Pub Date : 2020-06-28DOI: 10.16265/J.CNKI.ISSN1003-3033.2020.06.004
Du Xiuli, Cao Xiuxiu, Zhong Zilan, Hou Benwei, Wang Wei
In order to address uncertainties of geotechnical parameters and loads in pile foundation designꎬ firstlyꎬ a RGD method considering multiple failure modes was proposed. Four typical failure modesꎬ vertical ultimate limit state (ULS)ꎬ vertical serviceability limit state (SLS)ꎬ horizontal strength failure and horizontal deformation failure were analyzed. Thenꎬ Monte Carlo simulation (MCS) and point estimate method (PEM) nesting were adopted to compute mean value and standard deviation of failure probability for soil ̄pile foundation systemꎬ and the latter was used as an indicator to measure robustness. Finallyꎬ optimal design of soil ̄pile foundation system was finalized with robustness and cost as objectives. The results show that piles with different geometries have different dominant failure modes. With the increase of geometriesꎬ key failure mode changes from horizontal strength failure to vertical SLSꎬ which has significant influence on gradient of of system' failure probability. 中 国 安 全 科 学 学 报 China Safety Science Journal 第30卷 2020年
{"title":"Robust geotechnical design of soil-pile foundation system considering multiple failure modes","authors":"Du Xiuli, Cao Xiuxiu, Zhong Zilan, Hou Benwei, Wang Wei","doi":"10.16265/J.CNKI.ISSN1003-3033.2020.06.004","DOIUrl":"https://doi.org/10.16265/J.CNKI.ISSN1003-3033.2020.06.004","url":null,"abstract":"In order to address uncertainties of geotechnical parameters and loads in pile foundation designꎬ firstlyꎬ a RGD method considering multiple failure modes was proposed. Four typical failure modesꎬ vertical ultimate limit state (ULS)ꎬ vertical serviceability limit state (SLS)ꎬ horizontal strength failure and horizontal deformation failure were analyzed. Thenꎬ Monte Carlo simulation (MCS) and point estimate method (PEM) nesting were adopted to compute mean value and standard deviation of failure probability for soil ̄pile foundation systemꎬ and the latter was used as an indicator to measure robustness. Finallyꎬ optimal design of soil ̄pile foundation system was finalized with robustness and cost as objectives. The results show that piles with different geometries have different dominant failure modes. With the increase of geometriesꎬ key failure mode changes from horizontal strength failure to vertical SLSꎬ which has significant influence on gradient of of system' failure probability. 中 国 安 全 科 学 学 报 China Safety Science Journal 第30卷 2020年","PeriodicalId":9976,"journal":{"name":"中国安全科学学报","volume":"13 1","pages":"23"},"PeriodicalIF":0.0,"publicationDate":"2020-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"75624341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-28DOI: 10.16265/J.CNKI.ISSN1003-3033.2020.06.013
Jia Bo, Sun Yanjin, Zhang Guiming
In order to grasp causes of bounced landing of aircraft which is a frequently occurring issue during flight operationꎬ and effectively prevent such incidentsꎬ a prediction method for bounced landing based on DBN was proposed. Secondlyꎬ correlation between incidents and landing airports ' environment was evaluated by using aviation dataꎬ and with an actual incident of China Eastern Airlines as an exampleꎬ changing trend of bounced landing along with throttle stick position at touchdown was explored. Thenꎬ impacts of pilot controlꎬ aircraft status and unstable approach on incidents were discussed. Finallyꎬ different combinations of information were used as inputs to train the modelꎬ and their prediction accuracy was compared to find optimal one. The results show that DBN ̄based method is suitable for predicting bounced landing by utilizing flight data. When network input includes direct influencing factors such as airports' environmentꎬ throttle lever positionꎬ as well as indirect ones like unstable approachꎬ this model can accurately predict accidents with a prediction accuracy as high as 94 78%.
