The application of convergent beam electron diffraction (CBED) analysis on transformation‐induced plasticity (TRIP) steels

Convergent beam electron diffraction (CBED) in transmission electron microscopy (TEM) was applied to determine local carbon concentrations in low‐carbon transformation‐induced plasticity (TRIP) steels. High‐order Laue‐zone (HOLZ) lines were experimentally obtained for comparison with simulation results. A new procedure for calculating carbon content is thus proposed. Retained austenite (RA) is classified into three types by morphology; the relationship between the carbon content and the corresponding RA morphology is discussed based on CBED results. Furthermore, results of X‐Ray diffractometry measurements are also used for comparison.     

Rapid fabrication of organic/organic photonic bandgap films with tuneable mechanical properties using blended polymer spheres

In this study, the photonic bandgap (PBG) film with tunable mechanical properties and photonic stop band was prepared by a simple and feasible approach. Colloid polymer spheres with a relatively large diameter (approximate D_n of 200 nm) and different glass transition temperatures (T_g) were blended with small polystyrene (PS) latex (D_n = 20 nm) and were subsequently casted on a substrate for 3 h at 50°C for self‐assembly of the PBG film. The monodispersed polymer spheres were synthesized by soap‐free emulsion polymerization in the boiling state. The T_g values of the spheres were predetermined based on the Fox equation, and designed to fall in the region of ?34°C to 112°C. Small PS could also be synthesized by this approach using the comonomer, sodium p‐styrenesulfonate (NaSS), to ensure the small diameter. The long‐range ordered structure constructed by embedding the small PS in the PBG film was indirectly confirmed on the basis of SEM analysis, from which the monochromatic film color was determined based on Bragg's diffraction law. Tunable film color was achieved by adjusting the diameter of the spheres, as evaluated using UV–Vis. Tunable mechanical properties of the PBG film were also achieved by varying the T_g of the spheres or the filling ratio of small PS. Based on these approaches, the ultimate tensile strength could be tuned in the region between 0.39 to 4.7 Mpa, and the relative strain could be varied from 1236% to 16%, illustrative of the excellent deformability of the film. Furthermore, by variation of these two parameters, the film properties could be changed from typical elastomer behavior to brittle plastic polymer type behavior, greatly extending the prospective application fields. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014 , 131, 40276.     

Detecting removed attributes in the cyber system for smart manufacturing

The Journal of Supercomputing - According to the concept of edge computing, some service and data should be moved from the centralized data server to the data source for enhancing the computational...     

Boron‐ and nitrogen‐doped penta‐graphene as a promising material for hydrogen storage: A computational study

We fulfill a comprehensive study based on density functional theory (DFT) computations to cast insight into the dissociation mechanism of hydrogen molecule on pristine, B‐, and N‐doped penta‐graphene. The doping effect has been also illustrated by varying the concentration of dopant from 4.2 at% (one doping atom in 24 host atoms) to 8.3 at% (two doping atoms in 24 host atoms) and by contemplating different doping sites. Our theoretical investigation shows that the adsorption energy of H₂ molecule and H atom on the substrate can be substantially enhanced by incorporating boron or nitrogen into penta‐graphene sheet. The B‐ and N‐doped penta‐graphene can effectively decompose H₂ molecule into two H atoms. Our results demonstrate that activation energies for H₂ dissociation and H diffusion on the B‐ and N‐doped penta‐graphene are much smaller than the pristine penta‐graphene. Further investigation of increasing concentration dopants of the penta‐graphene sheet gives sufficiently low activation barrier for H₂ dissociation process. This investigation reveals that the boron and nitrogen dopants can act as effective active site for H₂ dissociation and storage.     

Effect of [6,6]‐phenyl‐C61‐butyric acid methyl ester on the morphology of poly(3‐hexylthiophene) film

The change of morphology of poly(3‐hexylthiophene) (P3HT) film as a result of blending with [6,6]‐phenyl‐C₆₁‐butyric acid methyl ester (PCBM) was studied using a freeze‐dry method. A porous structure was observed as the P3HT/PCBM solution was freeze‐dried. The pore size decreased as the proportion of PCBM increased in the P3HT/PCBM blended film. Additionally, the freeze‐dried P3HT/PCBM film was more resistant to the formation of PCBM crystals than that prepared by a spin‐coating method during the thermal annealing process. Homogeneous distribution of PCBM in the freeze‐dried P3HT/PCBM film was the main reason for the reduction of large PCBM crystal formation. Copyright © 2011 Society of Chemical Industry     

A two‐parameter quasi‐linear model for gauged river basins

Abstract

Two rainfall intensity dependent parameters are incorporated into a quasi‐linear representation of the outflow to analyze the hydro‐logic response problems of a gauged river basin.

The model is employed to generate the unit hydrographs of a (non‐linear) small basin due to different rainfall inputs, to exhibit the storage‐discharge relation in a medium basin due to a single storm event, and to synthesize the rainfall‐runoff process in two large river basins due to storm events at different times. In all three cases, the analytical results from the model compare nicely with the experimental observations.     

Decomposition of singular large sparse matrix by adding dummy links and dummy degrees

Abstract

This paper proposes a simple scheme to decompose an n×n nonpositive definite matrix, A, associated with simultaneous equations, A X = B, into a triple‐factors (lower triangular, diagonal, and upper triangular matrices), i.e., Å = L D U, without interchanging rows or columns of A, but with A expanded with new rows and new columns to an m×m matrix Å. Whenever a near‐zero diagonal element, say ā_ii , is encountered and used as a pivoting element, an appropriate positive real number, say p, is added to this diagonal element, and a new term —px_k is also added to the i‐th equation, where x_k is a new variable called “dummy variable'’. If we also add a new equation —px_i + px_k = 0 to enforce the new added variable x_k equal to x_i then the modified i‐th equation has the same effect as the original equation. Therefore, the original solution X can be found directly from the expanded solution of the modified expanded equation. The method is very useful in solving the following problems: (1) nonlinear problems near the limit state, (2) postbuckling analysis, (3) system equations with constraint conditions, and (4) getting eigenvectors from eigenvalues.