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241.
渗透胁迫对玉米幼苗膜脂过氧化及过氧化氢酶活性的影响 总被引:6,自引:0,他引:6
本实验以三个玉米品种新实多2号、东单7号、中原单32为实验材料,采用PEG 6000模拟土壤干旱条件,研究渗透胁迫下不同玉米品种M DA(丙二醛)含量、CAT(过氧化氢酶)活性以及膜相对透性间的相互关系,结果表明,渗透胁迫下三个玉米品种M DA含量和质膜相对透性均随胁迫强度的增加而增加,而CAT活性则随胁迫强度的增加而减少,CAT活性与M DA含量、质膜相对透性均呈显著或极显著负相关关系,且品种间存在差异,通过分析比较,可初步判断三个玉米品种幼苗的抗渗透胁迫能力为新实多2号优于中原单32和东单7号. 相似文献
242.
A power system with proton exchange membrane fuel cells (PEMFC) was designed for thermal underwater glider.Heat generated by PEMFC is used as the propulsion power of the glider,and the electricity is used in the control and sensor system.An electric energy storage system (ESS) is required which possesses high power density with good cycle life.Ultracapacitors which exhibit high power density and cycle life are considered as energy storage devices.Simulations based on a specific voyage condition indicate that ESS with ultracapacitors has positive effects on reducing the output power demand of PEMFC and lightening the power system.Experimental results show that the state of charge (SOC) is related to the capacitance and resistance in ultracapacitor ESS. 相似文献
243.
肖黎明 《广东技术师范学院学报》2009,(12):1-5
本文用修正因子方法讨论了二维线性Koiter型弹性壳模型方程与二维线性膜壳模型方程解之间的偏差估计。 相似文献
244.
目的:比较金属针与非金属针针刺对长时间电刺激诱发的骨骼肌细胞膜电位变化的影响。方法:取雄性蟾蜍半腱肌,分离出两束肌细胞(随机分为对照组和实验组),每束骨骼肌细胞数量在20个左右。采用细胞内微电极技术,记录长时间电刺激对骨骼肌细胞膜电位的作用。实验组在刺激结束后即刻给予不锈钢针或竹针斜刺。结果:长时间电刺激导致骨骼肌细胞的膜电位向去极化方向发展;不锈钢针和竹针针刺均具有促进长时间电刺激后骨骼肌细胞膜电位恢复的作用,二者作用无显著差异。结论:针刺对骨骼肌损伤的疗效与针的材质无关,只要取"阿是穴"斜刺,则可能取得良好的治疗效果。 相似文献
245.
丹参对大鼠疲劳性游泳运动时红细胞自由基代谢的影响 总被引:6,自引:0,他引:6
从红细胞自由基代谢的角度对丹参的抗氧化作用进行研究,发现丹参能明显提高大鼠红细胞超氧化物歧化酶(SOD)活性,清除O2-,降低红细胞膜脂质过氧化终产物丙二醛(MDA)含量,保护细胞免受脂质过氧损伤。表现为红细胞膜流动性在疲劳性游泳后无明显降低,高分子聚合物的相对百分含量升高的幅度较小。 相似文献
246.
This paper presented a control design methodology for a proton exchange membrane fuel cell (PEMFC) generation system for residential applications. The dynamic behavior of the generation system is complex in such applications. A compre- hensive control design is very important for achieving a steady system operation and efficiency. The control strategy for a 60 kW generation system was proposed and tested based on the system dynamic model. A two-variable single neuron proportional-integral (PI) decoupling controller was developed for anode pressure and humidity by adjusting the hydrogen flow and water injection. A similar controller was developed for cathode pressure and humidity by adjusting the exhaust flow and water injection. The desired oxygen excess ratio was kept by a feedback controller based on the load current. An optimal seeking con- troller was used to trace the unique optimal power point. Two negative feedback controllers were used to provide AC power and a suitable voltage for residential loads by a power conditioning unit. Control simulation tests showed that 60 kW PEMFC generation system responded well for computer-simulated step changes in the load power demand. This control methodology for a 60 kW PEMFC generation system would be a competitive solution for system level designs such as parameter design, performance analysis, and online optimization. 相似文献
247.
248.
Sandesh Mohan Kiran Kalia Jyoti Mannari 《Indian journal of clinical biochemistry : IJCB》2012,27(4):333-339
Abnormal glomerular permeability is the primary step towards the glomerulosclerosis. The progression rate of glomerulosclerosis is proportionate to abundance and severity of lesions created at incipient stage, which is reflected as proteinuria even though eGFR remains in the normal range. Therefore, there is a current need to find out the association between relative risks for the factors leading to proteinuria. The relations could be more informative, if it is with respect to the macromolecules like “IgG” excretion in urine. Type 2 diabetic patients were selected for this study with eGFR > 75 ml/min/1.73 m2 and grouped into four quartiles based on UIgGCR. The markers of key factors affecting progression of proteinuria were estimated through biochemical tests. The impact of these markers on proteinuria was accessed by applying multinomial logistic regression. The adjusted odds ratio for the UGAGCR was 1.186 (95 % CI: 1.061–1.327) P < 0.003 in highest quartiles of UIgGCR, followed by odds ratio for markers of collagen catabolism 1.051 (95 % CI: 1.025–1.079) P < 0.001, and USACR 1.044 (95 % CI: 1.013–1.077) P < 0.006 respectively. The marker of glycation, i.e., glycated hemoglobin showed the highest odds ratio 5.449 (95 % CI: 1.132–26.236) P < 0.035. In addition, odds for the systolic blood pressure was observed 1.387 (95 % CI: 1.124–1.712) P < 0.002. The higher odds inform and could help to discriminate the diabetic patients with fast progressive diabetic nephropathy. The study describes critical relationship between the urinary excretion of IgG and factors leading to proteinuria in type 2 diabetic patients. 相似文献
249.
大叶黄杨叶片衰老与细胞膜脂质过氧化的关系 总被引:1,自引:0,他引:1
植物器官衰老,往往发生膜脂过氧化作用,丙二醛(MDA)是膜脂过氧化作用的最终分解产物,其含量可以反映植物衰老的程度。在衰老的器官中丙二醛含量较高,而在幼嫩的器官中丙二醛含量较少。 相似文献
250.
本文在以复合式膜生物反应器系统为基础,以模拟城市污水为处理对象。通过运行条件优化研究,综合脱氮除磷效果及经济因素,将复合区水力停留时间控制在7h左右。此时系统总去除率为:CODcr≧96.28%、NH3-N≧97.54%、TN≧74.87%、TP≧74.34%,出水可以稳定保证在CODcr≦14.35mg/L、NH3-N≦0.74mg/L、TN≦9.02mg/L、TP≦1.05mg/L。效果较好。 相似文献