检索结果-南通市图书馆

The joint knowledge reasoning model based on knowledge representation learning for aviation assembly domain

Science China(Technological Sciences) 2024年第1期67卷 143-156页

作者： LIU PeiFeng QIAN Lu LU Hu xue Lei ZHAO XingWei tao Bo State Key Laboratory of Digital Manufacturing Equipment and Technology Department of MechanicalHuazhong University of Science and TechnologyWuhan 430074China School of Transportation and Logistics Engineering Wuhan University of Technology(WHUT)Wuhan 430063China Shanghai Aircraft Manufacturing Co. Ltd.Shanghai 201324China

Knowledge graph technology is widely applied in the domain of general knowledge reasoning with an excellent *** fine-grained professional fields,professional knowledge graphs can provide more accurate information in practical industrial *** on an aviation assembly domain-specific knowledge graph,the article constructs a joint knowledge reasoning model,which combines a named entity recognition model and a subgraph embedding learning *** performing knowledge reasoning tasks,the two models vectorize entities,relationships and entity attributes in the same space,so as to share parameters and optimize learning *** knowledge reasoning model,which provides intelligent question answering services,is able to reduce the assembly error rate and improve the assembly *** system can accurately solve general knowledge reasoning problems in the assembly process in actual industrial scenarios of general assembly and component assembly under interference-free ***,this paper compares the proposed knowledge reasoning model based on knowledge representation learning and the question-answering system based on large-scale pre-trained *** the application scenario of system functional testing in general assembly,the joint model attains an accuracy rate of 95%,outperforming GPT with 78%accuracy and enhanced representation through knowledge integration with 71%accuracy.

关键词： intelligent manufacturing knowledge graph aviation assembly knowledge representation knowledge-based question an-swering

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

Dynamic response of water-rich tunnel subjected to plane P wave considering excavation induced damage zone

引用

Underground Space 2024年第2期15卷 113-130页

作者： Gongliang Xiang Ming tao rui Zhao Huatao Zhao Muhammad Burhan Memon Chengqing Wu School of Resources and Safety Engineering Central South UniversityChangsha 410083China School of Geoscience and Technology Southwest Petroleum UniversityChengdu 610500China School of Civil and Environmental Engineering University of Technology SydneyNSW 2007Australia

The stability analysis of a deep buried tunnel subjected to dynamic disturbance is an important *** this study,the transient response has been obtained by establishing a water-rich tunnel model considering excavation damage zone(EDZ).Based on Biot’s two-phase dynamic theory and wave function expansion method,the analytical solution of dynamic response around the water-rich tunnel containing EDZ subjected to P wave is ***,Fourier transform and Duhamel’s integral technique is introduced to calculate the transient response,and the equivalent blasting curve is adopted to input excitation *** dimensionless parameters thickness N and shear modulus ratio lare defined to characterize the degree of damage in the surrounding rock,investigating the influencing factors,such as the parameters and the incident source *** results indicate that the dynamic stress concentration factor(DSCF)gradually decreases as the dimensionless parameters ***,it is observed that the DSCF is more sensitive to changes in the thickness parameter ***,the influence of the waveform parameters has been taken into account in the analysis of transient response,and the stress state and transfer process in each time stage of the EDZ are *** study establishes a theoretical foundation for comprehending the mechanical behavior and support design considerations associated with a deep-buried water-rich tunnel containing EDZ.

