Yuanchun Mou

Bio: Yuanchun Mou is an academic researcher from East China University of Science and Technology. The author has contributed to research in topics: Terahertz radiation & Surface modification. The author has an hindex of 1, co-authored 1 publications receiving 20 citations.

Morphology, Surface Layer Evolution, and Structure–Dye Adsorption Relationship of Porous Fe3O4 MNPs Prepared by Solvothermal/Gas Generation Process

Abstract: A new system based on dimethylacetamide, ethanolamine, and azobis(isobutyronitrile) (AIBN) was employed to synthesize porous Fe3O4 magnetic nanoparticles (MNPs) for the first time. The formation mechanism, morphology, and surface layer evolution of MNPs at the different AIBN ratios were revealed. The MNPs prepared without AIBN showed a randomly assembled morphology with a BET surface area of 174 m2/g, which is almost the highest reported until now. After AIBN was added, N2 gas and radical were produced by the thermal decomposition reaction. The high gas pressure enhanced the growth and self-assembly of nanounits, leading to a microsphere morphology. The radical caused a surface modification effect, which led to a decline in both the specific saturation magnetization and surface area of Fe3O4 MNPs. The surface of MNPs was fully modified when prepared at a high AIBN ratio. The methyl orange (MO) adsorption revealed that the modification coverage and surface composition of Fe3O4 MNPs are responsible for its ...

A Hybrid Parametric Scattering Model for an Object on a Dielectric Rough Surface

Abstract: In this communication, we combine the facet-based bidirectional reflection distribution function (BRDF) and four-path model (FPM) to establish the attribute scattering center (ASC) model for composite scattering simulations. This hybrid method is beneficial for simulating scattering echoes of large composite scenes with high efficiency. The model consists of three parts: the ASC model for the target, the BRDF-ASC model for the rough dielectric background, and the FPM-BRDF-ASC model for the coupling scattering between the target and the background. Two simple composite scenes and two large composite scenes are taken as examples to verify the accuracy and feasibility of the proposed model. The validation results show that the radar cross sections (RCSs) of the proposed hybrid method are consistent with those of the multilevel fast multipole algorithm (MLFMA) with higher simulation efficiency. In addition, the ghosting image caused by the multipath effect can be well displayed in the simulated synthetic aperture radar (SAR) images.

An Adaptive Irregular Grid Generation Method for Scattering Simulation of Electrically Large Terrains

Abstract: This paper provides a novel adaptive irregular grid model (AIGM) to improve the scattering simulation efficiency of electrically large terrains. This model distinguishes the steep and flat regions of the measured topographic point cloud models by a threshold. To determine the optimal threshold, we present the height gradient as the criterion to describe the topographic undulation. The optimal threshold is located at the inflection point of the curve describing topographic similarity in the range of height gradient. This generated AIGM can reduce the grid quantity and maintain consistency with the original point cloud model. It is also valuable in the popular coherent and incoherent (C&I) scattering model of Global Navigation Satellite System Reflectometry (GNSS-R). In this paper, the coherent component can be expressed by a simple product of the electric field of the conductor grid, the characteristic function of roughness, and the Fresnel reflection coefficient. The incoherent component comes from the diffuse scattering simulated by the integral equation method (IEM). Compared with the traditional solution to coherent and incoherent scattering by using the Kirchhoff approximation (KA), the modified C&I model has a more extensive application. The precision of the AIGM-based-C&I model is verified by traditional PO. The excellent simulation efficiency of the AIGM-based-C&I model is also demonstrated.

SAR image shadow effect simulation by target facet model and parameterized scattering model

Abstract: This paper proposes a fast method to simulate the shadow effect in SAR images by using target facet model and parameterized scattering model of rough surface. The shadow region of each incident angle is calculated through the projection of the target facet model on the background plane. The large-scale facet model of target is used in projection calculation to reduce computation burden. To verify the accuracy of the proposed method, the SAR result of a cube located above a rough surface is compared with the result of PO method, the similarity is 70%. And to prove the feasibility of the proposed method, SAR image of the low-flying target above the sea surface are obtained.

