期刊文献+
共找到798,034篇文章
< 1 2 250 >
每页显示 20 50 100
基于SPH-FEM大蒜切茎装置动力学分析及参数优化
1
作者 李骅 高涵 +3 位作者 王永健 於海明 傅杰一 郭靳枭 《农业机械学报》 北大核心 2026年第4期192-202,共11页
针对目前大蒜联合收获机切茎装置切削性能较差、切割阻力较大、切割不及时易造成大蒜鳞茎损伤以及夹持输送装置堵塞等问题,基于SPH-FEM耦合算法设计了一种大蒜双圆盘式切茎装置,并进行了动力学分析及参数优化。根据大蒜茎秆的结构、物... 针对目前大蒜联合收获机切茎装置切削性能较差、切割阻力较大、切割不及时易造成大蒜鳞茎损伤以及夹持输送装置堵塞等问题,基于SPH-FEM耦合算法设计了一种大蒜双圆盘式切茎装置,并进行了动力学分析及参数优化。根据大蒜茎秆的结构、物理参数和力学特性参数,确定了大蒜茎秆的材料模型。利用ANSYS/LS-DYNA构建大蒜切割过程仿真模型,通过有限元仿真结果确定最优圆盘刀结构参数,圆盘刀厚度2 mm、圆盘刀刃角15°和圆盘刀重叠量15 mm。运用仿真模型进行单因素仿真试验,确定了大蒜切茎装置的喂入速度、圆盘刀转速、圆盘刀间距的取值范围分别为1.5~2.5 km/h、400~600 r/min、1~3 mm;采用Box-Behnken设计三因素三水平正交组合试验方案,通过台架试验确定各因素水平下圆盘刀最大切割阻力,运用Design-Expert 13对试验结果进行方差和响应面分析,得到大蒜切茎装置实际最佳工作参数,喂入速度为2.1 km/h、圆盘刀转速为560 r/min、圆盘刀间距为1 mm。台架试验结果表明,在最优工作参数下最大切割阻力为7.33 N,误差为7.5%。本文所设计的双圆盘式切茎装置切割阻力小、工作性能稳定,茎秆切割面较为平整,并且在试验过程中无鳞茎损伤,满足大蒜收获茎秆切割要求,可为大蒜联合收获机械的设计提供参考。 展开更多
关键词 大蒜切茎 有限元 SPH-fem耦合算法 双圆盘式切茎装置 参数优化
在线阅读 下载PDF
基于SPH-FEM流固耦合作用下多级拦挡坝动力响应分析
2
作者 王永胜 龚蕓 祝佳 《灾害学》 北大核心 2026年第1期104-114,共11页
为探明泥石流与多级拦挡结构间的相互作用机制,该文建立了耦合的光滑粒子流体动力学(SPH)和有限元方法(FEM)的数值模型,模拟泥石流浆体与块石的相互耦合过程,分析了格栅-重力坝、格栅-格栅坝和重力-重力坝三种组合坝在泥石流作用下动力... 为探明泥石流与多级拦挡结构间的相互作用机制,该文建立了耦合的光滑粒子流体动力学(SPH)和有限元方法(FEM)的数值模型,模拟泥石流浆体与块石的相互耦合过程,分析了格栅-重力坝、格栅-格栅坝和重力-重力坝三种组合坝在泥石流作用下动力响应,包括泥石流速度、冲击力、坝体支反力和Von Mises应力。结果表明:多级拦挡坝承泥石流冲击力与坝体结构密切相关,格栅坝透水性强、整体荷载小但局部应力集中;重力坝借浆体缓冲层降低局部应力。此外,一级坝支反力普遍高于二级坝,当一级为重力坝时应力剧增,为格栅坝则使荷载分配合理、减小应力差。因此坝体结构特性对荷载分配具有调控作用,为工程实践中优选坝型组合可提供设计参考。 展开更多
关键词 泥石流 SPH-fem耦合 多级拦挡坝 动力响应
在线阅读 下载PDF
基于XFEM和响应面法的某地铁车站基坑近接既有已损建筑物施工扰动影响分区
3
作者 雷明锋 李倡万 +2 位作者 杨鹏亮 贾朝军 李垂忝 《隧道建设(中英文)》 北大核心 2026年第1期69-79,共11页
新建基坑施工会对邻近既有建筑产生扰动影响,如何对施工扰动程度进行快速有效评估以合理制定设计与施工方案是亟待解决的工程难点。鉴于此,依托实际工程,通过有限元FEM-扩展有限元XFEM两阶段数值模型开展多工况分析,与实测数据对比验证... 新建基坑施工会对邻近既有建筑产生扰动影响,如何对施工扰动程度进行快速有效评估以合理制定设计与施工方案是亟待解决的工程难点。鉴于此,依托实际工程,通过有限元FEM-扩展有限元XFEM两阶段数值模型开展多工况分析,与实测数据对比验证模型的可靠性,进而构建响应面预测模型,结合参数敏感性分析,建立以裂缝扩展面积为指标的基坑近接施工参数与建筑物初始损伤程度的影响分区。研究结果表明:1)FEM-XFEM两阶段模型适用于分析新建基坑施工扰动下建筑物裂缝扩展问题。2)裂缝扩展面积与扰动等级显著相关,处在Ⅱ级影响工况的裂缝扩展面积大多在0.8~1.4 m^(2),可将0.8 m^(2)与1.4 m^(2)作为Ⅰ/Ⅱ、Ⅱ/Ⅲ区分界阈值。3)基坑与建筑物之间的距离D与既有建筑物裂缝扩展面积呈现显著相关性,D>21 m时为Ⅰ级影响,3.9 m<D≤21 m时为Ⅱ级影响,D≤3.9 m时为Ⅲ级影响。4)考虑建筑物初始损伤时,当初始裂缝长度为墙体长度41%以下且宽度为墙体厚度67%以下,基坑施工扰动为I级影响;当初始裂缝长度达到墙体长度66%以上或宽度达到墙体厚度83%以上,基坑施工扰动为Ⅲ级影响。 展开更多
关键词 地铁车站 基坑施工 建筑物损伤 裂缝扩展 扩展有限元法 两阶段分析法 响应面法
在线阅读 下载PDF
Construction of Bionic Non-Smooth Surface of Cu-Based Friction Materials Based on Finite Element Method
4
作者 Lekai Li Juxiang Zhu +3 位作者 Zhaohua Yao Mengting Xing Yitong Tian Ma Yunhai 《Journal of Bionic Engineering》 2026年第1期326-340,共15页
To solve the problem of abnormal abrasion of Cu-Based Friction Materials(CBFMs),Bionic Non-Smooth Surface(BNS)on friction surface of CBFMs was constructed based on bionic principles,and the optimal bionic prototype wa... To solve the problem of abnormal abrasion of Cu-Based Friction Materials(CBFMs),Bionic Non-Smooth Surface(BNS)on friction surface of CBFMs was constructed based on bionic principles,and the optimal bionic prototype was selected by Finite Element Method(FEM).In addition,the bionic parameters were optimized by Response Surface Method(RSM).Samples holding BNS were prepared by Laser Processing,tribological properties were tested by a Friction and Wear Tester and worn surface morphology was characterized by a Scanning Electron Microscope(SEM).The results showed that BNS on friction surface could regulate the stress distribution and alleviate the peak stress.Among all samples,the coupled texture of pit-hexagonal got the minimum peak stress.During braking,bionic texture could also collect wear debris or change the motion forms from sliding to rotation,which can reduce abnormal abrasion.The wear rate was reduced by 19.31%.The results in this paper can provide a new idea for enhancing the tribological properties of CBFMs,and can also lay the foundation for further research of bionic tribology. 展开更多
关键词 Bionic non-smooth surface Friction materials fem Wear mechanism
在线阅读 下载PDF
Study on the effect of preparation method on denitration performance of Co-modified Ce/TiO_(2) catalyst
5
作者 YU Chao ZHANG Boya +2 位作者 SHEN Kai HAN Yuxuan ZHANG Yaping 《燃料化学学报(中英文)》 北大核心 2026年第3期79-91,共13页
