Publications by authors named "Jianguo Wan"

The dissociation of acidic molecules within a microscopic water environment is crucial for understanding intermolecular interactions such as hydrogen bonding. This study explores the optimal configurations of HBr(HO) using hybrid density functional theory. According to the different mixed cluster structures, the corresponding HBr bond lengths, single-point energies, and introduced proton-transfer parameters are computed and analyzed.

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Low dimensional hybrid organic-inorganic perovskites (HOIPs) have become one of the most promising materials in solar cells, photodetectors, and lasers due to their low exciton binding energy, high bipolar carrier mobility, and long carrier lifetime. The effective separation and collection of photo-generated electrons and holes have always been crucial for a perovskite as a working medium for optoelectronic devices. However, the surface state of pristine perovskite nanowires causes recombination of electrons and holes at the edge of the energy band, leading to deactivation of charge carriers.

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This paper quantitatively examines why dipole moments of HCl(HO) cannot serve as the dissociation criterion for acid molecules using the Hirshfeld-I approach. Also, we propose the possible experimental parameter 〈〉, whose statistical average enables the assessment of acid dissociation in mixed clusters. Furthermore, our calculations reveal that a minimum of four water molecules are necessary to dissociate an HCl molecule.

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The combination of transition-metal (TM) elements with two-dimensional (2D) transition-metal dichalcogenides (TMDs) provides an effective route to realizing a 2D controllable magnetic order, leading to significant applications in multifunctional nanospintronics. However, in most TM atoms@TMDs nanostructures, it is challenging for the magnetic anisotropy energy (MAE) to exceed 30 meV when affected by the crystal field. Hence, the stronger magnetic anisotropy of TMDs has yet to be developed.

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Single-atom magnetism switching is a key technique towards the ultimate data storage density of computer hard disks and has been conceptually realized by leveraging the spin bistability of a magnetic atom under a scanning tunnelling microscope. However, it has rarely been applied to solid-state transistors, an advancement that would be highly desirable for enabling various applications. Here, we demonstrate realization of the electrically controlled Zeeman effect in Dy@C single-molecule transistors, thus revealing a transition in the magnetic moment from 3.

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We systematically investigate the mechanical, dynamical, and piezoelectric properties of MAZ monolayers (M = Mo, W; A = Si, Ge and Z = N, P, As) based on first-principles calculations. The structural properties, cohesive energy and formation energy analyses show that all of the considered MAZ monolayers are dynamically stable. molecular dynamics simulations further indicate that the MAZ monolayers can sustain stability at high temperatures.

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Purpose: To investigate the correlation and prognostic significance of low triiodothyronine (T3) syndrome and norepinephrine dosage in patients with sepsis and septic shock.

Methods: This single-center, retrospective, cohort study enrolled 169 patients with sepsis and septic shock that were admitted to the intensive care unit of First Hospital of Nanchang, Nanchang, China from June 2017 to July 2019. All included patients were followed up for 28 days or died, whichever was earlier.

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The plasmonic response of gold clusters with atom number () = 100-70 000 was investigated using scanning transmission electron microscopy-electron energy loss spectroscopy. For decreasing , the bulk plasmon remains unchanged above = 887 but then disappears, while the surface plasmon firstly redshifts from 2.4 to 2.

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Through the density functional theory, we studied molecular devices composed of single tetrathiafulvalene (TTF) molecules connected with zigzag graphene nanoribbon electrodes by four different junctions. Interestingly, some devices have exhibited half-metallic behavior and can bring out a perfect spin filtering effect and remarkable negative differential resistance behavior. The current-voltage characteristics show that these four devices possess different spin current values.

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Rolling up two-dimensional (2D) materials into nanoscrolls could not only retain the excellent properties of their 2D hosts but also display intriguing physical and chemical properties that arise from their 1D tubular structures. Here, we report a new class of black phosphorus nanoscrolls (bPNSs), which are stable at room-temperature and energetically more favorable than 2D bP. Most strikingly, these bPNSs hold tunable direct band gaps and extremely high mobilities (e.

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In this article, we present a modified Velocity-Verlet algorithm that makes cluster system converge rapidly and accurately. By combining it with molecular dynamics simulations, we develop an effective global sampling method for extracting isomers of bimetallic clusters. Using this method, we obtain the isomers of icosahedral PdAg (x = 0-13).

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Recently, the ferroelectric photovoltaic (FePV) effect has attracted great interest due to its potential in developing optoelectronic devices such as solar cell and electric-optical sensors. It is important for actual applications to realize a controllable photovoltaic process in ferroelectric-based materials. In this work, we prepared well-ordered microarrays based on epitaxially tetragonal BiFeO (T-BFO) films by the pulsed laser deposition technique.

