Microelement analysis of source of raw materials of terracotta warriors and horses of Qin's Mausoleum in pits No.1 and No.2

In order to search for sources of the raw material of the Qin’s terracotta warriors and horses, we selected 20 samples of pottery warriors and pottery horses of the Qin’s Mausoleum from pit No. 1,19 samples of pottery warriors and brick from pit No. 2, 20 samples of clays near the Qin’s Mausoleum and 2 samples of Yaozhou porcelain bodies. The 32 kinds of element content of each sample were measured by neutron activation analysis (NAA). These data were analyzed by fuzzy cluster analysis, the trend cluster analysis diagram was obtained. The results showed that samples of terracotta warriors and horses from pits No.1 and No. 2 were closely related to the loam layer near Qin’s Mausoleum, but their relations with the loess layers were not so close, and they were out of all relation to Yaozhou porcelain bodies. Thus, it could be deduced that the Li Mountain clay may be considered as the original place of the raw materials of the terracotta warriors and horses, the kiln sites might be located nearby the Qin’s

Chronic hypoperfusion due to intracranial large artery stenosis is not associated with cerebralβ-amyloid deposition and brain atrophy

Background:Insufficient cerebral perfusion is suggested to play a role in the development of Alzheimer disease(AD).However,there is a lack of direct evidence indicating whether hypoperfusion causes or aggravates AD pathology.We investigated the effect of chronic cerebral hypoperfusion on AD-related pathology in humans.Methods:We enrolled a group of cognitively normal patients(median age:64 years)with unilateral chronic cerebral hypoperfusion.Regions of interest with the most pronounced hypoperfusion changes were chosen in the hypoperfused region and were then mirrored in the contralateral hemisphere to create a control region with normal perfusion.11C-Pittsburgh compound-positron emission tomography standard uptake ratios and brain atrophy indices were calculated from the computed tomography images of each patient.Results:The median age of the 10 participants,consisting of 4 males and 6 females,was 64 years(47-76 years).We found that there were no differences in standard uptake ratios of the cortex(volume of interest[VOI]:P=0.721,region of interest[ROI]:P=0.241)and grey/white ratio(VOI:P=0.333,ROI:P=0.445)and brain atrophy indices(Bicaudate,Bifrontal,Evans,Cella,Cella media,and Ventricular index,P>0.05)between the hypoperfused regions and contralateral normally perfused regions in patients with unilateral chronic cerebral hypoperfusion.Conclusion:Our findings suggest that chronic hypoperfusion due to large vessel stenosis may not directly induce cerebralβ-amyloid deposition and neurodegeneration in humans.

Nucleation growth quenching for superior cluster catalysts

Cluster catalysts are rapidly growing into an important sub-field in heterogeneous catalysis,owing to their distinct geometric structure,neighboring metal sites,and unique electronic structure.Although the thermodynamics and kinetics of the formation of nanoparticles have been largely investigated,the precise synthesis of clusters in wet chemical methods still faces great challenges.In the study,a quenching strategy of asymmetric temperature in solution for the rapid generation of vacancy-defect rich clusters is reported.The quenching process can be used to synthesize multitudinous metal compound clusters,including metal oxides,fluorides,oxygen-sulfur compounds,and tungstate.For oxygen evolution reaction(OER),IrO_(2)clusters with abundant oxygen vacancies were obtained and uniformly dispersed in the solution.Compared to commercial IrO_(2),the prepared IrO_(2)cluster can be directly loaded on carbon paper and used as binder-free electrodes,which exhibit higher OER activity and long-term operational stability in alkaline electrolytes.The quenching strategy provides a simple and efficient method for the synthesis of clusters,which has tremendous potential for industrial-scale preparation and application,especially can be further applied to flow electrochemical generators.