Investigation and Simulation Study on the Cascading Trip-off Fault of a Large Number of Wind Turbines in China on May 14, 2012

Ying Qiao,Zong-Xiang Lu,Ji Lu,Jia-Yang Ruan,Lin-lin Wu 대한전기학회 2015 Journal of Electrical Engineering & Technology Vol.10 No.6

The integration of the large-scale wind power brings great challenge to the stability of the power grid. This paper investigates and studies the fault on May 14, 2012 of the large-scale cascading trip-off of wind turbines in North China. According to the characteristics of the voltage variation, the fault process is divided into three stages: the pre-event stage, the critical stage before cascading, and the cascading stage. The scenes in the fault are reproduced, using the full-size actual power system model. Simulation models of double-fed induction generators (DFIGs) and SVCs including protection settings and controller strategies are carefully chosen to find out the reason of voltage instability in each stage. Some voltage dynamic that have never been observed before in the faults of the same kind are analyzed in detail, and an equivalent voltage sensitive dynamic model of DFIG is proposed for the fast computation. The conclusions about the voltage dynamics are validated by the actual PMU observation evidence.

Syntrophic Propionate Degradation Response to Temperature Decrease and Microbial Community Shift in an UASB Reactor

( Qiao Ying Ban ),( Jian Zheng Li ),( Li Guo Zhang ),( Ajay Kumar Jha ),( Yu Peng Zhang ),( Bin Ling Ai ) 한국미생물 · 생명공학회 2013 Journal of microbiology and biotechnology Vol.23 No.3

Propionate is an important intermediate product during the methane fermentation of organic matter, and its degradation is crucial for maintaining the performance of an anaerobic digester. In order to understand the effect of temperature on propionate degradation, an upflow anaerobic sludge blanket (UASB) reactor with synthetic wastewater containing propionate as a sole carbon source was introduced. Under the hydraulic retention time (HRT) of 10 h and influent propionate of 2,000 mg/l condition, propionate removal was above 94% at 30-35ºC, whereas propionate conversion was inhibited when temperature was suddenly decreased stepwise from 30ºC to 25ºC, to 20ºC, and then to 18ºC. After a long-term operation, the propionate removal at 25ºC resumed to the value at 30- 35ºC, whereas that at 20ºC and 18ºC was still lower than the value at 35ºC by 8.1% and 20.7%, respectively. Microbial community composition analysis showed that Syntrophobacter and Pelotomaculum were the major propionate-oxidizing bacteria (POB), and most POB had not changed with temperature decrease in the UASB. However, two POB were enriched at 18ºC, indicating they were low temperature tolerant. Methanosaeta and Methanospirillum were the dominant methanogens in this UASB and remained constant during temperature decrease. Although the POB and methanogenic composition hardly changed with temperature decrease, the specific CODPro removal rate of anaerobic sludge (SCRR) was reduced by 21.4%-46.4% compared with the control (35ºC) in this system.

Generation of Quantum Phase Gates via an Unconventional Geometric Phase Shift in an Ion-Trap System

Ying-Qiao Zhang,Shou Zhang,연규황,Xing-Ri Jin 한국물리학회 2007 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.51 No.5

We propose a scheme to generate a quantum phase gate via an unconventional geometric phase shift in an ion-trap system. Since the gate time is only related to the frequency of the vibrational mode, the present scheme, based on the resonant interaction of the trapped ions with a standing-wave laser beam, requires a much shorter gate time than the scheme based on the resonant interaction of the atoms and the cavity. Also the heating effect of the vibrational mode is negligible under certain conditions. We propose a scheme to generate a quantum phase gate via an unconventional geometric phase shift in an ion-trap system. Since the gate time is only related to the frequency of the vibrational mode, the present scheme, based on the resonant interaction of the trapped ions with a standing-wave laser beam, requires a much shorter gate time than the scheme based on the resonant interaction of the atoms and the cavity. Also the heating effect of the vibrational mode is negligible under certain conditions.

