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南美奥连特盆地坎潘阶碳酸盐岩建隆的识别及科迪勒拉运动早期抬升对Main-M1储集层沉积的控制作用 被引量:1
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作者 丁峰 王光付 +6 位作者 孙建芳 孙钰 李发有 薛明喜 吴洁 班舒悦 鲍志东 《古地理学报》 CAS CSCD 北大核心 2024年第1期5-16,共12页
厄瓜多尔奥连特盆地Main-M1砂岩储集层是该盆地近年来重要的构造-岩性圈闭勘探目的层系,寻找砂体和岩性尖灭带是Main-M1砂岩勘探的关键。该盆地为晚白垩世弧后热沉降盆地和新生代前陆盆地的叠合盆地,在构造上分为西部逆冲褶皱带、中部... 厄瓜多尔奥连特盆地Main-M1砂岩储集层是该盆地近年来重要的构造-岩性圈闭勘探目的层系,寻找砂体和岩性尖灭带是Main-M1砂岩勘探的关键。该盆地为晚白垩世弧后热沉降盆地和新生代前陆盆地的叠合盆地,在构造上分为西部逆冲褶皱带、中部前渊带和东部斜坡带,在前渊带发育一系列近N-S走向长轴背斜。综合观察和分析发现,在研究区内长轴背斜上生长了1个碳酸盐岩建隆,地震上具有明显的边界反射形成丘状外观和较连续的弱振幅内部反射,测井上具有厚层、近箱型低GR响应特征。该建隆表明在其沉积的坎潘阶时期,长轴背斜已经开始抬升,将背斜顶部推升至古水面附近,形成建隆局部生长的条件。压实回剥方法恢复古地貌证实,长轴背斜在坎潘阶早期开始发育,构造抬升幅度为7~10 m。由于构造抬升和建隆发育始于Main-M1沉积前,抬升古地貌可影响砂岩沉积。根据背斜上数十口已钻井Main-M1砂体厚度统计,发现背斜顶部砂岩储集层整体较发育,但古建隆顶部砂层厚度减薄或者缺失,在背斜的南部延伸段,构造顶部砂岩缺失,仅在东部侧翼富集。提出了近N-S向背斜古地貌影响Main-M1砂体沉积,使砂岩于富集于构造下倾方向的控砂模式。该模式可形成上倾尖灭型构造-岩性圈闭,从而提供了通过古地貌恢复在奥连特盆地前渊带寻找新圈闭的勘探思路。 展开更多
关键词 奥连特盆地 科迪勒拉运动 碳酸盐岩建隆 古地貌 main-M1储集层 构造-岩性圈闭
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Two New Main Group Metal Coordination Polymers Based on 2,5-Furandicarboxylic Acid: Syntheses and Crystal Structures 被引量:2
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作者 王浩 刘洋 +2 位作者 陈飞 郭雨萌 章应辉 《Chinese Journal of Structural Chemistry》 SCIE CAS CSCD 2015年第4期585-593,共9页
By using solvothermal method, two new main group metal coordination polymers based on 2,5-furandicarboxylic acid (H2FDA) ligand, [Sr2(FDA)E(H2O)5]n (1) and [Ba4(FDA)4(H2O)10]n (2), were produced and char... By using solvothermal method, two new main group metal coordination polymers based on 2,5-furandicarboxylic acid (H2FDA) ligand, [Sr2(FDA)E(H2O)5]n (1) and [Ba4(FDA)4(H2O)10]n (2), were produced and characterized by single-crystal X-ray diffraction analyses, elemental analyses, IR, and powder X-ray diffraction. Compound 1 crystallizes in monoclinic, space group C2/c with a = 13.454(3), b = 13.426(3), c = 20.166(4) A, β = 107.06(3)°, V = 3482.4(13)A^3, Dc = 2.188 g/cm^3, CIEH14Sr2O15, Mr = 573.47, F(000) = 2256,μ(MoKα)= 6.21 mm^-1, Z = 8, R = 0.0522 and wR = 0.1229 for 2493 observed reflections (I〉 2σ(I)), and R = 0.0689 and wR = 0.1324 for all data. Compound 2 crystallizes in triclinic, space group el with α = 6.8382(14), b = 10.932(2), c = 25.571(5) A,α = 94.64(3), β= 95.41(3), γ = 107.83(3)°, V= 1799.4(6) A3, Dc = 2.484 g/cm^3, C24H28Ba4O30, Mr = 1345.82, F(000) = 1272,μ(MoKa) = 4.43 mm^-1, Z = 2, R = 0.0485 and wR = 0.0906 for 5020 observed reflections (I〉 2σ(I)), and R = 0.0706 and wR = 0.0991 for all data. In 1, the trinuclear clusters Sr3 are connected with adjacent four clusters by a carboxylate group to produce a two-dimensional (2D) sheet, which is extended by a FDA-based pillar into a 3D framework. In 2, neighbouring trinuclear clusters Ba3 are linked through two -O-C-O- of FDA^2- ligands to form one-dimensional (1D) chains, which are connected by a FDA-based pillar to construct a 2D framework. The thermal stabilities of 1 and 2 are also investigated. 展开更多
关键词 2 5-furandicarboxylic acid main group crystal structure
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Structure of the Intermetallic Compound Ni_3Al Synthesized under Compression of the Powder Mixture of Pure Elements Part Ⅰ: Phase Composition and Microstructure of Main Phase 被引量:4
