全文获取类型
收费全文 | 120008篇 |
免费 | 12698篇 |
国内免费 | 6272篇 |
专业分类
电工技术 | 9047篇 |
技术理论 | 12篇 |
综合类 | 8679篇 |
化学工业 | 18324篇 |
金属工艺 | 7291篇 |
机械仪表 | 7902篇 |
建筑科学 | 9634篇 |
矿业工程 | 4070篇 |
能源动力 | 3679篇 |
轻工业 | 8055篇 |
水利工程 | 2753篇 |
石油天然气 | 6132篇 |
武器工业 | 1339篇 |
无线电 | 13964篇 |
一般工业技术 | 13721篇 |
冶金工业 | 5428篇 |
原子能技术 | 1677篇 |
自动化技术 | 17271篇 |
出版年
2024年 | 624篇 |
2023年 | 2231篇 |
2022年 | 4394篇 |
2021年 | 5881篇 |
2020年 | 4421篇 |
2019年 | 3571篇 |
2018年 | 4053篇 |
2017年 | 4411篇 |
2016年 | 4076篇 |
2015年 | 5575篇 |
2014年 | 6805篇 |
2013年 | 7965篇 |
2012年 | 9019篇 |
2011年 | 9514篇 |
2010年 | 8202篇 |
2009年 | 7761篇 |
2008年 | 7436篇 |
2007年 | 6838篇 |
2006年 | 6436篇 |
2005年 | 5345篇 |
2004年 | 3777篇 |
2003年 | 3073篇 |
2002年 | 3011篇 |
2001年 | 2537篇 |
2000年 | 2193篇 |
1999年 | 2066篇 |
1998年 | 1477篇 |
1997年 | 1173篇 |
1996年 | 1168篇 |
1995年 | 918篇 |
1994年 | 703篇 |
1993年 | 554篇 |
1992年 | 449篇 |
1991年 | 293篇 |
1990年 | 238篇 |
1989年 | 167篇 |
1988年 | 175篇 |
1987年 | 91篇 |
1986年 | 89篇 |
1985年 | 55篇 |
1984年 | 38篇 |
1983年 | 28篇 |
1982年 | 27篇 |
1981年 | 17篇 |
1980年 | 16篇 |
1979年 | 17篇 |
1977年 | 10篇 |
1976年 | 12篇 |
1959年 | 9篇 |
1951年 | 9篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
31.
Bin Feng Xin Jiang Guisheng Zou Wengan Wang Tianming Sun Heng Yang Guanlei Zhao Mingye Dong Yu Xiao Hongwei Zhu Lei Liu 《Advanced functional materials》2021,31(29):2102359
The realization of liquid metal-based wearable systems will be a milestone toward high-performance, integrated electronic skin. However, despite the revolutionary progress achieved in many other components of electronic skin, liquid metal-based flexible sensors still suffer from poor sensitivity due to the insufficient resistance change of liquid metal to deformation. Herein, a nacre-inspired architecture composed of a biphasic pattern (liquid metal with Cr/Cu underlayer) as “bricks” and strain-sensitive Ag film as “mortar” is developed, which breaks the long-standing sensitivity bottleneck of liquid metal-based electronic skin. With 2 orders of magnitude of sensitivity amplification while maintaining wide (>85%) working range, for the first time, liquid metal-based strain sensors rival the state-of-art counterparts. This liquid metal composite features spatially regulated cracking behavior. On the one hand, hard Cr cells locally modulate the strain distribution, which avoids premature cut-through cracks and prolongs the defect propagation in the adjacent Ag film. On the other hand, the separated liquid metal cells prevent unfavorable continuous liquid-metal paths and create crack-free regions during strain. Demonstrated in diverse scenarios, the proposed design concept may spark more applications of ultrasensitive liquid metal-based electronic skins, and reveals a pathway for sensor development via crack engineering. 相似文献
32.
