共查询到19条相似文献,搜索用时 125 毫秒
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研究了一类非线性奇摄动方程的激波问题.利用间接匹配法,构造出激波在区间内的激波解.
关键词:
非线性方程
激波
间接匹配 相似文献
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计算原子吸收法间接测定钒 总被引:5,自引:0,他引:5
本文研究了用空气-乙炔火焰原子吸收法间接测定钒一种计算分析方法,利用钒对原子吸收法测定铬时的干扰效应,以多项式作为表面其干扰效应的数学模型,在已知铬含量的铬钒混合液中测定铬的吸光度,并从数学模型中解出钒的浓度,从而间接测定了钒。 相似文献
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本文通过理论分析和数值模拟系统地研究了辐射热损失对球形火焰传播速度的影响。研究结果表明辐射热损失的影响分为直接影响和间接影响;直接影响指辐射热损失会降低火焰温度,从而降低火焰传播速度;间接影响指辐射热损失导致的冷却会引起逆向火焰传播的流动,从而降低火焰传播速度。对近可燃极限预混气体,直接影响起主导作用;对高辐射强度预混气体,间接影响起主导作用。本文研究的结果对球形火焰法测量火焰传播速度有着重要的指导意义。 相似文献
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分析了间接测量的不确定度教学中的不足,提出了不确定传递系数和传递分量的概念,使间接测量的不确定度评定系统化。 相似文献
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对实验数据处理中经常遇到的线性参数估计和作为间接测量量计算的问题进行了分析、比较。指出最小二乘参数不确定度不同时应该使用不同的对应公式,如果此情况下将参数作为间接测量量计算,往往更方便、简单。 相似文献
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The influences of specific heat capacity CP, temperature step △T, electric field step △ E, and initial electric field E1 on predicted electrocaloric (EC) temperature △ T of monodomain BaTiO3 are examined by combining the Maxwell equation and phenomenological theory. Since the procedure is similar to indirect measurement of the EC effect, the results can serve as a reference for experiments. The results suggest that (i) it is reasonable to use zero-field CP, (ii) optimized △ T should be 2 K, (iii) it is better to keep △ E<EC, and (iv) E1<EC. Here, EC is the coercive field of material. 相似文献
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采用间接比较法,就是利用已知的标准量作为参考,通过比较公式,来测量某未知量.该方法可使实验操作过程大为简化,不仅减少了测量量,且单位不必国际化,计算更简单,有效数字位数只由已知标准量来确定,从而提高了测量的精度,使比较公式的物理意义更加明确.该方法使学生的视野大为开阔,为很多的实验,提供了多选方案,为进一步拓展学生的思... 相似文献
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文章讨论间接测量的随机误差的计算。认为当各直接测量的测量次数不相同时,在随机误差的计算中应考虑测量次数对间接测量值的随机误差的影响。 相似文献
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Identifying influential nodes in complex networks has attracted the attention of many researchers in recent years. However, due to the high time complexity, methods based on global attributes have become unsuitable for large-scale complex networks. In addition, compared with methods considering only a single attribute, considering multiple attributes can enhance the performance of the method used. Therefore, this paper proposes a new multiple local attributes-weighted centrality (LWC) based on information entropy, combining degree and clustering coefficient; both one-step and two-step neighborhood information are considered for evaluating the influence of nodes and identifying influential nodes in complex networks. Firstly, the influence of a node in a complex network is divided into direct influence and indirect influence. The degree and clustering coefficient are selected as direct influence measures. Secondly, based on the two direct influence measures, we define two indirect influence measures: two-hop degree and two-hop clustering coefficient. Then, the information entropy is used to weight the above four influence measures, and the LWC of each node is obtained by calculating the weighted sum of these measures. Finally, all the nodes are ranked based on the value of the LWC, and the influential nodes can be identified. The proposed LWC method is applied to identify influential nodes in four real-world networks and is compared with five well-known methods. The experimental results demonstrate the good performance of the proposed method on discrimination capability and accuracy. 相似文献