Study of momentum transfers within a vegetation canopy

Two models have been developed by applying conditions of continuity between the roughness sublayer and the top of vegetation canopy having constant foliage distribution. Massman's cosh-type of wind profile and Albini's exponential wind profile have been used to derive expressions for shear stress, displacement height and roughness length in analytical forms. The computed results compared with those of Massman models (1987, 1997) show similarity with the present models.     

侧扫声纳系统成图中的位移、变形和噪声问题

侧扫声纳声图判读的正确性和准确性对海洋工程的实施和维护中具有非常重要的作用。但诸多影响因素的存在使得声纳声图不能真实反映海底状况。了解这些因素，并在判读过程中尽可能消除其影响，以达到正确和准确判读是非常有意义的。本文将这些影响因素按照作用结果分为位移、变形和噪声3个大类，并对其校正或消除方法进行讨论。     

Juvenile-adult Colour Patterns and Coexistence in the Territorial Coral Reef Fish Pomacanthus imperator

Abstract. The coexistence of juvenile and adult territorial Pomacanthus imperator was studied in the Red Sea. The role played by their divergent colouration in the settlement of juveniles among adults on the reef is interpreted as the intraspecific equivalent of character displacement.     

Wavimeter

A method of extracting wave parameters from surface displacement measured from a moving platform is presented. The article first presents a method for accurately measuring surface displacement using a single beam altimeter and heave sensor. A least squares approach is presented to estimate wave parameters using vessel velocity and perceived wave frequency that eliminates Doppler due to vessel motion. Two techniques for estimating wave frequency are presented: a block data method using MUSIC and a real-time method using demodulation. Sea trial results demonstrate that this method is as effective as a WaveRider buoy for estimating wave parameters.     

GBInSAR在大坝变形监测中的应用

评判水工建筑物的工作性态,需高精度的变形、应力等信息。根据大坝安全监测特点和要求,介绍GBSAR监测系统构成和测量基本原理,分析该系统测量误差来源及特征,探讨该技术在大坝变形监测中的可行性。以隔河岩大坝3d的实测数据为例,分析该技术实际测量精度,研究显示成果达亚毫米级,能够满足大坝变形监测的精度要求。     

Global retail capital and the city: towards an intensification of gentrification

The emerging literature on retail gentrification has not paid much attention to the link between recent reconfigurations of retail capital (concentration, internationalization, and financialization) and the contemporary wave of “generalized gentrification”. In this paper, I argue that analyzing the strategies of stakeholders involved in sectors other than housing (in this case, the retail sector) should allow us to identify different forms of gentrification intensification. I investigate the case of the Marais – that is, one of the first Parisian neighborhoods having undergone gentrification – by mapping the frontier of retail gentrification over the long term (1965–2011) and at the scale of an entire neighborhood (more than 130 ha comprising over 2,000 commercial units). The key drivers of the process (commercial real estate, new brand development strategies, changing commercial environment, the role of public policies) and its social stakes (displacement/replacement of former stores) are then discussed.     

Voluntary resettlement in land grab contexts: examining consent on the Ecuadorian oil frontier

Forced resettlement, central to state-led development throughout the twentieth century, still paves the way for agroindustrial, hydroelectric, urban, and other forms of development in much of the global South today. In response to pressures from social movements challenging human displacement, states, firms, and multinational institutions increasingly seek the consent of impacted communities, often offering monetary compensation and resettlement, along with development assistance. Some states obtain consent by offering resettlements with urban infrastructures and public services. In Ecuador, the state has planned 200 urban-like resettlements called “Millennium Cities” for communities on the Amazonian oil and mining frontiers. Although resettlement in this context transforms human–environment relations and generates new social ills by isolating residents from food supplies and market networks, many communities do consent to resettlement. In this paper, I call attention to voluntary rural–urban resettlement in land grab governance and I explore why communities might consent to their own displacement. This paper suggests the need to account for the material and social conditions that structure consent.     

Seabed Ground Improvement in Coastal Reclamation Area by Heavy Tamping After Rockfilling Displacement

Considering the characteristics of seabed ground in coastal reclamation area, ultra soft clay improvement method by heavy tamping after rockfilling displacement was proposed combined with a case study. The improvement mechanisms of the method can primarily be attributed to rockfilling displacement (RD), dynamic compaction (DC), dynamic replacement (DR) and dynamic replacement and mixing (DRM). For the case study given in this article, heavy tamping construction program was proposed based on field pilot tests. Furthermore, the effectiveness of the proposed ground improvement method was verified through in situ plate load test, sand fill test and the analyses of observed settlement data. Thus, the method of heavy tamping after rockfilling displacement is applicable for the improvement of seabed ground in coastal reclamation area. It is proposed for similar projects that heavy tamping of fills may be performed by layers and correspondingly tamping energy increased to further enhance the improvement effect of DC, DR and DRM. In addition, delayed improvement effect or time effect of soil mass after heavy tamping is still an issue to be further studied.     

More than gentrification: geographies of capitalist displacement in Los Angeles 1994–1999

Little is understood about displacement in urban contexts. While some of the difficulties are methodological, the more serious problem is conceptual. Outside of the rent gap hypothesis or the philosophy of property rights, there has been little theoretical inquiry into the causal dynamics of displacement. In this article, I present a study of evictions in Los Angeles that addresses these conceptual and empirical shortcomings. A spatial analysis of more than 70,000 georeferenced evictions between 1994 and 1999 documents the existence of four distinct geographies of displacement, each produced by separate types of causal circumstances. Gentrification explains only one of the four displacement geographies, while the other three are nongentrifying or pre-gentrifying contexts and more appropriately described through growth machine models, global city theory, and financial restructuring. The extent of displacement in pre- and nongentrifying areas reinforces Mark Davidson’s emphasis on Lefebvre’s production of space as a crucial framework for understanding displacement processes.     

加劲桩配合工法桩在软土基坑中的支护效果评价

以嘉兴晶辉广场深基坑工程为背景,研究了旋喷加劲桩在软土深基坑中的支护效果。结合监测数据,利用FLAC 3D有限差分软件,对旋喷加劲桩配合SMW工法桩(劲性水泥土搅拌桩)这种组合结构在基坑各个开挖工况下的受力情况以及深层土体水平位移变化情况进行模拟计算。结果表明:深层土体水平位移曲线呈"鼓肚状",最大水平位移安全合理,位于基坑开挖底面以上1m~2m处;SMW工法桩所受剪力随开挖深度的加深而增大;三排加劲桩所受拉力呈现为越接近基坑开挖底面越大的规律。模拟结果与实际监测结果基本一致,且均在安全范围内。说明旋喷加劲桩在软土基坑中的支护效果较好,此次模型的建立较合理,为今后类似基坑工程的设计计算提供了参考。