在总太阳辐射(TSR,total solar radiation)中,对植物光合作用有效的太阳辐射称为光合有效辐射(PAR,photosynthetically active radiation),波长范围约为400-700 nm,其吸收系数(FPAR)是碳循环研究的一个关键生理变量,也是表征植被生态系...在总太阳辐射(TSR,total solar radiation)中,对植物光合作用有效的太阳辐射称为光合有效辐射(PAR,photosynthetically active radiation),波长范围约为400-700 nm,其吸收系数(FPAR)是碳循环研究的一个关键生理变量,也是表征植被生态系统的基本变量之一。基于30米空间分辨率的Landsat反射率数据,得到青藏高原区域的地表植被类型分类结果,以及不同植被类型生长季内归一化植被指数(NDVI)累积频率的98%(NDVI_max)和2%(NDVI_min)。为克服简单比值指数(SR)和NDVI在单独估算FPAR时分别存在低估和高估的问题,构建基于SR和NDVI的FPAR联合估算模型,生产了1987-2022年青藏高原区域4-9月平均FPAR产品。FPAR作为计算植被固碳量的参数之一,可用于评价植被生态系统状态,在生态环境监测、气候变化研究以及自然资源管理等领域有广泛的潜在应用价值。本产品以Geo TIFF格式保存,空间参考为地理坐标系GCS_WGS_1984(ESPG:4326)。展开更多
The static thrust output on a superconducting coated conductor coil at different excitation and alternating current suspended above a three phase alternating current long-stator comprised of copper coils is presented....The static thrust output on a superconducting coated conductor coil at different excitation and alternating current suspended above a three phase alternating current long-stator comprised of copper coils is presented.Excitation current up to 45 A was applied through the superconducting coil acting as the excitation system of the superconducting linear synchronous motor(SLSM),alternating current up to 9 A was applied to the armature and magnetic air gaps of 10 and 15 mm were investigated for four different cases;coreless,with an iron core or yoke and both a core and yoke.By scaling up and converting the studied superconducting single pancake racetrack coil into a double pancake coil and connecting four of such coils in series,an SLSM prototype capable of generating 400 N of thrust output and 1 kW of power output with a 12 mm mechanical air gap operating at 77 K is proposed.展开更多
The superconducting Ion Linac(iLinac)of High Intensity Heavy-ion Accelerator Facility(HIAF)is composed of an ECR ion source,low energy beam transport line(LEBT),81.25 MHz radio frequency quadrupole(RFQ)accelerator,med...The superconducting Ion Linac(iLinac)of High Intensity Heavy-ion Accelerator Facility(HIAF)is composed of an ECR ion source,low energy beam transport line(LEBT),81.25 MHz radio frequency quadrupole(RFQ)accelerator,medium energy beam transport line(MEBT)and superconducting section composed by Quarter Wave Resonators(QWR007)and Half Wave Resonators(HWR015).The ^(238)U^(35+)beam is accelerated by the RFQ accelerator from 0.014 to 0.8 MeV/u and then to 17 MeV/u by 96 SC cavities.The layout of the linac is shown in Fig.1.展开更多
High Intensity heavy ion Accelerator Facility(HIAF)consists of a Super-conducting ECR Ion Source(SECR),Superconducting linac(iLinac),Booster Ring(BRing),Fragment Separator(HFRS),Spectrometer Ring(SRing),and several tr...High Intensity heavy ion Accelerator Facility(HIAF)consists of a Super-conducting ECR Ion Source(SECR),Superconducting linac(iLinac),Booster Ring(BRing),Fragment Separator(HFRS),Spectrometer Ring(SRing),and several transport lines and terminals.It contains more than 600 room-temperature magnets,100 superconducting magnets,and a range of injection and extraction components.The latest general layout of the HIAF is shown in Fig.1.展开更多
文摘在总太阳辐射(TSR,total solar radiation)中,对植物光合作用有效的太阳辐射称为光合有效辐射(PAR,photosynthetically active radiation),波长范围约为400-700 nm,其吸收系数(FPAR)是碳循环研究的一个关键生理变量,也是表征植被生态系统的基本变量之一。基于30米空间分辨率的Landsat反射率数据,得到青藏高原区域的地表植被类型分类结果,以及不同植被类型生长季内归一化植被指数(NDVI)累积频率的98%(NDVI_max)和2%(NDVI_min)。为克服简单比值指数(SR)和NDVI在单独估算FPAR时分别存在低估和高估的问题,构建基于SR和NDVI的FPAR联合估算模型,生产了1987-2022年青藏高原区域4-9月平均FPAR产品。FPAR作为计算植被固碳量的参数之一,可用于评价植被生态系统状态,在生态环境监测、气候变化研究以及自然资源管理等领域有广泛的潜在应用价值。本产品以Geo TIFF格式保存,空间参考为地理坐标系GCS_WGS_1984(ESPG:4326)。
基金Traction Power State Key Laboratory of Southwest Jiaotong University(2009TPL_Z02)Fundamental Research Funds for the Central Universities(SWJTU09CX056)
文摘The static thrust output on a superconducting coated conductor coil at different excitation and alternating current suspended above a three phase alternating current long-stator comprised of copper coils is presented.Excitation current up to 45 A was applied through the superconducting coil acting as the excitation system of the superconducting linear synchronous motor(SLSM),alternating current up to 9 A was applied to the armature and magnetic air gaps of 10 and 15 mm were investigated for four different cases;coreless,with an iron core or yoke and both a core and yoke.By scaling up and converting the studied superconducting single pancake racetrack coil into a double pancake coil and connecting four of such coils in series,an SLSM prototype capable of generating 400 N of thrust output and 1 kW of power output with a 12 mm mechanical air gap operating at 77 K is proposed.
文摘The superconducting Ion Linac(iLinac)of High Intensity Heavy-ion Accelerator Facility(HIAF)is composed of an ECR ion source,low energy beam transport line(LEBT),81.25 MHz radio frequency quadrupole(RFQ)accelerator,medium energy beam transport line(MEBT)and superconducting section composed by Quarter Wave Resonators(QWR007)and Half Wave Resonators(HWR015).The ^(238)U^(35+)beam is accelerated by the RFQ accelerator from 0.014 to 0.8 MeV/u and then to 17 MeV/u by 96 SC cavities.The layout of the linac is shown in Fig.1.
文摘High Intensity heavy ion Accelerator Facility(HIAF)consists of a Super-conducting ECR Ion Source(SECR),Superconducting linac(iLinac),Booster Ring(BRing),Fragment Separator(HFRS),Spectrometer Ring(SRing),and several transport lines and terminals.It contains more than 600 room-temperature magnets,100 superconducting magnets,and a range of injection and extraction components.The latest general layout of the HIAF is shown in Fig.1.
