Mapping ambivalence: Exploring the geographies of community change and rails-to-trails development using photo-based Q method and PPGIS

As the literature on trail development suggests, recreational trail projects can generate conflicts and controversies, particularly when built on abandoned rail corridors through developed areas. These conflicts are often understood as “not in my back yard” (NIMBY) reactions, suggesting a spatial proximity to conflict which increases as one draws closer to the proposed trail. This research seeks to understand local residents’ perceptions and reactions to recreational trail development in the City of Delaware (Ohio, USA). It addresses two spatially infused questions: Does the potential for conflict related to trail development increase as people live closer to a potential trail (the NIMBY factor)? Can important qualitative factors about favorable and unfavorable land uses including potential recreational trail sites be defined using a participatory methodology and then represented in GIS? The study used a mixed-method approach to collect and analyze qualitative data from a group of local residents. Each participant was interviewed and asked to sort 19 pictures related to trail development. After each of the sorts, participants were asked to explain why they ranked the pictures the way they did. Results of the picture sorts were then analyzed using Q method and mapped with GIS. The results show that spatial proximity matters in the context of trail development and potential NIMBY reactions to trails. Significant differences were found in the picture sorts that reveal the importance of proximity and location, although in a manner contrary to the assumptions in the writings on rails-to-trails. Through combining qualitative methods, Q analysis and PPGIS analysis, the research shows that qualitative place-based studies are capable of generating insights about the complexities of situated geographic change such as recreational trail development.     

Geochronology of Pliocene volcanism in the Dzhavakheti Highland (the Lesser Caucasus). Part 1: Western part of the Dzhavakheti Highland

Isotopic-geochronological study of the Pliocene magmatic activity in western part of the Dzhavakheti Highland (northwestern region of the Lesser Caucasus) is carried out. The results obtained imply that the Pliocene magmatic activity lasted in this part of the highland approximately 2 million years from 3.75 to 1.75–1.55 Ma. As is established, the studied volcanic rocks correspond in composition mostly to K-Na subalkaline and more abundant normal basalts. Time constraints of main phases in development of basic volcanism within the study region are figured out. We assume that individual pulses of silicic to moderately silicic volcanism presumably took place in the Dzhavakheti Highland about 3.2 and 2.5 Ma ago.     

Room-temperature equation of state of Li<Subscript>2</Subscript>VOSiO<Subscript>4</Subscript> up to 8.5 GPa

High-pressure single-crystal X-ray diffraction measurements of lattice parameters of the compound Li₂VOSiO₄, which crystallises with a natisite-type structure, has been carried out to a pressure of 8.54(5) GPa at room temperature. Unit-cell volume data were fitted with a second-order Birch-Murnaghan EoS (BM-EoS), simultaneously refining V ₀ and K ₀ using the data weighted by the uncertainties in V. The bulk modulus is K ₀ = 99(1) GPa, with K′ fixed to 4. Refinements of third order equations-of-state yielded values of K′ that did not differ significantly from 4. The compressibility of the unit-cell is strongly anisotropic with the c axis (K ₀(c) = 49.7 ± 0.5 GPa) approximately four times more compressible than the a axis (K ₀(a) = 195 ± 3 GPa).     

Numerical estimation of REV and permeability tensor for fractured rock masses by composite element method

The Monte Carlo method is used to generate parent stochastic discrete fracture network, from which a series of fractured rock samples of different sizes and orientations are extracted. The fracture network combined with a regular grid forms composite element mesh of the fractured rock sample, in which each composite element is composed of sub‐elements incised by fracture segments. The composite element method (CEM) for the seepage is implemented to obtain the nodal hydraulic potential as well as the seepage flow rates through the fractured rock samples. The application of CEM enables a large quantity of stochastic tests for the fractured rock samples because the pre‐process is facilitated greatly. By changing the sizes and orientations of the samples, the analysis of the seepage characteristics is realized to evaluate the variation of the permeability components, the existence of the permeability tensor and the representative element volume. The feasibility and effectiveness are illustrated in a numerical example. Copyright © 2008 John Wiley & Sons, Ltd.     