{"title":"A prediction method for bounced landing of aircraft based on DBN","authors":"Jia Bo, Sun Yanjin, Zhang Guiming","doi":"10.16265/J.CNKI.ISSN1003-3033.2020.06.013","DOIUrl":"https://doi.org/10.16265/J.CNKI.ISSN1003-3033.2020.06.013","url":null,"abstract":"In order to grasp causes of bounced landing of aircraft which is a frequently occurring issue during flight operationꎬ and effectively prevent such incidentsꎬ a prediction method for bounced landing based on DBN was proposed. Secondlyꎬ correlation between incidents and landing airports ' environment was evaluated by using aviation dataꎬ and with an actual incident of China Eastern Airlines as an exampleꎬ changing trend of bounced landing along with throttle stick position at touchdown was explored. Thenꎬ impacts of pilot controlꎬ aircraft status and unstable approach on incidents were discussed. Finallyꎬ different combinations of information were used as inputs to train the modelꎬ and their prediction accuracy was compared to find optimal one. The results show that DBN ̄based method is suitable for predicting bounced landing by utilizing flight data. When network input includes direct influencing factors such as airports' environmentꎬ throttle lever positionꎬ as well as indirect ones like unstable approachꎬ this model can accurately predict accidents with a prediction accuracy as high as 94 78%.","PeriodicalId":9976,"journal":{"name":"中国安全科学学报","volume":"44 1","pages":"84"},"PeriodicalIF":0.0,"publicationDate":"2020-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86325800","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-28DOI: 10.16265/J.CNKI.ISSN1003-3033.2020.06.009
Zhang Jianshe, Zhang Wenyu, chen ruiya, Lu Chunyang, Wang Tianxing
In order to investigate how safety accidents affect network capability of construction enterprisesꎬ connotation of network capability was defined and it was divided into five dimensionsꎬ network visionꎬ network constructionꎬ network managementꎬ network learning and emotional embedding. Thenꎬ hypothesis of relationship between safety accidents and network capability was put forwardꎬ data were collected through questionnaire survey and empirical analysis was made using SEM. The results show that safety incidents have a significant and direct impact on network visionꎬ network constructionꎬ network management and emotional embeddingꎬ among which influence on network vision and emotional embedding is greater than that on network construction and network management. And they exert a significant and indirect impact on network learning through intermediary role of network vision and emotional embeddingꎬ among which that role of emotional embedding is greater than that of network vision. Thereforeꎬ construction enterprises can reduce impacts of safety accidents on network capacity through strategic planning of network in timeꎬ strengthening coordination between organizations and emotional ties.
{"title":"Structural equation model between safety accidents and network capability of construction enterprises","authors":"Zhang Jianshe, Zhang Wenyu, chen ruiya, Lu Chunyang, Wang Tianxing","doi":"10.16265/J.CNKI.ISSN1003-3033.2020.06.009","DOIUrl":"https://doi.org/10.16265/J.CNKI.ISSN1003-3033.2020.06.009","url":null,"abstract":"In order to investigate how safety accidents affect network capability of construction enterprisesꎬ connotation of network capability was defined and it was divided into five dimensionsꎬ network visionꎬ network constructionꎬ network managementꎬ network learning and emotional embedding. Thenꎬ hypothesis of relationship between safety accidents and network capability was put forwardꎬ data were collected through questionnaire survey and empirical analysis was made using SEM. The results show that safety incidents have a significant and direct impact on network visionꎬ network constructionꎬ network management and emotional embeddingꎬ among which influence on network vision and emotional embedding is greater than that on network construction and network management. And they exert a significant and indirect impact on network learning through intermediary role of network vision and emotional embeddingꎬ among which that role of emotional embedding is greater than that of network vision. Thereforeꎬ construction enterprises can reduce impacts of safety accidents on network capacity through strategic planning of network in timeꎬ strengthening coordination between organizations and emotional ties.","PeriodicalId":9976,"journal":{"name":"中国安全科学学报","volume":"1 1","pages":"57"},"PeriodicalIF":0.0,"publicationDate":"2020-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"86362072","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-28DOI: 10.16265/J.CNKI.ISSN1003-3033.2020.06.006
Fu Shigen, Liu Quanming, Huang Jiaguo, Dong Hewei
In order to prevent harm caused by respiratory dust and to monitor mass concentration of individual exhalation dustꎬ a portable personal concentration monitoring test prototype was developed by using infrared light emitting photodiode as a light source according to principle of light scatteringꎬ and its pneumatic control circuit and optical control and detection circuit were designed. Thenꎬ prototype and comparison instrument were put in a self ̄made dust test device together with dust gas which featured a flow rate of 2 L / min and a particle size of 5 μm. The results show that when mass concentration of dust is between 0-150 mg / mꎬ measured voltage of prototype increases along with increase of dust concentrationꎬ and they maintain a good linear relationship. The relative error between measured concentration value of prototype by using regression equation and that of comparison instrument is within ±4%ꎬ indicating that the 中 国 安 全 科 学 学 报 China Safety Science Journal 第30卷 2020年 device meets requirements of relevant dust verification regulations.
