Macerals of lignite and the effect of alkali treatment on the structure and combustion performance of lignite

Suppressing the spontaneous combustion of lignite is of great significance for safe transportation and efficient utilization of lignite. Taking the Shengli lignite as the research object, two different macerals, inertinite and huminite, were selected by optical microscope, and treated with NaOH respectively to study the relationship between the structure and combustion reaction performance of different macerals and lignite treated with NaOH. The structure of the prepared coal samples was characterized by SEM-EDS, XPS, FT-IR, XRD and Raman, and the changes of the main functional groups were analyzed. The effect of NaOH treatment on the combustion performance of different maceral lignite was investigated by TGA. The results showed that the ignition temperature of huminite lignite was about 10 ℃ earlier than that of inertinite, but the comprehensive combustion characteristic index of inertinite lignite was slightly higher than that of huminite. After the NaOH treatment, the lignite of different macerals showed a hysteresis of combustion, there were two obvious weight losses in the range of 200−500 ℃ and 650−800 ℃, respectively, and the mass loss was mainly concentrated in the second weight loss, in particular, the effect of huminite lignite was more significant, and the temperature corresponding to the maximum combustion reaction rate was about 60 ℃ behind that of inertinite. The kinetic analysis of the combustion process of the coal samples showed that the activation energy of combustion reaction of lignite with different macerals significantly increased after the NaOH treatment, and the huminite lignite was higher than that of inertinite lignite. The XPS/FT-IR results revealed that the contents of carboxylic oxygen-containing functional groups in different macerals of lignite treated by NaOH decreased, the main reason is that in the process of NaOH treatment, Na+ interacted with the carboxylic oxygen-containing functional groups in lignite to form the sodium carboxylate structure, and the relative amount of the sodium carboxylate structure in huminite coal was relatively large. It is believed that the inhibitory effect on the combustion of lignite with different macerals is attributed to the stability of the sodium carboxylate structure, and the number of the sodium carboxylate structure formed by combining with Na is the main reason for the difference in its combustion performance. The XRD/Raman analysis indicates that the formation of the sodium carboxylate structure in lignite leads to the increase of the order degree of carbon microcrystalline structure, and the order degree of huminite lignite is higher than that in inertinite

A novel and highly efficient Zr-containing catalyst supported by biomass-derived sodium carboxymethyl cellulose for hydrogenation of furfural

Functional use of biomass based on its structural properties is an efficient approach for the valuable utilization of biomass resources. In this work, carboxymethyl cellulose zirconium-based catalyst (Zr-CMC) was constructed by the coordination between the carboxylic groups in sodium carboxymethyl cellulose (CMC-Na) with transition metal Zr4+. The prepared catalyst was applied into the synthesis of furfuryl alcohol (FAL) by catalytic transfer hydrogenation of biomass-derived furfural (FF) using isopropanol as hydrogen donor. Both the preparation conditions and the reaction conditions of Zr-CMC catalyst were investigated and optimized. The results showed that Zr-CMC was efficient for the reaction with the FF conversion, FAL yield and selectivity reaching to 92.5%, 91.5 %, and 99.0%, respectively, under the mild conditions (90°C). Meanwhile, the Zr-CMC catalyst could be reused at least for five times without obvious decrease in efficiency, indicating the catalyst had excellent stability. With the advantages of sustainable raw materials, high efficiency, and excellent stability, the prepared catalyst is potential for application in the field of biomass conversion

NTIRE 2024 Quality Assessment of AI-Generated Content Challenge

This paper reports on the NTIRE 2024 Quality Assessment of AI-Generated Content Challenge, which will be held in conjunction with the New Trends in Image Restoration and Enhancement Workshop (NTIRE) at CVPR 2024. This challenge is to address a major challenge in the field of image and video processing, namely, Image Quality Assessment (IQA) and Video Quality Assessment (VQA) for AI-Generated Content (AIGC). The challenge is divided into the image track and the video track. The image track uses the AIGIQA-20K, which contains 20,000 AI-Generated Images (AIGIs) generated by 15 popular generative models. The image track has a total of 318 registered participants. A total of 1,646 submissions are received in the development phase, and 221 submissions are received in the test phase. Finally, 16 participating teams submitted their models and fact sheets. The video track uses the T2VQA-DB, which contains 10,000 AI-Generated Videos (AIGVs) generated by 9 popular Text-to-Video (T2V) models. A total of 196 participants have registered in the video track. A total of 991 submissions are received in the development phase, and 185 submissions are received in the test phase. Finally, 12 participating teams submitted their models and fact sheets. Some methods have achieved better results than baseline methods, and the winning methods in both tracks have demonstrated superior prediction performance on AIGC

