开山石填海挤淤区非均匀软弱地基的治理

对开山石填海挤淤形成的非均匀软弱地基进行处理时，由于工程性质很差、厚度较大、沉降固结历时较长且数值较大的淤泥层位于开山石回填层之下，地基处理比较困难。本文介绍了一个经济、合理的地基处理方法，对沿海地区大量存在的同类工程具有参考价值。     

Transformations in resource peripheries: an analysis of the Chilean experience

Building on Hayter et al.'s (2003 ) characterisation of resource peripheries in terms of four institutional dimensions, this article conceptualises four, similar 'transformations' (political, economic, socio-cultural and environmental) intended to evolve this conceptual framework. The case of Chile is analysed in order to ground the analysis, emphasising the structural aspects of its historical experience as a resource periphery. It is clear that the country's condition as a resource periphery has been central to the transformations that have taken place since the early colonial period. In order to illustrate this, the article briefly explores the links between Latin American structuralist and emerging resource periphery accounts. As such, we discuss some of the policy options that might allow the country to move beyond resource periphery status – a goal which is necessary if uneven development in Chile is to be tackled. We conclude that if even and equitable development are goals of geographical analysis then structuralist-informed political-economic work of this nature warrants renewed emphasis.     

覆岩层破坏理论在采区地基稳定性评价中的应用 ——以吉林九台营城煤矿为例

煤层开采后,上覆岩层将形成冒落带、裂缝带和弯曲带。根据营城煤矿研究区自然地理条件、区域地质条件和工程水文地质条件,应用覆岩层破坏理论,得出营城煤矿最大冒落裂隙带高度和建筑物荷载的最大影响深度之和为270 m,远小于该区域煤层最小开采深度( 838 m) ,该区不会产生较大的不均匀沉降。     

The divergent city: unequal and uneven development in St. Louis

In St. Louis, as in many other cities, decline and displacement occurred when key policies, prejudices, and plans interacted with broad economic restructuring to devastate poor and minority communities, while leaving White and middle-class communities largely intact. Amidst overall population loss and neighborhood decline are pockets of prosperity and gentrification within the central city. In this article, we analyze three significant planning interventions in St. Louis, Missouri, that spurred displacement of populations—urban renewal, triage, and the foreclosure crisis. We argue that the differential experiences of Black and White during each of these periods represent two faces of development: one in the north of the city that is largely Black, experiencing vacant land, high crime, and crumbling infrastructure; another in the south of the city that is largely White, enjoying pockets of vibrant commercial development, larger homes, and stable real estate markets. We analyze each period through a framework of uneven and unequal development and displacement, which we call the Divergent City Theory. Based on this theory, planners face an ethical obligation to plan for the future of their cities in a way that seeks to reconcile the structured race and class inequalities of the divergent city.     

China’s metropolises in transformation: neoliberalizing politics,land commodification,and uneven development in Beijing

ABSTRACT

Existing theory of urban transformation under neoliberalization describes cities as the institutional arena in and through which neoliberal strategies of urbanism emanate and are contested. Emphasis is placed on the interaction between state and market without paying adequate attention to their internal dynamics. This study of urban transformation in the Beijing metropolis identifies a distinct trajectory whereby commodification of urban land has been actively pursued in response to the decentralization of developmental responsibilities and recentralization of tax revenue collection instituted by the central state. An urban development strategy is practiced whereby land commodification, city planning, and mega event hosting are integrated and mutually reinforcing. The research shows a pattern of land commodification and development dominated by newly developed construction land in the near suburbs, and reveals a picture of increased spatial inequality and intensified social discontent as a consequence of city-centered land development. Contrary to popular perception of the state and market as diametrically opposed principles of political organization, the Chinese state is found to have transformed and reshuffled itself to embrace and take advantage of the market for its developmental agenda.     

