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1.
试论人类身高的地域差异规律及其成因   总被引:1,自引:0,他引:1  
人类身高高纬高于低纬,牧区高于农区、沿海高于内地、低海拔高于高海拔、城市高于农村、发达国家高于发展中国家。其主要原因是气温的高低、光照的多少和营养的差异。  相似文献   
2.
The bodies and glazes of 27 early Western Zhou proto‐porcelain samples from Yejiashan cemetery, Hubei Province, were analysed using LA‐ICP–AES, SEM, XRD, a thermal expansion instrument and other analytical methods. The results indicated that the bodies of all samples were characterized by high silicon and low aluminium, and were made with porcelain stone raw materials found in the south of China. The glazes are typical of high‐temperature calcium glazes of the CaO (MgO) – K2O (Na2O) – Al2O3 – SiO2 series, with relatively high Mn and P content, which was probably caused by the addition of plant ashes. The physical properties and phase compositions of Yejiashan proto‐porcelain show that firing processes were still in the early stages of development in ancient China. Multivariate statistical analyses indicated that Yejiashan proto‐porcelain might have come from the Deqing area, in Zhejiang Province. These results provide new archaeological evidence for research on issues related to material flow in the Western Zhou dynasty.  相似文献   
3.
古砖的烧制温度决定了其物理力学性质。本研究提出基于磁化率来确定古砖烧制温度的方法。通过对古砖重新加温,测量不同温度下古砖的磁化率,得到磁化率差值的平方-温度曲线图。图中第一个较大的偏差对应的横坐标即为古砖的烧制温度。利用上述方法测得实际烧制温度为700℃、800℃和900℃的黏土砖的烧制温度分别为690℃、810℃和870℃。二者误差较小,认为利用该方法确定砖的烧制温度可行。本研究利用该方法确定了平遥古城10块古砖的烧制温度,发现其烧制温度在650~690℃和850~870℃两个区间范围内。据此推测平遥古城古砖是以秸秆和木柴为燃料烧制而成。本研究实验结果可为古建筑修复和保护提供理论参考。  相似文献   
4.
本文利用激光拉曼光谱仪和能量色散X-射线荧光光谱仪对21件取自故宫博物院院藏宋代官窑完整器及42件取自杭州老虎洞官窑窑址的青瓷样品表面釉层进行了测量与分析。通过计算瓷釉样品拉曼光谱中位于500cm-1附近宽带与位于1000cm-1附近宽带的面积比值(Ip值)及利用EDXRF分析样品的元素成分,讨论了这些样品的主要助熔剂成分Ca O、K2O含量与Ip值之间的关系,并通过对成分具有两类典型官窑瓷器釉料特征且在不同烧成温度下烧制的模拟釉块进行拉曼分析,对宋官窑青瓷样品的釉烧温度进行了讨论。  相似文献   
5.
Historical park visitation and weather data, taken at the daily time scale from 2000 to 2009 for Pinery Provincial Park in southern Ontario (Canada), were analysed as an objective measure of the weather sensitivity, temperature thresholds, and potential impacts of projected climate change for park visitation. Three seasonal weather-visitation models were constructed using multivariable linear regression (peak, shoulder, off-season). To account for both natural and institutional seasonality, the weather-visitation models included both climatic (temperature, precipitation) and social (weekends, holidays) variables, which demonstrated equably comparable effects on visitation across the three models. Critical temperature thresholds were identified for each season using one-way analysis of variance to determine the range of temperatures within which the threshold was evident; the specific degree of temperature associated with the threshold was identified within the seasonal regression models. Temperatures over 33 °C during the peak season and over 29 °C during the shoulder season indicated critical thresholds at which point conditions that were ‘too hot’ for some caused a decline in visitation. Furthermore, temperatures below 11 °C indicated another critical threshold, where conditions were ‘too cold’ for most and therefore park visitation was less sensitive to temperature variability below this threshold. A partial sensitivity analysis for the impact of a warmer, wetter climate on park visitation was conducted, illustrating the effect of a 1 °C to 5 °C warming in maximum temperatures, coupled with a 5% to 15% increase in total precipitation. In response to projected climate change, the weather-visitation models suggested that for each additional degree of warming experienced, despite the negative effects of increasing precipitation and more frequent heat extremes, annual park visitation could increase by 3.1%, annually. The projected increase in park visitation as a result of rising temperatures was mainly associated with shoulder season visitation, with only minor increases in peak season visitation.  相似文献   
6.
