全文获取类型
收费全文 | 132篇 |
免费 | 6篇 |
专业分类
化学工业 | 20篇 |
金属工艺 | 9篇 |
机械仪表 | 18篇 |
建筑科学 | 7篇 |
能源动力 | 2篇 |
轻工业 | 1篇 |
无线电 | 27篇 |
一般工业技术 | 43篇 |
自动化技术 | 11篇 |
出版年
2023年 | 1篇 |
2022年 | 4篇 |
2021年 | 10篇 |
2020年 | 7篇 |
2019年 | 6篇 |
2018年 | 5篇 |
2017年 | 2篇 |
2016年 | 9篇 |
2015年 | 1篇 |
2014年 | 9篇 |
2013年 | 10篇 |
2012年 | 11篇 |
2011年 | 9篇 |
2010年 | 11篇 |
2009年 | 6篇 |
2008年 | 13篇 |
2007年 | 7篇 |
2006年 | 5篇 |
2005年 | 3篇 |
2004年 | 1篇 |
2003年 | 5篇 |
2002年 | 1篇 |
2001年 | 1篇 |
1996年 | 1篇 |
排序方式: 共有138条查询结果,搜索用时 15 毫秒
1.
A statically recrystallized Mg-3Al-1Zn alloy was fabricated by low temperature roll heating (140 °C) processes and subsequent
annealing at 250 °C for 5 min. The fabricated sheet, with a grain size of 4.1 m, shows an improved planar anisotropy and higher
elongations to failure at room temperature and 200 °C, compared with those of the sheet fabricated by conventional hot rolling
processes, due to the weak basal texture along with the refined microstructure. 相似文献
2.
Quantitative analysis of microbial community structure in two-phase anaerobic digesters treating food wastewater 总被引:1,自引:0,他引:1
Woong Kim Byung-Gon Ryu Sungwhan Kim Sung-Woon Heo Donghyun Kim Jungmin Kim Haechan Jo Jong-Hee Kwon Ji-Won Yang 《Korean Journal of Chemical Engineering》2014,31(3):381-385
An acidogenic reactor with a 0.5-L working volume and a methanogenic digester with a 5-L of working volume were operated for 150 days on a continuous mode to investigate the structure of a microbial community during food wastewater treatment. During the steady state of anaerobic digestion, volatile solids (VS) removal efficiency in the pilot plant was approximately 65%. The bacterial population was higher than any other methanogens detected during the entire anaerobic process and treatment of raw food wastewater. Methanomicrobiales (MMB), Methanosarcinales (MSL), and Methanobacteriales (MBT) were detected during digestion. The methanogenic population present in the acidogenic reactor was directly affected by the archaeal community in raw food wastewater. However, the shift of microbial community in the methanogenic digester was relatively gradual. The performance of methanogenic digester might be more related to the change of microbial metabolism affected by the physicochemical properties of the input substrate. 相似文献
3.
Donghyun Kang Joobeom Seo So Young Lee Jai Young Lee Kyu Seong Choi Shim Sung Lee 《Inorganic chemistry communications》2007,10(12):1425-1428
A new dicadmium(II) complex [Cd2(L)2(H2O)2](NO3)4 · 8H2O (1) with the tripodal amide ligand L (tris[3-aza-2-oxo-4-(2-pyridyl)butyl]amine) was synthesized and structurally characterized. Complex 1 is revealed as a dinuclear 2:2 (Cd:L) complex, in which each cadmium(II) ion is hepta-coordinated with the coordination surrounding of distorted monocapped octahedral geometry. Two cadmium(II) ions are dibridged by two carbonyl μ-O atoms forming a Cd2(μ-O)2 parallelogram-type moiety. Interestingly, the dinuclear coordination sphere can be seen as resulting from the fusion of two distorted monocapped octahedral [Cd(L)(H2O)]2+ units through sharing one edge originated from the two carbonyl μ-O atoms as a first example. Comparative NMR, IR and FAB-mass data of 1 are also discussed. 相似文献
4.
