In this paper. the cause of cavitation noise limiting value is analyzed. and the de- termining method of cavitation noise limiting value of body os giving.
Seasonal changes in the photosynthetic characteristics of Ammopiptantus mongolicus (Maxim. )Chen f. were studied. When the net photosynthetic rate decreased with the elevation of air temperature, thestomatal conductan...Seasonal changes in the photosynthetic characteristics of Ammopiptantus mongolicus (Maxim. )Chen f. were studied. When the net photosynthetic rate decreased with the elevation of air temperature, thestomatal conductance and stomatal limitation value tended to decline simultaneously, while the interoellularCO2 concentration was increased. According to the two criteria discriminating the stomatal limitation of Photosynthesis suggeSted by Fmrquhar and Sharkey, the seasonal changes in these parameters indicated that the decrease in Pn may not be due to stomatal factor. These studies proved that the relative contents of the large subunit of Rubisco and the photochemical activities correlated with the seasonal changes in the net photosyntheticrate, whieh may show that these two factors contribute primarily to the seasonal changeS in CO2 assimilation.展开更多
Rubber isolation is the most mature control technology in practical application, and is widely used by short rigid buildings. However, many high isolation buildings have been built around the world in recent years, wh...Rubber isolation is the most mature control technology in practical application, and is widely used by short rigid buildings. However, many high isolation buildings have been built around the world in recent years, which do not follow the existing criterions and codes. Many researchers began to research the special problems caused by larger height-width ratio isolation structures. The overturning effect of high height-width ratio structures with rubber bearing is firstly studied. Considering the main factors, such as the height-width ratio of structures, type of site, the designed basic acceleration of ground motion and the decouple factor in horizon, computing experiment is defined with the Uniform Design Method, which is also known as designing isolation structure. The forces of the bearing under edge of structures based on the position of the rubber bearing are calculated. The result indicates that the rubber bearings will lose its functionality under very high tension and compressing force of earthquake motion in horizon and vertical, when the height-width ratio is over a certain value. Thus, based on the calculation result of isolation structures defined in the uniform design method, regression analysis is conducted, and also the rubber edge force regression formula are gotten, which has higher correlation and smaller standard deviation. This formula can be used to roughly calculate whether the pull force occurs at the edge of the building. By the edge bearings of isolation structure minimum force formula, the height-width ratio limited value of the isolation structure is deducted when rubber bearing has minimum force of zero.展开更多
Most reinforced concrete(RC)frame structures did not achieve the "strong column-weak beam" failure mode in recent big earthquakes, resulting in a large number of casualties and significant property loss. To ...Most reinforced concrete(RC)frame structures did not achieve the "strong column-weak beam" failure mode in recent big earthquakes, resulting in a large number of casualties and significant property loss. To deal with this serious problem, a new column-beam relative factor was proposed to characterize the relative yield situation of column ends and beam ends. By limiting the column-beam relative factor, RC frame structures could achieve the "strong column-weak beam" failure mode under the excitation of strong ground motions. The limit values of column-beam relative factor were calculated, analyzed and verified by using structural simulation models for corner columns in the bottom story of structures, which are destroyed most seriously in earthquakes. The results show that the limit values should be analyzed under bi-directional ground motion and with different axial compression ratios of columns. The peak ground acceleration(PGA)of ground motions has no significant effect on the limit values, while the type of strong ground motions has a significant effect on the limit values.展开更多
The objective is to develop an approach for the determination of the target reliability index for serviceability limit state(SLS) of single piles. This contributes to conducting the SLS reliability-based design(RBD) o...The objective is to develop an approach for the determination of the target reliability index for serviceability limit state(SLS) of single piles. This contributes to conducting the SLS reliability-based design(RBD) of piles. Based on a two-parameter,hyperbolic curve-fitting equation describing the load-settlement relation of piles, the SLS model factor is defined. Then, taking into account the uncertainties of load-settlement model, load and bearing capacity of piles, the formula for computing the SLS reliability index(βsls) is obtained using the mean value first order second moment(MVFOSM) method. Meanwhile, the limit state function for conducting the SLS reliability analysis by the Monte Carlo simulation(MCS) method is established. These two methods are finally applied to determine the SLS target reliability index. Herein, the limiting tolerable settlement(slt) is treated as a random variable. For illustration, four load test databases from South Africa are compiled again to conduct reliability analysis and present the recommended target reliability indices. The results indicate that the MVFOSM method overestimates βsls compared to that computed by the MCS method. Besides, both factor of safety(FS) and slt are key factors influencing βsls, so the combination of FS and βsls is welcome to be used for the SLS reliability analysis of piles when slt is determined. For smaller slt, pile types and soils conditions have significant influence on the SLS target reliability indices; for larger slt, slt is the major factor having influence on the SLS target reliability indices. This proves that slt is the most key parameter for the determination of the SLS target reliability index.展开更多
The present paper analyzes the relationship between the body speed and the cavitation noise. The results indicate that there is the limiting value of cavitation noise.