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作者 M. V. Fedorischeva, V.E.Ovcharenko, O.B.Perevalova and E. V. Kozlov(Institute of Strength Physics and Materials Science, Russian Academy of Sciences, Siberian Branch, Tomsk, Russia) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1999年第6期531-535,共5页
It was shown by TEM and X-ray analysis that there are four types of grains of the main Ni3Al phase in the structure of the intermetallic obtained by the self-propagation high temperature method (SHS). Every type of gr... It was shown by TEM and X-ray analysis that there are four types of grains of the main Ni3Al phase in the structure of the intermetallic obtained by the self-propagation high temperature method (SHS). Every type of grains has its own domain and dislocation structure. There are mono- and polydomains with and without dislocations. The grains of the main phase of monoand polydomains without dislocations and polydomains with dislocations were formed by diffusion in the solid phase. In these conditions NiAl3 phase is located on the grain boundary of the main phase. The Ni2Al3 phase is located at the triple joints of the main phase. 展开更多
关键词 In Al structure of the Intermetallic Compound Ni3Al Synthesized under Compression of the Powder Mixture of Pure Elements Part Phase Composition and Microstructure of main Phase Ni
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Damage and deterioration mechanism and curing technique of concrete structure in main coal cleaning plants 被引量:10
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作者 LV Heng-lin ZHAO Cheng-ming +2 位作者 SONG Lei MA Ying XU Chun-hua 《Mining Science and Technology》 EI CAS 2009年第6期750-755,共6页
Concrete structures in main coal cleaning plants have been rebuilt and reinforced in the coal mines of the Shanghai Datun Energy Sources Co. Ltd., the first colliery of the Pingdingshan Coal Co. Ltd. and the Sanhejian... Concrete structures in main coal cleaning plants have been rebuilt and reinforced in the coal mines of the Shanghai Datun Energy Sources Co. Ltd., the first colliery of the Pingdingshan Coal Co. Ltd. and the Sanhejian mine of the Xuzhou Mining Group Co. Ltd. In these projects, the operating environment and reliability of concrete structures in the main plants of the three companies were investigated and the safety of the structures inspected. Qualitative and quantitative analyses were made on the special natural, technological and mechanical environments around the structures. On the basis of these analyses, we discuss the long-term, combined actions of the harsh natural (corrosive gases, liquids and solids) and mechanical environments on concrete structures and further investigated the damage and deteriorating mechanisms and curing techniques of concrete structures in the main coal cleaning plants. Our study can provide a theoretical basis for ensuring the reliability of concrete structures in main coal cleaning plants. 展开更多
关键词 混凝土结构 净化装置 固化技术 退化机制 煤炭 三河尖煤矿 徐州矿务集团 作业环境
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FORMATION OF MESOPHASE MONO-DOMAINS AND MICRO-STRUCTURES IN THIN FILMS OF A SERIES OF COPOLYETHERS CONTAINING BOTH ODD-NUMBERED METHYLENE UNITS
