全文获取类型
收费全文 | 73篇 |
免费 | 0篇 |
国内免费 | 3篇 |
专业分类
电工技术 | 2篇 |
综合类 | 8篇 |
化学工业 | 8篇 |
金属工艺 | 2篇 |
机械仪表 | 5篇 |
建筑科学 | 31篇 |
矿业工程 | 9篇 |
轻工业 | 1篇 |
水利工程 | 5篇 |
冶金工业 | 1篇 |
原子能技术 | 1篇 |
自动化技术 | 3篇 |
出版年
2024年 | 1篇 |
2023年 | 4篇 |
2022年 | 2篇 |
2021年 | 1篇 |
2020年 | 2篇 |
2019年 | 2篇 |
2018年 | 2篇 |
2017年 | 1篇 |
2015年 | 1篇 |
2014年 | 3篇 |
2013年 | 4篇 |
2012年 | 2篇 |
2011年 | 3篇 |
2010年 | 2篇 |
2009年 | 7篇 |
2008年 | 5篇 |
2007年 | 8篇 |
2006年 | 3篇 |
2005年 | 3篇 |
2004年 | 4篇 |
2003年 | 2篇 |
2002年 | 2篇 |
2000年 | 1篇 |
1994年 | 3篇 |
1993年 | 1篇 |
1991年 | 2篇 |
1990年 | 1篇 |
1979年 | 2篇 |
1964年 | 1篇 |
1955年 | 1篇 |
排序方式: 共有76条查询结果,搜索用时 227 毫秒
61.
针对作为我国缓冲/回填材料的高压实高庙子膨润土,采用自主研制的膨胀力-渗透性一体化测试仪器开展膨胀力试验,分别测定圆饼状试样的轴向膨胀力和径向膨胀力发展规律,研究试样初始干密度、初始吸力和尺寸效应对其膨胀力各向异性特征的影响。试验结果显示,轴向膨胀力和径向膨胀力均随着试样初始干密度的增加呈指数增大,膨胀力各向异性特征愈加显著。轴向膨胀力和径向膨胀力均随着试样初始吸力的增加而呈减小趋势;相同初始吸力条件下,径向膨胀力均大于轴向膨胀力,但是膨胀力各向异性系数随着初始吸力增大而不断减小。试样尺寸对膨胀力有显著影响,增加试样高度,轴向膨胀力不断增加,径向膨胀力增加到某一数值后不再随高度增加,膨胀力各向异性系数随着试样高度的增加逐渐减小。最后,基于膨润土膨胀机理、压实效应和尺寸效应,分析了膨胀力各向异性特征的形成机理。 相似文献
62.
在详细阐述处置库中施工接缝封闭和自愈合过程的基础上,全面回顾和总结了有关施工接缝对缓冲材料膨胀力、渗透系数、界面水力强度和自愈合性能影响的研究成果。接缝的存在使缓冲材料的膨胀性能及防渗性能明显弱化,特别是在处置库运行初期,接缝作为力学薄弱区极有可能在高水压环境下发生水力劈裂。总体而言,考虑接缝对缓冲材料水–力特性影响的试验研究还远远不够,主要是通过物理试验,采用整体平均化的方法来分析接缝对缓冲材料总体膨胀力和渗透系数的影响,这种方法的不足在于难以表述接缝处真实的水–力特性指标;现有试验仪器不能实时监测接触界面膨胀力和孔隙水压力的分布情况,无法有效揭示界面的应力传递特征与水分传输特性,这也是导致相关机理分析缺乏的一个重要原因。为此,提出在细化影响因素、深入机理分析及数值模拟等方面开展进一步研究的建议。 相似文献
63.
64.
65.
灌注桩后压浆施工工艺 总被引:1,自引:0,他引:1
为了改善灌注桩持力层受力状况。在地质条件为碎石、卵石层的土层中进行灌注桩施工后,再将水泥浆液在压力作用下由预埋钢管向碎石、卵石层的孔隙里四周扩散。这相当于增加了灌注桩端部的直径和桩长。对提高灌注桩桩基的承载力和控制沉降量效果明显。 相似文献
66.