关键词： Water-rich tunnel Two-phase dynamic theory Wave scattering Transient response Dynamic stress concentration

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

LaMnO_(3)/Co_(3)O_(4) nanocomposite for enhanced triethylamine sensing properties

引用

Journal of Rare Earths 2024年第4期42卷 733-742页

作者： Jian Zhang Yanping Chen Ling Li xue Chen Wenya An Xiujuan Qian Yuye tao School of Science Shandong Jianzhu UniversityJinan250100China

LaMnO_(3) modified Co_(3)O_(4) nanocomposites were prepared by simple hydrothermal method co mbined with sol-gel *** gas sensitivity properties of pure Co_(3)O_(4) and LaMnO_(3)/Co_(3)O_(4) with different composite proportions are *** is found that 0.6-LMO/Co_(3)O_(4) sensor has higher sensitivity to triethylamine(TEA)than pure Co_(3)O_(4) sensor,which is improved by 9.27 *** the working temperature is reduced from 150 to 130℃.Besides,it has excellent gas selectivity and *** improvement of the gas sensitivity of LaMnO_(3)/Co_(3)O_(4) sensor may be due to the fact that LaMnO_(3) is an effective catalyst,and the catalytic performance perhaps is beneficial to improving the sensing *** addition,the formation of p-p heterojunctions may be the key factor to improve the gas sensing *** work provides a new Co_(3)O_(4)-based gas sensing material for the detection of TEA.

关键词： Gas sensing Co_(3)O_(4) LaMnO_(3) Triethylamine Rareearths

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

Effect of ceramic work rolls on surface roughness of rolled SUS304 ultra-thin strips

引用

Journal of Iron and Steel Research International 2024年第7期31卷 1704-1718页

作者： Peng-cheng Li tao Wang Chen-chen Zhao Qi Liu Qing-xue Huang College of Mechanical and Vehicle Engineering Taiyuan University of TechnologyTaiyuan 030024ShanxiChina Engineering Research Center of Advanced Metal Composites Forming Technology and Equipment of Ministry of Education Taiyuan University of TechnologyTaiyuan 030024ShanxiChina National Key Laboratory of Metal Forming Technology and Heavy Equipment Taiyuan University of TechnologyTaiyuan 030024ShanxiChina

Surface morphology and roughness are important parameters of surface quality of cold-rolled ultra-thin strip *** order to study the effect of Si_(3)N_(4) ceramic work rolls on the surface roughness of SUS304 ultra-thin strip,ABAQUS finite element model calculation,3D laser profilometry,and other methods were adopted based on the physical characteristics of Si_(3)N_(4) ceramic roll and 9Cr2MoV steel roll,like anti-flattening performance and oil *** surface morphology and roughness of SUS304 ultra-thin strip rolled by different material work rolls under oil lubrication conditions were *** results showed that under the rolling force of 10 kN,the maximum flattening amount of Si_(3)N_(4) ceramic roll was reduced by 35.14%compared to that of 9Cr2MoV steel *** reduction rate of SUS304 ultra-thin strip rolled by ceramic roll was 34.19%,while that rolled by steel roll was only 22%;Si_(3)N_(4) ceramic roll can further increase the number of alternating convex peaks and concave valleys in the rolled thin strip,reduce the profile steepness,reduce surface roughness,and enhance the planarization effect of surface micro-convex bodies,with improving surface quality and surface ***,the mechanism of Si_(3)N_(4) ceramic roll significantly improving the surface roughness of rolled SUS304 ultra-thin strip was proposed.

关键词： Ceramic work roll-Steel roll SUS304 ultra-thin strip Reduction Surface roughness

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

Learning to Branch in Combinatorial Optimization With Graph Pointer Networks

引用

IEEE/CAA Journal of Automatica Sinica 2024年第1期11卷 157-169页

作者： rui Wang Zhiming Zhou Kaiwen Li tao Zhang Ling Wang Xin Xu Xiangke Liao IEEE the Xiangjiang Laboratory and the College of Systems Engineering National University of Defense TechnologyChangsha 410073China the Institute of Automation Chinese Academy of SciencesBeijing 100190China the College of Systems Engineering National University of Defense TechnologyChangsha 410073 the Hunan Key Laboratory of Multi-Energy System Intelligent Interconnection Technology Changsha 410073China the Department of Automation Tsinghua UniversityBeijing 100084China the College of Intelligence Science and Technology National University of Defense TechnologyChangsha 410073China the College of Computer Science and Technology National University of Defense TechnologyChangsha 410073China

