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As a piezoelectric material, K0.5Na0.5NbO3 (KNN) has broad application prospects in ultrasonic transducers, sensors, and biomedicine areas. Its structure information under high pressures is of great significance for guiding device design. In this study, the high-pressure structural evolution of KNN has been studied. Two structural phase transitions were revealed by high-pressure Raman spectrum. The phase transition boundary was found by Raman vibration mode analysis, with transformation ranges of 2.5–4.6 and 6.8–9.4 GPa. The phase structures were determined by in situ neutron diffraction, with a phase transformation path of orthogonal Amm2 (O) → tetragonal P4mm (T) → cubic Pm 3 ¯ m (C) structure at high pressures. Synchrotron x-ray diffraction further confirmed the phase transformation path. During the processes of phase transitions, the path of Nb atom was clearly described as moving toward [ 1 ¯ 01] and then [100] direction. An output power density of KNN ceramic devices was comparable to that of commercially available PZT 95/5. The density of KNN ceramic is approximately half that of PZT 95/5, which means a significant advantage in terms of weight reduction and miniaturization of equipment in global demand. The phase transition of ferroelectric materials under high pressures provides scientific guidance for the development of high-power pulse power devices. [ABSTRACT FROM AUTHOR]

Hafnium carbide (HfC) and tantalum carbide (TaC), as potential ultra-high temperature ceramics (UHTCs), have attracted widespread attention due to their unique physical and chemical properties. Here, dense HfC and TaC ceramics are synthesized under high pressure and high temperature 15 GPa and 1700 °C, respectively. The sound velocities and elasticity behavior of sintered HfC and TaC under high pressure have been experimentally investigated by using ultrasonic interferometry and validated by first-principles study. The bulk and shear moduli with their pressure dependence have been determined as B 0 = 272.6(2.7) GPa, G 0 = 215.8(2.2) GPa, ∂ B / ∂ P = 3.44 (5) , and ∂ G / ∂ P = 1.74 (3) for HfC, B 0 = 355.9(3.6) GPa, G 0 = 236.6(2.4) GPa, ∂ B / ∂ P = 3.98 (5) , and ∂ G / ∂ P = 1.65 (2) for TaC. The Vickers hardness and fracture toughness of HfC and TaC are generated from empirical models. The present work provides deep insights into the engineering application of UHTCs HfC and TaC under high-pressure extreme conditions. [ABSTRACT FROM AUTHOR]

Breast cancer is one of the most common malignant tumors in women worldwide. Early diagnosis, treatment, and prognosis of breast cancer are global challenges. Identification of valid predictive diagnosis and prognosis biomarkers and drug targets are crucial for breast cancer prevention. This study characterizes differentially expressed genes (DEGs) based on the TCGA database by using DESeq2, edgeR, and limma. A total of 2032 DEGs, including 1026 up-regulated genes and 1006 down-regulated genes were screened. Followed with WGCNA, PPI analysis, GEPIA 2, and HPA database verification, thirteen hub genes including CDK1, BUB1, BUB1B, CDC20, CCNB2, CCNB1, KIF2C, NDC80, CDCA8, CENPF, BIRC5, AURKB, PLK1, MAD2L1, and CENPE were obtained, and they may serve as potential therapeutic targets of breast cancer. Especially, overexpression of CCNB1 and PLK1 are strongly associated with the low survival rate of breast cancer patients, demonstrating their potentiality as prognostic markers. Moreover, CCNB1 and PLK1 are highly expressed in all breast cancer stages, suggesting that they could be further studied as potential drug targets. Taken together, our study highlights CCNB1 and PLK1 as potential anti-breast cancer drug targets and prognostic markers. [ABSTRACT FROM AUTHOR]

Alternative splicing of pre-mRNA is a key mechanism for increasing the complexity of proteins in humans, causing a diversity of expression of transcriptomes and proteomes in a tissue-specific manner. Alternative splicing is regulated by a variety of splicing factors. However, the changes and errors of splicing regulation caused by splicing factors are strongly related to many diseases, something which represents one of this study's main interests. Further understanding of alternative splicing regulation mediated by cellular factors is also a prospective choice to develop specific drugs for targeting the dynamic RNA splicing process. In this review, we firstly concluded the basic principle of alternative splicing. Afterwards, we showed how splicing isoforms affect physiological activities through specific disease examples. Finally, the available treatment methods relative to adjusting splicing activities have been summarized. [ABSTRACT FROM AUTHOR]

In γ -LiAlO 2 ceramic, Li ion diffusion plays a key role both in tritium release as a solid tritium breeder material in nuclear fusion and in phase stability as a matrix material in molten carbonate fuel cells (MCFC). Yet fundamental understanding of the diffusive process in γ -LiAlO 2 is still missing, especially considering the interaction of the lattice dynamics and Li ion motion. Herein, we demonstrated that two specific optical phonon modes are coupled with Li ion diffusion in γ -LiAlO 2 , by investigating the temperature-dependent lattice dynamics via Raman scattering experiments, as well as first-principles calculations and neutron diffraction experiments (ND). The high-temperature ND experiments showed that γ -LiAlO 2 undergoes partial Li ion disordering in Li sublattice at high temperature. Notably, the lattice dynamics studies demonstrated that B 1 mode at 226 cm−1 and A 1 mode at 263 cm−1 are responsible for Li ion motion through the oscillation of Li–O in <010> and <001> direction, respectively. Our results further suggest that the behavior of tritium release and phase stability in γ -LiAlO 2 at elevated temperature may be controlled by tuning the two specific phonon modes through photon/electron-phonon coupling. [ABSTRACT FROM AUTHOR]

We analyzed the compression process of the centrally caved Bridgman-anvil cell by a simplified mechanics model and proposed that the pressure limitation for a given configuration is governed by the compressibility and compression ratios (V0/V) of the gasket and sample. Then we replaced the middle part of the sample that is prone to undergo plastic deformation with a diamond plate, which will obviously change the stress state of the sample and gasket. The results of ex situ and in situ pressure testing experiments show that this way doubles the efficiency of the pressure generation and largely expands the pressure limitation. The pressure of sample Ni can reach 29.4 GPa in the double toroidal sintered-diamond anvil cell with a sample volume of 17 mm3 even at the loading force of 1500 kN. [ABSTRACT FROM AUTHOR]

The widespread industrial applications of binary transition metal carbides (TMCs) are closely related to their complex chemical bonds. Owing to the high number of ionic components of chromium carbide (Cr 3 C 2), it is a challenge to accurately estimate its elasticity and mechanical properties. Pure polycrystalline Cr 3 C 2 was synthesized via high pressure and high temperature method, and its sound velocities, elasticity, and mechanical properties were investigated using high-pressure ultrasonic interferometry combined with density functional theory calculations. Furthermore, its bulk modulus, shear modulus, Young's modulus, Poisson's ratio, and Vickers hardness were 319 GPa, 182 GPa, 459 GPa, 0.26, and 24.0 GPa, respectively. The results revealed that Cr 3 C 2 is more ductile than most covalent carbides, and its Vickers hardness is higher than that reported in previous studies. The intrinsic properties of Cr 3 C 2 were obtained, which are relying on the advantages of sintering the pure polycrystalline ceramics. [Display omitted] [ABSTRACT FROM AUTHOR]

