Journal of Spectroscopy
·
2015
·
IF 0.538
Y. J. Li,F. Y. Sun,Y. Zhou,L. Zeng
Different dispersants were added in the dispersion process to improve the efficiency of fluorite flotation. The types and dosage of dispersant on the improvement of fluorite flotation were investigated; when the sodium polyacrylate (SPA) was used as the dispersant and its addition is 0.5%, the concentrate grade of CaF2 increased from 90% to 98% and the fluorite recovery increased from 81% to 85%. Methods of X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), and Energy dispersive X-ray spectrometer (EDX) were used to characterize the sample. According to the analysis of results, the optimal sample consisted of CaF2 and very little CaCO3 in the size range of 0–5 μm. It could be concluded that the mechanism of improvement for the concentrate grade and recovery of CaF2 was attributed to the change of potential energy barrier which caused the separation of particles with different charge. All results indicate that SPA has a great potential to be an efficient and cost-effective dispersant for the improvement of fluorite flotation.
研究领域:
矿物加工工程
·
材料科学与工程
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高影响因子
CATALYSIS LETTERS
·
2020
·Vol. 150
·期 8
·2437-2445
·
IF 2.482
Yang Zhi,Luo Mingsheng,Liu Qinglong,Shi Buchang
A potassium- and copper-modified iron-based catalyst (K–Cu–Fe/SiO 2 ) was synthesized by the co-precipitated method. The general structural properties of the catalyst were characterized with various techniques, including SEM, XRD, H 2 -TPR, N 2 adsorption–desorption and Raman spectroscopy. The results reveal that the fresh catalyst is mainly composed of α-Fe 2 O 3 phase with rod-shaped morphology formed by nanoparticles. The effect of activation process on the Fischer–Tropsch synthesis catalytic performance was then investigated. It shows that activation process has an important influence on the reactive stability. The in situ XRD and in situ Raman spectroscopy were used to study the structural changes of the Fe-based catalyst during reduction and reaction processes. The Fe 2 C iron carbide as the main active phase was observed after reduction process. Graphic Abstract
研究领域:
催化化学
·
材料科学
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高影响因子
MINERALS ENGINEERING
·
2025
·
IF 5
Hao Fu,Xuesong Jiang,Xiaotian Chen,Zhenyi Hu,Jifei Sun,Zongrong Zhou,Ling Wang,Boyuan Ban,Jian Chen
Al is one of the most difficult to remove impurities from quartz. Even with HF, only a limited removal efficiency was demonstrated. This study proposes a novel and environmentally friendly strategy centered on a combined process of ball milling, Na 2 CO 3 roasting, fluorine-free acid leaching, and chlorination roasting. The core innovation lies in the strategic induction of a consecutive and reversible phase transformation cycle (α-quartz → cristobalite → α-quartz), which serves as an internal grain refiner to achieve continuous microstructure refinement, thereby constructing abundant fast pathways for impurity migration. A comprehensive XRD analysis was introduced to observe the microstructure evolution. The results indicate that Na 2 CO 3 promotes the phase transformation from α-quartz into cristobalite at a relatively low temperature, while chlorination roasting facilitates the reverse transformation back to α-quartz. It revealed that these two distinct phase transformations not only disrupt the crystal integrity but also lead to significant microstructure refinement accompanied by abundant lattice defects. Through these defects, Al impurities rapidly migrate to the quartz particle surface, where they react with the acid solution and HCl gas, enabling efficient removal. Under the optimal process, the Al removal rate reached 90.5 %, the total impurity removal rate attained 98 %, and the quartz purity increased from 99.683 wt% to 99.994 wt%. This work highlights the crucial role of reversible phase transformation-induced grain refinement as an efficient strategy for lattice impurity removal, offering a green and high-performance alternative to HF-based purification with demonstrated advantages in environmental safety, energy efficiency, and product yield.
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Scientific Reports
·
2017
·Vol. 7
·期 1
·1-10
·
IF 4.259
Feng Shanglei,Yang Yingguo,Li Li,Zhang Dongsheng,Yang Xinmei,Xia Huihao,Yan Long,Tsang Derek K. L.,Huai Ping,Zhou Xingtai
An in-situ real-time synchrotron-based grazing incidence X-ray diffraction was systematically used to investigate the crystal structural evolution of carbon fiber reinforced carbon matrix (C/C) composite impregnated with FLiNaK molten salt during the heat-treatment process. It was found that the crystallographic thermal expansion and contraction rate of interlayer spacing d
002 in C/C composite with FLiNaK salt impregnation is smaller than that in the virgin sample, indicating the suppression on interlayer spacing from FLiNaK salt impregnated. Meanwhile the crystallite size L
C002 of C/C composite with FLiNaK salt impregnation is larger than the virgin one after whole heat treatment process, indicating that FLiNaK salt impregnation could facilitate the crystallization of C/C composite after heat treatment process. This improved crystallization in C/C composite with FLiNaK salt impregnation suggests the synthetic action of the salt squeeze effect on crooked carbon layer and the release of internal residual stress after heating-cooling process. Thus, the present study not only contribute to reveal the interaction mechanism between C/C composite and FLiNaK salt in high temperature environment, but also promote the design of safer and more reliable C/C composite materials for the next generation molten salt reactor.
