检索结果-南通市图书馆

Right ventricular-arterial uncoupling as an independent prognostic factor in acute heart failure with preserved ejection fraction accompanied with coronary artery disease

在线全文

学校读者我要写书评

暂无评论

Chinese Medical Journal 2023年第10期136卷 1198-1206页

作者： Hongdan Jia li liu Xile Bi Ximing li hongliang Cong Department of Cardiology Clinical School of ThoracicTianjin Medical UniversityTianjin 300222China Department of Cardiology The First Hospital of QinhuangdaoQinhuangdaoHebei 066000China

Background:Right ventricular(RV)-arterial uncoupling is a powerful independent predictor of prognosis in heart failure with preserved ejection fraction(HFpEF).Coronary artery disease(CAD)can contribute to the pathophysiological characteristics of HFpEF.This study aimed to evaluate the prognostic value of RV-arterial uncoupling in acute HFpEF patients with CAD.Methods:This prospective study included 250 consecutive acute HFpEF patients with CAD.Patients were divided into RV-arterial uncoupling and coupling groups by the optimal cutoff value,based on a receiver operating characteristic curve of tricuspid annular plane systolic excursion to pulmonary artery systolic pressure(TAPSE/PASP).The primary endpoint was a composite of all-cause death,recurrent ischemic events,and HF hospitalizations.Results:TAPSE/PASP≤0.43 provided good accuracy in identifying patients with RV-arterial uncoupling(area under the curve,0.731;sensitivity,61.4%;and specificity,76.6%).Of the 250 patients,150 and 100 patients could be grouped into the RV-arterial coupling(TAPSE/PASP>0.43)and uncoupling(TAPSE/PASP≤0.43)groups,respectively.Revascularization strategies were slightly different between groups;the RV-arterial uncoupling group had a lower rate of complete revascularization(37.0%[37/100]vs.52.7%[79/150],Pling group.The cohort with TAPSE/PASP≤0.43 had a significantly worse prognosis than the cohort with TAPSE/PASP>0.43.Multivariate Cox analysis showed TAPSE/PASP≤0.43 as an independent associated factor for the primary endpoint,all-cause death,and recurrent HF hospitalization(hazard ratios[HR]:2.21,95%confidence interval[CI]:1.44-3.39,Pling,based on TAPSE/PASP,is independently associated with adverse outcomes in acute HFpEF patients with CA

关键词： Heart failure with preserved ejection fraction Coronary artery disease Right ventricular-arterial coupling Prognosis Revascularization

Glacier mass balance and its impacts on streamflow in a typical inland river basin in the Tianshan Mountains, northwestern China

在线全文

学校读者我要写书评

暂无评论

Journal of Arid Land 2022年第4期14卷 455-472页

作者： PENG Jiajia li Zhongqin XU liping MA Yuqing LI hongliang ZHAO Weibo FAN Shuang College of Sciences Shihezi UniversityShihezi 832003China Xinjiang Production and Construction Corps Key Laboratory of Oasis Town and Mountain-basin System Ecology Shihezi 832003China State Key Laboratory of Cryospheric Sciences/Tianshan Glaciological Station Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China College of Geography and Environmental Science Northwest Normal UniversityLanzhou 730070China

Glaciers are known as natural ’’solid reservoirs’ ’, and they play a dual role between the composition of water resources and the river runoff regulation in arid and semi-arid areas of China. In this study, we used in situ observation data from Urumqi Glacier No. 1, Xinjiang Uygur Autonomous Region, in combination with meteorological data from stations and a digital elevation model, to develop a distributed degree-day model for glaciers in the Urumqi River Basin to simulate glacier mass balance processes and quantify their effect on streamflow during 1980–2020. The results indicate that the mass loss and the equilibrium line altitude(ELA) of glaciers in the last 41 years had an increasing trend, with the average mass balance and ELA being-0.85(±0.32) m w.e./a(meter water-equivalent per year) and 4188 m a.s.l., respectively. The glacier mass loss has increased significantly during 1999–2020, mostly due to the increase in temperature and the extension of ablation season. During 1980–2011, the average annual glacier meltwater runoff in the Urumqi River Basin was 0.48×108 m3, accounting for 18.56% of the total streamflow. We found that the annual streamflow in different catchments in the Urumqi River Basin had a strong response to the changes in glacier mass balance, especially from July to August, and the glacier meltwater runoff increased significantly. In summary, it is quite possible that the results of this research can provide a reference for the study of glacier water resources in glacier-recharged basins in arid and semi-arid areas.

