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Automatic ship detection in SAR images plays an essential role in both military and civilian fields. However, most of the existing deep learning detection methods introduce complex models and huge calculations while improving the detection accuracy, which is not conducive to the application of real-time ship detection. To solve this problem, an efficient lightweight network YOLO-Lite is proposed for SAR ship detection in this paper. First, a lightweight feature enhancement backbone (LFEBNet) is designed to reduce the amount of calculation. Additionally, a channel and position enhancement attention (CPEA) module is constructed and embedded into the backbone network to more accurately locate the target location by capturing the positional information. Second, an enhanced spatial pyramid pooling (EnSPP) module is customized to enhance the expression ability of features and address the position information loss of small SAR ships in high-level features. Third, we construct an effective multi-scale feature fusion network (MFFNet) with two feature fusion channels to obtain feature maps with more position and semantic information. Furthermore, a novel confidence loss function is proposed to effectively improve the SAR ship target detection accuracy. Extensive experiments on SSDD and SAR ship datasets verify the effectiveness of our YOLO-Lite, which can not only accurately detect SAR ships in different backgrounds but can also realize a lightweight architecture with low computation cost. [ABSTRACT FROM AUTHOR]

Bi metal attached BiOBr with oxygen defect (BiOBr(3)-Bi(x%, x = 10, 20, 30)) nanosheets was prepared via the hydrothermal process in this study. The different characterization techniques of x-ray diffraction, x-ray photoelectron spectrometer, electron spin resonance (ESR), field emission scanning electron microscope, and high resolution transmission electron microscope were used to distinguish the composition, crystal structure, and morphology of the samples. Under visible light irradiation, the BiOBr(3)-Bi(x%, x = 10, 20, 30) samples exhibited improved photocatalytic activity for the degradation of colored dyes (RhB) and colorless tetracycline hydrochloride. Such an improvement was ascribed to the widened visible light absorption and enhanced separation of the photogenerated electron–hole pairs because of the synergistic effect of oxygen vacancies and Bi metal with plasmon resonance effects. A possible photocatalytic mechanism of the quasi Z-scheme process was proposed on the basis of ESR measurements and radical-trapping experiments. [ABSTRACT FROM AUTHOR]

Abstract The Bi 2 WO 6 /BiOBr composites were synthesized via a simple one-step solvothermal method by using reactable ionic liquid of [C 16 mim]Br as Br source. XRD, XPS, SEM, and TEM were used to characterize the structure and morphology of the composites. Because of the IL, the Bi 2 WO 6 nanoparticles uniformly covered on the surface of flower-like BiOBr, forming special flower-like Bi 2 WO 6 /BiOBr composites. The photoactivity of Bi 2 WO 6 /BiOBr was evaluted by the photocatalytic degradation of rhodamineB (RhB), methylene blue (MB), and colorless tetracycline hydrochloride (TC). The UV–vis DRS spectra indicated that the composites displayed enhanced visible light absorption. The photoelectrochemical and PL measurements confirmed the improved spatial transfer and separation of the charge carries and suppressed recombination of the charge carries. Because of enhanced light absorption and improved spatial transfer and separation of the charge carries, caused by construction of the Type II heterojuction and using [C 16 mim]Br as Br source, the composites showed dramatic photocatalytic activity. Based on the radical-trapping experiments, a possible photocatalytic mechanism has been proposed. Highlights • Composites were prepared by one step using reactable ionic liquid. • Composite exhibits enhanced visible absorption and separation of carries. • Synergetic effect of heterojunction and ionic liquid was studied. [ABSTRACT FROM AUTHOR]

In actual applications of inverse synthetic aperture radar (ISAR), continuous measurements may be impossible or the collection of data during some periods are not valid in a long coherent processing interval (CPI). Hence, it is significant to study the ISAR imaging strategy with a short CPI. Compressive sensing is a recently proposed technique that allows recovering an unknown sparse signal with overwhelming probability from very limited samples. However, the standard compressive sensing framework has been developed for real-valued signals. One disadvantage of this method is that any prior phase information is not exploited, which may improve the reconstruction quality by applying some extra constraints. In this paper, a new strategy for ISAR imaging based on improved compressive sensing is proposed, which transforms the ISAR imaging problem into a joint optimization problem over the representation of the magnitude and phase of the complex-valued scatter coefficient. Because of using phase information in the algorithm, the image quality is improved. Experimental results confirm the effectiveness of the proposed method. © 2015 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc. [ABSTRACT FROM AUTHOR]

Hollow Gd 2 O 3 :Eu 3+ (denoted as H-Gd 2 O 3 :Eu 3+ ) nanospheres with excellent magnetic and luminescence properties were prepared through a self-template method using Gd(OH)CO 3 :Eu as template to form hollow precursors. The size of Gd 2 O 3 :Eu 3+ shell is 20 nm for H-Gd 2 O 3 :Eu 3+ nanospheres annealed at 600 °C with particle diameter of 200 nm. The hollow structure improved the luminescent intensity in contrast to solid spheres. The systematic studies about the effect of calcination temperature on the luminescence and magnetic properties were reported. Luminescent spectra shows that the I 610/590 (asymmetry factor of luminescence) varies with the calcination temperature, indicating that the color purity and local environment of Eu 3+ in Gd 2 O 3 changes. Moreover, the magnetization (M) becomes stronger while increasing the calcination temperature. The H-Gd 2 O 3 :Eu 3+ nanospheres may have potential application in magnetic resonance image (MRI), drug delivery, and drug loading and release. [ABSTRACT FROM AUTHOR]

