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121.
应用核磁共振技术找水是核磁共振技术应用的新领域,核磁共振找水是一种直接探测地下水的地球物理方法。本文介绍了在贫水地区一个指定范围内探测地下水例子。比较所做的三个僚共振测点的工作结果,确定出含中水情况较好部位,配合做了率对四极测探,其工作结果指示出一低阻区域,是地下水富集带。在设计的钻井位置钻探探打出了优质 下水,验证了核磁共振找水方法的推断结果。在对该磁共振找水方法研究和实践的基础上,指出:核磁共 相似文献
122.
123.
A combined photovoltaic–thermal (PV/t) panel is proposed to produce simultaneously electricity and heat from one integrated unit. The unit utilizes effectively the solar energy through achieving higher PV electrical efficiency and using the thermal energy for heating applications. To predict the performance of the PV/t at a given environmental conditions, a transient mathematical model was developed. The model was integrated in a heating application for a typical office space in the city of Beirut to provide the office needs for electricity, heating during winter season, and dehumidification and evaporative cooling during the summer season. To minimize the yearly office energy (electrical and heat) needs, the PV/t panel cooling air flow rate and the dehumidification regeneration temperature were determined for opimal unit operation. Thermal energy savings of up to 85% in winter and 71% in summer were achived compared to conventional systems at a payback period of 8 years for the panels. 相似文献
124.
In this paper, wind energy potential of four locations in Xinjiang region is assessed. The Weibull distribution as well as the Logistic and the Lognormal distributions are applied to describe the distributions of the wind speed at different heights. In determining the parameters in the Weibull distribution, four intelligent parameter optimization approaches including the differential evolutionary, the particle swarm optimization, and two other approaches derived from these two algorithms and combined advantages of these two approaches are employed. Then the optimal distribution is chosen through the Chi-square error (CSE), the Kolmogorov–Smirnov test error (KSE), and the root mean square error (RMSE) criteria. However, it is found that the variation range of some criteria is quite large, thus these criteria are analyzed and evaluated both from the anomalous values and by the K-means clustering method. Anomaly observation results have shown that the CSE is the first one should be considered to be eliminated from the consequent optimal distribution function selection. This idea is further confirmed by the K-means clustering algorithm, by which the CSE is clustered into a different group with KSE and RMSE. Therefore, only the reserved two error evaluation criteria are utilized to evaluate the wind power potential. 相似文献
125.
Zhenshu Wang Yunpeng Shi Xiaodi Wang Qi Zhang Shichao Qu 《International Journal of Green Energy》2016,13(12):1267-1280
The drying up of the fossil energy sources and the damage from unchecked carbon emissions demand the development of low carbon economy, which promotes the development of new energy sources, such as wind power and photovoltaic. However, the direct connections of wind/photovoltaic power into power grid bring great impacts on power systems, thus affecting the security and stability of power system operations, which challenges the power system dispatching. In despite of many methods for power system dispatch, lack of the models, for power system containing wind power and photovoltaic considering carbon trading and spare capacity variation (PSCWPCCTSCV), restricts the further optimal operations of power systems. This paper studies the economic dispatch modeling problem of power system containing wind power and photovoltaic, establishes the model of economic dispatch of PSCWPCCTSCV. On this basis, adaptive immune genetic algorithm is applied to conduct the economic operation optimization, which can provide the optimal carbon trading price and the optimal power distribution coefficient. Finally, simulations based on the newly proposed models are made to illustrate the economic dispatch of PSCWPCCTSCV. The results show that optimization with the proposed model can not only weaken the volatility of the new energy effectively, but also reduce carbon emissions and reduce power generation costs. 相似文献
126.
Scholars of environmental injustice have pushed to see beyond the spatial distribution of environmental harms in studies of unwanted land uses. Building upon this work, this article examines how the complex geographies of environmental injustice play out in a coalition to prevent the construction of a coal-fired power plant in Surry County, Virginia. While spatially dispersed coalitions of negatively affected actors can strengthen efforts to prevent the construction of an unwanted land use, they can also perpetuate the environmental injustices surrounding it. To make this argument, particular attention is paid to the diverse reasons and ways differentially situated actors oppose an unwanted land use. It is demonstrated how the disparate concerns and differential tactics deployed by actors in coalitions against unwanted land uses are often embedded in and potentially contribute to longer histories of social injustice. 相似文献
127.