Grain rotation caused by the movement of dislocations is a determinant factor for the mechanical behavior of metals. In general, the grain rotation may be mediated by grain boundary dislocations (GB-dis) and intragranular dislocations (In-dis), which are closely associated with grain size. Few works have investigated how grain size depends on grain rotation, and the competitive mechanism between GB-dis and In-dis remains unclear. The present work investigates the structural evolution and deformation of coarse-grained tungsten under high pressure. The results show that under high pressure, the nano-sized grains preferentially rotate with dislocation climbing in GBs. Under high pressure, In-dis migrate faster across coarse grains and are absorbed by GBs on the other side, resulting in grain rotation. Elevated temperature also facilitates the migration of In-dis to arrive GBs where they can be absorbed by GBs, thus promoting grain rotation. The theoretical results show that grain rotation occurs easily under high pressure and high temperature. With increasing grain size, the stress-induced rotation mechanism goes from being dominated by GB-dis to being dominated by In-dis migration. The competitive relationship between GB-dis and In-dis during grain rotation is elaborated, providing a new strategy for designing materials under high pressure. [ABSTRACT FROM AUTHOR]

ZrW 2 O 8 /Cu composites with high thermal conductivity and low coefficients of thermal expansion (CTE) are desired to be utilized in thermal management applications. The ZrW 2 O 8 /Cu composites were synthesized under high-pressure and high-temperature (HPHT) conditions and annealing method. We found that the thermal conductivity and CTE of the ZrW 2 O 8 /Cu composites could be controlled through suitable HPHT sintering. In addition, cyclic heating-cooling is crucial to recrystallize the composite and reduce the thermal mismatch stress to produce a composite with high thermal conductivity and a low CTE. Under HPHT (3 GPa, 500 °C) conditions and annealing at 700 °C, the thermal conductivity and CTE of the ZrW 2 O 8 /Cu composites have been determined directly to 165 W/(m k) and 6.8×10 −6 K −1 . Our results help to understand the structural origins of the high thermal conductivity and low CTE, and aid in designing ZrW 2 O 8 /Cu composites with improved performance. [ABSTRACT FROM AUTHOR]

ZrW2O8as the typical negative thermal expansion (NTE) material has attracted much attention for the potential applications in various fields such as tailored coefficient of thermal expansion (CTE) composites. The hexagonal ZrW2O8(h-ZrW2O8), with the combination of ZrO2and WO3in a composite, was synthesized at a pressure of 2 GPa and the temperature between 600°C and 700°C. We found h-ZrW2O8decomposes to ZrO2+WO3oxides that start from 500°C and end at 800°C, and determined the CTE of h-ZrW2O8is−16.3×10−6°C−1in the temperature range from 150°C to 450°C. The results show that ZrW2O8with a hexagonal structure is metastable and exhibits high NTE property like its cubic structure. [ABSTRACT FROM AUTHOR]

Abstract: The stability and decomposition of graphitic C3N4 (g-C3N4) were studied in the pressure and temperature range of 10–25GPa and up to 2000°C by multi-anvil experiments and phase characterization of the quenched products. g-C3N4 was found to remain stable at relatively mild temperatures, but decomposes to graphite and nitrogen at temperatures above 600–700°C and up to 15GPa, while it decomposes directly to diamond (plus nitrogen) above 800–900°C and between 22 and 25GPa. The estimated decomposition curve for g-C3N4 has a positive slope (~0.05GPa/K) up to ~22GPa, but becomes inverted (negative) above this pressure. The diamond formed through decomposition is characterized by euhedral crystals which are not sintered to each other, but loosely aggregated, suggesting the crystallization in a liquid (nitrogen) medium. The nitrogen release from the graphitic Crk may also play an important role in lowering the activation energy required for diamond formation and enhancing the grain growth rate. No phase transition of g-C3N4 was found in the studied P–T range. [Copyright &y& Elsevier]

As a most widely applied structure material, the deformed characteristics of steels primarily presented the adiabatic shear band (ASB) formation and phase transitions, instead of its intrinsic structure evolution at different strain rates. In previous works, seldom investigations on the high strain rates dependence of the dislocations, low angle grain boundaries (LAGBs) and high angle grain boundaries (HAGBs) were reported, and the transition mechanism among the three microstructural factors was not clear. Here, we used a gas gun to generate shock wave to compress the AISI 1045 steels and investigated their structures under different stain rates of 4.3 × 105 s−1 (low) and 3.3 × 106 s−1 (high), respectively. A gradient structure was formed along shock compression direction. Surprisingly, the structure evolution of the steel has a strong rate effect. At high strain rates, the dislocations would form the LAGBs, while the LAGBs would difficultly transform into HAGBs. At low strain rates, the LAGBs preferred to transform into HAGBs. Furthermore, the LAGBs to HAGBs transformation was accompanied with the grain rotation. The texture under the low strain rates was changed from annealing {111} <211> to R-Cube {001} <110>, while that of the high strain rates became R-Goss {110} <110>→Goss {011} <100>→Cube {001} <100>. These results indicate that the rate effect of the structures under loading plays an important role in guiding the materials design and applications. - The gradient structure was formed along the shock-wave compression direction. - The structural evolution of AISI 1045 steels presented a strong strain rate effect. - At low strain rates, the LAGBs preferred to transform into HAGBs. - At high strain rates, the dislocations preferred to transform into LAGBs. - Transition mechanism among the dislocations, LAGBs and HAGBs were revealed. [ABSTRACT FROM AUTHOR]

Pyrophyllite is widely used both as a gasket material and as a pressure-transmitting medium, especially for a large-volume press. Its pressure-transmitting efficiency mainly depends on the following factors: geometry of anvil and pyrophyllite block, chemical composition, density and strength. For a long time, most studies have been devoted to the first two factors, whereas the third one has been studied less. In this work, we report that the pressure-transmitting efficiency of pyrophyllite is improved by precompressing. The results show that pyrophyllite was fully densified when the pressure reached about 1 GPa. The press load for Ba I-II transition in the cubic large-volume pressure cell is reduced more than 8×105 N by using the densified pyrophyllite, compared with the unprecompressed pyrophyllite. Namely, the press-load utilization efficiency was improved above 15% when the precompressed pyrophyllite is used as a pressure-transmitting medium. [ABSTRACT FROM AUTHOR]

Raman spectroscopy is very sensitive to the U‐O bonding strength changes under high pressure, and it could reveal important information about the bonding and stoichiometry of the U‐O systems. The pressure and temperature (P–T) phase diagram of U3O8 was investigated by Raman spectroscopy via four independent P–T experimental paths. The phase boundaries between different phases have been determined by the changes in Raman spectra. A new phase (α′‐U3O8) was observed below 233 K at 0.6 GPa or 198 K at zero pressure accompanied by the discontinuities in Raman wavenumber and the new shoulder peak near the B2(6) Raman modes. Upon compressing at low temperature (123 K), the high‐pressure irreversible phase transition from orthorhombic to cubic structure (α′‐δ) was observed at around 11.3 GPa, evidenced by the merging of B2(6) and B′2(6) Raman modes. [ABSTRACT FROM AUTHOR]

