diff --git a/wiki/pages/model.html b/wiki/pages/model.html
index 642d2bd6c949bde4940b670b7683e85d0a5ab0a5..54d32a708fd4467955e3d863954feb215df93c2d 100644
--- a/wiki/pages/model.html
+++ b/wiki/pages/model.html
@@ -7,9 +7,7 @@
     <link rel="icon" type="image/png" href="https://static.igem.wiki/teams/5187/art/icon1.png" sizes="364x370">
     <link rel="stylesheet" href="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.5.1/styles/default.min.css">
     <script src="https://cdnjs.cloudflare.com/ajax/libs/highlight.js/11.5.1/highlight.min.js"></script>
-    <script>
-        hljs.highlightAll();
-    </script>
+    <script>hljs.highlightAll();</script>
     <title>Tsinghua - IGEM 2024</title>
     <script type="text/javascript" async src="https://cdn.jsdelivr.net/npm/mathjax@3/es5/tex-mml-chtml.js"></script>
     <style>
@@ -163,7 +161,8 @@
                     \[ V_{\text{inhale}}(t) =\frac{Q_{\text{inhale}}}{5}(u(t)-u(t-5)) \]
                 </p>
 
-                <p><strong>Explanation</strong>：This describes the rate equation for inhaling muscone over five seconds,
+                <p><strong>Explanation</strong>: This describes the rate equation for inhaling muscone over five
+                    seconds,
                     where the total amount \( Q \) remains constant. The function \( u(t) \) is a step function, which
                     takes the value of \( \frac{Q_{\text{inhale}}}{5} \) from \( t=0s \) to \( t=5s \), and is \( 0 \)
                     otherwise, simulating the scenario of resting human respiration.</p>
@@ -183,7 +182,7 @@
 
                 <ul>
                     <li>
-                        \ k_{\text{exhale}} \): Since most of the muscone is rapidly exhaled, this value is relatively
+                        \( k_{\text{exhale}} \): Since most of the muscone is rapidly exhaled, this value is relatively
                         large, taken as \( 10 \ \text{min}^{-1} \)
                     </li>
                     <li>
@@ -987,6 +986,24 @@
                         lactic acid in the time interval \(\frac{t_0}{n}\).</li>
                 </ol>
                 <h3>Model Equation</h3>
+                <p>
+                    According to Fick's law :
+                </p>
+                <p>
+                    \[
+                    \frac{dQd}{dt} = -D \frac{dC}{dx}
+                    \]
+                </p>
+                <p>
+                </p>
+                Because the distance between diffusion is very small, the concentration difference between the two sides
+                of the system replaces the concentration gradient, so this formula can be simplified to:
+                </p>
+                <p>
+                    \[
+                    \frac{dQd}{dt} = K\times Qd
+                    \]
+                </p>
                 <h4>Direct Administration</h4>
                 <p>In the case of direct lactic acid intake, the content of lactic acid in the intestine can be
                     described by the following equation:</p>
@@ -1007,7 +1024,6 @@
                 </ul>
 
                 <h4>Induced Secretion</h4>
-                <p>According to Fick's Law</p>
                 <p>The remaining lactic acid content in the intestinal environment has a recursive relationship over
                     time:</p>
                 <p>