工程机械板块12月9日跌0.81%，同力股份领跌，主力资金净流出2.28亿元

Group 1 - The engineering machinery sector experienced a decline of 0.81% on December 9, with Tongli Co., Ltd. leading the losses [1] - The Shanghai Composite Index closed at 3909.52, down 0.37%, while the Shenzhen Component Index closed at 13277.36, down 0.39% [1] - A detailed table of individual stock performance within the engineering machinery sector was provided [1] Group 2 - The net capital outflow from the engineering machinery sector amounted to 228 million yuan, with retail investors contributing a net inflow of 240 million yuan [2] - The main funds saw a net outflow of 12.04 million yuan, indicating a shift in investment dynamics within the sector [2] - A table detailing the capital flow for individual stocks in the engineering machinery sector was included [2]