正态曲线内切线原理及其在森林经营中的应用

PRINCIPLE AND APPLICATION ON FORESTRY OF INNER TANGENT OF NORMAL CURVE

联令正态方程和其内切线方程可得到一个超越方程,应用二分法和计算机解此超越方程可得到一个解,并命名为定比平方参数 z。结果表明:z=2.51286280;内切线斜率可描述正态曲线的平坦程度;由正态曲线的2个内切线和 x 轴共组三角形的面积可约占正态曲线与 x 轴之间面积的88%;正态曲线上的切点和拐点不重合,是曲线连续的两个临界点;纵切比常数和纵拐比常数从理论上证明了采伐强度在30%左右时最好,最大不能起过50%。

A transcendental equation was derived from simultaneous equations of a normal one and its inner tangent one.After the equation was extracted with a computer and method of bisection.one root was acquired and called as constant ratio square number with z.The results show that z=2.51286280;normal curve leptokurtic value is described by gradient k;the triangle area,constituted of two inner tangent lines and one axis x,is 88% of the area between normal curve and the x;the point of tangency and point of inflection are not covered each other, and they are two critical points on continuous normal curve;the best fell intensity of about 30% and the maximum fell intensity of about 50%,gotten from many cut experiments,was interpreted theoretically by longitudinal ratio constant and longitudinal inflection ratio constant.