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141.
介绍了UG/OpenAPI的基本概念和特点,研究了标题栏和明细表自动生成的一些关键技术和方法。并用VC++6.0编制出标题栏和明细表自动生成程序,弥补了UG的不足。  相似文献   
142.
安太堡露天煤矿1993-1998年土地复垦试验结果表明,在排土场逆境条件下,刺槐可以正常生长。坡度、坡向、地表物质组成和植物配置模式是影响其生长的主要因子。在阳向坡、避风处生长良好。黄土母质有利于1年生刺板的生长,岩土混排则更有利于2年生以上刺槐的生长、刺槐与草混交抑制刺槐生长。  相似文献   
143.
ABSTRACT

Reflecting on the 2019 Open Science Meeting of the Global Land Program and on commentaries since, we argue that the time is ripe for the land system science community to fully embrace the thorny issue of land ownership and control. Beyond land governance and institutions, the issue of who actually owns and controls land, and how land holding and rents are distributed across society, is central to the future of sustainability initiatives, biodiversity protection, social justice, climate change mitigation, and long-term food security and sovereignty. By explicitly tracking and visualizing just Who Owns the Earth, the land system science community could provide much-needed data and insights to inform public debate and advance political action in these arenas.  相似文献   
144.
环境信息公开及在中国的实践   总被引:19,自引:0,他引:19  
环境信息公开是一种新的环境管理制度,对于提高环境决策的质量和执行,控制污染有着一定的作用。我国已在政府环境信息公开、企业环境信息公开和其它形式环境信息公开进行了一些探索和实践。在实践中,我国存在着环境信息公开法规体系不完善、公开的环境信息不准确、企业及产品的环境信息公开不充分等问题,应在健全环境信息公开的法规体系、加大企业环境信息公开力度、建设公共环境信息系统等方面做进一步的工作。  相似文献   
145.
中国入世不仅对中国的社会经济产生深远影响,对长江流域的可持续发展也将产生深刻影响。主要的负面影响是:(1)长江流域的钢铁、汽车、化工、农业等产业将受到国际竞争的巨大挑战;(2)新开放、开发、投资、建设热将对长江流域的生态环境带来新的巨大压力。主要的正面影响是:(1)入世加快了各级政府的职能转变,政府转变职能使长江的保护进入一个历史的新阶段;(2)入世强化了绿色壁垒,绿色壁垒作为一种外的在强制将大大有利于长江生态环境的根本改善;(3)入世使中国进入了新的大开放时代,新的大开放背景将使世界在开发、保护诸方面都关注长江;(4)入世和申奥成功使中国大跨度的调水战略提前实施,中国和世界将进入“以水为核心”配置资源、布局经济的时代,这必将更加凸现长江流域开放、开发的重要性。  相似文献   
146.
Despite their opposition to the dominant agri-food system, alternative agri-food initiatives may unwittingly reproduce central features of neoliberalism. Julie Guthman has been a particularly strong proponent of this view, arguing that food activism and neoliberalism have shaped one another dialectically in California in recent decades. This paper responds to her argument, with a view to distinguishing between what it reveals and what it may conceal about the transformative potential of alternative agri-food initiatives in North America. Drawing on primary research on a variety of community-based food initiatives in Eastern Ontario, Canada, we show how a neoliberal lens does help to illuminate some problematic characteristics of these initiatives, including assumptions about market-based solutions and focus on self-improvement at the expense of state involvement. However, this lens underestimates those aspects of community-based food initiatives that may appear commensurate with neoliberal rationalities but which also push in more progressive directions.  相似文献   
147.