Through the study on data of analytic tree, the fitting empirical equation for tree growth was obtained, i.e. , the function with increment as variable and annual precipitation as the independent variable. The thresho...Through the study on data of analytic tree, the fitting empirical equation for tree growth was obtained, i.e. , the function with increment as variable and annual precipitation as the independent variable. The threshold value of annual precipitation for tree growth was obtained through mathematical operation including derivation. It was concluded that Larix gmelinii grows the fast under the annual precipitation of about 545.1 mm, and negative growth would occur if the annual precipitation is lower than 349 mm and higher than 1 132.8 mm. Furthermore, the application value, research direction and matters needing attention were pointed out.展开更多
Artificial bee colony (ABC) algorithm is one of the popular swarm intelligence algorithms. ABC has been developed by being inspired foraging and waggle dance behaviors of real bee colonies in 2005. Since its invention...Artificial bee colony (ABC) algorithm is one of the popular swarm intelligence algorithms. ABC has been developed by being inspired foraging and waggle dance behaviors of real bee colonies in 2005. Since its invention in 2005, many ABC models have been proposed in order to solve different optimization problems. In all the models proposed, there are only one scout bee and a constant limit value used as control parameters for the bee population. In this study, the performance of ABC algorithm on the numeric optimization problems was analyzed by using different number of scout bees and limit values. Experimental results show that the results obtained by using more than one scout bee and different limit values, are better than the results of basic ABC. Therefore, the control parameters of the basic ABC should be tuned according to given class of optimization problems. In this paper, we propose reasonable value ranges of control parameters for the basic ABC in order to obtain better results on the numeric optimization problems.展开更多
In 2019, the goal of the OEKO-TEX■ Association is again to reinforce consumer protection and sustainability along the value creation chain for textiles and leather; the existing guidelines for the OEKO-TEX■ product ...In 2019, the goal of the OEKO-TEX■ Association is again to reinforce consumer protection and sustainability along the value creation chain for textiles and leather; the existing guidelines for the OEKO-TEX■ product portfolio have thus been amended again for the start of the year. The new regulations will come into effect after a three-month transition period on April 1st, 2019.展开更多
文摘In this paper. the cause of cavitation noise limiting value is analyzed. and the de- termining method of cavitation noise limiting value of body os giving.
文摘Seasonal changes in the photosynthetic characteristics of Ammopiptantus mongolicus (Maxim. )Chen f. were studied. When the net photosynthetic rate decreased with the elevation of air temperature, thestomatal conductance and stomatal limitation value tended to decline simultaneously, while the interoellularCO2 concentration was increased. According to the two criteria discriminating the stomatal limitation of Photosynthesis suggeSted by Fmrquhar and Sharkey, the seasonal changes in these parameters indicated that the decrease in Pn may not be due to stomatal factor. These studies proved that the relative contents of the large subunit of Rubisco and the photochemical activities correlated with the seasonal changes in the net photosyntheticrate, whieh may show that these two factors contribute primarily to the seasonal changeS in CO2 assimilation.
文摘Rubber isolation is the most mature control technology in practical application, and is widely used by short rigid buildings. However, many high isolation buildings have been built around the world in recent years, which do not follow the existing criterions and codes. Many researchers began to research the special problems caused by larger height-width ratio isolation structures. The overturning effect of high height-width ratio structures with rubber bearing is firstly studied. Considering the main factors, such as the height-width ratio of structures, type of site, the designed basic acceleration of ground motion and the decouple factor in horizon, computing experiment is defined with the Uniform Design Method, which is also known as designing isolation structure. The forces of the bearing under edge of structures based on the position of the rubber bearing are calculated. The result indicates that the rubber bearings will lose its functionality under very high tension and compressing force of earthquake motion in horizon and vertical, when the height-width ratio is over a certain value. Thus, based on the calculation result of isolation structures defined in the uniform design method, regression analysis is conducted, and also the rubber edge force regression formula are gotten, which has higher correlation and smaller standard deviation. This formula can be used to roughly calculate whether the pull force occurs at the edge of the building. By the edge bearings of isolation structure minimum force formula, the height-width ratio limited value of the isolation structure is deducted when rubber bearing has minimum force of zero.
