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Ultra high frequency (UHF) partial discharge (PD) detection is a common method for transformer oil-paper insulation defect location. However, the accuracy of PD positioning in practical application is easily affected by noise and sensor layout. In order to ensure the effectiveness of PD positioning detection of transformer oil-paper insulation defect, an UHF PD positioning detection platform for oil-paper insulation defects is established. Based on the conventional K-means method, a modified clustering demarcation PD anti-interference positioning method is proposed, which effectively reduces the positioning error. Aiming at the problem of sample clustering demarcation aliasing, when the optimal correction coefficient L is 1.1, the UHF PD positioning error can be reduced to less than 0.1 m, which verifies the effectiveness of the proposed method. Finally, the variation law of positioning error of different sensor layout is analyzed, and the optimal layout scheme of UHF sensor for transformer oil-paper insulation defect detection is proposed, which can provide reference for the layout and positioning of transformer on-line monitoring sensor.

A new method was proposed for point-of-care testing (POCT) of immunosuppressants in blood using thin-layer paper spray ionization and a miniature mass spectrometer. The aluminum thin-layer plate was used as paper spray substrate, and cut into an equilateral triangle. Aliquots of 10 μL blood sample were loaded on the aluminum thin-layer plate, and then 20 μL methanol was dropped as elution/spray solvent. The tip of the triangular plate was placed 1.0 cm in front of the discontinuous atmospheric pressure interface (DAPI) of the miniature mass spectrometer. When the spray voltage was applied, the sample was eluted from the triangular plate and formed paper spray ionization at the tip. Coupled with the miniature mass spectrometer, five immunosuppressants were detected under negative ion mode. The precursor ions ［M-H］- of tacrolimus, sirolimus, everolimus, ciclosporin A, and mycophenolic acid are m/z 802.6, 912.6, 957.1, 1 200.8, 319.1, and product ions are m/z 560.2 and 604.3, m/z 590.3 and 321.2, m/z 590.3 and 365.2, m/z 1 088.8, m/z 287.4 and 275.1, respectively. Based on the observed signal-to-noise ratio (S/N) of the most intense tandem mass spectrometry (MS/MS) fragment peaks and using the S/N=3 and 10 as the criteria, the limits of detection (LODs) and quantitation (LOQs) are estimated to be 0.5-5 mg/L and 1-10 mg/L, respectively. The internal standard method was used for quantitative analysis, and indapamide was used as the internal standard compound. Sufficient linearity for each analyte is obtained with the correlation coefficients (r) greater than 0.99. The proposed method displays good recoveries in the range of 91.0%-114.3% with the relative standard deviations (RSDs) less than 8.4%. Moreover, the developed method was used for the analysis of blood samples, which spiked with tacrolimus, sirolimus, everolimus, cyclosporine A and mycophenolic acid at the concentration of 100 mg/L. The analytical results demonstrated the consistency between the proposed method and the traditional liquid chromatography-mass spectrometry (LC-MS) method. The entire analysis procedure can be completed within 1 min. The proposed method is simple, fast, accurate, efficient, and suitable for POCT of immunosuppressants in blood.

Based on the selective quenching effect of the flavonoid rutin on the fluorescence of carbon dots prepared by asparagine pyrolysis, a method for rapid detection of rutin content in the flower buds of Sophora japonica by using chitosan-based carbon dot paper chip was developed. A filter paper was immersed in the casting solution of carbon dots and chitosan. After drying, a carbon dot chitosan film was formed on the surface of the filter paper, so that the chitosan-based carbon dot paper chip was obtained. After samples were dripped on the chip, chromogenic reaction occurred uniformly within a limited region, and pictures were taken under an ultraviolet (UV) lamp at 365 nm for analysis of the red (R), green (G), and blue (B) values of the colored spots in order to optimize the preparation conditions and detection conditions. The results showed that the optimal conditions were as follows: chitosan concentration of 20 mg/mL, carbon spot concentration of 1.0 mg/mL, 50% ethanol as sample solvent, and reaction time of 20 min. Under these conditions, the difference (ΔG) in G-value between sample and solvent spots had a linear relationship with rutin concentration (C) in the range of 4 to 120 mg/mL. Using this method, the average contents of rutin in the flower buds of S. japonica from three batches were determined to be 23.85%, 22.83% and 20.30%, the average relative standard deviations (RSDs) were 6.1%, 5.6% and 6.7%, and the recoveries were 91.27% to 107.5%, which were close to the results of high performance liquid chromatography (HPLC). The proposed method is simple and rapid, and can be used for rapid on-site determination of rutin content in the flower buds of S. japonica.

