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951.
综放采空区防灭火注氮数值模拟与参数确定 总被引:7,自引:2,他引:7
李宗翔 《中国安全科学学报》2003,13(5):53-57
用有限元数值方法 ,求解了综放开采采空区注氮情况下的漏风渗流方程和氧浓度渗流耗散方程 ;结合计算机图形技术 ,直观展示了注氮前后采空区流场、流态和氧浓度分布动态变化 ;模拟了在不同注氮量下注氮控制区边界的变化过程 ,得到控制区边界位置与注氮流量呈负指数关系 ;重点探讨了用数值模拟方法确定合理注氮参数 (注氮流量、注氮位置和注氮时间 )的新方法。 相似文献
952.
VIRGINIA GALLEGOS PÉRULA RAFAEL M. NAVARRO CERRILLO PILAR FERNÁNDEZ REBOLLOo GEMADEL VALLE MURILLO 《Environmental management》2003,31(1):0086-0099
The objective of this study was to examine postfire regeneration of tree, shrub, and dwarf shrub species, in relation to levels
of damage in four planted pine forests (Pinus pinea, Pinus pinaster) in Andalusia. A prefire vegetation map was used for detailing species composition, vertical structure, and density and another
for detailing the extent and intensity of fire damage. Between 3 and 7 years after the fires, an inventory was made of the
vegetation in each area, using the step-point method. The information thus obtained was used to determine the amount of cover
in the dwarf/shrub and tree layers, the frequency of species in each of the layers, floristic richness, and diversity (Shannon
index). The botanical composition of the dwarf and shrub layer was analyzed using TWINSPAN. Variables were poorly correlated
with level of fire damage, which suggests that the forests in this study followed the autosuccession model. Because of the
artificial origin or seminatural condition, regeneration of the dominant tree species is poor, and it seems unlikely that
forests will recover to their prefire state. Therefore action is recommended to restore these ecosystems. 相似文献
953.
Managing the activities of commercial wildlife viewing tends to involve either restricting the number of industry participants
and/or regulating the activities or industry participants. We report on operator compliance with regulations regarding humans
swimming with free-ranging bottlenose dolphins (Tursiops sp.) in Port Phillip Bay, Victoria, Australia. A total of 128 commercial dolphin-swim trips was studied between September
1998 and April 2000. Four permit conditions were investigated: approach type, swim time, time in proximity of dolphins, and
presence of “fetal fold” calves. Results demonstrate noncompliance by operators to all of the four permit conditions studied.
Compliance with temporal conditions was poorer than with other conditions. When conducting studies on the extent to which
tourism affects cetaceans, investigators should consider whether tourist operations comply with existing regulations or guidelines. 相似文献
954.
MARKKU T. KUITUNEN JOHANNA VILJANEN ESKO ROSSI ARTO STENROOS 《Environmental management》2003,31(1):0079-0085
The impact of dense traffic on the breeding success in pied flycatchers (Ficedula hypoleuca) was studied using roadside nest-boxes. Nest site selection and breeding success of flycatchers were observed in relation
to the distance from the road. The number of occupied territories was no higher closer to the road than it was deeper inside
the forest. The distance to the road had no effect on the laying date, clutch size, or brood size. However, nests closer to
the road were more likely to fail at the chick stage. The number of broods that were closer to roads and were lost completely
was significantly higher than those further away. As a consequence, the number of fledglings per breeding attempt decreased
closer to roads. The nestlings typically died as older chicks when the parent birds were providing them with maximum quantities
of food. A possible reason for the declining reproductive success was the traffic-related mortality of parent birds, as weather
conditions were not especially adverse for raising healthy offspring. 相似文献
955.
Philip M. Fearnside 《Environmental management》1997,21(4):553-570
956.
Ruud Pleune 《Environmental management》1997,21(5):733-745
2 problem, which brought the issue into the energy debate, as well as the more general definition of the problem in the late
1980s as a greenhouse problem, were very important for determining the strategies of the organizations. It can be concluded
that strategies of Dutch environmental organizations with regard to climate change were strongly dependent on the context. 相似文献
957.
长三角地区石油和化工行业上市公司绿色竞争力的实证研究 总被引:4,自引:0,他引:4
企业绿色竞争力是企业在“绿色化”的前提下,与对手相比的一种竞争优势。石油和化工行业是能源和资源的生产和消耗大户.也是众所周知的重污染行业.对石油和化工企业的绿色竞争力进行实证研究具有重要意义。本文以长三角地区的石油和化工行业上市公司为案例。构建基于DEA法的绿色竞争力评价模型.评估了它们的绿色竞争力。实证结果显示:长三角地区石油和化工企业的绿色竞争力还有待加强.在此基础上提出了石油和化工企业提高绿色竞争力的一些具体措施。 相似文献
958.
在白银露天矿污染气象站五年的污染气象观测基础上,分析了采场粉尘浓度与污染源强度和气象因素之间的相关性,提出了粉尘污染预报的模式和方法,其准确率达到66.9%。并以粉尘污染预报模式为依据。提出了污染源控制管理模式。试验表明利用本模式对污染源实施控制管理具有实用意义和价值。 相似文献
959.
Renat Heuberger Alan Brent Luis Santos Christoph Sutter Dieter Imboden 《Environment, Development and Sustainability》2007,9(1):33-48
Under the Clean Development Mechanism (CDM) of the Kyoto Protocol, industrialised countries may finance greenhouse gases mitigation
projects in developing countries. The Kyoto Protocol explicitly requires that the CDM shall assist developing countries to
achieve sustainable development. However, a clear definition of sustainability for CDM projects is still debatable. MATA-CDM
(Multi-Attributive Assessment of CDM Projects) is an approach that facilitates a quantitative assessment of potential projects
regarding their contribution to sustainable development. This paper presents applications of MATA-CDM in two different countries.
In South Africa, the application was done mainly for academic and demonstrative purposes, whereas in Uruguay it was implemented
together with the responsible Designated National Authority (DNA). The work in both countries included the selection of sustainability
criteria and measurable indicators. Experts weighted the criteria using personal interviews and a multi-stakeholder workshop.
This method was applied to three potential CDM projects in South Africa and one in Uruguay. Results show that under the conditions
of this study, the MATA-CDM approach yet fails to yield a perfect quantitative overall sustainability assessment of CDM projects
but that several findings could be useful to further develop the approach with the aim to translate the vague term sustainable development to a mainstream project level. Valuable experience was in particular collected with different stakeholder processes to perform
criteria weighting. 相似文献
960.
根据最新文献,对我国企业的现状,促进我国企业实现清洁生产的可能途径进行述评,认为应该针对我国不同行业、不同企业的实际情况,有所侧重地通过各种途径的共同作用,促进我国企业实现清洁生产。 相似文献