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排序方式： 共有1363条查询结果，搜索用时 15 毫秒
1.
江立 《仲恺农业技术学院学报》1996,9(2):1-4,19
本文述了“广东山区开发理论与实践研讨会”所达成共识的观点：广东山区开发具有重要的战略意义，广东山区开发必须走可持续肆展，农业产业化经营、工业化道路，同时必须搞好基础设施建设，组织好商品流通工作，优化资源配置。 相似文献
2.
The US Department of Agriculture's Farm and Ranch Irrigation Survey collects the most detailed and comprehensive data on US irrigation practices. Yet, because the data are only easily available in cross‐tab form, data are rarely used for statistical analysis of irrigator behavior. Using data from Arizona and New Mexico, this study illustrates how statistical measures of association can be used test hypotheses about how farm size (measured by sales class) affects (i) use of water management information, (ii) investment in irrigation improvements, and (iii) participation in conservation programs. Parametric (Cochran–Armitage trend test) and nonparametric (Goodman–Kruskall gamma) methods yielded similar results. Reliance on low‐cost, general information was common among all size classes, while larger operations relied more on private, tailored information. Larger operations were more likely to use directly provided data (e.g. media and Internet reports) than smaller operators, who relied more on information provided by intermediaries. Smaller farms were less likely to investigate irrigation improvements, use management‐intensive methods for irrigation scheduling, or participate in cost‐share programs to encourage adoption of improved irrigation practices. Adoption of scientific irrigation scheduling methods was low for all groups, but especially low for small‐scale irrigators. There appear to be significant barriers to information acquisition, use of management‐intensive irrigation practices, and participation in conservation programs among smaller‐scale irrigators. Copyright © 2012 John Wiley & Sons, Ltd. 相似文献
3.
Mammalian parental investment (i.e. care of descendant offspring) is largely biased towards maternal contributions due to the specific feeding needs of mammalian offspring; however, varying degrees of paternal investment have been reported in about 10% of all mammalian species. Within the order Carnivora, paternal contribution to rearing offspring is particularly high: an estimated 32% of all studied carnivore species exhibit direct paternal care. Despite the prominence of paternal investment in carnivores, the endocrine basis of this behaviour is not well understood. This review examines the current – highly constrained – state of knowledge about the endocrine basis of carnivore paternal investment. We attempt to link changes in androgen and glucocorticoid levels with variation in direct and indirect paternal care behaviour making specific predictions regarding the way forward. Well-studied species, such as bat-eared foxes (Otocyon megalotis), dwarf mongoose (Helogale parvula) and meerkats (Suricata suricatta), where social dynamics are relatively well understood, can act as ideal model systems through which we may further investigate the endocrine basis of paternal investment in carnivores. 相似文献
4.
本文作者根据自己多年的工程实践,并结合我国国情,对工程监理在公路投资控制中的作用的全过程进行了较全面的论述。 相似文献
5.
Jiaping Wu 《Asia Pacific viewpoint》2008,49(2):244-253
Abstract: With the increase of global integration, the peri‐urban area (PUA) of megacities in Asia has become a favourite destination for foreign direct investment (FDI). This paper uses the PUA of Shanghai as a case study to investigate the impact of global forces on the urban expansion of the city, and the link between urban growth and sustainable development in this mega‐urban context. Shanghai has grown impressively during the past two decades in terms of economic and physical transformation. Much of this transformation has rested on the unbridled exploitation of land and other environmental resources in its peri‐urban area. This is characterised by the designation of development zones and the concentration of manufacturing FDI, resulting in dispersed growth and environmental degradation. The disruption of the physical environment, combined with the concentration of the urban poor in these areas (in particular ‘temporary migrants’), has turned the PUA into a potential crisis point threatening the social and economic development of the city. 相似文献
6.
Vacant land, a product of population and economic decline resulting in abandonment of infrastructure, has increased substantially in shrinking cities around the world. In Cleveland, Ohio, vacant lots are minimally managed, concentrated within low-income neighborhoods, and support a large proportion of the city’s urban forest. We quantified abundance, richness, diversity, and size class of native and exotic tree species on inner-city vacant lots, inner-city residential lots, and suburban residential lots, and used i-Tree Eco to model the quantity and economic value of regulating ecosystem services provided by their respective forest assemblages. Inner-city vacant lots supported three times as many trees, more exotic than native trees, and greater tree diversity than inner-city and suburban residential lots, with the plurality of trees being naturally-regenerated saplings. The urban forest on inner-city vacant lots also had two times as much leaf area and leaf biomass, and more tree canopy cover. The quantity and monetary value of ecosystem services provided by the urban forest was greatest on inner-city vacant lots, with exotic species contributing most of that value, while native taxa provided more monetary value on residential lots. The predominately naturally-regenerated, minimally managed exotic species on vacant land provide valuable ecosystem services to inner-city neighborhoods of Cleveland, OH. 相似文献
7.
杨培兴 《北京林业大学学报》1991,(2)
本文分析论述了建立和完善责任会计的必要件,并用非平衡系统协同学原理对林业企业经济系统加以分析。林业企业现行的内部银行制度,在正确处理企业内部结算关系和加强资金管理方面起着积极作用。按责任会计的有关理论和方法进一步充实和完善内部银行制度,是加强林业企业内部管理的迫切需要。本文以某林业局实行的内部银行为研究对象,提出了该局实行责任会计与财务会计双轨核算的模式,以进一步加强林业企业经济核算和内部管理。 相似文献
8.
This paper demonstrates the utility of the real options approach to forestry investment analysis. The main objectives are to discuss the real option theory and show how it can be adopted to model uncertainty and managerial flexibility in forest management and investment. Secondly, we show how to calculate the option values of selected options that may be available to managers of forest industry firms. The paper provides an empirical application, which compares a forestry investment using the static Faustmann model and the real options approach. Four management options are used for the real options approach: an option to delay reforestation, an option to expand the size of the wood processing plant, an option to abandon the processing plant if timber prices fall below a certain level or due to corporate take-over, and multiple options that evaluated all three options together. All options were evaluated using the binomial option-pricing model, where timber values are assumed to follow a multiplicative binomial process. The results show that the Faustmann analysis rejected the investments as unprofitable, while the option analysis showed that all three options were highly valuable if exercised. When real options are considered, the traditional Faustmann model for assessing the profitability of a forestry investment may fail to provide an adequate decision-making framework because it does not properly value management's ability to adjust to shocks in the economy, as well as risks and uncertainty. 相似文献
9.
洪彤 《农业图书情报学刊》2012,24(5):14-17
针对普通高校图书馆外文阅览室多年来利用率低的现状,着眼于工作实践,以天津商业大学图书馆为例研究非语言类高校中读者的阅读取向与需求对外文阅览室的馆藏结构调整、读者导读与馆员基本素质培训的意义。为避免立场不同,采取抽样调查方式对天津商业大学外语系200名学生针对其满意度与服务开发的期待值进行调查统计,指出在外文阅览室中开展针对性服务的必要性,并提出在普通高校图书馆外文阅览室开展相关服务的具体举措。 相似文献
10.
试图从科普旅游和休闲农业的内涵特征入手,分析提出二者间的错位投入思路,旨在以较低的投入,获得促进二者间良性互动发展的实效. 相似文献