Results 41 to 50 of about 4,101 (143)
Investigation of the kinetic and fixed-bed reactor for selective oxidation of durene to pyromellitic dianhydride [PDF]
, 2014 均苯四甲酸二酐（英文简称PMDA）是一种非常重要的有机化工原料，其用途广泛，是生产有机高分子材料聚酰亚胺的关键单体。国内外均苯四甲酸二酐供不应求，具有非常广阔的市场前景。目前国内外主要采用均四甲苯气相氧化法生产均苯四甲酸二酐，该法工艺较简单，污染小，易实现自动化控制，但是该工艺普遍存在均苯四甲酸二酐收率较低的问题，为此许多研究人员在研制高效催化剂方面做了大量工作，但是对于该反应体系热力学、动力学及反应器方面的研究却少之甚少,而这些对反应器及工艺的分析设计具有重要意义。因此本文对该反应体系的热力学 ...
曹茂洪
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Transient Characteristics Analysis of He-Xe Cooled Space Reactor Coupled with Brayton Cycle Nuclear Power System [PDF]
Space nuclear power is crucial for future space missions, providing reliable energy for long-duration operations. Gas-cooled nuclear reactors, with high coolant outlet temperatures, are well-suited for integration with a closed Brayton cycle to achieve ...
WU Yangmao1, 2, TANG Simiao1, 2, ZHU Longxiang1, 2, LIAN Qiang1, 2, ZHANG Luteng1, 2, MA Zaiyong1, 2, SUN Wan1, 2, PAN Liangming1, 2
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World Water Policy, Volume 10, Issue 3, Page 971-985, August 2024.Abstract Quality water is essential to people's health and social and economic well‐being. Evaluation of the quality of the water sources provides benchmark data on quality status and insights into the development of further protective measures. A laboratory‐based cross‐sectional study design was conducted in the diarrheal hotspot area of the North ...
Tsegahun Asfaw Abebe +5 more
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Gaoya dianqi, 2017 为提高变压器的热模型准确性,在35 kV变压器绕组上布置了基于光纤光栅（fiber bragg grating,FBG）温度传感器的测温系统,实时、精确地获取变压器内部的热点温度,充分掌握了变压器绕组温度的分布情况。通过与传统热模型计算结果进行的对比分析,结果表明:绕组热点出现在距顶端1/4处,且理论计算值平均高于测量结果3.29℃。为准确获取变压器绕组热点温度和热路模型,建议将光纤测温技术推广应用至高电压等级变压器上,以实测数据构建变压器绝缘性能及暂态过载能力的评判依据 ...
李鑫 +5 more
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Influence of microclimate and forest management on bat species faced with global change
Conservation Biology, Volume 38, Issue 4, August 2024.Abstract Climate refugia, areas where climate is expected to remain relatively stable, can offer a near‐term safe haven for species sensitive to warming temperatures and drought. Understanding the influence of temperature, moisture, and disturbance on sensitive species is critical during this time of rapid climate change.
Chelsea L. Andreozzi +3 more
wiley +1 more source
Gaoya dianqi, 2016 为更准确地掌握树脂浇注干式变压器的内部温度场分布,为变压器的绝缘寿命评估提供依据,在分析变压器产热散热机理及导热途径的基础上,依据干式变压器的实际对流传热和热辐射特性及温度场计算的流固耦合模型,在多物理场仿真软件COMSOL中实现了树脂浇注干式变压器温度场分布的建模计算,得到了干式变压器铁心和绕组的温度分布。同时将计算结果与干式变压器温升试验实测数据进行了对比,两者吻合较好,误差±5.5%,说明了计算结果的正确性。此外,计算结果表明:干式变压器绕组和铁心底部到顶部的温度分布呈现低—高—低走势 ...
刘国坚, 王丰华
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Jianzhu Gangjiegou Jinzhan, 2023 外墙保温性能是制约装配式钢结构建筑推广应用的关键问题之一，目前对于钢结构外围护体系热工性能的研究还不充分，尚无关于我国严寒地区钢结构框架-ALC外墙传热机理和热桥效应的相关研究。针对严寒地区气候特点和建筑节能要求，基于ABAQUS软件，开展了钢结构框架-ALC外墙的传热性能有限元分析，揭示了钢梁、钢管混凝土柱以及梁柱节点等对墙体热工性能的影响机理，分析了保温体系类型、保温层热阻、ALC墙板热阻、钢梁连接件类型、框架柱截面形式、有无楼板等对墙体平均传热系数、热桥效应和内表面温度的影响。结果表明 ...
张相勇 +5 more
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Conservation Biology, Volume 38, Issue 1, February 2024.Abstract Identifying locations of refugia from the thermal stresses of climate change for coral reefs and better managing them is one of the key recommendations for climate change adaptation. We review and summarize approximately 30 years of applied research focused on identifying climate refugia to prioritize the conservation actions for coral reefs ...
Tim R. McClanahan +13 more
wiley +1 more source
, 2002 研究了在常规加热和微波辐射两种不同加热方式下ZnNi/HZSM 5催化剂上混合碳四烃及正己烷芳构化反应的性能 .考察了高 /径比、反应温度及反应时间对反应性能的影响 .探讨了微波辐射诱导催化反应的作用机理
万惠霖 +4 more
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Gaoya dianqi, 2013 开关柜内接触发热是造成柜内导体过热及绝缘损坏的主要原因。以典型箱式固定式开关柜XGN2-12/3150为研究对象,利用三维建模软件Solidworks及有限元分析软件ANSYS中进行开关柜接触发热温度场数值仿真。对额定电流运行时不同接触电阻造成局部过热状态下的高压开关柜温度场分布进行了数值计算和比较,计算分析认为隔离开关旋转触头、断路器触头、母排压接接头处的局部发热最高温度随接触电阻的增加呈线性增大趋势。在接头附近设置的温度监控点的温度与实际最高温度间的温差随接触电阻的增大而增大 ...
王秉政 +5 more
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