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801.
空间低频滤波对人类整体和局部知觉的影响 总被引:2,自引:0,他引:2
利用功能磁共振(fMRI)测量血液动力学反应, 研究空间低频滤波对周边视觉加工刺激整体和局部性质的神经机制的影响. 实验中使用的复合字母具有宽带空间频率成分(宽带刺激)或通过反差平衡技术滤除其空间低频成分(CB刺激), 随机呈现在左或右视野. 被试分别辨别复合字母的整体和局部形状. 实验发现, 与注意局部性质相比, 注意宽带或CB刺激的整体性质在中央枕区皮层引起更强的激活. 注意整体性质还在右侧颞顶联合区(宽带刺激)和右侧梭状回(CB刺激)引起更强的激活. 注意CB刺激的局部性质激活中央额区、双侧额下回和双侧颞上回. 根据这些结果讨论了整体和局部性质加工的相互竞争对参与整体和局部加工的脑区的影响. 相似文献
802.
The ground surface quality of Cr 2O 3 coatings is investigated in this paper. The influence of some typical grinding parameters on ground surface integrity is discussed in detail. It is found that the ground surface roughness increases with the increase of depth-of-cut. The surface finish is improved as the increase of grinding speed, but too high grinding speed may result in serious vibration of the system. The increase of workpiece speed causes deterioration of surface finish and produces big grinding n... 相似文献
803.
Synthesis and characterization of copper foams through a powder metallurgy route using a compressible and lubricant space-holder material
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In the present work, a compressible and lubricating space-holder material commonly known as “acrawax” was used to process Cu foams with various pore sizes and various porosities. The foams were processed without using binders to avoid contamination of their metal matrices. The lubricant space-holder material was found to facilitate more uniform flow and distribution of metal powder around the surface of the space holder. In addition, the use of acrawax as a space-holder material yielded considerably dense cell walls, which are an essential prerequisite for better material properties. The foams processed with a smaller-sized space holder were found to exhibit better electrical and mechanical properties than those processed with a coarser-sized space holder. The isotropic pore shape, uniform pore distribution throughout the metal matrix, and uniform cell wall thickness were found to enhance the properties pertaining to fine-pore foam samples. The processed foams exhibit properties similar to those of the foams processed through the lost-carbonate sintering process. 相似文献
804.
This paper presents short‐ and long‐term composite leading indicators (CLIs) of underlying inflation for seven EU countries, namely Belgium, Germany, France, Italy, the Netherlands, Sweden and the UK. CLI and CPI reference series are calculated in terms of both growth rates and in deviations from its trend. The composite leading indicators are based on leading basic series, such as sources of inflation, series containing information on inflation expectations and prices of intermediate goods and services. Neftci's decision rule approach has been applied to transfer movements in the CLIs into a measure of the probability of a cyclical turning point, which enables the screening out of false turning point predictions. Finally, CLIs have been used to analyse the international coherence of price cycles. The forecast performance of CLIs of inflation over the past raises hope that this forecast instrument can be useful in predicting future price movements. Copyright © 1999 John Wiley & Sons, Ltd. 相似文献
805.
Sara Canato João D. Santos Ana S. Carvalho Kerman Aloria Margarida D. Amaral Rune Matthiesen André O. Falcao Carlos M. Farinha 《Cellular and molecular life sciences : CMLS》2018,75(24):4495-4509
Misfolded F508del-CFTR, the main molecular cause of the recessive disorder cystic fibrosis, is recognized by the endoplasmic reticulum (ER) quality control (ERQC) resulting in its retention and early degradation. The ERQC mechanisms rely mainly on molecular chaperones and on sorting motifs, whose presence and exposure determine CFTR retention or exit through the secretory pathway. Arginine-framed tripeptides (AFTs) are ER retention motifs shown to modulate CFTR retention. However, the interactions and regulatory pathways involved in this process are still largely unknown. Here, we used proteomic interaction profiling and global bioinformatic analysis to identify factors that interact differentially with F508del-CFTR and F508del-CFTR without AFTs (F508del-4RK-CFTR) as putative regulators of this specific ERQC checkpoint. Using LC–MS/MS, we identified kinesin family member C1 (KIFC1) as a stronger interactor with F508del-CFTR versus F508del-4RK-CFTR. We further validated this interaction showing that decreasing KIFC1 levels or activity stabilizes the immature form of F508del-CFTR by reducing its degradation. We conclude that the current approach is able to identify novel putative therapeutic targets that can be ultimately used to the benefit of CF patients. 相似文献
806.
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808.
一类生态系统的持续生存和全局稳定性 总被引:1,自引:0,他引:1
讨论了一类具有连续时滞和功能性反应的两种群两缀块的一类生态系统的动力学行为。两种群之一能在两缀块中迁移,另一种群限制在一个缀块中,应用微分方程定性和稳定性的方法,证明了系统在一定条件下是持续生存的。进一步,得到了系统为全局稳定的充分条件 相似文献
809.
810.
A novel coenzyme from bacterial primary alcohol dehydrogenases. 总被引:11,自引:0,他引:11