检索结果-南通市图书馆

Efficacy and Safety of the WATCHMAN Left Atrial Appendage System for Stroke Prevention in Chinese Patients with Nonvalvular Atrial Fibrillation： A Single-center, Prospective, Observational Study

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2017年第4期130卷 434-438页

作者： Wei-Ping huang Yong-hua Zhang Lei He Xi Su Xin-Wei Yang Zai-Xiong Guo Department of Cardiology Wuhan Asia Heart Hospital Wuhan Hubei 430022 China

Background： In patients with nonvalvular atrial fibrillation （NVAF）, embolic stroke is thought to be associated with left atrial appendage （LAA） thrombi. The WATCHMAN LAA Occlusion Device has been shown to be noninferior to conventional oral anticoagulation with warfarin for stroke prevention in patients with NVAF. This study aimed to evaluate the procedural feasibility, safety and 12-month outcomes of the WATCHMAN LAA Occlusion Device in NVAF patients with high risk for stroke in China. Methods： The clinical data of 106 NVAF patients, who were consecutively underwent LAA closure with the WATCHMAN Device between April 2014 and May 2015, were collected. Patients were followed up at 1,3, 6, and 12 months after discharge. A transesophageal echocardiograph was performed at 45 days after implantation and repeated in case of an unexpected event during the follow-up period. Results： This study included 106 NVAF patients with a mean age of 64.2 ± 8.6 years （ranging from 50 to 88 years）, and the mean CHA,DS,-VASc score of all patients was 3.6 ± 1.6 （ranging from 2 to 9）. Among those 106 NVAF patients, 100 （94.3%） patients were implanted with the device successfully. The procedural success rate was 94.3% （100/106）, and the occlusion rate was 100.0% （100/100）. There were one tamponade, one ischemic stroke, and eight minor pericardial effusions during hospitalization. During 12-month follow-up period, two patients developed a tbrombus layer on the device that resolved with additional anticoagulation： one with visible device-thrombus experienced transient ischemic stroke, and one had a hemorrhagic stroke. There were no deaths in this study. The overall survival rate was 100.0%, and nonmajor adverse event rate was 95.0% （95/100）. In this study, the expected annual rate ofischemic stroke risk in these patients according to the CHA2DS2-VASc score was 4.0%, while the observed ischemic stroke rate was 2.0% per year. Conclusions： LAA closure with the WATCHMAN Device was feasible, effi

关键词： Atrial Fibrillation Left Atrial Appendage Closure Stroke Prevention

在线全文

学校读者我要写书评

暂无评论

管片拼装机回转系统齿轮啮合动力学分析

振动．测试与诊断 2020年第1期40卷 127-134,207页

作者：李杰马超张斌黄元俊石家庄铁道大学机械工程学院

为了研究管片拼装机回转系统齿轮啮合的动力学特性,以管片拼装机小齿轮-大齿圈的传动系统为研究对象,采用集中参数法建立了考虑齿面摩擦的六自由度直齿轮动力学模型,依据管片拼装机实际工况参数,利用Runge-Kutta方法分析了管片拼装机回... 详细信息

为了研究管片拼装机回转系统齿轮啮合的动力学特性,以管片拼装机小齿轮-大齿圈的传动系统为研究对象,采用集中参数法建立了考虑齿面摩擦的六自由度直齿轮动力学模型,依据管片拼装机实际工况参数,利用Runge-Kutta方法分析了管片拼装机回转系统在空载和负载两种工况下小齿轮和大齿圈的振动位移情况,对管片拼装机回转系统进行了振动测试,验证了模型及求解的正确性,并提出了可以通过增大管片拼装机回转系统刚度来减小振动的方法。研究结果对管片拼装机回转系统的减振和降噪处理,以及提高管片拼装机回转系统的精度有重要的理论和实用价值。

关键词：管片拼装机回转系统齿轮啮合动力学

China is initiating the Aquatic 10-100-1,000 Genomics Program

在线全文

学校读者我要写书评

暂无评论

Science China(Life Sciences) 2017年第3期60卷 329-332页

作者： Yingjie Liu Pao Xu Junmin Xu Yu huang Yongxin Liu Hui Fang Yinchang Hu Xinxin You chao Bian Min Sun Ruobo Gu Lifeng Cui Xianliang Zhang Peng Xu Qiong Shi Chinese Academy of Fishery Sciences Beijing 100141 China BGI Research Center for Aquatic Genomics Chinese Academy of Fishery Sciences Shenzhen 518083 China Freshwater Fisheries Research Center Chinese Academy of Fishery Sciences Wuxi 214081 China BGI Shenzhen Academy of Marine Sciences BGI Fisheries BGI Shenzhen 518083 China Pearl River Fisheries Research Institute Chinese Academy of Fishery Sciences Guangzhou 510380 China Marine Research Center College of Life Sciences and Oceanography Shenzhen University Shenzhen 518060 China

On June 17 of 2016,a group of scientists from Chinese Academy of Fishery Sciences（CAFS）and Shenzhen BGI Fisheries Sci＆Tech ***.（BGI Fisheries）met together in Shenzhen,China to launch a novel project,the China Aquatic 10-100-1,000 Genomics Program,to conduct molecular breeding of-10 aquaculture species and sequence genomes of-100 and transcriptomes of-1,000 aquatic species.

