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1.
桔园植保协调管理的多目标群决策研究 总被引:1,自引:0,他引:1
植保系统工程是植保工作科学化的必然趋势,有关系统工程与具体植保工作相结合的理论研究较为丰富,然而,在更高的层次上,植保系统是多决策者、多目标的复杂系统,这就要求植保工作者必须学会用系统工程理论解决植保系统的协调管理问题。迄今这方面的研究 相似文献
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为提高农村污水工艺选择的科学性和合理性,本研究构建了生命周期可持续性评估(LCSA)和多准则决策分析(MCDA)耦合模型,以人工湿地(CW)、序批式活性污泥法(SBR)、“厌氧-缺氧-好氧”工艺(A2O)、膜生物反应器(MBR)和生物接触氧化(BCO)为研究对象,在出水水质达到《城镇污水处理厂污染物排放标准》一级A标准的条件下进行评价并提出改进建议。结果表明,各系统在运行阶段贡献了绝大多数环境影响(超过85%)和经济成本(60%以上)。CW的环境可持续性和经济可持续性最优,但占地面积较大;MBR环境和经济可持续性最差,但其社会可持续性较好。A2O运行过程中需要较多的能源,使其环境和经济可持续性表现不佳,而SBR和BCO各方面的可持续性较为均衡。针对不同利益相关者进行的MCDA结果表明:MBR、SBR和BCO在不同的偏好下各有优势,CW可持续性最优(0.59~0.70);然而,当占地面积的主观权重达到65%后,CW不再是最优方案。基于评价结果,使用者可以通过优化运行阶段消耗、根据排水去向灵活调整排放标准等方式提升污水处理工艺的可持续性,降低环境... 相似文献
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基于2007年Landsat TM遥感影像和影响防护林的主导环境因子,对三峡库区的森林立地进行分类,并通过选取水源涵养量、生物量和林分生产力3个指标,利用多目标灰色局势决策模型对库区现有的针叶林、阔叶林、针阔混交林和灌木林4种防护林类型进行空间优化配置.结果表明: 2007年,三峡库区森林立地可划分为40种类型;空间配置优化后,研究区针叶林、阔叶林、针阔混交林和灌木林的面积比例分别为32.55%、29.43%、34.95%和3.07%.与优化前相比,优化后针叶林和灌木林的面积比例分别减少了8.79%和28.55%,阔叶林和针阔混交林分别增加了10.23%和27.11%.通过防护林类型的空间优化,三峡库区整体的水源涵养能力、生物量和林分生产力分别增加14.09×108 m3、0.35×108 t和1.08×106 t. 相似文献
4.
基于多判据决策的水体营养状态评价 总被引:2,自引:0,他引:2
为了准确地评价水生态系统营养状态和综合决策,通过最大熵原理耦合模糊性与随机性,建立了最大熵模糊评价模型(FAME);利用逼近理想解排序法(TOPSIS),以待决策水体样本的实测值为理想解,以评价结果中与实测值相差最大的为负理想解,建立了多判据决策模型(MCDM).经12个湖泊实测数据验证,最大熵模糊评价与随机评价、模糊评价和灰色评价的结果较为一致,但提高了评价水体营养状态问题各层次的分辨力.多判据决策模型可解决多种方法评价结果不相容问题,使评价结果更接近水体实际情况.FAME和MCDM适用于各种水质的综合评价及决策. 相似文献
5.
