Inter- and intraspecific variations of the chemical properties of high-Arctic mosses along water-regime gradients

We examined and compared the contents of organic chemical components (lignin-like compounds, total carbohydrates and extractives), carbon and nutrients (nitrogen, phosphorus, potassium, calcium, magnesium) among the mosses Calliergon giganteum, Hylocomium splendens, Racomitrium lanuginosum, and among three populations of H. splendens collected from habitats in contrasting water regimes in the Canadian high-arctic tundra. C:N:P ratios were analyzed among and within moss species. Mosses from hydric habitats had lower total carbohydrate and higher nutrients contents than did mosses from drier habitats; however, we found no intraspecific variations in nitrogen and calcium contents in the different populations of H. splendens along water-regime gradients. The contents in lignin-like compounds, extractives and carbon showed no clear trends along water-regime gradients. Mosses from hydric habitats had lower C:N, C:P and N:P ratios than mosses from drier habitats, although we found no intraspecific variations in C:N ratios in H. splendens along water-regime gradients. These results suggest that chemical properties of mosses, especially nutrient contents, are strongly correlated with water availability in high-Arctic tundra.     

Legal Geographies—Governing Through Law: Rightsbased Conflicts and Property Development in Shanghai

This article examines recent legislation on the mandatory practice of government adjudication and its impacts on community residents' legal challenges to chaiqian (demolition and relocation) in Shanghai. In recent years, rights-based grievances over community displacement have become a major source of social conflict in urban China. The new legislation represents the Chinese state's efforts to establish a law-based model through which to govern an increasingly rights-conscious society. It is argued that the mandatory practice of government adjudication has smoothed out the conflict-laden property development process by establishing a legalized channel for affected residents to express their claims of rights and interests. Yet, at the same time, legislative practice has also reinforced the government's control in defining social interests to which residents' individual rights are subordinate.     

South Central Farmers and Shadow Hills Homeowners: Land Use Policy and Relational Racialization in Los Angeles∗

This article draws from the recent relational turn in geography to develop a model of relational racialization. It argues that racism functions through the legal and discursive production of linked, interdependent, and unequal places. By comparing two social movements in Los Angeles, the South Central Farmers and the Shadow Hills homeowners, I examine two spatial discourses through which race is relationally reproduced: unequal abilities to mobilize the entitlements of “property rights” and unequal claims to represent hegemonic forms of local heritage. When materialized and naturalized in land use policy, these discourses re-create racial disparities in wealth and poverty and reproduce the qualitative nature of the physical places on which racism depends.     

少数民族村寨过度商业化个案研究 ——以贵州西江千户苗寨为例

以贵州西江千户苗寨为案例,基于“刺激―机体―反应”分析范式的M-R理论模型,提出影响个体游客商业化感知的外部环境因素和概念模型。通过结构方程模型实证检验影响游客商业化感知的先决变量及各变量间的影响路径,结果表明：旅游空间环境、居民社会形态与旅游产品附属对游客商业化感知具有显著的正相关影响作用,其中,旅游商业环境通过旅游空间环境间接对游客商业化感知产生正向影响作用。在实证分析基础上,从景区管理层面的商业化“刺激―反应”演变过程探讨其驱动机制及利益主体间的关系,认为产权配置不合理及缺乏有效的管理机制是民族村寨类景区过度商业化的根本原因,最后提出调控景区商业化的建议。     

吉林省德惠市土壤特性空间变异特征与格局

基于区变量理论,通过地统计学的半变异函数定量研究吉林省中部德惠市土壤有机质、全氮、速效钾和速效磷的空间异质性特征。表明土壤有机质的理论模型属于球状模型、全氮和速效钾的理论模型为指数模型、速效磷则属于有基台值的线状模型。空间结构上,有机质具有很强的空间相关性,全氮和速效钾的空间相关性属于中等程度,而速效磷则具有弱相关性。四种土壤养分的空间自相关范围具有明显的差异,有机质和全氮的有效变程最大,速效钾次之,速效磷的有效变程最小。受研究区形状、地形及土壤母质区域性差异的影响,速效磷各向同性显著,其他养分各向带状性比较明显。根据空间分异的分析结果,在GIS支持下,采用Kriging和IDW两种插值方法,分析研究区土壤养分的空间格局,表明土壤有机质、全氮、速效钾均自东北向西南有规律地分布;速效磷分布的随机性较强,较前三者结构性特征不明显。     

北京亚奥地区居住环境设计与管理的经济利益

为了推动城市居住区环境设计与管理模式的创新, 为相关政策提供决策依据, 有必要定量地把握环境设计与管理所带来的经济价值, 以及伴随政策导入各种利益关系可能发生的变化。运用北京市亚奥地区居住小区的调查数据, 探讨了居住区环境设计与管理的主要影响因素以及与居住区环境政策密切相关的经济利益驱动机制问题。分析表明, 居住小区的规划设计、与周边住宅区的协调性, 以及物业管理是居住区环境品质中最关键的影响因素。同时, 分析定量地证明了居住区环境设计和管理的经济价值, 由此明确了在居住区实行环境设计和管理的潜在动机, 和改善环境设计与管理对提升地区价值所产生的效果。在以上分析的基础上, 提出了推进旧住宅区的物业管理体制改革、通过政策来诱导和推动地区的有机融合、在居住区规划设计和管理方面注重地区文脉、设定适宜的物业收费标准等建议。     

