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131.
带有残差修正的GIM(1)模型在工业固体废弃物排放量预测中的应用 总被引:1,自引:0,他引:1
基于灰色系统理论,研究和提出了带有残差修正的GIM(1)模型,并给出了估计这种模型参数的简捷方法.实例表明,运用该方法得到的模型具有优良的预测精度,从而扩大了灰色预测方法在环境系统中的应用范围. 相似文献
132.
133.
Parental care is an energetically demanding activity that ensures genes are efficiently passed from one generation to the next. According to evolutionary theory, the greatest energetic investment should be directed towards offspring that are most closely related to the parent. Male fathead minnows, Pimephales promelas, provide this parental investment to developing embryos but not newly hatched larvae. Therefore, selection should favour recognition of embryonic kin to ensure energetic expenditure is optimally invested. In this study, adult male fathead minnows were tested using behavioural assays, with egg cannibalism as an endpoint, to determine whether adult males could discriminate between related and unrelated embryos. Egg cannibalism was highest when adult male fathead minnows were presented with unrelated eggs and lowest when presented with eggs fertilized by the test subject (related eggs). The degree of cannibalism was also a function of breeding status. Unrelated males in breeding condition showed an intermediate response between the low cannibalism demonstrated by related males and the high cannibalism demonstrated by unrelated males in a nonbreeding condition. These results suggest that although male fathead minnows can discriminate between unrelated and related embryos, at least some component of parental investment is a simple function of breeding status. 相似文献
134.
Michael K. Theodorou Alison H. Kingston-Smith Ana L. Winters Michael R. F. Lee Frank R. Minchin Phillip Morris John MacRae 《Environmental Chemistry Letters》2006,4(3):121-126
Polyphenols in plants can protect proteins from degradation and improve the efficiency of conversion of plant protein to animal protein (meat and milk), but can this be achieved in a way that is environmentally sustainable, profitable to the livestock farmer and is consistent with aspirations for improved livestock nutrition, health, welfare and product quality? Given that grazed and conserved forage is the bedrock of sustainable ruminant production, this paper attempts to consider what challenges are ahead in terms of enhancing productive efficiency, reducing the polluting footprint of livestock agriculture and alleviating the endemic parasitism that occurs with grazing animals. 相似文献
135.
In cooperatively breeding birds, the presence of helpers is expected to increase the reproductive success of the breeding pair. However, some studies fail to find this effect. A positive effect of helpers may be restricted to cases in which a breeding pair has a poor likelihood of raising the entire brood on its own, as would be the case under stressful environmental conditions or with enlarged brood sizes. We conducted brood size manipulations in a cooperative breeder, the sociable weaver, Philetairus socius, to investigate the relationship between the difficulty of raising nestlings and the effort and impact of helpers. Overall, sociable weavers did not work harder to raise the enlarged broods. However, the presence of helpers significantly increased the feeding rates at enlarged nests, but not controls. This was insufficient to prevent generalised brood reduction in enlarged broods, whether attended by pairs alone or with helpers. Nonetheless, the presence of helpers was associated with decreased nestling mortality and an increase in the numbers of young fledged. Our results suggest that groups are better able to respond to the needs of enlarged broods than pairs alone and that the presence of helpers has a beneficial effect on overall reproductive success.Communicated by J. Dickinson 相似文献
136.
Tyler A. Hallman W. Douglas Robinson Jenna R. Curtis Edward R. Alverson 《Conservation biology》2021,35(4):1256-1267
Globally, anthropogenic land-cover change has been dramatic over the last few centuries and is frequently invoked as a major cause of wildlife population declines. Baseline data currently used to assess population trends, however, began well after major changes to the landscape. In the United States and Canada, breeding bird population trends are assessed by the North American Breeding Bird Survey, which began in the 1960s. Estimates of distribution and abundance prior to major habitat alteration would add historical perspective to contemporary trends and allow for historically based conservation targets. We used a hindcasting framework to estimate change in distribution and abundance of 7 bird species in the Willamette Valley, Oregon (United States). After reconciling classification schemes of current and 1850s reconstructed land cover, we used multiscale species distribution models and hierarchical distance sampling models to predict spatially explicit densities in the modern and historical landscapes. We estimated that since the 1850s, White-breasted Nuthatch (Sitta carolinensis) and Western Meadowlark (Sturnella neglecta) populations, 2 species sensitive to fragmentation of oak woodlands and grasslands, declined by 93% and 97%, respectively. Five other species we estimated nearly stable or increasing populations, despite steep regional declines since the 1960s. Based on these estimates, we developed historically based conservation targets for amount of habitat, population, and density for each species. Hindcasted reconstructions provide historical perspective for assessing contemporary trends and allow for historically based conservation targets that can inform current management. 相似文献
137.
In-depth studies on the recycling of typical automotive exterior plastic parts are significant and beneficial for environmental protection, energy conservation, and sustainable development of China. In the current study, several methods were used to analyze the recycling industry model for typical exterior parts of passenger vehicles in China. The strengths, weaknesses, opportunities, and challenges of the current recycling industry for typical exterior parts of passenger vehicles were analyzed comprehensively based on the SWOT method. The internal factor evaluation matrix and external factor evaluation matrix were used to evaluate the internal and external factors of the recycling industry. The recycling industry was found to respond well to all the factors and it was found to face good developing opportunities. Then, the cross-link strategies analysis for the typical exterior parts of the passenger car industry of China was conducted based on the SWOT analysis strategies and established SWOT matrix. Finally, based on the aforementioned research, the recycling industry model led by automobile manufacturers was promoted. 相似文献
138.
王继斌 《中国环境管理干部学院学报》2001,(Z1)
党的十五大把环境保护问题作为基本国策,并强调:“正确处理经济发展同人口、资源、环境的关系”。这表明生态问题已经引起高度重视,建立和发展生态工业已成为当前一项重要任务。本文在介绍生态工业定义的基础上,说明了建立和发展生态工业的必要性及其如何建立和发展生态工业。 相似文献
139.
Yali Liu Jianqing Du Boyang Ding Yuexian Liu Wenjun Liu Anquan Xia Ran Huo Qinwei Ran Yanbin Hao Xiaoyong Cui Yanfen Wang 《Frontiers of Environmental Science & Engineering》2022,16(3):28
140.
According to the Kyoto Protocol, by 2012 Norwegian emissions of greenhouse gases must be reduced by about six per cent lower than the 1996 level. In order to achieve this target, the Norwegian Government intends to give greater priority to energy efficiency measures, renewable energy sources and the use of heat pumps.Even though Energy Management should be integrated in EMS, empirical data indicates that it is not. Energy Management is separated from EMS in Norwegian industry. Focusing on the quality of the energy consumed, facilitates the utilization of wasted, low temperature energy sources. However, empirical data indicate that energy intensive food companies do not emphasize the portion of renewable energy sources they consume, or the quality of their energy consumption. This paper discusses integration of Energy Management into EMS. Better integration of existing energy and environmental schemes represents a CO2 reduction potential that may be realised at short-term, net cost savings. This paper argues for the joint management of energy with the environment. 相似文献