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71.
李琪炯 《价值工程》2014,(2):253-254
公共图书馆作为公共文化服务体系的重要组成部分,在构建学习型社会的大背景下,为促进终身学习的理念,借鉴国外图书馆的前沿探索,提升人文素质和知识内涵,实现公共图书馆在新的历史形势下自身的转型与发展。  相似文献   
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73.
[目的]考虑环境和耕地约束,构建了城镇化效率测算指标体系,测算并分析我国2000~2014年区域城镇化效率,并且从城镇化发展模式与产业结构分布形态2个角度探索区域城镇化效率差异的机理。[方法]以"工业三废"和耕地面积减少量作为非合意产出,构建了由11个指标组成的投入—合意产出—非合意产出指标体系,进而利用优化ISBM模型测算了2000~2014年我国区域城镇化效率,并利用谱系聚类方法分析了其梯队层次特征。[结果]我国各省域城镇化效率总体较低,绝大多数省域处于效率缺损的状态;各省域城镇化效率表现为明显的5个梯队层次,不同区域、不同梯队省域城镇化效率存在明显差异,总体呈现出东、中、西依次递减的格局,并且省域之间城镇化效率差距自2000年以来呈不断缩小的趋势;东部地区城镇化效率较高,总体上城镇化与产业结构之间相互协调,城市群发展程度高而使得城市之间的分工合作程度高;中西部地区城镇化效率相对较低,产业结构对经济的支撑作用相对较弱,城市体系断层明显,城市群带动作用弱。[结论]我国区域城镇化效率总体较低且不平衡,这在很大程度上取决于城镇化模式和演进机制,区域之间的城镇化效率差异体现在产业结构层次、城市集聚方式以及劳动力转移方式等方面。  相似文献   
74.
Land use change is strongly modifying the traditional landscape of hilly productive Mediterranean sites. An example of these circumstances is the Langhe region (Piemonte, NW Italy), where woody plantations such as vineyards and orchards have been cultivated on hillslopes for centuries. In this paper we assess landscape changes occurred in the Diano study area (2651 ha) in the 1954–2000 period and we ascertain land use transition paths and rates of this rural ecosystem. Land use mapping obtained from object-oriented analysis of aerial photographs was used to quantify land use changes between 1954 and 2000. To examine the spatio-temporal patterns of land use change over time, a set of spatial statistics capturing different dimensions of landscape change was identified. An increase of landscape heterogeneity from 1954 to the present was observed due to the expansion of orchards and the fragmentation of field crops. A significant portion (55%) of current orchards surface is represented by former field crops, 24% by vineyards and 15% by forests. The strong expansion of hazelnut orchards concurred to the fragmentation of traditional rural landscape was dominated by vineyards, field crops and forests. Hazelnut orchards expansion was mainly located in places where grapes cultivation was less remunerative. A further expansion of hazelnut in the area should be planned, discussed and carefully monitored through change detection studies in order to avoid potential unsustainable use of the land.  相似文献   
75.
This article develops theory about an agency problem affecting the strategic human capital (SHC) of the firm. It proposes three categories of SHC‐related choices managers must make that imply a trade‐off between near‐ and long‐term performance. Dispersed shareholding, firm coverage by securities analysts, and their practice of publishing quarterly earnings forecasts are argued to entail a bias in management incentives, shifting the balance in this trade‐off toward near‐term performance. To restore the balance, securities analysts would need to distinguish transitory from recurring effects of SHC‐related choices in their valuation models (e.g., treating certain labor cost savings during cyclical downturns as transitory). Restoring the balance would also require them to anticipate long‐term effects in their long‐term earnings forecasts (e.g., long‐term positive effects of retaining employees with valuable skills during cyclical downturns). The article discusses specific transitory cost effects and long‐term effects they could potentially take into account. The skills and incentives needed by analysts to account for such effects are argued to vary across firm segments.  相似文献   
76.
