期刊文献+
共找到19,142篇文章
< 1 2 250 >
每页显示 20 50 100
Bilateral Dual-Residual Real-Time Semantic Segmentation Network
1
作者 Shijie Xiang Dong Zhou +1 位作者 Dan Tian Zihao Wang 《Computers, Materials & Continua》 2025年第4期497-515,共19页
Real-time semantic segmentation tasks place stringent demands on network inference speed,often requiring a reduction in network depth to decrease computational load.However,shallow networks tend to exhibit degradation... Real-time semantic segmentation tasks place stringent demands on network inference speed,often requiring a reduction in network depth to decrease computational load.However,shallow networks tend to exhibit degradation in feature extraction completeness and inference accuracy.Therefore,balancing high performance with real-time requirements has become a critical issue in the study of real-time semantic segmentation.To address these challenges,this paper proposes a lightweight bilateral dual-residual network.By introducing a novel residual structure combined with feature extraction and fusion modules,the proposed network significantly enhances representational capacity while reducing computational costs.Specifically,an improved compound residual structure is designed to optimize the efficiency of information propagation and feature extraction.Furthermore,the proposed feature extraction and fusion module enables the network to better capture multi-scale information in images,improving the ability to detect both detailed and global semantic features.Experimental results on the publicly available Cityscapes dataset demonstrate that the proposed lightweight dual-branch network achieves outstanding performance while maintaining low computational complexity.In particular,the network achieved a mean Intersection over Union(mIoU)of 78.4%on the Cityscapes validation set,surpassing many existing semantic segmentation models.Additionally,in terms of inference speed,the network reached 74.5 frames per second when tested on an NVIDIA GeForce RTX 3090 GPU,significantly improving real-time performance. 展开更多
关键词 real-time residual structure semantic segmentation feature fusion
在线阅读 下载PDF
Real-time seepage and instability of fractured granite subjected to hydro-shearing under different critical slip states
2
作者 Peng Zhao Zijun Feng +3 位作者 Hanmo Nan Peihua Jin Chunsheng Deng Yubin Li 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第4期2396-2415,共20页
In this study,a high-confining pressure and real-time large-displacement shearing-flow setup was developed.The test setup can be used to analyze the injection pressure conditions that increase the hydro-shearing perme... In this study,a high-confining pressure and real-time large-displacement shearing-flow setup was developed.The test setup can be used to analyze the injection pressure conditions that increase the hydro-shearing permeability and injection-induced seismicity during hot dry rock geothermal extraction.For optimizing injection strategies and improving engineering safety,real-time permeability,deformation,and energy release characteristics of fractured granite samples driven by injected water pressure under different critical sliding conditions were evaluated.The results indicated that:(1)A low injection water pressure induced intermittent small-deformation stick-slip behavior in fractures,and a high injection pressure primarily caused continuous high-speed large-deformation sliding in fractures.The optimal injection water pressure range was defined for enhancing hydraulic shear permeability and preventing large injection-induced earthquakes.