Zero net-liquid flow (ZNLF) is a special case of upward gas-liquid two-phase flow. It is a phenomenon observed as a gas-liquid mixture flows in a conduit but the net liquid flow rate is zero. Investigation on the liqu...Zero net-liquid flow (ZNLF) is a special case of upward gas-liquid two-phase flow. It is a phenomenon observed as a gas-liquid mixture flows in a conduit but the net liquid flow rate is zero. Investigation on the liquid holdup of ZNLF is conducted in a vertical ten-meter tube with diameter of 76 mm, both for Newtonian and nonNewtonian fluids. The gas phase is air. The Newtonian fluid is water and the non-Newtonian fluids are water-based guar gel solutions. The correlations developed for predicting liquid holdup on the basis of Lockhart-Martinelli parameter are not suitable to ZNLF. A constitutive correlation for the liquid holdup of vertical ZNLF was put forward by using the mass balance. It is found that the liquid holdup in ZNLF is dependent on both the gas flow rate and the flow distribution coefficient.展开更多
A novel chemical liquid reduction process was employed to prepare nanosized Mo-Cu powders. The precipitates were first obtained by adding ammonium heptamolybdate （（NH4）6Mo7024·4H2O） solution into excess hydra...A novel chemical liquid reduction process was employed to prepare nanosized Mo-Cu powders. The precipitates were first obtained by adding ammonium heptamolybdate （（NH4）6Mo7024·4H2O） solution into excess hydrazine hydrate solution, and then mixed the copper chloride solution. The precipitates were subsequently washed, dried, followed by reducing in H2 atmosphere to convert into Mo-Cu composite powders. The composition, morphology and particle size of the Mo-Cu composite powders were characterized by the XRD, SEM and TEM. The effects of the chemical reaction temperature and the magnetic stirring on the morphology of the Mo-Cu powders were also studied. The results show that Mo-Cu powders produced by the chemical liquid reduction process are nearly spherical shape and dispersive distribution state, with particle size ranging from 50 to 100 nm. The chemical reaction temperature and magnetic stirring will change the particle feature of the powders. Because of the Cu3M0209, the reduction process in H2 is the one-stage reduction from the precipitates to the Mo-Cu composite powders.展开更多
[Objective] The aim was to conduct HPLC analysis on Cordyceps Sinensis/Betaine compound feed nutriment. [Method] Cordyceps Sinensis/Betaine compound feed nutriment was under HPLC analysis to determine separation of Co...[Objective] The aim was to conduct HPLC analysis on Cordyceps Sinensis/Betaine compound feed nutriment. [Method] Cordyceps Sinensis/Betaine compound feed nutriment was under HPLC analysis to determine separation of Cordyceps Sinensis effluent and betaine. [Result] Different compositions in Cordyceps Sinensis/etaine compound feed nutriment would be well separated by the method. [Conclusion] The method provides a suitable platform of separation and analysis for Cordyceps Sinensis /Betaine compound feed nutriment.展开更多
文摘Zero net-liquid flow (ZNLF) is a special case of upward gas-liquid two-phase flow. It is a phenomenon observed as a gas-liquid mixture flows in a conduit but the net liquid flow rate is zero. Investigation on the liquid holdup of ZNLF is conducted in a vertical ten-meter tube with diameter of 76 mm, both for Newtonian and nonNewtonian fluids. The gas phase is air. The Newtonian fluid is water and the non-Newtonian fluids are water-based guar gel solutions. The correlations developed for predicting liquid holdup on the basis of Lockhart-Martinelli parameter are not suitable to ZNLF. A constitutive correlation for the liquid holdup of vertical ZNLF was put forward by using the mass balance. It is found that the liquid holdup in ZNLF is dependent on both the gas flow rate and the flow distribution coefficient.
基金Project(51274246) supported by the National Natural Science Foundation of China
文摘A novel chemical liquid reduction process was employed to prepare nanosized Mo-Cu powders. The precipitates were first obtained by adding ammonium heptamolybdate （（NH4）6Mo7024·4H2O） solution into excess hydrazine hydrate solution, and then mixed the copper chloride solution. The precipitates were subsequently washed, dried, followed by reducing in H2 atmosphere to convert into Mo-Cu composite powders. The composition, morphology and particle size of the Mo-Cu composite powders were characterized by the XRD, SEM and TEM. The effects of the chemical reaction temperature and the magnetic stirring on the morphology of the Mo-Cu powders were also studied. The results show that Mo-Cu powders produced by the chemical liquid reduction process are nearly spherical shape and dispersive distribution state, with particle size ranging from 50 to 100 nm. The chemical reaction temperature and magnetic stirring will change the particle feature of the powders. Because of the Cu3M0209, the reduction process in H2 is the one-stage reduction from the precipitates to the Mo-Cu composite powders.
文摘[Objective] The aim was to conduct HPLC analysis on Cordyceps Sinensis/Betaine compound feed nutriment. [Method] Cordyceps Sinensis/Betaine compound feed nutriment was under HPLC analysis to determine separation of Cordyceps Sinensis effluent and betaine. [Result] Different compositions in Cordyceps Sinensis/etaine compound feed nutriment would be well separated by the method. [Conclusion] The method provides a suitable platform of separation and analysis for Cordyceps Sinensis /Betaine compound feed nutriment.
