期刊文献+
共找到6,797篇文章
< 1 2 250 >
每页显示 20 50 100
Magnetic Anomaly Interpretation of the Northern Congo Craton Boundary: Results from Depth Estimation and 2.5D Modeling
1
作者 Basseka Charles Antoine Eyike Yomba Albert +3 位作者 Kenfack Jean Victor Njiteu Tchoukeu Cyrille Donald Som Mbang Constantin Mathieu Shandini Njankouo Yves 《Journal of Geoscience and Environment Protection》 2017年第12期90-101,共12页
A magnetic-based geophysical study was performed across the southern part of Cameroon to investigate the boundary between the Archean Congo craton and the Pan-African metamorphic belt. Magnetic gradient techniques inc... A magnetic-based geophysical study was performed across the southern part of Cameroon to investigate the boundary between the Archean Congo craton and the Pan-African metamorphic belt. Magnetic gradient techniques including Euler deconvolution and Tilt derivative have been applied to an aeromagnetic data profile to determine the depth of sources and their lateral extension. 2.5D magnetic modeling shows that the prominent magnetic positive anomalies observed on total magnetic map of south Cameroon are produced by deep and strongly magnetic bodies under the Pan-African formations mainly an important dyke formation structure with a high susceptibility of 0.041 (SI units), at an average depth of 4148 m and with a lateral extension of about 10 km. These bodies are interpreted to have emplaced at high crustal levels in a continental collision zone and were subsequently metamorphosed at granulite grade conditions, during the Pan-African orogeny about 620 Ma ago. 展开更多
关键词 CONGO CRATON Magnetic Anomalies EULER DECONVOLUTION TILT Derivative 2.5d modelING
暂未订购
2.5D Modelling of Aeromagnetic Data and their Mining Implications over the Ngaoundere Area (Adamawa Province, Cameroon)
2
作者 Meying Arsène Gouet Daniel Hervé +2 位作者 Ndougsa Mbarga Theophile Ndam Njikam Mouhamed Owono Amougou Olivier Ulrich Igor 《International Journal of Geosciences》 2019年第2期173-192,共20页
This study is based on the analysis and interpretation of aeromagnetic data using version 8.4 of the Geosoft Oasis Montaj Software, to map the subsurface or deep geological structures that affected the geological form... This study is based on the analysis and interpretation of aeromagnetic data using version 8.4 of the Geosoft Oasis Montaj Software, to map the subsurface or deep geological structures that affected the geological formations of the Ngaoundere area. The use of the standard aeromagnetic methods made it possible to draw up the maps of the residual magnetic field reduced to the equator (RTE), the horizontal gradient (HG), the analytical signal (AS) and that of the Euler solutions (ED) to find the main magnetic facies corresponding to these structures. The geological formations of the studied area thus appear to be intensely fractured by a NE-SW (N45°E) and ENE-WSW (N70°E) main orientation fault system, the depth of which has been estimated by combining the three-analytical methods HG, AS and ED. Advanced magmatic map analysis revealed dikes associated with vertical faults in the studied area. The development of an interpretative geological map taking into account the basic geology, the deep faults, the identified dikes and the mineralization index made it possible to extract a correlation between geological structures and mineralization of the studied area. The 2.5D modelling of two magnetic profiles plotted on the reduced residual map at the equator was performed to approximate the geometry and depth of the dikes sector, which are potential sources of mineralization here. 展开更多
关键词 AEROMAGNETIC Data ANALYTICAL Methods FAULTS MINERALIZATION 2.5d modelLING
暂未订购
Quantitative Interpretation of Gravity Anomalies in the Kribi-Campo Sedimentary Basin (South Cameroon) Based on Spectral Analysis and 2.5D Modelling: Structural Implications
