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31.
周、秦、汉、唐时期,关中农业较为发达,为多个王朝建都之地。京师之地的粮食问题十分重要,汉代以后屡屡出现粮食紧张局面,其原因除移民、战乱等因素外,自然灾害的影响不容忽视。研究发现,周、秦、汉、唐时期,关中的粮食在秦以前基本自给,两汉、魏晋以后依赖关东趋于明显,隋唐时期关中粮食所需则自产自给和漕运并重。这一演变过程,与关中自然灾害的发生状况有着紧密联系。随着西汉以后生态环境的破坏和人类垦殖活动的日益加剧,关中地区水旱灾害发生频繁,对粮食安全产生了严重影响。期间的中央政府不断采取扩大农业垦殖、提高农业生产技术和漕运等手段,以解决京师用粮。  相似文献   
32.
慢滑移及相关脉动和慢地震研究的历史和现状   总被引:1,自引:2,他引:1  
观测表明,慢滑移事件通常发生在活动断裂带内,为发震层之下的短暂滑移,能够造成地表的瞬态运动。与慢滑移密切相关的慢地震能够发射出频率在一定范围内的脉动信号,但不造成灾害性事件。慢滑移和慢地震很可能是断裂带上形变能释放的基本方式,其观测有可能为人们更深入地了解断裂带的动力学过程提供基础和依据。本文重点介绍近10年来关于慢地震和慢滑移事件的研究历史和现状。目前对慢滑移引发的地表形变和慢地震发射的脉动信号特征有了深入细致的研究,开展了对慢滑移的数值模拟和慢地震定位的研究;但对慢地震和慢滑移发生的位置、两者的关系以及物理机制等方面还存在很多争论和问题。  相似文献   
33.
Derek Hall 《Geoforum》2010,41(5):826-835
The years since 2000 have seen a constant stream of high-profile scandals relating to food safety and food labeling in Japan. One response of Japan’s Ministry of Agriculture, Forestry and Fisheries (MAFF) has been to promote food traceability as a mechanism to improve food safety and to provide reliable information to consumers about their food. MAFF’s main approach to traceability promotion, however, has not involved making traceability mandatory (as has been done in the EU) but encouraging private companies to adopt it. These actions constitute, I argue, an example of the public promotion of private governance. When viewed against the literature on the private governance of food safety and quality, MAFF’s traceability activities are surprising for three reasons: their forms and extent, the relative lack of interest the Ministry has shown in third-party certification, and the way MAFF has responded to concerns about the safety of imported food by focusing almost entirely on domestic traceability. I also argue, however, that looking at the literature from a Japanese perspective suggests that public encouragement is more central to the rise of private governance in the global agri-food system than is usually appreciated.  相似文献   
34.
While some non-profits have suffered under the political and economic pressures of neoliberal urban governance reform, others have emerged as important institutional players in local governance regimes. This article highlights how non-profits food banks in Chicago have commercialized in order to respond to increased demand, enhance their institutional independence from government, and reassert their local dominance in emergency food service delivery. From a food bank member agency perspective, the consolidation of food bank institutional power has produced new bureaucratic limitations, user fees, and increased competition. These shifts reveal the rise of metropolitan food banks as important players in neoliberal urban governance regimes, as they control the conceptualization of hunger, management of poverty, and organization of food distribution systems.  相似文献   
35.
Selenium like any other element can both be essential and toxic depending upon the concentration at which it occurs in human diet. This paper assessed the level of this trace element in twenty different (20) types of locally produced food items around Abeokuta town and the blood obtained from the antecubital fossa vein of eighty-eight (88) healthy adults resident in Abeokuta.  相似文献   
36.
Regularly monitoring the amount of food produced in food insecure, isolated, subsistence farming areas can be used to help identify households or communities who may be in need of additional food resources. Measuring seasonal food production in developing countries, particularly at a sub-national level, is complicated by lack of data. In this study we use high resolution remotely sensed data to calculate cultivated area in two different growing areas, during two different seasons in Kenya. The results of the research support the usefulness of this approach for agricultural monitoring in the developing world and suggest that monitoring cultivated area requires attention to the specific growing characteristics of an area.  相似文献   
37.
