Research on solar aided coal-fired power generation system and performance analysis

Integrating solar power utilization systems with coal-fired power units, the solar aided coal-fired power generation (SACPG) shows a significant prospect for the large-scale utilization of solar energy and energy saving of thermal power units. The methods and mechanism of system integration were studied. The parabolic trough solar collectors were used to collect solar energy and the integration scheme of SACPG system was determined considering the matching of working fluid flows and energy flows. The thermodynamic characteristics of solar thermal power generation and their effects on the performance of thermal power units were studied, and based on this the integration and optimization model of system structure and parameters were built up. The integration rules and coupling mecha- nism of SACPG systems were summarized in accordance with simulation results. The economic analysis of this SACPG system showed that the solar LEC of a typical SACPG system, considering CO2 avoidance, is 0.098 $/kW·h, lower than that of SEGS, 0.14 $/kW·h.

维生素D对小鼠精原干细胞增殖和凋亡的影响及机制研究

目的研究维生素D对小鼠精原干细胞增殖和凋亡的影响及其机制。方法体外培养小鼠精原干细胞C18-4细胞,采用CCK-8法检测不同浓度和作用时间1α,25-(OH)_(2)D_(3)处理对C18-4细胞活力和增殖的影响,采用流式细胞仪(AnnexinV/PI染色)检测1α,25-(OH)_(2)D_(3)处理对C18-4细胞凋亡的影响,采用qRT-PCR方法检测1α,25-(OH)_(2)D_(3)处理C18-4细胞后Bcl-2、Bax、Vdr和Pcna基因表达的情况。结果与对照组相比较,10^(-7)M浓度1α,25-(OH)_(2)D_(3)处理24h和48h后细胞增殖率显著降低(P<0.05)。10^(-7)M浓度1α,25-(OH)_(2)D_(3)处理48h后细胞的早期凋亡率显著增高(P<0.05)。10^(-7)M浓度1α,25-(OH)_(2)D_(3)处理48h后细胞的Bax基因和Vdr基因表达显著上调(P<0.05),而Bcl-2基因和Pcna基因表达显著下调(P<0.05)。结论较高浓度1α,25-(OH)_(2)D_(3)通过抑制Pcna的表达而抑制小鼠精原干细胞的增殖,通过上调Bax和下调Bcl基因表达而促进小鼠精原干细胞的凋亡。