Cadmium and pyrene in the soil modify the properties of earthworm-mediated soil.

Earthworms are pivotal in soil ecosystems due to their crucial role in shaping soil characteristics through casts and burrow walls. Previous research has predominantly focused on the direct impact of soil pollution on live earthworms, overlooking the subsequent effects on earthworm-mediated soil, such as casts and burrow walls. Using 2D-terraria as incubation containers and the geophagous earthworm species Metaphire guillelmi, this study assessed the change in various properties of earthworm-mediated soil in both uncontaminated soils and Cd- and Pye-contaminated soils. Overall, both Cd and Pye overall improved the ammonium nitrogen (NH4+-N), Olsen's phosphorus (Olsen-P) levels, and invertase and catalase activities while decreasing catalase activities in earthworm-mediated soil. They also fluctuating affected the pH, soil organic matter (SOM) content, soil urease, alkaline phosphatase activities, and microbial functional genes in the cast and burrow walls. These results indicated that earthworms remained crucial "ecosystem engineers" even in polluted soil. Additionally, differences were observed in the responses of properties between casts and burrow walls, showing unequal contributions of transit-through-gut and burrowing processes to soil modification. Specifically, transit-through-gut was found to have a more significant influence on soil NH4+-N and Olsen-P content compared to burrowing behavior. Regarding the pattern of microbial functional genes in earthworm-associated compartments, results revealed that they differed significantly in casts from those in bulk soil and burrow walls under unpolluted conditions, with pollution-enhancing disparities among compartments. Furthermore, NH4+-N and Olsen-P content, urease, and catalase activities in burrow walls and/or casts were identified as potential biomarkers for soil pollution, exhibiting a clear dose-effect relationship. Developing such biomarkers could address ethical concerns related to conventional earthworm biomarkers that require sacrificing earthworms. This study provides insights into the consequences of soil pollution on earthworm-mediated soil components, highlighting the importance of considering the indirect effects of contaminants on soil ecosystems.

Wafer-Scale Growth and Transfer of High-Quality MoS2 Array by Interface Design for High-Stability Flexible Photosensitive Device.

Transition metal disulfide compounds (TMDCs) emerges as the promising candidate for new-generation flexible (opto-)electronic device fabrication. However, the harsh growth condition of TMDCs results in the necessity of using hard dielectric substrates, and thus the additional transfer process is essential but still challenging. Here, an efficient strategy for preparation and easy separation-transfer of high-uniform and quality-enhanced MoS2 via the precursor pre-annealing on the designed graphene inserting layer is demonstrated. Based on the novel strategy, it achieves the intact separation and transfer of a 2-inch MoS2 array onto the flexible resin. It reveals that the graphene inserting layer not only enhances MoS2 quality but also decreases interfacial adhesion for easy separation-transfer, which achieves a high yield of ≈99.83%. The theoretical calculations show that the chemical bonding formation at the growth interface has been eliminated by graphene. The separable graphene serves as a photocarrier transportation channel, making a largely enhanced responsivity up to 6.86 mA W-1, and the photodetector array also qualifies for imaging featured with high contrast. The flexible device exhibits high bending stability, which preserves almost 100% of initial performance after 5000 cycles. The proposed novel TMDCs growth and separation-transfer strategy lightens their significance for advances in curved and wearable (opto-)electronic applications.

A 2 µm Wavelength Band Low-Loss Spot Size Converter Based on Trident Structure on the SOI Platform.

A 2 µm wavelength band spot size converter (SSC) based on a trident structure is proposed, which is coupled to a lensed fiber with a mode field diameter of 5 µm. The cross-section of the first segment of the tapered waveguide structure in the trident structure is designed as a right-angled trapezoidal shape, which can further improve the performance of the SSC. The coupling loss of the SSC is less than 0.9 dB in the wavelength range of 1.95~2.05 µm simulated by FDTD. According to the experimental results, the lowest coupling loss of the SSC is 1.425 dB/facet at 2 µm, which is close to the simulation result. The device is compatible with the CMOS process and can provide a good reference for the development of 2 µm wavelength band integrated photonics.

In Situ Growth of Wafer-Scale Patterned Graphene and Fabrication of Optoelectronic Artificial Synaptic Device Array Based on Graphene/n-AlGaN Heterojunction for Visual Learning.

