Geant4 材料设置

G4 中已经写好的材料种类（在文件 G4NISTStoppingData.hh 中）：
 1 static const G4String nameNIST[74] = {
 2   "G4_A-150_TISSUE", "G4_ACETYLENE","G4_ADIPOSE_TISSUE_ICRP","G4_Ag","G4_AIR",
 3   "G4_Al","G4_ALUMINUM_OXIDE","G4_Ar","G4_Au","G4_B-100_BONE", //0 - 9
 4   "G4_Be","G4_BONE_COMPACT_ICRU","G4_C","G4_GRAPHITE_POROUS","G4_ETHYLENE",
 5   "G4_C-552","G4_CARBON_DIOXIDE","G4_CALCIUM_FLUORIDE","G4_CERIC_SULFATE",
 6   "G4_CELLULOSE_NITRATE", // 10-19
 7   "G4_BONE_CORTICAL_ICRP","G4_CESIUM_IODIDE","G4_Cu","G4_Fe",
 8   "G4_FERROUS_SULFATE",
 9   "G4_Gd","G4_Ge","G4_Pyrex_Glass","G4_H","G4_He", //20-29
10   "G4_KAPTON","G4_Kr","G4_LITHIUM_TETRABORATE","G4_LITHIUM_FLUORIDE",
11   "G4_M3_WAX",
12   "G4_MS20_TISSUE","G4_METHANE","G4_Mo","G4_MUSCLE_WITH_SUCROSE",
13   "G4_MUSCLE_WITHOUT_SUCROSE", // 30 -39
14   "G4_MUSCLE_SKELETAL_ICRP","G4_MUSCLE_STRIATED_ICRU","G4_N",
15   "G4_SODIUM_IODIDE","G4_Ne",
16   "G4_NYLON-6-6","G4_O","G4_PARAFFIN","G4_Pb","G4_PHOTO_EMULSION", // 40-49
17   "G4_PLASTIC_SC_VINYLTOLUENE","G4_POLYCARBONATE","G4_POLYETHYLENE",
18   "G4_MYLAR","G4_PLEXIGLASS",
19   "G4_POLYPROPYLENE","G4_POLYSTYRENE","G4_TEFLON","G4_POLYVINYL_CHLORIDE",
20   "G4_PROPANE", // 50-59
21   "G4_Pt","G4_Si","G4_SILICON_DIOXIDE","G4_STILBENE","G4_Ti",
22   "G4_Sn","G4_TISSUE-METHANE","G4_TISSUE-PROPANE","G4_TOLUENE","G4_U",//60-69 
23   "G4_W","G4_WATER","G4_WATER_VAPOR","G4_Xe"};