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Cross section determination of^(27)Al(n,2n)^(26)Al reaction induced by 14-MeV neutrons uniting with D-T neutron activation and AMs techniques

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Nuclear science and Techniques 2024年第6期35卷 78-89页

作者： Xian-Lin Yang Chang-Lin Lan Yu-Ting Wei Yi Zhang Gong Jiang Bo Xie Yu Liu Hong-Tao shen Xiao-Jun sun school of Nuclear science and Technology Lanzhou UniversityLanzhou 730000China moe Frontiers science Center for Rare Isotopes Lanzhou UniversityLanzhou 730000China state key laboratory of environmental Geochemistry Institute of GeochemistryChinese Academy of SciencesGuiyang 550081China Guangxi key laboratory of Nuclear Physics and Nuclear Technology Guangxi Normal UniversityGuilin 541004China

Aluminum is the primary structural material in nuclear engineering,and its cross section induced by 14-MeV neutrons is of great *** address the issue of insufficient accuracy for the^(27)Al(n,2n)^(26)Al reaction cross section,the activation method and accelerator mass spectrometry(AMs)technique were used to determine the^(27)Al(n,2n)^(26)Al cross section,which could be used as a D-T plasma ion temperature monitor in fusion *** the china Academy of Engineering Physics,neutron activation was performed using a K-400 neutron generator produced by the T(d,n)4He ***^(26)Al∕^(27)Al isotope ratios were measured using the newly installed GYIG 1 MV AMs at the Institute of Geochemistry,Chinese Academy of *** neutron flux was monitored by measuring the activity of 92mNb produced by the 93Nb(n,2n)92mNb *** measured results were compared with available data in the experimental nuclear reaction database,and the measured values showed a reasonable degree of consistency with partially available literature *** newly acquired cross-sectional data at 12 neutron energy points through systematic measurements clarified the divergence,which has two different growth trends from the existing experimental *** obtained results are also compared with the corresponding evaluated database,and the newly calculated excitation functions with TALYs−1.95 and EMPIRE−3.2 codes,the agreement with CENDL−3.2,TENDL-2021 and EMPIRE−3.2 results are generally acceptable.A substantial improvement in the knowledge of the^(27)Al(n,2n)^(26)Al reaction excitation function was obtained in the present work,which will lay the foundation for the diagnosis of the fusion ion temperature,testing of the nuclear physics model,evaluation of nuclear data,etc.

关键词： 14-MeV neutron ^(27)Al(n,2n)^(26)Al Cross section AMs

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Construction of Z-scheme Cu-CeO_(2)/BiOBr heterojunction for enhanced photocatalytic degradation of sulfathiazole

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Chinese Chemical Letters 2024年第7期35卷 167-172页

作者： Xingmin Chen Yunyun Wu Yao Tang Peishen Li shuai Gao Qiang Wang Wen Liu sihui Zhan College of environmental sciences and Engineering Nankai UniversityTianjin 300350China laboratory for Micro-sized Functional Materials&College of Elementary Education and Department of Chemistry Capital Normal UniversityBeijing 100048China College of environmental sciences and Engineering The Key Laboratory of Water and Sediment Sciences(MOE)Peking UniversityBeijing 100871China

The utilization of an efficient photocatalyst is crucial for the photocatalytic degradation of antibiotics in water through visible light,which is an imperative requirement for the remediation of water *** this study,a novel Cu-CeO_(2)/BiOBr Z-type heterojunction was synthesized by calcination and hydrothermal methods,and the degradation rate of sulfathiazole(sTZ)antibiotic solution was studied using simulated illumination(300 W xenon lamp).The results indicated that 3%Cu-CeO_(2)/BiOBr achieved a degradation rate of 92.3%within 90 min when treating 20 mg/L sTZ solution,demonstrating its potential for practical water treatment *** using various chemical instruments revealed that 3%Cu-CeO_(2)/Bi OBr exhibited the lowest electron-hole recombination rate and electron transfer ***,the utilization of EsR data and quenching experiments has substantiated the involvement of hydroxyl radicals(·OH)and superoxide radicals(·O_(2)^(-))as the primary active ***,a plausible degradation mechanism has been *** findings offer a prospective approach for the development of heterojunction materials with appropriate band matching.