为了防止呼吸道粉尘的危害，监测个人呼出粉尘的质量浓度ꎬ根据光散射原理，研制了一种以红外发光光电二极管为光源的便携式个人浓度监测试验样机ꎬ，并设计了其气动控制电路和光学控制检测电路。将ꎬ样机和对比仪与流量为2 L / min、粒径为5 μm的粉尘气体一起放入自制的粉尘试验装置中。结果表明:当粉尘质量浓度为0 ~ 150 mg / mꎬ时，样机的实测电压随粉尘浓度的增加而增加ꎬ，两者保持良好的线性关系。回归方程对样机测定的浓度值与比较仪测定的浓度值的相对误差在±4%ꎬ以内，表明该装置符合相关粉尘检定规程的要求。
{"title":"Application research of light scattering principle in dust measurement system","authors":"Fu Shigen, Liu Quanming, Huang Jiaguo, Dong Hewei","doi":"10.16265/J.CNKI.ISSN1003-3033.2020.06.006","DOIUrl":"https://doi.org/10.16265/J.CNKI.ISSN1003-3033.2020.06.006","url":null,"abstract":"In order to prevent harm caused by respiratory dust and to monitor mass concentration of individual exhalation dustꎬ a portable personal concentration monitoring test prototype was developed by using infrared light emitting photodiode as a light source according to principle of light scatteringꎬ and its pneumatic control circuit and optical control and detection circuit were designed. Thenꎬ prototype and comparison instrument were put in a self ̄made dust test device together with dust gas which featured a flow rate of 2 L / min and a particle size of 5 μm. The results show that when mass concentration of dust is between 0-150 mg / mꎬ measured voltage of prototype increases along with increase of dust concentrationꎬ and they maintain a good linear relationship. The relative error between measured concentration value of prototype by using regression equation and that of comparison instrument is within ±4%ꎬ indicating that the 中 国 安 全 科 学 学 报 China Safety Science Journal 第30卷 2020年 device meets requirements of relevant dust verification regulations.","PeriodicalId":9976,"journal":{"name":"中国安全科学学报","volume":"194 1","pages":"37"},"PeriodicalIF":0.0,"publicationDate":"2020-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79744684","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-28DOI: 10.16265/J.CNKI.ISSN1003-3033.2020.06.020
Zhang Wei, Z. Ying, Liu Changwei, Yuan Dachao
In order to explore effects of different restricted forms on flow field of fire plumeꎬ fine thermocouple and PIV technologies were used to monitor fire plume's heightꎬ temperature and flow field of diffusion burner in free spaceꎬ side wall space and corner spaceꎬ and then flow field characteristics in different restricted forms were studied. The experimental results show that when dimensionless source power Q is less than 1 5ꎬ dimensionless flame height Lf / D increases linearly which will become steady approximately when Q exceeds 1 5. Lateral velocity in different restricted spaces all conform to approximate Gaussian distributionsꎬ and sidewall space and corner space cause a certain deviation of flame center. Vortex diameter is between 3 5 and 8 cm at Q is 1 982ꎬ and its size gradually increase along with increase of side wall surface because vortex will fall offꎬ which will release a lot of heat in a short time and exerts a stretching impact on fire plume. As a resultꎬ combustion reaction of fire is promotedꎬ and then a larger vortex is generated.