Investigation and Simulation Study on the Cascading Trip-off Fault of a Large Number of Wind Turbines in China on May 14, 2012

Qiao, Ying,Lu, Zong-Xiang,Lu, Ji,Ruan, Jia-Yang,Wu, Lin-lin The Korean Institute of Electrical Engineers 2015 Journal of Electrical Engineering & Technology Vol.10 No.6

The integration of the large-scale wind power brings great challenge to the stability of the power grid. This paper investigates and studies the fault on May 14, 2012 of the large-scale cascading trip-off of wind turbines in North China. According to the characteristics of the voltage variation, the fault process is divided into three stages: the pre-event stage, the critical stage before cascading, and the cascading stage. The scenes in the fault are reproduced, using the full-size actual power system model. Simulation models of double-fed induction generators (DFIGs) and SVCs including protection settings and controller strategies are carefully chosen to find out the reason of voltage instability in each stage. Some voltage dynamic that have never been observed before in the faults of the same kind are analyzed in detail, and an equivalent voltage sensitive dynamic model of DFIG is proposed for the fast computation. The conclusions about the voltage dynamics are validated by the actual PMU observation evidence.

뷰티 라이브 커머스 고객경험 요인이 뷰티상품 만족도에 미치는 영향: -중국 절강성 지역 20~30대 여성들을 대상으로-

응교몽 ( Qiao-meng Ying ),김경란 ( Kyeong-ran Kim ) 한국미용학회 2021 한국미용학회지 Vol.27 No.6

This study was conducted from March 29th to April 25th 2021 to investigate the effect of customer experience factors on beauty product satisfaction in beauty live commerce, focusing on women in their 20s and 30s who watched Chinese beauty live commerce broadcasts and purchased beauty products. By the 25th, WeChat and WenJuanXing program were used to analyze 323 copies investigated. For data analysis, we used t-test, one-way ANOVA, Scheffe's multiple range test, Correlation Analysis, and Multiple Regression Analysis on the basis of SPSSWIN 21.0 program, and the results are as follows. The group is generally characterized as women in their 20-30's years old and unmarried. Their final educational background is a university degree, and the monthly income is less than 1 million to 2 million won. Occupation among them is highest as a profession. The average of all customer experience factors of beauty products was 3.64, and the average of the overall satisfaction with beauty products was 3.68, which was high. There are significant differences in customer experience factors and satisfaction with beauty products in different occupations. It is found that both the quantitative and qualitative services of beauty product satisfaction are significantly positively correlated with the customer experience factors of beauty products. The results confirmed that customer experience factors such as information provision services and personalized services in Beauty Live Commerce have a great impact on the satisfaction of beauty products. Proposed direction of the services provided, in order to make more effective use of Chinese women live beauty product marketing business in the future.

<i>Yersinia pseudotuberculosis</i> Exploits CD209 Receptors for Promoting Host Dissemination and Infection

He, Ying-Xia,Ye, Cheng-Lin,Zhang, Pei,Li, Qiao,Park, Chae Gyu,Yang, Kun,Jiang, Ling-Yu,Lv, Yin,Ying, Xiao-Ling,Ding, Hong-Hui,Huang, Hong-Ping,Mambwe Tembo, John,Li, An-Yi,Cheng, Bing,Zhang, Shu-Sheng American Society for Microbiology 2019 Infection and immunity Vol.87 No.1

<P><I>Yersinia pseudotuberculosis</I> is a Gram-negative enteropathogen and causes gastrointestinal infections. It disseminates from gut to mesenteric lymph nodes (MLNs), spleen, and liver of infected humans and animals.</P><P><I>Yersinia pseudotuberculosis</I> is a Gram-negative enteropathogen and causes gastrointestinal infections. It disseminates from gut to mesenteric lymph nodes (MLNs), spleen, and liver of infected humans and animals. Although the molecular mechanisms for dissemination and infection are unclear, many Gram-negative enteropathogens presumably invade the small intestine via Peyer’s patches to initiate dissemination. In this study, we demonstrate that <I>Y. pseudotuberculosis</I> utilizes its lipopolysaccharide (LPS) core to interact with CD209 receptors, leading to invasion of human dendritic cells (DCs) and murine macrophages. These <I>Y. pseudotuberculosis</I>-CD209 interactions result in bacterial dissemination to MLNs, spleens, and livers of both wild-type and Peyer’s patch-deficient mice. The blocking of the <I>Y. pseudotuberculosis</I>-CD209 interactions by expression of O-antigen and with oligosaccharides reduces infectivity. Based on the well-documented studies in which HIV-CD209 interaction leads to viral dissemination, we therefore propose an infection route for <I>Y. pseudotuberculosis</I> where this pathogen, after penetrating the intestinal mucosal membrane, hijacks the <I>Y. pseudotuberculosis</I>-CD209 interaction antigen-presenting cells to reach their target destinations, MLNs, spleens, and livers.</P>

