混合教学作为在线学习的常态化路径,在自主学习阶段面临学习者认知投入不足的困扰。概念图能够通过帮助学习者在学习过程中有意识地从学习材料中提取新信息并与已有知识建立连接以促进认知投入。因此,围绕概念图工具在混合教学自主学习...混合教学作为在线学习的常态化路径,在自主学习阶段面临学习者认知投入不足的困扰。概念图能够通过帮助学习者在学习过程中有意识地从学习材料中提取新信息并与已有知识建立连接以促进认知投入。因此,围绕概念图工具在混合教学自主学习阶段的应用问题,本研究基于ICAP (Interactive,Constructive, Active, and Passive)学习方式分类学理论、有意义学习理论和活动理论双驱动认知投入干预策略,设计了指向交互建构的学习活动流程和促进有意义交互的学习策略。学习活动流程设计引导学习者在自主学习阶段从参与被动学习活动向参与交互学习活动发展;学习策略设计为学习者参与建构类和交互类学习活动过程提供可操作性的认知策略,确保在自主学习的过程中有意义交互的发生。同时,通过准实验研究验证基于干预策略的混合教学的有效性。实验结果表明,基于干预策略的混合教学对于学习者知识水平以及以元认知意识和沟通能力为代表的高阶思维能力具有促进作用。展开更多
Our previous work first reported the cooperative sensitized luminescence from Cu2＋ or Pb2＋ by three clustered Yb^3＋ ions, in which three NIR photons can be converted into a high energy photon. Could a reverse proce...Our previous work first reported the cooperative sensitized luminescence from Cu2＋ or Pb2＋ by three clustered Yb^3＋ ions, in which three NIR photons can be converted into a high energy photon. Could a reverse process happen that a high energy photon is cut into three NIR photons？ This work demonstrated an example of three-photon quantum cutting （QC） phosphor, CaF2：Ce^3＋,Yb^3＋, in which three clustered Yb^3＋ ions （Yb^3＋-trimer） cooperatively and indirectly received a 306 nm ultraviolet （UV） photon energy transferred from a Ce^3＋ ion in 5d excited state and emitted three 975 nm near-infrared （NIR） photons. The cluster destruction experiments were designed to verify the necessity of the presence of Yb^3＋-trimers for QC. The dynamical analysis on luminescence of Ce^3＋ ions confirmed the energy transfer from Ce^3＋ ions to Yb^3＋-trimers. The doping concentration effect on luminescence was investigated. Furthermore, the maximum energy transfer （ET） efficiency and the corresponding QC efficiency were estimated to be 61% and 222%, respectively. Therefore, the reported three-photon QC phosphor has an attractive prospect in efficiently harvesting solar energy for silicon solar cells.展开更多
<b>Objectives:</b> Allogeneic myoblast transplantation (AMT), cyclosporine immunosuppression and coronary artery bypass grafting (CABG) were used to treat end-stage heart failure (HF) subjects without hope...<b>Objectives:</b> Allogeneic myoblast transplantation (AMT), cyclosporine immunosuppression and coronary artery bypass grafting (CABG) were used to treat end-stage heart failure (HF) subjects without hope of obtaining a heart transplant. <b>Background:</b> Severe myocardial infarction conveys serious complications such as ventricular aneurysm, wall thinning and rupture with fatal consequences. <b>Methods: </b>After meeting Inclusion/Exclusion criteria and signing Patient Informed Consents, 10 HF subjects having mean thinnest wall thickness of 2.21 ± 0.55 mm and ventricular aneurysms were admitted under intensive care. Each subject took daily cyclosporine for three weeks. On the third day of cyclosporine administration, approximately 1 billion myoblasts were implanted <span>through 20 injections into the infarcted myocardium following CABG. <b>Results: </b><u>Safety</u> No subject suffered death, viral infection, malignant arrhythmia, reduction in cardiac output, immune rejection, or aneurysm growth. No significant difference was found before versus after treatment in the mean levels of blood routine, liver and kidney enzymes, electrolytes and fibrinogen. <u>Efficacy</u> Emission computed tomography (ECT) and magnetic resonance (MR) demonstrated significant increases in viability and perfusion. Mean left ventricular ejection fraction (LVEF) significantly increased (P < 0.05) by 20.1% and 19.3% at 6 months and at 2 years postoperatively. New York Heart Association (NYHA) class improved by 2 grades, including 6-minute walk test (6 MWT) distance increase, and reductions in the number of episodes of angina pectoris, chest tightness, shortness of breath after exercise, and nighttime sit-up breathing. <b>Conclusions: </b>For the first time, AMT in adjunct use with CABG and cyclosporine demonstrated that cell survived and engrafted in patients with ischemic cardiomyopathy;in this small study the cell transplant was safe. The improvement in heart function and quality of life could be secondary to combined effect of bypa展开更多