(2)Under the same experimental conditions,fracture sliding was deemed as the major factor that enhanced the hydraulic shear-permeability enhancement and the maximum permeability increased by 36.54 and 41.59 times,respectively,in above two slip modes.(3)Based on the real-time transient evolution of water pressure during fracture sliding,the variation coefficients of slip rate,permeability,and water pressure were fitted,and the results were different from those measured under quasi-static conditions.(4)The maximum and minimum shear strength criteria for injection-induced fracture sliding were also determined(μ=0.6665 andμ=0.1645,respectively,μis friction coefficient).Using the 3D(three-dimensional)fracture surface scanning technology,the weakening effect of injection pressure on fracture surface damage characteristics was determined,which provided evidence for the geological markers of fault sliding mode and sliding nature transitions under the fluid influence. 展开更多
关键词 Hydro-shearing Reservoir modification Injection-induced seismicity real-time shear-flowing Frictional noise
在线阅读 下载PDF
Contextual design and real-time verification for agile casting design
3
作者 Dong Xiang Chu-hao Zhou +3 位作者 Xuan-pu Dong Shu-ren Guo Yan-song Ding Hua-tang Cao 《China Foundry》 2025年第2期231-238,共8页
In the foundry industries,process design has traditionally relied on manuals and complex theoretical calculations.With the advent of 3D design in casting,computer-aided design(CAD)has been applied to integrate the fea... In the foundry industries,process design has traditionally relied on manuals and complex theoretical calculations.With the advent of 3D design in casting,computer-aided design(CAD)has been applied to integrate the features of casting process,thereby expanding the scope of design options.These technologies use parametric model design techniques for rapid component creation and use databases to access standard process parameters and design specifications.However,3D models are currently still created through inputting or calling parameters,which requires numerous verifications through calculations to ensure the design rationality.This process may be significantly slowed down due to repetitive modifications and extended design time.As a result,there are increasingly urgent demands for a real-time verification mechanism to address this issue.Therefore,this study proposed a novel closed-loop model and software development method that integrated contextual design with real-time verification,dynamically verifying relevant rules for designing 3D casting components.Additionally,the study analyzed three typical closed-loop scenarios of agile design in an independent developed intelligent casting process system.It is believed that foundry industries can potentially benefit from favorably reduced design cycles to yield an enhanced competitive product market. 展开更多
关键词 agile design context-design casting process design real-time verification smart manufacturing