CoFe2O4@SiO2@(Y,Gd)2O3:Eu3+ composites were synthesized by a three-step method, following post-treatment. The composites displayed excellent ferromagnetic and photoluminescence properties. Gd3+ doping in CoFe2O4@SiO2@(Y,Gd)2O3:Eu3+ composites improved the photoluminescent intensities while decreasing the saturation magnetization. When the ratio of Y3+/Gd3+ is 0.7/0.3, the composite displayed the highest photoluminescent intensity. In the composites, the doping Gd3+ has two roles: host matrix and activator. The effects of annealing temperature on photoluminescence properties for the CoFe2O4@SiO2@(Y0.7Gd0.3)2O3:Eu3+ composites were also investigated. Meanwhile, the CoFe1.8Gd0.2O4@SiO2@Y2O3:Eu3+ composite was also prepared and the ferromagnetic and photoluminescence properties of Gd3+ doping in CoFe1.8Gd0.2O4@SiO2@Y2O3:Eu3+ composite were also investigated. The possible mechanism of the improved photoluminescent intensity of the CoFe1.8Gd0.2O4@SiO2@Y2O3:Eu3+ composite was discussed. [ABSTRACT FROM AUTHOR]

Abstract: The magnetic and photoluminescent Fe@C@YBO3:Eu3+,Gd3+ nanocomposite with core–shell structure has been synthesized by a hydrothermal process. X-ray diffraction (XRD) and transmission electron microscopy (TEM) were used to determine the structure and morphology of the nanocomposites. Vibrating specimen magnetometer (VSM) and photoluminescence spectroscopy (PL) were used to analyze magnetic and luminescence properties of the nanocomposite. In the nanocomposites, the amorphous carbon layer acts as coupling agent, and it can conduct the excited electrons between magnetic part and luminescent part. The luminescence properties of Fe@C@YBO3:Eu3+,Gd3+ nanocomposite are discussed under magnetic field. Under the external magnetic field for 2 h, the nanocomposite displayed the biggest luminescent intensity. [Copyright &y& Elsevier]

Abstract: In this paper, co-precipitation synthesized Fe3O4 microspheres have been encapsulated with nonporous silica and further functionalized by the deposition of Y2O3:Eu3+ phosphors through a simple co-precipitation process, realizing a hollow structured material with mesoporous, magnetic and luminescent properties. The results reveal that the material shows typical ordered mesoporous characteristics, and have monodisperse spherical morphology with smooth surface and narrow size distribution. Additionally, the multifunctional nanocomposite shows the characteristic emission of Eu3+ (5D0–7F1–4). Magnetism measurement reveals the paramagnetic feature of the samples. Furthermore, we also compared the magnetic and fluorescent properties of solid Fe3O4@SiO2@Y2O3:Eu3+ and Fe3O4@HM-SiO2@Y2O3:Eu3+. [Copyright &y& Elsevier]

Highlights: [•] The CoFe2O4@SiO2@ Y2O3:Dy3+ composites with the core–shell, magnetic and luminescent properties were prepared. [•] Their structure, magnetic and luminescent properties are researched. [•] The composites are with good magnetic and luminescent properties. [Copyright &y& Elsevier]

Abstract: In this study, the bifunctional Fe@C@Gd2O3:Eu3+ composites were prepared via a simple co-precipitation progress followed by a subsequent heat treatment under N2 atmosphere. The reactive carbon interlayer offers many advantages including separating photoluminescent material from magnetic material and reducing magnetite Fe3O4 to metal Fe. X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), Fourier-transform infrared (FT-IR), vibrating sample magnetometer (VSM) and photoluminescence spectroscopy (PL) were used to analyze the structure, morphology, magnetic and luminescence properties of the composites. The Fe@C@Gd2O3:Eu3+ composites with well-crystallized and core–shell structure were prepared and displayed good ferrimagnetic behavior at room temperature and a strong red emission. In addition, due to the excellent magnetic and luminescence properties of the prepared composites, they may have many great potential applications in many fields, such as biological imaging, cell tracking and drug delivery. [Copyright &y& Elsevier]

In this paper, the magnetic, luminescence, and porous CoFeO@YO:Eu nanocomposite was synthesized by a facile three-step method. The porous structure of the nanocomposite had been produced by burning off the intermediate carbon layer. The CoFeO@YO:Eu nanocomposite consists of uniform, well-dispersed microspheres with a size of 260-275 nm. The nanocomposite shows excellent magnetic and luminescence properties. The prepared CoFeO/C microsphere and porous CoFeO@YO:Eu nanocomposite display higher coercivity than that of the obtained CoFeO particles. The size, magnetic, and photoluminescence properties of the nanocomposite can be adjusted by changing the annealing temperature, deposited amount of YO:Eu, and the concentration of glucose aqueous solution. The interactive effects of the magnetism and luminescence have been discussed. [ABSTRACT FROM AUTHOR]

With the improvement of public's environmental protection awareness, the market share of LED in the photocuring field is also expanding rapidly, so it is necessary to develop matching photoinitiators. Here, we prepared a molecule (ND-1) possessing both co-initiating and polymerizable groups, and it exhibits a good initiation effect on acrylate monomers under UV-LED irradiation. The double bond conversion rate reaches up to 80% especially for tripropylene glycol diacrylate (TPGDA). Due to excellent photocuring effect of ND-1 , it can initiate monomer polymerization in the presence of color paste and was successfully applied to photocurable inks. In addition, ND-1 exhibits low migration and low toxicity, which is very important to promote the application of packaging with photocurable inks in the food, medical, personal care and tobacco fields. Finally, the photoinitiation mechanism of ND-1 was explored. The free radicals not only come from the cleavage of C─O bond, but also intermolecular hydrogen abstraction. • A novel photoinitiator ND-1 with low toxicity and low-migration was synthesized. • ND-1 can initiate photopolymerization of acrylate monomers under UV-LED irradiation. • The free radicals are produced through ND-1 homolysis and intermolecular hydrogen abstraction. • ND-1 has been successfully applied to photocurable inks. [ABSTRACT FROM AUTHOR]

