This paper introduces the concepts of star semiring,star homomorphisms of semirings,the subdirect product of a family of star semirings and subdirectly irreducible star semiring,and then proves the subdirect decomposition theorem of star semirings.

And the subdirect decomposition theorem of semirings is proved.

Catalysts Cu_ZSM_5 and Co_ZSM_5 were prepared and used for the direct decomposition of NO.

he effect of catalyst preparation condition on the catalytic activity for NO direct decomposition over CuY, CuZSM-5 was studied by use of quadrupole MS as means of activity measurement in a recycling low pressure reaction system.

Boole complement elements and the direct product decomposition of R_0-algebra;

Further study is made on pseudo-t-norms and implication operators on a complete lattice, their direct products and direct product decompositions.

Then a direct sum decomposition of L(λ) is given as a Uq(sl(2))-module.

Construction of Cartesian authentication codes from direct sum decompositions of n-dimension at row vector space over finite field is presented,and the size paramenters of the code in construction are computed.