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作者 Feng-chao Xie Jie-ping Liu +3 位作者 Dong-hang Yan Tian-bai He Ru-qing Zheng Er-qiang Chen State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, Changchun 130022, China Department of Polymer Science and Engineering College of Chemistry Peking University Beijing 100871, China 《Chinese Journal of Polymer Science》 SCIE CAS CSCD 2001年第4期391-397,共7页
The structural and morphological evolution of mono-domains in thin films has been investigated for a series of liquid crystalline (LC) copolyethers. The copolyethers studied were synthesized by the reaction of 1-(4-hy... The structural and morphological evolution of mono-domains in thin films has been investigated for a series of liquid crystalline (LC) copolyethers. The copolyethers studied were synthesized by the reaction of 1-(4-hydroxy-4 ' -biphenylyl)-2-(4-hydroxyl-phenyl)propane (TPP) with 1,7-dibromoheptane and 1,11-undecane at different compositions (coTPPs-7/11). In contrast to the solution-cast thin films without annealing, which exhibit the isotropic homogeneous molecular orientation, mono-domains with a homeotropic alignment were found in coTPP-7/11(5/5) after the thin films were annealed in the high-temperature columnar phase (Phi '). Similar to the nucleation process in polymer crystallization, transmission electron microscopic observations show that small mono-domains appear in the initial stage of annealing, where molecules form a uniaxial in-plane chain orientation. With increasing annealing time, the molecular orientation gradually became tilted with respect to the substrate surface, and finally, a uniaxial homeotropic molecular orientation was achieved after a prolonged annealing time. The lateral size of mono-domains was found to increase continuously with annealing time and grew into a circular shape, indicating an isotropic lateral growth scheme which implies a hexagonal molecular packing proved by the electron diffraction experiments. 展开更多
关键词 main-chain liquid crystalline polymer structure morphology
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Structural,Kinematic and Geochronological Study of the Main Tianshan Shear Zone in the Borohoro Ranges,NW China 被引量:1
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作者 LIU Tianlun CHEN Siyu +5 位作者 ZHANG Bo CAI Keda HAN Baofu QU Junfeng GUO Lei WANG Meng 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2021年第5期1431-1455,共25页
The western segment of the Main Tianshan shear zone(MTSZ)branches into three major dextral strike-slip shear zones in the Borohoro Ranges,northwestern China.Mylonitic rocks within these zones exhibit vertical foliatio... The western segment of the Main Tianshan shear zone(MTSZ)branches into three major dextral strike-slip shear zones in the Borohoro Ranges,northwestern China.Mylonitic rocks within these zones exhibit vertical foliations,subhorizontal lineations,and dextral kinematics.The microstructures and CPO patterns of calcite and quartz in the tectonites suggest shearing at temperatures of 200℃ to 500℃ or above.The amount of dextral displacement along the zones is less than 100 km.LA-ICP-MS U-Pb dating of zircons from some pre-kinematic granites gave ages of 364-325 Ma and 316 Ma,and zircons from a syn-kinematic leucogranite gave an age of 291 Ma.We propose