全文获取类型
收费全文 | 1482篇 |
免费 | 109篇 |
国内免费 | 22篇 |
专业分类
电工技术 | 8篇 |
综合类 | 248篇 |
化学工业 | 136篇 |
金属工艺 | 40篇 |
机械仪表 | 82篇 |
建筑科学 | 748篇 |
矿业工程 | 4篇 |
能源动力 | 3篇 |
轻工业 | 13篇 |
水利工程 | 24篇 |
石油天然气 | 2篇 |
武器工业 | 1篇 |
无线电 | 12篇 |
一般工业技术 | 284篇 |
冶金工业 | 1篇 |
自动化技术 | 7篇 |
出版年
2023年 | 15篇 |
2022年 | 18篇 |
2021年 | 35篇 |
2020年 | 45篇 |
2019年 | 47篇 |
2018年 | 50篇 |
2017年 | 68篇 |
2016年 | 59篇 |
2015年 | 55篇 |
2014年 | 85篇 |
2013年 | 77篇 |
2012年 | 94篇 |
2011年 | 119篇 |
2010年 | 120篇 |
2009年 | 100篇 |
2008年 | 117篇 |
2007年 | 107篇 |
2006年 | 112篇 |
2005年 | 97篇 |
2004年 | 50篇 |
2003年 | 55篇 |
2002年 | 15篇 |
2001年 | 21篇 |
2000年 | 13篇 |
1999年 | 7篇 |
1998年 | 10篇 |
1997年 | 3篇 |
1996年 | 2篇 |
1995年 | 6篇 |
1994年 | 6篇 |
1993年 | 1篇 |
1992年 | 2篇 |
1987年 | 1篇 |
1979年 | 1篇 |
排序方式: 共有1613条查询结果,搜索用时 625 毫秒
91.
92.
碳纤维加固钢筋混凝土梁受弯性能非线性有限元分析 总被引:1,自引:0,他引:1
于龙 《水利与建筑工程学报》2010,8(2):113-116
研究混凝土、受拉钢筋和CFRP在开裂、屈服、破坏各阶段的工作状态和受力特点,对认识CFRP加固机理和性能有着重要意义。应用ANSYS建立碳纤维加固钢筋混凝土梁有限元模型,利用单元生死技术模拟CFRP的不同工作状态,对试件梁开裂、屈服、破坏全过程进行非线性有限元分析。分析表明:在钢筋屈服后,CFRP加固钢筋混凝土梁在后期抗弯刚度、延性和极限承载能力方面均有增强;在结构承受较大初始荷载情况下,二次受力问题对加固梁的抗弯刚度、极限承载能力、延性存在一定影响;由于CFRP是在钢筋进入屈服阶段,应力停止增长后才发挥巨大作用,二次受力时的加固也能取得较好效果;分析结果与实测数据吻合。 相似文献
93.
A flexible circular saw, which can be used in a novel machining process for high-speed carbon fiber-reinforced plastic (CFRP) plate cutting, was developed. In this process, the saw is deflected like a bowl-like shape. A cross-section of the saw body then forms a circular arc. A curved line can therefore be cut without interference by the bowl-like deflection. In addition, the radius of the cross-section of the saw body can be controlled by adjusting the deflection. This process therefore allows curves to be cut with a varied radius using a single saw. This process can carry out high-speed curved-line cutting with a feed rate of 3 m/min on a CFRP plate. However, it is difficult to cut free-form curves using a flexible circular saw. Therefore, in this research, a new technique that can cut free-form curves using a flexible circular saw was proposed. Then, a cutting test applying the technique was carried out. 相似文献
94.
95.
针对湖北省大中型灌区混凝土渡槽普遍存在老损率高、破坏严重、制约灌溉效益发挥的现象,以引丹灌区排子河渡槽为研究对象,探讨渡槽出现病险的原因。通过大型有限元分析软件ANSYS分析渡槽各种工况的运行情况。结果表明,若把水工结构中的肋形梁板结构计算模型应用到薄壁梁结构设计中,可能导致计算结果不可靠;将三维实体单元应用于渡槽的有限元分析中,可以最大限度地模拟原结构的实际受力情况。同时,介绍了碳纤维布在渡槽加固中的应用,实践证明用碳纤维布加固渡槽经济效益显著。 相似文献
96.
采用CFRP板施加预应力是目前有效的桥梁加固技术。论文完整介绍了一座采用CFRP预应力板加固后的桥梁动力性能试验,包括结构模态、跑车试验、刹车试验和跳车试验,监测了结构动位移、动应变及相关冲击作用,证明了CFRP预应力板加固效果十分理想。相关结论和数据可为类似桥梁的动力试验提供参考。 相似文献
97.
Repair method and residual bearing strength evaluation of a locally corroded plate girder at support
There is growing interest in the maintenance and repair of bridges according to the increase in their service time. Many corrosion problems have especially been reported in plate girder bridges in support regions because of their high moisture level due to the bad air circulation, sediments, deposition, rain water, and antifreeze penetration in the drainage-type expansion joint. In this study, CFRP repair of a plate girder with localized corrosion at its support was proposed, and this method was used to repair the locally corroded plate girder around its support to examine the applicability and effectiveness of the corrosion repair method using CFRP. FE analysis of the corroded plate girder model was carried out to clarify the residual bearing strength and failure mode due to the localized plate girder corrosion in the web and stiffener at the support region. The application of the CFRP repair method to the plate girder bridge with local corrosion at its support showed that such method can be useful for corroded bridges due to its rapid and simple application and the stress level improvement on the repaired corroded surface on account of the sectional reinforcement effect of the CFRP repair and the prevention of the corrosion progress in the plate girder. The evaluation of the residual bearing strength of the plate girder with local corrosion at its support showed that such strength was affected more by the corrosion related to the stiffener than by the local web corrosion at the support. Therefore, to prevent local corrosion of a plate girder at its support, the corrosion ratio of the stiffener must be considered more than that of the web, and a corroded stiffener must be repaired or reinforced ahead of a corroded web. 相似文献
98.
碳纤维复合材料在天线上的应用 总被引:6,自引:0,他引:6
本文叙述了碳纤维复合材料在天线上的应用情况,具体阐述了碳纤维复合材料天线结构形式及制作天线过程中的材料选择,铺层设计,表面金属化等问题。 相似文献
99.
Nondestructive inspection of carbon fibre-reinforced plastics (CFRP) using eddy current methods is not only based on the conductivity of the fibres. High frequencies (up to 10 MHz) enable the exploitation of capacitive effects reflecting the properties of the matrix. The paper presents a method using rotating eddy current probes to measure the anisotropic electrical properties. Potential applications of the method are structural identification of laminates and estimation of their degradation. For example, the strength properties of constructions based on unidirectional CFRP are very sensitive to small differences in fibre direction angle. Best detection of these angles could be obtained above 7.5 MHz. In addition, a signal perpendicular to the fibre orientation was found and termed the plateau effect. It is a result of capacitive connections between the fibres and presents new opportunities for the characterization of matrix properties. 相似文献
100.
为研究偏心率对碳纤维复合材料(Carbon Fiber Reinforced Polymer,CFRP)布加固钢管混凝土柱力学性能的影响规律,借助有限元软件ABAQUS对偏心率为0. 3%、0. 6%、0. 9%和1. 2%的构件分别进行数值模拟。结果表明:随着偏心率的增大,被动约束的紧箍力减小;偏心率对构件的荷载挠度曲线影响比较大,对于偏心率大的构件,其极限承载力较小;不同偏心率对于不同长细比的构件影响不同,长细比为28时,构件的承载力相应地整体降低。 相似文献