大型复杂电子系统开展“五性”一体化设计的必要性

本文首先对大型复杂电子系统的特点及"五性"一体化设计的思想进行了阐述,进而结合工程实际,分析了当前"五性"设计存在的问题,提出开展"五性"一体化设计是解决上述问题的根本出路,并提出了相应建议措施,对如何建立"五性"指标体系、综合设计模型、"五性"一体化信息平台进行了一定的阐述。     

Environmental,economic and social costs and benefits of a packaging waste management system: A Portuguese case study

The impact of the management of packaging waste on the environment, economic growth and job creation is analyzed in this paper. This integrated assessment intends to cover a gap in the literature for this type of studies, using the specific case study of the Portuguese packaging waste management system (SIGRE).The net environmental benefits associated with the management of packaging waste, are calculated using the Life Cycle Assessment methodology. The results show that, for the categories studied, the impacts associated to SIGRE's various activities are surpassed by the benefits associated to material and energy recovery, with special focus on recycling. For example, in 2011 SIGRE avoided the emission of 116 kt CO₂ equiv. – the equivalent carbon emission of the electricity consumption of 124.000 households in Portugal.The economic impact of SIGRE is evaluated through Input–Output Analysis. It was found that SIGRE's activities also have a significant economic impact. For example, their added value are ranked amongst the upper third of the economic activities with highest multiplier effect at national level: this means that for each Euro of value added generated within SIGRE, 1.25 additional € are added to the rest of the economy (multiplier effect of 2.25).Regarding the social impacts of SIGRE, the number of direct jobs associated with the system is estimated to be more than two thousand and three hundred workers. Out of these, 83% are connected to the management of municipal waste packaging (selective collection and sorting), 15% are connected to the management of non-municipal packaging waste and only 2% are connected to the Sociedade Ponto Verde (SPV, green dot society in English) – the management entity responsible for SIGRE.In general terms, the results obtained provide quantitative support to the EEA (2011) suggestion that moving up the waste hierarchy – from landfilling to recycling – creates jobs and boosts the economy.     

Optimal design of rainwater collecting systems for domestic use into a residential development

This paper proposes an optimization-based approach for designing rainwater harvesting systems for domestic use in a residential development. The optimization model accounts for the implementation of rainwater harvesting devices, pipes and reservoirs for the optimal sitting, collecting, storing and distribution of harvested rainwater. The optimization model consists in satisfying the water domestic demands and considers as objective function the minimization of the total annual cost associated to the fresh water, the capital costs for the catchment areas, storages and pumps, and the cost associated to the pumping, maintenance and treatment. A case study for a residential development in Morelia, Mexico is presented. The city of Morelia is characterized for having complications to satisfy the water demands, especially during dry seasons. The application of the proposed optimization approach shows that it is possible to satisfy a significant percentage of the domestic water demands using a harvesting rainwater system decreasing the associated cost in the time horizon. Several scenarios have been presented to show the potential solutions identified in the case study.     

A survey on heavy metal concentrations in residential neighborhoods: The influence of secondary water supply systems

Water quality deterioration often occurs in secondary water supply systems (SWSSs), and increased heavy metal concentrations can be a serious problem. In this survey, twelve residential neighborhoods were selected to investigate the influence of SWSSs on the seasonal changes in heavy metal concentrations from input water to tank and tap water. The concentrations of nine evaluated heavy metals in all groups of water samples were found to be far below the specified standard levels in China. The concentrations of Fe, Mn, and Zn increased significantly from the input water samples to the tank and tap water samples in spring and summer (p < 0.05), especially for the water samples that had been stagnant for a long time. Negative correlations were found between most of the heavy metals and residual chlorine (Fe, Cu, Zn, and As, r = -0.186 to -0.519, p < 0.05). In particular, a high negative correlation was observed between Fe and residual chlorine (r = -0.489 to -0.519, p < 0.01) in spring and summer. Fe and Mn displayed positive correlations with turbidity (r = 0.672 and 0.328, respectively; p < 0.05). In addition, Cr and As were found to be positively associated with some nutrients (NO₃⁻, TN, and SO₄²⁻; r = 0.420-0.786, p < 0.01). The material of the storage tanks had little influence on the difference in heavy metal concentrations. Overall, this survey illustrated that SWSSs may pose a chronic threat to water quality and could provide useful information for practitioners.     