This study systematically conducted preparation optimization and performance investigations on Co-modified Ce/TiO_(2) catalysts,with a focus on examining how preparation methods and Co loading regulate the catalyst’s... This study systematically conducted preparation optimization and performance investigations on Co-modified Ce/TiO_(2) catalysts,with a focus on examining how preparation methods and Co loading regulate the catalyst’s low-temperature denitrification activity.After identifying optimal preparation parameters via condition screening,multiple characterization techniques-including BET,XRD,XPS,H_(2)-TPR and in situ DRIFTS-were employed to deeply analyze the catalyst’s physicochemical properties and reaction mechanism.Results demonstrated that compared to the impregnation and co-precipitation methods,the Ce-Co_(0.025)/TiO_(2)-SG catalyst(prepared by the sol-gel method with a Co/Ti mass ratio of 0.025)exhibited significantly superior denitrification activity:NO conversion remained stably above 95%in the 225−350℃ temperature range,and it displayed high N_(2) selectivity.Characterization analysis revealed that abundant surface oxygen vacancies,a high proportion of Ce^(3+) species,and prominent acidic sites collectively contributed to enhancing its low-temperature denitrification performance.This work provides reference value for the development of highly efficient low-temperature denitrification catalysts. 展开更多
关键词 preparation method Co Ce/TiO_(2) low-temperature denitration NH3-SCR
在线阅读 下载PDF
A New Inversion-free Iterative Method for Solving the Nonlinear Matrix Equation and Its Application in Optimal Control
6
作者 GAO Xiangyu XIE Weiwei ZHANG Lina 《应用数学》 北大核心 2026年第1期143-150,共8页
In this paper,we consider the maximal positive definite solution of the nonlinear matrix equation.By using the idea of Algorithm 2.1 in ZHANG(2013),a new inversion-free method with a stepsize parameter is proposed to ... In this paper,we consider the maximal positive definite solution of the nonlinear matrix equation.By using the idea of Algorithm 2.1 in ZHANG(2013),a new inversion-free method with a stepsize parameter is proposed to obtain the maximal positive definite solution of nonlinear matrix equation X+A^(*)X|^(-α)A=Q with the case 0<α≤1.Based on this method,a new iterative algorithm is developed,and its convergence proof is given.Finally,two numerical examples are provided to show the effectiveness of the proposed method. 展开更多
关键词 Nonlinear matrix equation Maximal positive definite solution Inversion-free iterative method Optimal control
在线阅读 下载PDF
SPH-FEM耦合的山岭隧道长进尺掏槽爆破研究
7
作者 周松樊 孟春阳 管晓明 《低温建筑技术》 2026年第2期127-132,共6页
针对山岭隧道电子雷管进行长进尺爆破振动大、掏槽效果不佳的问题,文中采用SPH-FEM耦合方法建立掏槽爆破三维数值模型,研究单孔0~5 ms延期时间下岩石爆破粒子的抛掷情况,分析岩石破碎效果;研究不同延期时间下掏槽成腔演化历程,揭示延期... 针对山岭隧道电子雷管进行长进尺爆破振动大、掏槽效果不佳的问题,文中采用SPH-FEM耦合方法建立掏槽爆破三维数值模型,研究单孔0~5 ms延期时间下岩石爆破粒子的抛掷情况,分析岩石破碎效果;研究不同延期时间下掏槽成腔演化历程,揭示延期时间对掏槽爆破的影响机理。研究结果表明,掏槽孔同时起爆条件下粒子抛掷数量最多、距离最远;随着单孔延时增加,岩石爆破粒子数逐渐减小;其中单孔延时为1 ms时粒子数减少并不显著,2、3 ms时粒子数迅速衰减,4、5 ms时粒子数量减少趋于平缓;单孔延时为1 ms时掏槽腔面积占比最大,达到31.68%,爆破能量利用率最高,破碎效果最优。经现场试验验证,斜眼掏槽孔采用1 ms单孔延时方案,可同时实现高效破岩与爆破振动控制。研究为山岭隧道电子雷管爆破的合理延期时间的设定提供理论依据。 展开更多
关键词 隧道爆破 电子雷管 延时爆破 岩体破碎 SPH-fem耦合
在线阅读 下载PDF
Broadband ground motion simulation and analysis of a near-fault 3D basin-mountain coupling site based on the hybrid method
8
作者 Liu Zhongxian Tang Kang +2 位作者 Li Chengcheng Yuan Xiaoming Zhang Hai 《Earthquake Engineering and Engineering Vibration》 2026年第1期87-110,共24页
This study presents an effective hybrid simulation approach for simulating broadband ground motion in complex near-fault locations.The approach utilizes a deterministic approach based on the spectral element method(SE... This study presents an effective hybrid simulation approach for simulating broadband ground motion in complex near-fault locations.The approach utilizes a deterministic approach based on the spectral element method(SEM),which is used to simulate low-frequency ground motion(f<1 Hz)by incorporating an innovative efficient discontinuous Galerkin(DG)method for grid division to accurately model basin sedimentary layers at reduced costs.It also introduces a comprehensive hybrid source model for high-frequency