检索结果-南通市图书馆

A cumulative damage model for predicting and assessing raveling in asphalt pavement using an energy dissipation approach

在线全文

学校读者我要写书评

暂无评论

Frontiers of Structural and Civil Engineering 2024年第6期18卷 949-962页

作者： Kailing DENG Duanyi WANG Cheng TANG jianwen SITU Luobin CHEN School of Civil Engineering and Transportation South China University of TechnologyGuangzhou 510640China

Raveling is a common distress of asphalt pavements,defined as the removal of stones from the pavement *** predict and assess raveling quantitatively,a cumulative damage model based on an energy dissipation approach has been developed at the meso *** construct the model,a new test method,the pendulum impact test,was employed to determine the fracture energy of the stone-mastic-stone meso-unit,while digital image analysis and dynamic shear rheometer test were used to acquire the strain rate of specimens and the rheology property of mastic,*** of the model reveals that when the material properties remain constant,the cumulative damage is directly correlated with loading time,loading amplitude,and loading ***,damage increases with superimposed linear and cosine variations over time.A higher stress amplitude results in a more rapidly increasing rate of damage,while a lower load frequency leads to more severe damage within the same loading ***,an example of the application of the model has been presented,showing that the model can be utilized to estimate failure life due to *** model is able to offer a theoretical foundation for the design and maintenance of anti-raveling asphalt pavements.

关键词： asphalt pavement raveling cumulative damage dissipation energy theory

Analysis of the Erosion-Corrosion Mechanism of the Air Cooler in a Hydrocracking Unit:A Numerical and Experimental Study

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

China Petroleum Processing & Petrochemical Technology 2024年第1期26卷 126-138页

作者： Su Guoqing Li Yan Guo Hongli Zhang jianwen College of Mechanical and Electrical Engineering Beijing University of Chemical TechnologyBeijing 100029China

Corrosion leakages often occur in the air cooler of a hydrocracking unit,with the failure sites mainly located in the entrance area of the *** analysis of the macroscopic morphology and corrosion products confirmed that the damage was caused by erosion-corrosion(E-C).Numerical and experimental methods were applied to investigate the E-C mechanism in the air *** fluid dynamics(CFD)was used to calculate the hydrodynamic parameters of the air *** results showed that there was a biased flow in the air cooler,which led to a significant increase in velocity,turbulent kinetic energy and wall shear within 0.2 m of the tube entrance.A visualization experiment was then performed to determine the principles of migration and transformation of multiphase flow in the air cooler *** flow patterns(pure droplet flow,mist flow,and annular flow)and their evolutionary processes were clearly depicted *** initiation mechanism and processes leading to the development of E-C in the air cooler were also *** study provided a comprehensive explanation for the E-C failures that occur in air coolers during operation.

关键词： air cooler hydrocracking unit erosion-corrosion simulation visualization experiment multiphase flow

A unified intelligent control strategy synthesizing multi-constrained guidance and avoidance penetration

在线全文

学校读者我要写书评

暂无评论

Science China(Information Sciences) 2024年第7期67卷 329-330页

作者： Sibo ZHAO jianwen ZHU Weimin BAO Xiaoping LI School of Aerospace Science and Technology Xidian University College of Missile Engineering Rocket Force University of Engineering China Aerospace Science and Technology Corporation

Satisfying various terminal constraints and achieving evasive flight in no-flying-zones (NFZs) are two important flight missions undertaken by high velocity vehicles. We studied an intelligent maneuvering guidance strategy using deep reinforcement learning (DRL) methods to achieve the coordination and unification of evasive flight and multi-constrained guidance with minimal energy loss.

关键词： Energy dissipation

同方期刊数据库

Single depth image 3D face reconstruction via domain adaptive learning

在线全文

学校读者我要写书评

暂无评论

Frontiers of Computer Science 2024年第1期18卷 259-261页

作者： Xiaoxu CAI jianwen LOU Jiajun BU Junyu DONG Haishuai WANG Hui YU College of Computer Science and Technology Zhejiang UniversityHangzhou 310013China School of Creative Technologies University of PortsmouthPortsmouth PO12DJUK College of Computer Science and Technology Ocean University of ChinaQingdao 266100China

1 Introduction In this paper,we propose a novel domain-adaptive reconstruction method that effectively leverages deep learning and synthetic data to achieve robust 3D face reconstruction from a single depth *** method applies two domain-adaptive neural networks for predicting head pose and facial shape,*** networks undergo training with a customized domain adaptation strategy,using a combination of auto-labeled synthetic and unlabeled real data.

