Composite power law holdup correlations in horizontal pipes

A wide range of experimental holdup data, from different sources, are analyzed based on a theoretical model proposed in this work to evaluate the holdup in horizontal pipes. 2276 gas–liquid flow experiments in horizontal pipelines with a wide range of operational conditions and fluid properties are included in the database. The experiments are classified by mixture Reynolds number ranges and composite analytical expressions for the relationship between the liquid holdup and no-slip liquid holdup vs. the gas–liquid volumetric flow rate are obtained by fitting the data with logistic dose curves. The Reynolds number appropriate to classify the experimental data for gas–liquid flows in horizontal pipes is based on the mixture velocity and the liquid kinematic viscosity. Composite power law holdup correlations for flows sorted by flow pattern are also obtained. Error estimates for the predicted vs. measured holdup correlations together with standard deviation for each correlation are presented. The accuracy of the correlations developed in this study is compared with the accuracy of 26 previous correlations and models in the literature. Our correlations predict the liquid holdup in horizontal pipes with much greater accuracy than those presented by previous authors.     

软管流量调节器调节特性分析及设计准则

分析了大雷诺数下软管的流量调节行为；导出了流量随下游压力的函数关系，即流量调节特性曲线；提出了以软管作为能动元件的流量调节器设计准则．     

Power‐to‐Gas

The power‐to‐gas concept is a promising technology to chemically store energy and therefore a feasible approach to mitigate the challenges of energy transition. Heterogeneous catalysis plays a crucial role in CO₂ conversion to methane using nickel based catalysts. A thorough catalyst characterization facilitates the synthesis of optimized catalyst systems. The determination of reaction kinetics is fundamental for industrial reactor design.     

吡啶-2-甲醛肟钛氧簇合物的合成、结构调控及光电性质

通过溶剂热合成方法,以吡啶-2-甲醛肟（HPycox）和Ti（OⁱPr）₄合成了双核钛配合物[Ti₂（μ₂-O）（Pycox）₂（OⁱPr）₄] （1）。通过结构分析,分别使用二苯基膦酸和苯基膦酸对其进行结构调控,成功制备了三核钛配合物[Ti₃（μ₂-O）₂（Pycox）₂（Ph₂PO₂）₂（OⁱPr）₄] （2）和六核钛配合物[Ti₆（μ₂-O）₂（μ₃-O）₂（Pycox）₂（PhPO₃）₄（OⁱPr）₆]·2CH₃CN （3）。配合物1~3的光学带隙分别为2.89、3.00和2.87 eV,其中配合物2的光电流密度可达0.1 μA·cm^-2。     

线型和非线型分子转动光谱强度的统计模型

In this study, we found regular behavior, from a statistical point of view, in the intensities of rotational spectra for several organic and inorganic molecules at room temperature. Non-linear molecules, for which a common intensity behavior was derived, were especially interesting. We provided theoretical support for the obtained results based on the Boltzmann distribution. Boltzmann power laws were used to reproduce the statistical behavior of the intensities from the spectra of linear and non-linear molecules. We only used statistical arguments and no specific details of any molecule were used. Therefore, these results are applicable to a large class of atoms and molecules and the model is valid when considering similar conditions to those used in this study.     

Impact of lipid substitution on assembly and delivery of siRNA by cationic polymers

Characterization of a polymer library engineered to enhance their ability to protect and deliver their nucleotide cargo to the cells is reported. The ζ-potential continuously increased with higher polymer:siRNA weight ratio, and the ζ-potential of lipid-modified polymers:siRNA complexes were higher than PEI2 at all ratios. At polymer:siRNA ratio of 1:1, all lipid-substituted polymers showed complete protection against degradation. Lipid-modified polymers significantly increased the cellular uptake of siRNA complexes and down-regulation of GAPDH and P-gp (max. 66% and 67%, respectively). The results indicate that hydrophobic modification of low molecular PEI could render this otherwise ineffective polymer to a safe effective delivery system for intracellular siRNA delivery and protein silencing.     

Power law fluid model for blood flow through a tapered artery with a stenosis

In the present paper, blood flow through a tapered artery with a stenosis is analyzed, assuming the flow is steady and blood is treated as non-Newtonian power law fluid model. Exact solution has been evaluated for velocity, resistance impedance, wall shear stress and shearing stress at the stenosis throat. The graphical results of different types of tapered arteries (i.e. converging tapering, diverging tapering, non-tapered artery) have been examined for different parameters of interest. Some special cases of the problem are also presented.     

输出调节问题综述

对非线性输出调节问题的研究现状进行了概述,其中特别强调了非线性内模原理的建立以及它在为处理非线性输出调节问题的一般研究框架形成中所起到的作用.     

幂格的同余关系

研究分配格的幂格的同余关系,给出幂格的同余关系格的一些重要性质,并得到幂格的一个同余类和同余关系格的两个交半格。