An Improved Wavelet PWM Technique with Output Voltage Amplitude Control for Single-phase Inverters

Zheng, Chun-Fang,Zhang, Bo,Qiu, Dong-Yuan,Zhang, Xiao-Hui,Li, Rui The Korean Institute of Power Electronics 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.4

Unlike existing pulse-width modulation (PWM) techniques, such as sinusoidal PWM and random PWM, the wavelet PWM (WPWM) technique based on a Harr wavelet function can achieve a high fundamental component for the output voltage, low total harmonic distortion, and simple digital implementation. However, the original WPWM method lacks output voltage control. Thus, the practical application of the WPWM technique is limited. This study proposes an improved WPWM technique that can regulate output voltage amplitude with the addition of a parameter. The relationship between the additional parameter and the output voltage amplitude is analyzed in detail. Experimental results verify that the improved WPWM exhibits output voltage control in addition to all the merits of the WPWM technique.

An Improved Wavelet PWM Technique with Output Voltage Amplitude Control for Single-phase Inverters

Chun-Fang Zheng,Bo Zhang,Dong-Yuan Qiu,Xiao-Hui Zhang,Rui Li 전력전자학회 2016 JOURNAL OF POWER ELECTRONICS Vol.16 No.4

Unlike existing pulse-width modulation (PWM) techniques, such as sinusoidal PWM and random PWM, the wavelet PWM (WPWM) technique based on a Harr wavelet function can achieve a high fundamental component for the output voltage, low total harmonic distortion, and simple digital implementation. However, the original WPWM method lacks output voltage control. Thus, the practical application of the WPWM technique is limited. This study proposes an improved WPWM technique that can regulate output voltage amplitude with the addition of a parameter. The relationship between the additional parameter and the output voltage amplitude is analyzed in detail. Experimental results verify that the improved WPWM exhibits output voltage control in addition to all the merits of the WPWM technique.

Wavelet PWM Technique for Single-Phase Three-Level Inverters

Zheng, Chun-Fang,Zhang, Bo,Qiu, Dong-Yuan,Zhang, Xiao-Hui,Xiao, Le-Ming The Korean Institute of Power Electronics 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.6

The wavelet PWM (WPWM) technique has been applied in two-level inverters successfully, but directly applying the WPWM technique to three-level inverters is impossible. This paper proposes a WPWM technique suitable for a single-phase three-level inverter. The work analyzes the control strategy with the WPWM and obtains the design of its parameters. Compared with the SPWM technique for a single-phase three-level inverter under the same conditions, the WPWM can obtain high magnitudes of the output fundamental frequency component, low total harmonic distortion, and simpler digital implementation. The feasibility experiment is given to verify of the proposed WPWM technique.

Wavelet PWM Technique for Single-Phase Three-Level Inverters

Chun-Fang Zheng,Bo Zhang,Dong-Yuan Qiu,Xiao-Hui Zhang,Le-Ming Xiao 전력전자학회 2015 JOURNAL OF POWER ELECTRONICS Vol.15 No.6

The wavelet PWM (WPWM) technique has been applied in two-level inverters successfully, but directly applying the WPWM technique to three-level inverters is impossible. This paper proposes a WPWM technique suitable for a single-phase three-level inverter. The work analyzes the control strategy with the WPWM and obtains the design of its parameters. Compared with the SPWM technique for a single-phase three-level inverter under the same conditions, the WPWM can obtain high magnitudes of the output fundamental frequency component, low total harmonic distortion, and simpler digital implementation. The feasibility experiment is given to verify of the proposed WPWM technique.

Removal of Cs+, Sr2+, and Co2+ Ions from the Mixture of Organics and Suspended Solids Aqueous Solutions by Zeolites

Xiang-Hong Fang,Fang Fang,Chun-Hai Lu,Lei Zheng 한국원자력학회 2017 Nuclear Engineering and Technology Vol.49 No.3

Serving as an excellent adsorbent and inorganic ion exchanger in the water purification field, zeolite 4A has in this work presented a strong capability for purifying radioactive waste, such as Sr2+, Csþ, and Co2+ in water. During the processes of decontamination and decommissioning of suspended solids and organics in low-level radioactive wastewater, the purification performance of zeolite 4A has been studied. Under ambient temperature and neutral condition, zeolite 4A absorbed simulated radionuclides such as Sr2+, Csþ, and Co2+ with an absorption rate of almost 90%. Additionally, in alkaline condition, the adsorption percentage even approached 98.7%. After conducting research on suspended solids and organics of zeolite 4A for the treatment of radionuclides, it was found that the suspended clay was conducive to absorption, whereas the absorption of organics in solution was determined by the species of radionuclides and organics. Therefore, zeolite 4A has considerable potential in the treatment of radioactive wastewater.

