被引排行
On fire-safety of high-rises with IAHP-based method
WANG Zhen, LIU Mao(Urban Public Safety Research Center, Nankai University, Tianjin 300071, China)The present paper aims to study the fire-safety influencing factors of high-rises and their effects on the surrounding buildings. To overcome the difficulties in predicting some of the factors with traditional AHP method, the paper has established the model of fire safety hierarchy for high-rises, and then has worked out the decisions of the influencing factors with IAHP. Moreover, we have used the Interval number eigenvalue method with its consistence property being tested. It is proved that the rating of the influencing factors is: evacuation measures, management and maintenance, fire protection services, alarming and fire extinguishing system, ignition prevention and fire resistant construction, while the weight of each factor is also confirmed. The weight of each sub-factor can also get through same way. The result is consistent with the reality. IAHP is thus a good measure in evaluating the fire safety of the high-rising buildings.
On the relation between carbon storage and reinforced fixation of the coastal wetland vegetation in the Yellow River delta area
ZHANG Xu-liang1,2,ZHANG Zhao-hui3,XU Zong-jun3,HOU Xue-jing4,CAI Qing-fang5(1 Shandong Provincial Key Laboratory of Eco-Environmental Science for Yellow River Delta,Binzhou University,Binzhou 256603,Shandong,China;2 Department of Geography,Qingdao University,Qingdao 266071,Shandong,China;3 The First Institute of Oceanography,State Oceanic Administration,Qingdao 266061,Shandong,China;4 School of Ocean Sciences,China University of Geosciences(Beijing),Beijing 10083,China;5 College of Marine Geosciences,Ocean University of China,Qingdao 266100,Shandong,China)The present paper is aimed at introducing our research of the relation between carbon storage and reinforced fixation of the coastal wetland vegetation in the Yellow River Delta Area based on our sampling surveys and some correlated statistical reference data.For our research purpose,we have surveyed the acreage of natural vegetations of the coastal wetlands and paddy fields in the Delta area and classified its natural vegetations into 3 sorts,that is,such as halarch vegetation,hydromorphic vegetation and hydrophilic vegetation.Our research has also measured the biomass and the net primary productivity of the natural vegetations and paddy fields,and worked out the carbon storage and carbon fixation per unit area and the total carbon storage and carbon fixation of the wetland vegetations.The results of our research show that the total carbon storage and carbon fixation of the wetland vegetations and paddy fields in the Delta area are equal to 200.54×104 t and 69.91×104 t/a,with its carbon fixation of the hydromorphic vegetations and paddy fields much higher than the mean carbon fixation of the global terrestrial vegetation(0.41 kg/(m2·a)) and the all-China terrestrial vegetations(0.49 kg/(m2·a)).However,the carbon fixation of the hydromorphic vegetations remains lower than that of the corresponding local latitudinal deciduous broad-leaved forest(1.06 kg/(m2·a)).As to its carbon fixation of the halarch vegetation and hydrophilic vegetation,the area remains lower than that of the global terrestrial vegetations or all-China terrestrial vegetations.Our survey shows that the carbon storage and carbon fixation of the vegetations of coastal wetland in the Yellow River Delta remains low,which is likely to reflect the fragility of the coastal wetland ecosystem of the area.All in all,the ever-increasing tendency of the area in reinforcing its natural vegetation and carbon storage and ever-intensifying fixation of the vegetations,in addition to the necessary countermeasures to protect the natural vegetations,are surely strengthened particularly in the reed association of coastal wetlands in the area.
CASE RESEARCH AND ISSUE DISCUSSION OF ECOLOGICAL RISK ASSESSMENT
ZHU Lin, TONG Yu jie (College of Environmental Science and Engineering, Nankai University, Tianjin 300071, China)The given article aims to introduce the Ecological Risk Assessment (ERA) as well as to provide a case study on ERA. As is known, ERA is originated from the human health risk assessment (HRA), which is engaged in the research on the risk of the harmful chemicals to human health with its objectives focused on the improvement of ecosystem. As a new research field with remarkable advances in the recent decade, ERA has grown into a branch of science and technology based on ecological and environmental chemistry and toxicology. Since 1980s on, the European countries and the United States of America began to pay attention to the study of ERA, which has so far gained its due legal admission and enhanced its status steadily. Though still in beginning stage in China, ERA has won more and more attention. It has mainly found related application in agro chemistry and chemistry with heavy metals. Since the corresponding ERA researchers are still lacking in guideline and indexes concerned, they cannot but adopting some western models and systems in the related case studies, which may not fit our own ecological environment. In addition, such studies can still produce limited quantitative and qualitative biological effect with insufficient toxicological data and less valuable results. Based on its discussion of regional ERA as a branch of the entire ERA field, this paper has introduced the current researches of ERA in China by means of analyzing some case studies and proposing urgent research tasks to be done in our country. First of all, it is necessary to set up research organizations and institutions on ERA, including developing advanced experimental technologies and the related fields for its application, such as physics, statistics, and mathematics and computer technology so as to establish a comprehensive prophetic ecosystem paradigm. Secondly, environmental protection departments should legislate the research on ERA and prepare guidelines and index systems for ERA on mythology and technology line.