that dextral shearing along the MTSZ started in the earliest Permian.Our data indicate that collision between the Yili and Junggar plates might have finished before 325 Ma or 316 Ma,with a tectonic transformation from 325 Ma to 300 Ma,resulting in intracontinental transpression from 300 Ma or 291 Ma.We suggest that the formation of the Kazakhstan orocline(KO)took place in two stages,with the early stage of bending driven by convergence related to oblique subduction,and the late stage possibly associated with lateral disarticulation as a result of the dextral strike-slip shear zones. 展开更多
关键词 structural geology geochronology dextral shearing CPO pattern Late Paleozoic main Tianshan Shear Zone Yili-North Tianshan
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The Design of Water-reusing Network with a Hybrid Structure Through Mathematical Programming 被引量:4
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作者 刘永忠 段海涛 冯霄 《Chinese Journal of Chemical Engineering》 SCIE EI CAS CSCD 2008年第1期1-10,共10页
为一个再使用水的网络的一个新设计方法与混合结构,减少网络的复杂性并且最小化淡水消费,被建议。在这篇文章建议的方法论的唯一的特征是在一个再使用水的系统由控制数字的规定控制水网络的复杂性。它把一个常规再使用水的网络和一个... 为一个再使用水的网络的一个新设计方法与混合结构,减少网络的复杂性并且最小化淡水消费,被建议。在这篇文章建议的方法论的唯一的特征是在一个再使用水的系统由控制数字的规定控制水网络的复杂性。它把一个常规再使用水的网络和一个再使用水的网络的优点与内部自来水总管道相结合。为了说明建议方法,一个单个沾染物系统和一个多重沾染物系统,用作这些问题的例子。 展开更多
关键词 数学规划方法 工程设计 混合结构 水回用网络
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Pore structure characteristics of the relative water-resisting layer on the top of the Ordovician in Longgu Coal Mine 被引量:3
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作者 Rong Huren Bai Haibo 《International Journal of Mining Science and Technology》 SCIE EI 2014年第5期657-661,共5页
In order to study the permeability and water-resisting ability of the strata on the top of the Ordovician in Longgu Coal Mine, this paper tested the permeability and porosity of the strata, investigated the fracture a... In order to study the permeability and water-resisting ability of the strata on the top of the Ordovician in Longgu Coal Mine, this paper tested the permeability and porosity of the strata, investigated the fracture and pore structure features of the strata, and identified the main channels which govern the permeability and water-resisting ability of the strata. The permeability of the upper, central and lower strata shows as2.0504 ·10à3–2.782762 · 10à3, 4.1092 ·10à3–7.3387·10à3and 2.0891·10à3–3.2705 ·10à3lm2,respectively, and porosity of that is 0.6786–0.9197%, 0.3109–0.3951% and 0.9829–1.8655%, respectively.The results indicate that:(1) the main channels of the relative water-resisting layer are the pore throats with a diameter more than 6 lm;(2) the major proportion of pore throats in the vertical flow channel and the permeability first increases and then sharply decreases;(3) the fractures occurring from the top to20 m in depth of the strata were filled and there occurred almost no fracture under the depth of 40 m;and(4) the ratio of turning point of the main flow channel in the strata on top of Ordovician can be used to confirm the thickness of filled water-resisting layers. 展开更多
关键词 相对隔水层 孔结构 顶部 煤矿 奥陶系 地层深度 垂直流动 渗透性
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Design and Mechanical Characterization of an S-Based TPMS Hollow Isotropic Cellular Structure
