Publications by authors named "Botao Fu"

Based on the elastic-plastic theory, the analytical formula of the second invariant J of deviatoric stress at any point around the circular roadway under the non-uniform stress field is derived. The distribution law of J of surrounding rock under the three-dimensional non-isobaric stress field is studied by theoretical analysis and numerical simulation. Combined with the butterfly failure theory of surrounding rock of roadway, the close relationship between the distribution pattern of J and the distribution pattern of plastic zone is found, and the failure mechanism of surrounding rock is revealed.

View Article and Find Full Text PDF

Establishing strong seepage stability for tailings dams is crucial for ensuring their safety and mitigating the risk of failure. This study developed a three-dimensional seepage numerical model using finite element numerical computation for four different elevation conditions (5070 m, 5081 m, 5159 m, and 5213 m) encompassing the pond area and dam body. Seepage calculations were conducted under normal and flooding conditions, and the tailings pond's seepage stability was assessed for various stacking scenarios.

View Article and Find Full Text PDF
Article Synopsis
  • Thin film lithium niobate (TFLN) is gaining attention as a key material for photonic integrated circuits (PICs), particularly for on-chip lasers with narrow linewidths, crucial for high-speed communications and other advanced applications.
  • Recent advancements highlight the integration of TFLN with III-V semiconductors to develop compact, electrically tunable laser sources, addressing a significant gap in high-power laser research on TFLN platforms.
  • The review covers the current landscape of external cavity semiconductor lasers (ECSLs) and explores various TFLN-based photonic structures, concluding with insights and future directions for the TFLN PIC industry.
View Article and Find Full Text PDF

The diet in early life is essential for the growth and intestinal health later in life. However, beneficial effects of a diet enriched in branched short-chain fatty acids (BSCFAs) for infants are ambiguous. This study aimed to develop a novel fermented protein food, enriched with BSCFAs and assess the effects of dry and wet ferment products on young pig development, nutrient absorption, intestinal barrier function, and gut microbiota and metabolites.

View Article and Find Full Text PDF

The presence of lenses such as tailings slurry, frozen soil, and saturated zones disrupts the continuity of tailings dams and their normal seepage patterns, elevating the seepage line of the dam body and significantly impacting local stability. This study, to investigate how lenses affect the stability and failure mechanisms of tailings dams, employs numerical simulation and physical models and constructs a model of the tailings dam, incorporating tailings clay lens and void lens, to investigate variations in hydraulic gradients, seepage velocities, seepage flow, pore water pressure, and the patterns of seepage failure. This research reveals that the tailings clay lens within the dam body increases the hydraulic gradient in its vicinity due to its low permeability and raises the phreatic line.

View Article and Find Full Text PDF

We investigate the femtosecond laser ablation of copper with a dual-color double-pulse femtosecond laser at the wavelengths of 515 nm and 1030 nm. By properly choosing the energy of the 515 nm pulse, the optical properties such as surface reflectivity and absorption coefficient on copper surface can be modified to increase the absorption of the subsequent 1030 nm pulse. The ablation depth of dual-color double-pulse laser is at least 50% higher than the total ablation depth of both the 515 nm and 1030 nm pulses, provided that the inter-pulse delay of the double-pulse laser is within the electron-phonon coupling time.

View Article and Find Full Text PDF

Two-dimensional (2D) XY magnets with easy magnetization planes support the nontrivial topological spin textures whose dissipationless transport is highly desirable for 2D spintronic devices. Here, we predicted that Janus monolayer VXN (X = P, As) with a square lattice is a 2D-XY ferromagnet using first-principles calculations. Both magnetocrystalline anisotropy and magnetic shape anisotropy favor an in-plane magnetization, leading to an easy magnetization -plane in Janus monolayer VXN.

View Article and Find Full Text PDF

Hydrogen, a simple and magic element, has attracted increasing attention for its effective incorporation within solids and powerful manipulation of electronic states. Here, we show that hydrogenation tackles common problems in two-dimensional borophene, e.g.

View Article and Find Full Text PDF

We develop a background-free single-beam coherent Raman scattering technique enabling the high-sensitivity detection of greenhouse gases. In this scheme, Raman coherence prepared by a femtosecond laser is interrogated by self-generated narrowband air lasing, thus allowing single-beam measurements without complex pulse shaping. The unique temporal and spectral characteristics of air lasing are beneficial for improving the signal-to-noise ratio and spectral resolution of Raman signals.

View Article and Find Full Text PDF

Quantum coherence in quantum optics is an essential part of optical information processing and light manipulation. Alkali metal vapors, despite the numerous shortcomings, are traditionally used in quantum optics as a working medium due to convenient near-infrared excitation, strong dipole transitions and long-lived coherence. Here, we proposed and experimentally demonstrated photon retention and subsequent re-emittance with the quantum coherence in a system of coherently excited molecular nitrogen ions (N) which are produced using a strong 800 nm femtosecond laser pulse.

