放射性测量的

The air survey is specially superior in the regional environmental radioactivity survey, which is recommended by IAEA.

在区域环境放射性测量中，航测具有特殊的优势，是IAEA推荐的手段。

Intelligent nuclear instrument has been a dominant developing direction of radioactivity measurement instrument. The instrument for radon measurement of air pulse ionization chamber, based on the theory that alpha rays decayed by radon and its progeny can ionize the air molecules, can measure the radon concentration accurately.

智能核仪器已成为放射性测量仪器发展的一个主导方向，利用氡及其子体衰变放出α射线能使空气分子电离的理论设计的空气脉冲电离室α测氡仪可以准确地测量空气中的氡浓度。

This paper describes the principle and application of correlation method in the absolute radioactivity measurement .

本文介绍用于放射性核素活度绝对测量的相关方法的基本原理、应用及其优点。

The decay of ~(99m)Tc source was used to verify experimentally that in the measurement of the number of atoms of a radioactive isotope in a sample at time t_0, the error introduced through the inaccuracy of its decay constant can be reduced to a much smaller value by the careful selection of the time of measurement or measurements of its radioactivity at around one life time (1/λ) after t_0 and doing the calculation.

本文用~(99m)Tc源的衰变实验证明了：在测量一个样品中在t_0时的一种放射性同位素的原子数时只需精心选择一次或多次测量其放射性的时刻在t_0后约该同位素的一个寿期(1/λ)，并进行计算，则由它的衰变常数或其半衰期(T1/2)的不准确性而引进的误差可以被降低到较小值。

Basic nuclear physics and fundamental measuring techniques: The basic nuclear physics involves the main types of nuclear decay, law of decay, definition and units of radioactivity and the interaction of radiations and materials.

核物理基础与放射性测量技术：内容主要是核衰变的四种类型、衰变规律、放射性活度及其单位；射线与物质的相互作用，以及γ计数器及液体闪烁仪测量的基本原理和放射性测量的统计误差。

The volume of radon chamber is 4 m3, the range of radon concentration is 370~20 000 Bq/m3, and the relative expanded uncertainty of measurement results is no more than 5.8%. The whole testing system can verify/calibrate the radon monitor and study on the radioactive aerosol of radon decay product.

装置氡室体积为4 m3，氡浓度测量范围为370~20 000 Bq/m3，氡浓度值测量结果的相对扩展不确定度不超过5.8%，可用于测氡仪器的检定校准和氡子体放射性气溶胶的实验研究。

The β-activity of ~(89,90)Sr is measuured on GM counter after radiochemical separation.

放射性~(89，90)Sr是放化分离后在G-M计数器上测量的。

Some isobars or matrix may interfere in mass spectrometry analysis, and the low background technology is needed for radiochemical method .

这种包装盒既可以进行辐照，辐照后，也可以直接进行放射性测量，以避免辐照前后放射性测量的几何影响。

This contributed to the second phase of development of airborne radiometric survey techniques.

这就开始了航空放射性测量技术发展的第二阶段。

Exact dates for sites can be calculated and the method is more accurate than radiometric dating techniques.

用这种方法测量出的精确度要比放射性技术的高。

As she looked at Warrington's manly face, and dark, melancholy eyes, she had settled in her mind that he must have been the victim of an unhappy attachment.

每逢看到沃林顿那刚毅的脸，那乌黑、忧郁的眼睛，她便会相信，他一定作过不幸的爱情的受害者。

Maybe they'll disappear into a pothole.

也许他们将在壶穴里消失