Power inverter pcb boards
After nearly half a century of hard work, China's printed circuit industry has become an indispensable basis and guarantee in China's electronic information industry, and its output value has ranked second in the world.In 2004, China's total output value of PCB reached us $8.15 billion, and its total import and export value was us $8.9 billion.It is not expected to be for long.
PCB PCBS (polychlorinated biphenyls) is North America in 1929 until the late 1929 s a business using a synthetic organic compounds, while Canada not the chemical processing production, but also has been widely used in electrical equipment insulation, heat exchangers, water systems and other special applications.
It took decades for the global environmental pollution of PCBS to be recognized. PCBS are mixtures of various chlorinated biphenyls, which are extremely harmful to human health.The Canadian government has taken steps to try to eliminate PCB, but the illegal import, processing and sale of PCB occurred in Canada in 1977, and the illegal release of PCB into the natural environment in 1985, and the Canadian constitution allows the owners of PCB equipment to continue using the PCB until the life of the equipment.It was only in 1988 that provincial governments began to regulate the storage, transport and destruction of PCBS.
PCB is not easy to break down in a natural environment, but also spread very far, PCB in production and processing, use, transport and waste disposal process into the air, soil and river and sea, small Marine organisms and fish breathe to PCB, and they have become great Marine food, as a result, PCB went into the body of the all sea life, including mammals of Marine biology.PCB accumulates thousands of times more in the body of a Marine organism than it does in water.
other information required by process scheduling.(total time that the process has waited on the CPU, total time that the process has executed)
events.This is the event that the process waits for to occur as it transitions from an execution state to a blocking state.(cause of obstruction)
Is a static description of the entire process execution activity.This includes the values of the various registers in the computer system associated with the execution of the process, the set of machine instruction code formed by the program segment after compilation, the data set, and various stack values and PCB structures.Can be combined at a certain execution level, such as user - level context, system - level context, and so on.
The unique token that a process exists