Er3+, Ho3+ or Sm3+ single-doped hexaluminate CaAl 12 O 19 phosphors were successfully synthesized by a simple polyacrylamide gel method. Low concentration of Er3+, Ho3+ or Sm3+ ions doped CaAl 12 O 19 changed the lattice parameters of CaAl 12 O 19 but did not change its phase structure. A variety of characterization techniques confirmed that the Er3+, Ho3+ or Sm3+ ions occupied part of the position of Ca2+ ions and transformed the surface morphology from the lamellar CaAl 12 O 19 to nanoparticles. The color, optical properties and photoluminescence properties of CaAl 12 O 19 : Er, Ho, Sm phosphors are affected by different rare earth ions and their contents. Er3+, Ho3+ or Sm3+ ions introduces CaAl 12 O 19 which changes its color to bright white and decreases the Eg value. The nonlinear dependence between the reflectance of CaAl 12 O 19 : Er, Ho, Sm phosphors and the content of rare earth ions makes the back propagation neural network model play a great advantage in predicting their color properties. The CaAl 12 O 19 : Er, CaAl 12 O 19 : Ho, and CaAl 12 O 19 : Sm phosphors exhibits obvious emission peaks at 472, 533 and 418 nm with the excitation wavelengths of 310, 370 and 251 nm, respectively. Compared with the literature, CaAl 12 O 19 : Er, CaAl 12 O 19 : Ho, and CaAl 12 O 19 : Sm phosphors show novel luminescence phenomena and are strongly dependent on synthesis methods. The fluorescence emission intensity of CaAl 12 O 19 : Er, CaAl 12 O 19 : Ho, and CaAl 12 O 19 : Sm phosphors increased with the increasing of Er3+, Ho3+ or Sm3+ ion content. Anti-counterfeiting applications show that the CaAl 12 O 19 : Er, CaAl 12 O 19 : Ho, and CaAl 12 O 19 : Sm phosphors have potential applications in the fields of sky blue, green and dark blue luminescence, respectively. [ABSTRACT FROM AUTHOR]

Novel NiAl 2 O 4 (NAO)/high entropy alloy (HEA) (Ti), NAO/HEA (Mn) and NAO/HEA (Mo) heterojunction photocatalysts with high photocatalytic activity for the degradation of tetracycline hydrochloride (TC) under simulated sunlight irradiation were synthesized by the polyacrylamide gel method combined with a low temperature sintering technique. The effects of environmental parameters, including drug concentration, catalyst content and pH value, on the photocatalytic activity of NAO/HEA photocatalysts were investigated in detail on the basis of the response surface methodology (RSM) and experimental results. The optimal initial TC concentration, catalyst content, and pH were 100 mg/L, 1 g/L, and 5, respectively. The photocatalytic activity of NAO/HEA photocatalyst (84.6 %) was significantly improved compared to the degradation percentage of HEA (Ti) photocatalyst (36.5 %). The roles of active free radicals including h+, •O 2 −, •OH and oxygen vacancy in photocatalysis were verified using multiple characterization methods. In-depth analysis was conducted on the degradation pathway of TC, the safety of degradation intermediates, and the photocatalytic mechanism of NAO/HEA (Ti) photocatalyst. The Z - scheme heterojunction can significantly improve the transport efficiency of photogenerated carriers and inhibit the recombination rate of electron hole pairs in the system, which provides a new idea for exploring the application of new HEA - based heterojunction photocatalysts in the field of photocatalysis. [ABSTRACT FROM AUTHOR]

Cubic boron nitride (cBN) has been used as a tool material for several decades due to its high hardness and thermal stability. Various binders are commonly added to cBN to synthesise cBN composites for better cutting performance. However, most studies have only investigated properties such as hardness and bulk modulus, without comprehensively studying elastic properties through experiments. In this study, the sound velocities and elastic properties of cBN with AlN binder were determined by using the ultrasonic interferometry technique. The bulk and shear moduli with their pressure dependence were determined as B 0 = 351 (3) GPa, G 0 = 344 (3) GPa, B 0 ′ = 4.32 (4) and G 0 ′ = 1.74 (2) using the finite strain equation-of-state approaches. Elasticity-related thermal properties, such as Debye temperature, Grüneisen parameter, thermal conductivity and coefficient of thermal expansion were also estimated. The results show that the elastic properties of the cBN composite with vol. 8.8% AlN-binder are comparable to the pure cBN compact. Additionally, the thermal conductivity and coefficient of thermal expansion have little effect on cBN composite with AlN binder compared to pure cBN. [ABSTRACT FROM AUTHOR]

In molten carbonate fuel cells (MCFC), α -LiAlO 2 ceramic matrix, at higher temperature or H-rich atmosphere, undergoes an irreversible phase transition of α -LiAlO 2 to γ -phase that causes a large volume change and greatly impacts the lifetime of the cells. In this manuscript, we unravel an unusual coupling property between the lattice dynamic and Li+ ions diffusion for the first time, near the common operating temperature of 923 K. A temperature-dependent lattice dynamics study on α -LiAlO 2 was performed by probing the in-situ Raman spectroscopy. In addition, the phonon density of states was estimated theoretically through first-principles calculations. Notably, in-situ Raman spectroscopy combined with the calculated atom-projected phonons density of states (PDOS) and Bond Valence Energy Landscape (BVEL) calculations demonstrated that the phonon mode E g dominated by oxygen atoms decays into three acoustical phonons that couple with the diffusion of mobile Li+ ions in ab -plane above 600 K. In MCFC environments, large amounts of Li+ ions or H+ ion in the electrolyte will diffuse into the lattice of α -LiAlO 2. This would further enhance the coupling behavior between oxygen atoms and diffusion ion and finally results in the instability of lattice dynamics of oxygen atoms. [ABSTRACT FROM AUTHOR]

The solubility of NaCl in water is one of the most important thermo-physical properties. However, the solubility behavior of NaCl in water is poorly understood at high pressure and low temperature. Herein, we performed high pressure neutron diffraction and Raman scattering to investigate the solubility of NaCl in water and the corresponding structural change, respectively. With the pressure increasing, the solubility almost increases linearly below 0.2 GPa, beyond which it starts to level off and reaches its maximum at about 0.61 GPa. The Raman spectra suggested that the deformation of the hydrogen-bonded network in the NaCl aqueous solution promotes the formation of ions pairing and is responsible for the solubility increase of NaCl in water. Finally, we used a two-dimensional Mercedes-Benz model to descript the picture of solubility behavior of NaCl in water at high pressure. [ABSTRACT FROM AUTHOR]

The Ba 0.5 Sr 0.5 TiO 3 /BaFe 12 O 19 (BST5/BFO) magnetic photocatalysts were constructed by a polyacrylamide gel route combined with low temperature heat treatment process. The effect of different BFO contents on the phase, surface microstructure, magnetic and optical properties, and photocatalytic efficiency of BST5/BFO magnetic photocatalysts was investigated. The BST5, BFO and BST5/BFO magnetic photocatalysts were evaluated for the degradation of tetracycline hydrochloride (TC) under simulated sunlight irradiation for 120 min, pH=5, catalyst content of 1 g/L, initial TC concentration of 50 mg/L and the photocatalytic efficiency trend followed the order: pristine BFO < pristine BST5 < BST5/20%BFO < BST5/15%BFO < BST5/5%BFO

Size matching between anvils and the pressure transmitting medium (PTM) is a key factor that affects pressure generation and sealing for a large volume cubic press. In this work, we studied the influence of PTM sizes from 30.5 mm to 34.5 mm at a fixed anvil geometry dimension (23.5 mm) on the pressure efficiency and sealing performance by measuring the pressure of the gasket and cell simultaneously at room temperature. Wires made of Bi, Tl, Ba, or Manganin were used for pressure calibration experiments within a pressure range of up to 6 GPa. It was found that a PTM with an edge length of 33.5 mm had the highest pressure-generation efficiency, but its sealing performance was the worst. Furthermore, it was confirmed that a PTM with an edge length of 32.5 mm had the best overall performance for a 23.5 mm anvil when both efficiency and sealing were considered. The results show that the pressure-generation efficiency and sealing performance are highly sensitive to PTM size. It is less rigorous to gauge the performance of the assembly only by the pressure-generation efficiency. This work provides practical guidelines and contributes to optimizing the design of the high-pressure assembly. [ABSTRACT FROM AUTHOR]

