期刊文献+
共找到572篇文章
< 1 2 29 >
每页显示 20 50 100
Water-based processed and alkoxide-based processed indium oxide thin-film transistors at different annealing temperatures
1
作者 Xu-Yang Li Zhi-Nong Yu +4 位作者 Jin Cheng Yong-Hua Chen Jian-She Xue Jian Guo Wei Xue 《Chinese Physics B》 SCIE EI CAS CSCD 2018年第4期543-550,共8页
In this study,indium oxide(In2O3) thin-film transistors(TFTs) are fabricated by two kinds of low temperature solution-processed technologies(Ta ≤ 300℃),i.e.,water-based(DIW-based) process and alkoxide-based... In this study,indium oxide(In2O3) thin-film transistors(TFTs) are fabricated by two kinds of low temperature solution-processed technologies(Ta ≤ 300℃),i.e.,water-based(DIW-based) process and alkoxide-based(2-ME-based)process.The thickness values,crystallization properties,chemical structures,surface roughness values,and optical properties of In2O3 thin-films and the electrical characteristics of In2O3 TFTs are studied at different annealing temperatures.Thermal annealing at higher temperature leads to an increase in the saturation mobility(μsat) and a negative shift in the threshold voltage(VTH).The DIW-based processed In2O3-TFT annealed at 300℃ exhibits excellent device performance,and one annealed at 200℃ exhibits an acceptable μsat of 0.86 cm^2/V·s comparable to that of a-Si:H TFTs,whereas the 2-ME-based TFT annealed at 300℃ exhibits an abundant μsat of 1.65 cm^2/Vs and one annealed at 200℃ is inactive.The results are attributed to the fact that the DIW-based process induces a higher degree of oxidation and less defect states than the 2-ME-based process at the same temperature.The DIW-based process for fabricating the In2O3 TFT opens the way for the development of nontoxic,low-cost,and low-temperature oxide electronics. 展开更多
关键词 water-based process alkoxide-based process annealing temperature thin-film transistors
下载PDF
THE STRUCTURE CONTROL OF ALUMINUM FOAMS PRODUCED BY POWDER COMPACTED FOAMING PROCESS 被引量:4
2
作者 X.H.You F. Wang L.C.Wang 《Acta Metallurgica Sinica(English Letters)》 SCIE EI CAS CSCD 2004年第3期279-282,共4页
A new technique, powder compact foaming process for the production of aluminumfoams has been studied in this article. According to this method, the aluminum pow-der is mixed with a powder foaming agent (TiH_2). Subseq... A new technique, powder compact foaming process for the production of aluminumfoams has been studied in this article. According to this method, the aluminum pow-der is mixed with a powder foaming agent (TiH_2). Subsequent to mixing, the powderblend is hot compacted to obtain a dense semi--finished product. Upon heating to tem-peratures within the range