3
作者 Kue Petou Rokis Malquaire Owona Angue Marie Louise Clotilde +5 位作者 Njingti Nfor Eloundou Essama Lionel Mioumnde Arthur Paterne Kue Negham Martine Clémence Manguelle-Dicoum Eliezer Weiqi Song 《Open Journal of Earthquake Research》 2020年第3期240-254,共15页
Ground gravity survey was recently carried out in the Lolabe-Campo area, which constitutes the southern onshore portion of the Kribi-Campo sub-basin in South Cameroon. The obtained gravity data were processed and inte... Ground gravity survey was recently carried out in the Lolabe-Campo area, which constitutes the southern onshore portion of the Kribi-Campo sub-basin in South Cameroon. The obtained gravity data were processed and interpreted in order to elucidate the subsurface geology of the area in which preliminary studies highlighted the presence of an intrusive igneous body. In order to determine the nature and the characteristics of this body, spectral analysis, ideal body solution and 2.5D modelling methods were applied to the gravity data. The results suggest that the emplacement, breaking up and separation of the intrusive igneous body were the outcome of two tectonic events corresponding to an upward vertical translational tectonic movement followed by an anticlockwise rotational faulting tectonic movement. From a density contrast of 0.13 g&#183cm&#453, the two isolated bodies have an estimated density of 2.80 g&#183cm&#453 which is comparatively higher than the average density of 2.67 g&#183cm&#453 of the autochthonous rocks. These two blocks are completely surrounded by both sedimentary and metamorphic formations and are confined between the depths of 0.6 km and 3.5 km. The highly dense nature of the rocks and their location around the Atlantic Ocean led to the conclusion that the two intrusive bodies are composed principally of gabbro. The disposition and shape of the open zone resulting from the separation of the blocks are suggestive of a trap for the accumulation of hydrocarbons and mineral resources. 展开更多
关键词 Spectral Analysis IDEAL Body 2.5d modelLING Formation Depth INTRUSIVE BLOCKS
在线阅读 下载PDF
Delaminated lower slab thermal regime before slab break-off in the Pamirs:Implications from 3D kinematic modeling
4
作者 Haris Faheem YingFeng Ji +6 位作者 Waqar Ahmed Rui Qu Ye Zhu Fitriani Fitriani Jun Yang Shoichi Yoshioka Nobuaki Suenaga 《Earth and Planetary Physics》 2026年第1期13-21,共9页
The intracontinental subduction of a>200-km-long section of the Tajik-Tarim lithosphere beneath the Pamir Mountains is proposed to explain nearly 30 km of shortening in the Tajik fold-thrust belt and the Pamir upli... The intracontinental subduction of a>200-km-long section of the Tajik-Tarim lithosphere beneath the Pamir Mountains is proposed to explain nearly 30 km of shortening in the Tajik fold-thrust belt and the Pamir uplift.Seismic imaging revealed that the upper slab was scraped and that the lower slab had subducted to a depth of>150 km.These features constitute the tectonic complexity of the Pamirs,as well as the thermal subduction mechanism involved,which remains poorly understood.Hence,in this study,high-resolution three-dimensional(3D)kinematic modeling is applied to investigate the thermal structure and geometry of the subducting slab beneath the Pamirs.The modeled slab configuration reveals distinct along-strike variations,with a steeply dipping slab beneath the southern Pamirs,a more gently inclined slab beneath the northern Pamirs,and apparent upper slab termination at shallow depths beneath the Pamirs.The thermal field reveals a cold slab core after delamination,with temperatures ranging from 400℃to 800℃,enveloped by a hotter mantle reaching~1400℃.The occurrence of intermediate-depth earthquakes aligns primarily with colder slab regions,particularly near the slab tear-off below the southwestern Pamirs,indicating a strong correlation between slab temperature and seismicity.In contrast,the northern Pamirs exhibit reduced seismicity at depth,which is likely associated with thermal weakening and delamination.The central Pamirs show a significant thermal anomaly caused by a concave slab,where the coldest crust does not descend deeply,further suggesting crustal detachment or mechanical failure.The lateral asymmetry in slab temperature possibly explains the mechanism of lateral tearing and differential slab-mantle coupling. 