Traditional Chinese medicine for COVID-19 pandemic and emerging challenges: An online cross-sectional survey in China

Chun-Li Lu,Ruo-Xiang Zheng,Xue Xue,Xiao-Wen Zhang,Xue-Han Liu,Xin-Yan Jin,Feng-Lan Pu,Hui-Di Lan,Min Fang,Ling-Yao Kong,Merlin Willcox,Bertrand Graz,Joelle Houriet,Xiao-Yang Hu,Jian-ping Liu 한국한의학연구원 2021 Integrative Medicine Research Vol.10 No.-

Background We aimed to investigate use of infection control behaviours, preventative and therapeutic interventions, and outcomes among respondents to an online survey during the COVID-19 pandemic in China. Methods The survey was designed by an international team, translated and adapted to simplified Chinese, including 132 kinds of traditional Chinese medicine (TCM) preparation recommended by guidelines. It was distributed and collected from February to May 2021, with data analysed by WPS spreadsheet and wjx.cn. Descriptive statistics were used to describe demographics and clinical characteristics, diagnosis, treatments, preventative behaviours and interventions, and their associated outcomes. Results The survey was accessed 503 times with 341 (67.8%) completions covering 23 provinces and four municipalities in China. Most (282/341, 82.7%) respondents reported no symptoms during the pandemic and the majority (290/341, 85.0%) reported having a SARS-CoV-2 PCR test at some point. Forty-five (13.2%) reported having a respiratory infection, among which 19 (42.2%) took one or more categories of modern medicine, e.g. painkillers, antibiotics; 16 (35.6%) used TCM interventions(s); while seven respondents combined TCM with modern medicine. All respondents reported using at least one behavioural or medical approach to prevention, with 22.3% taking TCM and 5.3% taking modern medicines. No respondents reported having a critical condition related to COVID-19. Conclusion We found evidence of widespread use of infection control behaviours, modern medicines and TCM for treatment and prevention of COVID-19 and other respiratory symptoms. Larger scale studies are warranted, including a more representative sample exploring TCM preparations recommended in clinical guidelines. Background We aimed to investigate use of infection control behaviours, preventative and therapeutic interventions, and outcomes among respondents to an online survey during the COVID-19 pandemic in China. Methods The survey was designed by an international team, translated and adapted to simplified Chinese, including 132 kinds of traditional Chinese medicine (TCM) preparation recommended by guidelines. It was distributed and collected from February to May 2021, with data analysed by WPS spreadsheet and wjx.cn. Descriptive statistics were used to describe demographics and clinical characteristics, diagnosis, treatments, preventative behaviours and interventions, and their associated outcomes. Results The survey was accessed 503 times with 341 (67.8%) completions covering 23 provinces and four municipalities in China. Most (282/341, 82.7%) respondents reported no symptoms during the pandemic and the majority (290/341, 85.0%) reported having a SARS-CoV-2 PCR test at some point. Forty-five (13.2%) reported having a respiratory infection, among which 19 (42.2%) took one or more categories of modern medicine, e.g. painkillers, antibiotics; 16 (35.6%) used TCM interventions(s); while seven respondents combined TCM with modern medicine. All respondents reported using at least one behavioural or medical approach to prevention, with 22.3% taking TCM and 5.3% taking modern medicines. No respondents reported having a critical condition related to COVID-19. Conclusion We found evidence of widespread use of infection control behaviours, modern medicines and TCM for treatment and prevention of COVID-19 and other respiratory symptoms. Larger scale studies are warranted, including a more representative sample exploring TCM preparations recommended in clinical guidelines.

Patent Ductus Arteriosus and Pulmonary Valve Stenosis in A Patient with 18p Deletion Syndrome

Chun-Hong Xie,Jian-Bin Yang,Fang-Qi Gong,Zheng-Yan Zhao 연세대학교의과대학 2008 Yonsei medical journal Vol.49 No.3

We report on a patient with a partial deletion on the short arm of chromosome 18 (del 18p), who presented with dysmorphic features and delayed developmental milestones as well as with a patent ductus arteriosus (PDA) and pulmonary valve stenosis (PS). Several forms of congenital heart disease (CHD) are found in about 10% of patients with del (18p), but coexisting PDA and PS have not been reported. Del (18p) must be considered in patients with characteristic phenotypic abnormalities and congenital heart disease, including a combination of PDA and PS.