具有生育脉冲的Lotka-Volterra合作系统的正周期解的存在性 总被引:2,自引:0,他引:2
研究具有生育脉冲的两种群Lotka-Volterra合作系统,利用重合度理论,获得正周期解的存在的充分条件。 相似文献
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Dwayne R.J. Moore 《人类与生态风险评估》2001,7(2):231-237
Successful ecological risk assessments are all alike; every unsuccessful ecological risk assessment fails in its own way. Tolstoy posited a similar analogy in his novel Anna Karenina: “Happy families are all alike; every unhappy family is unhappy in its own way.” By that, Tolstoy meant that for a marriage to be happy, it had to succeed in several key aspects. Failure on even one of these aspects, and the marriage is doomed. In this paper, I argue that the Anna Karenina principle also applies to ecological risk assessments involving multiple stressors. In particular, I argue that multiple stressors assessments and environmental decision making will not have a happy marriage unless the following can be achieved: (1) there must be societal and political buy-in to the assessment and decision-making process; (2) the assessment must have the latitude to consider a wide range of stressors and potential risk management options; (3) there must be a commitment to following a rigorous focusing of the assessment and to expending resources for model development and data collection; and (4) an adaptive management strategy must be adopted wherein risk management actions are undertaken, system response intensively observed and assessed, and revised management actions taken as appropriate. Failure to meet any of the above criteria for success will doom a multiple stressors assessment and prevent its use in effective decision-making. 相似文献
8.
Joshua H. Ho 《Ocean Development & International Law》2013,44(2):233-247
In November 2004, the International Maritime Organization, as part of its Protection of Vital Shipping Lanes Initiative, decided to convene a high-level conference to address the security of ships plying the Straits of Malacca and Singapore in collaboration with the three littoral states of Indonesia, Malaysia, and Singapore. Three meetings were held over the period 2005 to 2007. The outcome was the creation of a framework for cooperation between the users of the straits and the littoral states known as the Cooperative Mechanism, a historic breakthrough as Article 43 of the Law of the Sea Convention was implemented for the first time. This article outlines the decisions made at the three meetings, analyzes the responses of the various stakeholders during the meetings, explains the reasons for the success of the Cooperative Mechanism, and concludes by proposing ways in which the momentum of cooperation between the users and the littoral states could be sustained. 相似文献
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介绍了在观测噪声和马尔可夫链不相互独立的条件下二阶隐马尔可夫模型(second-orderHMM:HMM2)的结构.研究了在多观测序列不相互独立的情况下HMM2的学习算法,并由此导出了该模型的参数重估公式. 相似文献
10.
Shalene Jha Monika Egerer Peter Bichier Hamutahl Cohen Heidi Liere Brenda Lin Azucena Lucatero Stacy M. Philpott 《Ecology letters》2023,26(3):369-383
Ecosystem services (ESs) are essential for human well-being, especially in urban areas where 60% of the global population will live by 2030. While urban habitats have the potential to support biodiversity and ES, few studies have quantified the impact of local and landscape management across a diverse suite of services. We leverage 5 years of data (>5000 observations) across a network of urban community gardens to determine the drivers of biodiversity and ES trade-offs and synergies. We found multiple synergies and few trade-offs, contrasting previous assumptions that food production is at odds with biodiversity. Furthermore, we show that natural landscape cover interacts with local management to mediate services provided by mobile animals, specifically pest control and pollination. By quantifying the factors that support a diverse suite of ES, we highlight the critical role of garden management and urban planning for optimizing biodiversity and human benefit. 相似文献
11.
Siddique MS Mogami G Miyazaki T Katayama E Uyeda TQ Suzuki M 《Biochemical and biophysical research communications》2005,337(4):1185-1191
Acto-S1 chimera proteins CP24 and CP18 carry the entire actin sequence, inserted in loop 2 of the motor domain of Dictyostelium myosin II, and have MgATPase activity close to that of natural Dictyostelium actomyosin [M.S.P. Siddique, T. Miyazaki, E. Katayama, T.Q.P. Uyeda, M. Suzuki, Evidence against essential roles of subdomain 1 of actin in actomyosin sliding movements, Biochem. Biophys. Res. Commun. 332 (2005) 474-481]. Here, we examined and detected cooperative structural change of actin filaments accompanying interaction with myosin motor domain in the presence of ATP using copolymer filaments consisting of pyrene-labeled skeletal actin (SA) and either CP24 or CP18. Upon addition of ATP, the fluorescence intensity increased over the range from 380 to 480nm using 365-nm excitation. The relative increases of fluorescence intensity at 390nm were 14%, 46%, and 77% for the copolymer filaments with the CP24 to actin molar ratios of 0.0625, 0.143, and 0.333, respectively, and demonstrated a sigmoid behavior. Stoichiometric analysis indicates that each CP24 molecule appears to affect four actin molecules, on average, in SA-CP24 copolymers, and each CP18 molecule appears to affect three actin molecules in SA-CP18 copolymers. 相似文献
12.
