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Identifying the Hydrochemical Characteristics,Genetic Mechanisms and Potential Human Health Risks of Fluoride and Nitrate Enriched Groundwater in the Tongzhou District,Beijing,North China

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Acta Geologica Sinica(English Edition) 2024年第2期98卷 468-476页

作者： ZHANG Shouchuan LIU Kai ma yan WANG Luyao SUN Junliang Chinese Academy of Geological Sciences Beijing 100037China School of Water Resources and Environment China University of Geosciences(Beijing)Beijing 100083China

Fluoride and nitrate enriched groundwater are potential threats to the safety of the groundwater supply that may cause significant effects on human health and public safety,especially in aggregated population areas and economic *** study focuses on the high F^(−)and NO_(3)^(−)concentration groundwater in Tongzhou District,Beijing,North China.A total of 36 groundwater samples were collected to analyze the hydrochemical characteristics,elucidate genetic mechanisms and evaluate the potential human health *** results of the analysis indicate:Firstly,most of the groundwater samples are characterized by Mg-HCO_(3) and Na-HCO_(3) with the pH ranging from 7.19 to 8.28 and TDS with a large variation across the range 471-2337 mg/*** NO_(3)^(−)concentration in 38.89%groundwater samples and the F^(−)concentration in 66.67%groundwater samples exceed the permissible limited ***,F^(−)in groundwater originates predominantly from water-rock interactions and the fluorite dissolution,which is also regulated by cation exchange,competitive adsorption of HCO_(3)−and an alkaline ***,the effect of sewage disposal and agricultural activities have a significant effect on high NO3-concentration,while the high F^(−)concentration is less influenced by anthropogenic *** alkaline environment favors nitrification,thus being conducive to the production of NO_(3)^(−).Finally,the health risk assessment is evaluated for different population *** results indicate that high NO_(3)^(−)and F^(−)concentration in groundwater would have the largest threat to children’s *** findings of this study could contribute to the provision of a scientific basis for groundwater supply policy formulation relating to public health in Tongzhou District.

关键词： fluoride concentration nitrate pollution genetic mechanism health risk assessment Tongzhou District

Boosted sustained-release with iron-based MOF-derived mesoporouscarbon-spheres as a nitroimidazole drugs carrier

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Particuology 2024年第3期86卷 269-280页

作者： Danping Wu Jiaying Zou Junyi Chen yan Li Na ma Wei Dai College of Chemistry and materials Science Zhejiang Normal UniversityJinhua321004China College of Life Sciences Zhejiang Normal UniversityJinhua321004China College of Geography and Environmental Sciences Zhejiang Normal UniversityJinhua321004China

Metal-organic framework(MoF)with a buildable internal structure has aroused great interest focus as self-sacrificing precursors of porous carbon(PC).However,as a drug carrier,the MOF-derived PC developed thus far are generally composed of irregular powder shape due to their crystalline nature,which consequently causing the cerebral infarction,cerebral thrombosis,and other blood *** this article,we propose a novel approach to constructing amorphous carbon microspheres(AcMs)by dis-torting the topological network through hydrothermal treatment precursors of MIL-101(Fe).Then,a distinctive MIL-101(Fe)-derived spherical porous carbons(MSPC)is achieved through high temperature calcination toward *** of the glucose initial concentration and hydrothermal treatment time on the sphericity of the as-prepared mesoporous MsPC were investigated in *** the loading capacities and sustained-release performances of nitroimidazole drugs over MsPC through simulation internal environment of human body at different pH values was systematically *** nitro-imidazole drugs loading rate and release time of MsPC are 10% and 17 h under preferred ***,the MSPC exhibited very low toxicity on Hela cells and 293T cells at the concentrations tested(10-800μg mL^(-1)).This study,therefore,supports the potential of the mesoporous carbon spheres as a carrierfor nitroimidazole drug delivery.