A uniform pollutant concentration in indoor environments can be an inappropriate representation of breathing concentration. This is especially true when local airflow in the vicinity of an occupant is dominant in transporting pollutants. The present study investigates the airflow in the vicinity of a human body, effects of respiration on breathing concentration of particulate and gaseous pollutants, and inhalation exposure in relation to source position and overall airflow patterns. It is based on experiments with a human simulator in a full-scale environmental chamber. Airflow and pollutant concentrations in the vicinity of a thermal manikin are monitored, while varying parameters including breathing, arm/hand movements, and ventilation system. Results show that breathing of a sedentary manikin has a measurable influence on the airflow in breathing zone, whereas it has very small impacts on occupant thermal plume. Also, localized hand motions have insignificant effects on the thermal plume. The results indicate that overall airflow pattern affect the inhaled particle concentrations. With highly mixed airflow in the space, relatively uniform concentration patterns occur in the occupant vicinity. However, with stratified airflow patterns, non-uniform concentration patterns are observed due to the occupant thermal plume. With a particle source at floor level and in near proximity to an occupant, inhaled particle concentrations are up to four times higher than the ambient concentrations. This finding implies that occupant thermal plume may play a significant role in transporting pollutants from floor level to the breathing zone. The non-uniform concentration observed with stratified flow also suggests caution in estimating inhalation exposure using a “well-mixed” mass balance model. 相似文献
5.
Stretchable Electrodes: Negatively Strain‐Dependent Electrical Resistance of Magnetically Arranged Nickel Composites: Application to Highly Stretchable Electrodes and Stretchable Lighting Devices (Adv. Mater. 19/2014) 下载免费PDF全文
6.
A discrete-component approach was taken to establish the operational feasibility of a novel, imaging, midinfrared, multispectral, polarimetric sensor for remote-sensing application. The sensor is designed to exploit the spectral and polarimetric characteristics of the scene as discriminants. Pixelated multispectral filters and polarization filters were designed and fabricated on sapphire and Si substrates, respectively, and both were characterized. A single-pixel spectropolarimetric composite filter was characterized by use of a Fourier transform infrared spectrometer and a Pt-Si thermal-imaging camera. The experimental results show excellent agreement with theoretical predictions. 相似文献
7.
Jaehyuck Shin Sock-yeon Yoon Hyunjoo Choi Seeun Shin Donghyun Bae 《Metals and Materials International》2013,19(4):851-854
The formation of an interstitially alloyed phase and its effects on mechanical properties are investigated for a magnesium-based composite containing fullerene (Mg/C60). The Mg/C60 composite was fabricated using the ball milling method followed by hot rolling and then the composite sheet was annealed at 425°C for up to 37 h. The fullerene was dispersed during the ball milling process and it was decomposed. The carbon atoms from the decomposed fullerene diffused into the magnesium matrix, which increasingly occupied the octahedral sites of the magnesium as the annealing continued. The formed interstitially alloyed phase expanded as the annealing time increased, and magnesium carbide was formed after 37 h. Vickers hardness value increased as the interstitially alloyed phase continuously formed and it decreased when the magnesium carbide was formed, because the carbon atoms at the magnesium interstices may interact with moving dislocations, resulting in an increase in the hardness of the magnesium. 相似文献
8.
Negatively Strain‐Dependent Electrical Resistance of Magnetically Arranged Nickel Composites: Application to Highly Stretchable Electrodes and Stretchable Lighting Devices 下载免费PDF全文
9.
Donghyun Kim Jaewook Jeong Hwarim Im Sungmo Ahn Heonsu Jeon Changhee Lee Yongtaek Hong 《Organic Electronics》2011,12(11):1841-1845
Vertical organic field-effect transistors (VOFETs) with nanoscale channel openings have been fabricated using pentacene as an active layer material. To achieve uniform nanoscale two-dimensional channel openings, a laser holography lithography has been introduced. Uniformly distributed and well-aligned holes with 250 nm diameter were successfully obtained with the laser holography lithography. VOFET devices with these channel openings have shown high on/off ratio of about 103 without any further treatment. Gate leakage current was also decreased with an additional insulating layer generated on the gate electrode sidewall via plasma oxidation. 相似文献
10.
An estimation of external force applied during hand-intensive work at actual work site has practical restrictions since direct measurement requires much equipment and time. This paper proposes a method that can estimate external forces applied at actual working environment on the basis of results of lab experiment. The psychophysical rating, specifically CR-10 scale developed by G. Borg, is adopted as the major tool to estimate external forces. This study also shows the general shape of the external force distribution for the most oommon and potentially risky hand postures of hand-intensive jobs. 相似文献