No abstract

Acetaldehyde oxime has been synthesized though the liquid-phase ammoximation of acetaldehyde with ammonia and hydrogen peroxide over various titanosilicate catalysts. Titanium mordenite (Ti-MOR), prepared from highly dealuminated mordenite and TiCl 4 vapor by a secondary synthesis method, was superior to TS-1 and Ti-MWW catalysts both in aldehyde conversion and in oxime selectivity. The reaction parameters were investigated systematically in a batch-type reactor for Ti-MOR, such as solvent effect, temperature, time, catalyst loading, amounts of ammonia and hydrogen peroxide relative to aldehyde as well as addition methods of the reactants. Under optimized conditions, Ti-MOR was capable of showing an aldehyde conversion of 99% and an oxime selectivity of 97%. In comparison with TS-1 and Ti-MWW, the advantage of Ti-MOR in acetaldehyde ammoximation was mainly attributed to its lower ability for oxidation to convert the aldehyde to acetic acid. There was almost no effect resulting from the addition mode of the reactants; Ti-MOR with its special characteristics was unique in catalytic behavior and easy handling. An overview of the reaction routes involved in acetaldehyde ammoximation has been provided.

A simple and sensitive method for simultaneous determination of furan and vinyl acetate (VA) in vapor phase of mainstream cigarette smoke with cold trap and gas chromatography-mass spectrometry (GC-MS) was developed. A Cambridge filter pad (CFP) was placed in front of the impingers of smoking machine to remove the particle phase from cigarette smoke. Furan and VA in vapor phase of mainstream cigarette smoke were collected in two impingers connected in series by filled with methanol at -78°C. The solutions were added with deuterium-labeled furan-d 4 and VA-d 6 as internal standards and analyzed by GC-MS. The results showed that the calibration curves for furan and VA were linear (r 2 > 0.9995) over the studied concentration range. The intra-and inter-day precision values for furan and VA were <7.07% and <9.62%, respectively. The extraction recoveries of furan and VA were in the range of 94.5-97.7% and 92.3-94.9%, respectively. Moreover, the limits of detection for furan and VA were 0.028 µg mL -1 and 1.3 ng mL -1 , respectively. The validated method has been successfully applied to determine the emissions of furan and VA in the vapor phase of mainstream cigarette smoke under International Organization for Standardization (ISO) and Canadian Intense (CI) smoking regimen.

At the end of 2019, the COVID-19 broke out in inland China, and the outbreak gradually spread worldwide. In prevention and control, the public's attention to this epidemic has increasingly grown and their demands for various types of information have shown an upward trend. The Medium Effect of Health Communication plays a vital role in the prevention and control of this epidemic. Shanghai, however, as one of the most densely populated cities and one of the most susceptible to outbreaks of the virus, has yet demonstrated excellent control effects. To study the impact of Health Communication on the prevention and control behaviour and awareness of Shanghai residents in the context of the COVID-19, this paper is based on The Theory of Planned Behavior (TPB) and actual data. Then, it is found that three factors are the crucial points in the role of Health Communication in the prevention and control of the COVID-19 in Shanghai. They are residents' attitudes towards collecting epidemic prevention information, friends' and relatives' attention to epidemic prevention information and ease of access to epidemic prevention information. In addition, these three factors can be addressed individually to improve the effectiveness of the prevention of the disease in the area. For example, the official media can engage the public by increasing entertaining and innovation in the dissemination of epidemic prevention information. The government can enact relevant laws and regulations to force people to implement epidemic prevention and control measures. Raising the frequency of Health Communication is an outstanding method as well. All in all, by studying Shanghai residents' behavior and awareness of epidemic prevention, this article will provide a reference for people all over the world to fight the COVID-19.