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Anomalous Nuclear Reaction in Earth’s Interior:a New Field in Physics Science?
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作者 蒋崧生 何明 《Plasma Science and Technology》 SCIE EI CAS CSCD 2012年第5期438-441,共4页
Tritium (3^H) in excess of the atmospheric values was found at volcanic Lakes Pavin (France), Laacher (Germany) and Nemrut (Turkey), as well as Kilauea Volcano at Hawaii (USA) and other volcanoes. Because 3^... Tritium (3^H) in excess of the atmospheric values was found at volcanic Lakes Pavin (France), Laacher (Germany) and Nemrut (Turkey), as well as Kilauea Volcano at Hawaii (USA) and other volcanoes. Because 3^H has a short half-life of 12.3 years, the tritium and the resulting 3^He must have formed recently in the Earth. The result suggests that nuclear reactions may generate a significant amount of tritium in the interior of the Earth, although we have not yet learned what the reaction mechanism may be responsible. The nuclear reaction that can be responsible for tritium production in the Earth is probably a new research field in physics science. Nuclear reactions that generate tritium might be a source of "missing" energy (heat) in the interior of the Earth. Finding in-situ 3^H in the mantle may exhibit an alternative explanation of 3^He origin in the deep Earth. 展开更多
关键词 tritium 3^He/4^He ratio anomalous nuclear reaction Earth's interior
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Measurement of anomalous nuclear reaction in deuterium-loaded metal
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作者 蒋崧生 李井怀 +5 位作者 汪建清 何明 武绍勇 张红涛 姚顺和 赵永刚 《Chinese Physics B》 SCIE EI CAS CSCD 2009年第4期1428-1435,共8页
This paper reports on an experiment for testing natural nuclear fusion at low temperature searching for evidence of the origin of 3He from natural nuclear fusion in deep Earth. The experiment was carried out using deu... This paper reports on an experiment for testing natural nuclear fusion at low temperature searching for evidence of the origin of 3He from natural nuclear fusion in deep Earth. The experiment was carried out using deuterium-loaded titanium foil samples and powder sample. Detection of charged particle was carried out using a low-level charged particle spectrometer. An A1 foil was used as an energy absorber for identification of charged particle. Although the counting rate is very low in the experiment, the emission of energetic particle from the sample is observed and the particle is identified as a proton having energy about 2.8 MeV after exiting the titanium sample. This work provides a positive result for the emission of charged particle in the deuterium-loaded titanium foil samples at low temperature, but a negative result for the deuterium-loaded titanium powder sample. The average reaction yield is deduced to be (0.46±0.08) protons/h for the foil samples. With the suggestion that the proton originates from d-d reaction, we calculate the reaction rate for d-d reaction, and the obtained result is 1.4×10^-24 fusion/d-d.sec. The negative result of the deuterium-loaded titanium powder sample suggests that the reaction yield might be correlated with the density or microscopic variables of deuterium-loaded titanium materials. The negative result also indicates that d-d reaction catalysed by μ-meson from cosmic ray can be excluded in the samples in this experiment. 展开更多
关键词 anomalous nuclear reaction deuterium-loaded metal natural nuclear fusion
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Sigma Meson Production in Nuclear Reactions
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作者 ZHENG Yu-Ming FUCHS C. +4 位作者 SRISAWAS Pornrad FAESSLER Amand YAN Yu-Peng KOBDAJ Chinorat XING Yong-Zhong 《Communications in Theoretical Physics》 SCIE CAS CSCD 2008年第9期725-728,共4页
