期刊：
Separation and Purification Technology,2024年335:126214 ISSN：1383-5866
通讯作者：
Xie, D
作者机构：
[Li, Suzhe; Tang, Zengming; Yang, Xiaomin] Univ South China, Sch Resource & Environm & Safety Engn, Hengyang 421001, Peoples R China.;[Xie, D; Xie, Dong; Li, Suzhe; Tang, Zengming; Yang, Xiaomin] Natl & Local Joint Engn Res Ctr Airborne Pollutant, Hengyang 421001, Peoples R China.;[Xie, D; Xie, Dong] Univ South China, Sch Civil Engn, Hengyang 421001, Peoples R China.
通讯机构：
[Xie, D ] N;Natl & Local Joint Engn Res Ctr Airborne Pollutant, Hengyang 421001, Peoples R China.;Univ South China, Sch Civil Engn, Hengyang 421001, Peoples R China.
摘要：
Finding an inexpensive and efficient porous adsorbent to capture the gaseous radioiodine generated during spent fuel reprocessing has been challenging. Herein, we present a design philosophy for waste control to develop porous carbon for gaseous iodine capture from sewage sludge waste. Among them, the novel in situ etching of polytetrafluoroethylene was employed to improve pore accessibility. The hazards of the conventional preparation of sludge-derived carbon using highly corrosive NaOH and HF solutions were overcome. Polytetrafluoro-ethylene etched porous carbon with large specific surface area (1103 m2/g), interconnected hierarchical porous structure, and excellent hydrophobicity (water contact angle 126.52 degrees), providing efficient adsorption of gaseous iodine in hot (30-150 degrees C) and humid (50-96% relative humidity [RH]) environments. The iodine adsorption of hierarchical porous carbon was tested under static and dynamic conditions, and high records have been achieved. Notably, due to the structural advantage of hydrophobicity, a considerable dynamic adsorption capacity (1746.77 mg/g) was also maintained in a mixed iodine gas stream containing water vapor in a humid (50% RH) hot (75 degrees C) condition. This study is the first to use an in situ etching strategy for polytetrafluoroethylene, which opens a new avenue for converting sludge waste into low-cost porous carbon and provides an attractive option for capturing iodine in hot and humid environments.
摘要：
This paper presents a theoretical solution for bond-slip behavior of SRC interface based on experiment, numerical simulation, and theoretical derivation. Push-out tests of five specimens were firstly carried out, based on which, the simplified bond-slip model was proposed. The specimen was fabricated using the Q345H-shape steel (400 mm x 200 mmx13 mm x 8 mm) and C50 concrete (350 mm x 600 mm) with a bonding length of 500 mm. A FE model was established based on the bond-slip model to analyze the nonlinear bonding stress that are difficult to obtain from the experiment. The research shows that although the bonding stress in the elastic stage is not uniformly distributed, it is basically uniformly distributed when the ultimate bearing capacity is reached. It proves that assuming the average interfacial bonding stress under ultimate load to replace the maximum bonding stress is reasonable, which is crucial for designer to estimate interface bearing capacity and maximum bonding stress. Moreover, five different stages were obtained by the FE model analysis and the theoretical equations of bonding stress nonlinear distribution were obtained based on the boundary condition of each stage. The theoretical solution clearly showed the relationship between interface nonlinear stress distribution and influencing parameters including the bond area, elasticity modulus of material, section area of specimen, bond-slip constitutive model, and the external load. Based on the theoretical model, the influences of different parameters can be directly obtained without conducting further experiments and establishing different FE models.
摘要：
Mining can provide abundant resources, but it also causes heavy metal wastewater pollution, which poses a serious threat to aquatic ecosystems. In this study, Cypridopsis vidua was used as the test organism to investigate the single and combined acute toxicity of common heavy metals (such as chromium (Cr) and nickel (Ni)) in mining wastewater. Then, a random forest model (RF model) was used to predict the combined toxicity of chromium and nickel. Single acute toxicity experiments showed that the 96 h-LC(50 )values of the Cr and Ni for Cypridopsis vidua were 0.81 mg/L and 4.3 mg/L, respectively. aCr was more toxic than Ni. Furthermore, the combined acute toxicity experiments demonstrated that the toxicity of Cr-Ni was higher than Ni but lower than Cr. The predicted results of the RF model were highly consistent with the experimental results of the Cr-Ni combined acute toxicity. So, the model has accurate toxicity prediction ability.
