全文获取类型
收费全文 | 49698篇 |
免费 | 4410篇 |
国内免费 | 2097篇 |
专业分类
电工技术 | 2838篇 |
技术理论 | 7篇 |
综合类 | 3244篇 |
化学工业 | 8259篇 |
金属工艺 | 2920篇 |
机械仪表 | 3204篇 |
建筑科学 | 3531篇 |
矿业工程 | 1582篇 |
能源动力 | 1531篇 |
轻工业 | 3109篇 |
水利工程 | 776篇 |
石油天然气 | 3138篇 |
武器工业 | 464篇 |
无线电 | 5829篇 |
一般工业技术 | 6363篇 |
冶金工业 | 2418篇 |
原子能技术 | 687篇 |
自动化技术 | 6305篇 |
出版年
2024年 | 113篇 |
2023年 | 877篇 |
2022年 | 1276篇 |
2021年 | 2093篇 |
2020年 | 1612篇 |
2019年 | 1334篇 |
2018年 | 1530篇 |
2017年 | 1768篇 |
2016年 | 1579篇 |
2015年 | 2055篇 |
2014年 | 2652篇 |
2013年 | 3183篇 |
2012年 | 3343篇 |
2011年 | 3594篇 |
2010年 | 3023篇 |
2009年 | 2891篇 |
2008年 | 2883篇 |
2007年 | 2736篇 |
2006年 | 2620篇 |
2005年 | 2239篇 |
2004年 | 1578篇 |
2003年 | 1357篇 |
2002年 | 1355篇 |
2001年 | 1160篇 |
2000年 | 1139篇 |
1999年 | 1144篇 |
1998年 | 957篇 |
1997年 | 810篇 |
1996年 | 754篇 |
1995年 | 582篇 |
1994年 | 493篇 |
1993年 | 330篇 |
1992年 | 264篇 |
1991年 | 195篇 |
1990年 | 171篇 |
1989年 | 134篇 |
1988年 | 111篇 |
1987年 | 57篇 |
1986年 | 56篇 |
1985年 | 34篇 |
1984年 | 28篇 |
1983年 | 23篇 |
1982年 | 24篇 |
1981年 | 14篇 |
1980年 | 9篇 |
1979年 | 6篇 |
1977年 | 3篇 |
1976年 | 6篇 |
1970年 | 2篇 |
1959年 | 2篇 |
排序方式: 共有10000条查询结果,搜索用时 19 毫秒
61.
62.
Hui-Yung Song Yi-Ping Yang Yueh Chien Wei-Yi Lai Yi-Ying Lin Shih-Jie Chou Mong-Lien Wang Chien-Ying Wang Hsin-Bang Leu Wen-Chung Yu Chian-Shiu Chien 《International journal of molecular sciences》2021,22(5)
The late-onset type of Fabry disease (FD) with GLA IVS4 + 919G > A mutation has been shown to lead to cardiovascular dysfunctions. In order to eliminate variations in other aspects of the genetic background, we established the isogenic control of induced pluripotent stem cells (iPSCs) for the identification of the pathogenetic factors for FD phenotypes through CRISPR/Cas9 genomic editing. We adopted droplet digital PCR (ddPCR) to efficiently capture mutational events, thus enabling isolation of the corrected FD from FD-iPSCs. Both of these exhibited the characteristics of pluripotency and phenotypic plasticity, and they can be differentiated into endothelial cells (ECs). We demonstrated the phenotypic abnormalities in FD iPSC-derived ECs (FD-ECs), including intracellular Gb3 accumulation, autophagic flux impairment, and reactive oxygen species (ROS) production, and these abnormalities were rescued in isogenic control iPSC-derived ECs (corrected FD-ECs). Microarray profiling revealed that corrected FD-derived endothelial cells reversed the enrichment of genes in the pro-inflammatory pathway and validated the downregulation of NF-κB and the MAPK signaling pathway. Our findings highlighted the critical role of ECs in FD-associated vascular dysfunctions by establishing a reliable isogenic control and providing information on potential cellular targets to reduce the morbidity and mortality of FD patients with vascular complications. 相似文献
63.
Xianwei Su Xiaojia Shang Yusi Che Shaolong Li Jianxun Song Jilin He 《Ceramics International》2021,47(15):21459-21465
Homogenous ZrCxOy powders have been successfully synthesized by in-situ electro-reduction of solid ZrO2–C composite precursors in molten CaCl2. The effect of applied cell voltage and molar ratio of ZrO2 to C on preparation of ZrCxOy were investigated. The reduction pathway of the composite electrode was studied based on the analysis of intermediate products using X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results show that ZrO2 is firstly converted to CaZrO3. The resulting CaZrO3 is then reduced to ZrCxOy. The ZrCxOy formation is dramatically influenced by electrolysis voltage and molar ratio of ZrO2 to C: a higher cell voltage and lower molar ratio of the ZrO2 to C are more preferable for the formation of ZrCxOy powder. Homogenous ZrCxOy powders with particle size of ~100 nm are synthesized by ZrO2/C starting elemental powders in CaCl2 molten salt at 1123 K for more than 3 h, when the cell voltage is 3.0 V and the molar ratio of the ZrO2 to carbon starting materials is 1:1.0. 相似文献
64.
