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The influence of high-yield-water characteristics on productivity of CBM wells and expulsion and production method carried out in Yanchuannan block of the Ordos basin, China 被引量:2
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作者 Xing-Long ZHAO Zu-Wei XU +2 位作者 Da-Zhen TANG Hao XU Shu TAO 《Journal of Coal Science & Engineering(China)》 2013年第4期514-521,共8页
In order to further study the influence of high-yield-water on the productivity of CBM (coalbed methane) wells and the expulsion and production method carried out in CBM wells, by means of analyzing and researching ... In order to further study the influence of high-yield-water on the productivity of CBM (coalbed methane) wells and the expulsion and production method carried out in CBM wells, by means of analyzing and researching production characteris- tics and geologic condition of the CBM wells with high water yield in Yanchuannan block located at the eastern margin of Or- dos basin, the mechanism of high water yield decreasing the productivity of CBM well was discussed, and the expulsion and production method for this type of CBM well was proposed. The results show that high water yield would decrease the produc- tivity of CBM wells, and the mechanism is: first, in some circumstances, high water yield could reflect that there was dissipa- tion during the process of coalbed methane reservoir forming, which would lower the gas saturation of coal gas reservoir and reduce the productivity of CBM well; second, a large quantity of coalbed methane dissipated in the form of solution gas, caus- ing the practical reservoir pressure when gas appeared in casing to be lower than critical desorption pressure of the coal bed; finally, the CBM well with high water yield would have higher requirements of discharge and mining installation, system and continuity, and any link with problems would have a great impact on the well's productivity and would increase the difficulty of discharge and mining. In the case of wells with high water yield, the key is to select applicable discharge and mining installa- tion, which should be able to make the bottom hole flowing pressure decline smoothly and fast, and make the wells produce gas as quickly as possible but able to slow down the rate of discharge and mining properly when gas has appeared. In addition, in view of the CBM wells with high water yield, an installation lectotype method based on Darcy's law was proposed, which was found with good accuracy and practicability through field application. 展开更多
关键词 Ordos basin Yanchuannan block CBM high water yield influence on productivity expulsion and productionmethod installation lectotype
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The influence of green barrier on China's agricultural products trade and countermeasure analysis
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作者 Ren Jing Huang 《International Journal of Technology Management》 2015年第11期20-22,共3页
With the change and development of modern international new situation, some of the more traditional tariff barriers declining, green barriers to trade with their own unique and distinct era characteristic become the m... With the change and development of modern international new situation, some of the more traditional tariff barriers declining, green barriers to trade with their own unique and distinct era characteristic become the mainstream of the development of international trade today. Along with the Western Europe in some developed countries protect their existing markets, with the name of environmental protection and green trade protection measures, construction of the green trade barriers, so in practice to a certain extent seriously hindered the of some agricultural products sales and foreign trade credits. In this paper, starting from the factors and characteristics of green barrier produces, analyzes the causes of the green trade barrier of positivity and negativity, and contact our country agricultural product export and the present situation of the green trade barrier causes, analysis the reason of the thwarted by the green trade barrier, the feasibility of the agricultural development status in China, and puts forward some operable countermeasures, in order to adapt to the new situation of the development of foreign trade of agricultural products in China and good circulation. 展开更多
关键词 Green barriers The trade of agricultural products influence COUNTERMEASURES
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Erosion and Sediment Production in Small Watershed in Purple Hilly Areas and Prevention Techniques 被引量:4
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作者 Zhang Bao-hua, He Yu-rong, Zhou Hong-yi, Zhu BoInstitute of Mountain Hazards and Environment, Chinese Academy of Sciences, Chengdu 610041, Sichuan, China Department of Geography, Liaocheng University, Liaocheng 252059, Shandong, China 《Wuhan University Journal of Natural Sciences》 CAS 2003年第03B期1041-1046,共6页