Copyright of China Journal of Oral & Maxillofacial Surgery is the property of Shanghai Jiao Tong University, College of Stomatology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Capital Institute of Physical Education is the property of Shoudu Tiyu Xueyuan and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Results of academic research require publication and need to be reviewed by peers before they can contribute to the existing body of knowledge. Among the various means of publishing research findings, researchers may, according to past academic practices, first present their research results in conferences, seminars or symposiums, and then submit their results to journals for publication. Hence, the issue of “extended publication”, where conference papers are revised and submitted to journals, has gained attention in the library and information science community. This study collected public documents on the Internet and applied document analysis to examine the ethical considerations regarding such extension practice. First, this research reviewed the basic principles of research integrity and responsible behavior. Secondly, this research listed several types of violation related to research paper writing and submission, and studied the guidelines established by both domestic and foreign academic organizations, publishers, and journals. The findings of the research were used to provide specific recommendations on the best practices for extending conference papers to journal articles.

To explore the microscopic mechanism of thermal stability of oil-paper insulation， a molecular model consistent with the actual oil-paper insulation is established. Through comparison with the experimental results， the effectiveness of the model is verified. With temperature as an independent variable， variation of the mechanical parameters and hydrogen bond energy of the cellulose molecular model under the action of a thermal field is investigated. The results show that parameters characterizing the mechanical properties of cellulose， such as bulk modulus （K）， Young's modulus （E）， shear modulus （G）， and Poisson's ratio （v） of the cellulose crystalline zone model are larger than those of the amorphous zone model at the same temperature， and the distribution of hydrogen bond energy remains the same. Thus， the cellulose crystalline zone is superior to the amorphous zone in mechanical properties and determines the insulation properties of cellulose insulating paper. The results of the study provide a theoretical basis and method for investigating the microscopic mechanism of thermal aging of oil-paper insulation.

Copyright of China Pulp & Paper is the property of China Pulp & Paper Magazines Publisher and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The insulation performance of transformer bushings is a crucial aspect that directly affects the safe operation of equipment. To diagnose the insulation status of transformer bushings and mitigate the impact of small-sample imbalanced data on diagnostic results, a particle swarm optimization combined with back propagation neural network (PSO-BPNN) and adaptive synthetic sampling (ADASYN) method are employed to fault diagnosis of transformer bushing. Initially, historical fault data of transformer bushings are gathered, and a sample set of dissolved gases in transformer oil with distinct fault categories is established. The ADASYN algorithm is used to synthesize the minority class samples in the original data, which allowed for obtaining balanced fault data. The balanced dissolved gases in oil served as the model input, and the fault status is used as the label output to diagnose the transformer bushings using the PSO-BPNN model. To diagnose the bushings under the original sample set, the back propagation neural network (BPNN), genetic combined with back propagation neural network (G-BPNN), cuckoo search combined with back propagation neural network (CS-BPNN), and PSO-BPNN models are used. The results reveal that the PSO-BPNN model based on ADASYN balanced data exhibited the highest accuracy among the various models for fault diagnosing the insulation status of transformer bushings. This approach effectively mitigate the impact of small sample imbalanced data on diagnostic results, and provide an effective method for assessing the insulation performance of transformer bushings.

“Lab on paper” is a paper-based microanalytical system with unique advantages such as high sensitivity, low cost, portability, and mass production, which breaks through the limitations of traditional detection technologies and shows great potential in the field of rapid on-site food detection. In this paper, the typical “labs on paper”, including chromatographic paper, chemical test chip, lateral flow assay (LFA), microfluidic paper-based analytical devices (μPADs), and synthetic biological paper, are systematically reviewed. Special emphasis is put on the application of “lab on paper” in the field of food detection. Finally, the advantages, challenges, and future prospects of paper-based analytic methods are discussed, which may provide theoretical support for better application of “lab on paper” in the field of food detection.