Determination of Herbicide Propisochlor in Soil, Water and Rice by Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) Method Using by UPLC-ESI-MS/MS

Wu, Xiaohu,Xu, Jun,Liu, Xingang,Dong, Fengshou,Wu, Yanbing,Zhang, Ying,Zheng, Yongquan Korean Chemical Society 2013 Bulletin of the Korean Chemical Society Vol.34 No.3

A simple, quick and reliable analytical method for the confirmation and quantification of propisochlor was developed. The propisochlor was extracted from water, soil and rice (stalks, rice and hull) matrices using acetonitrile, and cleaned up with primary secondary amine and determined by UPLC-MS/MS. The LODs of propisochlor ranged from 0.03 ${\mu}g/kg$ to 0.12 ${\mu}g/kg$, while the LOQs ranged from 0.1 ${\mu}g/kg$ to 0.4 ${\mu}g/kg$ in different matrixes. The mean recoveries of propisochlor at three levels (0.005, 0.01 and 0.05 mg/kg) were in the range of 73.7-94.9% with intra-day relative standard deviations (RSD) of 1.1-13.9% and inter-day $RSD_R$ of 3.3-12.7%. This method is suitable for routine analysis of propisochlor under field conditions. The half-lives of propisochlor in rice stalks, water and soil were 1.7, 1.5 and 2.3 days in Hunan, 5.7, 1.0 and 1.9 days in Anhui and 4.8, 1.0 and 3.1 days in Guangxi.

Clustering memory-guided anomaly detection model for large-scale screening of esophageal endoscopic images

Wu Yanbing,Zhao Zijian,Pang Xuejiao,Liu Jin 한국CDE학회 2022 Journal of computational design and engineering Vol.9 No.4

A deep learning screening model of esophageal endoscopic images can reduce the burden on endoscopists. However, most deep learning methods require many labeled data with balanced categories, and their ability to deal with new diseases not appearing in the training set is limited. This study elaborated a semi-supervised anomaly detection model for the initial screening of esophageal endoscopic images, requiring a single class of samples as a training set. The reconstruction-based method was used for anomaly detection. The model’s framework was a variational auto-encoder, with two memory modules added in latent space to restrain its generalization ability. In the memory module, a clustering operation was introduced to provide a better distribution of memory vectors, promoting their compactness with encoded features and separation from each other. A detailed description and theoretical substantiation of the proposed model were presented. A dataset containing 7989 esophageal endoscopic images labeled by experienced endoscopists was used for numerical experiments. The proposed model results were compared with those of other auto-encoder-based anomaly detection methods, outperforming them and achieving an area under the curve of 0.8212. The ablation study was also conducted to validate the effectiveness of each model’s part, and new data were successfully incorporated to assess the model feasibility and applicability range.

Determination of Herbicide Propisochlor in Soil, Water and Rice by Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) Method Using by UPLC-ESI-MS/MS

Xiaohu Wu,Jun Xu,Xingang Liu,Feng Shou Dong,Yanbing Wu,Ying Zhang,Yongquan Zheng 대한화학회 2013 Bulletin of the Korean Chemical Society Vol.34 No.3

A simple, quick and reliable analytical method for the confirmation and quantification of propisochlor was developed. The propisochlor was extracted from water, soil and rice (stalks, rice and hull) matrices using acetonitrile, and cleaned up with primary secondary amine and determined by UPLC-MS/MS. The LODs of propisochlor ranged from 0.03 μg/kg to 0.12 μg/kg, while the LOQs ranged from 0.1 μg/kg to 0.4 μg/kg in different matrixes. The mean recoveries of propisochlor at three levels (0.005, 0.01 and 0.05 mg/kg) were in the range of 73.7-94.9% with intra-day relative standard deviations (RSD) of 1.1-13.9% and inter-day RSDR of 3.3-12.7%. This method is suitable for routine analysis of propisochlor under field conditions. The half-lives of propisochlor in rice stalks, water and soil were 1.7, 1.5 and 2.3 days in Hunan, 5.7, 1.0 and 1.9 days in Anhui and 4.8, 1.0 and 3.1 days in Guangxi.