Preparation of CeO2/PbFe12O19 (CO/PFO) heterojunction photocatalysts with the different CO contents as visible‐light photocatalysts were synthesized by a polyacrylamide gel route combined with a low temperature sintering technique. A variety of characterization techniques have been used to confirm that the CO/PFO heterojunction photocatalysts contain only Ce, Pb, Fe and O elements, which also indicates that the special interfacial contact between CO and PFO is formed and there are a large number of oxygen vacancies and interfacial defects in CO/PFO heterojunction photocatalysts. The coupling of CO and PFO enhances the optical absorption coefficients of CO and PFO and slightly decreases the optical band gap (Eg) of the host lattice (PFO). Rhodamine B (RhB), phenol, bisphenol A (BPA) and oxytetracycline hydrochloride (OTC‐HCl) were used as target degradation pollutants to investigate the degradation preference of CO/PFO heterojunction photocatalysts. The degradation percentages of the RhB, Phenol, BPA and OTC‐HCl are 20.35 %, 38.77 %, 18.11 % and 75.32 %, respectively. The results showed that the hydroxyl radical played a dominant role in the degradation of pollutants by the CO/PFO heterojunction photocatalysts and preferred to degrade −C=O and −CONH2. This new idea will provide technical support for cutting functional groups of pollutants purposefully. [ABSTRACT FROM AUTHOR]

Various carbon -based MgAl 2 O 4 (MAO) adsorbents were synthesized by a simple ultrasound irradiation technology with the activated carbon (AC), carbon quantum dots (CQDs), C 3 N 4 (CN) and graphene oxide (GO) as carbon sources. The optimum synthesis conditions for the carbon -based MAO adsorbents were determined by the study of the addition of different types of carbon and different mass ratios of m Various carbon : m MAO = 2.5%, 5.0%, 7.5% and 10%. The carbon -based MAO adsorbents were used for the adsorption of Congo red (CR) dye, tetracycline hydrochloride (TCH), oxytetracycline hydrochloride (OCH), ciprofloxacin (CIP), naproxen sodium (NPS) and tetrabromobisphenol A (TBBPA) and the seven factors affecting the adsorption behavior were discussed, including the type of carbon, AC content, initial dye concentration (C CR), adsorbent dosage (C carbon -based MAO adsorbents), adsorption time (A t), pH value and reaction temperature (T). The corresponding adsorption isotherm models such as Langmuir, Tempkin, Koble-Corrigan, Toth and Freundlich models and thermodynamics of carbon -based MAO adsorbents for the adsorption of CR dye were also studied. When pH = 7.8, C CR = 200 mg/L, A t = 90 min, T = 287 K and C AC 5.0 wt%-MAO = 1 g/L, the removal rate of CR dye reaches 89.7%. The back propagation (BP) neural network model was used to predict the adsorption percentage of carbon-based MAO adsorbents, which was consistent with the experimental results. The high adsorption capacity of AC 5.0 wt%-MAO adsorbents for the adsorption of CR dye can be assigned to the synergistic effects of electrostatic interaction, intermolecular force, n-π interaction and hydrogen bonding, while for the adsorption of TCH, OCH and CIP can be ascribed to the electrostatic interaction. This study demonstrated a huge potential of carbon -based MAO adsorbents as an eco-friendly adsorbent for the adsorption of dyes and drugs. [ABSTRACT FROM AUTHOR]

Nitride perovskite LaWN3 has been predicted to be a promising ferroelectric material with unique properties for diverse applications. However, due to the challenging sample preparation at ambient pressure, the crystal structure of this nitride remains unsolved, which results in many ambiguities in its properties. Here, the authors report a comprehensive study of LaWN3 based on high‐quality samples synthesized by a high‐pressure method, leading to a definitive resolution of its crystal structure involving nitrogen deficiency. Combined with theoretical calculations, these results show that LaWN3 adopts an orthorhombic Pna21 structure with a polar symmetry, possessing a unique atomic polarization along the c‐axis. The associated atomic polar distortions in LaWN3 are driven by covalent hybridization of W: 5d and N: 2p orbitals, opening a direct bandgap that explains its semiconducting behaviors. The structural stability and electronic properties of this nitride are also revealed to be closely associated with its nitrogen deficiency. The success in unraveling the structural and electronic ambiguities of LaWN3 would provide important insights into the structures and properties of the family of nitride perovskites. [ABSTRACT FROM AUTHOR]

Cobalt plays a crucial role in the systematic understanding of magnetic phenomena originating from 3d transition metals. Particularly, recent studies of Co systems doped with nitrogen (Co–N) have attracted a lot of attention for applications in spintronics and high-density magnetic data-storage devices. In this work, in order to understand the effect of interstitial incorporation of N atoms into a face-center cubic (fcc) Co lattice, we have studied the structure, elastic, and magnetic properties of spherical-like bulk CoNx (x = 0.06–0.07) samples. These samples were synthesized through a high-pressure solid-state metathesis reaction. We demonstrate that the use of a certain concentration of interstitial N atoms tends to stabilize the lattice of fcc Co at ambient conditions. Such a stabilizing effect is found to originate from the covalent bond between Co atoms and N atoms. High-pressure synchrotron x-ray diffraction indicates that the incorporation of N atoms into fcc Co has little effect on the elastic property up to 27.2 GPa with a bulk modulus (B0) of 200 GPa; the latter is found to be comparable to that of fcc and hcp Co. CoNx samples exhibited ferromagnetic behavior with saturation magnetization up to 153.55 emu/g and coercivity of 16.25 Oe. The introduction of small amounts of nitrogen in the cobalt matrix was found to induce a significant decrease in the coercive force parameter. [ABSTRACT FROM AUTHOR]

Abstract Fenghuang has been upgraded to be the first neutron powder diffractometer at the China Mianyang Research Reactor (CMRR) dedicated to research on the microstructure of materials. It was firstly built in 2005 at the Swimming Pool Research Reactor-300 (SPRR-300) in Mianyang, and then moved to CMRR in 2013. Through the combination of a horizontally focusing neutron guide and a vertically focusing monochromator, the neutron flux at the sample position is up to 2.84 × 106 n s−1cm−2. The resolution of the diffractometer can be adjusted by a horizontal slit for different sample. The superposition scan mode enables each detector to measure the complete diffraction pattern and simplifies the correction of the efficiency of the counting channels. This diffractometer is equipped with temperature and pressure devices, and can be used for research at ambient and extreme conditions. Highlights • A new neutron powder diffractometer has been put into use since 2013 at CMRR in China. • The resolution and intensity can be conveniently adjusted by a slit for different sample. • The diffractometer has a good performance and is now in routinely service. [ABSTRACT FROM AUTHOR]

