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Titanium alloy is widely used in biomedical materials. Ti-Sn alloy is a new type β titanium alloy with no toxicity. In this paper, the mechanical and electronic properties of Ti5Sn3 with vacancy defects have been studied by using first-principles method. The vacancy formation energy, vacancy formation enthalpy, elastic constant, elastic modulus, hardness and electronic structure of perfect Ti5Sn3 and Ti5Sn3 with different vacancies were also calculated and discussed. The results show that Ti5Sn3 is more likely to form vacancies at VTi2. In addition, the bulk deformation resistance of Ti5Sn3 is weakened by the vacancy, and the shear resistance, stiffness and hardness of Ti5Sn3 are increased by the Ti vacancy, but the brittleness of Ti5Sn3 is increased. On the contrary, the presence of Sn vacancy decreases the shear resistance, stiffness and hardness of Ti5Sn3, and increases the toughness of Ti5Sn3. By analyzing the change of electronic structure, it is found that removing the Ti atom at the VTi2 position can improve the interaction between atoms, while Sn vacancy can weaken the interaction. [ABSTRACT FROM AUTHOR]

In our work, to figure out the effects of V and Si vacancies on formation energies, elastic properties, phonon dispersions, electronic structures, and thermodynamic properties of VSi2, we used first-principles calculations. VSi2 with V and Si vacancies are dynamically and thermodynamically stable from the calculated formation energies and phonon dispersions. Moreover, VSi2 with V and Si vacancies are mechanically stable certified by single-crystal elastic constants. The presence of different atomic vacancies can weaken the bond strength of V–Si and Si–Si bonds, and eventually leads to the decreasing phase stability and elastic modulus, but can increase elastic anisotropy and ductileness. Finally, thermodynamic properties, including Debye temperature, sound velocities, and directional sound velocities, of perfect VSi2 and VSi2 with different vacancies are calculated. Highlights Based on the calculated vacancy formation energies and phonon dispersions, the perfect VSi2 and VSi2 with different vacancies are thermodynamically and dynamically stable. The vacancies can reduce the thermodynamical stability of VSi2, VSi2 with V vacancies are more stable than those with Si vacancies, and among VSi2 with vacancies, VSi2 with V-Va1 is the most stable. The perfect VSi2 and VSi2 with different vacancies are brittle, and the atomic vacancies can improve the ductility of VSi2 slightly, but can weaken the elastic modulus. The order of elastic anisotropy is Si-va3 > Si-va1 > Si-va2 > V-va2 > V-va1 > perfect VSi2. The Si–Si and V–Si bonds are broken after Si or V atoms removed, resulting in the decreasing bond strength in VSi2 with vacancies, and eventually leading to the lower phase stability and elastic moduli of VSi2 with vacancies compared to the perfect VSi2. The calculated sound velocities also show anisotropy. [ABSTRACT FROM AUTHOR]

2D magnets, especially their multilayer structures exhibit promising applications in magnetic sensing and data storage due to magnetoresistance effect. Defects have significant influence on the performance of devices and are widely investigated for typical 2D magnets. However, the defects in multilayer structures are rarely studied. Here, based on density functional theory, an interesting synergy of the interlayer migration of I and Cr vacancies in bilayer CrI3 is found. Cr vacancies attract I vacancies in adjacent layers and greatly reduce the intermigration barrier of I. On the other hand, I vacancies also facilitate the interlayer migration of Cr vacancies. A monolayer/bilayer heterostructure is expected to form after annealing at about 500 K due to the fast hopping of vacancies between layers and the strong driving force for vacancies clustering. The interlayer hopping and merge of vacancies help eliminate defect states in bilayer CrI3. These results provide an atomic‐scale understanding of vacancy migration between CrI3 layers, which is important for defect engineering and applications of bilayer and multilayer CrI3. [ABSTRACT FROM AUTHOR]

As deformation and defects are inevitable during the manufacture and service of graphene resonators, comprehensive molecular dynamic (MD) simulations are performed to investigate the vibrational properties of the defective single-layer graphene sheets (SLGSs) during tension. Perfect SLGSs, SLGSs with single vacancy, SLGSs with low-concentration vacancies, and SLGSs with high-concentration vacancies are considered, respectively. The frequencies of the perfect and defective SLGSs at different stretching stages are investigated in detail. The effects of different external forces are also taken into account to study the vibration properties of the defective SLGSs. Results show that the perfect and defective SLGSs both successively perform four stages, i.e., the elastic stage, the yield stage, the hardening stage, and the fracture stage during stretching, and the elastic properties of the SLGSs are insensitive to the vacancy defects, while the ultimate strain is noticeably reduced by the vacancies. The single vacancy has no effect on the vibration properties of SLGS, while the frequency decreases with the increasing vacancy concentration for SLGS at the elastic stage. The frequency of yielded SLGS with a certain vacancy concentration is almost constant even with a varying external force. [ABSTRACT FROM AUTHOR]

The point defect plays an important role in high-temperature materials. Although PtAl2 is a promising high-temperature alloy, the mechanism of point defect in PtAl2 is entirely unknown. By using the first-principles calculations, here, we study the influence of vacancy on the structural stability, mechanical and thermodynamic properties of PtAl2. Two vacancy types – Al vacancy and Pt vacancy – are considered. The calculated result shows that PtAl2 prefers to form the Al vacancy in comparison to the Pt vacancy. The calculated elastic modulus of Al vacancy is larger than the Pt vacancy. Essentially, the low elastic modulus is that the removed atom changes the localised hybridisation between Pt and Al. PtAl2 with these vacancies also shows ductility behaviour. Finally, it is found that the calculated Debye temperature of Al vacancy is lower than the perfect PtAl2. However, the calculated Debye temperature of Pt vacancy is higher than the perfect PtAl2. Therefore, this work theoretical reveals the vacancy mechanism of PtAl2 alloy and provides a new path to improve the mechanical and thermodynamic properties of PtAl2 high-temperature alloy. [ABSTRACT FROM AUTHOR]

The article focuses on the everyday making of housing vacancy in Athens and discusses the multiple housing struggles and cross-tenure dispossessions this process entails. The analysis draws on interview material collected during a six-month fieldwork, particularly on the narratives of inhabitants in a neighbourhood of the city experiencing increasing vacancy levels and being represented as 'declining' in the public debate. Through a relational reading of vacancy, the often unknowingly related actors involved and affected by this process, their practices and understandings, are analysed. The findings reveal the different, perceived or actualised processes, human and material agencies sustaining vacancy in place, showing how (unequally) affected actors, despite their geographical and social distance, shape this process through their interdependencies. The paper discusses some dichotomies dominating the conceptualization of vacancy, suggesting also that these seemingly inactive spaces are not natural outputs or abstract representations of the market, but spaces constituted through action, embroiled in social antagonisms and conflicts over power and agency. [ABSTRACT FROM AUTHOR]

The electronic and magnetic properties of ZnO: (Mn, N) and the effect of vacancy defect on its magnetism were studied systematically, using the first-principle based on density functional theory (DFT). The results show that the introduction of the N atom would make the coupling between two Mn atoms turn into the ferromagnetic coupling, which resulted from a hybridization between Mn 3d and N 2p electrons. Mn (MnZn) and N (NO) atoms have a tendency toward staying close to each other to form the –Mn–N–Mn– complex with two Mn–N bonds. Furthermore, VZn or VO are the easiest to form at the first-nearest neighbor or at the second-nearest neighbor of the –Mn–N–Mn– complex, at which, VO basically has no influence on the magnetism, while VZn would weaken ferromagnetism. [ABSTRACT FROM AUTHOR]

