The elegant 2D multiquantum (MQ) MAS NMR has been applied to investigate the coordination of Al atoms in SAPO-34. The results show that the effects of the template and/or water on the coordination of Al atoms are sig...The elegant 2D multiquantum (MQ) MAS NMR has been applied to investigate the coordination of Al atoms in SAPO-34. The results show that the effects of the template and/or water on the coordination of Al atoms are significant, which lead to the formation of various Al species. Up to four kinds of Al species are distinctly resolved.展开更多
High quality Zn base powder with low oxygen content, fine particle size and fine microstructure can be obtained by gas atomization using nitrogen. Cast and sintered Zn 27%Al alloys (ZMJ) were prepared. Tribological be...High quality Zn base powder with low oxygen content, fine particle size and fine microstructure can be obtained by gas atomization using nitrogen. Cast and sintered Zn 27%Al alloys (ZMJ) were prepared. Tribological behaviors of the cast and sintered alloys under lubricated and non lubricated conditions were studied and compared. Worn surfaces and microstructures of these alloys were examined. Results indicate that although the strength of the sintered alloy is considerably less than that of the cast alloy, the sintered alloy has a better wear resistance. The fine microstructure obtained by rapid solidification is beneficial to the wear resisting property. The wear volume of sintered ZMJ is only 36% and 59% of the wear volume that found in cast ZMJ under non lubricated and lubricated conditions, respectively. For lubricated wear test, abrasive wear is the major wear mechanism and for non lubricated wear test, oxidation wear and adhesive wear are the major wear mechanisms.展开更多
The cross sections of <sup>27</sup>Al（d,pα）<sup>24</sup>Na reaction have been measured as a func-tion of deuteron energy from the threshould to 22 MeV by the stacked foil technique.The influ...The cross sections of <sup>27</sup>Al（d,pα）<sup>24</sup>Na reaction have been measured as a func-tion of deuteron energy from the threshould to 22 MeV by the stacked foil technique.The influence of <sup>27</sup>Al（n,α）<sup>24</sup>Na has been considered in the present measurement.Acomparison is made between our data and other available results.展开更多
In this study,the effects of low temperature on aluminum(Ⅲ)(Al)hydrolysis were examined both theoretically and experimentally by constructing a solubility diagram for amorphous aluminum hydroxide(Al(OH)_3(am))and a d...In this study,the effects of low temperature on aluminum(Ⅲ)(Al)hydrolysis were examined both theoretically and experimentally by constructing a solubility diagram for amorphous aluminum hydroxide(Al(OH)_3(am))and a distribution diagram of hydrolyzed Al species.First,thermodynamic data of Al species at 4℃were calculated from that at 25℃.A well confirmed polymeric Al species, AlO_4Al_(12)(OH)_(24)^(7+)(Al_(13)),was involved in building the diagrams and,correspondingly,the non-linear simultaneous equations wit...展开更多
基金We are grateful to the support of the National Natural Science Foundation of China and the Ministry of Science and Technology of China. We appreciate Dr. R. Fu (NHMFL Tallahassee) for his kind help regarding the MQ MAS NMR experiments.
文摘The elegant 2D multiquantum (MQ) MAS NMR has been applied to investigate the coordination of Al atoms in SAPO-34. The results show that the effects of the template and/or water on the coordination of Al atoms are significant, which lead to the formation of various Al species. Up to four kinds of Al species are distinctly resolved.
文摘High quality Zn base powder with low oxygen content, fine particle size and fine microstructure can be obtained by gas atomization using nitrogen. Cast and sintered Zn 27%Al alloys (ZMJ) were prepared. Tribological behaviors of the cast and sintered alloys under lubricated and non lubricated conditions were studied and compared. Worn surfaces and microstructures of these alloys were examined. Results indicate that although the strength of the sintered alloy is considerably less than that of the cast alloy, the sintered alloy has a better wear resistance. The fine microstructure obtained by rapid solidification is beneficial to the wear resisting property. The wear volume of sintered ZMJ is only 36% and 59% of the wear volume that found in cast ZMJ under non lubricated and lubricated conditions, respectively. For lubricated wear test, abrasive wear is the major wear mechanism and for non lubricated wear test, oxidation wear and adhesive wear are the major wear mechanisms.
文摘The cross sections of <sup>27</sup>Al（d,pα）<sup>24</sup>Na reaction have been measured as a func-tion of deuteron energy from the threshould to 22 MeV by the stacked foil technique.The influence of <sup>27</sup>Al（n,α）<sup>24</sup>Na has been considered in the present measurement.Acomparison is made between our data and other available results.
文摘In this study,the effects of low temperature on aluminum(Ⅲ)(Al)hydrolysis were examined both theoretically and experimentally by constructing a solubility diagram for amorphous aluminum hydroxide(Al(OH)_3(am))and a distribution diagram of hydrolyzed Al species.First,thermodynamic data of Al species at 4℃were calculated from that at 25℃.A well confirmed polymeric Al species, AlO_4Al_(12)(OH)_(24)^(7+)(Al_(13)),was involved in building the diagrams and,correspondingly,the non-linear simultaneous equations wit...
