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The deep understanding of the crystal structure and composition-structure relationship is important for modifying and designing solids to obtain functional materials with customized properties. However, because of multiple compositions and complex structures in some spinel solid solutions, the composition-structure relationship is unknown, or becomes very complicated and difficult to be controlled. In this work, the solid-state magic-angle spinning nuclear magnetic resonance (MAS NMR) technique and powder X-ray diffraction (XRD) Rietveld refinement were combined to characterize the crystal structure of quaternary disordered Mg

Inspired from the occlusion of macromolecules in mineral crystals during the biomineralization process, the occlusion mechanism of functional guest species into a host matrix is gradually revealed in artificial systems. However, the guest species within calcite crystals are limited to the nanometer scale. Herein, using amorphous calcium carbonate (ACC) as a precursor and taking advantage of the crystallization of vaterite by the attachment of ACC nanoparticles, micrometer-sized modified Escherichia coli (E. coli) was incorporated into vaterite crystals. The occlusion content of bacteria within the vaterite crystal could reach up to 16 wt%. On the contrary, the occlusion of E. coli into calcite crystals, which proceeded via ion-by-ion addition growth, was only confined to the surface layer. Through modifying the surface structure or chemical composition of bacteria, the strong interaction between the surface of the bacteria and calcium carbonate has proved to be the key factor for successful occlusion. Interestingly, the genetically modified green fluorescent protein (GFP)-E. coli/vaterite composites exhibited stable fluorescence for more than six months with little attenuation and the lifetime could be more than 1.2 μs. It was demonstrated that a combination of the amorphous precursor crystallization pathway and a suitable surface structure of the foreign species can significantly enhance the occlusion efficiency of micrometer-sized species in crystals.

Recent research has shown that very rapid heating of 3YSZ powder compacts (ultra-fast firing), whether by passing an electric current through the sample (flash sintering) or by using external heat sources, causes a great acceleration of densification rate for a given relative density and temperature. Here, the microstructural evolution of 3YSZ is studied using four sintering methods with widely differing heating rates, produced with or without electric fields. The microstructural development depended greatly on thermal history. Most significantly, slow, conventional heating resulted in pores much larger than the grain size, whereas most pores were smaller than the grain size with the rapid heating methods, whether the heating involved an electric field or not. The smaller pore size clearly provides a major contribution to the acceleration of densification following rapid heating. In contrast, grain growth was not suppressed by rapid heating but was suppressed by an electric field.

Simple Summary Due to the fact of their low toxicity, small side effects, and little residue, increasing attention has been paid to herbs as environmentally friendly immunostimulants. Results from the present study indicate that adding Glycyrrhiza uralensis to the feed can improve the growth and survival of Lates calcarifer and significantly promote the expression of immune-related genes in the liver and head kidney of Lates calcarifer. The optimum inclusion level of Glycyrrhiza uralensis should be 1–3%. Abstract To understand the impacts of dietary Glycyrrhiza uralensis on the immune responses of Lates calcarifer, the expression of immune-related genes including crp, c-3, c-4, mtor, mlst-8, eif4e, hsp-70, hsp-90, il-8il-8, il-10, tgfβ1, tnf, ifn-γ1, and mxf in L. calcarifer juveniles was evaluated in this study. Fish were fed experimental diets with G. uralensis levels of 0%, 1%, 3%, and 5% for 56 days. The results showed that dietary G. uralensis could improve the growth and survival of L. calcarifer and regulate the immune-related genes’ expression in L. calcarifer. Dietary G. uralensis significantly upregulated the expression level of crp, mtor, hsp-90, c-3, and c-4 genes in the liver of L. calcarifer, while hsp-70 gene expression was nearly downregulated. It did not upregulate the expression of elf4e and mlst-8 in the 1% and 3% inclusion groups, but it was the exact opposite in the 5% inclusion group. G. uralensis significantly affected the expression of il-8, il-10, tnf, ifn-γ1, mxf, and tgfβ1 in the head kidney of L. calcarifer. G. uralensis upregulated the expression of tnf and tgfβ1 consistently, but ifn-γ1 was at a low expression level. The expression of il-8 and il-10 was upregulated in the 1% group, while it was downregulated in the 5% group. The results from the present study indicate that dietary G. uralensis appeared to improve the immune function of L. calcarifer, and the optimum inclusion level should be between 1–3%.

