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991.
以二元酸和短链叔胺为原料,合成了已二酸三乙胺盐离子液体———R3NANR3。对该离子液体进行SO2气体的循环吸收和解吸行为的研究。实验结果表明,R3NANR3离子液体能对SO2气体进行有效的化学吸收。该吸收过程分二步进行,以第一步吸收为主。室温下(20℃)该离子液体在3 h以内吸收速率较快,3 h后吸收速率减慢并逐渐达到平衡。R3NANR3离子液体与SO2气体饱和吸收量的物质的量之比为1.08。较高温度将导致SO2气体的解吸,在90℃时饱和吸收液能较充分地解吸,残留量为0.0010 mol/L。多次吸收和解吸测试表明,R3NANR3离子液体能实现对SO2气体的循环吸收和分离,将成为烟气中SO2气体的脱除和利用的重要循环吸收剂。 相似文献
992.
陆地净第一性生产力(NPP)是陆地生态系统的一项重要指示性指标,与碳循环过程和全球气候变化密切相关,不仅已成为地学研究的热点问题,更受到各国政府的高度重视。长三角地区是我国经济最发达、最具综合竞争力的地区之一,该地区的陆地生态系统同时承受着自然因素及高强度人为活动的双重影响。因此,利用CASA模型,在RS和GIS技术支撑下,探讨近十年来长三角地区陆地NPP的时空演变规律及控制因子,以期为进一步开展高强度人为活动对陆地系统碳循环过程的影响研究提供基础参数。主要结论如下:(1)在时间上呈下降趋势:近十年长三角地区陆地NPP呈现3 a周期式波动下降;(2)在空间上分异规律明显:陆地NPP分布为浙江>江苏>上海,呈现南北高中间低的凹槽状;(3)控制NPP的自然要素是NDVI和太阳辐射,而城市化是NPP变化的主要社会经济要素 相似文献
993.
The diurnal atmospheric phosphine (PH3) concentrations and fluxes at the water-air interface in Lake Taihu were reported. The results showed that the PH3 flux at the water-air interface ranged from −69.9 ± 29.7 to 121 ± 42 ng m−2 h−1, with a mean flux of 14.4 ± 22.5 ng m−2 h−1. The fluxes were both negative and positive during the diurnal period, indicating that the lake can act as a sink and a source of PH3. In addition, the PH3 fluxes were positively correlated with water temperature, total soluble phosphorus and soluble reactive phosphorus, while they were negatively correlated with water redox potential. A similar diurnal variation curve of atmospheric PH3 concentrations was observed during all four seasons, with the maximum level occurring in early morning and the minimum appearing around midday. These findings suggest that light plays an important role in the elimination of atmospheric PH3. A significant positive correlation was also found between air temperature and atmospheric PH3 concentration. The mean flux of PH3 in Lake Taihu was higher than in other reported wetlands, with an estimated annual emission of PH3 to the atmosphere of 2.94 × 105 g y−1. 相似文献
994.
Life cycle assessment (LCA) can be successfully applied to municipal solid waste (MSW) management systems to identify the overall environmental burdens and to assess the potential environmental impacts. In this study, two methods used for current MSW management in Phuket, a province of Thailand, landfilling (without energy recovery) and incineration (with energy recovery), are compared from both energy consumption and greenhouse gas emission points of view. The comparisons are based on a direct activity consideration and also a life cycle perspective. In both cases as well as for both parameters considered, incineration was found to be superior to landfilling. However, the performance of incineration was much better when a life cycle perspective was used. Also, landfilling reversed to be superior to incineration when methane recovery and electricity production were introduced. This study reveals that a complete picture of the environmental performance of MSW management systems is provided by using a life cycle perspective. 相似文献
995.
Life cycle assessment-based environmental product declarations (EPDs) require the inclusion of biodiversity impacts across
the entire supply chain. The objective of this study is to test the applicability of a Scandinavian biodiversity assessment
tool, developed specifically for use with EPD applications, in an African desert environment, linking the industry types power
generation and mining. For this purpose, a GIS-based spatial analysis tool—the biotope method—was adapted to a framework approach
which allowed the selection of more suitable, site-specific biodiversity indicators. The biotope method provides a step-by-step
process of defining system boundaries, mapping biotopes, categorizing biotopes based on site-specific indicators, and evaluating
change in biotope status “before” and “after” the impact. The development of site-specific indicators was piloted in this
study and determined by the affected ecosystem and the status of knowledge on biodiversity in this geographic area. Thus plants
were used as indicators for biodiversity, and red-list status and endemism constituted the prime criteria for conservation
value of plants. This in turn represented the key criterion for classifying biotopes. The tested biodiversity assessment tool
has potential for application in different environments and operational settings but leaves room for improvement by including
secondary impacts in the assessment and using a wider range of taxa for indicators of biodiversity. 相似文献
996.