The presence and properties of long‐range correlations in temperature data reflect interactions among climate components; therefore, the quantitative characterization of scaling aspects of temperature patterns is important to climate research and can serve as an effective constituent of tests for climate models. The article presents the results of a study using multiscale characterization of daily atmospheric surface temperature patterns in Atlantic Canada. Important influences in this region are exerted from the west (the Pacific Ocean), the south (the Gulf of Mexico) and the north (the Arctic), while a significant easterly impact is due to the Atlantic Ocean; the corresponding processes involve a wide range of spatial and temporal scales. The objective of the present study of long‐term temperature recordings was to evaluate the scaling properties produced in this geographical context. The data consist of homogenized daily atmospheric temperature time series recorded in stations from Atlantic Canada over a time interval of more than 100 years. Detrended fluctuation analysis (DFA) was applied both to maximum and minimum temperature records. The atmospheric temperature pattern produced by the interplay of factors of different strengths and dominating various time‐space scales was found to be characterized by consistent scaling properties, expressed over time intervals ranging from months to decades. Higher values of DFA scaling exponents were obtained for minimum temperature compared to maximum temperature records. Site‐specific properties include stronger pattern persistence—higher DFA exponents—for oceanic than for coastal locations; persistence tends to decrease with increasing distance from the coast for distances up to 10 kilometres. Scaling exponents tend to increase with decreasing difference between average minimum and maximum temperature, which may be relevant for the assessment of future changes in pattern variability if climate change involves modified contrasts between minimum and maximum temperature values.  相似文献   
7.
Almost all archaeological ceramics undergo slow, progressive rehydroxylation by chemical combination with environmental water. The reaction is accompanied by an expansion, and also by the small but measurable mass gain that provides the basis of the RHX dating method. The rate of the RHX reaction increases with increasing temperature. Here we describe comprehensively the effects of temperature on the RHX process in relation to the dating methodology. We deal in turn with the kinetic model of the RHX reaction, the temperature dependence of the RHX rate, and the influence of varying environmental temperature on the RHX mass gain. We define an effective lifetime temperature and show how this is calculated from an estimated lifetime temperature history. Historical meteorological temperature data are used to estimate the lifetime temperature history, and this can be adjusted for long-term climate variation. We show also how to allow for the effects of burial in archaeological sites on the temperature history. Finally we describe how the uncertainties in estimates of RHX age depend on the estimates of temperature history and effective lifetime temperature.  相似文献   
8.
This study assessed the influence of the Inter-Tropical Discontinuity (ITD) on inter-annual rainfall characteristics in Nigeria between 1970 and 2000. This involved determining the strength and direction of the relationships between the total annual rainfalls in the extreme southern and northern parts of the country and the total annual rainfalls during the period of the Little Dry Season in southwestern Nigeria, and the surface locations of the ITD over Nigeria and some other factors that may impact ITD characteristics (such as the pressure differences between Azores, Libyan and St. Helena anticyclones and the sea surface temperature of the Gulf of Guinea). Results indicate that although the surface location of the ITD significantly accounts for rainfall inter-annual variability in Nigeria, it does so in the northern part of the country only. Pressure differences between the various anticyclones were observed to be another significant factor influencing inter-annual rainfall variability in the north. However, the influence of the sea surface temperature of the Gulf of Guinea on the rainfall characteristics in the northern region is ill-defined. It was also noted that the only factor influencing inter-annual variability in the Little Dry Season rainfall in the southwest and the total annual rainfalls in the south is the sea surface temperature of the Gulf of Guinea. The results obtained indicate that the total annual rainfalls in the north have significant positive relationships with the surface location of the ITD but significant negative relationships with the pressure differences between the Azores, Libyan and St. Helena anticyclones. The Little Dry Season rainfalls and total annual rainfalls in the south have significant positive relationships with the sea surface temperature of the Gulf of Guinea.  相似文献   
9.
在多年自然营力作用下,有些古建筑的砖体正遭受着严重的风化破坏,亟需修复和加固。为此,通过试验,研究烧制温度对红砖物理力学性质的影响,以期为古建筑修复和保护提供理论参考。利用模具手工制作边长为5 cm的立方体黏土砖。利用高温炉分别在700、800、900、1 000和1 100℃的温度下烧制成红砖。然后,测试不同烧制温度下红砖的块体密度、颗粒密度、开孔孔隙率、总孔隙率、常压吸水率、饱和吸水率、毛细吸水系数、纵波波速、孔径分布、单轴抗压强度。结果表明,烧制温度会影响物理力学性质,但物理力学性质并非随着烧制温度的增加而改善。烧制温度为1 100℃时砖的性能最优,烧制温度为800℃和900℃时砖的性能中等,烧制温度为700℃和1 000℃时砖的性能差。本文分析了烧制温度为1 000℃时红砖的物理力学性质差的原因。研究结果可为古建筑修复和保护提供理论参考。  相似文献   
10.
采用有毒化学药品防治动物标本害虫是博物馆使用的传统消杀方法。然而,考虑到化学药品对公众健康的潜在危害,迫切需要寻找更为安全的防治方法。采用安全无毒的-20℃低温冷冻法对标本害虫白腹皮蠹进行消杀实验,结果显示防治效果显著,寄生于动物标本皮毛的白腹皮蠹成虫在6小时内全部死亡。同时,研究结果还显示降温速度和标本制作材料的隔热特性是影响防治效果的重要因素。随着低温平衡时间的延长,害虫对低温冷冻的适应能力将逐渐增强,最终导致害虫消杀时间显著延长。此研究工作为博物馆采用安全无毒的低温冷冻法防治标本害虫提供了参考数据。  相似文献   
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