关键词： Cu-CeO_(2)/BiOBr nanoheterojunction Photocatalytic degradation sulfathiazole Z-scheme

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Longitudinal vibration characteristics of a tapered pipe pile considering the vertical support of surrounding soil and construction disturbance

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Earthquake Engineering and Engineering Vibration 2024年第1期23卷 51-63页

作者： Li Zhenya Pan Yunchao He Xianbin Lv Chong Mohammad Towhid key laboratory of Ministry of Education for Geomechanics and Embankment Engineering Hohai UniversityNanjing 210098China Geotechnical Research Institute Hohai UniversityNanjing 210098China moe key laboratory of soft soils and Geoenvironmental Engineering Zhejiang UniversityHangzhou 310058China

This research is concentrated on the longitudinal vibration of a tapered pipe pile considering the vertical support of the surrounding soil and construction ***,the pile-soil system is partitioned into finite segments in the vertical direction and the Voigt model is applied to simulate the vertical support of the surrounding soil acting on the pile *** surrounding soil is divided into finite ring-shaped zones in the radial direction to consider the construction ***,the shear complex stiffness at the pile-soil interface is derived by solving the dynamic equilibrium equation for the soil from the outermost to innermost *** displacement impedance at the top of an arbitrary pile segment is obtained by solving the dynamic equilibrium equation for the pile and is combined with the vertical support of the surrounding soil to derive the displacement impedance at the bottom of the upper adjacent ***,the displacement impedance at the pile head is obtained based on the impedance function transfer ***,the reliability of the proposed solution is verified,followed by a sensitivity analysis concerning the coupling effect of the pile parameters,construction disturbance and the vertical support of the surrounding soil on the displacement impedance of the pile.

关键词： tapered pipe pile longitudinal vibration vertical support of the surrounding soil construction disturbance displacement impedance

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Recent achievements in selenium-based transition metal electrocatalysts for pH-universal water splitting

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Nano Research 2024年第7期17卷 5763-5785页

作者： Yuwei Jiang sanshuang Gao Xijun Liu Yin Wang shuxing Zhou Qian Liu Abdukader Abdukayum Guangzhi Hu Xinjiang key laboratory of Novel Functional Materials Chemistry College of Chemistry and Environmental SciencesKashi UniversityKashi 844000China Institute for Ecological Research and Pollution Control of Plateau Lakes School of Ecology and Environmental ScienceYunnan UniversityKunming 650504China moe key laboratory of New Processing Technology for Non-ferrous Metals and Materials Guangxi Key Laboratory of Processing for Non-ferrous Metals and Featured MaterialsGuangxi UniversityNanning 530004China Hubei key laboratory of Low Dimensional Optoelectronic Materials and Devices Hubei University of Arts and ScienceXiangyang 441053China Institute for Advanced study Chengdu UniversityChengdu 610106China

The electrolysis of water to produce hydrogen is an important technique to replace traditional fossil fuel-based hydrogen *** method efficiently converts electrical energy into chemical energy,it is ostensibly a promising candidate for addressing the energy *** effort has been devoted to developing efficient electrocatalysts for water *** exploration of suitable catalytic materials for the hydrogen evolution reaction(HER),oxygen evolution reaction(OER),and other bifunctional electrocatalytic reactions is *** metal selenides(TMses)have emerged as potential HER and OER electrocatalysts because of their unique electronic structures,which are beneficial for charge transfer,tuneable bandgaps,distinctive morphologies,and *** review discusses the mechanisms and performance comparisons of TMses in overall water splitting under various pH *** an industrial and commercial perspective,the catalytic performance of TMses for the HER and OER is not *** for preparing electrocatalytic materials and optimizing materials for overall water decomposition and modulation mechanisms have been introduced to improve electrocatalytic performance,such as element doping,carbon composites,bimetallic systems,morphology control,and heterogeneous interface ***,the challenges and prospects of TMses were discussed.