Traditional expert-designed branching rules in branch-and-bound(B&B) are static, often failing to adapt to diverse and evolving problem instances. Crafting these rules is labor-intensive, and may not scale well with complex *** the frequent need to solve varied combinatorial optimization problems, leveraging statistical learning to auto-tune B&B algorithms for specific problem classes becomes attractive. This paper proposes a graph pointer network model to learn the branch rules. Graph features, global features and historical features are designated to represent the solver state. The graph neural network processes graph features, while the pointer mechanism assimilates the global and historical features to finally determine the variable on which to branch. The model is trained to imitate the expert strong branching rule by a tailored top-k Kullback-Leibler divergence loss function. Experiments on a series of benchmark problems demonstrate that the proposed approach significantly outperforms the widely used expert-designed branching rules. It also outperforms state-of-the-art machine-learning-based branch-and-bound methods in terms of solving speed and search tree size on all the test instances. In addition, the model can generalize to unseen instances and scale to larger instances.

关键词： Branch-and-bound(B&B) combinatorial optimization deep learning graph neural network imitation learning

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

Vortex identification based on the Liutex method and its effect on fish passage upstream

引用

Journal of Hydrodynamics 2024年第1期36卷 130-141页

作者： Chun-ying Shen rui-guo Yang Xiao-tao Shi Ming-ming Wang Shi-hua He Faculty of Electrical Power Engineering Kunming University of Science and TechnologyKunming650500China Hubei International Science and Technology Cooperation Base of Fish Passage China Three Gorges UniversityYichang443002China Shanghai Investigation Design and Research Institute Co.LtShanghai200434China

Fishway research is important for mitigating the fragmentation of river habitats caused by hydraulic *** vertical slit fishway is a broadly used fishway type because of its high efficiency and adaptability to water ***,the resulting vortex current disrupts the fish passage hence directly affecting fish *** study aims to accurately capture the vortex structure in the fishway and analyze the effect of vortex elements(vortex structure,vortex intensity,etc.)on *** conducted an analysis of the 3-D current flow field in the fishway through the utilization of an experimental model and the large eddy simulation(LES)***,we captured the vortex information in the fishway at different flow rates using the Liutex vortex identification method and investigated the effect of the vortex on fish *** results revealed that the structures inside the fishway pool occupy most of the room,however,the areas with higher vortex strength were primarily located in the vortex near the vertical seam and the mainstream,the vortex strength inside the fishway gradually increases with increasing flow,suppressing fish *** experienced significantly increased resistance when encountering strong *** suggests that the vortex may act as a physical barrier to fish *** findings highlight the potential negative effects of vortex on fish movement and reiterate the importance of understanding vortex dynamics for aquatic environmental *** an effective tool for identifying vortices in fluid flow,the Liutex method demonstrates features of vortex within the fishway,thereby providing important insights into the interaction between fluid dynamics and aquatic organisms.

关键词： Vertical slit fishway vortex identification method Liutex large eddy simulation(LES) fish experiment computational fluid dynamics

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

Enhanced red luminescence of Ca_(3)Si_(2−x)M_(x)O_(7):Eu^(3+)(M=Al,P)phosphors via partial substitution of Si^(4+) for applications in white light-emitting diodes

引用

Rare Metals 2024年第2期43卷 736-748页

作者： Yu-Hao Ma Xi Gao Wen-tao Zhang Zhen-rui Yang Zhou Zhao Chen Qu College of Materials and Chemistry and Chemical Engineering Chengdu University of TechnologyChengdu610059China State Key Laboratory of Geohazard Prevention and Geoenvironment Protection Chengdu University of TechnologyChengdu610059China International Advanced Energy Science Research and Education Center Graduate School of Energy ScienceKyoto UniversityYoshida-HonmachiKyoto606-8501Japan

