http://chineseinput.net/에서 pinyin(병음)방식으로 중국어를 변환할 수 있습니다.
변환된 중국어를 복사하여 사용하시면 됩니다.
- 中文 을 입력하시려면 zhongwen을 입력하시고 space를누르시면됩니다.
- 北京 을 입력하시려면 beijing을 입력하시고 space를 누르시면 됩니다.
RISS 인기검색어
- 검색키워드
- 저자 : Yunxiang Cheng (검색결과 4 건)
- 무료
- 기관 내 무료
- 유료
-
Biaoguang Sun,Yunxiang Xie,Hui Ma,Li Cheng 대한전기학회 2016 Journal of Electrical Engineering & Technology Vol.11 No.3
Active power filter (APF) has been proved as a flexible solution for compensating the harmonic distortion caused by nonlinear loads in power distribution power systems. Digital repetitive control can achieve zero steady-state error tracking of any periodic signal while the sampling points within one repetitive cycle must be a known integer. However, the compensation performance of the APF would be degradation when the grid frequency varies. In this paper, an improved repetitive control scheme with frequency adaptive capability is presented to track any periodic signal with variable grid frequency, where the variable delay items caused by time-varying grid frequency are approximated with Pade approximants. Additionally, the stability criterion of proposed repetitive control scheme is given. A three-phase shunt APF experimental platform with proposed repetitive control scheme is built in our laboratory. Simulation and experimental results demonstrate the effectiveness of the proposed repetitive control scheme.
-
Sun, Biaoguang,Xie, Yunxiang,Ma, Hui,Cheng, Li The Korean Institute of Electrical Engineers 2016 Journal of Electrical Engineering & Technology Vol.11 No.3
Active power filter (APF) has been proved as a flexible solution for compensating the harmonic distortion caused by nonlinear loads in power distribution power systems. Digital repetitive control can achieve zero steady-state error tracking of any periodic signal while the sampling points within one repetitive cycle must be a known integer. However, the compensation performance of the APF would be degradation when the grid frequency varies. In this paper, an improved repetitive control scheme with frequency adaptive capability is presented to track any periodic signal with variable grid frequency, where the variable delay items caused by time-varying grid frequency are approximated with Pade approximants. Additionally, the stability criterion of proposed repetitive control scheme is given. A three-phase shunt APF experimental platform with proposed repetitive control scheme is built in our laboratory. Simulation and experimental results demonstrate the effectiveness of the proposed repetitive control scheme.
-
Kawada, Kiyokazu,Mayu Kurosu,Yunxiang Cheng,Tsagaanbandi Tsendeekhuu,Wuyunna,Toru Nakamura,Ichiroku Hayashi 한국생태학회 2008 Journal of Ecology and Environment Vol.31 No.4
In order to assess the effect of grazing on grasslands using floristic composition, we studied the floristic composition and plant biomass of steppe vegetation in Hulunbeier, Inner Mongolia. The dominant species of the grasslands were Stipa krylovii, Stipa grandis and Leymus chinensis. Floristic composition changed according to grazing pressure, being light, heavy and moderate. Under heavy grazing conditions, the importance value of P. acaulis, C. korshinskyi and Cleistogenes squarrosa increased in the plant community. These species were indicators of heavily grazed stand. Plant biomass of the stands ranged within 11.6 g m-2 and 63.5 g m-² and 69.5 g m-² and 166.2 g m-² to the west and east of Lake Hulun, respectively. These values are equivalent to ca. 450~1,000 kg of atmospheric carbon per hector, which is retained within the stand during the summer season. In order to assess the effect of grazing on grasslands using floristic composition, we studied the floristic composition and plant biomass of steppe vegetation in Hulunbeier, Inner Mongolia. The dominant species of the grasslands were Stipa krylovii, Stipa grandis and Leymus chinensis. Floristic composition changed according to grazing pressure, being light, heavy and moderate. Under heavy grazing conditions, the importance value of P. acaulis, C. korshinskyi and Cleistogenes squarrosa increased in the plant community. These species were indicators of heavily grazed stand. Plant biomass of the stands ranged within 11.6 g m-2 and 63.5 g m-² and 69.5 g m-² and 166.2 g m-² to the west and east of Lake Hulun, respectively. These values are equivalent to ca. 450~1,000 kg of atmospheric carbon per hector, which is retained within the stand during the summer season.
-
Zheng Weiwei,Tian Yuting,Shi Haili,Chen Miaomiao,Hong Seungbeom,Xu Kai,Cheng Jianhui,Zang Yunxiang 한국원예학회 2023 Horticulture, Environment, and Biotechnology Vol.64 No.2
Salinity stress is a key factor aff ecting grape production in coastal areas. Two grape rootstock cultivars, ‘Beta’ (sensitive to salt stress) and ‘3309 C’ (resistant to salt stress), were used to investigate the physiological role of 5-aminolevlinic acid (5-ALA) in salinity tolerance. Functional capacities in the rhizosphere, leaf phenotype, photosynthetic parameters, antioxidant enzymes activities and certain physiological indexes were determined after treatment with seawater or seawa- ter followed by 100 mg/L 5-ALA application. The results showed that the functional capacities of the rhizosphere were distinct between the two management regimes. Microbial biomass and soil enzyme activities were reduced by salinity but promoted by 5-ALA. Salinity also suppressed the overall plant growth, leaf chlorophyll content, photosynthetic rate, maxi- mal photochemical effi ciency (Fv/Fm), photochemical quenching (qP), electron transport rate (ETR), root activity, ATP content, ATPase activity, and activities of the antioxidant enzymes ascorbate peroxidase (APX), peroxidase (POD), cata- lase (CAT), and superoxide dismutase (SOD) in both cultivars. Although plant growth, chlorophyll content, and activities of antioxidant enzymes in Beta were decreased to a greater extent than those in 3309 C under salinity stress, exogenous application of 5-ALA signifi cantly improved plant growth along with enhancement of all the above photosynthetic param- eters and activities of the four antioxidant enzymes in both cultivars. Seawater treatment alone signifi cantly increased non- photochemical quenching (NPQ), relative electrical conductivity (REC), and malondialdehyde (MDA) contents in leaves, especially for Beta. However, 5-ALA treatment decreased the levels of NPQ, REC, and MDA, but increased ATP content and ATPase activity in roots and leaves of both cultivars. Thus, application of 5-ALA would be benefi cial to improve the salt tolerance of grape rootstocks grown in coastal areas.
연관 검색어 추천
이 검색어로 많이 본 자료
활용도 높은 자료
