全文获取类型
收费全文 | 103720篇 |
免费 | 10144篇 |
国内免费 | 5570篇 |
专业分类
电工技术 | 7190篇 |
技术理论 | 9篇 |
综合类 | 9302篇 |
化学工业 | 15954篇 |
金属工艺 | 6073篇 |
机械仪表 | 6689篇 |
建筑科学 | 8073篇 |
矿业工程 | 2776篇 |
能源动力 | 2896篇 |
轻工业 | 10384篇 |
水利工程 | 2108篇 |
石油天然气 | 5232篇 |
武器工业 | 1032篇 |
无线电 | 11084篇 |
一般工业技术 | 10902篇 |
冶金工业 | 3814篇 |
原子能技术 | 1147篇 |
自动化技术 | 14769篇 |
出版年
2024年 | 228篇 |
2023年 | 1677篇 |
2022年 | 3109篇 |
2021年 | 4402篇 |
2020年 | 3361篇 |
2019年 | 2662篇 |
2018年 | 2900篇 |
2017年 | 3353篇 |
2016年 | 2928篇 |
2015年 | 4372篇 |
2014年 | 5649篇 |
2013年 | 6484篇 |
2012年 | 7687篇 |
2011年 | 8420篇 |
2010年 | 7555篇 |
2009年 | 7126篇 |
2008年 | 7112篇 |
2007年 | 6631篇 |
2006年 | 6332篇 |
2005年 | 5033篇 |
2004年 | 3591篇 |
2003年 | 3025篇 |
2002年 | 3065篇 |
2001年 | 2574篇 |
2000年 | 2135篇 |
1999年 | 1841篇 |
1998年 | 1325篇 |
1997年 | 1026篇 |
1996年 | 908篇 |
1995年 | 686篇 |
1994年 | 562篇 |
1993年 | 395篇 |
1992年 | 329篇 |
1991年 | 246篇 |
1990年 | 167篇 |
1989年 | 146篇 |
1988年 | 92篇 |
1987年 | 70篇 |
1986年 | 54篇 |
1985年 | 28篇 |
1984年 | 15篇 |
1983年 | 22篇 |
1982年 | 23篇 |
1981年 | 22篇 |
1980年 | 32篇 |
1979年 | 10篇 |
1965年 | 2篇 |
1960年 | 2篇 |
1959年 | 8篇 |
1951年 | 3篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
43.
Breast cancer is one of the most common types of cancer in women, and histopathological imaging is considered the gold standard for its diagnosis. However, the great complexity of histopathological images and the considerable workload make this work extremely time-consuming, and the results may be affected by the subjectivity of the pathologist. Therefore, the development of an accurate, automated method for analysis of histopathological images is critical to this field. In this article, we propose a deep learning method guided by the attention mechanism for fast and effective classification of haematoxylin and eosin-stained breast biopsy images. First, this method takes advantage of DenseNet and uses the feature map's information. Second, we introduce dilated convolution to produce a larger receptive field. Finally, spatial attention and channel attention are used to guide the extraction of the most useful visual features. With the use of fivefold cross-validation, the best model obtained an accuracy of 96.47% on the BACH2018 dataset. We also evaluated our method on other datasets, and the experimental results demonstrated that our model has reliable performance. This study indicates that our histopathological image classifier with a soft attention-guided deep learning model for breast cancer shows significantly better results than the latest methods. It has great potential as an effective tool for automatic evaluation of digital histopathological microscopic images for computer-aided diagnosis. 相似文献
44.
Peng Wang Yan Li Yujiao Qu Baowei Wang Jingxin Sun Chunwei Miao Ming Huang He Huang Congxiang Zhang 《International Journal of Food Science & Technology》2022,57(6):3428-3439
The effects of cellulose microfibres (CMFs, Average size: 100 ± 5 μm) and cellulose nanofibres (CNFs, Average size: 60 ± 3 nm) on the properties of myofibrillar protein (MP) gels from duck breast meat were studied. The results demonstrated that CMFs and CNFs were mostly connected to MP by non-covalent bonds, the diffusion and cross-linking of MP molecules was promoted, and a denser and more complete gel network was formed. With the increases of CMFs and CNFs concentration (0–10%), the hardness was increased by 13.15% and 19.78% for CMFs10% and CNFs10% gels, respectively, and the elasticity was increased by 40% and 80%, respectively. At the same concentration (0–10%), the increase in gel hardness, viscoelasticity and immobilised water content was greater in the CNFs-MP group than in the CMFs-MP group. The CNFs-MP group had a tighter gel network, and CNFs had a better potential to improve the gelation performance of MP. 相似文献
45.
46.
47.
48.
Layer-structured regenerated silk fibroin (SF)/graphene oxide (GO) composite films were fabricated by a facile solution casting method. Fourier transform infrared spectroscopy, X-ray diffraction, and thermal gravity analysis confirmed the successful incorporation and uniform dispersion of graphene oxides in the SF matrix. To visualize GO's effect on the morphological evolution, atomic force microscopic images were recorded in real-time during the composite elongation to establish a correlation between microscopic structural characters and macroscopic mechanical properties. The result showed that the incorporation of graphene oxide into the SF matrix resulted in chain conformational transition, film surface flattening, and mechanical reinforcement. Surface roughness dramatically decreased from 65 to 10 nm, while tensile modulus increased substantially from 8.61 to 22.37 MPa by adding well-dispersed graphene oxide up to 1 wt% into the SF matrix. Through the real-time AFM observation under the horizontal stretching mode, the surface topography of original SF films varied from tori-spherical aggregations to rod-like ones resulting from GO's incorporation. In the meantime, SF's hydrophobicity was also increased, as manifested by contact angle increase from 30.81° to 45.09°. 相似文献
49.
目的 介绍国内外智能假肢膝关节研究的主要进展,为相关领域的研发提供可借鉴的思路.方法 基于机械结构、调控方式、驱动方式,对典型假肢膝关节进行了分类比较,并从假肢穿戴者的运动意图识别、驱动控制、人机协调控制等方面做了分析.此外,对假肢膝关节在智能化研究与安全性、个性化与通用性、人机共融技术、科学伦理、关键技术等方面需要注意的问题,提出了研发要点和技术思路.结论 智能假肢膝关节应注重安全性与稳定性,规避用户在使用过程中的潜在危险因素;实现假肢控制参数的自整定和灵活适配,在个性化与通用性上达到平衡;综合考虑人—机—环境因素,实现协调控制;坚持"以人为本",在技术方法和科学伦理两个方面开展医工结合的研究;突破关键技术限制,建立完善的社会医疗康复保障服务体系. 相似文献
50.
Kelin Hu Feipeng Wang Yuyang Yan Hongcheng Liu Zijia Shen 《Ceramics International》2021,47(11):15228-15236
In this paper, a novel hybrid structure of Pd doped ZnO/SnO2 heterojunction nanofibers with hexagonal ZnO columns was one step synthesized from electrospun precursor nanofibers. Due to the synergistic effect of hexagonal ZnO, SnO2 and Pd, the structure exhibited excellent hydrogen (H2) gas sensing properties. At low-temperature of 120 °C, the response (Ra/Rg) to 100 ppm H2 gas exceeded 160, the response/recovery time was only 20 s and 6 s respectively and the limit of detection was only 0.5 ppm. Meanwhile, it also had good selectivity for H2 gas and excellent linearity. In addition, the materials were characterized by XRD, FESEM, HRTEM, XPS, and the synthesis mechanism and gas sensing mechanism were proposed. 相似文献