{"title":"Flow field characteristics of fire plume in different restricted forms based on PIV","authors":"Zhang Wei, Z. Ying, Liu Changwei, Yuan Dachao","doi":"10.16265/J.CNKI.ISSN1003-3033.2020.06.020","DOIUrl":"https://doi.org/10.16265/J.CNKI.ISSN1003-3033.2020.06.020","url":null,"abstract":"In order to explore effects of different restricted forms on flow field of fire plumeꎬ fine thermocouple and PIV technologies were used to monitor fire plume's heightꎬ temperature and flow field of diffusion burner in free spaceꎬ side wall space and corner spaceꎬ and then flow field characteristics in different restricted forms were studied. The experimental results show that when dimensionless source power Q is less than 1 5ꎬ dimensionless flame height Lf / D increases linearly which will become steady approximately when Q exceeds 1 5. Lateral velocity in different restricted spaces all conform to approximate Gaussian distributionsꎬ and sidewall space and corner space cause a certain deviation of flame center. Vortex diameter is between 3 5 and 8 cm at Q is 1 982ꎬ and its size gradually increase along with increase of side wall surface because vortex will fall offꎬ which will release a lot of heat in a short time and exerts a stretching impact on fire plume. As a resultꎬ combustion reaction of fire is promotedꎬ and then a larger vortex is generated.","PeriodicalId":9976,"journal":{"name":"中国安全科学学报","volume":"19 1","pages":"135"},"PeriodicalIF":0.0,"publicationDate":"2020-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73695679","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-28DOI: 10.16265/J.CNKI.ISSN1003-3033.2020.06.007
Xiao Junfeng, Chen Jian, Dai Chengcheng, Lu Ping
In order to study interrelation between influencing factors in high ̄sulfur natural gas leakage accidentsꎬ single ̄factor analysis and uniform design method were used to study influence of CH4 and H2S content ratioꎬ ventilation rate and pipeline pressure on explosion and toxicity risk of high ̄sulfur natural gas based on numerical simulation by FLACS software. The results show that factors influencing explosion limit of natural gas is ventilation rate > pipe pressure > CH4 and H2S content ratioꎬ among which the first factor is negatively correlated with limit range while the other two are positively correlated with itꎬ and ventilation rate has the most significant effect. It is the opposite for factors that affect gas leakage toxicity which is negatively correlated with ventilation rate and content ratio but positively correlated with pipeline pressureꎬ and content ratio exerts the most significant effect on gas toxicity.
{"title":"Influencing factors on explosion and toxicity of high-sulfur natural gas","authors":"Xiao Junfeng, Chen Jian, Dai Chengcheng, Lu Ping","doi":"10.16265/J.CNKI.ISSN1003-3033.2020.06.007","DOIUrl":"https://doi.org/10.16265/J.CNKI.ISSN1003-3033.2020.06.007","url":null,"abstract":"In order to study interrelation between influencing factors in high ̄sulfur natural gas leakage accidentsꎬ single ̄factor analysis and uniform design method were used to study influence of CH4 and H2S content ratioꎬ ventilation rate and pipeline pressure on explosion and toxicity risk of high ̄sulfur natural gas based on numerical simulation by FLACS software. The results show that factors influencing explosion limit of natural gas is ventilation rate > pipe pressure > CH4 and H2S content ratioꎬ among which the first factor is negatively correlated with limit range while the other two are positively correlated with itꎬ and ventilation rate has the most significant effect. It is the opposite for factors that affect gas leakage toxicity which is negatively correlated with ventilation rate and content ratio but positively correlated with pipeline pressureꎬ and content ratio exerts the most significant effect on gas toxicity.","PeriodicalId":9976,"journal":{"name":"中国安全科学学报","volume":"1 1","pages":"43"},"PeriodicalIF":0.0,"publicationDate":"2020-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88827549","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-06-28DOI: 10.16265/J.CNKI.ISSN1003-3033.2020.06.024
Zhisheng Li, Gao Yunji, Xiaosong Li, Yu-chun Zhang, Pengfei Mao
In order to explore transverse and longitudinal length and flame area distribution features of ceiling jet flow driven by strong plume in a bifurcation tunnelꎬ 5 groups of fire locations (0 1ꎬ 0 3ꎬ 0 5ꎬ 0 7 and 0 9 m) and 4 HRR (47 9ꎬ 63 8ꎬ 77 7 and 95 7 kW) were selected. Transverse lengths of intermittent flame and transverse continuous flame for typical working conditions were calculated and corresponding critical temperature values were determinedꎬ which were 325 and 620 °C respectively. Based on critical values of continuous flameꎬ its transverse and longitudinal flame length as well as flame area were obtained. The results show that there is a non ̄monotonic trend for transverse flame length as distance from fire source to sidewall increases from 0 1 m to 0 7 mꎬ and it will reach maximum value at 0 3 m. Neverthelessꎬ longitudinal length continuously decreases as distance rises from 0 1 m to 0 9 mꎬ and it is always larger than transverse length under same conditions. Flame area increases first with spacing grows 第 6 期 李智胜等: 分岔隧道强羽流驱动的顶棚射流火焰特征 from 0 1 m to 0 3 m and then decreases as it continuously increases to 0 7 m.
