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Study on the simulation of acoustic logging measurements in horizontal and deviated wells 认领 引用 被引量：16
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作者 刘鹤 王兵 +2 位作者 陶果 张阔 岳文正 《Applied Geophysics》 SCIE CSCD 2017年第3期337-350,459,共14页
The conventional acoustic logging interpretation method, which is based on vertical wells that penetrate isotropic formations, is not suitable for horizontal and deviated wells penetrating anisotropic formations. This... The conventional acoustic logging interpretation method, which is based on vertical wells that penetrate isotropic formations, is not suitable for horizontal and deviated wells penetrating anisotropic formations. This unsuitability is because during horizontal and deviated well drilling, cuttings will splash on the well wall or fall into the borehole bottom and form a thin bed of cuttings. In addition, the high velocity layers at different depths and intrinsic anisotropy may affect acoustic logging measurements. In this study, we examine how these factors affect the acoustic wave slowness measured in horizontal and deviated wells that are surrounded by an anisotropic medium using numerical simulation. We use the staggered-grid finite difference method in time domain （FDTD） combined with hybrid-PML. First, we acquire the acoustic slowness using a simulated array logging system, and then, we analyze how various factors affect acoustic slowness measurements and the differences between the effects of these factors. The factors considered are high-velocity layers, thin beds of cuttings, dipping angle, formation thickness, and anisotropy. The simulation results show that these factors affect acoustic wave slowness measurements differently. We observe that when the wavelength is much smaller than the distance between the borehole wall and high velocity layer, the true slowness of the formation could be acquired. When the wavelengths are of the same order （i.e., in the near-field scenarios）, the geometrical acoustics theory is no longer applicable. Furthermore, when a thin bed of cuttings exists at the bottom of the borehole, Fermat＇s principle is still applicable, and true slowness can be acquired. In anisotropic formations, the measured slowness changes with increments in the dipping angle. Finally, for a measurement system with specific spacing, the slowness of a thin target layer can be acquired when the distance covered by the logging tool is sufficiently long. Based on systematical simulations with different dipping angles and anisotropy in homogenous TI media, slowness estimation charts are established to quantitatively determine the slowness at any dipping angle and for any value of the anisotropic ratio. Synthetic examples with different acoustic logging tools and different elastic parameters demonstrate that the acoustic slowness estimation method can be conveniently applied to horizontal and deviated wells in TI formations with high accuracy. 展开更多
关键词 Horizontal well deviated well high velocity layer cuttings bed acoustic slowness estimation
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Non-symmetric distributions of solids deposition for solid-water stratified flow in deviated tubing strings 认领 引用 被引量：3
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作者 Xin-Fu Liu Chun-Hua Liu +7 位作者 Zhong-Xian Hao Ying Zheng Kai Zhang Jian-Feng Wang Song-Bo Wei Ai-Gang Hao Jun-Ling Tao Hui Cheng 《Petroleum Science》 SCIE EI CAS CSCD 2023年第5期3048-3061,共14页
Dynamic performance on solids flow with water in deviated tubing is essential for the reliability of pump and normal operation of horizontal and directional wells.Compared with coal-water flow in vertical tubing and s... Dynamic performance on solids flow with water in deviated tubing is essential for the reliability of pump and normal operation of horizontal and directional wells.Compared with coal-water flow in vertical tubing and sand-oil flow with high production in deviated tubing,solids deposition with water shows obvious non-symmetric distributions in deviated tubing from simulations and experiments.The mathematical model of two phase flow was developed under coupling conditions of deviated tubing,low flow rate and viscosity based on the kinetic theory of granular flow and first-order discrete scheme.The results show that solid-water stratified flow in deviated tubing can be divided into two zones of suspension bed and the moving bed throughout the flow field.The solid flowing velocity with water is negative and particles slide down at the bottom of moving bed zone.The process of solids flow with water in deviated tubing will produce pressure loss and consume the