摘要：
To investigate the strengthening effects and mechanisms of bioaugmentation on the microbial remediation of uranium-contaminated groundwater via bioreduction coupled to biomineralization, two exogenous microbial consortia with reducing and phosphate-solubilizing functions were screened and added to uranium-contaminated groundwater as the experimental groups (group B, reducing consortium added; group C, phosphate-solubilizing consortium added). β-glycerophosphate (GP) was selected to stimulate the microbial community as the sole electron donor and phosphorus source. The results showed that bioaugmentation accelerated the consumption of GP and the proliferation of key functional microbes in groups B and C. In group B, Dysgonomonas, Clostridium_sensu_stricto_11 and Clostridium_sensu_stricto_13 were the main reducing bacteria, and Paenibacillus was the main phosphate-solubilizing bacteria. In group C, the microorganisms that solubilized phosphate were mainly unclassified_f_Enterobacteriaceae. Additionally, bioaugmentation promoted the formation of unattached precipitates and alleviated the inhibitory effect of cell surface precipitation on microbial metabolism. As a result, the formation rate of U-phosphate precipitates and the removal rates of aqueous U(VI) in both groups B and C were elevated significantly after bioaugmentation. The U(VI) removal rate was poor in the control group (group A, with only an indigenous consortium). Propionispora, Sporomusa and Clostridium_sensu_stricto_11 may have played an important role in the removal of uranium in group A. Furthermore, the addition of a reducing consortium promoted the reduction of U(VI) to U(IV), and immobilized uranium existed in the form of U(IV)-phosphate and U(VI)-phosphate precipitates in group B. In contrast, U was present mainly as U(VI)-phosphate precipitates in groups A and C. Overall, bioaugmentation with an exogenous consortium resulted in the rapid removal of uranium from groundwater and the formation of U-phosphate minerals and served as an effective strategy for improving the treatment of uranium-contaminated groundwater in situ.
摘要：
The emergence of antibiotic resistance genes (ARGs) and antibiotic-resistant bacteria (ARB) in the environment is well established as a human health crisis. The impact of radioactive heavy metals on ecosystems and ultimately on human health has become a global issue, especially for the regions suffering various nuclear activities or accidents. However, whether the radionuclides can affect the fate of antibiotic resistance in bacteria remains poorly understood. Here, the dynamics of ARB, three forms of ARGs-intracellular ARGs (iARGs), adsorbed extracellular ARGs (aeARGs), and free extracellular ARGs (feARGs)-and microbial communities were investigated following exposure to uranium (U), a representative radioactive heavy metal. The results showed that 90-d of U exposure at environmentally relevant concentrations of 0.05mg/L or 5mg/L significantly increased the ARB concentration in activated sludge (p<0.05). Furthermore, 90-d of U exposure slightly elevated the absolute abundance of aeARGs (except tetO) and sulfonamide iARGs, but decreased tetracycline iARGs. Regarding feARGs, the abundance of tetC, tetO, and sul1 decreased after 90-d of U stress, whereas sul2 showed the opposite trend. Partial least-squares path model analysis revealed that the abundance of aeARGs and iARGs under U stress was predominantly driven by increased cell membrane permeability/intI1 abundance and cell membrane permeability/reactive oxygen species concentration, respectively. Conversely, the changes in feARGs abundance depended on the composition of the microbial community and the expression of efflux pumps. Our findings shed light on the variations of ARGs and ARB in activated sludge under U exposure, providing a more comprehensive understanding of antibiotic resistance risks aggravated by radioactive heavy metal-containing wastewater.
期刊：
Applied Radiation and Isotopes,2024年205:111145 ISSN：0969-8043
通讯作者：
Xie, SB
作者机构：
[Xie, Shuibo; Mai, Yingqing; Wang, Guohua; Zhang, Haibo] Univ South China, Sch Civil Engn, Hengyang 421001, Peoples R China.;[Xie, Shuibo] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Min, Hengyang 421001, Peoples R China.;[Wang, Shuiyun] Nonferrous Met Design & Res Inst, Changsha 410000, Peoples R China.;[Xie, Shuibo] Univ South China, 28 Changshen Rd, Zhengxiang Dist, Hengyang 421001, Peoples R China.
