主题语境:人物故事篇幅:360词建议用时:7分钟.1 After nearly two weeks lost in the remote Western Australian bush,26-year-old backpacker Carolina Wilga has been found alive and is now recovering in a Perth hospital.Her su...主题语境:人物故事篇幅:360词建议用时:7分钟.1 After nearly two weeks lost in the remote Western Australian bush,26-year-old backpacker Carolina Wilga has been found alive and is now recovering in a Perth hospital.Her survival story is being described as nothing short of a miracle.展开更多
Elaeagnaceae Juss. belongs to the family Elaeagnus L. and Shepherdia Nutt. This study aims at the significance and vegetative reproduction of species of the family (Elaeagnus macrophylla Thunb. and Shepherdia canadens...Elaeagnaceae Juss. belongs to the family Elaeagnus L. and Shepherdia Nutt. This study aims at the significance and vegetative reproduction of species of the family (Elaeagnus macrophylla Thunb. and Shepherdia canadensis (L.) Nutt.) in the national economy. The trials were carried out in the experimental site of SamSU’s Botanic Garden, which is named after Sharof Rashidov. The study’s findings are based on the results obtained by planting cuttings of S. canadensis and E. macrophylla species of varying sizes and durations, as well as the cuttings’ roots and the impacts of growth chemicals.展开更多
In Xinjiang,China,Oil-immersed paper bushings used in reactors are highly susceptible to discharge breakdown faults due to drastic fluctuations in environmental and oil temperatures.To mitigate this problem,oil-free a...In Xinjiang,China,Oil-immersed paper bushings used in reactors are highly susceptible to discharge breakdown faults due to drastic fluctuations in environmental and oil temperatures.To mitigate this problem,oil-free and explosion-proof epoxy resin-impregnated paper(ERIP)bushings are recommended as replacements.This study develops a multi-physics(electric-thermal-fluid)coupling model for 750 kV high voltage reactors ERIP bushings.The model aims to comprehensively assess their thermal and electrical performance under extreme ambient temperatures ranging from−40℃ to 90℃ and oil temperatures varying from−10℃ to 90℃.The results demonstrate that the bushing temperature rises consistently with increases in ambient temperature.Additionally,the location of the hottest point on the conductive rod exhibits an upward shift as the ambient temperature climbs.Significantly,when a temperature difference exists between the oil and the external environment,this upward movement remains relatively constrained.Even when the external temperature increases from−40℃ to 80℃,the hottest point shifts upward only 2457 mm.Conversely,in the absence of a temperature difference between the oil and external environment,a modest 10℃ increase in ambient temperature(from 80℃ to 90℃)triggers a substantial 11,356 mm upward displacement of the hottest point.Moreover,this study reveals that the electric field distribution within the bushings remains largely unaffected by environmental temperature changes.展开更多
The influences of power spinning process parameters on the mechanical properties of spinning parts were analyzed with an SXD100/3-CNC numerical control power spinning machine.The unidirectional tensile tests were carr...The influences of power spinning process parameters on the mechanical properties of spinning parts were analyzed with an SXD100/3-CNC numerical control power spinning machine.The unidirectional tensile tests were carried out.Based on the experimental data,a ternary quadratic regression equation was established by orthogonal experiment.The Ramberg-Osgood constitutive model of tin-bronze connecting rod bushing was obtained.Referred to the constitutive relation of macroscopic incremental,the incremental elastoplastic constitutive relation of spinning parts was deduced based on the Mises yield criterion and kinematic hardening model.The results can be applied to the elastoplastic analysis in finite element numerical simulation.展开更多
以某型号着陆器软着陆机构为研究对象,采用MSC.Patran/Nastran对软着陆机构进行模态分析,得到结构模态的主要影响因素,主要包括机构尺寸和装配连接方式.主要分析了软着陆机构中主支柱、辅助支柱活塞杆和活塞筒壁厚、以及活塞筒端盖厚度...以某型号着陆器软着陆机构为研究对象,采用MSC.Patran/Nastran对软着陆机构进行模态分析,得到结构模态的主要影响因素,主要包括机构尺寸和装配连接方式.主要分析了软着陆机构中主支柱、辅助支柱活塞杆和活塞筒壁厚、以及活塞筒端盖厚度对模态频率的影响,并对主支柱、辅助支柱活塞杆和活塞筒装配连接方式进行研究,接着提出一种基于Bush单元的装配连接方式,有效地解决了传统方法中用MPC(Multiple Point Constraint)刚性连接来模拟装配连接的不足,使仿真结果更加准确.最后对收拢状态下的模型进行了频率响应分析,结果发现在给定的频率范围内结构不会发生共振,进一步说明结构设计的合理性.展开更多
文摘主题语境:人物故事篇幅:360词建议用时:7分钟.1 After nearly two weeks lost in the remote Western Australian bush,26-year-old backpacker Carolina Wilga has been found alive and is now recovering in a Perth hospital.Her survival story is being described as nothing short of a miracle.
