Based on the provided diagram which appears to be a pressure-volume (P-V) diagram for a thermodynamic process, identify the states and processes shown.

Analysis of the Diagram:

• The diagram shows a closed rectangular loop with four distinct points labeled 1, 2, 3, and 4.
• The vertical axis represents pressure (P) and the horizontal axis represents volume (V).
• There are pressure values indicated as $$P_0$$ and $$2P_0$$, and volume values as $$V_0$$ and $$1.7V_0$$.
• Arrows indicate the direction of the process: 1 $$\rightarrow$$ 2, 2 $$\rightarrow$$ 3, 3 $$\rightarrow$$ 4, and 4 $$\rightarrow$$ 1.

Processes and States:

• State 1: Pressure = $$P_0$$, Volume = $$V_0$$
• State 2: Pressure = $$2P_0$$, Volume = $$V_0$$
• State 3: Pressure = $$2P_0$$, Volume = $$1.7V_0$$
• State 4: Pressure = $$P_0$$, Volume = $$1.7V_0$$
• Process 1 $$\rightarrow$$ 2: Isochoric (constant volume) process where pressure increases from $$P_0$$ to $$2P_0$$.
• Process 2 $$\rightarrow$$ 3: Isobaric (constant pressure) process where volume increases from $$V_0$$ to $$1.7V_0$$.
• Process 3 $$\rightarrow$$ 4: Isochoric (constant volume) process where pressure decreases from $$2P_0$$ to $$P_0$$.
• Process 4 $$\rightarrow$$ 1: Isobaric (constant pressure) process where volume decreases from $$1.7V_0$$ to $$V_0$$.
• This cycle is a rectangular thermodynamic cycle, often used to illustrate concepts like work done and heat transfer in engines.

Figure label: Рис. 135