To investigate the possible effects of sulfamonomethoxine (SMM) on Nile tilapia (Oreochromis niloticus), we quantitatively evaluated the microbial shifts in the intestines of Nile tilapia in response to different doses of SMM (200 and 300 mg/kg) using 16S rRNA gene sequencing. At the phylum level, the control group (0 mg kg−1 SMM) was dominated by Actinobacteria, Proteobacteria, and Firmicutes. In the treatment groups, Firmicutes, Proteobacteria, and Chloroflexi were the dominant phyla. Cluster analysis indicated that the two groups treated with SMM clustered together. Similarly, the bacterial families that dominated the control group differed from those dominating the treatment groups. The changes in intestinal microbial composition over time were similar between the two SMM treatment groups. In both groups, the abundances of some families, including the Bacillaceae, Streptococcaceae, and Pseudomonadaceae, increased first and then decreased. Overall, the addition of SMM to the feed changed the structure of the intestinal microbiota in Nile tilapia. This study improves our understanding of the impact of SMM on the intestinal microenvironment of Nile tilapia. Our results provide guidelines for the feasibility of SMM use in aquaculture production., This study was conducted to investigate the possible impact of sulfamonomethoxine (SMM) on Nile tilapia (Oreochromis niloticus). The data indicate that the addition of SMM in the feed had a significant effect on the intestinal microbiota structure. The community richness decreased with time after treatment with 300 mg/kg of SMM added to the feed. Therefore, it is recommended to shorten the medication time and to use a low dose of SMM mixed with the feed.

The densification behaviors of pure B4C and B4C-ZrO2 mixtures were compared during hot pressing. The results showed that in-situ formed ZrB2 effectively enhanced the densification process of B4C-ZrO2 mixtures, more significantly during the intermediate stage. Within the relative density ranging from 0.75 to 0.90, the B4C-15 wt%ZrO2 mixture (B15Z) achieved the maximum densification rate as twice much as that of pure B4C. The stress exponent n>3 indicated plastic deformation was the dominant densification mechanism of B15Z. The viscosities of plastic flow were evaluated using Murray-Rodger-William equation and the viscosity of B15Z was only a quarter of that in pure B4C. The sintering activation energy was calculated to be 305.9 kJ/mol for pure B4C and 197 kJ/mol for B15Z, respectively. It was proposed that the lower viscosity of plastic flow and activation energy accelerated the sliding and propagating motions of plastic flow, by which underlain the enhanced densification behaviors of B4C-ZrO2 mixtures.

Non-stoichiometric MgO·1.8Al2O3 spinel transparent ceramic was prepared from synthesized single phase powder through an aqueous gel-casting forming technique. In order to prevent hydrolysis, the powder was specially treated in toluene with stearic acid and then dispersed in an aqueous solution with the help of amphoteric compound Tween 80 and dispersant TMAH. The surface modification process was confirmed by various techniques such as Fourier transmission infrared absorption spectroscopy (FT-IR), pH value, zeta potentials and rheological properties. Afterwards, gel-casted green compacts were debinded, pressureless-sintered (PS) and hot-isostatic-pressed (HIP). Highly transparent MgO·1.8Al2O3 ceramics (3.6 mm in thickness) with in-line transmittance values of 77–82 % in visible region and higher than 85% in near infrared region were obtained. The samples exhibited Knoop hardness of 12.2 ± 0.2 GPa, Young’s modulus of 302 GPa, refractive index of 1.7046, and Abbe's number of 75.8.

A novel method, namely flash spark plasma sintering (FSPS), combining flash sintering and electric field assisted sintering, was utilized to densify boron carbide/titanium diboride (B4C/TiB2) composites. Further, sintering homogeneity of the composites with different contents of TiB2 was systematically investigated and theoretical model was built. Results indicated that addition of 50 wt% TiB2 led to the densification of B4C/TiB2 composite by up to 97.7% with regional range 1.9% at 1872 °C under pressure of 4 MPa in 60 s. The preferential pathway of TiB2 network proves to disperse the central current and distribute thermal flow throughout the specimen possibly via tunneling, electronic field emission effect at first stage and lower-resistance composite pathway latter, contributing to the increased homogeneity.

High-quality boron nitride nanotubes were successfully synthesized via a novel two-step method, including citrate-nitrate combustion reaction and catalytic chemical vapor deposition. The composition, bonding features and microstructures of as-synthesized sample were investigated by X-ray diffraction, Fourier transform infrared spectroscopy, Raman microscopy, X-ray photoelectron spectroscopy, scanning electron microscopy coupled with energy dispersive X-ray spectroscopy, transmission electron microscopy and selected area electron diffraction techniques. The results show that the as-synthesized boron nitride nanotubes with smooth surface are relatively pure. The diameter ranges between 20 and 80 nm, while the length is about dozens of micrometers. During the synthesis process of boron nitride nanotubes, citric acid chelates the cobalt ions and reacts with nitrate to form the cobalt oxide, depositing on the surface of boron powder homogeneously. The catalyst content and annealing temperature have a significant impact on the composition and microstructures of the final products. Based on the experimental results and thermodynamic analysis, the possible chemical reactions are listed, and vapor-liquid-solid mechanism is proposed to be dominant for the formation of boron nitride nanotubes.

