The second acidic dissociation constants of protonated piperazine-N,N′-bis-2-hydroxypropane-sulfonic acid (POPSO sesquisodium salt) have been determined at 12 different temperatures from (278.15 to 328.15) K includin...The second acidic dissociation constants of protonated piperazine-N,N′-bis-2-hydroxypropane-sulfonic acid (POPSO sesquisodium salt) have been determined at 12 different temperatures from (278.15 to 328.15) K including 310.15 K. Electromotive-force measurement technique was used employing hydrogen-silver chloride cells without liquid junction. The results of pK2 are given by the equation: pK2 = -1041.77/T + 51.0459 - 6.97646lnT. The uncertainty of the fit is ±0.0008. At 289.15 K, pK2 = 7.8029;whereas, at 310.15 K (body temperature), pK2 = 7.6862. Thus, the buffer solutions of POPSO and its sodium salt are useful for pH control in the physiological pH region of (7.0 to 8.5). The changes of Gibbs free energy (G°), enthalpy (H°), entropy (S°) and heat capacity Cp° were computed from the temperature derivative of the pK2 for the dissociation of the zwitterionic acid POPSO±-3 = POPSO-4 + H+ in the standard state. At 298.15 K, these results are compared with those of similar components, which are the derivatives of the parent compounds TAURINE, PIPERAZINE and MORPHOLINE.展开更多
讨论了电动汽车镍氢动力电池荷电状态(State of Charge,简称SOC)的估计方法。提出用电动势(EMF)等效电路模型法来估计电池的SOC。研究确定了EMF与SOC之间的关系,并通过电路分析,计算得出电池EMF与端电压之间的关系,最终建立了端电压与SO...讨论了电动汽车镍氢动力电池荷电状态(State of Charge,简称SOC)的估计方法。提出用电动势(EMF)等效电路模型法来估计电池的SOC。研究确定了EMF与SOC之间的关系,并通过电路分析,计算得出电池EMF与端电压之间的关系,最终建立了端电压与SOC关系。通过实测数据并利用模型估计数据的对比得出,SOC的误差在混合动力汽车的允许误差范围内。该方法在车辆停车和行驶时均适用。展开更多
文摘The second acidic dissociation constants of protonated piperazine-N,N′-bis-2-hydroxypropane-sulfonic acid (POPSO sesquisodium salt) have been determined at 12 different temperatures from (278.15 to 328.15) K including 310.15 K. Electromotive-force measurement technique was used employing hydrogen-silver chloride cells without liquid junction. The results of pK2 are given by the equation: pK2 = -1041.77/T + 51.0459 - 6.97646lnT. The uncertainty of the fit is ±0.0008. At 289.15 K, pK2 = 7.8029;whereas, at 310.15 K (body temperature), pK2 = 7.6862. Thus, the buffer solutions of POPSO and its sodium salt are useful for pH control in the physiological pH region of (7.0 to 8.5). The changes of Gibbs free energy (G°), enthalpy (H°), entropy (S°) and heat capacity Cp° were computed from the temperature derivative of the pK2 for the dissociation of the zwitterionic acid POPSO±-3 = POPSO-4 + H+ in the standard state. At 298.15 K, these results are compared with those of similar components, which are the derivatives of the parent compounds TAURINE, PIPERAZINE and MORPHOLINE.
文摘讨论了电动汽车镍氢动力电池荷电状态(State of Charge,简称SOC)的估计方法。提出用电动势(EMF)等效电路模型法来估计电池的SOC。研究确定了EMF与SOC之间的关系,并通过电路分析,计算得出电池EMF与端电压之间的关系,最终建立了端电压与SOC关系。通过实测数据并利用模型估计数据的对比得出,SOC的误差在混合动力汽车的允许误差范围内。该方法在车辆停车和行驶时均适用。