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作者 Junjian Fu Pengfei Sun +3 位作者 Yixian Du Lei Tian Qihua Tian Xiangman Zhou 《Computer Modeling in Engineering & Sciences》 SCIE EI 2022年第5期695-713,共19页
Cellular structures are regarded as excellent candidates for lightweight-design,load-bearing,and energy-absorbing applications.In this paper,a novel S-based TPMS hollow isotropic cellular structure is proposed with bo... Cellular structures are regarded as excellent candidates for lightweight-design,load-bearing,and energy-absorbing applications.In this paper,a novel S-based TPMS hollow isotropic cellular structure is proposed with both superior load-bearing and energy-absorbing performances.The hollow cellular structure is designed with Boolean operation based on the Fischer-Koch(S)implicit triply periodic minimal surfaces(TPMS)with different level parameters.The anisotropy and effective elasticity properties of cellular structures are evaluated with the numerical homogenization method.The finite element method is further conducted to analyze the static mechanical performance of hollow cellular structure considering the size effect.The compression experiments are finally carried out to reveal the compression properties and energy-absorption characteristics.Numerical results of the Zener ratio proved that the S-based hollow cellular structure tends to be isotropic,even better than the sheet-based Gyroid TPMS.Compared with the solid counterpart,the S-based hollow cellular structure has a higher elastic modulus,better load-bearing and energy absorption characteristics. 展开更多
关键词 Hollow cellular structure triply periodic minimal surfaces isotropic property energy absorption load-bearing
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Pore-throat structure characteristics and its impact on the porosity and permeability relationship of Carboniferous carbonate reservoirs in eastern edge of Pre-Caspian Basin
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作者 LI Weiqiang MU Longxin +8 位作者 ZHAO Lun LI Jianxin WANG Shuqin FAN Zifei SHAO Dali LI Changhai SHAN Fachao ZHAO Wenqi SUN Meng 《Petroleum Exploration and Development》 2020年第5期1027-1041,共15页
Carboniferous carbonate reservoirs at the eastern edge of the Pre-Caspian Basin have undergone complex sedimentation,diagenesis and tectonism processes,and developed various reservoir space types of pores,cavities and... Carboniferous carbonate reservoirs at the eastern edge of the Pre-Caspian Basin have undergone complex sedimentation,diagenesis and tectonism processes,and developed various reservoir space types of pores,cavities and fractures with complicated combination patterns which create intricate pore-throats structure.The complex pore-throat structure leads to the complex porosity-permeability relationship,bringing great challenges for classification and evaluation of reservoirs and efficient development.Based on the comprehensive analysis on cores,thin sections,SEM,mercury intrusion,routine core analysis and various tests,this paper systematically investigated the features and main controlling factors of pore-throats structure and its impact on the porosity-permeability relationship of the four reservoir types which were pore-cavity-fracture,pore-cavity,pore-fracture and pore,and three progresses are made.