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School of Energy Resources,University of Wyoming Fostering energy-driven economic development

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Clean Energy 2020年第4期4卷 389-392页

作者： Holly Krutka School of Energy Resources University of Wyoming1000 E.University AveLaramieWY 82071USA

1 Our mission The School of Energy Resources(SER)at the University of Wyoming(UW)was created in 2006 to enhance the university’s energy-related education,research and outreach.SER directs and integrates cutting-edge energy research and academic programmes at UW and bridges academics and industry through targeted outreach programmes.

关键词： education Foster bridges

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IN THE ZONE

Beijing Review 2023年第50期66卷 12-17页

作者： Yuan Yuan 不详

At the crossroads of Shanghai and its neighboring Zhejiang and Jiangsuprovinces,a quadrangle complex is under construction as part of a demonstration zone for integrated ecological and green development in the Yangtze River Delta,one of China's most robust,open and innovative regions.Built directly over the Taipu River,which flows through Shanghai,Zhejiang and Jiangsu,the complex will be designed as four pavilions connected by three bridges over the river,showcasing Shanghai,Jiangsu,Zhejiang and Anhui provinces.

关键词： Anhui bridges Jiangsu

Factors affecting the seismic behavior of segmental precast bridge columns

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Frontiers of Structural and Civil Engineering 2014年第4期8卷 388-398页

作者： Haitham DAWOOD Mohamed ELGAWADY Joshua HEWES Virginia Polytechnic Institute and State University Blacksburg VA 24061-0002 USA Department of Civil Architectural and Environmental Engineering Missouri University of Science and Technology Rolla MO65409 USA Department of Civil and Environmental Engineering Northern Arizona University Flagstaff AZ 86011 USA

This manuscript discusses the design parameters that potentially affect the lateral seismic response of segmental precast post-tensioned bridge piers. The piers consist ofprecast circular cross section segments stacked one on top of the other with concentric tendons passing through ducts made in the segments during casting. The bottommost segments of the piers were encased in steel tubes to enhance ductility and minimize damage. An FE model was used to investigate different design parameters and how they influence the lateral force - displacement response of the piers. Design parameters investigated included the initial post-tensioning stress as a percentage of the tendon yield stress, the applied axial stresses on concrete due to post-tensioning, pier aspect ratios, construction details, steel tube thicknesses, and internal mild steel rebar added as energy dissipaters. Based on the data presented, an initial tendon stress in the range of 40%-60% of its yield stress and initial axial stress on concrete of approximately 20% of the concrete＇s characteristic strength is appropriate for most typical designs. These design values will prevent tendon yielding until lateral drift angle reaches approximately 4.5%. Changing the steel tube thickness, height, or a combination of both proved to be an effective parameter that may be used to reach a target performance level at a specific seismic zone.

关键词： finite element analysis concrete precast units bridges

Reduction of local scour around bridge pier groups using collars

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International Journal of Sediment Research 2010年第4期25卷 411-422页

作者： Manouchehr HEIDARPOUR Hossein AFZALIMEHR Elham IZADINIA Department of Water Engineering Isfahan University of Technology Isfahan Iran Graduate Student of Water Engineering Isfahan University of Technology Isfahan Iran Department of Water Engineering Isfahan University of Technology Isfahan Iran

In this paper reduction of scour around group of two and three piers using circular collar has been carried out for the case of clear-water flow over uniform sediment. The efficiency of collars, with different sizes and spaces between piers is studied through experiments in group of two and three piers. The result reveals that collar has more influence in reduction of scour depth in rear piers than the first pier. Also, when the spacing between the piers increases the area without protection between the piers is washed away resulting deeper scour holes at the rear piers.

关键词： Scour bridges Group piers Collar

Why Does China-EU Cooperation Matter?

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China Today 2022年第5期71卷 16-18页

作者： ZHANG HUI 不详

China and the Eu need to build four bridges for peace, growth, reform, and progress of civilization, so that the china-Eu comprehensive strategic partnership will take on even greater global significance.EIGHT years ago, on his first visit to Europe after taking the presidency, Xi Jinping proposed that China and the EUaneed to build four bridges for peace, growth,reform, and progress of civilization, so that the China-EU comprehensive strategic partnership will take on even greater global significance,owhen addressing the College of Europe in Bruges,Belgium, on April 1, 2014.

