Tuning magneto-dielectric properties of Co_(2)Z ferrites via Gd doping for high-frequency applications

Magneto-dielectric properties of Co_(2)Z ferrite materials are tuned via Gd doping for applications in high-frequency antennas and filters in the present work.Ba_(3)Co_(2)Fe_(24-x)Gd_(x)O_(41)(x=0.00,0.05,0.10,0.15,and 0.20)materials are successfully prepared by using solid-state method at 925℃for 4 h with 2.5-wt%Bi_(2)O_(3)sintering aids.The content of Gd^(3+)ion can affect micromorphology,grain size,bulk density,and magneto-dielectric properties of the ferrite.With Gd^(3+)ion content increasing,saturation magnetization(Ms)first increases and then decreases.The maximum value of Ms is 44.86 emu/g at x=0.15.Additionally,sites occupied by Gd^(3+)ions can change magnetic anisotropy constant of the ferrite.Magnetocrystalline anisotropy constant(K_1)is derived from initial magnetization curve,and found to be related to spin-orbit coupling and intersublattice interactions between metal ions.The real part of magnetic permeability(μ′)and real part of dielectric permittivity(ε′)are measured in a frequency range of 10 MHz-1 GHz.When x=0.15,material has excellent magneto-dielectric properties(μ′≈12.2 andε′≈17.61),low magnetic loss(tanδμ≈0.03 at 500 MHz),and dielectric loss(tanδε≈0.04 at 500 MHz).The results show that Gd-doped Co_(2)Z ferrite has broad application prospects in multilayer filters and high-frequency antennas.

Photoelectrocatalytic principles for meaningfully studying photocatalyst properties and photocatalysis processes:From fundamental theory to environmental applications

Photocatalysis is critically important for environmental remediation and renewable energy technologies.The ability to objectively characterize photocatalyst properties and photocatalysis processes is paramount for meaningful performance evaluation and fundamental studies to guide the design and development of high-performance photocatalysts and photocatalysis systems.Photocatalysis is essentially an electron transfer process,and photoelectrocatalysis(PEC)principles can be used to directly quantify transferred electrons to determine the intrinsic properties of photocatalysts and photocatalysis processes in isolation,without interference from counter reactions due to physically separated oxidation and reduction half-reactions.In this review,we discuss emphatically the PEC-based principles for characterizing intrinsic properties of photocatalysts and important processes of photocatalysis,with a particular focus on their environmental applications in the degradation of pollutants,disinfection,and detection of chemical oxygen demand(COD).An outlook towards the potential applications of PEC technique is given.

Microstructure characterization and thermal properties of hypereutectic Si-Al alloy for electronic packaging applications

The rapid solidified process and hot press method were performed to produce three hypereutectic 55%Si-Al, 70%Si-Al and 90%Si-Al alloys for heat dissipation materials. The results show that the atomization is an effective rapid solidified method to produce the Si-Al alloy and the size of atomized Si-Al alloy powder is less than 50 μm. The rapid solidified Si-Al alloy powder were hot pressed at 550 ℃ with the pressure of 700 MPa to obtain the relative densities of 99.4%, 99.2% and 94.4% for 55%Si-Al, 70%Si-Al and 90%Si-Al alloys, respectively. The typical physical properties, such as the thermal conductivity, coefficient of thermal expansion （CTE） and electrical conductivity of rapid solidified Si-Al alloys are acceptable as a heat dissipation material for many semiconductor devices. The 55%Si-Al alloy changes greatly （CTE） with the increase of temperature but obtains a good thermal conductivity. The CTE of 90%Si-Al alloy matches with the silicon very well but its thermal conductivity value is less than 100 W/（m.K）. Therefore, the 70%Si-Al alloy possesses the best comprehensive properties of CTE and thermal conductivity for using as the heat sink materials.

