The importance of thermophoresis and its essential role in particle migration have led to many published reports (i.e. aim and objectives). However, there exists no report on thermo-migration of tiny/nano-sized particles in the motion of various fluids. A meta-analysis on the significance of either nano or tiny particles exposed to thermophoretic force owing to temperature gradient during the dynamics of liquid substances is deliberated upon in this report. The method of slope linear regression through the data point was adopted to scrutinize sixty (60) published reports in which the effects of thermophoresis (thermodiffusion) is deliberated upon. The outcome of the study shows that different responses to the force of a temperature gradient are sufficient enough to enhance the temperature distribution and the concentration of non-Newtonian fluid due to an increase in thermophoresis. Thermophoretic effect increases the concentration of fluids in which the relationship between the shear stress and shear strain is non-linear. Skin friction coefficients is a decreasing function of thermophoresis. Increase in thermophoretic deposition is achievable due to an increase in thermophoresis. The effect of haphazard motion of nanoparticles should be investigated when it increases negligibly and considerably large. Thermal radiation strongly influences the significance of thermo-migration of tiny particles on fluid flow. 相似文献
Acta Mathematicae Applicatae Sinica, English Series - This paper considers a competing risks model for right-censored and length-biased survival data from prevalent sampling. We propose a... 相似文献
Red phosphorus is a promising photocatalyst with wide visible-light absorption up to 700 nm, but the fast charge recombination limits its photocatalytic hydrogen evolution reaction (HER) activity. Now, [001]-oriented Hittorf's phosphorus (HP) nanorods were successfully grown on polymeric carbon nitride (PCN) by a chemical vapor deposition strategy. Compared with the bare PCN and HP, the optimized PCN@HP hybrid exhibited a significantly enhanced photocatalytic activity, with HER rates reaching 33.2 and 17.5 μmol h−1 from pure water under simulated solar light and visible light irradiation, respectively. It was theoretically and experimentally indicated that the strong electronic coupling between PCN and [001]-oriented HP nanorods gave rise to the enhanced visible light absorption and the greatly accelerated photoinduced electron–hole separation and transfer, which benefited the photocatalytic HER performance. 相似文献
Chinese Journal of Polymer Science - The aligned molecular packing structure is vital to the anisotropic charge transport in conjugated polymer and small molecule thin films. However, how this... 相似文献
Recently,the memory elements-based circuits have been addressed frequently in the nonlinear circuit theory due to their unique behaviors.Thus,the modeling and characterizing of the mem-elements become essential.In this paper,the analysis of the multiple fractional-order voltage-controlled memcapacitors model in parallel connection is studied.Firstly,two fractional-order memcapacitors are connected in parallel,the equivalent model is derived,and the characteristic of the equivalent memcapacitor is analyzed in positive or negative connection.Then a new understanding manner according to different rate factor K and fractional orderαis derived to explain the equivalent modeling structure conveniently.Additionally,the negative order appears,which is a consequence of the combination of memcapacitors in different directions.Meanwhile,the equivalent parallel memcapacitance has been drawn to determine that multiple fractional-order memcapacitors could be calculated as one composite memcapacitor.Thus,an arbitrary fractional-order equivalent memcapacitor could be constructed by multiple fractional-order memcapacitors. 相似文献
Aharoni and Howard and, independently, Huang et al. (2012) proposed the following rainbow version of the Erdős matching conjecture: For positive integers n, k and m with n ⩾ km, if each of the families \(F_{1},\ldots,F_{m}\subseteq\left(\begin{array}{c}[n]\\ k\end{array}\right)\) has size more than \(\max\{\left(\begin{array}{c}n\\ k\end{array}\right)-\left(\begin{array}{c}n-m+1\\ k\end{array}\right),\left(\begin{array}{c}km-1\\ k\end{array}\right)\}\), then there exist pairwise disjoint subsets e1,…,em such that ei ∈ Fi for all i ∈ [m]. We prove that there exists an absolute constant n0 such that this rainbow version holds for k = 3 and n ⩾ n0. We convert this rainbow matching problem to a matching problem on a special hypergraph H. We then combine several existing techniques on matchings in uniform hypergraphs: Find an absorbing matching M in H; use a randomization process of Alon et al. (2012) to find an almost regular subgraph of H − V(M); find an almost perfect matching in H − V(M). To complete the process, we also need to prove a new result on matchings in 3-uniform hypergraphs, which can be viewed as a stability version of a result of Łuczak and Mieczkowska (2014) and might be of independent interest.
A large variety of reduced titanium dioxide (TiO2-x) materials have been reported recently. Reduced TiO2, usually resulting from the removal of oxygen atoms or hydrogen incorporation, is proved to be efficient for achieving highly photocatalytic performance including photodegradation of organic compounds, hydrogen generation from water splitting, CO2 reduction for CH4 evolution, solar cells, etc. To further improve the properties and activities of TiO2-x, a combination of the Ti3+ self-doping and other traditional modifications like nonmetals doping has been proposed in the past decades. This paper provides a general and critical review on the further modifications on reduced TiO2 samples, including non-metal elements (N, B, S, F and I) doping, noble-metal (Au, Pt, Pd and Ag) and iron-group metal (Fe, Co and Ni) grafting, metal oxide compositing, carbon (nanotubes and graphene) and carbon-based-material compositing, special facets exposure (mainly dual {001}-{101} and {111}-{110} facets) of TiO2-x and ordered structure controlling of TiO2-x. These modifications enhance the physical and/or chemical properties of the reduced TiO2, or create new features for the modified TiO2-x samples, which finally leads to the enhancement of photocatalytic performance. Key examples such as N-doping, Au grafting and graphene-based compositing are discussed carefully, and the mechanisms for solar light enhancement, electron transfer and charge separation are also investigated. Finally, some challenging issues on TiO2-x catalysts are also proposed to encourage new approaches for preparation of TiO2-x catalysts with efficiently photocatalytic performance. 相似文献