In an injection moulding process, the mould cooling s ystem is very important as an efficient and uniform cooling effect can improve b oth the productivity and part quality. Due to the complexity of the process, muc h...In an injection moulding process, the mould cooling s ystem is very important as an efficient and uniform cooling effect can improve b oth the productivity and part quality. Due to the complexity of the process, muc h research on the mould cooling analysis and cooling design optimization has bee n focused on the core and the cavity, excluding other systems of injection mould s. However, the runner system introduces a considerable amount of heat into the mould. In recent years, more and more hot runner systems are being applied in th e moulding industry to save material and decrease losses of injection pressure. This raises the need to include the hot runner system in the cooling analysis. I n this paper, a photo frame part was studied. The mould was built with a hot run ner system. Two thermal sensors were installed: one measures the temperature of lateral surface of hot runner nozzle; the other measures the plastic temperature from the core side. A pressure sensor was also installed to measure the pressur e of the core impression. Cooling analysis was performed using ABAQUS, ananalysi s software based on the Finite Element Method (FEM). The assembly including core , cavity and plastic part was modeled. Heat conduction from hot runner to cavity and from polymer melt to the mould and force convection on the cooling channel surfaces were studied. The natural convection between the ambient air and the ex terior mould surface was ignored. The simulations were adjusted with the experim ental results to find out the heat input from hot runner and its influence on mo uld cooling. Finally, the optimal cooling design and optimal injection condition were obtained.展开更多
Metal-halide perovskite nanocrystals(NCs)have gained significant attention in the field of optoelectronic and photonic devices due to their promising applications.Despite their exceptional optical properties,the impac...Metal-halide perovskite nanocrystals(NCs)have gained significant attention in the field of optoelectronic and photonic devices due to their promising applications.Despite their exceptional optical properties,the impact of different synthetic strategies on the fundamental nature of NCs,such as nonradiative recombination centers,remains poorly understood.In this study,we investigated the photophysical properties of CsPbBr_(3) NCs synthesized using two distinct methods,hot injection and ligand-assisted reprecipitation,at the individual particle level.We observed different blinking behaviors under specific photoexcitation power densities and proposed,through intensity-lifetime analysis and Monte-Carlo simulations,that these different synthetic strategies can fabricate NCs with similar crystal structures but distinct surface quenchers with varying energy levels,which significantly affected the photo-induced blinking-down and blinking-up behaviors in individual NCs.Our findings indicate a practical and feasible approach for controlling defect engineering in perovskite NCs,with significant implications for their use in optoelectronic and other technological applications.展开更多
以氯化亚铜(CuCl)、氯化铟(InCl_3·4H_2O)作为金属源,溶解在三辛基膦(TOP)中的Se粉作硒源,利用油胺(OLA)作为配体、十八烯作为溶剂,采用热注入法合成出了CuInSe_2纳米晶(NCs),研究了反应温度对产物的影响。采用X射线衍射仪(XRD)、...以氯化亚铜(CuCl)、氯化铟(InCl_3·4H_2O)作为金属源,溶解在三辛基膦(TOP)中的Se粉作硒源,利用油胺(OLA)作为配体、十八烯作为溶剂,采用热注入法合成出了CuInSe_2纳米晶(NCs),研究了反应温度对产物的影响。采用X射线衍射仪(XRD)、透射电子显微镜(TEM)、能谱仪(EDS)和紫外-可见分光光度计(UV-Vis)等测试手段对CuInSe_2纳米晶的晶体结构、形貌、化学组分和光学性能进行了表征。实验结果表明:通过调控反应温度合成了具有不同形貌的黄铜矿结构的CuInSe_2纳米晶,纳米晶的形貌由三角形或四边形向球形演化,其晶粒平均尺寸为3.71~13.65 nm,其光学带隙Eg在1.75~1.50 e V之间变化。所得到的产物在有机溶剂甲苯中分散性良好,这样的"墨水"溶液在后期制备薄膜太阳能电池更有利。展开更多
文摘In an injection moulding process, the mould cooling s ystem is very important as an efficient and uniform cooling effect can improve b oth the productivity and part quality. Due to the complexity of the process, muc h research on the mould cooling analysis and cooling design optimization has bee n focused on the core and the cavity, excluding other systems of injection mould s. However, the runner system introduces a considerable amount of heat into the mould. In recent years, more and more hot runner systems are being applied in th e moulding industry to save material and decrease losses of injection pressure. This raises the need to include the hot runner system in the cooling analysis. I n this paper, a photo frame part was studied. The mould was built with a hot run ner system. Two thermal sensors were installed: one measures the temperature of lateral surface of hot runner nozzle; the other measures the plastic temperature from the core side. A pressure sensor was also installed to measure the pressur e of the core impression. Cooling analysis was performed using ABAQUS, ananalysi s software based on the Finite Element Method (FEM). The assembly including core , cavity and plastic part was modeled. Heat conduction from hot runner to cavity and from polymer melt to the mould and force convection on the cooling channel surfaces were studied. The natural convection between the ambient air and the ex terior mould surface was ignored. The simulations were adjusted with the experim ental results to find out the heat input from hot runner and its influence on mo uld cooling. Finally, the optimal cooling design and optimal injection condition were obtained.
基金supported by the National Natural Science Foundation of China(Nos.22073046,62011530133)the Fundamental Research Funds for the Central Universities(Nos.020514380256,020514380278)+1 种基金the Double-Innovation Doctor Program of Jiangsu Province,China(No.JSSCBS20211151)the Funding for School-level Research Projects of Yancheng Institute of Technology(No.xjr2021062).
文摘Metal-halide perovskite nanocrystals(NCs)have gained significant attention in the field of optoelectronic and photonic devices due to their promising applications.Despite their exceptional optical properties,the impact of different synthetic strategies on the fundamental nature of NCs,such as nonradiative recombination centers,remains poorly understood.In this study,we investigated the photophysical properties of CsPbBr_(3) NCs synthesized using two distinct methods,hot injection and ligand-assisted reprecipitation,at the individual particle level.We observed different blinking behaviors under specific photoexcitation power densities and proposed,through intensity-lifetime analysis and Monte-Carlo simulations,that these different synthetic strategies can fabricate NCs with similar crystal structures but distinct surface quenchers with varying energy levels,which significantly affected the photo-induced blinking-down and blinking-up behaviors in individual NCs.Our findings indicate a practical and feasible approach for controlling defect engineering in perovskite NCs,with significant implications for their use in optoelectronic and other technological applications.
文摘以氯化亚铜(CuCl)、氯化铟(InCl_3·4H_2O)作为金属源,溶解在三辛基膦(TOP)中的Se粉作硒源,利用油胺(OLA)作为配体、十八烯作为溶剂,采用热注入法合成出了CuInSe_2纳米晶(NCs),研究了反应温度对产物的影响。采用X射线衍射仪(XRD)、透射电子显微镜(TEM)、能谱仪(EDS)和紫外-可见分光光度计(UV-Vis)等测试手段对CuInSe_2纳米晶的晶体结构、形貌、化学组分和光学性能进行了表征。实验结果表明:通过调控反应温度合成了具有不同形貌的黄铜矿结构的CuInSe_2纳米晶,纳米晶的形貌由三角形或四边形向球形演化,其晶粒平均尺寸为3.71~13.65 nm,其光学带隙Eg在1.75~1.50 e V之间变化。所得到的产物在有机溶剂甲苯中分散性良好,这样的"墨水"溶液在后期制备薄膜太阳能电池更有利。
