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Effect of particle composition and consolidation degree on the wave-induced liquefaction of soil beds

Acta Oceanologica Sinica 2024年第2期43卷 11-22页

作者： Zhiyuan Chen Yupeng Ren Guohui Xu Meng Li Shandong Provincial key laboratory of Marine Environment and Geological Engineering Ocean University of ChinaQingdao 266100China Marine Ecological Restoration and Smart Ocean Engineering Research Center of Hebei Province Qinhuangdao 066000China key laboratory of Marine Environment and Ecology(Ocean University of China) Ministry of EducationQingdao 266100China key laboratory of Submarine Geoscience and Prospecting techniques(Ocean University of China) Ministry of EducationQingdao 266100China

The wave-induced liquefaction of seabed is responsible for causing damage to marine structures.Particle composition and consolidation degree are the key factors affecting the pore water pressure response and liquefaction behavior of the seabed under wave action.The present study conducted wave flume experiments on silt and silty fine sand beds with varying particle compositions.Furthermore,a comprehensive analysis of the differences and underlying reasons for liquefaction behavior in two different types of soil was conducted from both macroscopic and microscopic perspectives.The experimental results indicate that the silt bed necessitates a lower wave load intensity to attain the liquefaction state in comparison to the silty fine sand bed.Additionally,the duration and development depth of liquefaction are greater in the silt bed.The dissimilarity in liquefaction behavior between the two types of soil can be attributed to the variation in their permeability and plastic deformation capacity.The permeability coefficient and compression modulus of silt are lower than those of silty fine sand.Consequently,silt is more prone to the accumulation of pore pressure and subsequent liquefaction under external loading.Prior research has demonstrated that silt beds with varying consolidation degrees exhibit distinct initial failure modes.Specifically,a dense bed undergoes shear failure,whereas a loose bed experiences initial liquefaction failure.This study utilized discrete element simulation to examine the microscopic mechanisms that underlie this phenomenon.

关键词： wave flume liquefaction pore water pressure consolidation permeability experiment discrete element simulation

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Impact of short-term ambient air pollution exposure on the risk of severe COVID-19

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Journal of Environmental Sciences 2024年第1期135卷 610-618页

作者： Baihuan Feng Jiangshan Lian Fei Yu Dan Zhang Weizhen Chen QiWang Yifei Shen Guoliang Xie Ruonan Wang Yun Teng Bin Lou Shufa Zheng Yida Yang Yu Chen Department of laboratory Medicine The First Affiliated HospitalZhejiang University School of MedicineHangzhou 310000China key laboratory of Clinical In Vitro Diagnostic techniques of Zhejiang Province Hangzhou 310000China Institute of laboratory Medicine Zhejiang UniversityHangzhou 310000China Department of Infectious Diseases The First Affiliated HospitalZhejiang University School of MedicineHangzhou 310000China State key laboratory for Diagnosis and Treatment of Infectious Diseases National Clinical Research Center for Infectious DiseasesCollaborative Innovation Center for Diagnosis and Treatment of Infectious Diseasesthe First Affiliated HospitalZhejiang University School of MedicineHangzhou 310000China

Ecological studies suggested a link between air pollution and severe COVID-19 outcomes,while studies accounting for individual-level characteristics are limited.In the present study,we aimed to investigate the impact of short-term ambient air pollution exposure on disease severity among a cohort of 569 laboratory confirmed COVID-19 patients admitted to designated hospitals in Zhejiang province,China,from January 17 to March 3,2020,and elucidate the possible biological processes involved using transcriptomics.Compared with mild cases,severe cases had higher proportion of medical conditions as well as unfavorable results in most of the laboratory tests,and manifested higher air pollution exposure levels.Higher exposure to air pollutants was associated with increased risk of severe COVID-19 with odds ratio(OR)of 1.89(95%confidence interval(CI):1.01,3.53),2.35(95%CI:1.20,4.61),2.87(95%CI:1.68,4.91),and 2.01(95%CI:1.10,3.69)for PM_(2.5),PM_(10),NO_(2)and CO,respectively.OR for NO_(2)remained significant in two-pollutant models after adjusting for other pollutants.Transcriptional analysis showed 884 differentially expressed genes which mainly were enriched in virus clearance related biological processes between patients with high and low NO_(2)exposure levels,indicating that compromised immune response might be a potential underlying mechanistic pathway.These findings highlight the impact of shortterm air pollution exposure,particularly for NO_(2),on COVID-19 severity,and emphasize the significance in mitigating the COVID-19 burden of commitments to improve air quality.

