检索结果-南通市图书馆

Beta-blocker use and risk of symptomatic bradyarrhythmias： a hospital-based case-control study

Journal of Geriatric Cardiology 2016年第9期13卷 749-759页

作者： hou tee lu Jiyen Kam Rusli Bin Nordin Surinder Kaur Khelae Jing Mein Wang Chun Ngok Choy Chuey Yan Lee Clinical School Johor Bahru Jeffrey Cheah School of Medicine and Health Sciences Monash University Malaysia Johor Bahru Johor Malaysia Department of Cardiology Sultanah Aminah Hospital Jalan Masjid Abu Bakar Johor Bahru Johor Malaysia Department of Electrophysiology lnstitut Jantung Negara Jalan Tun Razak Kuala Lumpur Malaysia Department of Pharmacy Sultanah Aminah Hospital Jalan Masjid Abu Bakar Johor Bahru Johor Malaysia

Objective To investigate the risk factors of symptomatic bradyarrhythrnias in relation to β-blockers use. Methods A hospital-based case-control study [228 patients： 108 with symptomatic bradyarrhythmias （cases） and 120 controls] was conducted in Sultanah Aminah Hospital, Malaysia between January 2011 and January 2014. Results The mean age was 61.1 ~ 13.3 years with a majority of men （68.9%）. Cases were likely than control to be older, hypertensive, lower body mass index and concomitant use of rate-controlling drugs （such as digoxin, verapamil, diltiazem, ivabradine or amiodarone）. Significantly higher level of serum potassium, urea, creatinine and lower level of estimated glomerular filtration rate （eGFR） were observed among cases as compared to controls. On univariate analysis among patients on β-blockers, older age （crude OR： 1.07; 95% CI： 1.03-1.11, P = 0.000）, hypertension （crude OR： 5.6; 95% CI： 1.51-20.72, P = 0.010）, lower sodium （crude OR： 0.04; 95% CI： 0.81-0.99, P = 0.036）, higher potassium （crude OR： 2.36; 95% CI： 1.31-4.26, P = 0.004） and higher urea （crude OR： 1.23; 95% CI： 1.11-1.38, P = 0.000） were associated with increased risk of symptomatic bradyarrhythmias; eGFR was inversely and significantly associated with symptomatic bradyarrhythmias in both ＇β-blockers＇（crude OR： 0.97; 95% CI： 0.964）.98, P = 0.000） and ＇non-β-blockers＇（crude OR： 0.99; 95% CI： 0.97-0.99, P = 0.023） arms. However, eGFR was not significantly associated with symptomatic bradyarrhythmias in the final model of both ＇β-blockers＇（adjusted OR： 0.98; 95% CI： 0.96-0.98, P = 0.103） and ＇non-p-blockers＇（adjusted OR： 0.99; 95% CI： 0.97-1.01, P = 0.328） arms. Importantly, older age was a significant predictor of symptomatic bradyarrhythmias in the ＇β-blockers＇ as compared to the ＇non-β-blockers＇ arms （adjusted OR： 1.09; 95% CI： 1.03-1.15, P = 0.003 vs. adjusted OR： 1.03; 95% CI： 0.98-1.09, P = 0.232, respectively）. Conclusion Older age was a significant predictor of symptomatic bradyarr

关键词： Adverse drug reaction Beta-blocker Bradyarrhythmias Case-control

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Characteristics and sources of polycyclic aromatic hydrocarbons in impervious surface run-off in an urban area in Shanghai, China

引用

Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2013年第10期14卷 751-759页

作者： Juan hou lu BIAN Tian LI State Key Laboratory of Pollution Control and Resource Reuse Tongji University

Rainwater and run-off from three kinds of impervious surface in the Shanghai urban area,China were *** aromatic hydrocarbons(PAHs) were measured in the samples,and their sources were *** mean sum of the 16 PAH concentrations measured in rainwater and run-offs from ceramic tiles,asphalt roofs,and asphalt roads were 873,1404,1743,and 4023 ng/L,*** PAH concentrations found in this study were moderate compared to PAH concentrations found in run-offs in other *** main PAH components in the rainwater,roof run-off,and asphalt road run-off samples were 3-ring PAHs,3–4-ring PAHs,and 4–6-ring PAHs,*** apportionment results indicated that combustion(47.4%–55.5%) and vehicular emissions(30.5%–33.0%) were the major contributors to PAHs in roof *** emissions were the most significant contributors to asphalt road run-off(47.2%),followed by combustion(23.5%),and petroleum(16.3%).Vehicular emissions and coal and natural gas combustion are therefore the most significant sources of PAHs in run-off from impervious surfaces in the Shanghai urban area.