Water pollution has become a serious global issue owing to the large amounts of contaminants generated from industrial and agricultural development. Recently, various boron nitride-based micro/nano-materials have exhibited efficient sorption capacity for contaminants from water. Herein, novel urchin-like boron nitride hierarchical structure assembled by free-growing boron nitride nanotubes and crapy boron nitride nanosheets is firstly fabricated via a sample two-step approach, including the synthesis of analogous "core-shell" structured boron-containing precursor and thermal catalytic chemical vapor deposition. A combined growth mechanism of vapor-liquid-solid and vapor-solid is proposed to control the formation of BN hierarchical structure. The unique structure exhibits superior removal capacity of 115.07 mg g−1 and 92.85 mg g−1 for Pb2+ and Cu2+ in water solution, respectively. The excellent adsorption performance of the product mainly derives from the vast lattice imperfections, the high-density edge active sites, the expanded interplanar spacing, as well as the unique structural characteristics. They are beneficial for structural stability and enough space for accommodating the adsorbed heavy metal ions. These results indicate that the urchin-like boron nitride hierarchical structure is a promising adsorption material for water treatment.

B4C-TiB2-SiC composites were fabricated via hot pressing using ball milled B4C, TiB2, and SiC powder mixtures as the starting materials. The impact of ball milling on the densification behaviors, mechanical properties, and microstructures of the ceramic composites were investigated. The results showed that the refinement of the powder mixtures and the removal of the oxide impurities played an important role in the improvement of densification and properties. Moreover, the formation of the liquid phases during the sintering was deemed beneficial for densification. The typical values of relative density, hardness, bending strength, and fracture toughness of the composites reached 99.20%, 32.84 GPa, 858 MPa and 8.21 MPa m1/2, respectively. Crack deflection, crack bridging, crack branching, and microcracking were considered to be the potential toughening mechanisms in the composites. Furthermore, numerous nano-sized intergranular/intragranular phases and twin structures were observed in the B4C-TiB2-SiC composite.

Dense ZrB2-SiC-ZrC composites with four different compositions were prepared using ZrC, B4C and Si powders as the starting materials by reactive spark plasma sintering (R-SPS). The evolutions in the phases and microstructures were investigated using XRD, Raman spectrum and SEM. It was found that the formation of ZrB2 and SiC involved two steps. Lower initial content of ZrC results in microstructural refinement and mechanical enhancement. The composite ZrB2− 47.9SiC-4.7ZrC prepared by 5 min sintering at 1800 °C under 30 MPa pressure exhibited the most satisfying combination of properties. The flexural strength, fracture toughness and Vickers hardness were 760 ± 19 MPa, 6.3 ± 0.3 MPa∙m1/2 and 22.7 ± 1.4 GPa, respectively.

The integration of a “brick and mortar” structure and superior fracture toughness of nacre has attracted intensive attention recently. Elucidating the interactions between biomacromolecules and inorganic phases is beneficial to understand the structure-forming process of nacre. Herein, a recombinant protein, ChiSifiCa, mimicking features of the organic matrix in nacre is rationally designed. This protein contains three functional domains, chitin binding (Chi), silk fibroin (Sifi), and calcium ion binding (Ca). The domain order in ChiSifiCa is in the same manner as the distribution of organic matrix in nacre. When ChiSifiCa binds to the surface of chitin, it provides a confined microenvironment facilitating CaCO3 mineralization. The formation of spherical vaterite minerals with a hollow structure was observed under the function of ChiSifiCa. These minerals are assembled by well-aligned nanoplatelets and nanoparticles, distributed in the outer and inner region of the sphere, respectively. The nanoparticles ...

TiN–TiB2–hBN composite powders were synthesized by a nitride boronizing process using TiN and amorphous boron as the raw materials, and the reaction process of TiN–B powder mixture was investigated by heat treatment at elevated temperatures. At 1400 °C in a vacuum, TiN–TiB2–hBN composite powders with a core-shell structure of layered hBN-wrapped TiB2 were obtained, which can be used to prepare ceramic composites with excellent properties. The results showed that B atoms began to diffuse into TiN and replace the N atoms to form TiB2 at high temperature; then, the substituted N escaped outwards, and upon contacted with B, formed hBN at the surface of the TiB2 particles. The relative density, bending strength, and fracture toughness of the 70 vol% TiN–17.6 vol% TiB2–12.4 vol% hBN (TB73) composite prepared by reactive sintering were 98.90%, 521 MPa, and 4.22 MPa m1/2, respectively, which were much higher than that of fabricated via conventional method (TBN73: 88.02%, 198 MPa, and 2.58 MPa m1/2).