Kuldip Singh Sangwan Kailash Choudhary Chirag Batra 《International Journal of Sustainable Engineering》2018,11(3):211-216
The beginning of the twenty-first century saw a surge in the growth of construction industry, particularly the housing sector in India. This led to the growing demand of ceramic tiles. This growth is responsible for large-scale consumption of natural resources and generation of solid waste. The objective of this paper is to assess the environmental impact of vitrified ceramic floor tile supply chain by performing life cycle assessment (LCA) following international standards of ISO 14040 series guidelines. The impact has been determined by conducting a LCA using Umberto NXT software (eco-invent 3.0 database) with ReCiPe endpoint and midpoint methods. It has been found that the manufacturing stage of supply chain is generating highest impact on environment in all the categories. Impact analysis of different input resources/material shows that red oxide used in glaze preparation, electricity in manufacturing, packaging material, distribution by trucks, installation of tiles using concrete and disposal of packaging material are responsible for most of the environmental impact. This study will offer the essential quantitative assessment to recognise the phases and materials which are highly responsible for the degradation of environment so that appropriate interventions by the different stakeholders can be planed. 相似文献
997.
气相色谱法测定废水中N,N─二甲基甲酰胺 总被引:1,自引:0,他引:1
用气相色谱仪氢焰检测器,PEG20M毛细管柱测定废水中的N,N二甲基甲酰胺(DMF),结果表明与分光光度法基本一致 相似文献
998.
Humans are primarily exposed to fluoride (Fl), a widespread environmental pollutant, via contaminated drinking water and foodstuffs. The aim of this study was to examine whether sodium fluoride (NaF) exerted cytotoxic effects in human hepatocarcinoma (HepG2) cells. HepG2 cells were incubated with different concentrations of NaF and reactive oxygen species (ROS) levels, cell cycle, apoptosis, and DNA damage determined. Concentration-dependent studies showed that exposure to HepG2 cells with different concentrations of NaF for 24 hr significantly decreased cell viability and intracellular antioxidant capacity. Furthermore, NaF exposure increased lipid peroxidation levels and accumulation of intracellular ROS; and lowered antioxidant glutathione concentrations. In addition to oxidative impairments, NaF treatment enhanced HepG2 cell death via apoptotic pathway as evidenced by DNA fragmentation and cell cycle arrest. Sodium fluoride treatment unregulated p53 level, and Bax and Bcl2 expression. Diminished cell viability and changes in cell cycle accompanied a rise in p53 expression. 相似文献
999.
A Hydrologic Drying Bias in Water‐Resource Impact Analyses of Anthropogenic Climate Change
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P.C.D. Milly Krista A. Dunne 《Journal of the American Water Resources Association》2017,53(4):822-838
For water‐resource planning, sensitivity of freshwater availability to anthropogenic climate change (ACC) often is analyzed with “offline” hydrologic models that use precipitation and potential evapotranspiration (Ep) as inputs. Because Ep is not a climate‐model output, an intermediary model of Ep must be introduced to connect the climate model to the hydrologic model. Several Ep methods are used. The suitability of each can be assessed by noting a credible Ep method for offline analyses should be able to reproduce climate models’ ACC‐driven changes in actual evapotranspiration in regions and seasons of negligible water stress (Ew). We quantified this ability for seven commonly used Ep methods and for a simple proportionality with available energy (“energy‐only” method). With the exception of the energy‐only method, all methods tend to overestimate substantially the increase in Ep associated with ACC. In an offline hydrologic model, the Ep‐change biases produce excessive increases in actual evapotranspiration (E), whether the system experiences water stress or not, and thence strong negative biases in runoff change, as compared to hydrologic fluxes in the driving climate models. The runoff biases are comparable in magnitude to the ACC‐induced runoff changes themselves. These results suggest future hydrologic drying (wetting) trends likely are being systematically and substantially overestimated (underestimated) in many water‐resource impact analyses. 相似文献
1000.