The sigma meson production in p + ^12C and p A- ^40Ca reactions at the incident energy Ep = 1.5 GeV is investigated within the Quantum Molecular Dynamics model. The simulation results indicate a distinctive A depende... The sigma meson production in p + ^12C and p A- ^40Ca reactions at the incident energy Ep = 1.5 GeV is investigated within the Quantum Molecular Dynamics model. The simulation results indicate a distinctive A dependence of the sigma production, that is, the increase of A is followed by an increase of the production cross sections. We find that the σ meson production in proton-induced reactions is strongly medium-dependent, and the produced σ mesons decaying in a denser medium experience a stronger mass shift towards lower masses. This mass shift is an experimentally accessible observable in the final state pion pairs, which do not suffer from reabsorption by the surrounding nucleons. It is pointed out that the ratio of measured sigma cross sections as a function of the sigma invariant-mass from various reactions is a good probe to explore the existence of the σ meson in a dense nuclear environment. 展开更多
关键词 sigma meson production medium modification the invariant-mass distribution nuclear reaction quantum molecular dynamics model
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Strong screening effects on resonant nuclear reaction ^(23)Mg(p,γ) ^(24)Al in the surface of magnetars
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作者 Jing-Jing Liu 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2016年第5期117-124,共8页
Based on the theory of relativistic superstrong magnetic fields (SMFs), by using the method of Thomas-Fermi-Dirac approximations, we investigate the problem of strong electron screening (SES) in SMFs and the influ... Based on the theory of relativistic superstrong magnetic fields (SMFs), by using the method of Thomas-Fermi-Dirac approximations, we investigate the problem of strong electron screening (SES) in SMFs and the influence of SES on the nuclear reaction of 23Mg (p, Y)24A1. Our calculations show that the nuclear reaction will be markedly effected by the SES in SMFs in the surface of magnetars. Our calculated screening rates can increase two orders of magnitude due to SES in SMFs. 展开更多
关键词 physical data and processes: nuclear reactions NUCLEOSYNTHESIS abundances -- stars: neutron-- stars: magnetic fields
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Dynamical Behavior of Core ^3He Nuclear Reaction-Diffusion Systems and Sun's Gravitational Field
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作者 杜九林 申洪 《Transactions of Tianjin University》 EI CAS 2005年第1期30-34,共5页
The coupling of the sun's gravitational field with processes of diffusion and convection exerts a significant influence on the dynamical behavior of the core 3He nuclear reaction-diffusion system. Stability analys... The coupling of the sun's gravitational field with processes of diffusion and convection exerts a significant influence on the dynamical behavior of the core 3He nuclear reaction-diffusion system. Stability analyses of the system are made in this paper by using the theory of nonequilibrium dynamics. It is showed that, in the nuclear reaction regions extending from the center to about 0.38 times of the radius of the sun, the gravitational field enables the core 3He nuclear reaction-diffusion system to become unstable and, after the instability, new states to appear in the system have characteristic of time oscillation. This may change the production rates of both 7Be and 8B neutrinos. 展开更多
关键词 stellar nuclear reaction solar neutrino problem astrophysical hydrodynamics
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Study of nuclear reaction method for the determination of protein content in wheat seeds