We report a Yb-doped mode-locked fiber laser based on a nonlinear amplifying loop mirror[NALM],which is all-normaldispersion[ANDi],and allows the output wavelength to be tunable.The laser can generate a stable femtose...We report a Yb-doped mode-locked fiber laser based on a nonlinear amplifying loop mirror[NALM],which is all-normaldispersion[ANDi],and allows the output wavelength to be tunable.The laser can generate a stable femtosecond dissipative soliton with a maximum output power of 196 mW.Its repetition rate is 112.4 MHz,and the final pulse duration is 236 fs.By adjusting the angle of the reflective diffraction grating,the mode-locked fiber laser was realized to tune the output with a tuning range of 54 nm from 1011.8 nm to 1065.6 nm.To the best of our knowledge,this is the widest tuning range of an ANDi Yb-doped mode-locked fiber laser based on NALM.展开更多
Objectives:Based on the information from the random inspection of foods by the China Food and Drug Administration in 2022,the contamin-ation levels of lead ions are high in many edible products.Traditional methods of ...Objectives:Based on the information from the random inspection of foods by the China Food and Drug Administration in 2022,the contamin-ation levels of lead ions are high in many edible products.Traditional methods of detecting lead ions cannot meet the requirements of on-site analysis of food due to the need for large equipment.The immunochromatographic assay(iCA)is an effective,rapid,on-site analytical technique for determining lead ions in foods.However,the performance of ICA based on the traditional probe(AuNP-mAb)is limited by ignoring the influ-ence of theantibody orientation.Materials and Methods:In this study,we developed an efficient technology for constructing a universal probe(AuNP-PrA-mAb)based on the oriented immobilization of antibody.The performance of ICA was largely improved due to specific binding of the Fc region of the antibody with recombinant protein A(PrA)on the surface of a gold nanoparticle(AuNP).The ICA based on a universal probe was applied for the qualitative and quantitative detection of lead ions in Procambarus clarki within 30 min.Meanwhile,a simple and fast pretreatment method based on dilute acid extraction was developed forpretreating thePclarkii containing leadions.Results:The visual limit of detection and the scanning limit of quantization of the developed iCA strip for lead ions were O.5 ng/mL and 0.28 ng/mL,respectively.The sensitivity of ICA based on universal probe was 10-fold higher than that of the ICA using traditional probe.Furthermore,the detection results had no obvious difference between the ICA and ICP-MS with t-test statistical method.Conclusions:The developed ICA based on a universal probe presented broad application prospects in detecting contaminants in foods.展开更多
文摘混合教学作为在线学习的常态化路径,在自主学习阶段面临学习者认知投入不足的困扰。概念图能够通过帮助学习者在学习过程中有意识地从学习材料中提取新信息并与已有知识建立连接以促进认知投入。因此,围绕概念图工具在混合教学自主学习阶段的应用问题,本研究基于ICAP (Interactive,Constructive, Active, and Passive)学习方式分类学理论、有意义学习理论和活动理论双驱动认知投入干预策略,设计了指向交互建构的学习活动流程和促进有意义交互的学习策略。学习活动流程设计引导学习者在自主学习阶段从参与被动学习活动向参与交互学习活动发展;学习策略设计为学习者参与建构类和交互类学习活动过程提供可操作性的认知策略,确保在自主学习的过程中有意义交互的发生。同时,通过准实验研究验证基于干预策略的混合教学的有效性。实验结果表明,基于干预策略的混合教学对于学习者知识水平以及以元认知意识和沟通能力为代表的高阶思维能力具有促进作用。
基金Project supported by the National Natural Science Foundation of China(11274139)
文摘Our previous work first reported the cooperative sensitized luminescence from Cu2＋ or Pb2＋ by three clustered Yb^3＋ ions, in which three NIR photons can be converted into a high energy photon. Could a reverse process happen that a high energy photon is cut into three NIR photons？ This work demonstrated an example of three-photon quantum cutting （QC） phosphor, CaF2：Ce^3＋,Yb^3＋, in which three clustered Yb^3＋ ions （Yb^3＋-trimer） cooperatively and indirectly received a 306 nm ultraviolet （UV） photon energy transferred from a Ce^3＋ ion in 5d excited state and emitted three 975 nm near-infrared （NIR） photons. The cluster destruction experiments were designed to verify the necessity of the presence of Yb^3＋-trimers for QC. The dynamical analysis on luminescence of Ce^3＋ ions confirmed the energy transfer from Ce^3＋ ions to Yb^3＋-trimers. The doping concentration effect on luminescence was investigated. Furthermore, the maximum energy transfer （ET） efficiency and the corresponding QC efficiency were estimated to be 61% and 222%, respectively. Therefore, the reported three-photon QC phosphor has an attractive prospect in efficiently harvesting solar energy for silicon solar cells.