of the melting point, the foaming agent decomposes to evolvegas and the semi--finished product expands into a porous cellular aluminum. Foamingprocess is the key in this method. Based on experiments, the foaming characteris-tics were mainly analyzed and discussed. Experiments show that the aluminum--foamwith closed pores and a uniform cell structure of high porosity can be obtained usingthis method by adjusting the foaming parameters: the content of foaming agent andfoaming temperature. 展开更多
关键词 aluminum foams powder compact foaming process foam structure
下载PDF
Ti/Al_2O_3 Functionally Gradient Material Prepared by the Explosive Compaction/SHS Process 被引量:2
3
作者 Yimin LI(Powder Metallurgy Research Institute, Central-South University of Technology, Changsha 410083, China)Ziqiao ZHENG(Department of Materials Science and Engineering, Central-South University of Technology, Changsha 410083, China) 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 1999年第3期271-275,共5页
Ti1Al2O3 Functionally Gradient Material (FGM) was prepared by an explosive compaction/SHS process. Ten sheets of the compounding powder were laminated and pressed to get a green body of FGM. It was then compacted expl... Ti1Al2O3 Functionally Gradient Material (FGM) was prepared by an explosive compaction/SHS process. Ten sheets of the compounding powder were laminated and pressed to get a green body of FGM. It was then compacted explosively By burying the explosive compaction body into a stoichiometric Al/TiO2 mixture and igniting the combustion of the stoichiometric Al/TiO2 mixture, the SHS reaction of the explosive compaction body was initiated by the heat released from the combustion of the stoichiometric Al/TiO2 mixture. In this way, Ti/Al2O3 FGM was synthesized. The adiabatic temperatures of each gradient layer were calculated when the preheating temperatures were 298 K and 1173 K, respectively The microstructure, composition and properties of Ti/Al2O3 FGM and the reaction mechanism of each gradient layer were studied. It was found that Ti/Al2O3 FGM prepared by the explosive compaction/SHS process had a high density and a high microhardness. Its structure, composition and properties showed apparent gradient distribution. The structure of the standard stoichiometric ratio gradient layer of FGM was a network structure. Its reaction mode could be described as follows: Al powder melted first, then the molten Al penetrated into the TiO2 zone and reacted with TiO2, and big pores were left in the original positions of Al powder. The reaction of gradient layers with the addition of Al3O3 as diluents was similar to that of the standard stoichiometric ratio gradient layer, so were their structure and composition. However, the reaction of gradient layers with the addition of Ti as diluents was more complex and the composition deviated slightly from the designed one 展开更多
