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   118573篇
  免费   11404篇
  国内免费   6665篇
电工技术   8595篇
技术理论   2篇
综合类   8747篇
化学工业   17475篇
金属工艺   6965篇
机械仪表   7273篇
建筑科学   8911篇
矿业工程   3004篇
能源动力   3534篇
轻工业   10290篇
水利工程   2847篇
石油天然气   4820篇
武器工业   1036篇
无线电   15058篇
一般工业技术   13776篇
冶金工业   5766篇
原子能技术   1842篇
自动化技术   16701篇
  2024年   572篇
  2023年   1853篇
  2022年   3712篇
  2021年   5054篇
  2020年   3544篇
  2019年   2818篇
  2018年   3163篇
  2017年   3680篇
  2016年   3230篇
  2015年   4732篇
  2014年   6146篇
  2013年   7549篇
  2012年   8447篇
  2011年   9317篇
  2010年   8266篇
  2009年   7930篇
  2008年   7812篇
  2007年   7584篇
  2006年   7122篇
  2005年   5682篇
  2004年   3924篇
  2003年   3077篇
  2002年   3059篇
  2001年   2672篇
  2000年   2387篇
  1999年   2120篇
  1998年   1901篇
  1997年   1615篇
  1996年   1442篇
  1995年   1219篇
  1994年   939篇
  1993年   784篇
  1992年   622篇
  1991年   478篇
  1990年   404篇
  1989年   312篇
  1988年   265篇
  1987年   192篇
  1986年   164篇
  1985年   143篇
  1984年   111篇
  1983年   80篇
  1982年   71篇
  1981年   75篇
  1980年   59篇
  1979年   44篇
  1978年   32篇
  1977年   33篇
  1976年   58篇
  1959年   21篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
71.
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   
72.
73.
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   
74.
75.
76.
77.
This paper presents a novel approach to the localization of moving targets in a complex environment based on the measurement of the perturbations induced by the target presence on an independently‐generated time‐varying electromagnetic field. Field perturbations are measured via a set of sensors deployed over the domain of interest and used to detect and track a possible target by resorting to a particle Bernoulli filter (PBF). To comply with real‐time operation, the PBF works along with an artificial neural network (ANN) model of the environment trained offline via finite elements (FEs). The performance of the proposed algorithm is assessed via simulation experiments.  相似文献   
78.
Perovskite ferroelectrics possess the fascinating piezoelectric properties near a morphotropic phase boundary, attributing to a low energy barrier that the results in structural instability and easy polarization rotation. In this work, a new lead-free system of (1-x)BaTiO3-xCaHfO3 was designed, and characterized by a coexistence of ferroelectric rhombohedral-orthorhombic-tetragonal (R-O-T) phases. With the increase amount of CaHfO3 (x), a stable coexistence region of three ferroelectric phases (R-O-T) exists at 0.06  x  0.08. Both large piezoelectric coefficient (d33~400 pC/N), inverse piezoelectric coefficient (d33*~547 pm/V) and planar electromechanical coupling factor (kp~58.2%) can be achieved for the composition with x = 0.08 near the coexistence of three ferroelectric phases. Our results show that the materials with the composition located at a region where the three ferroelectric R-O-T phases coexist would have the lowest energy barrier and thus greatly promote the polarization rotation, resulting in a strong piezoelectric response.  相似文献   
79.
Kong  Hao  Lu  Canyi  Lin  Zhouchen 《Machine Learning》2021,110(7):1867-1900
Machine Learning - Recently, the $${ Tensor}~{ Nuclear}~{ Norm}~{ (TNN)}$$ regularization based on t-SVD has been widely used in various low tubal-rank tensor recovery tasks. However, these models...  相似文献   
80.
Itaconate (ITA) is an emerging powerhouse of innate immunity with therapeutic potential that is limited in its ability to be administered in a soluble form. A library of polyester materials that incorporate ITA into polymer backbones resulting in materials with inherent immunoregulatory behavior is developed. Harnessing hydrolytic degradation release from polyester backbones, ITA polymers result in the mechanism specific immunoregulatory properties on macrophage polarization in vitro. In a functional assay, the polymer-released ITA inhibits bacterial growth on acetate. Translation to an in vivo model of biomaterial associated inflammation, intraperitoneal injection of ITA polymers demonstrate a rapid resolution of inflammation in comparison to a control polymer silicone, demonstrating the value of sustained biomimetic presentation of ITA.  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