The reaction of chlorine atom Cl(2P)(Cl(2P3/2)and Cl^*(2P1/2))with D2 was investigated at collision energy from 4.5 kcal/mol to 6.5 kcal/mol with a high-resolution crossed molecular beam apparatus using the technique ...The reaction of chlorine atom Cl(2P)(Cl(2P3/2)and Cl^*(2P1/2))with D2 was investigated at collision energy from 4.5 kcal/mol to 6.5 kcal/mol with a high-resolution crossed molecular beam apparatus using the technique of D-atom Rydberg tagging detection.The contribution from the spin-orbit excited reaction Cl^*(2P1/2)+D2,which is prohibited by Born-Oppenheimer(BO)approximation,was observed.Collision-energy dependence of differential cross sections(DCSs)near the backward scattering direction was measured.The BOforbidden reaction Cl^*+D2 was found to be dominant at lower collision energy.As collision energy increases,reactivity of BO-allowed reaction Cl+D2 increases much faster than that of BO-forbidden reaction and becomes dominant at higher collision energy.Our experiment indicates that the additional energy of spin-orbit excitation in Cl^*facilitates BO-forbidden reaction to pass through the barrier at lower collision energy,while BO approximation is still valid at collision energy near and above the reaction barrier.This tendency of reactivity of Cl/Cl^*+D2 is similar to the isotopic reaction of Cl/Cl^*+H2.展开更多
Seven reinforced concrete （ RC ） beams strengthened in flexure using carbon fiber reinforced polymer （CFRP） sheets subjected to different sustaining loads were tested. The effects of initial load and load history ...Seven reinforced concrete （ RC ） beams strengthened in flexure using carbon fiber reinforced polymer （CFRP） sheets subjected to different sustaining loads were tested. The effects of initial load and load history on the ultimate strength of strengthened RC beams were examined by externally bonded CFRP sheets. The main experimental parameters included different levels of sustaining load at the time of strengthening, and load history. Experimental results show that sustaining load levels at the time of strengthening have important influences on the ultimate strength of strengthened RC beams. If the initial load is the same, the ultimate strength of RC beams strengthened with CFRP sheets is almost the same regardless of load history at the time of strengthening.展开更多
This research applies experimental measurements and NUBEAM,ONETWO and TRANSP modules to investigate the shine-through(ST)loss ratio and beam heating percentage of neutral beam injection on EAST.Measurements and simula...This research applies experimental measurements and NUBEAM,ONETWO and TRANSP modules to investigate the shine-through(ST)loss ratio and beam heating percentage of neutral beam injection on EAST.Measurements and simulations confirm that the ST loss ratio increases linearly with beam energy,and decreases exponentially with plasma density.Moreover,using the multi-step fitting method,we present analytical quantitative expressions of ST loss ratio and beam heating percentage,which are valuable for the high parameter long-pulse experiments of EAST.展开更多
A new type of semi-rigid thin-walled steel-concrete composite beam-to-column joint has been proposed in this paper.Five semi-rigid composite beam-to-column joint specimens subjected to hogging moments under monotonic ...A new type of semi-rigid thin-walled steel-concrete composite beam-to-column joint has been proposed in this paper.Five semi-rigid composite beam-to-column joint specimens subjected to hogging moments under monotonic loading were tested to study the static behavior of this new type of joint.The main variable parameters for the five joint specimens were the longitudinal reinforcement ratio and the joint type.The experimental results designated that the magnitude of extension of the longitudinal reinforcement is the most important factor that influenced the moment-rotation characteristic of the new type of joint.The concrete slabs could resist 3.8%-19.1% of the total shear load applied to the cross-sections near the beam-to-column connection.The edge stiffened elements,such as the flange of the lipped I-section thin-walled steel beam,were capable of having considerable inelastic deformation capacity although they had comparatively large width-to-thickness ratios.The shear failure of the concrete cantilever edge strip must be taken into account in practical design because it has significant influence on the anchorage of the longitudinal reinforcement in the new type of external joints.展开更多
