Further screening of SNP loci of eggshell translucency related genes and evaluation of genetic effects.

Eggshell translucency is a widespread issue in the field of egg quality. Previous research has established that the heritability of eggshell translucency is relatively low or moderate. Scientists have also successfully identified SNP loci related to eggshell translucency on different chromosomes by using gene chips and single-variant GWAS.

Melatonin alleviates endoplasmic reticulum stress to improve ovarian function by regulating the mTOR pathway in aged laying hens.

Granular cell apoptosis is a key factor leading to follicular atresia and decreased laying rate in aged laying hens. Endoplasmic reticulum stress (ERS) induced cell apoptosis is a new type of apoptosis pathway. Previous studies have shown that the ERS pathway is involved in the regulation of follicular development and atresia, and can be regulated by mTOR.

Helicity-resolved Raman scattering of MoS bulk crystal.

Helicity-resolved Raman spectroscopy (HRRS) can effectively distinguish the Raman modes of two-dimensional (2D) layered materials by phonon symmetry. In this paper, we systematically investigated the phonon helicity selection of basal and edge planes of MoS bulk by HRRS. We find that the symmetry of the crystal structure changes the helicity selection of the E, E , and A modes in the edge plane.

Intralayer Phonons in Multilayer Graphene Moiré Superlattices.

Moiré pattern in twisted multilayers (tMLs) induces many emergent phenomena by subtle variation of atomic registry to modulate quasiparticles and their interactions, such as superconductivity, moiré excitons, and moiré phonons. The periodic superlattice potential introduced by moiré pattern also underlies patterned interlayer coupling at the interface of tMLs. Although this arising patterned interfacial coupling is much weaker than in-plane atomic interactions, it is crucial in moiré systems, as captured by the renormalized interlayer phonons in twisted bilayer transitional metal dichalcogenides.

Phonon and Exciton Properties between WS and MoS Layers via Inversion Heterostructure Engineering.

Recently, two-dimensional (2D) van der Waals heterostructures (vdWHs) have exhibited emergent electronic and optical properties due to their peculiar phonons and excitons, which lay the foundation for the development of photoelectronic devices. The dielectric environment plays an important role in the interlayer coupling of vdWHs. Here, we studied the interlayer and extra-layer dielectric effects on phonon and exciton properties in WS/MoS and MoS/WS vdWHs by Raman and photoluminescence (PL) spectroscopy.

Magneto-Raman Study of Magnon-Phonon Coupling in Two-Dimensional Ising Antiferromagnetic FePS.

Recently, the coupling between magnons (quanta of spin waves) and phonons (quanta of lattice vibrations) in two-dimensional (2D) antiferromagnet FePS offers a myriad of applications ranging from spintronic devices to quantum information technologies. However, the reported magnon-phonon coupling in the FePS flake using Raman measurements requires an ultrahigh magnetic field up to 30 T. Here, we investigate the magnon-phonon coupling in FePS by near-resonant magneto-Raman spectroscopy under a relatively small magnetic field (|| ≤ 9 T).

Donor-Acceptor Pair Quantum Emitters in Hexagonal Boron Nitride.

Quantum emitters are needed for a myriad of applications ranging from quantum sensing to quantum computing. Hexagonal boron nitride (hBN) quantum emitters are one of the most promising solid-state platforms to date due to their high brightness and stability and the possibility of a spin-photon interface. However, the understanding of the physical origins of the single-photon emitters (SPEs) is still limited.

A tunable Raman system based on ultrafast laser for Raman excitation profile measurement.

The measurement of the Raman excitation profile (REP) is of great importance to obtain the energies of van Hove singularities and the lifetime of the excited state involved in the Raman process of semiconductors. In this Note, we develop a simple tunable Raman system based on an ultrafast laser and tunable Raman filters for REP measurement. The system is testified by measuring REP of twisted bilayer graphene, and the corresponding energy of van Hove singularity is determined.

Understanding angle-resolved polarized Raman scattering from black phosphorus at normal and oblique laser incidences.

The selection rule for angle-resolved polarized Raman (ARPR) intensity of phonons from standard group-theoretical method in isotropic materials would break down in anisotropic layered materials (ALMs) due to birefringence and linear dichroism effects. The two effects result in depth-dependent polarization and intensity of incident laser and scattered signal inside ALMs and thus make a challenge to predict ARPR intensity at any laser incidence direction. Herein, taking in-plane anisotropic black phosphorus as a prototype, we developed a so-called birefringence-linear-dichroism (BLD) model to quantitatively understand its ARPR intensity at both normal and oblique laser incidences by the same set of real Raman tensors for certain laser excitation.

Observation of nonreciprocal magnetophonon effect in nonencapsulated few-layered CrI.

"Magneto-optical" effect refers to a rotation of polarization plane, which has been widely studied in traditional ferromagnetic metal and insulator films and scarcely in two-dimensional layered materials. Here, we uncover a new nonreciprocal magnetophonon Raman scattering effect in ferromagnetic few-layer CrI We observed a rotation of the polarization plane of inelastically scattered light between -20 and +60 that are tunable by an out-of-plane magnetic field from -2.5 to 2.

Cross-dimensional electron-phonon coupling in van der Waals heterostructures.

The electron-phonon coupling (EPC) in a material is at the frontier of the fundamental research, underlying many quantum behaviors. van der Waals heterostructures (vdWHs) provide an ideal platform to reveal the intrinsic interaction between their electrons and phonons. In particular, the flexible van der Waals stacking of different atomic crystals leads to multiple opportunities to engineer the interlayer phonon modes for EPC.

Probing the Magnetic Ordering of Antiferromagnetic MnPS by Raman Spectroscopy.