Law of coal-gas mining accidents in China from 2008 to 2013
JING Guo-xun;School of Safety Science and Engineering,Henan Polytechnic University;The paper is oriented to make a research on the law of coal-gas mining accidents in China during the period from 2008 to2013 by applying the statistical analysis method and analyzing the dimensions of accident types,locations and times of the accidents,as well as the ownership forms of the coal mines.For our research goal,we just focus on the analysis of the general regularities of China's coal gas-coal mining accidents,the gas accident control from the point of view of analyzing the basic characteristic features.The results we have gained show that the frequency of gas accidents turns to be higher in Hunan and Guizhou Provinces,which are followed by Henan and Yunnan,for the frequency of major coal-gas accidents taking place in the above provinces.As to the frequency of the gascoal accidents from the point of view of seasons,March tends to be the highest in a year around.So far as the season features are concerned,the major coal-mining accidents occur in the following three months:October,November and December.Talking to the frequent hour points of a day,the coal-gas accidents take place most frequently from 8:00 to 11:59 and from 20:00 to 24:00.As for the kinds of mine accidents,they would happen most frequently in the process of mining blasting and outbursts,which tend to bring about the largest number of death casualty while the miners were working with mining activities going on.In addition,violent illegal mining activities should also account for the main accidents that are likely to lead to high frequency of the gas accidents in coal mines with poor production facilities and equipment.Besides,coal-gas accidents that take place with the large number of death and injuries in the township-owned coal mines,however,the township coal mines have now been remaining against the state order and stress on secure and security production measures.Furthermore,gas explosion and coal and gas outburst are most dangerous production disasters against the state laws and government orders.Therefore,the coal mine managerial departments should optimize their construction of accident-prevention and fighting measuring systems and impose the managerial and control roles over the production of the coal mines,strengthen the regularities of personnel management and reinforce their supervision so as to increase the production technology management and enhance implementation of the system.
Numeral simulation model and application of temperature rise process caused by natural burn of lossed coal in goaf
LI Zong-xiang~1, WU Zhi-jun~2, WANG Zhen-xiang~2( 1 College of Vocational, Liaoning Technical University, Fuxin 123000, Liaoning, China; 2 Wulong Mine, Fuxin 123000, Liaoning, China)The present paper aims to introduce the author's visual numerical simulation of temperature-rising process due to the spontaneous combustion in goaf. The simulation model has been established on the basis of the seepage equation of air leakage, the seepage flow-diffusion-consumption equation of oxygen concentration and heat transfer equation, as well as the non-steady numerical model of spontaneous combustion in goaf, all of which are combined and solved by the windward finite element based numerical simulation. As an example, air leakage seepage flow, oxygen concentration distribution, temperature distribution in goaf and their accelerated variation process with time are discussed first theoretically, and then quantitatively and emphatically as to the relation between the oxygen consumption of the losing coal during the spontaneous combustion and temperature rising. Thus, it can be concluded that usually high temperature zone appears at the inlet air side, where boundary air leakage has little influence. Therefore, it is necessary to point out that the traditional tri-zone division is ambiguous as to the cooled zone, the spontaneous combustion zone and the suffocating zone, while the mode presented in the paper will enable to solve the spontaneous combustion problem more ideally. The simulated result shows that the temperature rise during spontaneous combustion is an accelerated process and the conclusion would accord with the law obtained by the experimental analysis and actual observation.
