Extreme high temperature(EHT)events are among the most impact-related consequences related to climate change,especially for China,a nation with a large population that is vulnerable to the climate warming.Based on the...Extreme high temperature(EHT)events are among the most impact-related consequences related to climate change,especially for China,a nation with a large population that is vulnerable to the climate warming.Based on the latest Coupled Model Intercomparison Project Phase 6(CMIP6),this study assesses future EHT changes across China at five specific global warming thresholds(1.5℃-5℃).The results indicate that global mean temperature will increase by 1.5℃/2℃ before 2030/2050 relative to pre-industrial levels(1861-1900)under three future scenarios(SSP1-2.6,SSP2-4.5,and SSP5-8.5),and warming will occur faster under SSP5-8.5 compared to SSP1-2.6 and SSP2-4.5.Under SSP5-8.5,global warming will eventually exceed 5℃ by 2100,while under SSP1-2.6,it will stabilize around 2℃ after 2050.In China,most of the areas where warming exceeds global average levels will be located in Tibet and northern China(Northwest China,North China and Northeast China),covering 50%-70%of the country.Furthermore,about 0.19-0.44 billion people(accounting for 16%-41%of the national population)will experience warming above the global average.Compared to present-day(1995-2014),the warmest day(TXx)will increase most notably in northern China,while the number of warm days(TX90p)and warm spell duration indicator(WSDI)will increase most profoundly in southern China.For example,relative to the present-day,TXx will increase by 1℃-5℃ in northern China,and TX90p(WSDI)will increase by 25-150(10-80)days in southern China at 1.5℃-5℃ global warming.Compared to 2℃-5℃,limiting global warming to 1.5℃ will help avoid about 36%-87%of the EHT increases in China.展开更多
The true stress-sWain relationships of Ti-5A1-2Sn-2Zr-4Mo-4Cr（TC17） alloy with a wide range of strain rates were investigated by tmiaxial quasi-static and dynamic compression tests, respectively. Quasi- static compr...The true stress-sWain relationships of Ti-5A1-2Sn-2Zr-4Mo-4Cr（TC17） alloy with a wide range of strain rates were investigated by tmiaxial quasi-static and dynamic compression tests, respectively. Quasi- static compression tests were carried out with Instron 8874 test machine, while dynamic compression tests were performed with the split Hopkinson pressure bar （SHPB） which was installed with heating device and synchro- assembly system. The dynamic mechanical behaviors tests of TC17 were carded out from room temperature to 800 ℃ at intervals of 200 ℃ and at high sWain rates （5 500-1 9200 s-l）. The stress-strain curves considering temperature-sWain rate coupling actions were obtained. The Johnson-Cook constitutive model was developed through data fitting of the stress-sWain curves. The material constants in the developed constitutive model can be determined using isothermal and adiabatic stress-strain curves at different strain rates. The Johnson-Cook constitutive model provided satisfied prediction of the plastic flow stress for TC17 alloy.展开更多
The Dongfang 13-1 is located in the diapiric structure belt of the Yinggehai Basin. The formation pressure of its main gas res- ervoir in the Miocene Huangliu Formation is up to 54.6 MPa （pressure coefficient=l.91） ...The Dongfang 13-1 is located in the diapiric structure belt of the Yinggehai Basin. The formation pressure of its main gas res- ervoir in the Miocene Huangliu Formation is up to 54.6 MPa （pressure coefficient=l.91） and the temperature is as high as 143°C （geothermal gradient 4.36°C/100 m）, indicating that it is a typical high-temperature and overpressured gas reservoir. The natural gas is interpreted to be coal-type gas derived from the Miocene mature source rocks containing type Ⅱ2-Ⅲ kero- gens as evidenced by high dryness index of up to 0.98 and heavy carbon isotopes, i.e., the δ13C2 ranging from -30.76%o to -37.52%o and δ13C2 ranging from -25.02%o to -25.62%o. The high temperature and overpressured Miocene petroleum system is related mainly to diapir in the Yinggehai Basin and contains more pore water in the overpressured reservoirs due to under- compaction process. The experimental and calculated results show that the solubility of natural gas in formation water is as