关键词： Polycyclic aromatic hydrocarbons(PAHs) Impervious surface Run-off pollution Source apportionment

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Novel load balancing DHT scheme for the heterogeneous system

引用

Journal of Systems Engineering and Electronics 2008年第4期19卷 835-842页

作者： Li Yujun lu Xianliang hou Mengshu School of Computer Science and Engineering Univ. of Electronics Science and Technology of China Chengdu 610054 P. R. China

The capacities of the nodes in the peer-to-peer system are strongly heterogeneous, hence one can benefit from distributing the load, based on the capacity of the nodes. At first a model is discussed to evaluate the load balancing of the heterogeneous system, and then a novel load balancing scheme is proposed based on the concept of logical servers and the randomized binary tree, and theoretical guarantees are given. Finally, the feasibility of the scheme using extensive simulations is proven.

关键词： distributed hash table heterogeneity randomized binary tree load balancing

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Bifurcation characteristics analysis of a class of nonlinear dynamical systems based on singularity theory

引用

Applied Mathematics and Mechanics(English Edition) 2017年第9期38卷 1233-1246页

作者： Kuan lu Yushu CHEN Lei hou School of Astronautics Harbin Institute of TechnologyHarbin 150001China College of Engineering The University of IowaIowa CityIA 52242U.S.A. School of Energy Science and Engineering Harbin Institute of TechnologyHarbin 150001China

A method for seeking main bifurcation parameters of a class of nonlinear dynamical systems is proposed. The method is based on the effects of parametric varia- tion of dynamical systems on eigenvalues of the Frechet matrix. The singularity theory is used to study the engineering unfolding （EU） and the universal unfolding （UU） of an arch structure model, respectively. Unfolding parameters of EU are combination of concerned physical parameters in actual engineering, and equivalence of unfolding parameters and physical parameters is verified. Transient sets and bifurcation behaviors of EU and UU are compared to illustrate that EU can reflect main bifurcation characteristics of non- linear systems in engineering. The results improve the understanding and the scope of applicability of EU in actual engineering systems when UU is difficult to be obtained.

关键词： bifurcation singularity engineering unfolding (EU) universal unfolding(UU) nonlinear dynamics

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Numerical simulation of turbulent combustion: Scientific challenges

引用

Science China(Physics,Mechanics & Astronomy) 2014年第8期57卷 1495-1503页

作者： REN ZhuYin lu Zhen hou LingYun lu LiuYan School of Aerospace Tsinghua University Center for Combustion Energy Key Laboratory for Thermal Science and Power Engineering of Ministry of Education Tsinghua University Department of Thermal Engineering Tsinghua University Sibley School of Mechanical & Aerospace Engineering Cornell UniversityIthaca NY 14853 USA GE Global Research Center One research circle Niskayuna NY 12309 USA

Predictive simulation of engine combustion is key to understanding the underlying complicated physicochemical processes,improving engine performance,and reducing pollutant *** issues as turbulence modeling,turbulence-chemistry interaction,and accommodation of detailed chemical kinetics in complex flows remain challenging and essential for highfidelity combustion *** paper reviews the current status of the state-of-the-art large eddy simulation(LES)/probability density function(PDF)/detailed chemistry approach that can address the three challenging modelling *** as a subgrid model for LES is formulated and the hybrid mesh-particle method for LES/PDF simulations is *** the development need in micro-mixing models for the PDF simulations of turbulent premixed combustion is *** the different acceleration methods for detailed chemistry are reviewed and a combined strategy is proposed for further development.

