The rediscovery of black phosphorus (BP) has expanded the 2D family into Group 15 (Nitrogen Group) elements, among which bismuthene is the latest member with extraordinary opto-electronic, catalytic ...and biocompatible properties and potential as a 2D topological insulator. However, bulk Bi is not easily mechanically exfoliated as its counterpart of BP. Thus, to date, the reports on 2D Bi fabrication are rare, and investigations on its nonlinear optical properties are even less. Herein, we rationally designed a new strategy combining acid-interaction and liquid exfoliation to successfully transform metal bulk Bi into few-layer semiconductor, which resulted in unseen opto-electronic properties, such as tunable nonlinear responses all the way to the near-infrared (NIR) region. This band is critical for telecommunication and military purposes, but currently, functioning materials are extremely scarce. The origin of this strong saturable absorption was thoroughly explored through time-resolved spectroscopy spanning from the fs to μs timescale, which indicated ultrafast fs to ps carrier dynamics in the early stage and long exciton bleaching recovery up to μs. As a proof-of-concept application, the as-prepared 2D Bi was employed as a saturable absorber to mode-lock a Tm-doped fiber laser and successfully realized a 2 μm NIR-wavelength output. This study not only offers an effective and scalable method to fabricate the new 2D family member bismuthene with extraordinary stability, but also explores its strong and broad nonlinear responses extending into the NIR region and fundamental photoinduced dynamics, which demonstrate the full potential of 2D Bi for application in opto-electronic devices and nonlinear optics.
In this paper, we propose a new and efficient virtual element scheme for phase field modeling of the dynamic fracture using an explicit time integration scheme. The explicit time integrator divided ...the whole problem into two parts, namely, mechanical and damage sub-problems. The former is treated as an elastodynamic equation while the latter is treated as a Poisson equation with reaction terms subjected to irreversibility and bounded constraints. To test the performance of the proposed numerical framework, several benchmark problems are validated and the results are in good agreement with the corresponding numerical and experimental study. Moreover, VEM outperforms FEM in view of memory efficiency and choice of element type.
•1st time VEM for phase field modeling of dynamic fracture.•Without artificial parameter for stabilization, proposed VEM is more compact.•VEM outperforms standard FEM in view of memory usage.•Different mesh type and mesh size are tested for proposed scheme.•Results are in good agreement with benchmarks and experimental studies.
Metallic zinc is a promising anode material for rechargeable aqueous multivalent metal‐ion batteries due to its high capacity and low cost. However, the practical use is always beset by severe ...dendrite growth and parasitic side reactions occurring at anode/electrolyte interface. Here we demonstrate dynamic molecular interphases caused by trace dual electrolyte additives of D‐mannose and sodium lignosulfonate for ultralong‐lifespan and dendrite‐free zinc anode. Triggered by plating and stripping electric fields, the D‐mannose and lignosulfonate species are alternately and reversibly (de‐)adsorbed on Zn metal, respectively, to accelerate Zn2+ transportation for uniform Zn nucleation and deposition and inhibit side reactions for high Coulombic efficiency. As a result, Zn anode in such dual‐additive electrolyte exhibits highly reversible and dendrite‐free Zn stripping/plating behaviors for >6400 hours at 1 mA cm−2, which enables long‐term cycling stability of Zn||ZnxMnO2 full cell for more than 2000 cycles.
Hybrid aqueous electrolyte of ZnSO4 with trace dual electrolyte additives of D‐mannose and sodium lignosulfonate enables ultralong‐lifespan and dendrite‐free Zn metal anode by virtue of D‐mannose and lignosulfonate species alternately and reversibly adsorb on Zn surface to form dynamical molecular interphases and enter Zn2+ solvation sheath to boost de‐solvation kinetics. Zn anode in such dual‐additive electrolyte exhibits exceptional stability for >6400 hours.
This study innovatively addresses challenges in enhancing upconversion efficiency in lanthanide‐based nanoparticles (UCNPs) by exploiting Shewanella oneidensis MR‐1, a microorganism capable of ...extracellular electron transfer. Electroactive membranes, rich in c‐type cytochromes, are extracted from bacteria and integrated into membrane‐integrated liposomes (MILs), encapsulating core–shelled UCNPs with an optically inactive shell, forming UCNP@MIL constructs. The electroactive membrane, tailored to donate electrons through the inert shell, independently boosts upconversion emission under near‐infrared excitation (980 or 1550 nm), bypassing ligand‐sensitized UCNPs. The optically inactive shell restricts energy migration, emphasizing electroactive membrane electron donation. Density functional theory calculations elucidate efficient electron transfer due to the electroactive membrane hemes' highest occupied molecular orbital being higher than the valence band maximum of the optically inactive shell, crucial for enhancing energy transfer to emitter ions. The introduction of a SiO2 insulator coating diminishes light enhancement, underscoring the importance of unimpeded electron transfer. Luminescence enhancement remains resilient to variations in emitter or sensitizing ions, highlighting the robustness of the electron transfer‐induced phenomenon. However, altering the inert shell material diminishes enhancement, emphasizing the role of electron transfer. This methodology holds significant promise for diverse biological applications. UCNP@MIL offers an advantage in cellular uptake, which proves beneficial for cell imaging.