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作者 LUO Xiao-Bing ZHANG Ruan-Yu CHEN Shi-Guo LI Tai-Hua AN Zhu CAO Yang-Shu 《Nuclear Science and Techniques》 SCIE CAS CSCD 2005年第6期338-340,共3页
A 13.4 MeV deuteron beam from the 1.2 meter cyclotron of Sichuan University was used to determine theprotein content in wheat seeds on the basis of (d,p) reactions. The influence of the variation of the water content ... A 13.4 MeV deuteron beam from the 1.2 meter cyclotron of Sichuan University was used to determine theprotein content in wheat seeds on the basis of (d,p) reactions. The influence of the variation of the water content inseeds has been investigated. 展开更多
关键词 核反应 小麦 种子 放射化学分子 谷蛋白
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Study of the deuterated titanium Ti^2H_x sample by using nuclear reaction analysis and material analysis methods
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作者 WANG Tie-Shan, DING Bao-Wei, WANG Zhi-Guo, ZHENG Shi-Kui, JIANG You-Rong, LI Wei-Jun (Institute of Modern Physics, The Chinese Academy of Sciences, Lanzhou. 730000) (Institute of Nuclear Physics, Lanzhou University, Lanzhou 730000) (Nuclear Power inst 《Nuclear Science and Techniques》 SCIE CAS CSCD 2001年第3期190-194,共5页
Titanium is one of the best hydrogen loading material. The pre dieted maximum loading ratio of hydrogen in titanium may reach to 2.0. In this work, a titanium layer on molybdenum substrate was deuterated with the atom... Titanium is one of the best hydrogen loading material. The pre dieted maximum loading ratio of hydrogen in titanium may reach to 2.0. In this work, a titanium layer on molybdenum substrate was deuterated with the atomic: ratio X =2H/Ti≥1.6. The change of the surface topography and rnicrostructurc of the sample before and after loading was observed by using Scan Electron Microscopy (SEM). The surface segregation of the samples after deutcron bombardment was also observed. A fluctuatingly-incrcasing trend of the deutcriuin density in titanium target was detected in the deuteron implantation experiments. which indicated a suddenly explosion (segregation) or fast diffusion of deuterium in the titanium. Significant amount of nitrogen contamination was found in thc Ti2Hx sample by nuclear reaction analysis (NRA), which indicated that the Ti2Hx structure might have the feature to trap nitrogen from air. The nitrogen contamination in Ti2Hx significantly affects the increase of the atomic ratio X 展开更多
关键词 氘化钛 Ti2Hx样品 核反应试验 材料分析
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New Exotic Models of Cold Nuclear Reactions and the Creation of the World
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作者 Andrey B. Simakov 《Journal of High Energy Physics, Gravitation and Cosmology》 2018年第3期504-509,共6页
The work has the characters of a philosophical note, in which a new exotic version of the atom structure is discussed. According to this, the atomic nucleus consists of “normal” and “special” neutrons. Electrons a... The work has the characters of a philosophical note, in which a new exotic version of the atom structure is discussed. According to this, the atomic nucleus consists of “normal” and “special” neutrons. Electrons are internal part of both types of neutron. Electrons can leave “normal” neutrons of the nucleus and return back with a certain probability. These processes lead to the appearance of protons in the nucleus and form the electron orbits of the atom. At the same time, it is possible that the Coulomb’s barriers of atoms and nucleus disappear at some point in time and cold nuclear reactions pass through. This assumption leads to a new exotic model of the Universe structure, namely, the existence of neutron ether, consisting of special neutrons that do not emit their own electrons. In this ethereal ocean of special neutrons, periodically provoked disturbances arise. After that, it creates pockets, clusters of our normal neutrons inherent in our world, which can already emit electrons and, consequently, create atoms. The ether gets sick from time to time. However, as a result of this disease, stars arise. Some possible stages in the creation of our world are also discussed in this paper. 展开更多
