Showing papers by "Henan Normal University published in 2023"

Nickel iron alloy embedded, nitrogen doped porous carbon catalyst for efficient water electrolysis

Abstract: Metal-support electronic interaction is a feasible way to enhance the catalytic activity and bifunctionality for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER), and further the easily water electrolysis for hydrogen production at low cost. Herein, NiFe alloy embedded in N doped carbon support hybrid ([email protected]) was prepared by pyrolysis of metal ions impregnated bamboo precursor. In this [email protected] hybrid, the surface (oxy)hydroxide layer of alloy led to high OER efficiency (overpotential of 270 mV at 10 mA cm−2), and the alloy-support interaction enabled high catalytic efficiency for HER (overpotential of 206 mV at −10 mA cm−2). Benefitted by the bifunctional features, the symmetric water electrolyzer based on two identical [email protected] electrodes demonstrated acceptable input voltage and high faradaic efficiencies (FEs) for water electrolysis. The current work offers a feasible showcase for fulfilling of bifunctional catalyses in water electrolysis via the metal-support electronic interaction.

Status of the singlino-dominated dark matter in general Next-to-Minimal Supersymmetric Standard Model

Abstract: With the rapid progress of dark matter direct detection experiments, the attractiveness of the popular bino-dominated dark matter in economical supersymmetric theories is fading. As an alternative, the singlino-dominated dark matter in general Next-to-Minimal Supersymmetric Standard Model (NMSSM) is paying due attention. This scenario has the following distinct characteristics: free from the tadpole problem and the domain-wall problem of the NMSSM with a $Z_3$-symmetry, predicting more stable vacuum states than the $Z_3$-NMSSM, capable of forming an economical secluded dark matter sector to yield the dark matter experimental results naturally, and readily weaken the restrictions from the LHC search for SUSY. Consequently, it can explain the muon g-2 anomaly in broad parameter space that agrees with various experimental results while simultaneously breaking the electroweak symmetry naturally. In this study, we show in detail how the scenario coincides with the experiments, such as the SUSY search at the LHC, the dark matter search by the LZ experiment, and the improved measurement of the muon g-2. We provide a simple and clear picture of the physics inherent in the general NMSSM.

Catalytic Asymmetric Hydrophosphinylation of 2‐Vinylazaarenes to Access P‐Chiral 2‐Azaaryl‐Ethylphosphine Oxides

Abstract: A chiral Brønsted acid-catalysed asymmetric hydrophosphinylation of 2-vinylazaarenes by secondary phosphine oxides is described. A variety of P-chiral 2-azaaryl-ethylphosphine oxides are synthesized with high yields and ees, of which both the substituents of phosphines and azaarenes can be flexibly modulated, underscoring an exceptionally broad scope of substrates. These adducts are valuable to asymmetric metal catalysis since the resultant P-chiral tertiary phosphines from the reduction of them are verified as a kind of effective C1-symmetric chiral 1,5-hybrid P,N-ligands. Importantly, this catalysis platform enables the generic and efficient kinetic resolution of P-chiral secondary phosphine oxides. It thus provides an expedient approach to access the enantiomers of the P-chiral tertiary phosphine oxides derived from asymmetric hydrophosphinylation, further improving the utility of the method.

Synthetic K ⁺ Channels Constructed by Rebuilding the Core Modules of Natural K ⁺ Channels in an Artificial System

Abstract: Different types of natural K+ channels share similar core modules and cation permeability characteristics. In this study, we have developed novel artificial K+ channels by rebuilding the core modules of natural K+ channels in artificial systems. All the channels displayed high selectivity for K+ over Na+ and exhibited a selectivity sequence of K+≈Rb+ during the transport process, which is highly consistent with the cation permeability characteristics of natural K+ channels. More importantly, these artificial channels could be efficiently inserted into cell membranes and mediate the transmembrane transport of K+, disrupting the cellular K+ homeostasis and eventually triggering the apoptosis of cells. These findings demonstrate that, by rebuilding the core modules of natural K+ channels in artificial systems, the structures, transport behaviors, and physiological functions of natural K+ channels can be mimicked in synthetic channels.

Image steganalysis method based on cover selection and adaptive filtered residual network

Abstract: Image steganalysis aims to detect secret messages embedded in digital images. Nowadays, deep learning-based image steganalysis methods have achieved promising detection performance. However, few existing deep learning-based steganalysis methods take cover selection into consideration. While some networks only utilize fixed filter kernels, which make little use of the learning ability of the network. To alleviate the issue, we propose an image steganalysis method based on cover selection and adaptive filtered residual networks (CSRNet), which can be used for stego images classification. Firstly, we devise a cover selection method, which is specifically divided into two parts. One part is a gray-level co-generation matrix-based (GLCM) multi-scale texture complexity measure to quantify texture complexity. And the other is an inverse power law function-based (IPLF) learning curve, which can contribute to determining the number of selected cover images. Secondly, we design a deep learning steganalysis network based on adaptive filtered kernel and residual learning, which employs the cover-selected images for training, and utilizes the network powerful classification ability. Finally, based on BOSSbase 1.01 and BOWS2, the experimental results show that compared with the classical and state-of-the-art steganalysis methods, the proposed method can not only significantly improve the detection accuracy, but also reduce time-space cost.