研究领域:
材料科学
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核能工程
·
晶体学
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PubMed
高影响因子
CONSTRUCTION AND BUILDING MATERIALS
·
2024
·
IF 7.4
Jixiang Wang,Li Xiang,Caifu Ren,Tianyong Huang,Yingcan Zhu,Peng Wei,Dongmin Wang,Ze Liu
Solid waste-based binders offer intrinsic low-carbon advantages and non-primary resource consumption, making them one of the most promising low-carbon binders. However, the compositions of multiple components and the complex nature of their raw materials—mainly industrial solid wastes—make the stability and control of their quality very difficult, thereby limiting their practical applications in industry. The core of controlling product stability lies in quantifying the blended mixes. The progress in X-ray diffraction and its analysis methods has provided an opportunity to directly and non-destructively measure the phase compositions of solid waste-based binders. Rietveld refinement has been widely used to quantify the blend of crystals. However, due to the X-ray amorphous diffraction characteristics of aluminosilicates in most solid wastes, distinguishing and quantifying them is challenging. The PONCKS method has provided a strategy for indexing the amorphous phases and facilitating the distinction of different amorphous phases in various raw materials. In this study, by combining the Rietveld and PONCKS methods, a strategy has been presented that applies the XRD method to quantify the mixing proportions and their hydration products , and its validity has been verified. Factors such as crystal preferred orientation, background selection, and the structure for establishing the CASH model have been identified as more significant for accurate analysis and the optimal fitting strategy has been suggested. Lastly, in-situ XRD measurements , a very promising technology for studying the fresh paste hydration processes , have also been conducted. The real-time continuous determination has provided a more insightful understanding of the hydration and setting behaviors of the solid waste-based binder.
研究领域:
材料科学
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水泥与混凝土研究
·
废弃物资源化利用
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X射线衍射分析
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可持续建筑材料
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高影响因子
IRONMAKING & STEELMAKING
·
2026
·
IF 2.1
Jiawen Chen,Liang Yu,Shipeng Xu,Yu Wan
As a crucial functional material in the continuous casting process, mould fluxes play a significant role in ensuring smooth operation and improving the quality of cast billets. To mitigate the environmental impact of fluorides in mould fluxes, TiO2 has been introduced as a network former to reduce viscosity and melting temperature. The formation of perovskite instead of cuspidine also contributes to controlled heat transfer. However, preventing the formation of titanium carbide (TiC) under high-temperature conditions remains challenging. Experimental results indicate that during heating, both CaO–SiO2–TiO2 and CaO–SiO2–CaF2–TiO2 slag systems react to form perovskite. TiO2 participates more readily in solid-state reactions with CaO than CaF2 does, thereby inhibiting the formation of cuspidine. Furthermore, in carbon-containing CaO–SiO2–TiO2 systems, TiC forms along with CO at elevated temperatures. It is revealed that TiC formation does not result from the direct reaction between TiO2 and C, but rather from the reaction between CaTiO3 and C. Under high-temperature carbon-rich conditions, carbon reduces perovskite to form TiC. Consequently, in contrast to fluorine-based fluxes, titanium-bearing mould fluxes require careful optimisation of carbon content to prevent TiC precipitation.
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NANO
·
2024
·
IF 1
Chunjian Wang,Jiakun Xu,Jingmin Li,Chen He
X-ray diffraction (XRD) is one of the most essential techniques for characterizing various crystals. However, when nanocrystals are present, the diffraction peaks become significantly broadened and reduced in intensity, making phase and microstructure analysis challenging. To obtain more refined microstructural information from nanocrystals, various methods have been developed to enhance diffraction peaks, with step scanning being a commonly used approach. Additionally, increasing instrument broadening (IB) by adjusting slit sizes to enlarge the irradiation area is a convenient yet often overlooked method. In this study, the effects of IB on the diffraction peak intensities of nanocrystals and micron crystals in mixed materials were thoroughly investigated. The results show that the intensities of both nanocrystals and micron crystals increase as IB increases, a behavior similar to that observed when extending the testing time during step scanning. However, the rate of increase in peak heights for nanocrystals is higher than for micron crystals, while the rate of increase in peak width for nanocrystals is lower, which is a significant departure from the effects seen in step scanning. In other words, nanocrystal peaks become sharper and more distinct as IB increases. This phenomenon is explained by the different components of peak width for nanocrystals and micron crystals, based on Lorentz mathematical model analysis. Based on these findings, it is recommended to utilize larger IBs in combination with step scanning to further reinforce nanocrystal peaks in mixed materials.
