首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   73532篇
  免费   5578篇
  国内免费   2778篇
电工技术   3884篇
技术理论   6篇
综合类   4437篇
化学工业   12717篇
金属工艺   3973篇
机械仪表   4814篇
建筑科学   5226篇
矿业工程   2408篇
能源动力   2236篇
轻工业   4817篇
水利工程   1003篇
石油天然气   5291篇
武器工业   472篇
无线电   7679篇
一般工业技术   9440篇
冶金工业   3936篇
原子能技术   752篇
自动化技术   8797篇
  2024年   306篇
  2023年   1272篇
  2022年   2119篇
  2021年   2919篇
  2020年   2204篇
  2019年   1973篇
  2018年   2305篇
  2017年   2514篇
  2016年   2083篇
  2015年   2703篇
  2014年   3449篇
  2013年   4233篇
  2012年   4353篇
  2011年   4859篇
  2010年   4189篇
  2009年   3958篇
  2008年   3863篇
  2007年   3721篇
  2006年   3798篇
  2005年   3439篇
  2004年   2289篇
  2003年   2089篇
  2002年   1872篇
  2001年   1642篇
  2000年   1804篇
  1999年   2056篇
  1998年   1769篇
  1997年   1425篇
  1996年   1407篇
  1995年   1187篇
  1994年   957篇
  1993年   717篇
  1992年   548篇
  1991年   428篇
  1990年   327篇
  1989年   255篇
  1988年   226篇
  1987年   143篇
  1986年   120篇
  1985年   96篇
  1984年   66篇
  1983年   40篇
  1982年   42篇
  1981年   30篇
  1980年   25篇
  1979年   13篇
  1977年   7篇
  1976年   8篇
  1975年   5篇
  1945年   4篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
1.
With the emergence of large-scale knowledge base, how to use triple information to generate natural questions is a key technology in question answering systems. The traditional way of generating questions require a lot of manual intervention and produce lots of noise. To solve these problems, we propose a joint model based on semi-automated model and End-to-End neural network to automatically generate questions. The semi-automated model can generate question templates and real questions combining the knowledge base and center graph. The End-to-End neural network directly sends the knowledge base and real questions to BiLSTM network. Meanwhile, the attention mechanism is utilized in the decoding layer, which makes the triples and generated questions more relevant. Finally, the experimental results on SimpleQuestions demonstrate the effectiveness of the proposed approach.  相似文献   
2.
3.
4.
5.
6.
7.
8.
Zhang  Xi  Wang  Xianhai  Zhao  Hongke  Ordóñez de Pablos  Patricia  Sun  Yongqiang  Xiong  Hui 《Scientometrics》2019,119(3):1311-1344
Scientometrics - Altmetrics indices are increasingly applied to measure scholarly influence in recent years because they can reflect the influence of research outputs more timely comparing with...  相似文献   
9.
This paper presents a spatio-temporal fusion method for remote sensing images by using a linear injection model and local neighbourhood information. In this method, the linear injection model is first introduced to generate an initial fused image, the spatial details are extracted from the fine-resolution image at the base date, and are weighted by a proper injection gains. Then, the spatial details and the relative spectral information from the coarse-resolution images are blended to generate the fusion result. To further enhance its robustness to the noise, the local neighbourhood information, derived from the fine-resolution image and the fused result simultaneously, is introduced to refine the initial fused image to obtain a more accurate prediction result. The algorithm can effectively capture phenology change or land-cover-type change with minimum input data. Simulated data and two types of real satellite images with seasonal changes and land-cover-type changes are employed to test the performance of the proposed method. Compared with a spatial and temporal adaptive reflectance fusion model (STARFM) and a flexible spatio-temporal fusion algorithm (FSDAF), results show that the proposed approach improves the accuracy of fused images in phenology change area and effectively captures land-cover-type reflectance changes.  相似文献   
10.
This study evaluated several physical and sensory parameters of different types of cheese available in the Polish market. The measurements of textural properties were conducted in an Instron universal testing machine, while the colour properties of cheeses were measured using a Minolta chromameter. The chemical composition was determined by means of the near‐infrared spectroscopy (NIRs). Moreover, a trained sensory panel was invited to assess the cheese texture‐related properties. Generally, cheeses with reduced fat content were characterised by higher hardness, adhesiveness, cohesiveness and elasticity. Texture‐related parameters of cheese with canola oil were comparable to that of most of full‐fat cheeses. The correlation analysis between physical and sensory attributes related to cheese textural properties indicated the potential applications of TPA, shear and penetration tests (= 0.766, = 0.75 and = 0.765, respectively) for the evaluation of sensory properties related to the hardness. Meanwhile, the elasticity of cheese obtained from sensory evaluation was strongly correlated with the elasticity determined from the shear test (= 0.722) and moderately correlated with the elasticity from penetration test (= 0.588), indicating a need to refine the method of penetration test. In addition, cheeses exhibited higher meltability during convection heating at 230 °C than microwave heating. The values of meltability for cheese with reduced fat content were lower than those of full‐fat cheese.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号