During the operation and installation of offshore pipelines, high axial forces and pressures are experienced, and their effects cannot be neglected. In this article, the effect of internal flow velocity and functional...During the operation and installation of offshore pipelines, high axial forces and pressures are experienced, and their effects cannot be neglected. In this article, the effect of internal flow velocity and functional loads on vortex-induced vibration （VIV） response is investigated. On the basis of the Hamilton principle, a differential equation was derived to describe the motion of a pinned-pinned tensioned spanning pipeline conveying fluid. The VIV response was calculated according to DNV-RP-F105 under different functional loads. The results showed that functional loads influence free spanning pipeline VIV response by changing the natural frequency. Internal flow velocity was found less important for VIV response than other functional load factors, such as effective axial force, because the speed in reality is not high enough to be significant. The research may provide a reference for sensitivity studies of the effect of functional loads on allowable free span lengths.展开更多
The research objective is to design and construct a method for functional reliability analysis of concrete gravity dam. Firstly, the pseudo excitation method was utilized to analyze to calculate the probabilistic char...The research objective is to design and construct a method for functional reliability analysis of concrete gravity dam. Firstly, the pseudo excitation method was utilized to analyze to calculate the probabilistic characteristics of concrete gravity dam excited by random seismic loading. Meanwhile, the response surface method based on weighted regression was associated to that method to analyze functional reliability of concrete gravity dam. Eventually, a test example was given to verify and analyze the convergence and stability of this method.展开更多
The conventional approach to investigating functional connectivity in the block-designed study usually concatenates task blocks or employs residuals of task activation.While providing many insights into brain function...The conventional approach to investigating functional connectivity in the block-designed study usually concatenates task blocks or employs residuals of task activation.While providing many insights into brain functions,the block design adds more manipulation in functional network analysis that may reduce the purity of the blood oxygenation level-dependent signal.Recent studies utilized one single long run for task trials of the same condition,the so-called continuous design,to investigate functional connectivity based on task functional magnetic resonance imaging.Continuous brain activities associated with the single-task condition can be directly utilized for task-related functional connectivity assessment,which has been examined for working memory,sensory,motor,and semantic task experiments in previous research.But it remains unclear how the block and continuous design influence the assessment of task-related functional connectivity networks.This study aimed to disentangle the separable effects of block/continuous design and working memory load on task-related functional connectivity networks,by using repeated-measures analysis of variance.Across 50 young healthy adults,behavioral results of accuracy and reaction time showed a significant main effect of design as well as interaction between design and load.Imaging results revealed that the cingulo-opercular,fronto-parietal,and default model networks were associated with not only task activation,but significant main effects of design and load as well as their interaction on intra-and inter-network functional connectivity and global network topology.Moreover,a significant behavior-brain association was identified for the continuous design.This work has extended the evidence that continuous design can be used to study task-related functional connectivity and subtle brain-behavioral relationships.展开更多
功能负载(FL)原则预测高FL音位对比,例如/i:/和/?/,比低FL音位对比,例如/u:/和/?/,对发音的相互可懂度的影响更大。为了评估FL原则是否能准确预测英语作为通用语言(ELF)条件下的清晰度,本研究部分复制了由Munro和Derwing(2006)所做的第...功能负载(FL)原则预测高FL音位对比,例如/i:/和/?/,比低FL音位对比,例如/u:/和/?/,对发音的相互可懂度的影响更大。为了评估FL原则是否能准确预测英语作为通用语言(ELF)条件下的清晰度,本研究部分复制了由Munro和Derwing(2006)所做的第一项实证支持FL原则的研究。中国人录制了24个包含目标词的高低FL音素替换的英语句子,171名日本大学生听了这些句子并将目标词转写成书面英语。本研究的假设是,具有高FL音素替换的目标词比具有低FL音素替换的目标词更难理解。结果表明,具有高FL音素替换的目标词的清晰度确实低于具有低FL音素替换的目标词,而且多个高FL音素替换的叠加更加降低清晰度。本研究结果与Munro and Derwing (2006)的发现一致,即高FL音素替换比低FL音素替换更能降低清晰度,因此这项研究宣称在ELF条件下成功复制了该研究的一个方面。展开更多
基金Supported by the National Natural Science Foundation of China (No. 50879013)China National 111 Project (No.B07019)
文摘During the operation and installation of offshore pipelines, high axial forces and pressures are experienced, and their effects cannot be neglected. In this article, the effect of internal flow velocity and functional loads on vortex-induced vibration （VIV） response is investigated. On the basis of the Hamilton principle, a differential equation was derived to describe the motion of a pinned-pinned tensioned spanning pipeline conveying fluid. The VIV response was calculated according to DNV-RP-F105 under different functional loads. The results showed that functional loads influence free spanning pipeline VIV response by changing the natural frequency. Internal flow velocity was found less important for VIV response than other functional load factors, such as effective axial force, because the speed in reality is not high enough to be significant. The research may provide a reference for sensitivity studies of the effect of functional loads on allowable free span lengths.