关键词： Air pollution COVID-19 Severity Transcriptomics Immune response

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Method for rapid warning and activity concentration estimates in online waterγ-spectrometry systems

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nuclear Science and techniques 2024年第3期35卷 1-12页

作者： Meng Wang Yi Gu Mao-Lin Xiong Liang-Quan Ge Qing-Xian Zhang Guo-Qiang Zeng Heng Lu Sheng-Liang Guo College of nuclear Technology and Automation Engineering Chengdu University of TechnologyChengdu 610059China Applied nuclear Technology in Geosciences key laboratory of Sichuan Province (Chengdu University of Technology)Chengdu 610059China Chengdu New Ray Technology Co.Ltd Chengdu 610052China

Onlineγ-spectrometry systems for inland waters,most of which extract samples in situ and in real time,are able to produce reliable activity concentration measurements for waterborne radionuclides only when they are distributed relatively uniformly and enter into a steady-state diffusion regime in the measurement chamber.To protect residents’health and ensure the safety of the living environment,better timeliness is required for this measurement method.To address this issue,this study established a mathematical model of the online waterγ-spectrometry system so that rapid warning and activity estimates can be obtained for water under non-steady-state(NSS)conditions.In addition,the detection efficiency of the detector for radionuclides during the NSS diffusion process was determined by applying the computational fluid dynamics technique in conjunction with Monte Carlo simulations.On this basis,a method was developed that allowed the online waterγ-spectrometry system to provide rapid warning and activity concentration estimates for radionuclides in water.Subsequent analysis of the NSS-mode measurements of^(40)K radioactive solutions with different activity concentrations determined the optimum warning threshold and measurement time for producing accurate activity concentration estimates for radionuclides.The experimental results show that the proposed NSS measurement method is able to give warning and yield accurate activity concentration estimates for radionuclides 55.42 and 69.42 min after the entry of a 10 Bq/L^(40)K radioactive solution into the measurement chamber,respectively.These times are much shorter than the 90 min required by the conventional measurement method.Furthermore,the NSS measurement method allows the measurement system to give rapid(within approximately 15 min)warning when the activity concentrations of some radionuclides reach their respective limits stipulated in the Guidelines for Drinking-water Quality of the WHO,suggesting that this method considerably enhances the warning capacity of in si

关键词： Water radioactivity monitoring Dynamic detection efficiency Rapid warning Activity estimation

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Development of CONTHAC-3D and hydrogen distribution analysis of HPR1000

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nuclear Science and techniques 2024年第2期35卷 210-221页

作者： Hui Wang Jing-Jing Li Yuan Chang Gong-Lin Li Ming Ding China nuclear Power Engineering Co.LTD. Beijing 100084China Fundamental Science on nuclear Safety and Simulation Technology laboratory Harbin 100049China

An in-house code,CONTHAC-3D,was developed to calculate and analyze thermal-hydraulic phenomena in containments during severe accidents.CONTHAC-3D is a three-dimensional computational fluid dynamics code that can be applied to predict gas flow,diffusion,and steam condensation in a containment during a severe hypothetical accident,as well as to obtain an estimate of the local hydrogen concentration in various zones of the containment.CONTHAC-3D was developed using multiple models to simulate the features of the proprietary systems and equipment of HPR1000 and ACP100,such as the passive cooling system,passive autocatalytic recombiners and the passive air cooling system.To validate CONTHAC-3D,a GX6 test was performed at the Battelle Model Containment facility.The hydrogen concentration and temperature monitored by the GX6 test are accurately predicted by CONTHAC-3D.Subsequently,the hydrogen distribution in the HPR1000 containment during a severe accident was studied.The results show that the hydrogen removal rates calculated using CONTHAC-3D for different types of PARs agree well with the theoretical values,with an error of less than 1%.As the accident progresses,the hydrogen concentration in the lower compartment becomes higher than that in the large space,which implies that the lower compartment has a higher hydrogen risk than the dome and large space at a later stage of the accident.The amount of hydrogen removed by the PARs placed on the floor of the compartment is small;therefore,raising the installation height of these recombiners appropriately is recommended.However,we do not recommend installing all autocatalytic recombiners at high positions.The study findings in regard to the hydrogen distribution in the HPR1000 containment indicate that CONTHAC-3D can be applied to the study of hydrogen risk containment.

