Migrate from 'jekyll-katex' to 'kramdown-math-sskatex'

1 files changed, 11 insertions, 11 deletions

diff --git a/source/know/concept/fundamental-thermodynamic-relation/index.md b/source/know/concept/fundamental-thermodynamic-relation/index.md
index 392e0b3..0d945fa 100644
--- a/source/know/concept/fundamental-thermodynamic-relation/index.md
+++ b/source/know/concept/fundamental-thermodynamic-relation/index.md
@@ -10,35 +10,35 @@ layout: "concept"
 
 The **fundamental thermodynamic relation** combines the first two
 [laws of thermodynamics](/know/concept/laws-of-thermodynamics/),
-and gives the change of the internal energy $U$,
+and gives the change of the internal energy $$U$$,
 which is a [thermodynamic potential](/know/concept/thermodynamic-potential/),
 in terms of the change in
-entropy $S$, volume $V$, and the number of particles $N$.
+entropy $$S$$, volume $$V$$, and the number of particles $$N$$.
 
 Starting from the first law of thermodynamics,
-we write an infinitesimal change in energy $\dd{U}$ as follows,
-where $T$ is the temperature and $P$ is the pressure:
+we write an infinitesimal change in energy $$\dd{U}$$ as follows,
+where $$T$$ is the temperature and $$P$$ is the pressure:
 
 $$\begin{aligned}
     \dd{U} &= \dd{Q} + \dd{W} = T \dd{S} - P \dd{V}
 \end{aligned}$$
 
-The term $T \dd{S}$ comes from the second law of thermodynamics,
+The term $$T \dd{S}$$ comes from the second law of thermodynamics,
 and represents the transfer of thermal energy,
-while $P \dd{V}$ represents physical work.
+while $$P \dd{V}$$ represents physical work.
 
 However, we are missing a term, namely matter transfer.
-If particles can enter/leave the system (i.e. the population $N$ is variable),
-then each such particle costs an amount $\mu$ of energy,
-where $\mu$ is known as the **chemical potential**:
+If particles can enter/leave the system (i.e. the population $$N$$ is variable),
+then each such particle costs an amount $$\mu$$ of energy,
+where $$\mu$$ is known as the **chemical potential**:
 
 $$\begin{aligned}
     \dd{U} = T \dd{S} - P \dd{V} + \mu \dd{N}
 \end{aligned}$$
 
 To generalize even further, there may be multiple species of particle,
-which each have a chemical potential $\mu_i$.
-In that case, we sum over all species $i$:
+which each have a chemical potential $$\mu_i$$.
+In that case, we sum over all species $$i$$:
 
 $$\begin{aligned}
     \boxed{