关键词 AL SHS Ti/Al2O3 Functionally Gradient Material Prepared by the Explosive compaction/SHS process
下载PDF
AGGREGATE STRUCTURE OF FINE POWDER AND COMPACTION PROCESS
4
作者 王炳华 《Journal of Wuhan University of Technology(Materials Science)》 SCIE EI CAS 1993年第4期29-34,共6页
Compacting process of fine powder is greatly affected by the aggregate structure of particles. According to the experiment in which several kinds of silicon nitrides in different partical shape and size were compacted... Compacting process of fine powder is greatly affected by the aggregate structure of particles. According to the experiment in which several kinds of silicon nitrides in different partical shape and size were compacted in uniaxialorientation, it is found that the volume compacting rate offorming body differs with the pressure. The aggregatestructure of each sample A, B or C was estimated by applying Cooper's equation to the analysis of the compacting process of each sample 展开更多
关键词 fine powder aggregate structure compaction process packing process volume compaction rate
下载PDF
On Numerical Modelling of Industrial Powder Compaction Processes for Large Deformation of Endochronic Plasticity at Finite Strains
5
作者 A R Khoei A Bakhshiani M Mofid 《厦门大学学报(自然科学版)》 CAS CSCD 北大核心 2002年第S1期95-96,共2页
Compaction processes are one the most important par ts of powder forming technology. The main applications are focused on pieces for a utomotive, aeronautic, electric and electronic industries. The main goals of the c... Compaction processes are one the most important par ts of powder forming technology. The main applications are focused on pieces for a utomotive, aeronautic, electric and electronic industries. The main goals of the compaction processes are to obtain a compact with the geometrical requirements, without cracks, and with a uniform distribution of density. Design of such proc esses consist, essentially, in determine the sequence and relative displacements of die and punches in order to achieve such goals. A.B. Khoei presented a gener al framework for the finite element simulation of powder forming processes based on the following aspects; a large displacement formulation, centred on a total and updated Lagrangian formulation; an adaptive finite element strategy based on error estimates and automatic remeshing techniques; a cap model based on a hard ening rule in modelling of the highly