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Tungsten bronze has attracted global attention for its applications in near-infrared (NIR)-shielding windows. Here, alkali metal tungsten bronze (MxWO3, M = one or two types of Li, Na, and K)-doped glasses are prepared by a simple melt-quenching method. Their structure and properties were characterized by XRD, Raman spectroscopy, XPS and UV–Vis–NIR spectrophotometry. The effects of M on their structure and the NIR shielding performance are investigated. The LiF sample has the best NIR shielding performance, but its visible transmittance is sacrificed due to its low quality. The glasses containing mixed Li+ and K+ cooperate to form a high-quality Li+/K+-codoped tungsten bronze, while the glasses containing mixed Li+ and Na+ compete for limited tungsten resources to form Li+- and Na+-doped tungsten bronzes separately. The research here is helpful for understanding the role of different alkali metal ions in bulk energy-saving glass and is hugely significant for the guidance of the future applications of energy-saving glass without films.

Reversible thermochromic inorganic materials show stable and perceptible color change with changing environmental temperatures. This property makes them excellent materials for fabricating temperature indicators, military camouflage materials, and thermal warning devices. However, the mechanism of thermochromism has not been fully understood. Here, we prepared novel bismuth molybdate materials by calcination of Bi2O3 and MoO3 mixtures. The materials exhibit reversible thermochromism, gradually changing color from milky white at 25 °C to bright yellow at 500 °C. The phase composition of the product is tunable by adjusting the ratio of Bi2O3 and MoO3 in the starting materials, producing either single phase of α-Bi2Mo3O12 or mixed phases of α-Bi2Mo3O12, β-Bi2Mo2O9 and γ-Bi2MoO6. The mechanism of reversible thermochromism was studied by in situ UV/Vis diffuse reflectance spectroscopy (UV/Vis DRS), in situ synchrotron radiation powder X-ray diffraction (SRPXRD), and differential scanning calorimetry (DSC). In situ SRPXRD revealed no phase transition during heating and cooling, which agrees with DSC analysis with no thermal event detected until the melting temperature of α-Bi2Mo3O12 at 661.6 °C. With increasing temperature, in situ SRPXRD also revealed anisotropic expansion of the α-Bi2Mo3O12 lattice parameters, while in situ UV/Vis DRS showed a continuous red shift in the absorption edge and gradual decrease of band gap, suggesting that lattice expansion and shrinking upon heating and cooling is the main reason for the thermochromic behavior in bismuth molybdate materials.

In this work, the composition-dependent point defect types and formation energies of RE2Hf2O7 (RE = La, Ce, Pr, Nd, Pm, Sm, Eu and Gd) as well as the oxygen diffusion behavior are systematically investigated by first-principles calculations. The possible defect reactions and dominant defect complexes under stoichiometric and non-stoichiometric conditions are revealed. It is found that O Frenkel pairs are the predominant defect in stoichiometric pyrochlore hafnates. Hf-RE cation anti-site defects, accompanied by RE vacancies and/or oxygen interstitials, are stable in the non-stoichiometric case of HfO2 excess. On the other hand, RE-Hf anti-site defects together with oxygen vacancies and/or RE interstitials are preferable in the case of RE2O3 excess. The energy barriers for the migration along the VO48f - VO48f pathway of pyrochlore hafnates were calculated to be between 0.81 eV and 0.89 eV. Based on these results, a defect engineering strategy is proposed and the pyrochlore hafnates investigated here are predicted to exhibit potential oxygen ionic conductivity.

Designing the highly catalytic activity and durable bifunctional catalysts toward oxygen reduction/evolution reaction (ORR/OER) is paramount for metal–air batteries. Metal–organic frameworks (MOFs)-based materials have attracted a great deal of attention as the potential candidate for effectively catalyzing ORR/OER due to their adjustable composition and porous structure. Herein, we first introduce the Mn species into zeolitic-imidazole frameworks (ZIFs) and then further pyrolyze the Mn-containing bimetallic ZIFs to synthesize core-shell-structured Co@Co4N nanoparticles embedded into MnO-modified porous N-doped carbon nanocubes (Co@Co4N/MnO NC). Co@Co4N/MnO NC exhibits the outstanding catalytic activity toward ORR and OER which is attributed to its abundant pyridinic/graphitic N and Co4N, the optimized content of MnO species, highly dispersed catalytic sites and porous carbon matrix. As a result, the Co@Co4N/MnO NC-based Zn–air battery exhibits enhanced performances, including the high discharge capacity (762 mAh gZn−1), large power density (200.5 mW cm−2), stable potential profile over 72 h, low overpotential ( NC cathode-based Zn–air batteries are also designed which exhibit the superb electrochemical properties at different bending/twisting conditions.

