Using a 110v appliance in China

The standard plug in China has two slanting pins and one vertical pin. Is the vertical pin ground and the slanting pins 110v or 120v with respect to ground and out of phase so that it is 220v or 240v between the slanting pins. The standard power coming into American power boxes is 3 wire with ground and 2 hot wires that are 110v to ground and 180 degrees out of phase so that it is 220v between the hot wires. 220v appliances use all three wires. The rest of the circuits in a house use one of the hot wires and ground. Instead of a transformer then in China, I believe I could use an adapter connecting one of the slant pins and the vertical pin to the two vertical pins (American style) output. Is that correct?