模拟酸露对植物影响的实验

模拟酸露对植物影响的实验结果表明，用酸露处理后，蚕豆的生理指标发生一定的变化，尤以ｐＨ１３．０时的变化较明显，显示了模拟酸露对植物的伤害作用。     

Science in the public process of ecosystem management: lessons from Hawaii, Southeast Asia, Africa and the US Mainland

Partnerships and co-operative environmental management are increasing worldwide as is the call for scientific input in the public process of ecosystem management. In Hawaii, private landowners, non-governmental organizations, and state and federal agencies have formed watershed partnerships to conserve and better manage upland forested watersheds. In this paper, findings of an international workshop convened in Hawaii to explore the strengths of approaches used to assess stakeholder values of environmental resources and foster consensus in the public process of ecosystem management are presented. Authors draw upon field experience in projects throughout Hawaii, Southeast Asia, Africa and the US mainland to derive a set of lessons learned that can be applied to Hawaiian and other watershed partnerships in an effort to promote consensus and sustainable ecosystem management. Interdisciplinary science-based models can serve as effective tools to identify areas of potential consensus in the process of ecosystem management. Effective integration of scientific input in co-operative ecosystem management depends on the role of science, the stakeholders and decision-makers involved, and the common language utilized to compare tradeoffs. Trust is essential to consensus building and the integration of scientific input must be transparent and inclusive of public feedback. Consideration of all relevant stakeholders and the actual benefits and costs of management activities to each stakeholder is essential. Perceptions and intuitive responses of people can be as influential as analytical processes in decision-making and must be addressed. Deliberative, dynamic and iterative decision-making processes all influence the level of stakeholder achievement of consensus. In Hawaii, application of lessons learned can promote more informed and democratic decision processes, quality scientific analysis that is relevant, and legitimacy and public acceptance of ecosystem management.     

Effects of salinity on soil bacterial and archaeal community in estuarine wetlands and its implications for carbon sequestration: verification in the Yellow River Delta

Soils from two typical tidal salt marshes with varied salinity in the Yellow River Delta wetland were analysed to determine possible effects of salinity on soil carbon sequestration through changes in soil microbiology. The mean soil respiration (SR) of the salt water–fresh water mixing zone (MZ) was 2.89 times higher than that of the coastal zone (CZ) (4.73 and 1.63?μmol?m^?2?s^?1, respectively, p?Pseudomonas sp. and Limnobacter sp. that might have led to its higher dehydrogenase activity and respiratory rates. Additionally, the CZ possessed more Halobacteria and Thaumarchaeota with the ability to fix CO₂ than the MZ. Significantly lower soil salinity in MZ (4.25?g?kg^?1) was suitable for β-Proteobacteria, but detrimental for Halobacteria compared with CZ (7.09?g?kg^?1, p?相似文献   

Mapping Turbidity in the Charles River, Boston Using a High-resolution Satellite

The usability of high-resolution satellite imagery for estimating spatial water quality patterns in urban water bodies is evaluated using turbidity in the lower Charles River, Boston as a case study. Water turbidity was surveyed using a boat-mounted optical sensor (YSI) at 5 m spatial resolution, resulting in about 4,000 data points. The ground data were collected coincidently with a satellite imagery acquisition (IKONOS), which consists of multispectral (R, G, B) reflectance at 1 m resolution. The original correlation between the raw ground and satellite data was poor (R2 = 0.05). Ground data were processed by removing points affected by contamination (e.g., sensor encounters a particle floc), which were identified visually. Also, the ground data were corrected for the memory effect introduced by the sensor's protective casing using an analytical model. Satellite data were processed to remove pixels affected by permanent non-water features (e.g., shoreline). In addition, water pixels within a certain buffer distance from permanent non-water features were removed due to contamination by the adjacency effect. To determine the appropriate buffer distance, a procedure that explicitly considers the distance of pixels to the permanent non-water features was applied. Two automatic methods for removing the effect of temporary non-water features (e.g., boats) were investigated, including (1) creating a water-only mask based on an unsupervised classification and (2) removing (filling) all local maxima in reflectance. After the various processing steps, the correlation between the ground and satellite data was significantly better (R2 = 0.70). The correlation was applied to the satellite image to develop a map of turbidity in the lower Charles River, which reveals large-scale patterns in water clarity. However, the adjacency effect prevented the application of this method to near-shore areas, where high-resolution patterns were expected (e.g., outfall plumes).     