关键词： networks image learning

Nonalternant isomer of pentacene fusing two azulene units

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

Chinese Chemical Letters 2024年第5期35卷 244-248页

作者： Bo Yu Pengchen Du jianwen Guo Hanshen Xin Jianhua Zhang Department of Chemistry College of SciencesShanghai UniversityShanghai 200444China School of Microelectronics Shanghai UniversityShanghai 201800China

Azulene is a promising building block for creating innovative polycyclic aromatic hydrocarbons. This study involved the construction of three nonalternant isomers of pentacene by fusing two azulene units, named Az-PH1/2/3. Az-PH1 was initially developed through the rhodium(Ⅱ)-catalyzed cyclization of bis(N-tosylhydrazone)s. Intriguingly, Az-PH1 was also unexpectedly obtained during a nickel(0)-catalyzed one-step tandem reaction. We investigated the optical and electrochemical properties, aromaticity, and photo-oxidative stability of Az-PH1, comparing it with the well-known pentacene using density functional theory, electrochemical, and photophysical tests. Our results showed that the azulene-fusing strategy resulted in a molecule with narrow optical bandgaps(2.046 eV) and a long half-life time under ambient air conditions.

关键词： Azulene Isomer Polycyclic aromatic hydrocarbon Nickel(0)-catalyzed Photo-oxidative stability

Screening biomarkers for spinal cord injury using weighted gene co-expression network analysis and machine learning

在线全文

学校读者我要写书评

暂无评论

Neural Regeneration Research 2024年第12期19卷 2723-2734页

作者： Xiaolu Li Ye Yang Senming Xu Yuchang Gui Jianmin Chen jianwen Xu Department of Rehabilitation Medicine The First Affiliated Hospital of Guangxi Medical UniversityNanningGuangxi Zhuang Autonomous RegionChina Department of Rehabilitation Medicine Guilin People’s HospitalGuilinGuangxi Zhuang Autonomous RegionChina Department of Rehabilitation Medicine The First Affiliated Hospital of Fujian Medical UniversityFuzhouFujian ProvinceChina

Immune changes and inflammatory responses have been identified as central events in the pathological process of spinal co rd *** can greatly affect nerve regeneration and functional ***,there is still limited understanding of the peripheral immune inflammato ry response in spinal cord inju *** this *** obtained microRNA expression profiles from the peripheral blood of patients with spinal co rd injury using high-throughput *** also obtained the mRNA expression profile of spinal cord injury patients from the Gene Expression Omnibus(GEO)database(GSE151371).We identified 54 differentially expressed microRNAs and 1656 diffe rentially expressed genes using bioinformatics *** enrichment analysis revealed that various common immune and inflammation-related signaling pathways,such as neutrophil extracellular trap formation pathway,T cell receptor signaling pathway,and nuclear factor-κB signal pathway,we re abnormally activated or inhibited in spinal cord inju ry patient *** applied an integrated strategy that combines weighted gene co-expression network analysis,LASSO logistic regression,and SVM-RFE algorithm and identified three biomarke rs associated with spinal cord injury:ANO10,BST1,and *** verified the expression levels and diagnostic perfo rmance of these three genes in the original training dataset and clinical samples through the receiver operating characteristic *** polymerase chain reaction results showed that ANO20 and BST1 mRNA levels were increased and ZFP36L2 mRNA was decreased in the peripheral blood of spinal cord injury *** also constructed a small RNA-mRNA interaction network using ***,we evaluated the proportion of 22 types of immune cells in the peripheral blood of spinal co rd injury patients using the CIBERSORT *** proportions of naive B cells,plasma cells,monocytes,and neutrophils were increased while the proportions of memory B cells,C

关键词： bioinformatics analysis biomarker CIBERSORT GEO dataset LASSO miRNA-mRNA network RNA sequencing spinal cord injury SVM-RFE weighted gene co-expression network analysis

Enhanced structural damage behavior of liquid-filled tank by reactive material projectile impact

在线全文

学校读者我要写书评

暂无评论

Defence Technology（防务技术） 2024年第1期31卷 211-229页

作者： jianwen Xie Yuanfeng Zheng Zhenyang Liu Chengzhe Liu Aoxin Liu Pengwan Chen Haifu Wang State Key Laboratory of Explosion Science and Technology Beijing Institute of TechnologyBeijing 100081China