通讯机构：
[Xie, SB ] U;Univ South China, 28 Changshen Rd, Zhengxiang Dist, Hengyang 421001, Peoples R China.
关键词：
Acid wastewater;Adsorption;PT-CS;U(VI)
摘要：
With sodium tripolyphosphate (STPP) as cross-linker, Persimmon tannin-chitosan microspheres (PT-CS) were synthesized by hydrothermal for removing U(VI) from acidic effluent. The batch experiments indicated that PT-CS adsorbed U(VI) most effectively at pH 1.5, the maximum adsorption capacity for PT-CS was 245mg/g. Compared to pure CS dissolved at pH 3, PT-CS still maintain high stability at pH 1. Moreover, single system of common metal ions in rare earth wastewater only slightly affected the adsorption of uranium at pH 1.5, but this process was inhibited about 30% at pH 5. Those results indicated that the selectivity of PT-CS for uranium removal could be controlled by regulating the pH and there are excellent potentials for PT-CS using in acid metal water treatment. Its adsorption selectivity and ability to adapt different condition was demonstrated with uraniferous rare earth wastewater treatment. The adsorption for PT-CS to U(VI) were well fitted for both Langmuir isothern and pseudo-secondary kinetic model equations, and that meant chemisorption dominated the removal process. Spectroscopic analyses confirmed that the adsorption of U(VI) occurred via surface complexation by -OH and ion exchange with Na(+). Therefore, this study provides a high-efficiency, low-cost, valuable and highly adaptable method for the treatment of acidic uranium-containing effluents.
通讯机构：
[Yang, Y ] U;Univ South China, Sch Civil Engn, Hengyang 421001, Hunan, Peoples R China.;Key Lab Hunan Technol Energy Conservat Prefabricat, Hengyang 421001, Hunan, Peoples R China.
关键词：
Hot-humid climates;Evaporative-cooling condenser;Structure optimization;Heat transfer;Mass transfer
摘要：
The mechanical vapor compression system (MVC) coupled with the evaporative-cooling condenser is an effective method to improve its high temperature adaptability. However, this hybrid systems typically use an evaporative cooler as a single-stage pre-cooling unit of condenser and is mainly designed for hot-dry climates. In this paper, based on conventional evaporative-cooling condenser configuration, three two-stage evaporative-cooling condenser systems (MVC-TSEC(A), MVC-TSEC(B) and MVC-TSEC(C)) were proposed. The MVC-TSEC(A) consists of one condenser and an indirect/direct evaporative-cooler. The MVC-TSEC(B) and MVC-TSEC(C) have two condensers (in series), which are coupled with a two-stage evaporative cooling system. The refrigerant in the MVC-TSEC(C) forms a counter-flow configuration with the outdoor air, while it is concurrent flow in MVC-TSEC (B). Subsequently, the effects of the ambient parameters and outdoor air flowrate on the three two-stage hybrid systems were analyzed comparatively based on detailed numerical models. Finally, the application potential of these hybrid systems was evaluated comprehensively in hot-humid climates. The results showed that the seasonal COP and energy-saving rate for the MVC-TSEC(C) are reached by 4.2-4.7 and 12.7-21.1 %, respectively. Moreover, the static equipment payback period of the three two-stage hybrid systems are 3.8, 3.3 and 3.0 years, respectively.
期刊：
Theoretical and Applied Climatology,2024年155(1):117-129 ISSN：0177-798X
通讯作者：
Wang, HQ
作者机构：
[Wang, HQ; Liu, Xinyu; Wang, Hanqing; Zhu, Dongnan; Liu, Zhenming; He, Junyi] Univ South China, Sch Civil Engn, Hengyang, Peoples R China.;[Wang, HQ; Liu, Xinyu; Wang, Hanqing; Zhu, Dongnan; Liu, Zhenming; He, Junyi] Natl & Local Joint Engn Res Ctr Airborne Pollutant, Hengyang, Peoples R China.;[Wang, HQ; Wang, Hanqing] Cent South Univ Forestry & Technol, Sch Civil Engn, Changsha, Peoples R China.
通讯机构：
[Wang, HQ ] U;Univ South China, Sch Civil Engn, Hengyang, Peoples R China.;Natl & Local Joint Engn Res Ctr Airborne Pollutant, Hengyang, Peoples R China.;Cent South Univ Forestry & Technol, Sch Civil Engn, Changsha, Peoples R China.
