全文获取类型
收费全文 | 225896篇 |
免费 | 19899篇 |
国内免费 | 12836篇 |
专业分类
电工技术 | 34865篇 |
技术理论 | 23篇 |
综合类 | 25847篇 |
化学工业 | 10304篇 |
金属工艺 | 8004篇 |
机械仪表 | 19129篇 |
建筑科学 | 19253篇 |
矿业工程 | 9272篇 |
能源动力 | 8130篇 |
轻工业 | 4712篇 |
水利工程 | 6827篇 |
石油天然气 | 7268篇 |
武器工业 | 4525篇 |
无线电 | 23310篇 |
一般工业技术 | 13115篇 |
冶金工业 | 6840篇 |
原子能技术 | 2359篇 |
自动化技术 | 54848篇 |
出版年
2024年 | 286篇 |
2023年 | 2113篇 |
2022年 | 4036篇 |
2021年 | 5281篇 |
2020年 | 5689篇 |
2019年 | 4042篇 |
2018年 | 3557篇 |
2017年 | 5197篇 |
2016年 | 6136篇 |
2015年 | 7274篇 |
2014年 | 14271篇 |
2013年 | 12078篇 |
2012年 | 17037篇 |
2011年 | 18041篇 |
2010年 | 13609篇 |
2009年 | 13628篇 |
2008年 | 13901篇 |
2007年 | 17814篇 |
2006年 | 15993篇 |
2005年 | 14234篇 |
2004年 | 11669篇 |
2003年 | 10557篇 |
2002年 | 8010篇 |
2001年 | 6703篇 |
2000年 | 5492篇 |
1999年 | 4424篇 |
1998年 | 3328篇 |
1997年 | 2673篇 |
1996年 | 2429篇 |
1995年 | 2068篇 |
1994年 | 1705篇 |
1993年 | 1164篇 |
1992年 | 991篇 |
1991年 | 706篇 |
1990年 | 575篇 |
1989年 | 478篇 |
1988年 | 334篇 |
1987年 | 195篇 |
1986年 | 117篇 |
1985年 | 129篇 |
1984年 | 108篇 |
1983年 | 94篇 |
1982年 | 78篇 |
1981年 | 69篇 |
1980年 | 56篇 |
1979年 | 53篇 |
1978年 | 35篇 |
1977年 | 28篇 |
1976年 | 23篇 |
1959年 | 21篇 |
排序方式: 共有10000条查询结果,搜索用时 234 毫秒
1.
Recently, single image super-resolution (SISR) has been widely applied in the fields of underwater robot vision and obtained remarkable performance. However, most current methods generally suffered from the problem of a heavy burden on computational resources with large model sizes, which limited their real-world underwater robotic applications. In this paper, we introduce and tackle the super resolution (SR) problem for underwater robot vision and provide an efficient solution for near real-time applications. We present a novel lightweight multi-stage information distillation network, named MSIDN, for better balancing performance against applicability, which aggregates the local distilled features from different stages for more powerful feature representation. Moreover, a novel recursive residual feature distillation (RRFD) module is constructed to progressively extract useful features with a modest number of parameters in each stage. We also propose a channel interaction & distillation (CI&D) module that employs channel split operation on the preceding features to produce two-part features and utilizes the inter channel-wise interaction information between them to generate the distilled features, which can effectively extract the useful information of current stage without extra parameters. Besides, we present USR-2K dataset, a collection of over 1.6K samples for large-scale underwater image SR training, and a testset with an additional 400 samples for benchmark evaluation. Extensive experiments on several standard benchmark datasets show that the proposed MSIDN can provide state-of-the-art or even better performance in both quantitative and qualitative measurements. 相似文献
2.
Xiao-Lei Qiu Zi-Rui Fan Yang-Yang Liu Ding-Fu Wang Shi-Xin Wang Chun-Xia Li 《International journal of molecular sciences》2021,22(8)
A self-nanoemulsifying drug delivery system (SNEDDS) was developed to enhance the absorption of heparin after oral administration, in which heparin was compounded with phospholipids to achieve better fat solubility in the form of heparin-phospholipid (HEP-Pc) complex. HEP-Pc complex was prepared using the solvent evaporation method, which increased the solubility of heparin in n-octanol. The successful preparation of HEP-Pc complex was confirmed by differential scanning calorimetry (DSC), Fourier-transform infrared (FT-IR) spectroscopy, NMR, and SEM. A heparin lipid microemulsion (HEP-LM) was prepared by high-pressure homogenization and characterized. HEP-LM can enhance the absorption of heparin after oral administration, significantly prolong activated partial thromboplastin time (APTT) and thrombin time (TT) in mice, and reduce fibrinogen (FIB) content. All these outcomes indicate that HEP-LM has great potential as an oral heparin formulation. 相似文献
3.
4.
《中国有色金属学会会刊》2021,31(8):2468-2478
An acoustic emission (AE) experiment was carried out to explore the AE location accuracy influenced by temperature. A hollow hemispherical specimen was used to simulate common underground structures. In the process of heating with the flame, the pulse signal of constant frequency was stimulated as an AE source. Then AE signals received by each sensor were collected and used for comparing localization accuracy at different temperatures. Results show that location errors of AE keep the same phenomenon in the early and middle heating stages. In the later stage of heating, location errors of AE increase sharply due to the appearance of cracks. This provides some beneficial suggestions on decreasing location errors of structural cracks caused by temperature and improves the ability of underground structure disaster prevention and control. 相似文献
5.
邓乐善 《中国水能及电气化》2021,(1):56-58
针对民乐县农村人饮机井水位自动供水系统控制中存在的可靠性低、成本高等问题,文章结合深井泵提取地下水进行供水的实际情况,提出了软启动控制柜+浮球开关+微电脑时间控制器改进的思路和方法,运用效果良好。 相似文献
6.
7.
谭金军 《自动化技术与应用》2021,40(1):181-183
为进一步提升企业思想政治教育工作的信息化水平,本文详细介绍了企业思想政治教育系统的数据库设计方案,以便更加充分地发挥各种多媒体教学设备在企业思想政治教育工作方面的优势。 相似文献
8.
9.
10.
In this paper, a novel method is proposed for increasing the performance through coupling of top-down models adjusting the object detector based on a new loss function. Generally, object detectors and keypoint estimators are sequentially used in real-time multi-person pose estimations; however, these two models are separately trained. Therefore, the results of the object detector are not optimized for the keypoint estimator. To solve this problem, we analyze the relationship between the two models and propose a feedback-based loss optimization in the object detector, based on the estimation results of the keypoint estimator. In addition, the resulting bounding box of the object detector is readjusted to improve the accuracy of the keypoint estimation model. The experimental results demonstrate that the proposed approach can perform real-time operations with a high frame rate similar to that of the baseline model. Moreover, it achieved an accuracy of 74.2 average precision (AP), which is higher than the state-of-the-arts model including the human detector used in the experiment. 相似文献