Unified coordination control strategy for DC solid‑state transformer in DC microgrid

Yanbing Jia,Pei Zhao,Jinjie Tian,Xiangqi Meng,Han Wu 전력전자학회 2022 JOURNAL OF POWER ELECTRONICS Vol.22 No.8

The existing control strategies of DC solid-state transformer (DCSST) are based on DC distribution system, which is mainly concentrated on one side voltage stability control without considering the change of control objectives under different conditions. Thus, they are unsuitable for multiterminal and multisource DC microgrid. The coordinated control strategy of DCSST in multiterminal and multisource DC microgrid is studied in this paper. The DCSST circuit models based on the series–parallel structure of dual active full bridge converter are established, and the basic control modes are analyzed: control low voltage mode and control high voltage mode. Combined with the characteristics of DC bus voltage fluctuation and the operation conditions of DCSST, a unified coordinated control strategy is proposed. Experimental results show that the proposed control strategy can correctly identify the different power states of the two sides of the system, control the power exchange between the two sides of the system, and maintain the stable operation of the whole DC system.

Single-Source Precursor Route for Synthesis of High-Quality Green-emitting Quantum Dots and Their Hydrophilic Surface Modification

Sheng Wang,Yanbing Lv,Ruili Wu,Lin Song Li,Huaibin Shen,Ming Xing,Xia Chen 대한화학회 2017 Bulletin of the Korean Chemical Society Vol.38 No.7

The high-quality green-emitting CdS0 . 5Se0 .5/8Zn1 − x Cd x S/2ZnS QDs with “8” and “2” monolayers (ML) of corresponding shell were first synthesized by “thermal-cycling coupled single precursor” (TC-SP) approach. The component-gradient Zn1− x Cd x S interlayer played a key role in the growth of thick shell by gradually buffering the large lattice mismatch (~9%) between the CdS0 . 5Se0 .5 core and ZnS shell. Moreover, the Zn1− x Cd x S gradient interlayer as well as ZnS outshell increased the potential barrier to prevent excitons from being trapped by surface defects. The photoluminescence quantum yields of the as-synthesized CdS0 . 5Se0 .5/8Zn1 − x Cd x S/2ZnS core/shell QDs can reach to 70% in organic media and still maintain 60% after aqueous phase transfer. The green-emitting CdS0 . 5Se0 .5/8Zn1 − x Cd x S/2ZnS core/shell QDs may be good candidates for applications of biomedical and photoelectric field.

Computer-aided diagnosis system based on multi-scale feature fusion for screening large-scale gastrointestinal diseases

Pang Xuejiao,Zhao Zijian,Wu Yanbing,Chen Yong,Liu Jin 한국CDE학회 2023 Journal of computational design and engineering Vol.10 No.1

For endoscopists, large-scale screening of gastrointestinal (GI) diseases is arduous and time-consuming. While their workload and human factor-induced errors can be reduced by computer-aided diagnosis (CAD) systems, the existing ones mainly focus on a limited number of lesions or specific organs, making them unsuitable for diagnosing various GI diseases in large-scale disease screening. This paper proposes a transformer and convolutional neural network-based CAD system (called TransMSF) to assist endoscopists in diagnosing multiple GI diseases. This system constructs two feature extraction paths with different coding methods to obtain the lesions’ global and local information. In addition, downsampling is implemented in transformer to get global information of different scales, further enriching the feature representation and reducing the amount of computation and memory occupation. Moreover, a channel and spatial attention module with fewer parameters was successfully designed to pay more attention to the target and reduce the loss of important information during spatial dimension transformation. Finally, the extracted feature information is fused through the feature fusion module and then input into the linear classifier for disease diagnosis. The proposed system outperformed that of other state-of-the-art models on two datasets, reaching a 98.41% precision, a 98.15% recall, a 98.13% accuracy, and a 98.28% F1 score on the in-house GI dataset versus a 95.88% precision, a 95.88% recall, a 98.97% accuracy, and a 95.88% F1 score on the public Kvasir dataset. Moreover, TransMSF’s performance was superior to that of seasoned endoscopists. The above results prove that the proposed system is instrumental in diagnosing GI diseases in large-scale disease screening. It can also be used as a training tool for junior endoscopists to improve their professional skills by rendering helpful suggestions.

