查询词典 radioactive decay

Now, on the other hand, we're being told, in effect, Sure everything changed, but not radioactive bombardment and its rate of decay -- they have remained at the same level for billions of years.

"现在，在另一方面，我们被告知，实际上是"相信一切变了，但没有放射性轰击及其衰减率--他们都保持在同一水平，为十亿年。

What's more, an organism could conceivably seem to be, by today's assumptions of yesteryear's radioactive bombardment levels and rate of decay, thousands or even millions of years old only days or months after its death.

更何况，一个有机体可以想象似乎是，今天的假设的脸庞上的放射性水平轰炸和衰减率，十万甚至几百万年的历史，只有几天或几个月后，其死亡。

Pneumoniae FH strain was cloned and the sequence was analysed by M13 DNA sequencing method. Comparing the PCR product sequcence with MP M-129 strain P1 gene, we found that there are 4 bases different. This may result from the different MP DNA templates. The maximum homology is 98.8%. The result confirmed the fidelity and specificity of the amplified target DNA segment by PCP, and suggested that two categories of MP P1 gene still exist a few differences even in the conservation region. The cloning MP DNA segment was labelled by random hexanucleotide priming, after hybridization, the probe detection was completed using an anti-digoxigenin antibody alkaline phosphatase conjugate, and the substrates 5-bromo-4-chloro-3-indolyl phosphate and nitro blue tetrazolium. This hybridization system is much superior to the radioactive probe hybridization, because it is safe, easy to handle and has no limitation of decay time. The time required for colormetic detection is also much less than the corresponding autoradiographic exposure time needed to achieve similar detection limits with 32P-labelled probes. The Dig-probes could be used repeatedly, and this made them not only much convenient to use, but also lower the cost, and worthwhile to be used popularly.

将PCR产物进行重组，并将阳性重组质粒，应用M13测序系统对产物进行DNA序列分析，并与MPM-129株P1基因核苷酸进行同源性比较，发现有4个位置的碱基发生了变化，其同源性为98.8％，证实了PCR所扩增DNA片段的准确性和特异性，同时也证实了不同MP组型的P1基因即使在保守区也存在着一定的差异，将克隆的目的DNA片段用异羟基洋地黄毒苷配基用随机引物法标记制备MP DNA探针，杂交后用碱性磷酸酶标记的抗Dig多克隆抗体与杂交体反应，再用BCIP和NBT呈色，制备MP DNA探针，鉴定所扩增片段的特异性，与同位素探针比较，Dig探针不受半衰期限制，可反复使用，而且价格低廉，值得推广使用。

This is because radioactive nuclear elements are formed in the giant outbursts of energy, and some of these decay by releasing positrons.

这是因为放射性核素在这巨大的爆炸能量中形成，其中一些放射出正电子而衰变。

Meanwhile, positrons from the decay of a form of radioactive sodium are separately slowed and accumulated.

同时，来自放射性钠一种形式的衰减正电子被慢慢分开且累积起来。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。