199,057 research outputs found
Liu shi yu dan si ji
No full text劉鳳著.綫裝, 1函.框20.1x13.6公分, 9行18字. 白口, 左右雙邊, 單黑魚尾. 版心上鐫"澹思集", 中鐫卷次, 下鐫葉次及"劉漙卿刻"書名及版式據卷三.書根題"劉侍御澹思集", 每冊書根題後分別錄"樂", "御", "書", "數"見《香港中文大學圖書館古籍善本書錄》(2001, p. 244)鈐有"天一閣", "沈氏鳴野山房圖籍印"Library's copy: 館存卷三至五, 卷九至十六, 共四冊 ; 缺卷一至二[v.1], 卷六至八[v.3]Xian zhuang, 1 han.Kuang 20.1 x 13.6 gong fen, 9 hang 18 zi. Bai kou, zuo you shuang bian, dan hei yu wei. Ban xin shang juan "Dan si ji", zhong juan juan ci, xia juan ye ci ji "Liu Tuanqing ke"Shu ming ji ban shi ju juan san.Shu gen ti "Liu shi yu dan si ji", mei ce shu gen ti hou fen bie lu "Yue", "Yu", "Shu", "Shu"Jian "Xianggang Zhong wen da xue tu shu guan gu ji shan ben shu lu" (2001, p. 244)Liu Feng zhu.Qian you "Tian yi ge", "Shen shi Ming ye shan fang tu ji yin"Library's copy: guan cun juan san zhi wu, juan jiu zhi shi liu, gong si ce ; que juan yi zhi er [v.1], juan liu zhi ba [v.3
Amplitude-Phase Detection for Power Converters Tied to Unbalanced Grids with Large X/R Ratios
Get PDFAmplitude-phase information of the voltage/current phasor, which is the prerequisite for grid-tied converter control and protection, can change almost instantaneously in low-voltage distribution systems with small X/R ratios. However, the equivalent impedances of high-voltage power systems are usually inductive (with large X/R ratios), and the power flow of pertinent grids generates decaying dc (DDC) components with large amplitude and long duration during large disturbances. Therefore, the X/R ratios and DDC components must be fully considered in amplitude-phase detection to achieve effective converter control and protection. To this end, the main components present in the transient voltage/current of a high-voltage power system after unbalanced disturbance are first analyzed, and the general transient model is obtained by synthesizing multimode DDC components. Then, by resorting to waveform characteristics of different components, an amplitude-phase detection algorithm is proposed based on the multicomponent parallel-detection structure. Compared to existing techniques, the detection time is reduced to half grid cycle. Finally, an iterative variable-interval integral algorithm is developed, improving the antinoise ability of detection algorithm and overcoming the computational burden issue. This enables the direct integration of algorithm into the converter's embedded processor. Experiment results verified the effectiveness and superiority of the proposed technique
ZHANG, F. & LIU, X-W. (2009) A review of the subgenus Diestrammena (Gymnaeta) from China (Orthoptera: Rhaphidophoridae Aemodogryllinae). Zootaxa, 2272, 21-36.
No full textZhang, F., Liu, X-W. (2009): ZHANG, F. & LIU, X-W. (2009) A review of the subgenus Diestrammena (Gymnaeta) from China (Orthoptera: Rhaphidophoridae Aemodogryllinae). Zootaxa, 2272, 21-36. Zootaxa 2288 (1): 68, DOI: 10.11646/zootaxa.2288.1.5, URL: http://dx.doi.org/10.11646/zootaxa.2288.1.
Liu Kang
No full textLiu Kang: Essays on Art and Culture is a testament to the inexorable passion of an artist who knew no boundaries. This collection of essays, which Liu Kang wrote over 44 years, offers an insight into the artist’s myriad interests as well as his contributions as a first generation Nanyang artist and art educator. Translated into English for this volume, Liu Kang’s essays are accompanied by commentaries and photographs of the artist-author and his subjects
Test Make Sense?
No full textCorresponding author Changyu Liu should be listed as the first corresponding author.No Full Tex
Influence of ac ageing on space charge dynamics in LDPE
No full textPolymeric materials have been widely used as insulation in power industry due to their excellent electrical properties. However, these properties deteriorate in time irreversibly when the material is subjected to electric stress. Although space charge is believed to play an important role in ac ageing, exact mechanisms are poorly understood due to very limited experimental data. In the present work efforts have been made to investigate the influence of ac ageing on space charge dynamics in low-density polyethylene (LDPE). LDPE films with 200mm were aged at 50 kV/mm at 50 Hz for various times at ambient temperature. Space charge dynamics in the samples prior to and after ageing were monitored using the pulsed electroacoustic (PEA) technique under dc electric stress. The results indicate that there is a significant amount of homocharge accumulation in the unaged sample due to charge injection. These injected charges are the captured by the deep traps originated from the interface between crystalline and amorphous regions in LDPE. Ageing under ac condition does not necessarily lead to an increase in amount of charge in the bulk but leads to an increase in mobility of charge carriers. Chemical analysis by infrared spectroscope (FTIR) reveals there are chemical changes taken place in the bulk of the material after ac ageing. It is believed that the chemical changes introduce shallow traps which promote the movement of charge carriers in the bulk. Consequently, the injected charges spread across the sample
Effects of Rate Adaption on the Throughput of Random Ad Hoc Networks
No full textThe capacity of wireless ad hoc networks has been studied in an excellent treatise by Gupta and Kumar [1], assuming a fixed transmission rate. By contrast, in this treatise we investigate the achievable throughput improvement of rate adaptation in the context of random ad hoc networks, which have been studied in conjunction with a fixed transmission rate in [1]. Our analysis shows that rate adaptation has the potential of improving the achievable throughput compared to fixed rate transmission, since rate adaptation mitigates the effects of link quality fluctuations. However, even perfect rate control fails to change the scaling law of the per-node throughput result given in [1], regardless of the absence or presence of shadow fading. This result is confirmed in the context of specific adaptive modulation aided design examples
Dataset for: The importance of the heel effect in X-ray CT imaging of soils
No full textDataset supports the paper K. Liu, R. Boardman, M. Mavrogordato, F. A. Loveridge, and W. Powrie 'The importance of the heel effect in X-ray CT imaging of soils' in Environmental Geotechnics, https://doi.org/10.1680/jenge.20.00048</span
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