Summary: The Ga2O3 is a promising semiconductor, which is used in electric vehicles and 5G. However, the role of point defect of α‐Ga2O3 is unknown. To solve the problem, here, the influence of vacancy on the electronic and optical properties of α‐Ga2O3 is studied by the first‐principles calculations. Two typical vacancies, O vacancy and Ga vacancy, were designed. The calculated results show that the α‐Ga2O3 prefers to form O vacancy in comparison to the Ga vacancy. Furthermore, the calculated band gap of α‐Ga2O3 is 2.970 eV. However, the calculated band gap of O vacancy and Ga vacancy is 3.556 and 3.201 eV, which is bigger than the perfect α‐Ga2O3. Essentially, the wide band gap is that the removed atom results in a band shift from the Fermi level to the high‐energy regions. The change of band gap of these oxides is affirmed by the dielectric function. Finally, it is found that the α‐Ga2O3 oxide shows ultraviolet properties, which are in good agreement with the Ping and Berhanuddin's result. However, the calculated optical adsorption coefficient shows that the O vacancy induces the movement from the ultraviolet region to the visible light. The O vacancy and Ga vacancy weaken the storage optical properties of α‐Ga2O3 based on the analysis of loss function functional. [ABSTRACT FROM AUTHOR]

Although the synthesis of MoS2 thin film with a large area and excellent uniformity has been achieved through advanced synthesis techniques, such as metal–organic chemical vapor deposition (MOCVD), intrinsic defects such as vacancies and grain boundaries which degrade electrical performance still inevitably result from the process. In this paper, a method for controlling intrinsic defects in MOCVD‐grown MoS2 thin film to achieve enhanced electrical performance is reported. After applying the defect‐control process, high‐resolution transmission electron microscopy confirms that the MoS2 thin film maintains a hexagonal lattice structure without any destruction or distortion, indicating that this is a nondestructive method. In addition, the MoS2 thin film subjected to the defect‐control process exhibits enhanced n‐type characteristics in the photoluminescence and ultraviolet photoelectron spectroscopy analyses. Field‐effect transistors using the defect‐controlled MoS2 as the channel also show enhanced electrical performance, arising from reductions in sheet and contact resistances of 21% and 46%, respectively. This improvement in the resistances leads to an increase in field‐effect mobility from 3.2 up to 11.8 cm2 V−1 s−1. [ABSTRACT FROM AUTHOR]

Summary: The Ga2O3 is a promising semiconductor, which is used in electric vehicles and 5G. However, the role of point defect of α‐Ga2O3 is unknown. To solve the problem, here, the influence of vacancy on the electronic and optical properties of α‐Ga2O3 is studied by the first‐principles calculations. Two typical vacancies, O vacancy and Ga vacancy, were designed. The calculated results show that the α‐Ga2O3 prefers to form O vacancy in comparison to the Ga vacancy. Furthermore, the calculated band gap of α‐Ga2O3 is 2.970 eV. However, the calculated band gap of O vacancy and Ga vacancy is 3.556 and 3.201 eV, which is bigger than the perfect α‐Ga2O3. Essentially, the wide band gap is that the removed atom results in a band shift from the Fermi level to the high‐energy regions. The change of band gap of these oxides is affirmed by the dielectric function. Finally, it is found that the α‐Ga2O3 oxide shows ultraviolet properties, which are in good agreement with the Ping and Berhanuddin's result. However, the calculated optical adsorption coefficient shows that the O vacancy induces the movement from the ultraviolet region to the visible light. The O vacancy and Ga vacancy weaken the storage optical properties of α‐Ga2O3 based on the analysis of loss function functional. [ABSTRACT FROM AUTHOR]

The dependencies of concentrations of thermal equilibrium vacancies and interstitials on temperatures in Si crystals are determined directly, which has been a long-standing issue since the 1950s. They are evaluated by combining the formation energies and self-diffusion entropies deduced from the analyses of self-diffusion coefficients, and migration entropies deduced from diffusion coefficients of point defects. The concentrations as the number density of thermal equilibrium vacancies and interstitials at temperature T (K) are determined to be 5 × 1022exp(6.5)exp(â€"3.85 eV/ k B T) and 5 × 1022exp(10.6)exp(â€"4.3 eV/ k B T) cmâˆ'3, respectively. The diffusion coefficients of vacancies and interstitials are determined to be 2.7 × 10âˆ'3exp(â€"0.45 eV/ k B T) and 2.5 × 10âˆ'2 exp(â€"0.49 eV/ k B T) cm2 sâˆ'1, respectively. The results are discussed in comparison with those reported experimentally. [ABSTRACT FROM AUTHOR]

Modeling the microstructural evolution of irradiated materials requires knowledge of the migration energies of point defects, which results from energetic particle radiation. Herein, we measured the growth rate of self-interstitial atom (SIA) clusters in electron-irradiated α-iron at 275–320 K using in situ high-voltage electron microscopy. To improve the statistical accuracy of the measurement, we used photographic films and video data. This enabled analysis of a considerable amount of data by extracting several SIA clusters and tracking their size growth using image processing techniques. By fitting the temperature-dependent cluster growth rate to the Arrhenius relations derived using rate theory analysis, we obtained vacancy migration energy of 0.52 ± 0.03 eV. The validity of the estimation method was confirmed from the consistency of the dependence of the damage rate on the cluster growth rate using the applied rate theory analysis. We also investigated the possible roles of faster motion of tri-vacancies compared to those of mono- and di-vacancies, as demonstrated by first-principles calculations, on the obtained migration energy using a kinetic analysis model. In addition, the effects of impurities leading to decrease in the cluster growth rate were briefly discussed. [ABSTRACT FROM AUTHOR]

Temporary architecture is a way to produce an instant experience. It concentrates on a specific location and develops unique tactics to activate it. It adapts to the site, which is often abandoned and backward. Temporary use focuses on a single purpose and its influence at a given moment. It reflects the current economic state and situation in adjacent neighbourhood and community. It aims at becoming a catalyst for a permanent change. Empty buildings represent a valuable resource for urban development of an area. They belong to the category of areas suitable for reconstruction. Their activation contributes to the recycling of areas within the urban structure increasing the efficiency of land use and contributing to the sustainable development of the territory. A removal of abandoned buildings from a functioning urban organism has a negative impact on the integrity of the urban structure. Archipop is the author’s newly established database focusing on the topic of temporariness in architecture. Its aim is to map successful activations of abandoned buildings by the means of temporary interventions in Europe. Archipop deals with the subject of ‘pop–up’ in architecture. Its prime objective is to attract a target group of users over the shortest period of time possible by exclusivity of a presented activity, concentrating on temporary uses located in abandoned buildings in Europe. It examines successful projects of activation of unused objects by using temporary activity profile. Targeting at interested public, potential investors, and last but not least government and municipalities, Archipop was created to provide inspiration and opportunities of temporary use. Its ambition is to promote revitalisation of unused areas with the use of temporary architecture and to save historic heritage from its terminal destruction.

