共查询到20条相似文献，搜索用时 150 毫秒
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文（１）中讨论了Ｌ－统计量的Ｂｏｏｔｓｔｒａｐ逼近的一致性速度，本文则研究了其非一致性速度。 相似文献
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胡志荣 《商丘师范学院学报》1994,(Z3)
从Ｇａｕｓｓ原理出发，得到离散系统在加速度空间中变分原理的微分形式和积分形式，并对连续系统进行研究，直接得到流体力学中的Ｎａｖｉｅｒ－Ｓｔｏｋｅｓ万程． 相似文献
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利用古典Ｓｚａｓｚ算子和Ｓｚａｓｚ－Ｂａｓｋａｋｏｖ算子给出了新的混合Ｓｚａｓｚ－Ｂａｓｋａｋｏｖ型算子的表达式及其各阶矩，所给出了新算子包含了古典Ｓｚａｓｚ 算子和Ｂａｓｋａｋｏｖ算子，其各阶矩推广了已知Ｓｚａｓｚ算子和Ｂａｓｋａｋｏｖ算子各阶矩的结果。 相似文献
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1 Ｉｎｔｒｏｄｕｃｔｉｏｎ ＮｕｍｅｒｉｃａｌｌｙｓｏｌｖｉｎｇｔｈｅｉｎｃｏｍｐｒｅｓｓｉｂｌｅＮａｖｉｅｒ Ｓｔｏｋｅｓｅｑｕａｔｉｏｎｓｈａｓｔｗｏｄｉｆｆｉｃｕｌｔｉｅｓ :ｔｈｅｎｏｎｌｉｎｅａｒｆｏｒｍａｎｄｔｈｅｉｎｃｏｍｐｒｅｓｓｉｂｉｌｉｔｙｃｏｎｄｉｔｉｏｎ .Ｉｎｔｈｉｓｐａ ｐｅｒ ,ｗｅｃｏｎｓｉｄｅｒｔｈｅａｐｐｒｏｘｉｍａｔｉｏｎｂｙａ ｐｅｎａｌｔｙｍｅｔｈｏｄｆｏｒｔｈｅＮａｖｉｅｒ Ｓｔｏｋｅｓｅｑｕａｔｉｏｎｓｔｏｃｏｐｅｗｉｔｈｔｈｅｓｅｃｏｎｄｄｉｆｆｉｃｕｌｔ… 相似文献
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ＦｌｅｘｕｒａｌＢｅｈａｖｉｏｕｒｏｆＨｉｇｈ－ＳｔｒｅｎｇｔｈＳｔｅｅｌＦｉｂｅｒ－ＲｅｉｎｆｏｒｃｅｄＣｏｎｃｒｅｔｅＢｅａｍｓＱｉａｎＣｈｕｎｘｉａｎｇ（钱春香）（ＤｅｐａｒｔｍｅｎｔｏｆＭａｔｅｒｉａｌｓＳｃｉｅｎｃｅａｎｄＥｎｇｉｎｅｅｒｉ... 相似文献
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《云南教育(高教版)》1994,(1)
ＴＨＥＴＯＴＡＬＥＦＦＥＣＴＯＦＴＨＥＧＲＥＡＴＧＡＴＳＢＹＸｕＱｉｎ－ＳｕｎＴＨＥＧＲＥＡＴＧＡＴＳＢＹ，ｏｎｅｏｆＦｉｔｚｇｅｒａｌｄ’ｓｇｒｅａｔｅｓｔｎｏｖｅｌｓ，ｉｓａｎｏｄｄｃｏｍｂｉｎａ－ｔｉｏｎｏｆｒｏｍａｎｃｅａｎｄｒｅａｌｉｔｙ．... 相似文献
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助推器附近二维激波边界层干扰的数值分析 总被引：1，自引：0，他引：1
本文利用二维雷诺平均的Ｎａｖｉｅｒ－Ｓｔｏｋｅｓ方程,采用κ－ε湍流模式,运用有限体积法,对大型运载火箭的助推器与芯级的激波边界层干扰进行了二维数值模拟．数值结果表明在助推器激波的干扰下,芯级边界层流场明显出现了分离和再附过程．助推器头部形状对流场有显著的影响,在半球助推器头形状情形下由于产生了较强的弓形激波,边界层的分离和再附过程最显著,压力分布最复杂．助推器与芯级距离对流场也有显著的影响,距离较小时,压力系数较大,激波边界层的强干扰会产生分离区甚至分离泡． 相似文献
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鸡传染性法氏囊炎病毒（ＩｎｆｅｃｔｉｏｎｓＢｕｒｓａｌＤｉｓｅａｓｅＶｉｒｎｓ，ＩＢＤＶ）和禽呼肠孤病毒（ＡｖｉａｎＲｅｏｖｉ－ｒｕｓ，ＡＲＶ）的许多生物学特性和理化特性十分相似［１－４］，尤其在形态结构和理化特性上极为相似［５］，本文用ＳＤＳ—ＰＡＧＥ区别鉴定ＩＢＤＶ和ＡＲＶ是一种简便、快速、可靠的方法。 相似文献
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对0〈t〈1,引进了广义弱亚正规算子的概念,这类算子包含所有的弱亚正规算子。证出若T是广义弱亚正规算子,则T的谱半径与它的范数相等,并证出广义弱亚正规算子的点谱与联合点谱,近似点谱与联合近似点谱的非零点分别相同。 相似文献
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构建了计算某类六阶微分方程带权特征值的近似值的算法。主要结果的证明基于变分原理。首先证明了三个引理；其次采用Galerkin方法来构造适当的基函数，利用Cauchy不等式给出了其特征值计算的误差估计式；最后得到计算某类六阶微分方程带权特征值的近似值的算法，而且可以用第n次近似值来估计第n-1次的近似值的精确度。只要适当选取n，就可以求得所要精确度的特征值的近似值，这个算法具有广泛的实用价值和理论价值。 相似文献
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Brian D. Ray 《科学教学研究杂志》1991,28(2):147-161
Data were collected from students in grades three to eight (N = 377) in order to identify the determinants of their intentions to perform laboratory and nonlaboratory science activities. Fishbein and Ajzen's theory of reasoned action was used as the basis for the study. The theory posits that the immediate determinant of behavior is intention. Intention is determined by the weighted attitude toward the behavior and the weighted subjective norm. Attitude toward behavior and