kinetic energy.The thickness of deposited layer and the flowing velocity of solids flow downward with water at the moving bed zone enhance with the decreased inlet flow rate and the increased particle size,tubing inside diameter(ID)and inclination angle.Solids are easier into suspension from the upper part of moving bed zone to suspension bed zone and more solid particles flow with water towards the tubing outlet with the increase of inlet flowing velocity.The decision is made to reduce the screen width,tubing ID and inclination angle to maintain to be greater than critical deposition velocity in order to prevent solids settling.And it provides the theoretical basis and technical reserves for solid control and offers an effective approach to enhance tubing cleaning in deviated strings. 展开更多
关键词 Deviated tubing Stratified flow Solid deposition Critical velocity Prevent solids settling
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NONLINEAR BUCKLING ANALYSIS OF TUBING IN DEVIATED WELLS BY FINITE ELEMENT METHOD 认领 引用 被引量：10
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作者 刘峰 王鑫伟 《Transactions of Nanjing University of Aeronautics and Astronautics》 2004年第1期36-42,共7页
The equilibrium equations and the functional for tubing buckling in arbitrary straight wells are derived. The entire buckling process of tubing in deviated wells is analyzed for the first time by utilizing the finite ... The equilibrium equations and the functional for tubing buckling in arbitrary straight wells are derived. The entire buckling process of tubing in deviated wells is analyzed for the first time by utilizing the finite element method. The effects of gravity and torques on the buckling are included in the analyses and the calculated results are well compared with existing solutions. It is shown that the buckling only occurs at the lower portion of the tubing where the axial load is the largest, and the contact force of the well, the bending moment of the tubing and the buckling displacement of this portion vary periodically. The buckling spreads upwards from the bit with the increase of axial load. There is no buckling at the upper portion of the tubing where the bending moment is zero. And the contact force of this section increases only slightly with the increase of the axial load. With the increase of the deviation angle, the length of buckling portion and buckling displacement amplitude decrease, the contact force increases with the increase of load at the upper portion and its amplitude decreases at the lower buckling section, the bending moment remains zero at the upper portion and its amplitude decreases at the lower buckling portion. The buckling displacement increases with the increase of the torque, but the increment is very small. 展开更多
关键词 deviated wells drill-tubing buckling non-linearity finite element method
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Clinical Study on Deviated Nasal Septum and Its Associated Pathology 认领 引用 被引量：1
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作者 Prayaga N. Srinivas Moorthy Srikanth Kolloju +1 位作者 Srivalli Madhira Ali Behman Jowkar 《International Journal of Otolaryngology and Head & Neck Surgery》 2014年第2期75-81,共7页
Deviated nasal septum is a frequently occurring condition that can cause nasal obstruction in an individual. It may result in permanent changes in the nasal and sinus mucosa because of altered ventilation of the nasal... Deviated nasal septum is a frequently occurring condition that can cause nasal obstruction in an individual. It may result in permanent changes in the nasal and sinus mucosa because of altered ventilation of the nasal cavity. The present study makes an attempt to review its incidence and its associated pathology. Our study involves two groups of patients with 100 patients in each group. The first group consists of patients who are having nasal obstruction as a chief complaint and have deviated nasal septum. The second group consists of patients with either ear or throat complaints without any nasal symptoms, but were noted to have deviation of nasal septum on examination. An analysis was made to determine whether any particular type of deviation is more prone to develop pathology than other types. Our study shows that an “S” shaped deviation is more prone to be associated with ear, nose and throat pathology. 展开更多
关键词 Deviated Nasal Septum Symptoms Septoplasty
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Correction of cartilaginous oblique deviated noses 认领 引用
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作者 肖芃 《外科研究与新技术（中英文）》 2011年第4期269-269,共1页
