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131.
甲烷排放管控是国际石油公司推动低碳能源转型的一项重要举措,也是达成净零碳排放愿景的一个重要手段。研究发现,国内外石油公司的油气生产活动水平、甲烷排放控制水平、甲烷排放核算方法等3个方面均存在较大差异性。我国油井单井产量低,地面工程量大、工艺复杂,流程工艺中甲烷排放突出,油气系统甲烷排放水平较高,油气生产甲烷排放控制水平与国外石油公司相比尚有较大差距,与国外甲烷排放核算方法也存在较大差异性。着眼于甲烷排放管控,我国石油公司应充分衡量甲烷排放现状、生产活动水平、甲烷排放控制措施经济性和适用性等多重因素,严格控制潜在甲烷排放节点,并进一步做好甲烷排放检测、监测和数据统计工作,持续完善甲烷排放报告和核查体系。 相似文献
132.
重金属在牡蛎(Crassostrea virginica)中的生物积累及其影响因素的研究 总被引:6,自引:0,他引:6
牡蛎软体、贝壳和沉积物中Cd、Cr、Cu、Fe、Mn、Pb和Zn等重金属元素被同步分析研究.研究结果表明,重金属在牡蛎中的生物积累是牡蛎自身的新陈代谢、重金属元素的地球化学性质和环境诸因素综合影响的结果,其中牡蛎的生理作用对重金属在软体中的积累所产生的影响尤为重要,而贝壳中重金属的积累对来自环境的影响更为敏感. 相似文献
133.
浅水型湖泊蓝藻水华预警监测工作的思考 总被引:3,自引:0,他引:3
浅水型湖泊的富营养化进程不断加快,呈现出蓝藻水华暴发现象是逐年增加的。太湖作为长江中下游地区典型的浅水型湖泊更因近年来蓝藻水华频发的态势引起了政府和社会的广泛关注。为确保太湖地区饮水安全,提高政府应对蓝藻水华的能力,对太湖蓝藻水华进行预警监测是判断其发展趋势以及制定相应对策的重要手段。着力分析和总结了太湖蓝藻水华预警监测工作的主要内容,从预警监测工作的统筹、预警监测体系的建立、技术分析、预警监测的启动、分级与评价、预警信息的发布、预警监测的终止到预警监测的保障机制等,以利于同行们更好地应对浅水型湖泊蓝藻水华的发生。 相似文献
134.
Yang Xie Hua Zhong Zhixiong Weng Xinbiao Guo Satbyul Estella Kim Shaowei Wu 《Frontiers of Environmental Science & Engineering》2023,17(7):90
135.
The impact of land use and land cover changes on land surface temperature in a karst area of China 总被引:3,自引:0,他引:3
Satellite images have been used extensively to study temporal changes in land use and land cover (LULC) in China. However, few studies have been conducted in the karst areas despite the large area and population involved and the fragile ecosystem. In this study, LULC changes were examined in part of Guizhou Province of southern China from 1991 to 2001 based on Landsat Thematic Mapper (TM) images of November 7, 1991, December 5, 1994, and December 19, 2001. Land surface temperature (LST) and normalized difference vegetation index (NDVI) were computed based on LULC types. The results show that agricultural land decreased, while urban areas expanded dramatically, and forest land increased slightly. Barren land increased from 1991 to 1994, and then decreased from 1994 to 2001. These changes in LULC widened the temperature difference between the urban and the rural areas. The change in LST was mainly associated with changes in construction materials in the urban area and in vegetation abundance both in the urban and rural areas. Vegetation had a dual function in the temperatures of different LULC types. While it could ease the warming trend in the urban or built-up areas, it helped to keep other lands warmer in the cold weather. The study also reveals that due to the government's efforts on reforestation, rural ecosystems in some of the study area were being restored. The time required for the karst ecosystem to recover was shorter than previously thought. 相似文献
136.
Effects of environment, vehicle and driver characteristics on risky driving behavior at work zones 总被引:1,自引:0,他引:1
Jinxian Weng Qiang Meng 《Safety Science》2012,50(4):1034-1042
This study aims to analyze the effects of environment, vehicle and driver characteristics on the risky driving behavior at work zones. A decision tree is developed using the classification and regression tree (CART) algorithm to graphically display the relationship between the risky driving behavior and its influencing factors. This approach could avoid the inherent problems occurred in the conventional logistic regression models and further improve the model prediction accuracy. Based on the Michigan M-94/I-94/I-94BL/I-94BR highway work zone driving behavior data, the decision tree comprising 33 leaf nodes is built. Bad weather, poor road and light conditions, partial/no access control, no traffic control devices, turning left/right and driving in an old vehicle are found to be associated with the risky driving behavior at work zones. The middle-aged drivers, who are going straight ahead in their vehicles with medium service time and equipped with an airbag system, are more likely to take risky behavior at lower work zone speed limits. Further, the middle-aged male drivers engage in risky driving behavior more frequently than the middle-aged female drivers. The number of lanes exhibits opposing effects on risky behavior under different traveling conditions. More specifically, the risky driving behavior is associated with the single-lane road under bad light or weather conditions while drivers are more likely to engage in risky behavior on the multi-lane road under good light conditions. 相似文献
137.
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139.
The mechanical properties, including strength, deformational behavior, and wetting softening phenomena of municipal solid waste incinerator (MSWI) bottom ash are one of the major concerns for reuse applications. However, owing to the complex constituents of municipal solid waste, the properties of MSWI bottom ash are often highly variable. A series of artificial specimens with controlled chemical components were tested in this study. The test results show that the artificial bottom ash possesses the following mechanical characteristics: (1) for the strength, the frictional angles of the bottom ash under dry and saturated conditions vary from 34.8° to 51.1° and 26.0° to 37.2°, respectively; (2) for the deformation, the shear stiffness increases with the normal stress arises and degrades upon increased shearing; (3) significant wetting degradation of the strength and stiffness were observed.The multi-variable regression analysis was conducted to evaluate the associated influence of the chemical components on the strength. Among the evaluated components, Fe2O3 and Al2O3 are key factors; an increase in either results in higher strength at both dry and saturated conditions. The results were used to propose empirical relationships for ?dry and ?sat, expressed in terms of Fe2O3 and Al2O3. Accordingly, a strength classification chart is proposed for engineering purposes. 相似文献
140.
Ching Li Cheng-Ping Wang Sung-Ta Liu Li-Hsin Weng 《Journal of environmental management》2010,91(11):2342-2348
This study employs the notion of environmental value orientations as an approach to examine the relationships between forest value orientations and demand on services available in the National Forest Recreation Areas in Taiwan. Data for this investigation were collected from on-site, off-site, and online surveys (n = 1919). Statistical results suggest that the authorities should highlight the role of Taiwanese forest as public property with aesthetic, historic, and cultural values, and the use of more comprehensive dimensions of environmental value orientations is warranted when using value-related variables to address natural resource management issues. The correlation evidence of service demands of tourists with different forest value orientations indicates that the authorities should focus on maintaining and improving basic services available in the National Forest Recreation Areas. 相似文献