• A direct Z-scheme hollow mesoporous g-C 3 N 4 /Ag 2 CrO 4 photocatalysis was prepared. • Synergistic effect between hollow mesoporous and direct Z-scheme. • Extended light absorption and construction of direct Z-scheme lead to super spatial transfer and separation of carries. • Internal electric field and band bending are responsible for direct Z-scheme. The hollow mesoporous g-C 3 N 4 /Ag 2 CrO 4 (HCN/ACO-x (x = 0.5, 1, 2, 4, 6)) photocatalysts with outstanding degradation activity for antibiotics and dyes under visible light irradiation were prepared in this study. XRD, XPS, FESEM, HRTEM, N 2 adsorption-desorption, and UV–vis DRS were used to characterize the phase structure, morphology, and optical properties of the prepared samples. The HCN/ACO-x (x = 0.5, 1, 2, 4, 6) composites had enhanced photocatalytic activity for photodegradation of colorless antibiotics tetracycline hydrochloride (TC) and rhodamine (RhB) than those of g-C 3 N 4 (CN), hollow mesoporous g-C 3 N 4 (HCN), and Ag 2 CrO 4 (ACO) samples, with HCN/ACO-4 sample showing the highest photocatalytic performance. The hollow mesoporous structure is expected to trap more incident photons in the HCN microspheres, further improving visible light absorption. Moreover, by building the internal electric field and forming of band bending in the interface between HCN and ACO, a direct Z-scheme HCN/ACO photocatalysis was produced, which exhibited superior separation of photogenerated holes and electrons, further leading to excellent photocatalytic performance for degradation of antibiotics and dyes. [ABSTRACT FROM AUTHOR]

Terahertz time domain spectroscopy imaging systems suffer from the problems of long image acquisition time and massive data processing. Reducing the sampling rate will lead to the degradation of the imaging reconstruction quality. To solve this issue, a novel terahertz imaging model, named the dual sparsity constraints terahertz image reconstruction model (DSC-THz), is proposed in this paper. DSC-THz fuses the sparsity constraints of the terahertz image in wavelet and gradient domains into the terahertz image reconstruction model. Differing from the conventional wavelet transform, we introduce a non-linear exponentiation transform into the shift invariant wavelet coefficients, which can amplify the significant coefficients and suppress the small ones. Simultaneously, the sparsity of the terahertz image in gradient domain is used to enhance the sparsity of the image, which has the advantage of edge preserving property. The split Bregman iteration scheme is utilized to tackle the optimization problem. By using the idea of separation of variables, the optimization problem is decomposed into subproblems to solve. Compared with the conventional single sparsity constraint terahertz image reconstruction model, the experiments verified that the proposed approach can achieve higher terahertz image reconstruction quality at low sampling rates. [ABSTRACT FROM AUTHOR]

Three-dimensional/two-dimensional (3D/2D) rare earth Ln3+ (Ln = Er or Eu)-doped BiOBr wrapped with reduced graphene oxide (Bi-Ln/rGO) was obtained via a two-step solvothermal–hydrothermal process. The doping of Ln3+ and the construction of heterojunction between 3D Ln3+-doped BiOBr microspheres and 2D rGO nanosheets were beneficial to the wide absorption of visible light and the efficient separation of photoinduced electrons and holes, further improving the photocatalytic activity of Bi-Ln/rGO composites for RhB photodegradation. The photocatalytic activity of Bi-Ln/rGO was higher than those of pure BiOBr, Ln3+-doped BiOBr, and BiOBr/rGO. The radical-trapping experiments on active species indicated that h+ and ·O2− were mainly responsible for the photodegradation of RhB. The mechanism of the enhanced photocatalytic performance was proposed on the basis of radical-trapping experiments on active species. [ABSTRACT FROM AUTHOR]

In this study, the magnetically recyclable Fe3O4@C/BiOBr heterojunction with enhanced visible light-driven photocatalytic ability was obtained by two-step solvothermal method. The phase, morphology, and structure of the samples were investigated by XRD, FESEM, HRTEM, and XPS. The Fe3O4@C/BiOBr heterojunction was composed of Fe3O4@C sphere and BiOBr microsphere with diameters of 200 nm and 1000 nm, respectively. The photocatalytic performance of Fe3O4@C/BiOBr composite for RhB was examined under visible light irradiation. The photocatalytic activity of Fe3O4@C/BiOBr composite was much higher than that of pure BiOBr and Fe3O4@C. After 35 min of irradiation, 97% of RhB could be removed with the Fe3O4@C/BiOBr photocatalyst. Based on radical trapping experiments of active species, the mechanism of enhanced photocatalytic performance was proposed. In addition, the superparamagnetic property of the photocatalyst not only allows its easy recyclability by an external magnetic field but also maintains high photocatalytic activity after five cyclic experiments.ᅟ [ABSTRACT FROM AUTHOR]

Pomegranate plasma heterostructure regulated 1D biomass derived microtube networks were developed to achieve full-band microwave absorption at an ultralow loading of 8.3 wt%. [Display omitted] • Recycling the resource-rich and renewable Platanus ball microtubes. • The one-dimensional carbon microtubes is facilitate to constructing effective absorbing network structures (8.3 wt%). • The pomegranate seed-like Co-C heterostructure was constructed without hard agglomeration. • Such pomegranate plasma heterostructure can effectively modulate the impedance of CM/CMT. • Such plasma heterostructure decorated CM/CMT networks achieves 85 % microwave absorption in the full frequency band (2–18 GHz). The excessive aggregation of magnetic metal particles and the resulting skin effect tend to cause a serious imbalance in impedance matching, which hinders its application in aerospace and military wave absorption fields. Obviously, effective dispersion configuration and network construction are two practical measures to develop broadband lightweight absorbers. Based on the recycling theme, pomegranate plasma heterostructure regulated one-dimensional (1D) biomass derived microtube networks are achieved through the conversion and utilization of waste Platanus ball fibers. The metal–organic framework strategy successfully avoids the hard agglomeration of metal particles. The pomegranate seed-like heterostructure effectively modulated the impedance of carbon microtubes, resulting in coordinated dielectric and magnetic losses. Such composites exhibited an effective absorbing bandwidth of 6.08 GHz and a minimum reflection loss of −29.8 dB. This work provides a new approach for constructing sustainable ultralight electromagnetic wave absorbers using plasmon modification and a 1D built-up network structure. [ABSTRACT FROM AUTHOR]

