This paper deals with the validation and theoretical analyses of a simple method for calculating the intrinsic rate of increase, rm, of aphids and mites. This method does not require a detailed fecundity table data. T...This paper deals with the validation and theoretical analyses of a simple method for calculating the intrinsic rate of increase, rm, of aphids and mites. This method does not require a detailed fecundity table data. The value of rm can be estimated by the simple equation: rm=0.74ln (Md)/d, where d is the time from birth to first reproduction; Md is the number of female offspring produced per original female in 2d. This method was developed by Wyatt and White. We reached the following conclusions from our study: When the parameter, Md is less than 1, this equation is not appropriate for estimating rm of populations; When the parameter, Md is larger than 1 and about 70% or more of the reproductive contribution to the rm is achieved in 2d, the equation is appropriate for calculatng the rm of aphids and mites.As Md decreases, the required reproductive contribution to the rm in 2d corresponding to the constant 0.74 will increase. However, whether 70% or more of reproductive contribution to rm is achieved in 2d still is a problem for whole taxa of aphids and mites. Therefore, further siudy on reproductive distribution will be required for practical application of this method.展开更多
An extremely simple formula to estimate the heat of formation of complexes between an ion and a polar molecule or between highly polar systems is presented.The formula is entirely electrostatic and the expression used...An extremely simple formula to estimate the heat of formation of complexes between an ion and a polar molecule or between highly polar systems is presented.The formula is entirely electrostatic and the expression used is verified by means of perturbation theory.This formula is test- ed for several ion-molecule and molecule-molecule pairs.It is also applied to estimate the heat of hydration of simple salts.展开更多
文摘This paper deals with the validation and theoretical analyses of a simple method for calculating the intrinsic rate of increase, rm, of aphids and mites. This method does not require a detailed fecundity table data. The value of rm can be estimated by the simple equation: rm=0.74ln (Md)/d, where d is the time from birth to first reproduction; Md is the number of female offspring produced per original female in 2d. This method was developed by Wyatt and White. We reached the following conclusions from our study: When the parameter, Md is less than 1, this equation is not appropriate for estimating rm of populations; When the parameter, Md is larger than 1 and about 70% or more of the reproductive contribution to the rm is achieved in 2d, the equation is appropriate for calculatng the rm of aphids and mites.As Md decreases, the required reproductive contribution to the rm in 2d corresponding to the constant 0.74 will increase. However, whether 70% or more of reproductive contribution to rm is achieved in 2d still is a problem for whole taxa of aphids and mites. Therefore, further siudy on reproductive distribution will be required for practical application of this method.
文摘An extremely simple formula to estimate the heat of formation of complexes between an ion and a polar molecule or between highly polar systems is presented.The formula is entirely electrostatic and the expression used is verified by means of perturbation theory.This formula is test- ed for several ion-molecule and molecule-molecule pairs.It is also applied to estimate the heat of hydration of simple salts.
