dx1/dt=-d*x1;
dx2/dt=kTL*x1-b*x2;
dx3/dt=-d*x3;
dx4/dt=kTL*x3-b*x4;
dx5/dt=-d*x5;
dx6/dt=kTL*x5/2-b*x6;
dx7/dt=-d*x7;
dx8/dt=kTL*x7-3*b*x8/4;
y1=x2;
y2=x4;
y3=x6;
y4=x8;
x1(0)=1;
x2(0)=0;
x3(0)=1/2;
x4(0)=0;
x5(0)=1;
x6(0)=0;
x7(0)=1;
x8(0)=0