A new species of Aphis Linnaeus from Guangxi, China (Hemiptera, Aphididae), based on morphological characters and DNA sequences

Xu Ying,Chen Jing,Jiang Li-Yun,Qiao Ge-xia 한국응용곤충학회 2021 Journal of Asia-Pacific Entomology Vol.24 No.1

A new species of the genus Aphis with stridulatory apparatus, Aphis gnetuma Qiao sp. n., feeding on Gnetum parvifolium which is a new host plant record for aphids from Guangxi, China is described. The new species is distinguished by a well-developed median frontal tubercle and body bearing white wax powder in life. The taxonomic position of this new species is supported by analysis results of COI and gnd genes. A key to Aphis species with stridulatory spines on the hind tibiae of apterous viviparous females is provided. The type specimens studied are deposited in the National Zoological Museum of China, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.

Ceratovacuna atrovirensa Qiao, a new species from China (Aphididae: Hormaphdinae)

Jiang Li-Yun,Chen Jing,Xu Ying,Qiao Ge-xia 한국응용곤충학회 2021 Journal of Asia-Pacific Entomology Vol.24 No.3

Ceratovacuna atrovirensa Qiao sp.n., a woolly aphid on Indocalamus tessellatus from China, is described and illustrated. The new species is supported by both morphological and molecular data. An updated key to apterous viviparous females of Ceratovacuna is provided. The type specimens are deposited in the National Zoological Museum of China, Institute of Zoology, the Chinese Academy of Sciences, Beijing, China and the Natural History Museum, London, United Kingdom.

Teacher`s Gender-Related Beliefs about Mathematics

( Qiao Ping Zhang ),( Ngai Ying Wong ),( Chi Chung Lam ) 한국수학교육학회 2013 수학교육연구 Vol.17 No.3

Mathematics has been stereotyped as a male-dominated subject, and there is considerable evidence to support this belief. There has been much research in the past three decades on gender-related differences in elementary and secondary school mathematics. The re-search found that teachers possess different beliefs about male and female students that influence their teaching behaviour, which then directly or indirectly impact their students` behaviours, beliefs, and achievements in mathematics. Based on data collected from teacher questionnaire surveys in the Chinese Mainland and Hong Kong, this study exam-ines teachers` beliefs about the achievements of boys and girls in mathematics. The study also compares the findings in the two regions surveyed. Results showed that teachers gave more attention to boys than girls, regardless of the teacher`s gender. Not only are teachers more likely to recall more boys than girls, but also more boys than girls with av-erage academic standards.

Ultrasonic-Microwave Synergistic Synthesis of RGO–Bi2WO6 Photocatalyst with High Photoactivity for Basic Nitrogen Compounds in Light Oil

Ying Chen,Shenglun Ji,Tengfei Qiao,Shuang Miao,Yu Zhao 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2016 NANO Vol.11 No.5

Graphene–Bi2WO6 composite photocatalyst with excellent photocatalytic properties were synthetized by ultrasonic-microwave synergistic method. The obtained samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier infrared (FT-IR) spectrum, specific surface area analyzer (BET) and UV-Vis diffuse reflectance spectra. The photocatalytic activities of as-prepared samples were evaluated by degradation of pyridine in light oil under visible light irradiation. The results show that graphene changed appearance structure of Bi2WO6, which prevented the Bi2WO6 nanosheets reunion arrangement, and increased specific surface area of the catalyst. It can also reduce the recombination probability of photogenerated carrier, so as to improve the photocatalytic activity of the composite catalyst. The optimal amount of graphene is 2%, with the denitrification rate as high as 89.28%, much higher than that of pure Bi2WO6.