文摘The research objective is to design and construct a method for functional reliability analysis of concrete gravity dam. Firstly, the pseudo excitation method was utilized to analyze to calculate the probabilistic characteristics of concrete gravity dam excited by random seismic loading. Meanwhile, the response surface method based on weighted regression was associated to that method to analyze functional reliability of concrete gravity dam. Eventually, a test example was given to verify and analyze the convergence and stability of this method.
基金supported by the National Natural Science Foundation of China(62071109 and 61871420)the Provincial Natural Science Foundation of Sichuan(2022NSFSC0504).
文摘The conventional approach to investigating functional connectivity in the block-designed study usually concatenates task blocks or employs residuals of task activation.While providing many insights into brain functions,the block design adds more manipulation in functional network analysis that may reduce the purity of the blood oxygenation level-dependent signal.Recent studies utilized one single long run for task trials of the same condition,the so-called continuous design,to investigate functional connectivity based on task functional magnetic resonance imaging.Continuous brain activities associated with the single-task condition can be directly utilized for task-related functional connectivity assessment,which has been examined for working memory,sensory,motor,and semantic task experiments in previous research.But it remains unclear how the block and continuous design influence the assessment of task-related functional connectivity networks.This study aimed to disentangle the separable effects of block/continuous design and working memory load on task-related functional connectivity networks,by using repeated-measures analysis of variance.Across 50 young healthy adults,behavioral results of accuracy and reaction time showed a significant main effect of design as well as interaction between design and load.Imaging results revealed that the cingulo-opercular,fronto-parietal,and default model networks were associated with not only task activation,but significant main effects of design and load as well as their interaction on intra-and inter-network functional connectivity and global network topology.Moreover,a significant behavior-brain association was identified for the continuous design.This work has extended the evidence that continuous design can be used to study task-related functional connectivity and subtle brain-behavioral relationships.
文摘功能负载(FL)原则预测高FL音位对比,例如/i:/和/?/,比低FL音位对比,例如/u:/和/?/,对发音的相互可懂度的影响更大。为了评估FL原则是否能准确预测英语作为通用语言(ELF)条件下的清晰度,本研究部分复制了由Munro和Derwing(2006)所做的第一项实证支持FL原则的研究。中国人录制了24个包含目标词的高低FL音素替换的英语句子,171名日本大学生听了这些句子并将目标词转写成书面英语。本研究的假设是,具有高FL音素替换的目标词比具有低FL音素替换的目标词更难理解。结果表明,具有高FL音素替换的目标词的清晰度确实低于具有低FL音素替换的目标词,而且多个高FL音素替换的叠加更加降低清晰度。本研究结果与Munro and Derwing (2006)的发现一致,即高FL音素替换比低FL音素替换更能降低清晰度,因此这项研究宣称在ELF条件下成功复制了该研究的一个方面。