The unique optical and electrical properties of graphene-based heterojunctions make them significant for artificial synaptic devices, promoting the advancement of biomimetic vision systems. However, mass production and integration of device arrays are necessary for visual imaging, which is still challenging due to the difficulty in direct growth of wafer-scale graphene patterns. Here, a novel strategy is proposed using photosensitive polymer as a solid carbon source for in situ growth of patterned graphene on diverse substrates. The growth mechanism during high-temperature annealing is elucidated, leading to wafer-scale graphene patterns with exceptional uniformity, ideal crystalline quality, and precise control over layer number by eliminating the release of volatile from oxygen-containing resin. The growth strategy enables the fabrication of two-inch optoelectronic artificial synaptic device array based on graphene/n-AlGaN heterojunction, which emulates key functionalities of biological synapses, including short-term plasticity, long-term plasticity, and spike-rate-dependent plasticity. Moreover, the mimicry of visual learning in the human brain is attributed to the regulation of excitatory and inhibitory post-synapse currents, following a learning rule that prioritizes initial recognition before memory formation. The duration of long-term memory reaches 10 min. The in situ growth strategy for patterned graphene represents the novelty for fabricating fundamental hardware of an artificial neuromorphic system.

The AlN lattice-polarity inversion in a high-temperature-annealed c-oriented AlN/sapphire originated from the diffusion of Al and O atoms from sapphire.

AlN films are widely used owing to their superior characteristics, including an ultra-wide bandgap, high breakdown field, and radiation resistance. High-temperature annealing (HTA) makes it easy to obtain high-quality AlN films, with the advantages of a simple process, good repeatability, and low cost. However, it is always found that there is a lattice-polarity inversion from a N-polarity near the sapphire to an Al-polarity in the HTA c-oriented AlN/sapphire. Currently, the formation mechanism is still unclear, which hinders its further wide applications. Therefore, the formation mechanism of the polarity inversion and its impacts on the quality and stress profile of the upper AlN in the HTA c-oriented AlN/sapphire were investigated. The results imply that the inversion originated from the diffusion of the Al and O atoms from the sapphire. Due to the presence of abundant Al vacancies (VAl) in the upper AlN, Al atoms in the sapphire diffuse into the upper AlN during the annealing to fill the VAl, resulting in the O-terminated sapphire, leading to the N-polar AlN. Meanwhile, O atoms in the sapphire also diffuse into the upper AlN during the annealing, forming an AlxOyNz layer and causing the inversion from N- to Al-polarity. The inversion has insignificant impacts on the quality and stress distribution of the upper AlN. Besides, this study predicts the presence of a two-dimensional electron gas at the inversion interface. However, the measured electron concentration is much lower than that predicted, which may be due to the defect compensation, low polarization level, and strong impurity scattering.

Photogating-assisted tunneling boosts the responsivity and speed of heterogeneous WSe2/Ta2NiSe5 photodetectors.

Photogating effect is the dominant mechanism of most high-responsivity two-dimensional (2D) material photodetectors. However, the ultrahigh responsivities in those devices are intrinsically at the cost of very slow response speed. In this work, we report a WSe2/Ta2NiSe5 heterostructure detector whose photodetection gain and response speed can be enhanced simultaneously, overcoming the trade-off between responsivity and speed. We reveal that photogating-assisted tunneling synergistically allows photocarrier multiplication and carrier acceleration through tunneling under an electrical field. The photogating effect in our device features low-power consumption (in the order of nW) and shows a dependence on the polarization states of incident light, which can be further tuned by source-drain voltages, allowing for wavelength discrimination with just a two-electrode planar structure. Our findings offer more opportunities for the long-sought next-generation photodetectors with high responsivity, fast speed, polarization detection, and multi-color sensing, simultaneously.

Effects of cadmium and pyrene on earthworm-associated bacterial communities: Unveiling new perspectives for soil pollution management.