• Coum-Ph-OC 12 H 25 possesses strong visible-light absorption and photobleaching ability. • The dual curing behavior could be activated by both visible light and ultrasound. • An excellent curing depth of 15 cm was achieved by this novel curing strategy. • The models (V≈30 cm3) could be completely cured within 30 min by this strategy. Although photocuring is currently the most commonly used method in 3D additive manufacturing, it still faces significant challenges in rapid prototyping of thick materials due to the limited penetration of light. Ultrasonic technology has the advantages of high penetration depth and unparalleled cavitation, offering opportunities for enabling additive manufacturing of thick materials. In this study, a coumarin-based two-component system composed of Coum-Ph-OC 12 H 25 and N-phenylglycine as initiator and hydrogen supplier, respectively, was developed to achieve ultrasonic curing of tripropylene glycol diacrylate (TPGDA). The ideal curing efficiency of this two-component system was optimized to 90 %, and ultrasonic curing of thick materials was achieved with a penetration depth of up to 15 cm. Moreover, electron spin resonance (ESR) spectroscopic measurements demonstrated the free-radical reaction mechanism. It is believed that this research has the potential to expand the 3D additive manufacturing technology and pave the way for future developments in this field. [ABSTRACT FROM AUTHOR]

Fe 3 C/Fe nanocomposites were synthesized by a sol–gel method. Using urea as carbon source and reduce agent in the reaction process. The CTAB works as the surfactant and the bromine contained in CTAB plays a catalytic role. Appropriate choices of the amount of urea and CTAB, reaction temperature and time are very important to obtain high-quality of products. Above 650 °C, the precursor gel turned into the nanocomposites composed of iron carbide and iron. Their structures and magnetic properties are characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), and vibrating sample magnetometry (VSM). The possible formation mechanism of as-prepared nanostructures is discussed. [ABSTRACT FROM AUTHOR]

The checkerboard-like NIDG based on plasma heterostructure shows excellent EWA in the C-band at ultra-low filler loading of 6.2 wt%. [Display omitted] To solve the problem of dispersion of magnetic nanoparticles in ultralight electromagnetic absorption field, checkerboard-like nickel nanoislands/defect graphene aerogel (NIDG) with enhanced surface plasmon resonance was designed and prepared through electrostatic self-assembly method. This special structure successfully overcame the aggregation phenomenon of magnetic metals and built high-density gap regions to enhance surface plasmon resonance. And the NIDG has achieved excellent electromagnetic wave absorption performance in C band. Specially, NIDG is superior in ultra-lightness with only 6.2 wt%, compared to some recently reported magnetic electromagnetic wave absorbers. Such great performance can be attributed to the enhanced surface plasmon resonance and improved impedance matching. This work is significant for achieving effective dielectric loss and designing lightweight low-frequency EMW absorbing materials. [ABSTRACT FROM AUTHOR]

Three-dimensional carbon-based materials have attracted much attention for electromagnetic wave absorption because low-dimensional materials have failed to meet the needs of constructing effective networks with ultra-light properties due to their easy agglomeration and in-plane stacking. The 3D element of quadrangular cone carbon was innovatively applied in this work to construct interconnected networks (MFC). This material successfully overcomes the disadvantages of easy agglomeration and in-plane stacking in low-dimensional elements, allowing for more efficient construction of absorbing networks. The prepared MFC exhibits excellent EAB (6.70 GHz) and RL (−50.92 dB), especially at an ultra-low filling ratio (1.04 wt%). Such superior performance can be attributed to the MFC effective network constructed by quadrangular cone carbon facilitating the entrance and diffuse scattering of electromagnetic waves. This study may provide new inspiration for constructing an effective absorbing network of pure carbon with 3D elements (quadrangular cone carbon), realizing ultra-low filling and broadband microwave performance. [ABSTRACT FROM AUTHOR]

A novel permittivity adjustable ultralight microwave absorbent was achieved by constructing efficient high aspect-ratio Sycamore biomass microtube networks. [Display omitted] • High aspect-ratio CMT successfully synthesized derived from Sycamore biomass fiber. • ZnO/PCMT achieved great EAB performance at ultralow filler loading of 6.7 wt.%. • Such excellent EMW performance can be attributed to its unique 1D carbon microtube unit constructed network structure. • Heterogeneous structure constructed by columnar ZnO and carbon skeleton increases the interfacial polarization. Excessive conductivity of carbon-based materials led to poor impedance matching, hindering their electromagnetic absorbing application in aerospace and military fields. While, one-dimensional carbon materials are more favorable to build networks, satisfying impedance matching. One-dimensional carbon materials, such as carbon fibers, carbon nanotubes, carbon microtubes, etc., are recently limited by strict preparation and hard to industrialize. Inspired by the traditional handicraft of candied haw, ZnO/porous carbon micron tubes (ZnO/PCMT), are achieved by conducting a dip-coating and thermal etching process on recycling the abandoned Sycamore microtube. The prepared ZnO/PCMT exhibits higher specific surface area (1076 m2 g−1) and excellent microwave absorption performance. With a filler loading of only 6.7 wt.%, the ZnO/PCMT achieved a great electromagnetic wave absorbing performance. Such excellent ultralight absorption performance can be attributed to their distinct hollow tubular structure of Sycamore based carbon microtube, which can easily construct conductive networks, improving the impedance matching. This work expands a new direction for the development of one-dimensional natural Sycamore microtube as ultra-light and broadband high-performance microwave absorbing materials. [ABSTRACT FROM AUTHOR]

The synthetic strategy for the creation of Double-shell structure is based on a facile calcining process, in which carbon middle layer of Fe 3 O 4 @C@Y 2 O 3 :Eu 3+ @C@Y 2 O 3 :Eu 3+ composite nanostructures was calcined away. We obtained the Fe 3 O 4 @Y 2 O 3 :Eu 3+ @Y 2 O 3 :Eu 3+ nanocomposites with luminescent and magnetic properties. X-ray diffraction (XRD), transmission electron microscopy (TEM), vibrating sample magnetometer (VSM) and photoluminescence spectroscopy (PL) were used to analyze the structure, morphology, magnetic and luminescence properties of the composites. The nanocomposites has spherical morphology with narrow size distribution. In addition, they exhibit good magnetization with the saturation magnetization of 1.99 emu/g) and unique red emission for Eu 3+ at 610 nm. [ABSTRACT FROM AUTHOR]