Kinetic analysis of the low temperature spontaneous oxidation combustion of the coal seams due to the different metamorphism extents
DENG Jun;ZHANG Min;LEI Chang-kui;WANG Cai-ping;BAI Zu-jin;ZHAO Xiao-yong;The present paper is aimed at investigating the characteristic features of the coal seam low-temperature oxidative spontaneous combustion at the different metamorphism degrees and the impact of the degrees of the coal samples on the spontaneous combustion process. And,for such a purpose,we have managed to apply a self-designed temperature-programmed experimental system in the paper,and simultaneously traced the gas and coal characteristic temperature changes at low temperature oxidation with the different degrees of deterioration. And,consequently,we have also analyzed the corresponding relations between the oxygen consumption rate,the exothermic intensity and the related temperature through calculating its oxygen consumption rate and the exothermic intensity. Besides,we have also analyzed the influence of the deterioration degree of the coal samples on the CO,CO2 gas,the oxygen consumption rate and exothermic intensity. It is just based on the above said experimental conditions of the program warning and the Arrhenius equation that we have established a computational model of CO and temperature through the linear regression linear slope of the equation based on the low-temperature oxidative activation energy of coal with the different degrees of metamorphosis calculated and the relationship between the degree of metamorphosis and activation energy of the coal samples being validated. And,consequently,we have further elaborated the differences between the main coalseam quality indicators for each coal species and their relevance to the specific coal quality industrial analytic indicators,as well as the correlation between the main indicators and the spontaneous combustion oxidation parameters of the coal program warming test. And,furthermore,we have also analyzed the impact of the main industrial analytic indicators on each of the characteristic parameters. Thus,the experimental results we have gained can demonstrate that the gas emission of CO and CO2,the oxygen consumption rate and the exothermic intensity of the coal in the low-temperature oxidative spontaneous combustion process tend all to increase exponentially with the rise of the temperature.Nevertheless,with the increase of the deterioration degree of the coal sample,less change would take place with the oxygen consumption rate and the exothermic intensity of CO,CO2 gas,it can be found that,the higher the degree of the metamorphism of the coal,the higher the characteristic temperature and the more energetic the activation energy would be. Hence,correspondingly,the less coal-like spontaneous combustion would be taking place so as to make the activation energy less dangerous. Thus,it can be seen that the combination of the proximate analysis of the coal samples and the activation energy can help to reveal that the moisture,ash and volatile fraction ought to be correlated negatively with the activation energy.
Status quo and trend of urban soil contamination research
JIANG Hai-yan~1, LIU Min~1, HUANG Shen-fa~2, SHEN Gen-xiang~2, WU Jian~2(1 Department of Geography, Open Laboratory of Geo-information Science of Ministry of Education, East China Normal University, Shanghai 200062, China; 2 Shanghai Academy of Environmental Sciences, Shanghai 200233,China)The present paper aims to give a general survey of the status quo and trends of the urban soil contamination research in China in recent years. As is known, urban soil is one of the essential constituent parts of research that has had an important effect on the urban sustainable development. So the problems of urban soil contaminations have been paid more and more attention. During the last decade, the studies concerning the heavy metal pollution, organic pollution and biogenic pollution of surface soils in the urban areas, have been conducted around the world. However, large urban areas are seriously contaminated with concentrations of pollutants. These research results could systemically provide important scientific proofs of urban ecological environment quality. Since soil contaminations in urban environment are attached with more and more concern among the international scientific communities, the recent trends and emphases in research have been put on such issues as the conception and kinds of urban soil contaminations, the research about the combined pollution of urban soil, thirdly, remediation technologies, especially bioremediation technologies, the last but not the least environmental management policy.
Risk assessment of the gas pipeline corrosion based on the improved AHP and fuzzy comprehensive evaluation method
BA Zhen-ning;HAN Ya-xin;LIANG Jian-wen;Department of Civil Engineering,Tianjin University;Key Laboratory of Coastal Structures in Civil Engineering and Safety of Ministry of Education;The paper is aimed at establishing a risk assessment model for the underground-buried gas pipeline corrosion.In order to realize the forecast and prediction of the pipeline corrosion damage risks,we have established an index system by analyzing the cases of the pipeline corrosion damage status in reference to some other related papers.The indexical system can be said including 5 first-level indicators and 7 second-level indicators based on the ready-made research items so as to improve the AHP(Analytic Hierarchy Process) and the fuzzy comprehensive evaluation method we have worked out in regard to the corrosion risk assessment.As compared with the traditional AHP,the improved and perfected AHP model can be said more objective and easy to gain the judgment matrix by determining the weights of each index through the so-called 3-scaled method.In addition,we have also worked out a corrosion risk assessment model through the fuzzy comprehensive evaluation,which can better react to the fuzzy status-in-situ of the objective factors involved more objectively and accurately.Thus,it can be believed that the method we have worked out should be more suitable and convenient for assessing the risk of the underground buried pipeline corrosion situation under the impact of the multiplicity of the factors invloved.Moreover,it can also be said that the membership function should be an indespensible part of the comprehensive fuzzy evaluation method,for the membership function selection may have a great influence on the result of the assessment.This is because that,in accordance with the project assessment practice,the equal-difference triangular membership function can generally be adopted as a kind of fuzzy analysis method.It can be supposed that in the multiple factors,there may exist equal weights and different assessment levels,which can be inserted and substituted into the afforementioned model.Therefore,through comparing the theoretical results with the calculation ones,it would be possible to work out the degree of the consistency of the above mentioned two methods to reach the similar result whose accuracy can be as high as up to96% with a difference merely being 0.28(with the equal-difference being 0.28),which suggests that the model can be properly used for the said purpose.Therefore,the detective spots or positions of the underground buried gas pipeline can be made to stay at a medium risk state,which is consistent with the result of the reference system.From what is said above,the model we have proposed and established can be entrusted suitable for assessing such risk status-in-situ.And,in turn,the said fuzzy comprehensive evaluation method should be entrusted with a certain practical value and a proper application prospect with a reference to the risk management of the buried gas pipeline in the urban areas.
