• 青藏高原5—10月地表潜热通量与青海同期降水之间的关系

    Subjects: Geosciences >> Other Disciplines of Geosciences submitted time 2019-09-10 Cooperative journals: 《干旱区研究》

    Abstract:利用1981—2015年ERA-Interim再分析资料和青海省43个观测站气象资料,采用气象经验正交函数分解(EOF)、相关分析法及合成分析等方法,对青藏高原(以下简称高原)5—10月地表潜热通量的时空分布特征及其与青海省同期降水之间的关系进行了分析,结果表明:① 高原地表潜热通量第1模态空间分布主要呈现高原东西部变化不一致的特征,青海东北部、高原西部和南部地区表现为正异常,其余地区为负异常;第1模态时间系数呈现显著下降趋势,并以2001年为界,前正后负,表明青海东北部及高原西部和南部地表潜热通量在2001年以前(后)增加(减少)。② 高原地表潜热通量与青海省东北部降水存在显著的负相关关系,当高原地表潜热通量增加(减少)时,青海省东北部降水减少(增加)。③ 将通过0.1显著性检验的区域作为研究二者之间关系的关键区(35.0°~38.5°N,98°~103.0°E),以1个标准差为依据,挑选潜热通量高值年和低值年。结果表明,关键区内地表潜热通量在近35 a表现为显著下降的趋势,潜热通量高值年关键区降水增加,潜热通量低值年关键区东北部降水减少,其余地区降水增加,且在南部存在大于60 mm正异常中心;在潜热通量高(低)值年,关键区位势偏低(高),风速偏大(小),关键区南部水汽辐合较弱(强)。通过分析100 hPa南亚高压中心强度与300 hPa温度场,在地表潜热通量异常偏高(低)年,南亚高压强度略低(高),300 hPa暖中心略低(高),且南亚高压初上(撤离)高原较早。

  • Advancements in Cryogenic Purification System for Gas Cell

    Subjects: Physics >> Nuclear Physics submitted time 2023-11-03

    Abstract: Multinucleon transfer reactions involving heavy actinide projectile and target nuclei hold significant potential as a groundbreaking method to synthesize
    neutron-rich superheavy nuclei. The construction of a Principled Spectrometer for Neutron-rich Superheavy Nucleus Research is highly desirable to establish the technical, methodological, and device foundation to explore the stability island in superheavy nuclei and to study the mechanism of multinucleon transfer reactions. The gas cell of the Principled Spectrometer requires a continuous supply of high-purity helium gas to stop the energetic radioactive reaction products and to extract the energy-reduced ions to the subsequent experimental setup. The paper focuses on a newly developed cryogenic purification system for the gas cell of the spectrometer. This cryogenic purification system is designed to provide recyclable and high-purity helium for the Principled Spectrometer. With a series of tests, the cryogenic purification system has been proven to be able to purify the 99% helium gas to 99.999% or higher, fulfilling the requirements of the gas cell when used in conjunction with the chemical purification system.