太阳能在智能生态农业中的应用

针对太阳能养殖、太阳能干燥、薄膜太阳能农业大棚、太阳能灌溉及太阳能杀虫灯等5个太阳能的利用技术进行了论述,并将太阳能技术与传统技术进行了比较,分析了各项技术的优缺点,探索了太阳能在农业生产方面进行利用的前景.     

Solar energy and electric utilities: should they be interfaced?

Analyses of the economics of solar collection in the firm- and shifting-peak cases (that is, with off-peak electricity indefinitely available or with a flat load curve) indicate that, for many important applications, solar energy systems that interface with electric utilities can be justified only in terms of the value of the off-peak utility fuels that they displace. In regions where off-peak electricity costs are low, the most economically efficient solar energy systems will be those that use electricity as the auxiliary energy source. This implies extremely low break-even costs for a number of important solar energy applications. In regions where the cost of off-peak electricity is higher than that of competing energy forms, the most economical solar energy systems will utilize auxiliary fuels other than electricity. The general conclusion is that conventional electric utility systems and most solar energy systems represent a poor technological match. The basic problem is that both technologies are very capital intensive. The electric utility, because of the high fixed costs of generation, transmission, and distribution capacity, represents a poor backup for solar energy systems. On the other hand, the solar collection system, because it represents pure, high-cost capital and because of its outage problems, cannot be considered as a part-load source of auxiliary energy for the electric utility system.     

农村被动式太阳房动态能耗数值模拟与优化研究

对采用附加阳光间的天津某农村被动式太阳房围护结构的全年动态能耗及附加阳光间的全年太阳得热量进行了数值模拟,并比较分析了采用附加阳光间前后该住宅的全年围护结构能耗。同时,利用数值模拟手段,对采用了保温材料的墙体和Low-E玻璃的阳光间的全年动态能耗进行了模拟,并与未采用保温材料和Low-E玻璃的情况进行了对比分析。结果表明采用Low-E玻璃的附加阳光间能耗降低了80%,采用保温材料的围护结构墙体能耗降低了43.5%。通过经济效益比对分析,采用保温材料和Low-E玻璃增加的投资约97 396元,约5年内即可收回。     

村镇住宅太阳能技术应用研究

从我国太阳能的资源及应用技术现状等方面入手,着重介绍了现阶段村镇住宅建筑中可利用的太阳能技术,并对不同的应用形式作了必要的分析。     

Solar energy for village development

The National Academy of Sciences held a joint workshop with the Government of Tanzania last August on the potential of solar energy for the villages of that country. Costs of five solar technologies (mini-hydroelectric generators, wind, methane generation from organic wastes, photovoltaic cells, and flat-plate solar collectors) were compared with costs of diesel-generated electricity and with electricity from the national grid. Each of the five technologies is either now competitive with diesel or will be in a few years. Although the figures presented are not conclusive since they are derived from calculations rather than an actual test, the results are encouraging enough to warrant serious testing in Third World villages.     

烟叶烘烤节能技术研究进展

介绍了烤烟烘烤耗能情况,并从烤房的转型、烤房配套设备的改进、烘烤工艺、新型能源燃料和技术的利用等方面综述烟叶烘烤节能技术的研究进展。认为今后应围绕国家节能减排战略,抓住机遇进行烤烟节能减排共性和关键技术及相关机制、体制的创新;提高烤烟节能科研力度;建立大型的专业化烘烤工厂,培养专业技术人员,并向集约化方向转型;充分利用生物质能源、风能、太阳能、水利能等,同时将红外线等物理干燥技术应用于烟叶烘烤中,以实现烘烤行业的可持续发展。     

农村沼气发酵温度控制技术及经济性分析

沼气是一种清洁、绿色能源,温度是保证高效生产沼气的关键条件之一。该文对比分析了几种沼气生产增温技术,建立了一个8m~3的沼气池模型,对模型的热平衡及几种加热技术的经济性进行了分析和计算,结果表明：太阳能热水器水循环沼气池加热系统更为经济有效。     