展开更多
关键词 PAMIRS SUBDUCTION 3D kinematic modeling slab geometry intermediate-depth earthquake crustal delamination seismicity distribution
在线阅读 下载PDF
Automatic gating and riser system design and defect control for K4169 superalloy guide blade casting based on parametric 3D modeling-simulation integrated system
5
作者 Le-chuan Li Ya-jun Yin +4 位作者 Bing-zheng Fan Guo-yan Shui Xiao-yuan Ji Jian-xin Zhou Lei Jin 《China Foundry》 2026年第1期20-30,共11页
Automation and intelligence have become the primary trends in the design of investment casting processes.However,the design of gating and riser systems still lacks precise quantitative evaluation criteria.Numerical si... Automation and intelligence have become the primary trends in the design of investment casting processes.However,the design of gating and riser systems still lacks precise quantitative evaluation criteria.Numerical simulation plays a significant role in quantitatively evaluating current processes and making targeted improvements,but its limitations lie in the inability to dynamically reflect the formation outcomes of castings under varying process conditions,making real-time adjustments to gating and riser designs challenging.In this study,an automated design model for gating and riser systems based on integrated parametric 3D modeling-simulation framework is proposed,which enhances the flexibility and usability of evaluating the casting process by simulation.Firstly,geometric feature extraction technology is employed to obtain the geometric information of the target casting.Based on this information,an automated design framework for gating and riser systems is established,incorporating multiple structural parameters for real-time process control.Subsequently,the simulation results for various structural parameters are analyzed,and the influence of these parameters on casting formation is thoroughly investigated.Finally,the optimal design scheme is generated and validated through experimental verification.Simulation analysis and experimental results show that using a larger gate neck(24 mm in side length) and external risers promotes a more uniform temperature distribution and a more stable flow state,effectively eliminating shrinkage cavities and enhancing process yield by 15%. 展开更多
关键词 numerical simulation automatic design investment casting parametric 3D modeling gating and riser system
在线阅读 下载PDF
Development of Patient-Derived Conditionally Reprogrammed 3D Breast Cancer Culture Models for Drug Sensitivity Evaluation
6
作者 Jing Cai Haoyun Zhu +4 位作者 Weiling Guo Ting Huang Pangzhou Chen Wen Zhou Ziyun Guan 《Oncology Research》 2026年第1期500-520,共21页
Background:Therapeutic responses of breast cancer vary among patients and lead to drug resistance and recurrence due to the heterogeneity.Current preclinical models,however,are inadequate for predicting individual pat... Background:Therapeutic responses of breast cancer vary among patients and lead to drug resistance and recurrence due to the heterogeneity.Current preclinical models,however,are inadequate for predicting individual patient responses towards different drugs.This study aimed to investigate the patient-derived breast cancer culture models for drug sensitivity evaluations.Methods:Tumor