关键词：
WRF;Deep learning;Downscaling
摘要：
The Weather Research and Forecasting (WRF) model improves the accuracy of climate prediction and obtains meteorological parameters for fine grids; however, fine-grid climate predictions for different time periods and regions often consumes a great amount of computational resources. In this letter, the Multi Residual Attention Generative Adversarial Network (MRA-GAN) is proposed based on the generative adversarial network; the technique is applied to restore a simulated image from a coarse-grid WRF model to a simulated image from a fine-grid WRF model. The fine-grid image generated by MRA-GAN is very similar to the original fine-grid image. When compared with Super-Resolution Wasserstein Generative Adversarial Network with Gradient Penalty (SRWGAN-GP), the average of peak signal-to-noise was improved by approximately 0.54dB, and the average structural similarity index was improved by approximately 3%. After comparing the downscaling results of temperature, wind speed, and relative humidity of various models with the original data, the results show that MRA-GAN has the highest correlation, the lowest data dispersion, and the smallest data error. The trained network model was able to efficiently transform the coarse-grid meteorological fields from different time periods and different simulation variables into fine-grid meteorological fields, and it greatly reduced the computational workload.
作者：
Su, Chi;Hua, Yilong;Liu, Yi;Tao, Shu;Jia, Fei;...
期刊：
PLOS ONE,2024年19(3):e0300800 ISSN：1932-6203
通讯作者：
Lin, WY
作者机构：
[Hua, Yilong; Liu, Yi; Su, Chi; Zhao, Wenhui] Univ South China, Sch Resources Environm & Safety Engn, Hengyang 421001, Peoples R China.;[Tao, Shu] Univ South China, Sch Math & Phys, Hengyang, Peoples R China.;[Jia, Fei] Univ South China, Sch Civil Engn, Hengyang, Peoples R China.;[Zhao, Wenhui] Shanxi Prov Changzhi City Wuxiang Cty Jia Huo Town, Changzhi, Peoples R China.;[Lin, WY; Lin, Wangyang] Univ South China, Coll Mech Engn, Hengyang, Peoples R China.
通讯机构：
[Lin, WY ] U;Univ South China, Coll Mech Engn, Hengyang, Peoples R China.
摘要：
Mining wastewater with heavy metals poses a serious threat to the ecological environment. However, the acute single and combined ecological effects of heavy metals, such as chromium (Cr) and nickel (Ni), on freshwater ostracods, and the development of relevant prediction models, remain poorly understood. In this study, Heterocypris sp. was chosen to investigate the single and combined acute toxicity of Cr and Ni. Then, the quantitative structure-activity relationship (QSAR) model was used to predict the combined toxicity of Cr and Ni. The single acute toxicity experiments revealed high toxicity for both Cr and Ni. In addition, Cr exhibited greater toxicity compared to Ni, as evidenced by its lower 96-hour half-lethal concentration (LC50) of 1.07 mg/L compared to 4.7 mg/L for Ni. Furthermore, the combined acute toxicity experiments showed that the toxicity of Cr-Ni was higher than Ni but lower than Cr. Compared with the concentration addition (CA) and independent action (IA) models, the predicted results of the QSAR model were more consistent with the experimental results for the Cr-Ni combined acute toxicity. So, the high accuracy of QSAR model identified its feasibility to predict the toxicity of heavy metal pollutants in mining wastewater.
摘要：
The properties of a large number of concrete infrastructures in China are deteriorating year by year, raising the need for repairing and strengthening these infrastructures. By introducing waterborne polymers into a cement concrete system, brittle cracks and easy bonding performance defects of concrete can be compensated for to form a long-life, semi rigid, waterborne polymer-modified cementitious repair material with a promising development prospect. This paper investigates the modification effect of polymer emulsions on ordinary cement mortar. Our research mainly focused on the physical and mechanical properties, durability, microstructure and application status of waterborne polymer-modified cementitious composites. Literature studies show that with the increase in waterborne polymer content (0 wt%similar to 20 wt%), the performance of cement mortar significantly improves, which in turn expands its application range. Compared with ordinary cement mortar, the introduction of waterborne polymers blocks some of the pores in the cement to a certain extent, thus improving its permeability, freeze-thaw resistance and durability. Finally, this paper describes the application of waterborne polymer-cementitious composites in western saline soil environments, as well as discusses the prospects of their development.
