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1.
许经勇 《攀登》2007,26(6):65-67
马克思在《资本论》中所论述的劳动力买卖、平均利润与生产价格,都是以完全竞争或自由竞争为前提条件的。但是,马克思指出,这是一种"理论上的假定"。这就存在着如何把马克思抽象化的理论运用于活生生的现实的问题。在现实生活中,劳动力市场既有竞争的一面,又有分割的一面,而且二者往往是交错在一起的。  相似文献   
2.
瓦当上雕刻的篆体文字是极富研究意义的中华文化元素,为中华文字的研究提供了研究对象。本研究提出一种以曲率为基础,通过粗细两次分割实现瓦当三维文字分割的方法,解决了瓦当上雕刻文字的提取问题。首先通过计算模型表面曲率进行粗分割,并利用聚类修复方法进行细分割。由顶点曲率值衍生出的平面点集进行多平面拟合,实现瓦当表面文字的精确分割。最后应用平行细化子迭代方法进行骨架线提取,实现瓦当文字的提取。实验结果证明,文中方法可以有效地实现瓦当三维文字提取。  相似文献   
3.
陈梅  刘晶晶  崔枫  厉新建  潘澜 《人文地理》2017,32(2):152-160
自20 世纪80 年代以来,现代邮轮旅游作为一种休闲度假方式,已经成为欧美国家中产阶级出游的重要选择之一。深入了解中国邮轮旅游者的特点并进行市场细分,有助于推动中国邮轮旅游市场开发。本研究根据顾客终身价值理论,测算了邮轮旅游者的未来价值,并通过探索性因子分析和验证性因子分析研究了邮轮旅游者的消费偏好,建立了邮轮旅游者未来价值评估模型。基于中国大陆、香港和台湾邮轮旅游者的相关数据,通过AMOS21.0 对邮轮旅游者未来价值模型进行了检验,发现了对邮轮旅游者未来价值有显著影响的因素;通过R13.0 软件进一步对显著影响邮轮旅游者未来价值的因素进行了潜类分析,识别出了未来价值较高的邮轮旅游市场,进而为有效地市场开发提供依据。  相似文献   
4.
An illustrated methodology for the morphodynamic sectoring of the Neigette River (Québec) Fluvial hydrogeomorphology is little recognized in policy management and planning in Québec. A better understanding would result in more enlightened planning for waterways. The deficiency could result from the fact that too few methodologies have been developed that take account of the particular nature of Québec rivers. This study tests the applicability of a methodology of dividing rivers into homogeneous morphodynamic units. This compartmentalization results from the analysis of longitudinal changes in stream power, sedimentary composition of the banks, channel entrenchment, and planform geometry. The method is tested on a section of the Neigette River, which encompasses a wide variety of forms and processes frequently found in Québec rivers. Results suggest the presence of three morphodynamic sections: wandering with multiple channels, dynamic meandering and stable meandering. The method provides an effective basis for discriminating between these morphodynamic environments and their respective limits. Stream power is the variable with the greatest discriminating capacity. The efficacy of the approach, the ease of its application, and its flexibility make this a valuable tool for the management of fluvial environments.  相似文献   
5.
在经济地理学的研究中,劳工常常被看作是与自然资源、资金、技术等同类的经济要素,只重视劳动成本,忽视了劳工作为社会活动主要参与者的角色。近年来,劳工地理研究取得了长足的进展,弥补了传统地理学研究的不足。全球化背景下的工人运动、劳工组织和地方劳工控制体制,劳工市场的空间分割,不同政治、经济和文化背景下的农区劳工地方化逐渐成为劳工地理的重要研究方向。  相似文献   
6.
旅游发展初期的自然旅游地社区居民旅游影响感知分类及影响因素在文献中讨论较少。以天堂寨景区为例利用分层聚类法与多分类名义变量逻辑斯蒂回归模型对居民旅游影响感知群体分类并识别其关键影响因素。研究发现:天堂寨周边社区居民旅游影响感知分为盲目乐观派、社区经济挂帅派、谨慎支持派、悲观反对派,分类的关键影响因素为年龄与居住时间、居住村、现在工作。基于深度访谈数据与研究文献分析了相关因素影响居民旅游影响感知群体分类的内在机制。本研究证实了一个事实:即使在偏远的山区农村社会分化也越来越明显,哪怕是针对像旅游业这样的具体议题,同时本研究也呼应了经典社会学中的社会分层理论。  相似文献   
7.
周亚庆 《旅游科学》2003,17(4):19-22
本提出基于盈利细分的竞争战略,即饭店应关注高盈利价值的顾客群体,致力于满足这些顾客群体的真正需要。  相似文献   
8.
9.
Vigorous hydrothermal convection transfers 10 times the average continental heat flow through the central Taupo Volcanic Zone (TVZ), a region of active extension (approximately 8 mm year?1) and productive rhyolitic volcanism. Over 20 high‐temperature (>250°C) geothermal fields occur within Quaternary pyroclastic basins, with convective circulation to depths of 7–8 km presumably extending through basement rocks. Parallel‐striking normal faults, fractures and dikes dissect the convective regime, interacting with fluids to either enhance or restrict flow according to the relative permeability of structure and host rock. In the basement, high bulk permeability is maintained by focussed flow through faults and associated fractures well oriented for reactivation in the prevailing stress field. In contrast, distributed flow through fault‐bounded compartments prevails within Quaternary basins, masking any signal of deeper structural control. Exceptions occur where more competent rocks are exposed at the surface. As in narrow magmatic rifts elsewhere, the extensional fabric is partitioned into discrete rift segments linked along strike by accommodation zones. Eighty per cent of TVZ geothermal fields correlate spatially with rift architecture, with 60% located in accommodation zones. We suggest that segmented rift fabrics generate bulk permeability anisotropy that is to some extent predictable, with rift segments characterized by enhanced axial flow, and accommodation zones characterized by locally enhanced vertical permeability that is tectonically maintained. This provides a plausible explanation for the common occurrence of geothermal fields within accommodation zones and their notable absence within densely faulted rift segments. Maintenance of structural permeability in zones of active hydrothermal precipitation necessarily requires repeated brittle failure. Geothermal plumes therefore exploit tectonically maintained permeability within accommodation zones, with rift segments functioning mostly as drawdown regions. The influence of rift architecture on flow paths has important implications for geothermal extraction and epithermal mineral exploration within the TVZ and other structurally segmented hydrothermal systems, both active and extinct.  相似文献   
10.
The main goal of this work was the non-destructive testing (NDT) of an ancient fresco (15th century) preserved in the Santa Maria di Collemaggio Church (L’Aquila, Italy) and damaged after the 2009 earthquake. Active infrared thermography (IRT), near-infrared (NIR) reflectography and ultraviolet imaging (UV) were used. In addition, the state of the fresco prior to the earthquake was analyzed by electronic speckle pattern interferometry (ESPI), digital speckle correlation (DSC), raking light, tap, and chemical NDT techniques. The use of these techniques was important for the monitoring of new damages and for a comparison between the results over the years. Square heating thermography (SHT) data were processed using principal component thermography (PCT) and pulsed phase thermography (PPT) algorithms, in order to improve the defects’ signature and to reduce the impact of non-uniform heating and emissivity variations due to the painting’s pigments. A multi-analysis approach, segmentation operators and a specific data correlation method emphasize the overall study of the fresco. Furthermore, the facade and the high altar area were inspected by passive thermography and ground-penetrating radar (GPR), respectively. In the present case, the combined use of NDT techniques was useful to fill in the gaps in the construction history of the building.  相似文献   
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