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551.
The purpose of this article is to gather results of studies on the relationship between median frequency (MF) and mean power frequency (MPF) and the level of muscle contraction, and to use those results to discuss the differences in the trends according to factors related to measurement technique and subject. Twenty-one studies with 63 cases for upper limb muscles and nine studies with 31 cases for lower limb muscles were analysed. Most results showed an increase in parameters with an increased level of muscle contraction, only some studies showed a decrease. The influence on parameters of the level of muscle contraction and factors such as subjects, type of contraction, muscle length and electrodes was analysed for each muscle. It was concluded that when analysing the influence of different factors on MF and MPF, because those factors interact they should be considered together, not separately. 相似文献
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上海气象参数与太阳活动和ENSO的关系 总被引:6,自引:0,他引:6
运用2进小波的分解与重构技术分析了太阳活动、厄尔尼诺—南方涛动(ENS0)与上海地区月降水量、月均气压和月均温度序列之间的可能关系。研究结果表明,在不同的时间尺度(频带)上太阳活动和ENS0对上海的月降水量、月均气压和月均温度有不同的影响;在某种程度上ENS0活动对上海月降水量和月均气温的影响强于太阳活动的影响。结果还清楚表明和证实了在不同频带上太阳活动与ENS0活动之间的密切联系。 相似文献
555.
ABSTRACTEnergy optimization is performed on hybrid solar-geothermal power plant working according to Organic Rankine Cycle and installed in southern Tunisia. The performances of four different configurations of the power plant are studied. Mass and energy balances are established for the different compounds. The effects of the main operating parameters such as the geothermal water temperature, ambient temperature and direct normal irradiation on the power plant performances are analyzed. A code is established using Engineering Equation Solver software (EES) to perform the required calculations. Obtained results show that the hybrid solar-geothermal power plant with a heat recovery system is the most suitable configuration design giving a better overall energy efficiency of 15.77 and13.11% and a maximum net power of 1089 and 1882 kW in winter and summer, respectively. However, in the summer season, using a heat recovery system can valuable only when the water temperature is higher than 66°C. For air-cooled condenser, the suitable condensing pressure is 1 bar in winter and 1.9 bars in summer. 相似文献
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太阳能光伏产业是21世纪备受世界各国重视的高新技术产业之一,拥有广阔发展前景,基于对太阳能光伏产业链、国内太阳能光伏产业现状的分析及连城太阳能光伏产业现状与面临挑战的分析,提出连城太阳能光伏产业发展战略。 相似文献
558.
为研究煤氧化过程中活性基团的演变规律及热效应的变化特征,利用原位红外实验装置,实时测量煤升温过程中官能团的动态变化,数据处理得到弱粘煤红外波谱图,利用差减法对特征温度点下的红外光谱图进行处理,得到煤样的差示光谱,计算特征温度点下的红外结构参数;采用差示扫描量热仪,测量煤氧化过程中热流的变化,得到弱粘煤的热流曲线图,并对热流曲线进行阶段划分和氧化动力学计算。结果表明:弱粘煤中芳环数量比较少,环周围侧链较长,内部结构疏松,内部毛细管比较发达,内表面积较大,更容易发生自燃;整个氧化过程中羟基最为活跃,含氧官能团次之,其次是脂肪烃;红外参数计算结果HAL,I2整体呈减小趋势,I1,I3整体呈增大趋势;弱粘煤放热阶段的活化能值为25.12~61.26 kJ/mol,并随着升温速率的增大而减小,与此阶段放热量随升温速率的增大而增大相对应。 相似文献
559.
好氧颗粒污泥膜生物反应器中的污泥性质与膜污染研究 总被引:3,自引:0,他引:3
好氧颗粒污泥膜生物反应器运行了75 d,其COD、氨氮和总氮去除率分别为91%~95%、89.57%~100%和48.25%~90.84%;运行过程中颗粒污泥出现了一定程度的解体,污泥沉降性能出现了恶化,污泥比阻由起始的1.085×1013m/kg上升到反应末期的2.712×1013m/kg;胞外聚合物维持在44.71~72.23 mg/g之间.对膜组件污染特性进行研究,发现膜表面滤饼层阻力和膜孔堵塞阻力分别为5.32×1011m-1和2.34×1011m-1,占到总阻力的67.42%和29.66%.通过对膜污染物质进行红外光谱分析,发现膜污染的主要物质为蛋白质和糖类物质. 相似文献
560.
Hideyuki Katsumat Syunya Koike Satoshi Kaneco Tohru Suzuki Kiyohisa Ohta 《环境科学学报(英文版)》2010,22(9):1455-1461
The decolorization of Reactive Yellow 86(RY 86),one of reactive azo dyes,was investigated in the presence of Fenton reagent under solar light irradiation.The decolorization rate was strongly influenced by pH,initial concentrations of H 2 O 2 and Fe(II),and so on.An initial concentration of 40 mg/L was decolored more than 90% after 20 min under optimum conditions.The activation energy of the solar photo-Fenton reaction was 1.50 kJ/mol for RY 86 in the temperature range of 10-60°C.In the kinetic study,the rate constant of RY 86 with OH· radicals could be estimated to be 1.7 × 10 10 L/(mol·sec).The decolorization efficiency of RY 86 under solar light irradiation was comparable to the artificial light irradiation.The decrease of TOC as a result of mineralization of RY 86 was observed during photo-Fenton process.The rate of RY 86 mineralization was about 83% under UV irradiation after 24 hr.The formation of chloride,sulfate,nitrate and ammonium ions as end-products was observed during the photocatalytic process.The decomposition of RY 86 gave two kinds of intermediate products.The degradation mechanism of RY 86 was proposed on the base of the identified intermediates. 相似文献