This paper presents a cascode configuration synchronous rectifier device based on silicon MOSFET and Schottky diode,which can replace traditional power diode directly.This structure has self-driven ability with simple...This paper presents a cascode configuration synchronous rectifier device based on silicon MOSFET and Schottky diode,which can replace traditional power diode directly.This structure has self-driven ability with simple external circuit,and the conduction characteristic is preferable to a power diode.Static characterization and switching behavior analysis of proposed structure are conducted in this paper.The switching process is illustrated in detail using real model which considers the parasitic inductances and the nonlinearity of junction capacitors.The real time internal voltage and current value during switching transition are deduced with the equivalent circuit.To validate the analysis,two voltage specification rectifiers are built.Finally,double-pulse test results and the practical design example verify the performance advantages of proposed structure.展开更多
Objective： The aim of this study is to compare the effectiveness of surgery with stereotactic radiosurgery （SRS） for patients with a single synchronous brain metastasis from successfully treated non-small cell lung...Objective： The aim of this study is to compare the effectiveness of surgery with stereotactic radiosurgery （SRS） for patients with a single synchronous brain metastasis from successfully treated non-small cell lung cancer. Methods： Between 1995 and 2002, 53 patients underwent resection of both primary non-small cell lung cancer and the associated single brain metastasis. There were 33 men and 20 women with a mean age of 57 years （range, 32-85 years）. At the time of diagnosis, 42 patients experienced lung cancer related symptoms, whereas 11 patients experienced brain metastases-related symptoms. 42 patients had received thoracic surgery first, and 11 patients had undergone neurosurgery or radiosurgery first. Pneumonectomy was performed in 9 out of 42 patients （21.4%）, lobectomies in 30 （71.4%）, and wedge resection in 3 （7.2%）. 48 patients （90.5%） underwent complete lymphadenectomy. 35 patients underwent brain metastasectomy. 18 underwent SRS. Results： There was no postoperative mortality and severe complications after either lung or brain surgery. Histology showed 34 adenocarcinomas, 16 squamous cell carcinomas, and 3 large cell lung cancers. 15 patients （28.3%） had no evidence of lymph node metastases （No）, 20 patients （37.7%） had hilar metastases （N1）, and 18 patients （34%） had mediastinal metastases （N2）. The 1-, 2-, 3- and 5-year overall survival rates were 49%, 19%, 10%, and 5%, respectively. The corresponding data for neurosurgery group were 55%, 17%, 11%, and 6%, respectively. The median survival time was 13 months. For SRS group the corresponding data were 44.8%, 20.9% 10.5%, and 2%, respectively. The median survival time was 14 months. The differences between the two groups were not significant （P〉0.05）. In lymph node negative patients （No）, the overall 5-year survival rate was 10%, as compared with a 1% survival rate in patients with lymph node metastases （N1-2）. The difference was significant （P〈0,01）. For adenocarcinomas, the 5-year survival rate was 5%. The correspondent data for squamous cell lung cancers was 3%. The difference was not significant （P〉0.05）. Conclusion： Although the overall survival rate for patients who have brain metastases from NSCLC is poor, surgical resection or radiosurgery may be beneficial in a select group of patients with synchronous brain metastases and lung cancer without lymph node metastases.展开更多
Diode rectifiers-synchronous machine system has a wide range of applications in isolated power system,whose low frequency oscillation emerges under certain parameters.Considerable error is produced when the state spac...Diode rectifiers-synchronous machine system has a wide range of applications in isolated power system,whose low frequency oscillation emerges under certain parameters.Considerable error is produced when the state space averaging model is used to analyze its small signal stability.Therefore,this paper has presented a periodic orbit model of diode rectifiers-synchronous machine system to solve these problems.Using trapezoidal integration method,it is possible to derive equation of periodic orbit and its Poincaré mapping.Jacobian matrix of the Poincaré mapping of periodic orbit can be calculated by chain derivative method.Besides,stability margin index and linearized Poincaré mapping model have also been proposed.Thus small signal stability of diode rectifiers-synchronous machine system can be assessed through orbitally asymptotical stability of its periodic orbit so as to lay a foundation for isolated power system analysis and its control design.Simulation test demonstrates that the proposed model and algorithm are effective and practicable.展开更多
A Bi2Sr2Co2Oy/Si heterojunction is obtained by growing a layer of p-type oxygen-deficient Bi2Sr2Co2Oy film on a commercial n-type silicon wafer by pulsed laser deposition. Its rectifying and photovoltaic properties ar...A Bi2Sr2Co2Oy/Si heterojunction is obtained by growing a layer of p-type oxygen-deficient Bi2Sr2Co2Oy film on a commercial n-type silicon wafer by pulsed laser deposition. Its rectifying and photovoltaic properties are studied in a wide temperature range from 20 K to 300 K. The transport mechanism under the forward bias can be attributed to a trap- filled space-charge-limited current conduction mechanism. Under the irradiation of a 532-nm continuous wave laser, a clear photovoltaic effect is observed and the magnitude ofphotovoltage increases as the temperature decreases, The results demonstrate the potential application of a Bi2SrzCo2Oy-based heterojunction in the photoelectronic devices.展开更多
基金supported in part by the National Natural Science Foundation of China (No.51777093)
文摘This paper presents a cascode configuration synchronous rectifier device based on silicon MOSFET and Schottky diode,which can replace traditional power diode directly.This structure has self-driven ability with simple external circuit,and the conduction characteristic is preferable to a power diode.Static characterization and switching behavior analysis of proposed structure are conducted in this paper.The switching process is illustrated in detail using real model which considers the parasitic inductances and the nonlinearity of junction capacitors.The real time internal voltage and current value during switching transition are deduced with the equivalent circuit.To validate the analysis,two voltage specification rectifiers are built.Finally,double-pulse test results and the practical design example verify the performance advantages of proposed structure.
