Treasury Secretary Tim Geithner is set to meet with several high-ranking members of the Chinese leadership this week, marking the Obama administration’s first major overture to the powerhouse nation. Geithner left Saturday for meetings in Beijing, where he’ll discuss ways to strengthen relations between China and the United States, according to the Treasury Department. China is one of America’s most important trading partners, and its economy is tightly intertwined with efforts to reverse the global downturn