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期刊论文 2

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2019 2

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Detection of Huanglongbing (citrus greening) based on hyperspectral image analysis and PCR

Kejian WANG, Dongmei GUO, Yao ZHANG, Lie DENG, Rangjin XIE, Qiang LV, Shilai YI, Yongqiang ZHENG, Yanyan MA, Shaolan HE

《农业科学与工程前沿(英文)》 2019年 第6卷 第2期   页码 172-180 doi: 10.15302/J-FASE-2019256

摘要:

Huanglongbing (HLB, citrus greening) is one of the most serious quarantine diseases of citrus worldwide. To monitor in real-time, recognize diseased trees, and efficiently prevent and control HLB disease in citrus, it is necessary to develop a rapid diagnostic method to detect HLB infected plants without symptoms. This study used Newhall navel orange plants as the research subject, and collected normal color leaf samples and chlorotic leaf samples from a healthy orchard and an HLB-infected orchard, respectively. First, hyperspectral data of the upper and lower leaf surfaces were obtained, and then the polymerase chain reaction (PCR) was used to detect the HLB bacterium in each leaf. The PCR test results showed that all samples from the healthy orchard were negative, and a portion of the samples from the infected orchard were positive. According to these results, the leaf samples from the orchards were divided into disease-free leaves and HLB-positive leaves, and the least squares support vector machine recognition model was established based on the leaf hyperspectral reflectance. The effect on the model of the spectra obtained from the upper and lower leaf surfaces was investigated and different pretreatment methods were compared and analyzed. It was observed that the HLB recognition rate values of the calibration and validation sets based on upper leaf surface spectra under 9-point smoothing pretreatment were 100% and 92.5%, respectively. The recognition rate values based on lower leaf surface spectra under the second-order derivative pretreatment were also 100% and 92.5%, respectively. Both upper and lower leaf surface spectra were available for recognition of HLB-infected leaves, and the HLB PCR-positive leaves could be distinguished from the healthy by the hyperspectral modeling analysis. The results of this study show that early and nondestructive detection of HLB-infected leaves without symptoms is possible, which provides a basis for the hyperspectral diagnosis of citrus with HLB.

关键词: citrus     HLB     hyperspectral     identification     PCR    

Performance and emission characteristics of a diesel engine operating on different water in diesel emulsion fuels: optimization using response surface methodology (RSM)

Seyed Saeed HOSEINI, Mohammad Amin SOBATI

《能源前沿(英文)》 2019年 第13卷 第4期   页码 636-657 doi: 10.1007/s11708-019-0646-7

摘要: The nitrogen oxide (NO ) release of diesel engines can be reduced using water in diesel emulsion fuel without any engine modification. In the present paper, different formulations of water in diesel emulsion fuels were prepared by ultrasonic irradiation. The water droplet size in the emulsion, polydisperisty index, and the stability of prepared fuel was examined, experimentally. Afterwards, the performance characteristics and exhaust emission of a single cylinder air-cooled diesel engine were investigated using different water in diesel emulsion fuels. The effect of water content (in the range of 5%–10% by volume), surfactant content (in the range of 0.5%–2% by volume), and hydrophilic-lipophilic balance (HLB) (in the range of 5–8) was examined using Box-Behnken design (BBD) as a subset of response surface methodology (RSM). Considering multi-objective optimization, the best formulation for the emulsion fuel was found to be 5% water, 2% surfactant, and HLB of 6.8. A comparison was made between the best emulsion fuel and the neat diesel fuel for engine performance and emission characteristics. A considerable decrease in the nitrogen oxide emission (–18.24%) was observed for the best emulsion fuel compared to neat diesel fuel.

关键词: water in diesel emulsion fuel     hydrophilic-lipophilic balance (HLB)     response surface methodology (RSM)     emulsion stability     engine performance     exhaust emission    

标题 作者 时间 类型 操作

Detection of Huanglongbing (citrus greening) based on hyperspectral image analysis and PCR

Kejian WANG, Dongmei GUO, Yao ZHANG, Lie DENG, Rangjin XIE, Qiang LV, Shilai YI, Yongqiang ZHENG, Yanyan MA, Shaolan HE

期刊论文

Performance and emission characteristics of a diesel engine operating on different water in diesel emulsion fuels: optimization using response surface methodology (RSM)

Seyed Saeed HOSEINI, Mohammad Amin SOBATI

期刊论文