E=[0:.1:1.4];
Aray=[6 10 14];
figure(1);clf;
for k=1:3
	a=Aray(k);
	Ec(k,:)=(1)./(1+exp(-(a*E-5)));
	end
	
	plot(E,Ec,[0 1.4],[0 1.4]);xlabel('E');ylabel('E of fe');
	text (1,.4,'a=6');text(.2,1,'a=14')