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Article Synopsis
  • Graphene nanomeshes (GNMs) are innovative structures with adjustable properties that could enhance future technology in electronics, photonics, and energy applications.
  • Research focused on how argon (Ar) impacts the creation of GNMs, affecting their density and shape over different growth periods.
  • Advanced imaging techniques confirmed GNMs' hexagonal structure and highlighted the importance of copper oxide nanoparticles formed during oxidization, suggesting they are crucial for the GNM growth process in purified Ar.
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Using a full-dimensional Monte Carlo classical ensemble method, we present a theoretical study of atomic nonsequential double ionization (NSDI) with mid-infrared laser fields, and compare with results from near-infrared laser fields. Unlike single-electron strong-field processes, double ionization shows complex and unexpected interplays between the returning electron and its parent ion core. As a result of these interplays, NSDI for mid-IR fields is dominated by second-returning electron trajectories, instead of first-returning trajectories for near-IR fields.

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Ferroelectric resistive switching (RS), manifested as a switchable ferroelectric diode effect, was observed in well-ordered and high-density nanocapacitor arrays based on continuous BiFeO3 (BFO) ultrathin films and isolated Pt nanonelectrodes. The thickness of BFO films and the lateral dimension of Pt electrodes were aggressively scaled down to <10 nm and ∼60 nm, respectively, representing an ultrahigh ferroelectric memory density of ∼100 Gbit/inch(2). Moreover, the RS behavior in those nanocapacitors showed a large ON/OFF ratio (above 10(3)) and a long retention time of over 6,000 s.

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Multiferroic La-doped BiFeO3 thin films have been prepared by a sol-gel plus spin-coating process, and the local magnetoelectric coupling effect has been investigated by the magnetic-field-assisted scanning probe microscopy connected with a ferroelectric analyzer. The local ferroelectric polarization response to external magnetic fields is observed and a so-called optimized magnetic field of ~40 Oe is obtained, at which the ferroelectric polarization reaches the maximum. Moreover, we carry out the magnetic-field-dependent surface conductivity measurements and illustrate the origin of local magnetoresistance in the La-doped BiFeO3 thin films, which is closely related to the local ferroelectric polarization response to external magnetic fields.

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Using a classical ensemble method, we revisit the topic of recollision and nonsequential double ionization with elliptically polarized laser fields. We focus on how the recollision mechanism transitions from short trajectories with linear polarization to long trajectories with elliptical polarization. We propose how this transition can be observed by meansuring the carrier-envelop-phase dependence of the correlated electron momentum spectra using currently available few-cycle laser pulses.

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To solve the fundamental dilemma in data storage applications, it is crucial to manipulate the magnetic anisotropy energy (MAE). Herein, using first-principles calculations, we predict that the system of double-vacancy graphene decorated by iridium atoms possesses high stability, giant MAE, perpendicular-anisotropy and long-range ferromagnetic coupling. More importantly, the amplitude of MAE can be manipulated by electric fields.

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Recently, ferroelectric perovskite oxides have drawn much attention due to potential applications in the field of solar energy conversion. However, the power conversion efficiency of ferroelectric photovoltaic effect currently reported is far below the expectable value. One of the crucial problems lies in the two back-to-back Schottky barriers, which are formed at the ferroelectric-electrode interfaces and blocking most of photo-generated carriers to reach the outside circuit.

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The quantum anomalous Hall effect (QAHE) is predicted to be realized at high temperature in a honeycomb bilayer consisting of Au atoms and single-vacancy graphene (Au2-SVG) based on the first-principles calculations. We demonstrate that the ferromagnetic state in the Au2-SVG can be maintained up to 380 K. The combination of spatial inversion symmetry and the strong SOC introduced by the Au atoms causes a topologically nontrivial band gap as large as 36 meV and a QAHE state with Chern number C = -2.

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A lateral heterojunction of topological insulator Sb2Te3/Bi2Te3 was successfully synthesized using a two-step solvothermal method. The two crystalline components were separated well by a sharp lattice-matched interface when the optimized procedure was used. Inspecting the heterojunction using high-resolution transmission electron microscopy showed that epitaxial growth occurred along the horizontal plane.

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Magnetic graphene-based materials have shown great potential for developing high-performance electronic devices at sub-nanometer such as spintronic data storage units. However, a significant reduction of power consumption and great improvement of structural stability are needed before they can be used for actual applications. Based on the first-principles calculations, here we demonstrate that the interaction between tungsten atoms and nitrogenized-divacancies (NDVs) in the hybrid W@NDV-graphene can lead to high stability and large magnetic anisotropy energy (MAE).

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Background: Novel influenza A viruses of avian-origin may be the precursors of pandemic strains. This descriptive study aims to introduce a novel avian-origin influenza A (H10N8) virus which can infect humans and cause severe diseases.

Methods: Collecting clinical data of three cases of human infection with a novel reassortment avian influenza A (H10N8) virus in Nanchang, Jiangxi Province, China.

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Cognitive deficits are the core symptoms of schizophrenia and major contributors to disability in schizophrenic patients, but effective treatments are still lacking. Previous studies have demonstrated that impaired BDNF/TrkB signaling is associated with the cognitive impairments of schizophrenia. 7,8-Dihydroxyflavone (7,8-DHF) has recently been identified as a specific TrkB agonist that crosses the blood-brain barrier after oral or intraperitoneal administration.

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