The formation mechanisms and growth kinetics of Al3 Ni and Al3Ni2 in Ni-Al diffusion couple prepared by electrodeposition of Ni on Al substrate were investigated. The nickel coating with 20 μm thickness was applied o...The formation mechanisms and growth kinetics of Al3 Ni and Al3Ni2 in Ni-Al diffusion couple prepared by electrodeposition of Ni on Al substrate were investigated. The nickel coating with 20 μm thickness was applied on 6061 aluminum alloy by direct current electroplating. The samples were then heat-treated for different durations at 450, 500 and 550 °C under argon atmosphere. The intermetallic phases were identified by means of scanning electron microscopy（SEM）, energy dispersive spectrometry（EDS） and X-ray diffraction（XRD）. The results showed that the formation of intermetallic phases consisted of two important steps. The first step was the lateral growth of intermetallic phase from separate sites, resulting in the formation of a continuous layer. The second step was the growth of the continuous intermetallic layer in the direction perpendicular to the interface. However, excessive increase in thickness of intermetallic phases led to the detachment of reaction products, i.e., Al3 Ni and Al3Ni2, from the substrate. It was also observed that aluminum was the dominant diffusing element during Al3 Ni growth, while nickel diffusion was dominant during Al3Ni2 growth. The growth kinetics of both Al3 Ni and Al3Ni2 phases obeyed a parabolic law.展开更多
At the present time, more than one-half of all cancer patients are treated with radiation therapy. Despite a good therapeutic index, radiotherapy can disable normal tissue injury to normal tissues in long-term cancer ...At the present time, more than one-half of all cancer patients are treated with radiation therapy. Despite a good therapeutic index, radiotherapy can disable normal tissue injury to normal tissues in long-term cancer survivors.Thus, an important challenge to modern radiation therapy is to increase the tolerance of normal tissues,展开更多
Typical wastes from nickel plating operations include excess drag-out solution. An electrochemical approach was made to recover the nickel and remove the organic pollutants from the spent electroless nickelplating bat...Typical wastes from nickel plating operations include excess drag-out solution. An electrochemical approach was made to recover the nickel and remove the organic pollutants from the spent electroless nickelplating bath. An electrolyte cell which was constructed by the cathode of porous nickel foam and the anode of Ti/RuO2 was used. During electrolysis, the nickel ion was electrodeposited at the cathode and the oxidation of the organics in the hath was conducted at the anode. The current （i） , time （t） , temperature （T） and pH of the solution affected the recovery efficiency of nickel with constant potential electrolysis. With the optimum experimental conditions of pH=7.6, i = 0.45 A. T = 65℃ andt = 2 h, the concentration of nickel ion was reduced from 2.09 g/L to 0. 053 g/L and the recovery rate of nickel, the current efficiency and the consumed energy wer 97.5%, 17. 1%, 12.2 kWh/kg Ni, respectively. Meanwhile, total organic carbon （TOC） of the bath was reduced from 5 800 mg/L to 152.5 mg/L and the removal efficiency of TOC was 97.3%. The recovery rate of nickel could keep to about 97% when eleetrodeposit was used to recover nickel for 40 hours in a laboratol.w batch reactor containing the spent bath. Dull nickel containing phosphorus was obtained on the cathode.展开更多
Objective: To study extracellular multi-neuron activity in the nervous system based on wavelet-fractal technique. Methods: The wavelet transform was employed to decompose the original signal and obtain 4 sub-patterns....Objective: To study extracellular multi-neuron activity in the nervous system based on wavelet-fractal technique. Methods: The wavelet transform was employed to decompose the original signal and obtain 4 sub-patterns. The dividing fractal dimensions of these sub-patterns were computed. A knn-classier was used to classify feature vectors. Results: Not all the elements in feature vector DimDC were very powerful for this pattern recognition problem through the empirical study of noise signals. The most effective feature vector was defined as DimDC= (d3:d4) above. Conclusion:Wavelet fractal algorithm has high accuracy and provides a powerful tool for clinical application.展开更多
To summarize surgical treatments an d their corresponding curative effects on sciatic nerve injuries. Methods: Surgical treatments on sciatic nerve injury were perfo rmed in 28 patients from January 1990 to July 2000....To summarize surgical treatments an d their corresponding curative effects on sciatic nerve injuries. Methods: Surgical treatments on sciatic nerve injury were perfo rmed in 28 patients from January 1990 to July 2000. The treatments included neur olysis, neurolysis plus partial nerve anastomosis, nerve anastomosis and nerve t ransplantation. The curative effect was evaluated according to Sunderland criter ia. Results: Of 28 cases, 22 patients were followed up with a follo w up period of 13 months to 5 years (average 30 months). Of 22 nerves, 7 were e xcellent, 5 good, 7 fair and 3 poor, with an excellence rate of 54.5 %. Conclusions: The fair results of sciatic nerve injury are relat ed to its structural character. Surgical exploration should be performed if nerv e function does not recover 3 months after primary operation and if Tinels sig n and electromyogram show no signs of nerve regeneration. Electrophysiological m onitoring in the operation is useful in electing surgical methods and predicting the results of nerve anastomosis.展开更多
