Papers by Author: Jian Liu

Abstract: Biological monitoring for arsenic(As) is usually based upon a determination of urine, blood, nail and hair arsenic concentration, however, saliva has been suggested as a non-invasive biological matrix for assessing exposure. To further evaluate the potential utility of saliva for arsenic biomonitoring, Atomic Fluorescence Spectrometry(AFS-230) and Inductively Coupled Plasma Mass Spectrometer (ICP-MS) were used to evaluate the concentration of arsenic in drinking water, saliva and urine in endemic arsenicosis area in Shanyin County of Shanxi Province. The results showed that the arsenic concentration in drinking water was 0.55-720.0ug/L, and there were 66.67% samples above the arsenic level (50μg/L) of standards for drinking water quality. The median value of arsenic in drinking water was 127.22 μg/L. The salivary and urinary arsenic both can reflect the exposure of arsenic in drinking water. Additionally, there was a significant positive association of salivary arsenic compared with arsenic in drinking water (r=0.674, P<0.05)and urinary arsenic(r=0.794, P<0.05). These results demonstrated that, similar to urinary arsenic, salivary arsenic also can be used as a biomarker for assessing human exposue to arsenic.

Abstract: Films of linear-low density polyethylenes, made from metallocene catalyst and Ziegler-Natta catalyst , were exposed to accelerate photo-oxidation conditions. The investigations were focused on the changes of the physical and chemical structures and elongation at break occurring in the photo-oxidation process. The results showed that ethylene-hexene m-LLDPE was more favorer to photo-oxidize than ethylene-octene LLDPE. The other two ethylene-ocetene m-LLDPEs were comparable to LLDPE with the same comonomer. The oxidation rate of LDPE is slower than those of all the LLDPEs.

Abstract: Moisture-absorbent poly- (acrylate-co-methacrylate) was synthesized by solution polymerization, using N,N’-methylene bisacrylamide as the crossinglinking agent, sodium bisulfate and ammonium persulfate as the initiator. The moisture absorption properties of the copolymer in different temperatures and humidities have been systematically studied. Experimental results indicated that the moisture absorption behavior has been enhanced with the increase amount of methacrylate. Under different relative humidity, the moisture adsorption ability was distinct. When the relative moisture reached 40%, the humidity behavior became less evident. As the increase of moisture, the absorbency for moisture improves correspondingly. When the relative moisture get to 90%, the properties of this copolymer was obviously improved compared with the traditional materials, such as silica gel and molecular sieve.