A simple polyacrylamide gel method combined with low temperature sintering technology has been used to synthesize the C–O functional groups grafted MgAl2O4/C3N4/YMnO3 (MAO–CN–YMO) heterojunction photocatalysts with enhanced visible‐light‐induced photodegradation toward oxytetracycline hydrochloride (OTC‐HCl). A variety of characterization methods are used to gain insight into the phase purity, crystal structure, microstructure, functional group information, elemental composition, surface defect, light response capability, and photocatalytic activity of the as‐synthesized samples. The influences of the mass ratios of mCN/mYMO, mCN/mMAO, and mMAO/(mCN + mYMO) in CN–YMO, CN–MAO, and MAO–CN–YMO heterojunction photocatalysts on the photocatalytic activity for the degradation of OTC‐HCl was also discussed, and the optimal mass ratio of mMAO/(mCN + mYMO) is identified as 15 wt%. The photocatalytic experiments confirmed that the MAO–CN–YMO heterojunction photocatalysts had high selectivity for the degradation of antibiotics. The prediction of the photocatalytic activity of the MAO–CN–YMO heterojunction photocatalysts for the degradation of OTC‐HCl was made by a variety of intelligent algorithm models. The results of the whale optimization algorithm are highly consistent with the experimental results. Combined with the energy band theory and the characterization results of high‐performance liquid chromatography–tandem mass spectrometry, the free radicals in the reaction solution preferentially attacked the –CH3, –NCH2, and –OH of OTC‐HCl during the degradation of OTC‐HCl by MAO–CN–YMO heterostructure photocatalysts, and then attack –C=O and –C=O–NH2, and finally perform ring‐opening reaction to degrade OTC‐HCl into nontoxic and harmless products of small molecules such as CO2, H2O, and NH4+. This work provides a new idea for the development of novel double p–n junction MAO–CN–YMO heterojunction photocatalysts for antibiotic degradation and the prediction of photocatalytic activity of multiple heterojunction photocatalysts by intelligent algorithms. [ABSTRACT FROM AUTHOR]

Crystal solubility is one of the most important thermo-physical properties and plays a key role in industrial applications, fundamental science, and geoscientific research. However, high-pressure in situ measurements of crystal solubility remain very challenging. Here, we present a method involving high-pressure neutron diffraction for making high-precision in situ measurements of crystal solubility as a function of pressure over a wide range of pressures. For these experiments, we designed a piston-cylinder cell with a large chamber volume for high-pressure neutron diffraction. The solution pressures are continuously monitored in situ based on the equation of state of the sample crystal. The solubility at a high pressure can be obtained by applying a Rietveld quantitative multiphase analysis. To evaluate the proposed method, we measured the high-pressure solubility of NaCl in water up to 610 MPa. At a low pressure, the results are consistent with the previous results measured ex situ. At a higher pressure, more reliable data could be provided by using an in situ high-pressure neutron diffraction method. [ABSTRACT FROM AUTHOR]

Understanding pressure-induced acoustic velocity-elasticity behavior has extraordinary significance in the fields of materials science and earth science. Herein, we used an advanced high-pressure high-temperature (HPHT) method to synthesize pure-phase β-Mo 2 C bulk ceramics. The sound velocity-elasticity behavior, thermodynamic properties, and mechanical behavior of the synthesized β-Mo 2 C ceramics were systematically investigated by in-situ high-pressure ultrasonic interferometry and theoretical calculations. The compressive and shear wave velocities, isothermal bulk modulus, shear modulus, Vickers hardness, fracture toughness, Debye temperature, and melting temperature of polycrystalline β-Mo 2 C exhibited a monotonic increase with increasing pressure. The experimental and calculation results showed that β-Mo 2 C had strong ductile behavior and was a ductile ceramic. Additionally, the temperature-hardness relationship of the as-synthesized polycrystalline β-Mo 2 C was investigated by in-situ high-temperature Vickers indentation measurements. The hardness of β-Mo 2 C gradually decreased with increasing temperature, and this ceramic still maintained a hardness as high as 12.3 GPa at 500 °C. These results suggest that the intrinsic mechanical and thermodynamic properties of β-Mo 2 C are dominated by its unique electronic structure and bonding mode. [ABSTRACT FROM AUTHOR]

High-strain-induced microstructural refinement and dislocations are critical for the strengthening of metallic materials; however, this is difficult to achieve in ceramic materials due to their unique bonding characteristics and electronic structure. Here, a series of β -Mo 2 C bulk ceramics are consolidated by the high pressure and high temperature (HPHT) strategy. Our results demonstrate that high strain-induced grain plastic deformation at high pressure produces a lamellar sub-grain structure with high-density dislocations, and that the dislocations at the lath-like grain boundaries eventually evolve into low-angle grain boundaries. The mechanical properties, superconducting behavior, and onset of oxidation of the specimens are investigated. It is found that superconductivity and hardness arise from the high density of states at the Fermi level, while the high intrinsic hardness is attributed to the strong hybridization between Mo-4 d orbitals and C-2 p orbitals. Furthermore, strain-induced defect structure (dislocations and low-angle grain boundaries) mainly mainly enhances the intrinsic structure of β-Mo 2 C. [ABSTRACT FROM AUTHOR]

The polyacrylamide gel method combined with low temperature sintering technology (PGMCLTST) have been used to synthesize the BaTiO3/TiO2 heterojunction photocatalysts. The BaTiO3/TiO2 heterojunction photocatalyst only contains tetragonal BaTiO3, rutile TiO2 and anatase TiO2, without any other impurities. Based on a variety of characterization, it was confirmed that a special heterojunction was formed between BaTiO3 and TiO2, and there were a large number of interface defects or oxygen defects in the samples. The BaTiO3/10 wt % TiO2 heterojunction photocatalysts have high photocatalytic activity for the degradation of tetrabromobisphenol A (TBBPA) under simulated sunlight irradiation. The interfacial defects enhance the transfer and separation efficiency of charge carriers in BaTiO3/TiO2 heterojunction photocatalysts. This technique provides a new idea for the application of BaTiO3/TiO2 heterojunction photocatalysts and other heterojunction photocatalysts in the degradation of persistent organic pollutants (POPs). [ABSTRACT FROM AUTHOR]

Ferroelectric pulsed-power sources with rapid response time and high output energy are widely applied in the defense industry and mining areas. As the core materials, ferroelectric materials with large remnant polarization and high electrical breakdown field should generate high power under compression. Currently, lead zirconate titanate 95/5 ferroelectric ceramics dominated in this area. Due to environmental damage and limited output power of lead-based materials, lead-free ferroelectrics are highly desirable. Here, the electrical response of 0.9BiFeO3-0.1BaTiO3 (BFO-BT) ferroelectric ceramics under shock-wave compression was reported, and a record-high power density of 4.21 × 108 W/kg was obtained, which was much higher than any existing lead-based ceramics and other available energy storage materials. By in situ high-pressure neutron diffraction, the mechanism of shock-induced depolarization of the BFO-BT ceramics was attributed to pressure-induced structural transformation, and the excellent performance was further elaborated by analyzing magnetic structure parameters under high pressures. This work provides a high-performance alternative to lead-based ferroelectrics and guidance for the further development of new materials. [ABSTRACT FROM AUTHOR]

The C-O functional group decorated ZnO nanoparticles with high UV absorption and VIS/NIR reflectance were synthesized by a simple wet chemistry method using various chelating agents. This study attempts to explore the internal mechanism of the piezoelectric catalytic activity, photocatalytic activity and adsorption performance of ZnO nanoparticles. The phase purity, particle size, optical band gap and photocatalytic activity of ZnO nanoparticles showed strong chelating agent - dependent behavior. The ZnO nanoparticles prepared by using EDTA as a chelating agent exhibits smallest particle size, highest photocatalytic activity for the degradation of methyl orange, methylene blue and rhodamine B, high adsorption capacity for the adsorption of Congo red and high vibration-catalytic performance for the vibration degradation of rhodamine B. The synergies mechanism among piezoelectric catalysis, photocatalysis and adsorption capacity of ZnO nanoparticles are discussed on the basis of the experimental results. [ABSTRACT FROM AUTHOR]