抗拔不抗剪(uplift-restricted and slip-permitted,URSP)连接件技术,通过释放组合梁负弯矩区的部分组合作用,达到降低混凝土板拉应力的目的,是一种新型组合技术。该文研究发现:布置抗拔不抗剪连接件时,界面抗剪区域和界面不抗剪区域存...抗拔不抗剪(uplift-restricted and slip-permitted,URSP)连接件技术,通过释放组合梁负弯矩区的部分组合作用,达到降低混凝土板拉应力的目的,是一种新型组合技术。该文研究发现:布置抗拔不抗剪连接件时,界面抗剪区域和界面不抗剪区域存在耦合受力现象,该耦合受力对抗拔不抗剪组合梁的抗裂机制有较大影响。以往关于抗拔不抗剪组合梁的研究很少提及类似耦合效应,不能正确揭示抗拔不抗剪组合梁的受力性能。为了正确考虑不同界面连接区域的耦合受力带来的影响,该研究采用连续组合梁开展试验研究。试验制作并测试了3个连续组合梁试件。该文从6个方面对试件的性能进行详细地对比和分析,具体包括:开裂荷载、裂缝分布和发展模式、界面滑移、变形和刚度、内力重分布情况和应变分布。研究发现:抗拔不抗剪连接件能实现部分组合作用的释放,对负弯矩区混凝土裂缝宽度的控制有显著作用;同时,采用抗拔不抗剪连接件,对组合梁的刚度、承载力、钢梁应变等几乎没有影响。展开更多
Neutral beam injector for EAST is designed to deliver deuterium beams with a power of 2 MW to 4 MW at an energy of 50 keV to 80 keV into the plasma with a beam dimension of 12 cm× 48 cm. Considering the beam gene...Neutral beam injector for EAST is designed to deliver deuterium beams with a power of 2 MW to 4 MW at an energy of 50 keV to 80 keV into the plasma with a beam dimension of 12 cm× 48 cm. Considering the beam generation and transmission, a columniform beam-line of Ф 250 cm × 400 cm is designed with a neutralizer, ion dump, calorimeter, bending magnet and cryopanels. The arrangement of the internal elements for the beam-line is reported. A rectangular sleeve coupled to the ion source is employed as the neutralizer. At the downstream of the neutralizer, a dipole magnet separates the residual ions from the beam passage with a reflection radius of 42 cm for the full energy particles. The calorimeter and the ion dump serve as high heat flux components, which will work as thermal inertia targets in the first phase of operation.展开更多
In this paper the semi-analytical analyses of the flexible cantilever tapered functionally graded beam under combined inclined end loading and intermediate loading are studied.In order to derive the fully non-linear e...In this paper the semi-analytical analyses of the flexible cantilever tapered functionally graded beam under combined inclined end loading and intermediate loading are studied.In order to derive the fully non-linear equations governing the non-linear deformation,a curvilinear coordinate system is introduced.A general non-linear second order differential equation that governs the shape of a deflected beam is derived based on the geometric nonlinearities,infinitesimal local displacements and local rotation concepts with remarkable physical properties of functionally graded materials.The solutions obtained from semi-analytical methods are numerically compared with the existing elliptic integral solution for the case of a flexible uniform cantilever functionally graded beam.The effects of taper ratio,inclined end load angle and material property gradient on large deflection of the beam are evaluated.The Adomian decomposition method will be useful toward the design of tapered functionally graded compliant mechanisms driven by smart actuators.展开更多
轨道梁作为跨座式单轨交通三大核心技术之一,其核心技术的创新与发展一直都是制约我国单轨交通发展的重要因素之一。结合“新型25 m PC轨道梁优化设计与制造工艺”课题,自主开发了“PC轨道梁配筋计算程序”和“PC轨道梁标准定型化设计...轨道梁作为跨座式单轨交通三大核心技术之一,其核心技术的创新与发展一直都是制约我国单轨交通发展的重要因素之一。结合“新型25 m PC轨道梁优化设计与制造工艺”课题,自主开发了“PC轨道梁配筋计算程序”和“PC轨道梁标准定型化设计软件”,并设计完成了跨座式单轨交通新型25 m PC轨道梁。通过智能软件自动生成25 m PC轨道梁的预应力钢筋和普通钢筋布置图,对轨道梁进行足尺25 m PC轨道梁静载、扭转、开裂、300万次疲劳和破坏试验验证。为验证新型25 m PC轨道梁优化设计与软件计算的正确性,将其试验数据与自制软件计算出的数据和理论数据进行对比。结果表明:软件自动设计的轨道梁,最大竖向挠度实测值为21.75 mm,校验系数为0.89,挠跨比为1/1122,而水平挠度实测值为2.36 mm,校验系数为0.72,满足规范要求;结合偏心及中心加载两种工况下试验结果,梁体应力差值在-0.51~0.61 MPa之间,扭转对直梁影响较小;开裂试验中,实测开裂荷载值为947 kN,实测重裂荷载为707 kN,由此得到梁体实际有效预应力975.26 MPa,实测值略大于设计有效预应力972.26 MPa,上述数据说明自动绘制的配筋图可以用于实际工程中。开发的智能软件对跨座式单轨交通轨道梁的智能建造提供技术支撑。展开更多
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences (No.XDB17000000)the National Natural Science Foundation of China (No.21573226,No.21822305,No.21688102).