Comprehensive temperature monitoring in an in-vessel forced-aeration static-bed composting process

Comprehensive temperature monitoring was done in an in-vessel forced-aeration static-bed composting process using sewage sludge. The three layers that divided the compost pile horizontally showed different temperature distributions. The temperature of the top layer appeared not to be influenced by the ambient temperature. The temperature of the center area of the top layer was taken to be the representative temperature for evaluating composting start-up performance. The temperature of the bottom layer was strongly influenced by the ambient temperature, and the temperature of the center area of the bottom layer was taken to be the representative temperature for pathogen control as it was the minimum temperature in the reactor. Composting start-up performance was influenced by several factors when the ambient temperature was either below or above 20°C. When the ambient temperature was below 20°C, the time taken to reach 65°C (T ₆₅) was influenced by the temperature of inflowing air, but when the temperature was higher than 20°C, it was influenced by the ratio of sewage sludge to seed compost (F/S). T ₆₅ was least when F/S was 1–2. Received: January 9, 2001 / Accepted: October 10, 2001     

紫外分光光度法测定海水中石油类的不确定度评定

对紫外分光光度法测定海水中石油类浓度进行了不确定度评定。通过对标准溶液、标准工作曲线拟合、前处理过程等影响测定结果的不确定度分量进行分析,计算出测定结果的扩展不确定度,并找出影响该不确定度的主要因素。结果表明,紫外分光光度法测定海水中石油类浓度的不确定度的主要来源是实验中前处理过程的不确定度,本次实验所测海水中石油类浓度的不确定度报告为19.98±1.326 mg/L。     

Improvement of soil aggregate stability by repeated applications of organic amendments to a cultivated silty loam soil

The objective of this study was to compare the effects of repeated field applications of three urban compost amendments and one farmyard manure amendment over a 9-year period on aggregate stability in a silty loam soil initially characterized by low clay and initial organic matter contents and poor aggregate stability. Three different aggregate stability tests with increasing disruptive intensities (fast wetting > mechanical breakdown > slow wetting tests) and different disaggregation mechanisms, were used. All of the amendments, which were applied at approximately 4 Mg C ha⁻¹ every other year, increased the organic carbon content and improved the stability of the aggregates against the disruptive action of water, as determined by each of the stability tests. However, the year-to-year variations in the aggregate stability that related to factors other than the organic inputs were greater than the cumulative increase in aggregate stability relative to the control. The positive effects of the tested amendments on aggregate stability were linked to their contribution to soil organic C contents (r = 0.54 for the fast wetting test and r = 0.41-0.42 for the mechanical breakdown and slow wetting tests; p < 0.05). The addition of urban composts had a larger positive effect on aggregate stability than farmyard manure at the majority of sampling dates. The addition of biodegradable immature compost, such as municipal solid waste (MSW), improved the aggregate stability through an enhanced resistance to slaking. The addition of mature composts, such as the co-compost of sewage sludge and green wastes (GWS) or biowaste compost (BW), improved the aggregate stability by increasing interparticular cohesion. The MSW compost was the most efficient in improving aggregate stability during the first 6 years of the experiment (average improvements of +22%, +5% and +28% in the fast wetting, mechanical breakdown and slow wetting tests, respectively, compared to the control treatment); this result was likely due to the larger labile organic pool of the MSW compost that was highly effective at stimulating soil microbial activity. After the first 6 years, the two other composts, GWS and BW, became more efficient (average improvements of +25%, +61% and +33% in the fast wetting, mechanical breakdown and slow wetting tests, respectively, compared to the control treatment), which was probably linked to the greater increase in soil organic C contents. Therefore, the application of urban compost to silty soil that is susceptible to water erosion was effective at improving aggregate stability and thus could be used to enhance the resistance of soil to water erosion.     

