71 research outputs found
UV-Assisted Room-Temperature Fabrication of Lignin-Based Nanosilver Complexes for Photothermal-Mediated Sterilization
Green and controllable preparation of silver nanoparticles
(AgNPs)
remains a great challenge. In this work, ethanol-extracted lignin-based
nanosilver composites (AgNPs@EL) were synthesized at room temperature
with the assistance of ultraviolet (UV) radiation. The ethanol-extracted
lignin (EL) could serve as natural dispersion carriers and reducing
agents for AgNPs. The reducing ability of EL could be further improved
under UV irradiation, which enables the rapid synthesis of AgNPs at
room temperature. More importantly, due to the good photothermal conversion
capacity of EL, AgNPs@EL exhibits remarkably enhanced photothermal
performance and excellent photothermal antibacterial ability, which
could cause 7.2 and 5.3 log10 CFU/mL reduction against Escherichia coli and Staphylococcus
aureus, respectively, under near-infrared (NIR) irradiation
(808 nm, 1.8 W/cm2) for 5 min. Furthermore, the composite
film obtained by impregnating bacterial cellulose onto AgNPs@EL solution
also shows significantly improved mechanical properties and photothermal
antimicrobial activity. Therefore, this work may provide insights
into the design of lignin-based photothermal-mediated antimicrobial
materials
Local and global point sampling for structured point cloud simplification
A new method is proposed...</p
Regression results of dynamic panel model under system GMM model.
Regression results of dynamic panel model under system GMM model.</p
Regression results of analyst ratings on stock price collapse risk.
Regression results of analyst ratings on stock price collapse risk.</p
The moderating effect of information disclosure quality.
The moderating effect of information disclosure quality.</p
Analyst rating, quality of information disclosure and robustness test of stock price collapse risk.
Analyst rating, quality of information disclosure and robustness test of stock price collapse risk.</p
Variable definition.
This study selects stock data of listed companies in China’s A-share stock market from 2011 to 2020 as research samples. Using a fixed-effects model, it examines the impact of analyst optimism on stock price collapses and the moderating effect of information disclosure quality. Simultaneously, it conducts additional research to explore the potential transmission mechanisms involved. The main findings are as follows: Firstly, a positive correlation exists between analyst optimism and the risk of stock price collapse. Secondly, improving information disclosure quality of listed companies can enhance the positive impact of analyst optimism on the risk of stock price collapses and expedite the market’s adjustment of overly optimistic valuations of listed companies. Additionally, analyst optimism can increase the risk of stock price collapses by affecting institutional ownership. These findings provide theoretical support for regulatory authorities to revise and improve the "information disclosure evaluation" system, regulate the analyst industry, guide analyst behavior, and encourage listed companies to enhance internal governance and improve information disclosure practices.</div
Surface Acidity and As(V) Complexation of Iron Oxyhydroxides: Insights from First-Principles Molecular Dynamics Simulations
Iron hydroxides are ubiquitous in
soils and aquifers and have been
adopted as adsorbents for As(V) removal. However, the complexation
mechanisms of As(V) have not been well understood due to the lack
of information on the reactive sites and acidities of iron hydroxides.
In this work, we first calculated the acidity constants (pKas) of surface groups on lepidocrocite (010),
(001), and (100) surfaces by using the first-principles molecular
dynamics (FPMD)-based vertical energy gap method. Then, the desorption
free energies of As(V) on goethite (110) and lepidocrocite (001) surfaces
were calculated by using constrained FPMD simulations. The point of
zero charges and reactive sites of individual surfaces were obtained
based on the calculated pKas. The structures,
thermodynamics, and pH dependence for As(V) complexation were derived
by integrating the pKas and desorption
free energies. The pKa data sets obtained
are fundamental parameters that control the charging and adsorption
behavior of iron oxyhydroxides and will be very useful in investigating
the adsorption processes on these minerals. The pH-dependent complexation
mechanisms of As(V) derived in this study would be helpful for the
development of effective adsorbent materials and the prediction of
the long-term behavior of As(V) in natural environments
Descriptive statistics of variables.
This study selects stock data of listed companies in China’s A-share stock market from 2011 to 2020 as research samples. Using a fixed-effects model, it examines the impact of analyst optimism on stock price collapses and the moderating effect of information disclosure quality. Simultaneously, it conducts additional research to explore the potential transmission mechanisms involved. The main findings are as follows: Firstly, a positive correlation exists between analyst optimism and the risk of stock price collapse. Secondly, improving information disclosure quality of listed companies can enhance the positive impact of analyst optimism on the risk of stock price collapses and expedite the market’s adjustment of overly optimistic valuations of listed companies. Additionally, analyst optimism can increase the risk of stock price collapses by affecting institutional ownership. These findings provide theoretical support for regulatory authorities to revise and improve the "information disclosure evaluation" system, regulate the analyst industry, guide analyst behavior, and encourage listed companies to enhance internal governance and improve information disclosure practices.</div
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