high as 10.5 m3/m3 under the temperature and pressure conditions of the Sanya Formation, indicating that at least part of the gas may migrate in the form of water-soluble phase. Meanwhile, the abundant gas source in the Basin makes it possible for the rapid saturation of natural gas in formation water and exsolution of soluble gas. Therefore, the main elements controlling formation of the Dongfang 13-1 gas pool include that （1） the diapir activities and accompanying changes in temperature and pressure accelerate the water-soluble gas exsolution and release a lot of free gas; （2） submarine fan fine sandstone in the Huangliu Formation provides good gas-water segregation and accumulation space; and （3） the overlying overpressured mud rocks act as effective caps. The accumulation mechanism reveals that the high temperatural and high pressure structure belt near the diapir structures has a good potential for large and medium-sized gas field exploration.展开更多
Y_(1-x)Ho_xBa_2Cu_3O_(7-δ)(0<x<1) sinsle crystal thin films oriented with the caxis perpendicular to the sur-face were grown by DC magnetron sputtering technique. Target was pieced together with half of YBa_2Cu...Y_(1-x)Ho_xBa_2Cu_3O_(7-δ)(0<x<1) sinsle crystal thin films oriented with the caxis perpendicular to the sur-face were grown by DC magnetron sputtering technique. Target was pieced together with half of YBa_2Cu_3O_(7-δ)(YBCO) and half of HoBa_2Cu_3O_(7-δ)(HBCO) superconducting materials. As the distance between HBCO targetmaterial and substrate is varied , the Ho content in material is changed respectively. When the content of Ho is0. 7 (atom ratio) , the T_c>83K.展开更多
C\-3N\-4 crystals with the size of several micrometers have been synthesized from C\-3N\-4H\-4 in the presence of nickel\|based alloy or cobalt as catalyst under high pressure of 7 GPa and temperature of about 1400℃ ...C\-3N\-4 crystals with the size of several micrometers have been synthesized from C\-3N\-4H\-4 in the presence of nickel\|based alloy or cobalt as catalyst under high pressure of 7 GPa and temperature of about 1400℃ for 10 min. Scanning electron microscopy, energy\|disperse X\|ray analysis, and X\|ray diffraction were used to examine the grown crystals. The general rule on selecting the starting materials for synthesis of carbon nitride crystals at high pressures and high temperatures is suggested.展开更多
基金supported by the National Key Research and Development Program of China(2017YFA0603804)the National Natural Science Foundation of China(41831174 and 41430528)+1 种基金the Postgraduate Research&Practice Innovation Program of Jiangsu Province(KYCX19_1026)Guwei ZHANG was supported by the China Scholarship Council(NO.201908320503)。
文摘Extreme high temperature(EHT)events are among the most impact-related consequences related to climate change,especially for China,a nation with a large population that is vulnerable to the climate warming.Based on the latest Coupled Model Intercomparison Project Phase 6(CMIP6),this study assesses future EHT changes across China at five specific global warming thresholds(1.5℃-5℃).The results indicate that global mean temperature will increase by 1.5℃/2℃ before 2030/2050 relative to pre-industrial levels(1861-1900)under three future scenarios(SSP1-2.6,SSP2-4.5,and SSP5-8.5),and warming will occur faster under SSP5-8.5 compared to SSP1-2.6 and SSP2-4.5.Under SSP5-8.5,global warming will eventually exceed 5℃ by 2100,while under SSP1-2.6,it will stabilize around 2℃ after 2050.In China,most of the areas where warming exceeds global average levels will be located in Tibet and northern China(Northwest China,North China and Northeast China),covering 50%-70%of the country.Furthermore,about 0.19-0.44 billion people(accounting for 16%-41%of the national population)will experience warming above the global average.Compared to present-day(1995-2014),the warmest day(TXx)will increase most notably in northern China,while the number of warm days(TX90p)and warm spell duration indicator(WSDI)will increase most profoundly in southern China.For example,relative to the present-day,TXx will increase by 1℃-5℃ in northern China,and TX90p(WSDI)will increase by 25-150(10-80)days in southern China at 1.5℃-5℃ global warming.Compared to 2℃-5℃,limiting global warming to 1.5℃ will help avoid about 36%-87%of the EHT increases in China.
