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ZnO nanostructures are widely used for detecting hydrogen at atmospheric pressure by measuring variation in resistance. However, low-pressure gas sensing using ZnO is still underdeveloped due to the weak resistance effect. Herein, we report a low-pressure hydrogen sensing method based on the field emission of defect-controlled ZnO nanorods in a wide pressure range from 10−3 to 10−7 Pa. The investigation reveals that while hydrogen atoms adsorb on the site of the oxygen defect, the field emission of ZnO could increase with the reduction of the effective work function (WF) of ZnO, leading to improved hydrogen sensing performance. Conversely, the effective WF of ZnO will increase with hydrogen adsorption on the site of the zinc defect. In addition, the sensing performance could be enhanced with increasing contents of oxygen defects. This study not only provides insight into the low-pressure hydrogen sensing mechanism from the field emission of ZnO but also expands the understanding of the electronic properties of the ZnO nanomaterial with various defects and under different annealing conditions. [ABSTRACT FROM AUTHOR]

We investigate the existence and blow-up profile of normalized solutions to the fractional nonlinear Schrödinger equation$ \begin{align} \begin{cases} (-\Delta)^su+V(x)u+\lambda u = |u|^{\frac{4s}{N}}u, \ \text{in}\ \mathbb{R}^N, \\ \int_{\mathbb{R}^N}|u|^2\mathrm{d}x = \alpha, \end{cases} \end{align} $with $ N\ge 2, s\in(0, 1), \alpha>0 $, $ \lambda\in\mathbb{R} $, and negative potentials $ V(x) $. Firstly, we prove the existence and nonexistence of normalized solutions for negative potentials $ V\in L^p(\mathbb{R}^N)+L^{q}(\mathbb{R}^N) $ with $ \frac{N}{2s}\le p

This paper adopted numerical simulation based on the MD method to research the effect of different shear rates and wax contents on wax deposition focused on crude oil. The findings indicated that under shear flow conditions, there were primarily four steps during deposition. Diffusion was the initial stage when wax diffused onto the metal surface. In the second stage, wax adsorbed onto a metal surface aligned itself parallel to the surface via Brownian motion, generating two different kinds of deposits. Subsequently, agglomerates were formed between the adsorbed deposits and the wax as a result of molecular interactions and bridging effects. Furthermore, the second and third deposited layers gradually showed peeling off and sliding under shear force. The wax deposition process was comparable for crude oil systems with varying shear rates and wax concentrations, and the deposited layer's thickness on the metal surface was constant. The first, second, and third deposits were mainly adsorbed at 0.122 nm, 0.532 nm, and 1.004 nm away from the Fe surface, and the interaction energy between crude oil molecules and the Fe surface was mainly vdW force. The contact between Fe and wax progressively increased as the shear rate and wax content rose, promoting the wax adsorption on the metal surface and causing more of the wax to congregate in the deposited wax. The findings of the research can theoretically help a more thorough comprehension of the wax deposition. [ABSTRACT FROM AUTHOR]

In this paper, with the application of a MARS 60 high-pressure rheometer, experimental tests are conducted on Shengli crude oil to test its gel point, viscosity and thixotropy under different static pressures. Consequently, the effect of static pressure on the rheological parameters of waxy crude oil is revealed. It is proven that with the increase in the static pressure, the gel point of Shengli crude oil increases linearly, and the viscosity also gradually increases. The power law equation is employed to describe the relationship between the apparent viscosity and shear rate of Shengli crude oil under different static pressures. With the increase in the static pressure, the consistency coefficient (K) increases linearly, and the rheological index (n) decreases linearly. The relationship between the viscosity of Shengli crude oil and the static pressure and shear rate can be obtained. The Cross thixotropic model is used to describe the thixotropic curve of Shengli crude oil under different static pressures. With the increase in the static pressure, the thixotropic coefficient of consistency (ΔK) and the structure fracture constant (b) increase linearly. This is because a high pressure results in high structure strength and strong non-Newton rheological behavior in gelled crude oil and also causes remarkable structure fracture in crude oil. The results in this paper can provide an important theoretical basis for crude oil production and transportation. [ABSTRACT FROM AUTHOR]

Transmission line planning is affected by a variety of geographic information factors, and traditional path planning methods are difficult to meet the future intelligent planning needs. Here, based on the geographic information system platform for geographic information data processing, the triangular fuzzy number analytic hierarchy process (TFN‐AHP) is utilized for weight analysis to construct the cost layer. Meanwhile, guided mechanism, dimension‐reducing mechanism, and avoidance mechanism are proposed to improve the ant colony optimization (ACO) algorithm, to shorten the planning time and improve the route planning effect. Finally, a local area in Guizhou Province is selected for case study and compared with the results of traditional ant colony optimization, and the results prove the effectiveness of the transmission line planning model proposed here. [ABSTRACT FROM AUTHOR]