全文获取类型
收费全文 | 126436篇 |
免费 | 12184篇 |
国内免费 | 6663篇 |
专业分类
电工技术 | 8460篇 |
技术理论 | 3篇 |
综合类 | 8878篇 |
化学工业 | 20284篇 |
金属工艺 | 7745篇 |
机械仪表 | 8747篇 |
建筑科学 | 9813篇 |
矿业工程 | 4126篇 |
能源动力 | 3474篇 |
轻工业 | 8196篇 |
水利工程 | 2431篇 |
石油天然气 | 6737篇 |
武器工业 | 1201篇 |
无线电 | 15212篇 |
一般工业技术 | 14845篇 |
冶金工业 | 5853篇 |
原子能技术 | 1457篇 |
自动化技术 | 17821篇 |
出版年
2024年 | 496篇 |
2023年 | 1931篇 |
2022年 | 3948篇 |
2021年 | 5480篇 |
2020年 | 4018篇 |
2019年 | 3412篇 |
2018年 | 3731篇 |
2017年 | 4062篇 |
2016年 | 3778篇 |
2015年 | 5508篇 |
2014年 | 6615篇 |
2013年 | 7950篇 |
2012年 | 8809篇 |
2011年 | 9577篇 |
2010年 | 8442篇 |
2009年 | 8356篇 |
2008年 | 8103篇 |
2007年 | 7691篇 |
2006年 | 7334篇 |
2005年 | 6152篇 |
2004年 | 4220篇 |
2003年 | 3608篇 |
2002年 | 3377篇 |
2001年 | 2955篇 |
2000年 | 2629篇 |
1999年 | 2587篇 |
1998年 | 1901篇 |
1997年 | 1661篇 |
1996年 | 1450篇 |
1995年 | 1190篇 |
1994年 | 950篇 |
1993年 | 672篇 |
1992年 | 534篇 |
1991年 | 450篇 |
1990年 | 366篇 |
1989年 | 326篇 |
1988年 | 233篇 |
1987年 | 164篇 |
1986年 | 123篇 |
1985年 | 77篇 |
1984年 | 63篇 |
1983年 | 50篇 |
1982年 | 51篇 |
1981年 | 37篇 |
1980年 | 45篇 |
1979年 | 25篇 |
1978年 | 23篇 |
1976年 | 25篇 |
1975年 | 13篇 |
1973年 | 15篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Feng Wenran Li Zhen Chen Yingying Chen Jinyang Lang Haoze Wan Jianghong Gao Yan Dong Haitao 《Journal of Materials Science》2022,57(3):1881-1889
Journal of Materials Science - Although chalcogenide materials continue to generate considerable interest due to great potentials for various optoelectronic devices, annealing for a long time in... 相似文献
2.
Zhao Jiandong Lei Wei Li Zijian Zhao Dongfeng Han Mingmin Hou Xiaoqing 《Multimedia Tools and Applications》2022,81(4):4753-4780
Multimedia Tools and Applications - The crowding in bus is an important factor affecting passenger satisfaction and bus dispatching level. However, how to use video images to detect crowding... 相似文献
4.
5.
7.
Qian Wu Xiangmei Liu Bo Li Lei Tan Yong Han Zhaoyang Li Yanqin Liang Zhenduo Cui Shengli Zhu Shuilin Wu Yufeng Zheng 《材料科学技术学报》2021,67(8):70-79
Pathogens pose a serious challenge to environmental sanitation and a threat to public health.The frequent use of chemicals for sterilization in recent years has not only caused secondary damage to the environment but also increased pathogen resistance to drugs,which further threatens public health.To address this issue,the use of non-chemical antibacterial means has become a new trend for environmental disinfection.In this study,we developed red phosphorus nanoparticles(RPNPs),a safe and degradable photosensitive material with good photocatalytic and photothermal properties.The red phosphorus nanoparticles were prepared using a template method and ultrasonication.Under the irradiation of simulated sunlight for 20 min,the RPNPs exhibited an efficiency of 99.98%in killing Staphylococcus aureus due to their excellent photocatalytic and photothermal abilities.Transmission electron microscopy and ultraviolet–visible spectroscopy revealed that the RPNPs exhibited degradability within eight weeks.Both the RPNPs and their degradation products were nontoxic to fibroblast cells.Therefore,such RPNPs are expected to be used as a new type of low-cost,efficient,degradable,biocompatible,and eco-friendly photosensitive material for environmental disinfection. 相似文献
8.
Photoresponsive biomaterials are experiencing a transition from in vitro models to in vivo demonstrations that point toward clinical translation. Dynamic hydrogels for cell encapsulation, light-responsive carriers for controlled drug delivery, and nanomaterials containing photosensitizers for photodynamic therapy are relevant examples. Nonetheless, the step to the clinic largely depends on their combination with technologies to bring light into the body. This review highlights the challenge of photoactivation in vivo, and presents strategies for light management that can be adopted for this purpose. The authors’ focus is on technologies that are materials-driven, particularly upconversion nanoparticles that assist in “direct path” light delivery through tissue, and optical waveguides that “clear the path” between external light source and in vivo target. The authors’ intention is to assist the photoresponsive biomaterials community transition toward medical technologies by presenting light delivery concepts that can be integrated with the photoresponsive targets. The authors also aim to stimulate further innovation in materials-based light delivery platforms by highlighting needs and opportunities for in vivo photoactivation of biomaterials. 相似文献
9.
Tao Feng Mingde Tong Shuotian Yao Hejun Li Shifeng Wen Hongjiao Lin 《Journal of the European Ceramic Society》2021,41(1):158-166
Composites based on hafnium carbide and reinforced with continuous naked carbon fiber with and without PyC interface were prepared at low temperature by precursor infiltration and pyrolysis and chemical vapor deposition method. The microstructure, mechanical property, cyclic ablation and fiber bundle push-in tests of the composites were investigated. The results show that after three times ablation cycles, the bending strength of samples without PyC interface decreased by 63.6 %; the bending strength of samples with PyC interface only decreased by 37.8 %. The force displacement curve of the samples with PyC interface presented a well pseudoplastic deformation state. The mechanical behavior difference of two kinds of composites was due to crucial function of PyC interface phase including protection of fiber and weakening of fiber/matrix interface. 相似文献
10.