65.
Formation of SiC whiskers/leucite-based ceramic composites from low temperature hardening geopolymer
Siqi Ma Peigang He Shengjian Zhao Hualong Yang Qikun Wang Wenjiu Duan Song Chen Xiaoming Duan Dechang Jia Yu Zhou 《Ceramics International》2021,47(13):17930-17938
In this study, SiC whiskers (SCWS) reinforced geopolymer composites (SCWS/KGP) and their ceramic products (SCWS/leucite) were prepared, and effects of SiC whiskers contents on the microstructure and flexural strength of the SCWS/KGP and SCWS/leucite composites were investigated. The results show that the whisker addition has little influence on both phase composition and thermal shrinkage of the KGP composites, but a suitable content of whisker will result in the improved flexural strength, and when the SCWS content is 2 wt%, flexural strength of the SCWS/KGP composite is enhanced by 95% compared with the neat geopolymer. The flexural strength of the composites can be further enhanced significantly after the composites being treated at 1100 °C and 1200 °C and flexural strength of the composite with SCWS content of 2 wt% was 107% and 125% higher than the untreated counterpart, respectively. The increase in flexural strength of the composites should be attributed to the strong leucite formation, whisker debonding and pulling out from matrix during the fracturing process based on the good interfacial bonding state between whisker and leucite matrix. 相似文献
66.
Sudong Chae Seungbae Oh Kyung Hwan Choi Jin Woong Lee Jiho Jeon Zhixiang Liu Cong Wang Chaeheon Woo Liyi Shi Joohoon Kang Si Young Song Sung Jae Kim Jung Heon Lee Hak Ki Yu Jae-Young Choi 《Ceramics International》2021,47(9):11935-11941
To achieve the stable dispersion of 1D van der Waals crystal Mo6S3I6 in aqueous media, the tri-block copolymer (Poloxamer) is used as dispersant. The head group of Poloxamer, hydrophobic polypropylene oxide parts can be adsorbed to Mo6S3I6 surface by hydrophobic interaction and the tail group with hydrophilic polyethylene oxide exposed to the outside of the Mo6S3I6 is soluble in water and can form sufficient steric hindrance, resulting in stable aqueous dispersion in nm scale. The excellent biocompatibility of aqueous dispersed nm scale 1D Mo6S3I6 was demonstrated by effective proliferation of C2C12 cells. 相似文献
67.
Wei Shao Qianqian Pan Qiaoli Chen Chongzhi Zhu Weijian Tao Haiming Zhu Huijun Song Xuelu Liu Ping-Heng Tan Guan Sheng Tulai Sun Xiaonian Li Yihan Zhu 《Advanced functional materials》2021,31(3):2006738
Metallic nanocrystals manifest themselves as fascinating light absorbers for applications in plasmon-enhanced photocatalysis and solar energy harvesting. The essential challenges lie in harvesting the full-spectrum solar light and harnessing the plasmon-induced hot carriers at the metal–acceptor interface. To this end, a cooperative overpotential and underpotential deposition strategy is proposed to mitigate both the challenges. Specifically, by utilizing both ionic additive and thiol passivator to introduce symmetry-breaking growth over gold icosahedral nanocrystals, the microscopic origin can be attributed to the site-specific nucleation of stacking faults and dislocations. By adopting asymmetric crystal shape and unique surface facets, such nanocrystals attain high activity toward photocatalytic ammonia borane hydrolysis, arising from combined broadband plasmonic properties and enhanced direct transfer of hot electrons across the metal–adsorbate interface. 相似文献
68.
Limin Jin Xiaoli Yang Siufung Yu Puran Zheng Xian Chen Shumin Xiao Qinghai Song 《Journal of the American Ceramic Society》2022,105(9):5764-5773
Ultraviolet (UV) lasers with dynamic wavelength-tunability and high monochromaticity are crucial in a multitude of practical applications yet still remarkable challenges. Here, we show wide wavelength-tuning of single-mode UV lasing based on lanthanide-doped upconversion nanoparticles (UCNPs). The rationally designed Yb3+/Er3+/Tm3+/Gd3+/Ce3+ co-doped multilayer UCNPs, which exhibits a broad gain spectrum with the full width of half maximum of around 57 nm in the UV regime, are developed. More importantly, by taking advantages of a diffraction grating as the tuning component, stable single-mode emission can be achieved in the UCNPs-based external-cavity-extended Fabry–Pérot laser at room temperature. Specifically, the lasing threshold is around 137 µJ cm–2, which is two orders of magnitude lower than that in the previously reported articles. Precise wavelength-tuning from 310 to 363 nm can be realized by adjusting the Littrow angle. This achievement highlights a portable alternative to continuously wideband-tunable UV lasers and opens up new opportunities for constructing compact solid-state UV photon sources. 相似文献
69.
"建筑随想曲"源于莱昂纳多·科克兰特(Leonardo Coccorante,1680-1750).封面油画以克劳德·洛林(Claude Lorraine)的方式进行了大量涂抹,以传达地中海强烈阳光下石头表面的炽热辐射温度所维持的独特的暖夜氛围. 相似文献
70.