关键词： hydrogen energy source electrocatalysis water splitting selenium-based materials transition metal

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Covalent organic frameworks doped with manganese-metal organic framework for peroxymonosulfate activation

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Chinese Chemical Letters 2024年第4期35卷 199-203页

作者： Yinyin Xu Yuanyuan Li Jingbo Feng Chen Wang Yan Zhang Yukun Wang Xiuwen Cheng key laboratory for environmental Pollution Prediction and Control College of Earth and Environmental SciencesLanzhou UniversityLanzhou 730000China key laboratory of Pollutant Chemistry and environmental Treatment College of Chemistry and Environmental ScienceYili Normal UniversityYining 835000China

A novel N, O modified Mn_(3)O_(4)@porous carbon catalyst(NOC-Mn_(3)O_(4)) was prepared by direct carbonization using the manganese-metal organic framework(Mn-MOF) and covalent organic framework(COF) as precursors to activate peroxymonosulfate(PMs) for the degradation of bisphenol A(BPA) and rhodamine B(Rh B). Benefiting from the N and O co-doping of COF, larger specific surface area, faster electron transfer and Mn cycling, the optimum 1NOC-Mn_(3)O_(4)could significantly improve the degradation performance of BPA and Rh B(92.1% and 96.9% within 30 min) as compared to C-Mn_(3)O_(4)without COF doping. In addition, 1NOC-Mn_(3)O_(4) showed good reusability and strong anti-interference ability. Radical quenching experiments, X-ray photoelectron spectroscopy(XPs), Electron paramagnetic resonance spectrometer(EPR) and electrochemical tests showed that the 1NOC-Mn_(3)O_(4)/PMs system degraded BPA and Rh B by both radical and non-radical pathways. Moreover, the possible degradation pathways of BPA and Rh B were proposed by liquid chromatography-mass spectrometry(LC-Ms). Except for that, the toxicity of BPA, Rh B and their intermediates were evaluated. This study opens up a new prospect for the design of COF-doped PMs catalysts.

关键词： Peroxymonosulfate Covalent organic framework Mn-metal organic framework Organic pollutant Degradation

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Physical mechanism of the rapid increase in intense and long-lived extreme heatwaves in the Northern Hemisphere since 1980

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science china Earth sciences 2024年第7期67卷 2103-2121页

作者： Yuqing WANG Wen ZHOU Chunzai WANG key laboratory of Polar Atmosphere-ocean-ice system for Weather and Climate of the moe Department of Atmospheric and Oceanic Sciences&Institute of Atmospheric SciencesFudan UniversityShanghai 200438China key laboratory for Polar science of the MNR Polar Research Institute of ChinaShanghai 201209China state key laboratory of Tropical Oceanography South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China Global Ocean and Climate Research Center South China Sea Institute of OceanologyChinese Academy of SciencesGuangzhou 510301China

since 1980,both the intensity and duration of summer heatwaves in the middle and high latitudes of the Northern Hemisphere have significantly increased,leading this region to become a critical area for a significant increase in the frequency of intense and long-lived extreme *** found that stronger and more persistent high-pressure systems and lower soil moisture before the events were the main drivers of intense and long-lived extreme heatwaves in western Europe and the middle and high latitudes of North ***,in eastern Europe and siberia,lower cloud cover before events is also a main driver of this type of extreme heatwave,in addition to the above *** factors are coupled with each other and can change heatwave intensity and duration by influencing surface radiation processes during *** the self-organizing map classification method,we found that 6 weather patterns with increased frequency,intensity,and duration were the main dynamic reasons leading to the increase in intense and long-lived extreme heatwaves after *** addition,the decrease in summer average soil moisture in most areas of the mid-high latitudes of the Northern Hemisphere and the decrease in average cloud cover in eastern Europe and siberia are found to be the main thermodynamic reasons leading to the increase in these extreme heatwaves.

关键词： High intensity Long duration Extreme heatwaves High pressure system soil moisture Cloud cover

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Quantitative studies on charcoalification:Physical and chemical changes of charring wood

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Fundamental Research 2024年第1期4卷 113-122页

作者： Gang Li Linlin Gao Fengwen Liu Menghan Qiu Guanghui Dong moe key laboratory of western china's environmental systems College of Earth&Environmental SciencesLanzhou UniversityLanzhou 730000China Institute for Ecological Research and Pollution Control of Plateau Lakes School of Ecology and Environment ScienceYunnan UniversityKunming 650504China

