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31.
ABSTRACTCurrent debates on knowledge-based and creative locational development have come to deal with small urban places of novelty that formerly remained unnoticed. A plethora of new forms of producing and working recently emerged in unplanned and uncoordinated ways, bearing odd names such as FabLabs, Open Worklabs, RealLabs, Open Design Cities, Techshops, Repair Cafés, and more (Smith, A., M. Fressoli, D. Abrol, E. Arond, and A. Ely. 2017. Grassroots Innovation Movements. London: Routledge). Political initiatives have been taken by surprise; at the same time, standard epistemic tools of the social sciences and economics have been rendered unfit. More concise analytical reconstructions are needed to adequately capture the variety and complexity of these “labs”, their heterogeneous causation, their contingent proceedings, their surplus of latency, their peculiar power relations and their local embeddings. Urban social contexts have a strong triggering function as they help to re-configure older, and create new, combinations of heterogeneous social and economic agency. Meanwhile strong elements of grassroots innovation (Smith et al. 2017) have informed the formation of various models of alternative work and production. Taking the phenotype of open workshops as a revealing example, we take assemblage theory to describe the constitutive features of these new types of self-organised work, and the associated places of innovation. A fresh gaze on the complexity and open-endedness of socio-material formations may help to better understand the nature of emerging post-growth economies. 相似文献
32.
Ecosystem services provided by the landscapes of regions and cities are critical to human and environmental health, quality of life, environmental justice, biodiversity and climate mitigation and adaptation. In the Pacific Northwest region of the US, a team led by the University of Washington Green Futures Lab is working to identify, conserve and enhance regionally-significant landscapes and to evaluate their contributions as ecosystem or “open space” services. This paper outlines the goals and planning methods of the ongoing Regional Open Space Strategy for Central Puget Sound (ROSS) project, and the frameworks and processes being developed to evaluate ecosystem and open space services in order to inform and influence local and regional governance structures and decisions. 相似文献
33.
Sheng Xu Xingyuan He Kent Burkey Wei Chen Pin Li Yan Li Bo Li Yijing Wang 《环境科学学报(英文版)》2019,31(10):42-50
Ethylenediurea(EDU)has been used as a chemical protectant against ozone(03).However,its protective effect and physiological mechanisms are still uncertain.The present study aimed to investigate the changes of foliar visible injury,physiological characteristics and emission rates of volatile organic compounds(VOCs)in one-year-old Populus alba"Berolinensis"saplings pretreated with EDU and exposed to elevated O_3(EO,120μg/m~3).The results showed that foliar visible injury symptoms under EO were significantly alleviated in plants with EDU application(p0.05).Under EO,net photosynthetic rate,the maximum photochemical efficiency of PSII and the photochemical efficiency of PSII of plants pretreated with 300 and600 mg/L EDU were similar to unexposed controls and significantly higher compared to EOstressed plants without EDU pretreatment,respectively.Malondialdehyde content was highest in EO without EDU and decreased significantly by 14.9%and 21.3%with 300 and600 mg/L EDU pretreatment,respectively.EDU pretreatment alone increased superoxide dismutase activity by 10-fold in unexposed plants with further increases of 88.4%and 37.5%in EO plants pretreated with 300 and 600 mg/L EDU pretreatment,respectively(p0.05).Abscisic acid content declined under EO relative to unexposed controls with the effect partially reversed by EDU pretreatments.Similarly,VOCs emission rate declined under EO relative to unexposed plants with a recovery of emission rate observed with 300 and 600 mg/L EDU pretreatment.These findings provided significant evidence that EDU exerted a beneficial effect and protection on the tested plants against 03 stress. 相似文献
34.
