【单选题】二元 溶液 , T, P 一定时 ,Gibbs—Duhem 方程的正确形式是 (). A. X 1 dlnγ 1 /dX 1 + X 2 dlnγ 2 /dX 2 = 0 B. X 1 dlnγ 1 /dX 1 + X 2 dlnγ 2 /dX 1 = 0 C. X 1 dlnγ 1 /dX 2 + X 2 dlnγ 2 /dX 1 = 0 D. X 1 dlnγ 1 /dX 1 – X 2 dlnγ 2 /dX 1 = 0

二元溶液，T, p一定时,Gibbs—Duhem 方程的正确形式是（） A: x1dlnγ1/dx1+ x2dlnγ2/dx2 = 0 B: x1dlnγ1/dx2+ x2 dlnγ2/dx1 = 0 C: x1dlnγ1/dx1+ x2dlnγ2/dx1 = 0 D: x1dlnγ1/dx1– x2 dlnγ2/dx1 = 0

Gibbs--Duhem 方程正确的形式是( )。 A: X1dlnγ1+ X2dlnγ2= 0 B: X1dlnγ1- X2dlnγ2= 0 C: X1dlnγ1/dX1 - X2dlnγ2/dX1 = 0 D: X1dlnγ1/dX1 + X2dlnγ2/dX2 = 0

设\(z = \int_ { { x^2}}^y { { e^t}\sin t} dt\)，则\({z_{xx}=}\) A: \(2{e^ { { x^2}}}\left[ {\left( {1 + 2{x^2}} \right)\sin {x^2} + 2{x^2}\cos {x^2}} \right]\) B: \( - 2{e^ { { x^2}}}\left[ {\left( {1 + 2{x^2}} \right)\sin {x^2} - 2{x^2}\cos {x^2}} \right]\) C: \( - 2{e^ { { x^2}}}\left[ {\left( {1 + 2{x^2}} \right)\sin {x^2} + 2{x^2}\cos {x^2}} \right]\) D: \( - 2{e^ { { x^2}}}\left[ {\left( {1 + 2{x^2}} \right)\cos {x^2} + 2{x^2}\sin {x^2}} \right]\)

数学式 A: (e^(2*x)*Log(x)+x^2)/Sqr(Abs(Sinx^2-Cos2x)) B: (Exp(2*x)*Log(x)+x^2)/Sqr(Abs(Sin(x^2)-Cos(x)^2)) C: (Exp(2*x)*Ln(x)+x^2)/Sqr(Abs(Sin(x^2)-Cos(x)^2)) D: (e^(2*x)*Log(x)+x^2)/Sqr(Abs(Sin(x)^2-Cos(x)^2))

与数学关系式[img=114x22]1803bce8722f322.png[/img]等价的C语言关系表达式是？ A: x < -2 && x > 2 B: x < -2 || x > 2 C: -2 < x < 2 D: !(-2 <= x <=2) E: !(-2 <=x && x <= 2) F: x < -2, x > 2

求微分方程[img=101x35]17da5f15503f795.png[/img] 的通解,实验命令为(). A: dsolve(Dy+2*x*y=x*exp(-x^2))ans=C1*exp(-x^2) + (x^2*exp(-x^2))/2 B: dsolve('Dy+2*x*y=x*exp(-x^2)','x')ans=C1*exp(-x^2) + (x^2*exp(-x^2))/2 C: dsolve('Dy+2*x*y=x*exp(-x^2)')ans=C1*exp(-x^2) + (x^2*exp(-x^2))/2

求不定积分[img=132x48]17da6537fc8dad6.png[/img]； （ ） A: -(4*(cos(x/2)/2 + 2*sin(x/2)))/(17*exp(2*x)) B: (4*(sin(x/2)/2 + 2*sin(x/2)))/(17*exp(2*x)) C: (4*(cos(x/2)/2 + 2*sin(x/2)))/(17*exp(2*x)) D: (4*(cos(x/2)/2 + 2*cos(x/2)))/(17*exp(2*x))

求函数[img=148x49]17da6537a5eee98.png[/img]的导数； ( ) A: 1/(x^2*(2/x^2 + 1)) B: -1/(x^2*(2/x^2 + 1)) C: (x^2*(2/x^2 + 1)) D: -1/(x^2*(2/x^2 + 1))+2/x^2 + 1

在x值处于-2～2、4～8时值为“真”，否则为“假”的表达式是______。 A: (2＞x＞-2)||(4＞x＞8) B: !(((x＜-2)||(x＞2))&&((x＜=4)||(x＞8))) C: (x＜2)&&(x＞=-2)&&(x＞4)&&(x＜8) D: (x＞-2)&&(x＞4)||(x＜8)&&(x＜2)