A versatile and reliable approach is created to fabricate wafer-scale colloidal crystal that consists of a monolayer of hexagonally close-packed polystyrene （PS） spheres. Making wafer-scale colloidal crystal is usua...A versatile and reliable approach is created to fabricate wafer-scale colloidal crystal that consists of a monolayer of hexagonally close-packed polystyrene （PS） spheres. Making wafer-scale colloidal crystal is usually challenging, and it lacks a general theoretical guidance for experimental approaches. To obtain the optimal conditions for self-assembly, a systematic statistical design and analysis method is utilized here, which applies the pick-the-winner rule. This new method combines spin-coating and thermal treatment, and introduces a mixture of glycol and ethanol as a dispersion system to assist self-assembly. By controlling the parameters of self-assembly, we improve the quality of colloidal crystal and reduce the effect of noise on the experiment. To our best knowledge, we are first to pave this path to harvest colloidal crystals. Importantly, a theoretical analysis using an energy landscape base on our process is also developed to provide insights into the PS spheres＇ self-assembly.展开更多
The dynamic characteristics of a gas-solid fluidized bed with different rod promoters have been investigated in terms of bed expansion and fluctuation, minimum fluidization velocity and distributor-to-bed pressure dro...The dynamic characteristics of a gas-solid fluidized bed with different rod promoters have been investigated in terms of bed expansion and fluctuation, minimum fluidization velocity and distributor-to-bed pressure drop ratio at minimum fluidization velocity. Experimentation based on statistical design has been carried out and model equations using factorial design of experiments have been developed for the above mentioned quantities for a promoted gas-solid fluidized bed. The model equations have been tested with additional experimental data. The system variables include four types of rod promoters of varying blockage volume, bed particles of four sizes and four initial static bed heights. A comparison between the predicted values of the output variables using the proposed model equation with their corresponding experimental ones shows fairly good agreement.展开更多
Synthesis of CuO nanoparticles by hydrothermal technique in presence of cetyltrimethylammonium bromide (CTAB) as surfactant was carried out by statistically designed experiments based on Box Behnken method. Reaction p...Synthesis of CuO nanoparticles by hydrothermal technique in presence of cetyltrimethylammonium bromide (CTAB) as surfactant was carried out by statistically designed experiments based on Box Behnken method. Reaction parameters as time, temperature and surfactant concentration have been studied to show their effect on CuO particle size and morphology. The results of experimental design indicate that the surfactant concentration, reaction time and temperature were significant in. CuO particles were characterized using XRD and SEM. These work findings showed that CuO nanoparticles were formed at 100oC. On other hand, their crystallinity was improved with rising temperature from 100 to 200oC to achieve particle size of CuO in the range of 49-92 nm.展开更多
药品生产上市申请人在开展关键注册临床试验之前,通常会和国家药品监督管理局药品审评中心(center for drug evaluation,CDE)针对临床试验方案开展沟通交流,咨询CDE关于试验设计等方面的考虑或者建议。本文将对临床试验方案沟通交流中...药品生产上市申请人在开展关键注册临床试验之前,通常会和国家药品监督管理局药品审评中心(center for drug evaluation,CDE)针对临床试验方案开展沟通交流,咨询CDE关于试验设计等方面的考虑或者建议。本文将对临床试验方案沟通交流中常见的统计学设计咨询问题进行总结和分析解答,以期为同类问题的解决提供参考和帮助,指导关键注册临床试验的设计与实施,加快药品上市的进程,提高药物研发的效率。展开更多
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11504264,51501128,and 61274064)
文摘A versatile and reliable approach is created to fabricate wafer-scale colloidal crystal that consists of a monolayer of hexagonally close-packed polystyrene （PS） spheres. Making wafer-scale colloidal crystal is usually challenging, and it lacks a general theoretical guidance for experimental approaches. To obtain the optimal conditions for self-assembly, a systematic statistical design and analysis method is utilized here, which applies the pick-the-winner rule. This new method combines spin-coating and thermal treatment, and introduces a mixture of glycol and ethanol as a dispersion system to assist self-assembly. By controlling the parameters of self-assembly, we improve the quality of colloidal crystal and reduce the effect of noise on the experiment. To our best knowledge, we are first to pave this path to harvest colloidal crystals. Importantly, a theoretical analysis using an energy landscape base on our process is also developed to provide insights into the PS spheres＇ self-assembly.
文摘The dynamic characteristics of a gas-solid fluidized bed with different rod promoters have been investigated in terms of bed expansion and fluctuation, minimum fluidization velocity and distributor-to-bed pressure drop ratio at minimum fluidization velocity. Experimentation based on statistical design has been carried out and model equations using factorial design of experiments have been developed for the above mentioned quantities for a promoted gas-solid fluidized bed. The model equations have been tested with additional experimental data. The system variables include four types of rod promoters of varying blockage volume, bed particles of four sizes and four initial static bed heights. A comparison between the predicted values of the output variables using the proposed model equation with their corresponding experimental ones shows fairly good agreement.
文摘Synthesis of CuO nanoparticles by hydrothermal technique in presence of cetyltrimethylammonium bromide (CTAB) as surfactant was carried out by statistically designed experiments based on Box Behnken method. Reaction parameters as time, temperature and surfactant concentration have been studied to show their effect on CuO particle size and morphology. The results of experimental design indicate that the surfactant concentration, reaction time and temperature were significant in. CuO particles were characterized using XRD and SEM. These work findings showed that CuO nanoparticles were formed at 100oC. On other hand, their crystallinity was improved with rising temperature from 100 to 200oC to achieve particle size of CuO in the range of 49-92 nm.
文摘药品生产上市申请人在开展关键注册临床试验之前,通常会和国家药品监督管理局药品审评中心(center for drug evaluation,CDE)针对临床试验方案开展沟通交流,咨询CDE关于试验设计等方面的考虑或者建议。本文将对临床试验方案沟通交流中常见的统计学设计咨询问题进行总结和分析解答,以期为同类问题的解决提供参考和帮助,指导关键注册临床试验的设计与实施,加快药品上市的进程,提高药物研发的效率。
