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核态沸腾中汽化核心密度的分形分布 总被引:1,自引:0,他引:1
本文首先回顾了在核态沸腾传热中影响汽化核心密度分布的几个关键因素,然后运用分形理论讨论了加热壁面微结构和汽化核心密度之间的关系并分析了两个核态沸腾实验中汽化核心密度的数据。一个实验是考察加热壁面在老化过程中汽化核心密度的变化,另一个实验是考察两个不同材料制成的加热壁面上汽化核心密度的差异。实验数据分析结果表明汽化核心密度与最小成核半径之间呈分形关系。不同加热壁面对应不同的分形维数,分形维数是一个定量描述加热壁面状况的参数。 相似文献
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中药有效成分,是我国传统中药治疗疾病的物质基础。然而中药所含成分复杂,有效成分的提取分离成为了制约中药开发关键环节。传统提取法虽然工艺流程简单,易于生产实现,但在有效成分的提取上,普遍存在着周期长、提取率不高、杂质清除率低等问题法;而现代提取法虽然具有产率高、纯度高、提取速度快等优点,但这些新技术需要复杂的高耗电辅助设备,在规模化生产过程中导致了能耗的大幅度的上升,不利于产业化的实现。内部沸腾法对中药有效成分的提取有较好的效果,文章对该方法的研究进展作一个介绍。 相似文献
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热水锅炉锅水汽化是危及热水锅炉安全的严重问题,会给锅炉和热网带来很大的危害是热水锅炉正常工作所不允许的。本文主要分析热水锅炉锅水在突然停电时的汽化,压火停炉后的汽化,正常运行中的汽化,三种情况下的汽化,指出防止汽化和汽化后应采取的措施。 相似文献
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重点介绍了沸腾燃烧锅炉在燃烧过程中存在的主要问题,热效率低与磨损大。通过对燃烧过程、燃烧状态的分析,可采用一定防范措施加以治理、解决。 相似文献
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车用LPG蒸发减压器的汽化计算 总被引:1,自引:0,他引:1
陈淑玲 《内蒙古科技与经济》1999,(1):49-50
本文简要介绍了车用液化石油气(LPG)蒸发减压器的工作原理,较详细地讨论了LPG汽化计算方法。 相似文献
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哈锅工业锅炉设计开发中心应某市高新热力公司要求,对46MW热水锅炉汽化问题进行优化改造,并要求其满足锅炉参数条件。 相似文献
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离子液体是一种有机盐。由于其具有较低的熔点、良好的导电性和可以忽略的蒸汽压等优点,引起了科学界和工业界的广泛关注。近年来,随着研究的日益深入,离子液体已经被开发和应用到了诸多领域。 相似文献
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液体变阻器是一种用于改善大中型绕线异步电机启动性能的新型起动装置,其性能远优于频敏变阻器,具有起动平稳可靠、起动电流小、对电网、机械设备无冲击、能连续多次起动、投资少等优点.该文针对液体变阻器安装使用中的问题提出一些看法. 相似文献
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Apostasioideae, a small subfamily of Orchidaceae, is largely distributed in tropical
Asia with its northern limit extending to the Ryukyu Islands and south China. The first Chinese
species of this subfamily was reported by E. D. Merrill (1927) based on a specimen collected
from Hainan (McClure 9519, AMES), which he regarded as Apostasia wallichii R. Br. As
later labelled by E. F. de Vogel, it is in fact identical with A. odorata Bl., a widespread spe-
cies also found in southern Guangdong, Guangxi and Yunnan of China. It was not until re-
cently that the true A. wallichii was collected from southwestern Yunnan bordering on Burma,
which is initially reported here. In addition, an interesting new species, A. ramifera S. C. Chen
et K. Y. Lang, is described from Hainan.
The only Chinese species of Neuwiedia has long been known as N. veratrifolia Bl. (of.
Iconographia Cormophytorum Sinicorum 5: 602, t. 8034. 1976, and Flora Hainanica 4 180, t.
1078. 1977), which, however, was considered by de Vogel (1969) to be not found in China. In
de Vogel's revision, no Chinese taxon but a variety, N. zollingeri Rchb. f. var. singapureana
(Baker) de Vogel, is cited with some doubt based on a specimen of Hainan (F. C. How 73122,
in young fruit, AMES). N. zollingeri var. singapureana is in fact quite different from N.
veratrifolia by having glandular hair, much shorter inflorescence and flattened filaments. As
recently pointed out by de Vogel and G. Barretto (in Journ. Taiwan Museum 37: 78. 1984),
the plants found in Hongkong, as well as those in Guangdong and Yunnan, possess glandular
hair and short inflorescence. They are identical with the Vietnamese species N. balansae Gagnep.,
which was reduced by de Vogel to a synonym of N. zollingeri var singapureana. E. F. de
Vogel's suggestion seems to be acceptable except the varietal rank. It is treated here as a se-
parate species, N. singapureana (Baker) Rolfe, according to its fruit and hair characters. Thus
we have altogether one species of Neuwiedia and three species of Apostasia in China, including a new species and a newly recorded one. 相似文献