Aim To study the chemical composition of Opuntia dillenii Haw. Methods Manykinds of chromatogra-phy methods were used in the isolation procedure, while the structures ofisolated compounds were determined on the aids o...Aim To study the chemical composition of Opuntia dillenii Haw. Methods Manykinds of chromatogra-phy methods were used in the isolation procedure, while the structures ofisolated compounds were determined on the aids of NMR and MS spectral analysis. Result Three newcompounds, together with 14 known compounds, were isolated form the 80% ethanolic extract of itsstems. Conclusion The three new compounds, opuntioside Ⅰ (2), 4-ethoxyl-6-hydroxymethyl-α-pyrone(3) and kaempferol 7-O-β-D-glucopyranosyl (1→4)-β-D-glucopyranoside (4), were characterized.展开更多
The third UN World Congress on Disaster Risk Reduction, held in Sendai, Japan in March 2015, agreed on a new framework to guide disaster risk reduction policy and practice for the next 15 years. The Sendai Framework f...The third UN World Congress on Disaster Risk Reduction, held in Sendai, Japan in March 2015, agreed on a new framework to guide disaster risk reduction policy and practice for the next 15 years. The Sendai Framework for Disaster Risk Reduction 2015–2030(SFDRR) leaves important implementation issues unspecified and potentially creates both problems and opportunities for complex,multilevel governance systems in coping with hazards and disastrous events. Early warning systems(EWS), if built into the mainstream of planning for development and disaster relief and recovery, could present a significant opportunity to realize many SFDRR goals. We explore the complexities of using hydrometeorological EWS to prepare for drought and flood disasters in the densely populated communities of Pakistan’s Indus River Basin in contrast to the African Sahel’s less densely settled grasslands. Multilevel governance systems are often dominated by a topdown, technocentric, centralized management bias and have great difficulty responding to the needs of peripheral and vulnerable populations. People-centered, bottom-up approaches that incorporate disaggregated communities with local knowledge into a balanced, multilevel disaster risk management and governance structure have adramatically better chance of realizing the SFDRR goals for disaster risk reduction.展开更多
Spine is the sharpest and hardest part of many plants, which contains highly aligned fiber cells. Here, we report the micro- structures and mechanical properties as well as their correlation of single spine fiber cel...Spine is the sharpest and hardest part of many plants, which contains highly aligned fiber cells. Here, we report the micro- structures and mechanical properties as well as their correlation of single spine fiber cells （SFCs） from the cactus Echinocactus grusonii. It is found that the SFCs are 0.32-0.57 mm in length and 4.6-6.0 gm in width, yielding an aspect ratio of 53-124. X-ray diffraction and Fourier transform infrared spectrophotometry show that the spine fiber is mainly made up of cellulose I with a crystallinity index up to -76%. Nanoindentation tests show that a natural spine presents a high modulus of -17 GPa. Removing hemicellulose and lignin from the SFC significantly reduces its modulus to -0.487 GPa, demonstrating the critical role of adhesives hemicellulose and lignin in affecting the mechanical properties of the SFCs. This finding sheds light on de- signing novel bio-inspired high-performance composite nanomaterials with aligned nanofibers, such as using hemicellulose and lignin as adhesive in making carbon nanotube fibers.展开更多
文摘Aim To study the chemical composition of Opuntia dillenii Haw. Methods Manykinds of chromatogra-phy methods were used in the isolation procedure, while the structures ofisolated compounds were determined on the aids of NMR and MS spectral analysis. Result Three newcompounds, together with 14 known compounds, were isolated form the 80% ethanolic extract of itsstems. Conclusion The three new compounds, opuntioside Ⅰ (2), 4-ethoxyl-6-hydroxymethyl-α-pyrone(3) and kaempferol 7-O-β-D-glucopyranosyl (1→4)-β-D-glucopyranoside (4), were characterized.
基金funding from the National Science Foundation for EPS-1101317 project on ‘‘Research on Adaptation to Climate Change’’NSF-SESYNC/NIMBIOS DBI-1052875 project on ‘‘Integrating Human Risk Perception of Global Climate Change into Dynamic Earth System Models’’
文摘The third UN World Congress on Disaster Risk Reduction, held in Sendai, Japan in March 2015, agreed on a new framework to guide disaster risk reduction policy and practice for the next 15 years. The Sendai Framework for Disaster Risk Reduction 2015–2030(SFDRR) leaves important implementation issues unspecified and potentially creates both problems and opportunities for complex,multilevel governance systems in coping with hazards and disastrous events. Early warning systems(EWS), if built into the mainstream of planning for development and disaster relief and recovery, could present a significant opportunity to realize many SFDRR goals. We explore the complexities of using hydrometeorological EWS to prepare for drought and flood disasters in the densely populated communities of Pakistan’s Indus River Basin in contrast to the African Sahel’s less densely settled grasslands. Multilevel governance systems are often dominated by a topdown, technocentric, centralized management bias and have great difficulty responding to the needs of peripheral and vulnerable populations. People-centered, bottom-up approaches that incorporate disaggregated communities with local knowledge into a balanced, multilevel disaster risk management and governance structure have adramatically better chance of realizing the SFDRR goals for disaster risk reduction.
基金supported by the National Key Basic Research Program of China("973"program)(Grant Nos.2013CB932604,2012CB933403)the National Natural Science Foundation of China(Grant No.91023026)+2 种基金the Fundamental Research Funds for the Central Universities(Grant NosNP2013309,NS2012043)Jiangsu Planned Projects for Postdoctoral Research Funds(Grant No.1302015B)the NUAA Research Initiative for New Stuff(Grant No.1011-YAH13042)
文摘Spine is the sharpest and hardest part of many plants, which contains highly aligned fiber cells. Here, we report the micro- structures and mechanical properties as well as their correlation of single spine fiber cells （SFCs） from the cactus Echinocactus grusonii. It is found that the SFCs are 0.32-0.57 mm in length and 4.6-6.0 gm in width, yielding an aspect ratio of 53-124. X-ray diffraction and Fourier transform infrared spectrophotometry show that the spine fiber is mainly made up of cellulose I with a crystallinity index up to -76%. Nanoindentation tests show that a natural spine presents a high modulus of -17 GPa. Removing hemicellulose and lignin from the SFC significantly reduces its modulus to -0.487 GPa, demonstrating the critical role of adhesives hemicellulose and lignin in affecting the mechanical properties of the SFCs. This finding sheds light on de- signing novel bio-inspired high-performance composite nanomaterials with aligned nanofibers, such as using hemicellulose and lignin as adhesive in making carbon nanotube fibers.