Purple Soil distributes extensively and mainly in China. Because of abundant easily weatherable parent rocks/ materials and unstable soil structure, and also influenced by parent materials, usage systems, and slope gr... Purple Soil distributes extensively and mainly in China. Because of abundant easily weatherable parent rocks/ materials and unstable soil structure, and also influenced by parent materials, usage systems, and slope gradients, erosion and sediment production of purple soils are very severe with main fashions of water erosion and gravitational erosion. Basing on observed data in small watersheds, rainfall erosivity, vegetation coverage, previous soil water content, flow and relating factors such as climate, topograph of small watershed, land usage, and soil kinds are all the influence factors of erosion and erodibility of purple soil as well as sediment production and transport in small watershed of purple hilly areas. The effective technological countermeasures of ecosystem restoration, agricultural tillage for water conservation and erosion prevention, agriculture project, and soil changing for fertility and anti-erosion were provided. 展开更多
关键词 purple soil characteristics of erosion and sediment production) influence factors prevention techniques
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Effects of Environmental Conditions and Aboveground Biomass on CO2 Budget in Phragmites australis Wetland of Jiaozhou Bay,China 被引量:2
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作者 GAO Manyu KONG Fanlong +2 位作者 XI Min LI Yue LI Jihua 《Chinese Geographical Science》 SCIE CSCD 2017年第4期539-551,共13页
Estuarial saline wetlands have been recognized as a vital role in CO_2 cycling.However,insufficient attention has been paid to estimating CO_2 fluxes from estuarial saline wetlands.In this study,the static chamber-gas... Estuarial saline wetlands have been recognized as a vital role in CO_2 cycling.However,insufficient attention has been paid to estimating CO_2 fluxes from estuarial saline wetlands.In this study,the static chamber-gas chromatography(GC) method was used to quantify CO_2 budget of an estuarial saline reed(Phragmites australis) wetland in Jiaozhou Bay in Qingdao City of Shandong Province,China during the reed growing season(May to October) in 2014.The CO_2 budget study involved net ecosystem CO_2 exchange(NEE),ecosystem respiration(Reco) and gross primary production(GPP).Temporal variation in CO_2 budget and the impact of air/soil temperature,illumination intensity and aboveground biomass exerted on CO_2 budget were analyzed.Results indicated that the wetland was acting as a net sink of 1129.16 g/m^2 during the entire growing season.Moreover,the values of Reco and GPP were 1744.89 g/m^2 and 2874.05 g/m^2,respectively;the ratio of Reco and GPP was 0.61.Diurnal and monthly patterns of CO_2 budget varied significantly during the study period.Reco showed exponential relationships with air temperature and soil temperature at 5 cm,10 cm,20 cm depths,and soil temperature at 5 cm depth was the most crucial influence factor among them.Meanwhile,temperature sensitivity(Q10) of Reco was negatively correlated with soil temperature.Light and temperature exerted strong controls over NEE and GPP.Aboveground biomass over the whole growing season showed non-linear relationships with CO_2 budget,while those during the early and peak growing season showed significant linear relationships with CO_2 budget.This research provides valuable reference for CO_2 exchange in estuarial saline wetland ecosystem. 展开更多
关键词 net ecosystem CO_2 exchange ecosystem respiration gross primary production influencing factor estuarial saline reed wetland static chamber-GC method
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Analysis of the influencing factors of PAEs volatilization from typical plastic products 被引量:5
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作者 Weidong Chen Chenchen Chi +3 位作者 Chen Zhou Meng Xia Cees Ronda Xueyou Shen 《Journal of Environmental Sciences》 SCIE EI CAS CSCD 2018年第4期61-70,共10页
The primary emphasis of this research was to investigate the foundations of phthalate(PAEs) pollutant source researches and then firstly confirmed the concept of the coefficient of volatile strength, namely phthalat... The primary emphasis of this research was to investigate the foundations of phthalate(PAEs) pollutant source researches and then firstly confirmed the concept of the coefficient of volatile strength, namely phthalate total content in per unit mass and unit surface area of pollutant sources. Through surveying and evaluating the coefficient of volatile strength of PAEs from typical plastic products, this research carried out reasonable classification of PAEs pollutant sources into three categories and then investigated the relationship amongst the coefficient of volatile strength as well as other environmental