Rapidly deactivation of Cu/SiO2 catalysts at high liquid hour space velocity (LHSV) has been an important obstacle for scale-up application. Herein, silver modified copper phyllosilicate nanotubes were fabricated by different strategies, and implemented to the selective hydrogenation of ethylene carbonate (EC) to methanol and ethylene glycol (EG) as alternative route for the indirect utilization of CO2. The CuPs Ag–copre catalyst synthesized by the co–ammonia evaporation hydrothermal process achieved 79% methanol and 99% EG yield within various ranges of EC LHSV, which was attributed to the balanced Cu+/Cu0 ratio and the enhanced H2 dissociation ability. Inlaid silver species over copper phyllosilicate promoted the interaction between the metal and the support, which substantially regulated the reducibility and dispersion of copper species, meanwhile, increased the stability for long-term running of the catalyst.

Metallic Ni bridged NiS@mesoporous carbon nitride hybrids were for the first time fabricated through a one-pot electroless-assisted hydrothermal method. The intimate Ni bridge between the interface of mesoporous carbon nitride and NiS was confirmed by HRTEM and in-depth XPS analysis using an Ar+-cluster sputtering gun and a possible mechanism was put forward to elucidate the formation process of the unique structure. Without adding any noble metals as cocatalysts, the optimized catalyst 10% NiS/m-CN-160-12 showed a H2 evolution rate of 1419 μmol·g−1·h−1, which is about 34 and 14 fold higher than that of bare mesoporous carbon nitride and NiS, respectively. The dramatically enhanced photocatalytic performance was mainly ascribed to the synergistic effect of NiS cocatalyst loading and the formation of metallic Ni between the interface of mesoporous carbon nitride and NiS, which served as a charge-transfer bridge to facilitate the transfer and separation of photo-induced electron-hole pairs.

Cell-selective biomaterials, i.e. favoring the functions of gingival cells and simultaneously reducing the adhesion of pathogenic bacteria, is highly desired in dental implants. However, due to the same mechanisms shared in attachment by mammalian and microbial cells, it is hard to increase the functions of the former while acting against the latter. Herein, a cell-selectivity was established on titanium oxide coatings by combining a plasma immersion ion implantation & deposition (PIII) and a UV pre-illumination. The titanium oxide coatings were produced on pure titanium substrates by using a plasma electrolytic oxidation technique and then doped of hafnium (Hf) by using a cathodic arc sourced PIII. The Hf-doped titanium oxide coatings (Hf-PIII groups) were capable of delaying the recombination of UV-illumination generated electron-hole pairs, which decreased the adhesion of bacterial cells at the later period (cultured for 24 h). Titanium oxide coating doped of 4.87 at.% hafnium (Hf) gained the biggest decrease (decreased 52.9% compared to its UV negative counterparts) in bacterial adhesion among the UV positive (UV+) groups. This study demonstrates that coupling Hf-doping and UV pre-illumination is promising for improving the cell-selective performance of titanium-based dental implants. Keywords: Titanium, Surface modification, Ultraviolet, Bacteria, Hafnium

Electroplating industry is an important application field of per- and polyfluoroalkyl substances (PFASs) as the chromium mist suppressants. 6:2 chlorinated polyfluoroalkyl ether sulfonate (6:2 Cl-PFAES) and perfluorooctanesulfonate (PFOS) have been the two widely used mist suppressants, and after the ban of PFOS, 6:2 Cl-PFAES will become the dominant suppressant. The behavior and mechanisms of 6:2 Cl-PFAES in the electroplating industry and the receiving environment were studied and compared with PFOS. 6:2 Cl-PFAES behaved similarly with PFOS due to their similar chemical structure. However, some difference exists for the relatively stronger hydrophobicity of 6:2 Cl-PFAES. Up to 35.7 mg/L of PFOS and 13.4 mg/L of 6:2 Cl-PFAES were found in the industrial wastewater influents, and were effectively reduced to 0.3-0.8 mg/L by the interaction with chromium hydroxide through hydrophobic interaction and ligand exchange. The stronger hydrophobicity of 6:2 Cl-PFAES than PFOS resulted in its accumulation in the surface of foams and comparable or less removal during the industrial and municipal wastewater treatment. 6:2 Cl-PFAES exhibited higher bioaccumulation potential than PFOS in the surface water. 6:2 Cl-PFAES emitted by both mists and water may pose health risks to humans. More attentions towards 6:2 Cl-PFAES are needed after the replacement of PFOS by it in the electroplating industry as a global contaminant of emerging concerns.

