利用华北地区夏季日降水资料和NCEP/NCAR再分析环流资料,采用功率谱分析、Butterworth带通滤波等方法,对华北地区夏季降水低频特征与大气低频环流演变进行了综合分析。结果表明:(1)华北地区夏季降水存在低频特征,主要以准双周振荡为主。(2)500 h Pa高度场大气低频环流表现为闭合的高、低压系统;850 h Pa低频流场演变要复杂一些,但它们伴随高层低频系统移动会发生有规律的变化。500 h Pa高度场上,在35°N以北,低频系统向东移动,有时也从鄂霍次克海附近向西的扩展;在35°N以南,低频系统表现为由西北太平洋向西北移动,然后再向西移动。华北夏季降水主要是直接受中高纬度低频系统影响,低纬度低频系统很难直接影响华北地区,但它们可以通过偏南偏北气流的变化影响向华北地区的水汽输送或冷空气活动,进而加强或减弱华北地区的降水强度。(3)当500h Pa 40°N-60°N范围内有低频低压从西向东移近华北地区,并诱发850 h Pa气旋或切变线生成,从而在华北地区出现明显的降水过程;当500 h Pa低频低压向东移出而后部低频高压移来时,华北地区低层850 h Pa流场就会转为辐散气流或为一致的偏北气流,降水过程结束。(4)华北地区降水发生时,高、低空低频环流有较好的配合。
The Artificial Bee Colony (ABC) algorithm is one of the most recent swarm intelligence based algorithms which simulates the foraging behavior of honey bee colonies. In this work, a particle swarm inspired multi-elitis...
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The Artificial Bee Colony (ABC) algorithm is one of the most recent swarm intelligence based algorithms which simulates the foraging behavior of honey bee colonies. In this work, a particle swarm inspired multi-elitist ABC algorithm named PS-MEABC is proposed and applied for real-parameter optimization. In this modified version, the global best solution and an elitist randomly selected from the elitist archive are used to modify parameters of each food source in either onlooker bees or employed bees phases. PS-MEABC is compared with 5 state-of-the-art swarm based algorithms on CEC05 and BBOB12 benchmark functions in terms of four metrics: the mean error, the best error, the success rate (SR) and the expected running time (ERT). Wilcoxon signed ranks test results on the mean and the best error show that the performance of PS-MEABC is significantly better than or at least similar to these algorithms, and PS-MEABC has wider application range in terms of the success rate and faster convergence speed in terms of the expected running time. Our algorithm is comparable to its competitors with a fewer control parameters to be tuned.
CFRP is a new kind of building materials popularly used in structure strengthening. In order to study the reinforcement technique for masonry walls of school buildings, the walls with window opening strengthened by CF...
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ISBN:
(纸本)9783037859018
CFRP is a new kind of building materials popularly used in structure strengthening. In order to study the reinforcement technique for masonry walls of school buildings, the walls with window opening strengthened by CFRP were studied in the paper. Based on the experiment result, the finite element simulation and theoretical calculation analysis were done to study the mechanical behavior and shear capacity of the wall with window opening reinforced by CFRP. The CFRP pasted at the corner of window opening were proved to be effectively in improving shear capacity of the walls, and simple calculation formulas of shear capacity were provided in the paper, which proved to be accurate.
CFRP is a new kind of building materials popularly used in structure *** order to study the reinforcement technique for masonry walls of school buildings,the walls with window opening strengthened by CFRP were studied...
详细信息
CFRP is a new kind of building materials popularly used in structure *** order to study the reinforcement technique for masonry walls of school buildings,the walls with window opening strengthened by CFRP were studied in the *** on the experiment result,the finite element simulation and theoretical calculation analysis were done to study the mechanical behavior and shear capacity of the wall with window opening reinforced by *** CFRP pasted at the corner of window opening were proved to be effectively in improving shear capacity of the walls,and simple calculation formulas of shear capacity were provided in the paper,which proved to be accurate.
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