全文获取类型
收费全文 | 198300篇 |
免费 | 13665篇 |
国内免费 | 6861篇 |
专业分类
电工技术 | 9500篇 |
技术理论 | 12篇 |
综合类 | 10281篇 |
化学工业 | 29797篇 |
金属工艺 | 9126篇 |
机械仪表 | 10214篇 |
建筑科学 | 13217篇 |
矿业工程 | 4142篇 |
能源动力 | 5001篇 |
轻工业 | 13001篇 |
水利工程 | 3458篇 |
石油天然气 | 7987篇 |
武器工业 | 1198篇 |
无线电 | 21501篇 |
一般工业技术 | 23169篇 |
冶金工业 | 29223篇 |
原子能技术 | 1949篇 |
自动化技术 | 26050篇 |
出版年
2024年 | 519篇 |
2023年 | 2459篇 |
2022年 | 4101篇 |
2021年 | 5926篇 |
2020年 | 4272篇 |
2019年 | 3718篇 |
2018年 | 4520篇 |
2017年 | 5390篇 |
2016年 | 5255篇 |
2015年 | 6591篇 |
2014年 | 7884篇 |
2013年 | 9744篇 |
2012年 | 12232篇 |
2011年 | 13473篇 |
2010年 | 10302篇 |
2009年 | 9983篇 |
2008年 | 9673篇 |
2007年 | 9487篇 |
2006年 | 9380篇 |
2005年 | 10674篇 |
2004年 | 7577篇 |
2003年 | 6296篇 |
2002年 | 5075篇 |
2001年 | 4449篇 |
2000年 | 3897篇 |
1999年 | 4500篇 |
1998年 | 9705篇 |
1997年 | 6790篇 |
1996年 | 5271篇 |
1995年 | 3673篇 |
1994年 | 2976篇 |
1993年 | 2544篇 |
1992年 | 1369篇 |
1991年 | 1174篇 |
1990年 | 996篇 |
1989年 | 816篇 |
1988年 | 762篇 |
1987年 | 530篇 |
1986年 | 440篇 |
1985年 | 369篇 |
1984年 | 195篇 |
1983年 | 176篇 |
1982年 | 230篇 |
1981年 | 253篇 |
1980年 | 254篇 |
1979年 | 99篇 |
1978年 | 130篇 |
1977年 | 640篇 |
1976年 | 1373篇 |
1975年 | 113篇 |
排序方式: 共有10000条查询结果,搜索用时 50 毫秒
111.
112.
The application of deep learning in the field of object detection has
experienced much progress. However, due to the domain shift problem, applying an
off-the-shelf detector to another domain leads to a significant performance drop. A
large number of ground truth labels are required when using another domain to train
models, demanding a large amount of human and financial resources. In order to avoid
excessive resource requirements and performance drop caused by domain shift, this
paper proposes a new domain adaptive approach to cross-domain vehicle detection. Our
approach improves the cross-domain vehicle detection model from image space and
feature space. We employ objectives of the generative adversarial network and cycle
consistency loss for image style transfer in image space. For feature space, we align
feature distributions between the source domain and the target domain to improve the
detection accuracy. Experiments are carried out using the method with two different
datasets, proving that this technique effectively improves the accuracy of vehicle
detection in the target domain. 相似文献
114.
Neural Machine Translation (NMT) is an end-to-end learning approach for
automated translation, overcoming the weaknesses of conventional phrase-based translation
systems. Although NMT based systems have gained their popularity in commercial
translation applications, there is still plenty of room for improvement. Being the most
popular search algorithm in NMT, beam search is vital to the translation result. However,
traditional beam search can produce duplicate or missing translation due to its target
sequence selection strategy. Aiming to alleviate this problem, this paper proposed neural
machine translation improvements based on a novel beam search evaluation function. And
we use reinforcement learning to train a translation evaluation system to select better
candidate words for generating translations. In the experiments, we conducted extensive
experiments to evaluate our methods. CASIA corpus and the 1,000,000 pairs of bilingual
corpora of NiuTrans are used in our experiments. The experiment results prove that the
proposed methods can effectively improve the English to Chinese translation quality. 相似文献
115.
Journal of Mechanical Science and Technology - The idea of integral calculus is used in traditional milling force prediction methods. In the traditional method, the milling cutter is divided into... 相似文献
116.
117.
The red grape berry pigments, anthocyanins, were characterized in the early 20th century, but investigations of wine pigments were stymied during that era. The question of their identity was a major challenge for wine chemists. A number of techniques showed that the pigments were polymeric in nature. Some structures were postulated by mid-century based on reactions between anthocyanins and condensed tannin, and later postulated wine pigments were observed in model reactions. Some related compounds were then observed in wine. By the end of the 20th century, the ionization of non-volatiles for mass spectrometry opened the door to these compounds. In addition, a new class of compounds was observed, the pyranoanthocyanins, a product of fermentation and aging metabolites with anthocyanins. These compounds possess the pigment stability to SO2 and pH change that is characteristic of aged red wine. Aging experiments show a dynamic situation with shifts in the population of pigment classes over time. The very large number of diverse pigments explains why it has been so difficult to answer the century-old question of the structure of wine pigments. Our current understanding is founded on the use of mass spectral analysis using electrospray and related ionization techniques over the last 25 years. Future progress will rely on more sophisticated analysis of this very complex mixture of substances. © 2019 Society of Chemical Industry 相似文献
118.
119.