The long-term existence of dam structures significantly modified the river channel. In accordance with a drastic increase of low-head dams under consideration for removal in recent years, it is important to predict th...The long-term existence of dam structures significantly modified the river channel. In accordance with a drastic increase of low-head dams under consideration for removal in recent years, it is important to predict the effects of low-head dam removal from the modified river channel by the low-head dam construction. This study intends to investigate the long-term channel evolution process following low-head construction and removal and to find out the influential parameters (sediment diameter, river bed slope, dam height) for those channel evolution by two-dimensional numerical simulation model. Following the low-head dam construction, sediment deposition rates in upstream of the low-head dam are varied with the influential parameters. The sediment deposition rates and sandbar formation with riparian vegetation settlement on sandbars have significantly affected for channel evolution following low-head dam removal. Especially the knickpoint formation and the types of vegetation (grass type and tree type) on the sandbars are critical factors for channel evolution following low-head dam removal. Through the numerical simulation results of low-head dam construction (50 years) and low-head dam removal (50 years), it is identified that the modified river channel by low-head dam may not be easily restored to pre-dam conditions following its removal especially in river geomorphology and riparian vegetation. Consequently, this study found that the reversibility following low-head dam construction and removal depends on the sediment deposition rates in upstream of the low-head dam.展开更多
目前的脑电(EEG)情感识别模型忽略了不同时段情感状态的差异性,未能强化关键的情感信息。针对上述问题,提出一种多上下文向量优化的卷积递归神经网络(CR-MCV)。首先构造脑电信号的特征矩阵序列,通过卷积神经网络(CNN)学习多通道脑电的...目前的脑电(EEG)情感识别模型忽略了不同时段情感状态的差异性,未能强化关键的情感信息。针对上述问题,提出一种多上下文向量优化的卷积递归神经网络(CR-MCV)。首先构造脑电信号的特征矩阵序列,通过卷积神经网络(CNN)学习多通道脑电的空间特征;然后利用基于多头注意力的递归神经网络生成多上下文向量进行高层抽象特征提取;最后利用全连接层进行情感分类。在DEAP(Database for Emotion Analysis using Physiological signals)数据集上进行实验,CR-MCV在唤醒和效价维度上分类准确率分别为88.09%和89.30%。实验结果表明,CR-MCV在利用电极空间位置信息和不同时段情感状态显著性特征基础上,能够自适应地分配特征的注意力并强化情感状态显著性信息。展开更多
目的:探讨与评价Bestrophin 3在激素性股骨头坏死(Osteonecrosis of the femoral head,ONFH)中的作用。方法:研究时间为2017年8月-2018年6月,收集河北医科大学第一医院收治的股骨颈骨折患者自愿捐赠的股骨头骨组织32例作为对照组,激素...目的:探讨与评价Bestrophin 3在激素性股骨头坏死(Osteonecrosis of the femoral head,ONFH)中的作用。方法:研究时间为2017年8月-2018年6月,收集河北医科大学第一医院收治的股骨颈骨折患者自愿捐赠的股骨头骨组织32例作为对照组,激素性股骨头坏死患者术后股骨头骨组织32例作为观察组,采集两组标本的骨髓基质细胞,使用PCR方法检测骨髓基质细胞Bestrophin 3的表达水平。结果:观察组中的股骨头骨组织Bestrophin 3 mRNA相对表达量高于对照组,比较差异有统计学意义(P<0.05)。结论:Bestrophin 3作为一种氯离子通道抑制剂,在激素性股骨头坏死组织中的呈现高表达状况。展开更多
文摘The long-term existence of dam structures significantly modified the river channel. In accordance with a drastic increase of low-head dams under consideration for removal in recent years, it is important to predict the effects of low-head dam removal from the modified river channel by the low-head dam construction. This study intends to investigate the long-term channel evolution process following low-head construction and removal and to find out the influential parameters (sediment diameter, river bed slope, dam height) for those channel evolution by two-dimensional numerical simulation model. Following the low-head dam construction, sediment deposition rates in upstream of the low-head dam are varied with the influential parameters. The sediment deposition rates and sandbar formation with riparian vegetation settlement on sandbars have significantly affected for channel evolution following low-head dam removal. Especially the knickpoint formation and the types of vegetation (grass type and tree type) on the sandbars are critical factors for channel evolution following low-head dam removal. Through the numerical simulation results of low-head dam construction (50 years) and low-head dam removal (50 years), it is identified that the modified river channel by low-head dam may not be easily restored to pre-dam conditions following its removal especially in river geomorphology and riparian vegetation. Consequently, this study found that the reversibility following low-head dam construction and removal depends on the sediment deposition rates in upstream of the low-head dam.
文摘目前的脑电(EEG)情感识别模型忽略了不同时段情感状态的差异性,未能强化关键的情感信息。针对上述问题,提出一种多上下文向量优化的卷积递归神经网络(CR-MCV)。首先构造脑电信号的特征矩阵序列,通过卷积神经网络(CNN)学习多通道脑电的空间特征;然后利用基于多头注意力的递归神经网络生成多上下文向量进行高层抽象特征提取;最后利用全连接层进行情感分类。在DEAP(Database for Emotion Analysis using Physiological signals)数据集上进行实验,CR-MCV在唤醒和效价维度上分类准确率分别为88.09%和89.30%。实验结果表明,CR-MCV在利用电极空间位置信息和不同时段情感状态显著性特征基础上,能够自适应地分配特征的注意力并强化情感状态显著性信息。
文摘目的:探讨与评价Bestrophin 3在激素性股骨头坏死(Osteonecrosis of the femoral head,ONFH)中的作用。方法:研究时间为2017年8月-2018年6月,收集河北医科大学第一医院收治的股骨颈骨折患者自愿捐赠的股骨头骨组织32例作为对照组,激素性股骨头坏死患者术后股骨头骨组织32例作为观察组,采集两组标本的骨髓基质细胞,使用PCR方法检测骨髓基质细胞Bestrophin 3的表达水平。结果:观察组中的股骨头骨组织Bestrophin 3 mRNA相对表达量高于对照组,比较差异有统计学意义(P<0.05)。结论:Bestrophin 3作为一种氯离子通道抑制剂,在激素性股骨头坏死组织中的呈现高表达状况。
