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1.
Estimation and prediction of black carbon emissions in Beijing City   总被引:1,自引:0,他引:1  
Black carbon is a by-product of incomplete combustion of carbon containing fuels. It can alter atmospheric radiation property and make adverse impacts on human health. The energy consumption in Beijing City depends largely on coal burning. Recently, Beijing City has been performing the municipal energy structure adjustment as a tool for air pollution abatement, aiming at the air quality goal for the Beijing 2008 Olympic Games. Based on Beijing energy use data in 2000, combined with emission factors of major sources of black carbon, the emission of black carbon in Beijing City is estimated to be 7.77 Gg. Coke, raw coal and biomass as non-commercial energy are the main contributors to municipal black carbon emissions. Based on Beijing energy planning in the year 2008, the emission of black carbon in 2008 will be 2.97 Gg if the contribution from biomass is not taken into account. Assuming that the black carbon emission from rural biomass in 2008 is the same as that in 2004, the biomass burning will be the largest emitter of black carbon to Beijing City in 2008.  相似文献   

2.
肖卫 《科技信息》2013,(24):185-187
Translating is a cross-cultural activity,and value is an important element of it.Therefore,it is undoubtedly that value will play an important role in English-Chinese translation,which is a learned organization of rules for making choices and resolving conflicts.These rules may serve to teach us to distinguish right and wrong,good and evil,what can be done and what cannot be.Accordingly,in this thesis,the notable differences in values in English-Chinese translation will be firstly dealt with,and then the main presentations of the value differences in English-Chinese translation will be analyzed.Furthermore,some effective methods to solve value-bound problems in English-Chinese translation will be discussed.  相似文献   

3.
《科技导报(北京)》2014,32(8):94-96
正博士后[美国]Pennsylvania State University Pennsylvania State University opens a postdoctoral fellowshipposition.The focus of the research will be the study of geneticvariants for the involvement in cancer risk in human populations.Large case-control populations will be screened in geneticassociation studies,in vivo measurements of metabolite levels inhuman samples will be compared to genotype,and in vitro activityassays and expression studies will be performed to assessfunction of genetic variants.See the following link for  相似文献   

4.
Hydrogen metallurgy is a technology that applies hydrogen instead of carbon as a reduction agent to reduce CO_2 emission, and the use of hydrogen is beneficial to promoting the sustainable development of the steel industry. Hydrogen metallurgy has numerous applications,such as H_2reduction ironmaking in Japan, ULCORED and hydrogen-based steelmaking in Europe; hydrogen flash ironmaking technology in the US; HYBRIT in the Nordics; Midrex H_2TM by Midrex Technologies, Inc.(United States); H_2FUTURE by Voestalpine(Austria); and SALCOS by Salzgitter AG(Germany). Hydrogen-rich blast furnaces(BFs) with COG injection are common in China. Running BFs have been industrially tested by AnSteel, XuSteel, and BenSteel. In a currently under construction pilot plant of a coal gasification–gas-based shaft furnace with an annual output of 10000 t direct reduction iron(DRI), a reducing gas composed of 57 vol% H_2 and 38 vol% CO is prepared via the Ende method. The life cycle of the coal gasification–gas-based shaft furnace–electric furnace short process(30 wt% DRI + 70 wt% scrap) is assessed with 1 t of molten steel as a functional unit. This plant has a total energy consumption per ton of steel of 263.67 kg standard coal and a CO_2 emission per ton of steel of 829.89 kg, which are superior to those of a traditional BF converter process. Considering domestic materials and fuels, hydrogen production and storage, and hydrogen reduction characteristics, we believe that a hydrogen-rich shaft furnace will be suitable in China. Hydrogen production and storage with an economic and large-scale industrialization will promote the further development of a full hydrogen shaft furnace.  相似文献   

5.
The types of substances in coal rock used by microbes,the specific ways in which microbes produce secondary biogenic gas(SBG)and whether substances exist in the coal seam for the formation of a large amount of SBG are important basic scientific issues.This paper conducts a systematic and comprehensive research study on the above issues using methods such as the isotopic tracing of gas,the analysis of coal organic geochemistry,and gas-producing simulation experiments of coal.Results show that the formation of SBG is by the microbial reduction of CO2and the SBG-producing coal seam undergoes microbial degradation.The thermogenic heavy gaseous hydrocarbons have also been degraded by microorganisms and possibly transformed into microbialoriginated CO2.A large amount of CO2,a relatively large amount of H2and a certain amount of heavy gaseous hydrocarbons may form in the thermal evolution of coal.These substances and the microbial-originated CO2and coal seam water can finally become parent materials of SBG.These components are rich in coal seams of medium–low thermal evolution,which should be the main coal seams for SBG formation and exploration.  相似文献   