文摘<b>Objectives:</b> Allogeneic myoblast transplantation (AMT), cyclosporine immunosuppression and coronary artery bypass grafting (CABG) were used to treat end-stage heart failure (HF) subjects without hope of obtaining a heart transplant. <b>Background:</b> Severe myocardial infarction conveys serious complications such as ventricular aneurysm, wall thinning and rupture with fatal consequences. <b>Methods: </b>After meeting Inclusion/Exclusion criteria and signing Patient Informed Consents, 10 HF subjects having mean thinnest wall thickness of 2.21 ± 0.55 mm and ventricular aneurysms were admitted under intensive care. Each subject took daily cyclosporine for three weeks. On the third day of cyclosporine administration, approximately 1 billion myoblasts were implanted <span>through 20 injections into the infarcted myocardium following CABG. <b>Results: </b><u>Safety</u> No subject suffered death, viral infection, malignant arrhythmia, reduction in cardiac output, immune rejection, or aneurysm growth. No significant difference was found before versus after treatment in the mean levels of blood routine, liver and kidney enzymes, electrolytes and fibrinogen. <u>Efficacy</u> Emission computed tomography (ECT) and magnetic resonance (MR) demonstrated significant increases in viability and perfusion. Mean left ventricular ejection fraction (LVEF) significantly increased (P < 0.05) by 20.1% and 19.3% at 6 months and at 2 years postoperatively. New York Heart Association (NYHA) class improved by 2 grades, including 6-minute walk test (6 MWT) distance increase, and reductions in the number of episodes of angina pectoris, chest tightness, shortness of breath after exercise, and nighttime sit-up breathing. <b>Conclusions: </b>For the first time, AMT in adjunct use with CABG and cyclosporine demonstrated that cell survived and engrafted in patients with ischemic cardiomyopathy;in this small study the cell transplant was safe. The improvement in heart function and quality of life could be secondary to combined effect of bypa
基金supported by the Natural Science Basic Research Plan in Shaanxi Province of China(No.2021JM316)National Natural Science Foundation of China(No.61905193)International Cooperative Program(No.2014DFR10780)。
文摘We report a Yb-doped mode-locked fiber laser based on a nonlinear amplifying loop mirror[NALM],which is all-normaldispersion[ANDi],and allows the output wavelength to be tunable.The laser can generate a stable femtosecond dissipative soliton with a maximum output power of 196 mW.Its repetition rate is 112.4 MHz,and the final pulse duration is 236 fs.By adjusting the angle of the reflective diffraction grating,the mode-locked fiber laser was realized to tune the output with a tuning range of 54 nm from 1011.8 nm to 1065.6 nm.To the best of our knowledge,this is the widest tuning range of an ANDi Yb-doped mode-locked fiber laser based on NALM.
基金supported by the National Natural Science Foundation of China(No.32102072).
文摘Objectives:Based on the information from the random inspection of foods by the China Food and Drug Administration in 2022,the contamin-ation levels of lead ions are high in many edible products.Traditional methods of detecting lead ions cannot meet the requirements of on-site analysis of food due to the need for large equipment.The immunochromatographic assay(iCA)is an effective,rapid,on-site analytical technique for determining lead ions in foods.However,the performance of ICA based on the traditional probe(AuNP-mAb)is limited by ignoring the influ-ence of theantibody orientation.Materials and Methods:In this study,we developed an efficient technology for constructing a universal probe(AuNP-PrA-mAb)based on the oriented immobilization of antibody.The performance of ICA was largely improved due to specific binding of the Fc region of the antibody with recombinant protein A(PrA)on the surface of a gold nanoparticle(AuNP).The ICA based on a universal probe was applied for the qualitative and quantitative detection of lead ions in Procambarus clarki within 30 min.Meanwhile,a simple and fast pretreatment method based on dilute acid extraction was developed forpretreating thePclarkii containing leadions.Results:The visual limit of detection and the scanning limit of quantization of the developed iCA strip for lead ions were O.5 ng/mL and 0.28 ng/mL,respectively.The sensitivity of ICA based on universal probe was 10-fold higher than that of the ICA using traditional probe.Furthermore,the detection results had no obvious difference between the ICA and ICP-MS with t-test statistical method.Conclusions:The developed ICA based on a universal probe presented broad application prospects in detecting contaminants in foods.
