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核转变能与理论地质年表
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作者 蒋志 《矿物岩石地球化学通报》 CAS CSCD 2001年第3期165-171,共7页
本文讨论了地球内部长寿期放射性同位素衰变能的存量 ,给出地球脉动频率和频数公式 ,并据以重新建立了理论地质年表 ,解释了地球自转变化、地磁场倒转和黄赤交角变化等。
关键词 核转变 产率 存量 脉动频率 地质年表 地球自转 地磁场倒转 黄赤交角
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核地球化学闪烁着先哲的智慧和创新的光辉——纪念侯德封院士诞辰100周年
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作者 欧阳自远 《第四纪研究》 CAS CSCD 北大核心 2000年第1期24-29,共6页
60年代初 ,我国著名的地质学家、地球化学家侯德封院士 ,在他 4 0多年从事地质矿产调查和研究的基础上 ,运用现代核物理学的基本原理 ,创立并系统提出了“核地球化学”的基本原理、研究对象、内容和方法 ,并于 196 1年发表了著名的《核... 60年代初 ,我国著名的地质学家、地球化学家侯德封院士 ,在他 4 0多年从事地质矿产调查和研究的基础上 ,运用现代核物理学的基本原理 ,创立并系统提出了“核地球化学”的基本原理、研究对象、内容和方法 ,并于 196 1年发表了著名的《核子地球化学》。随后 ,在不断补充、修正和完善核地球化学理论的基础上 ,侯德封先生发表了有关地球物质演化的能源、地球演化的阶段性、核转变的产物对地球的化学成分及同位素组成变异的影响等内容的、为地球科学向更深的物质层次发展具有巨大推动作用的《核转变能与地球物质的演化》科学专著 ,从而开辟了地球科学一个崭新的领域———核地球化学。侯德封先生在核地球化学领域上的丰硕成就与在学术上严谨的学风无不闪烁着一位先哲的智慧和创新的光辉。 展开更多
关键词 地球化学 核转变 诱发裂变 侯德封 铀矿
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核反应的类型、特点及其应用
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作者 巫明锐 《西昌师范高等专科学校学报》 2003年第3期125-126,共2页
本文针对中学物理教材中的原子物理方面的内容,对教材在历史和核反应方面做些深入,以期扩展学生在原子物理方面的知识,达到相应的科普目的。
关键词 反应 衰变 人工核转变 裂变 聚变
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水果核不再是废物
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作者 杜丽妃 《心血管病防治知识》 2009年第12期44-44,共1页
来自加拿大西部大学的研究者艾高(Christina Engels)发现了一种变废为宝的方法:即可将人们丢弃的芒果核转变为天然食品防腐剂,该防腐剂可阻止李特斯菌(Listeriosis)的暴发流行。去年,由于李特斯菌的暴发感染导致21名加拿大人死亡。
关键词 加拿大 暴发流行 西部大学 人死亡 天然食品防腐剂 核转变 芒果 研究者 单宁酸 感染
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布莱克特对威耳逊云室的改进及相关研究 被引量:5
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作者 刘战存 王新颜 朱南 《大学物理》 北大核心 2009年第10期45-50,60,共7页
简述了布莱克特的生平,回顾了他对威耳逊云室的改进及利用威耳逊云室所做的证明原子核人工转变、验证正电子的存在和对宇宙射线的研究工作,分析了他成功的因素.