Increasing attention by consumers to the social and environmental dimensions of the food they eat has generated many different responses, including certification programs, watch lists and local/slow food movements. This article examines the more recent entry of seafood into these consumer social movements. Although a concern with the family farm—as well as tendency to equate national security with food security—has long connected terrestrial food production with other cultural concerns, fisheries have tended to be regarded more as natural resources. Considering seafood as part of the “food system” would enhance the management of fisheries, while the long engagement in fisheries with co- and adaptive management and the politics of knowledge would enrich the debate in the agri-foods literature. The article also offers suggestions on how fisheries management could better govern for sustainable food systems, and provides further ideas about food, sustainability and governance.  相似文献   
38.
中巴公路沿线地质灾害多发,通过微小变形对于其沿线地质灾害进行早期识别是一种重要的防灾措施。本文以中巴公路公格尔山至墓士塔格山段为研究区,选用2007年7月12日至2011年1月20日获取的16景PALSAR合成孔径雷达数据,采用小基线集干涉测量技术(SBAS-InSAR,Small Baseline Subset Interferometric Synthetic Aperture Radar)进行了变形干涉计算,识别并分析了沿线地质体的变形情况:(1)冰川运动与冰川泥石流作为沿线最主要的地质灾害,变形相对较大,较易识别,有效PS点主要分布在前缘冰碛物部分,反映为正负大变形相间的高异常值点团,其中公格尔山与墓士塔格山山麓的冰碛物运动最为显著; (2)沿线较软弱顺坡结构岩体发育,且风化严重,稳定性较差,易形成溜石坡灾害,表现为顺坡负异常变形; (3)宽谷区PS点变形以正值和较小的负值为主,该区域主要为底部冰水堆积物,上部洪积物,冰川融水补给充足,土体水分含量较高,可能产生冻胀变形,同时也可能存在斜坡重力梯度方向的变形,二者变形合成在测量结果上表现为视线向的正异常; (4)中巴公路主要在湖盆和洪积扇上展布,推测由于不均匀分布软土的变形,使较为刚性的公路部分路段产生了下沉; (5)SBAS-InSAR的高精度变形观测覆盖范围广,对于线性工程周围地质体稳定性的识别具有很好的应用前景。  相似文献   
39.
Biosecurity, in broad terms, aims to reduce the impact and incidence of threats to life through regulatory means. For reasons we raise in this paper, such regulation can often lead to the specification of disease free processes within the food and farming industry, with biosecurity success measured in terms of the degree of compliance with and allegiance to modern farming practice. We counter this progressive narrative in three ways. First we draw on UK-based qualitative fieldwork with vets, farmers and pigs to demonstrate how biosecure farming and disease freedom are translated and qualified, in practice, to pathogen free, pathogen management and ultimately to configuring health through immunity management. Second, these translations demonstrate how building health is dependent on spatial and microbiological diversity rather than uniformity. Crucially, health involves patch-work and situated knowledge practices that are under threat within an industry increasingly marked by control and homogeneity. Third, in conceptual terms, we argue that while pig farming is organised through both biosecurity and a biopolitical regulation of life, immunity opens up political space for exploring an alternative politics of life, one where farmers and others are not so much made responsible for disease prevention, but make valued contributions to understandings of animal health and food security.  相似文献   
40.
This paper explores the powerful and mediating role of celebrity chefs over audience relationships with food through analysis of Jamie Oliver and his recent series Save with Jamie. The paper firstly situates the role of celebrity chefs theoretically, defining them as ‘talking labels’ who may act both as knowledge intermediaries and boundary objects to connect audiences with food in multiple ways. Here chefs actively construct and mediate discourses around ‘good food’. As trusted, credible, well-liked public figures, chefs step into out private home spaces through our televisions to convey food information in a charismatic, entertaining and accessible way. Like traditional food labels, chef’s words can be ‘sticky’ and take hold in public imaginations in a way that goes far beyond the capacity of food products labels. Yet the relationship between chefs and audiences is far from straightforward and so the paper secondly aims to explore how these talking labels are understood and ‘used’ by audiences in their everyday food practices. Drawing selectively from a large scale audience survey (n = 600) as well as the series, Save with Jamie, this paper reveals the different ways that audiences ‘talk back’ to chefs both positively and negatively to create moments of simultaneous possibility and resistance for audience relations with food. This revealed complex relationships between audiences, chefs and food. It also suggests that the powerful work on celebrity chefs functions as part of a new mediated mechanism within today’s food governance.  相似文献   
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