Influence of Pinewood Nematode, Bursaphelenchus xylophilus, on the Growth of Endoparasitic Fungus Esteya vermicola

Chun Yan Wang(왕춘연),Chung Ha Lee(이청하),Mi Ra Lee(이미라),Beom Sik Yun(윤범식),Lei Liu(유뢰),Zhen Wang(왕젠),Zhe Ming Fang(방철명),Dong Liang Zhang(장동량),Zheng Li(이정),Chang Keun Sung(성창근) 한국생명과학회 2010 생명과학회지 Vol.20 No.5

본 논문은 선충 포식성 곰팡이에 대한 선충의 영향을 조사한 연구로, 소나무 기생곰팡이인 E. vermicola에 미치는 소나무 선충의 영향을 체계적으로 분석하였다. 선충 대사물과 선충 균질액 모두 E. vermicola의 성장을 빠르게 촉진하였으나, 선충 대사물이 선충 균질액보다 약간 높은 효과를 보였다. 또한 소나무 선충이 생성하는 휘발성 물질이 E. vermicola 성장에 미치는 영향을 분석하는 새로운 실험방법을 개발하였다. 본 연구결과에 따르면, 선충의 휘발성 물질은 E. vermicola에 아무런 영향을 끼치지 않는다는 재현성 있는 결과를 도출하였다. 본 연구는 소나무 선충의 생물학적인 조절인자로서 E. vermicola을 적용할 수 있는 정보를 제공할 수 있을 것이다. The influence of nematodes on nematophagous fungi has seldom been investigated. In the present study, the influence of pinewood nematode on its endoparasitic fungus, Esteya vermicola, was investigated systemically. Although both nematodal metabolite and nematodal homogenate could stimulate and speed up the growth of E. vermicola, the impact of nematodal metabolite was slightly higher than that of nematodal homogenate. In addition, a method was developed to investigate the influence of volatiles, discharged by pinewood nematodes in their metabolic process, on the growth of E. vermicola. Reproductive results were given and confirmed that nematodal volatiles have no influence on the cell growth of E. vermicola. This study may provide information for the application of E. vermicola as biological control agent of pinewood nematode.

Transition over 35 Years in the Incidence Rates of Primary Central Nervous System Tumors in Shanghai, China and Histological Subtyping Based on a Single Center Experience Spanning 60 Years

Shen, Fang,Wu, Chun-Xiao,Yao, Yu,Peng, Peng,Qin, Zhi-Yong,Wang, Yin,Zheng, Ying,Zhou, Liang-Fu Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.12

Background: Only few epidemiological data on primary central nervous system (CNS) tumors in Shanghai have been reported. Methods: All cases of primary CNS tumors that were registered at Center for Disease Control and Prevention (CDC) were collected (1973-2007: urban Shanghai; 2003-2007: whole Shanghai city). Trends were analyzed using joinpoint analysis and rates were stratified by age, gender and region. Histological data were collected from both CDC and Huashan Hospital. Results: From 1973 to 2007, the five-year average incidence rate in urban Shanghai increased in both genders, especially in the elderly population. Joinpoint analysis showed the age-adjusted incidence rate for males increased first but then plateaued, whilst rates for females continued increasing over the 35 years. For the five-year status quo (2003-2007), rural had a higher age-adjusted incidence rate than urban populations, and females higher than males, especially those with advanced age. According to CDC (2003-2007) and Huashan Hospital (1951-2011), the two most common histological subtypes were neuroepithelial tumors (with male predominance) and meningiomas (with female predominance). Conclusions: In Shanghai, a steadily increased incidence rate of primary CNS tumors was observed in general, and in the elderly and female population in particular.

Physiological character and molecular mapping of leaf-color mutant wyv1 in rice (Oryza sativa L.)

Xian-chun Sang,Li-kui Fang,Yuenyong Vanichpakorn,Ying-hua Ling,Peng Du,Fang-ming Zhao,Zheng-lin Yang,Guang-hua He 한국유전학회 2010 Genes & Genomics Vol.32 No.2

The seed of an excellent indica restorer line Jinhui10 (Oryza sativa L. ssp. indica) was treated by ethyl methanesulfonate (EMS); a leaf-color mutant displaying distinct phenotype throughout development grown in paddy field was identified from the progeny. The mutant leaf showed white-yellow at seedling stage and then turned to yellow-green at tillering stage, after that, virescent color appeared until to maturity. The mutant was thus temporarily designed as wyv1. The chlorophyll contents decreased significantly and the changing was consistent with the chlorotic level of wyv1 leaves. Chlorophyll fluorescence kinetic parameters measured at the seedling stage showed that co-efficiency of photochemical quenching (qP),actual photosystem II efficiency (ΦPS II), electron transport rate (ETR) and initial chlorophyll fluorescence level (Fo), net photosynthetic rate (Pn) and maximum photochemical efficiency (Fv / Fm) significantly decreased in severe chlorotic leaf of the mutant compared with that of wild type. However,no significant differences were observed for Pn and Fv/Fm between virescent leaf and normal green leaf. Genetic analysis suggested that the mutant phenotype was controlled by a single recessive nuclear gene which was finally mapped between SSR marker Y7 and Y6 on rice chromosome 3 based on F2 population of Xinong1A / wyv1. Genetic distances were 0.06 cM and 0.03 cM respectively, and the physical distance was 84kb according to the sequence of indica rice 9311. The results must facilitate map-based cloning and functional analysis of WYV1 gene.