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251.
Variability in water cycles driven by climate change is considered likely to impact rice production in the near future. Rice
is the main staple food for the population in the lower Mekong Basin and the demand for food is expected to grow due to increase
in population. This paper examines the impact of climate change on rice production in the lower Mekong Basin, evaluates some
widely used adaptation options, and analyses their implications for overall food security by 2050. Climate change data used
in the study are the future climate projection for two IPCC SRES scenarios, A2 and B2, based on ECHAM4 General Circulation
Model downscaled to the Mekong region using the PRECIS (Providing Regional Climates for Impact Studies) system. In general,
the results suggest that yield of rainfed rice may increase significantly in the upper part of the basin in Laos and Thailand
and may decrease in the lower part of the basin in Cambodia and Vietnam. Irrigated rice may not be affected by climate change
if increased irrigation requirements are met. Negative impact on the yield of rainfed rice can be offset and net increase
in yield can be achieved by applying widely used adaptation options such as changing planting date, supplementary irrigation
and increased fertilizer input. Analysis of the projected production, considering population growth by 2050, suggests that
food security of the basin is unlikely to be threatened by the increased population and climate change, excluding extreme
events such as sea level rise and cyclones. 相似文献
252.
Zhuolu Li Yingjie Lyu Zhao Ran Yujia Wang Yang Zhang Nianpeng Lu Meng Wang Michel Sassi Thai Duy Ha Alpha T. N'Diaye Padraic Shafer Carolyn Pearce Kevin Rosso Elke Arenholz Jenh-Yih Juang Qing He Ying-Hao Chu Weidong Luo Pu Yu 《Advanced functional materials》2023,33(17):2212298
Magnetic spinel oxides have attracted extensive research interest due to their rich physics and wide range of applications. However, these materials invariably suffer suppressed magnetization, due to structural imperfections (e.g., disorder, anti-site defects, etc.). Herein, a dramatic enhanced magnetization is obtained with an increasement of 5 µB/u.c in CoFe2O4 (CFO) through ionic liquid gating induced hydrogen doping. The intercalated hydrogen ions lead to both distinct lattice expansion of ≈0.7% and notable Fe valence state reduction through electron doping, in which ≈17% Fe3+ is reduced into Fe2+. These facts collectively trigger a site-specific spin-flip on tetrahedrally coordinated Co2+ sites that enhances the net ferrimagnetic moment nearly to its theoretical maximum for perfect CFO. 相似文献
253.
254.
This paper presents an effective control method for three-dimensional (3D) overhead cranes with six degrees of freedom (DOF). Two payload swings and an axial payload oscillation should be minimized besides driving the bridge, trolley, and hoisting drum to bring the payload to the desired position in space. First, a novel 3D-6DOF crane model is developed, where the sixth degree of freedom is axial cargo oscillation that has never been considered in previous studies. A controller is then designed using the hierarchical sliding mode control method. Moreover, a radial basis function neural network (RBFNN) is used to approximate the system's unknown dynamic model accurately. According to the Lyapunov principle, a control law and an updated law for the neural network's weight matrices are designed to ensure the stability of the closed-loop system. Simulation results on Matlab software show the proposed approach's effectiveness, such as smaller swing, minor axial oscillation, and precise position as desired. 相似文献
255.
Thanh-An Truong Tuan Khoa Nguyen Xinghao Huang Aditya Ashok Sharda Yadav Yoonseok Park Mai Thanh Thai Nhat-Khuong Nguyen Hedieh Fallahi Shuhua Peng Sima Dimitrijev Yi-Chin Toh Yusuke Yamauchi Chun Hui Wang Nigel Hamilton Lovell John A. Rogers Thanh Nho Do Nam-Trung Nguyen Hangbo Zhao Hoang-Phuong Phan 《Advanced functional materials》2023,33(34):2211781
Wide bandgap (WBG) semiconductors have attracted significant research interest for the development of a broad range of flexible electronic applications, including wearable sensors, soft logical circuits, and long-term implanted neuromodulators. Conventionally, these materials are grown on standard silicon substrates, and then transferred onto soft polymers using mechanical stamping processes. This technique can retain the excellent electrical properties of wide bandgap materials after transfer and enables flexibility; however, most devices are constrained by 2D configurations that exhibit limited mechanical stretchability and morphologies compared with 3D biological systems. Herein, a stamping-free micromachining process is presented to realize, for the first time, 3D flexible and stretchable wide bandgap electronics. The approach applies photolithography on both sides of free-standing nanomembranes, which enables the formation of flexible architectures directly on standard silicon wafers to tailor the optical transparency and mechanical properties of the material. Subsequent detachment of the flexible devices from the support substrate and controlled mechanical buckling transforms the 2D precursors of wide band gap semiconductors into complex 3D mesoscale structures. The ability to fabricate wide band gap materials with 3D architectures that offer device-level stretchability combined with their multi-modal sensing capability will greatly facilitate the establishment of advanced 3D bio-electronics interfaces. 相似文献