An accurate estimation of the applied load pattern is an essential component in each pushover procedure. Recently, a number of adaptive pushover methods have been proposed in which the effects of the higher modes as w...An accurate estimation of the applied load pattern is an essential component in each pushover procedure. Recently, a number of adaptive pushover methods have been proposed in which the effects of the higher modes as well as the progressive changes in the dynamic characteristics of structures are taken into account to compute the applied load pattern. The basic shortcoming of these advanced pushover methods is related to employing the quadratic modal combination rule, whereby the sign reversals of the modal load vectors are suppressed. In this study, an improved displacement-based adaptive pushover method is developed in which the applied load pattern is computed using the factor modal combination rule(FMC). In the proposed procedure, multiple load patterns, depending on the number of the modes considered, are determined in order to take into account the sign reversals of different modal load vectors. The accuracy of the proposed method is verifi ed for seven moment resisting frame buildings of 3, 9 and 20 stories with regularity or vertically geometric and mass irregularities subjected to 60 earthquake ground motion records. The results showed that the proposed methodology is capable of reproducing the peak dynamic responses with very good accuracy.展开更多
[Objective] The change rules of Lycium barbarum and meteorological factors in Qaidam Basin were studied. [Method] Botanical characteristics,growth characteristics and physiological factor changes of Ningqi 1 were anal...[Objective] The change rules of Lycium barbarum and meteorological factors in Qaidam Basin were studied. [Method] Botanical characteristics,growth characteristics and physiological factor changes of Ningqi 1 were analyzed,and the change laws of Ningqi 1 and environmental factors(including sunlight,temperature,water and soil) were investigated by using meteorological observation data in 1973-2008. [Results] The results showed that Ningqi 1 belonged to light preferring plant,and the higher photosynthetic rate showed double peak type with the peaks appearing at 12:00 and 16:00,having midday depression of photosynthesis. The diurnal variation of transpiration rate in leaves showed a double peak,and the temperature around leaves was 0.2-0.5 ℃ higher than that in the field. The average relative humidity and temperature were the key factors to affect forming L. barbarum fruits. The suitable temperature for developing big seeds was 18 ℃. [Conclusions] Ningqi 1 could be taken as the first choice variety to plant and popularize in Qaidam Basin.展开更多
文摘An accurate estimation of the applied load pattern is an essential component in each pushover procedure. Recently, a number of adaptive pushover methods have been proposed in which the effects of the higher modes as well as the progressive changes in the dynamic characteristics of structures are taken into account to compute the applied load pattern. The basic shortcoming of these advanced pushover methods is related to employing the quadratic modal combination rule, whereby the sign reversals of the modal load vectors are suppressed. In this study, an improved displacement-based adaptive pushover method is developed in which the applied load pattern is computed using the factor modal combination rule(FMC). In the proposed procedure, multiple load patterns, depending on the number of the modes considered, are determined in order to take into account the sign reversals of different modal load vectors. The accuracy of the proposed method is verifi ed for seven moment resisting frame buildings of 3, 9 and 20 stories with regularity or vertically geometric and mass irregularities subjected to 60 earthquake ground motion records. The results showed that the proposed methodology is capable of reproducing the peak dynamic responses with very good accuracy.
文摘[Objective] The change rules of Lycium barbarum and meteorological factors in Qaidam Basin were studied. [Method] Botanical characteristics,growth characteristics and physiological factor changes of Ningqi 1 were analyzed,and the change laws of Ningqi 1 and environmental factors(including sunlight,temperature,water and soil) were investigated by using meteorological observation data in 1973-2008. [Results] The results showed that Ningqi 1 belonged to light preferring plant,and the higher photosynthetic rate showed double peak type with the peaks appearing at 12:00 and 16:00,having midday depression of photosynthesis. The diurnal variation of transpiration rate in leaves showed a double peak,and the temperature around leaves was 0.2-0.5 ℃ higher than that in the field. The average relative humidity and temperature were the key factors to affect forming L. barbarum fruits. The suitable temperature for developing big seeds was 18 ℃. [Conclusions] Ningqi 1 could be taken as the first choice variety to plant and popularize in Qaidam Basin.