[Display omitted] • Wafer-scale high-quality MoSe 2 nanosheets were achieved by ALD-CVD composite process. • High on/off ratio (3.6 × 107) and significant hysteresis window (6.8 k) of MoSe 2 synaptic devices were achieved. • We proposed horizontal diffusion driven mechanism for Se vacancy. Recently, researches have revealed that synaptic transistors based on two-dimensional materials (2DMs) have substantial advantages and potential for modeling neural synapses. However, the mechanism of artificial synaptic device with 2DMs as conducting channels remains to be further clarified. Here, high-quality wafer-scale MoSe 2 nanosheets were achieved by ALD-CVD process, where further 23 × 23 × 4 synaptic arrays were fabricated in situ. Notably, the outstanding MoSe 2 synaptic device exhibits an on/off ratio of 3.6 × 107 with hysteresis ratio of 6.8k and simulates crucial biological synaptic behaviors such as paired pulse facilitation and excitatory postsynaptic currents. The mechanism of Se vacancy induction and horizontal diffusion driven is revealed based on high-resolution transmission electron microscopy characterization with first-principles calculations, which suggests a possible mechanistic explanation for the resistive switching behavior of 2DMs transistors. Artificial synaptic devices with 2DMs based on the working mechanism of vacancy diffusion are capable of satisfying the needs of complex neural network applications. [ABSTRACT FROM AUTHOR]

Reducing carbon dioxide (CO 2) into methane (CH 4) through photocatalysis technology can effectively decrease carbon emissions and ease the energy crisis. However, the low photocatalytic efficiency and high electron-hole recombination rates still hinder the large-scale utilization of photocatalysis. Vacancy engineering can reduce electron-hole pair complexation, however, the effects of oxygen (O) and sulfur (S) vacancies on the CO 2 reduction properties of bismuth (Bi)-based photocatalysts are unclear. This study prepared different Bi-based photocatalysts, including α-Bi 2 O 3 , α-Bi 2 O 3-X , Bi 2 S 3 , and Bi 2 S 3-X. The introduction of vacancies was found to greatly increase the specific surface areas, effectively reduce electron-hole recombination, decrease charge transfer resistance, and enhance electron transfer, leading to enhanced CH 4 production. Comparatively, Bi 2 S 3-X has substantially demonstrated a superior efficiency in the photocatalytic conversion of CO 2 to CH 4 compared to Bi 2 S 3 , while α-Bi 2 O 3-X exhibited slightly higher than α-Bi 2 O 3. There are more S vacancies in Bi 2 S 3-X (x=0.581) than O vacancies in α-Bi 2 O 3-X (x=0.329), leading to its superior photocatalytic activity, with CO and CH 4 production rates of 3.706 μmol·g−1·h−1 and 7.697 μmol·g−1·h−1, respectively. Moreover, the CH 4 selectivity of Bi 2 S 3-X reaches 67.50 %, which is 1.67 times that of α-Bi 2 O 3-X. Therefore, Bi 2 S 3-X holds great promise as a photocatalyst for CO 2 reduction. This work proves that in Bi-based photocatalyst, S vacancy is more effective than O vacancy in enhancing the selective reduction of CO 2 to CH 4 , offering a pathway for achieving selective CO 2 reduction to CH 4. [Display omitted] • Vacancy structure of Bi-based photocatalysts were synthesized via ultrasound irradiation. • Presence of vacancies significantly increases the active sites for CO 2 photoreduction. • S vacancy enhances the selective reduction of CO 2 to CH 4 more than O vacancy. • Bi 2 S 3-X shows a higher CH 4 production rate of 7.70 μmol·g−1·h−1. [ABSTRACT FROM AUTHOR]

Skyrmion, a local bubble-like topological magnetization structure, can collectively emergent in magnets in a lattice form skyrmion crystal (SkX). SkX has great application potential in functional devices because it can manipulate material properties via coupling with atomic lattices. The lattice defects such as vacancy widely exist in the SkX as well, and they have rich dynamic behaviors and have great implications for the host material. However, although the nature of ideal SkX is well studied, the characteristics of SkX defects are relatively underdeveloped. Here, we deeply studied the structural properties of a vacancy defect in the SkX by a thermodynamic phase-field simulation. We found that the higher external magnetic and temperature fields favor rigid skyrmions (crystal), in which the SkX vacancy is less deformed, while the lower fields favor softer skyrmions where the SkX vacancy structure is considerably deformed. Such unique deformation and stability of the SkX vacancy are mainly the results of the competition between free energies in the view of thermodynamics. Our study demonstrated that the external field-controlled static properties of SkX vacancy highly depend on the quasiparticle nature of skyrmions. This indicates the properties of SkX defects can be controlled by the SkX features under different fields, which should open an avenue for the study and design of smart materials and advanced devices by engineering skyrmion crystals. [Display omitted] [ABSTRACT FROM AUTHOR]

The introduction of isovalent dopants (D = carbon (C), silicon (Si), tin (Sn) and lead (Pb)) in the germanium (Ge) lattice can lead to the association with the prevalent intrinsic defect (vacancy) to form dopant-vacancy pairs (DV) or more extended defects such as (VDV or DVV). Here we employ spin-polarized density functional theory (DFT) calculations to predict the lowest energy structures of D, DV, VDV and DVV (D = C, Si, Sn and Pb) defects in Ge. All the defects considered with the larger isovalent dopants are predicted to be strongly bound. The defects' structural parameters, ionization energy, Bader charges and electronic structures are thoroughly discussed. [ABSTRACT FROM AUTHOR]

The structural and electrical properties of vanadium-copper-phosphate glasses with compositions of xV 2 O 5 –(40—x)Cu 2 O–60P 2 O 5 (where x = 10, 20, 30, and 40 mol%) have been thoroughly investigated. As the amount of V 2 O 5 increases, the density falls, and the molar volume rises. This effect may be attributed to the polarizing power strength, which reflects the ratio of the cation's charge to its diameter. As the concentration of V 2 O 5 increases, the DC conductivity shows an upward trend while the activation energy decreases. Additionally, the microstructure—more specifically, the dimensions of vacancy-type defects-studied utilizing using positron annihilation lifetime (PAL) spectroscopy. A correlation was established between the sample characteristics and the PAL results. By computing the distribution of the long lifetime inferred from the PAL, the magnitude of the vacancy-type flaws was verified. The findings offer insightful information about how the PAL and sample characteristics relate to one another. [ABSTRACT FROM AUTHOR]

Recently, 2D materials based on IV-V group have attracted great attention because of their interesting physical properties. In this work, Janus Ge 2 PAs monolayer with good stability is predicted using first-principles calculations. Our simulations assert its non-magnetic semiconductor nature with an indirect band gap of 1.11(1.75)eV obtained by PBE(HSE06)-based calculations. Further, vacancy defects and doping with transition metals (TMs = Cr and Mn) are explored in order to induce novel physical aspects. It is found significant magnetization of Janus Ge 2 PAs monolayer induced by Ge vacancies with total magnetic moments between 1.58 and 1.97 μ B , where magnetism is produced mainly by atomic species around the defect sites. Herein, single Ge vacancy metalizes the monolayer, while the half-metallicity is obtained by creating a pair Ge vacancies. Regardless doping site, feature-rich diluted magnetic semiconductor and half-metallic behaviors are also obtained in Janus Ge 2 PAs monolayer by doping with Cr and Mn atom, respectively. In these case, TM impurities originate mainly the system magnetism with total magnetic moments between 2.00 and 3.03 μ B. In addition, the coexistence of Ge vacancy and doping is also investigated. The calculated spin density shows an antiparallel spin orientation of Cr dopant and its neighboring atoms, meanwhile a parallel spin orientation is observed for Mn impurity and its neighboring atoms. Consequently, small total magnetic moment of 0.53 μ B is obtained by the synergistic effects of doping with Cr and Ge vacancy, meanwhile the coexistence of Mn dopant and Ge vacancy generates a larger value of 4.88/4.89 μ B. In all cases, the origin of electronic and magnetic properties is unraveled. Our results introduce new prospective spintronic 2D materials made from a new Janus Ge 2 PAs monolayer. [ABSTRACT FROM AUTHOR]