Ambient temperature is an important abiotic factor that influences growth performance and physiological functions in sea cucumbers. To understand the molecular responses of the sea cucumber Holothuria leucospilota to acute temperature stress, we performed a de novo transcriptome analysis of body wall tissue from H. leucospilota exposed to 2 hoursh of acute heat (35 ± 1 °C) and cold stress (15 ± 1 °C). A total of 99,015 unigenes were obtained after assembly of the sequenced reads. Compared with a control group maintained at 25.0 ± 1 °C, 1169 differentially expressed unigenes (DEGs) were identified after heat stress, 781 were up-regulated and 388 were down-regulated. After cold stress, 1464 DEGs were identified; 900 were up-regulated and 564 were down-regulated. The annotation of DEGs revealed that heat shock proteins play important roles in protecting H. leucospilota from high temperature stress. Furthermore, KEGG pathway enrichment analysis showed that the categories: “Ribosome” and “Protein processing in endoplasmic reticulum” were strongly affected by heat stress. These two pathways are associated with biosynthesis and processing of proteins, and refolding of misfolded proteins. The lipid metabolism pathways “Sphingolipid metabolism” and “Ether lipid metabolism”, were affected by cold stress. The RNA-Seq results for eight selected DEGs were verified the expression by quantitative real-time PCR analysis. Our results will improve the understanding of the molecular response mechanisms of H. leucospilota to ambient temperature stress.

A novel ZnGa2O4 transparent ceramic was prepared from synthesized single-phase powders by pressureless sintering combined with hot isostatic pressing (HIP) and a post-annealing treatment. The transparent ceramic was fully densified with the average grain size of ∼3.2 μm, which possesses outstanding optical properties, including a high in-line transmittance of 82.03% at 2 μm comparable to its single crystal counterpart (82.52% at 2 μm) and a wide transmission range (0.27-8.7 μm). Such an extended infrared transmission range could be attributed to the lower phonon frequency of ZnGa2O4 spinel. This material also exhibits excellent mechanical properties of Vickers hardness (10.56 ± 0.08 GPa), Young's modulus (227.04 GPa) and fracture toughness (1.83 ± 0.08 MPa/m1/2), as well as high thermal conductivity (19.46 W/m•K) at ambient temperature.

A series of ab initio simulations were performed to investigate the electronic, transparent, and elastic properties of Ca 3 Al 2 Si 3 O 12 and Mg 3 Al 2 Si 3 O 12 which have potential applications in lithography optics, lenses and phosphor materials. From the simulated electronic structure and optical properties, we found that the theoretical transmittance of both compounds reaches 90% above 198 nm in the UV region. The bulk modulus and shear modulus of Ca 3 Al 2 Si 3 O 12 were calculated to be 181.41 and 115.84 GPa, respectively. The anisotropy in elastic properties along different crystallographic direction were found greater in Ca 3 Al 2 Si 3 O 12 than that in Mg 3 Al 2 Si 3 O 12 . The distinct dodecahedral coordinated Ca and Mg in the crystal structures result in the maximum Young's modulus existing in different direction, which is along [1 0 0] direction for Ca 3 Al 2 Si 3 O 12 but [1 1 1] direction for Mg 3 Al 2 Si 3 O 12 . Our theoretical investigations provided a basic understanding on the materials design of Ca 3 Al 2 Si 3 O 12 and Mg 3 Al 2 Si 3 O 12 .

Oyster reefs, which can maintain coastal ecosystems by absorbing storm surge energy, are composed of aggregated oyster shells bonded by bioadhesive secretions containing inorganic minerals. Bioadhesive secretions are formed by cross-linking extracellular liquid, which is rich in organic and inorganic ions, with sand, bacteria, or diatoms. Inspired by such bioprocesses, a mineral hydrogel with excellent 3D printability, rapid self-healing ability (85% recovery within 1 min), high stretchability (>1500% tensile elongation) and ionic conductivity was synthesized by the chelation of polyacrylic acid (PAA) with calcium ions (Ca2+) and subsequent physical cross-linking of PAA with modified amorphous calcium phosphate (ACP) nanoparticles. With such mineral hydrogels, ionic skin was successfully prepared, which could recognize the bending degrees of the index finger and sensitively sense the tensile strain (approximately 33 ms). Moreover, the ionic skin can distinguish external temperature stimuli and work stably at a temperature of 75 °C. These performances exhibit the great mechano-sensing and thermosensing abilities of ionic skin, showing promising applications in various fields, such as wearable sensors, for withstanding high ambient temperatures and the next generation of soft intelligent robots.

