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1.
本文简要地介绍并评述了中国原子能科学研究院现在正在进行的和将要进行的与核能相关的、特别是与聚变能相关的中子实验工作. Neutron expertrients related to the development of nuclear energy, especially fusion energy,in CIAE at Ptesent and in the near future are briefly introduced and reviewed.  相似文献   

2.
核对称能的密度依赖性对于原子核物理和天体物理中的许多问题很重要。基于密度依赖的结团模型,奇特的结团放射性被用来约束核对称能及其斜率的大小。在密度依赖的结团模型中,清楚地给出了结团放射性子核208Pb的中子皮大小与对称能的斜率参数Lρ0) 之间的关联。发现从M3Y核子-核子相互作用得到的结团-208Pb 同位旋矢量势对于对称能的斜率参数Lρ0) 非常重要。基于结团放射性实验数据和新的208Pb 的中子皮大小实验数据,成功得到对称能的斜率参数Lρ0) 的大小。也讨论了利用质子放射性数据提取的斜率参数Lρ0)。The density-dependence of symmetry energy is of particular importance to many problems in nuclear physics and astrophysics. Exotic cluster radioactivity is proposed to constrain the density slope of symmetry energy L(ρ0) by using the density-dependent cluster model (DDCM) where the cluster radioactivity serves as a link between the neutron skin thickness of 208Pb and the density slope L(ρ0). The isovector part of cluster-208Pb potential constructed from the M3Y nucleon-nucleon interaction is found to be very important in determining the density slope parameter L(ρ0). The correlation between the neutron skin thickness of 208Pb and the density slope parameter are obtained from cluster radioactivities around 208Pb with measured data. The constraint of L(ρ0) from proton radioactivity is also discussed.  相似文献   

3.
在不同能量下, 利用核束缚能对虚光子四动量的平方项进行修正, 分别计算了Sn核碰撞中核束缚能对反应截面中湮灭项和康普顿散射项及K因子的影响。 结果表明, 核束缚能在小x区域对反应截面中湮灭项和康普顿散射项及K因子的影响明显, 并且能量越低这种影响越显著, 随着x2增大影响逐渐消失。 We made a revision of square of virtual photon four momentum by means of using nuclear bin ding energy formula in different energy, and we also made an accurate calculation for the effect of nuclear binding energy on K factor and Compton term and annihilate term in the Drell Yan process of the Sn Sn collision. The outcome indicates that the effect of nuclear binding energy on the annihilate term and the Compton term is marked in little x region and the effect will become more obvious with decrease of the energy and come to disappear with increase of the x.  相似文献   

4.
Data on Coulomb Displacement Energies in the mass rangeA=40?240 are analyzed in the deformed Liquid Drop model and in the independent particle model. Reduced half-widths of Woods-Saxon mean-field potential of the resulting neutron-excess distributions are deduced. It is argued that the Nolen-Schiffer anomaly may be lifted by allowing for a slight binding-energy dependence of the mean-field potential geometry.  相似文献   

5.
5 我国核电的发展 5.1我国核电已由起步进入发展阶段 我国是重视发展核电的,早在1956年制订的《国家原子能发展规划12年大纲》中就明确指出:“用原子能发电是动力发展的新纪元,是有远大前途的”,“在有条件下应用原子能发电,组成综合动力系统”.但是,在我国第一颗原子弹爆炸成功后,国家正拟起步核电之时,又逢文化大革命,受其干扰,致使我国核电起步较晚.1974年3月31日周恩来总理主持中央专门委员会,批准了30万千瓦级的压水堆核电方案,作为科技开发项目列入国家计划,核电才开始起步.这就是秦山核电站的由来.秦山核电站是第一座由我国自主创新建成的核电站,它于1983年基本完成研究开发和工程设计,1985年3月20日正式开工建设,1991年12月15日并网发电,结束了我国大陆无核电的历史,实现了我国核电技术的重大突破.我国从法国成套进口的两台90万千瓦级的核电机组也于1987年在广东大亚湾开工,两套机组分别于1993年和1994年并网发电.秦山核电站(见本期封底图)和大亚湾核电站(见本期封底图)的建成发电,为我国核电发展打下了良好的基础.  相似文献   

6.
核能的和平利用始于20世纪50年代,那时美国、前苏联等工业发达国家在进行核军备竞赛的同时,也竞相发展核电站.1954年,前苏联建成电功率为5千千瓦的试验性原子能电站,为世界上首座核电站;1957年,美国建成电功率为9万千瓦的希平港原型核电站;这些成就证明了利用核能发电的技术可行性.国际上把上述试验性和原型核电机组称为第一代核电机组.  相似文献   