6.
金怡 《科技信息》2013,(36):286-288
In this paper, 3 different foreign/second language-learning classrooms will be presented. There will be a comparison between those classes and TEFL classes in China, including background of different education systems and different teaching methodologies and approaches. In the end, some suggestions will be given to Chinese TEFL classes. The aim is mainly to show the differences between language teaching and learning in the UK and in China, and also to give people a chance to think deeply over the current TEFL teaching and learning in China.  相似文献   

7.
Shaker screen is one of important equipments in the industry of oil,metallurgy,coal and timbering. The movement locus of shaker screen affects the capacity and efficiency of shaker screen to split the solid particle from crude ore directly.To test movement of shaker locus,two eddy current transducers are employed. A discussion of the usage of these eddy current transducer to test and acceleration sensors will be made.The experiment results from a real elliptic shaker screen have good agree with the design requirements.  相似文献   

8.
Schema theory indicates that prior knowledge forms a schema in the mind and this will inevitably influence reading comprehension. Therefore, in the teaching of reading, teachers should find ways to activate the schemata in the mind of the students. Titles, headlines and pictures in a text may serve the function. All texts are related to cultnre to some degree, especially in the case of texts introducing foreign cultures. Therefore, it is also important to integrate cultural factors in teaching, which will form new schemata in the mind of the students. Besides that, teaching materials should be chosen in accordance with the students' level of knowledge. New knowledge should be kept in an appropriate proportion to the old knowledge. Only in this way can the schemata stored in the mind of the students be activated easily, and new knowledge will also be acquired at the same time.  相似文献   

9.
Hybrid wheat is recognized as a preferred approach to improve wheat yield,and it will be a competi-tion focus in high-tech seed industry in the future. We have made a breakthrough for the first time in...  相似文献   

10.
《科技导报(北京)》2013,31(2):90-92
博士后[美国]American Philosophical Society American Philosophical Society(APS)is pleased to announce a new fellowship program:the American Philosophical Society Postdoctoral Fellowship in Biological Science.Applicants must have received the PhD from an institution in the United States and should be either entering or already affiliated with a U.S.institution at the postdoctoral level.Applications will be judged on their innovative nature.Applications for academic year2013-2014,eligible forrenewal in academic year2014-2015,will be based on existing problems in  相似文献   

11.
煤制甲醇燃料矿井到油箱的生命周期评价   总被引:4,自引:0,他引:4  
为探讨中国煤制甲醇技术的发展和应用,设计了5种从矿井到油箱过程的煤制甲醇方案,特别针对多联产战略制订了3种甲醇、电的多联产技术路线。运用生命周期评价方法对这些方案的环境影响、经济性和能源利用效率进行评价,并根据国情计算了7种主要污染物排放量,对若干参数进行了敏感性分析。结果表明:甲醇、电的多联产系统在环境影响、经济性和能源利用效率方面都要优于单产系统。该文的计算结果和方法可以作为未来煤制甲醇系统选择的参考。  相似文献   

12.
二十世纪九十年代以来,全球气候变暖,灾难性的气候现象频繁发生,这主要归因于温室气体(主要为二氧化碳CO2)引发的温室效应。探索可行的CO2控制技术路线是本世纪能源与环境科学的一个主要议题。为此,要探索控制温室气体的一体化理论与开拓相关的新技术。本文分析了控制CO2的技术难点,指出了CO2控制应在能源系统革新上寻找潜力和突破口。本文剖析了能源系统集成新机理,提出了CO2控制一体化系统——燃烧与CO2分离一体化系统、清洁燃料生产与CO2分离一体化系统,以及适合我国国情的控制CO2的全国能源网络技术路线图。  相似文献   

13.
以天然气为原料,构建全新天然气制烯烃发电多联产系统,实现制烃系统和联合循环发电系统的有机耦合.采用Aspen Plus模拟软件对该系统进行流程模拟,计算出各物流的(火用)值,并对各单元进行热力学分析.输入输出(火用)分析结果表明,当甲醇合成单元的未反应气全部循环时系统的(火用)效率最高,为53.5%.从系统的(火用)损失量来看,(火用)损主要发生在天然气制合成气和尾气发电单元,两者分别占系统总(火用)损的36.4%和42.1%.  相似文献   

