植保机械雾化场雾滴特征分析与二维重建

针对植保机械雾化性能检测中对雾滴尺寸分布特征检测常用方法中存在的不足,提出了利用高速摄像结合数字图像处理技术对药液雾化场中空间雾滴特征参数进行检测统计的方法,并根据检测到的雾滴特征参数信息实现了雾滴分布图像的二维重建。试验结果表明,该方法实现了对喷雾场中的雾滴分布特征的快速准确检测,同时避免了对喷雾场的干扰,为进一步研究喷雾场中的雾滴分布特征以及运动情况提供了方法基础。     

Analysis of the seasonal characteristics of forest fires in South Korea using the multivariate analysis approach

For efficient forest fire management, special precautions are required in dry and strong-wind seasons vulnerable to severe forest fires. To extract the seasonal characteristics of forest fires in South Korea, the statistics over the past 16 years, 1991 through 2005, were investigated. The daily records of the number of fire occurrences, the total area burned and the average burned area per occurrence were examined to identify the seasonal patterns of forest fires using cluster analysis and principal component analysis; the risk of daily fires was also assessed using the ordered logit model. As a result, the fire patterns were classified into five clusters and a general danger index for forest fires was derived from the first principal component, showing relatively large-scaled fire regimes in spring, and frequent small-scaled fire regimes in autumn and winter. In connection with the ordered logit model, the probability for the five ranks of forest fire risk was calculated and the threshold for high-risk fires was detected. As an implementation of the results above, the proper forest fire precautionary period in South Korea was estimated, and consequently October 21 through May 17 was recognized as a dry season at a high risk of forest fires. This period began 10 days earlier in autumn and extended into midwinter (late December and January) as opposed to the existing precautionary period, indicating the need of more cautious forest fire management earlier in autumn and continuing through midwinter.     

蚕种改良复式冷藏法效果的探讨

根据《蚕桑通报》１９９５年第４期“现行夏秋蚕品种春制越年蚕种保护冷藏技术研究”一文所提供的技术,桐乡市１９９６年徐５．６６万盒蚕种的生产应用,未能收到预期效果,造成较大经济损失,认为改良复式冷藏法技术不需进一步研究和改进。     

Alleviating cancer drug toxicity by inhibiting a bacterial enzyme

The dose-limiting side effect of the common colon cancer chemotherapeutic CPT-11 is severe diarrhea caused by symbiotic bacterial β-glucuronidases that reactivate the drug in the gut. We sought to target these enzymes without killing the commensal bacteria essential for human health. Potent bacterial β-glucuronidase inhibitors were identified by high-throughput screening and shown to have no effect on the orthologous mammalian enzyme. Crystal structures established that selectivity was based on a loop unique to bacterial β-glucuronidases. Inhibitors were highly effective against the enzyme target in living aerobic and anaerobic bacteria, but did not kill the bacteria or harm mammalian cells. Finally, oral administration of an inhibitor protected mice from CPT-11-induced toxicity. Thus, drugs may be designed to inhibit undesirable enzyme activities in essential microbial symbiotes to enhance chemotherapeutic efficacy.     

基于机器视觉的常温烟雾机喷雾角测量系统

针对常温烟雾机喷雾角测量方法中存在的问题，提出了利用数字图像处理技术结合最小二乘拟合方法对常温烟雾机的喷雾角进行图像检测的方法。该方法实现了喷雾角的非接触测量，避免了常用方法对喷雾现场的干涉，减少了人工测量方法带来的误差。试验结果表明，该方法简单可行，而且能够实现快速检测。     

Field evaluations of a deep learning-based intelligent spraying robot with flow control for pear orchards

Precision Agriculture - This study proposes a deep learning-based real-time variable flow control system using the segmentation of fruit trees in a pear orchard. The real-time flow rate control,...     

丹毒丝菌SpaA基因免疫保护区的克隆及其在毕赤酵母中的表达

【目的】以毕赤酵母Pichia pastoris X-33为宿主表达猪丹毒丝菌Erysipelothrix rhusiopathiae Spa A基因氨基端的免疫保护区蛋白.【方法】以采集于广东某猪场的猪丹毒丝菌为模板,根据NCBI中已发表的Spa基因c DNA序列设计1对引物,通过PCR扩增得到Spa A-N,并将其连接到表达载体p PICZαC上,得到重组表达质粒p PICZαC-Spa A-N;用Sac I酶将重组表达质粒p PICZαC-Spa A-N线性化后电转化入毕赤酵母X-33,经含博来霉素ZencinTM抗性的YPDS平板筛选和PCR鉴定的阳性转化子,用含不同浓度博来霉素抗性的YPDS平板筛选出高拷贝子并进行甲醇诱导培养,分别于诱导48、72、96 h后离心收集上清液,立即做SDS-PAGE,并进行SDS-PAGE及Western-blot试验.【结果和结论】成功克隆并表达了Spa A-N基因,构建了重组表达质粒p PICZαC-Spa A-N,并以毕赤酵母X-33为宿主成功表达了猪丹毒丝菌Spa A基因氨基端的免疫保护区蛋白.丹毒丝菌Spa A-N作为免疫保护区在酵母宿主中得以成功表达.