Rutile titanium dioxide (TiO 2 ) is a promising photocatalyst with the wide band gap of 3.03 eV, which restricts its sunlight absorbance and renders pure TiO 2 inefficient for solar energy conversion. In this study, the electronic structures of rutile TiO 2 with V implantation are investigated by using first-principles calculations. The calculation results indicate that the TiO 2 with V implantation shows obviously narrowed band gap with increasing V concentration by introducing localized energy levels within the forbidden gap. When the content of V exceeds 0.5, the rutile TiO 2 system presents metallic property. In addition, TiO 2 with V implantation presents an increase in the both absorption and reflectance of solar radiation, as compared to the pure TiO 2 , which is advantageous to visible light absorption for TiO 2 .

Risk on the supply chain from various sustainability-related factors has increasingly become relevant to companies in many industries. There however still lacks a comprehensive method to quantitatively evaluate supply chain sustainability risk taking into account the triple bottom line of sustainability (economic, social, and environmental). This study develops a framework to evaluate supply chain sustainability risk by measuring supply chain-wide operational risk, social risk, and environmental risk to form an aggregate metric. A set of indicators readily available in literature are used to represent various aspects of supply chain sustainability risk. Risk assessment space and materiality analysis are then used to prioritize resource allocation among supply chain stages from two distinct perspectives for mitigating supply chain sustainability risk. Two case studies are provided to demonstrate the application of the developed framework, representing two main types of supply chain structure. The apparel industry example represents the deep-structure supply chain driven by relatively simple products, while the automotive industry example represents the broad-structure supply chain driven by more complex products. While the case studies focus on industry-level assessment for demonstration purpose, the developed framework can be flexibly applied to evaluate supply chain sustainability risk for specific companies in any industry.

Understanding the method of inducing magnetism and the source of magnetism in two-dimensional (2D) materials is essential for the development of spintronic devices. Here, we present a spin-polarized first-principles study on the electronic and magnetic properties of a ZnO monolayer with adsorbed noble metals NM (NM = Pd, Pt, Ag, Au, Cu). The results demonstrate that the most preferable adsorption sites for all the considered noble metals NM (NM = Pd, Pt, Ag, Au, Cu) are located on top of the O atoms (TO). Furthermore, both Pd and Pt adsorbed on the ZnO monolayer remain nonmagnetic. Interestingly, sufficient Ag, Au, and Cu adsorbates can induce magnetic properties, and the magnetic moments mainly originate from the adsorbates. Moreover, as the distance between the two atoms of the same element (Ag, Au, or Cu) increases, the ZnO monolayer undergoes FM-AFM transitions, which expand the utilization of ZnO monolayers in nanoelectronics and spintronics. These results may pave the way for future experiments based on 2D noble metal-adsorbed ZnO materials, which can serve as potential materials in nanoelectronics and spintronics.

Vanadium dioxide (VO2) is an important thermochromic material due to its reversible metal-insulator transition at 340 K. However, the high phase transition temperature of VO2 prevents its practical application in smart windows. Here, we use first-principles calculations to study the effect of rare-earth (RE = La, Ce, Pr, Nd, Eu, Gd, Tb) dopants on the variation of the local octahedral volumes, lattice distortion of VO2 and dimerization of the V-V chain in VO2. Interestingly, Tb and La dopants with a concentration of 3.1 at.% decreased the phase transition temperature of VO2 to 206 K and 225 K, respectively. Moreover, three factors, including the V-V chain change, distortion of the REO6 octahedron, and formation of impurity states contributed by RE-f states, assist the phase transition of VO2. Additionally, the incorporation of an RE dopant scaled the band gap of VO2 and further tuned its near-IR absorption. These findings provide novel insights and guidance on chemically tailoring the phase transition of VO2.

