计算雨水（淡水）的pH值（二氧化碳与大气处于溶解平衡状态）25℃

Hp = sqrt( K0*K1*pCO2+Kw );
pH = -log( K0*K1*pCO2+Kw )/2;
/* 溶解无机碳 (DIC) */

DIC = Hp + K0*pCO2;
H2CO3 = K0*pCO2;
HCO3m = K1*H2CO3/Hp;

print(Hp);
print(pH);
print(DIC);
print(H2CO3);
print(HCO3m);
print(DIC*10^6);
print(H2CO3*10^6);
print(HCO3m*10^6);