通讯机构：
[Zeng, S ] U;Univ South China, Sch Resource Environm & Safety Engn, Hengyang 421001, Peoples R China.
关键词：
Anchor bolts;Pull-out load;Cement-sand ratio;Anchorage defect;Key dynamic testing signal
摘要：
Pull-out load and the cement -sand ratio (CSR) can affect the non-destructive testing (NDT) results of anchor bolts. Therefore, in this article, NDT experiments were conducted on both fully and defectively grouted anchor bolts, and variation patterns of key dynamic testing signal parameters were analyzed. A longitudinal vibration model of defectively grouted anchor bolts considering dynamic and static damping was proposed, and simulated NDT of anchor bolts with varying qualities. The results indicated that grouting defects resulted in an increase in wave velocity, along with a decrease in the fundamental frequency and dynamic stiffness of anchor bolts. When grouting defects and pull-out load acted concurrently, the fundamental frequency, and dynamic stiffness of the defectively grouted anchor bolts were consistently smaller than those of fully grouted ones during the initial loading phase. With pull-out load increasing, wave velocity decreased first, then increased; fundamental frequency increased, followed by a decrease; dynamic stiffness rose. When the CSR of defectively grouted anchor bolts was reduced, wave velocity decreased, fundamental frequency increased slightly, and a substantial increase in dynamic stiffness was observed. Pull-out loads were more sensitive to anchor bolt key dynamic signals than defects and CSR. Simulated validation demonstrated the reliability of the proposed theory.
摘要：
Levels of cadmium (Cd) and lead (Pb) correspond to common composition in acid mine wastewater of Hunan Province of China. The removal path of Cd and Pb and the structure of microbial community were investigated by developing constructed wetlands (CWs) with different layer positions of biochar. The biochar as a layer at the bottom of CW (BCW) system exhibited maximum Cd and Pb removal efficiencies of 96.6-98.6% and 97.2-98.9%, respectively. Compared with original soil, BCW increased the relative proportions of Proteobacteria, Firmicutes, Acidobacteriota, Verrucomicrobiota, Desulfobacterota, Armatimonadota, Bacteroidota, Patescibacteria, Basidiomycota (phylum level) and Burkholderia-Caballeronia-Paraburkholderia, Citrifermentans, Chthonomonadales, Cellulomonas, Geothrix, Terracidiphilus, Gallionellaceae, Microbacterium, Vanrija, Apiotrichum, Saitozyma, Fusarium (genus level). The concentrations of Cd and Pb were positively correlated with the abundance of Verrucomicrobiota, Basidiomycota (phylum level), and Methylacidiphilaceae, Meyerozyma, Vanrija (genus level). This study demonstrates that BCW system can improve removal performance toward Cd and Pb, as well as alter microbial community.
摘要：
In order to solve the problem of uranium pollution during the development and application of nuclear energy, magnetic ZnFe2O4/Zr-O2(ZFOZO) composite material was synthesized by hydrothermal method to treat uranium containing wastewater. In this study, the surface properties and mechanism of the synthesized ZFOZO were analyzed by various characterization methods. The effects of adsorption time, pH, dosage of adsorbent, coexisting ions, and initial concentration of uranium (VI) solution on the adsorption performance of uranium (VI) by ZFOZO were investigated. ZFOZO exhibited the maximum adsorption rate of 99.8% under the conditions of CU (VI) = 10 mg/L, pH = 6, M/V = 0.3g/L, t =120 min, and T = 303K. The adsorption process was found to be a spontaneous endothermic process and conformed to the pseudo-second-order kinetic model and the Freundlich isothermal adsorption model. The adsorption mechanism of ZFOZO on U (VI) is mainly electrostatic adsorption, surface complexation, and oxygen vacancy. The maximum adsorption capacity of ZFOZO for U (VI) can reach 552.36mg/g. Adsorption-desorption experiment demonstrated that ZFOZO has a good reusability, after five cycles of adsorption and desorption, the adsorption efficiency is still above 75%. Cu2+ and Fe3+ will produce competitive adsorption and reduce the adsorption performance of ZFOZO on U (VI). In summary, this study provides a high efficiency, low cost, and rapid recovery adsorbent for the treatment of uranium containing wastewater in the future.
