全文获取类型
收费全文 | 73332篇 |
免费 | 5548篇 |
国内免费 | 2770篇 |
专业分类
电工技术 | 3879篇 |
技术理论 | 6篇 |
综合类 | 4427篇 |
化学工业 | 12698篇 |
金属工艺 | 3949篇 |
机械仪表 | 4805篇 |
建筑科学 | 5190篇 |
矿业工程 | 2404篇 |
能源动力 | 2231篇 |
轻工业 | 4767篇 |
水利工程 | 1000篇 |
石油天然气 | 5278篇 |
武器工业 | 460篇 |
无线电 | 7654篇 |
一般工业技术 | 9430篇 |
冶金工业 | 3932篇 |
原子能技术 | 750篇 |
自动化技术 | 8790篇 |
出版年
2024年 | 301篇 |
2023年 | 1264篇 |
2022年 | 2104篇 |
2021年 | 2903篇 |
2020年 | 2196篇 |
2019年 | 1960篇 |
2018年 | 2297篇 |
2017年 | 2503篇 |
2016年 | 2076篇 |
2015年 | 2694篇 |
2014年 | 3438篇 |
2013年 | 4218篇 |
2012年 | 4344篇 |
2011年 | 4853篇 |
2010年 | 4171篇 |
2009年 | 3952篇 |
2008年 | 3850篇 |
2007年 | 3711篇 |
2006年 | 3792篇 |
2005年 | 3430篇 |
2004年 | 2285篇 |
2003年 | 2084篇 |
2002年 | 1870篇 |
2001年 | 1636篇 |
2000年 | 1799篇 |
1999年 | 2049篇 |
1998年 | 1767篇 |
1997年 | 1425篇 |
1996年 | 1406篇 |
1995年 | 1187篇 |
1994年 | 957篇 |
1993年 | 717篇 |
1992年 | 546篇 |
1991年 | 428篇 |
1990年 | 327篇 |
1989年 | 254篇 |
1988年 | 226篇 |
1987年 | 142篇 |
1986年 | 120篇 |
1985年 | 96篇 |
1984年 | 66篇 |
1983年 | 40篇 |
1982年 | 43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 15 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.
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.
Correlation between instrumental texture and colour quality attributes with sensory analysis of selected cheeses as affected by fat contents 下载免费PDF全文
A. Półtorak J. Wyrwisz M. Moczkowska M. Marcinkowska‐Lesiak A. Stelmasiak U. Ulanicka M. Zalewska A. Wierzbicka Da‐Wen Sun 《International Journal of Food Science & Technology》2015,50(4):999-1008
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 (r = 0.766, r = 0.75 and r = 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 (r = 0.722) and moderately correlated with the elasticity from penetration test (r = 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