A New Two-Parameter Heteromorphic Elliptic Equation: Properties and Applications

The ellipse and the superellipse are both planar closed curves with a double axis of symmetry. Here we show the isoconcentration contour of the simplified two-dimensional advection-diffusion equation from a stable line source in the center of a wide river. A new two-parameter heteromorphic elliptic equation with a single axis of symmetry is defined. The values of heights, at the point of the maximum width and that of the centroid of the heteromorphic ellipse, are derived through mathematical analysis. Taking the compression coefficient θ = b/a = 1 as the criterion, the shape classification of H-type, Standard-type and W-type for heteromorphic ellipse have been given. The area formula, the perimeter theorem, and the radius of curvature of heteromorphic ellipses, and the geometric properties of the rotating body are subsequently proposed. An illustrative analysis shows that the inner contour curve of a heteromorphic elliptic tunnel has obvious advantages over the multiple- arc splicing cross section. This work demonstrates that the heteromorphic ellipses have extensive prospects of application in all categories of tunnels, liquid transport tanks, aircraft and submarines, bridges, buildings, furniture, and crafts.

Magnetic Properties and Applications of Newly-developed Fe_(73.5)Cu_1Nb_(1.5)V_(1.5)Si_(13.5)B_9 Alloy

The synthetical soft magnetic properties including d.c. and a.c. magnetic properties and pulse magnetic property are reported for a newly-developed nanocrystalline Fe73.5Cu1 Nb1.5V1.5Si13.5B9 alloy The new alloy possesses high d.c. relative initial permeability of 12.5×104 and low coerciv ity of 0.54 A/m. Under the conditions of Bm=0.3 T, f=100 kHz and Bm=0.2 T, f=200 kHz the core losses of the new alloy are 543 kW·m-3 and 834 kW.m-3, respectively which can be compa rable with those of nanocrystalline Fe73.5Cu1Nb3Si13.5B9 alloy. The analyses of core losses have been carried out in the wider range of f=20～104 kHz and Bm=0.0025～0.8 T and the approxi mate expression P(kW·m-3)=1.803 B:f1.77 has been obtained. The analyses of core losses in the range of f=20～104 kHz and Bmf=(10～40)×103(T.Hz) have shown that the core loss and the corresponding amplitude permeability roughly vary as P = 2.347×10-6(Bmf)1.97f-0.2231 and μa = 9.56× 105f-0.7464, respectively for the given product B.f. Some practical applica tions have also been mentioned.

Sintering and Mechanical Properties of Magnesium and Fluorine Co-Substituted Hydroxyapatites

Biological apatites contain several elements as traces. In this work, Magnesium and fluorine co-substituted hydroxyapatites with the general formula Ca9Mg(PO4)6(OH)2-yFy, where y = 0, 0.5, 1, 1.5 and 2 were synthesized by the hydrothermal method. After calcination at 500℃, the samples were pressureless sintered between 950℃ and 1250℃. The substitution of F- for OH- had a strong influence on the densification behavior and mechanical properties of the materials. Below 1200℃, the density steeply decreased for y = 0.5 sample. XRD analysis revealed that compared to hydroxylfluorapatite containing no magnesium, the substituted hydroxyfluorapatites decomposed, and the nature of the decomposition products is tightly dependent on the fluorine content. The hardness, elastic modulus and fracture toughness of these materials were investigated by Vickers’s hardness testing. The highest values were 622 ± 4 GPa, 181 ± 1 GPa and 1.85 ± 0.06 MPa.m1/2, respectively.