在线阅读 下载PDF
Real-time monitoring of disc cutter wear in tunnel boring machines:A sound and vibration sensor-based approach with machine learning technique
4
作者 Mohammad Amir Akhlaghi Raheb Bagherpour Seyed Hadi Hoseinie 《Journal of Rock Mechanics and Geotechnical Engineering》 2025年第3期1700-1722,共23页
Large portions of the tunnel boring machine(TBM)construction cost are attributed to disc cutter consumption,and assessing the disc cutter's wear level can help determine the optimal time to replace the disc cutter... Large portions of the tunnel boring machine(TBM)construction cost are attributed to disc cutter consumption,and assessing the disc cutter's wear level can help determine the optimal time to replace the disc cutter.Therefore,the need to monitor disc cutter wear in real-time has emerged as a technical challenge for TBMs.In this study,real-time disc cutter wear monitoring is developed based on sound and vibration sensors.For this purpose,the microphone and accelerometer were used to record the sound and vibration signals of cutting three different types of rocks with varying abrasions on a laboratory scale.The relationship between disc cutter wear and the sound and vibration signal was determined by comparing the measurements of disc cutter wear with the signal plots for each sample.The features extracted from the signals showed that the sound and vibration signals are impacted by the progression of disc wear during the rock-cutting process.The signal features obtained from the rock-cutting operation were utilized to verify the machine learning techniques.The results showed that the multilayer perceptron(MLP),random subspace-based decision tree(RS-DT),DT,and random forest(RF)methods could predict the wear level of the disc cutter with an accuracy of 0.89,0.951,0.951,and 0.927,respectively.Based on the accuracy of the models and the confusion matrix,it was found that the RS-DT model has the best estimate for predicting the level of disc wear.This research has developed a method that can potentially determine when to replace a tool and assess disc wear in real-time. 展开更多
关键词 TBM disc cutter WEAR SOUND VIBRATION Machine learning real-time wear estimation
在线阅读 下载PDF
Lightweight YOLOM-Net for Automatic Identification and Real-Time Detection of Fatigue Driving
5
作者 Shanmeng Zhao Yaxue Peng +2 位作者 Yaqing Wang Gang Li Mohammed Al-Mahbashi 《Computers, Materials & Continua》 2025年第3期4995-5017,共23页
In recent years,the country has spent significant workforce and material resources to prevent traffic accidents,particularly those caused by fatigued driving.The current studies mainly concentrate on driver physiologi... In recent years,the country has spent significant workforce and material resources to prevent traffic accidents,particularly those caused by fatigued driving.The current studies mainly concentrate on driver physiological signals,driving behavior,and vehicle information.However,most of the approaches are computationally intensive and inconvenient for real-time detection.Therefore,this paper designs a network that combines precision,speed and lightweight and proposes an algorithm for facial fatigue detection based on multi-feature fusion.Specifically,the face detection model