdao 266237China School of Information Science and Engineering Shandong UniversityQingdao 266237China

Dynamic infrared thermal camouflage technology has attracted extensive attention due to its ability to thermally conceal targets in various environmental backgrounds by tuning thermal *** use of phase change materials(PCMs)offers numerous advantages,including zero static power,rapid modulation rate,and large emissivity tuning ***,existing PCM solutions still encounter several practical application challenges,such as temperature uniformity,amorphization achievement,and adaptability to different *** this paper,we present the design of an electrically controlled metal-insulator-metal thermal emitter based on a PCM metasurface,and numerically investigate its emissivity tunability,physical mechanisms,heat conduction,and thermal camouflage performance across different ***,the influence of the quench rate on amorphization was studied to provide a guidance for evaluating and optimizing device *** results reveal that the thermal emitter exhibits a wide spectral emissivity tuning range between 8 and 14μm,considerable quench rates for achieving amorphization,and the ability to provide thermal camouflage across a wide background temperature ***,it is anticipated that this contribution will promote the development of PCM-based thermal emitters for practical dynamic infrared thermal camouflage technology with broad applications in both civilian and military domains.

关键词： thermal dynamic phase

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

14.1 W continuous-wave dual-end diode-pumped Er:Lu_(2)O_(3)laser at 2.85μm

引用

Chinese Optics Letters 2024年第1期22卷 84-89页

作者：梁洋洋李涛张百涛何京良 Sascha Kalusniak 赵显 Christian Kränkel key laboratory of Laser&infrared system Ministry of EducationShandong UniversityQingdao 266237China School of Information Science and Engineering Shandong Provincial Key Laboratory of Laser Technology and ApplicationShandong UniversityQingdao 266237China Institute of Novel Semiconductors State Key Laboratory of Crystal MaterialsShandong UniversityJinan 250100China Leibniz-Institut für Kristallzüchtung(IKZ) Berlin 12489Germany

We present our efforts towards power scaling of Er:Lu_(2)O_(3)lasers at 2.85μ*** applying a dual-end diode-pumped resonator scheme,we achieve an output power of 14.1 W at an absorbed pump power of 59.7 W with a slope efficiency of 26%.In a single-end pumped resonator scheme,an output power of 10.1 W is reached under 41.9 W of absorbed pump *** the best of our knowledge,this is the first single crystalline mid-infrared rare-earth-based solid-state laser with an output power exceeding 10 W at room temperature.

关键词： high-power continuous-wave laser mid-infrared laser dual-end pump scheme

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Control Policy Learning Design for Vehicle Urban Positioning via BeiDou Navigation

引用

Journal of systems Science & Complexity 2024年第1期37卷 114-135页

作者： QIN Yahang ZHANG Chengye CHEN Ci XIE Shengli LEWIS Frank L School of Automation Guangdong University of TechnologyGuangzhou 510006China Guangdong key laboratory of IoT Information technology Guangzhou 510006China. Center for Intelligent Batch Manufacturing Based on IoT technology key laboratory of Intelligent detection and The Internet of Things in Manufacturing Ministry of EducationGuangzhou 510006China Guangdong-HongKong-Macao Joint laboratory for Smart Discrete Manufacturing Guangzhou 510006China key laboratory of Intelligent Information Processing and system Integration of IoT Ministry of EducationGuangzhou 510006China. UTA Research Institute The University of Texas at ArlingtonFort WorthTX 76019USA

This paper presents a learning-based control policy design for point-to-point vehicle positioning in the urban environment via BeiDou *** navigating in urban canyons,the multipath effect is a kind of interference that causes the navigation signal to drift and thus imposes severe impacts on vehicle localization due to the reflection and diffraction of the BeiDou ***,the authors formulated the navigation control system with unknown vehicle dynamics into an optimal control-seeking problem through a linear discrete-time system,and the point-to-point localization control is modeled and handled by leveraging off-policy reinforcement learning for feedback *** proposed learning-based design guarantees optimality with prescribed performance and also stabilizes the closed-loop navigation system,without the full knowledge of the vehicle *** is seen that the proposed method can withstand the impact of the multipath effect while satisfying the prescribed convergence rate.A case study demonstrates that the proposed algorithms effectively drive the vehicle to a desired setpoint under the multipath effect introduced by actual experiments of BeiDou navigation in the urban environment.

