This paper proves that if (A,B) is set system pair satisfying the upper necessary conditions and X∈U(A) D(B), then WA(X)=0, so that accordding to the equality of AhlswedeCai, the upper necessary conditions also is sufficiency conditions for extremal pair; when k=1 and k=2, the structure theorems .

The elements ranked as Cu >Zn>Ni>Pb according to their concentrations in weeds, while the accumulation coefficients were in order of Zn>Cu>Pb>Ni in weeds.

It is found that Alternanthera philoxeroides has great (capa-)city of accumulating Zn~(2+) and Pb~(2+) in hydroponic tests and the highest accumulation coefficients are 94.

Accumulation coefficients of different crops is in following order: Astragalus .

Application of water system integration technology with water mains in catalyzer factory;

Application of windows inter-process communication in system integration;

Analysis of system integration technology in intelligent building;

The technical flow types of the oil and gas gathering system and the concerned equipment are varous,which makes the system complex.

The standard design of the gathering system of Sulige gas field is in accordance with the function and flow of the well station.

It is introduced the function, characteristics together with the application procedure of FAST Piper in analyzing gas field gathering system.