Highly anisotropic 2D large-sized iron-based coral were produced using an ammonium nitrate-assisted blow molding strategy in order to achieve a coverage of 100 % for C-band. [Display omitted] • High anisotropy 2D LCIC were successfully fabricated using the NH 4 NO 3 -assisted blow molding separation strategy. • The LCIC hierarchical configuration was formed without any significant agglomeration. • The high anisotropy of the two-dimensional large-size layer structure significantly enhances the magnetic properties. • The LCIC exhibits excellent full C-band microwave absorption. • A 2D coralloid structure allows for the production of lightweight microwave absorption materials (20 wt.%). Lightweight microwave-absorbing (MA) materials with broadband absorption in the C-band remain challenging to date. Recent studies have shown that promoting anisotropy in materials is expected to break the Snoek limit and enhance the absorption performance of magnetic materials in the C-band. In this paper, two-dimensional (2D) large-size coral-like iron-based composites (LCIC) were prepared using an NH 4 NO 3 -assisted blow molding separation strategy. The special structure with large shape anisotropy realizes a wide and strong natural magnetic resonance, leading to strong magnetic loss. The enhanced natural resonance effectively broadens the effective absorption bandwidth (EAB) of the LCIC in the C-band. The minimum reflection loss (RL min) of LCIC is −41.64 dB, and the EAB is 5.42 GHz (3.83–9.25 GHz), covering the entire C-band. Strong natural resonance is necessary to improve the dissipation of magnetic losses in low-frequency electromagnetic waves. This work explores the important role of size effect in enhancing the C-band absorption properties of magnetic materials. It provides a feasible reference for the preparation of C-band broadband, strongly absorbing MA materials. [ABSTRACT FROM AUTHOR]

Three-dimensional (3D) porous carbon has sufficient specific surface area and anchor positioning points. The pore structure facilitates uniform charge distribution, and buffers volume changes during stripping. However, single carbon materials have limited theoretical capacity and short cycle life. Here, 3D porous carbon material BCN/Mn-6 (B,N and Mn co-doped porous carbon with 6 mmol Mn content) co-doped with manganese, boron and nitrogen was synthesized by heat treatment. Affective modulation of the material structure and surface functional groups was achieved by adjusting the amount of manganese doping. The metal element doping can promote the diffusion of lithium ions, and the formed vacancies and defects can be used as lithium storage sites. Nitrogen doping can improve the dispersion and stability of metals and oxides, and regulate the redox capacity. Co-doping of metals and heteroatoms synergistically improves electrical conductivity. Thus, BCN/Mn-6 exhibits excellent cycling stability (99.60 % Coulombic efficiency after 300 cycles) and specific capacity (779.9 mAh/g), and shows capacity rise. This study provides a new direction for the preparation of carbon-based electrode materials doped with heteroatoms and the study of capacitive energy storage mechanisms. [Display omitted] • Metals (Mn) and heteroatoms (N, B) doping can enhance carbon materials' capacitive energy storage mechanism. [ABSTRACT FROM AUTHOR]

Abstract: As-synthesized Fe3O4 nanoparticles were encapsulated with carbon layers through a simple hydrothermal process. Fe3O4/C nanoparticles were coated with YVO4:Dy3+ phosphors to form bifunctional Fe3O4@C@YVO4:Dy3+ composites. Their structure, luminescence and magnetic properties were characterized by XRD, SEM, TEM, HRTEM, PL spectra and VSM. The experimental results indicated that the as-prepared bifunctional composites displayed well-defined core–shell structures. The ∼12nm diameter YVO4:Dy3+ shell exhibited tetragonal structure. Additionally, the composites exhibited a high saturation magnetization (13emu/g) and excellent luminescence properties, indicating their promising potential as multifunctional biosensors for biomedical applications. [Copyright &y& Elsevier]

In this study, the co-precipitation method has been developed for the synthesized FeO nanoparticles which are encapsulated with SiO/C/TiO via the facile and further functionalized by the deposition of YO:Eu phosphors. Transmission electron microscopy images revealed that the nanocomposites show a spherical morphology with size distribution around 100-250 nm, and the thickness of the coupling agents was 3-4 nm. The X-ray diffraction patterns showed that a cubic spinel structure of FeO core and a tetragonal phase of YO:Eu shell was obtained. The multifunctional nanocomposites showed ferrimagnetic behavior, the negligible coercivity Hc and remanence Mr at room temperature and showed unique europium fluorescence properties with strong red emission peak from the electric-dipole transition D → F of Eu ions at 611 nm. Therefore, the multifunctional nanocomposites are expected to develop many potential applications in biomedical fields and magnetic photocatalyst. [ABSTRACT FROM AUTHOR]

Abstract: A novel Fe3O4@C/YVO4:Sm3+ composites with magnetic and luminescent properties were reported. Firstly, the as-synthesized Fe3O4 nanoparticles were coated by carbon as a shell via a simple hydrothermal method. Furthermore, the Fe3O4@C nanoparticles were modified by YVO4:Sm3+ phosphors through a simple sol–gel process to prepared the Fe3O4@C/YVO4:Sm3+ microspheres. The characterization of as-prepared products were measured by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), photoluminescence (PL) spectra, and vibrating sample magnetometer (VSM). It is shown that Fe3O4@C/YVO4:Sm3+ composites with well-crystallized and core–shell structure were prepared. Additionally, the Fe3O4@C/YVO4:Sm3+ composites show excellent magnetic properties (13 emu/g) and luminescent properties, which made the composites useful for applications in biomedical devices such as magnetic bio-separation and drug/gene delivery. [Copyright &y& Elsevier]

