全文获取类型
收费全文 | 31701篇 |
免费 | 2498篇 |
国内免费 | 1434篇 |
专业分类
电工技术 | 1627篇 |
技术理论 | 6篇 |
综合类 | 2109篇 |
化学工业 | 5424篇 |
金属工艺 | 2001篇 |
机械仪表 | 2019篇 |
建筑科学 | 2517篇 |
矿业工程 | 859篇 |
能源动力 | 873篇 |
轻工业 | 1832篇 |
水利工程 | 566篇 |
石油天然气 | 2129篇 |
武器工业 | 187篇 |
无线电 | 3493篇 |
一般工业技术 | 3964篇 |
冶金工业 | 1696篇 |
原子能技术 | 430篇 |
自动化技术 | 3901篇 |
出版年
2024年 | 127篇 |
2023年 | 527篇 |
2022年 | 864篇 |
2021年 | 1228篇 |
2020年 | 948篇 |
2019年 | 778篇 |
2018年 | 881篇 |
2017年 | 941篇 |
2016年 | 941篇 |
2015年 | 1121篇 |
2014年 | 1482篇 |
2013年 | 1807篇 |
2012年 | 1862篇 |
2011年 | 2121篇 |
2010年 | 1883篇 |
2009年 | 1808篇 |
2008年 | 1747篇 |
2007年 | 1536篇 |
2006年 | 1554篇 |
2005年 | 1421篇 |
2004年 | 1053篇 |
2003年 | 1072篇 |
2002年 | 1099篇 |
2001年 | 1071篇 |
2000年 | 826篇 |
1999年 | 916篇 |
1998年 | 773篇 |
1997年 | 603篇 |
1996年 | 535篇 |
1995年 | 446篇 |
1994年 | 387篇 |
1993年 | 281篇 |
1992年 | 214篇 |
1991年 | 157篇 |
1990年 | 123篇 |
1989年 | 110篇 |
1988年 | 78篇 |
1987年 | 53篇 |
1986年 | 54篇 |
1985年 | 25篇 |
1984年 | 30篇 |
1983年 | 27篇 |
1982年 | 20篇 |
1981年 | 19篇 |
1980年 | 10篇 |
1979年 | 12篇 |
1978年 | 5篇 |
1976年 | 13篇 |
1970年 | 6篇 |
1966年 | 4篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
91.
根据继电保护运行和维护特点,结合运城供电系统当前实际情况,分析了二次设备状态检修的各种问题并提出相应采取的措施。 相似文献
92.
红外制导武器的现状及发展趋势 总被引:11,自引:2,他引:11
红外制导可分为红外半自动制导、点源寻的制导、成像制导和未敏制导等几类。综述了各国研制的红外制导武器及其发展趋势。 相似文献
93.
94.
With the emerging connected autonomous driving paradigm,more advanced applications leveraging vehicular communications are drawing tremendous attentions.In orde... 相似文献
95.
Liu Yang Yan Liu Mingli Yue Ping Li Yulong Liu Fei Ye Ying Fu 《International journal of molecular sciences》2022,23(11)
A new chemosensor, namely N-(2-morpholinoethyl)acetamide-4-morpholine-1,8-naphthimide (MMN), was designed and synthesized through an amidation reaction. MMN was fabricated as a multifunctional fluorescent probe for monitoring pH and isoxaflutole. MMN exhibited excellent stability in MeCN/H2O (v/v, 9/1), with an obvious “off–on” fluorescence response toward pH changes due to intramolecular charge transfer (ICT), where the linear response ranges of MMN in the weakly acidic system were from 4.2 to 5.0 and from 5.0 to 6.0 with apparent pKa = 4.62 ± 0.02 and 5.43 ± 0.02. Based on morpholine as the lysosome targetable unit, MMN could selectively locate lysosomes in live cells. MMN also successfully detected the presence of H+ in test papers. Finally, MMN could specifically recognize isoxaflutole at a detection limit of 0.88 μM. A possible sensing mechanism was identified based on density function theory calculations. These results indicate that MMN could be a superior potential chemosensor for detecting pH and isoxaflutole selectively and sensitively and could be used in real sample detection. 相似文献
96.
二维有机-无机杂化钙钛矿因在光伏、光电子等领域的巨大应用潜力而备受关注.此外,该类材料具有突出的结构可调性和材料稳定性,为功能性质的设计调控及器件应用提供了丰富的材料设计平台.然而,将多种物理通道的性质整合实现材料的多功能性仍具有挑战性,而对其进行快速有效的调节更是难上加难.迄今为止,尚未成功实现可调谐的光电多通道响应... 相似文献
97.
Rui Li Yan Zhao Zhen Sun Zhenying Wu Honglun Wang Chunxiang Fu Hongbo Zhao Feng He 《International journal of molecular sciences》2022,23(12)
Plant laccase genes belong to a multigene family, play key roles in lignin polymerization, and participate in the resistance of plants to biotic and abiotic stresses. Switchgrass is an important resource for forage and bioenergy production, yet information about the switchgrass laccase gene family is scarce. Using bioinformatic approaches, a genome-wide analysis of the laccase multigene family in switchgrass was carried out in this study. In total, 49 laccase genes (PvLac1 to PvLac49) were identified; these can be divided into five subclades, and 20 of them were identified as targets of miR397. The tandem and segmental duplication of laccase genes on Chr05 and Chr08 contributed to the expansion of the laccase family. The laccase proteins shared conserved signature sequences but displayed relatively low sequence similarity, indicating the potential functional diversity of switchgrass laccases. Switchgrass laccases exhibited distinct tissue/organ expression patterns, revealing that some laccases might be involved in the lignification process during stem development. All five of the laccase isoforms selected from different subclades responded to heavy metal. The immediate response of lignin-related laccases, as well as the delayed response of low-abundance laccases, to heavy-metal treatment shed light on the multiple roles of laccase isoforms in response to heavy-metal stress. 相似文献
98.
Po Hu Zhi-Guo Ma Kai Zhao Guo-Qiang Zhang De-Qing Fang Bao-Ren Wei Chang-Bo Fu Yu-Gang Ma 《核技术(英文版)》2021,32(6):84-92
With the development of laser technologies,nuclear reactions can happen in high-temperature plasma environments induced by lasers and have attracted a lot of at... 相似文献
99.
100.
Multiplexed Bioassays: Dual‐Encoded Microbeads through a Host–Guest Structure: Enormous,Flexible, and Accurate Barcodes for Multiplexed Assays (Adv. Funct. Mater. 34/2016) 下载免费PDF全文