关键词 Low Energy nuclear reaction COULOMB Barrier NEUTRON Proton Electron VACANCY NEUTRON ETHER DARK Matter
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Fusion hindrance in the neck evolution of symmetric nuclear reactions 被引量:2
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作者 WANG XiaoLin SHEN CaiWan +1 位作者 LI QingFeng LIU Ling 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2011年第3期470-473,共4页
Fusion hindrance in the radial degree of freedom for massive nuclear reactions is known for a long time. However the present work shows that the fusion hindrance also exists in the neck evolution. We calculate the pot... Fusion hindrance in the radial degree of freedom for massive nuclear reactions is known for a long time. However the present work shows that the fusion hindrance also exists in the neck evolution. We calculate the potential at different distances and different neck parameters by the two-center liquid drop model and then check whether fusion hindrance exists in the neck evolution by examing the sign of slope of potential vs. the neck parameter. The area of fusion hindrance in the neck evolution is shown. 展开更多
关键词 nuclear reaction fusion hindrance neck evolution neck parameter
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Resonant nuclear reaction 23Mg(p,γ) 24Al in strongly screening magnetized neutron star crust
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作者 刘晶晶 刘冬梅 《Chinese Physics C》 SCIE CAS CSCD 2017年第12期122-132,共11页
Based on the relativistic theory of superstrong magnetic fields(SMF), by using three models those of Lai(LD), Fushiki(FGP), and our own(LJ), we investigate the influence of SMFs due to strong electron screenin... Based on the relativistic theory of superstrong magnetic fields(SMF), by using three models those of Lai(LD), Fushiki(FGP), and our own(LJ), we investigate the influence of SMFs due to strong electron screening(SES) on the nuclear reaction 23Mg(p,γ) 24Al in magnetars. In a relatively low density environment(e.g., ρ7 〈0.01)and 1 〈 B12 〈 102, our screening rates are in good agreement with those of LD and FGP. However, in relatively high magnetic fields(e.g., B12 〉102), our reaction rates can be 1.58 times and about three orders of magnitude larger than those of FGP and LD, respectively(B12, ρ7 are in units of 1012G, 107 g cm-3). The significant increase of strong screening rate can imply that more 23Mg will escape from the Ne-Na cycle due to SES in a SMF. As a consequence,the next reaction, 24Al(+β, ν) 24Mg, will produce more 24Mg to participate in the Mg-Al cycle. Thus, it may lead to synthesis of a large amount of A〉20 nuclides in magnetars. 展开更多
关键词 dense matter: nuclear reactions NUCLEOSYNTHESIS abundances stars: magnetic fields stars: magnetars
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Explanation of Cold Nuclear Fusion and Biotransmutations
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作者 Auguste Meessen 《Journal of Modern Physics》 2023年第7期1087-1116,共30页
Low energy nuclear reactions are possible in condensed matter because of image forces. They result from induced charges at the surface of metals or very polarizable media. The height and width of the Coulomb barrier i... Low energy nuclear reactions are possible in condensed matter because of image forces. They result from induced charges at the surface of metals or very polarizable media. The height and width of the Coulomb barrier in free space can thus be reduced. Nuclear fusion requires also the formation of a compound nucleus in one of its excited states, but two deuterons yield an α particle that has 2 excited states. They are respectively accessible at high or low energies. Since the reduction of the Coulomb barrier depends on the local curvature of the interface, cold fusion becomes autocatalytic, but heat production is controllable. Even microbes, plants and animals can produce transmutations. They are also due to image forces. This solves a basic problem in nuclear physics and there are possible applications: facilitated synthesis of superheavy elements and development of a new type of energy sources. They are moderate, but safe. 展开更多