random scattering and a nonlinear analysis module for basin sedimentary layers.Deterministic outcomes are combined with modified three-dimensional stochastic finite fault method(3D-EXSIM)simulations of high-frequency ground motion(f>1 Hz).A fourth-order Butterworth filter with zero phase shift is employed for time-domain filtering of low-and high-frequency time series at a crossover frequency of 1 Hz,merging the low and high-frequency ground motions into a broadband time series.Taking an Ms 6.8 Luding earthquake,as an example,this hybrid method was used for a rapid and efficient simulation analysis of broadband ground motion in the region.The accuracy and efficiency of this hybrid method were verified through comparisons with actually observed station data and empirical attenuation curves.Deterministic method simulation results revealed the effects of mountainous topography,basin effects,nonlinear effects within the basin’s sedimentary layers,and a coupling interaction between the basin and the mountains.The findings are consistent with similar studies,showing that near-fault sedimentary basins significantly focus and amplify strong ground motion,and the soil’s nonlinear behavior in the basin influences ground motion to varying extents at different distances from the fault.The mountainous topography impacts the basin’s response to ground motion,leading to barrier effects.This research provides a scientific foundation for seismic zoning,urban planning,and seismic design in nearfault mountain basin regions. 展开更多
关键词 hybrid ground motion simulation method spectral element method three-dimensional stochastic finite fault method near-fault basin-mountain coupling effect basin effect nonlinear effect
在线阅读 下载PDF
Establishment of a Determination Method for Fruit Texture in Chieh-qua Using Texture Analyzer
9
作者 Ying WANG Xuan DU Na LIU 《Agricultural Biotechnology》 2026年第1期54-59,共6页
[Objectives]This study was conducted to establish a quantitative assessment method for the textural quality of chieh-qua fruit.[Methods]Using two modes of a texture analyzer,namely TPA(texture profile analysis)and pun... [Objectives]This study was conducted to establish a quantitative assessment method for the textural quality of chieh-qua fruit.[Methods]Using two modes of a texture analyzer,namely TPA(texture profile analysis)and puncture,the index data of the fruit were obtained by setting different trigger forces,deformation levels,test speeds,as well as puncture speeds and puncture depths.The data included TPA hardness,adhesiveness,springiness,cohesiveness,gumminess,chewiness,resilience,as well as skin hardness,skin toughness,flesh hardness,fracturability,and compactness.[Results]Different deformation levels had a significant impact on all parameters.Hardness,adhesiveness,gumminess and chewiness showed a trend of first increasing and then decreasing with the deformation level increasing.When the deformation level was 30%,the adhesiveness,gumminess and chewiness reached their maximum values.When the deformation level was 50%,TPA hardness reached its maximum.When the compression speed was 3 mm/s,the measured values of TPA hardness,adhesiveness,chewiness,and resilience were at their maximums.The skin hardness varied significantly under different trigger forces.When the trigger force was 15 g,the skin hardness reached a maximum value of 944.63 g,and the skin toughness,flesh hardness,fracturability,and compactness also reach their maximum values respectively.When the puncture depth was 12 mm,the flesh hardness and skin toughness reached their maximums of 682.51 g and 1.82 mm,respectively.In the TPA mode,the flesh hardness of chieh-qua showed an extremely significant negative correlation with springiness,cohesiveness,and resilience(P<0.01).The fruit fracturability detected by puncture had an extremely significant positive correlation with compactness(P<0.01).[Conclusions]The evaluation method for measuring chieh-qua texture by combining TPA and the puncture mode could accurately and quantitatively reflect the differences in the flesh texture quality of chieh-qua.The optimal parameters for texture measurement of chieh-qua fruit were determined as a 15 g trigger force with 50%deformation and a 3 mm/s compression speed in TPA mode,and a 15 g trigger force with a 12 mm puncture depth in puncture mode.Puncture speed was found to have no significant effect on the texture indices of chieh-qua. 展开更多