Biological materials have excellent mechanical properties due to their organized structures from nano- to macro-scale. Artificial manufacture of materials with anisotropic microstructures still remains challenging. We described a stress-induced method to fabricate anisotropic alginate fibers. Organic-inorganic composite fibers were obtained by incorporating aligned hydroxyapatite (HAP) nanowires into the alginate fiber. Detailed structural characterization revealed the bone-like structure of the HAP-reinforced alginate fibers. Tensile test results showed that the maximum Young's modulus and tensile strength were 4.3 GPa and 153.8 MPa, respectively. A multiscale reinforcing mechanism is proposed after the discussion of the structure-property relationship: highly ordered and compacted nanofibrils aligned along the longitudinal direction at the microscale, and two kinds of alginate gels with different mechanical behaviors at the nanoscale coexisted (acidic alginate gel and calcium-alginate gel). This work validates the effectiveness of the bioinspired fabrication strategy, which inspires further manufacturing and optimization of materials for diverse applications.

Two-dimensional tin sulfides are attracting extensive attention owing to their various potential applications. However, the synthesis methods of tin sulfides are general sophisticated. In addition, the problems of low conductivity and aggregation during charge and discharge severely degrade capacity and long-term cycling stability of lithium ions battery. Herein, we employ bacteria as biotemplate to synthesize homogeneous rod-shaped tin sulfides assembled by interconnected nanosheets. The evolution of structure is revealed elaborately subsequently. The solid rod-shaped structure is firstly formed through adsorbing positively charged Sn4+ on the surface of bacteria. After interacting with S2− source, the SnS2 nanosheets initially appear on the surface, and gradually grow toward interior space to form interconnected structure. Finally, carbon is coated from in situ decomposition of Escherichia coli after calcination in inert atmosphere and thus improves conductivity of material. As lithium ions battery, this anode exhibits a stable cycle capacity of 655 mAh g−1 at 0.5 A g−1 after 200 cycles. This synthesis method is low-cost and provides an ingenious rod-shaped structure which can solve problem of easy agglomeration during charge and discharge. Furthermore, this study may facilitate the development of commercial applications of lithium ions battery.

On the basis of the bond valence model, a new prediction model of thermal expansion coefficient for cubic inorganic crystals using a simple formula is presented. The bond linear thermal expansion coefficient is introduced as a parameter deduced by bond valence and bond length, and can directly describe the thermal expansion of chemical bonds. For cubic multibond crystal systems, the linear thermal expansion coefficient can be obtained by an average of the linear thermal expansion coefficients of all constituted binary systems. Our model has been applied to well predict typical cubic ANB8-N, AmBn, and multibond crystals with spinel, garnet, pyrochlore, chalcopyrite, and perovskite type structures. The empirical model can offer a simple and reliable thermal expansion prediction by the bond linear thermal expansion coefficients and structure parameters based on the well-described nature of chemical bonding, which makes it powerful for exploring materials with potential applications related to thermal expansion.

A new quaternary Li0.19Al2.72O3.64N0.36 transparent ceramic with the Vickers hardness of 17.91 ± 0.2 GPa at a load of 9.8 N and the in-line transmittance of 83.4% at 3.5 µm was prepared by hot isostatic press sintering (HIP) after pressureless sintering. The 7Li and 27Al magic-angle spinning (MAS) NMR spectra combined with the XRD Rietveld refinement was adopted to analyze the crystal structure. It is revealed that all the lithium ions are located in octahedra and the cation vacancies are mainly concentrated in tetrahedra. Based on the bond valance models, the complicated relationship among composition, crystal structure and intrinsic hardness of the spinel-type transparent ceramic were disclosed. Compared with the γ-AlON, the higher hardness of Li0.19Al2.72O3.64N0.36 transparent ceramic is attributed to the coupling effect of enhanced hardness of bonds in octahedra and the slightly weakened hardness of bonds in tetrahedra.