This study was designed to investigate the neuroprotective effect of hyperoxygenate hydrogen-rich saline (HOHS) against brain injury induced by carbon monoxide (CO) poisoning in rats. A rat model of CO poisoning was established by administering CO via intraperitoneal injection to male Sprague-Dawley rats. Forty-eight adult male rats were randomly divided into the following groups: normal control group (NG), CO poisoning group (CO), HOS treatment group (hyperoxygenated solution, HOS) and HOHS treatment group (HOHS). After CO poisoning, the carboxyhemoglobin (COHb) contents in the blood of rats in all the CO poisoning groups were increased significantly. However, HOS and HOHS significantly decreased COHb contents, furthermore, the HOHS group had lower COHb contents than the HOS group. Arterial oxygen partial pressure (PaO2) and arterial oxygen saturation (SaO2) results showed that HOS and HOHS could improve the oxygenation of the rats with CO poisoning. Compared with the CO group, the HOS group and the HOHS group had persistently neuroprotective effect on CO-induced brain injury, as assessed by modified neurological severity score (mNSS), furthermore, the HOHS group had better neurological functional recovery than the HOS group. The neuronal apoptosis induced by CO was also evaluated. Except the NG group, all the CO-poisoning groups had varying degrees of neuronal apoptosis. There was lesser degree of neuronal apoptosis in both the HOS group and the HOHS group than that in the CO group. Moreover, the HOHS group had more minor degree of neuronal apoptosis than the HOS group. Compared with the CO group, the free radicals production in the HOS group and the HOHS group were significantly inhibited. In addition, there were significantly difference in the free radicals production between the HOS group and the HOHS group. We could conclude that HOHS exerted a stronger neuroprotective effect against CO-induced brain injury than HOS, and the neuroprotective mechanism of HOHS may be related with inhibition of both neuronal apoptosis and free radicals.

In the present work, Gadolinium zirconate (GZ) films were prepared by laser CVD (LCVD) method. The influence of preparation conditions, involving preheating temperature (Tpre) and laser output power density (Pl) on morphology, microstructure, substrate temperature (Tsub) and deposition rate was thoroughly investigated. An extended formation region of GZ films, based on Tpre and Pl values, was observed at a pressure of about 0.9 kPa. Laser irradiation mainly plays a photolytic role when Pl

Vanadium dioxide (VO2) is an attractive material for energy-saving smart windows due to its metal-to-insulator reversible phase transition near ambient temperature, accompanied by large changes in its optical properties. We conducted first-principles calculations to study the phase-transition temperature and optical properties of alkaline earth metal (Be, Mg, Ca, Sr or Ba)-doped VO2. The results show that the Be atom prefers to locate at the octahedral interstitial site, while Mg, Ca, Sr and Ba atoms prefer to substitute for the V atom in VO2. Be, Mg, Ca, Sr and Ba doping reduces the phase-transition temperature of VO2 0by 51.4, 59.7, 61.5, 58.4 and 58.3 K, respectively, when the doping concentration is set at one atomic percentage. In addition, the introduction of alkaline earth metal scales the band structures of VO2, which enhances the ability to block the infrared light (in the order of Be > Mg > Ca > Sr > Ba) and promotes the transmission of visible light (in the order of Be > Mg ≈ Ca > Sr > Ba).

Seneca Valley virus (SVV) is related to vesicular disease in pigs, and its clinical symptoms are indistinguishable from other notifiable clinical symptoms of vesicular disease such as foot-and-mouth disease. The rapid and accurate detection of SVV is essential to confirm the pathogenic factors and initiate the implementation of control measures. The development of a rapid, simple, convenient, and low-cost molecular (nucleic acid amplification) test that can be used at the sample collection point has been identified as a key component for controlling SVV. This study describes the development and demonstration of recombinase polymerase amplification (RPA) test targeting the conserved regions of SVV for detection of SVV. The Primers and probes designed by us have shown good sensitivity and specificity in RPA test, which is helpful for RPA to be an effective tool for rapid diagnosis of SVV.

Inducing and manipulating the magnetism in ZnO monolayer is crucial for both fundamental study and practical applications. Herein, the effects of Co adatoms and charge injection on the electronic and magnetic properties of ZnO monolayer are studied by the first-principles calculations. The results reveal that the most stable configuration for Co1/ZnO monolayer is the one that Co is located on the top of O atom. As the numbers of Co atoms increase, the arrangement of Co atoms on the monolayer may change from linear to plane structure, and finally convert to tetrahedral structure. Furthermore, Con/ZnO monolayers (n = 1, 2, 3, 4) have superior electron behavior in comparison with pristine ZnO monolayer. With an increase in the Co cluster size, the work functions of Con/ZnO monolayers are decreased gradually. The characteristics of Con/ZnO monolayers change from semiconducting to semi-metallic state, but remain magnetic behavior. Moreover, the total magnetic moments of Con/ZnO monolayers are increased from 3.548 µB to 6.521 µB with increasing the Co content. Besides, the changes of Co-3d states are responsible for the tunable the magnetic moment in Co1/ZnO monolayer by the charge injection. These results are helpful to improve the understandings of electronic and magnetic behavior of Con/ZnO monolayers and broaden the valuable potential for the design of spintronic nano-devices.