Objective To summarize the experiences of treating secondary,cartilaginous oblique deviated noses and explore an effective technique to improve the clinical efficacy. Methods Through open approach,anterior and inferio... Objective To summarize the experiences of treating secondary,cartilaginous oblique deviated noses and explore an effective technique to improve the clinical efficacy. Methods Through open approach,anterior and inferior margin of quadrangular cartilage was 展开更多
关键词 Correction of cartilaginous oblique deviated noses
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The Evolution of urban agglomerations in China and how it deviates from Zipf’s law 认领 引用 被引量：2
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作者 Bowen Cai Zhenfeng Shao +4 位作者 Shenghui Fang Xiao Huang Yun Tang Muchen Zheng Hao Zhang 《Geo-Spatial Information Science》 SCIE EI CSCD 2024年第1期38-48,共11页
Urban Agglomeration(UA)is regarded as an emerging complex urban system in China.The development of UA demands a reasonable scale structure,which can be investigated by Zipf’s law.However,few studies have been conduct... Urban Agglomeration(UA)is regarded as an emerging complex urban system in China.The development of UA demands a reasonable scale structure,which can be investigated by Zipf’s law.However,few studies have been conducted to quantify the optimal scale of UA and how its development deviates from the optimal scale.With the continuous urban expansion,the problem of UAs’scale structure has received increasing attention.In this study,we propose a method based on Zipf’s law for estimating the theoretical optimal scale of UAs in China and assessing the deviation rate from their optimal scales.Twelve typical UAs in China are selected,and their development is assessed via urban impervious surface data from 2000 to 2018.The results show that the average deviation rate of the investigated UAs decreased from 3.40%in 2000 to 2.32%in 2018,demonstrating that these UAs are on a positive evolution trajectory.Furthermore,according to the development stage,we make recommendations on“large cities vs.medium/small-sized cities and promoting vs.restraining”to each UA based on its size.The conceptual and analytical knowledge,as well as the results from this study,are expected to offer valuable insights and new references for regulating and managing UAs’development in China. 展开更多
关键词 Urban agglomeration Zipf’s law scale structure deviation urban impervious surface
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Aesthetic and Functional Outcomes of Open versus Closed Septorhinoplasty in Deviated Nose Deformity 认领 引用
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作者 Seyed Mousa Sadr Hosseini Mohammad Sadeghi +2 位作者 Babak Saedi Amin Safavi Ghasem Reza Hedaiati 《International Journal of Otolaryngology and Head & Neck Surgery》 2012年第2期7-13,共7页
Background: Over the years, an optimal surgical method for septorhinoplasty in deviated nose as a challenging problem was the one of common interest of plastic surgeon;the purpose of this study is to compare outcomes ... Background: Over the years, an optimal surgical method for septorhinoplasty in deviated nose as a challenging problem was the one of common interest of plastic surgeon;the purpose of this study is to compare outcomes of open and closed methods of septorhinoplasty in patients with deviated noses. Methods: Through a prospective study, we selected seventy patients with deviated nose. Based on their deviation severity, they underwent open or closed septorhinoplasty. Patients were evaluated for deviation angles of nasal bony and cartilage components, nasal projection, nasolabial angle, nasofacial angle, and nasofrontal angle;for which three standard photos were captured pre and postoperatively. Finally the outcomes were analyzed according to their surgical methods. Results: Closed septorhinoplasty could grant a mean 11 degrees correction to nasal bony component and a mean 8.6 degrees correction to cartilage component. That’s while open septorhinoplasty could bring a mean 19.5 degrees deviation correction to the bony component and a mean 12.5 degrees deviation correction to the cartilage component. Cosmetic angles were not improved significantly after the surgery, maybe because of complicated deformities our series of patients had. Conclusion: Open septorhinoplasty resulted in better cosmetic and functional outcomes than the closed method. 展开更多
关键词 Deviated Nose Rhinoplasty Septorhinoplasty Cosmetic Function
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Research on the Application of Highly Deviated Directional Well Technology 认领 引用
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作者 LIJuan 《外文科技期刊数据库（文摘版）工程技术》 2022年第5期202-205,共4页