文摘The reaction of chlorine atom Cl(2P)(Cl(2P3/2)and Cl^*(2P1/2))with D2 was investigated at collision energy from 4.5 kcal/mol to 6.5 kcal/mol with a high-resolution crossed molecular beam apparatus using the technique of D-atom Rydberg tagging detection.The contribution from the spin-orbit excited reaction Cl^*(2P1/2)+D2,which is prohibited by Born-Oppenheimer(BO)approximation,was observed.Collision-energy dependence of differential cross sections(DCSs)near the backward scattering direction was measured.The BOforbidden reaction Cl^*+D2 was found to be dominant at lower collision energy.As collision energy increases,reactivity of BO-allowed reaction Cl+D2 increases much faster than that of BO-forbidden reaction and becomes dominant at higher collision energy.Our experiment indicates that the additional energy of spin-orbit excitation in Cl^*facilitates BO-forbidden reaction to pass through the barrier at lower collision energy,while BO approximation is still valid at collision energy near and above the reaction barrier.This tendency of reactivity of Cl/Cl^*+D2 is similar to the isotopic reaction of Cl/Cl^*+H2.
文摘Seven reinforced concrete （ RC ） beams strengthened in flexure using carbon fiber reinforced polymer （CFRP） sheets subjected to different sustaining loads were tested. The effects of initial load and load history on the ultimate strength of strengthened RC beams were examined by externally bonded CFRP sheets. The main experimental parameters included different levels of sustaining load at the time of strengthening, and load history. Experimental results show that sustaining load levels at the time of strengthening have important influences on the ultimate strength of strengthened RC beams. If the initial load is the same, the ultimate strength of RC beams strengthened with CFRP sheets is almost the same regardless of load history at the time of strengthening.
基金Supported by the Collaborative Innovation Program of Hefei Science Center,CAS (Grant No.2019HSC-CIP015)the National Natural Science Foundation of China (Grant Nos.11875290,1170529,11875253,and 11975276)+2 种基金the Fundamental Research Funds for the Central Universities (Grant No.WK3420000004)the Anhui Provincial Natural Science Foundation (Grant No.2008085J04)the National Key Research and Development Program of China (Grant No.2019YFE03020004)。
文摘This research applies experimental measurements and NUBEAM,ONETWO and TRANSP modules to investigate the shine-through(ST)loss ratio and beam heating percentage of neutral beam injection on EAST.Measurements and simulations confirm that the ST loss ratio increases linearly with beam energy,and decreases exponentially with plasma density.Moreover,using the multi-step fitting method,we present analytical quantitative expressions of ST loss ratio and beam heating percentage,which are valuable for the high parameter long-pulse experiments of EAST.
基金Sponsored by the National Natural Science Foundation of China (Grant No.50478027)
文摘A new type of semi-rigid thin-walled steel-concrete composite beam-to-column joint has been proposed in this paper.Five semi-rigid composite beam-to-column joint specimens subjected to hogging moments under monotonic loading were tested to study the static behavior of this new type of joint.The main variable parameters for the five joint specimens were the longitudinal reinforcement ratio and the joint type.The experimental results designated that the magnitude of extension of the longitudinal reinforcement is the most important factor that influenced the moment-rotation characteristic of the new type of joint.The concrete slabs could resist 3.8%-19.1% of the total shear load applied to the cross-sections near the beam-to-column connection.The edge stiffened elements,such as the flange of the lipped I-section thin-walled steel beam,were capable of having considerable inelastic deformation capacity although they had comparatively large width-to-thickness ratios.The shear failure of the concrete cantilever edge strip must be taken into account in practical design because it has significant influence on the anchorage of the longitudinal reinforcement in the new type of external joints.
