The breeding biology of a captive, isolated population of Dalmatian Pelicans (Pelecanus crispus) at theShanghaiZoo,China, was studied from 2007 to 2019. The breeding age of the Dalmatian Pelicans was estimated at thre...The breeding biology of a captive, isolated population of Dalmatian Pelicans (Pelecanus crispus) at theShanghaiZoo,China, was studied from 2007 to 2019. The breeding age of the Dalmatian Pelicans was estimated at three to four years old, and they started breeding in late October or early November. The clutch size varied between one and two eggs per nest, and the eggs were 83.2 ±4.8 mmin length, 55.6 ±2.9 mmin breadth and 136.1 ±21.5 gin weight. The fertility fluctuated slightly, with an average rate of 38.7% ± 9.7%, but remained consistently low. The survival rate of chicks fluctuated substantially from 0% to 100%, with an average survival rate of 68.6% ± 27.6%. The averaged values of observed heterozygosity, expected heterozygosity and polymorphism information content were 0.468, 0.465 and 0.446, respectively. It indicated that the population had a low heterozygosity and genetic diversity. There was a significant change in the breeding index compared to that recorded 40 years ago, which indicates that inbreeding depression has occurred in this small, isolated, captive population of Dalmatian Pelicans. These results can be used to improve management of Dalmatian Pelicans in captivity.展开更多
At first,the ecological restoration technology of abandoned mines is summarized,and the paths and models of mine ecological restoration in Zoige grassland area under the background of carbon neutrality are analyzed.Mo...At first,the ecological restoration technology of abandoned mines is summarized,and the paths and models of mine ecological restoration in Zoige grassland area under the background of carbon neutrality are analyzed.Moreover,the problems and deficiencies in the current research on mine ecological restoration in Zoige grassland area are initially identified,and the future research trend is prospected to provide a reference for the path of carbon reduction by mine ecological restoration in Zoige grassland area and other alpine grassland areas in the future.展开更多
Peatlands,as a special type of wetland,occupy only 3%of the Earth’s surface,but bear about one-third of the world’s soil carbon storage and play an important role in the global carbon cycle.The Zoige Wetland is loca...Peatlands,as a special type of wetland,occupy only 3%of the Earth’s surface,but bear about one-third of the world’s soil carbon storage and play an important role in the global carbon cycle.The Zoige Wetland is located on the eastern edge of the Qinghai-Tibet Plateau,and its peat reserves are up to 1.9 billion tons,accounting for more than 40%of the country’s peat resources,which is an important support for China to achieve the“double carbon”goal.This paper reviews the research status and storage estimation of soil organic carbon in Zoige Wetland.The statistical results show that there is a large difference in the estimation of carbon storage in the peatland of Zoige(0.43-1.42 Pg).The reasons are mainly related to marked differences in values reported for soil densities,organic carbon levels,and accumulation rates.There are still great uncertainties in the estimation of wetland carbon stocks,and future studies should focus on reducing soil carbon sink uncertainties,climate change,the impact of permafrost melting on carbon sink functions,the impact of degraded ecosystem restoration and sink enhancement pathways,and other greenhouse gas functions.In order to accurately reveal the current situation and future trend of carbon sink in peat wetlands,a model-multi-source observation data fusion system was constructed to complement the observation shortcomings in key areas,and provide reference and support for the construction of carbon neutral ecological civilization.展开更多
The chain/wire rope/chain combination is a common choice for mooring offshore floating platforms. However, data of the drag coefficients of chain links are rather limited, resulting in uncertainties with the calculati...The chain/wire rope/chain combination is a common choice for mooring offshore floating platforms. However, data of the drag coefficients of chain links are rather limited, resulting in uncertainties with the calculations of the drag force, and hence the damping of the mooring system. In this paper, the importance of the selection of the drag coefficient is first investigated. The computational fluid dynamics(CFD) method is then used to determine the drag coefficients of a studless chain under steady flows. Numerical model validation is first completed by simulating a smooth circular cylinder under steady flows. In particular, the performance of different turbulence models is assessed through the comparisons between the calculations and the experimental results. The large eddy simulation(LES) model is finally selected for the simulation of steady flows past a chain. The effects of the Reynolds number on the drag coefficient of a stud-less chain is also studied. The results show that the calculated drag coefficients of a stud-less chain are fairly consistent with the available experimental data.展开更多
