Objective To preliminarily investigate the conditions of the performance of chlorine dioxide generator for drinking water disinfection and know the overall situation of the industry.Methods From 2007 to 2008,6 companies'products were chosen for this investigation according to certain rules,and their performance indicators,such as chlorine dioxide output and conversion rate were tested by using the Five-step iodimetry method.Results On-site generating technology was commonly used,and the average conversion rate of the compound type generator was 57.06%,and the pure type generator was 84.78%.Conclusion The conversion rate of the pure type generator is better than the compound type,and the newly invented pure type generator has much better performance and lower disinfection cost.

Objective By population survey,to explore the epidemiological characteristics of gastric precancerous lesions in Lishui District of Nanjing and provide objective basis for the prevention and treatment of early gastric cancer.Methods From July 2021 to December 2022,21 977 patients who received endoscopy and/or 13C-UBT in Lishui District People's Hospital and 6 medical community units in Nanjing City were retrospectively analyzed for demography characteristics,detection rate of gastric precancerous lesions,and H.Pylori infection rate.Results(1)590 cases of gastric precancerous lesions were detected(detection rate 2.68%);(2)The total detection rate of precancerous lesions and three pathological types in males were all higher than those in females(all P<0.001);(3)The minimum age for the total detection rate of precancerous lesions in males and the mini-mum age for each pathological type were lower than in females(P<0.001,0.009,0.005,0.002);(4)The popu-lation total H.pylori infection rate was 23.10%,the H.pylori infection rate in patients with precancerous lesions was higher than that in non-precancerous lesions(P<0.001),both H.pylori infection rate of male and female in precancerous lesions were all higher than those of non-precancerous lesions of the same sex(all P<0.001),in addition,the H.pylori infection rate of male whether in precancerous or non-precancerous lesions was higher than that of female(all P<0.001);(5)The precancerous lesions detection rate in male,female,and the overall age range of 20～29 to 70～79 years is positively correlated with age growth(P<0.001),and rapidly decreases after the age of 79,the of H.pylori infection rate was also positively correlated with age growth(P<0.001),and the trend of age change(P<0.001)was parallel to the precancerous lesions detection rate.Conclusions The detec-tion rate of gastric precancerous lesions in this region is above the average level in China;the total H.pylori infec-tion rate is at a relatively low level in China;the H.pylori infection rate is parallel to the age trend of the detection rate of gastric precancerous lesions,and increases with age.