Under the background of the rapid development of current scientific and technological level, more and more oilfield exploitation technologies have emerged and have been widely applied rapidly. As far as the actual sit... Under the background of the rapid development of current scientific and technological level, more and more oilfield exploitation technologies have emerged and have been widely applied rapidly. As far as the actual situation is concerned, China's highly deviated directional well technology has been able to penetrate through the surface of multiple oil layers, thus fundamentally improving China's oil production. However, in some undeveloped areas, local staff are not able to use this technology correctly to carry out the relevant work, so that the mining efficiency cannot be greatly improved. Based on this, this paper takes highly deviated directional well technology as the main core, and comprehensively expounds its application in oilfield exploitation. 展开更多
关键词 highly deviated directional wells energy extraction specific application
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PVIIAD:industrial visual anomaly detection method based on partially visible image inpainting 认领 引用
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作者 Qiliang Wu Dongce Fei +2 位作者 Minghui Yao Yan Niu Cong Wang 《Optoelectronics Letters》 EI 2026年第1期34-40,共7页
Industrial anomaly detection is dedicated to identifying and locating regions that deviate from the standard appearance.The prevailing approach achieves unsupervised anomaly detection through the reconstruction of ima... Industrial anomaly detection is dedicated to identifying and locating regions that deviate from the standard appearance.The prevailing approach achieves unsupervised anomaly detection through the reconstruction of images using autoencoders.Due to the simplistic structure of some abnormal regions,the autoencoder can effectively reconstruct these areas,consequently diminishing the model’s anomaly detection capabilities.To address this issue,this paper transforms the reconstruction task into the inpainting-filling-reconstruction task to increase the reconstruction error between abnormal samples and normal samples.The masked regions inpainted by the filling network are used to fill in the input image,thereby achieving an effect similar to masking.Unlike typical masking processes,this approach retains partial authentic information in the input image,rendering it partially visible.This is beneficial for the reconstruction network to repair the masked areas.Due to the consistent structure between the masked region inpainted by the filling network and the normal region,the filled abnormal regions display a complex structure that has not been learned,making it difficult for the reconstruction network to reconstruct the abnormal regions.Experimental results indicate that our method performs better than other methods on both the MVTec AD dataset and the MVTec LOCO AD dataset. 展开更多
关键词 reconstruction error partially visible image inpainting masking autoencoder reconstruction images identifying locating regions deviate standard appearancethe industrial visual anomaly detection anomaly detection
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CFD-DEM simulation of the hole cleaning process in a deviated well drilling: The effects of particle shape 认领 引用 被引量：14
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作者 Siamak Akhshik Mehdi Behzad Majid Rajabi 《Particuology》 SCIE EI CAS CSCD 2016年第2期72-82,共11页
We investigate the effect of particle shape on the transportation mechanism in well-drilling using a three-dimensional model that couples computational fluid dynamics （CFD） with the discrete element method （DEM）. ... We investigate the effect of particle shape on the transportation mechanism in well-drilling using a three-dimensional model that couples computational fluid dynamics （CFD） with the discrete element method （DEM）. This numerical method allows us to incorporate the fluid-particle interactions （drag force, contact force, Saffman lift force, Magnus lift force, buoyancy force） using momentum exchange and the non-Newtonian behavior of the fluid. The interactions of particle-particle, particle-wall, and particle-drill pipe are taken into account with the Hertz-Mindlin model. We compare the transport of spheres with non-spherical particles （non-smooth sphere, disc, and cubic） constructed via the multi- sphere method for a range of fluid inlet velocities and drill pipe inclination angles. The simulations are carried out for laboratory-scale drilling configurations. Our results demonstrate good agreement with published experimental data. We evaluate the fluid-particle flow patterns, the particle velocities, and the particle concentration profiles. The results reveal that particle sphericity plays a major role in the fluid-solid interaction. The traditional assumption of an ideal spherical particle may cause inaccurate results. 展开更多