(1)A set of classification and descriptive approach for pore-throat structure of Carboniferous carbonate reservoirs applied to the eastern edge of the Pre-Caspian Basin was established.Four types of pore-throat structures were developed which were wide multimodal mode,wide bimodal mode,centralized unimodal mode and asymmetry bimodal mode,respectively.The discriminant index of pore-throat structure was proposed,realizing the quantitative characterization of pore-throat structure types.(2)The microscopic heterogeneity of pore reservoir was the strongest and four types of pore-throat structures were all developed.The pore-fracture and pore-cavity-fracture reservoirs took the second place,and the microscopic heterogeneity of pore-cavity reservoir was the weakest.It was revealed that the main controlling factor of pore-throat structure was the combination patterns of reservoir space types formed by sedimentation,diagenesis and tectonism.(3)It was revealed that the development of various pore-throat structure types was the important factor affecting poroperm relationship of reservoirs.The calculation accuracy of permeability of reservoirs can be improved remarkably by subdividing the pore-throat structure types.This study deepens the understanding of pore-throat structure of complicated carbonate reservoirs,and is conducive to classification and evaluation,establishment of precise porosity-permeability relationship and highly efficient development of carbonate reservoirs. 展开更多
关键词 Pre-Caspian Basin CARBONIFEROUS carbonate reservoir pore-throat structure main controlling factors porosity-permeability relationship
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Basic Structural Forms of Main Roof
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《岩石力学与工程学报》 EI CAS CSCD 1995年第S1期425-437,共13页
BasicStructuralFormsofMainRoofByJiangFuxing;SongZhenqiandSongYang(ShandongInstituteofCoalMiningandTechnology... BasicStructuralFormsofMainRoofByJiangFuxing;SongZhenqiandSongYang(ShandongInstituteofCoalMiningandTechnology,Taian271019)SUMM... 展开更多
关键词 Basic structural Forms of main Roof
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Ultra-low Friction and High Load-Bearing Hydrogel with Tubular Structure Based on Controllable Light-Induced Dissociation
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作者 Song Yang Jianqing Yu +7 位作者 Zhizhi Zhang Hao Yang Yaling Wan Bo Yu Shuanhong Ma Yanfei Ma Feng Zhou Weimin Liu 《Chinese Journal of Chemistry》 SCIE CAS CSCD 2023年第20期2679-2683,共5页
With high water content,excellent biocompatibility and lubricating properties,and a microstructure similar to that of the extracellular matrix,hydrogel is becoming one of the most promising materials as a substitute f... With high water content,excellent biocompatibility and lubricating properties,and a microstructure similar to that of the extracellular matrix,hydrogel is becoming one of the most promising materials as a substitute for articular cartilage.However,it is a challenge for hydrogel materials to simultaneously satisfy high loading and low friction.Most hydrogels are brittle,with fracture energies of around 10 J·m^(-2),as compared with∼1000 J·m^(-2) for cartilage.A great