关键词 布莱克特 威耳逊云室 人工核转变 正电子 宇宙射线
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分析研究地震成因,探索防震减灾科学实践与理论,创建防震减灾科学理论体系 被引量:6
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作者 庄庆祥 《能源与环境》 2014年第6期2-3,7,共3页
通过地震成因的讨论分析与研究,找出地震孕育、发生、发展的规律,剖析各种地震成因说的作用与真伪;确立震源爆炸物质-地壳岩石与地幔岩浆中富集浓缩的核类物质是地震发生的根本决定性因素。地震,地应力与断层活动作用力不是爆炸物质,只... 通过地震成因的讨论分析与研究,找出地震孕育、发生、发展的规律,剖析各种地震成因说的作用与真伪;确立震源爆炸物质-地壳岩石与地幔岩浆中富集浓缩的核类物质是地震发生的根本决定性因素。地震,地应力与断层活动作用力不是爆炸物质,只会引起的岩石或岩浆平面上的破裂或断裂,而绝不会发生爆炸,也绝对不会产生地震冲击波即不会发生地震;在地震成因分析研究取得突破的基础上,力争在较短的时间内创立起释放地热能转换地震能量防震减灾的科学理论体系。 展开更多
关键词 地震成因 核转变 震源爆炸 地应力与断层活动作用力 释放地热能 防震减灾
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关于干热岩热源与热通、热盖的研究
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作者 庄庆祥 《能源与环境》 2015年第5期2-2,4,共2页
通过干热岩热源、热通的阐述,可让我们对干热岩地热资源的成因、来源、通道与去处有了进一步的了解,对干热岩地热资源的勘查探索具重要的指导意义。
关键词 干热岩 地热资源 热源 热通 类物质 衰变生热 核转变
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STUDY ON GMA-DNA ADDUCTS
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作者 方福德 左瑾 +1 位作者 雷海新 谭明家 《Chinese Medical Sciences Journal》 CAS CSCD 1999年第1期1-6,共6页
Objective. DNA modification fixed as mutations in the cells may be an essential factor in the initiation step of chemical carcinogenesis. In order to explore the mechanism of gene mutation... Objective. DNA modification fixed as mutations in the cells may be an essential factor in the initiation step of chemical carcinogenesis. In order to explore the mechanism of gene mutation and cell transformation induced by glycidyl methacrylate (GMA), the current test studied the characteristics of GMA DNA adducts formation in vitro. Methods. In vitro test, dAMP, dCMP, dGMP, dTMP and calf thymus DNA were allowed to react with GMA (Glycidyl Methacrylate). After the reaction, the mixtures were detected by UV and subjected to reversed phase HPLC on ultrasphere ODS reversed phase column, the reaction products were eluted with a linear gradients of methanol (solvent A) and 10mmol/L ammonium formate, pH5 0 (solvent B). The synthesized adducts were then characterized by UV spectroscopy in acid (pH1 0), neutral (pH7 2), alkaline (pH11 0) and by mass spectroscopy. Results. The results showed that GMA could bind with dAMP, dCMP, dGMP and calf thymus DNA by covalent bond, and the binding sites were specific (N 6 of adenine, N 3 of cytosine). Meanwhile, a main GMA DNA adduct in the reaction of GMA with calf thymus DNA was confirmed as N 3 methacrylate 2 hydroxypropy1 dCMP. Conclusions. GMA can react with DNA and /or deoxynucleotide monophosphate and generate some adducts such as N 6 methacrylate 2 hydroxypropyl dAMP and N 3 methacrylate 2 hydroxypropyl dCMP, ets. Formation of GMA DNA adducts is an important molecular event in gene mutation and cell transformation induced by GMA. 展开更多
关键词 glycidyl methacrylate covalent bond DNA adducts
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Austenite formation during intercritical annealing in C-Mn cold-rolled dual phase steel 被引量:1
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作者 李声慈 康永林 +1 位作者 朱国明 邝霜 《Journal of Central South University》 SCIE EI CAS CSCD 2015年第4期1203-1211,共9页
Two different kinds of experimental techniques were used to in-situ study the austenite formation during intercritical annealing in C-Mn dual phase steel. The microstructure evolution was observed by confocal laser sc... Two different kinds of experimental techniques were used to in-situ study the austenite formation during intercritical annealing in C-Mn dual phase steel. The microstructure evolution was observed by confocal laser scanning microscope, and the austenite isothermal and non-isothermal transformation kinetics were studied by dilatometry. The results indicate that banded structure is produced for the reason of composition segregation and the competition between recrystallization and phase transformation. Austenite prefers to nucleate not only at ferrite/ferrite grain boundaries, but also inside the grains of ferrite.Furthermore, the austenitizing process is accomplished mainly via migration of the existing austenite/ferrite interface rather than nucleation of new grains. The incubation process can be divided into two stages which are controlled by carbon and manganese diffusion, respectively. During the incubation process, the nucleation rate of austenite decreases, and austenite growth changes from two-dimensional to one-dimensional. The partitioning coefficient, defined as the ratio of manganese content in the austenite to that in the adjacent ferrite, increases with increasing soaking time. 展开更多
关键词 dual phase steel confocal laser scanning microscope dilatometry austenitizing in situ observation
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Shape Decoupling Effects and Rotation of Deformed Halo Nuclei
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作者 SUN Xiangxiang ZHOU Shangui 《原子核物理评论》 CAS CSCD 北大核心 2024年第1期75-85,共11页