关键词： glacier mass balance glacier meltwater runoff glacier modelling Urumqi River Basin Tianshan Mountains

Non-uniform Compressive Sensing Imaging Based on Image Saliency

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Electronics 2023年第1期32卷 159-165页

作者： LI hongliang DAI Feng ZHAO Qiang MA Yike CAO Juan ZHANG Yongdong University of Chinese Academy of Sciences Key Lab of Intelligent Information Processing of Chinese Academy of Sciences Institute of Computing Technology Chinese Academy of Sciences University of Science and Technology of China

For more effective image sampling, compressive sensing(CS) imaging methods based on image saliency have been proposed in recent years. Those methods assign higher measurement rates to salient regions,but lower measurement rate to non-salient regions to improve the performance of CS imaging. However, those methods are block-based, which are difficult to apply to actual CS sampling, as each photodiode should strictly correspond to a block of the scene. In our work, we propose a non-uniform CS imaging method based on image saliency, which assigns higher measurement density to salient regions and lower density to non-salient regions,where measurement density is the number of pixels measured in a unit size. As the dimension of the signal is reduced, the quality of reconstructed image will be improved theoretically, which is confirmed by our experiments. Since the scene is sampled as a whole, our method can be easily applied to actual CS sampling. To verify the feasibility of our approach, we design and implement a hardware sampling system, which can apply our non-uniform sampling method to obtain measurements and reconstruct the images. To our best knowledge, this is the first CS hardware sampling system based on image saliency.

关键词： Compressive sensing Non-uniform Measurement density Image saliency

Effect of topography on the changes of Urumqi Glacier No.1 in the Chinese Tianshan Mountains

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Journal of Arid Land 2022年第7期14卷 719-738页

作者： LI hongliang WANG Puyu li Zhongqin JIN Shuang XU Chunhai MU Jianxin HE Jie YU Fengchen State Key Laboratory of Cryosphere Science Northwest Institute of Eco-Environment and ResourcesChinese Academy of SciencesLanzhou 730000China University of Chinese Academy of Sciences Beijing 100049China College of Sciences Shihezi UniversityShihezi 832000China College of Geography and Environmental Science Northwest Normal UniversityLanzhou 730070China

Topography plays an important role in determining the glacier changes.However,topography has often been oversimplified in the studies of the glacier changes.No systematic studies have been conducted to evaluate the relationship between the glacier changes and topographic features.The present study provided a detailed insight into the changes in the two branches(east branch and west branch)of Urumqi Glacier No.1 in the Chinese Tianshan Mountains since 1993 and systematically discussed the effect of topography on the glacier parameters.This study analyzed comprehensive recently observed data(from 1992/1993 to 2018/2019),including mass balance,ice thickness,surface elevation,ice velocity,terminus,and area,and then determined the differences in the changes of the two branches and explored the effect of topography on the glacier changes.We also applied a topographic solar radiation model to analyze the influence of topography on the incoming shortwave radiation(SW_(in))across the entire glacier,focusing on the difference in the SW_(in) between the two branches.The glacier mass balance of the east branch was more negative than that of the west branch from 1992/1993 to 2018/2019,and this was mainly attributed to the lower average altitude of the east branch.Compared with the west branch,the decrease rate of the ice velocity was lower in the east branch owing to its relatively increased slope.The narrow shape of the west branch and its southeast aspect in the earlier period resulted in a larger glacier terminus retreat of the west branch.The spatial variability of the SW_(in) across the glacier surface became much larger as altitude increased.The SW_(in) received by the east branch was slightly larger than that received by the west branch,and the northern aspect could receive more SW_(in),leading to glacier melting.In the future,the difference of the glacier changes between the two branches will continue to exist due to their topographic differences.This work is fundamental to understanding how topographic features affec

关键词： glacier changes topography solar radiation glacier terminus retreat climate warming Urumqi Glacier No.1 Chinese Tianshan Mountains

Stability and Convergence of the Canonical Euler Splitting Method for Nonlinear Composite Stiff Functional Differential-Algebraic Equations

在线全文

学校读者我要写书评

暂无评论

Advances in Applied Mathematics and Mechanics 2022年第6期14卷 1276-1301页

作者： hongliang liu Yameng Zhang Haodong li Shoufu li School of Mathematics and Computational Science&Hunan Key Laboratory for Computation and Simulation in Science and Engineering Xiangtan UniversityXiangtanHunan 411105China

A novel canonical Euler splitting method is proposed for nonlinear compositestiff functional differential-algebraic equations, the stability and convergence of themethod is evidenced, theoretical results are further confirmed by some numerical experiments.Especially, the numerical method and its theories can be applied to specialcases, such as delay differential-algebraic equations and integral differential-algebraicequations.

关键词： Canonical Euler splitting method nonlinear composite stiff functional differentialalgebraic equations stability convergence.

A multi-index assessment method for evaluating coverage effectiveness of remote sensing satellite

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

Chinese Journal of Aeronautics 2018年第10期31卷 2023-2033页

作者： hongliang li Dong li Yunhua li School of Automation Science and Electrical Engineering Beihang University Beijing Aeronautical Science and Technology Research Institute of COMAC School of Aeronautic Science and Engineering Beihang University

This paper deals with the multi-index assessment method for evaluating coverage effectiveness of remote sensing satellite. Because a series of satellite activities such as imaging, moving target observation, and environment investigation need to know the coverage characteristics, the coverage capability of the remote sensing satellite is the most important index. Thus, it is very important to establish the method of effectiveness evaluation of coverage characteristics. This paper focuses on the assessment of coverage effectiveness of remote sensing satellite, and proposes and designs a multi-index evaluation method based on index weight using entropy weight method and analytic hierarchy process. With a simulation case, the effectiveness evaluation results of single satellite coverage and multi-satellite coverage performance are given for the proposed assessment.The experimental results show that the established coverage characteristic model and the proposed assessment method are effective and right.