Earthworms are considered to be excellent bioindicators of soil pollution. In recent years, there has been increasing interest in examining the effects of soil pollution on earthworm-associated microbiomes, with a particular focus on the gut microbiomes. However, relatively little effort has been invested in comprehensively investigating other microbiomes associated with earthworms and their responses to soil pollution. To fill this gap, we systematically studied the effects of Cd, pyrene, and combined pollution on the bacterial community in different vermicompartments, i.e., burrow wall, gut, and cast, in both epigeic Eisenia fetida and anecic Metaphire guillelmi, using a 2D-terraria incubator and high-throughput sequencing techniques. The results showed that bacterial alpha diversity followed the order of burrow wall > cast > gut, and this did not vary with soil pollution or earthworm ecotypes. Moreover, the dominant phyla in the vermicompartments were similar across different pollution treatments. Principal coordinate analysis (PCoA) revealed that the bacterial communities in different vermicompartments and ecotypes of earthworm were separated from each other, whereas they were grouped together in polluted treatments and unpolluted conditions. These results imply that even in polluted soil, vermicompartment and earthworm ecotypes remain the most significant factors affecting earthworm-associated microbiomes. However, the impacts of soil pollution on the bacterial composition in each vermicompartment were still evident. A comprehensive analysis revealed that the gut bacterial communities are more sensitive to soil contamination than casts and burrow wall in different ecotypes. Additionally, linear discriminant analysis of effect size (LefSe) identified several bacteria in Gemmatimonadota, the Firmicutes phylum in the burrow walls, and Patescibacteria (phyla) in the gut as potential biomarkers for pyrene contamination in soil. This research provides a comprehensive understanding of the effects of soil pollution on earthworm-associated microbiomes, thereby enhancing our understanding of earthworm ecotoxicology and soil pollution management.

Multiplexing of bias-controlled modulation modes on a monolithic III-nitride optoelectronic chip.

III-nitride optoelectronic chips have tremendous potential for developing integrated computing and communication systems with low power consumption. The monolithic, top-down approaches are advantageous for simplifying the fabrication process and reducing the corresponding manufacturing cost. Herein, an ultraviolet optical interconnection system is investigated to discover the way of multiplexing between emission and absorption modulations on a monolithic optoelectronic chip. All on-chip components, the transmitter, monitor, waveguide, modulator, and receiver, share the same quantum well structure. As an example, two bias-controlled modulation modes are used to modulate video and audio signals in the experiment presented in this Letter. The results show that our on-chip optoelectronic system works efficiently in the near ultraviolet band, revealing the potential breadth of GaN optoelectronic integration.

Mechanistic understanding of the interfacial properties of metal-PtSe2 contacts.

With the advantages of a moderate band gap, high carrier mobility and good environmental stability, two-dimensional (2D) semiconductors show promising applications in next-generation electronics. However, the accustomed metal-2D semiconductor contact may lead to a strong Fermi level pinning (FLP) effect, which severely limits the practical performance of 2D electronics. Herein, the interfacial properties of the contacts between a promising 2D semiconductor, PtSe2, and a sequence of metal electrodes are systematically investigated. The strong interfacial interactions formed in all metal-PtSe2 contacts lead to chemical bonds and a significant interfacial dipole, resulting in a vertical Schottky barrier for Ag, Au, Pd and Pt-based systems and a lateral Schottky barrier for Al, Cu, Sc and Ti-based systems, with a strong FLP effect. Remarkably, the tunneling probability for most metal-PtSe2 is significantly high and the tunneling-specific resistivity is two orders of magnitude lower than that of the state-of-the-art contacts, demonstrating the high efficiency for electron injection from metals to PtSe2. Moreover, the introduction of h-BN as a buffer layer leads to a weakened FLP effect (S = 0.50) and the transformation into p-type Schottky contact for Pt-PtSe2 contacts. These results reveal the underlying mechanism of the interfacial properties of metal-PtSe2 contacts, which is useful for designing advanced 2D semiconductor-based electronics.

Nonradiative Dynamics Induced by Vacancies in Wide-Gap III-Nitrides: Ab Initio Time-Domain Analysis.

Insightful understanding of defect properties and prevention of defect damage are among the biggest issues in the development of photoelectronic devices based on wide-gap III-nitride semiconductors. Here, we have investigated the vacancy-induced carrier nonradiative dynamics in wide-gap III-nitrides (GaN, AlN, and AlxGa1-xN) by ab initio molecular dynamics and nonadiabatic (NA) quantum dynamics simulations since the considerable defect density in epitaxy samples. E-h recombination is hardly affected by Vcation, which created shallow states near the VBM. Our findings demonstrate that VN in AlN creates defect-assisted nonradiative recombination centers and shortens the recombination time (τ) as in the Shockley-Read-Hall (SRH) model. In GaN, VN improves the NA coupling between the CBM and the VBM. Additionally, increasing x in the AlxGa1-xN alloys accelerates nonradiative recombination, which may be an important issue in further improving the IQE of high Al-content AlxGa1-xN alloys. These findings have significant implications for the improvement of wide-gap III-nitrides-based photoelectronic devices.