With the development of radioactive-ion-beam facilities,many exotic phenomena have been discovered or predicted in the nuclei far from the stability line,including cluster structure,shell structure,deformed halo,and s... With the development of radioactive-ion-beam facilities,many exotic phenomena have been discovered or predicted in the nuclei far from the stability line,including cluster structure,shell structure,deformed halo,and shape decoupling effects.The study of exotic nuclear phenomena is at the frontier of nuclear physics nowadays.The covariant density functional theory(CDFT)is one of the most successful microscopic models in describing the structure of nuclei in almost the whole nuclear chart.Within the framework of CDFT,toward a proper treatment of deformation and weak binding,the deformed relativistic Hartree-Bogoliubov theory in continuum(DRHBc)has been developed.In this contribution,we review the applications and extensions of the DRHBc theory to the study of exotic nuclei.The DRHBc theory has been used to investigate the deformed halos in B,C,Ne,Na,and Mg isotopes and the theoretical descriptions are reasonably consistent with available data.A DRHBc Mass Table Collaboration has been founded,aiming at a high precision nuclear mass table with deformation and continuum effects included,which is underway.By implementing the angular momentum projection based on the DRHBc theory,the rotational excitations of deformed halos have been investigated and it is shown that the deformed halos and shape decoupling effects also exist in the low-lying rotational excitation states of deformed halo nuclei. 展开更多
关键词 exotic nuclei deformed halo shape decoupling effect nuclear mass rotational excitation density functional theory
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“点”汞成金
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作者 吕承良 《第二课堂(A)》 2004年第1期67-67,共1页
自古以来,人们以黄金为贵。谁不想“点石成金“,瞬间变成百万富翁。历史上的“炼金士”更是历尽千辛万苦,梦想把铁、铜等冶炼成金,结果得到的是一次又一次的失败,一次又一次的徒劳。lll$藏20世纪20年代,人工核转变的成功。
关键词 “点” 正电子 同位素 黄金 百万富翁 20世纪 中子 金原子 人工核转变 天然汞
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Collective rotations of fission isomers in actinide nuclei 被引量:2
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作者 XIE KePing KE WeiYao +4 位作者 LIANG WuYang FU XiMing JIAO ChangFeng PEI JunChen XU FuRong 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2014年第2期189-193,共5页
Using the total-Routhian-surface (TRS) method, the rotational behaviors of fission isomers in the second well of actinide nuclei 234-242U, 236-244pu and 238-246Cm were investigated. The pairing-deformation-frequency... Using the total-Routhian-surface (TRS) method, the rotational behaviors of fission isomers in the second well of actinide nuclei 234-242U, 236-244pu and 238-246Cm were investigated. The pairing-deformation-frequency self-consistent TRS calculations repro- duced reasonably the experimental moments of inertia extracted from spectroscopic data. It is calculated that, in these largely elongated (β2 ≈0.65 and β4≈ 0.03) fission isomers, the ν1/2-[981] neutron and π1/2+[651] proton align simultaneously at rotational frequency hω≈0.4 - 0.6 MeV (corresponding to spin I≈80h), which leads to clear upbending in moments of inertia (MoI's). Our calculations have indicated that the hexadecapole deformation f14 influenced significantly the frequency of the rotational alignment of the proton 1/2+[651] orbit. 展开更多
关键词 fission isomers total Routhian surface moments of inertia upbending ALIGNMENT
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The Gravity Field Variation Caused by Inner Core Super Rotation 被引量:1
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作者 CHEN Wei SHEN Wenbin HAN Jiancheng 《Geo-Spatial Information Science》 2008年第4期283-288,共6页
Due to the super rotation of the Earth's inner core, the tilted figure axis of the inner core would progress with respect to the mantle and thus cause the variation of the Earth's external gravity field. This paper ... Due to the super rotation of the Earth's inner core, the tilted figure axis of the inner core would progress with respect to the mantle and thus cause the variation of the Earth's external gravity field. This paper improves the present model of the gravity field variation caused by the inner core super rotation. Under the assumption that the inner core is a stratifying ellipsoid whose density function is fitted out from PREM and the super rotation rate is 0.27-0.53°/yr, calculations show that the global temporal variations on the Earth's surface have a maximum value of about 0.79-1.54×10^3 pGal and a global average intensity of about 0.45-0.89×10^ 3 μGal in the whole year of 2007, which is beyond the accuracy of the present gravimetry and even the super conducting gravimeter data. However, both the gravity variations at Beijing and Wuhan vary like sine variables with maximal variations around 0.33 pGal and 0.29 pGal, respectively, in one cycle. Thus, continuous gravity measurements for one or two decades might be able to detect the differential motion of the inner core. 展开更多
关键词 inner core super rotation gravity variation
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