Background. The pandemic period, the sanctions impact, geopolitical events in-fluenced the development of the countryʼs economy, including the labor market. In recent years, a number of trends have been identified in the labor market: the problem of labor imbalance has worsened, employment forms and working conditions have changed. These transformations were accompanied by the automation of business processes, the erasure of the geographical boundaries of the labor market, changes in the norms that simplified the labor relationship between the employee and the employer. The issue of population decline remained relevant, which escalated due to the consequences of the spread of coronavirus infection. The above processes greatly influenced the field of employment. The purpose of this article is to study the trends in the development of the Russian labor market in the modern period. Materials and methods. The work used an institutional and structural-functional approach, which made it possible to comprehensively analyze the problem of the Russian labor market in modern conditions. Data from Russian Public Opinion Research Center (RPORC) was used, statistics from Rosstat and the HeadHunter service were ana-lyzed. Results. Based on the studied material, an analysis of the state of the labor market was carried out, the impact of political and socio-economic changes on the employment of the working-age population was revealed; the main directions of the development of the Russian labor market in the post-covid period were highlighted; described the behavior of employers and job seekers in the labor market, formed under the influence of modern trends in the development of labor relations. Conclusions. The study made it possible to identify trends that have formed in the modern labor market. In connection with the consequences of the pandemic, the previously existing problem worsened – the shortage of labor re-sources of the most popular age cohorts, which led to a deepening imbalance in the labor market, as a result of which a “race for qualified employees” was formed between employ-ers. This contributed to a change in the practice of attracting specialists in the company, stimulated employers to develop an internal HR brand.

We systemically investigated helium (He) interacting with 27 substitutional solute elements in vanadium by first-principles calculations. The interactions between early three 3d/4d/5d transition solutes and He are attractive while they are repulsive for other solute elements, He still favors tetrahedral sites. We predicted the influence of substitutional solutes on He effective diffusivity, Sc/Ti/Y/La can obviously reduce He diffusivity while other solutes show little effect. Moreover, we studied the synergistic interactions of the defect complex with He, solute and vacancy. The binding of group IIIB/IVB solution elements and vacancy reduce vacancy capturing for He, inhibiting He clustering in vacancies. The presence of He increases the stability of solute–vacancy clusters. The results can help to understand the effect of solute elements on He accumulation and embrittlement in vanadium alloys under irradiation.

The Romanian labor market shows the signs of many regional issues, especially those that involve economic factors. Disparities generate forms of interregional symmetry, approached through the lens of poor socio-economic performance. The Romanian economy has rapidly adapted to the open European labor market, which, on the one hand, has brought many benefits to the Romanian employees who migrated to other European countries, while, on the other hand, this process has caused serious deficits of the labor force in some Romanian economic sectors of activity. In this regard, this study brings its contribution to the literature with a statistical analysis conducted on the symmetry and inflections points in the case of three Romanian development regions: South-East region, South-West Oltenia and North-West region. Results show that these regions face similar labor market issues up to a certain degree – the identified inflection point deals with two economic sectors that had to suffer the most: the public administration and the defense sectors.

Abstract The efficient electrocatalysis plays the key role in the development of electrochemical energy conversion technologies to alleviate energy crisis. Given their multiple active sites and large specific surface areas as electrocatalysts, metal‐organic frameworks (MOFs) and their derivatives have attracted considerable interests in recent years. Specially, exploring the roles of the enhanced active sites in MOFs and their derivatives is significant for understanding and developing new effective electrocatalysts. Recently, the vital role of vacancies has been proven to promote electrocatalytic processes (such as H2 or O2 evolution reactions, O2 reduction reactions, and N2 reduction reactions). In order to in‐depth exploring the effect of vacancies in electrocatalysts, the vacancies classification, synthetic strategy, and the recent development of various vacancies in MOFs and their derivatives for electrocatalysis are reviewed. Also, the perspectives on the challenges and opportunities of vacancies in MOFs and their derivatives for electrocatalysis are presented.

A first-principles study of the atomic structure and electron density distribution at the Zr/Nb interface under the influence of helium impurities and helium–vacancy complexes was performed using the optimised Vanderbilt pseudopotential method. For the determination of the preferred positions of the helium atom, the vacancy and the helium–vacancy complex at the interface, the formation energy of the Zr-Nb-He system has been calculated. The preferred positions of the helium atoms are in the first two atomic layers of Zr at the interface, where helium–vacancy complexes form. This leads to a noticeable increase in the size of the reduced electron density areas induced by vacancies in the first Zr layers at the interface. The formation of the helium–vacancy complex reduces the size of the reduced electron density areas in the third Zr and Nb layers as well as in the Zr and Nb bulk. Vacancies in the first niobium layer near the interface attract the nearest zirconium atoms and partially replenish the electron density. This may indicate a possible self-healing of this type of defect.

The synergetic effect of vacancy and dual-metals on defective V 2 CO 2 can greatly enhance the NRR activity. [Display omitted] • Vacancies and dual-metals can efficiently modulate surface electronic properties. • FeNi@V 2 CO 2-x is predicted to possess the best NRR performance. • 2V O -V 2 CO 2 possess better NRR properties among the vacancy system. Electrocatalytic nitrogen reduction reaction (NRR) is considered as a promising method for ammonia synthesis under ambient conditions. However, its practical applications have been hindered due to the high activation energy of inert N≡N triple bond and the competitive hydrogen evolution reaction (HER). Herein, employing density-functional theory (DFT) method, the effect of different vacancies on V 2 CO 2 (V O , V M , V M+O , and 2V O -V 2 CO 2) and dual-metals anchored on defective V 2 CO 2 (TM1TM2@V 2 CO 2-x , TM = Ti, V, Cr, Mn, Fe, Co, Ni, and Mo) stability, NRR activity and selectivity are investigated. Results show that 2Vo-V 2 CO 2 delivers the highest NRR activity via enzymatic pathway with the corresponding U L = −0.25 V among the four vacancy systems. In addition, six electrocatalysts exhibit excellent performance for NRR and inhibition of competitive HER among the studied DACs materials, with limiting potentials (U L) ranging from −0.13 to −0.41 V, in which FeNi@V 2 CO 2-x (U L = −0.13 V) via distal pathway and TiTi@V 2 CO 2-x (U L = −0.41 V) via enzymatic pathway show particularly low U L among heteronuclear and homonuclear catalysts, respectively. The outstanding catalytic activity is attributed to the "pull-pull effect" of transition-metal dimer, which plays a significant role in regulating the binding strength between the substrate and intermediate *NNH. The charge density difference and density of states results indicate that the vacancies and dual-metals can efficiently modulate electronic properties of MXenes and reduce the activation energy of N 2. 2Vo-V 2 CO 2 and FeNi@V 2 CO 2-x are predicted thermodynamically stable at reaction temperature by the AIMD simulations. This study indicates that dual-metals anchored on defective V 2 CO 2 not only enhance its original NRR activity, but also provide a novel strategy for the future design of NRR electrocatalysts. [ABSTRACT FROM AUTHOR]