non-linear behaviour of material; and the use of an efficient contact algorithm in the context of an interface element fo rmulation. In these references, the non-linear behaviour of powder was adequately desc ribed by the cap plasticity model. However, it suffers from a serious deficiency when the stress-point reaches a yield surface. In the flow theory of plasticit y, the transition from an elastic state to an elasto-plastic state appears more or less abruptly. For powder material it is very difficult to define the locati on of yield surface, because there is no distinct transition from elastic to ela stic-plastic behaviour. Results of experimental test on some hard met al powder show that the plastic effects were begun immediately upon loading. In such mater ials the domain of the yield surface would collapse to a point, so making the di rection of plastic increment indeterminate, because all directions are normal to a point. Thus, the classical plasticity theory cannot deal with such materials and an advanced constitutive theory is necessary. In the present paper, the constitutive equations of powder materials will be discussed via an endochronic theory of plasticity. This theory provides a unifi ed point of view to describe the elastic-plastic behaviour of material since it places no requirement for a yield surface and a ’loading function’ to disting uish between loading an unloading. Endochronic theory of plasticity has been app lied to a number of metallic materials, concrete and sand, but to the knowledge of authors, no numerical scheme of the model has been applied to powder material . In the present paper, a new approach is developed based on an endochronic rate independent, density-dependent plasticity model for describing the isothermal deformation behavior of metal powder at low homologous temperature. Although the concept of yield surface has not been explicitly assumed in endochronic theory, it is shown that the cone-cap plasticity yield surface (Fig.1), which is the m ost commonly used plasticity models for describing the behavior of powder materi al can be easily derived as a special case of the proposed endochronic theory. Fig.1 Trace of cone-cap yield function on the meridian pl ane for different relative density As large deformation is observed in powder compaction process, a hypoelastic-pl astic formulation is developed in the context of finite deformation plasticity. Constitutive equations are stated in unrotated frame of reference that greatly s implifies endochronic constitutive relation in finite plasticity. Constitutive e quations of the endochronic theory and their numerical integration are establish ed and procedures for determining material parameters of the model are demonstra ted. Finally, the numerical schemes are examined for efficiency in the model ling of a tip shaped component, as shown in Fig.2. Fig.2 A shaped tip component. a) Geometry, boundary conditio n and finite element mesh; b) density distribution at final stage of 展开更多
