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91.
The quantitative analysis of glass, ceramics and related silicate systems by means of energy dispersive X-ray fluorescence spectrometry is considered and problems arising from the selective absorption of X-rays in multi-element specimens are discussed. A computer programme written in FORTRAN and based upon a “semi-fundamental parameters” approach to the correction of matrix effects in glass and chemically similar materials is fully described. Model data are provided to enable the programme to be run and tested. An “empirical coefficients” computer programme for the quantitative analysis of silicate systems is outlined and the limitations of this type of programme are pointed out. The importance of adequate sample preparation prior to X-ray spectrometric analysis is stressed.  相似文献   
92.
Abstract

Food security has guided Russia’s food policy since 2010. The article examines the impact of food security policy on the food system. The Russian model of food security combines government intervention in the form of assistance for domestic production while simultaneously restricting market access. Food security does not appear to have a deleterious impact on the food system. We measure impact on four dimensions. Financial support for agriculture continues to increase in nominal rubles. In food production, the beef and dairy branches continue to lag, but increased grain production has made Russia a global leader in grain exports. Average per capita food consumption improved, although the poor consume much less, and the decline of the ruble affects the way Russians shop. The largest impact of food security has been on food trade. Food security policy has brought food to the forefront as an instrument of foreign policy. Food trade is politicized, witnessed by the food embargo against the West and food import bans against Turkey and Ukraine.  相似文献   
93.
This study deployed statistical and spatial (GIS) analyses to test the effects of geographic, demographic and occupational factors in predicting health centre visits among the elderly (≥60 years) with chronic ailments in Kanchanaburi Province, western Thailand. Datasets from the Kanchanaburi Demographic Surveillance System (2004 baseline survey and a 2006 project follow-up) comprised five land-use landscape and occupational strata: urban/semi-urban (industrial), rice field, plantation crop, upland and mixed economy. Travel distance to the nearest health centre was calculated following transportation routes and the GPS coordinates of individual home locations, and the number of healthcare visits under the national free universal coverage (UC) scheme reported for the previous year was used as a dependent variable in regressions. Broadly, the study found that distance was not a significant predictor of the rate of elderly health centres visits for those with co-residing spouses and/or adult children (77% of sample), and for the elderly still working (48% of the sample) who were the least likely to access healthcare. Owning motorised vehicles did not encourage visits, which also varied by land-use and occupational strata.  相似文献   
94.
In this article, we analyze the role of the economic rationale in modern cultural policy decision communication and ask why it remains such an important factor, even though research has argued against it. Based on Luhmann’s system theory, we show how the economic rationale manifests itself in the cultural political communication as parasitic and complementary couplings, and how different communication forms are in play: the indirect, direct, and the both-and form. The point is to construct communicative positions in cultural policy. The positions involve the economic rationale in their own particular way and each of them offers themselves as a communicative platform which the culture politician can optionally step into and out of. The arts system stands out from other systems by not distinguishing itself in one single distinction and coding. In exactly this issue lies the communicative complexity which the communicating cultural politician faces and must handle. As our analysis shows, this complexity is handled by communicating within the economic rationale and coding, with the result that complexity is reduced.  相似文献   
95.
Abstract

Youth have been a malleable resource in the fight against hunger, variously conceived as volunteers, political activists, global citizens and financial donors. This article uncovers competing (and sometimes complementary) visions for the participation of British youth in Youth Against Hunger, part of the United Nations Freedom from Hunger Campaign. In doing so, it makes two key contributions to the field. First, by uncovering the professionals and commentators who sought to involve adolescents in humanitarian activity, it accounts for the agency of a more diverse range of non-state participants and experts than are usually included in histories of humanitarianism. Second, in highlighting the pragmatic difficulties in aligning humanitarian and youth-work contexts, it illustrates how domestic concerns about British youth actively shaped the development of the humanitarian sector in this period.  相似文献   
96.
The Krafla geothermal system is located in Iceland's northeastern neovolcanic zone, within the Krafla central volcanic complex. Geothermal fluids are superheated steam closest to the magma heat source, two‐phase at higher depths, and sub‐boiling at the shallowest depths. Hydrogen isotope ratios of geothermal fluids range from ?87‰, equivalent to local meteoric water, to ?94‰. These fluids are enriched in 18O relative to the global meteoric line by +0.5–3.2‰. Calculated vapor fractions of the fluids are 0.0–0.5 wt% (~0–16% by volume) in the northwestern portion of the geothermal system and increase towards the southeast, up to 5.4 wt% (~57% by volume). Hydrothermal epidote sampled from 900 to 2500 m depth has δD values from ?127 to ?108‰, and δ18O from ?13.0 to ?9.6‰. Fluids in equilibrium with epidote have isotope compositions similar to those calculated for the vapor phase of two‐phase aquifer fluids. We interpret the large range in δDEPIDOTE and δ18OEPIDOTE across the system and within individual wells (up to 7‰ and 3.3‰, respectively) to result from variable mixing of shallow sub‐boiling groundwater with condensates of vapor rising from a deeper two‐phase reservoir. The data suggest that meteoric waters derived from a single source in the northwest are separated into the shallow sub‐boiling reservoir, and deeper two‐phase reservoir. Interaction between these reservoirs occurs by channelized vertical flow of vapor along fractures, and input of magmatic volatiles further alters fluid chemistry in some wells. Isotopic compositions of hydrothermal epidote reflect local equilibrium with fluids formed by mixtures of shallow water, deep vapor condensates, and magmatic volatiles, whose ionic strength is subsequently derived from dissolution of basalt host rock. This study illustrates the benefits of combining phase segregation effects in two‐phase systems during analysis of wellhead fluid data with stable isotope values of hydrous alteration minerals when evaluating the complex hydrogeology of volcano‐hosted geothermal systems.  相似文献   
97.
本文从历史、经验和理论三个角度论证了乡村地理学以乡村区域系统为研究对象。在对乡村区域系统特征分析的基础上概括出当代乡村地理学13个方面65个要点的基本研究内容,并偿试性地建构了以结构、进化和与环境关联为主体的乡村区域系统理论框架。  相似文献   
98.
文本提出了风景植被的含义,阐述了风景植被的发生是人类文明进化的结果,分析了风景植被的宏观构景和微观信息特征。同时还以西安临潼骊山旅游区为例,介绍了风景植被的分类系统。  相似文献   
99.
汉文化为中心的唐代文化大融合   总被引:4,自引:2,他引:2  
张雪莲 《人文地理》1997,12(3):30-33
唐文化是我国传统文化发展的高峰,也是居于当时世界的领先地位。它有着其独特的色彩和先进性。本文着重从地理环境的高度来分析唐代文化生态及文化融合,分析文化与地理环境内在的机制和规律。从而在面对现代外来文化冲击的情况下,更理性地安排人类文化活动空间,并用以改造环境,丰富本土文化,为文化发展创造一个良好的环境。  相似文献   
100.
体育服务设施的空间组织优化问题   总被引:2,自引:0,他引:2  
田至美 《人文地理》1995,10(2):67-72
本文运用中心地方理论,讨论了体育产业化、职业化和体育市场充分发育的背景下,体育服务设施的空间组织的理论化模型。  相似文献   
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