[目的]探索叶尔羌河平原绿洲土地生态安全预警问题及其时空格局变化,旨在为叶尔羌河平原绿洲土地生态安全及可持续利用提供科学的参考依据。[方法]文章运用PSR模型构建预警指标体系,采用熵值法测算各指标权重,对2000—2016年叶尔羌河平原绿洲土地生态安全警情格局进行综合分析,并利用GIS技术分析其2000年、2005年、2010年和2016年土地生态安全空间格局变化,最后运用障碍度模型探索其障碍因子。[结果](1)2000—2016年叶尔羌河平原绿洲土地生态安全综合预警指数总体呈上升态势,生态预警状态由"较不安全"转为"临界安全",警度亦由"重警"变为"中警"。(2)从空间格局来看,空间上各县域土地生态安全水平差异明显,研究初期西部地区土地生态安全状态优于东部地区, 2016年呈现出中部高、东北—西南部低的态势。(3)近17年叶尔羌河平原绿洲各县域土地生态环境状况有所改善,安全状态经历了"极不安全—临界安全—较安全"的发展历程。(4)影响土地生态安全的主要障碍因子包括单位面积耕地农药负荷、人口密度、单位面积耕地化肥负荷、土地垦殖率、人口自然增长率和单位面积耕地地膜负荷等。[结论]研究期间叶尔羌河平原绿洲土地生态安全得到明显的提升与改善,并在良好的方向发展。  相似文献   
77.
随着中国经济的快速发展,能源消费也快速增长。随着节能减排的压力越来越大,能源的代谢需要根据需求进行更替。论文就京津冀城市群能源代谢时空特征分析并对能量代谢进行优化和调控提出建议。  相似文献   
78.
Based on construal level theory, this research addresses the moderating role of an individual's psychological distance towards a disease in the effectiveness of advertising messages framed by two distinctive construal level terms (high-level and low-level). In Experiment 1, two different disease types (bronchitis/distant disease vs. influenza/proximal disease) were featured, with the result that an advertisement with high-level construal terms was more persuasive for a psychologically distant disease (bronchitis) than for a psychologically proximal disease (flu). The reverse was true for an ad framed with low-level construal terms. To replicate Experiment 1 and further test the hypothesis, in Experiment 2, the perceived distance individuals have towards one disease (cancer) was measured and used as independent variable. Consistent with the results from Experiment 1, the low-level construal messages were more effective under the psychologically close condition than the psychologically distant condition. Reverse was true for the high-level construal messages.  相似文献   
79.
Delineating travel patterns and city structure has long been a core research topic in transport geography. Different from the physical structure, the city structure beneath the complex travel-flow system shows the inherent connection patterns within the city. On the basis of taxi-trip data from Shanghai, we built spatially embedded networks to model intra-city spatial interactions and to introduce network science methods into the analysis. The community detection method is applied to reveal sub-regional structures, and several network measures are used to examine the properties of sub-regions. Considering the differences between long- and short-distance trips, we reveal a two-level hierarchical polycentric city structure in Shanghai. Further explorations of sub-network structures demonstrate that urban sub-regions have broader internal spatial interactions, while suburban centers are more influential on local traffic. By incorporating the land use of centers from a travel-pattern perspective, we investigate sub-region formation and the interaction patterns of center–local places. This study provides insights into using emerging data sources to reveal travel patterns and city structures, which could potentially aid in developing and applying urban transportation policies. The sub-regional structures revealed in this study are more easily interpreted for transportation-related issues than for other structures, such as administrative divisions.  相似文献   
80.
土地是最基础与最重要的资源与资产,是国家经济政策拟定的依据,是实施规划纲要与落实方针政策的基础。土地是人类生存的基础,而且是不可再生的,只有加大土地管理的力度,高效合理地利用土地,才能实现我国可持续发展的目标。地籍管理是土地管理工作的重点领域,是土地产权得到保障的前提。目前的土地管理集中在对土地产权的管理,土地产权变化会涉及到地理实体时间、空间及属性的变化,时态GIS正好反映了此变化。目前时态GIS的研究集中在对时空数据模型的建构。时空数据模型决定了时态GIS系统的运行效率。无论是国内还是国外均对时空数据模型进行了研究,通过模型的构建的相应地提出了超过20种模型,而在实际的应用中,不同的模型有不同的特点。文章对典型的6种时空数据模型进行了分析,从模型的建模思路出发,分别探讨了模型的适合环境与优缺点,可以为人们在应用时空数据模型进行土地管理时提供帮助,有利于研究者对模型的进一步研究。  相似文献   
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