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1.
一、太阳与太阳能 众所周知,在浩翰的宇宙中有一颗离我们最近的恒星--太阳.现代科学表明太阳距离我们相当遥远,达到1.5亿km,虽然太阳光的传播速度为30万km/s,但我们在地球上所见到的光线已经是8min之前从太阳发出的光线了.太阳的直径为139万km,而地球直径仅为1.27万km,太阳的直径约为地球直径的109倍,其体积则比地球大130多万倍.尽管如此,由于距离遥远,太阳张角仅仅为32′.  相似文献   

2.
一物料干燥的能耗与环境污染 干燥作业涉及国民经济的广泛领域,是许多行业不可缺少的工序.在粮食、食品、果品、药材、木材、皮革、橡胶和陶瓷等许多产品的加工处理过程中,干燥作业对产品的质量和成本影响很大.  相似文献   

3.
燃料电池技术的发展现状   总被引:4,自引:0,他引:4  
燃料电池是不经燃烧过程直接把燃料的化学能转化为电能的装置,具有能量转换效率高、污染物排放量少的独特优点.简述燃料电池工作原理,比较各类燃料电池的特性,并介绍目前燃料电池在国内外的应用现状,同时指出目前影响燃料电池商品化的主要因素.  相似文献   

4.
基于CFD技术的迷宫式油气分离器优化设计   总被引:1,自引:0,他引:1  
应用计算流体动力学软件FLUENT对汽车发动机气门室罩内的迷宫式油气分离器进行三维两相流场和油滴颗粒分离效率的数值模拟.通过计算四种分离器结构参数(出口位置、出口直径、V型槽间距和V型槽宽度)下的分离器的分离效率和压降损失,分析了各参数对分离效率的影响,得到分离器性能的规律性结论和分离器的最佳结构参数,用于指导迷宫式油气分离器的设计.  相似文献   

5.
水资源对我国工业发展的影响及对策建议   总被引:2,自引:0,他引:2  
党的十六大提出了全面建设小康社会的奋斗目标,十六届三中全会又强调指出,要树立全面、协调、可持续的发展观,促进经济社会和人的全面发展.树立和贯彻科学的发展观,很重要的一个方面,就是要坚持人与自然的和谐,正确处理发展与资源、环境的关系.水是人类的生命线,因此,水不仅是重要的自然资源,而且是战略资源.  相似文献   

6.
一、生物质能概述 生物质能是人类使用的最古老的能源.随着世界经济持续快速地发展和人口数量迅速地增长,人类对能源的需求必然不断地增加,然而目前人类赖以生存的化石能源却正在迅速地减少.据预测,地球上蕴藏的可以开发利用的煤和石油化石能源将分别在200年、40年内耗竭,而天然气也只能用60年左右.  相似文献   

7.
壳牌基金会是荷兰皇家/壳牌集团设立的全球非赢利机构,旨在为由于能源生产和消费而产生的社会和环境问题制定可持续的解决方案,并充分开发全球化的潜能,以改善弱势群体的发展前景.为了将社会投资与壳牌的核心业务及其作为跨国公司的特点明确联系起来,基金会确定了三大核心领域--可持续能源、可持续社会和可持续交通.(如需了解有关壳牌基金会的更多信息,请访问www.shellfoundation.org)  相似文献   

8.
"十一五"期间钢铁工业的发展,要从人、自然资源、生态环境和科学技术更大的系统内来实现发展,在资源投入、生产、消费及废弃物处理的全过程中,不断提高资源的利用效率,把资源消耗、环境负荷的线性增加,转变为依靠科技进步、生态资源的循环来实现钢铁工业的发展,这种发展是可持续的、是符合科学发展观的本质要求的,济钢从"充分利用煤气资源"寻找到了突破口.  相似文献   