关键词 CFD-DEM method Deviated well drilling Particles transport Two-way coupling scheme Particle-fluid Interaction
Collaborative Assessment of Reflectivity Consistency between FY-3G Precipitation Measurement Radar and Ground-Based Radars 认领 引用
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作者 Chunyan ZHANG Heng HU +4 位作者 Jiashan ZHU Qinqiang ZHOU Lei WU Jianyong LI Xuan ZHU 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2026年第5期1065-1078,共14页
FY-3G is the first polar-orbiting satellite equipped with a precipitation measurement radar(PMR)operating at Ku-andKa-band frequencies in China.In this study,we compare the reflectivity data from the FY-3G PMR Ku prod... FY-3G is the first polar-orbiting satellite equipped with a precipitation measurement radar(PMR)operating at Ku-andKa-band frequencies in China.In this study,we compare the reflectivity data from the FY-3G PMR Ku product and groundbasedradars(GRs)during 2024.Also,the FY-3G PMR is used as a third-party reference to evaluate the reflectivityconsistency among different GRs.The FY-3G PMR and GRs share similarities in their general distribution,characteristics,and intensity of reflectivity in strong precipitation cloud systems,though the former presents less detailed system structure.Systematic deviations between the FY-3G PMR and GRs and between GRs are comparable,albeit the reflectivity of the FY-3G PMR is generally slightly stronger than that of GRs(especially X-band GRs),with a mean bias ranging from 0.7 to 1.7dB.S-band GRs exhibit the smallest systematic deviation(STD=3.09 dB)from the FY-3G PMR,whereas the X-band GRsshow the largest(STD=3.61 dB),indirectly indicating the highest internal consistency among S-band GRs and the lowestamong X-band GRs.Besides,both S-and C-band GRs display similar deviations when paired with the FY-3G PMR as wellas when paired with their adjacent S/C-band GRs,suggesting good consistency between these two bands.In contrast,XbandGRs exhibit relatively poor consistency with S-band GRs and the FY-3G PMR,showing a deviation ranging from 3.0to 4.6 dB. 展开更多
关键词 reflectivity deviation consistency FY-3G PMR ground-based radars
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Optimization of long-hole raise blasting considering drilling deviations:Theoretical and numerical approaches 认领 引用
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作者 Xianyang Qiu Wenbo Shen +4 位作者 Rihong Cao Xiuzhi Shi Yongsheng Xie Wei Liu Zhigang Tian 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2026年第7期5380-5395,共16页
Long-hole raise blasting(LHRB)is a highly efficientexcavation method that is used extensively in underground mining and civil engineering.However,deviations in drilling are usually not accounted for in LHRB,which may ... Long-hole raise blasting(LHRB)is a highly efficientexcavation method that is used extensively in underground mining and civil engineering.However,deviations in drilling are usually not accounted for in LHRB,which may adversely affect the efficiencyand progress of raise excavation.In this paper,the effect of drilling deviation on the optimization of LHRB is investigated.The actual trajectories of the blastholes were measured,and the deviation rates between different diameters were compared.The effects of the drilling deviation on the burn-cut blasting mode(BCBM)and spherical cartridge blasting mode(SCBM)of LHRB were theoretically analyzed.Numerical models with vertical holes that consider the actual hole location at different positions of the raise were subsequently developed to simulate the raise blasting damage.The results indicated that the BCBM relied substantially on the drilling accuracy to provide free surface and compensation space for further blasting,whereas the requirements of drilling deviation for the SCBM were less strict.With increasing hole deviation in the BCBM,the height of the failure area of the raise blasting increased.Optimization designs that combine the BCBM and SCBM were proposed to strike a balance between the efficiencyand reliability of LHRB.A 40 m high slot raise in a large-diameter long-hole(LDL)stope was successfully formed by multimode LHRB.The fieldtest results reveal that the optimization of LHRB is feasible in practical engineering. 展开更多
关键词 Long-hole raise blasting(LHRB) Drilling deviation Blasting optimization Numerical simulation Field test
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An explainable deep learning approach to enhance the prediction of shield tunnel deviation 认领 引用
