The dynamic load characteristics of a proton exchange membrane fuel cell（PEMFC） with a dead-ended anode were studied. In a 70 h experiment, the effects of anode pressure, operating temperature, and relative humidity...The dynamic load characteristics of a proton exchange membrane fuel cell（PEMFC） with a dead-ended anode were studied. In a 70 h experiment, the effects of anode pressure, operating temperature, and relative humidity of the cathode on the performances of the fuel cell were investigated. The obtained results show that, with different relative humidity of the cathode at 65 ℃, dynamic loading has little effect on the performances of fuel cell and the electrochemically active surface area（ECSA）. However, the fuel cell operating under dynamic load is unstable when the relative humidity is 50%, and at 50 ℃ with 100% relative humidity, applying a dynamic load has a significant influence on the fuel cell performances. Scanning electron microscopy（SEM） showed that both the upstream and middle catalyst layers of the cell were unchanged, whereas the downstream cathode catalyst layer thinned as a response to dynamic load.展开更多
目的分析感音神经性听力损失患者耳蜗死区(cochlear dead regions,CDR)检测结果。方法应用均衡噪声阈值TEN(HL)法检测273例302耳感音神经性听力损失患者的耳蜗死区,并分析耳蜗死区与其可能病因及听力曲线类型的关系。结果 273例(302耳)...目的分析感音神经性听力损失患者耳蜗死区(cochlear dead regions,CDR)检测结果。方法应用均衡噪声阈值TEN(HL)法检测273例302耳感音神经性听力损失患者的耳蜗死区,并分析耳蜗死区与其可能病因及听力曲线类型的关系。结果 273例(302耳)感音神经性听力损失患者中,112例117耳存在耳蜗死区,占总耳数的38.74%;存在耳蜗死区的患者在耳蜗死区频率处DPOAE均未引出,其中高频听力下降型占40.22%(74/184),低频下降型占47.14%(33/70),两端下降型占33.33%(2/6),平坦型占19.04%(8/42);噪声、耳毒性药物、突发性聋三种因素致聋者中耳蜗死区检出率较高。结论本组感音神经性听力损失患者耳蜗死区检出率约为38.74%,高频下降型者最多,噪声和/或耳毒性药物致聋者更易出现耳蜗死区。展开更多
基金Funded by the National Natural Science Foundation of China(Nos.51476119 and 51576147)the Natural Science Foundation of Hubei Province(No.2016CFA041)the Fundamental Research Funds for the Central Universities(No.2017 IVA 031)
文摘The dynamic load characteristics of a proton exchange membrane fuel cell（PEMFC） with a dead-ended anode were studied. In a 70 h experiment, the effects of anode pressure, operating temperature, and relative humidity of the cathode on the performances of the fuel cell were investigated. The obtained results show that, with different relative humidity of the cathode at 65 ℃, dynamic loading has little effect on the performances of fuel cell and the electrochemically active surface area（ECSA）. However, the fuel cell operating under dynamic load is unstable when the relative humidity is 50%, and at 50 ℃ with 100% relative humidity, applying a dynamic load has a significant influence on the fuel cell performances. Scanning electron microscopy（SEM） showed that both the upstream and middle catalyst layers of the cell were unchanged, whereas the downstream cathode catalyst layer thinned as a response to dynamic load.
文摘目的分析感音神经性听力损失患者耳蜗死区(cochlear dead regions,CDR)检测结果。方法应用均衡噪声阈值TEN(HL)法检测273例302耳感音神经性听力损失患者的耳蜗死区,并分析耳蜗死区与其可能病因及听力曲线类型的关系。结果 273例(302耳)感音神经性听力损失患者中,112例117耳存在耳蜗死区,占总耳数的38.74%;存在耳蜗死区的患者在耳蜗死区频率处DPOAE均未引出,其中高频听力下降型占40.22%(74/184),低频下降型占47.14%(33/70),两端下降型占33.33%(2/6),平坦型占19.04%(8/42);噪声、耳毒性药物、突发性聋三种因素致聋者中耳蜗死区检出率较高。结论本组感音神经性听力损失患者耳蜗死区检出率约为38.74%,高频下降型者最多,噪声和/或耳毒性药物致聋者更易出现耳蜗死区。