Fate of pharmaceuticals and personal care products in wastewater treatment plants - Conception of a database and first results 总被引:1,自引:0,他引:1
C. Miège J.M. Choubert L. Ribeiro M. Eusèbe M. Coquery 《Environmental pollution (Barking, Essex : 1987)》2009,157(5):1721-1726
We created a database in order to quantitatively assess the occurrence and removal efficiency of pharmaceuticals and personal care products (PPCPs) in wastewater treatment plants (WWTPs). From 117 scientific publications, we compiled 6641 data covering 184 PPCPs. Data included the concentrations of PPCPs in WWTP influents and effluents, their removal efficiency and their loads to the aquatic environment. The first outputs of our database allowed to identify the most investigated PPCPs in WWTPs and the most persistent ones, and to obtain reliable and quantitative values on their concentrations, frequency of detection and removal efficiency in WWTPs. We were also able to compare various processes and pointed out activated sludge with nitrogen treatment and membrane bioreactor as the most efficient ones. 相似文献
128.
An Assessment of Stakeholder Perceptions and Management of Noxious Alien Plants in Spain 总被引:1,自引:1,他引:0
Despite biological invasions being a worldwide phenomenon causing significant ecological, economic, and human welfare impacts,
there is limited understanding regarding how environmental managers perceive the problem and subsequently manage alien species.
Spanish environmental managers were surveyed using questionnaires to (1) analyze the extent to which they perceive plant invasions
as a problem; (2) identify the status, occurrence, and impacts of noxious alien plant species; (3) assess current effort and
expenditure targeting alien plant management; and, finally, (4) identify the criteria they use to set priorities for management.
In comparison to other environmental concerns, plant invasions are perceived as only moderately problematic and mechanical
control is the most valued and frequently used strategy to cope with plant invasions in Spain. Based on 70 questionnaires
received, 193 species are considered noxious, 109 of which have been the subject of management activities. More than 90% of
species are found in at least one protected area. According to respondents, the most frequently managed species are the most
widespread across administrative regions and the ones perceived as causing the highest impacts. The perception of impact seems
to be independent of their invasion status, since only half of the species identified as noxious are believed to be invasive
in Spain, while 43% of species thought to only be casual aliens are causing a high impact. Records of management costs are
poor and the few data indicate that the total actual expenditure amounted to 50,492,437 € in the last decade. The majority
of respondents stated that management measures are insufficient to control alien plants due to limited economic resources,
lack of public awareness and support, and an absence of coordination among different public administrations. Managers also
expressed their concern about the fact that much scientific research is concerned with the ecology of alien plants rather
than with specific cost-efficient strategies to manage alien species. 相似文献
129.
Arun Kansal Mukesh Khare Chandra Shekhar Sharma 《Journal of Environmental Planning and Management》2009,52(7):881-899
This study estimates minimum marginal health benefits (morbidity reduction only) of air pollution control and total health benefits arising from regulatory intervention regarding the adoption of the World Bank emission guidelines (WBEG) for thermal power plants (TPPs) in Delhi. The Industrial Source Complex-Short-Term Version–3 (ISCST3) model has been used to estimate the contribution to air pollution from TPPs. The household health production function (avertive behaviour) has been used to value health benefits of air pollution control. The study revealed that the ambient air pollution due to TPPs is reduced by between 62.17% to 83.45% by adopting the WBEG. Annual marginal benefit due to reduction in exposure to air pollution by 1 μg m?3 is estimated to be US$0.353 per person. Total annual health benefits for adopting the WBEG for TPPs are estimated at US$235.19 million. This study provides a novel methodology to evaluate health benefits of regulatory intervention. 相似文献
130.
Rita Castro Sofia Pereira Ana Lima Sofia Corticeiro Mnica Vlega Eduarda Pereira Armando Duarte Etelvina Figueira 《Chemosphere》2009,76(10):1348-1355
This work evaluates the role of a plant community in mercury (Hg) stabilization and mobility in a contaminated Portuguese salt marsh. With this aim, the distribution of Hg in below and aboveground tissues, as well as the metal partitioning between cellular fractions (soluble and insoluble) in four different species (Triglochin maritima L., Juncus maritimus Lam, Sarcocornia perennis (Miller) A.J. Scott, and Halimione portulacoides (L.) Aellen) was assessed. Mercury accumulation, translocation and compartmentation between organs and cellular fractions were related to the plant species.Results showed that the degree of Hg absorption and retention was influenced both by environmental parameters and metal translocation/partitioning strategies. Different plant species presented different allocation patterns, with marked differences between monocots (T. maritima and J. maritimus) and dicots (S. perennis, H. portulacoides). Overall, the two monocots, in particular T. maritima showed higher Hg retention in the belowground organs whereas the dicots, particularly S. perennis presented a more pronounced translocation to the aboveground tissues. Considering cellular Hg partitioning, all species showed a higher Hg binding to cell walls and membranes rather than in the soluble fractions. This strategy can be related to the high degree of tolerance observed in the studied species. These results indicate that the composition of salt marsh plant communities can be very important in dictating the Hg mobility within the marsh ecosystem and in the rest of the aquatic system as well as providing important insights to future phytoremediation approaches in Hg contaminated salt marshes. 相似文献