2篇
您的检索式：作者名="Longyan Hou"
|
|
|
题名
|
作者
|
年代
|
出处
|
被引量
|
| 1 | Grazing by wild giant pandas does not affect the regeneration of Arundinaria spanostachya显示文摘Arundinaria spanostachya is the main bamboo species on which giant pandas forage.Information on its regeneration capacity to meet the foraging demands of pandas is important to ensure the long-term survival of pandas.In 2014,2 plot types(grazed versus control)were selected in the winter habitat used by one wild giant panda.Various morphological and regeneration characteristics of the bamboo were assessed in the respective plots during 2014 and 2015.The panda avoided feeding on bamboo with a basal diameter of<6 mm,preferentially feeding on intermediate-sized bamboo.The density of new shoots and the recruitment rate of shoots were significantly higher in the grazed plots compared to the control plots.The annual recruitment rate of shoots was markedly higher than the annual mortality rate in the same plot type.After grazing,the basal diameter and height of new bamboo were similar between the 2 plots.In the grazed plots,the basal diameter of new bamboo was similar to that of the stumps.Innutrition and foraging by insects were the main factors influencing the survival of new shoots.Our results showed that grazing by giant pandas helped the clonal regeneration of A.spanostachya populations,with the basal diameter of new bamboo shoots meeting the foraging demand of pandas.However,information on the carrying capacity of A.spanostachya is necessary to ensure sufficient forage matter is available for reintroduced giant pandas.Furthermore,fertilization and insect control measures should be implemented during the shooting period to optimize A.spanostachya resources. | Longyan Zhang Xiaohong Gan Zhengyang Hou Zhisong Yang Zejun Zhang | 2019 | Journal of Forestry Research2019，30，4： | 2 |
| 2 | Dose rate effects on shape memory epoxy resin during 1 Me V electron irradiation in air显示文摘The effects of 1 Me V electron irradiation in air at a fixed accumulated dose and dose rates of 393.8,196.9,78.8,and 39.4 Gy s^(-1)on a shape memory epoxy(SMEP)resin were studied.Under low-dose-rate irradiation,accelerated degradation of the shape memory performance was observed;specifically,the shape recovery ratio decreased exponentially with increasing irradiation time(that is,with decreasing dose rate).In addition,the glass transition temperature of the SMEP,as measured by dynamic mechanical analysis,decreased overall with decreasing dose rate.The dose rate effects of 1 Me V electron irradiation on the SMEP were confirmed by structural analysis using electron paramagnetic resonance(EPR)spectroscopy and Fourier transform infrared(FTIR)spectroscopy.The EPR spectra showed that the concentration of free radicals increased exponentially with increasing irradiation time.Moreover,the FTIR spectra showed higher intensities of the peaks at 1660 and 1720 cm^(-1),which are attributed to stretching vibrations of amide C=O and ketone/acid C=O,at lower dose rates.The intensities of the IR peaks at 1660 and 1720 cm^(-1) increased exponentially with increasing irradiation time,and the relative intensity of the IR peak at 2926 cm^(-1)decreased exponentially with increasing irradiation time.The solid-state13 C nuclear magnetic resonance(NMR)spectra of the SMEP before and after 1 Me V electron irradiation at a dose of 1970 k Gy and a dose rate of 78.8 Gy s^(-1) indicated damage to the CH_(2)–N groups and aliphatic isopropanol segment.This result is consistent with the detection of nitrogenous free radicals,a phenoxy-type free radical,and several types of pyrolytic carbon radicals by EPR.During the subsequent propagation process,the free radicals produced at lower dose rates were more likely to react with oxygen,which was present at higher concentrations,and form the more destructive peroxy free radicals and oxidation products such as acids,amides,and ketones.The increase in peroxy free radicals at lower dose rates was thought to accelerate the degradation of the macroscopic performance of the SMEP. | Longyan Hou Yiyong Wu Debin Shan Bin Guo Yingying Zong | 2021 | Journal of Materials Science & Technology2021，，8： | 1 |
您所在的机构暂未开通此部分的功能，请联系管理员