放射性核

When blanket is designed, some necessary data, including tritium breeding ratio, irradiation damage ratio, intensity of activation radiation, magnet and thickness of shield, can be get through neutronics calculation. All of that must base on heat load and neutron power flux of first wall and divertor plate. So, the preparative calculation is prformed for that.

在设计包层时，需要进行中子学计算得到氚增殖率、辐射损伤率、活化放射性强度、磁体及其屏蔽厚度的计算、核加热产生率和冷却系统设计和安排的必要数据，而这一切都必须先知道第一壁和偏滤器靶板的中子壁负荷和热负荷；为此作了必要的先行准备计算工作。

People through nuclear reactions, have been synthesized 17 kinds of atomic number greater than 92 of the transuranic elements, and thousands of The new kinds of radioactive nuclides, and by high-energy and ultra-high energy-ray beam and the interaction of atomic nuclei and found hundreds of kinds of short-lived particles, namely, baryon, meson, lepton, and particle resonance states of these particles has led to a new field of study - the birth of particle physics since the age of .70, nuclear physics has entered a deep development and wide application of new, more mature stage, on the one hand the development of particle acceleration and detection techniques, expanding people's research in nuclear means, the other hand, nuclear technology to serve the national economy, for example, for the development and utilization of nuclear energy to provide more accurate nuclear data; the use of isotope tracer technique diagnosis and treatment of disease; the use of radiation and irradiation preservation of food, irradiation breeding .

人们通过核反应，已经人工合成了17种原子序数大于92的超铀元素和上千种新的放射性核素，并且通过高能和超高能射线束和原子核的相互作用，发现了上百种短寿命粒子、即重子、介子、轻子和共振态粒子，对这些粒子的研究导致了一门新学科——粒子物理学的诞生。70年代以来，核物理进入了纵深发展和广泛应用的新的更成熟的阶段，一方面发展粒子的加速技术和探测技术，扩充人们研究原子核的手段，另一方面将核技术服务于国民经济中，例如，为核能的开发利用提供更为准确的核数据；利用同位素示踪技术诊断和治疗疾病；利用射线及辐照技术保存食品、辐照育种等。

The concentration of neptunium and plutonium is extremely low in environmental samples.

核设施的运行，不可避免有放射性物质弥散到环境中。

Conventional radiochemical methods such as alpha spectrometry, neutron activation analysis, liquid scintillation system, fission track and gamma spectrometry for the quantitative determination of neptunium and plutonium often require complicated and time-consuming sample preparation and separation procedures.

研究环境中铀、镎、钚等长寿命放射性核素的精密测定，对保护公众安全和保护环境，对了解核设施的历史操作情况和现状，都具有重要意义。环境样品基体复杂，铀、镎和钚等锕系元素含量非常低，在复杂的生态条件下，这些核素常常具有复杂多变的化学形态，要准确测定其含量，必须要有灵敏可靠的检测方法。

Of course, nuclear energy also creates problems, such as the radioactive waste from nuclear power plants.

当然，核工程也存在问题，如核工厂的放射性废物等。

And sure enough, only a few months later the decay of the atom nucleus in the radioactive element cobalt 60 revealed that it did not follow the principles of mirror symmetry.

几个月以后，利用放射性元素Co60的核衰变所做的实验表明镜像对称性不成立。

Results show that NPSA and EMC are very simple and practical, and consequently, it is applicable for the upcoming large-scale nuclear facility decommissioning in our country, especially for radiation survey and site investigation of radioactively contaminated sites.

实践表明，MARSSIM提出的非参数统计方法和抬升测量比较方法简单实用，对我国即将面临的核设施退役，特别是在大面积放射性污染场地的监测与评估中，具有实际意义。

After being shot by neutron,~(74)Se isotope can be changed to be short decayed period to radioisotope.

经中子照射后~(74)Se同位素可变成短衰期放射性同位素~(75)Se，而90%以上高浓度的~(75)Se同位素做成的放射源在农业与核医学等方面有重要的应用价值。

Also it can be used in the nuclear science and engineering research for absolute measurement of nuclear decay rate.

它可供计量实验室建立放射性活度基准设备用，也可用于核科学研究和工程中核衰变率的绝对测量。

Quantitative assessment of the tracer concentration distribution across the body is the key for functional study of the tissues.

核医学的优势是对这些放射性示踪剂的定量分析。

The split between the two groups can hardly be papered over.

这两个团体间的分歧难以掩饰。

This approach not only encourages a greater number of responses, but minimizes the likelihood of stale groupthink.

这种做法不仅鼓励了更多的反应，而且减少跟风的可能性。