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51.
典型山区居民生活水平评价及空间差异——以四川省凉山州为例 总被引:1,自引:0,他引:1
通过建立城乡居民生活水平评价指标体系,以西南山区的四川省凉山州彝族自治州为例,运用主成分分析法,分别计算出各县(市)城乡居民综合生活水平指数、农村居民生活水平指数和城镇居民生活水平指数,并将其划分成较高、中等和较低三级。通过空间自相关模型分析发现,县域居民生活水平表现出较强的空间聚集性,空间差异明显;相对于城镇居民生活水平而言,农村居民生活水平空间聚集特征更加明显。造成凉山州城乡居民生活水平空间差异的原因有:1.少数民族人口的空间分布。县域城乡居民综合生活水平、农村居民生活水平与其少数民族人口比例呈高度负相关。2.地理资源的空间分布。凉山州地理资源条件较好的安宁河流域的"五县一市"城乡居民综合生活水平指数和农村居民生活水平指数均高于其他县域。3.农村居民生活水平的空间差异更加明显。凉山州城乡居民综合生活水平的空间差异主要体现为农村居民生活水平的空间差异。随后,对提高山区居民生活水平特别是农村居民生活水平,促进其区域协调发展的相关政策措施进行了简单探讨。 相似文献
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Ground water bodies are important resources for drinking water, including bottled water, and national regulatory bodies should assess their quality continuously. For this purpose, an effective assessment system of bottled water at source should be installed. A hierarchical nested balance design for the collection of random primary duplicate water samples, and their replicate analyses, is described, and the use of robust analysis of variance to estimate measurement uncertainty. The latter is subsequently used for the development of four probabilistic categories for the classification of element concentrations in bottled water with respect to legislative standard values, i.e., (a) compliant (below Lower Threshold Limit), (b) possibly non-compliant (possibly above Standard Value), (c) probably non-compliant (probably above Standard Value), and (d) non-compliant (above Upper Threshold Limit), for the reliable assessment of compliance to European Union and national drinking water standards. Overall, the quality of European bottled water is considered good, with the exception of a few that have concentrations in Mn, B, Ba, As, Fe, Ni, Se, and Al, which are definitely above the estimated respective Upper Threshold Limit and, thus, exceed the corresponding legislative standard value defined by European Union directives. National regulatory bodies should verify these results, and install an efficient assessment system of compliance to regulatory limits using the methodology described in this paper. 相似文献
55.
土层抗浮锚杆试验破坏标准选取的建议 总被引:6,自引:0,他引:6
因抗浮锚杆试验没有统一的破坏标准,测出的抗拔参数差异大,不能正确指导设计,文中根据几个典型试验实例,分析了现有相关规范中破坏标准的局限性,并对一些条款的修改提出了建议。 相似文献
56.
地图计算机颜色模型(MCCM)研究包括实用色谱印刷色标的制定、色标的屏幕再现与印刷复原、地图设色专家系统等。通过科学实验和系统分析,本文从色度学理论上阐明了屏幕再现印刷颜色出错的原因,从方法上解决了色标再现及复原研究长期存在的技术难题,建立了地图颜色模型数据库,为地图设包标准化、规范化提供了计算机手段。 相似文献
57.
Larry?A.?FahnestockEmail author Richard?Sause James?M.?Ricles Le-Wu?Lu 《地震工程与工程振动(英文版)》2003,2(2):255-268
Accurate estimates of ductility demands on buckling-restrained braced frames (BRBFs) are crucial to performance-based design of BRBFs. An analytical study on the seismic behavior of BRBFs has been conducted at the ATLSS Center, Lehigh University to prepare for an upcoming experimental program. The analysis program DRAIN-2DX was used to model a one-bay, four-story prototype BRBF including material and geometric nonlinearities. The bucklingrestrained brace (BRB) model incorporates both isotropic and kinematic hardening. Nonlinear static pushover and timehistory analyses were performed on the prototype BRBF. Performance objectives for the BRBs were defined and uscd to evaluate thc time-history analysis results. Particular emphasis was placed on global ductility demands and ductility demands oa the BRBs. These demands were compared with anticipated ductility capacities. The analysis results, along with results from similar previous studics, are used to evaluate the BRBF design provisions that have been recommended for codification in the United States. Thc results show that BRB maximum ductility demands can be as high as 20 to 25. These demands significantly exceed those anticipated by the BRBF recommended provisions. Results from the static pushover and timehistory analyses are used to demonstrate why the ductility demands exceed those anticipated by the recommended provisions.The BRB qualification testing protocol contained in the BRBF recommended provisions is shown to be inadequate because it requires only a maximum ductility demand of at most 7.5. Modifications to the testing protocol are recommended. 相似文献
58.