Charcoal is commonly preserved in both natural and artificial sediments,and is intensively used in paleontological,paleoenvironmental,and archaeological studies due to the abundant bio-information it *** biochemical properties of charcoal are also used for paleoclimatic reconstruction;however,the reliability of this approach has been challenged due to a lack of clarity on how physicochemical properties change during the charring process,as well as the temperatures required for *** address this lack,in this study,Qinghai spruce and Chinese pine wood samples from the northeastern Tibetan Plateau were heated at different temperatures and for different lengths of time under restricted oxygen *** reflectance;carbon,nitrogen,and oxygen content;and tracheid morphology were quantified before and after heating to assess changes related to the charring *** charcoal remains were then evaluated to determine the charcoalification temperatures by comparing with the experimental *** minimum temperature required for wood charcoalification was∼300℃,while temperatures recorded by archaeological charcoal were concentrated at 400-500℃.During the charring experiments,the tracheid cell walls gradually homogenized,and tracheid cell wall thickness and lumen area decreased by∼20%.On average,50%mass losses were observed;the carbon and oxygen content(%wt.)approximately changed from 47%to 60%and 48%to 35%respectively,while the nitrogen content(%wt.)fluctuated around 0.2%.The reflectance increased slightly from 0%to 0.5%.We propose that the charcoalification of wood tissue refers to charring(in restricted air)and carbonization(in the almost absence of air)when the wood is exposed to a heat source,which then finally transforms into a black,inert *** quantitative study provided valuable data and a thorough assessment of the process of wood charcoalification,as well as accurately estimated the feasibility of using charcoal phys

关键词： Charcoalification Quantitative study Charcoal formation Archaeological charcoal Tracheid cell wall thickness Reflectance

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Neural network equalization based on delta-sigma modulation

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Chinese Optics Letters 2024年第4期22卷 8-13页

作者：刘博任建新吴翔宇陈帅东毛雅亚赵利 Nanjing University of Information science&Technology Nanjng 210044China key laboratory for Information science of Electromagnetic Waves(moe) Fudan UniversityShanghai 200433China

We propose a neural network equalization delta-sigma modulation(DsM)*** performing DsM on the multiorder quadrature amplitude modulation(QAM)orthogonal frequency division multiplexing(OFDM)signal at the transmitting end,neural network equalizer technology is used in the digital signal processing at receiving *** this technology to a 4.6 km W-band millimeter wave system,it is possible to achieve a 1 Gbaud 8192-QAM OFDM signal *** data rate reached 23.4 Gbit/s with the bit error rate at 3.8×10^(-2),lower than soft-decision forward-error correction threshold(4×10^(-2)).

关键词： multi-order quadrature amplitude modulation W-band delta-sigma modulation neural network equalization nonlinear compensation

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Global dynamics and noise-induced transitions for a two-dimensional panel system in subsonic flow

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Acta Mechanica sinica 2024年第8期40卷 253-264页

作者： Xiaole Yue Huikang Zhang Yongge Li Yong Xu school of Mathematics and statistics Northwestern Polytechnical UniversityXi’an710129China moe key laboratory for Complexity science in Aerospace Northwestern Polytechnical UniversityXi’an710129China

A two-dimensional panel in subsonic flow with stochastic excitation is studied by assuming that the aerodynamic pressure contains random pressure *** on the global properties,the sensitivities of system parameters and noise intensities are ***,the parameter region with multiple coexisting attractors under different dynamic pressures is *** is found that the coexistence of multiple attractors extensively appears and the basin structure may be *** the periodic time history diagrams are calculated by simulating the random pressure fluctuation as Poisson white *** results show that under typical bistable conditions,the noise sensitivity of the subsonic panel system is related to the basin structures and the disposition of the coexisting attractors to the *** transition between two attractors diffuses along the unstable manifold and tends to the position where the basin boundary curvature is relatively *** findings underscore the importance of global analysis in assessing the noise load carrying capacity,which provides some valuable insights into the safety design of subsonic panel systems.

关键词： Global analysis Transition subsonic panel Multistability

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Does the continuous wetting of the Tibetan Plateau contribute to the accelerated degradation of permafrost?

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science china Earth sciences 2024年第5期67卷 1714-1718页

作者： Yuyang WANG Jinzhi DING shilong PIAO sino-French Institute for Earth system science College of Urban and Environmental SciencesPeking UniversityBeijing 100871China state key laboratory of Tibetan Plateau Earth system Environment and ResourcesInstitute of Tibetan Plateau ResearchChinese Academy of SciencesBeijing 100101China

Global warming is causing the Tibetan permafrost to degrade, as evidenced by rising ground temperatures, thicker active layer thickness, thinner permafrost layer, and melting underground ice, etc.(Ran et al., 2018;Wang et al., 2020).The degradation of permafrost not only profoundly alters the carbon cycling processes in high-altitude ecosystems,thereby influencing the regional climate system, but also affects landscape hydrological connectivity。

关键词： Tibetan landscape altitude

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