关键词： Ornidazole Metronidazole Carbon spheres Sustained-release performance Biocompatibility

Thermally Conductive,Healable Glass Fiber Cloth Reinforced Polymer Composite based onβ-Hydroxyester Bonds Crosslinked Epoxy with Improved Heat Resistance

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Chinese Journal of Polymer Science 2024年第5期42卷 643-654,I0009页

作者： Fang Chen Xiao-yan Pang Ze-ping Zhang Min-Zhi Rong Ming-Qiu Zhang Key Laboratory for Polymeric Composite and Functional materials of Ministry of Education GD HPPC LabIGCMESchool of ChemistrySun Yat-sen UniversityGuangzhou510275China Guangdong Provincial Laboratory of Chemistry and Fine Chemical Engineering Jieyang Center Jieyang515200China

To simultaneously endow thermal conductivity,high glass transition temperature(Tg)and healing capability to glass fiber/epoxy(GFREP)composite,dynamic crosslinked epoxy resin bearing reversibleβ-hydroxyl ester bonds was reinforced with boron nitride nanosheets modified glass fiber cloth(GFC@BNNSs).The in-plane heat conduction paths were constructed by electrostatic self-assembly of polyacrylic acid treated GFC and polyethyleneimine decorated ***,the GFC@BNNSs were impregnated with the mixture of lower concentration(3-glycidyloxypropyl)trimethoxysilane grafted BN micron sheets,3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexanecarboxylate and hexahydro-4-methylphthalic anhydride,which accounted for establishing the through-plane heat transport pathways and avoiding serious deterioration of mechanical *** resultant GFREP composite containing less boron nitride particles(17.6 wt%)exhibited superior in-plane(3.29 W·m^(-1)·K^(-1))and through-plane(1.16 W·m^(-1)·K^(-1))thermal conductivities,as well as high Tg of 204℃(Tg of the unfilled epoxy=177℃).The reversible transesterification reaction enabled closure of interlaminar cracks within the composite,achieving decent healing efficiencies estimated by means of tensile strength(71.2%),electrical breakdown strength(83.6%)and thermal conductivity(69.1%).The present work overcame the disadvantages of conventional thermally conductive composites,and provided an efficient approach to prolong the life span of thermally conductive GFREP laminate for high-temperature resistant integrated circuit application.

关键词： Thermally conductive composites Boron nitride High-temperature resistance β-Hydroxyl ester bond Healing

Strong-coupling superconductivity with Tc above 70 K in Be-decorated monolayer T-graphene

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Science China(Physics,Mechanics & Astronomy) 2024年第1期67卷 99-105页

作者： Liu yang Peng-Fei Liu Hao-Dong Liu Ya-ping Li Na Jiao Hong-yan Lu Bao-Tian Wang ping Zhang School of Physics and Physical Engineering Qufu Normal UniversityQufu 273165China Institute of High Energy Physics Chinese Academy of SciencesBeijing 100049China Spallation Neutron Source Science Center Dongguan 523803China Institute of Applied Physics and Computational mathematics Beijing 100088China

Using first-principles calculations,we predict a new type of two-dimensional(2D)beryllium(Be)-decorated T-graphene named BeC_(2),where Be atoms are inserted into C–C bonds linking the carbon tetrarings of *** band structure shows that BeC_(2)is metallic,thus,the possible phonon-mediated superconductivity is explored based on the Eliashberg *** calculated electron-phonon coupling(EPC)constantλis up to 4.07,and the corresponding superconducting critical temperature(Tc)is 72.1 K,approaching the liquid nitrogen *** reason for the high Tc is the strong *** it is proved to be an anisotropic single-gap superconductor by analyzing the superconducting gap?kof BeC_(2).The electronic susceptibility calculation shows strong nesting effect in BeC_(2).Since rare 2D superconductors show such a strong EPC constantλwhich originates from the coupling between electrons in C-pzorbital and in-plane vibrations of Be and C atoms,the predicted BeC_(2)provides a new platform for investigating strong EPC 2D superconductor.

关键词： two-dimensional carbon-based superconductor electron-phonon coupling strong coupling high superconducting critical temperature

Coupled dynamic response analysis of multi-column floating offshore wind turbine with low center of gravity

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Journal of Ocean Engineering and Science 2024年第1期9卷 25-39页

作者： Jie yang yan-ping He Yong-sheng Zhao Xiao-yan yang Guo-rong Zhang State Key Laboratory of Ocean Engineering Shanghai Jiao Tong UniversityShanghai 200240China Collaborative Innovation Center for Advanced Ship and Deep-Sea Exploration(CISSE) Shanghai Jiao Tong UniversityShanghai 200240China School of Naval Architecture Ocean&Civil EngineeringShanghai Jiao Tong UniversityShanghai 200240China Faculty of maritime and Transportation Ningbo UniversityNingbo 315211China

