打字猴:1.701008063e+09
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1701008067 上式变形如下,仅求解上半球的表面积:
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1701008072 求方程中z对x、y偏导数为:
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1701008077 则球半盖的表面积积分为:
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1701008082 当且仅当H=R,S=2πR2=2π×302=5654.9。
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1701008084 实际用量将会比清真寺顶部面积多1.5%。
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1701008089 具体的MATLAB程序如下:
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1701008091     clc,clear,close all         %清屏和清除变量    warning off                 %消除警告    syms x y z R r H    z=sqrt(R^2-x^2-y^2);    dz_dx=diff(z);    dz_dy=diff(z,‘y’);    z1=sqrt((dz_dx)^2+(dz_dy)^2+1);    z2=R/sqrt(R^2-r^2);    z3=z2*r;    Intxy=int(int(z3,‘r’,0,‘R’),‘y’,0,2*pi);    >> pretty(Intxy)                                        2 1/2                                    2 (R )    R pi    >> R=30;     >> Intxy=2*(R^2)^(1/2)*R*pi    Intxy =      5.6549e+003        >> Intxy*1.015    ans =      5.7397e+003
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1701008093 (2)对于半椭球而言,其方程如下:
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1701008098 其偏导数为:
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1701008103 则椭圆球半盖的表面积积分编程如下:
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1701008105     clc,clear,close all   %清屏和清除变量    warning off           %消除警告    >> syms x y z a b c    >> z=sqrt(c^2*(1-y^2/b^2-x^2/a^2));    >> dz_dx=diff(z,‘x’)    dz_dx =    -1/(c^2*(1-y^2/b^2-x^2/a^2))^(1/2)*c^2*x/a^2         >> dz_dy=diff(z,‘y’)    dz_dy =    -1/(c^2*(1-y^2/b^2-x^2/a^2))^(1/2)*c^2*y/b^2         >> z1=sqrt((dz_dx)^2+(dz_dy)^2+1);    >> pretty(z1)                 /        2  2                   2  2            \1/2                 |       c  x                   c  y             |                 |––––––— + ––––––— + 1|                 |/      2      2 \      /      2      2 \       |                 ||     y      x  |  4   |     y      x  |  4    |                 ||1 - –- - –-| a    |1 - –- - –-| b     |                 ||      2      2 |      |      2      2 |       |                 \     b      a  /      \     b      a  /       /    >> %Intxy=int(int(z1,‘x’,-sqrt(a^2*(1-y^2/b^2)),sqrt(a^2*(1-y^2/b^2))),‘y’,-b,b)
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1701008107 整理结果如下:
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1701008112 从上式中可知,该方程为二次椭圆积分问题方程无相应的原函数与之对应求解,故运用MATLAB较难无法求解,采用半椭圆体表面积计算公式(GB)有:
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