期刊：
Chemical Engineering Journal,2023年474:145565 ISSN：1385-8947
通讯作者：
Ma, XC;Li, LQ;Su, RK
作者机构：
[Wen, Tao; Huo, Haoling; Ma, Xiancheng; Xu, Wenjun; Yuan, Zhipeng] Cent South Univ Forestry & Technol, Coll Mech & Elect Engn, Changsha 410004, Hunan, Peoples R China.;[Li, LQ; Zeng, Zheng; Li, Liqing] Cent South Univ, Sch Energy Sci & Engn, Changsha 410083, Hunan, Peoples R China.;[Su, Rongkui; Wang, Hanqing] Cent South Univ Forestry & Technol, Coll Environm Sci & Engn, Changsha 410083, Hunan, Peoples R China.;[Huo, Haoling] Jinan Univ, Inst Adv Wear & Corros Resistant & Funct Mat, Guangzhou 510632, Peoples R China.;[Liang, Xin] China Construct Fifth Engn Div Corp Ltd, Changsha 410004, Hunan, Peoples R China.
通讯机构：
[Li, LQ ; Su, RK ; Ma, XC ] C;Cent South Univ Forestry & Technol, Coll Mech & Elect Engn, Changsha 410004, Hunan, Peoples R China.;Cent South Univ, Sch Energy Sci & Engn, Changsha 410083, Hunan, Peoples R China.;Cent South Univ Forestry & Technol, Coll Environm Sci & Engn, Changsha 410083, Hunan, Peoples R China.
关键词：
Porous carbon;Acetone and methanol adsorption;Acetone/methanol selectivity;Pore structure;Oxygen groups
摘要：
Currently, the focus of research on carbon-based materials primarily revolves around studying the adsorption properties of methanol and acetone. However, there is limited research on the adsorption and separation of methanol and acetone azeotropes, and the mechanism is still unclear. Here, the impact of oxygen groups and pore size on the adsorption and separation of acetone and methanol in porous carbon materials was investigated using molecular simulations. The results demonstrated that the adsorption capacity of acetone and methanol is influenced by the micropore structure and oxygen content at relatively low pressures, while at relatively high pressures, the adsorption capacity primarily depends on pore structure. Notably, the micropore structure emerged as a key determinant of acetone/methanol selectivity, while the doping of oxygen groups in porous carbon has a negative impact on selectivity. To validate our theoretical findings, three types of porous carbons with varying oxygen contents and gradient pore size distributions were synthesized. The acetone and methanol adsorption isotherms were measured, and the acetone/methanol selectivity was calculated. Comparative analysis of the impact of pore size and oxygen content on the adsorption and separation performance of acetone and methanol yielded consistent results between experimental and theoretical calculations. These findings elucidate the effects of oxygen content and pore size on the adsorption performance of acetone and methanol adsorption and separation performance from both experimental and theoretical perspectives, providing a basis for further design and development of adsorbents of high-performance volatile organic compounds (VOCs) adsorbents.
摘要：
D-limonene is one of the main olefin gas compounds released from citrus and its relative content changes most obviously with the infection time of Bactrocera dorsalis (Hendel). Thus, it is necessary to detect D-limonene content released from citrus, which may lead to detect the presence of early infestation by B. dorsalis in citrus. In this study, a gas-sensing system based on quartz crystal microbalance (QCM) sensors coated with ethyl cellulose (EC) was developed to detect D-limonene aromas emanating from Australian citrus. There was a linear relationship between the frequency shift and D-limonene concentrations ranging from 60 mg m(-3) to 6000 mg m(-3) with a determination coefficient (R-2) of 0.9899, and the limit of detection for D-limonene in pure gas was 300 mg m(-3). It has also been observed that the QCM sensor has better selectivity towards D-limonene aroma. Additionally, the sensor was found to be repeatable with an average R value of 96.31 %, and the lifetime of the sensor can be extended at least to one month with an acceptable drift (3.40 %) in their sensing characteristics. Furthermore, it was confirmed that there was high consistency between the QCM sensor's response and the GC-MS for D-limonene aroma. The six VOCs contributing the most to differentiating citrus infested with B. dorsalis were identified. The gas-sensing system based on QCM sensors has potential feasibility for the rapid detection of the presence of B. dorsalis infestations in postharvest citrus.