The sonographic diagnosis of fetal neural tube defects (NTDs) has been enhanced by the recognition of associated brain and skull anomalies. Previous reports have found these anomalies to be accurate in predicting spina bifida after 16 weeks' gestation, and an inverse correlation was suggested between the presence of these sonographic markers and gestational age. Therefore, we assumed that early second-trimester sonography would be at least as accurate as that performed after 16 weeks' gestation. To examine this hypothesis, we looked for the presence of these cranial sonographic markers suggestive of open NTDs in 8011 low-risk cases, using transvaginal sonography (TVS), between the 12th and 17th week of gestation (menstrual age). Fetal NTDs were identified in ten cases (l.25%o). The NTDs were cervico-cranial in three, lumbo-sacral in six, and thoracal in one of the ten cases. None of the seven cases examined was dyskaryotic. Cerebellar dysmorphism, ‘banana’ sign, cerebellar absence, and hypoplasia were detected in all the low NTDs, usually before the detection of the spinal lesion. All the sonographically diagnosed malformations were confirmed by post-abortal examination except in one case, where the patient decided to continue the pregnancy and refused follow-up. We therefore conclude that transvaginal sonographic examination of the fetal skull before the 17th week of gestation is an accurate method for the detection of low NTDs. 相似文献
35.
Poonam Singh Shashi Bhushan Agrawal 《Environmental pollution (Barking, Essex : 1987)》2009,157(3):871-880
A field study was conducted to evaluate the impact of ambient ozone on mustard (Brassica campestris L. var. Kranti) plants grown under recommended and 1.5 times recommended NPK doses at a rural site of India using filtered (FCs) and non-filtered open top chambers (NFCs). Ambient mean O3 concentration varied from 41.65 to 54.2 ppb during the experiment. Plants growing in FCs showed higher photosynthetic rate at both NPK levels, but higher stomatal conductance only at recommended NPK. There were improvements in growth parameters and biomass of plants in FCs as compared to NFCs at both NPK levels with higher increments at 1.5 times recommended. Seed yield and harvest index decreased significantly only at recommended NPK in NFCs. Seed quality in terms of nutrients, protein and oil contents reduced in NFCs at recommended NPK. The application of 1.5 times recommended NPK provided protection against yield loss due to ambient O3. 相似文献
36.
Air pollutant emissions from rice straw open field burning in India, Thailand and the Philippines 总被引:4,自引:0,他引:4
Butchaiah Gadde Sébastien Bonnet Christoph Menke Savitri Garivait 《Environmental pollution (Barking, Essex : 1987)》2009,157(5):1554-1558
Rice is a widely grown crop in Asia. China (30%) and India (21%) contribute to about half of the world's total rice production. In this study, three major rice-producing countries in Asia are considered, India, Thailand and the Philippines (the later two contributing 4% and 2% of the world's rice production). Rice straw is one of the main field based residues produced along with this commodity and its applications vary widely in the region. Although rice production practises vary from one country to another, open burning of straw is a common practice in these countries.In this study, an approach was followed aiming at (a) determining the quantity of rice straw being subject to open field burning in those countries, (b) congregating pollutant specific emissions factors for rice straw burning, and (c) quantifying the resulting air pollutant emissions. Uncertainties in the results obtained as compared to a global approach are also discussed. 相似文献
37.
2010年7月—8月间对海州露天煤矿区的采场、排土场、排矸场不同年龄梯田层以及矿区农田、村庄周围土壤线虫群落特征进行研究。研究结果表明:露天煤矿区土壤线虫群落中,植物寄生类群线虫数量占主导优势(77.8%),其次是食细菌类群(16.64%)、食真菌类群(5.80%),捕食/杂食类群数量最少(0.39%),排土场(除覆盖表土层)、排矸场土壤线虫数量随着梯田年限增加而增高;捕食/杂食类在远郊山坡最高(每kg干土67条),排土场与排矸场混排岩土中、农田、村庄周围土壤中没有发现敏感的捕食/杂食类线虫;线虫成熟指数在排土场稳定土壤环境中较高,在严重干扰地如农田、年轻梯田中很低。土壤线虫群落特征的研究为露天煤矿区土壤生态系统稳定性、土壤生物评价实践提供科学依据。 相似文献
38.
