Civil gas energy accidents in China from 2012-2021

In this study,civil gas energy accidents reported by the China Gas Network and related organizations from 2012 to 2021 were collected,and a comprehensive multidimensional correlation analysis was conducted considering factors such as accident timing,geography,causes,and casualties.The results identified July and August,Mondays and Sundays,and the morning,mid-day,and evening cooking times as the high-incidence months,days,and times for gas accidents,respectively.Gas accidents were found to occur more frequently in eastern coastal areas,provincial capitals,and larger cities,while residential and construction sites were identified as high-risk areas for gas accidents.Explosions were the most prevalent type of gas accident,followed by leaks,fires,and poisoning.Third-party construction and valve issues were identified as the primary factors contributing to gas leakage,whereas cooking was identified as the most common ignition source.An analysis of the Pearson correlation coefficient indicated a significant correlation among the gas accident factors.Moreover,a time-series prediction model was developed to forecast gas accidents in China,with the results demonstrating fluctuating gas accidents.This study proposes targeted preventive measures in terms of publicity,education,equipment,and facilities to provide scientific support to government units to improve civil gas energy security measures.

Macroporous composite capacitive bioanode applied in microbial fuel cells

Interfacial electron transfer between electroactive biofilm and the electrode was crucial step for microbial fuel cells(MFCs).A three-dimensional multilayer porous sponge coating with nitrogen-doped carbon nanotube/polyaniline/manganese dioxide(S/N-CNT/PANI/MnO2)electrode has been developed for MFC anode.Here,the S/N-CNT/PANI/MnO2 anode can function as a biocapacitor,able to store electrons generated from the degradation of organic substrate under the open circuit state and release the accumulated electrons upon requirement.Thus,the mismatching of the production and demand of the electricity can be overcome.Comparing with the sponge/nitrogen-doped carbon nanotube(S/N-CNT)bioanode,S/N-CNT/PANI/MnO2 capacitive bioanode displays a strong interaction with the microbial biofilm,advancing the electron transfer from exoelectrogens to the bioanode.The maximum power density of MFC with S/N-CNT/PANI/MnO2 capacitive bioanode is 1019.5 mW/m^2,which is 2.2 and5.8 times as much as that of S/N-CNT/MnO2 bioanode and S/N-CNT bioanode(470.7 mW/m^2 and176.6 mW/m^2),respectively.During the chronoamperometric experiment with 60 min of charging and 20 min of discharging,the S/N-CNT/PANI/MnO2 capacitive bioanode was able to store 10743.9 C/m^2,whereas the S/N-CNT anode was only able to store 3323.4 C/m^2.With a capacitive bioanode,it is possible to use the MFC simultaneously for production and storage of electricity.

Quantitative analysis of school safety events in China

Recent years have seen increasing school safety events along with growing numbers of students in China.In this paper,more than 400 serious school safety events between 2000 and 2018 in China were collected.The causes and characteristics of these events,taking into account the occurrence years,months,regions,education stages and types,were investigated.The results indicate that the number of school safety events has generally increased annually from 2000 to 2018 and can significantly vary each month,showing a higher frequency of occurrence during the“First Semester”(generally from September to December in China).Moreover,spatial distribution of school safety events is normally related to regional economic development;it was found that Guangdong,Jiangsu and Shandong is a first-level occurrence hotspots,followed by Zhejiang,Henan,Hebei and Sichuan,which are secondary occurrence hotspots.Furthermore,statistical analysis shows that the number of school safety events that occurred in kindergartens,primary schools and middle schools are approximately equal(around 1/3).Finally,it was found that the school safety events caused by“Accident”(such as school bus accidents,school fires,crowded stampedes and the collapses of school buildings)occupy a large proportion(57%).

Risk assessment of large-scale winter sports sites in the context of a natural disaster

Accidents induced by natural disasters at sports sites may cause catastrophic loss of great concern.However,previous studies on risk assessments of sports sites have only focused on operational risk and equipment failure.With the frequent occurrence of extreme disasters,the risk of domino chains caused by natural disasters at large-scale events,such as large-scale winter sports sites,cannot be ignored.In this study,a natural disaster-induced accident-chain evolution analysis model(NAEA model)is proposed.Based on the results of the NAEA model,a fuzzy Bayesian network for domino accidents triggered by an earthquake at large-scale winter sports sites was established.Through sensitivity analysis and scenario analysis,it was found that fire and explosion accidents and crowded stampede accidents are the main causes of serious loss in domino disaster chains in large-scale sports sites.Simultaneously,improving the early warning capability,reliability of electrical equipment,and automatic sprinkler systems are the most effective ways to prevent and control major accidents.In addition,an optimal safety strategy improvement analysis was performed to facilitate the decision-making of safety managers to prevent serious accidents and reduce accident loss.