The present work is a visualization study of a typical kerosene （RP-3） flowing through vertical and horizontal quartz-glass tubes under both sub- and supercritical conditions by a high speed camera. The experiments ...The present work is a visualization study of a typical kerosene （RP-3） flowing through vertical and horizontal quartz-glass tubes under both sub- and supercritical conditions by a high speed camera. The experiments are accomplished at temperatures of 300-730 K under pressures from 0.107-5 MPa. Six distinctive two-phase flow patterns are observed in upward flow and the critical point of RP-3 is identified as critical pressure pc=2.33 MPa and critical temperature Tc=645.04 K and it is found that when the fluid pressure exceeds 2.33 MPa the flow can be considered as a single phase flow. The critical opalescence phenomenon of RP-3 is observed when the temperature is between 643.16 K and 648.61 K and the pressure is between 2.308 MPa and 2.366 MPa. The region filled by the critical opalescence in the upward flow is clearly larger than that in the downward flow due to the interaction between the buoyancy force and fluid inertia. Morecover, obvious layered flow phenomenon is observed in horizontal flow under supercritical pressures due to the differences of gravity and density.展开更多
相对论重离子碰撞(又称高能核-核碰撞)为研究极端条件下核物质内禀性质、致密星体内部结构和大爆炸之后宇宙的早期演化过程提供了途径.强相互作用的量子色动力学(QCD)理论预言存在着解禁闭的新物质状态夸克-胶子等离子体(QGP).经过近30...相对论重离子碰撞(又称高能核-核碰撞)为研究极端条件下核物质内禀性质、致密星体内部结构和大爆炸之后宇宙的早期演化过程提供了途径.强相互作用的量子色动力学(QCD)理论预言存在着解禁闭的新物质状态夸克-胶子等离子体(QGP).经过近30年的努力,在极端相对论能区的核-核对撞实验中,包括RHIC和LHC的实验,科学家找到了QGP存在的证据.目前,高能核物理的一个重要的科学问题是高重子密度区的相结构,包括寻找相边界和可能存在的QCD临界点.量子热动力学基本原理告诉我们只有找到相边界或临界点才能最终确定新的物质相QGP的存在.我们首先回顾了高能核物理实验的研究现状,其中包括RHIC能量扫描实验中的强子集体运动、手征特性的研究和QCD临界点的寻找.然后对利用我国重离子加速器群,如Heavy Ion Research Facility in Lanzhou (HIRFL)和High Intensity heavy-ion Accelerator Facility (HIAF)以及CSR-External-target Experiment等开展高能核物理实验研究进行了展望.展开更多
This paper introduces how crustal thickening controls the growth of the Himalaya by summarizing the P-T-t evolution of the Himalayan metamorphic core.The Himalayan orogeny was divided into three stages.Stage 60–40 Ma...This paper introduces how crustal thickening controls the growth of the Himalaya by summarizing the P-T-t evolution of the Himalayan metamorphic core.The Himalayan orogeny was divided into three stages.Stage 60–40 Ma:The Himalayan crust thickened to~40 km through Barrovian-type metamorphism(15–25°C/km),and the Himalaya rose from<0 to~1000 m.Stage 40–16 Ma:The crust gradually thickened to 60–70 km,resulting in abundant high-grade metamorphism and anatexis(peak-P,15–25°C/km;peak-T,>30°C/km).The three sub-sheets in the Himalayan metamorphic core extruded southward sequentially through imbricate thrusts of the Eo-Himalayan thrust,High Himalayan thrust,and Main Central thrust,and the Himalaya rose to≥5,000 m.Stage 16–0 Ma:the mountain roots underwent localized delamination,causing asthenospheric upwelling and overprinting of the lower crust by ultra-high-temperature metamorphism(30–50°C/km),and the Himalaya reached the present elevation of~6,000 m.Underplating and imbricate thrusting dominated the Himalaya’growth and topographic rise,conforming to the critical taper wedge model.Localized delamination of mountain roots facilitated further topographic rise.Future Himalayan metamorphic studies should focus on extreme metamorphism and major collisional events,contact metamorphism and rare metal mineralization,metamorphic decarbonation and the carbon cycle in collisional belts.展开更多
基金National Natural Science Foundation of China(50676005)
文摘The present work is a visualization study of a typical kerosene （RP-3） flowing through vertical and horizontal quartz-glass tubes under both sub- and supercritical conditions by a high speed camera. The experiments are accomplished at temperatures of 300-730 K under pressures from 0.107-5 MPa. Six distinctive two-phase flow patterns are observed in upward flow and the critical point of RP-3 is identified as critical pressure pc=2.33 MPa and critical temperature Tc=645.04 K and it is found that when the fluid pressure exceeds 2.33 MPa the flow can be considered as a single phase flow. The critical opalescence phenomenon of RP-3 is observed when the temperature is between 643.16 K and 648.61 K and the pressure is between 2.308 MPa and 2.366 MPa. The region filled by the critical opalescence in the upward flow is clearly larger than that in the downward flow due to the interaction between the buoyancy force and fluid inertia. Morecover, obvious layered flow phenomenon is observed in horizontal flow under supercritical pressures due to the differences of gravity and density.