关键词 CHIEH-QUA Texture analyzer Texture quality Determination method
在线阅读 下载PDF
A novel scaling method for the elastic ring supporting structure of an aero-engine rotor system: analytical and experimental investigations
10
作者 Lei LI Tianyue MA +4 位作者 Zhong LUO Dongwu GAO Xiangdong GE Hui MA Shibin WANG 《Applied Mathematics and Mechanics(English Edition)》 2026年第1期1-18,共18页
The testing of large structures is limited by high costs and long cycles, making scaling methods an attractive solution. However, the scaling process of elastic rings introduces complexities in multi-parameter geometr... The testing of large structures is limited by high costs and long cycles, making scaling methods an attractive solution. However, the scaling process of elastic rings introduces complexities in multi-parameter geometric distortions, leading to a diminution in the predictive accuracy of the distorted similitude. To address this challenge, this study formulates a novel set of scaling laws, tailored to account for the intricate geometric distortions associated with elastic rings. The proposed scaling laws are formulated based on the intrinsic deformation characteristics of elastic rings, rather than the traditional systemic governing equations. Numerical and experimental cases are conducted to assess the efficacy and precision of the proposed scaling laws, and the obtained results are compared with those achieved by traditional methods. The outcomes demonstrate that the scaling laws put forth by this study significantly enhance the predictive capabilities for deformations of elastic rings. 展开更多
关键词 rotor system AERO-ENGINE elastic ring scaling method supporting structure
在线阅读 下载PDF
Multiphysics Implicit Coupling Method for Fluid,Particles,and Large-Deformation Structures
11
作者 Xiangxiang Wang Hualong Xie +3 位作者 Yue Yu Min Li Yubin Wang Fei Xing 《Computer Modeling in Engineering & Sciences》 2026年第2期367-401,共35页
This study presents an implicit multiphysics coupling method integrating Computational Fluid Dynamics(CFD),the Multiphase Particle-in-Cell(MPPIC)model,and the Finite Element Method(FEM),implemented with OpenFOAM,Calcu... This study presents an implicit multiphysics coupling method integrating Computational Fluid Dynamics(CFD),the Multiphase Particle-in-Cell(MPPIC)model,and the Finite Element Method(FEM),implemented with OpenFOAM,CalculiX,and preCICE to simulate fluid-particle-structure interactions with large deformations.Mesh motion in the fluid field is handled using the radial basis function(RBF)method.The particle phase is modeled by MPPIC,where fluid-particle interaction is described through momentum exchange,and inter-particle collisions are characterized by collision stress.The structural field is solved by nonlinear FEM to capture large deformations induced by geometric nonlinearity.Coupling among fields is realized through a partitioned,parallel,and non-intrusive iterative strategy,ensuring stable transfer and convergence of interface forces and displacements.Notably,the influence of particles on the structure is not direct but mediated by the fluid,while structural motion directly affects particle dynamics.The results demonstrate that the proposed approach effectively captures multiphysics interaction processes and provides a valuable reference for numerical modeling of coupled fluid-particle-structure systems. 展开更多
关键词 Fluid-particle-structure interaction large deformation partitioned method non-intrusive coupling
在线阅读 下载PDF
Healthcare professionals’perspectives on disclosure of diagnosis and related issues in childhood cancer:A mixed methods systematic review
12
作者 Run Xie Xiaoyan Huang +4 位作者 Yiran Du Ying Gu Qiongfang Kang Hongsheng Wang Daqian Zhu 《International Journal of Nursing Sciences》 2026年第1期96-104,I0006,共10页