文摘The formation mechanisms and growth kinetics of Al3 Ni and Al3Ni2 in Ni-Al diffusion couple prepared by electrodeposition of Ni on Al substrate were investigated. The nickel coating with 20 μm thickness was applied on 6061 aluminum alloy by direct current electroplating. The samples were then heat-treated for different durations at 450, 500 and 550 °C under argon atmosphere. The intermetallic phases were identified by means of scanning electron microscopy（SEM）, energy dispersive spectrometry（EDS） and X-ray diffraction（XRD）. The results showed that the formation of intermetallic phases consisted of two important steps. The first step was the lateral growth of intermetallic phase from separate sites, resulting in the formation of a continuous layer. The second step was the growth of the continuous intermetallic layer in the direction perpendicular to the interface. However, excessive increase in thickness of intermetallic phases led to the detachment of reaction products, i.e., Al3 Ni and Al3Ni2, from the substrate. It was also observed that aluminum was the dominant diffusing element during Al3 Ni growth, while nickel diffusion was dominant during Al3Ni2 growth. The growth kinetics of both Al3 Ni and Al3Ni2 phases obeyed a parabolic law.
文摘At the present time, more than one-half of all cancer patients are treated with radiation therapy. Despite a good therapeutic index, radiotherapy can disable normal tissue injury to normal tissues in long-term cancer survivors.Thus, an important challenge to modern radiation therapy is to increase the tolerance of normal tissues,
文摘Typical wastes from nickel plating operations include excess drag-out solution. An electrochemical approach was made to recover the nickel and remove the organic pollutants from the spent electroless nickelplating bath. An electrolyte cell which was constructed by the cathode of porous nickel foam and the anode of Ti/RuO2 was used. During electrolysis, the nickel ion was electrodeposited at the cathode and the oxidation of the organics in the hath was conducted at the anode. The current （i） , time （t） , temperature （T） and pH of the solution affected the recovery efficiency of nickel with constant potential electrolysis. With the optimum experimental conditions of pH=7.6, i = 0.45 A. T = 65℃ andt = 2 h, the concentration of nickel ion was reduced from 2.09 g/L to 0. 053 g/L and the recovery rate of nickel, the current efficiency and the consumed energy wer 97.5%, 17. 1%, 12.2 kWh/kg Ni, respectively. Meanwhile, total organic carbon （TOC） of the bath was reduced from 5 800 mg/L to 152.5 mg/L and the removal efficiency of TOC was 97.3%. The recovery rate of nickel could keep to about 97% when eleetrodeposit was used to recover nickel for 40 hours in a laboratol.w batch reactor containing the spent bath. Dull nickel containing phosphorus was obtained on the cathode.
基金Supported by the National Natural Science Foundation of China (No. 60371034)
文摘Objective: To study extracellular multi-neuron activity in the nervous system based on wavelet-fractal technique. Methods: The wavelet transform was employed to decompose the original signal and obtain 4 sub-patterns. The dividing fractal dimensions of these sub-patterns were computed. A knn-classier was used to classify feature vectors. Results: Not all the elements in feature vector DimDC were very powerful for this pattern recognition problem through the empirical study of noise signals. The most effective feature vector was defined as DimDC= (d3:d4) above. Conclusion:Wavelet fractal algorithm has high accuracy and provides a powerful tool for clinical application.
文摘To summarize surgical treatments an d their corresponding curative effects on sciatic nerve injuries. Methods: Surgical treatments on sciatic nerve injury were perfo rmed in 28 patients from January 1990 to July 2000. The treatments included neur olysis, neurolysis plus partial nerve anastomosis, nerve anastomosis and nerve t ransplantation. The curative effect was evaluated according to Sunderland criter ia. Results: Of 28 cases, 22 patients were followed up with a follo w up period of 13 months to 5 years (average 30 months). Of 22 nerves, 7 were e xcellent, 5 good, 7 fair and 3 poor, with an excellence rate of 54.5 %. Conclusions: The fair results of sciatic nerve injury are relat ed to its structural character. Surgical exploration should be performed if nerv e function does not recover 3 months after primary operation and if Tinels sig n and electromyogram show no signs of nerve regeneration. Electrophysiological m onitoring in the operation is useful in electing surgical methods and predicting the results of nerve anastomosis.
