Sustainable and scalable in-situ synthesis of hydrochar-wrapped Ti3AlC2-derived nanofibers as adsorbents to remove heavy metals

To ensure a sustainable future, it is imperative to efficiently utilize abundant biomass to produce such as platform chemicals, transport fuels, and other raw materials; hydrochar is one of the promising candidates derived by hydrothermal carbonization of biomass in pressurized hot water. The synthesis of “hydrochar-wrapped Ti3AlC2-derived nanofibers” was successfully achieved by a facile one-pot hydrothermal reaction using glucose as the hydrochar precursor. Meanwhile, cellulose and pinewood sawdust as raw materials were also investigated. Products were characterized by XRD, N2 adsorption-desorption isotherms, SEM, TEM and FT-IR to investigate their crystal structures, textural properties, morphologies, and surface species. In the adsorption test to remove Cd(II) and Cu(II) in aqueous solution, hydrochar-wrapped nanofibers outperformed pure nanofibers derived from Ti3AlC2, hydrothermal carbon derived from glucose and commercial activated carbon. Finally, the regeneration, sorption kinetics, and possible adsorption mechanism were also explored

Driving factors and micro-mechanism of residents’ participation intention in individual pension system

The introduction of an individual pension system is crucial to improve the current pension system in China. To increase the rate of participation of individuals in this new pension system and to give full play to its pension security effect, in this study, we built a conceptual model of participation intention of residents based on the theory of planned behavior considering seven new factors. Data were obtained through a questionnaire survey, and empirical tests and analyses were conducted using methods such as structural equation modeling. According to the results, 77.8 % of residents were willing to participate in the individual pension system. The internal driving factors such as perceived usefulness, trust, family burden and policy support directly influenced the residents’ participation rate. Participation attitude was a key variable, with a partial mediating effect on participation intention. Thus, it is recommended to increase publicity and policy support, improve laws, regulations and the regulatory system, regulate market operations and enhance service quality for boosting residents' recognition and enthusiasm to participate and reducing their burden in old age

High Content of Thermoplastic Starch, Poly(butylenes adipate-co-terephthalate) and Poly(butylene succinate) Ternary Blends with a Good Balance in Strength and Toughness

The ternary blends of a high content of thermoplastic starch (TPS), poly(butylenes adipate-co-terephthalate) (PBAT), and poly(butylene succinate) (PBS) were first melt-compounded in a twin screw extruder. The TPS contents in ternary blends were fixed at 60 wt%. The miscibility, morphology, thermal behavior, mechanical properties, and thermal resistance of the blends were investigated. The results showed that dispersions of PBS and PBAT minor phases improved the tensile strength and elongation at break. TPS/PBS/PBAT60/10/30 formed a good balance in strength and toughness. Dynamic mechanical analysis of the blends exhibits an intermediate and peak suggesting the ternary blend is compatible. Minor phase-separated structure SEM results showed that TPS/PBS/PBAT60/10/30 blend formed a typical mixture with core−shell morphology. As the PBAT composition was increased, phase morphology changes occurred in the blends, leading to decreased values of complex viscosity, storage modulus, and loss modulus. Moreover, the thermal resistances and melt flow properties of the materials were also studied by analysis of the heat deflection temperature (HDT) and melt flow index (MFI) value in the work

Glutaraldehyde Crosslinked High Content of Amylose/Polyvinyl Alcohol Blend Films with Potent Tensile Strength and Young’s Modulus

In recent years, with the development of green environmental protection, starch film has become of interest due to the wide availability of sources, low price, and biodegradability. Amylose/polyvinyl alcohol (PVA) blend films crosslinked with different amounts of glutaraldehyde (GLU) were prepared by a solution casting method. The cross-linking degree, water sorption, tensile property, crystallization and section morphology of the films were examined. With the increase in glutaraldehyde concentration, the cross-linking degree of the blend film was improved. The wide-angle X-ray scattering (WAXS) result indicated that cross-linking hindered the crystallization of film. The section morphology of films was examined by scanning electron microscope (SEM). The results showed that the cross-linking degree of amylose film improved while the crystallinity decreased with the increase in glutaraldehyde content. Cross-linking had no obvious effect on the water sorption property of the blend films. The cross-linking modification significantly enhanced the tensile strength and Young’s modulus, while it reduced the elongation at break of the blend films. It was found that the film with 0.5 wt % glutaraldehyde possessed the best performance: the tensile strength increased by 115%, while the elongation at break decreased by 18% even at high relative humidity (RH) of 90% compared to non-crosslinked films. The developed amylose/PVA blend films have promising application prospects as agricultural mulch films and packaging materials

