Improving Dielectric Properties in Novel P(VDF‑HFP)/V2AlC MAX/Montmorillonite Composite Films via Interfacial Electric‑Leakage Depressing Strategy

Xiaofeng Xia,Junquan Zhou,Huimin Ding,Qin Li,Maolin Bo,Qihuang Deng,Yefeng Feng 대한금속·재료학회 2021 ELECTRONIC MATERIALS LETTERS Vol.17 No.1

Dielectric constants of polymer/conductor composites are often high, owing to strong interface interaction in those composites. They can be used for dielectric energy storage, but they usually have high dielectric loss and conductivity. In order toreduce the dielectric loss and conductivity in poly(vinylidene fluoride-hexafluoropropylene) (P(VDF-HFP))/V2AlC MAXcomposites, in this study, we explored the novel P(VDF-HFP)/V2AlC MAX/montmorillonite (MMT) ternary composites. Compared with binary composites, the ternary composites showed the mildly reduced dielectric constant, significantlydecreased dielectric loss and conductivity. Using highly-conductive V2AlCMAX filler aimed at taking advantage of thepolymer/MAX interface polarization to increase the dielectric response of composites. Employing well-insulating MMTfiller aimed at reducing the interface electric leakage conduction. At 1 kHz, the outstanding ternary composite with 2 wt%MMT and 20 wt% MAX could exhibit a high dielectric constant of ca. 27 and low dielectric loss of ca. 0.21. This workmight offer a new research idea for the construction of high-performance composite dielectric films containing modernMAX ceramic fillers.

Realizing Rationally-Balanced Dielectric Properties in Fluoropolymer/Cr2AlC MAX Composites Modified by 2D-BN

Qin Li,Junquan Zhou,Yanhui Chen,Xiaofeng Xia,Maolin Bo,Qihuang Deng,Yefeng Feng 한국고분자학회 2020 Macromolecular Research Vol.28 No.13

Polymer/conductor composite dielectric materials have a high dielectric constant. In recent years, composite dielectrics have become a study hotspot in highdensity energy storage capacitors. However, high dielectric loss and high electrical conductivity make the application of the composite materials very limited. In order to obtain composite materials with high dielectric constant, low dielectric loss and low conductivity, we added the insulating boron nitride (BN) filler into polymer/Cr2AlC composites. As a conductive filler, Cr2AlC ternary-layered-compound (MAX) ceramic has an interface polarization with the polymer matrix, thereby increasing the dielectric constant of the composites. The insulating BN has a very low electrical conductivity, which can effectively reduce the electrical conductivity and dielectric loss of the composites. Compared with the binary polymer/Cr2AlC composite materials, the ternary polymer/Cr2AlC/BN composite materials can achieve the low dielectric loss and low conductivity as well as properly-lowered dielectric constant. The ternary composite material filled with 10 wt% Cr2AlC and 2 wt% BN has a dielectric constant of about 30, a dielectric loss of about 0.7 and a conductivity of about 4.6×10- 7 S m-1 at 100 Hz. In this work, high-performance composite dielectrics were prepared through good cooperation between conductive and insulating ceramic fillers, which might provide an idea for design of promising energy storage capacitors.

Drying features of microwave and far-infrared combination drying on white ginseng slices

Xiaofeng Ning,Yulong Feng,Yuan Juan Gong,Yong Liang Chen,Junwei Qin,Danyang Wang 한국식품과학회 2019 Food Science and Biotechnology Vol.28 No.4

In this study microwave and far-infrared combinationdrying were conducted to investigate the effect ofmicrowave and far-infrared heating mode switching pointwater content (SW), ginseng slice thickness, and far-infrareddrying temperature on drying indicators (surfacecolour difference, ginsenosides content, and surfaceshrinkage rate) and drying efficiency (drying time) duringthe process of drying white ginseng slices. Regardingmicrowave drying, the microwave drying time cannotexceed 150 s, and the ginseng slice water content cannot beless 50%. For the combination drying, SW, far-infrareddrying temperature and slice thickness increased, the colourdifference and surface shrinkage rate first decreasedand then increased, and the content of ginsenosides firstincreased and then decreased. In addition, the combinationdrying showed faster drying rate, higher ginsenosidescontents value, colour difference (DE) value and lowersurface shrinkage rate than single far-infrared drying.