and adjacent tissues from female breast cancer patients were collected during surgery.Patient-derived breast cancer cells were cultured using the conditional reprogramming technique to establish 2D models.The obtained patient-derived conditional reprogramming breast cancer(CRBC)cells were subsequently embedded in alginate-gelatin methacryloyl hydrogel microspheres to form 3D culture models.Comparisons between 2D and 3D models were made using immunohistochemistry(tumor markers),MTS assays(cell viability),flow cytometry(apoptosis),transwell assays(migration),and Western blotting(protein expression).Drug sensitivity tests were conducted to evaluate patient-specific responses to anti-cancer agents.Results:2D and 3D culture models were successfully established using samples from eight patients.The 3D models retained histological and marker characteristics of the original tumors.Compared to 2D cultures,3D models exhibited increased apoptosis,enhanced drug resistance,elevated stem cell marker expression,and greater migration ability—features more reflective of in vivo tumor behavior.Conclusion:Patient-derived 3D CRBC models effectively mimic the in vivo tumor microenvironment and demonstrate stronger resistance to anti-cancer drugs than 2D models.These hydrogel-based models offer a cost-effective and clinically relevant platform for drug screening and personalized breast cancer treatment. 展开更多
关键词 Patient-derived breast cancer cells conditional reprogramming hydrogel microsphere 3D culture model drug screening
暂未订购
Motion In-Betweening via Frequency-Domain Diffusion Model
7
作者 Qiang Zhang Shuo Feng +2 位作者 Shanxiong Chen Teng Wan Ying Qi 《Computers, Materials & Continua》 2026年第1期275-296,共22页
Human motion modeling is a core technology in computer animation,game development,and humancomputer interaction.In particular,generating natural and coherent in-between motion using only the initial and terminal frame... Human motion modeling is a core technology in computer animation,game development,and humancomputer interaction.In particular,generating natural and coherent in-between motion using only the initial and terminal frames remains a fundamental yet unresolved challenge.Existing methods typically rely on dense keyframe inputs or complex prior structures,making it difficult to balance motion quality and plausibility under conditions such as sparse constraints,long-term dependencies,and diverse motion styles.To address this,we propose a motion generation framework based on a frequency-domain diffusion model,which aims to better model complex motion distributions and enhance generation stability under sparse conditions.Our method maps motion sequences to the frequency domain via the Discrete Cosine Transform(DCT),enabling more effective modeling of low-frequency motion structures while suppressing high-frequency noise.A denoising network based on self-attention is introduced to capture long-range temporal dependencies and improve global structural awareness.Additionally,a multi-objective loss function is employed to jointly optimize motion smoothness,pose diversity,and anatomical consistency,enhancing the realism and physical plausibility of the generated sequences.Comparative experiments on the Human3.6M and LaFAN1 datasets demonstrate that our method outperforms state-of-the-art approaches across multiple performance metrics,showing stronger capabilities in generating intermediate motion frames.This research offers a new perspective and methodology for human motion generation and holds promise for applications in character animation,game development,and virtual interaction. 展开更多
关键词 Motion generation diffusion model frequency domain human motion synthesis self-attention network 3D motion interpolation
在线阅读 下载PDF