Researchers have begun to pay close attention to the construction of artificial Z-scheme photocatalysts due to their excellent ability to separate photogenerated electron–hole pairs and prominent redox ability. In this study, Bi-bridged Z-scheme BiOCl/Bi2O3 (BiOCl/Bi–Bi2O3) heterojunctions with oxygen vacancies were prepared via a one-step hydrothermal method. The phase structure, morphology, and optical properties of the samples were characterized using XRD, XPS, ESR, FESEM, HRTEM, and UV–Vis DRS. Compared with BiOCl and Bi–Bi2O3, the prepared BiOCl/Bi–Bi2O3(25% and 50%) samples exhibited enhanced photocatalytic activity in degrading colorless antibiotics (tetracycline hydrochloride) and colored dyes (RhB) under visible light irradiation. This result indicated improved visible light absorption due to the presence of oxygen vacancies and enhanced separation efficiency of the photogenerated electron–hole pairs and high redox ability due to the construction of the Z-scheme. On the basis of the results of radical-trapping, photoelectron chemical experiments, and PL analysis, a possible photocatalytic mechanism of the Z-scheme BiOCl/Bi–Bi2O3 heterojunctions was proposed. [ABSTRACT FROM AUTHOR]

• Carbon microtubes were achieved massively from renewable planetree fruit hair. • High aspect-ratio carbon microtubes (about 400:1) are facilitated to construct three-dimensional bearing/conductive networks. • The carbon aerogel interlocked by carbon microtubes (MTCA) exhibited a good bearing capacity (9987.26 Pa). • MTCA achieved great RL and EAB performance at ultralow filler loading of 5 wt. %. • MTCA also performed excellent electromagnetic shielding properties (57.1 dB). Urgently, renewability and low energy consumption in such a carbon-neutral era is the main scheme for researchers. The renewable and lightweight nature of biomass carbon provides possibilities for the development of lightweight absorbers in aerospace applications. Carbon microtubes were achieved massively from renewing planetree fruit hair with a high aspect ratio of about 400:1. High aspect-ratio carbon microtubes are facilitated to construct three-dimensional (3D) bearing/conductive networks based on the Magpie nesting strategy of truss structure. Carbon aerogel interlocked by carbon microtubes (MTCA) exhibited a good bearing capacity (9987.26 Pa) and excellent electromagnetic wave absorption (EWA) (ultralow filler loading of 5 wt. %) and shielding performance (57.1 dB). It is confirmed that 3D networks constructed by high aspect-ratio carbon microtubes are facilitated to optimize carbon-based absorbers' impedance matching. This work explores the important role of high aspect ratio biomass carbon microtubes in regulating the dielectric parameters and provides a feasible strategy of carbon neutral scheme for novel ultralight EWA materials. Carbon aerogel interlocked by high aspect-ratio carbon microtubes (about 400:1) exhibited a good self-supporting ability (9987.26 Pa) and excellent electromagnetic wave absorption performance (5 wt. %). [Display omitted] [ABSTRACT FROM AUTHOR]

Currently, high-temperature thermal failure hinders the development of lithium-ion batteries (LIBs). Interfacial side reaction of electrolyte and electrode is the main cause of thermal failure at high temperature. Explicitly, suppressing interfacial side reactions at high temperatures can help the research of capacitive energy storage electrodes. While, thermo-electrochemical inert alumina can be facilitated to solve this problem. In this paper, pitaya configuration of nano-alumina islands uniformly dispersed in carbon matrix can be achieved from NOTT-300(Al). Nano-alumina contributes to the structural stability of porous carbon during carbonization and lithium deintercalation. And nano-alumina islands are effective in suppressing interfacial side reactions at high temperatures. Thus, NC-3 exhibits competitive specific capacity (717.1 mAh/g) and cycling stability (99.15% after 500 cycles). NC-3's capacity was confirmed to be mainly attributed to capacitive energy storage mechanism. This study provides a new research paradigm for nano-alumina to improve the high-temperature thermal stability management of LIBs. Nano-alumina islands enable superior capacitive lithium-ion storage of pitaya configuration porous carbon. [Display omitted] • Pitaya configuration of nano-alumina islands uniformly dispersed in carbon matrix can be achieved from NOTT-300(Al). • Nano-alumina contributes to the structural stability of porous carbon during carbonization and lithium deintercalation. • Nano-alumina islands are effective in suppressing interfacial side reactions at high temperatures. • NC-3's capacity can be mainly contributed to capacitive energy storage mechanism. • NC-3 exhibits competitive specific capacity (717.1 mAh/g) and cycling stability (99.15% after 500 cycles). [ABSTRACT FROM AUTHOR]

Explicitly, effective dispersion configuration and hierarchical network construction are two practicable measures to develop the broadband and lightweight absorbers. Based on the newly developed sugar blowing art, 3D Luffa aerogels heterostructure have been successfully developed through metal ion assisted caramel blowing (MCB) strategy. The Luffa foam hierarchical configuration with those dielectric, magnetic, and porous interfaces can be all achieved. Such hierarchical 3D lightweight aerogels are facilitated to building effective impedance matching networks (2.4 wt %) and exhibit an optimized polarization relaxation. Thus, the effective absorbing bandwidth (EAB) of the Luffa aerogel can be broadened up to 8.0 GHz. Moreover, the MCB strategy can be applicable to a wide range of divalent metal ions (Co2+, Ni2+, Mn2+, Zn2+ et al.). This study provides a new method for efficient synthesis of aerogel network structures and opens a way to realize lightweight and broadband electromagnetic wave absorbing (EWA) materials. Divalent metal ions assisted blowing strategy regulated 3D Luffa aerogels heterostructure were developed to achieve full-band EMW absorption at an ultra-low filling of 2.4 wt %. [Display omitted] • Metal ion assisted caramel blowing (MCB) aerogels have been successfully developed. • The Luffa foam hierarchical configuration was constructed without hard agglomeration. • The MCB strategy can be applicable to a wide range of divalent metal ions. • Such Luffa foam heterostructure exhibited an optimized polarization relaxation. • Such hierarchical 3D lightweight aerogels are facilitated to building effective impedance matching networks (2.4 wt %). • The EAB of luffa aerogel can expanded to 8.0 GHz. [ABSTRACT FROM AUTHOR]