Objectives This review aimed to systematically synthesize the available research on the disclosure of diagnosis and related issues in childhood cancer from the perspectives of healthcare professionals,with the goal of... Objectives This review aimed to systematically synthesize the available research on the disclosure of diagnosis and related issues in childhood cancer from the perspectives of healthcare professionals,with the goal of informing the optimization of disclosure processes and meeting the communication needs of affected families.Methods In accordance with the Joanna Briggs Institute(JBI)methodology for mixed methods systematic reviews,the convergent segregated approach was used in this review.Articles were retrieved from 11 databases,including PubMed,Web of Science,CINAHL,CENTRAL,Embase,Ovid/Medline,PsycINFO,PsycArticles,Scopus,ERIC,and China National Knowledge Infrastructure(CNKI).The quality of the selected articles was assessed using the Mixed Method Appraisal Tool(MMAT).The review protocol was registered on PROSPERO(CRD42024542746).Results A total of 21 studies from 10 countries were included.Their methodological quality was generally medium to high,with MMAT scores ranging from 60%to 100%.The synthesis yielded three core themes:1)the spectrum of professional and societal attitudes toward disclosure;2)the dynamic practices of navigating disclosure amid uncertainty,including timing and environment,stakeholders,and content of disclosure;and 3)factors influencing disclosure,including children’s,parental,healthcare professionals’,and socio-cultural factors.Conclusions This review synthesized the perspectives and experiences of healthcare professionals regarding disclosure in childhood cancer,highlighting the complexity and multidimensional nature of this process in clinical practice.Future research should further investigate the experiences and needs of children and their parents,explore cultural variations in disclosure practices,develop context-appropriate assessment tools,and construct multidimensional intervention strategies to enhance the humanistic care and professional effectiveness of the disclosure process. 展开更多
关键词 Communication CANCER DISCLOSURE Healthcare professionals Mixed methods PEDIATRIC Systematic review
暂未订购
Investigation of equivalent strength parameters of soil-rock mixture using numerical manifold method
13
作者 Junfeng Li Yongtao Yang +2 位作者 Yang Xia Hong Zheng Shuilin Wang 《Journal of Rock Mechanics and Geotechnical Engineering》 2026年第1期637-650,共14页
As binary geological media,soil-rock mixtures(SRMs)exhibit a distinct gradational composition,leading to their unique mechanical behaviors.To appraise the stability of SRM slopes,it is essential to determine equivalen... As binary geological media,soil-rock mixtures(SRMs)exhibit a distinct gradational composition,leading to their unique mechanical behaviors.To appraise the stability of SRM slopes,it is essential to determine equivalent parameters of SRMs,which are typically obtained through experimental and numerical methods.In contrasted to other numerical methods,the numerical manifold method(NMM)is more effective in addressing SRM problems.This is because the high-precision regular mathematical meshes in NMM can be used without aligning with the soil-rock interfaces and boundaries of SRMs.In the current research,the equivalent strength parameters of SRMs,i.e.the equivalent cohesion ce and internal friction angleϕ_(e),are determined using NMM.Initially,an NMM triaxial numerical model is established and validated based on triaxial experiments.Subsequently,the soil and rock parameters are derived through parameter inversion.Moreover,the impacts of rock content,size,shape and rock blocks'major-axis orientation on ce andϕ_(e) of SRMs are thoroughly examined using the NMM triaxial numerical model.Additionally,a fitting function is proposed to linkϕ_(e) to the rock content and size of SRMs.When other influencing factors are fixed,the above fitting model leads to the following conclusions:(1)the predictedϕ_(e) of SRMs increase with the increase of rock content;and(2)SRM samples with smaller rocks display a higher predictedϕ_(e). 展开更多
