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Liu Y.,CAS Yantai Institute of Coastal Zone Research | Liu Y.,Inner Mongolia University | Liu Y.,Nanjing University | Liu F.,Tianjin University of Technology | And 4 more authors.
Catena | Year: 2015

Alpine shrubs and soils in catchments of the headwaters of the Yangtze River in west China are very important for reducing flooding and sustaining base flow during the summer. However, the contributions of precipitation, throughfall, and interflow to soil water and their effective contribution times in alpine shrub soil are not fully understood. In this study, we investigated a time series of stable isotopes in soil water, precipitation, canopy throughfall, interflow, litter, and humus water in a hillslope area. In addition, the spatial variation of water isotopes in soil profile in the Wolong Valley, located in the upper watershed of the Yangtze River, Sichuan, China, was considered. We found that (1) precipitation and throughfall significantly affected water isotopes in litter, humus, and shallow soil (0cm to 50cm deep) by affecting preferential flows. (2) Rainwater from a small precipitation event (about 4.0mm d-1) also penetrated soil to depths of 40cm to 50cm. (3) Interflow could comprise as much as 96% of water in soil columns during non-rainy days, but the proportion would decrease quickly after the precipitation amount reached more than 3mm d-1. (4) Mean effective contribution times of recharge in soil (0cm to 50cm deep) occurred 3 to 5days despite the occurrence of large precipitation events (15.0mm and 18.9mm). Therefore, preferential flows composed of precipitation/throughfall and interflow were dominant in hillslope hydrology in the southeast edge of Tibet, which caused runoff to increase during the rainy season. © 2014 Elsevier B.V. Source

Liu Y.,CAS Yantai Institute of Coastal Zone Research | Xu Z.,State Power Environmental Protection Research Institute | Duffy R.,CAS Yantai Institute of Coastal Zone Research | Chen W.,Institute of Chemical Defence | And 3 more authors.
European Journal of Soil Biology | Year: 2011

Stable isotopic characteristics of plant water represent an integrated response of root systems to water sources with different isotopic signatures. Analysis of these signatures can help to identify many ecological processes involved in the uptake, transport and utilization of different water sources. In August 2003, we collected soil water samples throughout the soil profile from a subalpine shrub ecosystem in Wolong Nature Reserve, West China, along with stem water samples from the two dominant shrub species, Quercus aquifolioides and Salix luctuosa. Stable isotope contents of the different water samples were determined in conjunction with rootlet biomass distribution of each species and soil water content throughout the soil profile. Results indicated that these subalpine non-phreatophytic shrubs utilized soil water primarily from the top 30 cm of the soil profile. Water uptake patterns were significantly positively correlated with rootlet biomass distribution as well as the soil water content profile. Hence, the two shrubs could play an important role in keeping rainwater from entering river channels quickly, thereby reducing risk of flooding. © 2011. Source

Liu Y.,CAS Yantai Institute of Coastal Zone Research | Liu Y.,Nanjing University | Xu Z.,State Power Environmental Protection Research Institute | Xu Z.,Nanjing University | And 5 more authors.
Clean - Soil, Air, Water | Year: 2013

Alpine shrub Quercus aquifolioides was selected to study the effects of shrub canopy on throughfall and phreatic water by analyzing the isotopic time series of precipitation, canopy throughfall and phreatic water and examining correlations among these series in Wolong Nature Reserve, Western China. Based on analysis of precipitation data in 2003, the local meteoric water line during the rainy season was δD=8.28×δ18O+8.93, and the primary precipitation moisture in this region originated from the Pacific Ocean in the summer. Stable isotope analysis showed that the main supply of throughfall and phreatic water was from precipitation, and the shrub canopy has an important effect on the processes of rainwater transmuted into throughfall and phreatic water. Moreover, the differences of δD and δ18O values between rainwater and throughfall were relevant to rainfall. Due to interception of the shrub canopy, there had a response hysteresis of phreatic water to the various rainfall events, which was mostly 2 days, except that this hysteresis was ≤1 day when rainfall was >15mm/day. © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Xie C.-Z.,South China University of Technology | Zhang Y.,South China University of Technology | Hao Y.-P.,South China University of Technology | Fan J.-B.,China Electric Power Research Institute | Yao Z.-Q.,State Power Environmental Protection Research Institute
Gaodianya Jishu/High Voltage Engineering | Year: 2010

Wind tunnel test, air flow field test and numerical simulation were used to study pollution deposit of ±800 kV UHV composite insulators. The result indicates that the flow field characteristics of the composite insulators are better than ceramic insulator, Three kinds of composite insulators are excellent aerodynamic flow pattern, In which #0 sample is the best. Source

Sun F.-R.,State Power Environmental Protection Research Institute | Yan C.-Q.,Harbin Engineering University | Gu H.-F.,Harbin Engineering University
Yuanzineng Kexue Jishu/Atomic Energy Science and Technology | Year: 2011

The working principle of density lock was introduced in this paper, and the experimental loop was built so that researches on working performance of density lock in the system were done at steady-state operation and pump trip conditions. The results show that at steady-state operation conditions, density lock can keep close in a long run, which will separate passive residual heat removal circuit from primary circuit. As a result, passive residual heat removal circuit is in the non-operating conditions, which does not influence normal operation of reactors. At the pump trip conditions, density lock can be automatically opened quickly, which will make primary and passive residual heat removal system communicated. The natural circulation is well established in the two systems, and is enough to ensure removal of residual heat. Source

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