关键词 Cold Fusion nuclear reactions Biological Transmutations Coulomb Barrier Image Force Superheavy Elements New Energy Source
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Spallation reaction and the probe of nuclear dissipation with excitation energy at scission 被引量:1
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作者 YE Wei WANG Ning 《Nuclear Science and Techniques》 SCIE CAS CSCD 2013年第5期113-116,共4页
We study in the framework of the Langevin model the influence of initial excitation energy(E*) of Hg compound nuclei(CNs) on the sensitivity of the excitation energy at scission(Esc*) to the nuclear friction strength(... We study in the framework of the Langevin model the influence of initial excitation energy(E*) of Hg compound nuclei(CNs) on the sensitivity of the excitation energy at scission(Esc*) to the nuclear friction strength(β).It is shown that the sensitivity is enhanced substantially with increasing E*.Moreover,we find that the significant sensitivity of Esc* to β at high E*is little affected by a marked difference in the neutron-to-proton ratio of a CN and in its size and fissility.Our findings suggest that,on the experimental side,a measurement of Esc* in energetic proton-induced spallation reactions can provide not only a sensitive but also a robust probe of nuclear dissipation in fission of highly excited nuclei.Further development of a suitable approach to spallation reaction is discussed. 展开更多
关键词 散裂反应 激发能量 核耗散 断裂 探针 佛罗里达州 汞化合物 模型框架
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Determining nitrogen depth distributions in seeds of grain by nuclear reaction method
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作者 张坤 曹建华 《Nuclear Science and Techniques》 SCIE CAS CSCD 1996年第1期58-60,共3页
DeterminingnitrogendepthdistributionsinseedsofgrainbynuclearreactionmethodZhangKun(张坤)andCaoJian-Hua(曹建华)(In... DeterminingnitrogendepthdistributionsinseedsofgrainbynuclearreactionmethodZhangKun(张坤)andCaoJian-Hua(曹建华)(InstituteofNuclearS... 展开更多
关键词 谷物 种子 氮深度分布 核反应方法
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The cross section calculation of 112Sn(α,γ)116Te reaction with different nuclear models at the astrophysical energy range 被引量:2
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作者 C. Yalcin 《Nuclear Science and Techniques》 SCIE CAS CSCD 2017年第8期103-109,共7页
The theoretical cross section calculations for the astrophysical p process are needed because most of the related reactions are technically very difficult to be measured in the laboratory. Even if the reaction was mea... The theoretical cross section calculations for the astrophysical p process are needed because most of the related reactions are technically very difficult to be measured in the laboratory. Even if the reaction was measured,most of the measured reactions have been carried out at the higher energy range from the astrophysical energies.Therefore, almost all cross sections needed for p process simulation have to be theoretically calculated or extrapolated to the astrophysical energies.