A new hydrazone derivative LL3 based on carbazole and coumarin was prepared by the condensation of 7-diethylaminocoumarin-3-carbohydrazide with 3-aldehyde-N-butyl carbazole and its structure was characterized using FT-IR, 1H NMR, 13C NMR, MS and elemental analysis techniques. LL3 could be used as a dual-functional fluorescent probe to identify Cu2+ and ClO−. Probe LL3 could recognize Cu2+ and formed a 2:1 complex. Under a 365 nm UV lamp, the color changed from yellowish to blue-green which could be readily distinguished by the naked eye. Meanwhile, under the catalysis of ClO−, the imine bond of probe LL3 was hydrolyzed to obtain carbazolealdehyde, resulting in specific UV-Vis and fluorescence phenomena, so as to realize the detection of ClO−. The recognition mechanism was proved by spectrometric titrations, Job’s plots, FT-IR, 1H NMR, mass spectroscopy (MS) and density functional theory (DFT) calculation analysis. The results of live cell imaging showed that LL3 could be used as a fluorescent probe to detect Cu2+ and ClO− in Hela cells. In addition, the probe LL3 could also be made into a test strip for the detection of Cu2+ in actual water samples.

The monoclinic VO2(M) has promising applications in intelligent devices but its preparation still requires improvement to permit cost-effective mass production. In this work, we report a 2-stage approach for producing VO2(M) nanorods by (1) hydrothermal reduction of vanadium pentoxide by sodium bisulfate at 220 °C to form VO2(A), and (2) subsequent thermal activated phase transformation of VO2(A) to VO2(M) at 350–450 °C in vacuum. The obtained VO2(M) nanorods showed a reversible phase transition temperature at about 62.5 °C and a narrow thermal hysteresis width of 10 °C. The mechanism of the hydrothermal reduction was studied by combined ex situ microscopic and diffraction characterization of cooled samples as well as in situ PXRD experiments, in which the hydrothermal synthesis was monitored in real time by time-resolved diffraction datasets. It was found that the hydrothermal synthesis of VO2(A) is a 4-step process: (1) reduction of V2O5 to form VO2(B) nanoparticles, (2) oriented attachment of VO2(B) nanoparticles along the [110] direction, (3) formation of VO2(B) nanorods as a results of oriented attachments, and (4) hydrothermal transformation of the metastable intermediate VO2(B) nanorods to VO2(A) nanorods. This clear understanding of the mechanism will help the further optimization of synthesis temperature and time for preparing VO2(A). This method provides a low temperature thermal treatment alternative and hence helps the reduction of cost for the production of VO2(M), bring the mass application of VO2(M) one step closer.

Perovskite-type transparent conductive oxides have attracted continuous attentions due to their applications in optoelectronic devices, but the optimization of their transmittance and conductivity is under way. In this work, the energetics, electronic and optical properties of the perovskite stannates (ASnO3, A = Ca, Sr, Ba) with diverse dopants La, Sb and Nb are studied using density functional theory. The energetically preferred substitution positions are predicted as A site for La but Sn site for Sb and Nb. Therefore, the doped perovskite stannates are all identified as n-type semiconductors due to the extra electron from the dopants. The calculated absorption coefficient and reflectivity in La, Sb and Nb doped perovskite stannates decrease but their transmittance in the visible light range increases as a result of the adjusted band structures. In addition, the carrier concentration dependent electric conductivity of the doped perovskites is predicted. The uncovered mechanism of improved electronic and optical properties for doped perovskite stannates is expected to benefit the design of high performance perovskite transparent conductive materials.