takes YOLOv8(You Only Look Once version 8)as the basic framework,and replaces its backbone network with MobileNetv3.To focus on the significant regions in the image,CPCA(Channel Prior Convolution Attention)is adopted to enhance the network’s capacity for feature extraction.Meanwhile,the network training phase employs the Focal-EIOU(Focal and Efficient Intersection Over Union)loss function,which makes the network lightweight and increases the accuracy of target detection.Ultimately,the Dlib toolkit was employed to annotate 68 facial feature points.This study established an evaluation metric for facial fatigue and developed a novel fatigue detection algorithm to assess the driver’s condition.A series of comparative experiments were carried out on the self-built dataset.The suggested method’s mAP(mean Average Precision)values for object detection and fatigue detection are 96.71%and 95.75%,respectively,as well as the detection speed is 47 FPS(Frames Per Second).This method can balance the contradiction between computational complexity and model accuracy.Furthermore,it can be transplanted to NVIDIA Jetson Orin NX and quickly detect the driver’s state while maintaining a high degree of accuracy.It contributes to the development of automobile safety systems and reduces the occurrence of traffic accidents. 展开更多
关键词 Fatigue driving facial feature lightweight network MobileNetv3-YOLOv8 dlib toolkit real-time
在线阅读 下载PDF
Real-Time Prediction of Stress Response of Tubular Joints on the Jacket Platform Using a Reduced-Order Model
6
作者 LENG Jian-cheng MAO Hou-bin +1 位作者 DIAO Kai-xin FENG Hui-yu 《China Ocean Engineering》 2025年第1期13-26,共14页
Jacket platforms constitute the foundational infrastructure of offshore oil and gas field exploitation.How to efficiently and accurately monitor the mechanical properties of jacket structures is one of the key problem... Jacket platforms constitute the foundational infrastructure of offshore oil and gas field exploitation.How to efficiently and accurately monitor the mechanical properties of jacket structures is one of the key problems to be solved to ensure the safe operation of the platform.To address the practical engineering problem that it is difficult to monitor the stress response of the tubular joints of jacket platforms online,a digital twin reduced-order method for real-time prediction of the stress response of tubular joints is proposed.In the offline construction phase,multi-scale modeling and multi-parameter experimental design methods are used to obtain the stress response data set of the jacket structure.Proper orthogonal decomposition is employed to extract the main feature information from the snapshot matrix,resulting in a reduced-order basis.The leave-one-out cross-validation method is used to select the optimal modal order for constructing the reduced-order model(ROM).In the online prediction phase,a digital twin model of the tubular joint is established,and the prediction performance of the ROM is analyzed and verified through using random environmental load and field environmental monitoring data.The results indicate that,compared with traditional numerical simulations of tubular joints,the ROM based on the proposed reduced-order method is more efficient in predicting the stress response of tubular joints while ensuring accuracy and robustness. 展开更多