关键词： BeiDou navigation multipath effect prescribed convergence rate reinforcement learning urban localization.

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

FPGA-based position reconstruction method for neutron beam flux spatial distribution measurement in BNCT

引用

Nuclear Science and Techniques 2024年第3期35卷 96-108页

作者： Wei Jiang Ping Cao Yi-Ming Wu Xian-Ke Liu Zhu-Jun Fang Zhi-Yong Zhang Bin Shi Jun Chen State key laboratory of Particle detection and Electronics University of Science and Technology of ChinaHefei 230026China Department of Modern Physics University of Science and Technology of ChinaHefei 230026China School of Nuclear Science and technology University of Science and Technology of ChinaHefei 230026China National key laboratory for Metrology and Calibration Techniques China Institute of Atomic EnergyBeijing 102413China

A new measurement method for the spatial distribution of neutron beam flux in boron neutron capture therapy(BNCT)is being developed based on the two-dimensional Micromegas *** address the issue of long processing times in traditional offline position reconstruction methods,this paper proposes a field programmable gate array based online position reconstruction method utilizing the micro-time projection chamber *** method encapsulates key technical aspects:a self-adaptive serial link technique built upon the dynamical adjustment of the delay chain length,fast sorting,a coordinate-matching technique based on the mapping between signal timestamps and random access memory(RAM)addresses,and a precise start point-merging technique utilizing a circular combined *** performance test of the selfadaptive serial link shows that the bit error rate of the link is better than 10-12 at a confidence level of 99%,ensuring reliable data *** experiment utilizing the readout electronics and Micromegas detector shows a spatial resolution of approximately 1.4 mm,surpassing the current method’s resolution level of 5 *** beam experiment confirms that the readout electronics system can obtain the flux spatial distribution of neutron beams online,thus validating the feasibility of the position reconstruction *** online position reconstruction method avoids traditional methods,such as bubble sorting and traversal searching,simplifies the design of the logic firmware,and reduces the time complexity from O(n2)to O(n).This study contributes to the advancement in measuring neutron beam flux for BNCT.

关键词： Position reconstruction FPGA Readout electronics Neutron flux spatial distribution

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A hybrid attention model based on first-order statistical features for smoke recognition

引用

Science China(Technological Sciences) 2024年第3期67卷 809-822页

作者： GUO Nan LIU JiaHui DI KeXin GU Ke QIAO JunFei Beijing laboratory of Smart Environmental Protection Beijing Key Laboratory of Computational Intelligence and Intelligent SystemBeijing Artificial Intelligence InstituteBeijing 100124China Faculty of Information technology Beijing University of TechnologyBeijing 100124China

Smoke and fire recognition are of great importance on foreseeing fire disasters and preventing environmental pollution by monitoring the burning process of objects(e.g., straw, fuels). However, since fire images suffer from problems like the variability of the features, complexity of scenarios, interference from background, changeable weather conditions as well as image quality problems, identifying smoke and fire accurately and promptly from a given image still remains a substantial challenge. Automatically learning the features of smoke images by CNNs has improved the target recognition ability compared to traditional approaches,nonetheless, convolutions and pooling operations in CNNs may cause severe information loss which may lead to *** tackle the above problems, this paper proposed a hybrid attention model based on the characteristics of smoke images. This model adopted multiple optimized attention mechanism in several stages to quickly and precisely capture the important features,achieving state-of-the-art performance on smoke and fire recognition in terms of accuracy and speed. Our proposed module mainly consists of two stages: pooling and attention. In the first stage, we conducted several newly proposed first-order pooling methods. Through traversing the data space in a larger scope, features are better reserved, thus constructing a more intact feature space of smoke and fire in an image. In the second stage, feature maps are aggregated together to perform channel and spatial attention. The channel and spatial dependencies allow us to quickly catch the important features presented in an image. By fully exploring the feature space and prominent salient features, characteristics of smoke and fire are better presented so as to obtain better smoke and fire detection results. Experiments have been conducted on public smoke detection dataset and new proposed fine-grained smoke and fire detection database. Experimental results revealed that the propose

关键词： hybrid attention first-order pooling smoke and fire detection deep convolutional neural networks

来源：

维普期刊数据库

同方期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Adaptive and augmented active anomaly detection on dynamic network traffic streams

引用

Frontiers of Information technology & Electronic Engineering 2024年第3期25卷 446-460页

