Impact of organic interlayer anions on the CO2 adsorption performance of Mg-Al layered double hydroxides derived mixed oxides

Herein we report a systematical investigation on the promoting effect of the carbon chain length of the intercalated carboxylic anions on the COcapture performance of Mg-Al layer double hydroxides（LDHs）.A series of organo-LDHs were successfully synthesized via co-precipitation and calcination-rehydration methods. All as-prepared samples were characterized by many techniques including XRD, ATR-FTIR, BET,and TGA. The XRD and ATR-FTIR studies indicated that organic anions were successfully intercalated into LDHs. The influence of some important parameters such as calcination temperature, adsorption temperature, and coating with（Li-Na-K）NOmolten salt was investigated. The results exhibited that when the number of carbon is greater than 10, the COcapture capacity steadily increased with the increase in carbon number. After coating with 55 mol%（Li-Na-K）NOmolten salt, the COuptake of LDH-C16 sample with high Mg/Al ratios can be increased up to 3.25 mmol/g. The COadsorption/desorption cycling stability was also studied using temperature swing adsorption, which showed a stable COcapture performance even after 22 cycles. Considering its high COcapture capacity and good cycling stability, this novel COadsorbent is very promising in the sorption-enhanced water gas shift（SEWGS） processes.

Synthesis of layered double hydroxides/graphene oxide nanocomposite as a novel high-temperature CO_2 adsorbent

In this contribution, a novel high-temperature CO_2 adsorbent consisting of Mg-Al layered double hydroxide （LDH） and graphene oxide （GO） nanosheets was prepared and evaluated. The nanocomposite-type adsorbent was synthesized based on the electrostatically driven self-assembly between positively charged Mg-Al LDH single sheet and negatively charged GO monolayer. The characteristics of this novel adsorbent were investigated using XRD, FE-SEM, HRTEM, FT-IR, BET and TGA. The results showed that both the CO_2 adsorption capacity and the multi- cycle stability of LDH were increased with the addition of GO owing to the enhanced particle dispersion and stabilization. In particular, the absolute CO_2 capture capacity of LDH was increased by more than twice by adding 6.54 wt% GO as support. GO appeared to be especially effective for supporting LDH sheets. Moreover, the CO_2 capture capacity of the adsorbent could be further increased by doping with 15 wt% K_2CO_3. This work demonstrated a new approach for the preparation of LDH-based hybrid-type adsorbents for CO2 capture.

Is audit materiality informative?Evidence from China

To improve the usefulness of audit opinions,on 23 March 2021,the China Securities Regulatory Commission mandated that auditors disclose overall quantitative materiality of consolidated financial statements in special explanations of modified audit opinions.This paper selects Chinese A-share companies issued with modified audit opinions for the period of 2020-2022 as the research sample and analyzes the assessment of materiality in audit practice and the informativeness of audit materiality.Our findings are as follows.(1)The most commonly used bases for materiality by auditors are profit and income,with considerable differences in the percentages applied to the different bases and variations even within the same base.(2)The higher the materiality amount,the poorer the audit quality.This negative correlation is mainly observed in scenarios where the audited companies engage in downward earnings management and where the competency of audit firms or auditors is relatively low.(3)Companies that disclose quantitative materiality in the special explanations of modified audit opinions have a lower earnings response coefficient than companies that do not disclose audit materiality.This research sheds light on the“black box”of the audit process and verifies the information value of audit materiality.The conclusions are of significant value to auditing standard-setters,investors and regulators.

CFO变更与审计收费——声誉修复还是风险信号?

CFO作为财务信息最直接的负责人,对企业的财务及经营状况最为了解。本文基于审计师的视角,探究上市公司CFO变更究竟传递了企业的何种信号。研究发现,CFO变更与审计收费显著正相关,并且发生CFO变更企业的会计信息质量更低,审计师投入更多。分组检验发现,CFO变更与审计收费的正相关关系在CFO任期短和非国有企业的样本中更显著。进一步研究表明,CFO变更后,审计师仍然感知到企业存在较高的风险。上述结果表明,CFO变更释放了企业的风险信号。本文的研究结论为资本市场参与者识别上市公司的财务信息风险提供了直接的经验证据。

The effect of shared auditors in the supply chain on cost stickiness

Do supply chain audits have real effects?We focus on the effect of shared auditors in the supply chain on corporate cost stickiness.When a supplier shares auditors with its customers,the shared auditors provide informational advantages for suppliers’managers,thus revising their optimistic or pessimistic expectations and influencing suppliers’cost stickiness.Using a sample of Chinese A-share listed companies from 2009 to 2017,we explore the relationship between shared auditors and suppliers’cost stickiness conditional on management expectations.The results show that shared auditors in the supply chain reduce suppliers’cost stickiness significantly when suppliers’managers hold optimistic expectations,and increase suppliers’cost stickiness in cases of pessimistic expectations.Furthermore,the greater the number of shared auditors,the stronger the effect.Such effects are more pronounced when supplier firms share auditors with important customers,have higher demand uncertainty,and use big 10 auditors.

Preparation and evaluation of aminopropyl-functionalized manganese-loaded SBA-15 for copper removal from aqueous solution

A novel material, aminopropyl-functionalized manganese-loaded SBA-15（NH2-Mn-SBA-15）, was synthesized by bonding 3-aminopropyl trimethoxysilane（APTMS） onto manganeseloaded SBA-15（Mn-SBA-15） and used as a Cu2＋adsorbent in aqueous solution. Fourier transform infrared spectroscopy（FT-IR）, X-ray diffraction spectra（XRD）, N2adsorption/desorption isotherms, high resolution field emission scanning electron microscopy（FESEM）and X-ray photoelectron spectroscopy（XPS） were used to characterize the NH2-Mn-SBA-15.The ordered mesoporous structure of SBA-15 was remained after modification. The manganese oxides were mainly loaded on the internal surface of the pore channels while the aminopropyl groups were mainly anchored on the external surface of SBA-15. The adsorption of Cu2＋on NH2-Mn-SBA-15 was fitted well by the Langmuir equation and the maximum adsorption capacity of NH2-Mn-SBA-15 for Cu2＋was over two times higher than that of Mn-SBA-15 under the same conditions. The Elovich equation gave a good fit for the adsorption process of Cu2＋by NH2-Mn-SBA-15 and Mn-SBA-15. Both the loaded manganese oxides and the anchored aminopropyl groups were found to contribute to the uptake of Cu2＋. The NH2-Mn-SBA-15 showed high selectivity for copper ions. Consecutive adsorption–desorption experiments showed that the NH2-Mn-SBA-15 could be regenerated by acid treatment without altering its properties.

The impact of the Social Security Fund on auditor litigation risk

In this study,we examine the effect of the Social Security Fund on auditor litigation risk.Using audit fees as a proxy for auditor perceptions of litigation risk,we find that the Social Security Fund significantly reduces auditor litigation risk.Furthermore,we show that the Social Security Fund influences auditor litigation risk through reducing both the audit risk and the business risk of public companies.In addition,the impact of the Social Security Fund for reducing auditor litigation risk is more obvious in the group of firms with low levels of internal governance,which indicates that the Social Security Fund plays an important governance role as a high-quality institutional investor.In summary,we verify that the Social Security Fund,when acting as an institutional investor,plays an important role in corporate governance,and that it helps to reduce auditor litigation risk.Our results provide empirical support for expanding the governance role of the Social Security Fund as an institutional investor in China’s A-share market.