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高影响因子
Frontiers in Chemistry
·
2025
·
IF 4.2
Yang Yang,Xuemei Wei,Shuya Zhang,Yun Li,Jiazhen Wu,Suhua Cai,Biren Wang,Zhiming Yang,E. Yang,Junling Cao,Qinhua Chen,Guihong Chen
Background: Aconiti Lateralis Radix Praeparata (Fuzi), a vital yet toxic herbal medicine, faces significant challenges in standardization due to varied processing methods that undermine detoxification efficacy and hinder therapeutic optimization.Methods: An integrative analytical approach combining scanning electron microscopy (SEM), X-ray diffraction (XRD), metabolomics, and pharmacodynamic evaluation was employed to investigate the structural, compositional, and functional transformations during Fuzi processing.Results: SEM imaging and XRD data revealed that the morphological breakdown of starch granules varied according to processing technique. Metabolomics analysis based on mass spectrum identified 57 diterpenoid alkaloids, including 12 bioactive components, whose levels fluctuated across nine processing variants. Pharmacodynamic profiling revealed distinct efficacy-safety trade-offs across these variants, underscoring the pivotal role of processing methods in determining clinical risk profiles and therapeutic indices.Conclusion: This study elucidated the structure-composition-efficacy correlations in Fuzi processing, highlighting the relationship between starch reorganization, alkaloid modification, and therapeutic outcomes. These insights offer a mechanistic basis for refining traditional processing protocols, optimizing detoxification and therapeutic retention, and advancing standardization in herbal medicine.
研究领域:
中药炮制学
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天然药物化学
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代谢组学
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药效动力学
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晶体学
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植物药标准化
·
药物安全性评价
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DOI
PubMed
高影响因子
Separations
·
2022
·Vol. 9
·期 12
·428
·
IF 3.344
Zhen Wang,Chenteng Sun,Qian Xu,Xingli Zou,Hongwei Cheng,Xionggang Lu
Sodium silicate, a new type of CO2sorbent, has a relatively low cost, but its sorption reactivity is not yet good enough. Alkali carbonate doping is commonly used as an effective means to improve the CO2uptake reactivity of solid sorbents. In this study, sodium orthosilicate, Na4SiO4, was synthesized and mixed with 5, 10, and 20 mol% of Li2CO3–Na2CO3or Li2CO3–Na2CO3–K2CO3as CO2sorbents. The promotion of alkali carbonates on Na4SiO4in CO2capture was characterized using thermal analyses in an 80 vol% CO2–20 vol% N2atmosphere. The phase evolution and structural transformations during CO2capture were characterized by in situ XRD and Raman, and the results showed that the intermediate pyrocarbonate, C2O52−, which emerged from alkali carbonates, enhanced the CO2capture of Na4SiO4to form Na2CO3and Na2SiO3from 100 °C. Isothermal analyses showed that 10 mol% of Li2CO3–Na2CO3was the optimal additive for Na4SiO4to attain better CO2uptake performance. The alkali carbonates were effective in reducing the activation energy for both chemisorption and bulk diffusion, improving the cycle stability of Na4SiO4.Keywords:CO2capture;Na4SiO4;alkali carbonates;in situ XRD;in situ Raman;isothermal analysis;double exponential model;Eyring’s model
研究领域:
材料科学
·
环境科学
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高影响因子
JOURNAL OF SOILS AND SEDIMENTS
·
2024
·Vol. 24
·期 6
·2309-2317
·
IF 2.8
Mi Na,Yang Min,Wang Xiaohan,Sun Qian,He Jianzhou,Deng Shaopo,Fan Tingting
Purpose The application of silicon could effectively alleviate Cd contamination in the soil. However, the interaction between silicon and Cd in soils is not well understood. Our research aims to investigate the mechanism of the impact of silicate on the sorption of Cd on metal oxides in soils. Materials and methods Sodium silicate and Cd(II) co-sorption on γ-Al 2 O 3 and goethite at pH 5.5 and 7.5 was studied using a combination of batch sorption experiments, X-ray diffraction (XRD), and Fourier transform infrared spectroscopy (FTIR). Results and discussion Silicate enhanced the sorption of Cd(II) onto γ-Al 2 O 3 at pH 5.5 and 7.5. However, the sorption of Cd(II) on goethite at pH 5.5 and 7.5 was only promoted when the silicate concentration reached 1 mmol L −1 . Cadmium(II) enhanced silicate sorption on γ-Al 2 O 3 at pH 5.5 and on goethite at pH 7.5, while it decreased silicate sorption on γ-Al 2 O 3 at pH 7.5 and had no significant effect on goethite at pH 5.5. At pH 5.5, Cd(II) reacted with silicate to generate Cd 2 SiO 4 , and Cd-Si-Al ternary complexes were formed on γ-Al 2 O 3 . At pH 7.5, silicate promoted the formation of Cd(OH) 2 on γ-Al 2 O 3 , which ultimately transformed into CdCO 3 . When silicate concentration reached 1 mmol L −1 , more silicate complexes were formed through the Fe-O-Si bound on goethite at both pH 5.5 and 7.5 to promote the adsorption of Cd(II) owing to its electronegative functional group on the surface of the complex. Conclusions The type of clay minerals, pH, and the presence of silicate all significantly affected Cd sorption. Furthermore, the sorption mechanism of Cd on γ-Al 2 O 3 and goethite in the presence of silicate has been elucidated. The above findings improve our understanding of the mechanism for immobilizing Cd in soils using silicon-containing materials.
