全文获取类型
收费全文 | 7298篇 |
免费 | 235篇 |
国内免费 | 145篇 |
学科分类
工业技术 | 7678篇 |
出版年
2024年 | 11篇 |
2023年 | 43篇 |
2022年 | 71篇 |
2021年 | 144篇 |
2020年 | 118篇 |
2019年 | 67篇 |
2018年 | 76篇 |
2017年 | 139篇 |
2016年 | 153篇 |
2015年 | 193篇 |
2014年 | 335篇 |
2013年 | 393篇 |
2012年 | 361篇 |
2011年 | 440篇 |
2010年 | 343篇 |
2009年 | 348篇 |
2008年 | 346篇 |
2007年 | 454篇 |
2006年 | 463篇 |
2005年 | 416篇 |
2004年 | 375篇 |
2003年 | 370篇 |
2002年 | 305篇 |
2001年 | 227篇 |
2000年 | 238篇 |
1999年 | 220篇 |
1998年 | 172篇 |
1997年 | 159篇 |
1996年 | 113篇 |
1995年 | 81篇 |
1994年 | 89篇 |
1993年 | 69篇 |
1992年 | 58篇 |
1991年 | 45篇 |
1990年 | 47篇 |
1989年 | 21篇 |
1988年 | 17篇 |
1987年 | 16篇 |
1986年 | 6篇 |
1985年 | 11篇 |
1984年 | 11篇 |
1983年 | 6篇 |
1982年 | 7篇 |
1981年 | 8篇 |
1965年 | 9篇 |
1963年 | 5篇 |
1959年 | 7篇 |
1958年 | 10篇 |
1956年 | 8篇 |
1955年 | 13篇 |
排序方式: 共有7678条查询结果,搜索用时 0 毫秒
1.
论文将Fermat素性检验的思想运用于不可约多项式的判断,给出了一个对于不可约判断问题的Monte Carlo 算法,分析了该算法的计算复杂度问题,并且给出了次数在200以内的检验结果。 相似文献
2.
3.
4.
本文介绍一套先进的构件实验设备的功能及其在发动机构件疲劳试验方面的具体应用实例.通过对几种受力较复杂构件的受力分析设计出实验方法,使构件在实验室中受力情况与构件实际受力情况相似或相同,这样,得出的试验数据就可为构件的可靠性分析工作提供较好的依据. 相似文献
5.
Larry Wos 《Journal of Automated Reasoning》1987,3(4):433-435
This article is the fourth of a series of articles discussing various open research problems in automated reasoning. The problem proposed for research focuses on finding criteria that would enable an automated reasoning program to expand or contract definitions wisely. For evaluating a proposed solution to this research problem, we include suggestions concerning possible test problems.This work was supported by the Applied Mathematical Sciences subprogram of the Office of Energy Research, U.S. Department of Energy, under contract W-31-109-Eng-38. 相似文献
6.
Xiao-Ying Wang Jonathan M. Garibaldi Benjamin Bird Michael W. George 《Applied Intelligence》2007,27(3):237-248
Recently Fourier Transform Infrared (FTIR) spectroscopic imaging has been used as a tool to detect the changes in cellular
composition that may reflect the onset of a disease. This approach has been investigated as a mean of monitoring the change
of the biochemical composition of cells and providing a diagnostic tool for various human cancers and other diseases. The
discrimination between different types of tissue based upon spectroscopic data is often achieved using various multivariate
clustering techniques. However, the number of clusters is a common unknown feature for the clustering methods, such as hierarchical
cluster analysis, k-means and fuzzy c-means. In this study, we apply a FCM based clustering algorithm to obtain the best number
of clusters as given by the minimum validity index value. This often results in an excessive number of clusters being created
due to the complexity of this biochemical system. A novel method to automatically merge clusters was developed to try to address
this problem. Three lymph node tissue sections were examined to evaluate our new method. These results showed that this approach
can merge the clusters which have similar biochemistry. Consequently, the overall algorithm automatically identifies clusters
that accurately match the main tissue types that are independently determined by the clinician. 相似文献
7.
8.
针对地市级电视台的业务特点和需求,设计了基于网络的非线性编辑系统,并对系统工作流程、方案设计、拓扑结构、网络性能、系统管理要求进行了分析,提出了具体实现方法. 相似文献
9.
A new image analysis technique has been developed which allows maceral analysis of coal to be carried out. The technique is able to separate the liptinite component from the background resin by using two separate images of the surface captured with different camera exposure times. At normal exposure, the liptinite has a similar grey scale value to the surrounding resin, but at a higher exposure time, the resin remains black whilst the liptinite grey scale increases significantly enough to distinguish it from the resin. The method has been tested for repeatability and reproducibility and found to be within the ISO Standard requirements. 相似文献
10.
Allen Daniel N.; Strauss Gregory P.; Kemtes Karen A.; Goldstein Gerald 《Canadian Metallurgical Quarterly》2007,21(6):713
Hemispheric involvement in reasoning abilities has been debated for some time, and it remains unclear whether the right hemisphere's involvement in problem solving is modality specific or dependent on the type of spatial reasoning required. In the current study, 2 types of nonverbal reasoning abilities were examined, spatial reasoning and proportional reasoning, in 109 patients with cerebrovascular disease that was confined to either the right or the left hemisphere or was diffuse in nature. Results indicated that no lateralizing effects were present based on type of spatial reasoning. Findings are consistent with the suggestion that higher order cognitive processes involved in nonverbal abstraction and problem solving are not strongly lateralized to the right hemisphere but rather are more generally distributed throughout the cortex. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献