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作者 Jiajie Zhen Fengwen Lai +4 位作者 Ming Huang Junjie Zheng Jim S.Shiau Ping Wang Jinhuo Zheng 《Journal of Rock Mechanics and Geotechnical Engineering》 SCIE CSCD 2026年第1期566-579,共14页
Although machine learning models have achieved high enough accuracy in predicting shield position deviations,their“black box”nature makes the prediction mechanisms and decision-making processes opaque,leading to wea... Although machine learning models have achieved high enough accuracy in predicting shield position deviations,their“black box”nature makes the prediction mechanisms and decision-making processes opaque,leading to weaker explanations and practicability.This study introduces a novel explainable deep learning framework comprising the Informer model with enhanced attention mechanisms(EAMInfor)and deep learning important features(DeepLIFT),aimed at improving the prediction accuracy of shield position deviations and providing interpretability for predictive results.The EAMInfor model attempts to integrate channel attention,spatial attention,and simple attention modules to improve the Informer model's performance.The framework is tested with the four different geological conditions datasets generated from the Xiamen metro line 3,China.Results show that the EAMInfor model outperforms the traditional Informer and comparison models.The analysis with the DeepLIFT method indicates that the push thrust of push cylinder and the earth chamber pressure are the most significant features,while the stroke length of the push cylinder demonstrated lower importance.Furthermore,the variation trends in the significance of data points within input sequences exhibit substantial differences between single and composite strata.This framework not only improves predictive accuracy but also strengthens the credibility and reliability of the results. 展开更多
关键词 Shield tunnel position deviation Machine learning Explainable AI Deep learning important features
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Scrap PMMA valorization with optimized content of silicon carbide nanofiller in additive manufacturing 认领 引用
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作者 Nectarios Vidakis Nikolaos Michailidis +4 位作者 Nektarios K.Nasikas Vassilis Papadakis Maria Spyridaki Apostolos Argyros Markos Petousis 《Defence Technology（防务技术）》 SCIE EI CAS CSCD 2026年第7期15-32,共18页
Utilizing versatile techniques,such as additive manufacturing(AM)and recyclable materials,is a way of reducing material waste and cost while converting the manufacturing field into being environmentally friendly and s... Utilizing versatile techniques,such as additive manufacturing(AM)and recyclable materials,is a way of reducing material waste and cost while converting the manufacturing field into being environmentally friendly and sustainable.The latter is essential in the defense domain.Herein,recycled polymethylmethacrylate(PMMA)material was combined with silicon carbide(SiC)nanoparticles in material extrusion AM.The raw materials,nanocomposites,filaments,and specimens utilized and developed were thoroughly experimentally investigated.These included thermal evaluation via thermogravimetric analysis,differential scanning calorimetry,and rheological evaluation via viscosity and melt flow rate investigations.Mechanical evaluation via tensile,bending,Charpy impact,and Vickers micro-hardness tests,as well as structural and morphological examination viaμ-computed tomography and scanning electron microscopy,were performed.The aim was to examine the potential of these sustainable materials for use in demanding environments.PMMA/SiC 4.0 wt%(19.8%strength and 41.8%stiffness increase in the flexural test)and PMMA/SiC 12.0 wt%(55.9%Young's modulus increase)were distinguished for their mechanical performance;still,brittleness was increased.The results provided valuable information about the overall mechanical,thermal,and rheological properties of 3D printed sustainable PMMA/SiC nanocomposites,providing important insights for possible use in extreme environments and in defence. 展开更多
关键词 Polymethylmethacrylate (PMMA) Silicon carbide (SiC) Three-dimensional (3D) printing Mechanical characterization Dimensional deviation Scanning electron microscopy (SEM)
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Global variation in relative phylogenetic diversity in butterflies 认领 引用
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作者 Hong Qian Michael Kessler Shenhua Qian 《Journal of Systematics and Evolution》 SCIE CSCD 2026年第3期564-571,共8页