关键词 In On Numerical Modelling of Industrial Powder compaction processes for Large Deformation of Endochronic Plasticity at Finite Strains
下载PDF
Comparison between the Requirements of Flowability and Moldability and the Shape Retention of PIM Compacts during Debinding Process
6
作者 K.A.KhaliI, Baiyun HUANG and Yimin LI State Key Laboratory for Powder Metallurgy, Central South University, Changsha 410083, China M.M.El-Sayed Seleman Department of Materials Science and Engineering, Northeastern University, Shenyang 110006, China 《Journal of Materials Science & Technology》 SCIE EI CAS CSCD 2001年第5期490-494,共5页
To successfully employ powder injection molding (PIM) as a manufacturing technique, the function of the component, design of the part, material and process should be optimized for overall processing ability of the PIM... To successfully employ powder injection molding (PIM) as a manufacturing technique, the function of the component, design of the part, material and process should be optimized for overall processing ability of the PIM process. A comparison between the requirements of flowability and moldability and the compacts shape retention has been made in this work. There is often a contradiction between the requirements of flowability and the compacts shape retention. Many works have been done to attain good molding conditions. However, they fail to take into account the effect of some factors that satisfies good molding conditions on the compacts shape retention during debinding. This paper studies the effect of the powder-binder mixture characteristics and the molding conditions on the flowability and moldability and the shape retention of PIM compacts during debinding process so as to attain the benefits of each. 展开更多
关键词 PIM Comparison between the Requirements of Flowability and Moldability and the Shape Retention of PIM compacts during Debinding process
下载PDF
Deformation of ductile cuttings from sandstone in compaction process and experimental study of influence on porosity
7
作者 GAO Bo MA Rui +2 位作者 LIU Li LIU Na WANG Yang 《Global Geology》 2015年第1期10-15,共6页