Rapid development of the thermochromic glazing technique promises next-generation architectural windows with energy-saving characteristics by intelligently regulating indoor solar irradiation via modulating windows’ optical properties in response to the surrounding temperature. Vanadium dioxide (VO2) is a promising material for energy-saving smart windows due to its reversible metal-to-insulator transition near room temperature and accompanying large changes in its optical properties. This review provides a comprehensive overview of the application of VO2 to smart windows with particular emphasis on recent progress from the electronic, atomic, nano, and micron perspectives. The effects of intrinsic atomic defects, elemental doping, and lattice strain on VO2 nanocrystals are examined. Nano- and microscale morphology engineering approaches that aim to enhance the thermochromic performance and impart practical multi-functionalities are summarized. Finally, the challenges and future directions of VO2-based smart windows are elaborated to bridge the gap between the lab research and large-scale practical applications. Vanadium dioxide (VO2) is a promising material for energy-saving smart windows due to its reversible metal-to-insulator transition near room temperature. This thermally induced phase transition is reversible, and it is accompanied by a dramatic change in the optical properties in the near-infrared region from a low-temperature transparent state to a more blocking state at high temperatures, imbuing the VO2-based window with the ability to regulate solar heat flux by responding to temperature automatically. In this review, the progress in VO2-based smart windows is overviewed, from the band structure designing at the electronic and atomic scales to morphology engineering from nano- to microscales. We discuss the effects of intrinsic atomic defects, elemental doping, and lattice strain on the electronic and atomic structures of VO2. Subsequently, nano- and microscale engineering methods to enhance the performance of smart windows are presented, including incorporating particles, tuning the porosity, designing nanocomposites, developing biomimetic patterns, creating grids, and applying multifunctional antireflection coatings. The energy efficiency is also discussed from both simulations and experimental aspects. Lastly, challenges and future directions are discussed. We hope that this work may inspire more innovative progress and accelerate the development of this technique from the lab to industry. VO2 is a promising material for energy-saving smart windows due to its reversible metal-to-insulator transition near room temperature and accompanying large changes in its optical properties. This review provides a comprehensive overview of the application of VO2 to smart windows with particular emphasis on recent progress from the electronic, atomic, nano, and micron perspectives. The challenges and future directions of VO2-based smart windows are elaborated to bridge the gap between the lab research and large-scale practical applications. NRF (Natl Research Foundation, S’pore) MOE (Min. of Education, S’pore) Accepted version

Vanadium dioxide (VO2) has attracted great attention, with scientific and technological advances over the past few decades due to its reversible metal-insulator transition at 340 K. However, the high phase transition temperature (Tc) of VO2 limits its practical applications. Our first-principles calculations show that VO2(1 1 0) surfaces with adsorbed noble metals (Ag, Au, Pt) exhibit a lower work function compared with the clean surface and further induces a lower Tc due to charge transfer from the noble metals to the VO2(1 1 0) surface. However, the work functions of the VO2(1 1 0) surfaces after the incorporation of noble metals are higher than that of the clean surface. In addition, the results of formation energies of various configurations show that the VO2(1 1 0) surface with the adsorption and incorporation of Ag is energetically more favorable than those with Au and Pt. Therefore, it may be concluded that the adsorption and incorporation of noble metals can not only tailor the work function of VO2, in turn realizing the rational tuning of Tc of VO2, but also stabilize the structures of VO2 thin films. These results provide guidance for further exploration of VO2-based optical switching devices and smart windows.

Lanthanum zirconate (LZ) films with a controllable La/Zr composition were prepared by laser enhanced chemical vapor deposition (LCVD). The effects of different precursors ratio, i.e. the La(dpm) 3 /Zr(dpm) 4 molar ratio, on composition, crystal structure, morphology and electrical conductivity of films were investigated. The formation region of columnar and purely cubic pyrochlore structured LZ films with a controllable La/Zr molar ratio in a wide range of 0.51–2.53 was mapped. Crystal structure changed with the different precursor's ratio, which was caused by atomic substitution between lanthanum and zirconium, being proved by combining with experimental and theoretical XRD patterns. It is found that electrical conductivity of non-stoichiometric LZ films is up to 4.3 × 10 −3 S cm −1 at 1073 K. The columnar pyrochlore structured LZ films with a wide region of non-stoichiometric compositions are expected to be candidates for many potential applications, such as dielectric, thermal barrier coatings and nuclear waste treatment materials.

A novel blue-green-emitting and red-emitting phosphor MZnOS: Bi, Li (M = Ca, Ba) have been prepared, and the correlation between site occupation, valence state of Bi in MZnOS and their luminescence properties was investigated. In MZnOS, M sites are the most suitable and stable sites for Bi to occupy according to the Rietveld refinement and first principle calculation. Bi is found to be in trivalent state in CaZnOS, but is a mixture of divalent and trivalent states in BaZnOS. Under 366 nm excitation, Bi - doped CaZnOS and BaZnOS show strongly broad emission bands with the peak at about 485 and 507 nm, respectively, attributing to the 3P1,0 → 1S0 transition of Bi3+. However, another broad band emission with the peak at 627 nm is observed for BaZnOS: Bi, Li upon 297 nm excitation. The X-ray excited luminescence (XEL) of Bi in MZnOS exhibit the similar properties as observed under UV excitation. The thermal stability of MZnOS: Bi, Li is relatively good enough for practical application. MZnOS: Bi, Li show potential applications as blue-green and red emission phosphor for LED devices considering the suitable absorption and emission wavelength range, high stability, as well as low cost.