国内首个MW级分布式能源系统烟囱合理性分析

介绍了分布式能源系统的构成、运行特点及技术发展情况,研究了国内首个MW级分布式供能系统工程的烟囱高度和形式,预测和分析了项目大气污染物对环境的影响,证明了该项目烟囱选择的合理性,为下阶段国内分布式能源系统烟囱选型奠定技术基础。     

Farmers’ perceptions of climate variability and barriers to adaptation: lessons learned from an exploratory study in Vietnam

Southeast Asian countries are confronting climate variability, challenging agricultural sustainability and rural livelihoods. However, little research effort has been devoted to exploring how farmers in those countries perceive climate variability and how the perceptions link to adaptive responses. This paper deploys information from three focus group discussions with 30 male farmers; and six in-depth interviews with one female and five male agricultural officers in the Mekong Delta, Vietnam. Recorded 34-year meteorological data in the delta from 1978 to 2011 is also incorporated to demonstrate the actual climate variability of the region. We find that farmers are becoming increasingly conscious of local climate variability issues. However, they have limited understanding of the importance of adaptation to their livelihoods. They also have limited knowledge of where and who to contact for appropriate climate change adaptation information. No opinions about the link between global warming and local climate variability and change were observed. Casual observation via public media and personal experience dominated farmers’ sources of information. Barriers to farmers’ adaptation are not exclusively restricted to socio-economic factors and resource constraints; e.g. land tenure, technical knowledge, market, social relationship, credit, information, health care, and demographics. Maladaptation, habit, and the perception of the importance of climate variability and adaptation are found as additional constraints. Observed differences in farmers’ and agricultural officers’ perspectives regarding barriers to farmers’ adaptation suggest important policy implications.     

Arsenic residue in residential area after cleanup of pesticide illegal dumping sources in Thanh Hoa province,Central Vietnam

In Vietnam, Nicotex's site is perhaps the most infamous case of illegal disposal of toxic pesticides near residential areas. In 2013, affected villagers discovered illegal burials of around 1,000 tons of expired pesticides in the Nicotex factory. Organic pesticides were detected in illegal burial areas (IBAs) around 60 times greater than acceptable levels, but no attention was paid to contamination of metals, metalloids, and other classes of organic contaminants, which could be co-contaminants in pesticide formulation. This study assessed the contaminants remaining in the IBAs and surrounding residential areas two years after the source removal conducted in 2014. Additionally, a preliminary health risk assessment from residual contaminants was performed. Nine classes of chemicals including parental pesticides, inorganic and organic degradation byproducts, and metals and metalloids, comprising 123 chemicals were quantified in soil, sediment, and water samples from Nicotex and surrounding residential areas. Although concentrations of organic pesticides were below acceptable levels, arsenic contamination in the soil in a Nicotex IBA named NCT5 and Nap village (NV) exceeded the acceptable level. The enrichment factor and log-probability plot indicate that arsenic enrichment at NV is not from natural sources but is associated with arsenic contamination in NCT5. Arsenic may be a co-contaminant in pesticide manufacturing or an arsenical pesticide, such as monosodium methanearsonate. Arsenic found in NV was toxic arsenate for which the preliminary risk assessment yielded an unacceptable excess carcinogenic risk (1 × 10^?4). While all attention was paid to investigate and treat contamination of organic pesticides, it turns out that arsenic is the major existing threat which poses an unacceptable cancer risk in good agreement with the high cancer rate claimed by villagers near Nicotex. This justifies the need for further investigation of the extent of the arsenic contamination and restoration of the contaminated land.