Deformation of ductile cuttings from sandstone in the mechanical compaction process was designed through the "experimental system of triaxial rock deformation",and the influence on porosity was studied by lo... Deformation of ductile cuttings from sandstone in the mechanical compaction process was designed through the "experimental system of triaxial rock deformation",and the influence on porosity was studied by looking into the deformation characteristics of ductile cuttings. The design indexes are as follows: simulated depth 0- 4 000 m,interval depth 500 m,and pressure range 0- 120 MPa at interval of 1. 5 MPa. The experimental results show that the porosity decreases as buried depth increases,indicating a negative relationship between them. The amount of compression was mainly obtained by porosity reduction and cutting deformation. Deformation of ductile cuttings is mainly ductile deformation; and deformation of crystal fragments is mainly expressed as brittle fracture,resulting in decrease of particle size. The research is of certain value for the exploration and development of oil and gas. 展开更多
关键词 ductile cuttings SANDSTONE compaction process POROSITY deformation characteristics
下载PDF
混凝土振捣密实性研究进展 被引量:1
8
作者 田正宏 马元山 李佳杰 《建筑材料学报》 EI CAS CSCD 北大核心 2024年第1期46-57,共12页
混凝土振捣工艺效果是影响成型质量的主要因素,但实践中仍以经验判断为主,缺乏可行的理论指导和科学量化的评价判据.针对拌和物振捣施工,从振捣密实理论、密实性影响因素、拌和物成型质量评价以及信息化工艺等方面,阐述了混凝土振捣施... 混凝土振捣工艺效果是影响成型质量的主要因素,但实践中仍以经验判断为主,缺乏可行的理论指导和科学量化的评价判据.针对拌和物振捣施工,从振捣密实理论、密实性影响因素、拌和物成型质量评价以及信息化工艺等方面,阐述了混凝土振捣施工的现状与技术进展,分析了振捣理论与应用存在的问题,展望了数字振捣技术的发展方向. 展开更多
关键词 振捣密实理论 振动设备 工艺参数 量化评价模型 信息化振捣
下载PDF
公路土质路基振动压实特性数值模拟 被引量:1
9
作者 刘萌成 陶君军 《路基工程》 2024年第3期35-41,共7页
采用ABAQUS有限元软件模拟压路机振动压实过程,研究不同碾压方式、碾压组合、松铺厚度D和压路机碾压速度V下路基土的动力响应与压实度变化规律。结果表明:不同碾压方式下最大竖向应力(S_(33))_(max)和竖向位移(U_(3))_(max)大小顺序为强... 采用ABAQUS有限元软件模拟压路机振动压实过程,研究不同碾压方式、碾压组合、松铺厚度D和压路机碾压速度V下路基土的动力响应与压实度变化规律。结果表明:不同碾压方式下最大竖向应力(S_(33))_(max)和竖向位移(U_(3))_(max)大小顺序为强振>弱振>静压,(S_(33))_(max)随碾压遍数N增加保持不变,而(U_(3))_(max)和压实度K在N=1时急剧增加;碾压组合对不同碾压方式下路基土体积应力p影响极小,碾压组合中碾压方式排列次序对路基土竖向位移U_(3)变化影响较大;组合1下不同松铺厚度的路基土竖向位移百分比P、压实度K值均大于碾压组合2,不同组合下D=40 cm时P、K值均为最大;在确定的松铺厚度下,碾压组合与碾压速度对P、K具有显著影响,碾压速度较小时P、K更大,但组合1条件下P、K关于碾压速度的差异较组合2显著。 展开更多
关键词 道路工程 土质路基 振动压实 碾压方案 碾压工艺 压实特性
下载PDF
考虑同层后道工序的柔性设备网络综合调度算法
10
作者 谢志强 刘冬梅 《电子与信息学报》 EI CAS CSCD 北大核心 2024年第7期2961-2969,共9页
针对柔性设备网络综合调度算法,难以合理选择加工设备加工相关工序进而影响产品完工时间的问题,该文提出考虑同层后道工序的柔性设备网络综合调度算法(SP-FENIS)。首先,采用逆序层优先策略,将各工序分配至逆序层待调度工序集;然后,提出... 针对柔性设备网络综合调度算法,难以合理选择加工设备加工相关工序进而影响产品完工时间的问题,该文提出考虑同层后道工序的柔性设备网络综合调度算法(SP-FENIS)。首先,采用逆序层优先策略,将各工序分配至逆序层待调度工序集;然后,提出均值逆序紧后路径策略,确定了各逆序层待调度工序集中工序的调度顺序;最后,提出最早完工时间策略和设备空闲插入策略,当工序在柔性设备上最早完工时间相同时,考虑了在柔性设备上的加工时间和同层后道工序的加工设备,确定了目标工序的加工设备以及加工时间。实例表明,和已有算法相比,该算法能够缩短产品完工时间。 展开更多
关键词 综合调度 同层后道工序 柔性设备网络 均值逆序紧后路径 最早完工时间
下载PDF
裂隙发育过程对采动裂隙椭抛带压实区的影响研究
11
作者 刘奇 笪雨欣 +3 位作者 曹广勇 李青海 赵金海 蒋长宝 《煤炭科学技术》 EI CAS CSCD 北大核心 2024年第5期25-35,共11页