关键词： Hydrogen risk mitigation Pressurized water reactor HPR1000 Thermal hydraulic CONTHAC-3D

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Exploring the Cation Regulation Mechanism for Interfacial Water Involved in the Hydrogen Evolution Reaction by In Situ Raman Spectroscopy

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Nano-Micro Letters 2024年第3期16卷 303-312页

作者： Xueqiu You Dongao Zhang Xia‑Guang Zhang Xiangyu Li Jing‑Hua Tian Yao‑Hui Wang Jian‑Feng Li School of Ocean Information Engineering Fujian Provincial Key Laboratory of Oceanic Information Perception and Intelligent ProcessingJimei UniversityXiamen 361021People’s Republic of China State key laboratory of Physical Chemistry of Solid Surfaces MOE Key Laboratory of Spectrochemical Analysis and InstrumentationiChEMCollege of Chemistry and Chemical EngineeringCollege of MaterialsCollege of EnergyXiamen UniversityXiamen 361005People’s Republic of China key laboratory of Green Chemical Media and Reactions Ministry of EducationCollaborative Innovation Center of Henan Province for Green Manufacturing of Fine ChemicalsCollege of Chemistry and Chemical EngineeringHenan Normal UniversityXinxiang 453007People’s Republic of China Innovation laboratory for Sciences and Technologies of Energy Materials of Fujian Province(IKKEM) Xiamen 361005People’s Republic of China

Interfacial water molecules are the most important participants in the hydrogen evolution reaction(HER).Hence,understanding the behavior and role that interfacial water plays will ultimately reveal the HER mechanism.Unfortunately,investigating interfacial water is extremely challenging owing to the interference caused by bulk water molecules and complexity of the interfacial environment.Here,the behaviors of interfacial water in different cationic electrolytes on Pd surfaces were investigated by the electrochemistry,in situ core-shell nanostructure enhanced Raman spectroscopy and theoretical simulation techniques.Direct spectral evidence reveals a red shift in the frequency and a decrease in the intensity of interfacial water as the potential is shifted in the positively direction.When comparing the different cation electrolyte systems at a given potential,the frequency of the interfacial water peak increases in the specified order:Li+

关键词： In situ Raman Interfacial water Hydrogen evolution reaction Cations

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Effect of Interface Form on Creep Failure and Life of Dissimilar Metal Welds Involving Nickel-Based Weld Metal and Ferritic Base Metal

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Chinese Journal of Mechanical Engineering 2024年第1期37卷 265-285页

作者： Xiaogang Li Junfeng Nie Xin Wang Kejian Li Haiquan Zhang Institute of nuclear and New Energy Technology Key Laboratory of Advanced Reactor Engineering and Safety of Ministry of EducationTsinghua UniversityBeijing 100084China Department of Mechanical Engineering Tsinghua UniversityBeijing 100084China

For dissimilar metal welds(DMWs)involving nickel-based weld metal(WM)and ferritic heat resistant steel base metal(BM)in power plants,there must be an interface between WM and BM,and this interface suffers mechanical and microstructure mismatches and is often the rupture location of premature failure.In this study,a new form of WM/BM interface form,namely double Y-type interface was designed for the DMWs.Creep behaviors and life of DMWs containing double Y-type interface and conventional I-type interface were compared by finite element analysis and creep tests,and creep failure mechanisms were investigated by stress-strain analysis and microstructure characterization.By applying double Y-type interface instead of conventional I-type interface,failure location of DMW could be shifted from the WM/ferritic heat-affected zone(HAZ)interface into the ferritic HAZ or even the ferritic BM,and the failure mode change improved the creep life of DMW.The interface premature failure of I-type interface DMW was related to the coupling effect of microstructure degradation,stress and strain concentrations,and oxide notch on the WM/HAZ interface.The creep failure of double Y-type interface DMW was the result of Type IV fracture due to the creep voids and micro-cracks on fine-grain boundaries in HAZ,which was a result of the matrix softening of HAZ and lack of precipitate pinning at fine-grain boundaries.The double Y-type interface form separated the stress and strain concentrations in DMW from the WM/HAZ interface,preventing the trigger effect of oxide notch on interface failure and inhibiting the interfacial microstructure cracking.It is a novel scheme to prolong creep life and enhance reliability of DMW,by means of optimizing the interface form,decoupling the damage factors from WM/HAZ interface,and then changing the failure mechanism and shifting the failure location.