Taxonomic diversity(TD)and phylogenetic diversity(PD)are two important metrics of biodiversity,but they are often mismatched in many areas across the world.This geographic mismatch,typically identified through assessm... Taxonomic diversity(TD)and phylogenetic diversity(PD)are two important metrics of biodiversity,but they are often mismatched in many areas across the world.This geographic mismatch,typically identified through assessment of relative phylogenetic diversity(RPD),is associated with climatic conditions and is critical not only to understanding the origin and maintenance of biodiversity but also conservation planning.Here,using a comprehensive data set of butterflies across the world,we explore geographic patterns of RPD and its relationships with climatic factors.Butterfly species assemblages used in this study are species in 12407 grid cells across the world.We use two different metrics to measure RPD:one directly relating PD to TD(PDdev)and the other exploring variation on phylogenetic branch length(Mishler's RPD).We find that RPD is higher in humid subtropical and tropical regions,where butterflies originated and maintain many distinct phylogenetic lineages,and is lower in temperate and arid tropical regions as well as in geologically young mountains,where there are fewer major phylogenetic lineages and where regional radiations form clusters of closely related species.The patterns of PDdevand Mishler's RPD are largely similar,but PDdevis more strongly related to temperature,whereas Mishler's RPD is more strongly related to precipitation,suggesting that these metrics capture different ways in which climate influences PD.Overall,areas with higher RPD likely hold higher evolutionary potential than areas with equivalent species richness but lower RPD,so that areas of high RPD would be of particular interest for biodiversity conservation. 展开更多
关键词 butterfly climate phylogenetic diversity phylogenetic diversity deviation species richness taxonomic diversity.
Analysis of damage and energy evolution characteristics of pre-flawed red sandstone based on infrared thermography 认领 引用
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作者 Lu Chen En Wang +4 位作者 Longfei Chang Mingyuan Zhang Ruifeng Huang Yingjun Li Dejian Li 《Acta Mechanica Sinica》 SCIE EI CAS CSCD 2026年第7期387-405,共19页
The unstable extension of rock fractures is the fundamental cause of danger to the safety of underground engineering.Clarifying the damage and fracture characteristics of rocks under loading is the basis for ensuring ... The unstable extension of rock fractures is the fundamental cause of danger to the safety of underground engineering.Clarifying the damage and fracture characteristics of rocks under loading is the basis for ensuring the safety of geological engineering.In this paper,an infrared thermography,and acoustic emission(AE)system were used to monitor the damage evolution of red sandstone containing different pre-flawed under uniaxial loading.The mechanical,infrared radiation and AE characteristics of representative specimens containing pre-flawed were investigated.The results show that the crack extension process and failure modes are affected by the different pre-flawed inclinations of the specimens.With the increasing inclination angles,the failure modes of the red sandstones change from axial splitting to tensile-shear conformal damage mode.In addition,the absolute deviation matrix of infrared radiation temperature was proposed,which not only reflects the damage and crack extension process of the specimens but also has an early warning of specimen failure consistent with the AE characteristics.Moreover,the constitutive model of rocks containing pre-flawed under the uniaxial loading was established by combining with cluster analysis,and compared to the experimental results.It is found that the two results have consistency at the peak stresses,while the model stresses of infrared radiation were higher than the test stresses in the initial compaction stage and microcrack extension stage.Furthermore,the rock energy release rate and energy dissipated rate based on infrared radiation were proposed to illustrate the relative intensity of rock energy accumulation and dissipation,which can characterize the rock damage intensity.The research results can provide theoretical and experimental references for real-time,nondestructive,and green monitoring of geoengineering problems using infrared thermography. 展开更多
关键词 Infrared radiation Absolute deviation matrix of infrared radiation temperature Cluster analysis Infrared damage variable Acoustic emission(AE)
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Uniform Large Deviations for Stochastic Generalized Burgers-Huxley Equation Driven by Multiplicative Noise 认领 引用
