To understand the strengths and limitations of a low-resolution version of Flexible Global Ocean Atmosphere-Land-Sea-ice （FGOALS-gl） to simulate the climate of the last millennium, the energy balance, climate sensit...To understand the strengths and limitations of a low-resolution version of Flexible Global Ocean Atmosphere-Land-Sea-ice （FGOALS-gl） to simulate the climate of the last millennium, the energy balance, climate sensitivity and absorption feedback of the model are analyzed. Simulation of last-millennium climate was carried out by driving the model with natural （solar radiation and volcanic eruptions） and anthropogenic （greenhouse gases and aerosols） forcing agents. The model feedback factors for （model sensitivity to） different forcings were calculated. The results show that the system feedback factor is about 2.5 （W m-2） K-1 in the pre-industrial period, while 1.9 （W m-2） K-1 in the industrial era. Thus, the model＇s sensitivity to natural forcing is weak, which explains why it reproduces a weak Medieval Warm Period. The relatively reasonable simulation of the Little Ice Age is caused by both the specified radiative forcing and unforced linear cold drift. The model sensitivity in the industrial era is higher than that of the pre-industrial period. A negative net cloud radiative feedback operates during whole-millennial simulation and reduces the model＇s sensitivity to specified forcing. The negative net cloud radiative forcing feedback under natural forcing in the period prior to 1850 is due to the underestimation （overestimation） of the response of cloudiness （in-cloud water path）. In the industrial era, the strong tropospheric temperature response enlarges the effective radius of ice clouds and reduces the fractional ice content within cloud, resulting in a weak negative net cloud feedback in the industrial period. The water vapor feedback in the industrial era is also stronger than that in the pre-industrial period. Both are in favor of higher model sensitivity and thus a reasonable simulation of the 20th century global warming.展开更多
以不同分子量聚乙二醇(PEG)为基体,PEG接枝改性的炉法炭黑(PEG g CB)为导电载流子,采用溶液分散工艺制得一种新颖的气敏传感器材料。研究了PEG分子量对接枝率及对各种溶剂蒸气的响应性、响应灵敏度的影响;用透射电子显微镜(TEM)和紫... 以不同分子量聚乙二醇(PEG)为基体,PEG接枝改性的炉法炭黑(PEG g CB)为导电载流子,采用溶液分散工艺制得一种新颖的气敏传感器材料。研究了PEG分子量对接枝率及对各种溶剂蒸气的响应性、响应灵敏度的影响;用透射电子显微镜(TEM)和紫外—可见分光光度计考察了两种炭黑粒子分散行为、表面特性差异及其对响应重复性、稳定性的影响。结果表明,PEG/PEG g CB复合材料化学敏电阻体对其良溶剂蒸气如THF、氯仿、丙酮具有很强的响应性,其电阻值可提高到初始电阻的104～106倍。将这种材料再放入干燥空气中时,电阻又恢复到初始值;而对其不良溶剂如正己烷、甲苯几乎不响应。随PEG分子量的提高,响应灵敏度下降;响应的重复稳定性受炭黑粒子分散行为的影响,从聚合物溶胀行为及逾渗导电理论解释了实验结果。展开更多
CO_(2)dissolution into an aqueous phase and water evaporation into a gaseous phase takes place during CO_(2)injection into an oil reservoir.This study aims to evaluate the phase behaviors of the oil-gas-water system i...CO_(2)dissolution into an aqueous phase and water evaporation into a gaseous phase takes place during CO_(2)injection into an oil reservoir.This study aims to evaluate the phase behaviors of the oil-gas-water system in the displacement of crude oil by CO_(2).The composition of the JL oilfield in the northeast of China is taken as an example.The flash calculation of the oil-gas-water system was performed,based on the method presented by Li and Nghiem.The research results show that CO_(2)dissolution in the aqueous phase declines as the NaCl concentration in formation water rises.CO_(2)injection is beneficial for the evaporation of formation water.The NaCl concentration in formation water has little effect on water evaporation and dissolved-gas escape.When the injection-gas mole fraction of CO_(2)is 0.5,CO_(2)injection can reverse the phase behavior of the petroleum mixture and the oil-gas system is converted to a pure gas-condensate system.For CO_(2)injection,water vapor has little effect on the miscibility of multiple contacts,but can reduce the miscibility of the first contact.展开更多
Strong environmental dependence is an intractable problem for vapor cell clocks,for which the high-temperature sensitivity of the physics package is considered one of the dominant reasons.In this paper,we report the d...Strong environmental dependence is an intractable problem for vapor cell clocks,for which the high-temperature sensitivity of the physics package is considered one of the dominant reasons.In this paper,we report the design and realization of a low-temperature-sensitive physics package for vapor cell clocks.The physics package comprises three layers of magnetic shields,three layers of heating ovens,and the cavity-cell assembly.The cavity-cell assembly employs a compact magnetron-type cavity and a Rb vapor cell sealed with N2-Ar mixed buffer gas.The dependence of the clock frequency on temperature fluctuation is evaluated to be 2×10^(−11)/℃.In pursuit of the stable temperature,a three-stage temperature regulator is implemented on the physics package.It adopts a combination of open andclosed-loop control to address the problem of significant thermal coupling between the heating ovens.Under a laboratory environment,the measured Hadamard deviation of the temperature variation is 4×10^(−5)℃in 1 day of averaging.展开更多
Electrically conducting fabrics used as flexible sensors can be produced by vacuumed vapor deposition.The research of what impacts the wide and reliable application of the flexible sensors shows that the stability of ...Electrically conducting fabrics used as flexible sensors can be produced by vacuumed vapor deposition.The research of what impacts the wide and reliable application of the flexible sensors shows that the stability of flexible sensors is one of the critical issues.The electrical performance of weft knitted fabrics in course and wale direction does not show significant differences under different ambient conditions,which include time,temperature,and relative humidity.Tests of stimuli responding sensitivity of conductive fabrics indicate that the sensitivity keeps at a constant level and the average sensitivity is stable over 38 days.展开更多
