查询词典 radon seed

Main contents and conclusions are: 1 The ionization current was measured continuously by a charge-integration method with a computer after the introduction of radon into the chamber.

主要内容及结论：1充氡后利用计算机连续进行电离电流累积测量，得到了精细的电流随时间的变化曲线，可清楚看出氡及其子体的生成衰变造成的电离电流的生长—稳定—衰减过程，与理论计算值进行了比较，由电离电流衰减速度的变化得出氡吸附作用的影响，并测量到电离室冲洗后氡的反扩散现象；2由已知活度的标准源定出相对测量的刻度系数K值，K=24.62 Bq／pA，对同一个监测源以半年为周期进行多次测量后得出稳定性符合要求；3通过测量电离电流和气压的关系曲线以及不同气压下的饱和曲线，确定了常规的工作条件；4测量了盐酸清洗电离室内表面降低本底的效果；5不确定度分析表明相对测氡的扩展不确定度(k=2)小于5％，由本底涨落得出探测下限为0.5 Bq；6理论上对壁损失修正进行了计算，实验上保持电离室工作在饱和区的情况下，测量了不同气压下电离电流的变化，从中得出了壁损失随气压变化的规律，可以看出，电离电流的实测值和计算值随气压变化规律基本一致；当气压大于125 kPa时，端效应等其它因素造成的影响不大于2％，因而在此工作条件下，测量电离电流后通过计算修正壁损失可以实现近似的绝对测氡，提出了进一步提高绝对测量准确度的方法。

Any of several radioactive gases that are isotope s of radon and are products of radioactive decay.

"几种氡的同位素的放射性气体，是放射性物质衰变的产物。"

Radon variable; Mathematical expectation; Applications of mathematical expectation

随机变量；数学期望；数学期望的应用

However, source wavelet and near offset traces information will be needed for applying this technique. Energy minimizing method and band-limited parabolic Radon transform is employed to meet the above two conditions.

在逆散射级数法的实现过程中，地震子波和近道波场是必不可少的信息，本文采用能量最低法则和带限抛物Radon变换法来弥补原始地震资料中所缺失的这些信息。

The numerical solutions for different coefficient and different boundary conditions are obtained for two models of radon field which have respectively source in the side and inside of collapse column.

根据流体场的扩散理论和对流理论，建立了扩散系数与对流速度为常量或变量情况下的氡气场三维状态方程；对于陷落柱柱体侧面有源氡气场和柱体体内有源氡气场两种理论模型，给出了不同系数和边界条件下的数值解的形式。

First, by the style of convolution and deconvolution operator in frequency domain, the aliasing problem in parabolic Radon transform is researched, and the critical sample of the parameter q and x is formulated.

首先通过频率域中褶积和反褶积算子的形式，对抛物线Radon变换中的假频问题进行了研究，得出了变量q和x的临界采样率的定量公式。

To achieve better results,we make use of the discrete Radon transform and a set of discrete orthogonal Tchebichef polynomials to establish relationship between the projection moments and the image moments,and then estimate the unknown projections from the known projections using this relationship.

提出一种新的投影数据估计算法，利用离散Radon变换和Tchebichef正交多项式建立图像矩和投影矩之间的关系，并用这种关系从已知投影数据中估计未知投影数据，达到提高重建图像质量的目的。

This paper presents a new method to estimate unknown projections. To achieve better results, we make use of the discrete Radon transform and a set of discrete orthogonal Tchebichef polynomials to establish relationship between the projection moments and the image moments, and then estimate the unknown projections from the known projections using this relationship.

提出一种新的投影数据估计算法，利用离散Radon变换和Tchebichef正交多项式建立图像矩和投影矩之间的关系，并用这种关系从已知投影数据中估计未知投影数据，达到提高重建图像质量的目的。

As for updating the periodic table, element 118 would slot in just below radon in the column that contains inert gases.

至于元素周期表的升级，118号元素的位置就在氡列那些气体元素之后。

" Noble gas:Any of the six chemical elements that make up the rightmost group of the periodic table as usually arranged: helium, neon, argon , krypton, xenon, and radon."

稀有气体：通常排列在周期律中最右边一族的六种化学元素：氦、氖、氩、氪、氙和氡。

Listen,point and check your answers.

听，指出并且检查你的答案。

Warming needle is one of effective treatment methods for knee arthralgia aggravated by cold,and it is simple,safety,so it should be developed in clinical acupuncture and moxibustion extensively.

但以本院科针灸门诊在2005年1月—2006年6月期间共收治膝痛患者100余例，经过临床的诊断后，其中施以温针治疗的48例，疗效显著，报道如下。1临床资料本组病例48