Electroluminescent characteristics of n-ZnO/p-GaN heterojunctions under forward and reverse biases are studied. Emissions at 389nm and 57Ohm are observed under forward bias. An unusual emission at 390ram appears under...Electroluminescent characteristics of n-ZnO/p-GaN heterojunctions under forward and reverse biases are studied. Emissions at 389nm and 57Ohm are observed under forward bias. An unusual emission at 390ram appears under reverse bias, and is attributed to the recombination in the p-GaN side of the heterojunction. The yellow emission peaked at 57Ohm is suppressed under reverse bias. The light intensity exponentially depends on the reverse current. The emission under reverse bias is correlated to tunnelling carrier transport in the heterostructure. Our results also support that the well-known yellow band of GaN comes from the transitions between some near-conduction-band-edge states and deep localized acceptor states.展开更多
We investigate the geometric phase and dynamic phase of a two-level fermionic system with dispersive interaction, driven by a quantized bosonic field which is simultaneously subjected to parametric amplification. It i...We investigate the geometric phase and dynamic phase of a two-level fermionic system with dispersive interaction, driven by a quantized bosonic field which is simultaneously subjected to parametric amplification. It is found that the geometric phase is induced by a counterpart of the Stark shift. This effect is due to distinct shifts in the field frequency induced by interaction between different states （｜e〉 and ｜g〉 ） and cavity field, and a simple geometric interpretation of this phenomenon is given, which is helpful to understand the natural origin of the geometric phase.展开更多
We report a case of a 71 -year- old female with trichoblastic fibroma, a rare benign tumor of the skin, found in the left breast, associated with an invasive contralateral breast cancer. On clinical examination, a sol...We report a case of a 71 -year- old female with trichoblastic fibroma, a rare benign tumor of the skin, found in the left breast, associated with an invasive contralateral breast cancer. On clinical examination, a solitary, firm nodule was found in the subcutaneous tissue of the left breast with no changes in the overlying skin. Radiological examination showed disconcordant results. Conventional mammography and ultrasound suggested benign nature, while magnetic resonance mammography and spectroscopy raised the presumption of the malignant nature of the lesion. After performing excisional biopsy, the diagnosis of trichoblastic fibroma was established. Microscopically, it was composed of fibrous stroma, basaloid germs and strands and lace-like epithelial components, with no obvious connection with overlying epithelium or adjacent adnexal structures.展开更多
基金Supported by the National Natural Science Foundation under Grant Nos 60476044, 60376004 and 60021403, and the National Key Basic Research and Development Programme of China under Grant Nos 2002CB311903 and 2002CB613500.
文摘Electroluminescent characteristics of n-ZnO/p-GaN heterojunctions under forward and reverse biases are studied. Emissions at 389nm and 57Ohm are observed under forward bias. An unusual emission at 390ram appears under reverse bias, and is attributed to the recombination in the p-GaN side of the heterojunction. The yellow emission peaked at 57Ohm is suppressed under reverse bias. The light intensity exponentially depends on the reverse current. The emission under reverse bias is correlated to tunnelling carrier transport in the heterostructure. Our results also support that the well-known yellow band of GaN comes from the transitions between some near-conduction-band-edge states and deep localized acceptor states.
基金Supported by the National Natural Science Foundation of China under Grant No 10575040.
文摘We investigate the geometric phase and dynamic phase of a two-level fermionic system with dispersive interaction, driven by a quantized bosonic field which is simultaneously subjected to parametric amplification. It is found that the geometric phase is induced by a counterpart of the Stark shift. This effect is due to distinct shifts in the field frequency induced by interaction between different states （｜e〉 and ｜g〉 ） and cavity field, and a simple geometric interpretation of this phenomenon is given, which is helpful to understand the natural origin of the geometric phase.
文摘We report a case of a 71 -year- old female with trichoblastic fibroma, a rare benign tumor of the skin, found in the left breast, associated with an invasive contralateral breast cancer. On clinical examination, a solitary, firm nodule was found in the subcutaneous tissue of the left breast with no changes in the overlying skin. Radiological examination showed disconcordant results. Conventional mammography and ultrasound suggested benign nature, while magnetic resonance mammography and spectroscopy raised the presumption of the malignant nature of the lesion. After performing excisional biopsy, the diagnosis of trichoblastic fibroma was established. Microscopically, it was composed of fibrous stroma, basaloid germs and strands and lace-like epithelial components, with no obvious connection with overlying epithelium or adjacent adnexal structures.