In order to explore the common and unique physiological changes in tissues of juvenile barramundi Lates calcarifer in acidified water environment, RNA sequence analysis was used to analyze the molecular responses of liver, head kidney, and gill of juvenile barramundi in pH 7.4 and pH 8.1 seawater environment. The number of differential expression genes identified in liver, head kidney and gill were 860, 388 and 1792, respectively. Through functional enrichment analysis, the differential expression genes common to the three tissues were all related to immunity. Among the unique differential genes in the liver, pathways related to digestion, endocrine, and metabolism were enriched. Among the unique differential expression genes in gill, pathways related to genetic information processing, immunity and metabolism were enriched. The findings of the present study uncover the transcriptional changes in fish correspond to environmental pH change, and provide a better understanding on the biological process at molecular level to environmental pH adapting. This work highlights that assessments for the potential of estuarine fishes to cope with environmental pH change to develop the future conservation strategies.

In recent decades, high entropy alloys (HEAs) have given rise to much attention of researchers all over the world as emerging materials. VAlTiCrCu coating has good corrosion resistance, but its low hardness results in poor wear resistance. In this work, the novel VAlTiCrCu/WC multilayer coatings were fabricated by magnetron sputtering. The effects of modulation period (17 nm and 90 nm) on the corrosion resistance and tribological properties of the VAlTiCrCu/WC multilayer coatings were investigated. The results show that the VAlTiCrCu layer in the VAlTiCrCu/WC multilayer coatings has a typical BCC phase structure, and the WC layer significantly improves the mechanical behaviors of the HEA coating. In addition, a large number of interfaces in VAlTiCrCu/WC multilayers effectively inhibit the penetration of corrosive species into coatings, improving the tribo-corrosion performance. In comparison to the VAlTiCrCu coating, the VAlTiCrCu/WC multilayer coating with small modulation period (17 nm) has better adhesion, higher and more stable open circuit potential (OCP), and the wear resistance is increased by nearly 5 times.

Both photocatalysis and Fenton-like catalysis present promising and potential technologies for water purification. However, single photocatalysis or Fenton-like catalysis cannot meet the practical demand for complicated pollutes treatment in water. Herein, we report an environmentally benign Ag 3 PO 4 /CuO catalysts that combine the two catalysis. The synthesized Ag 3 PO 4 acts as an efficient photocatalyst, and Fenton-like CuO catalysis decomposes organic pollutes in the presence of H 2 O 2 . A series of Ag 3 PO 4 /CuO composites were obtained by regulating the molar ratio of Ag 3 PO 4 to CuO via hydrothermal and ion exchange reactions. The optimized composite shows a significant improvement in catalytic activity over pure Ag 3 PO 4 under visible light or CuO with H 2 O 2 , owing to the synergistic effect of photocatalysis and Fenton-like catalysis. It is noticeable that the Ag 3 PO 4 /CuO composites retain efficient performance even after five cycling runs. The catalytic mechanism involves matched band structures, Z-scheme photocatalytic mechanism, and the generation of a large amount of hydroxyl radicals.

We proposed a new method, electroplating followed by spark plasma sintering (SPS), to fabricate laminated TiB2-B4C/Cu-Ni composites with high strength and high toughness. It is found that a thin intermediate Cu layer can effectively enhance the strength of the interface between the ceramics and the metals, resulting in a high flexural strength and toughness of the laminated TiB2-B4C composites simultaneously. A flexural strength and fracture toughness of 651 MPa and 11.6 MPa m1/2 respectively, are achieved, an approximately 90% improvement over TiB2-B4C bulk.

A novel Mn 2+ activated green-emitting MgAlON transparent ceramic phosphor was synthesized from Mg 0.21 Al 2.57 O 3.80 N 0.20 :0.03Mn 2+ (MgAlON:Mn) phosphor powder by pressureless sintering combining with hot isostatic pressing. By crystalline structure refinement and cathodoluminescence (CL) characterization, it is demonstrated that Mn 2+ was dissolved in the spinel lattice and occupied the tetrahedral site. The ceramic, retaining high transmittance in UV–vis region (up to 82% at 800 nm) and excellent thermal-mechanical properties of MgAlON transparent ceramic-matrix, shows a strong green emission at 513 nm under 445 nm light excitation. Compared with its powder counterpart, the ceramic phosphor exhibits higher green color purity, higher internal quantum efficiency (47%) and lower thermal quenching. It is suggested that this novel green solid phosphor could be applied in high color rendering and high-power white light-emitting diodes when combined with a red solid phosphor and a blue LED chip.

