It is challenging to make an ultrafast diagnosis of the temporal evolution of small and short-lived plasma in two dimensions. To overcome this difficulty, we have developed a well-timed diagnostic utilizing an x-ray s...It is challenging to make an ultrafast diagnosis of the temporal evolution of small and short-lived plasma in two dimensions. To overcome this difficulty, we have developed a well-timed diagnostic utilizing an x-ray streak camera equipped with a row of multi-pinhole arrays. By processing multiple sets of one-dimensional streaked image data acquired from various pinholes, we are capable of reconstructing high-resolution two-dimensional images with a temporal resolution of 38 ps and a spatial resolution of 18 μm. The temporal fiducial pulses accessed from external sources can advance the precise timing and accurately determine the arrival time of the laser. Moreover, it can correct the nonlinear sweeping speed of the streak camera. The effectiveness of this diagnostic has been successfully verified at the Shenguang-II laser facility,providing an indispensable tool for observing complex physical phenomena, such as the implosion process of laser-fusion experiments.展开更多
The thermodynamic and kinetic mechanisms of Taixi anthracite during its graphitization process were explored.To understand the variation trends of carbon arrangement order,microcrystal size,and graphitization degree a...The thermodynamic and kinetic mechanisms of Taixi anthracite during its graphitization process were explored.To understand the variation trends of carbon arrangement order,microcrystal size,and graphitization degree against temperature during the graphitization process,a series of experiments were performed using Raman spectroscopy and X-ray diffraction(XRD).Subsequently,the influencing factors of the dominant reaction at different temperatures were analyzed using thermodynamics and kinetics.The results showed that the graphitization process of Taixi anthracite can be divided into three stages from the perspective of reaction thermodynamics and kinetics.Temperature played a crucial role in the formation and growth of a graphitic structure.Meanwhile,multivariate mechanisms coexisted in the graphitization process.At ultrahigh temperatures,the defects of synthetic graphite could not be completely eliminated and perfect graphite crystals could not be produced.At low temperatures,the reaction is mainly controlled by dynamics,while at high temperatures,thermodynamics dominates the direction of the reaction.展开更多
基金supported by the Strategic Priority Research Program of the Chinese Academy of Sciences (Grant Nos. XDA25030700 and XDA25030500)the National Key R&D Program of China (Grant Nos. 2022YFA1603200 and 2022YFA1603203)the National Natural Science Foundation of China (Grant Nos. 12175018, 12135001, 12075030, and 11903006)。
文摘It is challenging to make an ultrafast diagnosis of the temporal evolution of small and short-lived plasma in two dimensions. To overcome this difficulty, we have developed a well-timed diagnostic utilizing an x-ray streak camera equipped with a row of multi-pinhole arrays. By processing multiple sets of one-dimensional streaked image data acquired from various pinholes, we are capable of reconstructing high-resolution two-dimensional images with a temporal resolution of 38 ps and a spatial resolution of 18 μm. The temporal fiducial pulses accessed from external sources can advance the precise timing and accurately determine the arrival time of the laser. Moreover, it can correct the nonlinear sweeping speed of the streak camera. The effectiveness of this diagnostic has been successfully verified at the Shenguang-II laser facility,providing an indispensable tool for observing complex physical phenomena, such as the implosion process of laser-fusion experiments.
基金financially supported by the China Postdoctoral Science Foundation and China National “Twelfth Five-Year” Plan for Science & Technology (No. 2014BAB01B02)Shenhua Ningxia Coal Industry Group for financial support and providing Taixi anthracite samplesthe support of Advanced Analysis & Computation Center of China University of Mining and Technology
文摘The thermodynamic and kinetic mechanisms of Taixi anthracite during its graphitization process were explored.To understand the variation trends of carbon arrangement order,microcrystal size,and graphitization degree against temperature during the graphitization process,a series of experiments were performed using Raman spectroscopy and X-ray diffraction(XRD).Subsequently,the influencing factors of the dominant reaction at different temperatures were analyzed using thermodynamics and kinetics.The results showed that the graphitization process of Taixi anthracite can be divided into three stages from the perspective of reaction thermodynamics and kinetics.Temperature played a crucial role in the formation and growth of a graphitic structure.Meanwhile,multivariate mechanisms coexisted in the graphitization process.At ultrahigh temperatures,the defects of synthetic graphite could not be completely eliminated and perfect graphite crystals could not be produced.At low temperatures,the reaction is mainly controlled by dynamics,while at high temperatures,thermodynamics dominates the direction of the reaction.
