Aphids are a major global wheat,pest that can cause considerable loss of yield.Modeling of aphid population dynamics is an integral part of management strategies to manage or control aphid populations.In this paper,fi...Aphids are a major global wheat,pest that can cause considerable loss of yield.Modeling of aphid population dynamics is an integral part of management strategies to manage or control aphid populations.In this paper,first,a wheat aphid population dynamics model was developed based on a logistic model and theⅠlollingⅢfunctional response,which includes three factors:temperature,natural enemies and insecticide.Second,this model fitted with a cusp catastrophe model to describe how abrupt changes in the wheat aphid population were influenced by these factors,Finally,the system was validated with field data from 2016 to 2018.The bifurcation set of the cusp catastrophe model was deemod to be the quantified dynamic control threshold,so an outbreak of aphid's population can be explained according to the variation of control variables.In short,this aphid population model was successfully validated on survey data,which can be used to guide the prevention and control of aphids.展开更多
By means of CUSP model of catastrophe theory. this paper has studied thephysics process of rockburst occured on circular chamber. The present paper has nolonly described the instability process of rockburst more deepl...By means of CUSP model of catastrophe theory. this paper has studied thephysics process of rockburst occured on circular chamber. The present paper has nolonly described the instability process of rockburst more deeply. but also got the crilicaldepth of plastic softening area of chamber that is valuable in the controlling engineering of rockburst. the chamber displacement jump and energy liberation have been derived. the influence of rock parameters on the rockburst has been discussed .展开更多
Cusp displacement catastrophe theory can be introduced to propose a new method about instability failure of the interbed for gas storage cavern in bedded salt in solution mining.We can calculate initial fracture drawi...Cusp displacement catastrophe theory can be introduced to propose a new method about instability failure of the interbed for gas storage cavern in bedded salt in solution mining.We can calculate initial fracture drawing pace of this interbed to obtain 2D and 3D gas storage shapes at this time.Moreover,Stability evaluation of strength reduction finite element method(FEM)based on this catastrophe theory can used to evaluate this interbed stability after initial fracture.A specific example is simulated to obtain the influence of the interbed depth,cavern internal pressure,and cavern building time on stability safety factor(SSF).The results indicate:the value of SSF will be lower with the increase of cavern building time in solution mining and the increase of interbed depth and also this value remains a rise with the increase of cavern internal pressure Especially,we can conclude that the second-fracture of the interbed may take place when this pressure is lower than 6 MPa or after 6 days later of the interbed after initial fracture.According to above analysis,some effective measures,namely elevating the tube up to the top of the interbed,or changing the circulation of in-and-out lines,can be introduced to avoid the negative effects when the secondfracture of the interbed may occur.展开更多
The abandoned roadways(ARs)in front of the longwall face catastrophic instability will seriously hamper mining progress,which is a complicated process related to the stress environment,the roadway section,and the mech...The abandoned roadways(ARs)in front of the longwall face catastrophic instability will seriously hamper mining progress,which is a complicated process related to the stress environment,the roadway section,and the mechanical properties of the surrounding rock.The cusp catastrophe theory is employed to establish a state identification model for the irregular coal pillar-roof system(CPRS)formed by the ARs and re-mining entries.To begin,the state discrimination equation(4p)for the gradual CPRS is derived,and the critical value at which the system transitions into an unstable state under quasi-static conditions is determined.The results indicated that when 16.49 m≤L≤22.63 m(L denotes the equivalent span of the intersection roof)and 0<R_(e)≤2.61 m(Re denotes the width of the elastic zone within the triangular coal pillar),the triangular CPRS is inherently unstable.Similarly,for trapezoidal CPRS configurations where the length Lm(the span of the right-angled trapezoid roof in the propulsion direction)varies from 4.0 to 12.60 m,the system is unstable as well.Subsequently,the model was further enhanced by accounting for the impact of the P.(advance stress increment load),where a critical criterion for the catastrophic instability of the CPRS was proposed,which represented the external energy required to transition the CPRS from an unstable state to catastrophic instability in diferent mining stages.After that,the stability degree of the irregular coal pillar was categorized,and a coupling zoning control technology was applied to CPR operations.Field monitoring results demonstrated the effectiveness of the zoning control technology,providing valuable guidance for similar mining practices.展开更多
基金This research was funded by the National Key Research and Development Program of China(2018YFD0200402)Ph.D.Programs of the Foundation of Ministry of Education of China(20130204110004).
