Monocyclic aromatic hydrocarbons(MAHS) from the smoke of coal-fired house stoves were collected by multi-bed adsorbent tube,and determined by GC/MSD after thermodesorption.

Based on a purposebuilt approach, single aromatic ring type high performance water reducer was synthesized methodically beginning with its molecular structure and introduction of functional groups, correlation of molecular structure characteristics, type and quantity of functional groups and water reducing performance was studied.

Study on the linearization of single-loop feedforward power amplifiers;

In this paper the main results are following theorems: (1)A prime ring is a primitre ring, asimple ring with unit or a division ring, respectively, if and only if there exists its ideal which is aprimitre ring, a sinple ring with unit or a division ring.

The aim of this note is to show the following:If all maximal left ideals of R are conjugate,then so are all maximal left ideals of matrix ring Rn×n,moreover,R is a local ring or R/J is a simple ring,where J is the Jacobson radical of R.

Using the properties of the ideal of the ring theory,we obtain a sufficient condition of a simple ring to be a division ring and its corollary,and with the weaker inverse proposition of Lagrange s theorem in the group theory,we get the conclusion that the group without proper subgroup must be a finite group of prime order.