to stop rowimg your boat upstream is to fall back in the

英语翻译
The compressed air pipe section immediately upstream of the engine has to be removed and visually inspected.

一个电力英文词组的所指
Upstream/Downstream Unit
搞不清楚
好像以前还遇到
Upstream/Downstream Transformer
初级/次级应该是primary/secondary，还是两种表达？

翻译：机械英语,高手帮忙!
pressure upstream of valve; pressure outlet of silencer

英语翻译
His salmon don't swim upstream
He shoots blanks
字面意思我都懂,可是按照字面来翻译的话放电影里完全不通
求内涵帝来翻译下

求教关于matlab的问题
M=1.5;%mach number
gamma=5/3;
Pr=2/3;
%upstream states:
r1=1.0;
u1=1.0;
mu1=0.0005;
p1=1/gamma/M^2;
T1=2*p1/r1;
%downstream states
r2=(gamma+1)*M^2/(2+(gamma-1)*M^2)*r1;
u2=((gamma-1)/(gamma+1)+2/(gamma+1)/M^2)*u1;
p2=(2*gamma/(gamma+1)*M^2-(gamma-1)/(gamma+1))*p1;
T2=2*p2/r2;
%conservation:
A=r1*u1;
B=r1*u1^2+p1;
C=(1/2*r1*u1^2+p1/(gamma-1)+p1)*u1;
%ODE solver:
y0=[T2;-u2*(1+eps)];
tspan=[0 0.25];
options=odeset('RelTol',1e-6,'AbsTol',[1e-9 1e-9]);
[t,y]=ode45('Fb,'tspan,y0,options);
x=-t;
T=y(:,1);
u=-y(:,2);
mu=mu*(T/T1).^0.8;
ux=-3/4./mu.*(B-A*u.^2+3/4*A*T-C+B*u);
Tx=4/5*Pr/mu.*(-1/2*A*u.^2+3/4*A*T-C+B*u);
r=A./u;
p=r.*T/2;
%plot T and u:
figure(1)
plot(x,u);
xlabel('x');
ylabel('u');
%output:
out(:,1)=x;
out(:,2)=u;
save u out -ascii;
out(:,1)=x;
out(:,2)=p;
save p out -ascii;
out(:,1)=x;
out(:,2)=r;
save r out -ascii;
out(:,1)=x;
out(:,2)=mu;
save mu out -ascii;
out(:,1)=x;
out(:,2)=ux;
save ux out -ascii;
out(:,1)=x;
out(:,2)=Tx;
save Tx out -ascii;
out(:,1)=x;
out(:,2)=4/3*mu.*ux./(2*p);
save v out -ascii;
out(:,1)=x;
out(:,2)=5/4/Pr*mu.*Tx./p./sqrt(gamma*T/2);
save h out -ascii
function dy=Fb(t,y);
M=1.5;
gamma=5/3;
Pr=2/3;
r1=1.0;
u1=1.0;
mu1=0.0005;
p1=1/gamma/M^2;
T1=2*p1/r1;
A=r1*u1;
B=r1*u1^2+p1;
C=(1/2*r1*u1^2+p1/(gamma-1)+p1)*u1;
mu=mu1*(y(1)/T1)^0.8;
dy[0;0];
dy(1)=4/5*Pr/mu*(1/2*A*y(2)^2-3/4*A*y(1)+C+B*y(2));
dy(2)=3/4/mu*(-B-A*y(2)-1/2*A*y(1)/y(2));
最后显示?Error:File:C:matlab6.5workshockshock.m Line:27 Column:18
")" expected,"identifier" found.

learning is like rowing upstream:not to advance isto dropback.

Learning is like rowing upstream,not to advance is to drop back.的中文意思是什么?