Further development of the uniqueness criteria of the steady state via the contraction mapping principle

Uniqueness criteria of the steady state in porous catalysts are derived by using the contraction mapping principle with different norms. Among the norms considered, the one involving the gradient of the steady state yields the strongest result. The criteria developed in the present study bear some resemblance to those developed by other methods     

Digital Cottage Industries

Mike Aling 's ProunStretcher project engages with the recent global revival of cottage industries, fuelled by the application of digital technologies, as a means to address ‘the manifold social issues present across our rural landscape-as-urban-extension’.     

Playgrounds: Radical Failure in the Amazon

Covering more than 8.1 million square kilometres (3.127 million square miles), the Amazon is a vast territory that has captured people's imaginations and ambitions. These range from Henry Ford's attempt in 1928 to build a rubber company town near Santarém, Brazil, to more contemporary projects that have aimed to boost and connect the continent's economy. Gary Leggett explores the failure of such totalising projects across time and asks why they might have proved inherently flawed. Copyright © 2011 John Wiley & Sons, Ltd.     

Recombinant Landscapes in the American City

How are urban actors, such as landscape designers, community groups, developers and local politicians, actively restructuring their environments to meet the challenges of the American city in the new global context? Grahame Shane outlines the approaches to landscape that have been emerging since the mid-20th century and are set to recombine urban assemblages whether they are located in historic city centres, postindustrial waterfronts or suburban sprawl. Copyright © 2007 John Wiley & Sons, Ltd.     

持续集成的概念与应用分析

持续集成是完全的自动化构建过程,使得一个开发团队在一天中多次构建并测试软件。本文阐明了持续集成的概念、优点、系统结构的基础上,还介绍出持续集成的部署方法和相应开发人员需要养成的开发习惯,对于需要搭建和使用接触持续集成系统的开发人员是一个入门的指引。     

Pro Pelle Cutem: Photographing Furs for the Hudson’s Bay Company’s 250th Anniversary Celebrations in Canada

In 1920, the Hudson’s Bay Company (HBC) celebrated its 250^th anniversary through national and international events, as well as honours and benefits for its employees. The year 1920 was an important moment for the HBC, as it underwent institutional change to support the expansion of its department store operations through public relations and advertising strategies. Central to these strategies was an emphasis on the HBC’s central role in Canadian nation formation, and in particular its fur trade history. This article discusses the use of photography in the HBC’s 250^th anniversary celebrations through an analysis of photographs of fur. I trace photographic representations of fur through three moments: in the process of extraction (as trapped animal or dead pelt); in the process of preparation (as Indigenous bush labour); and in the process of consumption (as fur goods in a department store window). While the fur trade was declining in significance at the time of the 250^th anniversary celebrations, its symbolic status was essential to the Company’s burgeoning retail operations. In this article, I argue that the photograph of fur replaced the fur pelt as the central trade item of the HBC, and, further, that photography fused together nationalist and capitalist expansion in Canada.     

硬币型裂缝介质的频散与衰减

为了快速、准确地模拟硬币型裂缝的频散和衰减，同时避免求解Galvin硬币型裂缝频变弹性模量表达式中存在的奇异性问题，基于Gauss-Lobatto等效离散积分的求解方法，将求解的第二类Fredholm积分方程转变为有限区间内的离散积分，并利用高阶近似方法将远场多重散射方程在零极限的求解问题与离散积分过程统一；进一步利用各向异性Gassmann方程，结合线性滑移理论与Hudson硬币型裂缝模型，分别给出了裂缝介质在高、低频极限条件下各个弹性模量的解析式。相速度和黏弹性反射系数数值模拟表明：随裂缝密度变大，衰减峰值变大；随裂缝尺度变大或流体黏度增强，衰减峰值频率向低频移动；相对于平行裂缝方向，垂直方向的速度和衰减变化最大，且当介质饱气时，反射系数明显大于含水、含油介质。数值模拟结果表明裂缝密度影响衰减，裂缝尺度和流体黏度影响介质由弛豫向非弛豫过渡的频带位置。     

The role of diet on long-term concentration and pattern trends of brominated and chlorinated contaminants in western Hudson Bay polar bears, 1991-2007

Adipose tissue was sampled from the western Hudson Bay (WHB) subpopulation of polar bears at intervals from 1991 to 2007 to examine temporal trends of PCB and OCP levels both on an individual and sum-(∑-)contaminant basis. We also determined levels and temporal trends of emerging polybrominated diphenyl ethers (PBDEs), hexabromocyclododecane (HBCD), polybrominated biphenyls (PBBs) and other current-use brominated flame retardants. Over the 17-year period, ∑ DDT (and p,p′-DDE, p,p′-DDD, p,p′-DDT) decreased (−8.4%/year); α-hexachlorocyclohexane (α-HCH) decreased (−11%/year); β-HCH increased (+ 8.3%/year); and ∑ PCB and ∑ chlordane (CHL), both contaminants at highest concentrations in all years (> 1 ppm), showed no distinct trends even when compared to previous data for this subpopulation dating back to 1968. Some of the less persistent PCB congeners decreased significantly (−1.6%/year to −6.3%/year), whereas CB153 levels tended to increase (+ 3.3%/year). Parent CHLs (c-nonachlor, t-nonachlor) declined, whereas non-monotonic trends were detected for metabolites (heptachlor epoxide, oxychlordane). ∑ chlorobenzene, octachlorostyrene, ∑ mirex, ∑ MeSO₂-PCB and dieldrin did not significantly change. Increasing ∑ PBDE levels (+ 13%/year) matched increases in the four consistently detected congeners, BDE47, BDE99, BDE100 and BDE153. Although no trend was observed, total-(α)-HBCD was only detected post-2000. Levels of the highest concentration brominated contaminant, BB153, showed no temporal change. As long-term ecosystem changes affecting contaminant levels may also affect contaminant patterns, we examined the influence of year (i.e., aging or “weathering” of the contaminant pattern), dietary tracers (carbon stable isotope ratios, fatty acid patterns) and biological (age/sex) group on congener/metabolite profiles. Patterns of PCBs, CHLs and PBDEs were correlated with dietary tracers and biological group, but only PCB and CHL patterns were correlated with year. DDT patterns were not associated with any explanatory variables, possibly related to local DDT sources. Contaminant pattern trends may be useful in distinguishing the possible role of ecological/diet changes on contaminant burdens from expected dynamics due to atmospheric sources and weathering.     

哈得逊地区二叠系火成岩钻井钻井液配方优选室内实验研究

塔里木油田哈得逊地区二叠系火成岩层段微裂缝多、节理丰富易塌易漏,一直是制约该地区钻井速度的主要原因。针对火成岩易漏易塌的钻井难点,从钻井液性能方面入手,通过室内实验优选出强封堵抑制剂(环保型低荧光成膜降滤失剂CMF),聚磺体系钻井液配方,实验表明:该配方钻井液具有流变性好、滤失量低、抑制性强的特点,起到了有效的封堵作用。     

基于Hudson的持续集成研究和应用

持续集成Continuous Integration（CI）是现代软件工程发展的一个重要里程碑。分析了现代软件开发集成存在的问题,以解决集成难题和提升项目可见性为目标,首次提出一套基于Hudson的持续集成设计与实施方案,并给出在J2EE项目中的实现指导,此方案在实际工程开发中取得了良好效果。