关键词 Soil-rock mixtures Equivalent strength parameters Numerical manifold method
在线阅读 下载PDF
Subtitle Translation Methods of The Good Wife From Functional Equivalence Perspective
14
作者 WANG Ya-kun BAO De-wang 《Journal of Literature and Art Studies》 2026年第1期26-30,共5页
The Good Wife is an American TV series that focuses on women’s independence,politics,and law.The drama has been remade in China,Japan,and South Korea.This research aims to use Nida’s Functional Equivalence Theory to... The Good Wife is an American TV series that focuses on women’s independence,politics,and law.The drama has been remade in China,Japan,and South Korea.This research aims to use Nida’s Functional Equivalence Theory to analyze the methods of its English-to-Chinese subtitle translation by considering social,cultural,and historic backgrounds between China and America.After data collection and case analysis,the study found that:(1)Five major translation methods are adopted in the subtitle translation of The Good Wife.They are free translation,variation,literal translation,addition,and omission.Among them,free translation is the most frequently used,while omission is used least.(2)The subtitle translation of films and TV series is limited by time and space restrictions,social-cultural differences,and other factors.When translating,translators should try to use humorous words,euphemism,intonation,and other ways,and combine different methods such as literal translation,free translation,variation,addition,omission,and other methods to seek equivalence both in the meaning and function of subtitles under the guidance of Functional Equivalence Theory. 展开更多
关键词 subtitle translation Functional Equivalence Theory The Good Wife translation methods
在线阅读 下载PDF
Pile installation effects in natural soft clays:A semi-analytical solution using strain path method
15
作者 Liang Li Pan Zhou +3 位作者 Jingpei Li Seyedmohsen Miraei Peng Feng Mingdong Wei 《Journal of Rock Mechanics and Geotechnical Engineering》 2026年第1期728-744,共17页
This paper develops a semi-analytical solution for pile penetration in natural soft clays using the strain path method(SPM).The stress-strain behavior of soils is characterized by the S-CLAY1S model,which can capture ... This paper develops a semi-analytical solution for pile penetration in natural soft clays using the strain path method(SPM).The stress-strain behavior of soils is characterized by the S-CLAY1S model,which can capture the anisotropic evolution and destructuring nature of soft clays.By integrating the S-CLAY1S model into the theoretical framework of the SPM,a set of ordinary differential equations is formulated with respect to the vertical coordinate of soil particles.The distribution of excess pore water pressure(EPWP)following pile installation is approximated through one-dimensional(1D)radial integration around the pile shaft.The distribution of stresses and EPWP,along with the evolution of fabric anisotropy within the soil surrounding the pile,is presented to illustrate the response of pile penetration in natural soft clays.The proposed solution is validated against existing theoretical solutions using the SPM and cavity expansion method(CEM),along with experimental data.The findings demonstrate that the SPM reveals lower radial effective stresses and EPWP at the pile shaft than that of CEM.Pile penetration alters the soil's anisotropic properties,inducing rotational hardening and affecting post-installation stress distribution.Soil destructuration eliminates bonding among particles near the pile,resulting in a complete disruption of soil structure at the pile surface,which is particularly pronounced for higher initial soil structure ratios.Minimal variation was observed in the three principal stresses and shear stress on the cone side surface as the angle increased from 18°to 60°,except for a slight reduction in EPWP. 展开更多
关键词 Pile penetration Strain path method Natural soft clays Anisotropy evolution Destructuration
在线阅读 下载PDF
Crushing evolution in pebble bed based on a novel method:a crushable DEM study