2.5D Crustal Models Derived from Analytical Polynomial Separation Technique and Spectral Analysis of Gravity Data with Their Probable Gold Mineralization Migrations (Batouri, SE-Cameroon) 被引量:1
8
作者 Ngoumou Paul Claude Assembe Stephane Patrick +4 位作者 Owono Amougou Olivier Ulrich Igor Meying Arsene Yandjimaing Justine Ngoh Jean Daniel Pepogo Man-Mvele Augustin Didier 《Advances in Remote Sensing》 2021年第1期1-24,共24页
Geophysical surveying is crucial in the investigation of mineral resources in poorly exposed areas such as SE-Cameroon, a region known for its gold mineral potential. In this paper, gravity survey is carried out in th... Geophysical surveying is crucial in the investigation of mineral resources in poorly exposed areas such as SE-Cameroon, a region known for its gold mineral potential. In this paper, gravity survey is carried out in the Batouri area, SE-Cameroon based on land gravity data from the Centre-south Cameroon. <span style="font-family:Verdana;">Therefore, an analytical polynomial separation program, based on least-square fi</span><span style="font-family:Verdana;">tting of a third-degree polynomial surface to the Bouguer anomaly map, was used to separate the regional/residual components in gravity data. This technique permitted to better understand the disposition of the deep and near surface structures responsible of the observed anomalies in the Batouri area. Spectral analysis and 2.5D modelling of two profiles P</span><sub><span style="font-family:Verdana;">1</span></sub><span style="font-family:Verdana;"> (SW-NE) and P</span><sub><span style="font-family:Verdana;">2</span></sub><span style="font-family:Verdana;"> (N-S) selected from the residual anomaly map provided depths to basement. These depths constrain the gravity models along the profiles, indicating a variable thickness of the sedimentary infill with an approximate anomaly of -</span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">33 mGal. The 2.5D model of the basement shows a gravity body, with a signature suggesting two close and similar masses, which characterize the quartz-bearing formations associated here to granite and gneiss. Our work highlights a main heavy gravity: Gwé-Batouri anomaly, containing the major part of auriferous deposits located along the NE-SW direction. Further, three tectonic sub-basins bounded by normal faults have been highlighted at Guedal, Gwé, and Bélimban, in the south of Guedal-Bélimban depression. They are associated with the extension tectonics, more or less vertical tangential cuts and accidents that have affected the region. A correlation with previous results from tectonic, lithological and gold mineralization activities proves the relevance of the study and the need to intensify geophysical surveying in the area.</span></span></span> 展开更多
关键词 Gravity Anomaly SE-Cameroon Polynomial Technique Spectral Analysis 2.5d modelling Gold Mineralization Batouri Area
在线阅读 下载PDF
2.5D forward modeling and inversion of frequency-domain airborne electromagnetic data 被引量:1
9
作者 李文奔 曾昭发 +3 位作者 李静 陈雄 王坤 夏昭 《Applied Geophysics》 SCIE CSCD 2016年第1期37-47,218,共12页
Frequency-domain airborne electromagnetics is a proven geophysical exploration method.Presently,the interpretation is mainly based on resistivity-depth imaging and onedimensional layered inversion;nevertheless,it is d... Frequency-domain airborne electromagnetics is a proven geophysical exploration method.Presently,the interpretation is mainly based on resistivity-depth imaging and onedimensional layered inversion;nevertheless,it is difficult to obtain satisfactory results for two- or three-dimensional complex earth structures using 1D methods.3D forward modeling and inversion can be used but are hampered by computational limitations because of the large number of data.Thus,we developed a 2.5D frequency-domain airborne electromagnetic