9.
光合光量子传感器校准的一些问题   总被引:1,自引:0,他引:1  
介绍了光合光量子传感器的校准方法,只要有符合国家标准的辐照度标准灯,并用标准灯对适当级别的光谱辐射计进行校准后,就可在日光下供此类仪器定期校准之用.并证明了所介绍方法的实际可行性.由于LI-COR公司随LI-190型仪器发放的使用说明书中有关量子传感器的光谱响应曲线图前后不相一致,且未加说明,文中对此进行了重点论证和讨论.当前并不存在真正意义上的光量子传感器,实际所用的也只有能量传感器,以光量子单位表示的测量结果是经公式计算得出的.此外,还证明了量子单位测量结果与能量单位测量结果关系的一致性,如有需要,在校准时就可同时得出量子的和能量的两种灵敏度,从而免除了由于单位互换带来的误差.  相似文献   

10.
在分析传统实体化视图连接算法的基础上,对EVM算法进行了改进,提出了分布连接算法,加入了选择性批处理思想并在限定时间内实现当DB中源数据发生变化时实体化视图得到相应的更新,确保DW能及时反映DB的现状及OLAP查询的一致性,达到对DW联机维护的目的.  相似文献   

11.
As part of a pilot study investigating the role of microorganisms in the immobilisation of As, Sb, B, Tl and Hg, the inorganic geochemistry of seven different active sinter deposits and their contact fluids were characterised. A comprehensive series of sequential extractions for a suite of trace elements was carried out on siliceous sinter and a mixed silica-carbonate sinter. The extractions showed whether metals were loosely exchangeable or bound to carbonate, oxide, organic or crystalline fractions. Hyperthermophilic microbial communities associated with sinters deposited from high temperature (92–94°C) fluids at a variety of geothermal sources were investigated using SEM. The rapidity and style of silicification of the hyperthermophiles can be correlated with the dissolved silica content of the fluid. Although high concentrations of Hg and Tl were found associated with the organic fraction of the sinters, there was no evidence to suggest that any of the heavy metals were associated preferentially with the hyperthermophiles at the high temperature (92–94°C) ends of the terrestrial thermal spring ecosystems studied.  相似文献   

12.
尿素喷射计量试验是完成车载尿素喷射计量装置的功能开发和性能考核的重要环节,而该试验内容离不开尿素喷射计量试验控制系统(UCDS)的开发,本文基于尿素喷射计量系统(UDS)的组成,开发出了试验所需的控制系统的硬件平台,用模块化的设计思想对UDCS控制器进行了方案设计,测试结果与设计目标一致,达到了尿素喷射计量试验的要求.  相似文献   

13.
Characterization and prediction of biomass pyrolysis products   总被引:2,自引:0,他引:2  
In this study some literature data on the pyrolysis characteristics of biomass under inert atmosphere were structured and analyzed, constituting a guide to the conversion behavior of a fuel particle within the temperature range of 200-1000 °C. Data is presented for both pyrolytic product distribution (yields of char, total liquids, water, total gas and individual gas species) and properties (elemental composition and heating value) showing clear dependencies on peak temperature. Empirical relationships are derived from the collected data, over a wide range of pyrolysis conditions and considering a variety of fuels, including relations between the yields of gas-phase volatiles and thermochemical properties of char, tar and gas. An empirical model for the stoichiometry of biomass pyrolysis is presented, where empirical parameters are introduced to close the conservation equations describing the process. The composition of pyrolytic volatiles is described by means of a relevant number of species: H2O, tar, CO2, CO, H2, CH4 and other light hydrocarbons. The model is here primarily used as a tool in the analysis of the general trends of biomass pyrolysis, enabling also to verify the consistency of the collected data. Comparison of model results with the literature data shows that the information on product properties is well correlated with the one on product distribution. The prediction capability of the model is briefly addressed, with the results showing that the yields of volatiles released from a specific biomass are predicted with a reasonable accuracy. Particle models of the type presented in this study can be useful as a submodel in comprehensive reactor models simulating pyrolysis, gasification or combustion processes.  相似文献   