Pt-modified β-NiAl is an alloy of special interest for bond coatings in the hot sections of the engines. Nevertheless, the site occupancy of Pt is still an open issue. In this work, we have constructed a Ni-Al-Pt interatomic potential and carried out the molecular dynamics simulations to reveal the atomic structures and displacement behaviours of Pt in B2-NiAl. The results of the simulations not only show that the Pt atoms have a strong preference for the Ni site in B2-NiAl but also suggest that an increasing Pt concentration leads to a more pronounced displacement of the Al atoms. Moreover, the simulations predict the occurrence of phase separation in B2-NiAl when the Pt concentration reaches 20%, which is confirmed in the subsequent experiments by the formation of a β-NiAl+Al2Pt dual-phase structure. The present findings promote the understanding of the atomic structures in B2-NiAl, which in turn may provide useful guidance for the fabrication of high-quality β-NiAl bond coatings.

The systematic research about the adsorption desulfurization and competitive behavior from 1-hexene over cesium-exchanged Y zeolites has been investigated. The structural properties of the adsorbents were characterized by X-ray diffraction (XRD), N 2 sorption (BET) and thermal analysis (TGA). The effects of calcination temperature, calcination atmosphere, and adsorption temperature were studied by the dynamic and static tests. The competitive adsorption mechanisms between thiophene and 1-hexene were studied by in-situ Fourier transform infrared spectroscopy (in-situ FTIR) and temperature-programmed desorption (TPD). CsY adsorbents exhibited high selectivity for thiophene even when a large amount of olefins exist. In-situ FTIR spectra of thiophene and 1-hexene adsorption indicated that both thiophene and 1-hexene were mainly adsorbed on CsY via π-complexation. The higher desorption activated energy and higher adsorption heat of thiophene than 1-hexene obtained by thiophene-TPD and hexene-TPD has revealed that thiophene is adsorbed more strongly in CsY adsorbents than 1-hexene.

Two-dimensional (2D) VS2 is expected to be an encouraging candidate for Li ion batteries owing to its good cycling stability and large capacity. Most of the recent works, however, focused on the ionic conductivity of 2D VS2, and little attention had been paid to its electronic conductivity. In this paper, first-principles calculations were carried out to figure out the electronic conductivity of 2D VS2 doped with all the transition elements (Me). The results show that W, Re, and Co are most effective dopants to improve the electronic conductivity of 2D VS2. It is also concluded that the electronic conductivity is associated with the band gap and lattice distortion of VS2. A narrowed band gap and a shrinkage of Me-S bond would lead to a high electronic conductivity of doped VS2 system.

Penicillium expansum is the most common spoilage-associated organism found in fruit, which causes serious economic loss and public health concerns. The aim of this study was to isolate lactic acid bacteria (LAB) from kefir in order to study its antifungal effect on mold growth and further analyze the possible antifungal mode of action of LAB, including antifungal component, lytic enzymes activity and nutrient competition. Lactobacillus kefiri M4 and Pediococcus acidilactici MRS-7 were isolated from kefir, and the overlay method was used as a qualitative approach to evaluate their antifungal activities against Penicillium expansum, the results showed that all tested strains were inhibited by the isolates, except for P. expansum LPH6. Different treatments were carried out to characterize the nature of the molecules that contributed to the antifungal activity of the cell-free supernatants produced by the isolates, and it was shown that all supernatants were pH-dependent, partly heat sensitive, and were not influenced by proteinaceous treatment. The cell-free supernatants of both species of LAB were analyzed by high-performance liquid chromatography (HPLC) and liquid chromatography-mass spectrometry (LC-MS), and it was found that the main antifungal compounds were organic acids and carboxylic acids. Both LAB species were able to produce lytic enzymes, such as cellulases, proteases, and glucanases, which formed a halo zone on the plate. L. kefiri M4 and P. expansum LPH10 exhibited nutrient competition when co-cultured together in a tissue culture plate insert. The results of this study showed that L. kefiri M4 and P. acidilactici MRS-7 isolated from kefir possess antifungal activity, which provides useful information of how P. expansum response to the LAB isolated from kefir.

Tibetan kefir grains (TKG) are multi-functional starter cultures used in foods and have been applied in various fermentation systems. This study aimed to investigate the microbial community composition of TKG, the detoxification abilities of TKG and their isolates towards common mycotoxins, and the potential for applying TKG and their associated microbial populations to avoid mycotoxin contamination in dairy products. Cultivation-independent high-throughput sequencing of bacterial and fungal rDNA genes indicated that Lactobacillus kefiranofaciens and Kazachstania turicensis were the most abundant bacterial and fungal taxa, respectively. In addition, 27 total isolates were obtained using cultivation methods. TKG removed more than 90% of the Ochratoxin A (OTA) after 24 h, while the isolate Kazachstania unisporus AC-2 exhibited the highest removal capacity (~46.1%). Further, the isolate exhibited good resistance to acid and bile salts environment. Analysis of the OTA detoxification mechanism revealed that both adsorption and degradation activities were exhibited by TKG, with adsorption playing a major detoxification role. Furthermore, the addition of OTA did not affect the microbial community structure of TKG. These results indicate that TKG-fermented products can naturally remove mycotoxin contamination of milk and could potentially be practically applied as probiotics in fermentation products.