关键词： Dissimilar metal weld Nickel-based weld metal Ferritic heat resistant steel Interface Creep strain Microstructure Failure mechanism Creep life

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In situ luminescence measurements of GaN/Al_(2)O_(3) film under different energy proton irradiations

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Chinese Physics B 2024年第5期33卷 704-710页

作者：蒋文丽欧阳潇仇猛淋英敏菊陈琳庞盼张春雷张耀锋廖斌 key laboratory of Beam Technology of Ministry of Education College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China Institute of Radiation Technology Beijing Academy of Science and TechnologyBeijing 100875China

Ion beam-induced luminescence(IBIL) experiments were performed to investigate the in situ luminescence of GaN/Al_(2)O_(3) at varying ion energies,which allowed for the measurement of defects at different depths within the material.The energies of H^(+)were set to 500 keV,640 keV and 2 MeV,the Bragg peaks of which correspond to the GaN film,GaN/Al_(2)O_(3) heterojunction and Al_(2)O_(3) substrate,respectively.A photoluminescence measurement at 250 K was also performed for comparison,during which only near band edge(NBE) and yellow band luminescence in the GaN film were observed.The evolution of the luminescence of the NBE and yellow band in the GaN film was discussed,and both exhibited a decrease with the fluence of H^(+).Additionally,the luminescence of F centers,induced by oxygen vacancies,and Cr^(3+),resulting from the ^(2)E →^(4)A_(2) radiative transition in Al_(2)O_(3),were measured using 2 MeV H^(+).The luminescence intensity of F centers increases gradually with the fluence of H^(+).The luminescence evolution of Cr^(3+)is consistent with a yellow band center,attributed to its weak intensity,and it is situated within the emission band of the yellow band in the GaN film.Our results show that IBIL measurement can effectively detect the luminescence behavior of multilayer films by adjusting the ion energy.Luminescence measurement can be excited by various techniques,but IBIL can satisfy in situ luminescence measurement,and multilayer structural materials of tens of micrometers can be measured through IBIL by adjusting the energy of the inducing ions.The evolution of defects at different layers with ion fluence can be obtained.

关键词： ion beam-induced luminescence(IBIL) GaN/Al_(2)O_(3) ion beam

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Study of primordial deuterium abundance in Big Bang nucleosynthesis

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nuclear Science and techniques 2024年第3期35卷 208-215页

作者： Zhi-Lin Shen Jian-Jun He key laboratory of Beam Technology of Ministry of Education College of Nuclear Science and TechnologyBeijing Normal UniversityBeijing 100875China Institute of Radiation Technology Beijing Academy of Science and TechnologyBeijing 100875China

Big Bang nucleosynthesis(BBN)theory predicts the primordial abundances of the light elements^(2) H(referred to as deuterium,or D for short),^(3)He,^(4)He,and^(7) Li produced in the early universe.Among these,deuterium,the first nuclide produced by BBN,is a key primordial material for subsequent reactions.To date,the uncertainty in predicted deuterium abundance(D/H)remains larger than the observational precision.In this study,the Monte Carlo simulation code PRIMAT was used to investigate the sensitivity of 11 important BBN reactions to deuterium abundance.We found that the reaction rate uncertainties of the four reactions d(d,n)^(3)He,d(d,p)t,d(p,γ)^(3)He,and p(n,γ)d had the largest influence on the calculated D/H uncertainty.Currently,the calculated D/H uncertainty cannot reach observational precision even with the recent LUNA precise d(p,γ)^(3) He rate.From the nuclear physics aspect,there is still room to largely reduce the reaction-rate uncertainties;hence,further measurements of the important reactions involved in BBN are still necessary.A photodisintegration experiment will be conducted at the Shanghai Laser Electron Gamma Source Facility to precisely study the deuterium production reaction of p(n,γ)d.

