This paper presents a novel mega-Hz-level super high frequency zero-voltage soft-switching converter for induction heating power supplies. The prominent advantage of this topology is that it can absorb both inductive ...This paper presents a novel mega-Hz-level super high frequency zero-voltage soft-switching converter for induction heating power supplies. The prominent advantage of this topology is that it can absorb both inductive and capacitive parasitic components in the converter. The switch devices operate in a zero-voltage soft-switching mode. Consequently, the high voltage and high current spikes caused by parasitic inductors or capacitors oscillation do not occur in this circuit, and the high power loss caused by high frequency switching can be greatly reduced. A large value inductor is adopted between the input capacitor and the switches, thus, this novel converter shares the benefits of both voltage-type and current-type circuits simultaneously, and there are no needs of dead time between two switches. The working principles in different modes are introduced. Results of simulation and experiments operated at around 1 MHz frequency verify the validity of parasitic components absorption and show that this convener is competent for super high frequency applications.展开更多
The objective of this investigation was to study whether it is possible to determine the air tightness of covered slurry storage tanks using tracer gas technique by injection of sulphur hexafluoride （SF6） and measur...The objective of this investigation was to study whether it is possible to determine the air tightness of covered slurry storage tanks using tracer gas technique by injection of sulphur hexafluoride （SF6） and measurements of the decay in gas concentrations with an infrared spectrophotometer in the air space above the slurry. By measuring the decay in concentration of injected tracer gas at different occasions, the air exchange rate was determined. Three different types of coverings were studied namely; wooden roof, plastic tent and concrete roof.展开更多
Efficient parallel screening of combinatorial libraries is one of the most challenging aspects of the high- throughput （HT） heterogeneous catalysis workflow. Today, a number of methods have been used in HT catalyst ...Efficient parallel screening of combinatorial libraries is one of the most challenging aspects of the high- throughput （HT） heterogeneous catalysis workflow. Today, a number of methods have been used in HT catalyst studies, including various optical, mass-spectrometry, and gas- chromatography techniques. Of these, rapid-scanning Fourier-transform infrared （FTIR） imaging is one of the fastest and most versatile screening techniques. Here, the new design of the 16-channel HT reactor is presented and test results for its accuracy and reproducibility are shown. The performance of the system was evaluated through the oxidation of CO over commercial Pd/AI203 and cobalt oxide nanoparticles synthesized with different reducer-reductant molar ratios, surfactant types, metal and surfactant concentrations, synthesis temperatures, and ramp rates.展开更多
Objective: Bronchopleural fistula (BPF) is a life threatening complication after pneumonectomy. Extra thoracic skeletal muscle transposition especially latissimus dorsi muscle flap (LDMF) had been used to prevent this...Objective: Bronchopleural fistula (BPF) is a life threatening complication after pneumonectomy. Extra thoracic skeletal muscle transposition especially latissimus dorsi muscle flap (LDMF) had been used to prevent this complication. The aim of this study was to assess the effectiveness of LDMF in preventing BPF developing after extrapleural pneumonectomy (EPP) and external radiation therapy in malignant pleural mesothelioma (MPM). Methods: Between May 1999 and Dec. 2008, 37 patients with MPM were operated upon by EPP using LDMF prophylactically to reinforce the bronchial stump, and then received external radiation therapy with or without postoperative chemotherapy. Results: The mean age of all patients was 46.7 (range 26-57) years. Twenty five patients were males and 12 patients were females. Twenty three patients had MPM of the right side and 14 patients had MPM of the left side. The peri-operative mortality was 2.7% and only few flap related postoperative morbidity were reported in the form of minor seroma and subcutaneous surgical emphysema. The median follow up was 17 (range 9-43) months. All cases completed their postoperative external radiation therapy with no reported cases of early or late BPF. Conclusion: Intrathoracic pedicled LDMF transposition is proved to be effective in prevention of BPF developing after EPP and external radiation therapy in MPM and it is advised to be a routine step in EPP in these cases and to use more sophisticated technique of postoperative external beam radiotherapy (3D conformal or IMRT) to minimize this complication.展开更多
In the field of near infrared H2O sensing, the acquisition of the absorption signal usually is from a noisy background, thus it is important to adopt an effective signal demodulation method. This study introduced the ...In the field of near infrared H2O sensing, the acquisition of the absorption signal usually is from a noisy background, thus it is important to adopt an effective signal demodulation method. This study introduced the research progress in the field of trace water vapor detection, covering different individual gas detection techniques. On the basis of the conventional double-beam differential absorption, the division method in voltage and the dual-peak method based on the differential value of two adjacent absorption lines have been studied. Voltage division has an excellent stability to temperature variation, mechanical extrusion, and fiber bend loss. The dual-peak method proved a linear relation with the water vapor concentration, and this method provided a way to measure the concentration at high pressure. Furthermore, the so called balanced ratiometer detection （BRD） was introduced. It has an outstanding self-adjusting capability, and it can also avoid an excess phase difference caused by the current-to-voltage converting circuit, thus this method has a high sensitivity. In addition, the second harmonic technique applied to gas detection was introduced, and for the high-frequency modulation via driving current, l/f was suppressed apparently; as a result, this technique realized a better sensitive detection by one to two orders of magnitude.展开更多
文摘This paper presents a novel mega-Hz-level super high frequency zero-voltage soft-switching converter for induction heating power supplies. The prominent advantage of this topology is that it can absorb both inductive and capacitive parasitic components in the converter. The switch devices operate in a zero-voltage soft-switching mode. Consequently, the high voltage and high current spikes caused by parasitic inductors or capacitors oscillation do not occur in this circuit, and the high power loss caused by high frequency switching can be greatly reduced. A large value inductor is adopted between the input capacitor and the switches, thus, this novel converter shares the benefits of both voltage-type and current-type circuits simultaneously, and there are no needs of dead time between two switches. The working principles in different modes are introduced. Results of simulation and experiments operated at around 1 MHz frequency verify the validity of parasitic components absorption and show that this convener is competent for super high frequency applications.
