It is a great challenge to finely tune the morphology of iron oxides for energy storage. In this work, we introduced a facile hydrothermal method to obtain single crystalline hematite （α-Fe2O3） nano-coffee beans （...It is a great challenge to finely tune the morphology of iron oxides for energy storage. In this work, we introduced a facile hydrothermal method to obtain single crystalline hematite （α-Fe2O3） nano-coffee beans （NCBs） with the assistance of acetic acid. Interestingly, α-Fe2O3 nanos- tructures with this special morphology were formed under the effect of Ostwald ripening and oriented etching of H^＋ ions along [001] direction, which could be proved by the scanning electron microscope/transmission electron microscope and X-ray diffraction. After calcination at high temperature, the as-prepared α-Fe2O3 NCBs were used as potential anode ma- terials, showing a very high reversible capacity of 810 mA h g^-1 （0.2 C）, excellent cycling stability, and high-rate performance for lithium storage. Hence, in virtue of the good performances, the structural design of nanomaterials would be promoted in the fabrication of electrode materials for lithiumion batteries.展开更多
通过设计四因素三水平正交试验,进行了水胶比、粉煤灰掺量、砂率和沙漠砂替代率不同沙漠砂混凝土28 d抗压强度和抗氯离子渗透性能试验,分析了各因素对C40沙漠砂混凝土28 d抗压强度和抗氯离子渗透性能影响。研究表明:对于沙漠砂混凝土28 ...通过设计四因素三水平正交试验,进行了水胶比、粉煤灰掺量、砂率和沙漠砂替代率不同沙漠砂混凝土28 d抗压强度和抗氯离子渗透性能试验,分析了各因素对C40沙漠砂混凝土28 d抗压强度和抗氯离子渗透性能影响。研究表明:对于沙漠砂混凝土28 d抗压强度,水胶比影响最大,粉煤灰掺量次之,沙漠砂替代率第三,砂率最小;对于28 d龄期沙漠砂混凝土电通量,粉煤灰掺量影响最大,水胶比次之,砂率第三,沙漠砂替代率最小。Resistance to the permeability of chloride ion of C40 desert sand展开更多
Recently, the L-mode to H-mode (L-H) transition in tokamak plasma confinement was found to be related to the presence of the poloidal flow shear near the plasma edge. An important mechanism is the ion orbit loss cause...Recently, the L-mode to H-mode (L-H) transition in tokamak plasma confinement was found to be related to the presence of the poloidal flow shear near the plasma edge. An important mechanism is the ion orbit loss caused by interaction with the limiter. A complementary explanation is the generation of poloidal flows by plasma fluctuations via the Reynolds stress and the poloidal spin-up of plasmas from poloidal asymmetryof particle and momentum sources.展开更多
The advantages of pellet injection as a competitive means of fuelling a tokamak are well known. They include： （ 1 ） deep deposition of fuel, （ 2 ） better fuelling efficiency, （ 3 ） purer plasma, and so on. Mea...The advantages of pellet injection as a competitive means of fuelling a tokamak are well known. They include： （ 1 ） deep deposition of fuel, （ 2 ） better fuelling efficiency, （ 3 ） purer plasma, and so on. Meanwhile, improving plasma performance by pellet injection has been proven in many tokamak experiments. The deposition of pellet particles following pellet injection causes a temporal change of the local plasma temperature and density gradients which affects the transport properties of the plasma, so pellet injection can be used as a method of studying the transport process as well.展开更多
基金supported by the National Natural Science Foundation of China (21671096 and 21603094)the Natural Science Foundation of Guangdong Province (2016A030310376)+3 种基金Shenzhen Key Laboratory Project (ZDSYS201603311013489)the Natural Science Foundation of Shenzhen (JCYJ20150630145302231 and JCYJ20150331101823677)the 61~(th) China Postdoctoral Science Foundation (2017M610485)the Innovative Entrepreneurship Training Program of Southern University of Science and Technology (2016S14 and 2017X07)
文摘It is a great challenge to finely tune the morphology of iron oxides for energy storage. In this work, we introduced a facile hydrothermal method to obtain single crystalline hematite （α-Fe2O3） nano-coffee beans （NCBs） with the assistance of acetic acid. Interestingly, α-Fe2O3 nanos- tructures with this special morphology were formed under the effect of Ostwald ripening and oriented etching of H^＋ ions along [001] direction, which could be proved by the scanning electron microscope/transmission electron microscope and X-ray diffraction. After calcination at high temperature, the as-prepared α-Fe2O3 NCBs were used as potential anode ma- terials, showing a very high reversible capacity of 810 mA h g^-1 （0.2 C）, excellent cycling stability, and high-rate performance for lithium storage. Hence, in virtue of the good performances, the structural design of nanomaterials would be promoted in the fabrication of electrode materials for lithiumion batteries.
文摘通过设计四因素三水平正交试验,进行了水胶比、粉煤灰掺量、砂率和沙漠砂替代率不同沙漠砂混凝土28 d抗压强度和抗氯离子渗透性能试验,分析了各因素对C40沙漠砂混凝土28 d抗压强度和抗氯离子渗透性能影响。研究表明:对于沙漠砂混凝土28 d抗压强度,水胶比影响最大,粉煤灰掺量次之,沙漠砂替代率第三,砂率最小;对于28 d龄期沙漠砂混凝土电通量,粉煤灰掺量影响最大,水胶比次之,砂率第三,沙漠砂替代率最小。Resistance to the permeability of chloride ion of C40 desert sand
文摘Recently, the L-mode to H-mode (L-H) transition in tokamak plasma confinement was found to be related to the presence of the poloidal flow shear near the plasma edge. An important mechanism is the ion orbit loss caused by interaction with the limiter. A complementary explanation is the generation of poloidal flows by plasma fluctuations via the Reynolds stress and the poloidal spin-up of plasmas from poloidal asymmetryof particle and momentum sources.
文摘The advantages of pellet injection as a competitive means of fuelling a tokamak are well known. They include： （ 1 ） deep deposition of fuel, （ 2 ） better fuelling efficiency, （ 3 ） purer plasma, and so on. Meanwhile, improving plasma performance by pellet injection has been proven in many tokamak experiments. The deposition of pellet particles following pellet injection causes a temporal change of the local plasma temperature and density gradients which affects the transport properties of the plasma, so pellet injection can be used as a method of studying the transport process as well.