Centimeter-Transferable III-Nitride Membrane Enabled by Interfacial Adhesion Control for a Flexible Photosensitive Device.

Flexible III-nitride-based optoelectronic devices are crucial for the next-generation foldable/wearable lighting sterilization and sensor working in the ultraviolet (UV) region. However, the strong bonding effect at the epitaxial interface of III-nitride and bare sapphire substrate makes it difficult for epilayer separation and flexible applications. Although the emerging van der Waals epitaxy (vdWE) with graphene insertion layer offers a feasible route for weakening the interfacial adhesion, the intact centimeter-transferable III-nitride membrane still remains challenging. The spontaneous delamination occurs due to the too weak interfacial adhesion of pure vdW force, and on the contrary, the structural damage of graphene by high-temperature hydrogen etching during the III-nitride growth might also cause separation failure. Up to now, the efficient control of vdWE interfacial adhesion is still an on-going research hotspot. Herein, we demonstrate the interfacial adhesion control of III-nitride vdWE by utilizing graded high-temperature nitridation treatment of the graphene insertion layer, which generates defects and N doping in different levels. The corresponding epitaxial modes of pure-vdWE, quasi-vdWE, and mixed epitaxy are achieved according to the interfacial adhesion difference. It reveals that the quasi-vdWE enabled by small graphene defects and proper N doping triggers the low formation energy for AlN nucleation; meanwhile, the proper interfacial adhesion ensures the growth integrality and intact separation of III-nitride membrane in the centimeter scale. The UV resin-assisted bonding technique is proposed for the successful transfer of III-nitride onto a flexible substrate. The flexible photodetector is fabricated by using a graphene monolayer as the photocarrier transport channel, and it achieves a high device yield of 90%, retaining ∼60% of its initial performance after 250 bending cycles. This work offers the promising strategy for controlling vdWE interfacial adhesion, and the separable and transferable III-nitride membrane lays the foundation for advances of future UV foldable and wearable devices.

Vermitoxicity of aged biochar and exploring potential damage factors.

Although biochar is a promising soil amendment, its characteristics change owing to its aging in soil. Studies have shown that some aged biochar is hazardous to plants and soil microbiota. Earthworms are well-known soil ecosystem engineers; nevertheless, the toxic effects of aged biochar on them (vermitoxicity) are yet unknown, and it is necessary to explore the potential risk factors. Here, a series of soil culture experiments were conducted to systematically examine the vermitoxicity of aged biochar at various levels utilizing the earthworm Eisenia fetida and corncob biochar.. Acute toxicity bioassays were also used to evaluate several potential harm factors utilizing modified aged biochar/leaching solutions. The findings showed that both fresh and aged biochar might have adverse effects on earthworms, and that aged biochar was more toxic than fresh biochar with LC50s reduced to 6.89%. Specifically, aged biochar caused earthworm death, growth inhibition with a maximum of 36.6%, and avoidance with 100% avoidance at the application rates of 2% at the individual-behavioral level. At the cellular and physiological-biochemical levels, aged biochar damaged coelomocyte lysosomal membrane stability, disrupted antioxidant enzyme activities, and improved the malondialdehyde (MDA) content in earthworms. Heat-treated and pH-modified aged biochar exhibited less acute toxicity on earthworms than aged biochar, whereas aqueous and acetone extracts showed weak vermitoxicity. As a result, earthworms may be harmed by volatile organic compounds (VOCs), an improper pH, and aqueous and acetone extracts. Additionally, the range of neural red retention times (NRRTs) was reviewed as ∼20-70 min mostly. This study, as far as we know, is the first to evaluate the vermitoxicity of aged biochar and its potential damage factors. The results may enhance our understanding of ecological toxicity of biochar, particularly over the long term, and lead to the development of application standards for biochar amendments to the soil.

A study on optimization of delayed production mode of iron and steel enterprises based on data mining.