辽东湾凝析气田超压成因及侧向传递机制初探

位于辽东湾西部低凸起北端的JZ20-2超压凝析气田,离供烃中心较远,压力系数却达到1.56~1.7,这在我国东部裂谷盆地比较少见。经过综合分析,作者认为JZ20-2凝析气田异常高压的形成与其所处的特殊地质背景紧密相关,辽中凹陷沙河街组三段超压凝析油气沿不整合面、砂体输导通道向辽东湾西部低凸起的运移、充注和能量的侧向传递是JZ20-2凝析气田异常高压形成的根本原因,而上覆东营组二段下亚段-东营组三段巨厚的强超压泥岩封盖和辽西3号边界断层侧向遮挡共同构成的优越封闭环境是超压保存的必要条件。本文分析了该气田超压特征及其远距离超压侧向传递的成因机制,不仅有助于揭示辽东湾西部低凸起超压流体运移聚集的规律和成藏作用,而且可能提供了一个超压远距离侧向传递的典型实例。     

Finite Element Modeling of Swelling Soil Pressures Using Joint/Interface Elements

There could be some discontinuities in a soil media such as layers, earth structures, cracks, and fissures so that estimation of stresses and deformations in these types of soil masses are somewhat different from continuous masses. The discontinuities in a soil mass could be considered as a special link between two blocks. Transmitted swelling pressures affected by the soil properties of the backfill especially at the interface between the backfill and retaining wall. In order to estimate the transmitted swelling pressure distribution behind a retaining wall, using with interface element, a new finite element model and a code (SWELPRES) have been developed. To evaluate the effect of backfill characteristics and interface element from the transmitted lateral swelling pressures, four cases of thickness of backfills with or without interface elements are investigated.     

江苏潮滩沉积物激光粒度仪与移液管-筛析分析结果的对比

激光粒度仪的广泛应用带来了与历史数据的对比问题,因此需要建立激光粒度仪与早期分析结果之间的关系。根据江苏海岸潮滩沉积物样品的激光粒度仪和移液管-筛析法分析,对粒度参数、粒度组分等进行了对比,对两种方法的差异进行了分析。结果表明,对于江苏潮滩沉积物粒度参数中平均粒径的激光粒度仪与移液管-筛析分析结果之间有良好的线性关系;筛分法测得的粗颗粒物质较激光法偏少,而移液管法法测得的细颗粒物质较激光法偏多;将样品分类之后再进行两种方法所获粒度参数的回归分析,相关性得以提高,说明不同粒度组成的沉积物对分析结果的对比有不同的影响。两种方法之间的换算关系不仅与研究区域有关,而且与沉积物本身的粒度组成有关。     

青藏高原西部赛利普中新世火山岩源区:地球化学及Sr-Nd同位素制约

青藏高原拉萨地块西部赛利普地区新生代火山岩依据主量元素可划分为超钾质、钾质和钙碱性系列,主要的岩石类型为粗面安山岩、粗面岩,一个超钾质岩石的40Ar-39Ar年龄为17.58Ma,指示出火山活动为中新世.超钾质、钾质和钙碱性火山岩都显示出富集LREE及LILE(Th、U)、亏损HFSE(Nb、Ta、Ti)的特征.超钾质火山岩具有较高的K2O(6.31%～8.55%)、MgO(6.75%～8.96%)、Cr(270.7×10-6～460.4×10-6)、Ni(142.3×10-6～233.9×10-6)含量,较高的(87Sr/86Sr)i(0.71883～0.72732)和较低的εNd(-14.78～-15.37),指示可能起源于一个前期亏损并经后期俯冲作用改造的富钾的方辉橄榄岩富集地幔源区.钾质火山岩具有比超钾质火山岩低的K2O、MgO、Cr、Ni含量以及高的Ba、Sr含量,初始87Sr/86Sr为0.71553～0.71628,初始143Nd/144Nd为0.51197～0.51198,在空间上与超钾质火山岩共生,可能是前者母岩浆的演化产物.钙碱性火山岩具有较高的Sr(881.7×10-6～1309.2×10-6)、Sr/Y比值(50～108)和较低的Y(12.05×10-6～18.02×10-6),明显亏损重稀土Yb(0.93×10-6～1.30×10-6),类似于典型的埃达克质岩成分特征但相对高钾,并具有相对低的(87Sr/86Sr);(0.70928～0.71374)以及高的εNd(-7.90～-10.91),指示起源于富钾增厚下地壳物质的部分熔融.区域上拉萨地块超钾质岩、钾质岩与N-S向地堑系在空间上共存、时间上相吻合,由此本文认为拉萨地块中新世钾质.超钾质岩和南北向地堑系的形成可能与中新世早期北向俯冲的印度大陆岩石圈断离有关.