摘要：
A sweeping electronic nose system (SENS) was self-developed to detect the presence of early infestation by Bactrocera dorsalis (Hendel) in citrus fruits. Principal component analysis (PCA) and linear discriminate analysis (LDA) were applied to analyze citrus fruits that were subjected to different types of treatments (invasion and incubation stage) caused infestation. The results indicated that the SENS could successfully detect the presence of early infestation by B. dorsalis in citrus fruits. The different types of treatments in citrus fruits could be effectively classified by PCA and LDA, respectively. Meanwhile, the specific infestation time of citrus fruits within treatment stage could be satisfactorily identified by LDA model with correct recognition rate of 98.21%. Importantly, an optimized sensor array achieved better performance in classification and discrimination than that of the non-optimized. This study showed the potential feasibility of the electronic nose technology for in-filed detection of postharvest pest infestation citrus fruits under market conditions.
通讯机构：
Key Laboratory of Key Technology for South Agricultural Machinery and Equipment, Ministry of Education, Engineering College, South China Agricultural University, Guangzhou, China
作者机构：
[李立君; 桑孟祥; 文韬; 郑立章; 龚中良; 董帅] School of Mechanical and Electrical Engineering, Central South University of Forestry and Technology, Changsha, 410004, China
通讯机构：
School of Mechanical and Electrical Engineering, Central South University of Forestry and Technology, Changsha, China
作者机构：
[李立君; 文韬; 桑孟祥; 龚中良; 郑立章; 董帅] School of Mechanical and Electrical Engineering, Central South University of Forestry and Technology, Changsha, 410004, China
通讯机构：
School of Mechanical and Electrical Engineering, Central South University of Forestry and Technology, Changsha, China
作者机构：
[李立君; 赵兵; 文韬; 张仟仟; 刘付] School of Mechanical and Electrical Engineering, Central South University of Forestry and Technology, Changsha, China;[郭鑫] School of Science, Central South University of Forestry and Technology, Changsha, China;[洪添胜] Division of Citrus Machinery, China Agriculture Research System, Guangzhou, China;[洪添胜; 文韬] Key Laboratory of Key Technology for South Agricultural Machinery and Equipment, Ministry of Education, Engineering College of South China agricultural University, Guangzhou, China
通讯机构：
Key Laboratory of Key Technology for South Agricultural Machinery and Equipment, Ministry of Education, Engineering College of South China agricultural University, Guangzhou, China
关键词：
模型;光谱检测;农业;霉变稻谷;脂肪酸;可见/近红外光谱;特征波段;样本集划分
摘要：
为了实现霉变稻谷脂肪酸含量无损、快速检测,该文研究应用可见/近红外光谱技术检测霉变稻谷的脂肪酸含量。考虑到直接选用霉变稻谷可见/近红外光谱数据构建脂肪酸含量预测模型存在建模费时、预测失准等问题,研究提出了霉变稻谷脂肪酸含量的可见/近红外优化校正模型。研究中通过光谱-理化值共生距离(sample set partitioning based on joint x-y distance, SPXY)算法结合偏最小二乘法初步分析了不同校正集样本预测霉变稻谷脂肪酸含量的差异;利用连续投影算法(SPA)提取了反映霉变稻谷脂肪酸含量变化的特征波段;采用偏最小二乘法(partial least square, PLS)和多元线性回归法(multivariable linear regression, MLR)分别建立了基于特征波段光谱反射值的霉变稻谷脂肪酸含量预测模型,并对比分析了采用SPXY样本集划分的模型预测效果。结果表明:采用SPXY法筛选出的65个校正集样本分布与初始校正集相近,脂肪酸含量变化范围为18.55~127.26 mg,其标准差为32.39;SPA算法最终从256个全光谱波段中优选出9个特征波段,实现了光谱数据的压缩;分别建立的SPXY-SPA-PLSR模型和SPXY-SPA-MLR模型预测霉变稻谷脂肪酸含量相关系数RP为0.922 1和0.915 9,预测均方根误差RMSEP为13.889 3和14.261 0;SPXY筛选校正集所构建模型预测精度与初始校正集所建模型相当,但校正集样本数量减少为初始校正集的41%,运算时长缩短为初始样本集的32%,提高了模型的校正速度。
作者机构：
[李立君; 谢洁飞; 文韬; 郑立章; 龚中良] School of Mechanical and Electrical Engineering, Central South University of Forestry and Technology, Changsha, 410004, China;[马强] School of Science, Central South University of Forestry and Technology, Changsha, 410004, China
通讯机构：
School of Mechanical and Electrical Engineering, Central South University of Forestry and Technology, Changsha, China