Pseudohalide induced tunable electronic and excitonic properties in two-dimensional single-layer perovskite for photovoltaics and photoelectronic applications

Two-dimensional(2D) layered organic-inorganic hybrid perovskites have attracted much more attention for some applications than their three-dimensional(3D) perovskite counterparts due to their promising thermal and moisture stabilities.In particular, the 2D perovskite devices have shown better promise for optoelectronic applications.However, tunability of optoelectronic properties is often demanded to improve the device performance.Herein, we adopt a newly method to tune the electronic properties of 2D perovskite by introducing pseudohalide into the structure.In this work, we designed a pseudohalidesubstituted 2D perovskite by substituting the out-of-plane halide with pseudohalide and studied the electronic and excitonic properties of 2D-BA2MX4 and 2D-BA2MX2Ps2(M=Ge^(2+), Sn^(2+), and Pb^(2+);X=I;Ps=NCO, NCS, OCN, SCN, Se CN).We revealed the dependence of electronic properties including band gaps, composition of band edges, bonding characteristics, work functions, effective masses, and exciton binding energies on different pseudohalides substituted in 2D perovskite.Our results indicate that the substitution of pseudohalide in 2D perovskites is energetically favorable and can significantly affect the bonding characteristics as well as the CBM and VBM that often play major role in determining their performance in optoelectronic devices.It is expected that the pseudohalide substitution will be helpful in developing more advanced optoelectronic device based on 2D perovskite by optimizing band alignment and promoting charge extraction.

Synthesis, properties, and applications of graphene oxide/reduced graphene oxide and their nanocomposites

Thanks to their remarkable mechanical, electrical, thermal, and barrier properties, graphene-based nanocomposites have been a hot area of research in the past decade. Because of their simple top-down synthesis, graphene oxide (GO) and reduced graphene oxide (rGO) have opened new possibilities for gas barrier, membrane separation, and stimuli-response characteristics in nanocomposites. Herein, we review the synthesis techniques most commonly used to produce these graphene derivatives, discuss how synthesis affects their key material properties, and highlight some examples of nanocomposites with unique and impressive properties. We specifically highlight their performances in separation applications, stimuli-responsive materials, anti-corrosion coatings, and energy storage. Finally, we discuss the outlook and remaining challenges in the field of practical industrial-scale production and use of graphene-derivative-based polymer nanocomposites.

Effects of Different Nitrogen Applications on Soil Physical, Chemical Properties and Yield in Maize (<i>Zea mays</i>L.)

Application of nitrogen (N) fertilizer is one of the most important approaches on improving maize grain yield. However, as is known to all, overuse N fertilizer not only leads to decline of N use efficiency and maize yield, but also leads to potential risk to environment pollution. This experiment was conducted to determine the effects of N fertilizer applications with nine different treatments on soil physical-chemical characters and maize grain yield using hybrid variety Zhengdan 958 in 2011 and 2012. Results indicated that the soil bulk densities of T2 (CK) and T1 were the lowest compared to other treatments in 2011 and 2012, respectively, whereas the soil bulk density of T5 in 2011 and T3 in 2012 were higher than other treatments. The soil porosity and field capacity of T5 in 2011 and T3 in 2012 were lower than other treatments, but those of CK in 2011 and T1 in 2012 were higher than other treatments. The pH values of T3 to T7 were lower than other treatments. These results indicated that the soil bulk densities were increased, whereas the soil porosity, field capacity and values pH were decreased by N application at different stages. N application could increase the N contents of leaf and stem, whereas less or excess N application should not significant improve maize yield. Although the soil organic matter and total N contents of T3 were the highest in both 2011 and 2012, the yield of T4 is the highest in both 2011 and 2012. The application amount, period and times of N fertilizer were important to maize yield.

Mechanical properties and potential applications of magnesium alloys

Magnesium alloys, having high specific strength, with a density only 2/3 of that of aluminum and 1/4 of carbon steels, have become ideal materials for low mass applications such as automobiles and electronic devices. It was dealt with the state of the art in developing cost effective, low mass, high ductility and high creep resistance magnesium alloys that are suitable for structures and power train applications.

