Apparent activation energy of mineral in open pit mine based upon the evolution of active functional groups

This study aimed to investigate the mechanism of mineral spontaneous combustion in an open pit. On the study of coal and mineral mixture in open pit mines, as well as through the specifc surface area and Search Engine Marketing (SEM) experiments, the specifc surface area and aperture characteristics of distribution of open pit coal sample and pit mineral mixture samples were analyzed. Thermal analysis experiments were used to divide the oxidation process was divided into three stages, and the thermal behavior characteristics of experimental samples were characterized. On the basis of the stage division, we explored the transfer law of the key active functional groups of the experimental samples. The apparent activation energy calculation of the key active groups, performed by combining the Achar diferential method with the Coats–Redfern integral method, microstructural and oxidation kinetic properties were revealed. The resulted showed that the mixed sample had high ash, the fxed carbon content was reduced, the specifc surface area was far lower than the raw coal, the large aperture distribution was slightly higher than the medium hole, the micropore was exceptionally low, the gas adsorption capacity was weaker than the raw coal, the pit coal sample had the exceedingly more active functional groups, easy to react with oxygen, more likely to occur naturally, and its harm was relatively large. The mixed sample contained the highest C–O–C functional group absorbance. The functional groups were mainly infuenced by the self-OH content, alkyl side chain, and fatty hydrocarbon in the sample. The main functional groups of the four-like mixture had the highest apparent activation energy, and the two reactions were higher in the low-temperature oxidation phase.

Ability of community-based prostate cancer screening to target an appropriate and underserved population

Screening is not universally beneficial due to over-and under-diagnosis,and false positives that beget additionaltesting and associated adverse events and expense.We examined data from all men who participated in a mass community prostate cancer screening between May 2009 and September 2010.The data contained information regarding patient demographics,family history of prostate cancer,lower urinary tract symptoms,prior history of prostate cancer,most recent digital rectal examination,and the presence of an established relationship with a physician.Current American Urological Association screening recommendations were then applied to determine the appropriateness of our outreach effort.A total of 438 men(mean age 66.5 years) underwent screening.A total of 106(24.2%) patients in our study met contemporary criteria for screening.Of these men,the vast majority was well educated,well insured,and well informed about the need for prostate cancer screening.Based on these data,mass community-based prostate cancer screening does not appear to identify and screen at-risk men.Future efforts at mass screening should more carefully target men most likely to benefit.

Technical specifcations issued to regulate QR code payment

The People’s Bank of China（PBOC）recently issued the regulations on QR code payment service（Trial）and two other relevant technical specifications to regulate payments by scanning two-dimensional barcode,which are to take effect on April 1,2018.Payment institutions must obtain proper permits to offer barcode-based payment services by then.Payments with QR codes are increasingly common in China for purchases in large or small shops,

Comparison of pretreatment,preservation and determination methods for foliar pH of plant samples

To compare current methods of pretreatment/determination for plant foliar pH,we proposed a method for longperiod sample preservation with little interference with the stability of foliar pH.Four hundred leaf samples from 20 species were collected and four methods of pH determination were used:refrigerated(stored at 4°C for 4 days),frozen(stored at−16°C for 4 days),oven-dried and fresh green-leaf pH(control).To explore the effects of different leaf:water mixing ratio on the pH determination results,we measured oven-dried green-leaf pH by leaf:water volume ratio of 1:8 and mass ratio of 1:10,and measured frozen senesced-leaf pH by mass ratio of 1:10 and 1:15.The standard major axis regression was used to analyze the relationship and the conversion equation between the measured pH with different methods.Foliar pH of refrigerated and frozen green leaves did not signifcantly differ from that of fresh green-leaf,but drying always overrated fresh green-leaf pH.During the feld sampling,cryopreservation with a portable refrigerator was an advisable choice to get a precise pH.For long-duration feld sampling,freezing was the optimal choice,and refrigeration is the best choice for the shorttime preservation.The different leaf:water mixing ratio signifcantly infuenced the measured foliar pH.High dilution reduced the proton concentration and increased the measured pH.Our fndings provide the conversion relationships between the existing pretreatment and measurement methods,and establish a connection among pH determined by different methods.Our study can facilitate foliar pH measurement,thus contributing to understanding of this interesting plant functional trait.

Specifc urban units identifed in tuberculosis epidemic using a geographical detector in Guangzhou,China

Background:A remarkable drop in tuberculosis(TB)incidence has been achieved in China,although in 2019 it was still considered the second most communicable disease.However,TB’s spatial features and risk factors in urban areas remain poorly understood.This study aims to identify the spatial diferentiations and potential infuencing factors of TB in highly urbanized regions on a fne scale.Methods:This study included 18 socioeconomic and environmental variables in the four central districts of Guangzhou,China.TB case data obtained from the Guangzhou Institute of Tuberculosis Control and Prevention.Before using Pearson correlation and a geographical detector(GD)to identify potential infuencing factors,we conducted a global spatial autocorrelation analysis to select an appropriate spatial scales.Results:Owing to its strong spatial autocorrelation(Moran’s I=0.33,Z=4.71),the 2 km×2 km grid was selected as the spatial scale.At this level,TB incidence was closely associated with most socioeconomic variables(0.31<r<0.76,P<0.01).Of fve environmental factors,only the concentration of fne particulate matter displayed signifcant correlation(r=0.21,P<0.05).Similarly,in terms of q values derived from the GD,socioeconomic variables had stronger explanatory abilities(0.08<q<0.57)for the spatial diferentiation of the 2017 incidence of TB than environmental variables(0.06<q<0.27).Moreover,a much larger proportion(0.16<q<0.89)of the spatial diferentiation was interpreted by pairwise interactions,especially those(0.60<q<0.89)related to the 2016 incidence of TB,ofcially appointed medical institutions,bus stops,and road density.Conclusions:The spatial heterogeneity of the 2017 incidence of TB in the study area was considerably infuenced by several socioeconomic and environmental factors and their pairwise interactions on a fne scale.We suggest that more attention should be paid to the units with pairwise interacting factors in Guangzhou.Our study provides helpful clues for local authorities implementing more efective intervention measures to reduce TB incidence in China’s municipal areas,which are featured by both a high degree of urbanization and a high incidence of TB.