7.
Biehl et al. (2021) present some interesting observations on an early formulation of the free energy principle. We use these observations to scaffold a discussion of the technical arguments that underwrite the free energy principle. This discussion focuses on solenoidal coupling between various (subsets of) states in sparsely coupled systems that possess a Markov blanket—and the distinction between exact and approximate Bayesian inference, implied by the ensuing Bayesian mechanics.  相似文献   

8.
本文简要分析了当前世界和我国核能发展的趋向和特点,说明核能发展虽因三里岛和切尔诺贝利核电站的重大事故而受到严重挫折,但仍表现出持续增长的趋势,并沿着更安全、更经济和综合利用的路途,在向新一代中、小型堆和未来快中子增殖堆、聚变堆的方向发展,核能将逐渐成为21世纪的世界主要能源. This paper briefly analyses the present developing trend and features of nuclear energyin the world and our country.Although the nuclear energy development was subjected to the serious set back because of the accidents of Three Mile Island and Chernobyl s nuclear power plants,it hasbeen growing toward the way of more safe、more economic、multiple purpose、medium and small re-actor and future fast neutron advanced reactor.The nuclear energy will be the main energy source of21th century all over the world.  相似文献   

9.
中子星内壳层中存在原子核、中子、电子等非均匀分布的物质。在Wigner-Seitz近似下,共存相方法和自洽Thomas-Fermi近似方法是描述这种非均匀物质的有效方法。中子在非均匀物质所占的比例远远大于其他组分,因此原子核的对称能对非均匀物质的性质会产生十分重要的影响,而原子核对称能的密度依赖关系在核物质饱和密度附近有较大的不确定性。采用相对论平均场理论描述核子间相互作用,研究原子核对称能对中子星内壳层的密度范围、pasta相结构、壳核相变密度等性质的影响,探寻其中可能存在的关联。计算结果表明,原子核对称能及其密度依赖性在决定中子星内壳层非均匀物质的性质中起着重要作用,这与之前相关研究中得到的结论基本相符。Within Wigner-Seitz approximation, both the coexisting phases method and the self-consistent Thomas-Fermi approximation can be used to describe the nonuniform matter consisting of nuclei, neutrons, and electrons, which may coexist in the inner crust of neutron star. Since the neutron fraction is very large, nuclear symmetry energy may have an important impact on the properties of nonuniform matter. However, the density dependence of nuclear symmetry energy around saturation density is still rather uncertain. This paper focuses on the influence of nuclear symmetry energy on the density range of inner crust, pasta phase structure, and crust-core transition density of neutron star, where the relativistic mean field theory is adopted to describe the nucleon-nucleon interaction. It is turned out that the nuclear symmetry energy and its density dependence play an import role in determining the properties of nonuniform matter in the inner crust of neutron star, which is consistent with the former related studies.  相似文献   

10.
It is the author's intention to demonstrate progress in the application of nuclear magnetic resonance (NMR) in industry over a period of nearly 30 years.  相似文献   

11.
We present nuclear physics programs based on the planned experiments using rare isotope beams (RIBs) for the future Korean Rare Isotope Beams Accelerator facility(KRIA). This ambitious facility has both an Isotope Separation On Line (ISOL) and fragmentation capability for producing RIBs and accelerating beams of wide range mass of nuclides with energies of a few to hundreds MeV per nucleon. Low energy RIBs at Elab = 5 to 20 MeV per nucleon are for the study of nuclear structure and nuclear astrophysics toward and beyond the drip lines while higher energy RIBs produced by inflight fragmentation with the reaccelerated ions from the ISOL enable to explore the neutron drip lines in intermediate mass regions. The planned programs have goals for investigating internal structures of the exotic nuclei toward and beyond the nucleon drip lines by addressing the following issues: how the shell structure evolves in areas of extreme proton to neutron imbalance; whether the isospin symmetry maintains in isobaric mirror nuclei at and beyond the drip lines; how two-proton radioactivity affects abundances of the elements; what the role of the continuum states including resonant states above protondecay threshold in exotic nuclei is in astrophysical nuclear reaction processes, and how the nuclear reaction rates triggered by unbound proton-rich nuclei make an effect on rapid proton capture processes in a very hot stellar plasma.  相似文献   

12.
核Drell–Yan过程中的能量丢失现象   总被引:1,自引:0,他引:1  
在考虑EMC效应的基础上进一步考虑了入射强子的能量丢失现象,用部分子演化模型预见核Drell-Yan过程,效果明显改进.  相似文献   

