Erodible soil fractions are usually dislodged from projections and trapped in depression . 可冲蚀土壤部分经常从凸出物剥蚀并降落于洼地。
2.
Vortex - induced vibrations of a submarine pipeline and the concomitant scour around the pipeline with close proximity to an erodible seabed are a complex dynamic interaction between current , pipeline and seabed 摘要海底管道涡激振动和管道周围海床冲刷是海流管道海床之间复杂的动力耦合问题。
3.
Liu lian - you , wang jianhua , li xiaoyan , liu yuzhang , ta wanquan & peng haimei . 1998 . determination of the erodible particles on cultivated soils by wind tunnel simulation . chinese science bulletin , 43 ( 19 ) : 1646 51 刘连友,王建华,李小雁,刘玉璋,拓万权,彭海梅. 1998 .土壤可蚀性颗粒的风洞模拟测定.科学通报, 43 ( 15 ) : 1663 1666
4.
By using the yearly data of water - sand that is gotten by a couple of adjacent hydrologic station in yellow river lower reaches , this paper makes use of kinds of math methods looking for the nonlinear disturbance among all of the factors , and introduces the thinking of analysis , logic , conclusion , inference , and random to nonlinear hydrologic forecasting . it realizes the valid approximation of the water level process in erodible - bed channel 本文选择黄河下游两对相邻水文站多年水沙资料,借助多种数学方法寻找其中的非线性扰动项,将随机数学中分析、逻辑、归纳、演绎、随机的思考问题方式引入到非线性水文预报中,实现冲淤河道相应水位过程的有效拟合。
5.
There are a lot of factors that work on the water level of erodible - bed channel together , each of them varies no role , but is correlative . in the adjacent years or the adjacent flood peak of a floodwater , the conditions of the factors that influence water level are always very different . so , there is a nonlinear relation between water level and the factors influencing it 冲淤河道水位受到很多因素的共同作用,各因素本身的变化没有规律且互相关联,相邻前后年份或同一场洪水的不同洪峰前后,影响水位的水、沙、河道等因素常差别很大,水位与其影响因素之间客观上是非线性关系。
6.
At first , this paper analyzes the factors of water - sand influencing water level of yellow river and the feasibility just using the factors of water - sand to study water level , and collects the corresponding data ; secondly , because there are strong nonlinear relation in the corresponding data , by meticulous theory analysis , this paper integrates basic nonlinear analysis method , theory of random analysis , method of least squares and so on . it puts forward a method which can get the high accuracy simulation of the data , perfects the multi - factor analysis of variable ( over three factors ) of the statistic ; thirdly , it applies the method to the approximation of corresponding water level process which belong to the capacity of sand of middle - high and middle - low , and get the high - accuracy simulation about the typical nonlinear relation ; at last , this paper definitudes the main influence mode that the capacity of sand . it mainly unite with other factors to work on the water level in the yellow river lower reaches ; mor eover , this paper analyzes the difficult point and the direction of improvement to realize the accuracy forecasting of the flood level of erodible - bed channel 首先,系统分析了影响黄河水位的水沙因素,及仅用水沙因素有效研究水位的可行性,并按变量对应思想采集它们的相应数据;其次,由于相应水位过程数据中含极强的非线性关系,本论文经细致的理论分析,将基本的非线性分析方法、统计建模方法、随机分析理论、最小均方误差原则等等数学理论及方法有机揉合,提出了能有效实现这类数据高精度拟合的分层筛选法,并改进了统计学中多因子(三个以上)方差分析法;再次,将这一方法用于黄河中高及中低含沙类洪水相应水位过程的拟合,实现了这一典型非线性关系的高精度拟合,各年汛期上下游相应洪水位过程的拟合误差都较小;最后,明确黄河下游含沙量对水位的主要影响方式,即含沙量主要是与其它因素联合对水位作用;另外分析了要实现变动河床洪水位过程准确预报的困难所在及改进方向。