AIM： To assess and compare the diurnal macular choroidal area fluctuation in normal and primary open angle glaucoma （POAG） groups using enhanced depth imaging optical coherence tomography （EDI-OCT）. METHODS： Tw...AIM： To assess and compare the diurnal macular choroidal area fluctuation in normal and primary open angle glaucoma （POAG） groups using enhanced depth imaging optical coherence tomography （EDI-OCT）. METHODS： Twenty-eight normal and 27 POAG eyes were enrolled in this study. EDI-OCT was used to measure the macular choroidal area every 3h from 9：00 a.m. to 21：00 p.m. RESULTS： Significant diurnal fluctuations of macular choroidal area were observed in both normal （P=-0.003） and POAG groups （P〈0.001）. But no significant macular choroidal area difference has been found between the two groups at all the five measurement time-points （512778＋166242 vs 455079：1：207278 pm2, P=-0.195 at 9：00 a.m.; 501526168953 vs 447846.：211147 pm2, P=-0.245 at 12：00 a.m.; 501982＋173158 vs 448024#.206653 pm2, P=-0.239 at 15：00 p.m.; 508912＋174589 vs 457783＋-207081 pm2, P=-0.252 at 18：00 p.m.; 503787＋171241 vs 453230＋_205955 pm2, P=-0.274 at 21：00 p.m.; respectively）. Furthermore, neither the fluctuation manners nor the change in macular choroidal area between the two adjacent measurement time points showed significant difference between normal and POAG groups （all P〉0.05）. In the meantime, significant diurnal intraocular pressure fluctuations were also observed in normal and POAG groups （both P〈0.001）. CONCLUSION： In diurnal time, the macular choroidal area in both normal and POAG groups fluctuated significantly; moreover, neither the value of macular choroidal area, nor the fluctuation of macular choroidal area in POAG group is significantly different from that in normal group.展开更多
By using the statistical data of grain yield in China's major grain producing areas from 1949 to 2008,and fluctuation theory,the historical process and main cause of fluctuation of grain yield in China's major...By using the statistical data of grain yield in China's major grain producing areas from 1949 to 2008,and fluctuation theory,the historical process and main cause of fluctuation of grain yield in China's major grain producing areas are analyzed.The results of research show that the grain yield in China's major grain producing areas grows in unstable fluctuation,with high-frequency fluctuation cycle and regular length;the amplitude of fluctuation,on the whole,is moderate,with not strong stability;the fluctuation of grain yield has correspondence,reflecting the N-shape developmental trend of grain production at present;the fluctuation of grain yield has gradient characteristics;in the process of comparison of grain yield,the average growth rate annually of grain yield in China's major grain producing areas is higher than that of the national average,but the relative fluctuation coefficient is also higher than that of the national average.From five aspects,namely natural disaster,agricultural policy,production input,grain price and grain circulation,the cause of fluctuation of grain yield in China's major grain producing areas is analyzed,and measures of preventing and arresting super-long fluctuation of grain yield are put forward.Firstly,stick to strict farmland protection system,and strive to promote farmland quality;secondly,strengthen infrastructure construction of grain production and beef up the ability of preventing natural disaster;thirdly,quicken the pace of agricultural technology and establish robust technology supporting system;fourthly,lay stress on innovation of agricultural organization system and provide implementation path and vehicle for application of agricultural technology measures;fifthly,perfect disaster precaution system and grain market system,and strengthen the ability of preventing risk of grain production.展开更多
【目的】三峡库区消落带受周期性的水位涨落及冬季长时间深水淹没影响,碳汇能力遭受严重破坏。如何恢复并充分发挥消落带生态系统的碳汇潜力,成为三峡库区生态治理的关键议题。【方法】针对复杂水位变化挑战,提出以林塘模式修复消落带...【目的】三峡库区消落带受周期性的水位涨落及冬季长时间深水淹没影响,碳汇能力遭受严重破坏。如何恢复并充分发挥消落带生态系统的碳汇潜力,成为三峡库区生态治理的关键议题。【方法】针对复杂水位变化挑战,提出以林塘模式修复消落带生态系统并提升碳汇能力的技术框架,选取位于三峡库区腹心的大浪坝消落带开展实证研究。运用CASA模型测算修复前后大浪坝消落带的净初级生产力(net primary productivity,NPP),基于植被生物量数据计算修复后大浪坝消落带与未修复对照组内不同高程带的碳汇能力,评估林塘碳汇系统的可持续效益。【结果】修复后大浪坝消落带的碳汇能力随时间推移明显提升,NPP由2012年的154.4 g C·m^(2)·a^(-1)增长至2016年的182.5 g C·m^(2)·a^(-1);各高程带的碳汇能力均显著高于对照组,并呈现出随海拔降低而减弱的趋势,170~175 m高程带碳汇能力达到1.827 kg C/m^(2),160~165 m高程带碳汇能力仅为0.830 kg C/m^(2)。林塘系统增强了生态系统的适应性和复原力,形成了适应水位变化的立体固碳模式并有效提升了碳汇效率。【结论】林塘碳汇系统是应对三峡库区复杂水位变化和长时间深水淹没挑战的适应性探索,显示出景观优化、生物多样性、经济效益与碳汇协同耦合的关键特征。研究成果能够为中国大型工程型水库消落带的治理及碳增汇提供科学依据与可复制推广的创新技术模式。展开更多
