The correct method used in forest soil respiration measurement by Li-6400 is a premise of data quality control. According to the study in a larch plantation, collars should be inserted at 12 hours in advance to effici...The correct method used in forest soil respiration measurement by Li-6400 is a premise of data quality control. According to the study in a larch plantation, collars should be inserted at 12 hours in advance to efficiently reduce the influence of CO2 spring-out.Moreover, collar insertion depth substantially affected soil respiration measurement, i.e. when collar was shallowly inserted into soil,transversal gas diffusion and the CO2 re-spring-out caused by unstable collars in the measurement could lead to overestimating soil respiration rate; however, when collar was deeply inserted into soil, root respiration decline caused by root-cut and the most active respiratory of the surface soil separated by the inserted collars could lead to underestimating soil respiration rate. Furthermore, an error less than 5% could be guaranteed in typical sunny day if the target [CO2] was set to the mean value of ambient [CO2] in most time of the day, but it should be carefully set in early morning and late afternoon according to changing ambient [CO2]. This protocol of measurement is useful in real measurement.展开更多
The propagation of circularly crested thermoelastic diffusive waves in an infinite homogeneous transversely isotropic plate subjected to stress free, isothermal/insulated and chemical potential conditions is investiga...The propagation of circularly crested thermoelastic diffusive waves in an infinite homogeneous transversely isotropic plate subjected to stress free, isothermal/insulated and chemical potential conditions is investigated in the framework of different thermo- elastic diffusion theories. The dispersion equations of thermoelastic diffusive Lamb type waves are derived. Some special cases of the dispersion equations are also deduced.展开更多
In this paper several different working gas mixtures for GEM-TPC were evaluated based on a Garfield simulation. Among them, Ar：CH4：CF4=90：7：3 （named herein TU gas） was selected for a detailed study because of it...In this paper several different working gas mixtures for GEM-TPC were evaluated based on a Garfield simulation. Among them, Ar：CH4：CF4=90：7：3 （named herein TU gas） was selected for a detailed study because of its better performance. Some performances of drift velocity, transverse diffusion, spatial resolution and the effective number of electrons in various electric fields were obtained. The performance of a GEM-TPC prototype working in the TU gas was studied and compared with that in Ar：CH4=90：10 （P10 gas）.展开更多
基金National Natural Science Foundation of China (30300271),Program of Key Basic Research from Ministry of Science and Technology (2004CCA02700) and Sina-Japan cooperation project on larch forest study.
文摘The correct method used in forest soil respiration measurement by Li-6400 is a premise of data quality control. According to the study in a larch plantation, collars should be inserted at 12 hours in advance to efficiently reduce the influence of CO2 spring-out.Moreover, collar insertion depth substantially affected soil respiration measurement, i.e. when collar was shallowly inserted into soil,transversal gas diffusion and the CO2 re-spring-out caused by unstable collars in the measurement could lead to overestimating soil respiration rate; however, when collar was deeply inserted into soil, root respiration decline caused by root-cut and the most active respiratory of the surface soil separated by the inserted collars could lead to underestimating soil respiration rate. Furthermore, an error less than 5% could be guaranteed in typical sunny day if the target [CO2] was set to the mean value of ambient [CO2] in most time of the day, but it should be carefully set in early morning and late afternoon according to changing ambient [CO2]. This protocol of measurement is useful in real measurement.
文摘The propagation of circularly crested thermoelastic diffusive waves in an infinite homogeneous transversely isotropic plate subjected to stress free, isothermal/insulated and chemical potential conditions is investigated in the framework of different thermo- elastic diffusion theories. The dispersion equations of thermoelastic diffusive Lamb type waves are derived. Some special cases of the dispersion equations are also deduced.
基金Supported by CAS/SAFEA International Partnership Program for Creative Research Teams
文摘In this paper several different working gas mixtures for GEM-TPC were evaluated based on a Garfield simulation. Among them, Ar：CH4：CF4=90：7：3 （named herein TU gas） was selected for a detailed study because of its better performance. Some performances of drift velocity, transverse diffusion, spatial resolution and the effective number of electrons in various electric fields were obtained. The performance of a GEM-TPC prototype working in the TU gas was studied and compared with that in Ar：CH4=90：10 （P10 gas）.