{"title":"Flame characteristics of ceiling jet flow driven by strong plume in bifurcation tunnels","authors":"Zhisheng Li, Gao Yunji, Xiaosong Li, Yu-chun Zhang, Pengfei Mao","doi":"10.16265/J.CNKI.ISSN1003-3033.2020.06.024","DOIUrl":"https://doi.org/10.16265/J.CNKI.ISSN1003-3033.2020.06.024","url":null,"abstract":"In order to explore transverse and longitudinal length and flame area distribution features of ceiling jet flow driven by strong plume in a bifurcation tunnelꎬ 5 groups of fire locations (0 1ꎬ 0 3ꎬ 0 5ꎬ 0 7 and 0 9 m) and 4 HRR (47 9ꎬ 63 8ꎬ 77 7 and 95 7 kW) were selected. Transverse lengths of intermittent flame and transverse continuous flame for typical working conditions were calculated and corresponding critical temperature values were determinedꎬ which were 325 and 620 °C respectively. Based on critical values of continuous flameꎬ its transverse and longitudinal flame length as well as flame area were obtained. The results show that there is a non ̄monotonic trend for transverse flame length as distance from fire source to sidewall increases from 0 1 m to 0 7 mꎬ and it will reach maximum value at 0 3 m. Neverthelessꎬ longitudinal length continuously decreases as distance rises from 0 1 m to 0 9 mꎬ and it is always larger than transverse length under same conditions. Flame area increases first with spacing grows 第 6 期 李智胜等: 分岔隧道强羽流驱动的顶棚射流火焰特征 from 0 1 m to 0 3 m and then decreases as it continuously increases to 0 7 m.","PeriodicalId":9976,"journal":{"name":"中国安全科学学报","volume":"24 1","pages":"166"},"PeriodicalIF":0.0,"publicationDate":"2020-06-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80459005","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-28DOI: 10.16265/J.CNKI.ISSN1003-3033.2020.04.022
H. Xia, Zhang Daowen, Che Yaoyue, Liu Qi, Dong Xiaofei, Dong Honglei
In order to study influence of trigger width on pedestrian crossing scenario results in AEB control strategyꎬ road and vehicle models were built by using automatic driving simulation software PreScan. Thenꎬ AEB longitudinal control algorithm was designed in Matlab model’ s control platform Simulink to simulate pedestrians crossing scenarios. And trigger width was continuously adjusted to observe whether collision was avoided. The results show that when car speed is 30-50 km / hꎬ the system's trigger width is at 1 75 mꎬ which can help avoid collision effectively. When speed is 50-80 km / hꎬ it needs to 中 国 安 全 科 学 学 报 China Safety Science Journal 第30卷 2020年 increase along with the increase of pedestrian speed. The wider it isꎬ the more information car receivesꎬ and the more possible AEB malfunction will be. Thereforeꎬ the maximum trigger width is set to be 3 5 m. When car speed reaches between 60-80 km / hꎬ it is necessary to optimize alue and full braking advance time simultaneously so as to avoid collision.
为了研究触发宽度对AEB控制策略中行人过马路情景结果的影响，利用自动驾驶仿真软件PreScan建立道路和车辆模型ꎬ。然后在Matlab模型的控制平台Simulink中设计ꎬAEB纵向控制算法，模拟行人过马路的场景。并不断调整触发宽度，观察是否避免碰撞。结果表明:当车速为30 ~ 50 km / hꎬ时，系统触发宽度为175 mꎬ，能有效避免碰撞;当速度为50-80公里/小时ꎬ时，需要随着行人速度的增加而增加。它越宽ꎬ汽车接收到的信息越多ꎬAEB故障的可能性越大。因此ꎬ最大触发宽度设置为35m。当车速达到60-80 km / hꎬ时，需要同时优化值和全制动提前时间，以避免碰撞。
{"title":"Optimization of AEB trigger width based on pedestrian crossing scenario","authors":"H. Xia, Zhang Daowen, Che Yaoyue, Liu Qi, Dong Xiaofei, Dong Honglei","doi":"10.16265/J.CNKI.ISSN1003-3033.2020.04.022","DOIUrl":"https://doi.org/10.16265/J.CNKI.ISSN1003-3033.2020.04.022","url":null,"abstract":"In order to study influence of trigger width on pedestrian crossing scenario results in AEB control strategyꎬ road and vehicle models were built by using automatic driving simulation software PreScan. Thenꎬ AEB longitudinal control algorithm was designed in Matlab model’ s control platform Simulink to simulate pedestrians crossing scenarios. And trigger width was continuously adjusted to observe whether collision was avoided. The results show that when car speed is 30-50 km / hꎬ the system's trigger width is at 1 75 mꎬ which can help avoid collision effectively. When speed is 50-80 km / hꎬ it needs to 中 国 安 全 科 学 学 报 China Safety Science Journal 第30卷 