^(112)Sn(α,γ)^(116)Te is an important reaction for the p process nucleosynthesis. The theoretical cross section of ^(112)Sn(α,γ)^(116)Te reaction was investigated for different global optical model potentials,level density, and strength function models at the astrophysically interested energies. Astrophysical S factors were calculated and compared with experimental data available in the EXFOR database. The calculation with the optical model potential of the dispersive model by Demetriou et al., and the back-shifted Fermi gas level density model and Brink-Axel Lorentzian strength function model best served to reproduce experimental results at an astrophysically relevant energy region. The reaction rates were calculated with these model parameters at the p process temperature and compared with the current version of the reaction rate library Reaclib and Starlib. 展开更多
关键词 核反应模型 天体物理学 截面计算 能量范围 光学模型势 模型参数计算 函数模型 能级密度
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A method of analysing experimental data of nuclear reaction cross sections
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作者 FengJun ShenWen-Qing 《Nuclear Science and Techniques》 SCIE CAS CSCD 1997年第1期10-13,共4页
AmethodofanalysingexperimentaldataofnuclearreactioncrossectionsFengJunandShenWenQing(ShanghaiInstituteofNucl... AmethodofanalysingexperimentaldataofnuclearreactioncrossectionsFengJunandShenWenQing(ShanghaiInstituteofNuclearResearch,the... 展开更多
关键词 原子核反应截面 实验数据 分析方法
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A Survey of New Methods for Production of Some Radionuclides, at Laboratory Scale, through Secondary Reactions in Nuclear Reactors
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作者 Isaac M. Cohen Sandra Siri Maria C. Fornaciari Iljadica 《Advances in Chemical Engineering and Science》 2014年第3期300-307,共8页
The studies performed in the frame of a project destined for the search of new (t,n) and (p,n) reactions of interest in nuclear reactors are described. Experimental evidences of the observations of the reactions: 46Ti... The studies performed in the frame of a project destined for the search of new (t,n) and (p,n) reactions of interest in nuclear reactors are described. Experimental evidences of the observations of the reactions: 46Ti(t,n)48V, 48Ti(p,n)48V, 52Cr(t,n)54Mn, 56Fe(p,n)56Co, 72Ge(t,n)74As and 74Ge(p,n)74As, are presented. Additional data on some secondary reactions, already characterised for the production of 7Be, 56Co, 58Co, 65Zn and 88Y, were also obtained. The significance of these data is discussed. 展开更多
关键词 nuclear reactionS nuclear Reactors Tritons RECOIL PROTONS
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Nuclear Stopping and Pauli Blocking in Heavy-Ion Reactions near Fermi Energy
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作者 邢永忠 刘晓斌 +2 位作者 师应龙 张鸿飞 郑玉明 《Chinese Physics Letters》 SCIE CAS CSCD 2016年第12期28-31,共4页
The dissipation phenomenon in the heavy-ion reaction at incident energy near the Fermi energy is studied by simulating the reaction ^129Xe+^129Sn with the isospin-dependent quantum molecular dynamics model. The calcu... The dissipation phenomenon in the heavy-ion reaction at incident energy near the Fermi energy is studied by simulating the reaction ^129Xe+^129Sn with the isospin-dependent quantum molecular dynamics model. The calculations involving a proper prescription of implementing the Pauli exclusion principle show that the isotropy ratio measured by free protons emitted in the reaction at energy slightly higher than the Fermi energy is in agreement with the experimental data recently released by the INDRA collaboration. A feasible value of the Pauli-blocking factor is estimated by comparing the theoretical results with the experimental data for the energy range considered here. 展开更多
关键词 in on of nuclear Stopping and Pauli Blocking in Heavy-Ion reactions near Fermi Energy been IS
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中国原子能科学研究院核物理基础研究最新进展与展望
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作者 郭冰 杨磊 +31 位作者 郑云 张英逊 李云居 连钢 吕冲 高早春 颜胜权 王友宝 席晓峰 贾会明 赵凯 南巍 李聪博 吴笛 崔莹 连占江 马南茹 温培威 吴晓光 杨峰 闫玉良 曾晟 李天晓 廖俊辉 贺创业 王钊 谌阳平 李志宏 林承键 张焕乔 王乃彦 柳卫平 《原子能科学技术》 EI CAS CSCD 北大核心 2024年第S02期191-216,共26页
