核素

There are 8.6%~10.91% foreign matter in the sphenes, in which radioactive elements of strontium, cesium and uranium range from 4.26% to 4.58%. The change of structural cell parameters of sphenes is still very little,Δa=-0.0009 nm~0.0041 nm,Δb=0.0018 nm~0.0004 nm,Δc=0.0002 nm~0.0048 nm,Δβ=-0.10°~0.09° with high crystallinity of 99.27%~96.46%. Though, the age of sphene from the Fenghuang Mountain is about 1000 Ma, and experienced 775 Ma~1758 Ma geological evolvement and alpha decay, its crystallinity only decreased 3%, and its crystal shape and structure are still fine, indicating that sphene is of good ability to solidify radioactive elements. Therefore, sphenes are ideal minerals for solidifying nucleus waste.

通过对北祁连牛心山变质杂岩体中榍石(775Ma)和山西凤凰山花岗岩中榍石(1758Ma)的XRD及EDS等测试与研究，结果表明：两地榍石的杂质元素质量分数高达8.6%~10.91%，放射性核素锶、铯和铀的质量分数达4.26%~4.58%；晶胞参数的变化极小，△a=-0.0009nm~0.0041nm、△b=0.0018nm~0.0004nm、△c=0.0002nm~-0.0048nm、△β=-0.10°~0.09°，结晶度仍高达99.27%~96.46%，榍石经过10×10^8a的地质作用，结晶度仅减少了3%，显示榍石固化放射性系列核素的能力较强，虽经历了约775Ma~1758Ma的复杂地质演化及其所含放射性核素的衰变作用，其晶体结构完好，稳定性极高，是值得期待的理想核废物固化矿物。

Migration of radioactive nuclides in groundwater of porous media is controlled not only by groundwater hydraulics, but also by many other physical, chemical processes. Nuclides transport model coupled chemical equilibrium action is to join convection-dispersion model and multicomponent chemical equilibrium model, it is different from traditional transport model based on K〓 completely in theory.

地下水中核素在多孔介质的迁移过程不仅受到水动力的控制，还受到多种物理化学作用的影响，耦合平衡化学作用的核素迁移模型就是把对流—弥散模型与多组分化学平衡模型有机地结合起来，这种模型与传统的基于K〓值的核素迁移模型在理论上是完全不同的。

So far found that there are more than 2800 kinds of nuclides, in addition to 271 kinds of stable isotope and the rest are about 2530 kinds of radiation nuclide, including natural and artificial radionuclides radionuclides.

到目前为止发现的核素有2800多种，除271种是稳定的核素，其余约有2530种是放射线核素，包括天然放射性核素和人工放射性核素。

In hypergensis process uranium tend to be activate and transfer while thorium tend to enrich in the relict phase.

在我们的研究中，通过计算，得到了放射性核素浓度与核素的比放射性活度之间的定量关系，进一步推算出α、β比放射性活度与核素浓度之间的定量换算公式，这对放射性环境监测具有一定的实际意义。

The concentration of Cosmogenic nuclides is not only constrained by production rates and exposure time, and also closely related to surface erosion. Furthermore, the concentration is affected by geomagnetic intensity, shielding, chemical weathering, and sample geometry as well. These factors affecting Cosmogenic nuclide concentration should be calibrated when surface exposure age is calculated.

地表物质中宇宙成因核素浓度除了受到核素生成速率和地表物质的暴露时间制约外，还与地表侵蚀速率密切相关，此外，地磁场强度、遮蔽、化学风化及样品的几何位置等也会对核素浓度产生一定影响，在求算样品的地表暴露年代时，应对这些因素进行相应的校正。

The atomic structure 、nuclide 、isotope 、isomere、 radionuclides、stable nuclide.

原子核的结构、核素、同位素、同质异能素、放射性核素与稳定性核素。

The complete radiation spectra for alpha and beta emitters are taken from MIRD. radionuclide data and decay schemes. For Auger-electron emitters, the radiation spectra are taken from American Association of Physicists in Medicine Task Group report No.

单细胞条件下，由于俄歇电子核素和硼中子俘获反应释放的粒子射程短，局部能量沉积高，细胞或细胞核的平均吸收剂量及其分布主要依赖于核素的辐射类型和能量、核素的空间分布以及靶区大小。

In the article, considering the potentially severe pollution of the subsurface environment from the low level radioactive waste , the dynamic integrated transport model of low level nuclide in vadose and saturate zones has been established and is used to predict the dynamic action of the nuclide in a disposition spot.

针对处置库中低中放核素释放对地下环境潜在性污染的严重性，建立了核素在包气带和含水层中联合迁移的数值模型，利用所建立模型对某一处置场核素迁移的动力学行为进行环境预测。

The stability ofradioactive microspheres can be improved by coating with ploT-L-lactic acid; however,about 60% of the activity leaches from the microspheres in this process, and approximately10% of the activity leaches after washing with saline. Fortunately, 30% of the activityremained stably in the resin microspheres.

体外稳定性实验结果表明：1采用离子交换法制备的放射性树脂微球标记核素脱落严重，使用聚乳酸包被放射性树脂微球可以提高其稳定性，但是包被过程中约有60％核素脱落，生理盐水洗涤约有10％的核素继续脱落，不过剩余的30％稳定存在于树脂微球上。

To take soil samples from test pit at different time after tracers were put in and to measure the distribution of specific activity at different depth is the usual method in studing nuclide migration in aerated zone at CIRP's Field Test Site.

野外试验场核素迁移试验通常采用的方法是在示踪核素投放后不同时间在试验坑取土样，测定不同深度处的核素比活度分布。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。