关键词：中国水产科学研究院基因组计划水产科技基因组序列 CAFS 分子育种 BGI 科学家

在线全文

学校读者我要写书评

暂无评论

三维复杂速度模型的交切法地震定位

地球物理学报 2012年第10期55卷 3347-3354页

作者：周建超赵爱华中国地震局地球物理研究所北京100081

地震定位是地震监测与减灾研究重要基础.基于均匀或横向均匀介质模型,利用震源轨迹确定震源位置的交切法具有稳健和效率高的优点,但定位精度较低,特别是震源深度.为提高震源定位精度,我们提出适用于三维复杂速度模型的地震定位交切法.... 详细信息

地震定位是地震监测与减灾研究重要基础.基于均匀或横向均匀介质模型,利用震源轨迹确定震源位置的交切法具有稳健和效率高的优点,但定位精度较低,特别是震源深度.为提高震源定位精度,我们提出适用于三维复杂速度模型的地震定位交切法.将地壳速度模型由均匀或横向均匀介质模型扩展为三维复杂速度模型;均匀或横向均匀介质模型对应的原假设为球面或双曲面的震源轨迹通过最小走时树射线追踪技术予以确定.确定震源位置的震源轨迹以到时差作为约束条件;将震源定位于震源轨迹交汇最密集的点处,即总的到时差残差(RDT)最小的点处.定位结果的不确定性可通过RDT值较小节点的空间分布予以定性表示.考察了准确速度模型、扰动速度模型、扰动观测到时及地震在台网外等4种情况下改进方法的地震定位效果,结果表明改进的交切法可用于三维复杂速度模型的地震定位;综合利用P波与S波的到时差信息,可明显改善震源位置约束;使用多条震源轨迹进行定位,有助于减少由随机因素导致的定位误差.

关键词：三维复杂速度模型地震定位交切法震源轨迹最小走时树算法

钢筋混凝土深受弯构件受剪承载力概率模型研究

在线全文

学校读者我要写书评

暂无评论

工程力学 2015年第11期32卷 210-217页

作者：吴涛黄凯刘喜刘伯权黄华长安大学建筑工程学院陕西西安710061

贝叶斯理论具有充分利用模型信息和数据信息且考虑先验分布等优点,已被广泛应用于各个领域。通过贝叶斯多元线性参数估计方法,建立基于影响参数的钢筋混凝土深受弯构件贝叶斯概率抗剪模型。基于该模型和271组钢筋混凝土深受弯构件试验结... 详细信息

贝叶斯理论具有充分利用模型信息和数据信息且考虑先验分布等优点,已被广泛应用于各个领域。通过贝叶斯多元线性参数估计方法,建立基于影响参数的钢筋混凝土深受弯构件贝叶斯概率抗剪模型。基于该模型和271组钢筋混凝土深受弯构件试验结果,完成了模型参数计算及基于贝叶斯理论的受剪承载力计算,同时,利用贝叶斯参数剔除法对抗剪模型进行简化,并与我国混凝土结构设计规范(GB50010-2010)、ACI318-08、CSA和EC2等现有规范计算结果进行了对比分析。研究表明:利用贝叶斯方法建立的基于影响参数的深受弯构件抗剪模型计算结果与试验吻合良好,采用贝叶斯动态更新后结果较规范值更接近试验值,简化后模型能较为合理的进行深受弯构件受剪承载力计算。

关键词：贝叶斯参数估计影响参数钢筋混凝土深受弯构件贝叶斯参数剔除受剪承载力

Sub-2.0-nm Ru and composition-tunable RuPt nanowire networks

同方期刊数据库博看期刊评论

在线全文

学校读者我要写书评

暂无评论

Nano Research 2016年第10期9卷 3066-3074页

作者： Weiyue Zhao Dabing huang Qiang Yuan Xun Wang College of Chemistry and Chemical Engineering Guizhou University Guiyang Guiyang 550025 China Department of Chemistry Tsinghua University Beijing 100084 China

Recently, the synthesis of ultrathin nanostructures has attracted increasing interest because of their unique structure and properties. In this work, we report the synthesis of sub-2.0-nm Ru and composition-tunable RuPt nanowire networks using an environmentally friendly aqueous method. The structures were characterized using transmission electron microscopy （TEM）, high-resolution TEM, X-ray diffraction （XRD）, and energy-dispersive X-ray （EDX） spectroscopy. Moreover, the combined utilization of sodium n-dodecyl sulfate and potassium fluoride was determined to play a key role in the formation of these ultrathin nanostructures. The electrocatalytic properties of the sub-2.0-nm RuPt nanowire networks were investigated for methanol oxidation in an acidic medium. The nanostructures displayed composition-dependent properties, and compared with commercial Ru50Pt50/C, the as-synthesized Ru56Pt44 ultrathin nanowire network exhibited enhanced stability.