View Article and Find Full Text PDF

Based on first principles calculations, we propose a new 2D ferroelectric material, triple-layer (TL) LaOBiS2, with an ultrahigh carrier mobility over 40 000 cm2 V-1 s-1 and large sunlight absorption. TL-LaOBiS2 is composed of a middle LaO layer and top-and-bottom BiS2 layers that can be possibly exfoliated from its bulk counterpart. We reveal that each BiS2 layer can hold spontaneous in-plane ferroelectric polarization that can be further enhanced by imposing extensive strain.

View Article and Find Full Text PDF

Two-dimensional (2D) materials have attracted great attention and spurred rapid development in both fundamental research and device applications. The search for exotic physical properties, such as magnetic and topological order, in 2D materials could enable the realization of novel quantum devices and is therefore at the forefront of materials science. Here, we report the discovery of twofold degenerate Weyl nodal lines in a 2D ferromagnetic material, a single-layer gadolinium-silver compound, based on combined angle-resolved photoemission spectroscopy measurements and theoretical calculations.

View Article and Find Full Text PDF

On the basis of ab initio calculations and a low-energy effective k· p model, we propose a Weyl nodal point-line (WNPL) fermion, composed of 0D Weyl points and a 1D Weyl nodal line, in the ferromagnetic material EuBi. In the absence of spin-orbital coupling (SOC), the spin-up bands host a pair of triply degenerate points together with a bird-cage-like node structure. In the presence of SOC with (001) magnetization, each triplet point splits into a double Weyl point and a single Weyl point accompanied by two nodal rings, forming two sets of WNPL fermions near the Fermi level.

View Article and Find Full Text PDF

Topological nodal line semimetals, a novel quantum state of materials, possess topologically nontrivial valence and conduction bands that touch at a line near the Fermi level. The exotic band structure can lead to various novel properties, such as long-range Coulomb interaction and flat Landau levels. Recently, topological nodal lines have been observed in several bulk materials, such as PtSn, ZrSiS, TlTaSe and PbTaSe.

View Article and Find Full Text PDF

Background: A randomized, double-blind, placebo-controlled multicenter trial was conducted in healthy Chinese infants to assess the efficacy and safety of a pentavalent live human-bovine reassortant rotavirus vaccine (RotaTeq™, RV5) against rotavirus gastroenteritis (RVGE).

Methods: 4040 participants aged 6-12weeks were enrolled and randomly assigned to either 3 oral doses of RV5 (n=2020) or placebo (n=2020), administered ∼4weeks apart. The participants also received OPV and DTaP in a concomitant or staggered fashion.

View Article and Find Full Text PDF

Based on DFT calculation, we predict that BiCN, i.e., bilayer Bi films passivated with -CN group, is a novel 2D Bi-based material with highly thermodynamic stability, and demonstrate that it is also a new kind of 2D TI with a giant SOC gap (~1 eV) by direct calculation of the topological invariant Z2 and obvious exhibition of the helical edge states.

View Article and Find Full Text PDF

This study evaluated the immunogenicity of the human rotavirus (RV) vaccine (RIX4414) when co-administered with routine childhood vaccines in Chinese infants (NCT01171963). Healthy infants aged 6-16 weeks received 2 doses of either RIX4414 or placebo according to a 0, 1-month schedule. Infants received routine diphtheria-tetanus-acellular pertussis (DTPa) and oral poliovirus (OPV) vaccines either separately from or concomitantly with RIX4414/placebo (separate and co-administration cohorts, respectively).

View Article and Find Full Text PDF

Rotaviruses (RV) are a major cause of severe gastroenteritis (GE) in children aged<5 y. For the first time in China, we assessed the efficacy of two oral doses of the human rotavirus vaccine (RIX4414) in infants during the first two years of life (113808/NCT01171963). Healthy infants aged 6-16 weeks were randomized (1:1) to receive two oral doses of either the RIX4414 vaccine/placebo according to a 0, 1 month schedule.

View Article and Find Full Text PDF

A PHP Error was encountered

Severity: Warning

Message: fopen(/var/lib/php/sessions/ci_session50nrek34n34f3f5lm202feqae0jmcc2d): Failed to open stream: No space left on device

Filename: drivers/Session_files_driver.php

Line Number: 177

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once

A PHP Error was encountered

Severity: Warning

Message: session_start(): Failed to read session data: user (path: /var/lib/php/sessions)

Filename: Session/Session.php

Line Number: 137

Backtrace:

File: /var/www/html/index.php
Line: 316
Function: require_once