基金Funded by the National Basic Research Program of China(No.2009CB724401)the Major Science and Technology Program of High-end CNC Machine Tools and Basic Manufacturing Equipment(No.2012ZX04003-041)
文摘The true stress-sWain relationships of Ti-5A1-2Sn-2Zr-4Mo-4Cr（TC17） alloy with a wide range of strain rates were investigated by tmiaxial quasi-static and dynamic compression tests, respectively. Quasi- static compression tests were carried out with Instron 8874 test machine, while dynamic compression tests were performed with the split Hopkinson pressure bar （SHPB） which was installed with heating device and synchro- assembly system. The dynamic mechanical behaviors tests of TC17 were carded out from room temperature to 800 ℃ at intervals of 200 ℃ and at high sWain rates （5 500-1 9200 s-l）. The stress-strain curves considering temperature-sWain rate coupling actions were obtained. The Johnson-Cook constitutive model was developed through data fitting of the stress-sWain curves. The material constants in the developed constitutive model can be determined using isothermal and adiabatic stress-strain curves at different strain rates. The Johnson-Cook constitutive model provided satisfied prediction of the plastic flow stress for TC17 alloy.
基金supported by National Science and Technology Major Project of China(Grant No.2011ZX05023-004)
文摘The Dongfang 13-1 is located in the diapiric structure belt of the Yinggehai Basin. The formation pressure of its main gas res- ervoir in the Miocene Huangliu Formation is up to 54.6 MPa （pressure coefficient=l.91） and the temperature is as high as 143°C （geothermal gradient 4.36°C/100 m）, indicating that it is a typical high-temperature and overpressured gas reservoir. The natural gas is interpreted to be coal-type gas derived from the Miocene mature source rocks containing type Ⅱ2-Ⅲ kero- gens as evidenced by high dryness index of up to 0.98 and heavy carbon isotopes, i.e., the δ13C2 ranging from -30.76%o to -37.52%o and δ13C2 ranging from -25.02%o to -25.62%o. The high temperature and overpressured Miocene petroleum system is related mainly to diapir in the Yinggehai Basin and contains more pore water in the overpressured reservoirs due to under- compaction process. The experimental and calculated results show that the solubility of natural gas in formation water is as high as 10.5 m3/m3 under the temperature and pressure conditions of the Sanya Formation, indicating that at least part of the gas may migrate in the form of water-soluble phase. Meanwhile, the abundant gas source in the Basin makes it possible for the rapid saturation of natural gas in formation water and exsolution of soluble gas. Therefore, the main elements controlling formation of the Dongfang 13-1 gas pool include that （1） the diapir activities and accompanying changes in temperature and pressure accelerate the water-soluble gas exsolution and release a lot of free gas; （2） submarine fan fine sandstone in the Huangliu Formation provides good gas-water segregation and accumulation space; and （3） the overlying overpressured mud rocks act as effective caps. The accumulation mechanism reveals that the high temperatural and high pressure structure belt near the diapir structures has a good potential for large and medium-sized gas field exploration.
文摘Y_(1-x)Ho_xBa_2Cu_3O_(7-δ)(0<x<1) sinsle crystal thin films oriented with the caxis perpendicular to the sur-face were grown by DC magnetron sputtering technique. Target was pieced together with half of YBa_2Cu_3O_(7-δ)(YBCO) and half of HoBa_2Cu_3O_(7-δ)(HBCO) superconducting materials. As the distance between HBCO targetmaterial and substrate is varied , the Ho content in material is changed respectively. When the content of Ho is0. 7 (atom ratio) , the T_c>83K.
文摘C\-3N\-4 crystals with the size of several micrometers have been synthesized from C\-3N\-4H\-4 in the presence of nickel\|based alloy or cobalt as catalyst under high pressure of 7 GPa and temperature of about 1400℃ for 10 min. Scanning electron microscopy, energy\|disperse X\|ray analysis, and X\|ray diffraction were used to examine the grown crystals. The general rule on selecting the starting materials for synthesis of carbon nitride crystals at high pressures and high temperatures is suggested.