Sulfur and Water Resistance of Mn-Based Catalysts for Low-Temperature Selective Catalytic Reduction of NOx: A Review

Selective catalytic reduction (SCR) with NH3 is the most efficient and economic flue gas denitrification technology developed to date. Due to its high low-temperature catalytic activity, Mn-based catalysts present a great prospect for application in SCR de-NOx at low temperatures. However, overcoming the poor resistance of Mn-based catalysts to H2O and SO2 poison is still a challenge. This paper reviews the recent progress on the H2O and SO2 resistance of Mn-based catalysts for the low-temperature SCR of NOx. Firstly, the poison mechanisms of H2O and SO2 are introduced in detail, respectively. Secondly, Mn-based catalysts are divided into three categories—single MnOx catalysts, Mn-based multi-metal oxide catalysts, and Mn-based supported catalysts—to review the research progress of Mn-based catalysts for H2O and SO2 resistance. Thirdly, several strategies to reduce the poisonous effects of H2O and SO2, such as metal modification, proper support, the combination of metal modification and support, the rational design of structure and morphology, are summarized. Finally, perspectives and future directions of Mn-based catalysts for the low-temperature SCR of NOx are proposed

Accelerating CPU-based Sparse General Matrix Multiplication with Binary Row Merging

Sparse general matrix multiplication (SpGEMM) is a fundamental building block for many real-world applications. Since SpGEMM is a well-known memory-bounded application with vast and irregular memory accesses, considering the memory access efficiency is of critical importance for optimizing SpGEMM. Yet, the existing methods put less consideration into the memory subsystem and achieved suboptimal performance. In this paper, we thoroughly analyze the memory access patterns of SpGEMM and their influences on the memory subsystem. Based on the analysis, we propose a novel and more efficient accumulation method named BRMerge for the multi-core CPU architectures. The BRMerge accumulation method follows the row-wise dataflow. It first accesses the $B$ matrix, generates the intermediate lists for one output row, and stores these intermediate lists in a consecutive memory space, which is implemented by a ping-pong buffer. It then immediately merges these intermediate lists generated in the previous phase two by two in a tree-like hierarchy between two ping-pong buffers. The architectural benefits of BRMerge are 1) streaming access patterns, 2) minimized TLB cache misses, and 3) reasonably high L1/L2 cache hit rates, which result in both low access latency and high bandwidth utilization when performing SpGEMM. Based on the BRMerge accumulation method, we propose two SpGEMM libraries named BRMerge-Upper and BRMerge-Precise, which use different allocation methods. Performance evaluations with 26 commonly used benchmarks on two CPU servers show that the proposed SpGEMM libraries significantly outperform the state-of-the-art SpGEMM libraries.Comment: This work has been submitted to the IEEE Access since May 31, 2022, and is currently under review by the IEEE Access. 15 pages, 6 fgures, 2 table

Fabrication of g-C3N4/Au/C-TiO2 hollow structures as visible-light-driven Z-scheme photocatalysts with enhanced photocatalytic H2 evolution

The Z-scheme photocatalytic system for water splitting based on semiconductors has exhibited great potential for H-2 fuel production from renewable resources. In this work, we constructed g-C3N4/Au/C-TiO2 hollow spheres as an all-solid-state Z-scheme photocatalytic system with Au nanoparticles as the electron mediator. The as-synthesized g-C3N4/Au/C-TiO2 photocatalyst showed a remarkably enhanced photocatalytic H-2 evolution rate under visible-light irradiation (lambda > 420nm), which was 86 and 42times higher than those of pure C-TiO2 and g-C3N4, respectively. The enhancement of photocatalytic performance can be mainly attributed to the intentionally designed Z-scheme system, which not only promoted the efficient transfer and separation of photogenerated electron-hole pairs, but also retained the strong redox ability of the charge carriers. In addition, the Z-scheme system also achieved high visible-light absorption and utilization owing to the surface plasmon resonance (SPR) effect of Au nanoparticles and hollow structures of C-TiO2. All the factors synergistically promote the photocatalytic activity of the g-C3N4/Au/C-TiO2 hollow nanospheres, providing a promising method for the rational design of highly efficient visible-light-driven photocatalysts