The vertical distribution of 137Cs activity in peat soil profiles and 137Cs activity concentration in plants of various species was studied in samples collected at two sites on a raised bog in central Sweden. One site (open bog) was in an area with no trees and only a few sparsely growing plant species, while the other (low pine) was less than 100 m from the open bog site and had slowly growing Scots pine, a field layer dominated by some ericaceous plants and ground well-covered by plants. The plant samples were collected in 2004–2007 and were compared with samples collected in 1989 from the same open bog and low pine sites. Ground deposition of 137Cs in 2005 was similar at both sites, 23?000 Bq m−2. In the open bog peat profile it seems to be an upward transport of caesium since a clear peak of 137Cs activity was found in the uppermost 1–4 cm of Sphagnum layers, whereas at the low pine site 137Cs was mainly found in deeper (10–12 cm) layers. The migration rate was 0.57 cm yr−1 at the open bog site and the migration centre of 137Cs was at a depth of 10.7, while the rate at the low pine site was 0.78 cm yr−1 and the migration centre was at 14.9 cm. Heather (Calluna vulgaris) was the plant species with the highest 137Cs activity concentrations at both sites, 43.5 k Bq−1 DM in 1989 decreasing to 20.4 in 2004–2007 on open bog and 22.3 k Bq kg−1 DM in 1989 decreasing to 11.2 k Bq−1 DM by the period 2004–2007 on the low pine site. 137Cs transfer factors in plants varied between 0.88 and 1.35 on the open bog and between 0.48 and 0.69 m2 kg−1 DM at the low pine site.  相似文献   
148.
Open burning of crop residues has been identified as an important emission source of PCDD/PCDF to the environment. This paper presents the first known data on the emission of PCDD/PCDF to the land considering the influence of pesticides applied in crops planting. Emission factor for PCDD/PCDF to the land from open burning of corn straw with pesticides contamination ranged from 0.07 to 0.57 ng WHO2005-TEQ/kg straw burned with a mean value of 0.24 ng WHO2005-TEQ/kg straw burned and median value of 0.20 ng WHO2005-TEQ/kg straw burned, respectively. The concentration was 35 to 270 times higher than that without additional pesticide contaminated. Initial observation was that emission factor for PCDD/PCDF from open burning of crop residues was overestimated in the former UNEP Dioxin Toolkit. Pesticides contamination should be considered in some hotpots where special and over dosed pesticides has been sprayed especially in developing countries.  相似文献   
149.
This article analyzes the effects of increasing urbanization on open space preserves within the metropolitan area of Phoenix, Arizona, USA. Time series analysis is used in 10-year increments over 40 years to study urban landscape change. Three landscape metrics—(1) matrix utility (measures intensity of adjacent land uses), (2) isolation (measures distances to other open space patches), and (3) connectivity (measures physical links to other open space patches and corridors)—are used to assess changes in landscape patterns and serve as indicators of urban ecological integrity of the open space preserves. Results show that in the case of both open space preserves, general decline in indicators of urban ecological integrity was evident. The matrix utility analysis demonstrated that increasing intensity of land uses adjacent to preserve is likely to increase edge effects, reducing the habitat value of interior or core habitat areas. Isolation analysis showed that both preserves have experienced increasing isolation from other open space elements over time. Also, connectivity analysis indicated that terrestrial connections to other open space elements have also deteriorated. Conclusions of this research demonstrate that while preservation of natural areas as open space is important in an urban context, intense development of surrounding areas reduces the urban ecological integrity significantly.  相似文献   
150.
We examined the prevalence of residential development that occurs with consideration of the natural features of the site, known as conservation design, within county-level planning jurisdictions across Northern Indiana. Using data from telephone interviews with representatives of planning departments, jurisdictions were ranked based on reported use of conservation design. Three categories of use emerged from the data: no use, use of individual practices associated with conservation design, and integration of multiple conservation design practices. Qualitative data analysis revealed that conservation design practices were not being used widely and, when used, were often used to fulfill stormwater requirements. Statistical analysis, using data from interviews, spatial data sets, and the U.S. Census Bureau, identified several significant positive predictors of the levels of conservation design use including conversion of forest or agricultural land cover to urban uses and education levels in the jurisdiction. Many of the interviewees noted that agricultural land is perceived to meet open space needs within their counties. Given that agricultural land does not fully meet all ecosystem needs, education about the benefits of other types of open space is suggested.
Linda Stalker Prokopy (Corresponding author)Email:
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