关键词 offshore jacket platform digital twin tubular joints proper orthogonal decomposition leave-one-out cross validation real-time prediction
在线阅读 下载PDF
基于模糊测试的Java反序列化漏洞挖掘
7
作者 王鹃 张勃显 +3 位作者 张志杰 谢海宁 付金涛 王洋 《信息网络安全》 北大核心 2025年第1期1-12,共12页
随着反序列化技术在Java Web应用开发中的广泛应用,针对Java反序列化机制的攻击也日益增多,已严重威胁Java Web应用的安全性。当前主流的黑名单防范机制无法有效防御未知的反序列化漏洞利用,而现有的Java反序列化漏洞挖掘工具大多依赖... 随着反序列化技术在Java Web应用开发中的广泛应用,针对Java反序列化机制的攻击也日益增多,已严重威胁Java Web应用的安全性。当前主流的黑名单防范机制无法有效防御未知的反序列化漏洞利用,而现有的Java反序列化漏洞挖掘工具大多依赖静态分析方法,检测精确度较低。文章提出一种基于模糊测试的Java反序列化漏洞挖掘工具DSM-Fuzz,该工具首先通过对字节码进行双向追踪污点分析,提取所有可能与反序列化相关的函数调用链。然后,利用基于TrustRank算法的函数权值分配策略,评估函数与反序列化调用链的关联性,并根据相关性权值对模糊测试种子分配能量。为进一步优化测试用例的语法结构和语义特征,文章设计并实现了一种基于反序列化特征的种子变异算法。该算法利用反序列化的Java对象内部特征优化种子变异过程,并引导模糊测试策略对反序列化漏洞调用链进行路径突破。实验结果表明,DSM-Fuzz在漏洞相关代码覆盖量方面较其他工具提高了约90%。此外,该工具还在多个主流Java库中成功检测出50%的已知反序列化漏洞,检测精确度显著优于其他漏洞检测工具。因此,DSM-Fuzz可有效辅助Java反序列化漏洞的检测和防护。 展开更多
关键词 java反序列化漏洞 模糊测试 污点分析 漏洞挖掘 程序调用图
在线阅读 下载PDF
人工智能在Java程序设计课程教学中的应用
8
作者 潘少伟 朱爱琴 《福建电脑》 2025年第2期98-102,共5页
为提高Java程序设计课程教学质量以及减轻教师的教学压力,本文构建了一个智能化的线上教学平台。平台采用Browser/Server模式,利用人工智能技术库Deeplearning4j、TensorFlow Java API和Encog等进行业务驱动,并采用MySQL、MongoDB、MinI... 为提高Java程序设计课程教学质量以及减轻教师的教学压力,本文构建了一个智能化的线上教学平台。平台采用Browser/Server模式,利用人工智能技术库Deeplearning4j、TensorFlow Java API和Encog等进行业务驱动,并采用MySQL、MongoDB、MinIO和Redis满足不同数据类型的存储需求。实践表明,该教学方式可有效提高学生的积极性与参与感,有助于提高学生的教学成绩。 展开更多
关键词 线上教育 人工智能 java程序设计 教学改革
在线阅读 下载PDF
基于Java和Matlab的在线光学衍射演示系统设计与实现
9
作者 郭中华 侯培琦 杨梅花 《甘肃高师学报》 2025年第1期70-74,共5页
文章开发了一个集成Java多技术栈和Matlab的光学衍射仿真演示系统.该系统基于Spring Boot构建微服务架构,确保了系统的可伸缩性和灵活性.通过Ajax技术实现前后端数据交互,采用Bootstrap框架实现响应式布局,以适应不同设备.系统采用分层... 文章开发了一个集成Java多技术栈和Matlab的光学衍射仿真演示系统.该系统基于Spring Boot构建微服务架构,确保了系统的可伸缩性和灵活性.通过Ajax技术实现前后端数据交互,采用Bootstrap框架实现响应式布局,以适应不同设备.系统采用分层和面向服务的架构设计,可提高维护性和扩展性.核心算法由Matlab编写并编译为Java库,与后端集成,可优化仿真效率.系统无需额外插件或服务器,适合云部署,并能在多种终端上运行,提供了一个直观的光学原理学习和演示平台. 展开更多
关键词 光学衍射 虚拟仿真 java多技术栈 Matlab集成 云存储
在线阅读 下载PDF
“1+X”证书制度背景下Java程序设计课程创新研究
10
作者 王颖 《科学与信息化》 2025年第1期96-98,共3页
近年来,乐山职业技术学院为提高物联网应用技术专业学生的Java程序设计水平,进行了多次教改项目的研究。为了进一步提高学生岗位能力及实践动手能力,开启了将“1+X”证书制度融入Java程序设计课程的研究,达到以考促学,岗课证融通的目的... 近年来,乐山职业技术学院为提高物联网应用技术专业学生的Java程序设计水平,进行了多次教改项目的研究。为了进一步提高学生岗位能力及实践动手能力,开启了将“1+X”证书制度融入Java程序设计课程的研究,达到以考促学,岗课证融通的目的。本文从研究目的入手,先介绍“1+X”证书制度的背景,国内兄弟院校发展情况,再结合乐山职业技术学院实际特点和情况,初步探讨了该校今后在开展此类项目的几点思考,为后续进一步开展深入研究打下基础。 展开更多
关键词 java程序设计 “1+X”证书制度 课程创新
在线阅读 下载PDF
类ChatGPT背景下Java程序设计教学模式构建
11
作者 张必英 吕友波 +1 位作者 张艳荣 姚桂林 《微型计算机》 2025年第1期244-246,共3页
在类ChatGPT技术的背景下,高等教育领域正面临着前所未有的机遇和严峻的挑战,传统的教学模式急需更新和改革。本文以Java程序设计课程为例,探讨了适应类ChatGPT技术的课程教学目标和教学方法。首先,对课程的教学目标进行了重设,强调培... 在类ChatGPT技术的背景下,高等教育领域正面临着前所未有的机遇和严峻的挑战,传统的教学模式急需更新和改革。本文以Java程序设计课程为例,探讨了适应类ChatGPT技术的课程教学目标和教学方法。首先,对课程的教学目标进行了重设,强调培养学生利用类ChatGPT技术提出问题的能力,以及提升学生的自主学习能力。其次,设计了一套适应类ChatGPT技术的教学方法和实施方案,采用以学生为中心的教学策略,充分考虑到学生的个人需求和差异性,通过实践、讨论和反思的循环,促进学生深入学习和理解新技术。不仅为Java程序设计课程提供了新的教学模式,而且为其他高等教育课程提供了应对快速技术变革的参考和借鉴。 展开更多
关键词 ChatGPT 教学模式 java程序设计 自主学习 个性化教学
在线阅读 下载PDF
应用Java EE技术实现仓库管理系统的开发研究
12
作者 王晴 《兰州石化职业技术大学学报》 2025年第1期31-36,共6页