[Display omitted] • The CaAl 12 O 19 based pigments were synthesized by a polyacrylamide gel method. • The phase composition, color and photoluminescence properties can be adjusted. • The GA optimized BP neural network can predict the color properties of pigments. • The photoluminescence mechanism of CaAl 12 O 19 based pigments has been deeply revealed. The polyacrylamide gel method was used to fabricate the Ca 1-x Co x Al 12 O 19 , Ca 1-x Ni x Al 12 O 19 , CaAl 12-x In x O 19 and CaAl 12-x W x O 19 (x = 0–0.5) pigments. The phase compositions, energy bands, color and photoluminescence properties of the pigments can be controlled by adjusting the type and content of doping ions. The color of CaAl 12 O 19 changed from white to blue with the Co2+ ion doping, from white to gray green with the Ni2+ ion doping, and from white to bright white with the In3+ and W6+ ions doping. The genetic algorithm optimized back propagation neural network can predict the color properties of CaAl 12 O 19 based pigments. The application of the pigments shows that they can be used in painting, coating and other fields. The Co2+ and Ni2+ doped CaAl 12 O 19 exhibits high blue emission, while In3+ and W6+ doped CaAl 12 O 19 shows strong green emission and the luminescence is highly dependent on the type and content of dopant ion, phase composition and energy transfer. [ABSTRACT FROM AUTHOR]

The multi-dimensional integrated methods have been explored for fabrication of CQDs/CeO 2 /PbFe 12 O 19 (CQDs/CO/PFO) photocatalysts with the different CQDs contents. A variety of structural and component characterization methods have been adopted to study the phase purity and composition of CQDs/CO/PFO photocatalysts, which does not contain any other impurities except the basic constituent substances. The microstructure and optical behavior proved the formation of heterojunction between CQDs, CO and PFO, and the absorption edge was significantly red shifted compared with the CO and CO/PFO photocatalysts. The experimental results show that the CQDs/CO/PFO photocatalyst has high photocatalytic rates for the degradation of oxytetracycline hydrochloride (OTC-HCl) under simulated sunlight irradiation. The photocatalytic efficiency of CQDs/CO/PFO photocatalysts is not linearly dependent on the content of CQDs, optical absorption coefficient, energy band (Eg) value and magnetic properties. The optimal CQDs content, the magnetic squareness ratio (SQR), the initial drug concentration, the catalyst content and initial pH value were 7 mL, 0.271, 50 mg/L, 1 g/L and 10, respectively. A variety of free radical verification experiments, degradation pathways and toxicity analysis confirmed that the hole (h+) and hydroxyl radical (•OH) were the two primary active species in CQDs/CO/PFO photocatalysts for the degradation of OTC-HCl. The multi-dimensional integrated methods have been explored for fabrication of CQDs/CeO 2 /PbFe 12 O 19 photocatalysts with the different CQDs contents. The CQDs/CeO 2 /PbFe 12 O 19 photocatalysts present excellent photocatalytic rate for degradation of oxytetracycline hydrochloride under simulated sunlight irradiation. [Display omitted] • The CQDs/CeO 2 /PbFe 12 O 19 photocatalysts were fabricated by the multi-dimensional integrated methods. • The photocatalysts present excellent photocatalytic rate for the degradation of OTC-HCl. • Possible photocatalysis mechanism and degradation pathway have been proposed. [ABSTRACT FROM AUTHOR]

The BaMoO 4 and BaMoO 4 /BaWO 4 phosphors were successfully prepared via a polyacrylamide gel method and low temperature calcination technology. The type-I band arrangement structure of BaMoO 4 /BaWO 4 phosphors is beneficial to enhance the photoluminescent properties of phosphors. [Display omitted] • A facile method have been used to synthesize the BaMoO 4 and BaMoO 4 /BaWO 4 phosphors. • The type-I band arrangement structure composite phosphors have been synthesized. • The structure, photoluminescence and photocatalytic properties were studied. • Photoluminescence mechanism of BaMoO 4 /BaWO 4 phosphors was proposed. A series of BaMoO 4 and BaMoO 4 /BaWO 4 phosphors were successfully prepared via a polyacrylamide gel method and low temperature calcination technology. The effects of sintering temperature and mass percentage of BaMoO 4 /BaWO 4 on the phase purity, functional group, surface morphology, charge state, photoluminescence properties and photocatalytic activity of the prepared products were studied in detail. The results indicate that the BaMoO 4 phosphor is a scheelite tetragonal structure with high crystallinity. The photoluminescence spectra indicates that the phosphors have a strong blue emission peak at 440 nm with excitation wavelength of 282 nm for the BaMoO 4 phosphor, and three emission peaks at 400, 440 and 460 nm with excitation wavelength of 284 nm for the BaMoO 4 /BaWO 4 phosphors. These photoluminescence behaviors can be ascribed to the 1T 2 →1A 1 transition, Jahn–Teller distorted tetrahedral symmetry of [MoO 4 ]2- and surface defect. Photocatalytic experiments further confirmed that the BaMoO 4 /BaWO 4 phosphors exhibit a high recombination rate of electron hole pairs. The result further indicates that the type-I band arrangement structure of BaMoO 4 /BaWO 4 phosphors is beneficial to enhance the photoluminescent properties of single-phase phosphors. This study provides a novel route for preparing the type-I band arrangement structure composite phosphors with high photoluminescent properties and potential applications in light emitting devices, optoelectronic devices, laser devices and white pigments. [ABSTRACT FROM AUTHOR]

Abstract: We report on the in situ electrical resistance measurements of Ti2AlC under high pressure up to 6 GPa using four-probe method in a cubic large volume press. The resistance of Ti2AlC changes smoothly with pressure without sharp anomalies, which reveals no phase transformations. The resistivity decreases with increasing pressure. At pressures above 3.5 GPa, the resistivity decreases slowly with a pressure dependence of about . In addition, the resistivity was also measured at the process of decompression. The resistivity changes slowly with a pressure dependence of about at pressures above 2.5 GPa. These results are associated with the resistivity change with temperature and could confirm that the transition metal plays the dominant role in electrical transport. [Copyright &y& Elsevier]

The sound velocities of polycrystalline Mg-phase D were investigated at the pressure up to 13.6 GPa and room temperature, using ultrasonic interferometry in a multi-anvil apparatus. The P (VP) and S (VS) wave velocities obtained at ambient conditions produced the results of VP = 9.26(3) km/s and VS = 5.46(1) km/s. The results are in accordance with the values for Mg-phase D by Brillouin scattering (VP = 9.25 km/s and VS = 5.51km/s). The results, i.e. Ks0 = 153.8(13) GPa and G0 = 99.8(5) GPa obtained through two-dimensional linear fitting analysis are self-consistent with Ks0 = 153.3(16) GPa and G0 = 99.5(10) GPa derived by third-order Eulerian finite strain equations. We also find that Vp of phase D is 1.8–2.2% lower than Fe-ringwoodite, but Vs is higher than Fe-ringwoodite at the bottom of the mantle transition zone by up to 1.3%. [ABSTRACT FROM AUTHOR]