文摘AIM： To assess and compare the diurnal macular choroidal area fluctuation in normal and primary open angle glaucoma （POAG） groups using enhanced depth imaging optical coherence tomography （EDI-OCT）. METHODS： Twenty-eight normal and 27 POAG eyes were enrolled in this study. EDI-OCT was used to measure the macular choroidal area every 3h from 9：00 a.m. to 21：00 p.m. RESULTS： Significant diurnal fluctuations of macular choroidal area were observed in both normal （P=-0.003） and POAG groups （P〈0.001）. But no significant macular choroidal area difference has been found between the two groups at all the five measurement time-points （512778＋166242 vs 455079：1：207278 pm2, P=-0.195 at 9：00 a.m.; 501526168953 vs 447846.：211147 pm2, P=-0.245 at 12：00 a.m.; 501982＋173158 vs 448024#.206653 pm2, P=-0.239 at 15：00 p.m.; 508912＋174589 vs 457783＋-207081 pm2, P=-0.252 at 18：00 p.m.; 503787＋171241 vs 453230＋_205955 pm2, P=-0.274 at 21：00 p.m.; respectively）. Furthermore, neither the fluctuation manners nor the change in macular choroidal area between the two adjacent measurement time points showed significant difference between normal and POAG groups （all P〉0.05）. In the meantime, significant diurnal intraocular pressure fluctuations were also observed in normal and POAG groups （both P〈0.001）. CONCLUSION： In diurnal time, the macular choroidal area in both normal and POAG groups fluctuated significantly; moreover, neither the value of macular choroidal area, nor the fluctuation of macular choroidal area in POAG group is significantly different from that in normal group.
基金Supported by Youth Initiation Fund Program of Jilin Agricultural University
文摘By using the statistical data of grain yield in China's major grain producing areas from 1949 to 2008,and fluctuation theory,the historical process and main cause of fluctuation of grain yield in China's major grain producing areas are analyzed.The results of research show that the grain yield in China's major grain producing areas grows in unstable fluctuation,with high-frequency fluctuation cycle and regular length;the amplitude of fluctuation,on the whole,is moderate,with not strong stability;the fluctuation of grain yield has correspondence,reflecting the N-shape developmental trend of grain production at present;the fluctuation of grain yield has gradient characteristics;in the process of comparison of grain yield,the average growth rate annually of grain yield in China's major grain producing areas is higher than that of the national average,but the relative fluctuation coefficient is also higher than that of the national average.From five aspects,namely natural disaster,agricultural policy,production input,grain price and grain circulation,the cause of fluctuation of grain yield in China's major grain producing areas is analyzed,and measures of preventing and arresting super-long fluctuation of grain yield are put forward.Firstly,stick to strict farmland protection system,and strive to promote farmland quality;secondly,strengthen infrastructure construction of grain production and beef up the ability of preventing natural disaster;thirdly,quicken the pace of agricultural technology and establish robust technology supporting system;fourthly,lay stress on innovation of agricultural organization system and provide implementation path and vehicle for application of agricultural technology measures;fifthly,perfect disaster precaution system and grain market system,and strengthen the ability of preventing risk of grain production.
文摘【目的】三峡库区消落带受周期性的水位涨落及冬季长时间深水淹没影响,碳汇能力遭受严重破坏。如何恢复并充分发挥消落带生态系统的碳汇潜力,成为三峡库区生态治理的关键议题。【方法】针对复杂水位变化挑战,提出以林塘模式修复消落带生态系统并提升碳汇能力的技术框架,选取位于三峡库区腹心的大浪坝消落带开展实证研究。运用CASA模型测算修复前后大浪坝消落带的净初级生产力(net primary productivity,NPP),基于植被生物量数据计算修复后大浪坝消落带与未修复对照组内不同高程带的碳汇能力,评估林塘碳汇系统的可持续效益。【结果】修复后大浪坝消落带的碳汇能力随时间推移明显提升,NPP由2012年的154.4 g C·m^(2)·a^(-1)增长至2016年的182.5 g C·m^(2)·a^(-1);各高程带的碳汇能力均显著高于对照组,并呈现出随海拔降低而减弱的趋势,170~175 m高程带碳汇能力达到1.827 kg C/m^(2),160~165 m高程带碳汇能力仅为0.830 kg C/m^(2)。林塘系统增强了生态系统的适应性和复原力,形成了适应水位变化的立体固碳模式并有效提升了碳汇效率。【结论】林塘碳汇系统是应对三峡库区复杂水位变化和长时间深水淹没挑战的适应性探索,显示出景观优化、生物多样性、经济效益与碳汇协同耦合的关键特征。研究成果能够为中国大型工程型水库消落带的治理及碳增汇提供科学依据与可复制推广的创新技术模式。