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作者 Hui GUO Xi-liang LI Jin MA 《Acta Mathematicae Applicatae Sinica》 SCIE CSCD 2026年第3期746-765,共20页
In this paper,we establish a Freidlin-Wentzell type large deviation principle uniformly with respect to initial condition in bounded subsets,that do not necessarily belongs to compact sets,of an infinite dimensional B... In this paper,we establish a Freidlin-Wentzell type large deviation principle uniformly with respect to initial condition in bounded subsets,that do not necessarily belongs to compact sets,of an infinite dimensional Banach space for stochastic 1D generalized Burgers-Huxley equation driven by multiplicative small noise.The proof is based on the weak convergence approach obtained by[Salins,Budhiraja and Dupuis;Trans.Amer.Math.Soc.,2019]. 展开更多
关键词 stochastic generalized Burgers-Huxley equation large deviation principle uniform large deviation principle weak convergence approach
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Nonlinear model predictive control strategy for vehicle path tracking with steering actuator’s dynamic characteristics 认领 引用
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作者 Bin Wang Zhiguo Zhao +1 位作者 Xiwen Yuan Yuyi Wang 《Control Theory and Technology》 EI CSCD 2026年第3期359-373,共15页
The dynamic characteristics of the steering actuator,including response time-delay and calibration deviation,are crucial to a vehicle’s path tracking performance.This study proposes a novel vehicle path tracking cont... The dynamic characteristics of the steering actuator,including response time-delay and calibration deviation,are crucial to a vehicle’s path tracking performance.This study proposes a novel vehicle path tracking control strategy by combining nonlinear model predictive control(NMPC),time-delay model control,and calibration deviation compensation control.In the first stage,the path tracking NMPC strategy is designed without considering the steering actuator’s dynamic characteristics.In the second stage,by combining polynomial fitting with linear matrix inequality(LMI)techniques,a nonlinear time-delay model control algorithm is designed to address the response time-delay.In the third stage,based on the inverse model of the calibration deviation,a nonlinear compensation algorithm is designed for steering actuator’s calibration deviation.Finally,simulation and real vehicle experiment results are provided to illustrate the effectiveness of the proposed vehicle path tracking control strategy. 展开更多
关键词 Nonlinear model predictive control(NMPC) Path tracking Nonlinear time-delay model control Calibration deviation compensation control
DEVIATION PROBABILITIES FOR SPECTRAL RADIUS OF PRODUCTS OF COMPLEX GINIBRE ENSEMBLES 认领 引用
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作者 Yutao MA Chaoyang SONG 《Acta Mathematica Scientia》 SCIE CSCD 2026年第2期937-956,共20页
Let X1,…,Xm_(n)be independent n×n complex Ginibre ensembles and Z1,…,Znbe the eigenvalues of Пmnj=1Xj.Suppose limn→∞mn=+∞,we obtain large and moderate deviations for max1≤i≤n... Let X1,…,Xm_(n)be independent n×n complex Ginibre ensembles and Z1,…,Znbe the eigenvalues of Пmnj=1Xj.Suppose limn→∞mn=+∞,we obtain large and moderate deviations for max1≤i≤nlog|Zi|. 展开更多
关键词 products of complex Ginibre ensembles spectral radius large deviations moderate deviations
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On Petrenko's Deviations and Complex Difference Equations 认领 引用
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作者 Lipeng XIAO Chunfang CHEN 《Journal of Mathematical Research with Applications》 CSCD 2026年第2期209-221,共13页
In this paper,the growth characteristic of meromorphic solutions for the following difference equation An(z)f(z+n)+…+A1(z)f(z+1)+A0(z)f(z)=0 with no dominating coefficient is studied.By imposing certain restriction o... In this paper,the growth characteristic of meromorphic solutions for the following difference equation An(z)f(z+n)+…+A1(z)f(z+1)+A0(z)f(z)=0 with no dominating coefficient is studied.By imposing certain restriction on the entire coefficients associated with Petrenko's deviation of the above equation,we obtain some results and partially address a question posed byⅠ.Laine and C.C.Yang.Furthermore,for the entire solutions f(z)of the difference equation An(z)f(z+n)+…+A1(z)f(z+1)+A0(z)f(z)=F(z),where Aj(z)(j=0,…,n),F(z)are entire functions,we discover a close relationship between the measure of common transcendental directions associated with classical difference operators of f(z)and Petrenko's deviations of the coefficients. 展开更多
关键词 complex difference equation difference operator Petrenko’s deviation transcenden-tal direction
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