上海市浦东新区城市街道“两抢一盗”犯罪的时空规律

以上海市浦东新区"两抢一盗"犯罪为研究对象,采用空间分析和统计分析的方法,分析其时空分布规律,并剖析街道环境与犯罪分布之间的关系。研究发现:1)犯罪时间分布与人们生活、工作的作息周期相关,街道空间使用频率高的时段犯罪相对高发;犯罪的昼夜分布差别与地区岗位、商业场所等环境的空间分布有关;2)在案发部位分布上,各部位的案件构成受到人流活动强度、自然监视的力度及逃逸便捷程度的影响;3)在宏观地理分布上,盗窃案件在浦东新区内以陆家嘴中央商务区一带为核心呈自西向东圈层递减分布,而"两抢"案件的高发区呈带状和点状分布的格局,较为分散在市区与镇区的各居民集中区附近;4)回归分析表明,交叉口是影响盗窃和"两抢"案件分布的重要环境要素之一,交叉口数量及密度均分别对"两抢"和盗窃量有正向影响。最后以研究结论为依据,提出相应的犯罪防控措施。     

EFFECTS OF SNOW JAMS ON FLUVIAL ACTIVITIES IN THE HIGH ARCTIC

During break-up in the High Arctic, ice jams are insignificant, but large quantities of snow accumulated in the valleys strongly affect fluvial processes. Near Resolute, Cornwallis Island, many channels were first formed in valley snow drifts and their positions were unstable. Channels carved in the snow can easily accommodate changing discharge by a modification of their width, depth, and velocity. This causes considerable variation in the at-a-station hydraulic geometry relationships.

The availability of sediment is locally restricted by the snow lining along the channels, although some fluvial sediments deposited on the snow revealed that peak flows could entrain very large boulders. Several depositional features observed in the study area also indicated that fluvial activities can extend over a broad zone beyond the confines of the summer channels.

This study suggests that, by increasing discharge, snow jams enhance the erosional power of streams, but by interposing between streamflow and the valley floor, the snow can limit the supply of sediments. Whether the erosional or the protectional tendency dominates will depend upon the snow jam characteristics along various segments of the High Arctic streams.     

蒙脱石的脱水作用对断层摩擦本构行为的影响

利用高温双轴摩擦装置，研究了含蒙脱石的断层带在不同温度下摩擦滑动的速度依赖性，以期了解脱水作用对摩擦行为的影响。结果表明，断层带摩擦强度随温度而升高，而速度依赖性较为复杂，以１．４ｕ／ｓ为界，室温和１００℃时，低滑动速率下表现为微弱的速度弱化，高滑动速率下则表现为速度强化；２００℃时均为速度强化；３００℃时高滑动速率下仍为速度强化，但低滑动速率下转变为速度弱化；４００℃以上，均为明显的速度弱化。摩擦行为的变化与脱水过程及相应的断层物质变形方式的变化密切相关     

Differential Characteristics of the Upper Ordovician-Lower Silurian Wufeng-Longmaxi Shale Reservoir and its Implications for Exploration and Development of Shale Gas in/around the Sichuan Basin

The Upper Ordovician Wufeng-Lower Silurian Longmaxi shale is widely distributed in the Sichuan Basin and its periphery, which is the key stratum for marine shale gas exploration and development(ED) in China. Based on sedimentary environment, material basis, storage space, fracability and reservoir evolution data, the reservoir characteristics of the Wufeng-Longmaxi shale and their significance for shale gas ED are systematically compared and analyzed in this paper. The results show that(1) the depocenter of the Wufeng(WF)-Longmaxi(LM) shale gradually migrates from east to west. The high-quality shale reservoirs in the eastern Sichuan Basin are mainly siliceous shales, which are primarily distributed in the graptolite shale interval of WF2-LM5. The high-quality reservoirs in the southern Sichuan Basin are mainly calcareous-siliceous and organic-rich argillaceous shales, which are distributed in the graptolite shale interval of WF2-LM7.(2) Deep shale gas(the burial depth 3500 m) in the Sichuan Basin has high-ultrahigh pressure and superior physical properties. The organic-rich siliceous, calcareous-siliceous and organic-rich argillaceous shales have suitable reservoir properties. The marginal area of the Sichuan Basin has a higher degree of pressure relief, which leads to the argillaceous and silty shales evolving into direct cap rocks with poor reservoir/good sealing capacity.(3) Combining shale gas exploration practices and impacts of lithofacies, depth, pressure coefficient and brittle-ductile transition on the reservoir properties, it is concluded that the favorable depth interval of the Wufeng-Longmaxi shale gas is 2200～4000 m under current technical conditions.(4) Aiming at the differential reservoir properties of the Wufeng-Longmaxi shale in the Sichuan Basin and its periphery, several suggestions for future research directions and ED of shale gas are formulated.