• Sound velocities and elasticity of submicron h -AlN are explored at high pressure using LVP-based ultrasonic interferometry technique. • Mechanical properties of submicron h -AlN are measured, as compared with the micro-grained counterparts. • Elastic-related properties of acoustic thermal conductivity for submicrion h -AlN, for the first time, was reported. Compressional (V P) and shear (V S) wave velocities of high pressure (P) and temperature (T) sintered submicron hexagonal aluminum nitride (h -AlN) have been measured up to 15 GPa using ultrasonic interferometry. Using finite strain equation-of-state approaches, yielding K S0 = 293.1 ± 2.9 GPa, G 0 = 141.9 ± 1.4 GPa and K′ S = 3.72 ± 0.04, G′ = 0.52 ± 0.02. It is found that the Vickers hardness of submicron h -AlN is as high as 11.7 GPa, and its fracture toughness is up to ∼4.25 MPa m1/2. Meanwhile, based on the elastic wave velocities and density data, the elastic-related properties of h -AlN are derived as Debye temperature Θ 0 = 1006 K, Grüneisen parameter γ = 1.72 and acoustic thermal conductivity λ acoustic = 196 W/mK. These results may provide a comprehensive elasticity and elastic-related properties of submicron h -AlN under high pressure, which may be of great importance for its uses at extreme conditions. [ABSTRACT FROM AUTHOR]

Barium hexaferrites (BaFe12O19) nanoparticles are prepared using γ-ray irradiation assisted polyacrylamide gel method (RIAPGM). The experiment parameters of as-prepared samples are investigated in detail, such as polymerization initiation mode and annealing temperature. The thermal decomposition behavior of BaFe12O19 xerogels were measured by thermogravimetric and differential scanning calorimetry (TG–DSC). The structure, optical, magnetic and electrochemical properties of BaFe12O19 nanoparticles were examined by various characterization techniques. The optical and magnetic properties of BaFe12O19 nanoparticles are emphatically researched by changing the annealing temperature. The BaFe12O19 nanoparticles prepared by RIAPGM exhibits uniform particle size distribution, excellent magnetic and electrochemical properties due to the effect of facet-dependent behaviour. [ABSTRACT FROM AUTHOR]

TATB (1,3,5-triamino-2,4,6-trinitrobenzene) is a widely used insensitive high-energy explosive. It is significant to study its structural evolution in order to get a credible understand of its properties and performances. Direct mechanical tests such as hardness tests are useful approaches to get information about its mechanical properties and shed light upon the microstructures. However, due to the poor solubility of TATB to most solvents, it is hard to produce large crystals for such tests. Fortunately, microcosmic approaches such as powder diffraction can reinforce it and has low requirement on samples. In this study, series of in-situ neutron diffraction experiments under different pressures are performed to investigate the structural change and mechanical properties of TATB. The recently reported phase transition at 4 GPa is studied. The microstrains in normal TATB (12–17 µm) are analysed to reveal the information of slip system and transitional process. The lattice parameters and bulk moduli of TATB under different conditions are given. These neutron diffraction results are significant supplement to correlative studies and will help to understand the performances of TATB, such as deformation and phase transition. [ABSTRACT FROM AUTHOR]

Ferroelectric materials under shock compression can generate current and power by a drastic change of the remnant polarizations and surface bound charge. This behavior has been employed in applications involving nuclear fusion trigger, energy storage devices, and high pulse power sources. Despite the large power output in lead‐containing ferroelectrics, lead‐free materials are highly desirable owing to the environmental concerns. Herein, the phase transition behaviors and current outputs of 0.92Bi0.5Na0.5TiO3‐0.08BiAlO3 (BNT‐8BA) materials are studied under high pressure. The BNT‐8BA ferroelectric ceramics can be completely depolarized from polar to the nonpolar state under shock compression, resulting in a current output in the external circuit. The phase‐transition‐induced depolarization pressures of BNT‐8BA are lower than those of the pure Bi0.5Na0.5TiO3 under both dynamic and static high‐pressure loads. These results can allow the understanding of the high‐pressure behavior of BNT‐8BA for application as ferroelectric pulsed power supply. [ABSTRACT FROM AUTHOR]

Pressure‐induced polymerization (PIP) of aromatics is a novel method for constructing sp3‐carbon frameworks, and nanothreads with diamond‐like structures were synthesized by compressing benzene and its derivatives. Here by compressing a benzene‐hexafluorobenzene cocrystal (CHCF), H‐F‐substituted graphane with a layered structure in the PIP product was identified. Based on the crystal structure determined from the in situ neutron diffraction and the intermediate products identified by gas chromatography‐mass spectrum, we found that at 20 GPa CHCF forms tilted columns with benzene and hexafluorobenzene stacked alternatively, and leads to a [4+2] polymer, which then transforms to short‐range ordered H‐F‐substituted graphane. The reaction process involves [4+2] Diels–Alder, retro‐Diels–Alder, and 1‐1′ coupling reactions, and the former is the key reaction in the PIP. These studies confirm the elemental reactions of PIP of CHCF for the first time, and provide insight into the PIP of aromatics. [ABSTRACT FROM AUTHOR]

Pressure‐induced polymerization (PIP) of aromatics is a novel method for constructing sp3‐carbon frameworks, and nanothreads with diamond‐like structures were synthesized by compressing benzene and its derivatives. Here by compressing a benzene‐hexafluorobenzene cocrystal (CHCF), H‐F‐substituted graphane with a layered structure in the PIP product was identified. Based on the crystal structure determined from the in situ neutron diffraction and the intermediate products identified by gas chromatography‐mass spectrum, we found that at 20 GPa CHCF forms tilted columns with benzene and hexafluorobenzene stacked alternatively, and leads to a [4+2] polymer, which then transforms to short‐range ordered H‐F‐substituted graphane. The reaction process involves [4+2] Diels–Alder, retro‐Diels–Alder, and 1‐1′ coupling reactions, and the former is the key reaction in the PIP. These studies confirm the elemental reactions of PIP of CHCF for the first time, and provide insight into the PIP of aromatics. Short‐range ordered H,F‐substituted graphane was obtained by compressing benzene and hexafluorobenzene cocrystals. By using neutron diffraction and GC‐MS, the reaction process and elementary reactions were identified. The reaction process involves [4+2]Diels–Alder, retro‐Diels–Alder, and 1‐1′ coupling reactions, and the Diels–Alder reaction is the key reaction in the polymerization process. [ABSTRACT FROM AUTHOR]

MgAl2O4 with a spinel structure was successfully synthesized using a gamma-ray irradiation assisted polyacrylamide gel method. The samples were synthesized at different calcining temperatures to study the effects on the phase purity, optical, color and fluorescence properties and photocatalytic activity of the as-prepared samples. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) analysis indicates that the calcining temperature has an obvious influence on the crystallinity and the formation of the MgAl2O4 spinel phase. Transmission electron microscopy (TEM) observation shows that the primary crystal of the MgAl2O4 nanoparticles is only 30 nm and exhibits a higher uniformity than those of MgAl2O4 nanoparticles fabricated using the conventional polyacrylamide gel method. Optical properties show that the optical energy gap (Eg) of the MgAl2O4 nanoparticles increases with the increasing calcining temperature, mainly due to the interaction between the N–O and C–O functional groups and the calcining temperature. An abnormal result for the color parameter of the MgAl2O4 xerogel powders calcined at 900 °C indicates the enhancement of the crystallinity and the phase purity of the MgAl2O4 nanoparticles. The fluorescence spectra indicates that the emission intensity of the emission peak at 395 nm decreases with the increasing calcining temperature. The photocatalytic activity of the MgAl2O4 nanoparticles prepared at different calcining temperature were then tested for photocatalytic degradation of the methylene blue (MB) dye. The result indicates that the MgAl2O4 xerogel powders calcined at 800 °C exhibit the highest photocatalytic activity, and that this is relevant to the light absorption ability, band edge position, separation and utilization efficiency of the photogenerated carriers of the as-prepared sample. The fluorescence and photocatalytic mechanisms show that a small number of N–O and C–O functional groups in the presence of the MgAl2O4 nanoparticles can help to improve the fluorescence properties and photocatalytic activity of the MgAl2O4 nanoparticles. [ABSTRACT FROM AUTHOR]

