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731.
This study explained the importance of environmental protection in tourism development and illustrated the relationship between recreational resource valuation and environmental consideration. We compare different models of travel cost method and reiterates long-time existing problems of multi-destination and treats of time opportunity cost (TOC). Taking Jiayuguan's cultural sights as an example, we establish an updated method called multi-destination zonal tourism cost method to evaluate the recreational values (RVs) of selected three cultural sights. We divide trip packages of Jiayuguan's tourists into 11 portfolios. Each portfolio can be seen as a separate commodity, and each commodity has its own demand curve. According to demand curves we can calculate consumer surplus (CS) of different portfolios of tourist destinations and later we sum up the total travel costs (including travel expenditure and TOC) and CS to come to the RVs of each portfolio. We then apply suitable proportions to calculate the RVs between different destinations in the portfolio. In the end, we add up all the RVs calculated for the objective destination. Using this method, we draw conclusions that Jiayuguan's RV in 2006 includes national and international values, summing up to 738.4762 million yuan. The tourist expenditure, CS and TOC of Jiayuguan is proportionating 62.96, 32.28 and 4.76%, respectively. This study is also an example of non-market valuation of cultural tourism resources.  相似文献   
732.
油田含油污泥热解制备烟气脱硫剂   总被引:1,自引:0,他引:1  
为实现油田含油污泥深度资源化,针对高含油的孤岛采油厂含油污泥采用热解处理,回收油气资源的同时将热解残渣制备成烟气脱硫剂。以苯吸附值和热解残渣含油率为基准对热解工艺进行了优化,对热解油品和残渣进行分析,热解残渣经过后续处理进行了烟气脱硫性能评价。通过正交实验得到热解最佳工艺条件为:氮气保护下,热解温度550℃,热解时间4h,升温速率10℃/min。此时苯吸附值为60.12mg/g,热解残渣含油率为0.29%。最佳工艺条件下,热解油品产率可达10%左右,回收率大于65%,热裂解作用明显,热解油品的品质较好,产生的不凝气体可以作为洁净燃料气;热解残渣经过后续处理,可用于脱除烟气中的SO2,吸附脱硫能力较好,穿透硫容达到3%以上。  相似文献   
733.
Wang HC  Hwang JF  Chi KH  Chang MB 《Chemosphere》2007,67(9):S177-S184
The PCDD/F concentrations and removal efficiencies achieved with air pollution control devices (APCDs) during different operating periods (start-up, normal operation, and shut-down) at an existing municipal waste incinerator (MWI) in Taiwan are evaluated via stack sampling and analysis. The MWI investigated is equipped with electrostatic precipitators (EP), wet scrubbers (WS), and selective catalytic reduction system (SCR) as APCDs. The sampling results indicate that the PCDD/F concentrations at the EP inlet during start-up period were 15 times higher than that measured during normal operation period. The PCDD/F concentration observed at shut-down period was close to that measured at normal operation period. The CO concentration was between 400 and 1000 ppm during start-up period, which was about 50 times higher compared with the normal operation. Hence, combustion condition significantly affected the PCDD/F formation concentration during the waste incineration process. In addition, the distributions of the PCDD/F congeners were similar at different operating periods. During the normal operation and shut-down periods, the EP decreases the PCDD/F concentration (based on TEQ) by 18.4-48.6%, while the removal efficiency of PCDD/Fs achieved with SCR system reaches 99.3-99.6%. Nevertheless, the PCDD/F removal efficiency achieved with SCR was only 42% during the 19-h start-up period due to the low SCR operating temperature (195 degrees C).  相似文献   
734.
735.
几种金属氧化物TPS性能比较   总被引:4,自引:2,他引:2  
侯相林  高荫本 《环境化学》1998,17(2):154-158
通过程度升温硫化研究了CuO,Fe2O3,SnO2,MnO2,CaO及ZnO等金属氧化物的脱硫性能,对各种金属氧化物的TPS曲线进行比较发现,其硫化温度及速度都不相同,氧化锰的硫化温度最低,从345K开始有较强的硫化氢吸收峰出现;氧化铜的硫化在373K左右进行;对氧化铁和氧化锌,硫化从473K开始,而氧化锡的硫化在650K左右发生;氧化钙的硫化发生在735K。粒度对TPS曲线有较明显的影响,粒度减  相似文献   
736.
