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991.
Limeng XIA 《Frontiers of Mathematics in China》2020,15(3):593
For all generic , when g is not of type A1; we prove that the quantum toroidal algebra Uq(gtor) has no nontrivial finite dimensional simple module. 相似文献
992.
《Numerical Methods for Partial Differential Equations》2018,34(2):385-400
A conservative two‐grid finite element scheme is presented for the two‐dimensional nonlinear Schrödinger equation. One Newton iteration is applied on the fine grid to linearize the fully discrete problem using the coarse‐grid solution as the initial guess. Moreover, error estimates are conducted for the two‐grid method. It is shown that the coarse space can be extremely coarse, with no loss in the order of accuracy, and still achieve the asymptotically optimal approximation as long as the mesh sizes satisfy in the two‐grid method. The numerical results show that this method is very effective. 相似文献
993.
重大灾害下应急物资储备决策是阻止突发灾难蔓延的有效手段之一。针对救灾信息具备不确定性与复杂性特点,构建基于区间二型梯形模糊集的应急物资储备动态协同决策模型,并给出应急物资储备策略。利用区间二型模糊集理论的决策方案并结合比例分析法(COPRAS),构建常态环境下应急物资供应商选择的群决策模型,解决不相容群决策属性之间的冲突问题;进而,充分考虑“救灾阶段性动态时间因素”对储备决策的影响,构建动态救灾环境下应急物资储备结构模糊优化模型,实现常态决策与非常态应急决策之间的动态协同;最后,以2012年云南丽江“6.14”突发特大山洪灾害为实例进行数值分析,验证该动态协同决策模型的合理性与可行性,能有效解决动态救灾环境下应急物资储备结构优化问题。 相似文献
994.
In this paper, we apply the two‐step Newton method to solve inverse eigenvalue problems, including exact Newton, Newton‐like, and inexact Newton‐like versions. Our results show that both two‐step Newton and two‐step Newton‐like methods converge cubically, and the two‐step inexact Newton‐like method is super quadratically convergent. Numerical implementations demonstrate the effectiveness of new algorithms. 相似文献
995.
mRNA degradation plays an important role in gene regulation. However, a defect in mRNA decay is expected to result in an increase in mRNA levels. In this paper, we will first establish a model of mRNA regulation by two pathways denoted by $5''\rightarrow 3''$ and $3''\rightarrow 5''$ for short, where there are two degradation rates $\delta_1$, $\delta_2$ on $5''\rightarrow3''$ pathway and the degradation rate on $3''\rightarrow 5''$ pathway is $\delta_3$. The advantage of this model is that it captures fundamental biochemical reactions in the gene expression process in eukaryotic cells. Then we obtain several basic principles on the monotonicity of the mean level of newly accumulated mRNAs. It is proved that (1) the newly mean level is strictly increasing in $p$ and $\kp$, but is strictly decreasing in $\gm$, where $p, \kp$ and $ \gm$ are the initial activation frequency, the activation rate, and the inactivation rate, respectively; (2) the newly mean level is strictly decreasing in both $\delta_2$ and $\delta_3$, remarkably, is strictly increasing in $\delta_1$ when $\delta_2<\delta_3$ and decreasing when $\delta_2>\delta_3$ and; (3) the newly mean level is strictly increasing in time $t$ when $p<\kp/(\kp+\gm)$. These conclusions not only provide a better understanding on gene expression dynamics but also would be helpful to design reasonable gene expression modules. 相似文献
996.
研究广义Hilbert空间中几何凸函数的性质,给出一些重要定理,并运用几何凸函数的Jensen不等式建立了三重的双参数Hlder不等式和三重的多参数Minkowski不等式. 相似文献
997.
Pasquale Candito 《Rendiconti del Circolo Matematico di Palermo》2006,55(1):43-52
We use critical point theory to establish the existence of at least two solutions to a nonlinear Neumann problem involving
the one-dimensional p-Laplacian without assuming asymptotic conditions at infinity on the nonlinearity. 相似文献
998.
给出了一元函数y=f(x)在x0可导与二元函数f(x)-f(y)/x-y在(x0,x0)处极限存在等价的条件,并通过反例系统地研究了它们之间的关系,指出了文[1]的错误. 相似文献
999.
本文研究无穷凹角区域上一类各向异性问题的自然边界元与有限元耦合法.利用自然边界归化原理,获得圆弧或椭圆弧人工边界上的自然积分方程,给出了耦合的变分形式及其数值方法,以及逼近解的收敛性和误差估计,最后给出了数值例子,以示方法的可行性和有效性. 相似文献
1000.
The angles of a cutting tool play a key role in determining its cutting efficiency. However, once the tool has been mounted on a machine tool, setting errors inevitably cause the working angles of the tool to deviate slightly from the designed cutting angles. Accordingly, this study develops mathematical models to analyze the interrelationships among the tool angles, the setting angles and the working angles. In the proposed approach, a process of homogeneous coordinate transformation is employed to develop a kinematic model of the cutting tool such that the working angles can be derived given the tool angles and setting angles. Mathematical formulae are then developed to inversely derive the tool angles required to generate the specified working angles given prior knowledge of the setting angles. An illustrative numerical example is presented to demonstrate the validity of the proposed approach. Overall, the numerical results confirm that the methodology presented in this study provides a comprehensive, simple and versatile means of modeling a variety of conventional single-point cutting tools. 相似文献