Mechanical engineering including mechanical and chemical engineering. At its simplest, thermodynamics is the study of energy, its use and transformation through a system. Typically, engineering thermodynamics is concerned with changing energy from one form to another. As an example, automotive engines convert chemical energy (enthalpy) from the fuel into heat, and then into mechanical work that eventually turns the wheels. Thermodynamics principles are used by mechanical engineers in the fields of heat transfer, thermofluids, and energy conversion. Mechanical engineers use thermo-science to design engines and power plants, heating, ventilation, and air-conditioning (HVAC) systems, heat exchangers, heat sinks, radiators, refrigeration, insulation, and others.
Dandong–Dalian intercity railway and a half years and was started on 17 March 2010. It started operation on 17 December 2015. Dandong–Dalian intercity railway The Dandong–Dalian intercity railway () is a high-speed line operated by China Railway High-speed within the Liaodong Peninsula of Liaoning province, connecting the coastal cities of Dandong and Dalian. Dandong–Dalian intercity railway is broken down into three segments: Dandong–Zhuanghe, Zhuanghe–Dengshahe, and Dengshahe–Dalian. It will have a total length of about , of which will be in the Dandong prefectural area, will be in the Dalian region. The total investment is estimated to be about 14.7 billion yuan with a