deal of effort has been devoted to the synthesis of hydrogels with improved mechanical properties,such as increasing the compactness of the polymer network,introducing dynamic non-covalent bonds,and increasing the hydrophobicity of the polymer,all at the expense of the lubricating properties of the hydrogel.Herein,we develop a hydrogel material with anisotropic tubular structures where the compactness gradually decreases and eventually disappears from the surface to the subsurface,achieving a balance between lubrication and load-bearing.The porous layer with hydrophilic carboxyl groups on the surface exhibits extremely low friction(coefficient of friction(COF)∼0.003,1 N;COF∼0.08,20 N)against the hard steel ball,while the bottom layer acts as an excellent load-bearing function.What is more,the gradual transition of the tubular structures between the surface and the subsurface ensures the uniform distribution of friction stress between a lubricating and bearing layers,which endows the material with long-lasting and smooth friction properties.The extraordinary lubricious performance of the hydrogels with anisotropic tubular structure has potential applications in tissue engineering and medical devices. 展开更多
关键词 Ultra-low friction HYDROGELS Anisotropic Hydroge structure High load-bearing Biomimetic synthesis Microstructures
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Modeling of 3D-structure for regular fragments of low similarity unknown structure proteins
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作者 彭志红 Chen Jie Lin Xiwen Sang Yanchao 《High Technology Letters》 EI CAS 2007年第4期431-435,共5页
关键词 3D结构模型 计算机模拟 相似性 技术性能
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美国“去风险”对中国产业链供应链安全的影响及应对 被引量:1
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作者 蔡宏波 郑涵茜 余天赐 《财经问题研究》 北大核心 2024年第1期33-43,共11页
在大国竞争加剧、突发公共卫生事件冲击和乌克兰危机持续等多重不确定性因素叠加的背景下,全球产业链供应链正进入重要的重塑阶段。与此同时,美国先后提出对华“脱钩”“去风险”,以减少其对中国产业链供应链的依赖,这严重影响了全球产... 在大国竞争加剧、突发公共卫生事件冲击和乌克兰危机持续等多重不确定性因素叠加的背景下,全球产业链供应链正进入重要的重塑阶段。与此同时,美国先后提出对华“脱钩”“去风险”,以减少其对中国产业链供应链的依赖,这严重影响了全球产业链供应链的稳定畅通。首先,本文界定产业链供应链安全范畴主要包括主体要素安全和结构要素安全。其次,辨析美国“脱钩”“去风险”政策意图的异同,并就现阶段美国“去风险”对中国产业链供应链安全的主要影响和中国所面临的现实挑战进行论述。分析发现,美国“去风险”对中国产业链供应链安全的主要影响包括:一是美国通过控制核心技术、中间品出口和关键资源危及中国产业链供应链主体要素安全。二是通过制造业回流、“近岸外包”“友岸外包”重塑全球产业空间布局,威胁中国产业链供应链结构要素安全。三是通过友好国家网络拉拢盟友,增加中国产业链供应链被排除风险。最后,本文据此提出中国如何在美国“去风险”背景下维护产业链供应链安全稳定的政策建议。 展开更多
关键词 产业链供应链安全 主体要素安全 结构要素安全 近岸外包 友岸外包
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弹−塑性基础边界两侧采空(留煤柱)基本顶板结构初次破断特征
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作者 陈冬冬 李子健 +5 位作者 谢生荣 何富连 罗昱 蒋再胜 马翔 李辉 《煤炭学报》 EI CAS CSCD 北大核心 2024年第5期2195-2211,共17页
为了研究两侧采空留煤柱工程条件下基本顶板结构的断裂位态及工程指导意义,构建考虑实体煤弹塑性变形与两侧煤柱宽度及支撑能力弱化的基本顶板结构双塑化基础边界力学模型,基于有限差分算法与主弯矩破断准则系统计算了在非对称煤柱区和... 为了研究两侧采空留煤柱工程条件下基本顶板结构的断裂位态及工程指导意义,构建考虑实体煤弹塑性变形与两侧煤柱宽度及支撑能力弱化的基本顶板结构双塑化基础边界力学模型,基于有限差分算法与主弯矩破断准则系统计算了在非对称煤柱区和长边实体煤区的断裂线形态、区位属性及整体位态特征,并从7个层面、横纵向4对区域与传统模型对比,阐明新模型所得新结论及工程意义。结论如下:(1)两侧非对称煤柱参数对长边实体煤区域的基本顶主弯矩及破断位置影响小,但分别显著影响煤柱区的主弯矩大小、位置及断裂形态。两侧煤柱区(较强/宽煤柱区+较弱/窄煤柱区)基本顶断裂线形态有3类演化模式,随基本顶厚度及弹模增大而煤柱宽度、支撑能力及悬顶跨度减小,其变化规律为:非对称的“连续单弧形+连续单弧形”→“连续单弧形+开口间断双短弧形”→非对称的“开口间断双短弧形+开口间断双短弧形”。(2)长边实体煤区基本顶的断裂线主要有3类区位属性,随基本顶厚度及弹模增大而实体煤的塑性区宽度、塑化程度及悬顶跨度减小,其演变规律为:断裂线在塑性煤体区(C-S式)→弹塑性煤体分界区(C-TS式)→弹性煤体区(C-T式);(3)考虑断裂线区位属性,随基本顶厚度和弹模增大而煤柱宽度、支撑能力及悬顶跨度减小的基本顶全区域破断模式及演变规律为:C-S式的■→C-TS式的■→C-T式的■→C-T式的■→C-T式的■。针对研究两侧采空(煤柱)基本顶板结构破断的3类力学模型,从7个层面对比了3类模型的重要区别,从横向4个区域(开采区域的前方与后方、两侧煤柱区)与纵向4个区域(非对称遗留煤柱下伏、下伏开采空间出/进煤柱/体)阐明了其重要工程作用。 展开更多