Crop residue open burning is an important emission source of ambient particles in China. This study analyzed the particle emission characteristics of crop residue open burning through combustion experiments with a novel open combustion simulation device using three typical crop straws in north China (corn, wheat, and rice). Particle samples size ranging from 0.006–9.890 µm were collected by an Electrical Low Pressure Impactor plus, a high size-resolution instrument capable of dividing particles into 14 size stages. The size distributions of organic carbon (OC), elemental carbon (EC), water-soluble ions, and elements were analyzed, and source chemical profiles were constructed for PM0.1, PM1, PM2.5, and PM10. The number concentration of particles was concentrated in the Aiken nuclei mode (0.006–0.054 µm), accounting for 75% of the total number, whereas the mass concentration was concentrated in the accumulation mode (0.054–0.949 µm), accounting for 85.43% of the mass loading. OC, EC, Cl?, and K(include total K and water-soluble K) were the major chemical components of the particles, whose mass percentage distributions differed from those of other components. These five main components exhibited a bell-shaped size distribution in the 0.006–9.890 µm range, whereas the other components exhibited a U-shaped distribution. Among the chemical profiles for PM0.1–PM10, OC was the most important component at 10–30%, followed by EC at 2%–8%. The proportions of K+, Cl?, and K varied substantially in different experimental groups, ranging from 0–15%, and K+ and Cl? were significantly correlated (r = 0.878, α = 0.000). 相似文献
39.
为对比研究开放与受限条件下的电缆火灾燃烧行为,采用CFD数值模拟软件建立了全尺寸电缆燃烧模型,同时考虑了不同间距对电缆燃烧特性的影响,并将开放与受限条件下的计算结果进行对比,分析了两种条件下电缆火灾中各工况的温度、O2浓度。结果表明:开放条件下的电缆燃烧主要属于燃料控制型,而受限条件下的电缆燃烧主要属于先燃料控制型,后通风控制型。在开放条件下,氧气充足,燃烧更为充分,形成的火焰高度及温度更高,更容易引燃上方可燃物体;而在受限条件下,电缆火焰受到顶板限制形成的顶棚射流,会加强火焰对电缆的热辐射作用,有助于电缆燃烧。但由于侧壁的存在,电缆燃烧过程中的空气卷吸受到了一定的限制,由于通风不足,受限空间内的O2浓度逐渐下降,电缆燃烧受到抑制,甚至熄灭,而随着空气的补充,电缆将可能出现复燃现象。此外,两种条件下电缆间距对燃烧的影响均较为明显,当间距较小时,燃烧电缆之间的影响显著,燃烧更为剧烈,而随着电缆间距增大,燃烧电缆间的相互热辐射减弱,更接近于单根电缆的独立燃烧,其中开放条件下相对更为明显。 相似文献
40.
Numerous studies have indicated a broad-based support for open space preservation and protection. Research also has characterized the public values and rationale that underlie the widespread support for open space. In recognition of the widespread public support for open space, various levels of government have implemented programs to provide public access to open space. There are many different types of open space, ranging from golf courses, ball parks, wildlife areas, and prairies, to name a few. This paper addresses questions related to the types of open space that should be prioritized by planners and natural resource managers. The results of this study are based on a stratified random sample of 5000 households in Illinois that were sent a questionnaire related to their support for various types of open space. Through a comparatively simple action grid analysis, the open space types that should be prioritized for public access include forest areas, stream corridors, wildlife habitat, and lakes/ponds. These were the open space types rated of the highest importance, yet were also the open space types rated the lowest in respondent satisfaction. This kind of analysis does not require the technical expertise of other options for land-use prioritizations (e.g., conjoint analysis, contingent valuation), yet provides important policy directives for planners. Although open space funds often allow for purchase of developed sites such as golf courses, ball parks, and community parks, this study indicates that undeveloped (or nature-based) open space lands are most needed in Illinois. 相似文献