全文获取类型
收费全文 | 745480篇 |
免费 | 84742篇 |
国内免费 | 43462篇 |
专业分类
电工技术 | 16666篇 |
技术理论 | 27篇 |
综合类 | 39401篇 |
化学工业 | 129715篇 |
金属工艺 | 52075篇 |
机械仪表 | 28335篇 |
建筑科学 | 19893篇 |
矿业工程 | 16091篇 |
能源动力 | 33482篇 |
轻工业 | 97700篇 |
水利工程 | 6503篇 |
石油天然气 | 7966篇 |
武器工业 | 4527篇 |
无线电 | 73188篇 |
一般工业技术 | 117597篇 |
冶金工业 | 33123篇 |
原子能技术 | 7687篇 |
自动化技术 | 189708篇 |
出版年
2024年 | 1737篇 |
2023年 | 17728篇 |
2022年 | 25861篇 |
2021年 | 31249篇 |
2020年 | 30482篇 |
2019年 | 25754篇 |
2018年 | 30136篇 |
2017年 | 33287篇 |
2016年 | 34435篇 |
2015年 | 37154篇 |
2014年 | 52101篇 |
2013年 | 62737篇 |
2012年 | 68526篇 |
2011年 | 69637篇 |
2010年 | 51896篇 |
2009年 | 52416篇 |
2008年 | 36106篇 |
2007年 | 45337篇 |
2006年 | 36772篇 |
2005年 | 19271篇 |
2004年 | 11290篇 |
2003年 | 10765篇 |
2002年 | 10616篇 |
2001年 | 9217篇 |
2000年 | 8022篇 |
1999年 | 8014篇 |
1998年 | 7223篇 |
1997年 | 4931篇 |
1996年 | 4311篇 |
1995年 | 3356篇 |
1994年 | 2947篇 |
1993年 | 2876篇 |
1992年 | 2409篇 |
1991年 | 2128篇 |
1990年 | 1922篇 |
1989年 | 1686篇 |
1988年 | 1512篇 |
1987年 | 1186篇 |
1986年 | 1062篇 |
1985年 | 1538篇 |
1984年 | 1355篇 |
1983年 | 1252篇 |
1982年 | 1189篇 |
1981年 | 1102篇 |
1980年 | 1037篇 |
1979年 | 1108篇 |
1978年 | 1084篇 |
1977年 | 914篇 |
1976年 | 919篇 |
1975年 | 765篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Journal of Materials Science - Three polyimides (PIs) were prepared from a diamine containing biphenyl ester group as a side chain and a corresponding dianhydride chosen from... 相似文献
3.
Recent generative adversarial networks (GANs) have yielded remarkable performance in face image synthesis. GAN inversion embeds an image into the latent space of a pretrained generator, enabling it to be used for real face manipulation. However, current inversion approaches for real faces suffer the dilemma of initialization collapse and identity loss. In this paper, we propose a hierarchical GAN inversion for real faces with identity preservation based on mutual information maximization. We first use a facial domain guaranteed initialization to avoid the initialization collapse. Furthermore, we prove that maximizing the mutual information between inverted faces and their identities is equivalent to minimizing the distance between identity features from inverted and original faces. Optimization for real face inversion with identity preservation is implemented on this mutual information-maximizing constraint. Extensive experimental results show that our approach outperforms state-of-the-art solutions for inverting and editing real faces, particularly in terms of face identity preservation. 相似文献
4.
Zhang Junbao Huang Haojun Yang Changlin Liu Jizhao Fan Yinting Yang Guan 《Wireless Networks》2022,28(3):1301-1312
Wireless Networks - Although centrality is widely used to differentiate the importance of nodes for social-aware routing in mobile opportunistic networks (MONs), it is destination-agnostic since... 相似文献
5.
Retrieving 3D shapes with 2D images has become a popular research area nowadays, and a great deal of work has been devoted to reducing the discrepancy between 3D shapes and 2D images to improve retrieval performance. However, most approaches ignore the semantic information and decision boundaries of the two domains, and cannot achieve both domain alignment and category alignment in one module. In this paper, a novel Collaborative Distribution Alignment (CDA) model is developed to address the above existing challenges. Specifically, we first adopt a dual-stream CNN, following a similarity guided constraint module, to generate discriminative embeddings for input 2D images and 3D shapes (described as multiple views). Subsequently, we explicitly introduce a joint domain-class alignment module to dynamically learn a class-discriminative and domain-agnostic feature space, which can narrow the distance between 2D image and 3D shape instances of the same underlying category, while pushing apart the instances from different categories. Furthermore, we apply a decision boundary refinement module to avoid generating class-ambiguity embeddings by dynamically adjusting inconsistencies between two discriminators. Extensive experiments and evaluations on two challenging benchmarks, MI3DOR and MI3DOR-2, demonstrate the superiority of the proposed CDA method for 2D image-based 3D shape retrieval task. 相似文献
6.
7.
Sandstorm is a meteorological phenomenon common in arid and semi-arid regions. A sandstorm can carry large volumes of sand unexpectedly, which leads to severe color deviations and significantly degraded visibility when an image is taken in such a scenario. However, existing image enhancement methods cannot enhance sandstorm images well due to the challenging degradations and the scarcity of sandstorm training data. In this paper, we propose a Transformer with rotary position embedding to perform sandstorm image enhancement via building multi-scale and multi-patch dependencies. Our key insights in this work are 1) a multi-scale Transformer can globally eliminate the color deviations of sandstorm images via aggregating global information, 2) a multi-patch Transformer can recover local details well via learning the spatial variant degradations, and 3) a U-shape Transformer with rotary position embedding as the core unit of multi-scale and multi-patch Transformer can effectively build the long-range dependencies. We also contribute a real-world Sandstorm Image Enhancement (SIE) dataset including 1,400 sandstorm images with different degrees of degradations and various scenes. Experiments performed on synthetic images and real-world sandstorm images demonstrate that our proposed method not only obtains visually pleasing results but also outperforms state-of-the-art methods qualitatively and quantitatively. 相似文献
8.
Namsar Orapim Autthawong Thanapat Boonprachai Ruttapol Yu Aishui Sarakonsri Thapanee 《Journal of Materials Science: Materials in Electronics》2022,33(9):6536-6548
Journal of Materials Science: Materials in Electronics - The new nanocomposites of silicon dioxide/reduced graphene oxide (SiO2/rGO) and silicon dioxide/nitrogen-doped reduced graphene oxide... 相似文献
9.
Kore Ekanath K. Shahane Guruling S. Mulik Ramesh N. 《Journal of Materials Science: Materials in Electronics》2022,33(13):9815-9829
Journal of Materials Science: Materials in Electronics - The Co1?xZnxFe2O4 (Co–Zn) ferrite nanoparticles with x varying from 0.0 to 0.4 have been manufactured by facile chemical... 相似文献
10.