基金Supported by the National Natural Science Foundation of China(No.51525803)the Scientific and Technological Development Plans of Tianjin Construction System(No.2013-35)+1 种基金International Science&Technology Cooperation Program of China(No.2012DFA70810)the Basic Science Research Foundation of IEM,CEA(No.2013B07)
文摘Most reinforced concrete(RC)frame structures did not achieve the "strong column-weak beam" failure mode in recent big earthquakes, resulting in a large number of casualties and significant property loss. To deal with this serious problem, a new column-beam relative factor was proposed to characterize the relative yield situation of column ends and beam ends. By limiting the column-beam relative factor, RC frame structures could achieve the "strong column-weak beam" failure mode under the excitation of strong ground motions. The limit values of column-beam relative factor were calculated, analyzed and verified by using structural simulation models for corner columns in the bottom story of structures, which are destroyed most seriously in earthquakes. The results show that the limit values should be analyzed under bi-directional ground motion and with different axial compression ratios of columns. The peak ground acceleration(PGA)of ground motions has no significant effect on the limit values, while the type of strong ground motions has a significant effect on the limit values.
基金Projects(51278216,51308241)supported by the National Natural Science Foundation of ChinaProject(2013BS010)supported by the Funds of Henan University of Technology for High-level Talents,China
文摘The objective is to develop an approach for the determination of the target reliability index for serviceability limit state(SLS) of single piles. This contributes to conducting the SLS reliability-based design(RBD) of piles. Based on a two-parameter,hyperbolic curve-fitting equation describing the load-settlement relation of piles, the SLS model factor is defined. Then, taking into account the uncertainties of load-settlement model, load and bearing capacity of piles, the formula for computing the SLS reliability index(βsls) is obtained using the mean value first order second moment(MVFOSM) method. Meanwhile, the limit state function for conducting the SLS reliability analysis by the Monte Carlo simulation(MCS) method is established. These two methods are finally applied to determine the SLS target reliability index. Herein, the limiting tolerable settlement(slt) is treated as a random variable. For illustration, four load test databases from South Africa are compiled again to conduct reliability analysis and present the recommended target reliability indices. The results indicate that the MVFOSM method overestimates βsls compared to that computed by the MCS method. Besides, both factor of safety(FS) and slt are key factors influencing βsls, so the combination of FS and βsls is welcome to be used for the SLS reliability analysis of piles when slt is determined. For smaller slt, pile types and soils conditions have significant influence on the SLS target reliability indices; for larger slt, slt is the major factor having influence on the SLS target reliability indices. This proves that slt is the most key parameter for the determination of the SLS target reliability index.
文摘The present paper analyzes the relationship between the body speed and the cavitation noise. The results indicate that there is the limiting value of cavitation noise.
文摘Through the study on data of analytic tree, the fitting empirical equation for tree growth was obtained, i.e. , the function with increment as variable and annual precipitation as the independent variable. The threshold value of annual precipitation for tree growth was obtained through mathematical operation including derivation. It was concluded that Larix gmelinii grows the fast under the annual precipitation of about 545.1 mm, and negative growth would occur if the annual precipitation is lower than 349 mm and higher than 1 132.8 mm. Furthermore, the application value, research direction and matters needing attention were pointed out.
基金supported by the Selcuk University Scientific Projects Coordinatorship
文摘Artificial bee colony (ABC) algorithm is one of the popular swarm intelligence algorithms. ABC has been developed by being inspired foraging and waggle dance behaviors of real bee colonies in 2005. Since its invention in 2005, many ABC models have been proposed in order to solve different optimization problems. In all the models proposed, there are only one scout bee and a constant limit value used as control parameters for the bee population. In this study, the performance of ABC algorithm on the numeric optimization problems was analyzed by using different number of scout bees and limit values. Experimental results show that the results obtained by using more than one scout bee and different limit values, are better than the results of basic ABC. Therefore, the control parameters of the basic ABC should be tuned according to given class of optimization problems. In this paper, we propose reasonable value ranges of control parameters for the basic ABC in order to obtain better results on the numeric optimization problems.
文摘In 2019, the goal of the OEKO-TEX■ Association is again to reinforce consumer protection and sustainability along the value creation chain for textiles and leather; the existing guidelines for the OEKO-TEX■ product portfolio have thus been amended again for the start of the year. The new regulations will come into effect after a three-month transition period on April 1st, 2019.
