北京市土地利用空间结构特征分析

分析北京市土地利用空间结构特征,对于北京市未来土地的合理利用具有重要意义。该文从景观、经济和生态3方面着手,应用区域土地利用类型多样化程度指数、土地利用程度综合指数、经济密度指数及生态价值等指标,借助1 km×1 km网格进行空间表达,阐述了2006年北京市土地利用空间结构特征。研究结果表明：2006年北京市土地利用类型比较齐全,北京市土地利用/覆盖多样化指数和土地利用程度指数呈由西北山区向东南平原逐渐增大的过渡趋势;2006年北京市平均土地经济密度为47.97×106元/km2;北京市西北林区经济密度最低,而城镇区域最高,且集中连片;2006年北京市总体生态价值约为13 488.13×106元,每平方千米约为0.82×106元,略高于全国平均水平。建议提高土地利用效率,使北京土地利用走上可持续发展的道路。     

经济学理论视域下图书馆政府信息公开服务研究

通过对政府信息资源经济学特征的分析,从经济学的角度论述了图书馆政府信息公开服务能力即从重视政府信息公开的经济学意义程度、法律法规保障、强化培训与营销组合以及加强合作,以提升图书馆政府信息公开服务能力,实现政府信息公开服务绩效的最大化。     

我国近年旱情演变及其对农业造成的影响

旱灾是世界上影响面最广、造成农业损失最大的自然灾害类型。新中国成立以后,我国对旱灾虽然有一定的控制,但仍不断发生,对我国的农业尤其是粮食生产造成了严重影响。文中总结了自1999年以来,我国发生的重大旱灾以及其对国民经济尤其是农业造成的影响。同时收集了1978-2008年来全国旱灾的土地受灾面积、成灾面积、成灾率,以及全国农作物播种面积等相关数据,分析农业受旱灾的影响情况。研究表明,由于人为和自然的因素,近年来我国旱灾有加重的趋势,对此我们应该提高警惕,在加强生态环境保护的同时增强自身的抗旱能力。     

城郊区农村土地流转调查——以山西省晋中市榆次区为例

城郊区农村土地流转是一类独特区域的问题。研究结果表明,城郊区农村土地流转发生率偏低,在形式上以继承方式为主,而且多为无偿流转。土地流转的影响因素为:一是征地补偿和农业补贴强化了土地经营权的意识;二是玉米机械化生产减少了劳动投入;三是劳动力就近转移和交通便捷使得外出劳动力容易返乡支持农业生产;四是农业生产树苗化不需要劳动投入。城郊区土地实现规模化经营是社会发展趋势,通过土地市场化流转实现土地规模化经营有一定难度,要积极探索城郊区土地流转的可行方式。     

Modeling the spatially dynamic distribution of humans in the Oregon (USA) Coast Range

A common approach to land use change analyses in multidisciplinary landscape-level studies is to delineate discrete forest and non-forest or urban and non-urban land use categories to serve as inputs into sets of integrated sub-models describing socioeconomic and ecological processes. Such discrete land use categories, however, may be inappropriate when the socioeconomic and ecological processes under study are sensitive to a range of human habitation. In this paper, we characterize the spatial dynamic distribution of humans throughout the forest landscape of western Oregon (USA). We develop an empirical model describing the spatial distribution and rate of change in historic building densities as a function of a gravity index of development pressure, existing building densities, slope, elevation, and existing land use zoning. We use the empirical model to project changes in building densities that are applied to a 1995 base map of building density to describe future spatial distributions of buildings over time. The projected building density maps serve as inputs into a multidisciplinary landscape-level analysis of socioeconomic and ecological processes in Oregon's Coast Range Mountains. This revised version was published online in July 2006 with corrections to the Cover Date.     

Comparing the roles of Pacific halibut and arrowtooth flounder within the Gulf of Alaska ecosystem and fishing economy

The fishing industry of the western and central regions of the coastal Gulf of Alaska (CGoA) directly employs over 17,000 people and processes fish with a wholesale value of US$618 million annually. Pacific halibut (Hippoglossus stenolepis) are a valued groundfish species because of the high quality of their flesh. In contrast, arrowtooth flounder (Atheresthes stomias) are much more abundant but of low value because their flesh degrades upon heating. Both are high trophic level predators but play different roles in the ecosystem because of differences in abundance and diet. Using an end‐to‐end ecosystem model, we evaluate the impact of alternate levels of fishing effort and large‐scale changes in oceanographic conditions upon both species, the ecosystem, and the fishing economy. Reduction of longline efforts to reduce Pacific halibut mortality led to reduction in total value of all CGoA landings but increase in value landed by sport fisheries, trawl fleets, and fish pot vessels as they exploit a greater share of available halibut, sablefish, and Pacific cod. Increased trawl effort to raise arrowtooth flounder mortality led to increase in total value of all landings but large reductions in value landed by longline, jig, fish pot, and sport fleets with greater competition for available Pacific cod, halibut, and sablefish. Oceanographic conditions that enhance pelagic food chains at the expense of benthic food chains negatively impact groundfish in general, though Pacific halibut and arrowtooth flounder are resilient to these effects because of the high importance of pelagic fish in their diets.     

软土地质大口径管线埋设技术方案优化

针对DN2000管线在软土地埋设设计,充分考虑地质因素,优化设计方案,论证了软土地质条件下管线埋设的最佳深度,达到节约工程投资,减轻施工难度的目的。     

文登市土地类型与开发利用

文登市土地类型的划分是在分析文登市区域自然地理背景、剖析各土地分异因素的基础上,根据成图比例尺采用“限区”作为分类制图对象,构成“限区”的分类等级系统,并据此编制文登市1:50000万土地类型图。另外,还重点阐述了第一级土地类型—限区科的基本特征、利用现状和改良整治建议。     

劳动经济学视角下饲料产品消费金融发展探析

随着经济社会的不断发展,劳动经济学相关理论在把握我国当前饲料产品消费金融规律和发展趋势方面发挥了重要作用,对推动我国经济高质量发展起到了重要作用.当前,在劳动经济学视角下,我国饲料产品消费金融发展的优势在于优化和丰富传统信贷系统、有助于维持供需平衡、有助于维持消费者消费水平的平衡.当前,为了进一步推动我国饲料产品消费金...     

我国农村土地地权资本化问题之法经济学分析

为寻找我国农村土地地权资本化法律制度困境的出路,结合法学与交易成本理论对我国农村土地制度和法律环境存在的问题进行研究分析。研究认为:制度条件对产权和交易的约束更为关键,国家、集体和农民三者所共同形成的权利主体关系和产权结构准确定位以及土地增值收益权和分配机制的保障是关键点;土地产权结构应当选择一个交易成本最小化的法律结构,通过构建分层式复合产权结构、制度化农村土地承包权期限和范围、法律化农村土地资本化权利主体持续受益机制、明确利害关系人各方权利义务范围等优化产权结构。权属完全赋予单一主体是消除当前农村土地权利冲突较为经济的方式。