Towards a public food infrastructure: Closing the food gap through state-run grocery stores

There has been a national movement towards closing the grocery gap through public-private partnerships. In this short review, we consider the limits of these interventions in addressing the economic barriers shaping food access and contend that the weaknesses are rooted in the politics of the neoliberal state. We then introduce the concept of the affirmative state and the examples of the military commissary and state-run alcohol stores to legitimate the notion that state-run grocery stores can overcome the limits of conventional grocery gap interventions.     

Scale Dependence of Species Richness Maps*

Mapping patterns of species richness is a longstanding tradition in biogeography and more recently in conservation planning. This paper describes the effects of sampling unit size on patterns of vertebrate richness across landscapes in the Intermountain Sagebrush and Rocky Mountain Forest ecoregions in Idaho. Variability of richness decreased with increasing size of the spatial sampling units at both sites, with greater overall variability in the forested site. Richness in the sagebrush region was best explained by alpha diversity, whereas beta diversity accounted for more of the variability in richness in the forested site.     

顶管工程中的地层损失参数和土体变形计算

目前的地层损失参数和土体变形计算方法不能反映顶管施工的动态过程,重新定义顶管施工过程中的地层损失参数,使之可以反映超挖、欠挖等不同工况。基于Mindlin解,改进间隙参数g,从而可以考虑管壁与土的摩擦力。基于开挖面周围土体的扰动分区,修正Loganathan土体变形公式,并将改进的间隙参数g代入修正公式,计算顶进距离不同时的土体变形,获得顶管推进过程中地表测点的动态变化。算例分析表明,计算结果与监测数据吻合较好。     

软盘额外磁道接缝加密系统

采用新颖实用的额外磁道接缝技术及一系列反动态、反静态跟踪技术,编制并实现了软磁盘加密程序Newlock,使得软磁盘加密变得更加可靠、方便.     

西安地铁隧道穿越地裂缝带的计算模型探讨

通过对西安地铁隧道穿越地裂缝带的大型物理模型试验成果的分析,提出在地裂缝活动时,穿越地裂缝带的地铁隧道有以下两个方面的变化特征：一是作用于隧道的荷载发生改变;二是在隧道底部产生脱空现象。这种脱空现象无论在整体式隧道还是盾构隧道中都会出现。造成隧道在界面上与土体脱空的原因是隧道和周围地层的变形不协调。脱空区域的大小对地铁隧道的变形与内力计算会产生明显影响。在对隧道变形特征分析的基础上,总结得出了西安地铁穿越地裂缝带隧道变形的4种计算模型：对于整体式长隧道,可以采用一端固定而另一端简支,或一端固定而另一端定向支承的计算模型;对于整体式短隧道,可以采用外伸梁模型;对于盾构隧道,可以采用一端固定而另一端定向支承的计算模型。最后,对脱空条件下隧道数值分析的建模问题进行了讨论。算例分析表明：在数值计算中,对于隧道与土体接触面的界面处理非常关键,否则将造成计算结果的重大误差。     

Balancing science and society through establishing indicators for integrated coastal zone management in the Balearic Islands

This paper explores the process by which indicators may be developed as tools for communicating science to decision-makers using the participatory approach demonstrated by the Balearic Indicators Project. This initiative reflects a series of compromises considered necessary to achieve the objective of generating an indicator system that is scientifically viable, comparative internationally yet locally relevant, and to facilitate its implementation. The article highlights questions regarding the utility of science for addressing current global issues related to sustainability and why science often fails to promote change at the societal level.     

南岭中生代陆壳重熔型花岗岩类成岩成矿的有关问题

南岭是中国重要的钨锡多金属成矿带。岩浆活动及成矿作用具有多阶段性的特点,成岩成矿作用具有统一的地质背景及构造应力场。陆壳重熔型花岗岩类不同成岩阶段具有极为一致的稀土元素分布模式,暗示它们的定位和冷却都是在深部同源岩浆分异事件中形成的;岩石和矿石稀土球粒陨石标准化曲线有着相似的变化特征,反映成矿与岩浆活动有着密切的成因联系,物质来源上具有一致性;矿石硫化物和岩石长石Pb同位素组成相近,显示成岩成矿物质有明显的亲缘关系。结合多数情况下矿脉切穿已固结岩体的地质事实,推测燕山中期陆壳重熔型花岗岩类成岩成矿物质主体来自深部同一岩浆源区,为同源岩浆分异演化不同阶段的产物;燕山晚期花岗质火山-侵入杂岩与相关锡铀矿化空间上密切伴生,物质来源也具同源性。典型复式岩体同源岩浆不同阶段侵位及相匹配的成矿作用时差一般小于10．0Ma,集中在0～8．0Ma。结合华南中生代岩石圈多次伸展活动的区域背景及矿床（田）地质特征,推测南岭地区的多阶段成岩成矿作用是脉动式构造演化的产物,成岩成矿物质来自深部同一岩浆房的不同演化阶段。     

Young adult households and domestic sustainabilities

Young adults in the Global North occupy a contradictory environmental identity: they are purportedly more environmentally concerned than older generations, but are also labelled hedonistic consumers. Most studies have focused on young adults still residing in parental homes, neglecting that Generation Y (born between 1975 and 1991) has ‘grown up’. The consumption patterns and environmental implications of their newly established households demand scholarly attention. Through a large-scale household sustainability survey, conducted in Australia, we have uncovered important inter-generational differences in environmental attitudes and everyday domestic practices. We found that generational cohorts hold distinct environmental attitudes. Younger households were most concerned with climate change, and least optimistic about future mitigation. However, generational differences influenced everyday domestic practices in more complex ways. All households engaged extensively with those ‘pro-environmental’ practices that reflected established cultural norms, government regulations and residential urban form. For other pro-environmental practices there were clear differences, with Generation Y households being the least engaged. A widening ‘value-action gap’ was apparent across our sample population, from oldest to youngest. However, rather than reflecting Generation Y’s supposed hedonism, we argue that this gap reflects generational geographies: how lifecourse intersects with housing and labour markets and norms of cleanliness to shape everyday domestic practices. Our research illuminates the shortcomings of a one-size-fits-all approach to household sustainability. The young adult stage is a time of transition during which homes and independent lifestyles are established, and practices are altered or become entrenched, for better or worse.