Electroactive membranes, derived from Shewanella oneidensis MR‐1 bacteria, are incorporated into membrane‐integrated liposomes (MILs), encapsulating core–shell upconversion nanoparticles (CS UCNPs) with an optically inert shell. CS UCNP@MIL exhibits enhanced upconversion emission. This enhancement process is facilitated by electron donation from the electroactive membrane through the optically inactive shell to the UCNPs and is supported by theoretical calculations and experimental evidence.
The impact of microplastic particles of micro- and nanometer sizes on microbial horizontal gene transfer (HGT) remains a controversial topic. Existing studies rely on traditional approaches, which ...analyze population behavior, leading to conflicting conclusions and a limited understanding. The present study addressed these limitations by employing a novel microfluidic chamber system for in situ visualization and precise quantification of the effects of different concentrations of polystyrene (PS) microbeads on microbial HGT at the single-cell level. The statistical analysis indicated no significant difference in the division times of both the donor and recipient bacteria across different PS microbead concentrations. However, as the concentration of PS microbeads increased from 0 to 2000 mg L–1, the average conjugation frequency of Escherichia coli decreased from 0.028 ± 0.015 to 0.004 ± 0.003. Our observations from the microfluidic experiments revealed that 500 nm PS microbeads created a barrier effect on bacterial conjugative transfer. The presence of microbeads resulted in reduced contact and interaction between the donor and recipient strains, thereby causing a decrease in the conjugation transfer frequency. These findings were validated by an individual-based modeling framework parameterized by the data from the individual-level microfluidic experiments. Overall, this study offers a fresh perspective and strategy for investigating the risks associated with the dissemination of antibiotic resistance genes related to microplastics.
In this work, the self-consistent clustering analysis (SCA) framework is extended to include homogenization and full field analysis of 3D anisotropic woven composite Representative Unit Cell (RUC). ...The developed extended framework has two new features, namely, (i), to reconstruct the local field variables, a strain refinement stage is presented by solving full field Lippmann–Schwinger equations within 3D anisotropic woven composite RUC following the online predictive stage in SCA, and (ii), discrete Green’s operator based on finite difference is adopted to improve the accuracy of refined point-wise physical field variables. To demonstrate the accuracy and efficiency of the proposed method, benchmark problems are analyzed, and results are compared to directly numerical simulation (DNS). For the reproducibility of presented results, the developed code can be freely downloaded from https://github.com/Tong-RuiLiu/Extended-SCA-and-FFT-based-strain-refinement-method-.
•1st time SCA with strain refinement stage is proposed for 3D woven composite RUC.•1st time performance of discrete Green’s operator is investigated in SCA.•Cause & effect analysis is carried for the convergence and accuracy of results.•Minimal change of code is needed from FFT homogenization and SCA.
A growth‐temperature‐mediated two‐step chemical vapor deposition strategy is designed to synthesize MoS2/WS2 and WS2/MoS2 stacks on Au foils. Predominantly A–A stacked MoS2/WS2 and A–B stacked ...WS2/MoS2 are selectively achieved and confirmed. Relative enhancements or reductions in photocatalytic activities of MoS2/WS2 or WS2/MoS2 are observed under illumination, because the type‐II band alignment enables directional electron flow from electrode to active site.
The corona discharge techniques, which are employed to orient dipoles and built up charges inside functional polymers, can develop important commercial applications of electroactive polymers (EAPs) ...and electrets for energy storage devices, air filters, electroacoustic and electromechanical transducers. We propose hereby an elective hybrid approach to the point-plane corona modeling in order to obtain more accurate electron flow in unipolar corona discharge system. A coupled system of partial differential equations (PDEs) w.r.t. Navier-stokes equations and hydrodynamic drift diffusion equations described the nature of photo-ionization, where the secondary avalanche in the discharge process was demonstrated. The simulation was verified by comparison with Surface Potential (SP) measurement of the nano-composites after corona polarization. Consequently, the spacial electric potential distribution and initial surface potential could be obtained by the means of finite elements method (FEM), which provided a good numerical approach for the experimental data of electrostatic surface potential. In addition, the influence of nano particle on the charge retain ability of the insulating polymers was also investigated, which could be a guideline for designing an effective poling method on the functional polymers applied in electrical energy storage devices sensors, actuators and transducer etc.
Adhesive effects in vacuum and disturbance-induced impact in microgravity make the friction different from the traditional theory. In this paper, an impact sliding contact model is developed by ...coarse-grained molecular dynamics simulations under the vacuum and microgravity environments. Textured surfaces are designed, and the effects of texture parameters on friction forces are investigated. The results show that the friction forces could be underestimated if the impact is ignored. Compared with a smooth surface, the textured surfaces can improve friction behaviors during impact sliding contact process. The average friction forces are increased as the increase of the texture width. The textured surface with 0° orientation produces a lower average friction force than other orientations and textured surface with rectangular shape shows the optimum friction behaviors.
•An impact sliding contact model is developed considering the motion of the vacuum and microgravity environment.•The coarse-grained molecular dynamics simulations are performed to study the impact sliding contact behaviors.•The textured surfaces are introduced to the Ag film, and the impact sliding contact behaviors are investigated.