forward modeling and inversion algorithm.To eliminate the source singularities in the numerical simulations,we split the fields into primary and secondary fields.The primary fields are calculated using homogeneous or layered models with analytical solutions,and the secondary(scattered) fields are solved by the finite-element method.The linear system of equations is solved by using the large-scale sparse matrix parallel direct solver,which greatly improves the computational efficiency.The inversion algorithm was based on damping leastsquares and singular value decomposition and combined the pseudo forward modeling and reciprocity principle to compute the Jacobian matrix.Synthetic and field data were used to test the effectiveness of the proposed method. 展开更多
关键词 Frequency-domain airborne electromagnetic finite element method 2.5d geoelectric model damped least-squares method
在线阅读 下载PDF
2.5D C_(f)/SiC复合材料与SiC陶瓷微磨削性能对比试验研究
10
作者 巩亚东 李远峰 +1 位作者 温泉 任启震 《东北大学学报(自然科学版)》 北大核心 2025年第1期52-60,共9页
为探究2.5D C_(f)/SiC复合材料与SiC陶瓷的微尺度磨削过程,对比2种材料在同一工艺参数下表面显微形貌、表面粗糙度与磨削力的差异,并分析工艺参数变化对磨削性能评价参数的影响;采用直径为0.9 mm的500#电镀金刚石微磨具对2种材料分别进... 为探究2.5D C_(f)/SiC复合材料与SiC陶瓷的微尺度磨削过程,对比2种材料在同一工艺参数下表面显微形貌、表面粗糙度与磨削力的差异,并分析工艺参数变化对磨削性能评价参数的影响;采用直径为0.9 mm的500#电镀金刚石微磨具对2种材料分别进行单因素微磨削试验.结果表明,2.5D C_(f)/SiC复合材料去除过程不同于SiC陶瓷,这是因为复合材料增强纤维的存在,有效抑制了微磨削过程中裂纹的扩展;在同一工艺参数下,2.5D C_(f)/SiC复合材料表面微观形貌较好、缺陷少、表面粗糙度小,而无纤维增强的SiC陶瓷表面微观形貌较差、缺陷多、表面粗糙度大;SiC陶瓷的平均磨削力大于2.5D C_(f)/SiC,并且在微磨削过程中,2.5D C_(f)/SiC的实时磨削力信号较平稳,而SiC陶瓷的实时磨削力信号存在尖刺. 展开更多
关键词 2.5d C_(f)/SiC复合材料 SIC陶瓷 微磨削过程 表面微观形貌 表面粗糙度 磨削力
在线阅读 下载PDF
2.5D封装冲击可靠性分析
11
作者 周春燕 卢琰 《北京理工大学学报》 北大核心 2025年第7期703-710,共8页
2.5D封装凭借其异构集成和低成本的优势,成为下一代集成电路的重要发展方向.电子器件中约20%的故障源自冲击与振动,因此分析2.5D封装在跌落冲击下的动态特性具有重要意义.以某2.5D封装为例,采用ANSYS/LSDYNA结合Input-G方法,焊点采用线... 2.5D封装凭借其异构集成和低成本的优势,成为下一代集成电路的重要发展方向.电子器件中约20%的故障源自冲击与振动,因此分析2.5D封装在跌落冲击下的动态特性具有重要意义.以某2.5D封装为例,采用ANSYS/LSDYNA结合Input-G方法,焊点采用线弹性模型和应变率相关的Johnson-Cook本构模型,对2.5D封装的跌落冲击瞬态响应进行了仿真.引入下填充材料以提高焊点的可靠性,分析了加速度幅值和脉冲时间对焊点可靠性的影响.结果表明:Johnson-Cook本构模型的焊点应力小于线弹性模型,且增加下填充材料能极大提高焊点的可靠性,填充面积越大效果越好;同时,加速度幅值和脉冲时间增大会降低焊点的可靠性. 展开更多
关键词 2.5d封装 冲击 下填充 应变率效应
在线阅读 下载PDF
基于硅转接板的2.5D封装中电源地平面研究和优化
12
作者 陈龙 宋昌明 +3 位作者 周晟娟 章莱 王谦 蔡坚 《电子与封装》 2025年第11期34-40,共7页
针对基于硅转接板的2.5D封装中电源分配网络(PDN)阻抗大、系统电压噪声大的电源完整性问题,建立2.5D封装模型,研究和优化封装系统的电源完整性。采用三维电磁场与电路协同仿真的方法,对硅转接板上的电源地平面进行阻抗优化,并通过合理... 针对基于硅转接板的2.5D封装中电源分配网络(PDN)阻抗大、系统电压噪声大的电源完整性问题,建立2.5D封装模型,研究和优化封装系统的电源完整性。采用三维电磁场与电路协同仿真的方法,对硅转接板上的电源地平面进行阻抗优化,并通过合理选择与布局深槽电容(DTC)对系统进行阻抗优化和电压噪声改善。结果显示,提高电源地平面的布线密度能够有效降低PDN的阻抗。电源地平面线宽/线距存在优化下限,当线宽/线距小于片间互连信号线线宽的2倍时会对片间互连信号线产生阻抗不连续的不良影响。在所建立的模型中,根据PDN阻抗的高频谐振峰选择DTC,使得PDN阻抗降低约83%,电压噪声减小约42%。同时,DTC的集成会在中高频段引入新的谐振峰,对PDN产生阻抗增大的不利影响。 展开更多
关键词 2.5d封装 硅转接板 电源完整性 电源地平面 深槽电容
在线阅读 下载PDF
2.5D C/SiC复合材料磁场/液体辅助皮秒激光制孔试验研究
13
作者 刘畅 王科骄 李丞 《航空制造技术》 北大核心 2025年第1期54-63,共10页
2.5D C/SiC复合材料是航空国防领域耐高温构件用关键复合材料,其高硬度、高耐磨性使该材料的高质量微孔加工异常困难。本文提出了一种基于磁场/液体辅助(MLM)的2.5D C/SiC复合材料皮秒激光制孔工艺,通过提取微孔的出/入口直径、锥度、... 2.5D C/SiC复合材料是航空国防领域耐高温构件用关键复合材料,其高硬度、高耐磨性使该材料的高质量微孔加工异常困难。本文提出了一种基于磁场/液体辅助(MLM)的2.5D C/SiC复合材料皮秒激光制孔工艺,通过提取微孔的出/入口直径、锥度、氧化、重铸层等特征,与皮秒激光加工(PM)、磁场辅助加工(MM)、液体辅助加工(LM)3种工艺进行了对比研究。结果表明,基于MLM的皮秒激光加工能够有效降低微孔的入口直径,同时增大出口直径,在两组不同的试验参数下分别获得了锥度1.3°及1.1°的微孔,比PM工艺的锥度分别降低了18.75%和45%,比MM工艺的锥度分别降低了13.33%和31.25%,比LM工艺的锥度分别降低了91.22%和79.63%。此外,利用EDS能谱分析、拉曼光谱以及XPS技术对制备的微孔开展了微观组织分析。可以发现,MLM工艺更有效地减少了孔壁的石墨化缺陷。其中,液体辅助避免了微孔入口处的氧化,同时清晰地观察到裸露的纤维和基体,有效避免了热损伤和重铸层缺陷。在皮秒激光制孔中,MLM的主要作用机制体现在液体的冷却效应、隔绝氧气机制,以及磁场纵向拉伸等离子体,从而减弱等离子体屏蔽效应。 展开更多
关键词 皮秒激光 磁场/液体辅助加工 2.5d C/SiC复合材料 孔锥度 烧蚀机理
在线阅读 下载PDF
Fatigue life prediction model of 2.5D woven composites at various temperatures 被引量:5
14
作者 Jian SONG Weidong WEN Haitao CUI 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2018年第2期310-329,共20页