关键词： Ru Pt alloy nanowire networks electrocatalysis

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

基于改进德尔菲法的舰船总体方案群决策方法

上海交通大学学报 2014年第4期48卷 515-519页

作者：郭海鹏黄胜王超哈尔滨工程大学船舶工程学院哈尔滨150001

根据舰船总体方案决策的特点,引入基于优化模型的改进德尔菲法.将群决策与个体决策方案排序关系转化为布尔矩阵,通过群决策与个体决策的布尔矩阵元素差值来反映决策结果的群体一致性,建立了基于排序一致性的优化模型.通过全息粒子群算... 详细信息

根据舰船总体方案决策的特点,引入基于优化模型的改进德尔菲法.将群决策与个体决策方案排序关系转化为布尔矩阵,通过群决策与个体决策的布尔矩阵元素差值来反映决策结果的群体一致性,建立了基于排序一致性的优化模型.通过全息粒子群算法在修正区间内对专家初始打分矩阵进行调整,寻找满足群体一致性的可行解.构造专家意见的可信度函数,对修正后的专家评价值进行整体可信度分析,使决策达成群体一致性的同时兼顾决策可信度.应用实例对比分析表明,该方法在舰船多方案优选时具有较好的最优方案稳定性及决策可信性.

关键词：舰船总体方案改进德尔菲法排序一致性可信度

在线全文

学校读者我要写书评

暂无评论

改进的VGG网络的二极管玻壳图像缺陷检测

图学学报 2019年第6期40卷 1087-1092页

作者：杜超刘桂华西南科技大学信息工程学院

针对于目前二极管玻壳缺陷检测中大多采用人工特征提取,识别准确率不高的问题,提出一种改进的VGG网络的二极管玻壳图像缺陷检测方法。首先对玻壳图像进行预处理,同时利用原始大样本数据集对卷积神经网络结构VGG-19模型进行预训练得到预... 详细信息

针对于目前二极管玻壳缺陷检测中大多采用人工特征提取,识别准确率不高的问题,提出一种改进的VGG网络的二极管玻壳图像缺陷检测方法。首先对玻壳图像进行预处理,同时利用原始大样本数据集对卷积神经网络结构VGG-19模型进行预训练得到预训练模型,然后通过迁移学习的方法将预训练模型中的部分卷积、池化等层权重参数迁移到改进网络模型的固定层中,非固定层用于模型改进,并将网络的全连接层结构重新进行超参数设置和优化,最后使用预处理后的玻壳图像数据集对改进模型进行训练,得到非固定卷积层和新的全连接层的参数和权重。在二极管玻壳数据集进行测试,实验结果表明,该方法能有效提高二极管玻壳图像分类识别准确率,达到了98.3%。

关键词：玻壳缺陷检测 VGG-19模型迁移学习图像分类准确率

Raw Trajectory Rectification via Scene-Free Splitting and Stitching

在线全文

学校读者我要写书评

暂无评论

Journal of Computer Science & Technology 2015年第2期30卷 364-372页

作者：郭春超胡晓军赖剑煌石世昌陈世哲 School of Information Science and Technology Sun Yat-sen University Guangzhou 510006 China

Trajectories carry rich motion cues and thus have been leveraged to many high-level computer vision tasks. Due to the easy implementation of simple trackers, most previous work on trajectory-based applications utilizes raw tracking outputs without explicitly considering tracking errors. Reliable trajectories are prerequisite for modeling and recognizing high-level behaviors. Therefore, this paper tackles such problems by rectifying raw trajectories, which aims to post-process existing trajectories. Our approach firstly splits them into short tracks, and then infers identity ambiguity to remove unqualified detection responses. At last, short tracks are stitched via maximum bipartite graph matching. This post- processing is completely scene-free. Results of trajectory rectification and their benefits are both evaluated on two challenging datasets. Results demonstrate that rectified trajectories are conducive to high-level tasks and the proposed approach is also competitive with state-of-the-art multi-target tracking methods.

关键词： raw trajectory rectification trajectory post-processing identity ambiguity multi-target tracking activity classification