The international marine ecological safety monitoring demonstration station in the Yellow Sea was developed as a collaborative project between China and Russia. It is a nonprofit technical workstation designed as a facility for marine scientific research for public welfare. By undertaking long-term monitoring of the marine environment and automatic data collection, this station will provide valuable information for marine ecological protection and disaster prevention and reduction. The results of some initial research by scientists at the research station into predictive modeling of marine ecological environments and early warning are described in this paper. Marine ecological processes are influenced by many factors including hydrological and meteorological conditions, biological factors, and human activities. Consequently, it is very difficult to incorporate all these influences and their interactions in a deterministic or analysis model. A prediction model integrating a time series prediction approach with neural network nonlinear modeling is proposed for marine ecological parameters. The model explores the natural fluctuations in marine ecological parameters by learning from the latest observed data automatically, and then predicting future values of the parameter. The model is updated in a “rolling” fashion with new observed data from the monitoring station. Prediction experiments results showed that the neural network prediction model based on time series data is effective for marine ecological prediction and can be used for the development of early warning systems.  相似文献   
737.
In this semi-arid area, many studies focused on the two-phase vegetation pattern were carried out to explore a changing vegetation trajectory on degraded land. However, this study conducted an analysis of a two-phase vegetation pattern and explored the successional vegetation trajectories in a positive succession without disturbance. In this work, 60 randomly distributed plots (1?×?1 m) were invested on four abandoned land areas (4-, 12-, 22-, and 50-year abandoned land) to determine attributes of vegetation, and soil physical and nutritional properties. It was found that vegetation distribution development went from homogeneous on 4-year abandoned land to heterogeneous on 50-year abandoned land, with a positive succession. Meanwhile, there was a significant difference in soil physical and nutritional properties for the inside and outside of vegetation patches. Vegetation patches can supply better soil physical and nutritional properties for vegetation than bare patches along the abandoned time. Vegetation diversity changes without a regular trend which may be due to the effect of environment and interspecies competition. This work picked up the slack for vegetation patterns succession research and provided a quantitative analysis approach.  相似文献   
738.
This study investigates the quality of stormwater runoff from a driveway in the southwest mountainous urban area of Chongqing, China, from 2010 to 2011. The results showed that the mean concentrations of chemical oxygen demand (COD), total nitrogen (TN), and total phosphorus (TP) were 4.1, 2.4, and 2.2 times the grade V levels of the national surface water standard of China. The pollutant concentration peak preceded or synchronized with the rainfall intensity peak and occurred 10 min after the runoff started. The significant high pollutant concentration in the initial stage of the rainfall suggested that first flush control is necessary, especially for the most polluted constitutes, such as total suspended solids, COD, and TN. Three potential pollution sources were identified: the atmospheric dry and wet deposition (TN, NO3 ?-N, NH4 +-N, and DCu), the road sediment and materials (total suspended solids, COD, and TP), and the vehicle emissions (DPb and DZn). Therefore, this study indicates that reductions in road sediments and material pollution and dry and wet deposition should be the priority factors for pollution control of road stormwater runoff in mountainous urban areas.  相似文献   
739.
采用膜分离—变压吸附耦合工艺处理DQ催化剂载体生产过程产生的高浓度挥发性有机物(VOCs)废气。实验结果表明:在进气正己烷和非甲烷总烃的质量浓度分别为95 000~212 000 mg/m3和100 000 ~220 000 mg/m3、渗余侧压力0.25 MPa、渗透侧真空度0.09 MPa、进气流量15 Nm³/h的条件下,膜分离单元对废气中正己烷及非甲烷总烃的平均去除率分别为97.88%和97.29%;变压吸附单元对正己烷及非甲烷总烃的平均去除率分别为99.35%和99.33%;整套装置对正己烷及非甲烷总烃的平均总去除率分别为99.99%和99.98%。平均正己烷回收率达95.56%。处理后废气中非甲烷总烃质量浓度小于70 mg/ m3,达到北京市DB 11/ 447—2007 《炼油与石油化学工业大气污染物排放标准》的一级指标。  相似文献   
740.
A single-plant biobased composite material was prepared from fibre and matrix constituents produced from the castor plant, ricinus communis. It is shown that the mechanical properties of the castor plant fibres are comparable to those of other bast fibres and that the stiffness and strength characteristics of the castor fibre/polyamide 11 biocomposite compare well with those of other natural fibre composites. By using a biobased thermoplastic matrix material the reliance on non-renewable feedstock sources is reduced and end-of-lifetime recyclability is improved. The analysis of the environmental performance of the new castor plant composite suggests that the biobased material has great potential as a sustainable alternative replacing glass fibre-reinforced plastics.  相似文献   
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