Domain Adaptation Image Classification Based on Multi-sparse Representation

( Xu Zhang ),( Xiaofeng Wang ),( Yue Du ),( Xiaoyan Qin ) 한국인터넷정보학회 2017 KSII Transactions on Internet and Information Syst Vol.11 No.5

Generally, research of classical image classification algorithms assume that training data and testing data are derived from the same domain with the same distribution. Unfortunately, in practical applications, this assumption is rarely met. Aiming at the problem, a domain adaption image classification approach based on multi-sparse representation is proposed in this paper. The existences of intermediate domains are hypothesized between the source and target domains. And each intermediate subspace is modeled through online dictionary learning with target data updating. On the one hand, the reconstruction error of the target data is guaranteed, on the other, the transition from the source domain to the target domain is as smooth as possible. An augmented feature representation produced by invariant sparse codes across the source, intermediate and target domain dictionaries is employed for across domain recognition. Experimental results verify the effectiveness of the proposed algorithm.

Study on the plane induction heating process strengthened by magnetic flux concentrator based on response surface methodology

Feng Li,Xuekun Li,Xiaofeng Qin,Yiming(Kevin) Rong 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.5

In the surface heat treatment process of metals, the induction heating strengthened by ferromagnetic metal powder bonded magnetic flux concentrator (MPB-MFC) possesses more advantages due to its high efficiency. However, the further research of strengthen mechanism of MPB-MFC is still needed. It is necessary to establish the analytical model for accurately control and optimization of the plane induction heating process with MPB-MFC. In this paper, the coupled electro-magnetic-thermal multi-physics FEM model of the MPBMFC assisted induction heating is established, which involves the consideration of the temperature dependent thermal and magnetic material properties. The comparison between the results of several middle-frequency experiments and the simulation proves that the precision of simulation model is reliable. In addition, the influence of combined input variables on the final temperature is studied based on the response surface methodology (RSM), which could provide a comprehensive understanding for the process control and optimization in industrial production.

On the forced vibration of high-order functionally graded nanotubes under the rotation via intelligent modeling

Liu, Yang,Wang, Xiaofeng,Liu Li,Wu, Bin,Yang, Qin Techno-Press 2022 Advances in nano research Vol.13 No.1

The present research investigates the dynamic behavior of a rotating functionally graded (FG) nonlocal cylindrical beam. The cylindrical beam is mathematically modeled via third-order beam theory linked with nonlocal strain gradient theory. The tube structure is made of functionally graded materials composed of Aluminum oxide coated on the Nickel, which the mechanical properties vary in the tube radius direction according to the power law. The bending harmonic force is applied in the tube length middle. The nonlocal spinning equations of the tube are derived via the energy method of the Hamilton principle, and they are solved via a robust numerical procedure for different boundary conditions. The main application of the rotating nanostructures is for the production of small-scale motors and devices and the drug-delivery application, the presented results can help the researcher have a better view regarding the different conditions.

Microsatellite Markers Linked to Quantitative Trait Loci Affecting Fatness in Divergently Selected Chicken Lines for Abdominal Fat

Zhang, Hui,Wang, Shouzhi,Li, Hui,Yu, Xijiang,Li, Ning,Zhang, Qin,Liu, Xiaofeng,Wang, Qigui,Hu, Xiaoxiang,Wang, Yuxiang,Tang, Zhiquan Asian Australasian Association of Animal Productio 2008 Animal Bioscience Vol.21 No.10

Abdominal fat characters are complex and economically important in the poultry industry. Their selection may benefit from the implementation of marker-assisted selection (MAS). The objective of this study was to identify the markers linked to QTL responsible for fatness traits. The Northeast Agricultural University broiler lines divergently selected for abdominal fat content (NEAUHLF) were used in the study. A total of 596 individuals from the divergent tails from the 6th to the 10th generations were genotyped at 23 microsatellite markers on chromosome 1. The differences of allele frequencies of all marker alleles between the divergent tails across the five generations were recorded. The allele frequencies of five markers, including LEI0209, LEI0146, MCW0036, ADL328 and MCW0115, had significant differences between the two tails in all five generations. The resulting p-values using Fisher's exact test on eleven markers, containing MCW248, MCW0010, MCW0106, LEI0252, LEI0068, MCW0018, MCW0061, LEI0088, MCW200, MCW283 and ROS0025, had a decreasing tendency from the 6th to the 10th generation. Statistical analysis showed that polymorphisms of the eight markers, including LEI0209, LEI0146, ROS0025, MCW0115, MCW0010, MCW0036, MCW283, ADL328, were significantly (p<0.0011) or suggestively (p<0.05) associated with abdominal fat content (AFW and AFP) across generations. It is concluded that the eight markers could be associated with the QTL affecting the deposition of abdominal fat in broiler chickens.