14.
In recent years, there has been considerable interest in the development of zero-emissions, sustainable energy systems utilising the potential of hydrogen energy technologies. However, the improper long-term economic assessment of costs and consequences of such hydrogen-based renewable energy systems has hindered the transition to the so-called hydrogen economy in many cases. One of the main reasons for this is the inefficiency of the optimization techniques employed to estimate the whole-life costs of such systems. Owing to the highly nonlinear and non-convex nature of the life-cycle cost optimization problems of sustainable energy systems using hydrogen as an energy carrier, meta-heuristic optimization techniques must be utilised to solve them. To this end, using a specifically developed artificial intelligence-based micro-grid capacity planning method, this paper examines the performances of twenty meta-heuristics in solving the optimal design problems of three conceptualised hydrogen-based micro-grids, as test-case systems. Accordingly, the obtained numeric simulation results using MATLAB indicate that some of the newly introduced meta-heuristics can play a key role in facilitating the successful, cost-effective development and implementation of hydrogen supply chain models. Notably, the moth-flame optimization algorithm is found capable of reducing the life-cycle costs of micro-grids by up to 6.5% as compared to the dragonfly algorithm.  相似文献   

15.
For modeling the formation of nitrogen oxides in combustion via both the prompt-NO and the fuel-NO mechanisms, as well as for modeling the reduction of nitrogen oxides via reburning, a good knowledge of the kinetics of oxidation of hydrogen cyanide (HCN) is required. The formation routes to HCN and the thermochemistry of HCN-related species are reviewed. The available kinetic data for the oxidation of HCN are presented and a comprehensive detailed chemical kinetic reaction mechanism for the oxidation of HCN is proposed and discussed.  相似文献   

16.
Water pumping has been one of the main applications for wind power in the past and despite the spread of mains-electric pumps, more than a million windpumps remain in regular use. This paper reviews the general technical and economic requirements for pumping water using wind energy and by way of example gives an overview of the development of the new ITP wind-pump. It then considers the future prospects for this kind of technology.  相似文献   

17.
The paper contains a survey of the author's results obtained at last ten years on a research of foliations with singularities on closed surfaces. The following problems of the qualitative theory of foliations are considered.(1) Generalization of the Poincaré–Bendixon theory.(2) Kneser problem and estimation of the number of quasiminimal sets.(3) Anosov problem about interrelation between geodesics and asymptotic behavior of leaves of foliations.(4) Topological classification of supertransitive foliations.  相似文献   

18.
利用安大略标准方法和在线汞监测技术对6套典型燃煤电站锅炉静电除尘器(ESP)和湿法烟气脱硫(WFGD)装置前后烟气汞的浓度及形态进行了测试,并研究了2种装置对烟气汞形态转化的影响及其汞控制能力.结果表明:ESP对飞灰的捕获直接降低了烟气中颗粒汞的比例,从已测试的典型燃煤锅炉来看,ESP前的燃煤烟气中颗粒汞的平均比例在30%左右,经ESP后颗粒汞所占比例降至5%左右;经WFGD装置洗涤后,烟气中汞的形态发生了较大的改变,二价汞基本被捕获,进入WFGD装置的烟气中二价汞的比例越高,WFGD装置对烟气汞的脱除效率也越高.配置有选择性催化还原(SCR)脱硝装置+ESP+WFGD尾部烟气处理装置的燃煤电厂,能够很好地控制燃煤烟气汞的排放.  相似文献   

19.
车用汽油机HC排放分布规律研究   总被引:1,自引:0,他引:1  
根据大量HC排放实测数据,运用数理统计手段,研究确定国产主要车型货车和轿车汽油机HC排放分布规律及分布参数,进而建立了相应国车用汽油机的HC排放分布计算模型。它对准确对计算车用汽油机HC排放分布数值和评价车用汽油机HC排放对大气环境的影响等,具有十分重要的作用。  相似文献   

20.
This study outlines a number of issues of a political nature, associated with the implementation of renewables, with the primary emphasis on the recent European push for the production of liquid biofuels. In recent years biofuels have been gaining increasing attention as a potential alternative to conventional automotive fuels. This potential has recently become an issue in the European Union (EU) with surplus agricultural land being considered for the production of energy crops. In this paper political issues at stake in the promotion of biofuel crops in the EU are examined. A critical analysis is made of the environmental claims put forward in defence of the promotion of these fuel crops and comparisons made with alternate woody biomass fuels. Contrasts are drawn between this case study and other examples of the implementation of renewables including the development of PV in the US and wind power in the UK. Conclusions are made regarding the impact of the issues thrown up on the future development of renewables.  相似文献   

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