VO2 is a promising thermochromic material for smart windows. The major challenge for its practical application is to strike a balance between a comfortable phase transition temperature (Tc) close to room temperature and high transmittance (T) in the visible light range. Herein, we investigated the phase transition behavior of Ru-doped VO2 using first-principles calculations. The results showed that Ru-doped VO2 can be more easily realized under O-rich conditions than under V-rich conditions. Tc is sensitive to the Ru-dopant concentration and dopant symmetry, which are related to changes in the atomic and electronic structures. Furthermore, the optical band gap for RuxV1-xO2(M) first increases and then decreases with increasing Ru content. Moreover, the switching between insulating and metallic states in RuxV1-xO2(M) can be modulated by controlling the Ru-dopant concentration, and the band gap is reduced from 0.69 eV to 0 eV with increasing Ru-dopant concentration. Additionally, Ru doping can enhance the visible and infrared light transmission (T) of VO2 materials within their very narrow energy ranges. These results provide another way to promote the thermochromic properties of VO2 for application in smart windows.

The development of available electronic structures and magnetism has received considerable interest for applications in nanoelectronic and spintronic devices. In this paper, we investigated the electronic and magnetic properties of Cu-doped defective ZnO monolayers by first-principles calculations. The results demonstrate that the formation energies of the VO + nCuZn complex under Zn-rich conditions are lower than those under O-rich conditions. However, the formation energies of the VZn + nCuZn complex under O-rich conditions are lower than those under Zn-rich conditions. Furthermore, the Cu dopant and vacancies both play an important role in the contribution of the magnetic moment. The total magnetic moments of the Cu2Zn14O15 monolayers remain at 1.822–1.868 µB, and the average local magnetic moment is approximately 0.439–0.443 µB per Cu atom. The magnetic moments of the O atoms close to the Cu atom are 0.124–0.163 µB per O atom. The magnetic moments of the VO + nCuZn complexes satisfy the odd-even doping rule, and the VO + nCuZn complexes undergo a transition from NM to FM with increasing Cu concentration. For the VZn + nCuZn complex, the total magnetic moments increase monotonically with an increase in the number of Cu atoms. The absolute value of total magnetic moment of the CuZn14O16 monolayer is 0.225 µB, which is contributed by the Cu dopant (0.433 µB), as well as the nearest O atoms around the Cu dopant. Furthermore, the combined effect of defect vacancy and Cu dopant could tune the ZnO monolayer from a direct semiconductor to an indirect semiconductor and even regulate the band gap. These findings are potentially useful for nanoelectronic and spintronic applications.

The development of efficient pure-blue emitters is of great significance for achieving high-quality display and lighting. Herein, a pure-blue emitter TPA-DPPI comprised of bisphenanthroimidazole and triphenylamine units with bipolar carrier transport property is designed and synthesized. For the two phenanthroimidazole units, one acts as the electron acceptor moiety, and the other is introduced to twist the molecule in order to suppress the intermolecular interactions in neat film. Highly twisted molecular configuration endows the compound with a high photoluminescence quantum efficiency yield of 0.56 in neat film. The non-doped device using TPA-DPPI as an emissive layer shows a pure-blue emission with a Commission International de l'Eclairage coordinates of (0.146, 0.097) and a high external quantum efficiency of 5.20%.

The interface between band insulator TiO2 and correlated insulator VO2 is a fertile ground for new behaviors. In the present paper, we conducted the first-principles calculations to study the interfaces of VO2(m)/TiO2(n) superlattices (referred as m/n for simplicity, where m and n denote the number of rutile VO2 and TiO2 layers, respectively). Interestingly, the VO2/TiO2 superlattices show insulating states in the 2/6, 4/6 and 6/6 systems with the oscillation of V-V distances, while the superlattices present metallic states in the 1/6, 3/6 and 5/6 systems as the oscillation of V-V distances is broken. Accordingly, we reported an alternating metal-insulator behavior in VO2/TiO2 superlattices with the increasing number of VO2 layers. These findings may help to better understand the Peierls structural transition in correlated insulator, and may bring a light to the Schottky barrier homojunction composed of different VO2(m)/TiO2(n) superlattices.