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Your search keyword '"He Chang-hong"' showing total 13 results
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13 results on '"He Chang-hong"'

5. Research on electrical aging lifetime model of insulation material under high voltage square impulses for inverter-fed motors

Author

Peng Qian, Deng Ming-li, Ai Bing, He Chang-hong, Wu Guangning, and Ye Qiang

Subjects
Condensed Matter::Quantum Gases, Engineering, Stator, business.industry, Electrical engineering, Mechanical engineering, High voltage, Impulse (physics), DC motor, law.invention, Traction motor, Sine wave, law, Inverter, Condensed Matter::Strongly Correlated Electrons, business, Voltage
Abstract

High voltage square impulses from converter can make stator insulation of inverter-fed motors damaged much earlier. There are many differences in insulation aging mechanism between under continuous impulses and under sine waves. In order to test insulation properties under continuous impulses, a new insulation aging test system is used to simulate the aging effect of converter on the winding insulation in the inverter-fed motors. The influences of impulse amplitude, frequency, on insulation lifetime are investigated by using polyimide film. Finally, an insulation electrical aging lifetime model is developed based on the test results.

Published
2008

6. The simulation analysis of harmonics and negative sequence with Scott wiring transformer

Author

He Chang-hong, Zhang Xue-yuan, Guang-ning Wu, Ye Qiang, Fan Chun-lei, and Deng Ming-li

Subjects
Isolation transformer, Engineering, Zigzag transformer, business.industry, Traction substation, Flyback transformer, Linear variable differential transformer, Electrical engineering, Energy efficient transformer, business, Distribution transformer, Delta-wye transformer
Abstract

In order to reduce the impact of harmonic and negative sequence on the power system, in traction substation can use Scott wiring traction transformer. By using MATLAB to establish a Scott wiring transformer model, the 110 kV side of the three-phase harmonic voltage and current with its harmonic content and negative sequence can be simulated. Comparing simulated results and actual data of one transformer substation, the correctness and accuracy is verified. Finally analyze the two situation of traction network with symmetrical or asymmetrical load. The results showed that adopting Scott wiring transformer in the traction transformer substation is one effective method. Electric railway should be running with the symmetric load as far as possible. So can greatly reduce the harm caused by asymmetric running of the transformer and effectively reduce the impact on power quality.

Published
2008

7. Correct identification and redescription of the larval stages and early juveniles of the slipper lobster Eduarctus martensii(Pfeffer, 1881) (Decapoda: Scyllaridae)

Author

Wakabayashi, Kaori, Yang, Chien-Hui, Shy, Jhy-Yun, He, Chang-Hong, and Chan, Tin-Yam

Abstract

The phyllosoma larvae of the slipper lobster Eduarctus martensii(Pfeffer, 1881) were first time successfully hatched in the laboratory and reared to Stage VI. It took 24 days for newly hatched larvae to reach Stage VI. We also confirmed the identities of wild-caught phyllosomas of this species by DNA barcoding of the mitochondrial 16S rRNA gene (sequence similarities 98.8%–99.8%), including two late-stage individuals that developed into a nisto and an early juvenile. The diagnoses for all nine phyllosoma stages, the nisto, and the early juvenile are provided, with the number of rows of aesthetascs on the antennule appearing to be useful in assigning the developmental stage of the phyllosomas in E. martensii. The present confirmation of the identities of the phyllosomas of E. martensiireveals that previous reports on the developmental stages of this species contain inaccurate information and some even refer to different taxa.

Published
2017
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13. Genetic variation of growth traits and wood properties in Chinese fir clones.

Author

LI Rong-li, HUANG Shou-xian, LIANG Ji, ZHOU Chuan-ming, HE Chang-hong, LI Long-mei, and TANG Guo-qiang

Abstract

Abstract; [Objective] Genetic variation of Chinese fir clones on growth traits and wood properties was studied to provide references for selecting superior clones in cultivation areas and boosting plantation benefits in Guangxi. [Method] First, the differences of individual tree volume (V), wood basic density (WBD) and tracheid shape (TS) between clones were analyzed. Then the clonal repeatability and genetic correlation were calculated. Lastly. Chinese fir clones with good growth traits and wood quality were selected based on comprehensive index of multiple traits selection. and the genetic gains of the selected clones were estimated. [Result]There were extensive genetic variations between clones on growth traits and wood properties. The coefficient of variation on V, diameter at breast height (DBH). and tree height (H) was 41.06%. 16.44%. and 12.41%. Extremely significant difference

Published
2014
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