关键词： turbulence-chemistry interaction detailed chemistry probability density function mixing models large eddy simulations

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Crack Fault Diagnosis and Location Method for a Dual-Disk Hollow Shaft Rotor System Based on the Radial Basis Function Network and Pattern Recognition Neural Network

引用

Chinese Journal of Mechanical Engineering 2023年第2期36卷 180-197页

作者： Yuhong Jin Lei hou Zhenyong lu Yushu Chen School of Astronautics Harbin Institute of TechnologyHarbin 150001China Institute of Dynamics and Control Science Shandong Normal UniversityJi’nan 250014China

The crack fault is one of the most common faults in the rotor system,and researchers have paid close attention to its fault ***,most studies focus on discussing the dynamic response characteristics caused by the crack rather than estimating the crack depth and position based on the obtained vibration *** this paper,a novel crack fault diagnosis and location method for a dual-disk hollow shaft rotor system based on the Radial basis function(RBF)network and Pattern recognition neural network(PRNN)is ***,a rotor system model with a breathing crack suitable for a short-thick hollow shaft rotor is established based on the finite element method,where the crack's periodic opening and closing pattern and different degrees of crack depth are ***,the dynamic response is obtained by the harmonic balance *** adjusting the crack parameters,the dynamic characteristics related to the crack depth and position are analyzed through the amplitude-frequency responses and waterfall *** analysis results show that the first critical speed,first subcritical speed,first critical speed amplitude,and super-harmonic resonance peak at the first subcritical speed can be utilized for the crack fault *** on this,the RBF network and PRNN are adopted to determine the depth and approximate location of the crack respectively by taking the above dynamic characteristics as *** results show that the proposed method has high fault diagnosis *** research proposes a crack detection method adequate for the hollow shaft rotor system,where the crack depth and position are both unknown.

关键词： Hollow shaft rotor Breathing crack Radial basis function network Pattern recognition neural network Machine learning

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

An effective crack position diagnosis method for the hollow shaft rotor system based on the convolutional neural network and deep metric learning

引用

Chinese Journal of Aeronautics 2022年第9期35卷 242-254页

作者： Yuhong JIN Lei hou Yushu CHEN Zhenyong lu School of Astronautics Harbin Institute of TechnologyHarbin 150001China Institute of Dynamics and Control Science Shandong Normal UniversityJi'nan 250014China

In recent years, the crack fault is one of the most common faults in the rotor system and it is still a challenge for crack position diagnosis in the hollow shaft rotor system. In this paper, a method based on the Convolutional Neural Network and deep metric learning(CNN-C) is proposed to effectively identify the crack position for a hollow shaft rotor system. Center-loss function is used to enhance the performance of neural network. Main contributions include: Firstly, the dynamic response of the dual-disks hollow shaft rotor system is obtained. The analysis results show that the crack will cause super-harmonic resonance, and the peak value of it is closely related to the position and depth of the crack. In addition, the amplitude near the non-resonant region also has relationship with the crack parameters. Secondly, we proposed an effective crack position diagnosis method which has the highest 99.04% recognition accuracy compared with other algorithms. Then,the influence of penalty factor on CNN-C performance is analyzed, which shows that too high penalty factor will lead to the decline of the neural network performance. Finally, the feature vectors are visualized via t-distributed Stochastic Neighbor Embedding(t-SNE). Naive Bayes classifier(NB) and K-Nearest Neighbor algorithm(KNN) are used to verify the validity of the feature vectors extracted by CNN-C. The results show that NB and KNN have more regular decision boundaries and higher recognition accuracy on the feature vectors data set extracted by CNN-C,indicating that the feature vectors extracted by CNN-C have great intra-class compactness and inter-class separability.