Tamanu Oil in Acne Management: Potential Anti-Inflammatory and Wound-Healing Properties for Scar Reduction

Tamanu oil, derived from the nuts of Calophyllum inophyllum, has gained increasing attention for its potential in acne management due to its purported anti-inflammatory and wound-healing properties. This analysis evaluates the efficacy of tamanu oil in acne treatment with a specific focus on its impact on inflammation and scar reduction. The novelty of this research lies in its comprehensive analysis of tamanu oil’s dual mechanism of action: reducing acne-related inflammation and promoting the healing of acne scars. Clinical trials and laboratory analyses were conducted to assess the oil’s effectiveness in diminishing erythema, swelling, and post-acne scarring compared to conventional treatments. Preliminary findings demonstrate that tamanu oil significantly reduces inflammation and accelerates wound healing, potentially offering a promising adjunct or alternative to standard acne therapies. Future research should aim to optimize formulation and application protocols, long-term effects, and comparative therapeutic efficacy with other anti-inflammatory agents. Tamanu oil offers a novel and effective approach to acne management, with potential advantages that go beyond inflammation reduction to include enhanced scar reduction, making it a subject that warrants further investigation.

Two/Quasi-two-dimensional perovskite-based heterostructures:construction,properties and applications

Two-dimensional(2D)/quasi-2D organic-inorganic halide perovskites are regarded as naturally formed multiple quantum wells with inorganic layers isolated by long organic chains,which exhibit layered structure,large exciton binding energy,strong nonlinear optical effect,tunable bandgap via changing the layer number or chemical composition,improved environmental stability,and excellent optoelectronic properties.The extensive choice of long organic chains endows 2D/quasi-2D perovskites with tunable electron-phonon coupling strength,chirality,or ferroelectricity properties.In particular,the layered nature of 2D/quasi-2D perovskites allows us to exfoliate them to thin plates to integrate with other materials to form heterostructures,the fundamental structural units for optoelectronic devices,which would greatly extend the functionalities in view of the diversity of 2D/quasi-2D perovskites.In this paper,the recent achievements of 2D/quasi-2D perovskite-based heterostructures are reviewed.First,the structure and physical properties of 2D/quasi-2D perovskites are introduced.We then discuss the construction and characterizations of 2D/quasi-2D perovskite-based heterostructures and highlight the prominent optical properties of the constructed heterostructures.Further,the potential applications of 2D/quasi-2D perovskite-based heterostructures in photovoltaic devices,light emitting devices,photodetectors/phototransistors,and valleytronic devices are demonstrated.Finally,we summarize the current challenges and propose further research directions in the field of 2D/quasi-2D perovskite-based heterostructures.

Microstructure and electrical properties of CeO_2 ultra-thin films for MFIS FeRAM applications

A detailed investigation about the dependence of microstructure and electrical properties on annealing temperature was carried out for cerium oxide(CeO2) ultra-thin films(18 nm to 110 nm) on n-type Si(100) substrates by RF magnetron sputtering. Substrate temperature was kept constant at 400 ℃ for all samples. The as-deposited films were subsequently annealed in air ambient at 700,800 and 900 ℃ for 1 h respectively. The crystallinity and surface morphology of the CeO2 films were analyzed with X-ray diffractometer(XRD),scanning electron microscope(SEM),atomic force microscope(AFM) and Raman scattering measurement. Electrical properties of the Au/CeO2/Si/Au structure were examined by high frequency capacitance-voltage(C-V) characteristics at 1 MHz and leakage current density-electric field(J-E) characteristics. A Raman peak of the CeO2 thin films was seen at 463 cm-1. From C-V data,these films exhibit dielectric constants ranging from 18 to 23,the hysteresis width(-VFB) ranging from 0.015 V to 0.12 V and the density of trapped charges ranging from 1.45×1011 to 3.01×1011 cm-2. A leakage current of 4.75×10-8 -9.0×10-7 A/cm2 at 2 MV/cm was observed. The experimental results show that the CeO2 buffer layers are suitable for non-volatile metal-ferroelectric-insulator-semiconductor(MFIS) structure field-effect-transistors(FETs) memory applications.

