Creation of ^174Yb Bose-Einstein Condensates in a Crossed FORT

Quantum degenerate gases of alkaline-earth-like atoms are unique systems used for quantum simulation, quantum computing and studies of quantum phase transitions. We report an all-optical formation of Bose Einstein eondensates of ytterbium atoms. About 106 atoms of ^174Yb are transferred to a far-off-resonance optical trap （FORT） and then cooled by evaporative cooling. Phase transition occurs at the critical temperature of 520 nK. A pure condensate containing approximately 2 × 10^4 atoms has been obtained in the crossed FORT, with an atomic peak density of -8 × 10^14 cm^-3. The condensate lifetime exceeds 1 s.     

12,52-二羟基-15,55-二甲基-14,16,34,36,54,56,74,76-八硝基-2,4,6,8-四氧桥连-1,3,5,7（1,3）-杯[4]芳烃的合成

以1,5-二氟-2,4-二硝基苯和3,4,5-三甲氧基甲苯为起始原料,经环化、甲基化、硝化和去甲基化反应,合成了一种新型杯芳烃衍生物,其结构经¹H NMR,¹³C NMR,¹⁵N NMR和元素分析表征。