J. Chem. Technol. Biotechnol.

BACKGROUNDBiosynthesis of silver nanoparticles (AgNPs) is considered a green method. Sunlight could induce the synthesis of AgNPs with bacteria and plant biomass, while animal and fungus biomass have not been investigated for synthesis of AgNPs under sunlight radiation. RESULTSUnder 80 000 lx sunlight intensity and 4 mg mL(-1) of tryptone solution, the maximum AgNPs yield was obtained after 60 min, and the Ag+ (1 mmol L-1) conversion rate reached 98 2%. Transmission electron microscopy revealed that T-Ag (tryptone-mediated) were circular and oval, with an average diameter of 11.63 +/- 4.17 nm, and Y-Ag (yeast extract-mediated) displayed similar shape and size to T-Ag. X-ray diffraction confirmed that T-Ag and Y-Ag were in the form of nanocrystals. As-prepared AgNPs showed obvious antimicrobial activity against B. subtilis and E. coli. Capping with peptides helped to maintain colloidal stability of AgNPs. Without sunlight, AgNPs showed high stability at pH 7-11 due to high -potential values, while the stability was destroyed at pH 4. Further exposure to sunlight for 48 h also resulted in sedimentation of AgNPs. CONCLUSION Sunlight could induce tryptone and yeast extract to synthesize AgNPs, and the stability of AgNPs could be regulated by capping peptides, pH, and sunlight exposure. (c) 2013 Society of Chemical IndustryBACKGROUNDBiosynthesis of silver nanoparticles (AgNPs) is considered a green method. Sunlight could induce the synthesis of AgNPs with bacteria and plant biomass, while animal and fungus biomass have not been investigated for synthesis of AgNPs under sunlight radiation

Advanced functional nanomaterials with microemulsion phase

Significant progress has been made in the formulation of the functional nanomaterials with microemulsion phase. Microemulsion phase can be considered as true nanoreactors, which can be used to synthesize nanomaterials. Properties and the mechanism of nanoparticle formation with microemulsion phase are reviewed in this paper. Preparation of the various nanomaterials, such as metal nanomaterials, oxide nanomaterials, magnetic nanoparticles, inorganic and inorganic compounds nanomaterials, metallic-organic composite nanomaterials, and other composite nanomaterials, are investigated with different microemulsion phases. The possible formation mechanisms are presented with the schematic diagram

O-carboxymethyl chitosan entrapped by silica: preparation and adsorption behaviour toward neodymium (III) ions

BACKGROUND: The recovery of neodymium from dilute solutions has become important because of its wide application in industry. This work reports the preparation of novel carboxymethyl chitosan adsorbents entrapped by silica (SiO2/CMCH) and their application for adsorption of neodymium(III) ions from aqueous solution. RESULTS: The effect of the CMCH content, equilibrium pH (pHe), contact time, initial concentrations of Nd(III) and temperature on the adsorption was investigated. The amount of Nd(III) adsorption increases with increasing pHe, which can be explained by the pH-titration curve of CMCH. Temperature has a positive effect on Nd(III) adsorption, and the amount adsorbed is 53.04 mg g-1 dry adsorbent or 434.75 mg g-1 CMCH at 328 K. Adsorption kinetics and isotherm can be described by the pseudo-second-order model and Langmuir equation. Both complexation and ion exchange mechanisms are believed to play an important role in Nd(III) adsorption, and possible coordination between CMCH and Nd(III) is speculated. Complete desorption can be reached when the concentration of HCl is more than 0.1 mol L-1. CONCLUSION: A novel method was developed to prepare SiO2/CMCH adsorbents through a one-step sol-gel strategy. The prepared adsorbents were biocompatible and non-toxic with a good adsorption ability for Nd(III), and could be used for adsorptive recovery of Nd(III) from aqueous solutions. (c) 2012 Society of Chemical Industr

