A 2-D numerical model was developed to predict the shape of weld pool in stationary GTA welding of commercial pure aluminium, without considering fluid flow in the weld pool. A Gaussian current density and heat input ...A 2-D numerical model was developed to predict the shape of weld pool in stationary GTA welding of commercial pure aluminium, without considering fluid flow in the weld pool. A Gaussian current density and heat input distribution on the surface of the workpiece were considered. The parameters of Gaussian distribution were modified by comparing calculated results with experimental ones. It was found that these distribution parameters are fimctions of applied current and arc length. Effects of arc length, applied current and welding time on the geometry of the weld pool were investigated. To check the validity of the model, a series of experiments were also conducted. In general, the agreement between calculated overall shape of the weld pool and the experimental one was acceptable, especially in low applied currents. Therefore, it can be concluded that in pure aluminium, the heat conduction is dominant mechanism of heat transfer in the weld pool.展开更多
A method for preparation of particle crystal film constructed from monodisperse silica colloidal particles in diameter of about 300 nm is reported. The films were prepared from an ethanol suspension by vertical deposi...A method for preparation of particle crystal film constructed from monodisperse silica colloidal particles in diameter of about 300 nm is reported. The films were prepared from an ethanol suspension by vertical deposition that relies on capillary forces to assemble colloidal crystal particles on a vertical substrate. The 3D ordered films were characterized by transmission spectra and scanning electric microscope (SEM). The effect of evaporation temperature, particle concentration and sintered temperature on the quality of colloidal particle crystal film was investigated.展开更多
Objective： To discuss the biodistribution of ^99mTc-Ciprofloxacin （^99mTc-CPF） and its effectiveness of imaging in infection disease in mice. Methods： CPF was labeled with ^99mTc and its radiochemical purity and l...Objective： To discuss the biodistribution of ^99mTc-Ciprofloxacin （^99mTc-CPF） and its effectiveness of imaging in infection disease in mice. Methods： CPF was labeled with ^99mTc and its radiochemical purity and labeling rate were measured. Mice model of infection was established and the biodistribution of ^99m Tc-CPF in the model and whole-body scintigraphy were achieved. Results： ^99mTc-Ciprotech was stable within 6 hours at room temperature. The labeling rate of ^99mTc-CPF was over 90%. Most of radioactivity was cleared in liver and kidney, and the clearance from blood was rapid. Both biodistribution and imaging results showed a high uptake of ^99mTc-CPF in infection site. The infection tissue/normal tissue reached a peak as 4.30 at 4 h after injection. Condusion： ^99mTc-CPF is a sensitive radiopharmaceutical agent for scintigraphy of infection lesions, and it is easy to prepare.展开更多
Proposed new cubic equation of state is more accurate than others in result and simple in form. The equation has been tried with 23 pure compounds including both polar and non-polar compounds. Experimental values of t...Proposed new cubic equation of state is more accurate than others in result and simple in form. The equation has been tried with 23 pure compounds including both polar and non-polar compounds. Experimental values of these compounds collected from various journals were compared with proposed model and found to be more accurate than other widely used cubic equations of state like SRK and Peng Robinson. The form of current EOS best suits to PVT data and total error is almost halved for a set of experimental data in the most cases.展开更多
文摘A 2-D numerical model was developed to predict the shape of weld pool in stationary GTA welding of commercial pure aluminium, without considering fluid flow in the weld pool. A Gaussian current density and heat input distribution on the surface of the workpiece were considered. The parameters of Gaussian distribution were modified by comparing calculated results with experimental ones. It was found that these distribution parameters are fimctions of applied current and arc length. Effects of arc length, applied current and welding time on the geometry of the weld pool were investigated. To check the validity of the model, a series of experiments were also conducted. In general, the agreement between calculated overall shape of the weld pool and the experimental one was acceptable, especially in low applied currents. Therefore, it can be concluded that in pure aluminium, the heat conduction is dominant mechanism of heat transfer in the weld pool.
基金Supported by the Chinese National Key Basic Research Special Fund (No.2001CB6104) and the National Natural Science Foundation of China(No.20076027)
文摘A method for preparation of particle crystal film constructed from monodisperse silica colloidal particles in diameter of about 300 nm is reported. The films were prepared from an ethanol suspension by vertical deposition that relies on capillary forces to assemble colloidal crystal particles on a vertical substrate. The 3D ordered films were characterized by transmission spectra and scanning electric microscope (SEM). The effect of evaporation temperature, particle concentration and sintered temperature on the quality of colloidal particle crystal film was investigated.
文摘Objective： To discuss the biodistribution of ^99mTc-Ciprofloxacin （^99mTc-CPF） and its effectiveness of imaging in infection disease in mice. Methods： CPF was labeled with ^99mTc and its radiochemical purity and labeling rate were measured. Mice model of infection was established and the biodistribution of ^99m Tc-CPF in the model and whole-body scintigraphy were achieved. Results： ^99mTc-Ciprotech was stable within 6 hours at room temperature. The labeling rate of ^99mTc-CPF was over 90%. Most of radioactivity was cleared in liver and kidney, and the clearance from blood was rapid. Both biodistribution and imaging results showed a high uptake of ^99mTc-CPF in infection site. The infection tissue/normal tissue reached a peak as 4.30 at 4 h after injection. Condusion： ^99mTc-CPF is a sensitive radiopharmaceutical agent for scintigraphy of infection lesions, and it is easy to prepare.
文摘Proposed new cubic equation of state is more accurate than others in result and simple in form. The equation has been tried with 23 pure compounds including both polar and non-polar compounds. Experimental values of these compounds collected from various journals were compared with proposed model and found to be more accurate than other widely used cubic equations of state like SRK and Peng Robinson. The form of current EOS best suits to PVT data and total error is almost halved for a set of experimental data in the most cases.