Statistics and analysis of coal mine gas accidents in China from 2015 to 2019
JING Guo-xun;LIU Meng-xia;This paper is to make research on the law of coal-gas mining accidents in China during the period from 2015 to 2019 by applying the statistical analysis method and analyzing the dimensions of accident types, regions, months, and inducement. For our research goals, we focus on analyzing the general laws of coal mine gas accidents in China and fundamentally analyze the general laws and characteristics of gas accidents. The results show that:(1) With the increase of mining depth, geological conditions are more complex and changeable and gas accidents increase year by year.(2) In these gas accidents, the main accident type is gas explosion and it often occurs in the process of gas outburst and mine blasting; The consequences of gas explosion include a large number of casualties and economic losses.(3) Gas accidents are more likely to occur in 10:00-12:00 and 18:00-20:00, and the two hours before and after the shift is the period for key prevention.(4) In terms of months, coal mines are most prone to gas accidents in May, October, and December; The highest number of gas accidents occurred in October and the highest number of deaths from gas accidents occurred in December.(5) The areas of Guizhou, Shanxi, Sichuan, and Hunan Provinces have high occurrence frequencies of gas accidents, among which Guizhou Province has the most gas accidents.(6)The main factor leading to coal mine gas accidents is illegal operation. To reduce the occurrence of coal mine gas accidents, coal mine enterprises must pay attention to the cultivation of workers' safety consciousness, strengthening the management of production technology, strengthening the safety inspection of ventilation facilities, strictly punishing violations in the mining process, increasing the intensity of punishment, strengthening safety management and safety supervision; strengthening safety supervision by relevant administrative departments.
Research on risk assessment model of prefabricated building hoisting construction based on game theory and extension theory
FANG Qian-cheng;LI Zhong-yuan;The present paper is aimed at establishing a new comprehensive safety evaluation model for prefabricated building hoisting construction based on the blind number theory and matter-element extension theory because of the randomness and fuzziness of prefabricated building hoisting construction. For this purpose, we, first of all, built a comprehensive evaluation index system according to the characteristics of prefabricated building hoisting construction, mainly including 23 factors: operation proficiency of hoisting operators, safety awareness of site construction personnel, the number of security commissioners, applicability of hoisting equipment, operation status of hoisting equipment, quality of prefabricated components, rationality of setting lifting points of prefabricated components, completeness of safety production management system construction, qualification of safety construction education and training, feasibility of construction scheme, climatic conditions of site operation, and so on. These factors are from the following 5 dimensions: human, equipment, components, environment, and management. What is also worth mentioning is that, in the given paper, we managed to G1 method for determining the weight of the above-mentioned factors. Secondly, we applied the expert scoring method for determining the index score range, and then we calculated the blind number matrix and the comprehensive score of the index based on the blind number theory. We worked out the single index attribute measure and comprehensive attribute measure based on the single index attribute measure function, as well as the risk grade of prefabricated building hoisting construction on the maximum membership degree principle. Finally, the new comprehensive safety evaluation model is applied to evaluate a prefabricated building community under construction in a city with the analysis results demonstrating that is low-risk, which is consistent with the field investigation. It shows that the comprehensive evaluation model of blind number theory and matter-element extension method established in this paper is applicable in the risk evaluation of prefabricated building hoisting construction, and can provide a new idea for the hoisting construction risk assessment of prefabricated buildings.