Pseudomorphic amorphization of three-dimensional superlattices through morphological transformation of nanocrystal building blocks.

Nanocrystal (NC) superlattices (SLs) have been widely studied as a new class of functional mesoscopic materials with collective physical properties. The arrangement of NCs in SLs governs the collective properties of SLs, and thus investigations of phenomena that can change the assembly of NC constituents are important. In this study, we investigated the dynamic evolution of NC arrangements in three-dimensional (3D) SLs, specifically the morphological transformation of NC constituents during the direct liquid-phase synthesis of 3D NC SLs. Electron microscopy and synchrotron-based in situ small angle X-ray scattering experiments revealed that the transformation of spherical Cu2S NCs in face-centred-cubic 3D NC SLs into anisotropic disk-shaped NCs collapsed the original ordered close-packed structure. The random crystallographic orientation of spherical Cu2S NCs in starting SLs also contributed to the complete disordering of the NC array via random-direction anisotropic growth of NCs. This work demonstrates that an understanding of the anisotropic growth kinetics of NCs in the post-synthesis modulation of NC SLs is important for tuning NC array structures.

Event-related alpha power in early stage of facial expression processing in social anxiety: Influence of language context.

Accurate interpretation of the emotional information conveyed by others' facial expressions is crucial for social interactions. Event-related alpha power, measured by time-frequency analysis, is a frequently used EEG index of emotional information processing. However, it is still unclear how event-related alpha power varies in emotional information processing in social anxiety groups. In the present study, we recorded event-related potentials (ERPs) while participants from the social anxiety and healthy control groups viewed facial expressions (angry, happy, neutral) preceded by contextual sentences conveying either a positive or negative evaluation of the subject. The impact of context on facial expression processing in both groups of participants was explored by assessing behavioral ratings and event-related alpha power (0-200 ms after expression presentation). In comparison to the healthy control group, the social anxiety group exhibited significantly lower occipital alpha power in response to angry facial expressions in negative contexts and neutral facial expressions in positive contexts. The influence of language context on facial expression processing in individuals with social anxiety may occur at an early stage of processing.

The effective removal of Pb2+ by activated carbon fibers modified by l-cysteine: exploration of kinetics, thermodynamics and mechanism.

Herein, we developed a low-cost fabrication route to prepare chemically grafted activated carbon fibers, which effectively removed Pb2+ from solution. Multiple characteristic results indicated that l-cyst-ACF had abundant nitrogen-containing and sulfur-containing functional groups. Based on the XPS and EDS analyses, the capture of Pb2+ was attributed to the abundant adsorption sites on the fiber surface. According to the analysis of the pseudo-second-order kinetic model and the Langmuir isotherm model, the adsorption process could be interpreted as monolayer adsorption and chemisorption, and the equilibrium adsorption capacity was determined to be 136.80 mg g-1 by fitting the pseudo-second-order kinetic model. The maximum adsorption capacity of l-cyst-ACF for Pb2+ was calculated to be 179.53 mg g-1 using the Langmuir model. In addition, the adsorption reaction was endothermic and spontaneous, as evidenced by the thermodynamic parameters. The outcomes of this study provide a low-cost and feasible strategy for the remediation of Pb2+ pollution in the environment.

Simulation study on comprehensive thermal treatment of oil sludge based on Aspen plus.

This article proposed an original comprehensive thermal treatment coupled with gasification and combustion (CGC) of oil sludge (OS), which was designed to produce hydrogen-rich syngas. Based on the experimental results of OS gasification with steam, the combustion characteristics of char from OS gasification were analyzed by thermogravimetric experiments under different heating rates of 10, 20 and 30 °C/min. The combustion process of OS gasification char can be divided into three stages, including water evaporation, volatile combustion and heavy component combustion. The average values of activation energy (E) obtained by Friedman, FWO and Starink methods were 89.98 kJ/mol, 147.61 kJ/mol and 143.09 kJ/mol, respectively. According to OS gasification and OS gasification char combustion experiments, the comprehensive thermal treatment process CGC of OS was simulated by Aspen Plus. The simulation results showed that increasing both gasification temperature and the mass ratio of steam to OS (SOS) could promote the hydrogen production. Considering energy consumption, the recommended OS gasification temperature, SOS and char combustion temperature were 800 ∼ 900 °C, 0.3 ∼ 0.5, and 900 ∼ 1000 °C, respectively, which could ensure full burning of char and reduce the generation of pollutants. The CGC process could reduce CO2 emissions by 44.2% from carbon flow analysis.

A review of application and development of combustion technology for oil sludge.

Oil sludge is a typical hazardous waste in the petrochemical and electric power industry. It has complex components and special properties, and has serious hazards to humans, plants, water, and soil. Therefore, how to realize the effective disposal of oil sludge has become an urgent issue to be solved worldwide. Among the existing oil sludge treatment approaches, combustion has been considered to be a promising technology to realize the large-scale industrial application. In the present work, the characteristics of oil sludge were described in detail. The application and development of oil sludge combustion technology were critically summarized and discussed, including factors affecting combustion, drying process, combustion characteristics, synergistic treatment technology, and formation and control of secondary pollution. Besides, the development of combustion equipment, and integrated thermal treatment technology for oil sludge were prospected. This work can be used for guiding the industrial disposal of oil sludge.