文摘Elaeagnaceae Juss. belongs to the family Elaeagnus L. and Shepherdia Nutt. This study aims at the significance and vegetative reproduction of species of the family (Elaeagnus macrophylla Thunb. and Shepherdia canadensis (L.) Nutt.) in the national economy. The trials were carried out in the experimental site of SamSU’s Botanic Garden, which is named after Sharof Rashidov. The study’s findings are based on the results obtained by planting cuttings of S. canadensis and E. macrophylla species of varying sizes and durations, as well as the cuttings’ roots and the impacts of growth chemicals.
基金supported by the Reliability Improvement Technology and Application of Epoxy Impregnated Paper Bushing in Extreme Environments under granted DQ30DK24001P.
文摘In Xinjiang,China,Oil-immersed paper bushings used in reactors are highly susceptible to discharge breakdown faults due to drastic fluctuations in environmental and oil temperatures.To mitigate this problem,oil-free and explosion-proof epoxy resin-impregnated paper(ERIP)bushings are recommended as replacements.This study develops a multi-physics(electric-thermal-fluid)coupling model for 750 kV high voltage reactors ERIP bushings.The model aims to comprehensively assess their thermal and electrical performance under extreme ambient temperatures ranging from−40℃ to 90℃ and oil temperatures varying from−10℃ to 90℃.The results demonstrate that the bushing temperature rises consistently with increases in ambient temperature.Additionally,the location of the hottest point on the conductive rod exhibits an upward shift as the ambient temperature climbs.Significantly,when a temperature difference exists between the oil and the external environment,this upward movement remains relatively constrained.Even when the external temperature increases from−40℃ to 80℃,the hottest point shifts upward only 2457 mm.Conversely,in the absence of a temperature difference between the oil and external environment,a modest 10℃ increase in ambient temperature(from 80℃ to 90℃)triggers a substantial 11,356 mm upward displacement of the hottest point.Moreover,this study reveals that the electric field distribution within the bushings remains largely unaffected by environmental temperature changes.
基金Project(2012011023-2)supported by the Natural Science Foundation of Shanxi Province,China
文摘The influences of power spinning process parameters on the mechanical properties of spinning parts were analyzed with an SXD100/3-CNC numerical control power spinning machine.The unidirectional tensile tests were carried out.Based on the experimental data,a ternary quadratic regression equation was established by orthogonal experiment.The Ramberg-Osgood constitutive model of tin-bronze connecting rod bushing was obtained.Referred to the constitutive relation of macroscopic incremental,the incremental elastoplastic constitutive relation of spinning parts was deduced based on the Mises yield criterion and kinematic hardening model.The results can be applied to the elastoplastic analysis in finite element numerical simulation.
文摘以某型号着陆器软着陆机构为研究对象,采用MSC.Patran/Nastran对软着陆机构进行模态分析,得到结构模态的主要影响因素,主要包括机构尺寸和装配连接方式.主要分析了软着陆机构中主支柱、辅助支柱活塞杆和活塞筒壁厚、以及活塞筒端盖厚度对模态频率的影响,并对主支柱、辅助支柱活塞杆和活塞筒装配连接方式进行研究,接着提出一种基于Bush单元的装配连接方式,有效地解决了传统方法中用MPC(Multiple Point Constraint)刚性连接来模拟装配连接的不足,使仿真结果更加准确.最后对收拢状态下的模型进行了频率响应分析,结果发现在给定的频率范围内结构不会发生共振,进一步说明结构设计的合理性.