关键词： significance bridges peace

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Characteristics of developing scour-holes at a sand-embedded cylinder

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International Journal of Sediment Research 2008年第3期23卷 258-266页

作者： Oscar LINK Florian PFLEGER Ulrich ZANKE Dept. of Civil Engineering University of Concepción Edmundo Larenas 270 Concepción Chile.Dr.-Ing. Assistant Prof. Doctoral Research Fellow Institute for Hydromechanics Technische Universitt München Arcisstrasse 21 80333 München Germany. Institute for Hydraulic and Water Resources Engineering Darmstadt University of Technology Rundeturmstraβe 1 64283 Germany.Full Prof.

Characteristics of developing scour-holes at a sand-embedded 0.2 m diameter circular cylinder are presented. Non-intrusive, high-resolution topographic measurements of developing scour-holes were made with an experimental installation using a laser distance sensor (LDS) and precision step-motors. A clear-water experiment was conducted with bed shear stress equal to 95% of the critical bed shear stress for the initiation of sediment motion at the undisturbed plane sand bed with a d50 of 0.26 mm. During the running experiment of 21 hours duration, measurements were taken by the LDS in different azimuthal half-planes with θ = 0, 15, 30, 45, 60, 75, 90, 105, 120, 135, 150, 165 and 180o in order to study the spatio-temporal variation of geometric properties in developing scour-holes. After 21 hours, the equilibrium condition was approached, with a scour rate less than d50 per hour. Measurement of maximum scour depth in different azimuthal half-planes at different points in time during the experiment show that scour started at the cylinder side and surrounded the cylinder after about 20% of experiment time. Slopes of developing scour-holes presented three regions with different inclinations, which were attributed to vortex action. Both maximum scour depth and maximum scour radius at different azimuthal half-planes are well correlated with the maximum scour depth at plane with θ = 0o. When providing maximum scour depth at the cylinder front, the presented correlations are useful for simple calculation of scour-hole topography. This work provides an experimental database for advanced numerical simulation for loose sediment hydraulics.

关键词： Scour bridges Piers Sediment transport Loose sediment hydraulics

Inference of change-point in single index models

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Science China Mathematics 2008年第10期51卷 1855-1870页

作者： CAO GuanQun WANG ZhanFeng WU YaoHua ZHAO LinCheng Department of Statistics and Finance University of Science and Technology of ChinaHefei 230026China

Single index models are widely used in medicine, econometrics and some other fields. In this paper, we consider the inference of a change point problem in single index models. Based on density-weighted average derivative estimation (ADE) method, we propose a statistic to test whether a change point exists or not. The null distribution of the test statistic is obtained using a permutation technique. The permuted statistic is rigorously shown to have the same distribution in the limiting sense under both null and alternative hypotheses. After the null hypothesis of no change point is rejected, an ADE-based estimate of the change point is proposed under assumption that the change point is unique. A simulation study confirms the theoretical results.

关键词： change point single index models density weighted average derivatives U-statistic Brownian bridges

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Breaking the Ice to Warm Relations-An Interview with Stephen Perry,Chairman of the 48 Group Club

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China Today 2022年第6期71卷 46-48页

作者： ZHOU LIN 不详

More bridges are needed to connect China to the world,fostering dialogue and mutual understanding.THIS year marks the 50th anniversary of the establishment of diplomatic relations at the ambassadorial level between Ch... 详细信息

关键词： mutual bridges Chairman

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Reimagining Our Future Together

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ChinAfrica 2023年第8期15卷 60-64页

Youth in five BRICS countries express their thoughts and hopes for cooperation and exchanges in a new era,As one passes through the bridges and dams that cross the ParanáRiver in Brazil,near the Jupiáand Ilha Solteira hydroelectric power plants,one witnesses a complex and challenging process of modernisation and technological renewal,which is currently the largest modernisation project of hydroelectric power plants in Brazil.

关键词： Together bridges Brazil