Ever since Mandate on Implementing National Legal Metrological Units was released by the State Council in February 27, 1984, China has formulated and promulgated national standards of quantities & units one after the other: GB3100～3102－1986 and GB3100～3102－1993, wherein the latter has been in use for nearly 10 years after it replaced the former. Before new national standard was released, GB3100～3102－1993 still is the fundamental, mandatory standard that must be implemented by all industries, and is also the specific application of national legal metrological units, which should be followed out unconditionally in writing and editing sci-tech books and journals.
　　Due to the fact that many contributors and even editors do not know well and think much of GB3100～3102－1993, nonstandard usages of quantities and symbols occur often when they write or edit academic articles, e.g.: ① continue to use nonstandard quantities and units such as specific gravity, molecular weight, atomic weight, equivalent weight, mu, meter, ppm etc.; ② continue to use or even slather nonstandard quantities and symbols such as electrical conductivity EC, coefficient of variation CV, centigrade temperature T, a.m. 8h10min etc.; ③ nonstandard applications can be found everywhere, including upper & lower case, upright & italic, superscript & subscript, designating unit etc. such as 5MM, 6KG, dx, dy, 50～60% and so on.
　　Hence, in order to avoid problems mentioned above, reading and editing public should persist in executing GB3100～3102－1993 in writing and editing sci-tech books and journals, so as to ensure that quantities and units are applied in a standard way, and to enhance readability.
        This standard includes the following series of standrads:
　　GB 3100－1993 SI units and recommendations for the use of their multiples and of certain other units
　　GB 3101－1993 Quantities and units－General principles
　　GB 3102.1－1993 Quantities and units－Space and time
　　GB 3102.2－1993 Quantities and units－Periodic and related phenomena
　　GB 3102.3－1993 Quantities and units－Mechanics
　　GB 3102.4－1993 Quantities and units－Heat
　　GB 3102.5－1993 Quantities and units－Electricity and magnetism
　　GB 3102.6－1993 Quantities and units－Light and related electromagnetic radiations
　　GB 3102.7－1993 Quantities and units－Acoustics
　　GB 3102.8－1993 Quantities and units－Physical chemistry and molecular physics
　　GB 3102.9－1993 Quantities and units－Atomic and nuclear physics
　　GB 3102.10－1993 Quantities and units－Nuclear reactions and ionizing radiation
　　GB 3102.11－1993 Quantities and units－Mathematical signs and symbols for use in the physical sciences and technology
　　GB 3102.12－1993 Characteristic numbers
　　GB 3102.13－1993 Quantities and units－Solid state physics

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