Based on the recently released NASA Earth Exchange Global Daily Downscaled Projections(NEX-GDDP)Coupled Model Intercomparison Project Phase 6(CMIP6) dataset and the gridded observational daily dataset CN05.1, this stu...Based on the recently released NASA Earth Exchange Global Daily Downscaled Projections(NEX-GDDP)Coupled Model Intercomparison Project Phase 6(CMIP6) dataset and the gridded observational daily dataset CN05.1, this study evaluates the performance of 26 CMIP6 models in simulating extreme high temperature(EHT) indices in southwestern China and estimates future changes in the EHT indices under the Shared Socioeconomic Pathways(SSPs) SSP1-2.6, SSP2-4.5, and SSP5-8.5 using 11 optimal CMIP6 models. Five EHT indices are employed:annual maximum value of daily maximum temperature(TXX), high temperature days(T35), warm days(TX90P),heat wave frequency(HWF), and heat wave days(HWD). The main results are as follows.(1) NEX-GDDP-CMIP6 is highly capable of simulating the spatial patterns of TXX and T35 in southwestern China but it presents a weaker ability to simulate the spatial patterns of TX90P, HWF, and HWD.(2) The simulated time series of T35, TX90P, HWF,and HWD in southwestern China exhibit consistent upward trends with the observations. The linear trends of increase in TX90P and HWD are much greater than those of increase in TXX, T35, and HWF.(3) The estimated increases in TXX and T35 in southwestern China are significantly greater in Chongqing and the adjacent areas of Sichuan than in the other regions. Spatial distributions of the increases in TX90P, HWF, and HWD generally show higher values in the west and lower values in the east.(4) In the three different scenarios, the projected future TXX,T35, TX90P, and HWD in southwestern China all display a continuous increase with time and radiative forcing levels, whereas HWF initially increases but then decreases under the SSP5-8.5 scenario. By the end of the 21st century, under the SSP5-8.5 scenario, TXX and T35 are projected to increase by 6.0℃ and 45.0 days, respectively. The duration of individual heat waves is also expected to increase.展开更多
In this study, the effect of multi-walled carbon nanotubes （MWCNTs） additive on the dehydriding properties of the Zn（BH4）2/NaCl composite prepared by high energy ball milling were investigated. X-ray diffraction ...In this study, the effect of multi-walled carbon nanotubes （MWCNTs） additive on the dehydriding properties of the Zn（BH4）2/NaCl composite prepared by high energy ball milling were investigated. X-ray diffraction （XRD）, Fourier transform infrared spectroscopy （FTIR） results demonstrated that Zn（BH4）2 was produced from mechanochemical reaction between ZnCl2 and NaBH4. Compared with the undoped sample, 10 wt% MWCNTs effectively lowered the decomposition temperature of Zn（BH4）2 by 15 ℃. The complex released 3.6 wt% hydrogen within 250 s at 100 ℃ and totally released 4.5 wt% hydrogen within 2500 s, indicating it has a considerable potential as a hydrogen storage material.展开更多
基金Supported by the China Meteorological Administration Innovation and Development Project (CXFZ2022J031 and CXFZ2021J018)National Natural Science Foundation of China (41875111 and 40975058)Natural Science Foundation of Chongqing,China(CSTB2022NSCQ-MSX0558 and CSTB2022NSCQ-MSX0890)。
文摘Based on the recently released NASA Earth Exchange Global Daily Downscaled Projections(NEX-GDDP)Coupled Model Intercomparison Project Phase 6(CMIP6) dataset and the gridded observational daily dataset CN05.1, this study evaluates the performance of 26 CMIP6 models in simulating extreme high temperature(EHT) indices in southwestern China and estimates future changes in the EHT indices under the Shared Socioeconomic Pathways(SSPs) SSP1-2.6, SSP2-4.5, and SSP5-8.5 using 11 optimal CMIP6 models. Five EHT indices are employed:annual maximum value of daily maximum temperature(TXX), high temperature days(T35), warm days(TX90P),heat wave frequency(HWF), and heat wave days(HWD). The main results are as follows.(1) NEX-GDDP-CMIP6 is highly capable of simulating the spatial patterns of TXX and T35 in southwestern China but it presents a weaker ability to simulate the spatial patterns of TX90P, HWF, and HWD.(2) The simulated time series of T35, TX90P, HWF,and HWD in southwestern China exhibit consistent upward trends with the observations. The linear trends of increase in TX90P and HWD are much greater than those of increase in TXX, T35, and HWF.(3) The estimated increases in TXX and T35 in southwestern China are significantly greater in Chongqing and the adjacent areas of Sichuan than in the other regions. Spatial distributions of the increases in TX90P, HWF, and HWD generally show higher values in the west and lower values in the east.(4) In the three different scenarios, the projected future TXX,T35, TX90P, and HWD in southwestern China all display a continuous increase with time and radiative forcing levels, whereas HWF initially increases but then decreases under the SSP5-8.5 scenario. By the end of the 21st century, under the SSP5-8.5 scenario, TXX and T35 are projected to increase by 6.0℃ and 45.0 days, respectively. The duration of individual heat waves is also expected to increase.
基金the financial support from Hunan Provincial Namral Science Foundation of China (No.10JJ2037)National Natural Science Foundation of China(Grant No.51021063)
文摘In this study, the effect of multi-walled carbon nanotubes （MWCNTs） additive on the dehydriding properties of the Zn（BH4）2/NaCl composite prepared by high energy ball milling were investigated. X-ray diffraction （XRD）, Fourier transform infrared spectroscopy （FTIR） results demonstrated that Zn（BH4）2 was produced from mechanochemical reaction between ZnCl2 and NaBH4. Compared with the undoped sample, 10 wt% MWCNTs effectively lowered the decomposition temperature of Zn（BH4）2 by 15 ℃. The complex released 3.6 wt% hydrogen within 250 s at 100 ℃ and totally released 4.5 wt% hydrogen within 2500 s, indicating it has a considerable potential as a hydrogen storage material.
