At present, the myopia illness of the students (including the students of university, middle schools andprimary schools) is a serious problem. For preventing and curing it, we must search for the developing lowsof myo...At present, the myopia illness of the students (including the students of university, middle schools andprimary schools) is a serious problem. For preventing and curing it, we must search for the developing lowsof myopia illness to provide the theory foundation for researches on and preventions from myopia illness.We provide the mathematial model on describing the poor eyesight of the students after analysing thedeveloping lows of the poor eyesight of the students as follows:where p(r,t) is the student’s myopia falling ill rate function at time t and age r, u(r) denotes the initial stagemyopia falling ill rate function and v(t), the baby myopia falling ill rate function. It is a first order quasi-展开更多
In this paper, we will discuss a class of integro-differential system of equations. It is a mathematicalmodel which is drown from the practical problems of the population control system with illness:where 0 【r<sup...In this paper, we will discuss a class of integro-differential system of equations. It is a mathematicalmodel which is drown from the practical problems of the population control system with illness:where 0 【r<sup>’</sup> m【r<sub>m</sub> and r<sub>m</sub> is the highest age over attained by individual of the population. In this pa-per, P<sub>1</sub>= P<sub>1</sub>（x,t） denotes the age density function of the healthy population; P<sub>2</sub> = P<sub>2</sub>（r,s,ts） denotes theage and period of illness density function of the morbid population; λ（r） =λ（r,t） denotes the relative inci-dence of diseases; η（r,s） =η（r.s.t）denotes the relative recovering rate of patients;μ<sub>2</sub>（r,s） = μ2（r,s,t）denotes the relative mortality of patients. And the other functions μ<sub>1</sub>,（r） =μ<sub>1</sub>,（r,t）, β=β（t） , h（r）展开更多
College English isone of the most important courses in college education.All the students spendalot of time and moneyon English learning.However,in therecentyears,moreandmorestudents areabsentintheEnglishclass.Forthis...College English isone of the most important courses in college education.All the students spendalot of time and moneyon English learning.However,in therecentyears,moreandmorestudents areabsentintheEnglishclass.Forthis,we’veconductedthisinvestigationonlytofindthatthereasons whystudentsareabsentaretheinconsistencyofteachingandlearning,theoverlargeclass,thebackwardin teachingequipmentandteachingmethod.展开更多
文摘At present, the myopia illness of the students (including the students of university, middle schools andprimary schools) is a serious problem. For preventing and curing it, we must search for the developing lowsof myopia illness to provide the theory foundation for researches on and preventions from myopia illness.We provide the mathematial model on describing the poor eyesight of the students after analysing thedeveloping lows of the poor eyesight of the students as follows:where p(r,t) is the student’s myopia falling ill rate function at time t and age r, u(r) denotes the initial stagemyopia falling ill rate function and v(t), the baby myopia falling ill rate function. It is a first order quasi-
基金The project is supported by the National Natural Science Foundation of P.R.China
文摘In this paper, we will discuss a class of integro-differential system of equations. It is a mathematicalmodel which is drown from the practical problems of the population control system with illness:where 0 【r<sup>’</sup> m【r<sub>m</sub> and r<sub>m</sub> is the highest age over attained by individual of the population. In this pa-per, P<sub>1</sub>= P<sub>1</sub>（x,t） denotes the age density function of the healthy population; P<sub>2</sub> = P<sub>2</sub>（r,s,ts） denotes theage and period of illness density function of the morbid population; λ（r） =λ（r,t） denotes the relative inci-dence of diseases; η（r,s） =η（r.s.t）denotes the relative recovering rate of patients;μ<sub>2</sub>（r,s） = μ2（r,s,t）denotes the relative mortality of patients. And the other functions μ<sub>1</sub>,（r） =μ<sub>1</sub>,（r,t）, β=β（t） , h（r）
文摘College English isone of the most important courses in college education.All the students spendalot of time and moneyon English learning.However,in therecentyears,moreandmorestudents areabsentintheEnglishclass.Forthis,we’veconductedthisinvestigationonlytofindthatthereasons whystudentsareabsentaretheinconsistencyofteachingandlearning,theoverlargeclass,thebackwardin teachingequipmentandteachingmethod.
