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A New Species of the Genus Thermophis(Serpentes: Colubridae) from Shangri-La, Northern Yunnan, China, with a Proposal for an Eclectic Rule for Species Delimitation 被引量:5
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作者 Lifang PENG Changhu LU +2 位作者 Song HUANG Peng GUO Yaping ZHANG 《Asian Herpetological Research》 SCIE 2014年第4期228-239,共12页
The hot-spring snakes,Thermophis, were previously known only from the Tibet Autonomous Region and Western Sichuan, China. During the past two years, three adult hot-spring snakes (2 females, 1 male) were sampled in ... The hot-spring snakes,Thermophis, were previously known only from the Tibet Autonomous Region and Western Sichuan, China. During the past two years, three adult hot-spring snakes (2 females, 1 male) were sampled in Shangri-La, northern Yunnan, China, thus expanding their known distribution region towards the southeast. This site is the southeastern-most corner of the Tibetan Plateau and the southernmost tip of the Hengduan Mountains (Mts.). Phylogenetic analysis of mitochondrial (mt) and nuclear (n) DNA segments suggested that the three specimens belong to the genus ofThermophis. Morphologically, the new species is more similar toT. zhaoermii. However, it is distinguished fromT.zhaoermiiin the number of maxillary teeth (15), distance between the two eyes/head width, rostral width/height, mental width/height, in one character limited to female: head width/length, and in four characters restricted to male: occurrence of the reduction from 10 to 8 (8 to 6, 6 to 4) scales in each dorsal row on the tail. There are differences in morphology, genetics (mtDNA, nDNA), and geography between the putative new species andT.zhaoermii,the new species meets our proposed eclectic and feasible "four-differences" rule. 展开更多
关键词 morphology PHYLOGENETICS "four-differences" rule thermophis Shangrila sp. nov.
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Tibetan Plateau Relict Snakes of the Genus Thermophis and Their Relationship to New World Relict Snakes 被引量:1
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作者 Xiaoyu SUN Shaoying LIU Song HUANG 《Asian Herpetological Research》 SCIE 2011年第3期161-168,共8页
The complete mitochondrial NADH dehydrogenase subunit 2(ND2) gene sequences of two species of Thermophis, T. baileyi and T. zhaoermii, were sequenced and compared to those of 86 sequences from other snakes(74 from Cae... The complete mitochondrial NADH dehydrogenase subunit 2(ND2) gene sequences of two species of Thermophis, T. baileyi and T. zhaoermii, were sequenced and compared to those of 86 sequences from other snakes(74 from Caenophidia and 12 from Henophidia). By using Bayesian inference(BI) and maximum likehood(ML) approaches, Thermophis was demonstrated as the sister group to the North American relicts of Dipsadinae, and rooted in Central and South American members of this subfamily. The results suggest that the closest relatives of Thermophis are the North American relicts, and thus support the hypothesis for an Asian-North American origin of xenodontine snakes as suggested by Vidal et al.(2000). Extensive sampling of Asian snakes and American dipsadines is needed to further test this hypothesis in the future. 展开更多
关键词 thermophis TIBET Dipsadinae ND2 Asian-North American origin
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三维横向紊动射流流场结构的数值分析 被引量:10
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作者 郭婷婷 李少华 徐忠 《动力工程》 CAS CSCD 北大核心 2004年第2期244-248,共5页
对横向紊动射流流场结构、流动机理的研究具有重要的学术意义,同时对解决工程应用中存在的许多问题具有指导作用。利用RNG模型对横流中单股紊动射流流场的流动特性进行了数值模拟。运用SIMPLEC算法求解了适体坐标系下的控制方程,壁面函... 对横向紊动射流流场结构、流动机理的研究具有重要的学术意义,同时对解决工程应用中存在的许多问题具有指导作用。利用RNG模型对横流中单股紊动射流流场的流动特性进行了数值模拟。运用SIMPLEC算法求解了适体坐标系下的控制方程,壁面函数法处理近壁区流动。得到了射流与主气流速度比为2和4的流场。结果表明:较大的射流速度对主气流流场影响大;射流内部已形成明显的反向涡旋对(CVP);射流喷孔上游处出现了主气流向喷孔内部流动的趋势;射流喷孔背风侧存在尾迹区。 展开更多
关键词 工程热物理 紊动射流 湍流模型 数值模拟 流场
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气化炉液池内单个高温气泡传热、传质的数值模拟 被引量:4
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作者 吴晅 李铁 袁竹林 《动力工程》 EI CSCD 北大核心 2008年第3期415-419,共5页
建立了气、液间传热传质数学模型,对单个热气泡在上升过程中与处于蒸发阶段的水之间的传热、传质规律进行了数值研究,获得了气泡半径、气泡温度、水蒸发速率以及蒸发量随时间的变化规律.研究表明:在水恒温蒸发阶段,由于传热传质的共同作... 建立了气、液间传热传质数学模型,对单个热气泡在上升过程中与处于蒸发阶段的水之间的传热、传质规律进行了数值研究,获得了气泡半径、气泡温度、水蒸发速率以及蒸发量随时间的变化规律.研究表明:在水恒温蒸发阶段,由于传热传质的共同作用,气泡半径随着气泡的上升而变小,并逐渐趋于稳定;随着气、液间温度差的增大,气泡半径缩小得越快;在气泡与水开始接触时,水的蒸发速率及气泡内的水蒸汽增量最大;气泡温度在较短时间内急剧下降,并趋于稳定;随着气泡半径的缩小,气泡冷却速率提高;但随着接触时间的继续增加,对气体的冷却效果却无明显作用. 展开更多
关键词 工程热物理 气化炉 激冷室 气泡 传热 传质 直接接触
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高湿空气在高温高压区域内的热物性计算及分析 被引量:5
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作者 杨文滨 苏明 《动力工程》 CSCD 北大核心 2004年第3期383-387,410,共6页
首先介绍了湿空气热物性的3种计算方法:工程计算法、基于维里方程的余函数计算法和基于R-K方程的余函数计算法,继而采用这3种方法对湿空气在不同压力、温度、湿度下的比容、焓值进行了计算,还对湿空气达到饱和状态时的含湿量进行了计算... 首先介绍了湿空气热物性的3种计算方法:工程计算法、基于维里方程的余函数计算法和基于R-K方程的余函数计算法,继而采用这3种方法对湿空气在不同压力、温度、湿度下的比容、焓值进行了计算,还对湿空气达到饱和状态时的含湿量进行了计算,计算完成后对计算结果进行了比较分析;结论认为3种方法对比容的计算不会产生很大偏差;压力、温度、湿度在不同的区域对焓值的影响各有不同;采用基于R-K方程的余函数计算法计算的饱和含湿量要高于采用工程计算法所计算的饱和含湿量5%~10%,很好的反映了实际的湿化情况。 展开更多
关键词 工程热物理 HAT循环 湿空气 热物性
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