16
作者 Jian Wang Ming‑Zhun Lei +4 位作者 Ming‑Zong Liu Qi‑Gang Wu Zi‑Cong Cai Kai‑Song Wang Hai‑Shun Deng 《Nuclear Science and Techniques》 2026年第1期212-224,共13页
In this paper,a novel method for investigating the particle-crushing behavior of breeding particles in a fusion blanket is proposed.The fractal theory and Weibull distribution are combined to establish a theoretical m... In this paper,a novel method for investigating the particle-crushing behavior of breeding particles in a fusion blanket is proposed.The fractal theory and Weibull distribution are combined to establish a theoretical model,and its validity was verified using a simple impact test.A crushable discrete element method(DEM)framework is built based on the previously established theoretical model.The tensile strength,which considers the fractal theory,size effect,and Weibull variation,was assigned to each generated particle.The assigned strength is then used for crush detection by comparing it with its maximum tensile stress.Mass conservation is ensured by inserting a series of sub-particles whose total mass was equal to the quality loss.Based on the crushable DEM framework,a numerical simulation of the crushing behavior of a pebble bed with hollow cylindrical geometry under a uniaxial compression test was performed.The results of this investigation showed that the particle withstands the external load by contact and sliding at the beginning of the compression process,and the results confirmed that crushing can be considered an important method of resisting the increasing external load.A relatively regular particle arrangement aids in resisting the load and reduces the occurrence of particle crushing.However,a limit exists to the promotion of resistance.When the strain increases beyond this limit,the distribution of the crushing position tends to be isotropic over the entire pebble bed.The theoretical model and crushable DEM framework provide a new method for exploring the pebble bed in a fusion reactor,considering particle crushing. 展开更多
关键词 Crushing behavior Granular material Discrete element method Pebble bed Fractal theory
在线阅读 下载PDF
Correction models of Reynolds number effects for through-flow method in axial compressors
17
作者 Xiaochen WANG Chunwei GU 《Chinese Journal of Aeronautics》 2026年第1期78-94,共17页
Aerodynamic performances of axial compressors are significantly affected by variation of Reynolds number in aero-engines.In the design and analysis of compressors,previous correction methods for cascades and stages ha... Aerodynamic performances of axial compressors are significantly affected by variation of Reynolds number in aero-engines.In the design and analysis of compressors,previous correction methods for cascades and stages have difficulties in predicting comprehensively Reynolds number effects on airfoils,matching and characteristics curves.This study proposes Re-correction models for loss,deviation angle and endwall blockage based on classical theories and cascade tests,and loss and deviation models show good agreement in test data of NACA65 and C4 cascades.Throughflow method considering Reynolds number effects is developed by integrating the correction models into a verified Streamline Curvature(SLC)tool.A three-stage axial compressor is investigated through SLC and CFD methods from design Reynolds number(Red=2106)to low Re=4104,and the numerical methods are validated with test data of characteristic curves and spanwise distributions at Red.With Re reduction,SLC method with correction models well predicts variation in overall performances compared with CFD calculations and Wassell's model.Streamwise and spanwise matching such as total pressure and loss distributions in SLC predictions are basically consistent with those in CFD results at near-stall points under design and low Reynolds numbers.SLC and CFD methods share similar detections of stall risks in the third stage(Stg3),and their analyses of diffusion processes deviate to some extent due to different predictions in separated endwall flow.The correction models can be adopted to consider Reynolds number effects in through-flow design and analysis of axial compressors. 展开更多