As one of the new structural layout in the family of woven composites, 2.5D Woven Composites(2.5D-WC) have recently attracted an increasing interest owing to its excellent properties, i.e. high specific strength and... As one of the new structural layout in the family of woven composites, 2.5D Woven Composites(2.5D-WC) have recently attracted an increasing interest owing to its excellent properties, i.e. high specific strength and fatigue resistance, in the aerospace and automobile industry. Indepth understanding of the fatigue behavior of this material at un-ambient temperatures is critical for the engineering applications, especially in aero-engine field. Here, fatigue behavior of 2.5D-WC at different temperatures was numerically investigated based on the unit cell approach. Firstly, the unit cell model of 2.5D-WC was established using ANSYS software. Subsequently, the temperature-dependent fatigue life prediction model was built up. Finally, the fatigue lives alongside the damage evolution processes of 2.5D-WC at ambient temperature(20 ℃) and unambient temperature(180 ℃) were analyzed. The results show that numerical results are in good agreement with the relevant experimental results at 20 and 180 ℃. Fatigue behavior of 2.5D-WC is also sensitive to temperature, which is partially attributed to the mechanical properties of resin and the change of inclination angle of warp yarns. We hope that the proposed fatigue life prediction model and the findings could further promote the engineering application of 2.5D-WC, especially in aero-engine field. 展开更多
关键词 ANSYS Fatigue behavior Fatigue life prediction model TEMPERATURE 2.5d woven composites
原文传递
Analytical Model of Elastic Modulus and Coefficient of Thermal Expansion for 2.5D C/SiC Composite 被引量:2
15
作者 孔春元 孙志刚 +1 位作者 NIU Xuming SONG Yingdong 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 2013年第3期494-499,共6页
To make better use of 2.5D C/SiC composites in industry, it is necessary to understand the mechanical properties. A finite element model'of 2.5D composites is established, by considering the fiber undulation and the ... To make better use of 2.5D C/SiC composites in industry, it is necessary to understand the mechanical properties. A finite element model'of 2.5D composites is established, by considering the fiber undulation and the porosity in 2.5D C/SiC composites. The fiber direction of warp is defined by cosine function to simulate the undulation of warp, and based on uniform strain assumption, analytical model of the elastic modulus and coefficient of thermal expansion (CTE) for 2.5D C/SiC composites were established by using dual- scale model. The result is found to correlate reasonably well with the predicted results and experimental results. The parametric study also demonstrates the effects of the fiber volume fraction, distance of warp yarn, and porosity in micro-scale on the mechanical properties and the coefficients of thermal expansion. 展开更多
关键词 2.5d C/SiC composites finite element model analytical model elastic modulus coefficient of thermal expansion
原文传递
基于双向JPS算法的室外移动机器人2.5D路径规划 被引量:3
16
作者 刘晓茜 刘海鹏 +1 位作者 毛剑琳 方奇文 《控制工程》 北大核心 2025年第2期233-241,共9页
针对室外移动机器人在不平坦地形上使用A*算法进行路径规划时冗余节点过多导致路径搜索时间长的问题,采用双向跳点搜索算法来解决。首先,为保证机器人在2.5D地图上的安全性,引入了最大爬坡度;其次,通过位运算快速识别出路径中的关键点,... 针对室外移动机器人在不平坦地形上使用A*算法进行路径规划时冗余节点过多导致路径搜索时间长的问题,采用双向跳点搜索算法来解决。首先,为保证机器人在2.5D地图上的安全性,引入了最大爬坡度;其次,通过位运算快速识别出路径中的关键点,并在评价函数中加入了高度参数来评估下一节点,极大减少了搜索过程中的冗余节点;同时,采用双向交替的搜索方式提高了算法的效率;最后,为了验证算法的有效性,在MATLAB上与传统的A*算法进行比较。仿真结果表明,改进后的算法在2.5D地图上提高了搜索速度,保证了机器人路径规划的安全性,满足了路径规划的要求。 展开更多
关键词 2.5d地图 双向跳点搜索 A*算法 位运算
原文传递
2.5D-SiC_f/SiC复合材料结构的拉伸行为和损伤模型
17
作者 陈超 代睿 +4 位作者 徐琳 范晓孟 赵东林 党潇琳 何江怡 《航空科学技术》 2025年第4期48-55,共8页
2.5D-SiC_f/SiC复合材料的经向与纬向力学性能存在明显差异,研究其微结构与拉伸行为关系对揭示2.5D-SiC_f/SiC复合材料各向异性损伤机理,提升应用性能具有重要意义。本文采用化学气相沉积法制备了2.5D-SiC_f/SiC复合材料,并对其微结构... 2.5D-SiC_f/SiC复合材料的经向与纬向力学性能存在明显差异,研究其微结构与拉伸行为关系对揭示2.5D-SiC_f/SiC复合材料各向异性损伤机理,提升应用性能具有重要意义。本文采用化学气相沉积法制备了2.5D-SiC_f/SiC复合材料,并对其微结构和拉伸性能进行表征。结果发现,材料内部存在典型的X形孔隙网络区域,在该区域经纱与轴向存在12°夹角。拉伸过程中,经纱除了承受拉应力外也同时承受剪切力的影响,导致经向纤维拉伸损伤容限下降,故断裂时经向拉伸断裂损伤程度(53%)低于纬向(63%)。以上结构特征导致经向纤维束体积分数是纬向纤维束的2.52倍,而经向拉伸强度(255.8MPa±5.5MPa)却只是纬向(156.1MPa±29.9MPa)的1.64倍。 展开更多
