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1.
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   

2.
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   

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.
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   

5.
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   

6.
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   

7.
"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   

8.
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   

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.
从20世纪80年代末期开始,世界各国相继电对电力工业进行了改革。在对国外电力工业重组的六类典型模式及其主要经验分析基础上,对我国深化电力体制改革及进行输、配、售电业务重组模式的选择提出了建议和对策。  相似文献   

12.
通过多年的探索与实践,南通市在循环经济发展方面取得了令人鼓舞的成绩。文中从南通市发展循环经济的现状、实践成果、未来目标和任务、问题探讨等几个方面对全市循环经济发展进行了详细的阐述,提出了循环经济发展的一些思路和方法。  相似文献   

13.
对世界核能概况和我国的核能现状做了较深入的分析,并就我国核电可持续发展的问题提出了若干建议;同时以广三核作为核电国产化的驱动项目,预测了我国核电发展的前景。  相似文献   

14.
碳质吸附剂吸附储氢的研究现状   总被引:4,自引:0,他引:4  
张超  顾安忠 《太阳能学报》2003,24(1):121-128
论述了活性炭、碳纳米纤维、碳纳米管吸附储氢的研究历程,从实验、理论研究两个方面总结了前人的研究成果:活性炭在低温下有好的吸附储氢特性,但在室温条件下的结果却不令人满意;碳纳米管和碳纳米纤维的实验结果令人振奋,但众多的实验结果并不一致;碳纳米材料的制备技术和净化技术还仅处在实验规模的阶段;蒙特卡罗、密度泛函等方法是常用的计算机模拟技术,但目前它们只是考虑了理想的物理模型,没有考虑碳纳米管表面的一些不规则现象;碳质吸附剂吸附储氢从理论到应用还有一段距离。  相似文献   

15.
C. Van Koppen 《Solar Energy》1998,62(6):379-386
In the past 5 years the general attitude towards solar energy has turned from negative to positive. This in itself, however, will not accelerate the introduction of solar energy very much. On the contrary, some of the plans and programs following from it are unrealistic and counter-productive. The better way to go is realism and inspiring the best scientists and politicians to take up the vast amount of R&D work and societal restructuring that has still to be done. Energy has become so vital to mankind that solar energy as a substitute for conventional energy sources will be indispensable for maintaining peace.  相似文献   

16.
Hans Ganander 《风能》2003,6(4):333-345
For many reasons the size of wind turbines on the rapidly growing wind energy market is increasing. Relations between aeroelastic properties of these new large turbines change. Modifications of turbine designs and control concepts are also influenced by growing size. All these trends require development of computer codes for design and certification. Moreover, there is a strong desire for design optimization procedures, which require fast codes. General codes, e.g. finite element codes, normally allow such modifications and improvements of existing wind turbine models. This is done relatively easy. However, the calculation times of such codes are unfavourably long, certainly for optimization use. The use of an automatic code generating system is an alternative for relevance of the two key issues, the code and the design optimization. This technique can be used for rapid generation of codes of particular wind turbine simulation models. These ideas have been followed in the development of new versions of the wind turbine simulation code VIDYN. The equations of the simulation model were derived according to the Lagrange equation and using Mathematica®, which was directed to output the results in Fortran code format. In this way the simulation code is automatically adapted to an actual turbine model, in terms of subroutines containing the equations of motion, definitions of parameters and degrees of freedom. Since the start in 1997, these methods, constituting a systematic way of working, have been used to develop specific efficient calculation codes. The experience with this technique has been very encouraging, inspiring the continued development of new versions of the simulation code as the need has arisen, and the interest for design optimization is growing. Copyright © 2003 John Wiley & Sons, Ltd.  相似文献   

17.
The shortage of high effective and reliable cathode catalysts with desirable performance for oxygen reduction needs to be addressed to accelerate the large-scale expansion of clean and sustainable fuel cells. Herein, we report a facile hydrothermal route to tailor a new type of N, P co-doped carbon architecture with Fe2P nanoparticles embedded/encapsulated in the crumped carbon nanosheets. The rational design of carbon shell structure in strong interaction with rGO endows the catalyst with graphitic-N abundance, mesoporous structure dominance and active Fe2P isolation. We propose the pyrolyzed dicyandiamide-derived carbon fragment as not only an additional nitrogen resource but a favorable micro-structured separator and protective porous layer for metal agglomeration and demetallation, which ensures the catalyst with excellent activity and stability. The co-doped carbon shows excellent activity with positive half-wave potential of +0.823 V via complete 4 electron pathway, close to that of Pt/C material (+0.831 V). The inspiring durability is confirmed by merely 2 mV negative potential shifts after 1000 cycles of CV tests. In the end, this paper provides a promising way to develop a high effective carbon-based bifunctional catalyst for both oxygen reduction and evolution reactions through electronic design and structural engineering.  相似文献   

