A reaction-diffusion model for a single species with age structure and nonlocal reaction for periodic time t is derived. Some results about the model with monotone birth function are firstly introduced, and then by co...A reaction-diffusion model for a single species with age structure and nonlocal reaction for periodic time t is derived. Some results about the model with monotone birth function are firstly introduced, and then by constructing two auxiliary equations and squeezing method, the spreading speed for the system with nonmonotone birth function is obtained.展开更多
Mixture of phosphoric and sulfuric acid solutions has been used to investigate the dissolution of natural phosphates (PN) by DRC. The effect of concentration, particle size and stirring speed reaction is examined. The...Mixture of phosphoric and sulfuric acid solutions has been used to investigate the dissolution of natural phosphates (PN) by DRC. The effect of concentration, particle size and stirring speed reaction is examined. Thermochimique properties of each kinetic parameters reaction are determined. It was found that these parameters have a considerable effect on the thermochemical aspect of the attack reaction. It is known that the process of PN sulphophosphoric acid attack leads to the formation of dihydrate (CaSO4.2H2O: DH). The present work shows the precipitation of other residues their formula depends on factors studied. The increase in concentration leads to the formation of hemihydrate (CaSO4v1/2H2O:HH) beside DH for the low values of% H2SO4 due to the solubility of dihydrate on the etching solution and the precipitation of (Ca (H2PO4)2.2H2O) next of DH for low agitation values because of the lack of turbulence between the liquid phase and the solid phase which favors the precipitation of this latter compound.展开更多
In order to achieve high speed of tufting machine,the oval gear is used as the transmission mechanism between the main shaft and the slave shaft. And then,mathematical model of tufting machine spindle system is establ...In order to achieve high speed of tufting machine,the oval gear is used as the transmission mechanism between the main shaft and the slave shaft. And then,mathematical model of tufting machine spindle system is established by transfer matrix method.Finally,the dynamic reaction force of the connection and the unbalanced response of the joint between the general tufting machine and the improved spindle system are studied by using Matlab numerical simulation. The analysis results showthat when the spindle speed reaches 1 000 r/min, the dynamic reaction force of the improved spindle system at the joint is far less than that of the general tufting machine,and the unbalanced response is reduced from 0. 22 mm to 0. 10 mm.展开更多
基金Supported by the NSF of China(11171120)Supported by the Doctoral Program of Higher Education of China(20094407110001)Supported by the NSF of Guangdong Province(10151063101000003)
文摘A reaction-diffusion model for a single species with age structure and nonlocal reaction for periodic time t is derived. Some results about the model with monotone birth function are firstly introduced, and then by constructing two auxiliary equations and squeezing method, the spreading speed for the system with nonmonotone birth function is obtained.
文摘Mixture of phosphoric and sulfuric acid solutions has been used to investigate the dissolution of natural phosphates (PN) by DRC. The effect of concentration, particle size and stirring speed reaction is examined. Thermochimique properties of each kinetic parameters reaction are determined. It was found that these parameters have a considerable effect on the thermochemical aspect of the attack reaction. It is known that the process of PN sulphophosphoric acid attack leads to the formation of dihydrate (CaSO4.2H2O: DH). The present work shows the precipitation of other residues their formula depends on factors studied. The increase in concentration leads to the formation of hemihydrate (CaSO4v1/2H2O:HH) beside DH for the low values of% H2SO4 due to the solubility of dihydrate on the etching solution and the precipitation of (Ca (H2PO4)2.2H2O) next of DH for low agitation values because of the lack of turbulence between the liquid phase and the solid phase which favors the precipitation of this latter compound.
文摘In order to achieve high speed of tufting machine,the oval gear is used as the transmission mechanism between the main shaft and the slave shaft. And then,mathematical model of tufting machine spindle system is established by transfer matrix method.Finally,the dynamic reaction force of the connection and the unbalanced response of the joint between the general tufting machine and the improved spindle system are studied by using Matlab numerical simulation. The analysis results showthat when the spindle speed reaches 1 000 r/min, the dynamic reaction force of the improved spindle system at the joint is far less than that of the general tufting machine,and the unbalanced response is reduced from 0. 22 mm to 0. 10 mm.