Highlights • A novel photocatalyst of Ag 2 O/g-C 3 N 4 heterostructure is reported. • Utilize a broad range of wavelengths from Visible to near-infrared (NIR) for various organic contaminants degradation. • The mechanism of visible-NIR photocatalysis of Ag 2 O/g-C 3 N 4 was proposed. Abstract A series of p-n junction Ag 2 O/g-C 3 N 4 photocatalysts with different Ag 2 O contents were successfully prepared though a facile chemical precipitation method at room temperature. The as-synthesized samples were characterized in detail by XRD, EDS, XPS, SEM and DRS. The experimental results demonstrated that Ag 2 O nanoparticles were well distributed on the surface of g-C 3 N 4 and the heterostructure of Ag 2 O/g-C 3 N 4 was constructed. As-synthesized Ag 2 O/g-C 3 N 4 heterojunction photocatalysts exhibited an excellent wide-spectrum response ranging from ultraviolet (UV) to near-infrared (NIR), indicating its potential for effective utilization of solar light energy. The as-prepared Ag 2 O/g-C 3 N 4 shows excellent photocatalytic properties for the degradation of Rhodamine B (RhB), phenol, imidacloprid, methylene blue (MB) and methyl orange (MO) under visible and NIR light irradiation. The degradation rate constants of Ag 2 O/g-C 3 N 4 (8:1) for RhB were 0.05188 and 0.01368 min−1 under visible and NIR irradiation, which are about 26 and 343 times higher than that of pure g-C 3 N 4 , respectively, and are even better than that of Ag 2 O under the same conditions. The enhanced photochemical activities are attributed to the formation of the heterostructure between Ag 2 O and g-C 3 N 4 , and efficient charge separation efficiency. Finally, a possible photocatalytic mechanism was proposed for this photocatalyst. [ABSTRACT FROM AUTHOR]

Abstract (Ho,Sb)-modified (Bi 0.5 Na 0.5) 0.945 Ba 0.065 TiO 3 (BNBT6.5) multifunctional ferroelectric ceramics were fabricated by a conventional solid-state reaction method. Results showed that (Ho, Sb)-modified BNBT6.5 materials exhibited a bright green photoluminescence while simultaneously obtaining a large electric-field-induced strain of 0.37% (80 kV/cm) in samples with x = 0.50% due to the appearance of an ergodic relaxor phase at zero field. Under the electric field, the ergodic relaxor phase could reversibly transform to ferroelectric phase. As a result, the strain is very resistant to field cycling due to the reversible field-induced phase transition between the ergodic relaxor and ferroelectric phase, giving the materials attractive for its good fatigue resistance. Besides the excellent strain properties, (Ho, Sb)-modified BNBT6.5 host exhibits a bright photoluminescence with a strong green emission located at around 549 nm owing to the 5S 2 →5I 8 transition under the 451 nm light excitation at room temperature. As a multifunctional material, (Ho,Sb)-modified BNBT6.5 ferroelectric materials showed great potential in optical-electro integration and coupling device applications. Highlights • An enhancement of strain with a peak at a value of 0.37% is obtained in this work. • The material is attractive for its exceptionally good fatigue resistance. • The material exhibits a bright photoluminescence with a strong green emission. [ABSTRACT FROM AUTHOR]

Recent developments in image processing play a significant role in processing the images clearly. Undoubtedly, identifying the target against clutter is another challenging task in Ground Penetrating Radar (GPR) image processing. To successfully distinguish targets from surrounding clutter, a novel Bidimensional Empirical Mode Decomposition (BEMD) system is proposed. The overall process can be broken down into four steps. First, images are decomposed using BEMD arithmetic to extract the Intrinsic Mode Functions (IMFs). Then, these IMFs could be examined using gradual single frequency signals to bring out and highlight the physical meaning of instantaneous amplitudes and instantaneous frequencies. To find the best-fitting hyperbolas, the object position of the vertex is estimated using maximum point estimation method and velocity is estimated using a minimum entropy method. Finally, the location of reflection hyperbolas can be extracted clearly. The simulation and experimental images show the effectiveness of this method in identifying targets. [ABSTRACT FROM AUTHOR]

• The Ferrites composite foams (NFC) were developed by the NH4NO3 assisted solution-combustion strategy and solid phase sintering. • Surficial oxygen vacancy concentration of the NFC can be up to 48.1%. • The concentration of oxygen vacancy can be effectively regulated by the NH4NO3. • Surficial oxygen vacancy is facilitated to achieve balanced impedance matching. • The NFC exhibits excellent EMA performance covering the whole X-band and Ku-band. Currently, the absorbing bandwidth of the Ferrites is enormously limited at X-band and Ku-band by the poor intrinsic dielectric properties. Thus, there are few reports about the pure Ferrites' application at 8-18 GHz. In this paper, the Ferrites composite foams (NFC) with a high surficial oxygen vacancy concentration (48.1%) were prepared by the NH 4 NO 3 assisted solution-combustion strategy and solid phase sintering. Noteworthily, the concentration of surficial oxygen vacancy can be effectively regulated by the NH 4 NO 3. This is facilitated to achieve balanced impedance matching. Therefore, the effective absorption bandwidth (EAB) of the NFC covered the whole X-band and Ku-band. Conduction loss and defect polarization relaxation realized by surficial oxygen vacancies were confirmed to be the key to such wide EAB for the NFC at 8-18 GHz. This work explores the important role of surficial oxygen vacancy engineering in regulating the dielectric parameters of the Ferrites, and provides a feasible strategy of surficial oxygen vacancy engineering for wide EAB electromagnetic performance at the high-frequency. Ultrahigh concentration surficial oxygen vacancy on Ferrites Foam achieves balanced impedance matching both in X-band and Ku-band. [Display omitted] [ABSTRACT FROM AUTHOR]