• BiOBr/g-C 3 N 4 , Bi/g-C 3 N 4 and BioBr/g-C 3 N 4 @Bi were prepared by adjusting Bi3+ : EG ratio. • BiOBr/g-C 3 N 4 @Bi showed a high activity and selectivity for CO 2 conversion to CO. • The photocatalytic activity of BioBr/g-C 3 N 4 @Bi was 4.0 times that of g-C 3 N 4. • The mechanism on photocatalysis of BioBr/g-C 3 N 4 @Bi was revealed. Three different heterojunctions, BiOBr/g-C 3 N 4 , Bi/g-C 3 N 4 , and BiOBr/g-C 3 N 4 @Bi modified with carbon vacancies and/or oxygen vacancies, were first synthesized via a facile solvothermal approach by adjusting the ratio of Bi(NO 3) 3 5H 2 O with ethylene glycol (EG). The as-prepared heterojunctions were characterized by various modern analytical instruments, and their visible-light photocatalytic performance for CO 2 conversion was evaluated. Our findings demonstrate that the ternary photocatalyst BiOBr/g-C 3 N 4 @Bi exhibits better activity toward visible-light-driven CO 2 reduction than pristine g-C 3 N 4 and its binary counterparts without hole scavengers, and its maximum CO yield (7.4 μmol h−1 g−1) is approximately four 4 times that of pure g-C 3 N 4. This is attributed to the V O and V C defects, which enhance the photon absorption capacity. On the other hand, the g-C 3 N 4 matrix exhibits strong interfacial interactions with BiOBr and metallic Bi, leading to an increase in the separation efficiency of the photoinduced carriers. In other words, the strong interfacial interactions among g-C 3 N 4 , BiOBr and metallic Bi, the vacancy defects V O and V C , and the metallic Bi particles cooperate to significantly improve the separation and transportation of the photoexcited charge carriers, thereby augmenting the CO 2 photoreduction activity of the BiOBr/g-C 3 N 4 @Bi ternary heterojunction in the absence of a sacrificial agent. This approach based on facile solvothermal treatment has promising potential in fabricating highly efficient photocatalysts suitable for visible-light-driven CO 2 reduction. Three different heterojunctions, BiOBr/g-C 3 N 4 , Bi/g-C 3 N 4 , and BiOBr/g-C 3 N 4 @Bi modified with carbon vacancies and/or oxygen vacancies, were first synthesized via a facile solvothermal approach by adjusting the ratio of Bi(NO 3) 3 · 5H 2 O with ethylene glycol (EG). Among them, the ternary photocatalyst BiOBr/g-C 3 N 4 @Bi exhibited the highest activity for photocatalytic CO 2 reduction into CO, with a maximum yield of 7.4 μmol h−1 g−1, about 4 times as much as that of g-C 3 N 4. The superior photocatalytic performance is predominantly ascribed to three factors: (i) V O in BiOBr and V C in g-C 3 N 4 could improve the light-harvesting capacity of BiOBr/g-C 3 N 4 @Bi. (ii) Both vacancies and metallic Bi could play the role of trapping the photogenerated electrons to inhibit the recombination of photogenerated carriers. (iii) The heterojunction between g-C 3 N 4 nanosheets and BiOBr as well as metallic Bi could enhance the separation efficiency of photogenerated charges. This work provides a novel in-situ synthesis method for constructing g-C 3 N 4 -related heterostructured catalyst with high efficiency for CO 2 reduction. [Display omitted] [ABSTRACT FROM AUTHOR]

A study has been conducted to quantify the effect of Ta on diffusion kinetics of the β-(Ti, Al) solid solution body-centered cubic (BCC) phase by determining the interdiffusion and impurity diffusion coefficients using the novel pseudo-binary diffusion couple technique. The interdiffusion coefficients (D ˜) for the ternary β-Ti(Al, Ta) system are higher than those of binary β-(Ti, Al) system for a particular annealing temperature and Al content. Increase in D ˜ with addition of Ta has been attributed to a decrease in activation energy for interdiffusion for the Ta-containing β-phase as compared to the Ta-free β-phase owing to a reduction of activation energies for the formation of point defects and migration of the diffusing atoms. A higher impurity diffusion coefficient of Al for Ta-containing β-(Ti, Al) than Ta-free β further suggests an increase in the preferential interaction of vacancies with Al in the presence of Ta in the β-phase. [Display omitted] [ABSTRACT FROM AUTHOR]

• Regulating the stoichiometric ratio in chemistry can reduce T tr , with little effect on T c. • A structural and magnetic phase diagram of Mn 1- x CoGe alloys was proposed. • Stoichiometric control can cause magnetic structure coupling and lead to a giant magnetocaloric effect. • A magnetic entropy change of 27.6 J kg−1K−1 and a cooling capacity of 212.1 J kg−1 were obtained under magnetic field of 5 T. As a family of rare-earth-free magnetocaloric materials, MnCoGe-based alloys have attracted intensive attention in the past few years. In this study, we reveal that the deficiency of either Mn or Co reduces the valence electron concentration of MnCoGe system, thereby lowering its structural transition temperature (T tr) by pushing the Fermi level away from the Mn-Mn antibonding electronic states. Moreover, T tr is found to be more sensitive to Co content. By systematically analyzing the temperature dependent magnetization plots and Arrott curves, it is proven that the magnetic and structural degrees of freedom are coupled in the Mn 0.97 CoGe alloy, resulting in a first-order magnetic phase transition. On the contrary, MnCo 0.98 Ge undergoes a second-order transition. As a consequence, the Mn 0.97 CoGe alloy exhibits a maximum magnetic entropy change of 27.6 J kg−1K−1 under a magnetic field of 5 T near the Curie temperature of 265 K, corresponding to a refrigeration capacity of 212.1 J kg−1. Our work demonstrates Mn/Co vacant MnCoGe alloy as a robust candidate of magnetic substance for room temperature magnetocaloric refrigeration. [ABSTRACT FROM AUTHOR]

In alkaline earth stannates, MgSnO 3 has low density, high specific strength and wide bandgap (∼4.0 eV), which is a particularly promising semiconductor material. However, the lack of single crystal film limits the application of such materials in photoelectric devices. Here, high-quality MgSnO 3 epitaxial film was grown on SrTiO 3 substrate by pulsed laser deposition (PLD). The film grown under an oxygen pressure of 5 Pa at 900 °C presented the best crystal quality, which has high transmittance (>93 %) and wide bandgap (3.94 eV). The in-plane and out-of-plane epitaxial relationships between the film and substrate are MgSnO 3 [1 1 ‾ 00] ⎜⎜SrTiO 3 [1 1 ‾ 0] and MgSnO 3 (0001) ⎜⎜SrTiO 3 (111), respectively. Due to the lower formation energy of Mg vacancies compared to Sn vacancies, the Mg/Sn molar ratio in the film is less than 1, increasing with the oxygen pressure rising during the film. For the solar-blind photodetector based on 10 Pa sample, the device presents a photo-responsivity of 3.76 × 10−3 A ∙ W−1 and a fast speed of photoresponse (<0.05 s). The excellent performance exhibited by single crystal thin films will undoubtedly promote the development of MgSnO 3 based single crystal devices. • High-quality MgSnO 3 epitaxial film with a XRC-FWHM of 2.01° was grown on SrTiO 3 substrate. • The epitaxial relationship between the film and substrate is MgSnO 3 (0001) ⎜⎜SrTiO 3 (111) with MgSnO 3 [1 1 ‾ 00] ⎜⎜SrTiO 3 [1 1 ‾ 0]. • DUV photodetector with a response speed of ∼0.045 s was fabricated based on the MgSnO 3 epitaxial film. [ABSTRACT FROM AUTHOR]