Porous Covalent Organic Framework Based Hydrogen‐Bond Nanotrap for the Precise Recognition and Separation of Gold

Abstract: Utilizing weak interactions to effectively recover and separate precious metals in solution is of great importance but the practice remains a challenge. Herein, we report a novel strategy to achieve precise recognition and separation of gold by regulating the hydrogen-bond (H-bond) nanotrap within the pore of covalent organic frameworks (COFs). It is found that both COF-HNU25 and COF-HNU26 can efficiently capture AuIII with fast kinetics, high selectivity, and uptake capacity. In particular, the COF-HNU25 with the high density of H-bond nanotraps exhibits an excellent gold uptake capacity of 1725 mg g−1, which is significantly higher than that (219 mg g−1) of its isostructural COF (COF-42) without H-bond nanostrap in the pores. Importantly, the uptake capacity is strongly correlated to the number of H-bonds between phenolic OH in the COF and [AuCl4]− in water, and multiple H-bond interactions are the key driving force for the excellent gold recovery and reusability of the adsorbent.

Metal-Free Photoredox Intramolecular Cyclization of N-Aryl Acrylamides

Abstract: A novel metal-free photoredox-catalyzed cyclization reaction of N-aryl acrylamide is herein reported that provides synthetically valuable oxindole derivatives through the bis-mediation of H2O and aldehyde. In this work, sustainable visible light was used as the energy source, and the organic light-emitting molecule 4CzIPN served as the efficient photocatalyst. The main characteristics of this reaction are environmentally friendly and high yields.

Understanding the Synthesis Kinetics of Single‐Crystal Co‐Free Ni‐Rich Cathodes

Abstract: Non-equilibrium kinetic intermediates are usually preferentially generated instead of thermodynamic stable phases in the solid-state synthesis of layered oxides. Understanding the inherent complexity between thermodynamics and kinetics is important for designing high cationic ordering cathodes. Single-crystal strategy is an effective way to solve the intrinsic chemo-mechanical problems of Ni-rich cathodes. However, the synthesis of high-performance single-crystal is very challenging. Herein, the kinetic reaction path and the formation mechanism of non-equilibrium intermediates in the synthesis of single-crystal Co-free Ni-rich were explored. We demonstrate that the formation of non-equilibrium intermediate and the electrochemical-thermo-mechanical failure can be effectively inhibited by driving low-temperature topotactic lithiation. This work provides a basis for designing high-performance single-crystal Ni-rich layered oxides by regulating the defective structures.

Euler-Maruyama Scheme for SDEs with Dini Continuous Coefficients

Abstract: In the study of Euler-Maruyama scheme for Stochastic Differential Equations, researchers focus on the convergence rate under different conditions, using analytical methods and Stochastic Partial Differential Equation. One of them is to study the Lipschitz continuous, mainly from drift coefficient and diffusion coefficient. The other is the study of non-Lipschitz continuous, since most of the real life is not Lipschitz continuous. Therefore, most researchers are looking at non-Lipschitz continuous. In my study, without loss of generality, we are also a continuous study of non-Lipschitz and a faster convergence rate. In this paper, we show the convergence rate of Euler-Maruyama scheme for non-degenerate SDEs where the drift term b and the diffusion term σ are the uniformly bounded, b and σ satisfy correlated conditions of Dini-continuous, by the aid of the regularity of the solution to the associated Kolmogorov equation of SPDE and common methods in stochastic analysis, including Itô’s formula, Jensen’s inequality, Hölder inequality BDG’s inequality, Gronwall’s inequality. We obtain the same conclusions by weakening the conditions of previous research using the properties of Dini continuous and Taylor expansion. At the same time, we also reached the same conclusion under local boundedness and local Dini-continuous. Moreover, my research results have laid the groundwork for the follow-up research.

Welcome to Fluorescent Chemosensors

Abstract: We would like to welcome you to the wonderful world of fluorescent chemosensors. This book consists of 16 chapters that take you on a journey from receptor-based to reaction-based sensing systems. The quest includes both molecular-based and nanoparticle-based systems that can be used for medical diagnostics, theranostics and environmental sensing applications. The techniques included embrace two-photon fluorescence, ratiometric and aggregation-induced emission.

Overview of CircRNAs Roles and Mechanisms in Liver Fibrosis

Abstract: Liver fibrosis represents the reversible pathological process with the feature of the over-accumulation of extracellular matrix (ECM) proteins within the liver, which results in the deposition of fibrotic tissues and liver dysfunction. Circular noncoding RNAs (CircRNAs) have the characteristic closed loop structures, which show high resistance to exonuclease RNase, making them far more stable and recalcitrant against degradation. CircRNAs increase target gene levels by playing the role of a microRNA (miRNA) sponge. Further, they combine with proteins or play the role of RNA scaffolds or translate proteins to modulate different biological processes. Recent studies have indicated that CircRNAs play an important role in the occurrence and progression of liver fibrosis and may be the potential diagnostic and prognostic markers for liver fibrosis. This review summarizes the CircRNAs roles and explores their underlying mechanisms, with a special focus on some of the latest research into key CircRNAs related to regulating liver fibrosis. Results in this work may inspire fruitful research directions and applications of CircRNAs in the management of liver fibrosis. Additionally, our findings lay a critical theoretical foundation for applying CircRNAs in diagnosing and treating liver fibrosis.