基金jointly supported by the"Strategic Priority Research Program-Climate Change:Carbon Budget and Related Is-sues"of the Chinese Academy of Sciences(Grant No.XDA05110301)NSFC under Grant Nos.40890054 and 41125017
文摘To understand the strengths and limitations of a low-resolution version of Flexible Global Ocean Atmosphere-Land-Sea-ice （FGOALS-gl） to simulate the climate of the last millennium, the energy balance, climate sensitivity and absorption feedback of the model are analyzed. Simulation of last-millennium climate was carried out by driving the model with natural （solar radiation and volcanic eruptions） and anthropogenic （greenhouse gases and aerosols） forcing agents. The model feedback factors for （model sensitivity to） different forcings were calculated. The results show that the system feedback factor is about 2.5 （W m-2） K-1 in the pre-industrial period, while 1.9 （W m-2） K-1 in the industrial era. Thus, the model＇s sensitivity to natural forcing is weak, which explains why it reproduces a weak Medieval Warm Period. The relatively reasonable simulation of the Little Ice Age is caused by both the specified radiative forcing and unforced linear cold drift. The model sensitivity in the industrial era is higher than that of the pre-industrial period. A negative net cloud radiative feedback operates during whole-millennial simulation and reduces the model＇s sensitivity to specified forcing. The negative net cloud radiative forcing feedback under natural forcing in the period prior to 1850 is due to the underestimation （overestimation） of the response of cloudiness （in-cloud water path）. In the industrial era, the strong tropospheric temperature response enlarges the effective radius of ice clouds and reduces the fractional ice content within cloud, resulting in a weak negative net cloud feedback in the industrial period. The water vapor feedback in the industrial era is also stronger than that in the pre-industrial period. Both are in favor of higher model sensitivity and thus a reasonable simulation of the 20th century global warming.
文摘 以不同分子量聚乙二醇(PEG)为基体,PEG接枝改性的炉法炭黑(PEG g CB)为导电载流子,采用溶液分散工艺制得一种新颖的气敏传感器材料。研究了PEG分子量对接枝率及对各种溶剂蒸气的响应性、响应灵敏度的影响;用透射电子显微镜(TEM)和紫外—可见分光光度计考察了两种炭黑粒子分散行为、表面特性差异及其对响应重复性、稳定性的影响。结果表明,PEG/PEG g CB复合材料化学敏电阻体对其良溶剂蒸气如THF、氯仿、丙酮具有很强的响应性,其电阻值可提高到初始电阻的104～106倍。将这种材料再放入干燥空气中时,电阻又恢复到初始值;而对其不良溶剂如正己烷、甲苯几乎不响应。随PEG分子量的提高,响应灵敏度下降;响应的重复稳定性受炭黑粒子分散行为的影响,从聚合物溶胀行为及逾渗导电理论解释了实验结果。
基金The National Major Science and Technology Projects of China(2017ZX05030)supported this work。
文摘CO_(2)dissolution into an aqueous phase and water evaporation into a gaseous phase takes place during CO_(2)injection into an oil reservoir.This study aims to evaluate the phase behaviors of the oil-gas-water system in the displacement of crude oil by CO_(2).The composition of the JL oilfield in the northeast of China is taken as an example.The flash calculation of the oil-gas-water system was performed,based on the method presented by Li and Nghiem.The research results show that CO_(2)dissolution in the aqueous phase declines as the NaCl concentration in formation water rises.CO_(2)injection is beneficial for the evaporation of formation water.The NaCl concentration in formation water has little effect on water evaporation and dissolved-gas escape.When the injection-gas mole fraction of CO_(2)is 0.5,CO_(2)injection can reverse the phase behavior of the petroleum mixture and the oil-gas system is converted to a pure gas-condensate system.For CO_(2)injection,water vapor has little effect on the miscibility of multiple contacts,but can reduce the miscibility of the first contact.
基金the National Natural Science Foundation of China under Grant No.11703031,U1731132in part by the West Light Foundation of the Chinese Academy of Sciences under Grant No.XAB2017B04.
文摘Strong environmental dependence is an intractable problem for vapor cell clocks,for which the high-temperature sensitivity of the physics package is considered one of the dominant reasons.In this paper,we report the design and realization of a low-temperature-sensitive physics package for vapor cell clocks.The physics package comprises three layers of magnetic shields,three layers of heating ovens,and the cavity-cell assembly.The cavity-cell assembly employs a compact magnetron-type cavity and a Rb vapor cell sealed with N2-Ar mixed buffer gas.The dependence of the clock frequency on temperature fluctuation is evaluated to be 2×10^(−11)/℃.In pursuit of the stable temperature,a three-stage temperature regulator is implemented on the physics package.It adopts a combination of open andclosed-loop control to address the problem of significant thermal coupling between the heating ovens.Under a laboratory environment,the measured Hadamard deviation of the temperature variation is 4×10^(−5)℃in 1 day of averaging.
文摘Electrically conducting fabrics used as flexible sensors can be produced by vacuumed vapor deposition.The research of what impacts the wide and reliable application of the flexible sensors shows that the stability of flexible sensors is one of the critical issues.The electrical performance of weft knitted fabrics in course and wale direction does not show significant differences under different ambient conditions,which include time,temperature,and relative humidity.Tests of stimuli responding sensitivity of conductive fabrics indicate that the sensitivity keeps at a constant level and the average sensitivity is stable over 38 days.
