Thick GaN films were grown on GaN/sapphire template in a vertical HVPE reactor. Various material characterization techniques,including AFM, SEM, XRD, RBS/Channeling, CL, PL, and XPS, were used to characterize these Ga...Thick GaN films were grown on GaN/sapphire template in a vertical HVPE reactor. Various material characterization techniques,including AFM, SEM, XRD, RBS/Channeling, CL, PL, and XPS, were used to characterize these GaN epitaxial films. It was found that stepped/terraced structures appeared on the film surface,which were indicative of a nearly step-flow mode of growth for the HVPE GaN despite the high growth rate. A few hexagonal pits appeared on the surface, which have strong light emission. After being etched in molten KOH, the wavy steps disappeared and hexagonal pits with {1010} facets appeared on the surface. An EPD of only 8 ×10^6cm^-2 shows that the GaN film has few dislocations. Both XRD and RBS channeling indicate the high quality of the GaN thick films. Sharp band-edge emission with a full width at half maximum（FWHM）of 67meV was observed, while the yellow and infrared emissions were also found. These emissions are likely caused by native defects and C and O impurities.展开更多
Ferromagnetism is induced in pure TiO2 single crystals by oxygen ion irradiation. The ferro- magnetism is observed up to room temperature and is with weak temperature dependence. By combining X-ray diffraction, Ruther...Ferromagnetism is induced in pure TiO2 single crystals by oxygen ion irradiation. The ferro- magnetism is observed up to room temperature and is with weak temperature dependence. By combining X-ray diffraction, Rutherford backseattering/channelling, Raman scattering, and electron-spin resonance spectroscopy, supperconducting quantum interference device, displacement per atom, we measured tile lattice damage accumulation with increasing flu- ences. A defect complex, i.e., Ti3＋ on the substitutional accoiflpanied by oxygen vacancies, has been identified in the irradiated Ti02. This kind of defect complex results in a local （TiO6-x） stretching Raman mode. We elucidate that Ti3＋ with one unpaired 3d electron provide the local magnetic moments.展开更多
AIM:To review our experience performing polypectomy in anticoagulated patients without interruption of anticoagulation.METHODS: Retrospective chart review at the Veterans Affairs Palo Alto Health Care System. Two hund...AIM:To review our experience performing polypectomy in anticoagulated patients without interruption of anticoagulation.METHODS: Retrospective chart review at the Veterans Affairs Palo Alto Health Care System. Two hundred and twenty five polypectomies were performed in 123 patients. Patients followed a standardized protocol that included stopping warfarin for 36 h to avoid supratherapeutic anticoagulation from the bowel preparation. Patients with lesions larger than 1 cm were generally rescheduled for polypectomy off warfarin. Endoscopic clips were routinely applied prophylactically. RESULTS: One patient (0.8%, 95% CI: 0.1%-4.5%) developed major post-polypectomy bleeding that required transfusion. Two others (1.6%, 95% CI: 0.5%-5.7%) had self-limited hematochezia at home and did not seek medical attention. The average polyp size was 5.1 ± 2.2 mm. CONCLUSION: Polypectomy can be performed in therapeutically anticoagulated patients with lesions up to 1 cm in size with an acceptable bleeding rate.展开更多
The Chinese Dream, adopted by General Secretary Xi Jinping, was used and spread in China. It is about Chinese prosperity, collective effort, socialism and national glory. It is also about the welfare, wellbeing, and q...The Chinese Dream, adopted by General Secretary Xi Jinping, was used and spread in China. It is about Chinese prosperity, collective effort, socialism and national glory. It is also about the welfare, wellbeing, and quality of life of every Chinese. Academics in higher education in China are facing changes both across the globe and in China, they must take the challenges. This paper does research on wellbeing of the academics from the aspects of the definition of wellbeing, the situation both in the world and in China, the Chinese concept of happiness, the possible influence of Confucius moral standards on wellbeing of Chinese. This paper may help school leaders implement policies that foster effective work environment in the new era in China.展开更多
文摘Thick GaN films were grown on GaN/sapphire template in a vertical HVPE reactor. Various material characterization techniques,including AFM, SEM, XRD, RBS/Channeling, CL, PL, and XPS, were used to characterize these GaN epitaxial films. It was found that stepped/terraced structures appeared on the film surface,which were indicative of a nearly step-flow mode of growth for the HVPE GaN despite the high growth rate. A few hexagonal pits appeared on the surface, which have strong light emission. After being etched in molten KOH, the wavy steps disappeared and hexagonal pits with {1010} facets appeared on the surface. An EPD of only 8 ×10^6cm^-2 shows that the GaN film has few dislocations. Both XRD and RBS channeling indicate the high quality of the GaN thick films. Sharp band-edge emission with a full width at half maximum（FWHM）of 67meV was observed, while the yellow and infrared emissions were also found. These emissions are likely caused by native defects and C and O impurities.
文摘Ferromagnetism is induced in pure TiO2 single crystals by oxygen ion irradiation. The ferro- magnetism is observed up to room temperature and is with weak temperature dependence. By combining X-ray diffraction, Rutherford backseattering/channelling, Raman scattering, and electron-spin resonance spectroscopy, supperconducting quantum interference device, displacement per atom, we measured tile lattice damage accumulation with increasing flu- ences. A defect complex, i.e., Ti3＋ on the substitutional accoiflpanied by oxygen vacancies, has been identified in the irradiated Ti02. This kind of defect complex results in a local （TiO6-x） stretching Raman mode. We elucidate that Ti3＋ with one unpaired 3d electron provide the local magnetic moments.
文摘AIM:To review our experience performing polypectomy in anticoagulated patients without interruption of anticoagulation.METHODS: Retrospective chart review at the Veterans Affairs Palo Alto Health Care System. Two hundred and twenty five polypectomies were performed in 123 patients. Patients followed a standardized protocol that included stopping warfarin for 36 h to avoid supratherapeutic anticoagulation from the bowel preparation. Patients with lesions larger than 1 cm were generally rescheduled for polypectomy off warfarin. Endoscopic clips were routinely applied prophylactically. RESULTS: One patient (0.8%, 95% CI: 0.1%-4.5%) developed major post-polypectomy bleeding that required transfusion. Two others (1.6%, 95% CI: 0.5%-5.7%) had self-limited hematochezia at home and did not seek medical attention. The average polyp size was 5.1 ± 2.2 mm. CONCLUSION: Polypectomy can be performed in therapeutically anticoagulated patients with lesions up to 1 cm in size with an acceptable bleeding rate.
文摘The Chinese Dream, adopted by General Secretary Xi Jinping, was used and spread in China. It is about Chinese prosperity, collective effort, socialism and national glory. It is also about the welfare, wellbeing, and quality of life of every Chinese. Academics in higher education in China are facing changes both across the globe and in China, they must take the challenges. This paper does research on wellbeing of the academics from the aspects of the definition of wellbeing, the situation both in the world and in China, the Chinese concept of happiness, the possible influence of Confucius moral standards on wellbeing of Chinese. This paper may help school leaders implement policies that foster effective work environment in the new era in China.