文摘Aphids are a major global wheat,pest that can cause considerable loss of yield.Modeling of aphid population dynamics is an integral part of management strategies to manage or control aphid populations.In this paper,first,a wheat aphid population dynamics model was developed based on a logistic model and theⅠlollingⅢfunctional response,which includes three factors:temperature,natural enemies and insecticide.Second,this model fitted with a cusp catastrophe model to describe how abrupt changes in the wheat aphid population were influenced by these factors,Finally,the system was validated with field data from 2016 to 2018.The bifurcation set of the cusp catastrophe model was deemod to be the quantified dynamic control threshold,so an outbreak of aphid's population can be explained according to the variation of control variables.In short,this aphid population model was successfully validated on survey data,which can be used to guide the prevention and control of aphids.
文摘By means of CUSP model of catastrophe theory. this paper has studied thephysics process of rockburst occured on circular chamber. The present paper has nolonly described the instability process of rockburst more deeply. but also got the crilicaldepth of plastic softening area of chamber that is valuable in the controlling engineering of rockburst. the chamber displacement jump and energy liberation have been derived. the influence of rock parameters on the rockburst has been discussed .
文摘Cusp displacement catastrophe theory can be introduced to propose a new method about instability failure of the interbed for gas storage cavern in bedded salt in solution mining.We can calculate initial fracture drawing pace of this interbed to obtain 2D and 3D gas storage shapes at this time.Moreover,Stability evaluation of strength reduction finite element method(FEM)based on this catastrophe theory can used to evaluate this interbed stability after initial fracture.A specific example is simulated to obtain the influence of the interbed depth,cavern internal pressure,and cavern building time on stability safety factor(SSF).The results indicate:the value of SSF will be lower with the increase of cavern building time in solution mining and the increase of interbed depth and also this value remains a rise with the increase of cavern internal pressure Especially,we can conclude that the second-fracture of the interbed may take place when this pressure is lower than 6 MPa or after 6 days later of the interbed after initial fracture.According to above analysis,some effective measures,namely elevating the tube up to the top of the interbed,or changing the circulation of in-and-out lines,can be introduced to avoid the negative effects when the secondfracture of the interbed may occur.
基金support from the Major Project of Regional Joint Foundation of China(Grant No.U21A20107)the Natural Science Foundation of China(Grant No.52074239)+1 种基金Xinjiang Uygur Autono-mous Region Key R&D Project Task Special-Department and Department Linkage Project(Grant No.2022B01051)the Xinjiang Uygur Autonomous Region Tianchi Introduction Plan(Grant No.2024XGYTCYC03).
文摘The abandoned roadways(ARs)in front of the longwall face catastrophic instability will seriously hamper mining progress,which is a complicated process related to the stress environment,the roadway section,and the mechanical properties of the surrounding rock.The cusp catastrophe theory is employed to establish a state identification model for the irregular coal pillar-roof system(CPRS)formed by the ARs and re-mining entries.To begin,the state discrimination equation(4p)for the gradual CPRS is derived,and the critical value at which the system transitions into an unstable state under quasi-static conditions is determined.The results indicated that when 16.49 m≤L≤22.63 m(L denotes the equivalent span of the intersection roof)and 0<R_(e)≤2.61 m(Re denotes the width of the elastic zone within the triangular coal pillar),the triangular CPRS is inherently unstable.Similarly,for trapezoidal CPRS configurations where the length Lm(the span of the right-angled trapezoid roof in the propulsion direction)varies from 4.0 to 12.60 m,the system is unstable as well.Subsequently,the model was further enhanced by accounting for the impact of the P.(advance stress increment load),where a critical criterion for the catastrophic instability of the CPRS was proposed,which represented the external energy required to transition the CPRS from an unstable state to catastrophic instability in diferent mining stages.After that,the stability degree of the irregular coal pillar was categorized,and a coupling zoning control technology was applied to CPR operations.Field monitoring results demonstrated the effectiveness of the zoning control technology,providing valuable guidance for similar mining practices.