In this work, a reaction coupling self-propagating high-temperature synthesis (RC-SHS) method was developed for the in situ controlled synthesis of novel, high activity TiB2/(TiB2–TiN) hierarchical/heterostructured nanocomposites using TiO2, Mg, B2O3, KBH4 and NH4NO3 as raw materials. The as-synthesized samples were characterized using X-ray diffraction (XRD), scanning electron microscope (SEM), X-ray energy dispersive spectroscopy (EDX), transition electron microscopy (TEM), high-resolution TEM (HRTEM) and selected-area electron diffraction (SAED). The obtained TiB2/TiN hierarchical/heterostructured nanocomposites demonstrated an average particle size of 100–500 nm, and every particle surface was covered by many multibranched, tapered nanorods with diameters in the range of 10–40 nm and lengths of 50–200 nm. In addition, the tapered nanorod presents a rough surface with abundant exposed atoms. The internal and external components of the nanorods were TiB2 and TiN, respectively. Additionally, a thermogravimetric and differential scanning calorimetry analyzer (TG-DSC) comparison analysis indicated that the as-synthesized samples presented better chemical activity than that of commercial TiB2 powders. Finally, the possible chemical reactions as well as the proposed growth mechanism of the TiB2/(TiB2–TiN) hierarchical/heterostructured nanocomposites were further discussed.

The novel carbon sources (including nano-carbon black, carbon nanotubes and graphene oxide nanosheets, etc.) have been extensively researched in low carbon Al 2 O 3 -C refractory systems. In the present work, ultrafine microcrystalline graphite (UMCG) and nickel-loaded ultrafine microcrystalline graphite (NMCG) were added into low carbon Al 2 O 3 -C slide gate plate refractories to partially replace graphite flake (GF), respectively. The mechanical properties, phase compositions and microstructures were investigated by three-point bending test, X-ray diffraction, scanning electron microscopy, transmission electron microscopy and energy dispersive X-ray spectroscopy. Also, the reaction mechanisms of in-situ formed ceramic phases were discussed by thermodynamic analysis. The results indicate that the existence of UMCG powders can facilitate the in-situ formation of intertwined ceramic whiskers, leading to increased densification and mechanical properties of low carbon Al 2 O 3 -C slide gate plate. Moreover, multi-walled carbon nanotubes and ceramic phases intensively interlock with each other in the Al 2 O 3 -C refractories containing NMCG powders, which results in their better mechanical properties; the cold modulus of rupture are 36.03±0.12 MPa and 32.14±0.17 MPa for the specimens after coking at 1200 °C and 1350 °C, respectively. This work puts forward a practical application for the microcrystalline graphite as a candidate carbon source in Al 2 O 3 -C slide gate plate refractories.

A bio-inspired layered material of reduced graphene oxide (RGOs) and calcium carbonate was synthesized via a one-pot strategy in DMF/H2O mixed solvent. The experimental results show that the product is a layered material of wrinkled RGOs networks and micron-sized calcium carbonate particles with uniform granular diameter and homogeneous morphology, which are distributed between the layered gallery of the graphene scaffold. The polymorph and the morphology of the in-situ produced calcium carbonate particles can be manipulated by simply changing the temperature scheme. Besides, the graphene oxide was reduced to a certain extent, and the hierarchical wrinkles were generated in the RGOs layer by the in-situ formation of the calcium carbonate particles. This work provides a facile and controllable strategy for synthesizing layered material of RGOs and carbonates, and also presents a platform for making three-dimensional porous wrinkled RGOs networks.

Zirconium carbide (ZrC 0.84 O 0.13 ) nanopowders were consolidated using plasma activated sintering with 0–8 wt% ZrH 2 as the sintering additive to improve the sinterability. Compared with pure ZrC sintering, ZrH 2 additive led to the higher sintering kinetics and lower sintering temperature. This improvement was attributed to the increased carbon-vacancy concentration in the non-stoichiometric ZrC in the presence of ZrH 2 additive during the sintering process. Fully dense and fine-grained ZrC ceramics (1.3 ± 0.2 μm) were achieved at 1650 °C with 6 wt.% ZrH 2 . The final product exhibited the Vicker’s hardness of 21.2 ± 1.0 GPa and fracture toughness of 2.2 ± 0.3 MPa m 1/2 .

Series of SnS 2 nanostructures were synthesized by a facile refluxing process. Influencing factors on the microstructures and properties of SnS 2 were investigated, including the reaction temperature, adding sequence of reagent and the solvent. The results indicated the as-prepared SnS 2 products in lower temperature had larger surface areas and superior adsorption capability than that in higher temperature. SnS 2 nanoflowers prepared at 120 °C in ethylene glycol exhibited remarkable adsorption capability for cationic dyes and heavy metal of Pb 2+ , Cd 2+ . Intriguingly, the products also showed prominent visible light photocatalystic activity for Methyl Orange (MO). The formation mechanisms of different SnS 2 nanostructures were proposed; the release of S 2- played a crucial role on controlling the morphology of SnS 2 . The simple shape-controlled method can be extended to the synthesis of other metal sulfides and the high adsorption property is favorable to it coupling with other semiconductors or noble metals to far improve photocatalytic activity.