factors and the concentration level of total PAEs in indoor air measured in environment chambers.Research obtained phthalate concentration results under different temperature, humidity,the coefficient of volatile strength and the closed time through the chamber experiment. In addition, this study further explored the correlation and ratio of influencing factors that affect the concentration level of total PAEs in environment chambers, including environmental factors, the coefficient of volatile strengths of PAEs and contents of total PAEs in plastic products. The research created an improved database system of phthalate the coefficient of volatile strengths of each type of plastic goods, and tentatively revealed that the volatile patterns of PAEs from different typical plastic goods, finally confirmed that the coefficient of volatile strengths of PAEs is a major factor that affects the indoor air total PAEs concentration, which laid a solid foundation for further establishing the volatile equation of PAEs from plastic products. 展开更多
关键词 Phthalate esters Air The coefficient of volatile strength Typical plastic products The influencing factors
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Impact of food to microorganism ratio and alcohol ethoxylate dosage on methane production in treatment of low-strength wastewater by a submerged anaerobic membrane bioreactor
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作者 Yulun Nie Xike Tian +1 位作者 Zhaoxin Zhou Yu-You Li 《Frontiers of Environmental Science & Engineering》 SCIE EI CAS CSCD 2017年第6期47-57,共11页
The effects of food to microorganism (FIM) ratio and alcohol ethoxylate (AE) dosage on the methane production potential were investigated in treatment of low-strength wastewater by a submerged anaerobic membrane b... The effects of food to microorganism (FIM) ratio and alcohol ethoxylate (AE) dosage on the methane production potential were investigated in treatment of low-strength wastewater by a submerged anaerobic membrane bioreactor (SAnMBR). The fate of AE and its acute and/or chronic impact on the anaerobic microbes were also analyzed. The results indicated that AE had an inhibitory effect to methane production potential (lag-time depends on the AE dosage) and the negative effect attenuated subsequently and methane production could recover at FIM ratio of 0.088-0.357. VFA measurement proved that AE was degraded into small molecular organic acids and then converted into methane at lower FIM ratio (FIM 〈 0.158). After long-term acclimation, anaerobic microbe could cope with the stress of AE by producing more EPS (extracellular polymeric substances) and SMP (soluble microbial products) due to its self-protection behavior and then enhance its tolerance ability. However, the methane production potential was considerably decreased when AE was present in wastewater at a higher FIM ratio of 1.054. Higher AE amount and FIM ratio may destroy the cell structure of microbe, which lead to the decrease of methane production activity of sludge and methane production potential. 展开更多
关键词 Anaerobic membrane bioreactor AnMBR F/M ratio Surfactant Wastewater Methane production influence
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Characterizing scientific elites:publication and citation patterns of outstanding scientists in biomedicine
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作者 Junwan Liu Chenchen Huang +3 位作者 Xiaofei Guo Yilin Wang Rui Wang Lixin Xie 《Data Science and Informetrics》 2022年第1期42-54,共13页
Science is principally driven by the efforts of a small fraction of researchers publishing the m ajority of scientific research and garnering the m ajority of citations.The quantitative analysis of outstanding scienti... Science is principally driven by the efforts of a small fraction of researchers publishing the m ajority of scientific research and garnering the m ajority of citations.The quantitative analysis of outstanding scientists’publication and citation patterns provides a new perspective fo r understanding of scientific talents.The study of outstanding scientists can enhance our understanding of the publication and citation patterns and their scientific careers more generally.Based on 35,315 research papers from the biomedical field,we analyzed the academic productivity and influence characteristics of 244 outstanding scientists in biomedical field.Several interesting patterns are observed as follows:as outstanding scientists’career age increased,(1)their scientific output shows a trend of decreasing after increasing,(2)their academic influence shows a trend of continuous growth,(3)their number of the co-authors in their scientific career first increases and then remains stable,and(4)the number of their research areas first decreases and then increases. 展开更多
关键词 Outstanding scientists Scientific career Quantitative analysis Academic productivity and influence
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