文摘抗拔不抗剪(uplift-restricted and slip-permitted,URSP)连接件技术,通过释放组合梁负弯矩区的部分组合作用,达到降低混凝土板拉应力的目的,是一种新型组合技术。该文研究发现:布置抗拔不抗剪连接件时,界面抗剪区域和界面不抗剪区域存在耦合受力现象,该耦合受力对抗拔不抗剪组合梁的抗裂机制有较大影响。以往关于抗拔不抗剪组合梁的研究很少提及类似耦合效应,不能正确揭示抗拔不抗剪组合梁的受力性能。为了正确考虑不同界面连接区域的耦合受力带来的影响,该研究采用连续组合梁开展试验研究。试验制作并测试了3个连续组合梁试件。该文从6个方面对试件的性能进行详细地对比和分析,具体包括:开裂荷载、裂缝分布和发展模式、界面滑移、变形和刚度、内力重分布情况和应变分布。研究发现:抗拔不抗剪连接件能实现部分组合作用的释放,对负弯矩区混凝土裂缝宽度的控制有显著作用;同时,采用抗拔不抗剪连接件,对组合梁的刚度、承载力、钢梁应变等几乎没有影响。
基金supported by National Natural Science Foundation of China (No. 10875146)the Knowledge Innovation Program of the Chinese Academy of Sciences:The study and simulation on beam interaction with background particles in neutralization area for NBI
文摘Neutral beam injector for EAST is designed to deliver deuterium beams with a power of 2 MW to 4 MW at an energy of 50 keV to 80 keV into the plasma with a beam dimension of 12 cm× 48 cm. Considering the beam generation and transmission, a columniform beam-line of Ф 250 cm × 400 cm is designed with a neutralizer, ion dump, calorimeter, bending magnet and cryopanels. The arrangement of the internal elements for the beam-line is reported. A rectangular sleeve coupled to the ion source is employed as the neutralizer. At the downstream of the neutralizer, a dipole magnet separates the residual ions from the beam passage with a reflection radius of 42 cm for the full energy particles. The calorimeter and the ion dump serve as high heat flux components, which will work as thermal inertia targets in the first phase of operation.
文摘In this paper the semi-analytical analyses of the flexible cantilever tapered functionally graded beam under combined inclined end loading and intermediate loading are studied.In order to derive the fully non-linear equations governing the non-linear deformation,a curvilinear coordinate system is introduced.A general non-linear second order differential equation that governs the shape of a deflected beam is derived based on the geometric nonlinearities,infinitesimal local displacements and local rotation concepts with remarkable physical properties of functionally graded materials.The solutions obtained from semi-analytical methods are numerically compared with the existing elliptic integral solution for the case of a flexible uniform cantilever functionally graded beam.The effects of taper ratio,inclined end load angle and material property gradient on large deflection of the beam are evaluated.The Adomian decomposition method will be useful toward the design of tapered functionally graded compliant mechanisms driven by smart actuators.
文摘轨道梁作为跨座式单轨交通三大核心技术之一,其核心技术的创新与发展一直都是制约我国单轨交通发展的重要因素之一。结合“新型25 m PC轨道梁优化设计与制造工艺”课题,自主开发了“PC轨道梁配筋计算程序”和“PC轨道梁标准定型化设计软件”,并设计完成了跨座式单轨交通新型25 m PC轨道梁。通过智能软件自动生成25 m PC轨道梁的预应力钢筋和普通钢筋布置图,对轨道梁进行足尺25 m PC轨道梁静载、扭转、开裂、300万次疲劳和破坏试验验证。为验证新型25 m PC轨道梁优化设计与软件计算的正确性,将其试验数据与自制软件计算出的数据和理论数据进行对比。结果表明:软件自动设计的轨道梁,最大竖向挠度实测值为21.75 mm,校验系数为0.89,挠跨比为1/1122,而水平挠度实测值为2.36 mm,校验系数为0.72,满足规范要求;结合偏心及中心加载两种工况下试验结果,梁体应力差值在-0.51~0.61 MPa之间,扭转对直梁影响较小;开裂试验中,实测开裂荷载值为947 kN,实测重裂荷载为707 kN,由此得到梁体实际有效预应力975.26 MPa,实测值略大于设计有效预应力972.26 MPa,上述数据说明自动绘制的配筋图可以用于实际工程中。开发的智能软件对跨座式单轨交通轨道梁的智能建造提供技术支撑。
