全文获取类型
收费全文 | 418篇 |
免费 | 20篇 |
国内免费 | 8篇 |
专业分类
电工技术 | 12篇 |
综合类 | 7篇 |
化学工业 | 19篇 |
金属工艺 | 3篇 |
机械仪表 | 8篇 |
建筑科学 | 186篇 |
矿业工程 | 15篇 |
能源动力 | 3篇 |
轻工业 | 3篇 |
水利工程 | 35篇 |
石油天然气 | 9篇 |
武器工业 | 1篇 |
无线电 | 29篇 |
一般工业技术 | 12篇 |
冶金工业 | 35篇 |
自动化技术 | 69篇 |
出版年
2024年 | 2篇 |
2023年 | 11篇 |
2022年 | 22篇 |
2021年 | 20篇 |
2020年 | 18篇 |
2019年 | 15篇 |
2018年 | 18篇 |
2017年 | 4篇 |
2016年 | 9篇 |
2015年 | 17篇 |
2014年 | 15篇 |
2013年 | 17篇 |
2012年 | 21篇 |
2011年 | 15篇 |
2010年 | 28篇 |
2009年 | 21篇 |
2008年 | 27篇 |
2007年 | 27篇 |
2006年 | 30篇 |
2005年 | 20篇 |
2004年 | 17篇 |
2003年 | 12篇 |
2002年 | 8篇 |
2001年 | 6篇 |
2000年 | 7篇 |
1999年 | 9篇 |
1998年 | 2篇 |
1997年 | 6篇 |
1996年 | 1篇 |
1995年 | 6篇 |
1994年 | 1篇 |
1993年 | 1篇 |
1990年 | 2篇 |
1989年 | 2篇 |
1988年 | 2篇 |
1987年 | 3篇 |
1986年 | 4篇 |
排序方式: 共有446条查询结果,搜索用时 203 毫秒
1.
2.
柳洪轶 《自动化与仪器仪表》2014,(9):25-26
在自动化翻拍的图像采集过程中,图像中各像素间的空间相互关系会随着采集发生变化,通过对空间失真复原算法的深入研究,利用几何极坐标、中值滤波等方法,提出自动化翻拍图像复原算法。实验结果表明,使用该算法能够消除由图像采集引起的空间畸变失真,提高图像的可识别性,是一种有效的方法。 相似文献
3.
4.
高校机房计算机由于其使用的频繁以及学生的误操作,经常造成系统故障。该文主要介绍了利用MaxDos软件对机房计算机系统方便有效的维护—网络克隆。 相似文献
5.
6.
提出了一种用SVR回归器识别脉冲噪声的思想,并将其应用于图像滤波和恢复,形成了用于对脉冲噪声进行滤波的SVR自适应滤波器。这种滤波器在滤波时,先用SVR对待识别像素作噪声识别,再对含噪声的像素作中值滤波。用SVR作噪声识别时,先对滤波窗口作SVR回归,通过待识别像素回归距的大小判断其是否含有噪声。在进行SVR回归时,使用鲁棒的Huber损失函数。由于更充分地利用了待识别像素点的局部背景信息,这种滤波器提高了脉冲噪声识别的正确率。实验表明,在保留原图像的细节信息方面,其滤波效果要优于基于SVC的中值滤波器。 相似文献
7.
Along 25 km of the Lake Ontario shoreline near Toronto, Ontario, small coastal embayments (0.4–32 ha) have been constructed or modified by lake-infilling to restore warmwater fish habitat. The variation in thermal habitat quality for warmwater fishes among these embayments is very high; temperatures range from those found within a small pond to those of much cooler Lake Ontario. Since meteorological conditions and surface heat fluxes are almost identical, the temperature variation among embayments must be caused by differences in bathymetry or exchange with Lake Ontario. However, a previous study on these embayments found paradoxically that temperatures were not strongly associated with channel size or embayment bathymetry. This paper resolves the paradox by showing that flushing times for almost all of the constructed embayments were less than 1 day, and often less than 12 h. With so little time to warm within the embayments, water temperatures of almost all embayments remained very close to the temperatures of the adjacent lake waters. The coldest embayments connected directly to open Lake Ontario and warmer embayments connected to Lake Ontario through other embayments or protected harbors, where the inflowing water from Lake Ontario had already substantially warmed. To allow embayments along the exposed shoreline of Toronto to reach acceptable temperatures for warmwater fish, we use heat budgets to calculate that average summer flushing times must be increased from their current length of 1.5 to 5.5 h to approximately 30 h. Such changes could be achieved through large reductions in the channel cross section. 相似文献
8.
P. A. Johnson 《Canadian Metallurgical Quarterly》2005,131(10):845-852
The primary cause of bridge failure in the United States is scour and channel instability around the bridge foundations. The ability to assess channel stability in the vicinity of bridges is needed to alert engineers to possible unstable conditions at the bridge foundations, to design stable road crossings, and to mitigate against erosion at those structures. This information is valuable for stream stabilization projects as well, particularly for cases where the reach to be restored includes a bridge. However, a systematic methodology for rapidly assessing channel stability that is applicable at bridges located in the various regions of the country does not currently exist. In this study, an assessment method for the preliminary documentation and rating of channel stability near bridges was developed, based on prior stability assessment methods as well as observations at bridges in 13 physiographic regions of the continental United States. This method provides an assessment of channel stability conditions as they affect bridge foundations. It is intended for a quick assessment of conditions for the purpose of documenting conditions at bridges and for judging whether more extensive geomorphic studies or complete hydraulic and sediment transport analyses are needed to assess the potential for adverse conditions developing at a particular bridge in the future. 相似文献
9.
着重介绍多种修复技术在冶金企业重载齿轮中的应用与修复工艺方法,对几种修复技术给出了力学模型和计算公式、计算方法,并提出了齿轮修复的经济性原则。经工厂实践证明修复重载齿轮是可行的、可靠的、经济的。 相似文献
10.
Total Variation (TV) is a widely used image restoration/decomposition model. It is observed that the classical TV l1 and TV l2 regularization, on the one hand, do not favor higher-gradient structures over lower-gradient details as expected for structure preserving image processing, and on the other hand, tend to reduce the horizontal and vertical gradients, and thus inevitably blur the oblique edges in images. In this paper, we address these two problems by defining Oriented Total Variation l1/2 (OTV l1/2). It is theoretically and experimentally demonstrated that applying l1/2 regularization to the directional derivatives of images leads to superior structure preservation. OTV l1/2 regularization can be applied to image denoising and video compression, and the experimental results verify that OTV l1/2 outperforms other similar models. 相似文献