Photocatalytic energy conversion is widely considered as a promising energy conversion method for solving the energy crisis, while efficient energy conversion has long been pursued by researchers. Among the strategies for improving energy conversion, element engineering, comprising doping and vacancies, has attracted extensive attention as a convenient and effective modification method. Focusing on graphitic carbon nitride (g-C 3 N 4), this review elaborated the mechanism of element engineering in the g-C 3 N 4 photocatalytic process and summarized the fabrication strategies for doping and vacancy. Furthermore, this review listed the applications of g-C 3 N 4 with element engineering in photocatalysis and described the prospects for its development. It is expected that this review could not only deepen the comprehension of element engineering but also open up inspirations and feasibilities for the design and application of g–C 3 N 4 –based materials. Element engineering, including doping and vacancy, is an effective strategy to improve the performance of g-C 3 N 4. However, exploration of the distinction and association between the strategies of doping and vacancy is still lacking for g-C 3 N 4 , which disturbs the comprehension on it. Thus, to fill this gap, this review summarized the recent progress in the doping and vacancy of g-C 3 N 4 from the point of element engineering and discussed their effects on photocatalytic performance. This review will deepen the comprehension of element engineering and provide inspiration and feasibility for the design and application of g–C 3 N 4 –based materials. [Display omitted] • The roles of element engineering in the g-C 3 N 4 photocatalytic process were elaborated. • The construction strategies for element doping and vacancy of g-C 3 N 4 were summarized. • The photocatalytic applications of vacancy and doping modified g-C 3 N 4 were presented. • The challenges and perspectives of element engineering-based g-C 3 N 4 were discussed. [ABSTRACT FROM AUTHOR]

Sulphate-induced corrosion of rebars has been reported to plague the lifespan of concrete structures. However, the associated mechanism underlying this issue is still unclear and therefore deserves further investigation. To fill in this gap, three electrochemical experiments including OCP, EIS and LPR were conducted in this study, alongside XPS and SEM characterizations. Moreover, a Density Functional Theory (DFT) was adopted to simulate the depassivation behaviour of rebar under the sulphate condition. Taking together, the underlying mechanism was disclosed. The results reveal that the presence of sulphate ions appeared to reduce the thickness of the rebar passive film and the Fe3+/Fe2+ ratio in the outer layer. In addition, the threshold value of [SO 4 2−]/[OH−] to cause the depassivation of rebar was experimentally found about 1.26–1.51 in the saturated Ca(OH) 2 solution. Further, the pristine and vacancy-contained α-Fe 2 O 3 (001) surfaces were chosen respectively, to simulate the passive film surface surrounding rebars via DFT. It was found that the SO 4 2− adsorption boosted the formation of surface vacancy, and compared to the pristine surface, the increase in SO 4 2− coverage also promoted the ensuing formation of Fe vacancy on the O vacancy-contained surface. Then, the Fe-O pair vacancy was so formed, and in turn, boosted the following adsorption of SO 4 2− on the passive film of rebars. Combining the experimental results and DFT simulation, the vicious cycle is believed to exist during the sulphate-induced depassivation of rebar, specifically composed of (i) the adsorption of SO 4 2−, (ii) the vacancy formation and increase, and (iii) the progressively enhanced adsorption of SO 4 2−. [Display omitted] • A threshold concentration of sulphate that induce the deterioration of rebar passive film was proposed. • Sulphate attack decreased the thickness of the passive film. • Sulphate mainly destructs the outer layer of rebar passive film. • Interactions of SO 4 2- with the α-Fe 2 O 3 surface were studied based on DFT. • The mutual effect between SO 4 2− adsorption and vacancy formation on the α-Fe 2 O 3 surface was revealed. [ABSTRACT FROM AUTHOR]

Prior to every ion implantation experiment a simulation of the ion range and other relevant parameters is performed using Monte-Carlo based codes. Although increasing computing power has improved the speed of these calculations, the demands on Monte-Carlo codes are also increasing, requiring evaluation of the optimal number of simulations while ensuring accuracy within threshold bounds. We evaluate the "Stopping and Range of Ions in Matter" (SRIM) code due to its widespread usage. We show how dividing simulations into multiple parallel simulations with different random seeds can lead to calculation speedup and find lower bounds for the required number of ion traces simulated based on an exemplar system of a Ga focused ion beam and a high energy C beam as used in high linear energy transfer testing. Our results indicate simulations can yield results within the underlying data accuracy of SRIM at 10X and 100X shorter simulation time than the SRIM default values. [ABSTRACT FROM AUTHOR]

Hydrogen capacity of (a) VLi6, (b) VSi and (c) VO in Li4SiO4 crystal [Display omitted] • H2 molecules are formed in Li vacancy. • The capacity of different vacancies in Li4SiO4 crystal are obtained. • Density of trapped H atoms achieves 1.96 × 1022 atom/cm3 in model with a Li vacancy. Tritium retention is of major importance to the performance of solid breeder in nuclear fusion. Hydrogen capacity, which represents the tritium capacity in the solid breeder materials, has attracted much attention in recent years. In this work, the accumulation behavior of H atoms in defect Li 4 SiO 4 models with vacancy is systematically investigated by first-principles calculations. Different Li 4 SiO 4 defect models with Li vacancy, Si vacancy, and O vacancy are built up and optimized, respectively. And H atoms are added into the vacancy one by one and fully relaxed. The Bader charge and the density of states analysis show the H atoms bond with O dangling bonds in the vacancy and the Li vacancy serves as a nucleation center for H 2 molecules. Moreover, by calculating the trapping energy, the Voronoi volume and the lattice distortion, the trapping and accumulation behavior of H atoms inside and outside different vacancies are obtained and compared. The results reveal that the defect models with vacancy present stronger trapping abilities than that of the perfect crystal, while defect models with a Li vacancy is able to accommodate more H atoms than that with a Si vacancy. 14 pairs of H 2 molecules are observed maximally in the defect model with a type of V Li 6 vacancy when the number of trapped H atoms can achieve 1.96 × 1022 atom/cm3. This work quantitatively determines the hydrogen capacity of the Li 4 SiO 4 crystal and the obtained results can help explain and understand the related tritium release and retention behaviors in Li 4 SiO 4 crystal. [ABSTRACT FROM AUTHOR]

• A comparison of segregation behaviors of Xe and vacancy at the UN Σ5(210) grain boundary is analyzed by first-principles calculation. • Xe is more likely to segregate to Σ5(210) grain boundary, enhancing the sensitivity of intergranular brittle fracture. • Effects of temperature and defect coverage on the fracture energy of Σ5(210) grain boundary are predicted. Segregation of irradiation-generated xenon (Xe) atoms and vacancies to grain boundary (GB) leads to instability and brittleness of uranium mononitride (UN). However, theoretical knowledge about the energetics of its defective interface is lacking, whereas there has been considerable attention on unirradiated UN in experiments. Using first-principles methods, herein we compute the energies of segregation and fracture for typical fission defects. We find that, compared with vacancy, Xe tends more to segregate to Σ5(210) GB, enhancing sensitivity to intergranular fracture. Our predictions clarify the fundamental embrittlement mechanism of irradiated UN GB, which has been discussed so far only on pristine one. [ABSTRACT FROM AUTHOR]

In this study, we investigate the temperature dependence of iodine vacancies in the organic-inorganic hybrid perovskite C H 3 N H 3 Pb I 3 through theoretical analysis. Iodine vacancies, as point defects, play a crucial role in the instability of perovskite solar cells. By employing molecular dynamics (MD) simulations, we calculate the formation energy of vacancies and examine its relationship with temperature. Our results reveal that the formation energy remains constant irrespective of temperature. However, elevated temperatures facilitate the provision of energy necessary for vacancy formation. To accurately determine the vacancy concentration, it is essential to consider the associated entropy changes. Analytical methods are employed to assess these entropy changes, offering valuable insights into the vacancy formation process. Utilizing the derived values, we quantify the concentration of vacancies and analyze their dependence on temperature. The findings obtained from this research contribute significant insights into the behavior of iodine vacancies within the studied C H 3 N H 3 Pb I 3 perovskite system. [ABSTRACT FROM AUTHOR]