关键词 Axial compressor Reynolds number effects Correction model Through-flow method Aerodynamic performance
原文传递
ANALYSIS OF A QUADRILATERAL EDGE ELEMENT METHOD FOR MAXWELL EQUATIONS
18
作者 Zhijie DU Huoyuan DUAN Caihong WANG 《Acta Mathematica Scientia》 2026年第1期275-292,共18页
A new quadrilateral edge element method is proposed and analyzed for Maxwell equations.This proposed method is based on Duan-Liang quadrilateral element(Math.Comp.73(2004),pp.1–18).When applied to the eigenvalue prob... A new quadrilateral edge element method is proposed and analyzed for Maxwell equations.This proposed method is based on Duan-Liang quadrilateral element(Math.Comp.73(2004),pp.1–18).When applied to the eigenvalue problem,the method is spectral-correct and spurious-free.Stability and error estimates are obtained,including the interpolation error estimates and the error estimates between the finite element solution and the exact solution.The method is suitable for singular solution as well as smooth solution,and consequently,the method is valid for nonconvex domains which may have a number of reentrant corners.Of course,the method is suitable for arbitrary quadrilaterals(under the usual shape-regular condition). 展开更多
关键词 Maxwell equations finite element method quadrilateral mesh STABILITY error bound spectral approximation
在线阅读 下载PDF
FEM-DEM颗粒介质软体机械手指灵活度与刚度变化研究
19
作者 汪键 薛祖武 +1 位作者 袁海洋 陈家贤 《制造技术与机床》 北大核心 2026年第3期74-82,共9页
本研究基于颗粒介质的阻塞相变效应,通过数值模拟探讨了软体机械手指的灵活度与变刚度特性。利用Abaqus软件构建了融合颗粒接触非线性力学与堆积状态演化的有限元-离散元(finite element-discrete element,FEM-DEM)耦合模型,系统模拟了... 本研究基于颗粒介质的阻塞相变效应,通过数值模拟探讨了软体机械手指的灵活度与变刚度特性。利用Abaqus软件构建了融合颗粒接触非线性力学与堆积状态演化的有限元-离散元(finite element-discrete element,FEM-DEM)耦合模型,系统模拟了机械手指在不同颗粒体积分数下的动力学响应。研究结果表明,颗粒体积分数是调控机械手指力学性能的关键参数:当体积分数低于50%时,系统处于超松散堆积状态,刚度增强有限(增幅低于2%);当体积分数处于不同堆积状态阈值内,软体机械手指的可观测性能有着明显差异。其中,体积分数超过临界阈值(约55%)进入随机紧密堆积状态后,机械手指指末端位移显著降低(最高达56.74%),整体刚度呈现非线性跃升,最大增幅可达151.29%,实现了从高灵活度向高刚度状态的转变。揭示了基于颗粒阻塞的变刚度机理,为软体机械手指的结构优化与性能预测提供了理论依据与有效的仿真设计工具。 展开更多
关键词 颗粒阻塞 体积分数 堆积态 灵活度 变刚度 软体机械手指 fem-DEM
在线阅读 下载PDF
A Deep Reinforcement Learning-Based Partitioning Method for Power System Parallel Restoration
20
作者 Changcheng Li Weimeng Chang +1 位作者 Dahai Zhang Jinghan He 《Energy Engineering》 2026年第1期243-264,共22页
Effective partitioning is crucial for enabling parallel restoration of power systems after blackouts.This paper proposes a novel partitioning method based on deep reinforcement learning.First,the partitioning decision... Effective partitioning is crucial for enabling parallel restoration of power systems after blackouts.This paper proposes a novel partitioning method based on deep reinforcement learning.First,the partitioning decision process is formulated as a Markov decision process(MDP)model to maximize the modularity.Corresponding key partitioning constraints on parallel restoration are considered.Second,based on the partitioning objective and constraints,the reward function of the partitioning MDP model is set by adopting a relative deviation normalization scheme to reduce mutual interference between the reward and penalty in the reward function.The soft bonus scaling mechanism is introduced to mitigate overestimation caused by abrupt jumps in the reward.Then,the deep Q network method is applied to solve the partitioning MDP model and generate partitioning schemes.Two experience replay buffers are employed to speed up the training process of the method.Finally,case studies on the IEEE 39-bus test system demonstrate that the proposed method can generate a high-modularity partitioning result that meets all key partitioning constraints,thereby improving the parallelism and reliability of the restoration process.Moreover,simulation results demonstrate that an appropriate discount factor is crucial for ensuring both the convergence speed and the stability of the partitioning training. 展开更多
关键词 Partitioning method parallel restoration deep reinforcement learning experience replay buffer partitioning modularity
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