Ferromagnetic/antiferromagnetic materials are of crucial importance in information storage and spintronics devices. Herein we present a comprehensive study of 2D Heisenberg-like antiferromagnetic material MnPS by optical contrast and Raman spectroscopy. We propose a criterion of 0.

Research progress on international studies on applied ecology based on Web of Science.

Applied ecology is one of the most important scientific and technological tools for natural resources management and environment protection. Under the current situation of natural resource shortage, serious environmental pollution, and ecosystem degradation, understanding the theoretical basis, research methods and research hotspots of international studies on applied ecology is of great significance for consolidating the knowledge base, indicating the research direction, defining the strategic position of China's studies on applied ecology. Based on the principle of bibliometrics and information visualization software (CiteSpace and Carrot), we took two document datasets as research objects which were searched from Web of Science based on different search strategies in the field of international studies on applied ecology from 1980 to 2018.

Phonon-Assisted Photoluminescence Up-Conversion of Silicon-Vacancy Centers in Diamond.

Phonon-assisted anti-Stokes photoluminescence (ASPL) up-conversion lies at the heart of optical refrigeration in solids. The thermal energy contained in the lattice vibrations is taken away by the emitted anti-Stokes photons' ASPL process, resulting in laser cooling of solids. To date, net laser cooling of solids is limited in rare-earth (RE)-doped crystals, glasses, and direct band gap semiconductors.

Stokes and anti-Stokes Raman scattering in mono- and bilayer graphene.

Stokes and anti-Stokes Raman spectroscopy associated with the intervalley double resonance process in carbon materials is a unique technique to reveal the relationship between their characteristic electronic band structures and phonon dispersion. In graphene, the dominant resonant behavior for its 2D mode is an intervalley triple resonance Raman process. In this paper, we report the Stokes and anti-Stokes Raman scattering of the 2D mode in pristine graphene.

The phonon confinement effect in two-dimensional nanocrystals of black phosphorus with anisotropic phonon dispersions.

The RWL model for the phonon confinement effect in nanocrystals (NCs) had been found to result in deviations and limitations for crystals exhibiting obvious anisotropic phonon dispersions and modified models have been proposed to overcome these deficiencies. Here, we examine this issue in black phosphorus (BP), a typical anisotropic two-dimensional crystal exhibiting pronounced anisotropy in phonon dispersions. A detailed study is performed on the Raman spectra of BP NCs prepared by the ion implantation technique.

Damage-free and rapid transfer of CVD-grown two-dimensional transition metal dichalcogenides by dissolving sacrificial water-soluble layers.

As one of the most important family members of two-dimensional (2D) materials, the growth and damage-free transfer of transition metal dichalcogenides (TMDs) play crucial roles in their future applications. Here, we report a damage-free and highly efficient approach to transfer single and few-layer 2D TMDs to arbitrary substrates by dissolving a sacrificial water-soluble layer, which is formed underneath 2D TMD flakes simultaneously during the growth process. It is demonstrated, for monolayer MoS, that no quality degradation is found after the transfer by performing transmission electron microscopy, Raman spectroscopy, photoluminescence and electrical transport studies.

Interfacial Interactions in van der Waals Heterostructures of MoS and Graphene.

Interfacial coupling between neighboring layers of van der Waals heterostructures (vdWHs), formed by vertically stacking more than two types of two-dimensional materials (2DMs), greatly affects their physical properties and device performance. Although high-resolution cross-sectional scanning tunneling electron microscopy can directly image the atomically sharp interfaces in the vdWHs, the interfacial coupling and lattice dynamics of vdWHs formed by two different types of 2DMs, such as semimetal and semiconductor, are not clear so far. Here, we report the ultralow-frequency Raman spectroscopy investigation on interfacial couplings in the vdWHs formed by graphene and MoS flakes.

Filter-based ultralow-frequency Raman measurement down to 2 cm for fast Brillouin spectroscopy measurement.

Simultaneous Stokes and anti-Stokes ultralow-frequency (ULF) Raman measurement down to ∼2 cm or 60 GHz is realized by a single-stage spectrometer in combination with volume-Bragg-grating-based notch filters. This system reveals its excellent performance by probing Brillouin signal of acoustic phonons in silicon, germanium, gallium arsenide, and gallium nitride. The deduced sound velocity and elastic constants are in good accordance with previous results determined by various methods.

[Spatial scale effect of land use landscape pattern in Yongdeng County, Gansu Province, China.].

Based on "patch-corridor-matrix" pattern, spatial scale effect of landscape pattern was studied in Yongdeng County of Lanzhou City, Gansu Province, China. The results showed that the grassland was the matrix of landscape structure in the studied area, road and river played the corridor role, and the other landscape elements (cultivated land, forest land, garden land, residential land, industrial and mineral land, public management and service land, and the other land) acted as patches. The patch level index and the landscape level index all showed obvious dependence on spatial extent.

Layer number identification of intrinsic and defective multilayered graphenes up to 100 layers by the Raman mode intensity from substrates.

An SiO2/Si substrate has been widely used to support two-dimensional (2d) flakes grown by chemical vapor deposition or prepared by micromechanical cleavage. The Raman intensity of the vibration modes of 2d flakes is used to identify the layer number of 2d flakes on the SiO2/Si substrate, however, such an intensity is usually dependent on the flake quality, crystal orientation and laser polarization. Here, we used graphene flakes, a prototype system, to demonstrate how to use the intensity ratio between the Si peak from SiO2/Si substrates underneath graphene flakes and that from bare SiO2/Si substrates for the layer-number identification of graphene flakes up to 100 layers.