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1.
Organic devices like organic light emitting diodes (OLEDs) or organic solar cells degrade fast when exposed to ambient air. Hence, thin-films acting as permeation barriers are needed for their protection. Atomic layer deposition (ALD) is known to be one of the best technologies to reach barriers with a low defect density at gentle process conditions. As well, ALD is reported to be one of the thinnest barrier layers, with a critical thickness – defining a continuous barrier film – as low as 5–10 nm for ALD processed Al2O3. In this work, we investigate the barrier performance of Al2O3 films processed by ALD at 80 °C with trimethylaluminum and ozone as precursors. The coverage of defects in such films is investigated on a 5 nm thick Al2O3 film, i.e. below the critical thickness, on calcium using atomic force microscopy (AFM). We find for this sub-critical thickness regime that all spots giving raise to water ingress on the 20 × 20 μm2 scan range are positioned on nearly flat surface sites without the presence of particles or large substrate features. Hence below the critical thickness, ALD leaves open or at least weakly covered spots even on feature-free surface sites. The thickness dependent performance of these barrier films is investigated for thicknesses ranging from 15 to 100 nm, i.e. above the assumed critical film thickness of this system. To measure the barrier performance, electrical calcium corrosion tests are used in order to measure the water vapor transmission rate (WVTR), electrodeposition is used in order to decorate and count defects, and dark spot growth on OLEDs is used in order to confirm the results for real devices. For 15–25 nm barrier thickness, we observe an exponential decrease in defect density with barrier thickness which explains the likewise observed exponential decrease in WVTR and OLED degradation rate. Above 25 nm, a further increase in barrier thickness leads to a further exponential decrease in defect density, but an only sub-exponential decrease in WVTR and OLED degradation rate. In conclusion, the performance of the thin Al2O3 permeation barrier is dominated by its defect density. This defect density is reduced exponentially with increasing barrier thickness for alumina thicknesses of up to at least 25 nm.  相似文献   
2.
随着社交媒体的发展,用户之间的关系网络对于社交媒体的分析有很大的帮助。因此,该文主要研究用户好友关系检测。以往的关于用户好友关系抽取的研究主要基于社交媒体上的结构化信息,比如其他好友关系,用户的不同属性等。但是,很多时候用户本身并没有大量的好友信息存在,同时也不一定有很多确定的属性。因此,我们希望基于用户发表的文本信息来对用户关系进行预测。不同于以往的潜在好友推荐算法,该文提出了一种基于注意力机制以及长短时记忆网络(long short-term memory,LSTM)的好友关系预测模型,将好友之间的评论分开处理,通过分析用户之间的评论来判断是否具备一定的好友关系。该模型将好友双方信息拼接后的结果作为输入,并将注意力机制应用于LSTM的输出。实验表明,用户之间的评论对于好友关系预测确实有较大的实际意义,该文提出的模型较之于多个基准系统的效果,取得了明显的提升。在不加入任何其它非文本特征的情况下,实验结果的准确率达到了77%。  相似文献   
3.
地震平衡技术是一种在地震反演中改善井震关系的新技术。它通过单井对比、空间分形建模以及平衡处理的手段 ,克服地震反演中子波空变的影响 ,使得经过地震平衡技术处理的地震剖面井震关系得到较好改善 ,从而可以用统一的子波对研究区的地震资料进行反演  相似文献   
4.
5.
Similarity retrieval of iconic image database   总被引:3,自引:0,他引:3  
The perception of spatial relationships among objects in a picture is one of the important selection criteria to discriminate and retrieve the images in an iconic image database system. The data structure called 2D string, proposed by Chang et al., is adopted to represent symbolic pictures. The 2D string preserves the objects' spatial knowledge embedded in images. Since spatial relationship is a fuzzy concept, the capability of similarity retrieval for the retrieval by subpicture is essential. In this paper, similarity measure based on 2D string longest common subsequence is defined. The algorithm for similarity retrieval is also proposed. Similarity retrieval provides the iconic image database with the distinguishing function different from a conventional database.  相似文献   
6.
O—O数据模型中实体联系的表达方法   总被引:2,自引:0,他引:2  
具有对实体和实体间联系的描述能力,是数据库的基本,吼是对数据库进逻辑设计的基本出发点。O-O数据模型不具备显式描术这实体联系的手段。且优于关系模型。  相似文献   
7.
本文基于静态相关性分析和动态调整相结合的方法,提出了一种逻辑程序的执行模型,它不仅开发了“与“并行,同进也开发了一定的“或“并行,从而有效地加速了逻辑程序的执行。  相似文献   
8.
M.A.H.  Ankush  R.C. 《Pattern recognition》2006,39(12):2312-2322
The tree representation of evolutionary relationship oversimplifies the view of the process of evolution as it cannot take into account the events such as horizontal gene transfer, hybridization, homoplasy and genetic recombination. Several algorithms exist for constructing phylogenetic networks which result from events such as horizontal gene transfer, hybridization and homoplasy. Very little work has been published on the algorithmic detail of phylogenetic networks with constrained recombination. The problem of minimizing the number of recombinations in a phylogenetic network, constructed using binary DNA sequences, is NP-hard. In this paper, we propose a pattern recognition-based O(n2) time approach for constructing the phylogenetic network, where n is the number of nodes or sequences in the input data. The network is constructed with the restriction that no two cycles in the network share a common node.  相似文献   
9.
For 30 years, A. G. Greenwald and H. G. Shulman's (1973) psychological refractory period (PRP) study has been cited as evidence for perfect timesharing with ideomotor (IM)-compatible tasks. Recently, M.-C. Lien, R. W. Proctor, and P. A. Allen (2002) failed to replicate these results and concluded that IM compatibility is neither necessary nor sufficient to eliminate the PRP effect. A. G. Greenwald (2003) attributed Lien et al.'s nonreplication to the use of (a) a non-IM-compatible task, (b) varied trial spacing, and/or (c) inappropriate instructions. The authors of the present article argue that the first 2 factors are not critical and that instructions merely affect the criterion for speed versus accuracy. In each of Greenwald's experiments, dual-task costs were evident on response time or error rates. Furthermore, the small dual-task costs in his study are consistent with a bottleneck model. Thus, Greenwald (2003) does not provide evidence that IM-compatible tasks enable perfect timesharing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
10.
This study provides a meta-analysis of research on the associations between relationship conflict, task conflict, team performance, and team member satisfaction. Consistent with past theorizing, results revealed strong and negative correlations between relationship conflict, team performance, and team member satisfaction. In contrast to what has been suggested in both academic research and introductory textbooks, however, results also revealed strong and negative (instead of the predicted positive) correlations between task conflict, team performance, and team member satisfaction. As predicted, conflict had stronger negative relations with team performance in highly complex (decision making, project, mixed) than in less complex (production) tasks. Finally, task conflict was less negatively related to team performance when task conflict and relationship conflict were weakly, rather than strongly, correlated. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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