茶碱：t½=8 h → k = 0.0866 h⁻¹ k = ln2/8 = 0.0866 h⁻¹。1 个半衰期后剩余 50%；4 个半衰期（32 h）消除约 94%（达稳态）；6.64 个半衰期（53.1 h）消除约 99%。{"result":"k = 0.0866 h⁻¹ (t½ = 8 h). Steady state ≈ 4–5 half-lives (32–40 h); ~99% eliminated at 6.64 half-lives (53.1455 h).","metadata":{"input":{"halfLife":8},"result":{"k":0.0866,"kUnit":"h⁻¹","halfLife":8,"fractionRemaining1HL":0.5,"fractionRemaining2HL":0.25,"fractionRemaining3HL":0.125,"fractionRemaining4HL":0.0625,"fractionRemaining5HL":0.0313,"halfLivesTo94Pct":4,"halfLivesTo97Pct":5,"timeTo94PctH":32,"timeTo97PctH":40,"halfLivesTo99Pct":6.6439,"timeTo99PctH":53.1455,"method":"k = ln2 / t½","model":"First-order (linear) elimination. Not medical advice."}}}
快速消除：t½=6 h → k = 0.1155 h⁻¹ k = ln2/6 = 0.1155 h⁻¹。半衰期越短 k 越大、消除越快；24–30 h 达稳态。{"result":"k = 0.1155 h⁻¹ (t½ = 6 h). Steady state ≈ 4–5 half-lives (24–30 h); ~99% eliminated at 6.64 half-lives (39.8591 h).","metadata":{"input":{"halfLife":6},"result":{"k":0.1155,"kUnit":"h⁻¹","halfLife":6,"fractionRemaining1HL":0.5,"fractionRemaining2HL":0.25,"fractionRemaining3HL":0.125,"fractionRemaining4HL":0.0625,"fractionRemaining5HL":0.0313,"halfLivesTo94Pct":4,"halfLivesTo97Pct":5,"timeTo94PctH":24,"timeTo97PctH":30,"halfLivesTo99Pct":6.6439,"timeTo99PctH":39.8591,"method":"k = ln2 / t½","model":"First-order (linear) elimination. Not medical advice."}}}