Facile Synthesis of Gold-nanoparticles-decorated Polymer Assemblies and Core-Shell Gold Nanoparticles Using Pluronic Block Copolymers

Synthesis of gold nanoparticles （AuNPs） and Pluronic triblock copolymer composite in aqueous medium was studied. Gold-polymer nanocomposite with different structures was fabricated by tailoring the molar ratio of gold precursors to Pluronic P123 molecules or pH value of the P123 solution. When a lower volume ratio of AuC14-/P123 （0.05） was employed at pH 11.1, a nanostmcture similar to plum pudding was obtained. AuNPs with an average diameter of 13.1 nm were embedded in Pluronic assemblies, and each one held about 21 single gold nanoparticles. When AuCln-/P123 was increased to 0.1, core-shell structure was obtained if the pH value was in the range of 10.6-11.6, while gold polyhedra were fabricated when pH value was 8.1. Typical core-shell AuNPs had an average diameter of 9.6 nm with a narrow size distribution, while gold polyhedras with a mean diameter of 12.8 nm was obtained. The specific morphologies of the resultant nanocomposite were presumably obtained due to the synergistic interaction among the reactants

Adsorption Properties toward Trivalent Rare Earths by Alginate Beads Doping with Silica

Novel alginate hybrid beads were prepared by doping with silica (abbreviated as ALG/SiO2), and their adsorption behavior toward rare earths(III) had been investigated. For the whole lanthanides, it exhibits a distinct "tetrad effect" with increasing atomic number. Taking Nd as an example, the effects of the pH, adsorption kinetics, isotherms, and regeneration of adsorbents had been studied systematically. Doped SiO2 can enhance the mechanical strength of the beads, and the hybrid adsorbents show no observable swelling during the adsorption process. It is interesting to note that Nd-III adsorption can be improved about 0.1 mmol/g after the first cycle and shows no apparent decline until the 12th cycle. Finally, it can be concluded that ALG/SiO2 is superior to the other hybrid alginate adsorbents for the adsorption of rare earths

Gas-Assisted Superparamagnetic Extraction for Potential Large-Scale Separation of Proteins

In this study, gas-assisted superparamagnetic extraction (GASE), a novel technology that combined superparamagnetic extraction technology with flotation technology, was proposed for potential large-scale separation of proteins. GASE includes adsorption for trapping proteins, and flotation and high gradient magnetic separator (HGMS) for recovering proteins-loaded magnetic particles from the dilute biosuspension. Citrate-modified superparamagnetic nanoparticles (CMNs) and bovine serum albumin (BSA) were used as a model. The feasibility of flotation for these particles enrichment was demonstrated. The results indicated that the BSA-loaded CMNs could be well concentrated in either foaming flotation or nonfoaming flotation by simple adjustment of the initial solution pH, without extra detergents and operations. The flotation conditions were consistent with the adsorption ones, and no proteins were desorbed from CMNs in the GASE process. Under the optimal conditions, the enrichment ratio and recovery percentage reached 31 and 99% in 1.5 min, respectively

Magnetic molecularly imprinted polymers for improved extraction of tanshinones from herbs via integrated extraction and cleanup system

A novel separation technology at room temperature for traditional Chinese medicines was proposed in this work by adding magnetic molecularly imprinted polymers (M-MIPs) into extraction solution and sample matrix. The M-MIPs show a more adsorption capacities and higher selectivity for the template than magnetic non-molecularly imprinted polymers (M-NMIPs) without the specific binding sites. Addition of the M-MIPs to the extraction solution provides one-step extraction and cleanup, the improvement of extraction rate and extraction yields of three tanshinones (from 0.40, 0.23 and 0.12 mg g(-1) in 240 min by solvent extraction to 0.52, 0.27 and 0.19 mg g(-1) in 5 min by 200 mg sorbent), and reusability of extraction solvent. The extraction yields of three tanshinones by this technology at room temperature in 5 min were higher than those by ultrasonic extraction in 30 min, by heat reflux extraction in 45 min and by solvent extraction at room temperature in 4 h. The integrated technology has the advantages of one-step extraction and cleanup, high extraction efficiency, low solvent consumption and room temperature. Crown Copyright (C) 2013 Published by Elsevier B.V. All rights reserved