A red-emitting phosphor Ca_(2.91)Si_(2)O_(7):0.09Eu^(3+) with partial Al^(3+)/P^(5+) substitution on Si^(4+) was synthesized via a simple solid-state method,and the effects of the introduction of the M^(3+/5+)(M=Al,P)ions on the crystal structure and photoluminescence performance of Ca_(2.91)Si_(2−x)M_(x)O_(7):0.09Eu^(3+) phosphors were *** X-ray diffraction(XRD),energy-dispersive X-ray spectroscopy(EDS),and X-ray photoelectron spectroscopy(XPS)results revealed that the structure of Ca_(3)Si_(2)O_(7) remained the same after the introduction of Al^(3+) and P^(5+) *** characteristic emission of Eu^(3+)-doped Ca_(3)Si_(2−x)M_(x)O_(7) phosphors exhibited two main peaks at 617 nm(red)and 593 nm(orange)under excitation at 394 nm,which originated from the^(5)D_(0)→^(7)F_(2)and^(5)D_(0)→^(7)F_(1) electron transitions of Eu^(3+) *** the partial substitution of Al^(3+) and P^(5+),the red emission intensities of the Ca_(2.91)Si_(2)O_(7):0.09Eu^(3+) phosphors were significantly enhanced by 1.88-and 1.42-fold,respectively,which is attributed to the crystal-field effect around Eu^(3+).Meanwhile,the luminescence intensities of the Ca_(2.91)Si_(1.96)Al_(0.04)O_(7):0.09Eu^(3+) and Ca_(2.91)Si_(1.94)P_(0.06)O_(7):0.09Eu^(3+) phosphors at 210℃ were 79.36%and 77.53%of those at 30°C,respectively,indicating their excellent thermal ***,the as-prepared Ca_(2.91)Si_(1.96)Al_(0.04)O_(7):0.09Eu^(3+)and Ca_(2.91)Si_(1.94)P_(0.06)O_(7):0.09Eu^(3+) red-emitting phosphors were combined with a near-ultraviolet chip of 395 nm to fabricate red-light-emitting diode(LED)and white(w)-LED devices with excellent chromaticity *** summary,Al^(3+)/P^(5+)-substituted Ca_(2.91)Si_(2)O_(7):0.09Eu^(3+) can serve as red-emitting phosphors for applications in w-LEDs.

关键词： Ca_(3)Si_(2)O_(7) Red-emitting phosphor Structure substitution Luminescence enhancement Crystal-field effect White light-emitting diode

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 spatial-temporal deep learning prediction model of industrial methanol-to-olefins process

引用

Frontiers of Chemical Science and Engineering 2024年第4期18卷 73-85页

作者： Jibin Zhou xue Li Duiping Liu Feng Wang tao Zhang Mao Ye Zhongmin Liu National Engineering Research Center of Lower-Carbon Catalysis Technology Dalian Institute of Chemical PhysicsChinese Academy of SciencesDalian 116023China Yulin Innovation Institute for Clean Energy Clean Energy Innovation Institute of Chinese Academy of SciencesYulin 719053China xuelang Industrial Intelligence Technology Co. Ltd.Wuxi 214000China

Methanol-to-olefins,as a promising non-oil pathway for the synthesis of light olefins,has been successfully *** accurate prediction of process variables can yield significant benefits for advanced process control and *** challenge of this task is underscored by the failure of traditional methods in capturing the complex characteristics of industrial processes,such as high nonlinearities,dynamics,and data distribution shift caused by diverse operating *** this paper,we propose a novel hybrid spatial-temporal deep learning prediction model to address these ***,a unique data normalization technique called reversible instance normalization is employed to solve the problem of different data ***,convolutional neural network integrated with the self-attention mechanism are utilized to extract the temporal ***,a multi-graph convolutional network is leveraged to model the spatial ***,the extracted temporal and spatial features are fused as input into a fully connected neural network to complete the ***,the outputs are denormalized to obtain the ultimate *** monitoring results of the dynamic trends of process variables in an actual industrial methanol-to-olefins process demonstrate that our model not only achieves superior prediction performance but also can reveal complex spatial-temporal relationships using the learned attention matrices and adjacency matrices,making the model more ***,this model is deployed onto an end-to-end Industrial Internet Platform,which achieves effective practical results.