Delayed production mode has been adopted by an increasing number of process production enterprises as a method to realize mass customization of multi-products. This paper used the convolutional neural network-long short-term memory artificial neural network algorithm (C-LSTM) in data mining technology to analyze and determine factors that have an impact on delayed production mode in the internal and external production and operation of enterprises. Combined with the actual production situation of iron and steel enterprises, a quantitative model of the delayed production was constructed. Lastly, data from a large iron and steel enterprise with good operation was used to verify the validity of the proposed model and analyze key influencing factors. According to the research, in scenarios of considering PDP alone, considering CODP alone, considering both PDP and CODP, considering PDP and CODP and using data mining technology to model, the matching degree of these methods with the actual situation of the enterprise is 31.8%, 61.4%, 71.6% and 86.6%, respectively. The numerical analysis results of the model based on data mining technology show that in delayed production, when customer service level improves or the delay penalty coefficient increases, the optimal locations of the product differentiation point (PDP) and customer order decoupling point (CODP) move toward the end of production, and the total cost increases gradually. When the difference in production cost or benefit of early delivery between the candidate locations of PDP and CODP is small, optimal locations of PDP and CODP are close to the beginning of the general and dedicated production processes. With an increase of cost difference or early delivery benefit, the optimal locations of PDP and CODP jumped to the end stage of the general and dedicated production processes, and the total cost begins to decrease.

The Reaction Products of the Al-Nb-B2O3-CuO System in an Al 6063 Alloy Melt and Their Influence on the Alloy's Structure and Characteristics.

To meet aero-engine aluminum skirt requirements, an experiment was carried out using Al-Nb-B2O3-CuO as the reaction system and a 6063 aluminum alloy melt as the reaction medium for a contact reaction, and 6063 aluminum matrix composites containing in situ particles were prepared with the near-liquid-phase line-casting method after the reaction was completed. The effects of the reactant molar ratio and the preheating temperature on the in situ reaction process and products were explored in order to determine the influence of in situ-reaction-product features on the organization and the qualities of the composites. Thermodynamic calculations, DSC analysis, and experiments revealed that the reaction could continue when the molar ratio of the reactants of Al-Nb-B2O3-CuO was 6:1:1:1.5. A kinetic study revealed that the Al thermal reaction in the system produced Al2O3 and [B], and the [B] atoms interacted with Nb to generate NbB2. With increasing temperature, the interaction between the Nb and the AlB2 produced hexagonal NbB2 particles with an average longitudinal size of 1 µm and subspherical Al2O3 particles with an average longitudinal size of 0.2 µm. The microstructure of the composites was reasonably fine, with an estimated equiaxed crystal size of around 22 µm, a tensile strength of 170 MPa, a yield strength of 135 MPa, an elongation of 13.4%, and a fracture energy of 17.05 × 105 KJ/m3, with a content of 2.3 wt% complex-phase particles. When compared to the matrix alloy without addition, the NbB2 and Al2O3 particles produced by the in situ reaction had a significant refinement effect on the microstructure of the alloy, and the plasticity of the composite in the as-cast state was improved while maintaining higher strength and better overall mechanical properties, allowing for industrial mass production.

Characteristics of oral microbiome of healthcare workers in different clinical scenarios: a cross-sectional analysis.

The environment of healthcare institutes (HCIs) potentially affects the internal microecology of medical workers, which is reflected not only in the well-studied gut microbiome but also in the more susceptible oral microbiome. We conducted a prospective cross-sectional cohort study in four hospital departments in Central China. Oropharyngeal swabs from 65 healthcare workers were collected and analyzed using 16S rRNA gene amplicon sequencing. The oral microbiome of healthcare workers exhibited prominent deviations in diversity, microbial structure, and predicted function. The coronary care unit (CCU) samples exhibited robust features and stability, with significantly higher abundances of genera such as Haemophilus, Fusobacterium, and Streptococcus, and a lower abundance of Prevotella. Functional prediction analysis showed that vitamin, nucleotide, and amino acid metabolisms were significantly different among the four departments. The CCU group was at a potential risk of developing periodontal disease owing to the increased abundance of F. nucleatum. Additionally, oral microbial diversification of healthcare workers was related to seniority. We described the oral microbiome profile of healthcare workers in different clinical scenarios and demonstrated that community diversity, structure, and potential functions differed markedly among departments. Intense modulation of the oral microbiome of healthcare workers occurs because of their original departments, especially in the CCU.

High-Performance Lithium-Ion Storage of FeTiO3 with Morphology Adjustment and Niobium Doping.