仓库管理系统与传统的人工管理仓库方式相比,效率更高、成本更低。但是时间一长,将产生大量的数据和文件,这将会给传统管理仓库以及物品的查找、更新和维护带来不少的问题,而使用仓库管理系统对物资进行管理将会极大地方便企业。因此,... 仓库管理系统与传统的人工管理仓库方式相比,效率更高、成本更低。但是时间一长,将产生大量的数据和文件,这将会给传统管理仓库以及物品的查找、更新和维护带来不少的问题,而使用仓库管理系统对物资进行管理将会极大地方便企业。因此,需要开发一个可以帮助企业管理仓库物资的仓库管理系统。该系统功能主要包括:系统管理模块(管理员管理、用户管理、系统管理),功能模块(仓库管理,分类管理,物品管理)。采用了B/S模式设计、前后端分离技术、Vue技术、element ui前端框架、Java开发、SpringBoot、MySQL 8.0、Tomcat 9.0.30服务器、Activiti工作流等技术。系统所有功能设计环节以方便企业使用为目标,用精简的界面向用户传达尽可能详尽的信息,操作界面简单,使用逻辑清晰。以仓库物品管理为核心,添加出入库审批,方便用户查看的同时,尽可能的简化操作,方便企业用户使用。 展开更多
关键词 仓库管理系统 B/S设计模式 J2EE java 前后端分离 Vue
在线阅读 下载PDF
基于JAVA语言的智能家居电子设备数据交互系统设计
13
作者 刘平 王丽娜 《电子产品世界》 2025年第2期61-64,共4页
针对当前智能家居设备缺乏统一的通信协议,部分设备存在数据传输响应速度慢、数据延迟发生等问题,设计了基于JAVA语言的智能家居电子设备数据交互系统。首先,进行了智能家居电子设备交互分析,阐述了智能家居环境架构和设备数据交互问题... 针对当前智能家居设备缺乏统一的通信协议,部分设备存在数据传输响应速度慢、数据延迟发生等问题,设计了基于JAVA语言的智能家居电子设备数据交互系统。首先,进行了智能家居电子设备交互分析,阐述了智能家居环境架构和设备数据交互问题。其次,提出了基于JAVA语言的智能家居电子设备数据交互系统总体方案,总结了系统需求,设计了系统方案,建立了智能家居电子设备网络节点。最后,建立了智能家居电子设备数据交互通信网络,构建了节点入网和IP地址分配,设计了数据交互系统软件。该数据交互系统能够成功实现多种智能家居设备的数据互联,大幅降低设备之间的数据延迟,从而使传输效率得到显著提升。 展开更多
关键词 java语言 智能家居 电子设备 数据交互 网络节点
在线阅读 下载PDF
“三核驱动,四元融通”策略在Java程序设计课程思政教学中的应用
14
作者 朱颖芳 孙玉荣 +1 位作者 黄慧华 叶萍 《计算机教育》 2025年第4期142-145,共4页
针对Java程序设计课程思政教学中存在的问题,提出“三核驱动,四元融通”的课程思政教学策略,阐述如何将课堂理论教学知识点和实践教学环节与思政元素有效结合,通过近3年的实践教学结果,说明教学成效。
关键词 思政教学 教学改革 java程序设计 三核驱动 四元融通
在线阅读 下载PDF
基于“岗课赛证”融合的Java编程课程教育教学改革的理论研究
15
作者 王征录 《家电维修》 2025年第1期40-42,共3页
部分院校在课程中开展了“岗课赛证”的融合,取得了很好的效果,提高了学生的学习效率,得到了广大教师和学生的一致好评,培养出的学生更受用人单位的欢迎,“岗课赛证”融合模式在教育领域有广阔的应用前景。我院的Java编程课程的教学还... 部分院校在课程中开展了“岗课赛证”的融合,取得了很好的效果,提高了学生的学习效率,得到了广大教师和学生的一致好评,培养出的学生更受用人单位的欢迎,“岗课赛证”融合模式在教育领域有广阔的应用前景。我院的Java编程课程的教学还是采用传统的课程体系,笔者结合自己从事多年的Java编程课程教学体会综合分析,发现存在课程内容落后于岗位需求、技能大赛的项目没有融入课程内容和考证知识没有融入课程内容的问题,因此函需进行“岗课赛证”融合的研究,来提升Java编程课程教育教学质量。 展开更多
关键词 岗课赛证 java编程 教育教学 改革
在线阅读 下载PDF
基于“岗课赛证”融合的Java编程课程教育教学改革的实践研究
16
作者 王征录 《家电维修》 2025年第2期27-29,共3页
随着信息技术的飞速发展,计算机科学领域对Java编程人才的需求日益增加,对Java编程课程的教学改革也提出了更高要求。本文基于“岗课赛证”融合的教育理念,对Java编程课程的教育教学改革进行实践研究,旨在提升教学质量,培养学生的实际... 随着信息技术的飞速发展,计算机科学领域对Java编程人才的需求日益增加,对Java编程课程的教学改革也提出了更高要求。本文基于“岗课赛证”融合的教育理念,对Java编程课程的教育教学改革进行实践研究,旨在提升教学质量,培养学生的实际工作能力和创新精神。近年来,职业教育强调“工学结合、校企合作、顶岗实习”的模式,通过技能大赛推动课程教学改革已成为共识。教育部提出的“岗课赛证”综合育人模式,即岗位需求、课程设置、技能竞赛与职业资格证书相结合[1],为Java编程课程的教学改革提供了新的思路。本研究旨在通过“岗课赛证”融合的方式,对Java编程课程进行教育教学改革实践,实现课程内容与企业需求对接并激发学生的创新精神。 展开更多
关键词 “岗课赛证” java编程课程 教育教学 实践
在线阅读 下载PDF
Phase behavior of gas condensate in porous media using real-time computed tomography scanning 被引量:2
17
作者 Wen-Long Jing Lei Zhang +5 位作者 Ai-Fen Li Jun-Jie Zhong Hai Sun Yong-Fei Yang Yu-Long Cheng Jun Yao 《Petroleum Science》 SCIE EI CAS CSCD 2024年第2期1032-1043,共12页
The phase behavior of gas condensate in reservoir formations differs from that in pressure-volume-temperature(PVT)cells because it is influenced by porous media in the reservoir formations.Sandstone was used as a samp... The phase behavior of gas condensate in reservoir formations differs from that in pressure-volume-temperature(PVT)cells because it is influenced by porous media in the reservoir formations.Sandstone was used as a sample to investigate the influence of porous media on the phase behavior of the gas condensate.The pore structure was first analyzed using computed tomography(CT)scanning,digital core technology,and a pore network model.The sandstone core sample was then saturated with gas condensate for the pressure depletion experiment.After each pressure-depletion state was stable,realtime CT scanning was performed on the sample.The scanning results of the sample were reconstructed into three-dimensional