摘要：
A novel chitosan/ZIF-8/algal powder (ZIF-8/CP/CT) composite adsorbent was synthesized for efficient adsorption of uranyl ions in seawater. The results demonstrate that ZIF-8/CP/CT exhibits excellent uranium adsorption performance within the pH range of 4.0-8.0, with an adsorption rate exceeding 89 %. Kinetic and thermodynamic experiments reveal that the theoretical maximum adsorption capacity of ZIF-8/CP/CT for U(VI) is 873 mg/g (308 K, pH = 6.0), indicating a spontaneous exothermic reaction. Mechanistic analysis reveals that the hydroxyl, amino, and P=O bonds on the surface of ZIF-8/CP/CT and the C=N bond within ZIF-8 play a pivotal role in facilitating uranium adsorption. In addition, quaternary phosphorus salt improves the competitiveness of the adsorbent toward uranium. Compared with ZIF-8 and unsupported ionic liquid ZIF-8/C/CT, the ratio of U-V partition coefficients of ZIF-8/CP/CT increases by 20-fold and 6-fold, respectively. Moreover, the implementation of adsorption treatment on genuine uranium tailings wastewater effectively reduces the uranium content to 40 mu g/L. Consequently, ZIF-8/CP/CT demonstrates promising potential for extracting uranium from seawater and holds significant value for uranium wastewater treatment.
摘要：
A 3D elastic-plastic FE model for simulating the force controlled stretch-bending process of double-cavity aluminum profile was established using hybrid explicit-implicit solvent method. Considering the computational accuracy and efficiency, the optimal choices of numerical parameters and algorithms in FE modelling were determined. The formation mechanisms of cross-section distortion and springback were revealed. The effects of pre-stretching, post-stretching, friction, and the addition of internal fillers on forming quality were investigated. The results show that the stress state of profile in stretch-bending is uniaxial with only a circumferential stress. The stress distribution along the length direction of profile is non-uniform and the maximum tensile stress is located at a certain distance away from the center of profile. As aluminum profile is gradually attached to bending die, the distribution characteristic of cross-section distortion along the length direction of profile changes from V-shape to W-shape. After unloading the forming tools, cross-section distortion decreases obviously due to the stress relaxation, with a maximum distortion difference of 13% before and after unloading. As pre-stretching and post-stretching forces increase, cross-section distortion increases gradually, while springback first decreases and then remains unchanged. With increasing friction between bending die and profile, cross-section distortion slightly decreases, while springback increases. Cross-section distortion decreases by 83% with adding PVC fillers into the cavities of profile, while springback increases by 192.2%.
关键词：
Bacteria;Cadmium sulfide;Crystallinity;Efficiency;II-VI semiconductors;Iron;Nanotechnology;Physicochemical properties;Sediments;Bacterial community;Contaminated sediment;Immobilisation;Immobilization efficiency;Nano-scale zero valent irons;Nanoscale zero-valent iron;Overlying water;Performance;Precursor;Sulphidized nanoscale zero-valent iron;Cadmium;adsorbent;cadmium;calcium ion;citric acid;humic acid;iron;iron nanoparticle;magnesium ion;pentetic acid;potassium ion;sodium ion;sulfidized nanoscale zero valent iron;sulfur;unclassified drug;water;cadmium;iron;cadmium;complexation;immobilization;iron nanoparticle;microbial community;organic acid;performance assessment;sediment pollution;speciation (chemistry);adsorption;Article;bioremediation;cadmium poisoning;complex formation;controlled study;correlation analysis;correlation coefficient;crystal structure;energy dispersive X ray spectroscopy;environmental factor;environmental impact;environmental parameters;heavy metal removal;high resolution transmission electron microscopy;immobilization;incubation time;iron reducing bacterium;leaching;microbial activity;microbial community;microbial diversity;micromorphology;nonhuman;oxidation;particle size;pH;physical chemistry;precipitation;precursor;process optimization;prokaryotes by metabolism;scanning electron microscopy;sediment;Shannon index;sulfate reducing bacterium;toxic concentration;transmission electron microscopy;water contamination;water sediment ratio;X ray diffraction;X ray photoemission spectroscopy;chemistry;water pollutant;Adsorption;Cadmium;Iron;Water;Water Pollutants, Chemical
摘要：
Sulfidized nanoscale zero-valent iron (S-nZVI) showed excellent removal capacity for cadmium (Cd) in aqueous phase. However, the remediation effects of S-nZVI on Cd-contaminated sediment and its interactions with microorganisms in relation to Cd fate remain unclear. The complexity of the external environment posed a challenge for Cd remediation. This study synthesized S-nZVI with different S and Fe precursors to investigate the effect of precursors and applied the optimal material to immobilize Cd in sediments. Characterization analysis revealed that the precursor affected the morphology, Fe(0) crystallinity, and the degree of oxidation of the material. Incubation experiments demonstrated that the immobilization efficiency of Cd using S-nZVI(Fe)(3+)(+S)(2-) (S/Fe = 0.14) reached the peak value of 99.54%. 1% and 5% dosages of S-nZVI significantly reduced Cd concentration in the overlying water, DTPA-extractable Cd content, and exchangeable (EX) Cd speciation (P<0.05). Cd leaching in sediment and total iron in the overlying water remained at low levels during 90 d of incubation. Notably, each treatment maintained a high Cd immobilization efficiency under different pH, water/sediment ratio, organic acid, and coexisting ion conditions. Sediment physicochemical properties, functional bacteria, and a range of adsorption, complexation and precipitation of CdS effects dominated Cd immobilization.
