全文获取类型
收费全文 | 22513篇 |
免费 | 2257篇 |
国内免费 | 1178篇 |
专业分类
电工技术 | 1440篇 |
综合类 | 1727篇 |
化学工业 | 3573篇 |
金属工艺 | 995篇 |
机械仪表 | 1158篇 |
建筑科学 | 1575篇 |
矿业工程 | 443篇 |
能源动力 | 593篇 |
轻工业 | 3065篇 |
水利工程 | 537篇 |
石油天然气 | 653篇 |
武器工业 | 142篇 |
无线电 | 2431篇 |
一般工业技术 | 2532篇 |
冶金工业 | 891篇 |
原子能技术 | 293篇 |
自动化技术 | 3900篇 |
出版年
2024年 | 146篇 |
2023年 | 462篇 |
2022年 | 952篇 |
2021年 | 1117篇 |
2020年 | 893篇 |
2019年 | 793篇 |
2018年 | 800篇 |
2017年 | 986篇 |
2016年 | 839篇 |
2015年 | 1148篇 |
2014年 | 1386篇 |
2013年 | 1719篇 |
2012年 | 1808篇 |
2011年 | 1872篇 |
2010年 | 1617篇 |
2009年 | 1513篇 |
2008年 | 1465篇 |
2007年 | 1271篇 |
2006年 | 1137篇 |
2005年 | 902篇 |
2004年 | 592篇 |
2003年 | 422篇 |
2002年 | 340篇 |
2001年 | 309篇 |
2000年 | 253篇 |
1999年 | 197篇 |
1998年 | 145篇 |
1997年 | 111篇 |
1996年 | 101篇 |
1995年 | 84篇 |
1994年 | 62篇 |
1993年 | 48篇 |
1992年 | 58篇 |
1991年 | 24篇 |
1990年 | 39篇 |
1989年 | 23篇 |
1988年 | 24篇 |
1987年 | 21篇 |
1986年 | 28篇 |
1985年 | 24篇 |
1984年 | 28篇 |
1983年 | 24篇 |
1982年 | 19篇 |
1981年 | 9篇 |
1980年 | 23篇 |
1979年 | 14篇 |
1978年 | 14篇 |
1977年 | 14篇 |
1976年 | 11篇 |
1974年 | 9篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
Hasan Abbasi Nozari Hamed Dehghan Banadaki Mohammad Mokhtare Somayeh Hekmati Vahed 《浙江大学学报:C卷英文版》2012,(9):701
This study deals with the neuro-fuzzy (NF) modelling of a real industrial winding process in which the acquired NF model can be exploited to improve control performance and achieve a robust fault-tolerant system. A new simulator model is proposed for a winding process using non-linear identification based on a recurrent local linear neuro-fuzzy (RLLNF) network trained by local linear model tree (LOLIMOT), which is an incremental tree-based learning algorithm. The proposed NF models are compared with other known intelligent identifiers, namely multilayer perceptron (MLP) and radial basis function (RBF). Comparison of our proposed non-linear models and associated models obtained through the least square error (LSE) technique (the optimal modelling method for linear systems) confirms that the winding process is a non-linear system. Experimental results show the effectiveness of our proposed NF modelling approach. 相似文献
42.
针对初学者在学习Access数据库中遇到的困难,设计了三个教学案例,介绍报表中计算控件的使用、if语句的语法格式和通配符“?”和“’,的使用.对于提高Access数据库的教学效果有一定的参考价值。 相似文献
43.
Lyndsay A. Cartwright Sue Hayes Douglas C. Tozer Dan Clayton Mary-Ann Burns Dena Lewis Noah Gaetz Namrata Shrestha 《Journal of Great Lakes research》2021,47(2):273-282
Beneficial use impairments (BUIs) under the Great Lakes Water Quality Agreement identify environmental issues requiring remedial action within the Great Lakes Areas of Concern (AOCs). We conducted this study to support the assessment of the wildlife component of BUI 3: degradation of fish and wildlife populations. We compared bird and amphibian (frogs and toads) data from the Toronto and Region Conservation Authority’s Terrestrial Long-term Monitoring Program in the Toronto and Region AOC to an adjacent, but otherwise similar, reference watershed, Duffins Creek. Twelve of 13 targets were met within the AOC for forest bird, wetland bird, meadow bird and amphibian populations based on averages of mean annual values at sites within the AOC that were within two standard deviations of averages at sites in the Duffins Creek reference watershed between 2008 and 2017. Even though wildlife populations within the AOC were within the normal range of variability expected from a reference watershed, they were often at lower levels than within the Duffins Creek reference watershed. In addition, forest bird and amphibian populations were negatively affected by urbanization within the AOC and meadow bird indices declined. We conclude that while wildlife populations within the AOC currently meet targets for BUI 3, they continue to be negatively impacted by numerous stressors that are primarily related to past and ongoing urbanization. Thus, continued restoration of wildlife habitat and protection of existing habitat within the AOC is highly recommended. 相似文献
44.
45.
Din Salah Ud Shao Junming Kumar Jay Mawuli Cobbinah Bernard Mahmud S. M. Hasan Zhang Wei Yang Qinli 《Knowledge and Information Systems》2021,63(9):2231-2276
Knowledge and Information Systems - Developing effective and efficient data stream classifiers is challenging for the machine learning community because of the dynamic nature of data streams. As a... 相似文献
46.
47.
Liu Yongsheng Chen Wenyu Qu Hong Mahmud S. M. Hasan Miao Kebin 《Neural computing & applications》2021,33(10):4965-4978
Neural Computing and Applications - With only global image-level annotations, weakly supervised learning of deep convolutional neural networks has shown enough capacity in classification and... 相似文献
48.
Aziz Romila Anwar Muhammad Waqas Jamal Muhammad Hasan Bajwa Usama Ijaz 《Neural computing & applications》2021,33(21):14707-14721
Neural Computing and Applications - Detecting and correcting misspelled words in a written text are of great importance in many natural language processing applications. Errors can be broadly... 相似文献
49.
Zhang Dan Li Pan Zhao Lei Xu Duanqing Lu Dongming 《Neural computing & applications》2021,33(19):12957-12971
Neural Computing and Applications - Deep convolutional neural networks have achieved great success for image denoising recently. However, increasing the depth of the neural network cannot... 相似文献
50.
针对一类由局部状态空间(LSS)Fornasini-Marchesini(FM)第二模型描述的,具有时变状态滞后的2-D离散系统,其中时变滞后项的上、下界均为正实数,研究了其稳定性和控制综合问题。首先,利用Lyapunov-Krasovski泛函方法,提出了系统的稳定性准则。再根据这一准则,分别设计状态反馈和动态输出反馈控制器保证系统的稳定性。状态反馈控制律和输出反馈矩阵可由线性矩阵不等式(LMI)求得。最后,通过数值算例说明所得结果的有效性。 相似文献