Binary ε -Fe 3 N 1.098 and ternary ε -Fe 2.322 Co 0.678 N 0.888 were synthesized as spherical bulk materials using novel high-pressure solid-state metathesis reactions (HPSSM). The structural and magnetic properties of the two nitrides were investigated using neutron powder diffraction (NPD), a vibrating sample magnetometer (VSM), and first-principle calculations. We found that at high pressure and high temperature (HPHT), nitrogen atoms enter the interstitial 2d sites of the nitrogen-rich ε -Fe 3 N 1.098 structure, space group P 6 3 22, which were previously reported to be vacant. The stoichiometry of the nitride (N/Me ratio) and the level of disorder have a significant influence on the site occupancies and local magnetic moments in these iron-based nitrides. The substitution of Fe by Co in ε -Fe 2.322 Co 0.678 N 0.888 did not reduce the mean magnetic moment ( μ m ) per metal atom at the Wyckoff 6 g site. NPD refinements showed that the magnetic moment per Fe atom in ε -Fe 3 N 1.098 (at 1.8 (4) μ B ) was slightly higher than that of ε -Fe 2.322 Co 0.678 N 0.888 , where the moment per Fe/Co atom is 1.7(2) μ B . [ABSTRACT FROM AUTHOR]

Abstract: Ferroelectrics with perovskite‐like layered (PL) structure are well‐known for their high Tc and the application prospect of high‐temperature‐piezoelectric sensing. In this study, the PL‐structure Eu2Ti2O7 was prepared by 1‐step high‐pressure sintering, which show the pyrochlore structure of Eu2Ti2O7 would change into PL structure at 11 GPa, 1300°C. The PL‐structure Eu2Ti2O7 is metastable, which will change back to pyrochlore structure at about 900°C in the air. The PL‐structure Eu2Ti2O7 was confirmed as a high‐temperature ferroelectric material for the first time. The ferroelectric domain switching was directly observed using piezoelectric force microscope. The piezoelectric constant of the PL Eu2Ti2O7 ceramic was measured as 0.7‐0.9 pC/N and its thermal depoling temperature (Td) was determined as 800°C, which is associated with the PL‐pyrochlore transition. [ABSTRACT FROM AUTHOR]

• All in-suit experiments use the diamond anvil cell (DAC) in this work. • Raman spectra and infrared spectra both use in this work for complementing each other. • The process of temperature and pressure rising was analyzed simultaneously. • High pressure, high temperature and high pressure synergize with high temperature were analyzed respectively. • Skeleton and ring and OH···O hydrogen bond changed under high pressure. • Temperature accelerated the change of the crystal stucture under pressure. High-pressure Raman and infra-red spectroscopies were employed to explore how the molecular structure of α-D-glucose changes under high pressure and temperature. At room temperature, the spectra show a significant pressure dependence and changed abruptly in the 5.7–5.9 GPa pressure range. The spectra of α-D-glucose crystals did not change significantly when the temperature was raised from 25 °C to 110 °C. However, the synergistic effect of temperature and pressure could reduce the pressure to 4.4 GPa, indicating that high temperature may accelerate the change of the molecular structure. [ABSTRACT FROM AUTHOR]

[Display omitted] • The double p-n junction MgAl 2 O 4 /CeO 2 /YMnO 3 photocatalysts were constructed. • The photocatalysts exhibits high photocatalytic activity for the degradation drugs. • Various models were used to predict the adsorption capacity of photocatalysts. • The degradation pathway and photocatalytic mechanisms were explored. A simple two step method was developed for fabrication of ternary heterojunctions of YMnO 3 /CeO 2 /MgAl 2 O 4 (YCM) composite photocatalysts, which shows well adsorption capacity for the adsorption of Congo red and photocatalytic activity for the degradation of tetracycline hydrochloride (TC-HCl) under visible light irradiation. Systematic studies suggested that the YCM composite photocatalysts exhibit high optical absorption coefficient, charge carrier transfer and separation efficiency, adsorbed oxygen concentration and interface defect, high adsorption capacity and photocatalytic activity. The back propagation (BP) neural network model, whale optimization algorithm (WOA) and genetic algorithm (GA) were used to predict the adsorption capacity of YC composite photocatalysts, and GA model demonstrated the best predictive ability. The high adsorption can be assigned to the synergistic effect of electrostatic interaction, ion exchange and hydrogen bonding. Capture experiments revealed that photogenerated holes, hydroxyl and superoxide radicals are the main active species during the photocatalytic process for the YCM composite photocatalysts. Possible degradation pathways of TC-HCl over YCM composite photocatalysts under visible light irradiation were proposed through the identification of intermediates using high-performance liquid chromatography-tandem mass spectrometry (HPLC–MS). This work demonstrated a huge potential of YCM composite photocatalysts as an eco-friendly photocatalyst for adsorption of dye and degradation of drug. [ABSTRACT FROM AUTHOR]

[Display omitted] • The effect of manganese salts on the phase purity of YMnO 3 phase is discussed. • YMnO 3 /MgAl 2 O 4 grafted by C O functional group was constructed. • The catalytic performance of YMnO 3 and YMnO 3 /MgAl 2 O 4 were compared. • The adsorption/photocatalytic mechanism of YMnO 3 /MgAl 2 O 4 was proposed. The YMnO 3 with different manganese salts includes MnSO 4 ·H 2 O, MnCO 3 and C 4 H 6 MnO 4 ·4H 2 O and YMnO 3 /MgAl 2 O 4 heterojunction photocatalysts (YMO/MAO) with different mass percentage of MgAl 2 O 4 were synthesized by a simple wet chemistry method combined with low temperature sintering technology. The effects of manganese salts on the structure, functional groups, morphology, charge states and optical properties of YMnO 3 phase were studied in detail. The pure YMnO 3 with the uniformity of particles can be obtained when only C 4 H 6 MnO 4 ·4H 2 O is used as manganese source. The results confirmed that the YMO/MAO heterojunction was constructed by one step low-temperature sintering technique. The YMnO 3 /wt 10 % MgAl 2 O 4 photocatalyst exhibits high optical absorption coefficient and highest adsorption capacity of 122.86 mg/g and degradation percentage of 98.98 % for the degradation of Congo red (CR), 86.16 % for the degradation of tetracycline hydrochloride (TC) and 72.51 % for the degradation of tetrabromo bisphenol A (TBBPA). The hydroxyl and superoxide radicals dominated the photocatalytic reaction process of YMO/MAO for the degradation of CR, TC and TBBPA. The present work pioneers the potential application of YMO/MAO grafted by C O functional group as dyes, antibiotics and persistent organic pollutants (POPS) adsorption / degradation catalyst and further provides technical reference for the synthesis of others heterojunction photocatalysts. [ABSTRACT FROM AUTHOR]