Amperometric Morphine Detection Using Pt-Co Alloy Nanowire Array-modified Electrode

Manlan Tao,Feng Xu,Yueting Li,Quanqing Xu,Yanbing Chang,Zaisheng Wu,Yunhui Yang 대한화학회 2010 Bulletin of the Korean Chemical Society Vol.31 No.7

Pt-Co alloy nanowire array was directly synthesized by electrochemical deposition with polycarbonate template at ‒1.0V and subsequent chemical etching of the template. The use of Pt-Co alloy nanowire array-modified electrode (Pt-Co NAE) for the determination of morphine (MO) is described. The morphology of the Pt-Co alloy nanowire array has been investigated by scanning electron microscopy (SEM) and energy disperse X-ray spectroscopy (EDS) analysis), respectively. The resulting Pt-Co NAE offered a linear amperometric response for morphine ranging from 2.35 × 10‒5 to 2.39 × 10‒3 M with a detection limit of 7.83 × 10‒6 M at optimum conditions. This sensor displayed high sensitivity and long-term stability.

Amperometric Morphine Detection Using Pt-Co Alloy Nanowire Array-modified Electrode

Tao, Manlan,Xu, Feng,Li, Yueting,Xu, Quanqing,Chang, Yanbing,Wu, Zaisheng,Yang, Yun-Hui Korean Chemical Society 2010 Bulletin of the Korean Chemical Society Vol.31 No.7

Pt-Co alloy nanowire array was directly synthesized by electrochemical deposition with polycarbonate template at -1.0V and subsequent chemical etching of the template. The use of Pt-Co alloy nanowire array-modified electrode (Pt-Co NAE) for the determination of morphine (MO) is described. The morphology of the Pt-Co alloy nanowire array has been investigated by scanning electron microscopy (SEM) and energy disperse X-ray spectroscopy (EDS) analysis), respectively. The resulting Pt-Co NAE offered a linear amperometric response for morphine ranging from $2.35\times10^{-5}$ to $2.39\times10^{-3}$ M with a detection limit of $7.83\times10^{-6}$ M at optimum conditions. This sensor displayed high sensitivity and long-term stability.

Research on a New Hybrid Intelligent Fault Diagnosis Method and its Application

Zhenhua Wang,Zhentao Liu,Xueyan Lan,Jian Liu,Shaowei Wang,Yangming Wu,Yanbing Xue 보안공학연구지원센터 2016 International Journal of Smart Home Vol.10 No.7

In order to overcome the shortcomings of slow convergence speed and easy falling into the local minimum values of the BP neural network, an improved particle swarm optimization(PSO) algorithm is proposed to optimize the redial basic function (RBF) neural network, in order to propose a new hybrid intelligent fault diagnosis(IMPSO-RBFNN) method. In the IMPSO-RBFNN method, the adaptive dynamic adjusting strategy is used to control the inertia weight of the PSO algorithm in order to an improved particle swarm optimization(IMPSO) algorithm. Then the IMPSO algorithm is selected to optimize the parameters of RBF neural network by encoding the particle and continuous iteration of the IMPSO algorithm in order to obtain the optimal combination values of the parameters of RBF neural network. The optimal combination values are regarded as the values of these parameters of the RBFNN for constructing the final IMPSO-RBFNN method. In order to test the effectiveness of the proposed IMPSO-RBFNN method, the data from bearing data center of CWRU is selected in this paper. The experiment results show that the IMPSO algorithm can effectively optimize the weights of RBFNN, the IMPSO-RBFNN method can accurately realize high precision fault diagnosis of rolling bearing.