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   21篇
  免费   3篇
电工技术   1篇
化学工业   2篇
轻工业   1篇
无线电   4篇
一般工业技术   9篇
冶金工业   4篇
自动化技术   3篇
  2021年   1篇
  2017年   2篇
  2015年   3篇
  2014年   2篇
  2011年   2篇
  2010年   1篇
  2009年   1篇
  2007年   2篇
  2006年   1篇
  2005年   2篇
  2004年   2篇
  2003年   1篇
  2000年   1篇
  1997年   1篇
  1995年   1篇
  1985年   1篇
排序方式: 共有24条查询结果,搜索用时 31 毫秒
1.
Hydrogen desorption curves were obtained from a sample composed of a square arrangement of Co dots with average diameter of 4.4 μm, separated by a distance of 11.6 μm. A macroscopic sample of Co dots grown on a 2.5 × 2.5 cm Si substrate was made by standard lithographic techniques and used in these experiments. Thermal programmed desorption (TPD) was performed under ultra-high vacuum conditions. Hydrogen TPD curves were obtained from a 1 × 1 cm Co dots samples displaying a maximum of intensity at 425 K. Hydrogen TPD curve was also obtained from 1 cm× 1 cm samples of Co films and Co foils for comparison. The hydrogen TPD curves have decreasing intensity from the Co foils to the Co dots and finally to the Co films. This indicates that there are more sites for hydrogen adsorption on the Co dots than in the Co films. This is a surprising result because there is approximately 8.7 times less Co atoms exposed in the Co dots that in the Co film sample. A desorption energy of 27 kcal/mol was obtained for the Co dots suggesting that hydrogen is adsorbed on an hcp hollow site of the Co dot crystalline structure.  相似文献   
2.
Exposure to mechanical vibrations at work (e.g., due to handling powered tools) is a potential occupational risk as it may cause upper extremity complaints. However, reliable and valid assessment methods for vibration exposure at work are lacking. Measuring hand-arm vibration objectively is often difficult and expensive, while often used information provided by manufacturers lacks detail. Therefore, a subjective hand-arm vibration assessment method was tested on validity and inter-observer reliability.  相似文献   
3.
In general, both consciously and unconsciously perceived stimuli facilitate responses to following similar stimuli. However, masked arrows delay responses to following arrows. This inverse priming has been ascribed to inhibition of premature motor activation, more recently even to special processing of nonconsciously perceived material. Here, inverse priming depended on particular masks, was insensitive to contextual requirements for increased inhibition, and was constant across response speeds. Putative signs of motor inhibition in the electroencephalogram may as well reflect activation of the opposite response. Consequently, rather than profiting from inhibition of primed responses, the alternative response is directly primed by perceptual interactions of primes and masks. Thus there is no need to assume separate pathways for nonconscious and conscious processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
4.
5.
Long-term memory impairment is often found in schizophrenia. The question remains whether this is caused by other cognitive deficits. One hundred eighteen first-episode patients were compared with 45 control participants on several memory tasks. The role of processing speed and central executive functions on memory performance was examined with regression analysis for all participants and for patients separately. Deficits were found in general verbal learning performance and retrieval in episodic memory and semantic memory. Processing speed reduced disease-related variance in all memory variables. Coordination, organization of information, and speed of processing were the best predictors for long-term memory deficits in patients. The amount of explained variance, however, is small, especially in general verbal learning performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
6.
This study investigated 4-, 6-, and 9-month-old infants' ability to perceive whether the width relation between a block and the opening of a box specified passing through or support. If infants could perceive which outcome was specified by the width relation, longer looking times would be expected for an outcome that violates this specification. Six- and 9-month-olds looked significantly longer when a block wider than a box opening passed through this opening and when a block with a width smaller than the opening seemed to become supported at the level of this opening. Results indicate that around 6 months of age, infants become able to perceive relations between objects that specify the outcomes of events. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
7.