The urgent needs of information security and the target stealth has led to an increasing demand for lightweight, high-performance electromagnetic wave absorbing materials. Recently, one-dimensional (1D) carbon-based materials based on their specific electrical conductivity and aspect ratios exhibits distinctive microstructural orientation, structural design, impedance matching, component modulation and surface modification. First, the high aspect ratio of the 1D dimensional material is much easier to construct effective conductive absorption networks. Second, the distinct voids in the networks built from 1D materials is facilitate to optimize the degree of impedance matching. In this paper, we review the recent research progress of 1D carbon-based microwave absorbing materials, including the types of 1D carbon-based composites, design strategies, synthesis methods, and the structure-function relationship of microwave absorbing materials. Finally, the challenges and prospects of 1D carbon-based materials for future applications are discussed. This critical review is timely and aims to provide researchers with a comprehensive understanding of the state-of-the-art in the design of 1D carbon-based material assemblies for lightweight microwave absorption, and to stimulate further innovation for ultralight carbon-based electromagnetic absorption material. 1D carbon-based materials with a pretty high aspect ratios are great facilitate to construct the effective electromagnetic absorption networks and provides more possibilities for designing lightweight EWA materials based on their novel and special mechanism of such network structures. [Display omitted] • 1D carbon-based EMW absorbing materials are great facilitate to construct the effective EMW absorption networks. • Clarifying the EMW absorption mechanism of 1D carbon-based composite EMW absorbing materials. • Reviewing the main contributions of 1D carbon-based composite microwave absorbing materials in EMW absorption. • Discussing future research directions and challenges for 1D carbon-based composite EMW absorbing materials. [ABSTRACT FROM AUTHOR]

Grain boundary capacitance effect in iron-based magnetic composites achieves 100% C-band absorption coverage. [Display omitted] • Grain boundary capacitance layer effectively broadens the absorption bandwidth of magnetic materials. • The grain boundary capacitance effect achieves 100% C-band absorption coverage. • Grain boundary capacitance layer can effectively enhance the dielectric constant of magnetic materials. • Magnetic materials with grain boundary capacitance layers can meet broadband impedance matching. • Grain boundary capacitance effect derives from the well-developed large-angle grain boundaries (120°). Urgently, the absorbing bandwidth of magnetic materials is enormously limited in C-band by the exorbitant magnetic response. There are few reports about C-band absorber. In this paper, iron-based magnetic composites with large-angle grain boundaries (120°) were prepared by gelatinized starch assisted separation nucleation and solid phase sintering. Noteworthily, grain boundary capacitance layer is formed at the grain boundaries, effectively enhancing its dielectric parameters. This is facilitated to achieve balanced impedance matching. Therefore, the effective absorption bandwidth (EAB) of FFC-B covered the whole C-band (4–8 GHz). Natural resonance and impedance matching realized by grain boundary capacitance effect were confirmed to be the key to such wide EAB for FFC-B in C-band. This work explores the important role of grain boundary capacitance effect in regulating the dielectric parameters of iron-based magnetic materials, and provides a feasible strategy of grain boundary engineering for the low-frequency and wide EAB electromagnetic performance. [ABSTRACT FROM AUTHOR]

Highlights: [•] Fe@C@YBO3:Eu3+ nanocomposites with the core-shell structured were synthesized. [•] Their structure, magnetic and luminescent properties are researched. [•] The electronic transmission between the luminescent and magnetic properties of Fe@C@YBO3:Eu3+ composites is discussed. [ABSTRACT FROM AUTHOR]

A series of different concentrations of Eu and Dy ions co-doping yttrium vanadate phosphors coated with FeO (YVO:Eu, Dy@FeO) was successful prepared by using two steps route including sol-gel method and hydrothermal method. The resulting phase formation, particle morphology, structure, luminescent, and magnetic properties were examined by X-ray diffraction, transmission electron microscopy, photoluminescence spectra, and vibrating sample magnetometer. The results indicate that the diameter of the YVO:Eu, Dy@FeO nanocomposites is 100-300 nm. The special saturation magnetization Ms of the nanocomposites is 53 emu/g. Additionally, the emission intensities of YVO:Eu or Dy ions are regularly changed with the emission doping concentrations. After coating with FeO, the variation of the luminescent intensity of YVO:Eu, Dy@FeO magnetic phosphors is different. [ABSTRACT FROM AUTHOR]

Facing environmental pollution, the development of semiconductor photocatalysts with efficient electron-hole pairs separation is necessary for better performance optimization and utilization. Here, a direct Z-scheme BiOBr–NiO-x% (x ​= ​5, 10, 20, 30) photocatalysts with outstanding photocatalytic activity for dye degradation were prepared via the hydrothermal process. The XRD, XPS, FESEM, HRTEM and UV–vis DRS were used to characterize the components, phase structure, morphology and optical properties of the prepared samples. The prepared nano-flower like BiOBr–NiO-x% (x ​= ​5, 10, 20, 30) composites had an extensive visible light absorption range and more vigorous absorption intensity than pure BiOBr. All the prepared composites exhibited better photocatalytic activity for rhodamine (RhB) degradation than that of pure BiOBr, with BiOBr/NiO-20% showing the best photocatalytic efficiency. The photocatalytic efficiency had reached 98% within 50 ​min for the BiOBr/NiO-20% composite. Due to the tight interfacial contact and matching band positions between BiOBr and NiO, a direct Z-scheme BiOBr/NiO heterojunction was built, which accelerated the visible light absorption, superior separation of photoinduced electron-hole pairs in space and improved the oxidation and reduction capacity of the catalysts, further leading to the excellent photocatalytic activity for degradation of RhB. • A direct Z-scheme nano-flower BiOBr–NiO heterojunction was prepared. • Tight interfacial contact and matching band positions are responsible for direct Z-scheme. • The direct Z-scheme accelerates light absorption, superior spatial separation of carries and re-dox capacity. [ABSTRACT FROM AUTHOR]