To realize the application of the floating offshore wind turbine(FOWT)from deep to relatively shallow waters,a new concept of multi-column floating wind turbine platform with low center of gravity(CG)is designed and *** multi-column low CG platform is designed to support a 6MW wind turbine class and operated at a water depth of 50m in the South China *** frequency domain software WADAM and time domain software NREL-FAST are used to simulate coupled dynamic responses of the floating wind turbine system with second-order wave loads *** dynamic behaviors of multi-column low CG FOWT system under normal operation and parked conditions are *** influence of second-order wave force on the motion responses of the multi-column platform,fore-aft force and moment of the tower base and mooring force are researched *** results demonstrate that the coupled dynamic responses at rated operating condition and extreme condition meet the normal operating requirements and extreme survival requirements of FOWT system in the shallow water(50m)of South China *** addition,it is found that,the wave frequency response gradually replaces the second-order low frequency response as the main influencing factor of the coupled dynamic response of the FOWT system with the increasing severity of the sea ***,in general,the magnitude of second-order low frequency response increases with the increasing severity of the design load ***,in the subsequent design of the shallow water FOWT system,the second-order effects should be paid enough attention.

关键词： Floating offshore wind turbine Multi-column platform Second-order wave force Concept design Coupled dynamic response

Effects of Lactobacillus paracasei N1115 on gut microbial imbalance and liver function in patients with hepatitis B-related cirrhosis

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World Journal of Gastroenterology 2024年第11期30卷 1556-1571页

作者： yan-Chao Hu Xiang-Chun Ding Hui-Juan Liu Wan-Long ma Xue-yan Feng Li-Na ma Department of Infectious Disease General Hospital of Ningxia Medical UniversityYinchuan 750004Ningxia Hui Autonomous RegionChina Infectious Disease Clinical Research Center of Ningxia Yinchuan 750004Ningxia Hui Autonomous RegionChina

BACKGROUND Hepatitis B cirrhosis(HBC)is a chronic disease characterized by irreversible diffuse liver damage and aggravated by intestinal microbial imbalance and metabolic *** the relationship between certain single probiotics and HBC has been explored,the impact of the complex ready-to-eat Lactobacillus paracasei N1115(LP N1115)supplement on patients with HBC has not been *** To compare the changes in the microbiota,inflammatory factor levels,and liver function before and after probiotic treatment in HBC *** This study included 160 HBC patients diagnosed at the General Hospital of Ningxia Medical University between October 2018 and December *** were randomly divided into an intervention group that received LP N1115 supplementation and routine treatment and a control group that received routine treatment *** samples were collected at the onset and conclusion of the 12-wk intervention *** structure of the intestinal microbiota and the levels of serological indicators,such as liver function and inflammatory factors,were *** Following LP N1115 intervention,the intestinal microbial diversity significantly increased in the intervention group(Pmatory factors(Pmatory factor levels.

关键词： Hepatitis B cirrhosis N1115 ready-to-eat lactobacillus Inflammation Liver function Lachnospiraceae incertae sedis Probiotic

An Improved Modulation Strategy for Single-phase Three-level Neutral-point-clamped Converter in Critical Conduction Mode

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Journal of Modern Power Systems and Clean Energy 2024年第3期12卷 981-990页

作者： Ning Li Yujie Cao Xiaokang Liu yan Zhang Ruotong Wang Lin Jiang Xiao-ping Zhang School of Electrical Engineering Xi’an University of TechnologyXi’anChina the Department of Electronics Information and BioengineeringPolitecnico di MilanoMilanItaly Xi’an Jiaotong University Xi’anChina the Department of Electrical Engineering and Electronics University of LiverpoolLiverpoolU.K. the Department of Electronic Electrical and Systems EngineeringUniversity of BirminghamBirminghamU.K.

Two-level totem-pole power factor correction(PFC)converters in critical conduction mode(CRM)suffer from the wide regulation range of switching ***,in highfrequency applications,the number of switching times increases,resulting in significant switching *** solve these issues,this paper proposes an improved modulation strategy for the single-phase three-level neutral-point-clamped(NPC)converter in CRM with *** optimizing the discharging strategy and switching state sequence,the switching frequency and its variation range have been efficiently *** detailed performance analysis is also presented regarding the switching frequency,the average switching times,and the effect of voltage gain.A 2 k W prototype is built to verify the effectiveness of the proposed modulation strategy and analysis *** with the totem-pole PFC converter,the switching frequency regulation range of the three-level PFC converter is reduced by 36.48%and the average switching times is reduced by 45.10%.The experimental result also shows a 1.2%higher efficiency for the three-level PFC converter in the full load range.

