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991.
In photoautotrophic cultures of pak-bung hairy roots, strong light irradiation (22 W/m2) increased the content of reactive oxygen species (ROS) in the cells, resulting in chlorophyll (Chl) degradation and DNA injury. The Chl degradation rate, RD, can be used as a parameter to measure the cellular damage caused by photo-induced stress. The presence of the antioxidants ascorbic acid, chlorogenic acid or catechin reduced the RD, while lowering the content of ROS and moderating the DNA injury.  相似文献   
992.
李元章 《冶金能源》2001,20(5):32-34
通过与传统热力除氧器相比较,分析了LHY-Ⅱ型催化除氧设备在节能降耗方面的重要功效,希望该除氧设备能迅速得到普及,从而达到节能及环保的双重目的。  相似文献   
993.
Oxygen potentials of oxide nuclear fuels are important thermodynamic data in development of nuclear fuel technologies. Minor actinide bearing MOX (mixed oxide) fuels have been developed as sodium cooled fast reactor fuels. Content of Am which is one of the minor actinide elements causes oxygen potentialto increase. The effects of the oxygen potential increase on the irradiation behavior were evaluated. Profiles of temperature and O/M (oxygen-to-metal) ratio in the pellets were evaluated to better understand the irradiation behavior. From these data, local oxygen potential in the radial direction of the pellets was calculated, and was compared with free energy of compounds composed of fission products. Based on this comparison, it was concluded that Cs2MoO4 was likely formed at pellet periphery of (U07Pu03)O1.98 and (U0.66Pu03Amoo16Npo.016)Ol.976 The extent of cladding tube inner surface oxidation was predicted by using the calculated oxygen potential. No significant difference between irradiation behaviors of (Uo.7Puo3)O2_x and (U0.66PUo 3Amo.016Npo.016)O2.x pellets was confirmed.  相似文献   
994.
An electrochemical deoxidation using a ZrO2 based solid electrolyte was investigated to control the interfacial oxygen concentration between the molten steel and ZrO2. The electrochemical deoxidation cell consisted of an MgO stabilized ZrO2 and an external power supply. In a previous study with constant external DC voltage, the oxygen concentration at the interface between the solid electrolyte and the molten steel was decreased to 2.2 ppm, which was the limit caused by the cathodic over‐potential when a constant external DC voltage was applied. In the present study, a novel process of using a periodic or cyclic voltage for the electrochemical deoxidation cell was developed, to surpass this limitation caused by the over‐optential of the electrochemical cell and thus decreasing the oxygen concentration to sub‐ppm levels at the interface between the molten Fe and the solid electrolyte.  相似文献   
995.
结合株冶工程实际,叙述了旋转补偿器在热力管网中的应用,归纳总结了制氧站施工图设计中,热工专业经常出现且带有普遍性的几个问题.  相似文献   
996.
BACKGROUND: A laboratory scale one‐compartment scale‐down system (1‐CSDS), used to generate dissolved oxygen tension (DOT) gradients was designed and characterized. The system consists of a 1.5‐L stirred‐tank bioreactor coupled to an automatic DOT controller that changes the oxygen partial pressure in the inlet gas through a feedback proportional–integral–derivative algorithm, while maintaining the hydrodynamic conditions constant. Oscillatory control of DOT was achieved by employing time‐dependent square wave or sinusoidal setpoints. RESULTS: The 1‐CSDS can be modeled as a first‐order dynamic system, but showing a permanent lag between the system response and the setpoint. The 1‐CSDS had a faster response rate for generating oscillating DOT when a square wave setpoint was used rather than a sinusoidal setpoint. The 1‐CSDS generated symmetric DOT oscillations at periods above of 100 s. CONCLUSION: The 1‐CSDS is suited to investigate the responses of microorganisms and cells, of biotechnological importance, to oscillatory DOT conditions. It was found that the response of the 1‐CSDS was limited by the kLa. Copyright © 2010 Society of Chemical Industry  相似文献   
997.
This paper presents the improvement of the resistance to fungi of some cotton textile materials by treating in the manufacturing process with oxygen plasma and chitosan. Thus, after the weaving and preliminary finishing, the fabrics were cleaned in oxygen plasma atmosphere and after dyeing, have been treated with chitosan solution with concentrations of 1 or 5 g/l, in order to confer them antimicrobial properties. The antimicrobial tests were performed with two fungi: Candida albicans and Tricophyton interdigitale. The obtained antimicrobial effect was considerably higher compared to that of the raw fabrics. The colour resistance of dyed fabrics was not significantly influenced by applying the treatment-based chitosan.  相似文献   
998.
Extending our previous observations, we have shown on HaCat cells that melatonin, at ~10−9 M concentration, transiently raises not only the expression of the neuronal nitric oxide synthase (nNOS) mRNA, but also the nNOS protein synthesis and the nitric oxide oxidation products, nitrite and nitrate. Interestingly, from the cell bioenergetic point of view, the activated NO-related chemistry induces a mild decrease of the oxidative phosphorylation (OXPHOS) efficiency, paralleled by a depression of the mitochondrial membrane potential. The OXPHOS depression is apparently balanced by glycolysis. The mitochondrial effects described have been detected only at nanomolar concentration of melatonin and within a time window of a few hours’ incubation; both findings compatible with the melatonin circadian cycle.  相似文献   
999.
由理论分析及经验得到溶解氧与尾气二氧化碳模型,通过布拉酵母菌发酵得到实测溶解氧及尾气二氧化碳检测数据,依据经验模型计算出近似溶解氧值。应用统计分析软件SPSS得到实测溶解氧与二氧化碳及计算溶解氧的Pearson相关系数分别为-0.632和0.862,说明溶解氧与尾气二氧化碳之间存在负相关关系,而经验模型计算的溶解氧值与实际溶解氧之间具有较强的相关性。进一步采用曲线拟合对计算溶解氧值进行修正,使其更接近实际溶解氧。  相似文献   
1000.
液氧集中供气新技术   总被引:1,自引:0,他引:1  
本文介绍了一种新型的液氧集中供气技术,阐述了该系统主要设备的技术参数选择、性能、安全使用和维护保养等问题。  相似文献   
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