期刊：
Physica Status Solidi-Rapid Research Letters,2024年18(2):2300334- ISSN：1862-6254
通讯作者：
Huo, SY
作者机构：
[Fu, Chun-Ming; Li, Hong-Kang; Huo, Shao-Yong; Yao, Long-Chao] Univ South China, Coll Mech Engn, Hengyang 421001, Peoples R China.
通讯机构：
[Huo, SY ] U;Univ South China, Coll Mech Engn, Hengyang 421001, Peoples R China.
关键词：
defect states;elastic valley edge states;power dividers;rainbow trapping;topological phononic crystals
摘要：
Topological phononic crystals (PnCs) with topologically protected boundary states have important applications in the fields of acoustic wave transmission and control. However, previous studies based on solid-state PnC systems are mostly limited by fixed structures, resulting in the difficulty to deform the edge states, which partly limits its practical applications. Herein, a 2D solid topological PnC coupled with the defect is designed to achieve the adjustable valley edge state and rainbow trapping. First, by breaking the spatial inversion symmetry, the valley Hall phase transition of elastic wave is realized and valley edge states are obtained. Next, by introducing defects of different widths between the two different valleys' topological PnCs, both the defect-adjusted valley edge state and defect state are achieved. Then, by designing different topological PnCs waveguides, the robust transport characteristics of the two above states are compared. Subsequently, a new power divider based on the defect-adjusted valley edge state is designed, which is found to possess various manners of operation such as equal and unequal power divisions. Finally, based on defect adjustment of the edge states, a rainbow trapping is implemented. This research provides an important guidance for ultrasonic devices, such as waveguides, energy harvesters, and power dividers. By introducing the line defects in the topological domain wall for the elastic wave, the defect-adjusted valley edge states and defect states are presented, which further are applied to design the novel elastic ultrasonic devices, such as the equal or unequal power dividers and the rainbow trapping effects.image & COPY; 2023 WILEY-VCH GmbH
摘要：
To explore the influence of lithology on the failure behavior of layered tunnel, true triaxial compression experiments were undertaken on cubical phyllite and yellow sandstone samples containing a "D" shaped hole. The failure progress of the hole sidewalls was monitored and captured using a miniature camera. The results reveal that the initial vertical failure stress of the phyllite samples presents a "U" shaped change as the bedding angle increases. At the bedding angle of 45 degrees, compared with the initial vertical failure stress of the yellow sandstone tunnel, that of the phyllite tunnel is lower, resulting in larger rock fragments and deeper V-shaped grooves. The failure pattern of the phyllite tunnel is primarily manifested as extensive shear sliding failure, and the failure is more severe. The failure of the yellow sandstone tunnel is primarily characterized by the sequential laminar fracturing along the maximum principal stress direction, predominantly manifesting as tensile failure. The primary factors influencing the failure of two types of layered rocks are the significant variations in the clay mineral content within the rocks. For the phyllite, it contains nearly one-third of montmorillonite (a clay mineral). This results in the formation of weak bedding planes within surrounding rocks, which induces shear slip failures along these bedding planes. In contrast, the yellow sandstone has a lower clay mineral content, leading to the absence of distinct weak bedding planes within the surrounding rock. In this case, bedding planes present ignorable effect on the surrounding rock.
期刊：
Journal of Diabetes Science and Technology,2024年18(3):752 - 753 ISSN：1932-2968
通讯作者：
Hongying Wang, PhD
作者机构：
[Ke Tian, MD*; Nan Yan, MD*; Hongying Wang, PhD] Department of Respiratory and Critical Care Medicine, The Affiliated Nanhua Hospital, Hengyang Medical School, University of South China, Hengyang, China
通讯机构：
[Hongying Wang, PhD] D;Department of Respiratory and Critical Care Medicine, The Affiliated Nanhua Hospital, Hengyang Medical School, University of South China, Hengyang, China
摘要：
Sandstone-type deposits have emerged as the primary uranium deposits being mined in China, utilizing in-situ leaching technology. However, the leaching of uranium resources within sandstone formations faces significant constraints due to their extremely low permeability, accounting for approximately seventy percent of the total. This paper aims to present recent advancements in the field in enhancing seepage-leaching mass-transfer properties in in-situ leaching of uranium from low-permeability sandstone. We will provide an overview of the main factors influencing the in-situ leaching process in low-permeability ore layers, discussing the technical characteristics of applicable methods designed to enhance permeability in low-permeability uranium-bearing sandstone based on the existing research. Additionally, we will also explore the suitability of various approaches from other fields in the in-situ leaching of uranium process. Finally, we will outline the prospects regarding process methodologies, leaching agents, and enhancing permeability methods.
期刊：
INTERNATIONAL JOURNAL OF RADIATION ONCOLOGY BIOLOGY PHYSICS,2024年120(2, Supplement):e766-e767 ISSN：0360-3016
通讯作者：
F. Liu
作者机构：
[F. Liu; C. Jiang; C. Fan; W. Liu; X. Ye; Y. Li; X. Wu; K. Chen; Y. Qiu; L. He; S. Xiao; Q. Zhao; W. Wu] Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China;Department of Radiation Oncology, Hunan Cancer Hospital & the Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan, China;Key Laboratory of Translational Radiation Oncology, Hunan Province, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China;[Y. Li] Hengyang Medical School, University of South China, Hengyang, China;Hunan Normal University School of Medicine, Changsha, China
通讯机构：
[F. Liu] H;Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, China