13.
加速器驱动系统 (ADS)是一种新型的洁净能源装置 ,它采用加速器提供的强流高能量质子束驱动次临界的核反应堆 ,既有安全可靠和产生核废料少的优点 ,还可以处理传统反应堆留下的核废料 .能量放大器是一个基于回旋加速器组合的 ADS方案 ,由三级回旋加速器组成的加速器系统可以产生流强为12 m A和能量为1 .2 Ge V的质子束 (束流功率1 4.4MW) ,用以驱动1500 MW的核反应堆. Accelerator Driving System (ADS) is a new device for cleaning energy. A high intensity, high power proton beam provided by accelerators is used to drive a sub critical nuclear reactor. It is safe, reliable and can produce less nuclear waste, and also can be used to treat the nuclear waste from the classical reactor. An Energy Amplifier (EA), which is composed of three cyclotrons, is one type of ADS. It will be used to produce 14.4 MW proton beam (12 mA, 1.2 GeV) and to operate a 1 500 MW nuclear reactor.  相似文献   

14.
Physics of Atomic Nuclei - The strategic line of development of a nuclear power system based on fission and fusion reactors which ensures electricity generation on a specified scale, solves the...  相似文献   

15.
对加速器驱动洁净核能系统散裂靶问题的探讨   总被引:3,自引:1,他引:2  
简述了加速器驱动洁净核能靶系统的研究现状和存在的问题,对进一步可开展的工作提出了建议. The present status of the study on the neutron production rate, the neutron energy spectrum and the radiative nuclear production from the target spallation in accelerator driven clean nuclear system is presented. The Monto Carlo simulation and the related physics are also discussed. Their further improvement and the suggestions for the work to be done in China are proposed.  相似文献   

16.
在晶格气体模型的框架中研究了129Xe系统在破裂过程中的热力学性质和轻粒子发射性质随核温度和系统的冻结密度的变化规律.计算发现在不同的冻结密度下,129Xe破裂过程的物理观测量呈现了不同的温度相关性.在这种情况下,核物质液气相变发生时的临界温度强烈地依赖于系统的冻结密度.当激发能代替温度作为一个自变量时,临界激发能将不再灵敏地依赖于系统的冻结密度.除此之外,由于不同冻结密度而引起的不同粒子发射产额的温度相关性,也随着激发能的应用,出现了几乎一致的激发能依赖性.从这些结果中可以认为,激发能可以作为一个控制核破裂的基本物理量和标度量.  相似文献   

17.
The bound state of three-nucleon system is studied as a three-body problem which is solved following the different approaches of the Faddeev formalism as well as the unitary pole approximation. The three-body problem is reduced to a set of coupled integral equations by using separable approximations. Numerical calculations are carried out for the resulting integral equations and the separable expansion. In the present work, we calculate the ground-state binding energy of the bound three-nucleon system 3H. The main interest of the present work is to investigate the sensitivity of the three-nucleon binding energy to different effects. For this reason, we study the dependence of this energy on different forms of local and separable nucleon-nucleon potentials, the effective range of the nucleon-nucleon interaction, and on the percent of the D state in the deuteron wave function. Also we test the sensitivity of the three-nucleon binding energy to the considered number of terms from the separable expansion.  相似文献   

18.
赵坚 《物理通报》2004,(10):39-40
云南省2004届高三年级第一次全省统一测试中,有这样一道选择题:将一质量为m的物体以初速度υ0竖直向上抛出,已知物体在运动过程中所受空气阻力的大小与其运动速率成正比,比例系数为k.若物体能够上升的最大高度为H,则其上升过程所用的时间应为  相似文献   

19.
通常人们在有限核与核子物质中研究对称能,而本工作利用相对论平均场模型研究包含超子和夸克自由度物质的对称能。发现了含超子和夸克自由度物质中对称能的表观软化,并用相对论模型对此做了阐述。该软化现象提示由重离子碰撞产生的含非核子自由度致密物质的对称能提取将有待细致的甄别。  相似文献   

20.
张敬业 《中国物理 C》1994,18(12):1119-1123
在低能核结构研究中,电四极跃迁的B(E2,)值和基态带的态与态能量比值R常被用来衡量核的集体运动属性.本文通过标准的位能面计算,系统地探讨了这些量与核形变参数间的关系.指出B(E2,)值主要取决于核的平衡(静态)形变,目前的Nilsson-Strutinsky-BCS方法可以良好地求得从Z=30到锕系区偶-偶核的合理的形变值,而能量比值R则反映的是位能面的整体结构,例如硬度及非谐和性等.  相似文献   

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