The Current and Future Potential Geographical Distribution of the Solanum Fruit Fly, Bactrocera latifrons (Diptera: Tephritidae) in China

Part 1: Decision Support Systems, Intelligent Systems and Artificial Intelligence ApplicationsInternational audienceThe solanum fruit fly, Bactrocera latifrons (Hendel), is a major pest throughout South and South East Asia, including very few parts of southern China, and has invaded Hawaii and recently the continent of Africa (Tanzania and Kenya). With the development of international trade in fruits and vegetables, B. latifrons has become a potential threat to Chinese agriculture. In this study, CLIMEX 3.0 and ArcGIS 9.3 were used to predict the current and future potential geographical distribution of B. latifrons in China. Under current climatic conditions, its projected potential distribution includes most parts of southern China (about 32.2% of all 748 meteorological stations), from 16.544°N to 32.442°N. Optimal climate conditions occur in most areas of Yunnan, Guizhou, Sichuan, Chongqing, Hunan, Hubei, Jiangxi, Zhejiang, Fujian, Guangdong, Guangxi, Hainan, Taiwan, Hong Kong and Macao. The factors limiting the boundary of its suitability range are mainly the cold and dry stress. Climate change scenario for the 2020s indicates that the future potential geographical distribution will be increased by 5% of the total land areas of China, and the northern distribution boundary will move from 32.442°N to 33.408°N. There are 34 non-suitable climate sites change into suitable, mainly in Jiangsu, Anhui, Henan, Shanxi, Gansu, Sichuan and Tibet, because of China is likely to become hotter and wetter in the 2020s. In order to prevent the introduction and spread of B. latifrons, the present plant quarantine and monitor measures should be enhanced more where are projected to be suitable areas under current as well as future climatic conditions. At the same time, we should strengthen education for the public’s awareness of plant protection

Decarburization of Levitated Fe-Cr-C Droplets by Carbon Dioxide

Experiments have been conducted at 1873K (1600°C) to study the kinetics of decarburization of Fe-Cr-C levitated droplets containing 10, 17 and 20 wt pct Cr using argon-carbon dioxide gas mixtures containing up to 30 pct CO2, at flow rates of 100, 1000, 3000 and 12200 mL per min. It was found that chromium did not have a strong influence on the kinetics of decarburization while showing only minor effects on the extent of carbon removal. The results indicate that, for high carbon concentrations in the melt, the decarburization rates were controlled by mass transfer in the gas phase. Conventional formulation of governing mass transport numbers did not adequately describe the experimental observations made in this work. The observed rates are consistently higher than the values predicted using either the Ranz-Marshall correlation or the Steinberger-Treybal equation. A new correlation has been proposed to express the decarburization kinetics of levitated droplets for gas-flows in the range of Reynolds numbers between 2 and 100. The experimentally-derived model was found to be in excellent agreement with rate data derived from studies conducted by other researchers using levitated droplets.Appreciation is expressed to the Natural Sciences and Engineering Research Council of Canada who provided funding in support of this project