grayscale images,and the gas condensate and condensate liquid were segmented based on gray value discrepancy to dynamically characterize the phase behavior of the gas condensate in porous media.Pore network models of the condensate liquid ganglia under different pressures were built to calculate the characteristic parameters,including the average radius,coordination number,and tortuosity,and to analyze the changing mechanism caused by the phase behavior change of the gas condensate.Four types of condensate liquid(clustered,branched,membranous,and droplet ganglia)were then classified by shape factor and Euler number to investigate their morphological changes dynamically and elaborately.The results show that the dew point pressure of the gas condensate in porous media is 12.7 MPa,which is 0.7 MPa higher than 12.0 MPa in PVT cells.The average radius,volume,and coordination number of the condensate liquid ganglia increased when the system pressure was between the dew point pressure(12.7 MPa)and the pressure for the maximum liquid dropout,Pmax(10.0 MPa),and decreased when it was below Pmax.The volume proportion of clustered ganglia was the highest,followed by branched,membranous,and droplet ganglia.This study provides crucial experimental evidence for the phase behavior changing process of gas condensate in porous media during the depletion production of gas condensate reservoirs. 展开更多
关键词 Gas condensate Pressure depletion real-time micro-computed tomography scanning Distribution of condensate liquid
在线阅读 下载PDF
基于Real-time PCR法检测乳粉中牛源性成分定量研究
18
作者 陈晨 史国华 +5 位作者 陈勃旭 张瑞 王玉欣 贾文珅 陈佳 周巍 《粮油食品科技》 CAS CSCD 北大核心 2024年第2期159-164,共6页
基于Real-timePCR建立了乳粉中牛源性成分相对定量检测方法,并对牛的特异性引物与探针进行了特异性、灵敏度和稳定性测试。通过模拟不同浓度牛乳粉与马乳粉混合样本,根据其△Ct值的函数关系进行线性拟合进而绘制标准曲线,建立乳粉中牛... 基于Real-timePCR建立了乳粉中牛源性成分相对定量检测方法,并对牛的特异性引物与探针进行了特异性、灵敏度和稳定性测试。通过模拟不同浓度牛乳粉与马乳粉混合样本,根据其△Ct值的函数关系进行线性拟合进而绘制标准曲线,建立乳粉中牛源性成分的相对定量检测。结果显示,该方法的最低检测限为0.00001 mg/mL,回收率为91.11%~119.2%,组间变异系数≤0.58%、组内变异系数≤1.44%。说明该方法在特异性与稳定性上适用于乳粉中牛源性成分及含量的掺假检测。 展开更多
关键词 牛乳粉 马乳粉 real-time PCR 掺假检测
在线阅读 下载PDF
A multifunctional shear apparatus for rocks subjected to true triaxial stress and high temperature in real-time 被引量:1
19
作者 Jun Zhao Xia-Ting Feng +2 位作者 Jia-Rong Wang Liang Hu Yue Guo 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2024年第9期3524-3543,共20页
Deep engineering disasters,such as rockbursts and collapses,are more related to the shear slip of rock joints.A novel multifunctional device was developed to study the shear failure mechanism in rocks.Using this devic... Deep engineering disasters,such as rockbursts and collapses,are more related to the shear slip of rock joints.A novel multifunctional device was developed to study the shear failure mechanism in rocks.Using this device,the complete shearedeformation process and long-term shear creep tests could be performed on rocks under constant normal stiffness(CNS)or constant normal loading(CNL)conditions in real-time at high temperature and true-triaxial stress.During the research and development process,five key technologies were successfully broken through:(1)the ability to perform true-triaxial compressioneshear loading tests on rock samples with high stiffness;(2)a shear box with ultra-low friction throughout the entire stress space