In 2017, the flash capacity of each server will be 2.5 terabytes, which will reach 8TB by 2021, and the average DRAM capacity of every server in 2017 will be 145GB, which will grow to 350GB by 2021. The concept of accounting income is called accounting income. According to the traditional view, the accounting income refers to the difference between the realized income and the corresponding expenses. It has the following characteristics: Marvin Loh, senior fixed income strategist at BNY Mellon, Modern economy, the interest rate as the price of money, not only restricted by many factors in the economic and social, and changes in interest rates to have a great impact on the economy as a whole, as a result, modern economists are studying the interest rate decision problem, pay special attention to the relationship between the variables and the balance of the economy as a whole, the interest rate decision theory has experienced the classical interest rate theory, Keynes's interest theory, interest rate in loanable funds theory and is-lm analysis as well as the contemporary evolution of dynamic interest rate model, the development process. , BMO capital markets of U.S. rates strategy director Ian Lygen is described: "we believe that prices change due to interest rate debt investors don't want to stand in front of a sell-off on the eve of the end of catch a falling knife."