Interface phonon transport in nanomaterials: numerical methods and modulation strategies.

The thermal properties of interfaces in nanomaterials are critical for various technological applications, including thermal management in electronic and photonic devices, thermoelectric conversion and thermal insulation. Recent advancements in numerical simulation tools (the non-equilibrium Green's approach, the Boltzmann transport equation and the Monte Carlo method, molecular dynamics simulations) have significantly enhanced our understanding of phonon transport and scattering processes in nanomaterials. These advances have led to the discovery of new thermal interfacial materials and enabled precise modulation of phonon thermal conductance to achieve desired thermal performance.

Efficient Energy Transfer Enabled by Dark States in van der Waals Heterostructures.

Dark exciton states show great potential in condensed matter physics and optoelectronics because of their long lifetime and rich distribution in band structures. Therefore, they can theoretically serve as efficient energy reservoirs, providing a platform for future applications. However, their optical-transition-forbidden nature severely limits their experimental exploration and hinders their current application.

High Thermoelectric Performance of a Novel -PbSnX (X = S, Se, Te) Monolayer: Predicted Using First Principles.

Two-dimensional (2D) group IV metal chalcogenides are potential candidates for thermoelectric (TE) applications due to their unique structural properties. In this paper, we predicted a 2D monolayer group IV metal chalcogenide semiconductor γ-PbSn (X = S, Se, Te), and first-principles calculations and Boltzmann transport theory were used to study the thermoelectric performance. We found that γ-PbSnX had an ultra-high carrier mobility of up to 4.

Nonrelativistic Spin-Momentum Coupling in Antiferromagnetic Twisted Bilayers.

Spin-momentum coupling, which depends strongly on the relativistic effect of heavy elements in solids, is the basis of many phenomena in spintronics. In this Letter, we theoretically predict nonrelativistic spin-momentum coupling in two-dimensional materials. By proposing magnetic symmetry requirements for spin splitting in two-dimensional systems, we find that a simple twisting operation can realize nonrelativistic spin splitting in antiferromagnetic bilayers.

Photoluminescence Lightening: Extraordinary Oxygen Modulated Dynamics in WS Monolayers.

Transition metal dichalcogenide monolayers exhibit ultrahigh surface sensitivity since they expose all atoms to the surface and thereby influence their optoelectronic properties. Here, we report an intriguing lightening of the photoluminescence (PL) from the edge to the interior over time in the WS monolayers grown by physical vapor deposition method, with the whole monolayer brightened eventually. Comprehensive optical studies reveal that the PL enhancement arises from the p doping induced by oxygen adsorption.

High-Temperature Excitonic Bose-Einstein Condensate in Centrosymmetric Two-Dimensional Semiconductors.

The realization of high-temperature excitonic Bose-Einstein condensation (BEC) in practical materials poses great challenges, because of strict constraints in symmetry, exciton binding, lifetime, and interaction. Here, using first-principles methods and symmetry analysis, we propose a new route to realize high-temperature excitonic BEC in centrosymmetric 2D materials, exploiting the parity symmetry of band edges and reduced Coulomb screening. We demonstrate it by taking monolayer TiS as an example, whose lowest-energy exciton shows small exciton mass, small Bohr radius, large binding, and long lifetime simultaneously.

Two-dimensional magnetic materials: structures, properties and external controls.

Since the discovery of intrinsic ferromagnetism in atomically thin Cr2Gr2Te6 and CrI3 in 2017, research on two-dimensional (2D) magnetic materials has become a highlighted topic. Based on 2D magnetic materials and their heterostructures, exotic physical phenomena at the atomically thin limit have been discovered, such as the quantum anomalous Hall effect, magneto-electric multiferroics, and magnon valleytronics. Furthermore, magnetism in these ultrathin magnets can be effectively controlled by external perturbations, such as electric field, strain, doping, chemical functionalization, and stacking engineering.

Real-Time Observing Ultrafast Carrier and Phonon Dynamics in Colloidal Tin Chalcogenide van der Waals Nanosheets.

Because of their earth-abundant, low-cost, and environmentally benign characteristics, two-dimensional (2D) group IV metal chalcogenides (e.g., SnSe) with layered structures have shown great potential in optoelectronic, photovoltaic, and thermoelectric applications.

Multifunctional Interlayer Based on Molybdenum Diphosphide Catalyst and Carbon Nanotube Film for Lithium-Sulfur Batteries.

A multifunctional interlayer, composed of molybdenum diphosphide (MoP ) nanoparticles and a carbon nanotube (CNT) film, is introduced into a lithium-sulfur (Li-S) battery system to suppress polysulfide migration. Molybdenum diphosphide acts as the catalyst and can capture polysulfides and improve the polysulfide conversion activity during the discharge/charge processes. The CNT film acts as a conductive skeleton to support the MoP nanoparticles and to ensure their uniform distribution.

Deterministic Role of Concentration Surplus of Cation Vacancy over Anion Vacancy in Bipolar Memristive NiO.

Migration of oxygen vacancies has been proposed to play an important role in the bipolar memristive behaviors because oxygen vacancies can directly determine the local conductivity in many systems. However, a recent theoretical work demonstrated that both migration of oxygen vacancies and coexistence of cation and anion vacancies are crucial to the occurrence of bipolar memristive switching, normally observed in the small-sized NiO. So far, experimental work addressing this issue is still lacking.

Occurrence, molecular characterization and predominant genotypes of Enterocytozoon bieneusi in dairy cattle in Henan and Ningxia, China.

Background: Enterocytozoon bieneusi is the most frequently diagnosed microsporidian species in humans and a wide range of animals. This study was conducted to assess the prevalence and molecular characteristics of E. bieneusi in dairy cattle in Henan Province of central China and the Ningxia Hui Autonomous Region of northwest China.

Zoonotic Cryptosporidium spp. and Enterocytozoon bieneusi in pet chinchillas (Chinchilla lanigera) in China.

Cryptosporidium and Enterocytozoon bieneusi are the most prevalent protist pathogens responsible for inducing human and animal diseases worldwide. The aim of the present work was to determine the occurrence of Cryptosporidium spp. and E.

Multilocus genotyping of potentially zoonotic Giardia duodenalis in pet chinchillas (Chinchilla lanigera) in China.

Giardia duodenalis is a common protozoan that colonizes and reproduces in the small intestine, causing giardiasis. This parasite infects a wide range of vertebrate hosts, including humans, domestic animals and wildlife. It has been suggested that chinchillas (Chinchilla lanigera) kept as domestic pets are potential reservoirs for the zoonotic transmission of G.

Cryptosporidiosis caused by Cryptosporidium parvum subtype IIdA15G1 at a dairy farm in Northwestern China.

Background: Cryptosporidium spp. are zoonotic parasites responsible for diarrhoeal diseases in animals and humans worldwide. Cattle are the most common mammalian species in which Cryptosporidium is detected, with pre-weaned calves considered to be reservoirs for zoonotic C.

Evolution of Ni nanofilaments and electromagnetic coupling in the resistive switching of NiO.

Resistive switching effect in conductor/insulator/conductor thin-film stacks is promising for resistance random access memory with high-density, fast speed, low power dissipation and high endurance, as well as novel computer logic architectures. NiO is a model system for the resistive switching effect and the formation/rupture of Ni nanofilaments is considered to be essential. However, it is not clear how the nanofilaments evolve in the switching process.