采空区瓦斯抽采的关键是了解工作面上覆岩层裂隙的演化过程。为了研究综采工作面覆岩采动压实区演化规律,高效进行煤矿采空区瓦斯抽采工作,以神东某矿区2207工作面为原型,通过物理相似模拟实验,利用自主研发的覆岩裂隙监测系统将图像进... 采空区瓦斯抽采的关键是了解工作面上覆岩层裂隙的演化过程。为了研究综采工作面覆岩采动压实区演化规律,高效进行煤矿采空区瓦斯抽采工作,以神东某矿区2207工作面为原型,通过物理相似模拟实验,利用自主研发的覆岩裂隙监测系统将图像进行直方图均衡化增强和中值滤波去噪处理,获得二值化裂隙图像后利用分形理论定量描述裂隙率,对典型周期来压覆岩垮落裂隙率进行统计分析,建立了裂隙发育程度受工作面推进时间的时空函数和采动裂隙椭抛带压实区演变修正模型。结果表明:覆岩平均裂隙率变化符合DoseResp函数关系,裂隙的发育过程包括产生、扩展蔓延、压实闭合3个阶段,裂隙在产生、闭合这2个阶段发育速率较平缓,而在扩展阶段发育速率陡增。采空区上覆岩层裂隙场形成旧裂隙区、压实区和新裂隙区3个区域,裂隙发育周期的不同导致旧裂隙区与新裂隙区在发育状态、压实程度和空间形态上有着明显差异,这些差异导致了采空区覆岩非对称性下沉现象的发生。通过分析覆岩应力恢复与覆岩内部裂隙演变关系,进一步验证了采用DoseResp时间函数曲线可以很好的表现采空区上覆岩层裂隙异速演变特征。最后建立了考虑覆岩裂隙异速演变效应的采动裂隙椭抛带压实区修正模型,并结合现场工程实践,有效提高瓦斯抽取高位钻孔布置的准确性,为工作面的安全开采提供理论指导。 展开更多
关键词 瓦斯抽采 裂隙发育过程 覆岩压实区 物理相似模拟
下载PDF
水泥乳化沥青混合料路面压实工艺参数研究
12
作者 张翠红 窦益华 +1 位作者 曹学鹏 贺雨田 《重庆交通大学学报(自然科学版)》 CAS CSCD 北大核心 2024年第4期14-19,29,共7页
为了精准预测水泥乳化沥青混合料路面达到目标密实度所需的压路机压实工艺参数组合,基于该混合料压实流变时变特性及压实Bodner-Partom(B-P)本构模型,采用数值仿真和路面压实试验相结合的方法开展研究。首先对ANSYS进行二次开发得到B-P... 为了精准预测水泥乳化沥青混合料路面达到目标密实度所需的压路机压实工艺参数组合,基于该混合料压实流变时变特性及压实Bodner-Partom(B-P)本构模型,采用数值仿真和路面压实试验相结合的方法开展研究。首先对ANSYS进行二次开发得到B-P材料模型,然后将阶段性变化的B-P模型参数代入压实组合仿真分析中,最后开展路面压实试验,进一步得到压实工艺参数优化组合。数值仿真研究结果表明:由仿真结果得到3个低频高幅高速组合,3个组合作用后沿轮宽方向的混合料竖向应变值减小幅度均较大,在路面深度6 cm处的混合料竖向应变衰减幅度值均较小,其中组合六的衰减幅度值为最小,路面目标成型厚度可控制在7 cm以下。路面压实试验表明,组合六(低频高幅高速压实6遍)的有效压实能量偏大,应将组合六的压实遍数优化为:低频高幅高速压实5遍+高频低幅高速压实2遍。 展开更多
关键词 道路工程 水泥乳化沥青混合料 压实流变时变特性 B-P本构模型参数 路面压实工艺参数组合
下载PDF
基于AHP-灰色关联度法的路基智能压实质量评价
13
作者 黄晓銮 李卓峰 《华南师范大学学报(自然科学版)》 CAS 北大核心 2024年第3期40-49,共10页
为了解决现有智能压实指标未考虑检测值属性数据的问题,采用AHP法和灰色关联度法,综合考虑检测值所含压路机工作参数、空间位置等属性数据,建立了智能压实检测值的AHP-灰色关联度模型,并计算验证了该模型的合理性。基于现场智能压实试... 为了解决现有智能压实指标未考虑检测值属性数据的问题,采用AHP法和灰色关联度法,综合考虑检测值所含压路机工作参数、空间位置等属性数据,建立了智能压实检测值的AHP-灰色关联度模型,并计算验证了该模型的合理性。基于现场智能压实试验数据,提出将该模型求解的最优压实检测值M_(R)作为压实代表值,并将M_(R)以及现行智能压实指标M_(V)分别与传统压实指标E_(vd)、K_(30)进行相关性校验、指标离散性分析。结果表明:M_(R)、M_(V)与E_(vd)、K_(30)的相关性校验结果均大于0.7,且M_(R)的评判结果精度优于M_(V),此外M_(R)指标的整体变异性亦小于M_(V),故M_(R)指标能更精确反映碾压单元的真实压实情况。该研究对智能压实检测指标完善具有参考价值。 展开更多
关键词 智能压实 AHP 灰色关联度法 压实质量评价 相关性校验
下载PDF
不同压实程度的大空隙沥青混凝土空隙细观特征
14
作者 王丽丽 于昂 +1 位作者 马翔 仲光昇 《上海公路》 2024年第2期141-146,I0013,I0014,共8页
为探究不同压实状态下的大空隙沥青混凝土空隙特性,揭示沥青混凝土内部空隙演化行为,基于CT和数字图像处理技术,对沥青混合料的欠压状态、标准压实状态和超压状态的空隙长宽比、空隙率、空隙数量、等效直径等参数进行研究。结果表明:空... 为探究不同压实状态下的大空隙沥青混凝土空隙特性,揭示沥青混凝土内部空隙演化行为,基于CT和数字图像处理技术,对沥青混合料的欠压状态、标准压实状态和超压状态的空隙长宽比、空隙率、空隙数量、等效直径等参数进行研究。结果表明:空隙长宽比和等效直径可以较好地表征空隙形状;截面面积、空隙率和空隙数量对空隙的空间分布有较好的描述。随着压实程度的不断增强,其内部的空隙面积和长宽比逐渐减小,空隙数量逐渐增大,空隙等效直径逐渐减小,空隙更加细化,分布更加均匀。 展开更多
关键词 大空隙沥青混凝土 压实程度 空隙特征 数字图像处理
下载PDF
水性B1B2工艺针孔问题的解决
15
作者 王兵 倪海华 +4 位作者 许能才 张进 万德俊 李文鹏 赖云飞 《电镀与涂饰》 CAS 北大核心 2024年第1期131-135,共5页
