In this paper,the following assignment problem is considered:there are persons to be assigned to do jobs,where,every person who is assigned to do one job,meanwhile,every job demands one person to do;then,this assignment problem is called standard assignment problem,furthermore,it is called general assignment problem.

Evaluate method and classification standard on lake eutrophication;

Research on index system and classification standard for household biogas region suitability evaluation;

Simultaneity,history of the measurement technology and the classification standards are mentioned.

A new testing method of biotoxicity and toxicity grading standard for oiifield chemicals and drilling fluids;

In order to explore the suitable way of establishing the pig carcass grading system, to achieve higher economy value with higher quality and to improve of quality of pigs in our country, the history, current situation and prospects of development pig carcass grading standards of foreign countries were summarized.

Objective To compare the prognostic value of different electroencephalography (EEG) grading standards of cerebral dysfunction after cerebrovascular diseases.