14.
通过对典型燃气轮机总能系统热力学分析,认为(火用)效率是各类燃气轮机总能系统具有可比性的热力学完善性指标,通过(火用)分析可查明(火用)损失分布。文中指出提高(火用)效率的主要途径是提高燃气透平进气温度,它是影响总能系统(火用)效率的主要因素,而余热的利用方式对其影响不大。从热能综合利用的角度来看,总能系统宜兼有高的热利率与(火用)效率,因此,对总能系统进行能分析仍属必要。  相似文献   

15.
为了科学全面地评价电厂锅炉系统能效,采用模糊综合评判法,从工程实践的技术经济性角度出发,以锅炉系统能效为一级目标层,选取了关于燃料水平、设备水平和运行状况作为二级准则层,并将具体影响因素归类整理为三级指标层.分析各因素值变化对系统能效的指向性影响,确定隶属度函数,通过专家组评议求得权重向量,建立了一套完整的锅炉系统能效模糊综合评判体系.该体系可对锅炉系统能效进行定量分析,评价某层面的能效利用现状,为后续优化指明方向,也可用于机组间的竞赛对比.  相似文献   

16.
针对热泵装置用能效率的计算方法进行了探讨,分析了热泵提升式系统用能效率的两种计算方法.以热能效率和效率作为评价指标,对热泵提升式系统和锅炉提升式系统这两种低温供热系统的用能情况进行了能量分析与分析.计算结果表明,热泵提升式系统的热能效率要低于锅炉提升式系统的热能效率,但其效率要高于后者的效率;当低温热源的供水温度较高可直接用于供暖时,应将低温热源的热量或作为"代价"计入供给能或供给来计算热泵装置的用能效率.  相似文献   

17.
开式地表水源热泵系统取水能耗限值确定方法   总被引:2,自引:0,他引:2  
对于开式地表水源热泵来说,取水能耗是决定系统节能性的关键因素.在水源热泵机组能耗模型、取水能耗模型等的基础上建立了开式地表水源热泵系统的能效比耦合模型,并得到了基于节能率的地表水源热泵系统的不同取水温度和不同取水能耗下的耦合限值.通过实际案例,计算得到了地表水源热泵系统不同取水温度下以及不同系统方式下的系统节能率,建立了开式地表水源热泵系统取水能耗限值方法.  相似文献   

18.
通过综合分析目前矿井制冷系统的现状,发现在满足矿井降温要求的前提下,优化矿井内降温系统的各耗能环节以及降低降温系统成本是提高矿井降温系统的经济性和节约能源的关键。为了找出提高矿井制冷系统能效的关键因素,从矿井制冷系统的能耗指标出发,通过对几种能效指标的对比分析,最终采用能效比EER(Energy Efficiency Ratio)指标进行分析。通过对南非Harmony金矿、孙村煤矿、唐口煤矿冰冷降温和井下集中制冷等四种系统形式,用对比分析的方法分别计算了它们的能效比、各设备的效率比等,结果表明采用冰制冷降温系统的能效比最高,唐口煤矿达到1.92;另一方面,冷水机组的功率比相对较高,说明降低冷水机组的功率是提高制冷系统能效比的关键。该结论将对降低矿井能耗、提高经济性起到一定的指导作用。  相似文献   

19.
分析了地表水源热泵系统的冷却水温度、流量和扬程等因素对水源热泵系统能效比的影响.以空调冷负荷和冷冻水参数作为控制目标,提出了包含水源热泵机组能耗的冷却水系统能效比分析模型.利用该模型分析了地表水直接进入热泵机组的地表水源热泵系统和以板式换热器间接换热的地表水源热泵系统的运行能效.结果显示,冷却水温度变化对能效比的影响大于冷却水系统静扬程变化对能效比的影响.部分负荷工况下冷却水温度为23~24℃时系统能效比达到最大值.  相似文献   

20.
目前为了解决压缩空气储能储气室的问题,液态空气储能和液态CO2储能得到了国内外广泛关注及研究。本文针对这两大储能系统,借助ASPEN PLUS软件搭建了热力学物理模型,并借助?分析对两大储能系统进行热力学和关键参数敏感性研究分析。研究表明:液态空气储能系统?损失主要发生在压缩机及蓄热蓄冷装置上,分别占比45.02%、37.61%。液态CO2储能系统?损失主要发生在低温膨胀机、压缩机及蓄冷蓄热装置上,分别占比26.99%、23.88%、30.41%。从电-电转化效率方面:在绝热条件下,两大储能系统由于在充放电过程能量消耗大,电-电转化效率都低于55%,相比液态空气储能,液态CO2储能效率高。从系统成熟度方面:液态空气储能已得到工程应用,而液态CO2储能还在研究阶段,未得到工程化应用。从投资成本方面;液态CO2储能单位千瓦投资成本高于液态空气储能约40%。  相似文献   

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