文摘相对论重离子碰撞(又称高能核-核碰撞)为研究极端条件下核物质内禀性质、致密星体内部结构和大爆炸之后宇宙的早期演化过程提供了途径.强相互作用的量子色动力学(QCD)理论预言存在着解禁闭的新物质状态夸克-胶子等离子体(QGP).经过近30年的努力,在极端相对论能区的核-核对撞实验中,包括RHIC和LHC的实验,科学家找到了QGP存在的证据.目前,高能核物理的一个重要的科学问题是高重子密度区的相结构,包括寻找相边界和可能存在的QCD临界点.量子热动力学基本原理告诉我们只有找到相边界或临界点才能最终确定新的物质相QGP的存在.我们首先回顾了高能核物理实验的研究现状,其中包括RHIC能量扫描实验中的强子集体运动、手征特性的研究和QCD临界点的寻找.然后对利用我国重离子加速器群,如Heavy Ion Research Facility in Lanzhou (HIRFL)和High Intensity heavy-ion Accelerator Facility (HIAF)以及CSR-External-target Experiment等开展高能核物理实验研究进行了展望.
基金supported by the Second Tibetan Plateau Scientific Expedition and Research program(Grant No.2019QZKK0703)the National Natural Science Foundation of China(Grant Nos.41972065 and 41888101)+1 种基金the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Grant No.2022065)the State Key Laboratory of Lithospheric Evolution(Grant No.E152510201).
文摘This paper introduces how crustal thickening controls the growth of the Himalaya by summarizing the P-T-t evolution of the Himalayan metamorphic core.The Himalayan orogeny was divided into three stages.Stage 60–40 Ma:The Himalayan crust thickened to~40 km through Barrovian-type metamorphism(15–25°C/km),and the Himalaya rose from<0 to~1000 m.Stage 40–16 Ma:The crust gradually thickened to 60–70 km,resulting in abundant high-grade metamorphism and anatexis(peak-P,15–25°C/km;peak-T,>30°C/km).The three sub-sheets in the Himalayan metamorphic core extruded southward sequentially through imbricate thrusts of the Eo-Himalayan thrust,High Himalayan thrust,and Main Central thrust,and the Himalaya rose to≥5,000 m.Stage 16–0 Ma:the mountain roots underwent localized delamination,causing asthenospheric upwelling and overprinting of the lower crust by ultra-high-temperature metamorphism(30–50°C/km),and the Himalaya reached the present elevation of~6,000 m.Underplating and imbricate thrusting dominated the Himalaya’growth and topographic rise,conforming to the critical taper wedge model.Localized delamination of mountain roots facilitated further topographic rise.Future Himalayan metamorphic studies should focus on extreme metamorphism and major collisional events,contact metamorphism and rare metal mineralization,metamorphic decarbonation and the carbon cycle in collisional belts.