CdS/Co-MoO 2-x @C Schottky junction with tunable Schottky barrier height and LSPR effect was successfully constructed by dual defect induced work function changes, thus achieving high electrons density for efficient H 2 generation. [Display omitted] • Tunable Schottky barrier height (SBH) and LSPR effect were achieved by dual defect induced work function change. • Promoted charge separation and hot electrons compensation contributes to high electron density for H 2 evolution. • Optimized d band center and decreased Gibbs free energy for H 2 evolution was substantiated. • The synergistic effect contributes to high full-spectrum H 2 evolution rate of 89.95 mmol g−1h−1. Photocatalytic water splitting for hydrogen evolution provides a desired approach for sustainable clean energy. However, increasing the effective electron density for proton reduction remains a huge challenge due to the fast charge recombination kinetic. Herein, we propose an efficient strategy, based on manipulating the Schottky barrier height (SBH) and localized surface plasmonic resonances (LSPR) effect of Co-MoO 2-x via dual defect (Co doping and oxygen vacancies) induced work function change, to achieve higher electrons density in plasmonic CdS/Co-MoO 2-x @C Schottky junction photocatalyst for the first time. Through varying the Co heteroatom doping and oxygen vacancies in our Co-MoO 2-x @C cocatalyst , we show adjustable SBH at the interface and tunable photothermal effect in CdS/Co-MoO 2-x @C, which leads to inhibited energetic electrons backflow in metallic Co-MoO 2-x to improve the electron density. Moreover, optimized electronic structure gives rise to a zero-approaching Gibbs free energy for intermediate state, enabling CdS/Co-MoO 2-x @C with promoted intrinsic H 2 evolution kinetics. Furthermore, the extended light absorption and elevated reaction temperature stemming from strong LSPR effect of Co-MoO 2-x contribute to the decrease of apparent activation energy from 13.824 to 6.579 kJ/mol for H 2 evolution. To this end, CdS/Co-MoO 2-x @C-7 photocatalyst yields a full-spectrum driven photocatalytic H 2 production rate of 89.95 mmol g−1h−1, surpassing most reported CdS-based photocatalyst. This study opens a new avenue toward construction of efficient broad-spectrum active photocatalyst. [ABSTRACT FROM AUTHOR]

[Display omitted] • g-C 3 N 4 with carbon vacancy (V C -g-C 3 N 4) was synthesized by DMF-assisted thermal polycondensation method as an efficient ECL emitter. • A novel zirconium-based MOF was prepared to load Ru(bpy) 3 2+. • The novel energy donor–acceptor pair was used to construct ECL-RET immunosensors for the detection of β2-Microglobulin. This work proposes a novel dual-signal electrochemiluminescence (ECL) immunosensor based on energy resonance transfer (RET) for the detection of β2-Microglobulin (β2-MG). Introducing carbon vacancy into g-C 3 N 4 (V C -g-C 3 N 4) can lead to the narrowing of the band gap and the reduction of LUMO, thereby significantly enhancing the ECL efficiency of the material. Meanwhile, Zr-MOF can effectively load Ru(bpy) 3 2+ (Ru-Zr-MOF), enabling its stable existence on the electrode. The ECL emission spectrum of V C -g-C 3 N 4 overlaps well with the fluorescence excitation spectrum of Ru-Zr-MOF, indicating an effective ECL-RET effect between them. As the concentration of β2-MG increases, the intensity of anodic ECL signal gradually increases, while the intensity of cathodic ECL signal gradually decreases. The difference between the cathodic and anodic ECL signals has a good linear relationship within the concentration range from 0.2 pg/mL to 200 ng/mL, with a detection limit of 27.73 fg/mL. The constructed immunosensor can be used for practical analysis in human serum. The proposed sensor has great potential in clinical detection of β2-MG, providing new insights for biomolecular detection and disease diagnosis. [ABSTRACT FROM AUTHOR]

• Vacancies at different lattice positions on the properties of MnWO 4 was studied. • The magnetization and transition temperatures of MnWO 4 were improved by non-stoichiometric. • The temperature range in which AF2 phase existed was enlarged by non-stoichiometric. • The effect of Mn vacancy on the properties of MnWO 4 was higher than that of W vacancy. Non-stoichiometric ceramic samples of Mn 0.97 WO 4 and MnW 0.97 O 4 were prepared by a solid-state reaction to study the effects of vacancies at different lattice positions on the structure and properties of MnWO 4 materials caused by non-stoichiometric. Positron annihilation technology was introduced to study the vacancy characteristics of the MnWO 4 , Mn 0.97 WO 4 , and MnW 0.97 O 4 ceramics. The results indicated that non-stoichiometric did not affect the monoclinic lattice structure of any of the MnWO 4 samples, and had no obvious effect on the lattice parameters of the samples. The analysis of positron annihilation lifetime spectroscopy showed that W vacancies were the main defects in MnW 0.97 O 4 samples, and Mn vacancies were favored in Mn 0.97 WO 4 samples, the vacancies concentration for non-stoichiometric MnWO 4 samples was higher than that of stoichiometric MnWO 4. It was observed that the magnetization and transition temperatures of the non-stoichiometric MnWO 4 system were increased, and the temperature range in which AF2 phase existed was enlarged. This study demonstrated that non-stoichiometric could enhance the magnetic properties of MnWO 4 , the effect of Mn vacancy on the properties of MnWO 4 is higher than that of W vacancy. The intimate correlation between the vacancy defects and magnetic properties provides us strong evidence that the magnetic properties of MnWO 4 can be enhanced by regulating vacancy defects. [ABSTRACT FROM AUTHOR]

Bismuth ferrite (BiFeO3, BFO) is still widely investigated both because of the great diversity of its possible applications and from the perspective of intrinsic defect engineering in the perovskite structure. Defect control in BiFeO3 semiconductors could provide a key technology for overcoming undesirable limitations, namely, a strong leakage current, which is attributed to the presence of oxygen vacancies (VO) and Bi vacancies (VBi). Our study proposes a hydrothermal method for the reduction of the concentration of VBi during the ceramic synthesis of BiFeO3.Using hydrogen peroxide (H2O2) as part of the medium, p-type BiFeO3 ceramics characterized by their low conductivity were obtained. Hydrogen peroxide acted as the electron donor in the perovskite structure, controlling VBi in the BiFeO3 semiconductor, which caused the dielectric constant and loss to decrease along with the electrical resistivity. The reduction of Bi vacancies highlighted by a FT-IR and Mott—Schottky analysis has an expected contribution to the dielectric characteristic. A decrease in the dielectric constant (with approximately 40%) and loss (3 times) and an increase of the electrical resistivity (by 3 times) was achieved by the hydrogen peroxide-assisted hydrothermal synthesized BFO ceramics, as compared with the hydrothermal synthesized BFOs.

