We report a clock transition spectrum approach,which is used to calibrate the zero-crossing temperature and frequency drift of an ultralow expansion(ULE)cavity with a Hertz level resolution.With this approach,the line...We report a clock transition spectrum approach,which is used to calibrate the zero-crossing temperature and frequency drift of an ultralow expansion(ULE)cavity with a Hertz level resolution.With this approach,the linear and nonlinear drifts of the ULE cavity along a variety of controlled temperatures are clearly presented.When the controlled temperature of ULE cavity is tuned away from the zero-crossing temperature of the ULE cavity,the cavity shows larger and larger nonlinear drift.According to our theoretical analysis and experimental results,we investigate more details of the drift property of the ULE cavity around the zero-crossing temperature,which has seldom been explored before.We can definitely conclude that the zero-crossing temperature of our ULE cavity used in an ytterbium(Yb)lattice clock is around 31.7℃.展开更多
Molecular dynamics simulation of a sympathetically-cooled ^(113)Cd^(+)ion crystal system is achieved.Moreover,the relationship between ions’axial temperature and different electric parameters,including radio frequenc...Molecular dynamics simulation of a sympathetically-cooled ^(113)Cd^(+)ion crystal system is achieved.Moreover,the relationship between ions’axial temperature and different electric parameters,including radio frequency voltage and endcap voltage is depicted.Under stable trapping condition,optimum radio frequency voltage,corresponding to minimum temperature and the highest cooling efficiency,is obtained.The temperature is positively correlated with end-cap voltage.The relationship is also confirmed by a sympathetically-cooled ^(113)Cd^(+) microwave clock.The pseudo-potential model is used to illustrate the relationship and influence mechanism.A reasonable index,indicating ions’temperature,is proposed to quickly estimate the relative ions’temperature.The investigation is helpful for ion crystal investigation,such as spatial configuration manipulation,sympathetic cooling efficiency enhancement,and temporal evolution.展开更多
Plants interact with a complex network of microorganisms,forming a dynamic holobiont that is crucial for their health,growth,and adaptation.This interconnected system is deeply influenced by environmental factors,whic...Plants interact with a complex network of microorganisms,forming a dynamic holobiont that is crucial for their health,growth,and adaptation.This interconnected system is deeply influenced by environmental factors,which modulate the relationships within the plant microbiome.Key environmental drivers such as light,temperature,and moisture can alter the balance of these interactions,impacting plant immunity,resilience,and overall fitness.The traditional disease triangle model,which emphasizes plant-pathogen-environment interactions,is enhanced by incorporating the role of the microbiome,revealing how microbial communities contribute to disease outcomes.This review highlights the importance of shifting focus from studying plants in isolation to embracing an integrated approach that accounts for the intricate interactions between plants,microbes,and their surrounding environments.Comprehending these interactions is pivotal as we explore new approaches,including advanced sequencing technologies and microbiome engineering,to optimize plant-microbe relationships for improved crop resilience.These insights are vital for developing sustainable agricultural practices to address the impacts of climate change and other environmental challenges.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
基金Project supported by the National Natural Science Foundation of China(Grant Nos.61227805,11574352,91536104,and 91636215)the Strategic Priority Research Program of the Chinese Academy of Sciences(Grant No.XDB21030100)
文摘We report a clock transition spectrum approach,which is used to calibrate the zero-crossing temperature and frequency drift of an ultralow expansion(ULE)cavity with a Hertz level resolution.With this approach,the linear and nonlinear drifts of the ULE cavity along a variety of controlled temperatures are clearly presented.When the controlled temperature of ULE cavity is tuned away from the zero-crossing temperature of the ULE cavity,the cavity shows larger and larger nonlinear drift.According to our theoretical analysis and experimental results,we investigate more details of the drift property of the ULE cavity around the zero-crossing temperature,which has seldom been explored before.We can definitely conclude that the zero-crossing temperature of our ULE cavity used in an ytterbium(Yb)lattice clock is around 31.7℃.
基金Project supported by the Beijing Natural Science Foundation(Grant No.1202011)the Tsinghua University Initiative Scientific Research Program,the National Natural Science Foundation of China(Grant No.12073015)the National Key Research and Development Program of China(Grant No.2016YFA0302101).
文摘Molecular dynamics simulation of a sympathetically-cooled ^(113)Cd^(+)ion crystal system is achieved.Moreover,the relationship between ions’axial temperature and different electric parameters,including radio frequency voltage and endcap voltage is depicted.Under stable trapping condition,optimum radio frequency voltage,corresponding to minimum temperature and the highest cooling efficiency,is obtained.The temperature is positively correlated with end-cap voltage.The relationship is also confirmed by a sympathetically-cooled ^(113)Cd^(+) microwave clock.The pseudo-potential model is used to illustrate the relationship and influence mechanism.A reasonable index,indicating ions’temperature,is proposed to quickly estimate the relative ions’temperature.The investigation is helpful for ion crystal investigation,such as spatial configuration manipulation,sympathetic cooling efficiency enhancement,and temporal evolution.
基金supported by a grant from the Institute for Basic Science(IBS-R021-D1-2024-a00)the National Research Foundation of Korea(NRF)grant funded by the Korea government(Ho-Seok Lee).
文摘Plants interact with a complex network of microorganisms,forming a dynamic holobiont that is crucial for their health,growth,and adaptation.This interconnected system is deeply influenced by environmental factors,which modulate the relationships within the plant microbiome.Key environmental drivers such as light,temperature,and moisture can alter the balance of these interactions,impacting plant immunity,resilience,and overall fitness.The traditional disease triangle model,which emphasizes plant-pathogen-environment interactions,is enhanced by incorporating the role of the microbiome,revealing how microbial communities contribute to disease outcomes.This review highlights the importance of shifting focus from studying plants in isolation to embracing an integrated approach that accounts for the intricate interactions between plants,microbes,and their surrounding environments.Comprehending these interactions is pivotal as we explore new approaches,including advanced sequencing technologies and microbiome engineering,to optimize plant-microbe relationships for improved crop resilience.These insights are vital for developing sustainable agricultural practices to address the impacts of climate change and other environmental challenges.
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.