基于应力分析法的士兵系统电子器件可靠性研究

目的 提高士兵系统元器件可靠性,提出一种可应用于士兵系统电子装备可靠性设计的方法。方法 以士兵某探测器设计过程为研究对象,依据军用电子元器件标准和规范对2种可靠性保证要求表征方法进行分析,采用应力分析法针对士兵电子器件进行可靠性设计。结果 该探测器的MTBF值为90 345.56 h,达到了该设备基本可靠性要求。当产品工作到2 a时,探测器任务可靠度为0.833,达到了该设备任务可靠性要求。结论 提出的方法可为士兵系统电子装备可靠性设计提供技术支撑。     

An interdisciplinary assessment of private conservation areas in the Western United States

Conservation easements are the fastest growing private conservation strategy in the United States. However, mechanisms to assess private land conservation as well as their support by the general public are not well understood. This study uses the ecosystem services framework for assessing existing private lands in Idaho and identifies areas for future conservation easements. Using conservation targets of the land trust as a guide for selecting ecosystem services, we (a) mapped the spatial delivery of conservation targets across public and private lands, (b) explored public awareness in terms of social importance and vulnerability, and (c) mapped future priority areas by characterizing conservation bundles. We found that public lands provided the highest levels of conservation targets, and we found no difference in conservation target provision between private areas and conservation easements. The spatial characterization of conservation target bundles identified potential future priority areas for conservation easements, which can guide planning of land trust conservation efforts.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01323-x) contains supplementary material, which is available to authorized users.     

Multiple environmental burdens and neighborhood-related health of city residents

Urban living environments are known to influence human well-being and health; however, little is known about the multidimensionality of different environmental burdens. The aim of this study is to examine the relations between multiple burdens and self-rated health of city residents in Berlin. A spatial analysis was conducted to determine neighborhood street blocks with high versus low levels of three environmental burdens (traffic noise, air pollution, lack of public green space) as study sites for a cross-sectional household questionnaire. Burden level served as a dichotomous predictor to compare residents' self-reports of neighborhood satisfaction, life satisfaction, health behavior, and psychological and physical health symptoms. Residents from high-burden blocks appraised the environmental conditions more stressful, reported poorer health behavior and were less satisfied with their neighborhood than residents from low-burden blocks. However, they did not differ in regard to more general health symptoms. Three other burdens (behavior-related noise, litter and dirt in public space, lack of urban vegetation), which could not be varied objectively, were assessed by their perceived intensity. Regression analyses of the relations between the perceived levels of all six burdens and outcomes in the total sample revealed the following: Neighborhood satisfaction could be predicted from multiple stressors and resources that co-occur independently, while more general health symptoms were related only to perceived air pollution. The results have implications for both urban planning and public health.     

Linkages between measures of biodiversity and community resilience in Pacific Island agroforests

Designing agroecosystems that are compatible with the conservation of biodiversity is a top conservation priority. However, the social variables that drive native biodiversity conservation in these systems are poorly understood. We devised a new approach to identify social–ecological linkages that affect conservation outcomes in agroecosystems and in social‐ecological systems more broadly. We focused on coastal agroforests in Fiji, which, like agroforests across other small Pacific Islands, are critical to food security, contain much of the country's remaining lowland forests, and have rapidly declining levels of native biodiversity. We tested the relationships among social variables and native tree species richness in agroforests with structural equation models. The models were built with data from ecological and social surveys in 100 agroforests and associated households. The agroforests hosted 95 native tree species of which almost one‐third were endemic. Fifty‐eight percent of farms had at least one species considered threatened at the national or international level. The best‐fit structural equation model (R² = 47.8%) showed that social variables important for community resilience—local ecological knowledge, social network connectivity, and livelihood diversity—had direct and indirect positive effects on native tree species richness. Cash‐crop intensification, a driver of biodiversity loss elsewhere, did not negatively affect native tree richness within parcels. Joining efforts to build community resilience, specifically by increasing livelihood diversity, local ecological knowledge, and social network connectivity, may help conservation agencies conserve the rapidly declining biodiversity in the region.     

Governing trade-offs in ecosystem services and disservices to achieve human–wildlife coexistence

Sustaining wildlife populations, which provide both ecosystem services and disservices, represents a worldwide conservation challenge. The ecosystem services and Ostrom's social–ecological systems frameworks have been adopted across natural and social sciences to characterize benefits from nature. Despite their generalizability, individually they do not include explicit tools for addressing the sustainable management of many wildlife populations. For instance, Ostrom's framework does not specifically address competing perspectives on wildlife, whereas the ecosystem services framework provides a limited representation of the social and governance context wherein such competing perspectives are embedded. We developed a unified social–ecological framework of ecosystem disservices and services (SEEDS) that advances both frameworks by explicitly acknowledging the importance of competing wildlife perspectives embedded in the social and governance contexts. The SEEDS framework emulates the hierarchical structure of Ostrom's social–ecological systems, but adds subsystems reflecting heterogeneous stakeholder views and experiences of wildlife-based services and disservices. To facilitate operationalizing SEEDS and further broader analyses across human–wildlife systems, we devised a list of variables to describe SEEDS subsystems, such as types and level of services and disservices, cost and benefit sharing, and social participation of stakeholders. Steps to implement SEEDS involve engaging local communities and stakeholders to define the subsystems, analyze interactions and outcomes, and identify leverage points and actions to remedy unwanted outcomes. These steps connect SEEDS with other existing approaches in social–ecological research and can guide analyses across systems or within individual systems to provide new insights and management options for sustainable human–wildlife coexistence.