文摘Objective： The aim of this study is to compare the effectiveness of surgery with stereotactic radiosurgery （SRS） for patients with a single synchronous brain metastasis from successfully treated non-small cell lung cancer. Methods： Between 1995 and 2002, 53 patients underwent resection of both primary non-small cell lung cancer and the associated single brain metastasis. There were 33 men and 20 women with a mean age of 57 years （range, 32-85 years）. At the time of diagnosis, 42 patients experienced lung cancer related symptoms, whereas 11 patients experienced brain metastases-related symptoms. 42 patients had received thoracic surgery first, and 11 patients had undergone neurosurgery or radiosurgery first. Pneumonectomy was performed in 9 out of 42 patients （21.4%）, lobectomies in 30 （71.4%）, and wedge resection in 3 （7.2%）. 48 patients （90.5%） underwent complete lymphadenectomy. 35 patients underwent brain metastasectomy. 18 underwent SRS. Results： There was no postoperative mortality and severe complications after either lung or brain surgery. Histology showed 34 adenocarcinomas, 16 squamous cell carcinomas, and 3 large cell lung cancers. 15 patients （28.3%） had no evidence of lymph node metastases （No）, 20 patients （37.7%） had hilar metastases （N1）, and 18 patients （34%） had mediastinal metastases （N2）. The 1-, 2-, 3- and 5-year overall survival rates were 49%, 19%, 10%, and 5%, respectively. The corresponding data for neurosurgery group were 55%, 17%, 11%, and 6%, respectively. The median survival time was 13 months. For SRS group the corresponding data were 44.8%, 20.9% 10.5%, and 2%, respectively. The median survival time was 14 months. The differences between the two groups were not significant （P〉0.05）. In lymph node negative patients （No）, the overall 5-year survival rate was 10%, as compared with a 1% survival rate in patients with lymph node metastases （N1-2）. The difference was significant （P〈0,01）. For adenocarcinomas, the 5-year survival rate was 5%. The correspondent data for squamous cell lung cancers was 3%. The difference was not significant （P〉0.05）. Conclusion： Although the overall survival rate for patients who have brain metastases from NSCLC is poor, surgical resection or radiosurgery may be beneficial in a select group of patients with synchronous brain metastases and lung cancer without lymph node metastases.
基金supported by the National Natural Science Foundation of China (Grant Nos. 51077130,50977090)the National Basic Research Program of China ("973" Program) (Grant No. 2012CB215103)
文摘Diode rectifiers-synchronous machine system has a wide range of applications in isolated power system,whose low frequency oscillation emerges under certain parameters.Considerable error is produced when the state space averaging model is used to analyze its small signal stability.Therefore,this paper has presented a periodic orbit model of diode rectifiers-synchronous machine system to solve these problems.Using trapezoidal integration method,it is possible to derive equation of periodic orbit and its Poincaré mapping.Jacobian matrix of the Poincaré mapping of periodic orbit can be calculated by chain derivative method.Besides,stability margin index and linearized Poincaré mapping model have also been proposed.Thus small signal stability of diode rectifiers-synchronous machine system can be assessed through orbitally asymptotical stability of its periodic orbit so as to lay a foundation for isolated power system analysis and its control design.Simulation test demonstrates that the proposed model and algorithm are effective and practicable.
基金Project supported by the National Basic Research Program of China (Grant No.2011CB612305)the National Natural Science Foundation of China (Grant No.51372064)+1 种基金the One Hundred Persons Project of Hebei Province of China (Grant No.CPRC001)the Science and Technology Research Project of Colleges and Universities in Hebei Province,China (Grant No.QN20131040)
文摘A Bi2Sr2Co2Oy/Si heterojunction is obtained by growing a layer of p-type oxygen-deficient Bi2Sr2Co2Oy film on a commercial n-type silicon wafer by pulsed laser deposition. Its rectifying and photovoltaic properties are studied in a wide temperature range from 20 K to 300 K. The transport mechanism under the forward bias can be attributed to a trap- filled space-charge-limited current conduction mechanism. Under the irradiation of a 532-nm continuous wave laser, a clear photovoltaic effect is observed and the magnitude ofphotovoltage increases as the temperature decreases, The results demonstrate the potential application of a Bi2SrzCo2Oy-based heterojunction in the photoelectronic devices.