Ferrous titanate (FeTiO3) has a high theoretical capacity and physical and chemical properties stability, so it is a potential lithium anode material. In this study, FeTiO3 nanopowder and nanosheets were prepared by the sol-gel method and the hydrothermal method. In addition, niobium-ion doping was carried out, the radius of Nb close to Ti so the Nb can easily enter into the FeTiO3 lattice. Nb can provide more free electrons to improve the electrochemical performance. Then, the effects of the morphology and niobium doping on the microstructure and electrochemical properties of FeTiO3 were systematically studied. The results show that FeTiO3 nanosheets have a better lithium storage performance than nanopowders because of its high specific surface area. A certain amount of niobium doping can improve the electrochemical performance of FeTiO3. Finally, a 1 mol% niobium-doping FeTiO3 nanosheets (1Nb-FTO-S) electrode provided a higher specific capacity of 782.1 mAh g-1 at 50 mA g-1. After 200 cycles, the specific capacity of the 1Nb-FTO-S electrode remained at 509.6 mAh g-1. It is revealed that an increased specific surface area and ion doping are effective means to change the performance of lithium, and the proposed method looks promising for the design of other inorganic oxide electrode materials.

Molecular-Shape-Controlled Binary to Ternary Resistive Random-Access Memory Switching of N-Containing Heteroaromatic Semiconductors.

In organic resistive random-access memory (ReRAM) devices, deeply understanding how to control the performance of π-conjugated semiconductors through molecular-shape-engineering is important and highly desirable. Herein, we design a family of N-containing heteroaromatic semiconductors with molecular shapes moving from mono-branched 1Q to di-branched 2Q and tri-branched 3Q. We find that this molecular-shape engineering can induce reliable binary to ternary ReRAM switching, affording a highly enhanced device yield that satisfies the practical requirement. The density functional theory calculation and experimental evidence suggest that the increased multiple paired electroactive nitrogen sites from mono-branched 1Q to tri-branched 3Q are responsible for the multilevel resistance switching, offering stable bidentate coordination with the active metal atoms. This study sheds light on the prospect of N-containing heteroaromatic semiconductors for promising ultrahigh-density data-storage ReRAM application.

Van der Waals Epitaxy of c-Oriented Wurtzite AlGaN on Polycrystalline Mo Substrates for Enhanced Heat Dissipation.

The epitaxy of III-nitrides on metallic substrates is competitive due to the advantages of vertical carrier injection, enhanced heat dissipation, and flexible application in various III-nitride-based devices. However, the serious lattice mismatch, atom diffusion, and interface reaction under the rigorous growth conditions have caused enormous obstacles. Based on the thermal and chemical stability of the graphene layer, we propose the van der Waals epitaxy of c-oriented wurtzite AlGaN on the polycrystalline Mo substrate by high-temperature metal-organic chemical vapor deposition. The insertion of a graphene layer interrupts the chaotic epitaxial relationship between the polycrystalline metal and epilayers, resulting in the single-crystalline orientation along the wurtzite (0002) plane and residual stress release in AlGaN because of the weak van der Waals interaction. We also demonstrate that the epitaxy of AlGaN on Mo metal possesses enhanced heat dissipation ability, in which the epilayer temperature is controlled at only 28.7 °C by the heating of a ∼54 °C hot plate. The heat dissipation enhancement for the present epitaxial structures provides a desirable strategy for the fabrication of efficient ultraviolet devices with excellent stability and lifetime.

Morphology and carrier mobility of high-B-content BxAl1-xN ternary alloys from an ab initio global search.

The excellent properties of III-nitrides and their alloys have led to significant applications in optoelectronic devices. Boron, the lightest IIIA group element, makes it possible to extend the flexibility of III-nitride alloys. However, both BxAl1-xN and BxGa1-xN ternary alloys suffer from poor material quality during crystal growth, their B contents in experimental reports are no higher than 22%, and the underlying mechanism is still unclear. Herein, ab initio global calculation by particle swarm optimization combined with density functional theory is carried out to identify the ground structures of BxAl1-xN alloys with different B contents (x = 0.25, 0.5, and 0.75). Furthermore, the electronic properties and intrinsic carrier mobility are studied. For B0.25Al0.75N and B0.75Al0.25N, quasi-wurtzite and quasi-hexagonal structures are energetically favourable, respectively, indicating a wurtzite-to-hexagonal structural transition due to the three-coordinated B atoms being incorporated into the lattice. When the B content is 50%, B0.5Al0.5N shows a ten-membered ring structure with an indirect bandgap of 3.52 eV and strong anisotropy of mobility. Our results uncover the mechanism of the structural and electronic property evolution with B content and pave a route for the application of B-containing III-nitride alloys.