裂隙是影响膨胀土工程性质的重要因素。以南阳某高速公路膨胀土为对象,采用大尺寸压实膨胀土试样进行不同环境湿度与温度下的裂隙发育试验,通过数码相机摄影并基于自编程序进行土样表面图像的定量化分析,获得裂隙率、均宽及总长等典型特征参数,进而探讨环境湿度与温度对膨胀土裂隙发育规律的影响。结果表明:大尺寸土样裂隙发育特征相较环刀样和薄层饱和泥浆样更接近路基与边坡等工程实际;环境湿度越高,初期裂隙发展越慢,发育持续时间越长,后期裂隙特征统计参数反而越大;环境温度越高,初期裂隙发展越快,但裂隙回缩稳定速度也越快,后期裂隙特征统计参数反而越小;低湿度或高温度使土样表面易于产生更多肉眼不可见的微裂隙,是裂隙特征统计参数与理论分析相比偏小的重要原因,而高湿度与低温度则有利于收缩应力向深层土体传递,促使裂隙偏向数量更少但更宽和更深方向发展。 相似文献
67.
68.
Using the orthogonal experimental design method involving three factors and three levels, the flexural strength and the compressive
strength of copolymer grouting material were studied with different compositions of water-cement ratio (mass fraction of water
to cement), epoxy resin content, and waterborne epoxy curing agent content. By orthogonal range and variance analysis, the
orders of three factors to influence the strength, the significance levels of different factors, and the optimized compound
ratio scheme of copolymer grouting material mixture at different curing ages were determined. An empirical relationship among
the strength of copolymer grouting material, the water-cement ratio, the epoxy resin content, and the waterborne epoxy curing
agent content was established by multivariate regression analysis. The results indicate that water-cement ratio is the most
principal and significant influencing factor on the strength. Epoxy resin content and waterborne epoxy curing agent content
also have a significant influence on the strength. But epoxy resin content has a greater influence on the 7-day and 28-day
flexural strength, and waterborne epoxy curing agent content has a greater influence on the 3-day flexural strength and the
compressive strength. The copolymer grouting material with water-cement ratio of 0.4, epoxy resin content of 8% (mass fraction)
and waterborne epoxy curing agent content of 2% (mass fraction) is the best one for repairing of cement concrete pavement.
The flexural strength and the compressive strength have good correlation, and the ratio of compressive strength to flexural
strength is between 1.0 and 3.3.
Foundation item: Projects(40728003, 40772180, 40802064) supported by the National Natural Science Foundation of China; Project (07JJ4012)
supported by the Hunan Provincial Natural Science Foundation of China; Project(20080430680) supported by China Postdoctoral
Science Foundation; Project(B308) supported by Shanghai Leading Academic Discipline Project 相似文献
69.
Removal of Pb^2+ and Cd^2+ by adsorption on clay-solidified grouting curtain for waste landfills 总被引:7,自引:0,他引:7
Pb^2+ and Cd^2+ in leachate were adsorbed on clay-solidified grouting curtain for waste landfills with equilibrium experiment. The cation exchange capacity was determined with ammonium acetate. And the concentration of heavy metal cations in leachate was determined with atomic absorption spectrophotometer. Their equilibrium isotherms were measured, and the experimental isotherm data were analyzed by using Freundlich and Langmuir models. The results show that the adsorption capacities of the heavy metal cations are closely related to the compositions of clay-solidified grouting curtain, and the maximum adsorption appears at the ratio of cement to clay of 2 : 4 in the experimental conditions. At their maximum adsorption and pH 5.0, the adsorption capacities of Pb^2+ and Cd^2+ are 16.19 mg/g and 1.21 mg/g. The competitive adsorption coefficients indicate that the adsorption of clay-solidified grouting curtain for Pb^2+ is stronger than that for Cd^2+. The adsorption process conforms to Freundlich's model with related coefficient higher than 0. 996. 相似文献
70.
Batch experiments were conducted to study the adsorption of phenol on clay-solidified grouting curtain (CSGC) and the effects of contact time,pH and adsorbent concentration on the adsorption were investigated.Under the experimental conditions used,2 d was adequate to determine the equilibrium of phenol adsorption onto CSGC.The amount of phenol adsorbed by CSGC from an initial concentration of 100mg/L was found to be 8.4mg/g.The adsorption process includes particle diffusion and liquid film diffusion,and the... 相似文献