关键词： Critical conduction mode(CRM) on-board charger switching frequency range switching times power factor correction(PFC) three-level converter

Graphdiyne oxide substrate-enhanced peroxidase-mimicking performance of Ru nanoparticles with physiological pH preference

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Nano Research 2024年第3期17卷 1123-1131页

作者： Cong Xu Wenjie ma Haozhi Wang Leihou Shao Weiqi Li ping Yu Lanqun mao Beijing National Laboratory for Molecular Science Key Laboratory of Analytical Chemistry for Living BiosystemsInstitute of ChemistryChinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing 100049China State Key Laboratory of marine Resource Utilization in South China Sea School of Materials Science and EngineeringHainan UniversityHaikou 570228China College of Chemistry Beijing Normal UniversityBeijing 100875China

Modulating electronic structure of metal nanoparticles via metal–support interaction has attracted intense interest in the field of catalytic ***,the roles of supporting substrates in regulating catalytic properties of nanozymes remain *** this study,we find that the use of graphdiyne oxide(GDYO)as the substrate for self-terminating growth of Ru nanoparticles(Ru@GDYO)endows the peroxidase-like activity of Ru nanoparticles with intrinsic physiological pH preference and natural horseradish peroxidase(HRP)comparable *** nanoparticles electrolessly deposited onto GDYO possess a partially oxidized electronic structure owing to limited charge transfer between Ru and GDYO,contributing to the intrinsic physiological pH preference of the peroxidase-mimicking *** importantly,the substrate GDYO plays an influential factor in enhancing catalytic activity,that is,the activity of Ru@GDYO is much higher than that of Ru nanoparticles deposited on other carbon substrates including graphene oxides and *** demonstrate the application of Ru@GDYO nanozyme in neutral solutions,we employ Ru@GDYO with nicotinamide adenine dinucleotide(NAD+)-dependent dehydrogenases in physiological conditions to realize a sustainable cascade reaction by means of forming continuous NAD^(+)/dihydronicotiamide adenine dinucleotide(NADH)*** finding represents a promising perspective on designing high-performance peroxidase-mimicking nanozymes with broader applicability,raising fundamental understanding of structure–activity relationship,and investigating new applications of nanozymes in biological systems.

关键词： nanozyme graphdiyne reactive oxygen species electroless deposition metal–support interaction

Experimental investigation of dynamic characteristics of leaching tubing for solution mining of salt cavern carbon and energy storage

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Petroleum Science 2024年第4期21卷 2703-2722页

作者： Yin-ping Li Xin-Bo Ge Xi-Lin Shi Hong-Ling ma State Key Laboratory of Geomechanics and Geotechnical Engineering Institute of Rock and Soil Mechanics Chinese Academy of Sciences University of Chinese Academy of Sciences College of Energy and Mining Engineering Shandong University of Science and Technology State Key Laboratory of Mining Disaster Prevention and Control Co-founded by Shandong Province and the Ministry of Science and Technology Shandong University of Science and Technology

Salt caverns are extensively utilized for storing various substances such as fossil energy, hydrogen,compressed air, nuclear waste, and industrial solid waste. In China, when the salt cavern is leached through single-well water solution mining with oil as a cushion, engineering challenges arise with the leaching tubing, leading to issues like damage and instability. These problems significantly hinder the progress of cavern construction and the control of cavern shape. The primary cause of this is the flowinduced vibration instability of leaching tubing within a confined space, which results in severe bending or damage to the tubing. This study presents a model experimental investigation on the dynamic characteristics of leaching tubing using a self-developed liquid-solid coupling physical model experiment apparatus. The experiment utilizes a silicone-rubber pipe(SRP) and a polycarbonate pipe(PCP) to examine the effects of various factors on the dynamic stability of cantilevered pipes conveying fluid. These factors include external space constraint, flexural rigidity, medium outside the pipe, overhanging length, and end conditions. The experiments reveal four dynamic response phenomena: water hammer, static buckling, chaotic motion, and flutter instability. The study further demonstrates that the length of the external space constraint has a direct impact on the flutter critical flow velocity of the cantilevered pipe conveying fluid. Additionally, the flutter critical flow velocity is influenced by the end conditions and different external media.

关键词： Salt cavern storage Solution mining Leaching tubing Experimental investigation Flutter instability