2020年 increase along with the increase of pedestrian speed. The wider it isꎬ the more information car receivesꎬ and the more possible AEB malfunction will be. Thereforeꎬ the maximum trigger width is set to be 3 5 m. When car speed reaches between 60-80 km / hꎬ it is necessary to optimize alue and full braking advance time simultaneously so as to avoid collision.","PeriodicalId":9976,"journal":{"name":"中国安全科学学报","volume":"15 1","pages":"141"},"PeriodicalIF":0.0,"publicationDate":"2020-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79996390","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-04-28DOI: 10.16265/J.CNKI.ISSN1003-3033.2020.04.010
Lou Hezhuang, Jiang Tinggui
In order to explore spontaneous combustion characteristics in low temperature oxidation process of coal after absorption in CO2 and N2 atmospheresꎬ with anthracite coal in No. 9 coal seam of Sihe No. 2 mine taken as research objectꎬ warming test and TG test of coal during low temperature oxidation were conducted to analyze gas product characteristics and weight loss characteristics of CO and CH4 during spontaneous combustion of coal. Thenꎬ a physical adsorption model of different gas moleculesꎬ such as O2ꎬ CO2 and N2ꎬ was established on the surface of coal macromoleculesꎬ and adsorption of O2 gas molecules was analyzed from a micro perspective using grand canonical Monte Carlo simulation (GCMC) method. Finallyꎬ difference in competitive adsorption between mixed gas molecules on surface of coal macromolecules were discussed. The research shows that spontaneous combustion characteristics of coal in low temperature oxidation process change after adsorption in CO2 and N2 atmospheresꎬ with concentration 第 4 期 娄和壮等: 惰性气氛对煤自燃过程的竞争吸附差异性研究 of CO and CH4 gas products being reduced and rate of weight loss of coal spontaneous combustion decreasingꎬ thus inhibiting low temperature oxidation capacity of coal. The mixed adsorption of coal macromolecules on gas moleculesꎬ like CO2 and N2ꎬ suppresses their adsorption of O2 molecules. And gas competitive adsorption on coal surface ranks as H2O>CO2>N2>O2>CH4>CO.
{"title":"Competitive adsorption difference during coal spontaneous combustion process in noble gas atmosphere","authors":"Lou Hezhuang, Jiang Tinggui","doi":"10.16265/J.CNKI.ISSN1003-3033.2020.04.010","DOIUrl":"https://doi.org/10.16265/J.CNKI.ISSN1003-3033.2020.04.010","url":null,"abstract":"In order to explore spontaneous combustion characteristics in low temperature oxidation process of coal after absorption in CO2 and N2 atmospheresꎬ with anthracite coal in No. 9 coal seam of Sihe No. 2 mine taken as research objectꎬ warming test and TG test of coal during low temperature oxidation were conducted to analyze gas product characteristics and weight loss characteristics of CO and CH4 during spontaneous combustion of coal. Thenꎬ a physical adsorption model of different gas moleculesꎬ such as O2ꎬ CO2 and N2ꎬ was established on the surface of coal macromoleculesꎬ and adsorption of O2 gas molecules was analyzed from a micro perspective using grand canonical Monte Carlo simulation (GCMC) method. Finallyꎬ difference in competitive adsorption between mixed gas molecules on surface of coal macromolecules were discussed. The research shows that spontaneous combustion characteristics of coal in low temperature oxidation process change after adsorption in CO2 and N2 atmospheresꎬ with concentration 第 4 期 娄和壮等: 惰性气氛对煤自燃过程的竞争吸附差异性研究 of CO and CH4 gas products being reduced and rate of weight loss of coal spontaneous combustion decreasingꎬ thus inhibiting low temperature oxidation capacity of coal. The mixed adsorption of coal macromolecules on gas moleculesꎬ like CO2 and N2ꎬ suppresses their adsorption of O2 molecules. And gas competitive adsorption on coal surface ranks as H2O>CO2>N2>O2>CH4>CO.","PeriodicalId":9976,"journal":{"name":"中国安全科学学报","volume":"7 1","pages":"60"},"PeriodicalIF":0.0,"publicationDate":"2020-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"80587490","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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