Learning from the process of biominerals formation provides tremendous ideas for developing advanced synthesis techniques. According to the structure formation of tooth enamel, a recombinant amelogenin his-AmelX was designed and constructed. The protein was over-expressed and could be conveniently purified in one-step heat treatment. The mineralization process of hydroxyapatite was initiated by enzyme AP and regulated by the recombinant amelogenin. Effects of solution pH value and mineralization duration were studied. It was demonstrated that his-AmelX could induce the nucleation of apatite and quicken the growth rate at pH 7.0-7.4, while impeded hydroxyapatite growth at pH 6.8. Moreover, a much denser layer of hydroxyapatite was achieved with the addition of his-AmelX. The present study may not only provide insight into the formation of natural biomaterials but also open a new path to prepare materials under environmentally benign conditions.

YAG ceramics were fabricated by spark plasma sintering assisted by the YAH-YAG phase transformation. These YAH powders were prepared by field-assisted rapid synthesis of the amorphous precursors using the planetary ball-milling. Moreover, the effects of ball-milling speed on the thermal behavior and morphology of the precursors and calcined YAH powders, as well as the subsequent sintering process were systematically studied. The results of thermal analysis of the YAH powders suggest that the exothermic peak for phase transformation shifts to the lower temperature and becomes sharper by increasing the ball-milling speed. The YAH powders synthesized from 225 rpm-milled precursors exhibit a relatively shallow and weak exothermic peak, indicating a slow phase transformation. Therefore, the samples sintered at 950 °C have the homogeneous microstructures from the center to edge. The in-line transmittances are 32% and 60% at 680 nm and 1000 nm, respectively. In the case of 250 rpm, however, the sharp and strong exothermic peak indicates a rapid phase transformation, resulting in an extremely rapid shrinkage between 890 °C and 900 °C during sintering. Microstructure evidence suggests that differential densification occurs during rapid phase transformation. The exterior of the sample is dense, while large pores trapped in the interior lead the sample to be opaque.

High-performance B 4 C–SiC nanocomposites with intergranular/intragranular structure were fabricated through spark plasma sintering assisted by mechanochemistry with B 4 C, Si and graphite powders as raw materials. Given their unique densification behaviour, two sudden shrinkages in the densification curve were observed at two very narrow temperature ranges (1000–1040 °C and 1600–1700 °C). The first sudden shrinkage was attributed to the volume change in SiC resulting from disorder–order transformation of the SiC crystal structure. The other sudden shrinkage was attributed to the accelerated densification rate resulting from the disorder–order transformation of the crystal structure. The high sintering activity of the synthesised powders could be utilised sufficiently because of the high heating rate, so dense B 4 C–SiC nanocomposites were obtained at 1700 °C. In addition, the combination of high heating rate and the disordered feature of the synthesised powders prompted the formation of intergranular/intragranular structure (some SiC particles were homogeneously dispersed amongst B 4 C grains and some nanosized B 4 C and SiC particles were embedded into B 4 C grains), which could effectively improve the fracture toughness of the composites. The relative density, Vickers hardness and fracture toughness of the samples sintered at 1800 °C reached 99.2±0.4%, 35.8±0.9 GPa and 6.8±0.2 MPa m 1/2 , respectively. Spark plasma sintering assisted by mechanochemistry is a superior and reasonable route for preparing B 4 C–SiC composites.

Glass fabrics were used to fabricate boron nitride nanotubes (BNNTs) with a broad diameter range through a combined chemical vapor deposition and self-propagation high-temperature synthesis (CVD-SHS) method at different holding times (0min, 30min, 90min, 180min and 360min). SEM characterization has been employed to investigate the macro and micro structure/morphology changes of the glass fabrics and BNNTs in detail. SEM image analysis has provided direct experimental evidences for the rationality of the optimized self-cracking catalyst VLS growth mechanism, including the transformation situations of the glass fabrics and the BNNTs growth processes respectively. This paper was the further research and compensation for the theory and experiment deficiencies in the new preparation method of BNNTs reported in our previous work. In addition, it is likely that the distinctive self-cracking catalyst VLS growth mechanism could provide a new idea to preparation of other inorganic functional nano-materials using similar one-dimensional raw materials as growth templates and catalysts.