The magnetic properties of Mn-doped ZnGa2S4 compound have been investigated using the first principle calculations within density functional theory. Our results demonstrate that Mn substitution changes the nonspin polarized state of pure ZnGa2S4 to spin-polarized. The total energy calculations for a number of supercells showed that ferromagnetic ordering is more favorable than antiferromagnetic ordering for Mn-doped ZnGa2S4. The nature of magnetism is mainly from the dopant Mn atom with magnetic moment 7.90μB. From studies of magnetism caused from vacancies, it was found that Ga vacancy has a significant influence on the magnetic properties, while S vacancy cannot lead to magnetic moment in system. [ABSTRACT FROM AUTHOR]

Copyright of Bulletin of the Chinese Ceramic Society is the property of Bulletin of the Chinese Ceramic Society Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

To ensure the safety and efficient operation of nuclear reactors, it is imperative to understand the effects of various dopants (Ti, Th, and Zr) on the solubility of the fission product Xe in UO2. In this study, Hubbard corrected density functional theory (DFT + U) and occupation matrix control were used to investigate the bulk and defect properties of UO2. The results show that the UO2-Ti system is more favorable for Xe dissolution in vacancies, whereas the UO2-Th system has little effect on the dissolution of Xe atoms. Th, Zr, and Ti inhibit the aggregation of Xe clusters, and Ti is the least favorable for the nucleation and growth of Xe clusters. [ABSTRACT FROM AUTHOR]

The magnetic properties of Mn-doped ZnGa2S4 compound have been investigated using the first principle calculations within density functional theory. Our results demonstrate that Mn substitution changes the nonspin polarized state of pure ZnGa2S4 to spin-polarized. The total energy calculations for a number of supercells showed that ferromagnetic ordering is more favorable than antiferromagnetic ordering for Mn-doped ZnGa2S4. The nature of magnetism is mainly from the dopant Mn atom with magnetic moment 7.90μB. From studies of magnetism caused from vacancies, it was found that Ga vacancy has a significant influence on the magnetic properties, while S vacancy cannot lead to magnetic moment in system. [ABSTRACT FROM AUTHOR]

This study investigated the causes of microstructural changes and the resultant electrical properties according to the sintering temperature of 0.96(K0.46−xNa0.54−x)Nb0.95Sb0.05O3-0.04Bi0.5(Na0.82K0.18)0.5ZrO3 lead-free ceramics by analyzing the correlation between vacancy concentrations and 2D nucleation. When sintered for 4 h, no grain growth occurred for the x = 0.000 composition over a wide temperature range, demonstrating that the existence of initial vacancies is essential for grain growth. As x increased, that is, as the vacancy concentration increased, the critical driving force (ΔGC) for 2D nucleation decreased, and abnormal grain growth was promoted. The number and size of these abnormal grains increased as the sintering temperature increased, but at sintering temperatures above 1100 °C, they decreased again owing to a large drop in ΔGC. The x = 0.005 specimen sintered at 1085 °C exhibited excellent piezoelectric properties of d33 = 498 pC/N and kp = 0.45 due to the large number of large abnormal grains with an 83% tetragonal phase fraction. The x = 0.000 specimen sintered at 1130 °C with suppressed grain growth exhibited good energy storage properties because of its very high relative density and small grain size of 300 to 400 nm. [ABSTRACT FROM AUTHOR]

Disposal of mortgaged property is one of the legal means by which the holder may approach the mortgagee creditor in the event that the mortgagee creditor proceeds to trace. It is worth mentioning that the Jordanian legislator did not define the concept of abandonment in its legal provisions, nor did the Jordanian Civil Law include a text authorizing the holder and guarantor in kind to practice the disposition of the property contrary to other Arab laws, which explicitly stated that the Egyptian legislator explicitly stated in Article 1060 / 1) of the Civil Code. Moreover, he did not specify the appropriate time for abandonment. He did not specify the procedures to be followed for the eviction process, so that the holder avoids the effects that can result from the traceability of the creditors, including expropriation. Finally, the Jordanian legislator did not regulate the vacillation of the mortgaged property, as did most Arab legislations. The most important recommendation is that the Jordanian legislator should set up a special regulation to vacate the mortgaged property. [ABSTRACT FROM AUTHOR]

As vacancy in Rust Belt cities becomes a focal point of planning and policy efforts, Chicago planners and private institutions attribute it to "disinvestment" and seek to remove barriers to real estate investment in order to unlock the market's purported ability to bring land to "productive use." Drawing on findings from an analysis of nearly 10,000 postwar property records in the South Side Chicago neighborhood of Englewood, this article demonstrates that vacancy stems not from disinvestment but from predatory and hyperextractive investments in housing that derive economic feasibility and legal sanction from property's historical articulation with race. I argue that racial regimes of ownership are endemic to the operation of real estate markets and function as central modalities for the appropriation of ground rent. As an analytical lens into the political economy of land, racial regimes of ownership expand urban geographers' capacity to address the mechanisms that mobilize difference to accommodate capital's circulation and, more broadly, to account for the racial logics that configure the terrain of contemporary land struggles. [ABSTRACT FROM AUTHOR]

Copyright of Electronic Components & Materials is the property of Electronic Components & Materials and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Unmaintained vacant land in urban areas is associated with a number of negative outcomes for residents of urban areas, including mental and physical health, safety, and quality of life. Community programs which promote land parcel maintenance in urban neighborhoods have been found to reverse some of the effects that unmaintained land has on nearby residents. We explored how land parcel maintenance is associated with mental health outcomes using data collected in Flint, MI in 2017–2018. Trained observers assessed the maintenance of approximately 7200 land parcels and surveyed 691 residents (57% Female, 53% Black, M age = 51). We aggregated resident and parcel rating data to 463 street segments and compared three structural equation models (SEM) to estimate the mediating effects of fear of crime on the association of parcel qualities on mental distress for residents. We found that fear of crime mediated the association between parcel maintenance values and mental distress indicating that poor maintenance predicted more fear of crime which was associated with mental distress. Our findings add to our understanding about the mechanism by which vacant lot improvements may operate to enhance psychological well‐being of residents who live on streets with vacant and unkept lots. High Lights: Land parcel greening is associated with positive outcomes for urban neighborhoods.Neighborhoods with greater parcel maintenance also had less fear of crime and less mental distress.Community greening may improve mental health outcomes through decreasing fear of crime. [ABSTRACT FROM AUTHOR]

Prior studies indicate that vacant houses (both derelict and occupiable) are often associated with increased crime. However, the majority of the research on that relationship has been conducted in large cities and urban areas. Thus, the present study aimed to provide additional clarity about vacancy's association with crime by examining a sample of smaller cities and towns. Additionally, while prior work has focused on various kinds of vacancy, only a few studies have examined the potentially criminogenic effects of different vacancy types simultaneously. The present research contributes to additional clarity on this point by including specific forms of empty occupiable housing as predictors. The analysis also controlled for other structural factors commonly associated with crime. The results indicated that overall vacancy had a significant association with burglary but not with robbery. The results for these smaller municipalities are compared to the findings of studies conducted in larger urban areas, and their policy implications are then discussed. [ABSTRACT FROM AUTHOR]

Defect engineering provides a highly potential way to yield exceptional catalytic performance. Herein, we first report the selenium (Se) vacancies‐decorated ultrafine platinum–nickel (PtNi‐Sev) nanowires, as a bifunctional catalyst for the hydrogen evolution reaction (HER) and methanol oxidation reaction (MOR). The optimized PtNi‐Sev exhibits obvious enhancement for HER and MOR compared to PtNi nanowires. It displays merely an overpotential of 18.8 mV for alkaline HER and the outstanding MOR performance (3.51 A/mgPt). When applying in one symmetric overall water splitting electrolyzer coupling with HER and MOR, an ultralow working voltage of 0.637 V with 100% Faraday efficiency for hydrogen production was achieved at the current density of 10 mA/cm2. Further investigations reveal that the weakened hydrogen binding energy, strong OH binding as well as relative weak CO binding are responsible for the improved HER and MOR activities. [ABSTRACT FROM AUTHOR]