核物理是物质科学研究的基础研究前沿和重大应用领域之一,对人类探索物质结构的微观层次、国家的地位与安全发挥了重大作用。中国原子能科学研究院(简称原子能院)核物理基础研究团队依托北京放射性核束装置、HI-13串列加速器、锦屏深地... 核物理是物质科学研究的基础研究前沿和重大应用领域之一,对人类探索物质结构的微观层次、国家的地位与安全发挥了重大作用。中国原子能科学研究院(简称原子能院)核物理基础研究团队依托北京放射性核束装置、HI-13串列加速器、锦屏深地核天体物理加速器等实验设施,开展了核物理基础相关实验与理论研究,在质子晕核破裂机制、不稳定核衰变新模式、核天体反应深地高精度测量、激光驱动核反应等方面取得了多项创新研究成果。本文评述了“十四五”期间原子能院在核物理基础研究方面取得的一些最新进展,并展望了原子能院未来在核物理大科学装置、特色中小型装置、核理论、新型实验技术、学科交叉融合等方面的发展思路。 展开更多
关键词 核反应 核结构 核理论 核天体物理 激光核物理
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Inelastic Scattering of Dark Matter with Heavy Cosmic Rays
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作者 Keyu Lu Yue-Lin Sming Tsai +1 位作者 Qiang Yuan Le Zhang 《Research in Astronomy and Astrophysics》 SCIE CAS CSCD 2024年第6期68-80,共13页
We investigate the impact of inelastic collisions between dark matter(DM)and heavy cosmic ray(CR)nuclei on CR propagation.We approximate the fragmentation cross-sections for DM-CR collisions using collider-measured pr... We investigate the impact of inelastic collisions between dark matter(DM)and heavy cosmic ray(CR)nuclei on CR propagation.We approximate the fragmentation cross-sections for DM-CR collisions using collider-measured proton-nuclei scattering cross-sections,allowing us to assess how these collisions affect the spectra of CR boron and carbon.We derive new CR spectra from DM-CR collisions by incorporating their cross-sections into the source terms and solving the diffusion equation for the complete network of reactions involved in generating secondary species.In a specific example with a coupling strength of b_(χ)=0.1 and a DM mass of m_(χ)=0.1 GeV,considering a simplified scenario where DM interacts exclusively with oxygen,a notable modification in the boron-to-carbon spectrum due to the DM-CR interaction is observed.Particularly,the peak within the spectrum,spanning from 0.1 to 10 GeV,experiences an enhancement of approximately 1.5 times.However,in a more realistic scenario where DM particles interact with all CRs,this peak can be amplified to twice its original value.Utilizing the latest data from AMS-02 and DAMPE on the boron-to-carbon ratio,we estimate a 95%upper limit for the effective inelastic cross-section of DM-proton as a function of DM mass.Our findings reveal that at m_(χ)?2 MeV,the effective inelastic cross-section between DM and protons must be less than O(10^(-32))cm^(2). 展开更多
关键词 elementary particles nuclear reactions NUCLEOSYNTHESIS ABUNDANCES SCATTERING astroparticle physics (cosmology:)dark matter
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纳米氧化铝改性地面井固井水泥水化机制研究
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作者 梁运培 刘莹 +1 位作者 邹全乐 王鑫 《煤炭科学技术》 EI CAS CSCD 北大核心 2024年第7期68-78,共11页
随着地面井固井技术发展加快,工程现场对于地面井固井水泥浆的早期流动性及凝结性能有了更高的要求。为了提高固井工程注水泥作业的顶替效率,改善固井工程现场作业应用情况,提出了纳米氧化铝颗粒改性固井水泥的方法,利用核磁共振技术对... 随着地面井固井技术发展加快,工程现场对于地面井固井水泥浆的早期流动性及凝结性能有了更高的要求。为了提高固井工程注水泥作业的顶替效率,改善固井工程现场作业应用情况,提出了纳米氧化铝颗粒改性固井水泥的方法,利用核磁共振技术对质量分数为0、0.05%、0.10%、0.15%及0.20%的纳米氧化铝改性水泥浆(水灰比为0.44)在不同水化龄期的水化反应变化特征进行了研究,探究了纳米氧化铝改性水泥的水相分布、物理结合水总信号量变化、峰形指数及迁移速率。结果表明:纳米氧化铝改性水泥浆在水化阶段的T2图谱会出现3个弛豫峰,分别对应絮凝结构填充水(0.1~10 ms)、毛细水(10 ms)、自由水(800~1000 ms);其物理结合水总信号随纳米氧化铝质量分数增加而逐步减少,其中质量分数为0.20%的纳米氧化铝改性水泥浆信号量减少速率最快;峰形指数呈现先上升后下降的趋势,当水化反应进行至600 min时,质量分数为0.20%的改性水泥浆变化速率最快,弛豫峰向短弛豫方向移动速率加快;结合迁移速率将纳米氧化铝改性固井水泥水化反应阶段划分,其水化机制分别作用在4个水化时期:①初始水化期(5~60 min),水化速率未发生明显改变;②加速水化期(60~600 min),纳米氧化铝使水泥浆中物理结合水转化为化学结合水所经历时间变短,水化进程加快,达到促进水泥水化的效果;③稳定水化期(600~1200 min),水泥体系趋于稳定;④延缓水化期(1200~1800 min),物理结合水转化为化学结合水速率变慢,水泥水化进程减慢。研究结论得到,纳米氧化铝改性水泥浆水化时期可以划分为4个阶段,分别起到物理填充、加速、稳定、延缓的作用。在加速期,纳米氧化铝促进水泥的早期流动,有利于水泥浆的泵送及流动,在延缓期,纳米氧化铝延缓水泥的进一步水化进程,利于发展早期强度。其中,质量分数为0.20%的纳米氧化铝改性水泥浆对于水泥水化进程影响最大,促进填充水向结合水的转化,在加速水化期间对于水泥浆水化反应加速程度最大,以此作为依据对现场固井水泥的制备及应用提供指导。 展开更多
关键词 地面井固井水泥 纳米氧化铝 核磁共振 水化反应 弛豫时间
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