1,166 research outputs found
A library of ab initio Raman spectra for automated identification of 2D materials
Raman spectroscopy is frequently used to identify composition, structure and
layer thickness of 2D materials. Here, we describe an efficient
first-principles workflow for calculating resonant first-order Raman spectra of
solids within third-order perturbation theory employing a localized atomic
orbital basis set. The method is used to obtain the Raman spectra of 733
different monolayers selected from the computational 2D materials database
(C2DB). We benchmark the computational scheme against available experimental
data for 15 known monolayers. Furthermore, we propose an automatic procedure
for identifying a material based on an input experimental Raman spectrum and
illustrate it for the cases of MoS (H-phase) and WTe
(T-phase). The Raman spectra of all materials at different excitation
frequencies and polarization configurations are freely available from the C2DB.
Our comprehensive and easily accessible library of \textit{ab initio} Raman
spectra should be valuable for both theoreticians and experimentalists in the
field of 2D materialsComment: 17 pages, 7 figure
Expression levels of vascular endothelial growth factors A and C in patients with peptic ulcers and gastric cancer
Purpose: Vascular endothelial growth factor (VEGF) is one of the most important growth factors for metastatic tumors. To clarify the role of VEGF-A and C in patients with peptic ulcer disease (PUD) or gastric cancer (GC), we evaluated the expression levels of these two molecules. We also analyzed the effect of Helicobacter pylori infection on VEGF-A and C expression levels
The First Integral Method to Nonlinear Partial Differential Equations
In this paper, we show the applicability of the first integral method for obtaining exact solutions of some nonlinear partial differential equations. By using this method, we found some exact solutions of the Landau-Ginburg-Higgs equation and generalized form of the nonlinear Schrödinger equation and approximate long water wave equations. The first integral method is a direct algebraic method for obtaining exact solutions of nonlinear partial differential equations. This method can be applied to nonintegrable equations as well as to integrable ones. This method is based on the theory of commutative algebra
Effect of Different Levels of Lavandula Stoechas Essence on Production Performance and Egg Quality of Laying Hens
The objective of this study was to evaluate the effects of different levels of Lavander stoechas essence on performance and egg quality of laying hens for 8 weeks. This experiment was conducted with 160 Hy-Line (W36) laying hens (30 wks of age), randomly divided into 4 experimental groups, 5 replicates and 8 birds per each (2 cages for each replicate and 4 birds in each cage). Treatments were control (without Lavander essence), and levels of 200, 400, and 600 ppm Lavander essence. All hens were provided the layer diets (2870 kcal/kg ME and 15.5 % CP) ad- libitum and received 16 h of light/ 8 h of dark. Performance parameters including egg weight and egg production were recorded daily and feed intake, feed conversion ratio (grams of feed:grams of egg) and egg quality were measured weekly. The following characteristics were recorded for the individual eggs: weight, shape index, eggshell breaking strength, shell thickness, yolk color, and Haugh unit. Levels of 200 and 400 ppm of Lavander essence showed a significant increase in production percentage and egg weight but these parameters decreased at level of 600 ppm. Feed intake was highest for control, 200 and 400 ppm essence dietary levels but level of 600 ppm showed significant decrease. Addition of essence to the diet had no effect on FCR. Shape index and Haugh unit were not significantly affected by the treatments. Higher yolk color score was observed in treatments containing Lavander essence in comparison with control (p<0.05). Levels of 200 and 400 ppm essence increased significantly egg shell quality including thickness, weight and shell breaking strength. The results showed that the addition of essences of Lavender up to 400 ppm increased production performance and improved egg quality
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