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排序方式: 共有1014条查询结果,搜索用时 62 毫秒
931.
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With the consideration of higher modes, an attempt is made to develop a spectral-acceleration-based linear combination-type earthquake intensity measure (IM) for high-rise buildings. The modal mass participation factors are determined to take weighting coefficients. A parametric analysis on the correlation between IM and the maximum interstory drift that utilizes the bend-shear coupled continuum model yields a bilinear relationship between the optimal number of modes involved and structural fundamental period. The proposed IM and several other combination-type IMs are shown to be efficient and sufficient, while the scaling robustness of the proposed IM is more stable compared with that of fundamental-mode-based IMs. 相似文献
933.
Qun Zhang Qian Wang Boyu Kong Chunxue Wang Dongya Yang Hong Zhu Quanchao Zhang 《Archaeological and Anthropological Sciences》2018,10(6):1319-1327
This study uses multiple scientific methods to analyse a case of trepanation from a cemetery located at the westernmost point along the ancient Silk Road in China dating back to the Early Iron Age. The skull of interest belonged to a middle-aged male; the opening is located on the left posterior side of the skull in the occipital bone. Computer tomography (CT) and microscopic observation show that the incision was unhealed, indicating an immediate death either during or after the operation. The procedure of trepanation might have been used to treat a depressed fracture from inflicted trauma on the individual’s right parietal bone, suggesting the presence of surgical trepanation in early Western China. 相似文献
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Tanya E. von Hunnius Dongya Yang Barry Eng John S. Waye Shelley R. Saunders 《Journal of archaeological science》2007,34(12):2091-2100
The search for the origins of syphilis has a long history in the medical and anthropological literatures. If we know more about the emergence of the pathogen that causes the disease in humans we will understand its evolution through time and space as well as shed light on its current state in living populations. Ancient DNA techniques used to isolate Treponema pallidum subsp. pallidum DNA from archaeological human specimens provide direct evidence of its existence in the past. However to date, only Kolman et al. (1999) have been successful in this endeavour, while other attempts have failed (e.g., Barnes and Thomas, 2006; Bouwman and Brown, 2005). Why has there been little success? This paper serves to compliment and add relevant information to Bouwman and Brown's and Barnes and Thomas' discussion concerning our inability to apply ancient DNA techniques to study venereal syphilis in past human populations.Our approach utilized 15 different human specimens from different geographies and different temporal periods: eight samples come from medically diagnosed individuals archived during the American Civil War period; six originate from the United Kingdom and predate 1492 with four of these samples having been previously analyzed by Bouwman and Brown and one sample comes from historic Canada. Human mitochondrial and amelogenin DNA, as well as several genes from the Treponema organism were analyzed revealing the relatively good preservation of human multi-copy and single copy DNA but not treponemal DNA. This study also incorporates a unique molecular experiment using rabbits infected with venereal syphilis to help illustrate that treponemal DNA disseminates to bone early during the first stages of infection but is not present in later stages of the disease using the techniques presented in this study. 相似文献
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1926年底到1927年夏,武汉国民党人的政策从左向右,发生了180度的大转变。导致武汉国民党人政策变化的一个重要原因,是共产党影响下的工农运动的迅猛发展。因为它严重损害了武汉政府赖以生存的脆弱的财政经济基础和军官们的忠诚度。事实上,无论是武汉国民党中央,还是中共中央,这时都曾极力控制工农运动。但中共基层干部的缺乏,特别是在联共(布)党内权力斗争推动下斯大林对中国革命政策的赤裸裸的干涉,不仅使中共的工农政策无法顺应形势做出相应的切实调整,而且更极大地刺激了武汉国民党人的疑惧心理。武汉国民党人从"联共"最终走向"分共",与此不无关联。 相似文献
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