Contesting authentic practice and ethical authority in adventure tourism

This paper examines the discourses of authenticity and ethics employed by adventure tourists regarding the use of the natural environment. In one case, full-time traveling rock climbers use their dedication to the sport and annual visits to the Red River Gorge as evidence for their authoritative voice on ethical climbing practice. While they identify the growing numbers of leisure climbers as a problem for sustainability, many also take up temporary employment as guides and are directly involved in the introduction of new climbers to the area. In another case, two groups of wilderness enthusiasts – “ADK 46ers” and “Summit Stewards” – lament the environmental and social impacts of other recreational users in the Adirondack Park. Despite being visitors themselves, Summit Stewards and 46ers use their sense of place and knowledge of Adirondack history and ecology to substantiate their authority as purveyors of ethical practice. In both cases, senses of responsibility are inspired by senses of place, but are articulated through notions of authenticity and used as justification for ethical authority. While validating their presence in these outdoor spaces, the use of such rhetoric also minimizes their own impacts yielding further tensions among user groups.     

黄土边坡稳定性分析的概率方法

黄土边坡稳定性分析是一个不确定性问题,包含很多不确定性因素,而且土的抗剪强度可变性很大。在进行了大量实验的前提下,估计抗剪强度的可变性,运用概率的方法进行边坡的稳定性分析,计算黄土边坡的失稳概率。     

遗传算法优化BP神经网络的岩质边坡稳定性预测

为了解决边坡工程中非线性变化给稳定性预测造成的困难,建立了GA-BP神经网络计算模型预测岩质边坡稳定性。采用定性评价和相互作用矩阵复核的方式,选取边坡坡度、边坡高度、斜坡结构类型、岩体强度、控滑结构面倾角、岩体结构特征、地表变形强度、人类活动强度8个评价因子作为BP神经网络的输入变量;利用遗传算法对神经网络的初始权值和阈值进行优化后训练岩质边坡稳定性预测模型;对比分析GA-BP神经网络和BP神经网络的预测效果。结果表明,优化后的预测结果误差绝对值小于0.15的占85%,未优化的传统神经网络仅占45%,优化后的预测结果更加接近真实值,表明遗传算法对传统BP神经网络的优化是有效的。研究结果对建立岩质边坡稳定性预测模型具有一定的参考价值。     

福建漳平市箭竹坪矿区主采煤层对比分析探讨

文章在对箭竹坪矿区岩资料收集整理的基础上,分析并研究了矿区的岩煤层对比。经过分析表明,在某些标志层特征不明显的情况下,找到其它某些特征明显的标志层对矿区的岩煤层对比可起到相当重要的作用。     

冀北超基性岩地质特征

冀北超基性岩带位于华北地台北缘，受崇礼－隆化深大断裂控制。该岩带从西往东可分为赤城、丰宁－滦平和承德－平泉三个超基性岩群。各岩群的形态、产状、岩石类型、矿物成份、化学成份各有特点，表现出一定的规律性。Ｋ－Ａｒ及Ｓｍ－Ｎｄ同位素年龄表明，这些超基性告形成于中元古宙、海西期及印支期。     

Price integration in the Australian rock lobster industry: implications for management and climate change adaptation

Rock lobster fisheries are Australia's most valuable wild fisheries in terms of both value of production and value of exports. Different states harvest and export different lobster species, with most of the landings being sent to the Hong Kong market. A perception in the Australian lobster industry is that the different species are independent on the export market, such that a change in landings of one species has no impact on the price of the others. This study investigates the market integration of Australian exports to Hong Kong for the four species and different exporting states. Our results indicate all four species and producers/export states are perceived to be substitutes for one another, so that, in the long run, prices paid to operators in the industry will move together. The integrated nature of the Hong Kong export market for Australian lobster suggests that the potential impacts of alternative fisheries management and development strategies at state and species levels cannot be considered in isolation, at least from an economic perspective. In addition, impacts of external shocks affecting production in one state (e.g. climate change) can be expected to affect all Australian lobster fisheries.     

JCCAD模块在超高层筏板基础计算中的应用

时于一座292米的超高层建筑,持力层为圃砾层,(地基承栽力f(ak)=650kPa,压缩模量E0=37),采用平板式筏基,这是一个大胆的尝试.虽说不一定是首创,但在技术上,也是一种挑战.另一方面,相对于桩基,筏基既可以缩短工期,也可以节省造价,在施工和经济两个方面都是首选.为了准确的计算基础的沉降、内力及配筋,本工程采用PKPM软件的JCCAD模块,准确输入地质状况,并建立多个模型进行比对.在基床反力系数的选取上,亦采纳多方面的意见,通过程序自动生成、当地经验值反算、安全系数调整等多次校核,得出较符合实际的沉降值.     

旺村水利枢纽一期施工导流设计与优化

旺村水利枢纽处于桂江与西江汇合口附近，受西江洪水位顶托严重，施工过程洪水情况非常复杂，因此该工程采用了过水围堰的方案，减少了上游库区淹没几率，节约了工程投资。文章着重介绍了施工时段选择，过水围堰的设计与优化，特别是采用了基坑预充水等一系列简单易行的措施后，石渣保护的过水围堰体很牢固，供同类工程设计人员借鉴。     

梧州河西防洪堤岸坡滑坡的特点及施工对策

文章通过对梧州河西防洪堤岸坡工程地质条件进行分析，总结了滑坡的形成分布特点。并结合堤防工程施工中发生岸坡滑坡案例原因的分析，探讨总结出“削坡减载、导流截渗、跳格开挖、坡脚先行”的施工对策。     

无拉应力分析在岩坡稳定性评价中的应用

本文对无拉应力分析在岩坡稳定性评价中的应用作了系统分析，并通过研究实例，阐明了这种方法的实用性和重要意义．