Mono-functionalized pillar[n]arenes: Syntheses, host–guest properties and applications

Pillar[n]arenes are a novel class of macrocyclic hosts reported by Ogoshi and co-workers in 2008. Because of their rigid pillar structures, interesting host-guest properties and ease of modifications, pillar[n]arenes have been developed rapidly in the field of functional materials and biomedicine. The modifications of pillar[n]arenes at different positions can give them varied characteristics. Functional groups can be introduced into one position of pillar[n]arenes without changing host-guest properties of pillar[n]arenes. A series of pillar[n]arene dimers, trimers, tetramers and metallacycles can be constructed by mono-functionalized pillar[n]arenes. In this review, two synthetic methods of mono-functionalized pillar[n]arenes are summarized and structures containing mono-functionalized pillar[n]arenes are described. Furthermore, the applications of mono-functionalized pillar[n]arenes in different fields (e.g., supramolecular polymers, sensors, molecular machines, catalysis, biological applications and light-harvesting systems) are also introduced. Hopefully, this article will be useful for researchers studying pillar[n]arenes, especially the mono-functionalized pillar[n]arenes.

Materials properties and device applications of semiconducting bismuth oxyselenide

Layered two-dimensional(2D)materials have garnered marvelous attention in diverse fields,including sensors,capacitors,nanocomposites and transistors,owing to their distinctive structural morphologies and superior physicochemical properties.Recently,layered quasi-2D materials,especially layered bismuth oxyselenide(Bi2O2Se),are of particular interest,because of their different interlayer interactions from other layered 2D materials.On this basis,this material offers richer and more intriguing physics,including high electron mobility,sizeable bandgap,and remarkable thermal and chemical durability,rendering it an utterly prospective contender for use in advanced electronic and optoelectronic applications.Herein,this article reviews the recent advances related with Bi2O2Se.Initially,its structural characterization,band structure,and basic properties are briefly introduced.Further,the synthetic strategies for the preparation of Bi_(2)O_(2)Se are presented.Furthermore,the diverse applications of Bi2O2Se in the field of electronics and optoelectronics,photocatalytic,solar cells and sensing were summarized in detail.Ultimately,the challenges and future perspectives of Bi2O2Se are included.

State-of-the-art of biomass-derived carbon dots: Preparation, properties, and applications

Carbon dots (CDs) have attracted considerable attention as a new type of fluorescent carbon nanomaterial because of their excellent optical properties, biocompatibility, and high electrical conductivity. Research on CDs has been conducted for nearly two decades and has focused on numerous precursors, various synthesis conditions and properties and applications of CDs. Biomass is critical in the green development of CDs because of its low cost, environmental friendliness, and sustainable properties. This review focuses on the advantages and applications of biomass-derived CDs. In addition, the challenges of photobleaching, toxicity, and stability of biomass-based CDs are discussed in detail. Lastly, the prospects and challenges of biomass-derived CDs are highlighted.

Additive manufacturing of promising heterostructure for biomedical applications

As a new generation of materials/structures,heterostructure is characterized by heterogeneous zones with dramatically different mechanical,physical or chemical properties.This endows heterostructure with unique interfaces,robust architectures,and synergistic effects,making it a promising option as advanced biomaterials for the highly variable anatomy and complex functionalities of individual patients.However,the main challenges of developing heterostructure lie in the control of crystal/phase evolution and the distribution/fraction of components and structures.In recent years,additive manufacturing techniques have attracted increasing attention in developing heterostructure due to the unique flexibility in tailored structures and synthetic multimaterials.This review focuses on the additive manufacturing of heterostructure for biomedical applications.The structural features and functional mechanisms of heterostructure are summarized.The typical material systems of heterostructure,mainly including metals,polymers,ceramics,and their composites,are presented.And the resulting synergistic effects on multiple properties are also systematically discussed in terms of mechanical,biocompatible,biodegradable,antibacterial,biosensitive and magnetostrictive properties.Next,this work outlines the research progress of additive manufacturing employed in developing heterostructure from the aspects of advantages,processes,properties,and applications.This review also highlights the prospective utilization of heterostructure in biomedical fields,with particular attention to bioscaffolds,vasculatures,biosensors and biodetections.Finally,future research directions and breakthroughs of heterostructure are prospected with focus on their more prospective applications in infection prevention and drug delivery.

