Measuring the growth parameters of Ge quantum dots （QDs） embedded in SiO2/Si hetero-structure is pre- requisite for developing the optoelectronic devices such as photovoltaics and sensors. Their optical properties c...Measuring the growth parameters of Ge quantum dots （QDs） embedded in SiO2/Si hetero-structure is pre- requisite for developing the optoelectronic devices such as photovoltaics and sensors. Their optical properties can be tuned by tailoring the growth morphology and structures, where the growth parameters＇ optimizations still need to be explored. We determine the effect of annealing temperature on surface morphology, structures and optical properties of Ge//SiO2//Si hetero-structure. Samples are grown via rf magnetron sputtering and subsequent characterizations are made using imaging and spectroscopic techniques.展开更多
Objective To provide new ideas for the effective treatment of many serious diseases and to solve many major medical problems faced by mankind.Methods In this paper,the invention patents in the field of stem cells in C...Objective To provide new ideas for the effective treatment of many serious diseases and to solve many major medical problems faced by mankind.Methods In this paper,the invention patents in the field of stem cells in China from 2010 to 2020 were taken as the research object,and the technology status quo in the field of stem cells was analyzed to predict the future development direction through quantitative analysis method.Results and Conclusion The development of stem cell technology in China is in a period of growth with great potential.Therefore,it is necessary to strengthen the ability of Chinese universities to combine production,education and research.Nowadays,the hotspots in stem cell technology are using culture medium to improve cell proliferation ability,production efficiency,and to induce differentiated cells.Meanwhile,the production efficiency of embryonic stem cells should be improved,and the immunomodulatory effect of embryonic stem cells can be exerted to screen drugs.Besides,the function of hematopoietic stem cells should be enhanced and apply mesenchymal cells in therapy.Since the potential technological gaps are the improvement of therapy,induced differentiation and efficiency of pluripotent stem cells,the improvement of progenitor cell proliferation and the control of cost,we should strengthen R&D investment in culture medium,embryonic stem cells and other technical fields,and achieve the purpose of reducing R&D costs and improving R&D efficiency.展开更多
The internal quantum efficiency（IQE） of the light-emitting diodes can be calculated by the ratio of the external quantum efficiency（EQE） and the light extraction efficiency（LEE）.The EQE can be measured experimen...The internal quantum efficiency（IQE） of the light-emitting diodes can be calculated by the ratio of the external quantum efficiency（EQE） and the light extraction efficiency（LEE）.The EQE can be measured experimentally,but the LEE is difficult to calculate due to the complicated LED structures.In this work,a model was established to calculate the LEE by combining the transfer matrix formalism and an in-plane ray tracing method.With the calculated LEE,the IQE was determined and made a good agreement with that obtained by the ABC model and temperature-dependent photoluminescence method.The proposed method makes the determination of the IQE more practical and conventional.展开更多
基金Supported by the Advanced Membrane Technology Research Center of the Universities Teknologi Malaysia under Grant No R.J130000.7609.4C112the Postdoctoral Grantthe Frontier Materials Research Alliance
文摘Measuring the growth parameters of Ge quantum dots （QDs） embedded in SiO2/Si hetero-structure is pre- requisite for developing the optoelectronic devices such as photovoltaics and sensors. Their optical properties can be tuned by tailoring the growth morphology and structures, where the growth parameters＇ optimizations still need to be explored. We determine the effect of annealing temperature on surface morphology, structures and optical properties of Ge//SiO2//Si hetero-structure. Samples are grown via rf magnetron sputtering and subsequent characterizations are made using imaging and spectroscopic techniques.
文摘Objective To provide new ideas for the effective treatment of many serious diseases and to solve many major medical problems faced by mankind.Methods In this paper,the invention patents in the field of stem cells in China from 2010 to 2020 were taken as the research object,and the technology status quo in the field of stem cells was analyzed to predict the future development direction through quantitative analysis method.Results and Conclusion The development of stem cell technology in China is in a period of growth with great potential.Therefore,it is necessary to strengthen the ability of Chinese universities to combine production,education and research.Nowadays,the hotspots in stem cell technology are using culture medium to improve cell proliferation ability,production efficiency,and to induce differentiated cells.Meanwhile,the production efficiency of embryonic stem cells should be improved,and the immunomodulatory effect of embryonic stem cells can be exerted to screen drugs.Besides,the function of hematopoietic stem cells should be enhanced and apply mesenchymal cells in therapy.Since the potential technological gaps are the improvement of therapy,induced differentiation and efficiency of pluripotent stem cells,the improvement of progenitor cell proliferation and the control of cost,we should strengthen R&D investment in culture medium,embryonic stem cells and other technical fields,and achieve the purpose of reducing R&D costs and improving R&D efficiency.
基金supported by the National Natural Science Foundation of China(Nos.11574306,61334009)the China International Science and Technology Cooperation Program(No.2014DFG62280)the National High Technology Program of China(No.2015AA03A101)
文摘The internal quantum efficiency（IQE） of the light-emitting diodes can be calculated by the ratio of the external quantum efficiency（EQE） and the light extraction efficiency（LEE）.The EQE can be measured experimentally,but the LEE is difficult to calculate due to the complicated LED structures.In this work,a model was established to calculate the LEE by combining the transfer matrix formalism and an in-plane ray tracing method.With the calculated LEE,the IQE was determined and made a good agreement with that obtained by the ABC model and temperature-dependent photoluminescence method.The proposed method makes the determination of the IQE more practical and conventional.