摘要：
In this study, we employed classic electrochemical techniques including cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) to perform electrochemical characterization on atomic-level single-crystal TiO2 electrodes and extract capacitive and resistive properties of single-crystal TiO2 electrode/solution interface in KCl and KCl/K3PO4 at various pH levels. The lattice structure and crystal appearance were characterized using X-ray diffractometry (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and Raman spectroscopy to facilitate the in-depth exploration of heterogeneous reaction dynamics and theory. Furthermore, this study aimed to verify and improve the theory and application of capacitance at the single-crystal TiO2 electrode/solution interface. The electrochemical measurements indicate that, in the same pH, the presence of PO43- significantly increases the total capacitance (C-T), outer capacitance (C-O), electrical double-layer capacitance (C-dl), and diffusion layer capacitance (C-diff) at single-crystal TiO2 electrode/solution interface. This enhancement is attributed to the direct interaction between PO43- and the single-crystal TiO2 electrode surface, leading to the specific adsorption of PO43- on the electrode surface, revealing higher current and stronger electrochemical activity in the interaction between TiO2 and PO43-. Additionally, our XPS results indicate the adsorption of PO43- on the single-crystal TiO2 electrode surface. The interaction of PO43- with the TiO2 surface demonstrates increased hydrophilicity and enhanced adsorption capacity through mechanisms such as ligand exchange or cation bridging, thereby augmenting the C-dl at the single-crystal TiO2 electrode/solution interface.
通讯机构：
[Duan, Y ] U;Univ South China, Sch Civil Engn, Hengyang 421001, Peoples R China.
摘要：
Pollution-related problems in the water environment caused by nuclear wastewater leakage has attracted widespread public attention. In this study, the strategy of treating waste with waste was adopted to prepare a tea waste-derived biochar/g-C3N4/MoS2 (BgM) Z-scheme composite for the photocatalytic reduction of U(vi) in water using thermal polymerization and hydrothermal methods. Among different proportions of BGMs, 10%BgM holds the highest removal efficiency of U(vi). Approximately all U(vi) was removed by 10%BgM under air atmosphere after 2 h of light irradiation (pH = 4.5, dosage is 0.5 g L-1). Furthermore, the removal efficiency of U(vi) by 10%BgM remained >80% after five cycles of tests, and it maintained a high selectivity in the presence of co-existing ions. Based on the quenching experiments and characterization analysis, photogenerated e- and O-center dot (2)- play an important role in the reduction of U(vi). The enhancement of the photoreduction activity can be attributed to the acceleration of photogenerated electron transfer by the incorporation of tea waste biochar and the formation of a Z-type charge transfer mechanism, which improved the visible light absorption capacity. This study presents a promising material and approach for the effective treatment of uranium wastewater using photocatalysis.
摘要：
Thermal-mechanical damage is an important problem threatening the safety of deep rock engineering. In this paper, the effects of coupling damage on the deformation and failure characteristics of rock mass were studied via cyclic loading damage, thermal damage and uniaxial compression acoustic emission (AE) tests, and the microscopic fracture process of the damaged rock mass was numerically simulated. Results showed that during heat treatment, the colour of the sample changed significantly, the mass, the P-wave velocity and the number of mineral species decreased. The peak strength and elastic modulus reach their maximum values at 600 degrees C and 300 degrees C, respectively, exhibiting a trend of initial increase and subsequent decrease. The rapid growth period of AE activity increased noticeably with increasing temperature, and the effect of energy accumulation became more significant at higher peak strengths. The failure mode was influenced primarily by the cyclic loading amplitude. In addition, an increase in the stress or temperature after crack initiation leads to a sharp increase in the damage within the rock. Temperature had a more significant effect on the generation of damage than stress. Stress-induced microcracks were concentrated in the weakly bonded particles, whilst temperature-induced microcracks were concentrated in the strongly bonded particles. Temperature had a significant effect on the mineral composition of rock mass.The rapid growth period of AE activity was prolonged with the temperature increase.The failure mode of rock mass was mainly influenced by cyclic loading amplitude.Temperature-induced microcracks were concentrated in strongly bonded particles.