作者： Bin LI Yijie WANG Li CHENG National key laboratory of Parallel and Distributed Computing College of ComputerNational University of Defense TechnologyChangsha 410073China College of system Engineering National University of Defense TechnologyChangsha 410073China

Active anomaly detection queries labels of sampled instances and uses them to incrementally update the detection model,and has been widely adopted in detecting network ***,existing methods cannot achieve desirable performance on dynamic network traffic streams because(1)their query strategies cannot sample informative instances to make the detection model adapt to the evolving stream and(2)their model updating relies on limited query instances only and fails to leverage the enormous unlabeled instances on *** address these issues,we propose an active tree based model,adaptive and augmented active prior-knowledge forest(A3PF),for anomaly detection on network trafic streams.A prior-knowledge forest is constructed using prior knowledge of network attacks to find feature subspaces that better distinguish network anomalies from normal *** one hand,to make the model adapt to the evolving stream,a novel adaptive query strategy is designed to sample informative instances from two aspects:the changes in dynamic data distribution and the uncertainty of *** the other hand,based on the similarity of instances in the neighborhood,we devise an augmented update method to generate pseudo labels for the unlabeled neighbors of query instances,which enables usage of the enormous unlabeled instances during model *** experiments on two benchmarks,CIC-IDS2017 and UNSW-NB15,demonstrate that A3PF achieves significant improvements over previous active methods in terms of the area under the receiver operating characteristic curve(AUC-ROC)(20.9%and 21.5%)and the area under the precision-recall curve(AUC-PR)(44.6%and 64.1%).

关键词： Active anomaly detection Network traffic streams Pseudo labels Prior knowledge of network attacks

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Shape recognition and size measurement of particles in hybrid particle field based on interference technology

引用

Optoelectronics Letters 2024年

作者：孙金露邱岳武宇航赵丹苗长云 Tianjin key laboratory of Optoelectronic detection technology and system School of Electronic and Information Engineering Tiangong University

An algorithm that can implement particle shape recognition and size measurement in hybrid particle field is proposed. Based on the defocused images obtained by the interferometric particle imaging system， shape recognition of particles can be realized through ResNet50. 2D Fourier transform and 2D autocorrelation transform are used to obtained the size of spherical and non-spherical particles， respectively. The shape and size of the particle in hybrid particle field are determined. Numerical simulation and experiment results suggest that the method has good accuracy in measuring the particle size of hybrid particle field.

关键词：

来源：

同方期刊数据库评论

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Review on the terahertz metasensor:from featureless refractive index sensing to molecular identification

引用

Photonics Research 2024年第2期12卷 194-217页

作者： JIAMING LYU LIHAO HUANG LIN CHEN YIMING ZHU SONGLIN ZHUANG THz technology Innovation Research Institute Shanghai Key Laboratory of Modern Optical SystemUniversity of Shanghai for Science and TechnologyShanghai 200093China Shanghai Institute of Intelligent Science and technology Tongji UniversityShanghai 200092China

The terahertz(THz)wave is at the intersection between photonics and electronics in the electromagnetic *** the vibration mode of many biomedical molecules and the weak interaction mode inside the molecules fall in the THz regime,utilizing THz radiation as a signal source to operate substance information sensing has its unique ***,the metamaterial sensor(metasensor)has greatly enhanced the interaction between signal and substances and spectral selectivity on the subwavelength ***,most past review articles have demonstrated the THz metasensor in terms of their structures,applications,or *** recently,with the rapid development of metasensing technologies,the molecular information has paid much more attention to the platform of THz *** this review,we comprehensively introduce the THz metasensor for detecting not only the featureless refractive index but also the vibrational/chiral molecular information of *** objectives of this review are to improve metasensing specificity either by chemical material-assisted analyte capture or by physical molecular ***,to boost THz absorption features in a certain frequency,the resonant responses of metasensors can be tuned to the molecular vibrational modes of target molecules,while frequency multiplexing techniques are reviewed to enhance broadband THz spectroscopic *** chiral metasensors are also summarized to specific identification chiral ***,the potential prospects of next generation THz metasensors are *** to featureless refractive index metasensing,the specific metasensor platforms accelerated by material modification and molecular information will lead to greater impact in the advancement of trace detection of conformational dynamics of biomolecules in practical applications.

关键词： refractive index sensor

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：