Evaluating the influences of measurement time and frequency on soil respiration in a semiarid temperate grassland

Soil respiration(Soil R)is one of the largest CO2fluxes from terrestrial ecosystems to the atmosphere.The largely seasonal and daily patterns of Soil R in semiarid grassland ecosystems indicate that measurement time and frequency would have significant influences on the assessment of seasonal soil carbon release.Based on a three-year continuous measurement of Soil R in a semiarid grassland,we found that the Soil R value measured at around 10:00 o’clock local time was the closest to its daily mean,while the value at 14:00 o’clock was found to be the highest daily rate.A measurement frequency higher than every 10 days was necessary for estimating the seasonal Soil R and its temperature sensitivity(Q10)reasonably.Our study would be useful as guidelines for manual Soil R measurements and model data selection in semiarid temperate grasslands.     

半群的Ω-模糊内理想

给定一个集合Ω,引入半群的Ω-模糊内理想的概念,讨论它的基本性质及其等价刻画,研究了半群的Ω-模糊内理想的同态像与原像的性质。此外,通过在SΩ上定义运算得到半群(SΩ,),研究了其内理想与Ω-模糊内理想。     

A-调和张量的双权积分不等式

利用加权技巧,证明了A-调和张量的局部Ar(λ1,λ2;Ω)-双权弱逆Holder不等式.作为局部结果的应用,证明了一个整体Ar(λ1,λ2;Ω)一双权积分不等式.这些结果可以看作是经典结论的推广.     

BL*Δ系统的完备性

研究了BL^*系统和BR0-代数.首先在BL^*系统的基础上添加了一元逻辑连接词Δ,得到BL^*系统的一种模式扩张BL^*_Δ系统,随后提出了Δ BR0-代数的概念,其次研究了Δ BR0-代数中的Δ-滤子及其性质,最后证明了BL^*_Δ系统的完备性,给出了BL^*_Δ系统的广义演绎定理.     

关于L~2(Ω,R~3)中方程div b=0

对于b∈L~2(Ω,R~3),v·b|аΩ=0,运用一个初等方法我们证明方程div b=0有一个解b=cur|φ,其中φ属于Sobolev空间H_0~1(Ω,R~3).     

Ω-滤子的一个等价刻画

对滤子公理进行重新解释,给出了文献[1]引入的Ω-滤子的一个等价刻画。