A series of ballistic experiments were performed to investigate the damage behavior of high velocity reactive material projectiles(RMPs) impacting liquid-filled tanks,and the corresponding hydrodynamic ram(HRAM) was studied in ***/Al/W RMPs with steel-like and aluminum-like densities were prepared by a pressing/sintering *** projectiles impacted a liquid-filled steel tank with front aluminum panel at approximately 1250 m/*** corresponding cavity evolution characteristics and HRAM pressure were recorded by high-speed camera and pressure acquisition system,and further compared to those of steel and aluminum *** different from the conical cavity formed by the inert metal projectile,the cavity formed by the RMP appeared as an ellipsoid with a conical *** RMPs were demonstrated to enhance the radial growth velocity of cavity,the global HRAM pressure amplitude and the front panel damage,indicating the enhanced HRAM and structural damage ***,combining the impact-induced fragmentation and deflagration characteristics,the cavity evolution of RMPs under the combined effect of kinetic energy impact and chemical energy release was *** mechanism of enhanced HRAM pressure induced by the RMPs was further revealed based on the theoretical model of the initial impact wave and the impulse ***,the linear correlation between the deformation-thickness ratio and the non-dimensional impulse for the front panel was obtained and *** was determined that the enhanced near-field impulse induced by the RMPs was the dominant reason for the enhanced structural damage behavior.

关键词： Reactive material projectile Hydrodynamic ram Enhanced structural damage Liquid-filled tank Impact

Numerical Simulation of Asphaltene Precipitation and Deposition during Natural Gas and CO_(2) Injection

在线全文

学校读者我要写书评

暂无评论

Fluid Dynamics & Materials Processing 2024年第2期20卷 275-292页

作者： Shasha Feng Yi Liao Weixin Liu jianwen Dai Mingying Xie Li Li Nanhai East Petroleum Research Institute Shenzhen Branch of CNOOC Ltd.Shenzhen518000China

Asphaltene deposition is a signiﬁcant problem during gas injection processes,as it can block the porous medium,the wellbore,and the involved facilities,signiﬁcantly impacting reservoir productivity and ultimate oil *** a few studies have investigated the numerical modeling of this potential effect in porous *** study focuses on asphaltene deposition due to natural gas and CO_(2) *** of the effect of gas injection on asphaltene deposition behavior have been made using a 3D numerical simulation *** results indicate that the injection of natural gas exacerbates asphaltene deposition,leading to a signiﬁcant reduction in permeability near the injection well and throughout the *** reduction in permeability strongly affects the ability of gas toﬂow through the reservoir,resulting in an improvement of the displacement *** displacement efﬁ-ciency of the injection gas process increases by up to 1.40%when gas is injected at 5500 psi,compared to the scenario where the asphaltene model is not ***_(2) injection leads to a miscible process with crude oil,extracting light and intermediate components,which intensiﬁes asphaltene precipitation and increases the viscosity of the remaining crude oil,ultimately reducing the recovery rate.

关键词： Reservoir simulation asphaltenes deposition natural gas injection CO_(2)injection

Physics-based seismic analysis of ancient wood structure:fault-to-structure simulation

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

Earthquake Engineering and Engineering Vibration 2024年第3期23卷 727-740页

作者： Ba Zhenning Fu Jisai Wang Fangbo Liang jianwen Zhang Bin Zhang Long State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation (Tianjin University)Tianjin 300350China School of Civil Engineering Tianjin UniversityTianjin 300350China Administrative Office of the Summer Palace Beijing 100091China School of Architecture Tianjin UniversityTianjin 300072China

Based on the domain reduction method,this study employs an SEM-FEM hybrid workflow which integrates the advantages of the spectral element method(SEM)for flexible and highly efficient simulation of seismic wave propagation in a three-dimensional(3D)regional-scale geophysics model and the finite element method(FEM)for fine simulation of structural response including soil-structure interaction,and performs a physics-based simulation from initial fault rupture on an ancient wood *** verification of the hybrid workflow,a large-scale model of an ancient wood structure in the Beijing area,The Tower of Buddhist Incense,is established and its responses under the 1665 Tongxian earthquake and the 1730 Yiheyuan earthquake are *** results from the simulated ground motion and seismic response of the wood structure under the two earthquakes demonstrate that this hybrid workflow can be employed to efficiently provide insight into the relationships between geophysical parameters and the structural response,and is of great significance toward accurate input for seismic simulation of structures under specific site and fault conditions.

关键词： spectral element method finite element method fault-to-structure simulation physical model domain reduction method