\documentclass[a4paper,10pt]{scrreprt}
\usepackage{pstricks,pst-text}
\DeclareFixedFont{\SF}{T1}{phv}{b}{ol}{5mm}
\newcommand{\p}{\partial}
\newcommand{\vs}{\vspace{.1in}}
\begin{document}

O

\begin{pspicture}(-4,-4)(4,4)
  \pstextpath[c]{\psarcn[linestyle=none](0,0){2}{170}{10}}
{$dx/dt = \sigma(y-x)~~~~~~~~~~ dy/dt = x(\rho-z) -y$}

  \pstextpath[c]{\psarc[linestyle=none](0,0){2}{230}{310}}
{$dz/dt = xy - \beta z$}

\end{pspicture}

\noindent{IV \it Equations for Lorenz attractor:} 


\vs



I

\begin{pspicture}(-4,-4)(4,4)
  \pstextpath[c]{\psarcn[linestyle=none](0,0){2}{130}{50}}
{$V_K(t) = t+t^3-t^4$}

  \pstextpath[c]{\psarc[linestyle=none](0,0){2}{150}{390}}
{$V_K(e^{\frac{2\pi i}{k+2}}) = -\frac{1}{Z}\int_{\mathcal A} 
\left (\mbox{Tr Pexp}\oint_KA\right )e^{\frac{ik}{4\pi}CS(A)}\mathcal{D}A $}

\end{pspicture}

II


\begin{pspicture}(-4,-4)(4,4)
  


  \pstextpath[c]{\psarc[linestyle=none](0,0){2}{180}{360}}
{$C_{ijk}\eta^{kl}C_{lmn} = C_{mjk}\eta^{kl}C_{lin}$}

\end{pspicture}

III
 
\begin{pspicture}(-4,-4)(4,4)
  


  \pstextpath[c]{\psarc[linestyle=none](0,0){2}{180}{360}}
{$R_{12}R_{23}R_{12} = R_{23}R_{12}R_{23}$}

\end{pspicture}


IV


V

\begin{pspicture}(-4,-4)(4,4)
  \pstextpath[c]{\psarcn[linestyle=none](0,0){2}{120}{60}}
{$\p_t v_i + v_j \p_j v_i $}

  \pstextpath[c]{\psarc[linestyle=none](0,0){2}{180}{360}}
{$= -\p_i p + \nu \p_j \p_j v_i$}




\end{pspicture}

VI 


\begin{pspicture}(-4,-4)(4,4)
  


  \pstextpath[c]{\psarc[linestyle=none](0,0){2}{180}{360}}
{$\int_{C_1}\vec{A}\cdot d\vec{\ell} - \int_{C_2}\vec{A}\cdot d\vec{\ell} 
= \frac{1}{2\pi}\Phi$}

\end{pspicture}

VII


\begin{pspicture}(-4,-4)(4,4)
  


  \pstextpath[c]{\psarc[linestyle=none](0,0){2}{180}{360}}
{$\partial\partial = 0$}

\end{pspicture}

VIII


\begin{pspicture}(-4,-4)(4,4)
  \pstextpath[c]{\psarcn[linestyle=none](0,0){2}{120}{60}}{$r_S=2Gm/c^2$}


\end{pspicture}

IX 


\begin{pspicture}(-4,-4)(4,4)
  \pstextpath[c]{\psarcn[linestyle=none](0,0){2}{120}{60}}{$\chi = V - E + F$}

  \pstextpath[c]{\psarc[linestyle=none](0,0){2}{180}{360}}
{$2\pi\chi = \int_M K~dA$}

\end{pspicture}


X

\begin{pspicture}(-4,-4)(4,4)
  \pstextpath[c]{\psarcn[linestyle=none](0,0){2}{170}{10}}
{$1;14;51;10 = 1.414213 $}
\end{pspicture}

XI

\begin{pspicture}(-4,-4)(4,4)
  \pstextpath[c]{\psarcn[linestyle=none](0,0){2}{130}{50}}
{$c^2 = a^2 + b^2$}
\end{pspicture}

XII

XIII

\begin{pspicture}(-4,-4)(4,4)
  \pstextpath[c]{\psarcn[linestyle=none](0,0){2}{115}{75}}
{$v = \frac{2}{3}V$}
\end{pspicture}

J


$$\vec{F} = m\vec{a}$$
\vs

\end{document}
\begin{pspicture}(-4,-4)(4,4)
  \pstextpath[c]{\psarcn[linestyle=none](0,0){2}{130}{50}}
{$V_K(t) = t+t^3-t^4$}

  \pstextpath[c]{\psarc[linestyle=none](0,0){2}{150}{390}}
{$V_K(e^{\frac{2\pi i}{k+2}}) = -\frac{1}{Z}\int_{\mathcal A} 
({\rm Tr} P e^{\oint_K\!\!A})e^{\frac{ik}{4\pi}CS(A)}\mathcal{D}A $}

\end{pspicture}