18.
As a fuel, rural biogas is a promising renewable energy source. Policy support is a key initial impetus for industry development. This study explores household biogas development in rural China based on policy support found in literature. Relevant policies, which mainly include directive and guiding policies, economic inspiring policies, research policies, market policies, and other constructive policies, are gradually issued. Moreover, the National People's Congress has enacted five relevant laws, including the Agricultural Law, Renewable Energy Law, Animal Husbandry Law, Energy Conservation Law, and the Act on the Development of Circular Economy. The Energy Law is currently under revision. Relational rules and regulations have also been formed in response to the national policies and laws, which have already produced significant effects. The development of rural household biogas in China is growing steadily, and the technology standard projects have been established. The number of household biogas digesters and biogas annual output in 2010 was double of that in 2005. The offered financial incentive increased from 47 million dollars in 2002 to 760 million dollars in 2011. Policy supports play an important role in rural biogas development. And thus, additional national policy supports are necessary in the fields of scientific research, technological development, and biogas use model.  相似文献   

19.
Directional electron transfer and effective charge separation facilitated by graphene sheets have provided an inspiring approach to enhance the efficiencies of photoelectric conversion and photocatalysis. Herein, we demonstrated the feasibility of constructing a high-performance of the dye-sensitized H2 evolution system using dispersible graphene sheets as both efficient electron transfer carrier and catalyst scaffold. Among the xanthene dyes sensitized H2 evolution catalysts in this study, photocatalyst of Rose Bengal (RB) sensitized graphene decorated with Pt is the most active one and exhibits the highest apparent quantum efficiency (AQE) of 18.5% at wavelength of 550 nm and rather long-term stability for H2 evolution. Dispersible graphene sheets can not only capture electrons from the excited dye and then transfer them to the decorated catalysts efficiently for improving charge separation with a small energy loss, but also afford large interfaces for highly dispersing catalyst nanoparticles with more active sites, thereby significantly enhancing the H2 evolution efficiency than graphite oxide (GO) and multiwall carbon nanotubes (MWCNTs). This work proposes a potential strategy to develop efficient photocatalytic systems for solar-energy-conversion and provides a new insight into mechanistic study of photoinduced electron transfer by effective synergetic combination of dispersible graphene sheets with an efficient dye and a H2 evolution catalyst.  相似文献   

20.
Recently, the demand for energy consumption has been increasing exponentially due to the exhaustion of fossil fuels in the environment. This is the foremost technical challenge to the researchers to progress clean and alternative sustainable energy sources. Among various kinds of energy sources, an environment-friendly fuel, hydrogen is recognized as a favorable energy carrier to reduce the necessity on fossil fuels and protect the environment by reducing the discharge of greenhouse and other toxic gases. Thus, effective production and storage of hydrogen through a cost-effective and significant approach are the important factors of sustainable hydrogen production. Electrocatalytic water splitting is a favorable method for the hydrogen evolution reaction (HER), which requires an efficient and strong electrocatalyst to accelerate the kinetics of HER. To date, the well-developed electrocatalysts for HER activity are Pt-group metals, but, these electrocatalysts are inadequate and more expensive. In recent years, significant improvement has been achieved in the development of carbon cloth-based HER electrocatalysts as a replacement to Pt-based catalysts for hydrogen production in acidic medium. In this review, we mainly focused on the recent growth in the establishment of carbon-cloth functionalized transition metal (Fe-, Co-, Ni-, Mo-, and W-) based electrocatalysts towards the enhancement of HER activity. Depending on the results, we believed that the transition metal-based electrocatalysts have been appearing as fascinating and future alternative catalysts due to their morphology improvements, synergistic effects, a significant enhancement in the production of active sites, charge transfer efficiency, and superior HER activity with great durability. In addition, we outline the remarkable challenges and future prospects in this inspiring field.  相似文献   

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