This article reports on the design and development of the Digital Farmer Field School (DFFS). The DFFS offers a tablet-based digital learning environment for farmers and extension agents for knowledge sharing and knowledge co-creation. It provides an alternative to conventional agricultural extension training and monitoring. The prototype DFFS applies Farmer Field School (FFS) learning principles and is designed and developed following user experience (UX) design principles and user interface (UI) design principles from a responsible innovation perspective, using existing FFS material and tailored films which support and enrich the content. The prototype DFFS has been tested in Sierra Leone to assess its success in providing a substitute for face-to-face voluntary sustainability standard certification training for cocoa farmers. Results show that the DFFS as an off-line, telephonically connected and regular on-line updated learning platform offers an appropriate environment in which collective and individual learning is stimulated and facilitated. The DFFS prototype was socio-culturally and technologically appropriate and fitted the operational and strategic communication skills of cocoa farmers and other value chain stakeholders. Films capturing the testing are available as additional learning media.  相似文献   
8.
Designing new functional materials is crucial for the development of efficient energy storage and conversion devices such as all solid‐state batteries. LiBH4 is a promising solid electrolyte for Li‐ion batteries. It displays high lithium mobility, although only above 110 °C at which a transition to a high temperature hexagonal structure occurs. Herein, it is shown that confining LiBH4 in the pores of ordered mesoporous silica scaffolds leads to high Li+ conductivity (0.1 mS cm?1) at room temperature. This is a surprisingly high value, especially given that the nanocomposites comprise 42 vol% of SiO2. Solid state 7Li NMR confirmed that the high conductivity can be attributed to a very high Li+ mobility in the solid phase at room temperature. Confinement of LiBH4 in the pores leads also to a lower solid‐solid phase transition temperature than for bulk LiBH4. However, the high ionic mobility is associated with a fraction of the confined borohydride that shows no phase transition, and most likely located close to the interface with the SiO2 pore walls. These results point to a new strategy to design low‐temperature ion conducting solids for application in all solid‐state lithium ion batteries, which could enable safe use of Li‐metal anodes.  相似文献   
9.
Type 2 diabetes mellitus (T2D) is one of the prominent risk factors for the development and progression of calcific aortic valve disease. Nevertheless, little is known about molecular mechanisms of how T2D affects aortic valve (AV) remodeling. In this study, the influence of hyperinsulinemia and hyperglycemia on degenerative processes in valvular tissue is analyzed in intact AV exposed to an either static or dynamic 3D environment, respectively. The complex native dynamic environment of AV is simulated using a software-governed bioreactor system with controlled pulsatile flow. Dynamic cultivation resulted in significantly stronger fibrosis in AV tissue compared to static cultivation, while hyperinsulinemia and hyperglycemia had no impact on fibrosis. The expression of key differentiation markers and proteoglycans were altered by diabetic conditions in an environment-dependent manner. Furthermore, hyperinsulinemia and hyperglycemia affect insulin-signaling pathways. Western blot analysis showed increased phosphorylation level of protein kinase B (AKT) after acute insulin stimulation, which was lost in AV under hyperinsulinemia, indicating acquired insulin resistance of the AV tissue in response to elevated insulin levels. These data underline a complex interplay of diabetic conditions on one hand and biomechanical 3D environment on the other hand that possesses an impact on AV tissue remodeling.  相似文献   
10.
Extraction of peak areas and mass spectral information from chromatography mass spectral data such as obtained in metabolomics measurements requires much effort and the quality is often subjective to the operator that handles the data at hand. In multiple file deconvolution, all samples are processed simultaneously and alignment issues are part of the modeling strategy. However, processing the total data set as a whole is an impossible task and therefore the data processing task requires segmentation. Two intertwined divide and conquer strategies are proposed. The first strategy divides the retention time axis into equal parts and the second strategy divides the total data set into a model and a prediction data set. Dividing the data into smaller segments allows us to conquer the total problem. Post processing of the resulting matrices with peak areas and mass spectra ensures that a matrix with peak areas ready for statistics and a matrix with mass spectral information ready for peak annotation is obtained. The proposed methodology is implemented within a package called TNO-DECO but can easily be implemented in other data pre-processing approaches.  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