add reference temperature for mechanical properties

data/INFO.json

@@ -28,6 +28,7 @@
     "chi_m": "Magnetic susceptibility; Molar susceptibility \[\chi\ti{m} = \kappa V\ti{m} = \kappa M / \rho \] where \(\kappa\) is the volume susceptibility, \(V\ti{m}\) is the molar volume of the substance, \(M\) the molar mass, and \(\rho\) the mass density. \(\kappa = \bold{M}/\bold{H}\) where \(\bold{H}\) is the magnetic filed and \(\bold{M}\) is magnetic moment per unit volume.",
   },
   "Mechanical Properties": {
+    "T": "Reference temperature",
     "Yield strength": "R_{p0.2}",
     "Ultimate tensile strength": "R_m",
     "Elongation": "A_5",
@@ -90,6 +91,7 @@
     "crystal": "cubic|cubic crystals"
   },
   "Mechanical Properties": {
+    "T": ["20-25", "°C"],
     "Yield strength": ["110-130", "MPa"],
     "Ultimate tensile strength": ["230-290", "MPa"],
     "Elongation": ["10-15", "%"],

data/aluminum.json

@@ -163,6 +163,7 @@
       "Temper": "homogenized and stress relieved, O3"
     },
     "Mechanical Properties": {
+      "T": ["20-25", "°C"],
       "Yield strength": ["110-130", "MPa"],
       "Ultimate tensile strength": ["230-290", "MPa"],
       "Elongation": ["10-15", "%"],