全文获取类型
收费全文 | 261篇 |
免费 | 52篇 |
国内免费 | 11篇 |
专业分类
电工技术 | 5篇 |
综合类 | 10篇 |
化学工业 | 103篇 |
金属工艺 | 9篇 |
机械仪表 | 12篇 |
建筑科学 | 50篇 |
矿业工程 | 2篇 |
能源动力 | 21篇 |
轻工业 | 21篇 |
水利工程 | 3篇 |
石油天然气 | 24篇 |
武器工业 | 1篇 |
无线电 | 10篇 |
一般工业技术 | 22篇 |
冶金工业 | 8篇 |
自动化技术 | 23篇 |
出版年
2024年 | 1篇 |
2023年 | 2篇 |
2022年 | 22篇 |
2021年 | 21篇 |
2020年 | 7篇 |
2019年 | 10篇 |
2018年 | 17篇 |
2017年 | 14篇 |
2016年 | 12篇 |
2015年 | 19篇 |
2014年 | 14篇 |
2013年 | 16篇 |
2012年 | 23篇 |
2011年 | 22篇 |
2010年 | 19篇 |
2009年 | 13篇 |
2008年 | 13篇 |
2007年 | 13篇 |
2006年 | 10篇 |
2005年 | 7篇 |
2004年 | 8篇 |
2003年 | 11篇 |
2002年 | 7篇 |
2001年 | 8篇 |
2000年 | 1篇 |
1999年 | 2篇 |
1997年 | 2篇 |
1996年 | 2篇 |
1995年 | 3篇 |
1994年 | 2篇 |
1990年 | 1篇 |
1951年 | 2篇 |
排序方式: 共有324条查询结果,搜索用时 15 毫秒
1.
Zhihong Xu Tao Jiang Hao Zhang Yujun Zhao Xinbin Ma Shengping Wang 《Frontiers of Chemical Science and Engineering》2021,15(3):698
Novel MgO-doped CaO sorbent pellets were prepared by gel-casting and wet impregnation. The effect of Na+ and MgO on the structure and CO2 adsorption performance of CaO sorbent pellets was elucidated. MgO-doped CaO sorbent pellets with the diameter range of 0.5-1.5 mm exhibited an excellent capacity for CO2 adsorption and adsorption rate due to the homogeneous dispersion of MgO in the sorbent pellets and its effects on the physical structure of sorbents. The results show that MgO can effectively inhibit the sintering of CaO and retain the adsorption capacity of sorbents during multiple adsorption-desorption cycles. The presence of mesopores and macropores resulted in appreciable change of volume from CaO (16.7 cm3∙mol−1) to CaCO3 (36.9 cm3∙mol−1) over repeated operation cycles. Ca2Mg1 sorbent pellets exhibited favorable CO2 capture capacity (9.49 mmol∙g−1), average adsorption rate (0.32 mmol∙g−1∙min−1) and conversion rate of CaO (74.83%) after 30 cycles. 相似文献
2.
吴建锋 《武汉理工大学学报(材料科学英文版)》2015,30(6):1247-1254
3.
基于蚁群聚类算法的离群挖掘方法 总被引:9,自引:4,他引:9
离群挖掘是数据挖掘研究的重要内容,在实际生活中获得广泛应用。该文首先给出了离群数据的量化定义,并用基于蚁群的聚类学习方法,产生了状态空间的整体特征。然后结合具体的设备对象,提出了离群数据的挖掘方法。最后进行了实验验证,结果表明该文提出的方法是有效的。 相似文献
4.
Zhu Yuxuan Dai Fuchu Yao Xin Tu Xinbin Shi Xinshuai 《Bulletin of Engineering Geology and the Environment》2019,78(8):5795-5809
Bulletin of Engineering Geology and the Environment - Landslides are one of the most common geological hazards in many parts of the world, which have brought catastrophic consequences to mankind.... 相似文献
5.
6.
本文将限制因素转变为建筑创作的创新点,将生态节能理念植根于设计思维中,成为自然流淌于建筑师笔尖的艺术灵感与文脉传承,进而创造出张弛有序的总体布局、繁简适度的特色空间。本文从体型节能、布局节能、空间节能、结构节能、装饰节能等不同方面,介绍了蒙中医院综合楼的几项建筑节能策略:双L布局、袋状流线、特色中庭、米字形绗架、遮阳百叶。从艺术与节能、文化与节能的视角审视建筑节能,探究建筑节能的设计策略。 相似文献
8.
Haiyang?Wang Zhenhua?LiEmail author Baowei?Wang Xinbin?MaEmail author Shaodong?Qin Shouli?Sun Qi?Sun 《Korean Journal of Chemical Engineering》2014,31(12):2157-2161
The catalytic activity of Mo-based catalysts prepared from (NH4)6Mo7O24 and (NH4)2MoS4 was compared in the sulfur resistant methanation process. The catalyst using oxide precursor had relatively higher activity than the catalyst using sulfide precursor, and the presulfidation procedure almost had no effect on the catalytic performance of the catalyst using oxide precursor. In view of the characterization results, it could be supposed that the amorphous MoS2 was more active for sulfur-resistant methanation than the crystalline MoS2. The molybdenum sulfides and oxides with lower valence states (Mo4+, Mo5+) could be responsible for the catalytic activity and make a possible contribution to the carbon monoxide methanation in the reaction condition. 相似文献
9.
Yifei Wang Shouying Huang Xinsheng Teng Hongyu Wang Jian Wang Qiao Zhao Yue Wang Xinbin Ma 《Frontiers of Chemical Science and Engineering》2020,14(5):802
The Fischer–Tropsch synthesis (FTS) continues to be an attractive alternative for producing a broad range of fuels and chemicals through the conversion of syngas (H2 and CO), which can be derived from various sources, such as coal, natural gas, and biomass. Among iron carbides, Fe2C, as an active phase, has barely been studied due to its thermodynamic instability. Here, we fabricated a series of Fe2C embedded in hollow carbon sphere (HCS) catalysts. By varying the crystallization time, the shell thickness of the HCS was manipulated, which significantly influenced the catalytic performance in the FTS. To investigate the relationship between the geometric structure of the HCS and the physic-chemical properties of Fe species, transmission electron microscopy, X-ray diffraction, N2 physical adsorption, X-ray photoelectron spectroscopy, hydrogen temperature-programmed reduction, Raman spectroscopy, and Mössbauer spectroscopy techniques were employed to characterize the catalysts before and after the reaction. Evidently, a suitable thickness of the carbon layer was beneficial for enhancing the catalytic activity in the FTS due to its high porosity, appropriate electronic environment, and relatively high Fe2C content. 相似文献
10.
The effect of boron on the performance of MoO_3/CeO_2–Al_2O_3 catalysts, which were prepared with impregnation method, was investigated. The catalysts were characterized with N_2 adsorption–desorption, XRD, H_2-TPR, and NH_3-TPD, and were tested in sulfur-resistant methanation. The results indicated that the MoO_3/CeO_2–Al_2O_3 catalysts modified by boron showed higher catalytic performance in sulfur-resistant methanation. The CO conversion increased from 47% to 62% with 0.5 wt% boron content. When the content of boron was under 0.5 wt%, the results suggested there was an increase in the amorphous form of MoO_3 caused by the generation of weak and intermediate acid sites, which had weakened the interaction between the active components and supports. While, the catalyst added 2.0 wt% boron showed the strong acid sites and the largest crystalline size resulting in the uneven distribution of ceria. 相似文献