关键词 2.5d-SiCf/SiC 微结构 拉伸试验 损伤过程 损伤演化模型
在线阅读 下载PDF
3D seismic response of a 2D hill-valley staggered topography modeled by a 2.5D multi-domain IBEM 被引量:1
18
作者 Zhenning Ba Qiaozhi Sang Jianwen Liang 《Earthquake Science》 2019年第3期125-142,共18页
A two and a half dimensional(2.5D)multi-domain indirect boundary element method(IBEM)is developed to study the wave scattering of obliquely incident P-,SV-and SH-waves by a hill-valley staggered topography in a multi-... A two and a half dimensional(2.5D)multi-domain indirect boundary element method(IBEM)is developed to study the wave scattering of obliquely incident P-,SV-and SH-waves by a hill-valley staggered topography in a multi-layered half-space.The IBEM algorithm includes using 2.5D full-space and half-space Green’s functions to construct scattered fields in decomposed closed and opened half-space regions,respectively,and using the dynamic stiffness method to solve the free fields.All regions are finally integrated by introducing the compatibility conditions to obtain the total wave fields.The proposed 2.5D IBEM has the flexibility in dealing with complex boundaries by directly applying the fictitious loads on the regions’boundaries,with a less storage requirement compared to the full 3D models.Besides,by combining the specific advantages of the two kinds of Green’s functions,the method is well suitable for handling coupled topographies with high accuracy.The method is validated by comparison with published results for a single valley as well as a single hill topography.The effects of height-to-width ratio of hill and layering on dynamic responses are further parametrically investigated by numerical implementations in frequency domain.Results show that the interaction between valley and hills can lead to a more significant amplification within the valley region,and dynamic responses are deeply influenced by the height-to-width of hill,simultaneously depending on incident angle and frequency.Besides,the site effects become more complex when the stratification feature is taken into account. 展开更多
关键词 2.5d multi-domain IBEM Green’s functions for moving load hill-valley staggered topography wave scattering layered half-space
在线阅读 下载PDF
多芯粒2.5D/3D集成技术研究与应用现状
19
作者 王根旺 李璐 +1 位作者 潘鹏辉 李宝霞 《电子科技大学学报》 北大核心 2025年第6期819-831,共13页
面向高性能计算机、人工智能、无人系统对电子芯片高性能、高集成度的需求,以2.5D、3D集成技术为代表的先进封装集成技术,不仅打破了当前集成芯片良率降低、成本骤升的困境,也是实现多种类型、多种材质、多种功能芯粒集成的重要手段。... 面向高性能计算机、人工智能、无人系统对电子芯片高性能、高集成度的需求,以2.5D、3D集成技术为代表的先进封装集成技术,不仅打破了当前集成芯片良率降低、成本骤升的困境,也是实现多种类型、多种材质、多种功能芯粒集成的重要手段。该文对多芯粒2.5D、3D集成方案研究现状与技术水平进行总结分析,包括大尺寸中介层2.5D技术、低互连节距3D堆叠互连技术、玻璃基集成技术等。并总结了不同集成方案技术的主要发展方向与亟待攻克的技术难点。在此基础上,进一步归纳了多芯粒2.5D、3D集成技术在数字、光电、微电子机械等集成芯片与器件领域的应用,分析了多芯粒2.5D、3D封装集成技术未来发展与应用方向,为微小型多功能一体化集成芯片提供发展思路。 展开更多
关键词 先进封装 2.5d集成 3D集成 中介层
在线阅读 下载PDF
基于2.5D FEM-MFS的高铁盾构隧道车致振动传播机制及环境响应研究
20
作者 徐晨 肖明清 +3 位作者 薛光桥 何应道 徐巍 王春晖 《隧道建设(中英文)》 北大核心 2025年第7期1260-1271,共12页
为在城市密集区的高铁选线及环境振动评价提供理论依据,明确高铁盾构隧道车致振动对沿线环境的振动影响特征与规律,采用基于2.5D有限元-基本解方法(2.5D FEM-MFS)的车致环境振动预测模型,以设计车速为350 km/h、外径为13.8 m的高铁盾构... 为在城市密集区的高铁选线及环境振动评价提供理论依据,明确高铁盾构隧道车致振动对沿线环境的振动影响特征与规律,采用基于2.5D有限元-基本解方法(2.5D FEM-MFS)的车致环境振动预测模型,以设计车速为350 km/h、外径为13.8 m的高铁盾构隧道为研究对象,通过轮轨耦合动力学与波数域场耦合分析,揭示典型工况高铁盾构隧道车致振动振源及传播规律。研究结果表明:1)高铁盾构隧道振动呈现显著的频段分化特征,30 Hz以下低频振动以围岩剪切波形式传播(波速为734 m/s),30~70 Hz频段为管片-围岩协同振动,80 Hz以上高频振动由管片弯曲波主导(波速为1 066 m/s或2 000 m/s);2)隧道内Z振级从轨道板处80.9 d B衰减至拱顶47.6 d B,隧道拱顶两侧因高阶振型出现55 d B局部放大;3)地表振动呈现非单调空间衰减特性,存在局部振动放大现象,最大Z振级46.7 d B出现在距隧道中线32 m处,满足Ⅰ类振动功能区限值要求,最大速度为1.73μm/s,满足VC-E级精密仪器容许标准;4)与典型地铁环境振动工况相比,高铁盾构隧道内具有Z振级较低、地表环境振动高频分频振级较低,但随距离衰减缓慢的特征。 展开更多
关键词 高铁地下线 盾构隧道 环境振动 2.5d有限元-基本解方法
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