太湖藻源性颗粒物分解过程中氨基酸的变化特征

在实验条件下研究了高浓度蓝藻堆积后水体中的藻源性颗粒物中氨基酸的分解速率、分解量和氨基酸态氮形态的变化情况.在自然光照组中,颗粒态氨基酸(PAA)的浓度从实验前的0.46 mmol/L降至实验后的0.30 mmol/L;而在无光分解组中PAA从0.44 mmol/L降至0.06 mmol/L.两种处理下PAA的降解速率常数分别为0.03916和0.17424 d~(-1).溶解态氨基酸(DAA)在分解过程中浓度比较低,随时间的变化表现出先增大后减小的趋势,在两种不同的处理下,最大值分别为10.94和7.94μmol/L,21 d后减小到与实验开始时持平,甚至低于初始值.实验初期,PAA所占比例高达74%~80%,但迅速被分解转化为DAA和铵态氮(NH_4~+-N),随着实验的进行NH_4~+-N又逐渐转化为硝态氮,其中无光分解组中的分解更为彻底,而自然光照组中PAA分解量小于无光分解组.实验结果表明,氨基酸作为水体中浮游植物的潜在氮源,可以被分解为水华过程中藻类所需的NH_4~+-N,对水华的维持具有一定的促进作用.     

牡蛎幼虫光照实验提示复杂遗传背景下基因互作的多样性

为研究光照对牡蛎幼虫生长成活率的影响,使用6组牡蛎幼虫家系,前三组为长牡蛎家系(GG1、GG2、GG3),后三组为长牡蛎与葡萄牙牡蛎杂交家系(GA1、GA2、GA3),其中GG1与GA1母本相同,GG2与GA2母本相同,GG3与GA3母本相同;每个家系分别在6个光照梯度下从1日龄饲养到10日龄,然后测量记录10日龄幼虫在各个光照梯度下的壳高和成活率。结果表明,在各个光照梯度下,牡蛎幼虫的壳高都没有显著差异,长牡蛎幼虫与杂交牡蛎幼虫之间的壳高也都没有显著差异,但长牡蛎幼虫和杂交牡蛎幼虫均在58 lx的光照强度下,表现出最高的成活率,这提示牡蛎育苗生产的前10天应当保持这样的光照强度,而杂交牡蛎幼虫在269 lx和58 lx两个光照梯度下的成活率均极显著的高于长牡蛎幼虫,提示了长牡蛎与葡萄牙牡蛎之间具有亲和性并且其杂交后代存在杂种优势,也在一定程度上支持长牡蛎与葡萄牙牡蛎同属一个物种的假设。而以壳高和成活率作为指标进行聚类分析和主成分分析后发现,长牡蛎3个家系幼虫的表型比较接近,而杂交牡蛎幼虫的表型虽然具有靠近各自同母本长牡蛎幼虫的趋势,但杂交家系之间差异非常大,提示了高杂合度高异质性遗传背景下基因互作的多样性。     

碎岩刀具工作面圆弧化机理及解决途径

通过分析孕镶金刚石刀头碎岩和磨损机理,找出引金刚石刀头工作端面弧化的原因,并提出了克服圆弧化现象的几种方法。     

基于结构光的不规则工业钣金件三维曲面重建

钣金件表面缺乏适合于影像匹配的纹理,设计了用投影器投射结构光到钣金件表面,对由CCD相机摄取的此影像进行结构光纹理特征提取的线与投影器本身投出的虚拟影像进行线匹配,通过空间前方交会解算出钣金件表面的空间点。实验证明,此方法为实现工业零件的自动化三维重建探索出一条可行的途径。     

Uneven development of the sustainable city: shifting capital in Portland,Oregon

Portland, Oregon, is renowned as a paradigmatic “sustainable city.” Yet, despite popular conceptions of the city as a progressive ecotopia and the accolades of planners seeking to emulate its innovations, Portland’s sustainability successes are inequitably distributed. Drawing on census data, popular media, newspaper archives, city planning documents, and secondary source histories, we attempt to elucidate the structural origins of Portland’s “uneven development,” exploring how and why the urban core of this paragon of sustainability has become more White and affluent while its outer eastside has become more diverse and poor. We explain how a “sustainability fix”—in this case, green investment in the city’s core—ultimately contributed to the demarcation of racialized poverty along 82nd Avenue, a major north–south arterial marking the boundary of East Portland. Our account of structural processes taking place at multiple scales contributes to a growing body of literature on eco-gentrification and displacement and inner-ring suburban change while empirically demonstrating how Portland’s advances in sustainability have come at the cost of East Portland’s devaluation. Our “30,000 foot” perspective reveals systemic patterns that might then guide more fine-grained analyses of particular political-socio-cultural processes, while providing cautionary insights into current efforts to extend the city’s sustainability initiatives using the same green development model.