目的:研究高功率微波(high power microwave,HPM)对心肌细胞和心脏间质细胞生存能力和细胞活性的影响。 方法:实验选用出生后1～3d的二级Wistar大鼠,体外培养Wistar大鼠乳鼠心肌细胞和心脏间质细胞,于HPM辐照后,用流式细胞仪检测细胞凋...目的:研究高功率微波(high power microwave,HPM)对心肌细胞和心脏间质细胞生存能力和细胞活性的影响。 方法:实验选用出生后1～3d的二级Wistar大鼠,体外培养Wistar大鼠乳鼠心肌细胞和心脏间质细胞,于HPM辐照后,用流式细胞仪检测细胞凋亡和坏死;用MTT实验测定细胞活力。 结果:HPM明显影响心肌细胞和间质细胞功能和形态结构,辐照后细胞活力降低,凋亡和坏死。辐照后6h,心肌细胞和间质细胞凋亡率分别为(36.76±5.12)％和(42.38±6.0)％,坏死率分别为(34.14±6.5)％和(22.98±7.4)％,与对照组相比,有显著的统计学意义(P<0.001)。 结论:心脏是微波辐照的靶器官之一,HPM可对心肌细胞和间质细胞功能和形态产生明显影响。结果提示在探讨HPM对心脏损伤时,应同时关注对心脏间质细胞的影响。展开更多
The change of light output power of LEDs based on A1GalnP heterostructures with multiple quantum wells （590 nm and 630 nm） under irradiation by fast neutrons depends on the operating current density. It can be disti...The change of light output power of LEDs based on A1GalnP heterostructures with multiple quantum wells （590 nm and 630 nm） under irradiation by fast neutrons depends on the operating current density. It can be distinguished the regions of high, average and low electron injection. Operating current, this corresponds to the position of the boundary between the selected levels of the electron injection, increases with increasing neutron fluence. The final stage of the reducing process of the light output power under irradiation is the regime of low electron injection. The relative change in light output power depends on the operating current （operating current density） and can be described by a fairly simple equation. Established relations predict radiation resistance of LEDs, and it makes the most rational justification of operating modes of light-emitting diodes in terms of radiation resistance.展开更多
PV （photovoltaic） systems need MPPT （maximum power point tracking） techniques to hamess maximum power from PV arrays. P＆O （perturb ＆ observe）, and incremental conductance methods are two basic MPPT algorithms ...PV （photovoltaic） systems need MPPT （maximum power point tracking） techniques to hamess maximum power from PV arrays. P＆O （perturb ＆ observe）, and incremental conductance methods are two basic MPPT algorithms applied to PV systems with fixed and variable step sizes. However, the existing variable step MPPT method exhibits complications which occur in the algorithm due to sudden, large irradiance changes which result in dips in power extraction. This paper proposes a modification to the existing variable step MPPT method to avoid such complications and hence improve the tracking accuracy under irradiance transients. The proposed technique is experimentally verified under sudden irradiance disturbances using a solar array. The results are compared with the existing variable step method. The superiority of the proposed technique is demonstrated through a laboratory prototype.展开更多
文摘The change of light output power of LEDs based on A1GalnP heterostructures with multiple quantum wells （590 nm and 630 nm） under irradiation by fast neutrons depends on the operating current density. It can be distinguished the regions of high, average and low electron injection. Operating current, this corresponds to the position of the boundary between the selected levels of the electron injection, increases with increasing neutron fluence. The final stage of the reducing process of the light output power under irradiation is the regime of low electron injection. The relative change in light output power depends on the operating current （operating current density） and can be described by a fairly simple equation. Established relations predict radiation resistance of LEDs, and it makes the most rational justification of operating modes of light-emitting diodes in terms of radiation resistance.
文摘PV （photovoltaic） systems need MPPT （maximum power point tracking） techniques to hamess maximum power from PV arrays. P＆O （perturb ＆ observe）, and incremental conductance methods are two basic MPPT algorithms applied to PV systems with fixed and variable step sizes. However, the existing variable step MPPT method exhibits complications which occur in the algorithm due to sudden, large irradiance changes which result in dips in power extraction. This paper proposes a modification to the existing variable step MPPT method to avoid such complications and hence improve the tracking accuracy under irradiance transients. The proposed technique is experimentally verified under sudden irradiance disturbances using a solar array. The results are compared with the existing variable step method. The superiority of the proposed technique is demonstrated through a laboratory prototype.