文摘The objective of this investigation was to study whether it is possible to determine the air tightness of covered slurry storage tanks using tracer gas technique by injection of sulphur hexafluoride （SF6） and measurements of the decay in gas concentrations with an infrared spectrophotometer in the air space above the slurry. By measuring the decay in concentration of injected tracer gas at different occasions, the air exchange rate was determined. Three different types of coverings were studied namely; wooden roof, plastic tent and concrete roof.
基金the South Carolina Smart State Center for Strategic Approaches to the Generation of Electricity (SAGE) for funding
文摘Efficient parallel screening of combinatorial libraries is one of the most challenging aspects of the high- throughput （HT） heterogeneous catalysis workflow. Today, a number of methods have been used in HT catalyst studies, including various optical, mass-spectrometry, and gas- chromatography techniques. Of these, rapid-scanning Fourier-transform infrared （FTIR） imaging is one of the fastest and most versatile screening techniques. Here, the new design of the 16-channel HT reactor is presented and test results for its accuracy and reproducibility are shown. The performance of the system was evaluated through the oxidation of CO over commercial Pd/AI203 and cobalt oxide nanoparticles synthesized with different reducer-reductant molar ratios, surfactant types, metal and surfactant concentrations, synthesis temperatures, and ramp rates.
文摘Objective: Bronchopleural fistula (BPF) is a life threatening complication after pneumonectomy. Extra thoracic skeletal muscle transposition especially latissimus dorsi muscle flap (LDMF) had been used to prevent this complication. The aim of this study was to assess the effectiveness of LDMF in preventing BPF developing after extrapleural pneumonectomy (EPP) and external radiation therapy in malignant pleural mesothelioma (MPM). Methods: Between May 1999 and Dec. 2008, 37 patients with MPM were operated upon by EPP using LDMF prophylactically to reinforce the bronchial stump, and then received external radiation therapy with or without postoperative chemotherapy. Results: The mean age of all patients was 46.7 (range 26-57) years. Twenty five patients were males and 12 patients were females. Twenty three patients had MPM of the right side and 14 patients had MPM of the left side. The peri-operative mortality was 2.7% and only few flap related postoperative morbidity were reported in the form of minor seroma and subcutaneous surgical emphysema. The median follow up was 17 (range 9-43) months. All cases completed their postoperative external radiation therapy with no reported cases of early or late BPF. Conclusion: Intrathoracic pedicled LDMF transposition is proved to be effective in prevention of BPF developing after EPP and external radiation therapy in MPM and it is advised to be a routine step in EPP in these cases and to use more sophisticated technique of postoperative external beam radiotherapy (3D conformal or IMRT) to minimize this complication.
基金This work was supported by the Natural Science Foundation of China （60977058 ＆ 61307101）, Independent Innovation Foundation of Shandong University （IIFSDU2012JC015）, the key technology projects of Shandong Province （2010GGX10137）, and promotive research fund for excellent young and middle-aged scientists of Shandong Province （BS2010DX028）.
文摘In the field of near infrared H2O sensing, the acquisition of the absorption signal usually is from a noisy background, thus it is important to adopt an effective signal demodulation method. This study introduced the research progress in the field of trace water vapor detection, covering different individual gas detection techniques. On the basis of the conventional double-beam differential absorption, the division method in voltage and the dual-peak method based on the differential value of two adjacent absorption lines have been studied. Voltage division has an excellent stability to temperature variation, mechanical extrusion, and fiber bend loss. The dual-peak method proved a linear relation with the water vapor concentration, and this method provided a way to measure the concentration at high pressure. Furthermore, the so called balanced ratiometer detection （BRD） was introduced. It has an outstanding self-adjusting capability, and it can also avoid an excess phase difference caused by the current-to-voltage converting circuit, thus this method has a high sensitivity. In addition, the second harmonic technique applied to gas detection was introduced, and for the high-frequency modulation via driving current, l/f was suppressed apparently; as a result, this technique realized a better sensitive detection by one to two orders of magnitude.
