首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   446篇
  免费   36篇
  国内免费   1篇
电工技术   5篇
综合类   1篇
化学工业   81篇
金属工艺   3篇
机械仪表   33篇
建筑科学   11篇
矿业工程   1篇
能源动力   35篇
轻工业   101篇
水利工程   3篇
石油天然气   6篇
无线电   34篇
一般工业技术   64篇
冶金工业   55篇
原子能技术   7篇
自动化技术   43篇
  2023年   4篇
  2022年   9篇
  2021年   24篇
  2020年   15篇
  2019年   10篇
  2018年   21篇
  2017年   22篇
  2016年   27篇
  2015年   17篇
  2014年   24篇
  2013年   45篇
  2012年   28篇
  2011年   34篇
  2010年   24篇
  2009年   19篇
  2008年   17篇
  2007年   16篇
  2006年   14篇
  2005年   9篇
  2004年   8篇
  2003年   4篇
  2002年   5篇
  2001年   3篇
  2000年   2篇
  1999年   8篇
  1998年   19篇
  1997年   10篇
  1996年   11篇
  1995年   10篇
  1994年   3篇
  1993年   4篇
  1992年   1篇
  1991年   2篇
  1990年   1篇
  1989年   3篇
  1988年   2篇
  1985年   1篇
  1979年   2篇
  1977年   1篇
  1976年   1篇
  1971年   1篇
  1965年   1篇
  1963年   1篇
排序方式: 共有483条查询结果,搜索用时 15 毫秒
61.
Thompson Seedless (TS) and Black (BS) grapes sanitised with 2, 4, 6, 8 mg L?1 O3 or NaOCl (100 mg L?1) were stored 21 days at 5 °C. Ozonated water stimulated the respiration rate, especially after 5 days of storage, and increased superoxide dismutase and catalase activity compared to NaOCl‐sanitised grapes. Total polyphenol content (TPC) was 23–50% higher in TS and 18.5–28% higher in BS samples sanitised with ozonated water. Twofold higher total antioxidant capacity (TAC) was registered in TS at all of the evaluated O3 doses while the doses of 6 and 8 mg L?1 increased TAC by 19–30% in BS. The use of ozonated water as a sanitising method, especially at 6 and 8 mg L?1 doses, improved the functional quality and maintained low microbial counts on fresh‐cut grapes being a good alternative for the industry.  相似文献   
62.
A novel set-up for remote sensing the turbidity of a solution using plastic optical fibres together with a mirror is proposed. The authors have estimated turbidity of a liquid in terms of the nephelometric turbidity unit – NTU, a standard unit that relates the solution appearance with its turbidity for two proposed set-ups. Its performance was also investigated using clay sample measurements over a concentration range of 0–10 g/L. The proposed set-ups are useful for detection of suspended particles in a solution even in small quantities due to its high sensitivity, simplicity and robustness.  相似文献   
63.
64.
The present work investigates the effect of the initial microstructure on phase transformation after intercritical annealing by measuring the amount of austenite, which was obtained by X-ray diffraction and saturation magnetisation. Pieces of 8?Mn steel were austenitised at 1100°C for 1?h followed by different cooling rates: water, air, and furnace. Samples of each piece were subsequently intercritically annealed from 600 to 800°C followed by air cooling. The microstructure was characterised using scanning electron microscopy and electron backscatter diffraction. Results show how changing the cooling rate affects the temperature of intercritical annealing at which the highest content of retained austenite was obtained.  相似文献   
65.
As the microelectronics technology continuously advances to deep submicron scales, the occurrence of Multiple Cell Upset (MCU) induced by radiation in memory devices becomes more likely to happen. The implementation of a robust Error Correction Code (ECC) is a suitable solution. However, the more complex an ECC, the more delay, area usage and energy consumption. An ECC with an appropriate balance between error coverage and computational cost is essential for applications where fault tolerance is heavily needed, and the energy resources are scarce. This paper describes the conception, implementation, and evaluation of Column-Line-Code (CLC), a novel algorithm for the detection and correction of MCU in memory devices, which combines extended Hamming code and parity bits. Besides, this paper evaluates the variation of the 2D CLC schemes and proposes an additional operation to correct more MCU patterns called extended mode. We compared the implementation cost, reliability level, detection/correction rate and the mean time to failure among the CLC versions and other correction codes, proving the CLCs have high MCU correction efficacy with reduced area, power and delay costs.  相似文献   
66.
Industrial production of lactose hydrolyzed milk powder (LHMP) remains challenging. Due to the presence of the monosaccharides glucose and galactose, lactose-free powders tend to suffer stickiness, caking, and browning during drying and storage. We sought to find ideal conditions spray dryer inlet air temperature (θair,in) and concentrated milk flow rate (mCM) for LHMP production. We tested θair,in settings of 115–160°C and mCM of 0.3–1.5?kg?·?h?1, and also applied mass and energetic balances. LHMP generally exhibited higher mass and energetic losses than the control (milk powder containing lactose), as a consequence of the relatively low dryability of LHMP. For a lab scale spray dryer, the ideal conditions settings for LHMP production were θair,in?=?145?±?2°C and mCM?=?1.0?kg?·?h?1, taking into account the mass yield and energetic cost (kJ?·?kg?1 of powder) of the process. These ideal conditions are a potential tool for the industrial development of lactose-free dairy powders.  相似文献   
67.
68.
69.
This paper shows that an important part of the power consumption of a biquad band‐pass filter is associated with the feedback loop that fixes the high‐pass frequency and blocks the direct current (dc) input signals. The dc input amplitude that can be blocked is related to the maximum output current that one of the transconductors can provide, hence impacting on the required consumption through this effect. Then, a technique that efficiently blocks the dc input signal and fixes the high‐pass frequency is introduced and analyzed in depth. Moreover, an architecture for ultra‐low‐power differential‐input biquads is fully presented. The proposed architecture enables lowering the power consumption or blocking higher levels of dc input without jeopardizing the power consumption. Results show that the proposed architecture, compared with a traditional one, presents a 30% reduction in power consumption and more than doubles the dc input that can be blocked. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   
70.
Annular folded imagers can be up to 10x thinner than corresponding full-aperture imagers, but have tight fabrication tolerances and relatively shallow depth of focus. Wavefront coding, the use of specialized optics with postdetection signal processing, has been used to improve the depth of focus in full-aperture imaging systems. Here we explore the application of wavefront coding to annular folded optics. We compare the design and experimental results for an imaging system with a 38 mm focal length and just 5 mm total track.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号