Jun Dong Cho Luis Cavazos Quero Jorge Iranzo Bartolom Do Won Lee Uran Oh Inae Lee 《Color research and application》2021,46(1):103-116
A recent development in tactile technology enables an improvement in the appreciation of the visual arts for people with visual impairment (PVI). The tactile sense, in conjunction with, or a possibly as an alternative to, the auditory sense, would allow PVIs to approach artwork in a more self‐driven and engaging way that would be difficult to achieve with just an auditory stimulus. Tactile colour pictograms (TCPs), which are raised geometric patterns, are ideographic characters that are designed to enable PVIs to identify colours and interpret information by touch. In this article, three TCPs are introduced to code colours in the Munsell colour system. Each colour pattern consists of a basic cell size of 10 mm × 10 mm to represent the patterns consistently in terms of regular shape. Each TCP consists of basic geometric patterns that are combined to create primary, secondary, and tertiary colour pictograms of shapes indicating colour hue, intensity and lightness. Each TCP represents 29 colours including six hues; they were then further expanded to represent 53 colours. Two of them did not increase the cell size, the other increased the cell size 1.5 times for some colours, such as yellow‐orange, yellow, blue, and blue‐purple. Our proposed TCPs use a slightly larger cell size compared to most tactile patterns currently used to indicate colour, but code for more colours. With user experience and identification tests, conducted with 23 visually impaired adults, the effectiveness of the TCPs suggests that they were helpful for the participants. 相似文献
33.
Nan Wu Xiaodong Li Mu Zhang Yi Ren Qi Zhu Haijun Peng Hongqiang Ru Xudong Sun 《Journal of the European Ceramic Society》2021,41(4):2898-2907
Refining ceramic microstructures to the nanometric range to minimize light scattering provides an interesting methodology for developing novel optical ceramic materials. In this work, we reported the fabrication and properties of a new nanocomposite optical ceramic of Gd2O3-MgO. The citric acid sol-gel combustion method was adopted to fabricate Gd2O3-MgO nanocomposites with fine-grain sizes, dense microstructures and homogeneous phase domains. Nanopowders with low agglomeration and improved sinterability can be obtained by elaborating Φ values. Further refining of the microstructure of the nanocomposites was achieved by elaborating the hot-pressing conditions. The sample sintered at 65 MPa and 1300 °C showed a quite high hardness value of 14.3 ± 0.2 GPa, a high transmittance of 80.3 %–84.7 % over the 3?6 μm wavelength range, due mainly to its extremely fine-grain size of Gd2O3 and MgO (93 and 78 nm, respectively) and high density. 相似文献
34.
Fluorescence‐Activated Cell Sorters: Standing Surface Acoustic Wave (SSAW)‐Based Fluorescence‐Activated Cell Sorter (Small 40/2018) 下载免费PDF全文
35.
37.
38.
39.
In vivo Kinetic Biodistribution of Nano‐Sized Outer Membrane Vesicles Derived from Bacteria 下载免费PDF全文
Su Chul Jang Sae Rom Kim Yae Jin Yoon Kyong‐Su Park Ji Hyun Kim Jaewook Lee Oh Youn Kim Eun‐Jeong Choi Dae‐Kyum Kim Dong‐Sic Choi Yoon‐Keun Kim Jaesung Park Dolores Di Vizio Yong Song Gho 《Small (Weinheim an der Bergstrasse, Germany)》2015,11(4):456-461
Evaluation of kinetic distribution and behaviors of nanoparticles in vivo provides crucial clues into their roles in living organisms. Extracellular vesicles are evolutionary conserved nanoparticles, known to play important biological functions in intercellular, inter‐species, and inter‐kingdom communication. In this study, the first kinetic analysis of the biodistribution of outer membrane vesicles (OMVs)—bacterial extracellular vesicles—with immune‐modulatory functions is performed. OMVs, injected intraperitoneally, spread to the whole mouse body and accumulate in the liver, lung, spleen, and kidney within 3 h of administration. As an early systemic inflammation response, increased levels of TNF‐α and IL‐6 are observed in serum and bronchoalveolar lavage fluid. In addition, the number of leukocytes and platelets in the blood is decreased. OMVs and cytokine concentrations, as well as body temperature are gradually decreased 6 h after OMV injection, in concomitance with the formation of eye exudates, and of an increase in ICAM‐1 levels in the lung. Following OMV elimination, most of the inflammatory signs are reverted, 12 h post‐injection. However, leukocytes in bronchoalveolar lavage fluid are increased as a late reaction. Taken together, these results suggest that OMVs are effective mediators of long distance communication in vivo. 相似文献
40.