A class B of complex functions is introduced and several existence theorems of unique(common) fixed points for mappings satisfying a B-implicit contraction are presented.Moreover, the existence results of common fixed...A class B of complex functions is introduced and several existence theorems of unique(common) fixed points for mappings satisfying a B-implicit contraction are presented.Moreover, the existence results of common fixed points for two mappings on a nonempty set with two complex valued metrics are provided. Our outcomes generalize and improve some known results, especially, for instance, Banach contraction principle, Chatterjea-type fixed point theorem and the corresponding fixed point theorems.展开更多
为使隐式曲线能够更好地拟合散乱数据点及其几何特征,提出一种带法向约束的隐式曲线重构渐进迭代(progressive and iterative approximation,PIA)方法.首先,基于隐式B样条函数提出有效的曲线拟合模型;其次,通过加入偏移数据点来消除额...为使隐式曲线能够更好地拟合散乱数据点及其几何特征,提出一种带法向约束的隐式曲线重构渐进迭代(progressive and iterative approximation,PIA)方法.首先,基于隐式B样条函数提出有效的曲线拟合模型;其次,通过加入偏移数据点来消除额外零水平集,同时加入法向项来控制曲线的法向误差;最后,经多次优化迭代得到高精度的拟合曲线.在配置为2.6 GHz英特尔处理器,内存为16 GB的电脑上采用MATLAB实现编程.经多条不同形态封闭曲线拟合的实验结果表明,与隐式PIA(implicit PIA,I-PIA)方法和T样条曲线重构方法相比,从数据点精度和法向误差以及收敛速度3个评价指标进行评估,该方法能够在保证数据点精度的前提下,有效地降低法向误差,并具有更快的收敛速度.此外,实例结果也表明该方法具备鲁棒性.展开更多
分子动力学模拟是研究包括RNA在内的生物大分子结构和功能的重要方法,但常规的显式溶剂模拟耗时较长,影响了其进一步应用。隐式溶剂模型通过用连续模型代替溶剂分子,能大大加速模拟速度,因此提高模拟效率。然而,现有的隐式溶剂模型都不...分子动力学模拟是研究包括RNA在内的生物大分子结构和功能的重要方法,但常规的显式溶剂模拟耗时较长,影响了其进一步应用。隐式溶剂模型通过用连续模型代替溶剂分子,能大大加速模拟速度,因此提高模拟效率。然而,现有的隐式溶剂模型都不能很好地描述核酸分子,尤其是RNA。在之前的研究中(已接收),我们提出了一个新的隐式溶剂模型,并分别测试了A型RNA双螺旋、28S r RNA和t RNA等多个系统,验证了该模型可以更好地计算隐式溶剂下的静电相互作用。由于上述系统均以稳定的结构作为起始,因此没有采集到大的构象变化。在本文中,我们将采用B型RNA双螺旋(B-RNA)作为测试系统来验证该模型是否能正确地采集到大尺度的构象转变过程。初步结果表明,在我们的模型下,B-RNA不仅能够正确地采集A型RNA双链构象,而且其搜索速度也比相应的显式模型快。展开更多
This study focuses on the transient analysis of nonlinear dispersion of a polymeric pollutant ejected by an external source into a laminar pipe flow of a Newtonian liquid under axi-symmetric conditions.The influence o...This study focuses on the transient analysis of nonlinear dispersion of a polymeric pollutant ejected by an external source into a laminar pipe flow of a Newtonian liquid under axi-symmetric conditions.The influence of density variation with pollutant concentration is approximated according to the Boussinesq approximation and the nonlinear governing equations of momentum,pollutant concentration are obtained together with and Oldroyd-B constitutive model for the polymer stress.The problem is solved numerically using a semi-implicit finite difference method.Solutions are presented in graphical form for various parameter values and given in terms of fluid velocity,pollutant concentration,polymer stress components,skin friction and wall mass transfer rate.The model can be a useful tool in understanding the dynamics of industrial pollution situations arising from improper discharge of hydrocarbon pollutants into,say,water bodies.The model can also be quite useful for available necessary early warning methods for detecting or predicting the scale of pollution and hence help mitigate related damage downstream by earlier instituting relevant decontamination measures.展开更多
文摘A class B of complex functions is introduced and several existence theorems of unique(common) fixed points for mappings satisfying a B-implicit contraction are presented.Moreover, the existence results of common fixed points for two mappings on a nonempty set with two complex valued metrics are provided. Our outcomes generalize and improve some known results, especially, for instance, Banach contraction principle, Chatterjea-type fixed point theorem and the corresponding fixed point theorems.
文摘分子动力学模拟是研究包括RNA在内的生物大分子结构和功能的重要方法,但常规的显式溶剂模拟耗时较长,影响了其进一步应用。隐式溶剂模型通过用连续模型代替溶剂分子,能大大加速模拟速度,因此提高模拟效率。然而,现有的隐式溶剂模型都不能很好地描述核酸分子,尤其是RNA。在之前的研究中(已接收),我们提出了一个新的隐式溶剂模型,并分别测试了A型RNA双螺旋、28S r RNA和t RNA等多个系统,验证了该模型可以更好地计算隐式溶剂下的静电相互作用。由于上述系统均以稳定的结构作为起始,因此没有采集到大的构象变化。在本文中,我们将采用B型RNA双螺旋(B-RNA)作为测试系统来验证该模型是否能正确地采集到大尺度的构象转变过程。初步结果表明,在我们的模型下,B-RNA不仅能够正确地采集A型RNA双链构象,而且其搜索速度也比相应的显式模型快。
文摘This study focuses on the transient analysis of nonlinear dispersion of a polymeric pollutant ejected by an external source into a laminar pipe flow of a Newtonian liquid under axi-symmetric conditions.The influence of density variation with pollutant concentration is approximated according to the Boussinesq approximation and the nonlinear governing equations of momentum,pollutant concentration are obtained together with and Oldroyd-B constitutive model for the polymer stress.The problem is solved numerically using a semi-implicit finite difference method.Solutions are presented in graphical form for various parameter values and given in terms of fluid velocity,pollutant concentration,polymer stress components,skin friction and wall mass transfer rate.The model can be a useful tool in understanding the dynamics of industrial pollution situations arising from improper discharge of hydrocarbon pollutants into,say,water bodies.The model can also be quite useful for available necessary early warning methods for detecting or predicting the scale of pollution and hence help mitigate related damage downstream by earlier instituting relevant decontamination measures.