Study of the Electronic Structure and Optical Properties of Rare Earth Luminescent Materials

Rare earth luminescent materials have attracted significant attention due to their wide-ranging applications in the field of optoelectronics. This study aims to delve into the electronic structure and optical properties of rare earth luminescent materials, with the goal of uncovering their importance in luminescence mechanisms and applications. Through theoretical calculations and experimental methods, we conducted in-depth analyses on materials composed of various rare earth elements. Regarding electronic structure, we utilized computational techniques such as density functional theory to investigate the band structure, valence state distribution, and electronic density of states of rare earth luminescent materials. The results indicate that the electronic structural differences among different rare earth elements notably influence their luminescence performance, providing crucial clues for explaining the luminescence mechanism. In terms of optical properties, we systematically examined the material’s optical behaviors through fluorescence spectroscopy, absorption spectroscopy, and other experimental approaches. We found that rare earth luminescent materials exhibit distinct absorption and emission characteristics at different wavelengths, closely related to the transition processes of their electronic energy levels. Furthermore, we studied the influence of varying doping concentrations and impurities on the material’s optical properties. Experimental outcomes reveal that appropriate doping can effectively regulate the emission intensity and wavelength, offering greater possibilities for material applications. In summary, this study comprehensively analyzed the electronic structure and optical properties of rare earth luminescent materials, providing deep insights into understanding their luminescence mechanisms and potential value in optoelectronic applications. In the future, these research findings will serve as crucial references for the technological advancement in fields such as LEDs, lasers, and bioimaging.

A Review on Metal-and Metal Oxide-Based Nanozymes:Properties,Mechanisms,and Applications

Since the ferromagnetic(Fe_(3)O_(4))nanoparticles were firstly reported to exert enzyme-like activity in 2007,extensive research progress in nanozymes has been made with deep investigation of diverse nanozymes and rapid development of related nanotechnologies.As promising alterna-tives for natural enzymes,nanozymes have broadened the way toward clinical medicine,food safety,environmental monitoring,and chemical production.The past decade has witnessed the rapid development of metal-and metal oxide-based nanozymes owing to their remarkable physicochemical proper-ties in parallel with low cost,high stability,and easy storage.It is widely known that the deep study of catalytic activities and mechanism sheds sig-nificant influence on the applications of nanozymes.This review digs into the characteristics and intrinsic properties of metal-and metal oxide-based nanozymes,especially emphasizing their catalytic mechanism and recent applications in biological analysis,relieving inflammation,antibacterial,and cancer therapy.We also conclude the present challenges and provide insights into the future research of nanozymes constituted of metal and metal oxide nanomaterials.

Emerging low-dimensional black phosphorus:from physical-optical properties to biomedical applications

Low-dimensional black phosphorus(BP)is a class of nanomaterial derived from layered semiconductor BP which has gained tremendous attention in a variety of fields,owing to its uncommon structural features and appealing physical properties.More surprisingly,it has addressed current biomedical obstacles due to its orthorhombic puckered honeycomb crystal structure and unique properties such as tunable direct-bandgap,high carrier mobility,and exceptional photo-responsiveness.However,few reviews have focused on the interactions of low-dimensional BP’s physical properties with its biomedical performances.Herein,we discuss the physical properties of low-dimensional BP and potential biomedical applications associated with these physical properties.Moreover,different preparation methods,surface modification techniques,and future challenges,as well as future outlooks,are presented.This comprehensive review will provide a clear understanding of the relationship between lowdimensional BP’s physical properties and biomedical performances,with the ultimate goal of better knowledge of utilizing BP.