作者机构：
[Ding, Rui] Univ South China, Sch Resources Environm & Safety Engn, Hengyang 421001, Peoples R China.;[Liu, Zehua] Univ South China, Sch Civil Engn, Hengyang 421001, Peoples R China.
通讯机构：
[Liu, ZH ] U;Univ South China, Sch Civil Engn, Hengyang 421001, Peoples R China.
关键词：
nuclear power plant building project;risk assessment;interval type-2 fuzzy set;analytic network process;cloud model
摘要：
This study proposes an approach for simultaneously treating fuzziness and randomness when conducting safety risk assessments of nuclear power plant building projects (NPPBPs). First, the interval type-2 fuzzy set (IT2FS) and analytic network process (ANP) were employed to establish an IT2FS-ANP method for modifying the solution for the weight vector and determining the mutual relationships between the assessment indexes and their weights. Second, the IT2FS and cloud model (CM) were used to establish the IT2FS-CM method to modify the solution for the expectation value. Third, the IT2FS-ANP and IT2FS-CM methods were combined to establish a model for ranking the safety risks and determining the overall safety risk level. Finally, the approach was applied to an NPPBP in northeast China to validate its applicability.
摘要：
The reduction of soluble U(VI) to insoluble and less toxic U(IV) by photocatalysis is an effective method to control uranium contamination. The graphitic carbon nitride nanosheet (CNN)/UiO-66 composites (CNNU) were prepared by thermal polymerization and solvothermal methods for the removal of U(VI). The morphology, crystal structure and optical properties of composites were analyzed by SEM, XRD, BET, UV-DRS, PL and EIS. The results showed the introduction of UiO-66 increased the specific surface of CNN from 9.07 m(2)/g to 46.24 m(2)/g, and effectively suppressed the recombination of photogenerated electrons and holes and improved the photocatalytic activity. The U(VI) removal capacity by adsorption and photocatalysis of CNNU was reached 779.47mg/g, which significantly higher than that of adsorption (478.38mg/g). The adsorption process was found to conform to the pseudo-second-order kinetic model and the Langmuir isothermal model. Meanwhile, U(VI) adsorbed on the CNNU was reduced to U(IV) via e(-) and ·O(2)(-) generated in the photocatalytic process. Therefore, this outstanding performance of CNNU in U(VI) removal is attributed to the synergistic effect of adsorption and photocatalytic reduction.
期刊：
NEW JOURNAL OF CHEMISTRY,2024年48(14):6211-6220 ISSN：1144-0546
通讯作者：
Liu, HJ
作者机构：
[Fu, Tianyu; Wang, Xinyi; Liu, Hongjuan; Liu, HJ] Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.;[Liu, Yingjiu] Univ South China, Hunan Prov Key Lab Pollut Control & Resources Reus, Hengyang 421001, Peoples R China.;[Liu, Hongjuan; Liu, HJ] Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Min, Hengyang 421001, Peoples R China.
通讯机构：
[Liu, HJ ] U;Univ South China, Sch Nucl Sci & Technol, Hengyang 421001, Peoples R China.;Univ South China, Key Discipline Lab Natl Def Biotechnol Uranium Min, Hengyang 421001, Peoples R China.
摘要：
The pore structure of metal-organic frameworks (MOFs) is crucial to their adsorption performance, and it is still a challenge to precisely control the pore size to realize superior removal of uranium. The pore size of MOF-A, MOF-B and MOF-C was fine-tuned by using three organic chains with different lengths (fumaric acid, terephthalic acid and naphthalene dicarboxylic acid, respectively). The synthesized MOF-A, MOF-B and MOF-C had ordered increase in pore sizes with 3.8 & Aring;, 5.7 & Aring; and 7.6 & Aring;, respectively. Pore size of 7.6 & Aring; in MOF-C was a little larger than the geometric dimension of the UO22+ ion (maximum length 6.04-6.84 & Aring;), which facilitated diffusion of UO22+ ions and achieved highly efficient adsorption. The maximum adsorption capacity (584 mg g(-1)) and removal rate (99.75%) of uranium for MOF-C were higher than those for MOF-A and MOF-B. The excellent adsorption performance of MOF-C was attributed to the specific pore structure of MOF-C and effective complexation of oxygen-containing groups with U(VI). Our work proposes a new strategy for the outstanding removal of uranium by using different organic chains to precisely regulate the pore size of MOF.