文摘The breeding biology of a captive, isolated population of Dalmatian Pelicans (Pelecanus crispus) at theShanghaiZoo,China, was studied from 2007 to 2019. The breeding age of the Dalmatian Pelicans was estimated at three to four years old, and they started breeding in late October or early November. The clutch size varied between one and two eggs per nest, and the eggs were 83.2 ±4.8 mmin length, 55.6 ±2.9 mmin breadth and 136.1 ±21.5 gin weight. The fertility fluctuated slightly, with an average rate of 38.7% ± 9.7%, but remained consistently low. The survival rate of chicks fluctuated substantially from 0% to 100%, with an average survival rate of 68.6% ± 27.6%. The averaged values of observed heterozygosity, expected heterozygosity and polymorphism information content were 0.468, 0.465 and 0.446, respectively. It indicated that the population had a low heterozygosity and genetic diversity. There was a significant change in the breeding index compared to that recorded 40 years ago, which indicates that inbreeding depression has occurred in this small, isolated, captive population of Dalmatian Pelicans. These results can be used to improve management of Dalmatian Pelicans in captivity.
基金Supported by the Financial Research Foundation of Sichuan Academy of Geological Survey(51000023Y000008287156).
文摘At first,the ecological restoration technology of abandoned mines is summarized,and the paths and models of mine ecological restoration in Zoige grassland area under the background of carbon neutrality are analyzed.Moreover,the problems and deficiencies in the current research on mine ecological restoration in Zoige grassland area are initially identified,and the future research trend is prospected to provide a reference for the path of carbon reduction by mine ecological restoration in Zoige grassland area and other alpine grassland areas in the future.
基金2023 financial research project of Sichuan Research Institute of Geological Survey“Carbon Storage Monitoring of Wetland Ecosystem in Northwest Sichuan Plateau based on Big Data and expert Knowledge” (SCIGS-CYBXM-2023014).
文摘Peatlands,as a special type of wetland,occupy only 3%of the Earth’s surface,but bear about one-third of the world’s soil carbon storage and play an important role in the global carbon cycle.The Zoige Wetland is located on the eastern edge of the Qinghai-Tibet Plateau,and its peat reserves are up to 1.9 billion tons,accounting for more than 40%of the country’s peat resources,which is an important support for China to achieve the“double carbon”goal.This paper reviews the research status and storage estimation of soil organic carbon in Zoige Wetland.The statistical results show that there is a large difference in the estimation of carbon storage in the peatland of Zoige(0.43-1.42 Pg).The reasons are mainly related to marked differences in values reported for soil densities,organic carbon levels,and accumulation rates.There are still great uncertainties in the estimation of wetland carbon stocks,and future studies should focus on reducing soil carbon sink uncertainties,climate change,the impact of permafrost melting on carbon sink functions,the impact of degraded ecosystem restoration and sink enhancement pathways,and other greenhouse gas functions.In order to accurately reveal the current situation and future trend of carbon sink in peat wetlands,a model-multi-source observation data fusion system was constructed to complement the observation shortcomings in key areas,and provide reference and support for the construction of carbon neutral ecological civilization.
基金financial support for the PhD study from GL-Nobel Denton based in London
文摘The chain/wire rope/chain combination is a common choice for mooring offshore floating platforms. However, data of the drag coefficients of chain links are rather limited, resulting in uncertainties with the calculations of the drag force, and hence the damping of the mooring system. In this paper, the importance of the selection of the drag coefficient is first investigated. The computational fluid dynamics(CFD) method is then used to determine the drag coefficients of a studless chain under steady flows. Numerical model validation is first completed by simulating a smooth circular cylinder under steady flows. In particular, the performance of different turbulence models is assessed through the comparisons between the calculations and the experimental results. The large eddy simulation(LES) model is finally selected for the simulation of steady flows past a chain. The effects of the Reynolds number on the drag coefficient of a stud-less chain is also studied. The results show that the calculated drag coefficients of a stud-less chain are fairly consistent with the available experimental data.
