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New insights in nano-copper chromite catalyzing ultrafine AP:Evaluation of dispersity and mixing uniformity
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作者 Yong Kou Peng Luo +8 位作者 Lei Xiao yanping xin Guangpu Zhang Yubing Hu Junqing Yang Hongxu Gao Fengqi Zhao Wei Jiang Gazi Hao 《Defence Technology(防务技术)》 SCIE EI CAS CSCD 2024年第2期120-133,共14页
Improving the application of nanomaterials has always been a research hotspot in the field of energetic materials(EMs)due to their obvious catalytic effect on the EMs,especially the uniformly dispersed nanomaterials.H... Improving the application of nanomaterials has always been a research hotspot in the field of energetic materials(EMs)due to their obvious catalytic effect on the EMs,especially the uniformly dispersed nanomaterials.However,few studies have reported the dispersion of nanomaterials.In this study,the dispersity and mixing uniformity of nano-CuCr_(2)O_(4)was evaluated based on the difference of solid UV light absorption between the nano-catalytic materials and EMs.The nano-CuCr_(2)O_(4)/ultrafine AP composites with different dispersity of nano-CuCr_(2)O_(4)were prepared by manual grinding and mechanical grinding with different grinding strength and griding time.And then,the absorbance of different samples at 212 nm was obtained by solid UV testing due to the high repeatability of the absorbance at 210-214 nm for three parallel experiments,and the dispersity of different samples was calculated through the established difference equation.Furthermore,the samples were characterized by XRD,IR,SEM,EDS,DSC and TG-MS,which confirmed that different mixing methods did not change the structure of the samples(XRD and IR),and the mixing uniformity improved with the increase of grinding strength and grinding time(SEM and EDS).The scientificity and feasibility of the difference equation were further verified by DSC.The dispersity of nano-CuCr_(2)O_(4)exhibits a positive intrinsic relationship with its catalytic performance,and the uniformly dispersed nano-CuCr_(2)O_(4)significantly reduces the thermal decomposition temperature of ultrafine AP from 367.7 to 338.8℃.The TG-MS patterns show that the dispersed nano-CuCr_(2)O_(4)advanced the thermal decomposition process of ultrafine AP by about 700 s,especially in the high temperature decomposition stage,and the more concentrated energy release characteristic is beneficial to further enhance the energy performance of AP-based propellants.The above conclusions show that the evaluation method of dispersity based on solid UV curves could provide new ideas for the dispersity characterization of nano-catalytic materials in EMs,which is expected to be widely used in the field of EMs. 展开更多
关键词 Nano-CuCr_(2)O_(4) Ultrafine AP Dispersity UVeVis diffuse reflectance spectroscopy Thermal decomposition
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Effect of Refrigerant on the Performance of a C3/MRC Liquefaction Process
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作者 Xiao Wu Zhaoting Wang +2 位作者 Longfei Dong yanping xin Tianshu Yu 《Fluid Dynamics & Materials Processing》 EI 2023年第1期25-36,共12页
The Mixed Refrigerant(MR)component is an important factor influencing the performances of natural gas lique-faction processes.However,there is a lack of systematic research about the utilization of propane pre-cooled(... The Mixed Refrigerant(MR)component is an important factor influencing the performances of natural gas lique-faction processes.However,there is a lack of systematic research about the utilization of propane pre-cooled(C3/MRC).In this paper,this mixed refrigerant cycle liquefaction process is simulated using the HYSYS software and the main influential parameters involved in the process are varied to analyze their influence on the liquefaction rate and power consumption.The results show that an effective way for lowering the power consumption of the compressor consists of reducing the flow through the compressor through optimization of the percentage of mixed refrigerant.The power consumption of the compressor in the hybrid refrigeration process is affected by both flow and pressure ratios.Its specific power consumption can be reduced by increasing the flow and decreasing the pressure ratio at the same time.The increase in refrigerant pressure at the high-pressure end can significantly mitigate the energy loss of the heat exchanger and compressor. 展开更多
关键词 REFRIGERANT C3/MRC process liquefaction performance power consumption pressure ratio hybrid refrigeration process
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5-Demethylnobiletin and its major metabolites:efficient preparation and mechanism of their anti-proliferation activity in HepG2 cells
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作者 yanping xin Ting Zheng +7 位作者 Man Zhang Ruiqiang Zhang Siyue Zhu Dongli Li Denggao Zhao Yanyan Ma Chi-Tang Ho Qingrong Huang 《Food Science and Human Wellness》 SCIE 2022年第5期1191-1200,共10页
5-Demethylnobile tin(5-DMN),a hydroxylated polymethoxyflavone(OH-PMF)identified in aged citrus peels,has demonstrated health benefiting effects in previous studies.5-DMN undergoes biotransformation in vivo,yielding 5,... 5-Demethylnobile tin(5-DMN),a hydroxylated polymethoxyflavone(OH-PMF)identified in aged citrus peels,has demonstrated health benefiting effects in previous studies.5-DMN undergoes biotransformation in vivo,yielding 5,3’-didemethylnobiletin(5,3’-DDMN),5,4’-didemethylnobiletin(5,4’-DDMN)and5,3’,4’-tridemethylnobiletin(5,3’,4’-TDMN).However,the anti-cancer effects of 5-DMN and its in vivo metabolites against HepG2 cells remain unclear.In this study,an efficient chemical synthetic method was developed to obtain 5-DMN and its 3 metabolites,and their molecular structures were confirmed by;H NMR and LC-MS.Cytotoxicity,cell cycle arrestment,apoptosis and caspase-3 expression were investigated to evaluate the anti-liver cancer effects of these OH-PMFs on HepG2 cells.The results showed that all 4 compounds inhibited the proliferation of HepG2 cells in a concentration-dependent manner.Their anti-proliferative activity was exerted through inducing G2/M phase arrestment,cell apoptosis and promoting expression of a key apoptotic protein called cleaved caspase-3.Our results indicated that 5,3’-DDMN and5,3’,4’-TDMN showed a stronger inhibitory activity on cell proliferation than 5-DMN,followed by 5,4’-DDMN.The expression of cleaved caspase-3 was the highest in cells treated with 5,4’-DDMN,implying that the apoptosis induced by other OH-PMFs might be mediated by other apoptotic execution proteins.Our research reveals the application potential and scientific evidence for the production and functionality of OH-PMFs. 展开更多
关键词 Hydroxylated polymethoxyflavones Chemical synthesis HEPG2 Cell cycle APOPTOSIS
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视频提示法对孤独症学生价格比较技能的干预研究 被引量:6
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作者 柳笛 张铎 +1 位作者 毛祎雯 yanping xin 《中国特殊教育》 CSSCI 北大核心 2022年第4期80-88,共9页
价格比较作为一项实用数学技能,能提升孤独症学生的社会适应能力与独立生活能力。研究采用单一被试实验中的跨被试多探测实验设计,选取三名8—10岁的孤独症学生,探索视频提示法对孤独症学生价格比较技能的干预效果。研究结果表明,干预... 价格比较作为一项实用数学技能,能提升孤独症学生的社会适应能力与独立生活能力。研究采用单一被试实验中的跨被试多探测实验设计,选取三名8—10岁的孤独症学生,探索视频提示法对孤独症学生价格比较技能的干预效果。研究结果表明,干预后三名被试价格比较任务的正确率有明显提高,且干预维持效果良好,在社区超市里泛化效果良好。基于以上发现,本研究提出对未来教学实践的建议。 展开更多
关键词 孤独症 视频提示 价格比较
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