Numerical modeling and performance evaluation of passive convergence-permeable reactive barrier(PC-PRB)

The passive convergence-permeable reactive barrier(PC-PRB)was proposed to address the limitations of traditional PRB configurations.To evaluate the hydraulic and pollutant removal performance of the PC-PRB system,we developed a simulation code named PRB-Trans.This code uses the two-dimensional(2D)finite element method to simulate groundwater flow and solute transport.Case studies demonstrate that PC-PRB technology is more efficient and cost-effective than continuous permeable reactive barrier(C-PRB)in treating the same contaminated plume.Implementation of PC-PRB technology results in a 33.3%and 72.7%reduction in PRB length(L_(PRB))and height(H_(PRB)),respectively,while increasing 2D horizontal and 2D vertical pollutant treatment efficiencies of PRB by 87.8%and 266.8%,respectively.In addition,the PC-PRB technology has the ability to homogenize the pollutant concentration and pollutant flux through the PRB system,which can mitigate the problems arising from uneven distribution of pollutants in the C-PRB to some extent.The L_(PRB)required for PC-PRB decreases as the water pipe length(L_(p))increases,while the H_(PRB)required initially decreases and then increases with increasing L_(p).The effect of passive well height(Hw)on H_(PRB)is not as significant as that of L_(p)on H_(PRB).Overall,PC-PRB presents a promising and advantageous PRB configuration in the effective treatment of various types of contaminated plumes.

Image formation of brain function in patients suffering from knee osteoarthritis treated with moxibustion

OBJECTIVES:Functional magnetic resonance imaging(fMRI) technology was used to study changes to the resting state blood flow in the brains of patients with knee osteoarthritis(KOA) before and after treatment with moxibustion at the acupoint of the left Dubi(ST 35) and to probe the cerebral mechanism underlying the effect of moxibustion.METHODS:The resting state brain function of 30 patients with left KOA was scanned with fMRI before and after treatment with moxibustion.The analytic methods of fractional amplitude of low frequency fluctuation(fALFF) and regional homogeneity(ReHo) were used to observe changes in resting state brain function.RESULTS:The fALFF values of the right cerebrum,extra-nucleus,left cerebellum,left cerebrum and white matter of patients after moxibustion treatment were higher than before treatment,and the fALFF values of the precentral gyrus,frontal lobe and occipital lobe were lower than before treatment(P<0.05,K≥85).The ReHo values of the thalamus,extra-nucleus and parietal lobe of patients were much higher than those before moxibustion treatment,and the ReHo values of the right cerebrum,left cerebrum and frontal lobe were lower than before treatment(P<0.05,K≥85).CONCLUSION:The influence of moxibustion on obvious changes in brain regions basically conforms to the way that pain and warmth is transmitted in the body,and the activation of sensitive systems in the body may be objective evidence of channel transmission.The regulation of brain function by moxibustion is not in a single brain region but rather in a network of many brain regions.

A tentative study on the ultrastructure of the Middle Permian Acritarch Micrhystridium from western Yunnan, China

A preliminary study on the ultrastructure of Middle Permian Acritarch Micrhystridiumfrom western Yunnan has been made using laser scanning confocal microscope (LSCM). Some quite new features about the texture and ultrastructure of this kind of Acritarch has been detected for the first time, which opens up a new application of this advanced technique to microfossil study.