Evaluation of Mechanism on Selective, Rapid, and Superior Adsorption of Congo Red by Reusable Mesoporous α-Fe2O3 Nanorods

Abstract: A large scale synthesis of mesoporous hematite (α-Fe2O3) nanorods with a high surface area of 98 m2/g and an average pore size of ∼26 nm was used for adsorption studies for pollutant dye removal. The nanorods exhibited rapid, superior, and selective adsorption efficiency toward Congo red, an organic dye present in wastewater. Highly selective adsorption capability of the mesoporous α-Fe2O3 nanorods has been attributed to the presence of abundant surface active sites with porous networks which make it highly water dispersible facilitating the formation of H-bonding and coordination effect between the -NH2 group of Congo red with its surface -OH groups and Fe3+, respectively. Adsorption studies concerning the effect of contact time, initial dye concentration, dosage of adsorbent, and effect of pH on adsorption kinetics were explored in addition to the desorption process investigation regarding the effect of solution pH from acidic to alkaline. To unravel the unresolved phenomenon toward selective adsorption...

Selective and Recyclable Congo Red Dye Adsorption by Spherical Fe 3 O 4 Nanoparticles Functionalized with 1,2,4,5-Benzenetetracarboxylic Acid

Abstract: In this study, the new material Fe3O4@BTCA has been synthesized by immobilization of 1,2,4,5-Benzenetetracarboxylic acid (BTCA) on the surface of Fe3O4 NPs, obtained by co-precipitation of FeCl3.6H2O and FeCl2.4H2O in the basic conditions. Characterization by P-XRD, FE-SEM, and TEM confirm Fe3O4 has a spherical crystalline structure with an average diameter of 15 nm, which after functionalization with BTCA, increases to 20 nm. Functionalization also enhances the surface area and surface charge of the material, confirmed by BET and zeta potential analyses, respectively. The dye adsorption capacity of Fe3O4@BTCA has been investigated for three common dyes; Congo red (C.R), Methylene blue (M.B), and Crystal violet (C.V). The adsorption studies show that the material rapidly and selectively adsorbs C.R dye with very high adsorption capacity (630 mg/g), which is attributed to strong H-bonding ability of BTCA with C.R dye as indicated by adsorption mechanism study. The material also shows excellent recyclability without any considerable loss of adsorption capacity. Adsorption isotherm and kinetic studies suggest that the adsorption occurs by the Langmuir adsorption model following pseudo-second-order adsorption kinetics.

Magnetite-Coated Boron Nitride Nanosheets for the Removal of Arsenic(V) from Water.

Abstract: It is widely known that the existence of arsenic (As) in water negatively affects humans and the environment. We report the synthesis, characterization, and application of boron nitride nanosheets ...

Surface Modification of Polyacrylonitrile Membrane by Chemical Reaction and Physical Coating: Comparison between Static and Pore-Flowing Procedures.

Abstract: The influences of static and pore-flowing procedures on the surface modification of a polyacrylonitrile (PAN) ultrafiltration membrane through chemical reaction and physical coating were investigated in detail. For chemical modification by ethanolamine, a membrane modified by the pore-flowing procedure showed a higher flux and different morphology. The reasons were explained by two effects: the pore-flowing resistance to the random thermal motion of PAN at high temperatures and different reaction kinetics related to the reactant concentration profile on the interface between the membrane and reaction solution and the kinetic property of the fluid (driving force and miscibility) and reaction (time and rate). For physical coating modification, a dense and flat layer via a loose and random layer was formed during the pore-flowing process and static process, which changed the flux and antifouling property of the membrane. The membrane prepared by dead-end filtration showed the best trade-off between the flux and antifouling property. Overall, the procedure kinetics plays an important role in the optimization of membrane modification.