40K is one of the most important atomic species for ultra-cold atomic physics. Due to the extremely low con- centration （0.012%） of 40K in natural abundance of potassium, most experiments use 4-10% enriched potassiu...40K is one of the most important atomic species for ultra-cold atomic physics. Due to the extremely low con- centration （0.012%） of 40K in natural abundance of potassium, most experiments use 4-10% enriched potassium source, which have greatly suffered from the extremely low annual production and significant price hikes in recent years. Using naturally abundant potassium source, we capture 5.4 × 10 6 cold 40K atoms with the help of a high performance of two-dimensional magneto-optical trap （2D＋ MOT）, which is almost three orders of magnitude greater than previous results without the 2D＋ MOT. The number of the 40K atoms is sufficient for most ultra-cold 40K experiments, and our approach provides an ideal alternative for the field.展开更多
A column study was carried out to assess the influence of accompanying anions on potassium （K） leaching at potato growing sites with different soil textures （sandy loam and clay loam） in northwestern India. Potass...A column study was carried out to assess the influence of accompanying anions on potassium （K） leaching at potato growing sites with different soil textures （sandy loam and clay loam） in northwestern India. Potassium was applied in the top 15 cm layer of soil column at 30 and 60 mg K kg-1 through different sources having different accompanying anions （CI-, SO^-, NO3 and H2PO4-）. Maximum K was retained in the top 0-15 cm layer with a sharp decrease in K content occurring in 15 30 cm layer of the soil column. The trend was similar for both levels of applied K as well as frequency of leaching and soil type. The decrease of K content in soil column after four leaching events was maximum in case of Khanaura sandy loam, while only minor decrease was observed in Hundowal clay loam when K was applied at 60 mg K kg-1, indicating higher potential of clay rich soil to adsorb K. In general, the K leaching in presence of the accompanying anions followed the order of SO4^2-≤ H2PO42- 〈 NO3 = Cl-. Highest 1 mol·L^-1 CH3COONH4-extractable K was retained when K was applied along with SO4^2- and H2PO4 anions, and the least was retained when accompanying anion was Cl-. The influence of anions was more pronounced in the light textured soil and at high amounts of K application. Higher levels of K application resulted in higher losses of K, especially in sandy loam soil as observed from the leachate concentration. Among the different K sources, the maximum amount of K leaching was noticed in the soil column amended with KC1. After four leachings, the maximum amount of K leached out was 6.40 mg L-1 in Hundowal clay loam and 9.29 mg L-1 in Khanaura sandy loam at 60 mg K kg-1 of soil application through KC1. These concentrations were lower than the recommended guideline of the World Health Organisation （12.00 mg L-1）.展开更多
基金Supported by the National Key Research and Development Program of China under Grant Nos 2016YFA0300600 and2016YFA0301500the National Natural Science Foundation of China under Grant Nos 11474347,61227902 and 61775232
文摘40K is one of the most important atomic species for ultra-cold atomic physics. Due to the extremely low con- centration （0.012%） of 40K in natural abundance of potassium, most experiments use 4-10% enriched potassium source, which have greatly suffered from the extremely low annual production and significant price hikes in recent years. Using naturally abundant potassium source, we capture 5.4 × 10 6 cold 40K atoms with the help of a high performance of two-dimensional magneto-optical trap （2D＋ MOT）, which is almost three orders of magnitude greater than previous results without the 2D＋ MOT. The number of the 40K atoms is sufficient for most ultra-cold 40K experiments, and our approach provides an ideal alternative for the field.
基金Supported by the Ph.D. Programme of Punjab Agricultural University (PAU), Inida
文摘A column study was carried out to assess the influence of accompanying anions on potassium （K） leaching at potato growing sites with different soil textures （sandy loam and clay loam） in northwestern India. Potassium was applied in the top 15 cm layer of soil column at 30 and 60 mg K kg-1 through different sources having different accompanying anions （CI-, SO^-, NO3 and H2PO4-）. Maximum K was retained in the top 0-15 cm layer with a sharp decrease in K content occurring in 15 30 cm layer of the soil column. The trend was similar for both levels of applied K as well as frequency of leaching and soil type. The decrease of K content in soil column after four leaching events was maximum in case of Khanaura sandy loam, while only minor decrease was observed in Hundowal clay loam when K was applied at 60 mg K kg-1, indicating higher potential of clay rich soil to adsorb K. In general, the K leaching in presence of the accompanying anions followed the order of SO4^2-≤ H2PO42- 〈 NO3 = Cl-. Highest 1 mol·L^-1 CH3COONH4-extractable K was retained when K was applied along with SO4^2- and H2PO4 anions, and the least was retained when accompanying anion was Cl-. The influence of anions was more pronounced in the light textured soil and at high amounts of K application. Higher levels of K application resulted in higher losses of K, especially in sandy loam soil as observed from the leachate concentration. Among the different K sources, the maximum amount of K leaching was noticed in the soil column amended with KC1. After four leachings, the maximum amount of K leached out was 6.40 mg L-1 in Hundowal clay loam and 9.29 mg L-1 in Khanaura sandy loam at 60 mg K kg-1 of soil application through KC1. These concentrations were lower than the recommended guideline of the World Health Organisation （12.00 mg L-1）.