[目的]传统汽车涂装的3C2B工艺逐渐被更为紧凑、环保的水性B1B2工艺替代,但由于B1与B2是湿碰湿,喷涂过程对环境的要求更为苛刻,出现质量缺陷的概率及调查的难度也大幅提升。[方法]对某主机厂水性B1B2工艺中色漆层出现的针孔进行调查及... [目的]传统汽车涂装的3C2B工艺逐渐被更为紧凑、环保的水性B1B2工艺替代,但由于B1与B2是湿碰湿,喷涂过程对环境的要求更为苛刻,出现质量缺陷的概率及调查的难度也大幅提升。[方法]对某主机厂水性B1B2工艺中色漆层出现的针孔进行调查及处理。[结果]发现色漆层脱水不足是主要原因。通过优化面涂各层厚度的均匀性及提高闪干温度解决了问题。[结论]在车身水性B1B2工艺的日常管理中,要做到对缺陷的精准识别,理清思路,并积累更多的经验。 展开更多
关键词 汽车涂装 水性涂料 紧凑工艺 针孔缺陷 故障处理
下载PDF
基于层次分析法的路基智能压实质量评价
16
作者 黄晓銮 《韶关学院学报》 2024年第3期53-59,共7页
智能压实技术由于其全过程实时控制等优点,逐渐被应用于路基压实作业中.针对目前路基智能压实质量评价指标体系仍较欠缺的情况,引入层次分析法,构建了相应的智能压实质量指标层次分析模型,并对该模型进行求解与编程,验证了该模型的合理... 智能压实技术由于其全过程实时控制等优点,逐渐被应用于路基压实作业中.针对目前路基智能压实质量评价指标体系仍较欠缺的情况,引入层次分析法,构建了相应的智能压实质量指标层次分析模型,并对该模型进行求解与编程,验证了该模型的合理性与可靠性;再结合路基试验段现场检测数据,得到了层次分析模型对应的智能压实检测特征值,并通过相关性校验等方法验证了该检测特征值的合理性与优势,对现有智能压实质量评价体系进行了补充完善. 展开更多
关键词 智能压实 层次分析法 压实质量 相关性校验 评价体系
下载PDF
铁路桥梁路基隧道关键工序监控技术分析
17
作者 邱丽琼 《科技资讯》 2024年第15期87-89,共3页
铁路桥梁路基隧道施工会对铁路整体运行产生直接影响,是保证交通运输质量及安全性的关键要素。为确保桥梁、路基、隧道等各部分施工均能够达到理想状态,需要通过对施工关键工序进行监控的方式做好桥梁预应力张拉、路基压实等各项施工,... 铁路桥梁路基隧道施工会对铁路整体运行产生直接影响,是保证交通运输质量及安全性的关键要素。为确保桥梁、路基、隧道等各部分施工均能够达到理想状态,需要通过对施工关键工序进行监控的方式做好桥梁预应力张拉、路基压实等各项施工,保证关键工序施工效果达到最优,进而为铁路的高质量运行奠定良好基础。为更好地完成关键工序监控,需要对关键工序监控技术展开探讨。通过对铁路桥梁路基隧道施工技术进行分析,对铁路桥梁路基隧道关键工序监控技术展开深度探讨,旨在保证铁路桥梁路基隧道施工水平、保证工序监控技术应用价值得到充分发挥。 展开更多
关键词 路基压实 桥梁预应力张拉 关键工序监控技术 地质勘测
下载PDF
正融过程中盐渍土路基抗剪强度影响因素分析
18
作者 孟博 朱晨 +1 位作者 胡峻晖 谢直树 《河北建筑工程学院学报》 CAS 2024年第3期57-66,共10页
对冀北地区非饱和盐渍土进行了正融过程中三种压实度和10个温度节点的直剪试验,用土壤参数速测平台记录了正融过程中土体的温度发展及孔隙水相变过程,并分析了未冻水、压实度对其力学特性的影响关系。结论如下:在正融过程中,该盐渍土未... 对冀北地区非饱和盐渍土进行了正融过程中三种压实度和10个温度节点的直剪试验,用土壤参数速测平台记录了正融过程中土体的温度发展及孔隙水相变过程,并分析了未冻水、压实度对其力学特性的影响关系。结论如下:在正融过程中,该盐渍土未冻水含量的变化呈现出“四阶段”,其中未冻水速增阶段相较于盐结晶失水阶段,增速较快。随着压实度的增大,土体温度变化速率、未冻水含量的增长以及试件强度下降速率都越快,黏聚力增加程度明显大于内摩擦角。当压实度较小、温度较低时,应力应变曲线则呈现脆性破坏特征。此外,土体黏聚力随温度的升高而显著降低,内摩擦角则出现很小幅度的增大,在-2℃到1℃之间,两者均出现短暂回滞现象。 展开更多
关键词 盐渍土 正融过程 压实度 抗剪强度 未冻水含量 冻结温度
下载PDF
公路填石路基施工技术要点分析
19
作者 叶宇翔 《黑龙江交通科技》 2024年第8期59-63,共5页
为了降低工程造价,实现就地取材,在山区修建公路时多采用填石路基。以莆炎高速公路三明境尤溪中仙至建宁里心段K237+500~K237+700处的填石路基为研究对象,总结了填石路基的分类和特点及施工技术要点,首先由饱和抗压强度试验和击实试验... 为了降低工程造价,实现就地取材,在山区修建公路时多采用填石路基。以莆炎高速公路三明境尤溪中仙至建宁里心段K237+500~K237+700处的填石路基为研究对象,总结了填石路基的分类和特点及施工技术要点,首先由饱和抗压强度试验和击实试验明确粗石料的最大粒径和最佳含水量。其次,从地基处理及路基摊铺、整平、压实等方面分析了填石路基的施工要点,施工中以孔隙率为控制指标,对压实质量进行检测,并用边坡安全系数优化了边坡码砌厚度。研究表明该填石路基的最大粒径应小于25 cm,最佳含水量在4.5%,地基宜冲击碾压处理,摊铺宜采用渐进式,压实宜采用振动压路机,并用50 cm厚的硬质石料对边坡进行码砌,路基压实质量和边坡稳定性均满足规范要求。 展开更多
关键词 填石路基 填料参数 摊铺整平 压实工艺 边坡码砌 安全系数
下载PDF
15吨蠕墨铸铁件工艺浅析
20
作者 傅强 吕清轲 +2 位作者 许景峰 梁亚茹 戚鹏超 《铸造设备与工艺》 2024年第4期11-15,共5页
近年来,生产高牌号灰铸铁大型船用发动机机体多次出现裂纹缺陷,影响发动机的整体性能和使用寿命,鉴于蠕墨铸铁的特殊性能,开发大型船用蠕墨铸铁机体成为必然趋势。从蠕化处理、熔炼工艺和铸件检测三个方面优化和试验验证,逐一解决大吨... 近年来,生产高牌号灰铸铁大型船用发动机机体多次出现裂纹缺陷,影响发动机的整体性能和使用寿命,鉴于蠕墨铸铁的特殊性能,开发大型船用蠕墨铸铁机体成为必然趋势。从蠕化处理、熔炼工艺和铸件检测三个方面优化和试验验证,逐一解决大吨位蠕墨铸铁生产技术难点,有效降低裂纹缺陷风险,最终实现对大型船用蠕墨铸铁件的批量稳定生产。 展开更多
关键词 蠕墨铸铁 喂线工艺 熔炼工艺
下载PDF
上一页 1 2 29 下一页 到第
使用帮助 返回顶部