Vasey N 《Primates; journal of primatology》2007,48(1):41-54
Captive studies have shown that ruffed lemurs (Varecia) have an unusual suite of reproductive traits combined with extremely high maternal reproductive costs. These traits include the bearing of litters, nesting of altricial young, and absentee parenting. To characterize the breeding system of this enigmatic lemur, reproductive traits must be contextualized in the wild. Here, I provide a preliminary report of mating and infant care in one community of wild red ruffed lemurs (Varecia rubra). Observations span a 15-month period covering two birth seasons and one mating season on the Masoala Peninsula, Madagascar. Factors that are not possible to replicate in captivity are reported, such as mating pattern, natality and mortality rates, the location of nests within the home range, and the structuring of infant care within a natural community. V. rubra at Andranobe have a fission-fusion, multifemale-multimale grouping pattern and a polygamous mating system. They do not mate monogamously or live strictly in family-based groups as suggested by previous workers. During the first 2 months of life, nests and infant stashing localities are situated within each mother's respective core area, and inhabitants of each core area within the communal home range provide care for young. As part of their absentee parenting system, infants are left in concealed, protected, and supportive spots high in the canopy, while mothers travel distantly. This practice is termed 'infant stashing'. Alloparenting appears to be an integral part of V. rubra's overall reproductive strategy in the wild, as it was performed by all age-sex classes. Among the alloparental behaviors observed were infant guarding, co-stashing, infant transport, and allonursing. Alloparenting and absentee parenting may mitigate high maternal reproductive costs. Furthermore, V. rubra may have a breeding system in which genetic partners (i.e., mating partners) do not always correspond to infant care-providers. Combined with recently available information on the behavioral ecology of wild ruffed lemurs, this preliminary report suggests directions for in-depth studies on Varecia's breeding system. 相似文献
13.
KEVIN E. DOHERTY DAVID E. NAUGLE BRETT L. WALKER 《The Journal of wildlife management》2010,74(7):1544-1553
Abstract: Considering habitat selection at multiple scales is essential to fully understand habitat requirements and management needs for wildlife species of concern. We used a hierarchical information-theoretic approach and variance decomposition techniques to analyze habitat selection using local-scale habitat variables measured in the field and landscape-scale variables derived with a Geographic Information System (GIS) for nesting greater sage-grouse (Centrocercus urophasianus) in the Powder River Basin (PRB), Montana and Wyoming, USA, 2003–2007. We investigated relationships between habitat features that can and cannot be mapped in a GIS to provide insights into interpretation of landscape-scale—only GIS models. We produced models of habitat selection at both local and landscape scales and across scales, yet multiscale models had overwhelming statistical and biological support. Variance decomposition showed that local-scale measures explained the most pure variation (50%) in sage-grouse nesting-habitat selection. Landscape-scale features explained 20% of pure variation and shared 30% with local-scale features. Both local- and landscape-scale habitat features are important in sage-grouse nesting-habitat selection because each scale explained both pure and shared variation. Our landscape-scale model was accurate in predicting priority landscapes where sage-grouse nests would occur and is, therefore, useful in providing landscape context for management decisions. It accurately predicted locations of independent sage-grouse nests (validation R2 = 0.99) and showed good discriminatory ability with >90% of nests located within only 40% of the study area. Our landscape-scale model also accurately predicted independent lek locations. We estimated twice the amount of predicted nesting habitat within 3 km of leks compared to random locations in the PRB. Likewise we estimated 1.8 times more predicted nesting habitat within 10 km of leks compared to random locations. These results support predictions of the hotspot theory of lek placement. Local-scale habitat variables that cannot currently be mapped in a GIS strongly influence sage-grouse nest-site selection, but only within priority nesting habitats defined at the landscape scale. Our results indicate that habitat treatments for nesting sage-grouse applied in areas with an unsuitable landscape context are unlikely to achieve desired conservation results. 相似文献