May 19 (Reuters) - NIU Technologies :: *NIU TECHNOLOGIES Q1 GROSS MARGIN 17.3% *NIU TECHNOLOGIES Q1 ADJUSTED NET INCOME RMB -31.4 MILLION *NIU TECHNOLOGIES Q1 NET INCOME RMB -38.8 MILLION *NIU TECHNOLOGIES Q1 REVENUE RMB 682 MILLION *NIU TECHNOLOGIES OUTLOOK Q2 REVENUE RMB 1,317-1,411 MILLION *NIU TECHNOLOGIES Q1 OPERATING EXPENSES RMB 165.1 MILLION *NIU TECHNOLOGIES - Q1 BASIC AND DILUTED NET LOSS PER ADS WERE BOTH RMB 0.49