Possible light neutral boson and particle mass quantization

Qualities of nucleons, such as the fundamental parameter mass, might be modified in extreme conditions relative to those of isolated nucleons. We show the ratio of the EMC-effect tagged nucleon mass to that of the free one(m*/m);these values are derived from the nuclear structure function ratio between heavy nuclei and deuterium measured in the electron Deep Inelastic Scattering(DIS) reaction in 0.3≤x≤0.7. The increase in m*/mwith A-1/3 is phenomenologically interpreted via the release of a color-singlet cluster formed by sea quarks and gluons in bound nucleons holding high momentum in the nucleus, from which the mass and fraction of non-nucleonic components in nuclei can be deduced. The mass of color-singlet clusters released per short range correlated(SRC) proton in the high momentum region(k > 2 fm-1) is extracted to be 16.890 ±0.016 MeV/c2, which evidences the possibility of a light neutral boson and quantized mass of matter.     

单胺类神经递质的样品前处理及分析方法研究进展

单胺类神经递质是人体内一类重要的神经递质,其含量测定对于疾病诊断与控制、药物开发与研究及神经学基础研究具有重要意义。生物样品中单胺类神经递质的含量低,基体复杂,选择快速高效的样品前处理方法,是建立高灵敏单胺类神经递质分析方法的关键。该文对近年来生物样品中单胺类神经递质的样品前处理方法的研究进展进行了详细阐述,对单胺类神经递质分析检测方法的新进展进行了介绍,并对其发展趋势进行了展望。     

赏析一道与垂心有关的向量试题

本文赏析一道涉及三角形垂心的向量竞赛题,从不同视角给出多种解法,既有解决向量问题通性通法的精彩演绎,也有出其不意的奇思妙解.