of the rock sample during loading;(3)a control system capable of maintaining high stress for a long time and responding rapidly to the brittle fracture of a rock sample as well;(4)a refined ability to measure the volumetric deformation of rock samples subjected to true triaxial shearing;and(5)a heating system capable of maintaining uniform heating of the rock sample over a long time.By developing these technologies,loading under high true triaxial stress conditions was realized.The apparatus has a maximum normal stiffness of 1000 GPa/m and a maximum operating temperature of 300C.The differences in the surface temperature of the sample are constant to within5C.Five types of true triaxial shear tests were conducted on homogeneous sandstone to verify that the apparatus has good performance and reliability.The results show that temperature,lateral stress,normal stress and time influence the shear deformation,failure mode and strength of the sandstone.The novel apparatus can be reliably used to conduct true-triaxial shear tests on rocks subjected to high temperatures and stress. 展开更多
关键词 True-triaxial shear apparatus ROCKS Complete shear stress-deformation process CREEP real-time high-temperature
在线阅读 下载PDF
A Real-time Lithological Identification Method based on SMOTE-Tomek and ICSA Optimization 被引量:1
20
作者 DENG Song PAN Haoyu +5 位作者 LI Chaowei YAN Xiaopeng WANG Jiangshuai SHI Lin PEI Chunyu CAI Meng 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2024年第2期518-530,共13页
In petroleum engineering,real-time lithology identification is very important for reservoir evaluation,drilling decisions and petroleum geological exploration.A lithology identification method while drilling based on ... In petroleum engineering,real-time lithology identification is very important for reservoir evaluation,drilling decisions and petroleum geological exploration.A lithology identification method while drilling based on machine learning and mud logging data is studied in this paper.This method can effectively utilize downhole parameters collected in real-time during drilling,to identify lithology in real-time and provide a reference for optimization of drilling parameters.Given the imbalance of lithology samples,the synthetic minority over-sampling technique(SMOTE)and Tomek link were used to balance the sample number of five lithologies.Meanwhile,this paper introduces Tent map,random opposition-based learning and dynamic perceived probability to the original crow search algorithm(CSA),and establishes an improved crow search algorithm(ICSA).In this paper,ICSA is used to optimize the hyperparameter combination of random forest(RF),extremely random trees(ET),extreme gradient boosting(XGB),and light gradient boosting machine(LGBM)models.In addition,this study combines the recognition advantages of the four models.The accuracy of lithology identification by the weighted average probability model reaches 0.877.The study of this paper realizes high-precision real-time lithology identification method,which can provide lithology reference for the drilling process. 展开更多
关键词 mud logging data real-time lithological identification improved crow search algorithm petroleum geological exploration SMOTE-Tomek
在线阅读 下载PDF
上一页 1 2 250 下一页 到第
使用帮助 返回顶部