Asian share markets were on the ropes for a second straight session on Tuesday as investors waited anxiously to see if Beijing can head off the latest selling stampede in Chinese stocks. An unnerving combination of global economic concerns and escalating tensions in the Middle East kept pressure on commodity prices while bolstering safe-haven sovereign bonds. Japan’s Nikkei (.N225) slipped another 0.5 percent, adding to Monday’s 3.1 percent dive.