▁ ▁These ▁equations ▁gave ▁a ▁first ▁explanation ▁to ▁the ▁Me iss ner ▁effect ▁( and , ▁so , ▁to ▁the ▁properties ▁of ▁super con duct ors ). ▁He ▁is ▁known ▁as ▁well ▁for ▁being ▁the ▁invent or ▁of ▁the ▁dil ution ▁re fr iger ator , ▁a ▁cry ogen ic ▁device ▁that ▁uses ▁liquid ▁hel ium . ▁ ▁Hon ours ▁and ▁awards ▁London ▁was ▁elected ▁a ▁Fellow ▁of ▁the ▁Royal ▁Society ▁in ▁ 1 9 6 1 , ▁his ▁nom ination ▁read ▁ ▁References ▁▁ ▁Category : 1 9 0 7 ▁birth s ▁Category : 1 9 7 0 ▁death s ▁Category : G erman ▁Jews ▁Category : G erman ▁at he ists ▁Category : J ew ish ▁at he ists ▁Category : F ell ows ▁of ▁the ▁Royal ▁Society ▁Category : A cadem ics ▁of ▁the ▁University ▁of ▁Br istol <0x0A> </s> ▁Def end ▁T ian an men ▁Square ▁Head quarters ▁was ▁formed ▁on ▁May ▁ 2 4 , ▁ 1 9 8 9 . ▁The ▁purpose ▁of ▁this ▁organization ▁was ▁to ▁create ▁a ▁strong ▁leadership ▁to ▁lead ▁the ▁student ▁movement . ▁ ▁Str ucture ▁Def end ▁T ian an men ▁Square ▁Head quarters ▁was ▁set ▁up ▁by ▁a ▁small ▁group ▁of ▁people . ▁More ▁than ▁half ▁of ▁the ▁organizations ▁were ▁famous ▁student ▁leaders ▁of ▁ 1 9 8 9 ▁student ▁protest s . ▁Ch ai ▁L ing ▁was ▁prominent ▁as ▁commander - in - ch ief ▁for ▁the ▁Square . ▁There ▁were ▁six ▁other ▁key ▁members ▁in ▁this ▁organization , ▁but