排序方式: 共有79条查询结果,搜索用时 15 毫秒
41.
阅读先秦诸子,发现其对语言的态度不尽相同。分析其不同,发现其关注点不同而使用的语言也有不同的层次。明白语言使用的层次性,至少对训诂、阐释、语文教学等有意义。 相似文献
42.
安徽省旅游业对经济增长拉动效应的实证研究——基于二维度与三指标的探讨 总被引:2,自引:0,他引:2
通过构建旅游业依存度、贡献率和拉动率三个指标,从时间和空间两个维度,本文探讨了安徽省旅游业对经济增长的拉动效应。结果表明,安徽省旅游业对经济增长的拉动效应逐渐加大;在中部六省中,安徽省旅游业拉动效应并不突出;在省域内部,各地市旅游业对经济增长拉动效应的空间非均衡现象较突出,且南强北弱的空间格局与旅游资源在等级上南高北低、景区在空间上“南热、中温、北冷”现状具有很强的共轭性。三个指标均具有相对性,当计算拉动效应时,应同时考虑区域尺度的因素。 相似文献
43.
本文分别采用微观结构观察、成分分析和吸水率-密度测定等方法,对比共出的夹砂陶和泥质陶,对孙家城遗址较为典型的夹植物陶进行分析。陶器坯体微观结构显示夹植物陶疏松多孔,植物类孱和料呈现的形式主要有植物碎屑、炭化颗粒、植物印痕等,应与夹炭陶相区别。成分分析表明夹砂陶、泥质陶和夹植物陶所用的制陶原料存在差异性且一定程度上有重合,后两者在制作工艺上有相似之处且有别于夹砂陶,而且夹植物陶鼎的口沿、腹部、足部的原料和制作工艺也不同。陶器胎体断面元素含量的变化可能是制陶过程中有意为之,也或与烧制过程和器表施加陶衣相关。吸水率-密度分析显示夹植物陶的质地最为疏松多孔,质量最轻,而且吸水饱和后更为脆弱易碎。 相似文献
44.
Luminescence dating techniques have been used extensively for archaeological and geological samples. Such techniques are based on thermally or optically stimulated signals. This paper presents simulations of several luminescence techniques for equivalent dose (ED) estimation for ceramic materials containing quartz. The simulations are carried out using a recently published comprehensive kinetic model for quartz, consisting of 11 electron and hole traps and centers. The complete sequence of the experimental protocols for several thermoluminescence (TL) and optically stimulated luminescence (OSL) techniques are simulated using the same set of kinetic parameters. The specific simulated protocols are: additive dose TL protocol, predose technique (both additive and multiple activation versions), phototransfer protocol, single aliquot regenerative optically stimulated luminescence (SAR-OSL) protocol, and SAR thermoluminescence protocol (SAR-TL). One hundred random variants of the natural samples were generated by keeping the transition probabilities between energy levels fixed, while allowing simultaneous random variations of the concentrations of the 11 energy levels. The relative intrinsic accuracy and precision of the protocols are simulated by calculating the equivalent dose (ED) within the model, for a given natural burial dose of the sample. The intrinsic accuracy of these techniques is estimated by simulating natural irradiation of the samples with a known burial dose, followed by simulation of the luminescence method used to recover the estimated dose ED. The percent difference between the burial dose and the ED value represents the simulated accuracy of the luminescence technique. The relative intrinsic precision of these techniques is estimated by fitting Gaussian probability functions to the ED values obtained with the 100 model variants. It is found that the various techniques can reproduce natural paleodoses in the range 10 mGy–10 Gy with a typical intrinsic accuracy of +1 to 10%. Techniques based on single aliquot protocols were found in general to be more precise than techniques requiring the use of multiple aliquots. In addition, techniques based on interpolation of experimental data were found to be consistently both more precise and accurate than those based on extrapolation of experimental data. 相似文献
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46.
西安市市民出游行为研究 总被引:21,自引:4,他引:17
本文在详细的市场调查基础上,分析了西安市民出游的行为特征,重点探讨了行为特征形成的深层原因,并对以西安为代表的内陆大城市和沿海城市居民出游规律做了对比分析,从而对西安市民的出游行为有了较深刻的认识,为西安市旅游决策提供了科学的依据。 相似文献
47.
The ventilation rate of a museum showcase is an important indicator for evaluating its sealing performance. In order to evaluate the ventilation rate of a showcase accurately, objectively and scientifically, some details of the detection and evaluation methods were comprehensively studied on the basis of GB/T 36110—2018. The results show that in order to achieve a better fitting effect, the carbon dioxide concentration outside a showcase should be fixed—a fixed concentration between 300 X 10 and 600 X 10 (volume fraction) had little influence on the fitting results. The average ventilation rate of the showcase at each moment was obtained by the numerical calculation method. When the detection time was short, values were unstable and fluctuated greatly; after stabilization, they were close to the fitted ventilation rates. The initial carbon dioxide concentration had a great influence on the fitting results of ventilation rate. The initial concentration of carbon dioxide gas in a showcase should be basically fixed between 20 000 X 10\" and 25 000 X 10 ~ (volume fraction) during detection, so that the testing results were comparable. The carbon dioxide mixture in the airtight showcase is relatively uniform, and no obvious dip occurred. The location of detection equipment has little influence on the fitting results of ventilation rate. If the fitted R reaches 0. 9, the results are considered valid, due to various errors in the detection process. © 2023, Sciences of Conservation and Archaeology. All Rights Reserved. 相似文献
48.
本文在分析我国人口形势的基础上,提出了九十年代结合我国人口实际情况开展人口地理研究的主要课题.同时对人口地理研究中理论与方法的提高也进行了讨论. 相似文献
49.
《Asian Population Studies》2013,9(3):241-243
Higher mortality among unmarried persons compared with currently married ones has been reported in many previous studies. There is paucity of such studies in developing countries. We analysed the association between marital status and mortality in Kuwait, an oil-rich Gulf Muslim country. Data were obtained from the Public Authority for Civil Information that has maintained a linked record database of population characteristics with death notifications since 2005. Deaths during 2005–2010 were aggregated for the analysis. Age-specific death rates and standardized mortality ratios (SMRs) were calculated according to marital status (married, never married, divorced and widowed), age (15–49, 50–64 and 65+), gender, and nationality (Kuwaiti vs. non-Kuwaiti). Among Kuwaiti nationals, the SMRs for widowed, divorced, and never married were 1.75, 1.68 and 1.15 compared to the married. Higher mortality was found among unmarried men and women at almost all ages. These findings may be indicative of considerable public health problems such as higher disability and depression among the unmarried. 相似文献
50.
《Asian Population Studies》2013,9(3):223-241
Korea has experienced marital transition since the 1920s, but recent data reveal rapid changes in marital behaviour and norms. Analysts usually relate these to the second fertility transition, fast growing gender equality, economic developments, and ideational changes, pointing to the necessity of understanding the process of change in marital behaviour in the context of societal transformation as well as demographic transition. With this background in mind, this paper constructs refined measures, such as age-specific first marriage rates and total first marriage rates, for different time periods and for different cohorts to present a clearer picture of marriage trends. The results are then examined in relation to various social and demographic factors, a procedure which provides an indirect check on the validity and usefulness of the method. 相似文献