关键词： methanol-to-olefins process variables prediction spatial-temporal self-attention mechanism graph convolutional network

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

Mechanism of local solidification time variations with melt rate during vacuum arc remelting process of 8Cr4Mo4V high-strength steel

引用

Journal of Iron and Steel Research International 2024年第2期31卷 377-388页

作者： tao Pan Hong-chun Zhu Zhou-hua Jiang Hua-bing Li rui Zhang Hao Feng School of Metallurgy Northeastern UniversityShenyang110819LiaoningChina State Key Laboratory of Rolling and Automation Northeastern UniversityShenyang110819LiaoningChina

A 2D axisymmetric numerical model was established to investigate the variations of molten pool with different melt rates during the vacuum arc remelting of 8Cr4Mo4V high-strength steel,and the ingot growth was simulated by dynamic mesh *** results show that as the ingot grows,the molten pool profile changes from shallow and flat to V-shaped,and both the molten pool depth and the mushy width ***,the variation of both the molten pool shape and the mushy width melt rate is clarified by the thermal equilibrium *** melt rate increases,both the molten pool depth and the mushy width *** is caused by the increment in sensible heat stored in the ingot due to the limitation of the cooling capacity of the *** nonlinear increment in sensible heat leads to a nonlinear increase in the mushy *** addition,as melt rate increases,the local solidification time(LST)of ingot decreases obviously at first and then *** melt rate is controlled in a suitable range,LST is the lowest and the secondary dendrite arm spacing of the ingot is the smallest,which can effectively improve the compactness degree of 8Cr4Mo4V high-strength steel.

关键词： 8Cr4Mo4V high-strength steel Vacuum arc remelting process Melt rate Molten pool Local solidification time

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

Disc-cutter induced rock breakage mechanism for TBM excavation in rock masses with different joint shear strengths

引用

Underground Space 2024年第6期19卷 119-137页

作者： Bolong Liu Bo Li Liang Zhang rui Huang Huicai Gao Shilin Luo tao Wang Key Laboratory of Rock Mechanics and Geohazards of Zhejiang Province Shaoxing UniversityShaoxing 312000China College of Civil Engineering Tongji UniversityShanghai 200092China College of Civil and Architectural Engineering Xi’an University of Science and TechnologyXi’an 710054China College of Civil Engineering Changsha UniversityChangsha 410022China School of Transportation Science and Engineering Harbin Institute of TechnologyHarbin 150040China Chongqing Research Institute of Harbin Institute of Technology Harbin Institute of TechnologyChongqing 401151China

When tunnel boring machines(TBMs)excavate through jointed rock masses,the cutting efficiency is strongly affected by the shear strength of joints,the mechanism of which,however,remains poorly *** this study,a series of disc-cutter indentation tests were conducted on granite rock mass specimens with different joint shear *** the indentation,the cracking process was recorded by a digital image correlation(DIC)*** deformation and strength of specimens,cracking behavior,rock breakage mode and cutting efficiency were quantitatively *** addition,to investigate the combined effects of joint shear strength,orientation and spacing on the rock breakage mechanism,numerical rock mass models were established based on a particle flow code *** results reveal that the cracking of primary and secondary cracks changes from the mixed shear-tensile to tensile mode in the initial stage,while the joint shear strength does not affect the cracking mode in the subsequent propagation *** rock breakage mode is classified to an internal block breakage mode,a cross-joint breakage mode and a cutters-dependent breakage *** cross-joint breakage mode is optimal for improving the cutting *** simulation results reveal that the increase in the joint shear strength changes the internal block breakage mode to cross-joint breakage mode for rock masses of particular ranges of joint orientation and *** findings provide basis for improving the TBM cutting efficiency through jointed rock masses.

关键词： Indentation test Joint shear strength Disc cutter Rock breakage mechanism Cutting efficiency

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

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：