关键词： Convolutional neural networks Cracked rotor Deep metric learning Fault diagnosis Hollow shaft rotor

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

In situ growth CNT@MOFs core-shell structures enabling high specific supercapacitances in neutral aqueous electrolyte

引用

Nano Research 2022年第7期15卷 6112-6120页

作者： Mingxia lu Gang Wang Xiping Yang Bo hou School of Chemistry and Chemical Engineering Henan University of TechnologyZhengzhou 450001China School of Physics and Astronomy Cardiff UniversityCardiff CF243AAUK

Conductive metal-organic frameworks(c-MOFs)are promising active electrode materials for electrochemical double-layer capacitors with a performance that already exceeds most carbon-based ***,their excellent supercapacitance is primarily based on organic or alkaline electrolytes,which largely impede their broad applications and *** this work,we propose a new synthesis approach for fabricating carbon nanotubes and c-MOFs(CNT@MOFs)core–shell structures,which result in high supercapacitance in neutral aqueous *** identify that CNTs provide abundant active sites to ensure high capacitance,and Ni3(2,3,6,7,10,11-hexaiminotriphenylene(HITP))2 nanoarrays that in situ grow on the surface of CNTs bundles can significantly improve the conductivity and provide enough ion transport pathways in aqueous ***,using CNT@MOFs core-shell structures as an electrode,we obtained a high initial capacitance of 150.7 F·g^(−1) at 0.1 A·g^(−1) in 1 M Na2SO4 solution and good capacity retention of 83.5%after 10,000 cycles at 4 A·g^(−1).We also found that the carboxyl groups on the surface of CNTs provide better anchor sites for the in situ growth of c-MOF,which promotes the uniform growth of c-MOF shells on the CNT surface and improves aqueous electrolyte *** believe that the high supercapacitance in aqueous electrolytes reported in this work would provide a good prospect for deploying c-MOF based energy storage devices into biomedical and other healthcare electronic applications.

关键词： carbon nanotubes metal-organic frameworks(MOFs) conductive MOFs supercapacitor neutral aqueous electrolyte

来源：

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

Accurate 3D geometry measurement for non-cooperative spacecraft with an unfocused light-field camera

引用

Journal of Systems Engineering and Electronics 2022年第1期33卷 11-21页

作者： XU Shengming lu Shan hou Yueyang SHI Shengxian School of Mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China Shanghai Key Laboratory of Space Intelligent Control Technology Shanghai Aerospace Control Technology InstituteShanghai 201109China

This work explores an alternative 3D geometry measurement method for non-cooperative spacecraft guiding navigation and proximity *** one snapshot of an unfocused light-field camera, the 3D point cloud of a non-cooperative spacecraft can be calculated from sub-aperture images with the epipolar plane image(EPI) based light-field rendering algorithm.A Chang'e-3 model(7.2 cm×5.6 cm×7.0 cm) is tested to validate the proposed *** measurement distances(1.0 m, 1.2 m, 1.5 m) are considered to simulate different approaching *** errors are quantified by comparing the light-field camera data with a high precision commercial laser *** mean error distance for the three cases are 0.837 mm, 0.743 mm, and 0.973 mm respectively, indicating that the method can well reconstruct 3D geometry of a non-cooperative spacecraft with a densely distributed 3D point cloud and is thus promising in space-related missions.

关键词： 3D geometry measurement non-cooperative spacecraft unfocused light-field camera

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

A modified vegetation water supply index(MVWSI) and its application in drought monitoring over Sichuan and Chongqing, China

引用

Journal of Integrative Agriculture 2016年第9期15卷 2132-2141页

作者： WU Men-xin lu hou-quan National Meteorological Center China Meteorological Administration

Based on the principle of vegetation water supply index（VWSI）, relative normalized difference vegetation index（RNDVI） and relative land surface temperature（RLST） are proposed, with which a modified vegetation water supply index（MVWSI） is constructed, i.e.,MVWSI=RNDVI/RLST^2. Compared with VWSI, MVWSI eliminates the difference caused by the spatial and temporal distribution of VWSI. MVWSI was applied to monitor drought over Sichuan and Chongqing, China in 2006, suggesting that MVWSI can demonstrate the whole process of drought from its emergence and development to its weakening and disappearance. The relative precipitation index（RPI） is used to examine the effectiveness of MVWSI. The examination result shows that MVWSI and RPI have high consistency in spatial distribution and in-site time series analysis. Compared with vegetation condition index（VCI）, temperature condition index（TCI）, vegetation temperature condition index（VTCI） and temperature vegetation drought index（TVDI）, MVWSI is simpler in calculation and more stable hence more easily realized in application.

关键词： MVWSI drought NDVI LST

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：