关键词 遗留煤柱 基本顶 两侧采空 弹−塑性基础 板结构
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基于相对拟牛顿法的自卫式欺骗干扰抑制算法
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作者 齐美彬 赵谦 +3 位作者 徐晋 项厚宏 杨艳芳 崔国龙 《现代雷达》 CSCD 北大核心 2024年第1期66-73,共8页
自卫式欺骗干扰与目标信号高度相似,且二者的到达角完全相同,传统的主瓣干扰抑制算法难以对其进行抑制。针对该问题,文中在极化单输入多输出(PSIMO)雷达系统下,提出一种基于相对拟牛顿法的盲源分离算法。该算法利用干扰和目标的极化特... 自卫式欺骗干扰与目标信号高度相似,且二者的到达角完全相同,传统的主瓣干扰抑制算法难以对其进行抑制。针对该问题,文中在极化单输入多输出(PSIMO)雷达系统下,提出一种基于相对拟牛顿法的盲源分离算法。该算法利用干扰和目标的极化特性差异,通过构建重叠子阵结构计算出联合自相关矩阵,并采用相对拟牛顿法估计出分离矩阵,从而将目标和干扰信号分离在不同的通道上,实现干扰抑制作用。仿真实验结果表明,该算法能够有效抑制自卫式欺骗干扰,且在低信噪比(SNR)和密集干扰场景下依然具有良好的干扰抑制性能,当输入SNR为-10 dB时,输出的目标检测概率仍可以达到51.6%,拥有较强的鲁棒性。 展开更多
关键词 主瓣干扰抑制 自卫式欺骗干扰 极化差异 相对拟牛顿法 重叠子阵结构
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问题导向的“钢结构设计原理”课堂理论教学改革
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作者 朱伟庆 刘永健 陈峰 《教育教学论坛》 2024年第15期73-76,共4页
“钢结构设计原理”是道路桥路与渡河工程专业的核心专业课程,扎实提升课堂理论教学效率和效果是该课程教学改革的重要任务和目标。细致分析“钢结构设计原理”的课程内容特点以及由此导致学生学习过程中存在的问题,有针对性地提出从多... “钢结构设计原理”是道路桥路与渡河工程专业的核心专业课程,扎实提升课堂理论教学效率和效果是该课程教学改革的重要任务和目标。细致分析“钢结构设计原理”的课程内容特点以及由此导致学生学习过程中存在的问题,有针对性地提出从多层次网格模块化教学内容、建立“思维主线”、引入真实工程案例、坚持精确理论推导与定性分析相结合、开展课程横向比较等方面开展课堂理论教学改革,进而从根本上提升课堂理论教学的效率与效果。 展开更多
关键词 钢结构设计原理 问题导向 课程特点 模块化 思维主线
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合肥市地下两层标准车站主体结构设计分析
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作者 张有桔 沈洪波 《智能城市》 2024年第1期74-76,共3页
文章结合合肥市2~7号线地下两层标准车站主体结构设计情况,从主要结构构件尺寸、配筋率、梁柱节点、诱导缝等方面进行总结,在统计已经成功实施的11座地下两层标准车站主体结构设计参数的基础上,根据站台宽度和结构的不同,从板、墙、梁... 文章结合合肥市2~7号线地下两层标准车站主体结构设计情况,从主要结构构件尺寸、配筋率、梁柱节点、诱导缝等方面进行总结,在统计已经成功实施的11座地下两层标准车站主体结构设计参数的基础上,根据站台宽度和结构的不同,从板、墙、梁、柱等主要受力构件的尺寸和配筋率等方面进行统计分析,得出规律和指导性指标,并对部分细节做法提出了完善建议。 展开更多
关键词 标准车站 地下两层 主体结构 设计要点
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基于主线不停运的城轨支线独立运营改造方案
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作者 戴志仁 李岩龙 +2 位作者 王泽宇 杨学金 张维驿 《铁道工程学报》 EI CSCD 北大核心 2024年第2期93-99,共7页
研究目的:针对大型铁路枢纽接入已运营轨道交通线路引起的既有线改造问题,为满足铁路枢纽与轨道交通连接线(支线)施工期间主线正常运营不受影响,对改造涉及的运营组织与接轨方案进行系统研究,并对土建、轨道、接触网、环网与动照、信号... 研究目的:针对大型铁路枢纽接入已运营轨道交通线路引起的既有线改造问题,为满足铁路枢纽与轨道交通连接线(支线)施工期间主线正常运营不受影响,对改造涉及的运营组织与接轨方案进行系统研究,并对土建、轨道、接触网、环网与动照、信号、综合监控与通信系统等的改造及影响进行深入研究,在统筹考虑实施难度、投资与工期的基础上,提出实施风险最小、技术最合理的改造方案。研究结论:(1)既有高架车站与区间改造影响范围较小且相对可控,可以实现主线正常运营情况下新建独立运营支线工程;(2)为最大程度保障主线运营不受影响,在现有技术水平条件下,应尽量避免在运营天窗期进行各类信号光电缆的割接;(3)支线独立运营方案,应尽量采取措施将新建支线与主线相连、轨道相通,以利于车辆检修与维保,并增加运营的灵活性;(4)桥梁浇筑与平移施工临近既有线,实施阶段应进一步完善工艺衔接与交叉施工统筹,增加既有线安全保障;(5)本研究结论可为类似工程提供参考。 展开更多
关键词 运营线路 主线 支线 实施风险 简支梁 连续梁 信号 帮接扩建
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天然酯绝缘油对220 kV电力变压器主绝缘性能的影响分析
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作者 杨莹 王建民 +3 位作者 杜振斌 马明元 张亚杰 李欣然 《绝缘材料》 CAS 北大核心 2024年第2期65-71,共7页
为了分析天然酯绝缘油对高压变压器绝缘性能的影响,本研究以一台220 kV电力变压器为研究对象,对其进行波过程计算得到雷电冲击全波下的节点电位与油道梯度电压,并建立变压器主绝缘电场计算模型得到工频及雷电全波电压下的电场分布,再计... 为了分析天然酯绝缘油对高压变压器绝缘性能的影响,本研究以一台220 kV电力变压器为研究对象,对其进行波过程计算得到雷电冲击全波下的节点电位与油道梯度电压,并建立变压器主绝缘电场计算模型得到工频及雷电全波电压下的电场分布,再计算绝缘裕度。结果表明:天然酯绝缘油变压器在工频下主绝缘裕度较大,而在雷电全波下该值较小。通过改进天然酯绝缘油变压器的绝缘结构,可缩小天然酯绝缘油变压器中压、高压绕组间主绝缘距离约6%,增大调压绕组匝绝缘厚度及角环半径,可使其在雷电全波下的绝缘裕度最小值提高15%,同时有效节约了成本。 展开更多
关键词 天然酯绝缘油变压器 波过程 主绝缘电场 绝缘裕度 结构优化
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