研究领域:
土壤科学
·
环境化学
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高影响因子
APPLIED CLAY SCIENCE
·
2022
·
IF 5.907
Yingya Wang,Lingyu Ran,Lingya Ma,Runliang Zhu,Jingming Wei,Hongmei Liu,Yunfei Xi,Jianxi Zhu,Hongping He
The variable structural characteristics of montmorillonite (Mnt) in salt solutions depend not only on the quantity and distribution of the Mnt layer charge, but also on the specificity of counterions, including their radius, valence, concentration, and hydratability. In order to determine the nanoscale chemomechanical processes in a clay mineral–water–salt system, in situ X-ray diffraction (XRD) and atomic force microscopy (AFM) methods were used to investigate the structural variations of Mnt caused by different counterion species ( e.g. , Li + , Na + , K + , Rb + , Cs + , Mg 2+ , Ca 2+ , and Sr 2+ ) at different concentrations (0.2–3.0 M). With an increasing concentration of counterions, separation of water molecules from the interlayer space of more weakly hydrated cations (Cs + , Rb + , and K + ) is faster than for the more strongly hydrated cations (Li + , Na + , Mg 2+ , Ca 2+ , and Sr 2+ ), water molecules are lost more slowly from the hydration shell, which remains stable even at high counterion concentrations . The sequential ion exchange in a monolayer Mnt observed by in situ AFM is consistent with the d (001) results from the real-time XRD analysis . Moreover, various defects on Mnt surfaces were visible in the high-resolution AFM images, which restrict the spatial arrangement of adsorbed cations. The water molecule partitioning between the interlayers in Mnt is controlled by the specificity of the counterions, and the cations can spontaneously form ordered structures on the surface of Mnt. These nonclassical interfacial phenomena occurred in the electric double layer (EDL) is controlled by the hydration of counterions, the surface structure and the charge distribution of Mnt.
研究领域:
矿物学
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材料科学
·
界面化学
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高影响因子
Journal of Environmental Chemical Engineering
·
2025
·
IF 7.2
Tao Wu,Xuewen Gao,Jiaxing Feng,Yuan Jin,Zhengye Feng
Accurate predictions of the distribution coefficient ( K d ) and effective diffusion coefficient ( D e ) of radionuclides in bentonite barriers is critical for the safety evaluation of high-level radioactive waste repositories. Clay properties have a crucial impact on both parameters. However, existing models do not adequately capture the complex physicochemical characteristics of clay minerals, thereby limiting their prediction accuracy. This study developed, a variational autoencoder-multi-task deep learning (VAE-MTDL) framework to improve the predictive accuracy for K d and D e by integrating radionuclide diffusion data with X-ray fluorescence (XRF), X-ray diffraction (XRD), and cation exchange capacity (CEC) data. The model was trained using a dataset comprising 1159 experimental instances and 49 input features. It achieved high predictive accuracy (R 2 = 0.96 for Kd and 0.93 for D e ). Shapley additive explanations (SHAP) analysis identified total porosity as the most influential predictor, while XRF and XRD data significantly contributed to the predictions. Experimental validation using through-diffusion tests for HCrO 4 − (as a surrogate for monovalent anionic radionuclide species) and metal-EDTA complexes (including Eu(III), Sm(III), Ce(III), and Co(II) as a surrogate for di- and trivalent cationic radionuclide species) in compacted bentonite-sand mixtures confirmed robust generalization, with predicted-to-experimental ratios ranging from 1/5 to 5 for K d , and from 1/3 to 3 for D e . The enhanced accuracies in K d and D e predictions have practical relevance in advancing the safety evaluation of repositories.
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