The objective of this work was to investigate nucleate pool boiling heat transfer performance and mechanism of R134a and R142b on a twisted tube with machine processed porous surface （T-MPPS tube） as well as to dete...The objective of this work was to investigate nucleate pool boiling heat transfer performance and mechanism of R134a and R142b on a twisted tube with machine processed porous surface （T-MPPS tube） as well as to determine its potential application to flooded refrigerant evaporators. In the experimental range, the boiling heat transfer coefficients of R134a on a T-MPPS tube were 1.8-2.0 times larger than those of R134a on a plain tube. In addition, the developed experimental correlations verified that the predictions of the heat transfer coefficients of boiling R134a and R142bon a T-MPPS tube at the experimental conditions were considerably accurate.展开更多
We introduce a class of singular integral operators on product domains along twisted surfaces.We prove that the operators are bounded on L^(p) provided that the kernels satisfy weak conditions.
Porous single crystals would significantly enhance their catalysis functionalities owing to the combination of structural coherence and porous microstructures. Porous single crystals have wormhole microstructures and ...Porous single crystals would significantly enhance their catalysis functionalities owing to the combination of structural coherence and porous microstructures. Porous single crystals have wormhole microstructures and then we define them as wormcrystals. The twisted surfaces in porous microstructures would produce surface lattice distortions that give rise to high-energy active surfaces. Here we grow porous iron single crystals at an unprecedented 2 cm scale with a lattice reconstruction strategy and create high-energy surfaces through the control of lattice distortions within a thickness region of 1~2 nm. The porous iron crystal therefore boosts electrochemical reduction of nitrobenzene to aminobenzene with ~100% conversion and > 95% selectivity. The exceptionally high current densities with porous iron crystals represent the first level electrocatalysis performance. The current work would open a new pathway not only to the creation of high energy surfaces but also to the growth of porous single crystals at large scales in wealth of other materials.展开更多
基金the Guangdong Provincial Scientific and Technological Development Program (2004B10201008)
文摘The objective of this work was to investigate nucleate pool boiling heat transfer performance and mechanism of R134a and R142b on a twisted tube with machine processed porous surface （T-MPPS tube） as well as to determine its potential application to flooded refrigerant evaporators. In the experimental range, the boiling heat transfer coefficients of R134a on a T-MPPS tube were 1.8-2.0 times larger than those of R134a on a plain tube. In addition, the developed experimental correlations verified that the predictions of the heat transfer coefficients of boiling R134a and R142bon a T-MPPS tube at the experimental conditions were considerably accurate.
文摘We introduce a class of singular integral operators on product domains along twisted surfaces.We prove that the operators are bounded on L^(p) provided that the kernels satisfy weak conditions.
基金supported by the Natural Science Foundation of China (91845202,21750110433)Dalian National Laboratory for Clean Energy (DNL180404)Strategic Priority Research Program of Chinese Academy of Sciences (XDB2000000)。
文摘Porous single crystals would significantly enhance their catalysis functionalities owing to the combination of structural coherence and porous microstructures. Porous single crystals have wormhole microstructures and then we define them as wormcrystals. The twisted surfaces in porous microstructures would produce surface lattice distortions that give rise to high-energy active surfaces. Here we grow porous iron single crystals at an unprecedented 2 cm scale with a lattice reconstruction strategy and create high-energy surfaces through the control of lattice distortions within a thickness region of 1~2 nm. The porous iron crystal therefore boosts electrochemical reduction of nitrobenzene to aminobenzene with ~100% conversion and > 95% selectivity. The exceptionally high current densities with porous iron crystals represent the first level electrocatalysis performance. The current work would open a new pathway not only to the creation of high energy surfaces but also to the growth of porous single crystals at large scales in wealth of other materials.