关键词： Analytic hierarchy process Coverage ability Effectiveness evaluation Entropy weight method Remote sensing satellite

Real‑Time Optimal Trajectory Planning for Autonomous Driving with Collision Avoidance Using Convex Optimization

在线全文

学校读者我要写书评

暂无评论

Automotive Innovation 2023年第3期6卷 481-491页

作者： Guoqiang li Xudong Zhang hongliang Guo Basilio Lenzo Ningyuan Guo School of Mechanical Engineering Beijing Institute of TechnologyBeijing 100081China Institute for Infocomm Research ASTARSingaporeSingapore Department of Industrial Engineering University of PadovaPaduaItaly

An online trajectory planning method for collision avoidance is proposed to improve vehicle driving safety and comfort simultaneously.The collision-free trajectory for autonomous driving is formulated as a nonlinear optimization problem.A novel approximate convex optimization approach is developed for the online optimal trajectory in both longitudinal and lateral directions.First,a dual variable is used to model the non-convex collision-free constraint for driving safety and is calculated by solving a dual problem of the relative distance between vehicles.Second,the trajectory is further optimized in a model predictive control framework considering the safety.It realizes continuous-time and dynamic feasible motion with collision avoidance.The geometry of object vehicles is described by polygons instead of circles or ellipses in traditional methods.In order to avoid aggressive maneuver in the longitudinal and lateral directions for driving comfort,rates of the acceleration and the steering angle are restricted.The final formulated optimization problem is convex,which can be solved by using quadratic programming solvers and is computationally efficient for online application.Simulation results show that this approach can obtain similar driving performance compared to a state-of-the-art nonlinear optimization method.Furthermore,various driving scenarios are tested to evaluate the robustness and the ability for handling complex driving tasks.

关键词： Trajectory planning Collision avoidance Model predictive control Autonomous driving

THE QUADRATIC SPECHT TRIANGLE

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

Journal of Computational Mathematics 2020年第1期38卷 103-124页

作者： hongliang li Pingbing Ming Zhongci Shi Department of Mathematics Sichuan Normal UniversityChengdu 610066China The State Key Laboratory of Scientific and Engineering Computing Academy of Mathematics and Systems ScienceChinese Academy of SciencesNo.55East Road ZhongGuanCunBeijing 100190China

We propose a class of 12 degrees of freedom triangular plate bending elements with quadratic rate of convergence.They may be viewed as the second order Specht triangle,while the Specht triangle is one of the best first order plate bending element.The convergence result is proved under minimal smoothness assumption on the solution.Numerical results for both the smooth solution and nonsmmoth solution confirm the theoretical prediction.

关键词： Specht triangle Plate bending element Basis functions

Effects of minor Sr addition on as-cast microstructure and mechanical properties of a Mg-3Sn-2Ca(wt.%) magnesium alloy

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

China Foundry 2014年第2期11卷 108-114页

作者： Yang Mingbo LI hongliang Duan Chengyu School of Materials Science & Engineering Chongqing University of Technology Key Laboratory of Manufacture and Test Techniques for Automobile Parts Ministry of EducationChongqing University of Technology

Minor Sr was introduced to the Mg-3Sn-2Ca(wt.%) alloy in this paper, and the effects of minor Sr addition on the as-cast microstructure and mechanical properties of the Mg-3Sn-2Ca(wt.%) alloy were investigated by using of optical and electron microscopies, differential scanning calorimetry(DSC) analysis, and tensile and creep tests. The results indicate that, after adding 0.034wt.%, 0.065wt.% or 0.10wt.% Sr to the Mg-3Sn-2Ca alloy, the morphology of the primary CaMgSn phase changes from the initial coarse needle-like net to relatively fi ne short block and/or particle-like shapes. At the same time, the additions of 0.034wt.% or 0.065wt.% Sr suppress the formation of the primary CaMgSn phase, and the addition of 0.10wt.% Sr not only suppresses the formation of the primary and eutectic CaMgSn phases but also promotes the formation of Mg2Ca phase. Furthermore, the addition of minor Sr to the Mg-3Sn-2Ca alloy can improve the tensile properties of the alloy both at room temperature and 150 ℃. The creep property of the Mg-3Sn-2Ca alloy at 150 ℃ is also improved by the additions of 0.034wt.% and 0.065wt.% Sr; however, the addition of 0.10wt.% Sr is not benefi cial to the creep properties of the Mg-3Sn-2Ca alloy.

关键词： magnesium alloys Mg-Sn-Ca alloys CaMgSn phase Sr addition