对"岩矿分析质量要求和检查办法"的建议 总被引:1,自引:0,他引:1
剖析了现行“岩矿分析质量要求和检查办法”存在的问题。建议对该行业标准进行必要的修正;充分考虑地质找矿、矿床评价、地学研究的实际需要,认真考虑国民经济有关部门对矿产资源应用的实际情况;全面深入细致考虑测试技术的实际水平并注意其经济性,避免按一种模式随意缩小或放大双差的允许范围;避免岩矿分析质量检查工作繁琐不便。 相似文献
59.
襄荆高速公路软弱地基高路堤填筑控制试验研究 总被引:2,自引:2,他引:2
软弱地基路堤填筑高度一般小于5 m,需时较长而影响工期,襄荆高速公路软弱地基路堤填筑高达8 m,加快施工进度与保证施工安全成为一大技术难题,为此进行了一系列的试验研究.现场详勘和试验表明该软弱地基存在1~1.5 m厚的硬壳层及下卧砂卵石层且原状土十字板剪切强度较高(Su = 44 kPa),有利于加快填土速率;选取了塑料排水板及砂垫层加土工格栅的软弱地基处理方案;基于排水条件得到了较大改善,经试验,证明适当降低规范要求的沉降控制标准是可行的.据此,根据监测数据进行动态调整后,填土速率得到了较大提高,施工安全也得到了保证;路堤填筑到设计高度后,通过堆载预压试验,对工后沉降预测值进行了验证,取得了良好的效果. 相似文献
60.
Large instrumental mass fractionation (IMF) may occur during measurements of oxygen isotope ratios by SIMS. Part of this fractionation depends on crystal structure and mineral composition. In order to improve the accuracy of SIMS measurements, we gathered 6 commonly used garnet standards and prepared 6 others to adequately cover the composition range Alm0-73, Prp0-99, Grs0-20. Electron microprobe analyses were performed at UBP-Clermont to check the chemical homogeneity of these standards. Oxygen isotope compositions were determined by laser fluorination and mass spectrometry at UW-Madison. Ten SIMS sessions and 336 δ18O measurements at CRPG-Nancy, on a Cameca IMS1270 instrument, demonstrate that the standards are homogeneous with external reproducibility of 0.3‰ (1σ). In terms of δ18O, SIMS measurements indicate that, during a single session, IMF can vary up to 6.3‰ from one garnet standard to another. In most of the sessions, IMF can be correlated with the grossular content. However, for a satisfactory correction scheme, we suggest the combination of the 3 main components (Ca, Fe, Mg). This is done using a simple least square calculation routine. The correction coefficients determined for each session can be used to calculate the IMF and correct the measured isotopic ratio of a garnet of known chemical composition. This way, we were able to reproduce the δ18O values of most of the Fe-Mg-Ca garnet standards within ± 0.6‰. Interestingly, the use of only 3 end-member standards (AlmCMG, PrpMM, GrsSE) plus a standard of intermediate composition (e.g. UWG-2) is sufficient to reproduce δ18O within the same precision. Thus, linear interpolation among end-member standards is satisfactory in the case of the garnet solid-solutions. Two studies carried out on zoned garnets from the Alps and the Pyrenees indicate that matrix effects become significant when variations in grossular contents are important (> 10%). In order to obtain reliable isotope ratio measurements on Fe-Mg-Ca garnets using a SIMS, we suggest a correction scheme using at least 3 reliable end-member standards plus a standard of intermediate composition (a garnet standard closest to the average composition of the analysed garnet). This allows cross-checking and incorporates a correction based on the variations in composition of zoned crystals. 相似文献