subjective norm are determined by combinations of beliefs, evaluations, and motivations to comply. Cores of salient beliefs related to attitude toward laboratory and nonlaboratory behaviors and cores of salient beliefs related to subjective norm for laboratory and nonlaboratory behaviors were identified. Hypotheses generated from the theory were confirmed. Attitude toward behavior and subjective norm explained significant amounts of variance in behavioral intention for both laboratory and nonlaboratory behaviors. Attitude toward behavior had a greater relative weight than subjective norm for both laboratory and nonlaboratory. The correlations between adjacent constructs in the theoretical model were significant in all cases. 相似文献
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田卫军 《咸阳师范学院学报》2006,21(6):8-11,30
用非协调有限元方法进行定常Navier-Stokes方程的求解,证明了解的稳定性问题,对揭示逼近解的变化规律有重要意义,为数值求解定常Navier-Stokes方程提供了新的思路。 相似文献
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刻划了定义在[0,1]上的非负函数φ,使加权Hardy Littlewood平均算子Uφ:f→∫10f(t·)φ(t)dt在齐次Herz空间中有界,并估计了Uφ相应的算子范数. 相似文献
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手写体数字识别系统中一种新的特征提取方案 总被引：1，自引：0，他引：1
针对数字笔画简单的特点,参考汉字的基本笔画定义,给出了环笔画等五种笔画的定义,并由此提出了一种将五种笔画特征值和环的数目一起作为神经网络特征输入的新的特征提取方案,达到用比较少的特征量取得理想识别效果的目的. 相似文献
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The relation between composition operators on the Dirichlet spaces in the open unit disk and derivative weighted composition operators on the Bergman spaces in the open unit disk is investigated firstly,and for a combination of several derivative weighted composition operators which acts on classic Bergman space,the lower bound of its essential norm is estimated in terms of the boundary data of the symbols of d-composition operators.Some similar results about composition operators on the Dirichlet space are also presented.A necessary condition is given to determine the compactness of the combination of several derivative weighted composition operators on Bergman spaces. 相似文献
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An approximate method for predicting the stationary response of stochastically excited nonlinear systems with continuous-time Markov jump is proposed. By using the stochastic averaging method, the original system is reduced to one governed by a 1D averaged Itô equation for the total energy with the Markov jump process as parameter. A Fokker-Planck- Kolmogorov (FPK) equation is then deduced, from which the approximate stationary probability density of the response of the original system is obtained for different jump rules. To illustrate the effectiveness of the proposed method, a stochastically excited Markov jump Duffing system is worked out in detail. 相似文献