关键词： Big Bang nucleosynthesis Abundance of deuterium Reaction cross section Reaction rate Monte Carlo method

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Hydrogen sulfide responsive nanoplatforms: Novel gas responsive drug delivery carriers for biomedical applications

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Asian Journal of Pharmaceutical Sciences 2024年第1期19卷 1-17页

作者： Jiafeng Zou Zeting Yuan Xiaojie Chen You Chen Min Yao Yang Chen Xiang Li Yi Chen Wenxing Ding Chuanhe Xia Yuzheng Zhao Feng Gao Shanghai Frontier Science Research Base of Optogenetic techniques for Cell Metabolism School of PharmacyEast China University of Science and TechnologyShanghai 200237China key laboratory of Neuropharmacology and Translational Medicine of Zhejiang Province School of Pharmaceutical SciencesZhejiang Chinese Medical UniversityHangzhou 310053China Shanghai key laboratory of Functional Materials Chemistry East China University of Science and TechnologyShanghai 200237China Shanghai key laboratory of New Drug Design School of PharmacyEast China University of Science and TechnologyShanghai 200237China Optogenetics and Synthetic Biology Interdisciplinary Research Center State Key Laboratory of Bioreactor EngineeringEast China University of Science and TechnologyShanghai 200237China CAS Center for Excellence in Brain Science Shanghai Institutes for Biological SciencesChinese Academy of SciencesShanghai 200031China Research Unit of New techniques for Live-cell Metabolic Imaging Chinese Academy of Medical SciencesBeijing 100050China

Hydrogen sulfide(H_(2)S)is a toxic,essential gas used in various biological and physical processes and has been the subject of many targeted studies on its role as a new gas transmitter.These studies have mainly focused on the production and pharmacological side effects caused by H_(2)S.Therefore,effective strategies to remove H_(2)S has become a key research topic.Furthermore,the development of novel nanoplatforms has provided new tools for the targeted removal of H_(2)S.This paper was performed to review the association between H_(2)S anddisease,relatedH_(2)S inhibitory drugs,aswell as H_(2)S responsive nanoplatforms(HRNs).This review first analyzed the role of H_(2)S in multiple tissues and conditions.Second,common drugs used to eliminate H_(2)S,as well as their potential for combination with anticancer agents,were summarized.Not only the existing studies on HRNs,but also the inhibition H_(2)S combined with different therapeutic methods were both sorted out in this review.Furthermore,this review provided in-depth analysis of the potential of HRNs about treatment or detection in detail.Finally,potential challenges of HRNs were proposed.This study demonstrates the excellent potential of HRNs for biomedical applications.

关键词： Hydrogen sulfide Disease mechanisms Removal of hydrogen sulfide Responsive nanoplatforms Challenges Biomedical applications

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Electromagnetic fields in ultra-peripheral relativistic heavy-ion collisions

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nuclear Science and techniques 2024年第2期35卷 103-109页

作者： Jie Zhao Jin-Hui Chen Xu-Guang Huang Yu-Gang Ma key laboratory of nuclear Physics and Ion-beam Application(MOE) Institute of Modern PhysicsFudan UniversityShanghai 200433China Shanghai Research Center for Theoretical nuclear Physics NSFC and Fudan UniversityShanghai 200438China Physics Department and Center for Particle Physics and Field Theory Fudan UniversityShanghai 200438China

Ultra-peripheral heavy-ion collisions(UPCs)offer unique opportunities to study processes under strong electromagnetic fields.In these collisions,highly charged fast-moving ions carry strong electromagnetic fields that can be effectively treated as photon fluxes.The exchange of photons can induce photonuclear and two-photon interactions and excite ions.This excitation of the ions results in Coulomb dissociation with the emission of photons,neutrons,and other particles.Additionally,the electromagnetic fields generated by the ions can be sufficiently strong to enforce mutual interactions between the two colliding ions.Consequently,the two colliding ions experience an electromagnetic force that pushes them in opposite directions,causing a back-to-back correlation in the emitted neutrons.Using a Monte Carlo simulation,we qualitatively demonstrate that the above electromagnetic effect is large enough to be observed in UPCs,which would provide a clear means to study strong electromagnetic fields and their effects.

关键词： Electromagnetic fields Neutrons Ultra-peripheral relativistic heavy-ion collisions(UPC)

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