全文获取类型
| 收费全文 | 155篇 |
| 免费 | 5篇 |
| 国内免费 | 1篇 |
专业分类
| 电工技术 | 3篇 |
| 化学工业 | 17篇 |
| 金属工艺 | 10篇 |
| 机械仪表 | 4篇 |
| 建筑科学 | 14篇 |
| 矿业工程 | 3篇 |
| 能源动力 | 8篇 |
| 水利工程 | 19篇 |
| 无线电 | 14篇 |
| 一般工业技术 | 26篇 |
| 冶金工业 | 6篇 |
| 原子能技术 | 1篇 |
| 自动化技术 | 36篇 |
出版年
| 2024年 | 1篇 |
| 2023年 | 11篇 |
| 2022年 | 4篇 |
| 2021年 | 7篇 |
| 2020年 | 3篇 |
| 2019年 | 2篇 |
| 2018年 | 5篇 |
| 2017年 | 10篇 |
| 2016年 | 22篇 |
| 2015年 | 6篇 |
| 2014年 | 8篇 |
| 2013年 | 9篇 |
| 2012年 | 7篇 |
| 2011年 | 4篇 |
| 2010年 | 8篇 |
| 2009年 | 3篇 |
| 2007年 | 2篇 |
| 2006年 | 2篇 |
| 2005年 | 1篇 |
| 2004年 | 3篇 |
| 2003年 | 1篇 |
| 2002年 | 2篇 |
| 2001年 | 5篇 |
| 2000年 | 2篇 |
| 1999年 | 2篇 |
| 1998年 | 4篇 |
| 1997年 | 1篇 |
| 1996年 | 1篇 |
| 1995年 | 1篇 |
| 1994年 | 1篇 |
| 1993年 | 1篇 |
| 1992年 | 1篇 |
| 1991年 | 3篇 |
| 1987年 | 6篇 |
| 1986年 | 3篇 |
| 1984年 | 1篇 |
| 1982年 | 1篇 |
| 1977年 | 1篇 |
| 1974年 | 1篇 |
| 1971年 | 1篇 |
| 1970年 | 1篇 |
| 1967年 | 1篇 |
| 1965年 | 1篇 |
| 1952年 | 1篇 |
排序方式： 共有161条查询结果，搜索用时 0 毫秒
71.
73.
74.
《Applied Energy》2005,80(1):23-33
Methods for protecting water pipes, in cold regions against freezing, by thermal insulation material and heating cable will be analyzed. Reliability of keeping the tube's wall temperature of a piping system at minimum value will be analyzed. A thermoeconomic optimization analysis is applied with a simple algebraic formula derived for estimating the optimum insulation thickness for tubes of different sizes. The optimization is based on a life-cycle cost analysis. The effects of design parameters on the optimum thickness are investigated. Predicted results of this study would provide useful reference data when considering design, practical operation or maintenance. 相似文献
75.
《Acta Metallurgica Materialia》1992,40(9):2177-2184
The effect of external tensile stress on continuous precipitation (DP) has been investigated in an Al21.8 at.% Zn alloy at high (215°C) and low (75 and 50°C) temperatures. The ratio of the macroscopic lattice diffusivity, D, to the DP boundary velocity, v, (D/v) is estimated to be larger than the interatomic spacing, λ, at the high temperature, and smaller than λ at the low temperatures. Under tensile stresses, the DP rates are enhanced at the grain boundary segments oriented transverse to the stress direction and suppressed at those oriented parallel to it at both high and low temperatures. Furthermore, Yi and Park show the DP rate changing continuously with temperature over the range where D/v increased from values much smaller than λ to those much larger. These results show that the diffusional coherency strain is the major driving force for DP even at low temperatures where, with D/v < λ, no solute diffusion is usually assumed to occur in front of the moving DP boundaries. 相似文献
76.
E. Villaescusa M. Seto G. Baird 《International Journal of Rock Mechanics and Mining Sciences》2002,39(5):603-615
A low-cost methodology that allows the estimation of in situ and induced stress using oriented rock core specimens has been investigated. The technique can be used to determine the stresses either during the early stages of a project, even in undeveloped areas of a mine, or to measure in situ and induced stress within active mine workings, such as stopes and pillars. The research aim was to compare the experimental results estimated by the Acoustic Emission and Deformation Rate Analysis methods with those estimated by conventional HI cell measurements. Data was collected from a number of sites with different geological environments and in most cases the core was obtained from the same hole in which a conventional stress measurement had been carried out. The studies have focused on the determination of the full stress tensor from a single oriented cored rock. In all cases, the rock core specimens recollected similar in situ stress values to those estimated using conventional overcoring methods. 相似文献
77.
Robert D. Athey 《Metal Finishing》2010,108(11-12):363-365
79.
In this study, the tensile characteristics of a friction connection using a high-strength bolt, based on the clamping force loss developed by sectional corrosion damage to the bolt head, was examined. Eighteen specimens with bolt connections were tested to evaluate the tensile strength. In these test specimens, artificial corrosion damage was introduced to the bolt head of the bolt connection, creating a clamping force loss. In the tensile strength tests, the tensile failures of connected steel plates were observed; the tensile strength was unaffected by the artificial sectional corrosion damage to the bolt head for this failure mode. However, the friction resistance of the specimens was affected by the clamping force of the bolt, and thus, their friction loads were slightly reduced depending on the sectional damage level of the bolt head. From the friction load–clamping force relationship, friction-resistance equations were used to approximate the friction resistance of the friction bolt connection. 相似文献
80.
The current methodology of assessing the compaction characteristic of subgrade fillers is time-consuming. The spot-sampling method and the following laboratory tests bring bias to engineering practice. This study proposes an advanced approach to determine the maximum dry density, optimum moisture content, and compactness of subgrade based on ANN algorithms. A large number of compaction tests are performed to assess the compaction quality of various types of subgrade fillers. The particle gradation is specifically considered. Wave propagations of the compacted specimen are assessed based on the ultrasonic test, and the anisotropic feature is demonstrated. The dynamic elastic parameters are derived to further reveal the interaction mechanism. A dataset is proposed by combining these laboratory data and the literature data. The PSO-BP-NN model is developed to automatically predict the compaction parameters of different filling materials. A positive correlation is demonstrated between the elastic modulus and the total density, and Poisson’s ratio illustrates an inverse trend. The compaction energy is influential to the maximum dry density while the moisture content has the greatest impact on the compactness. This study aims to develop an accurate model to replace the extensive Proctor test and efficiently evaluate the compaction quality of subgrade for highway constructions. 相似文献