German energy technology prospects

After more than 25 years of development of nuclear power and almost 10 years of research and development in numerous areas of nonnuclear energy, there is now a good basis for judging the future prospects of energy technologies in the Federal Republic of Germany. The development of nuclear power has provided an important and economically advantageous new source of energy. Further efforts are needed to establish the nuclear fuel cycle in all stages and to exploit the potential of advanced reactors. In all other areas of energy technology, including energy conservation, new energy sources, and coal, economics has turned out to be the key problem, even at today's energy prices. Opportunities to overcome these economic problems through additional R & D are limited. There is some potential for special applications, and there are many technologies that could contribute to the energy supply of developing countries. In general, however, progress in energy conservation and the use of renewable energy sources will depend on the degree to which energy policy measures can improve their economic basis. For some technologies, such as solar thermal power stations and coal liquefaction, large-scale economic deployment cannot be foreseen today. Instead of establishing costly demonstration projects, emphasis will be put on improving key components of these technologies with the aim of having the most advanced technology available when the economic parameters are more favorable.     

农村住宅节能技术研究进展

与城市居民住宅及公共建筑相比,在我国量大面广的农村地区住宅节能技术的应用相对滞后,其中很重要的原因就是适合农村住宅的节能技术的研发及其推广不够。对农村住宅节能技术的研究状况进行了分析,从建筑物的规划布局、新型建筑材料的研究使用、围护结构保温技术、太阳能在住宅上的利用、住宅通风降温技术及住宅节能的经济性分析等几个方面总结了农村建筑节能技术的研究进展,指出了当前农村节能技术研究存在的问题。在此基础上,展望了农村住宅节能技术研究的方向。     

Advanced technology paths to global climate stability: energy for a greenhouse planet

Stabilizing the carbon dioxide-induced component of climate change is an energy problem. Establishment of a course toward such stabilization will require the development within the coming decades of primary energy sources that do not emit carbon dioxide to the atmosphere, in addition to efforts to reduce end-use energy demand. Mid-century primary power requirements that are free of carbon dioxide emissions could be several times what we now derive from fossil fuels (approximately 10(13) watts), even with improvements in energy efficiency. Here we survey possible future energy sources, evaluated for their capability to supply massive amounts of carbon emission-free energy and for their potential for large-scale commercialization. Possible candidates for primary energy sources include terrestrial solar and wind energy, solar power satellites, biomass, nuclear fission, nuclear fusion, fission-fusion hybrids, and fossil fuels from which carbon has been sequestered. Non-primary power technologies that could contribute to climate stabilization include efficiency improvements, hydrogen production, storage and transport, superconducting global electric grids, and geoengineering. All of these approaches currently have severe deficiencies that limit their ability to stabilize global climate. We conclude that a broad range of intensive research and development is urgently needed to produce technological options that can allow both climate stabilization and economic development.     

西北地区设施园艺发展现状与对策探析

从西北地区自然条件出发,综述了该地区设施园艺的发展现状与存在的问题,提出了依靠研发高效节能节水日光温室和创建地域名优果菜品牌,提高西北设施园艺的技术含量,通过人才培训和市场培育促进西北设施园艺产业化发展,开拓筹资融资渠道解决资金短缺问题等对策,可为西北园艺设施的发展规划提供借鉴。     

Peak external photocurrent quantum efficiency exceeding 100% via MEG in a quantum dot solar cell

Multiple exciton generation (MEG) is a process that can occur in semiconductor nanocrystals, or quantum dots (QDs), whereby absorption of a photon bearing at least twice the bandgap energy produces two or more electron-hole pairs. Here, we report on photocurrent enhancement arising from MEG in lead selenide (PbSe) QD-based solar cells, as manifested by an external quantum efficiency (the spectrally resolved ratio of collected charge carriers to incident photons) that peaked at 114 ± 1% in the best device measured. The associated internal quantum efficiency (corrected for reflection and absorption losses) was 130%. We compare our results with transient absorption measurements of MEG in isolated PbSe QDs and find reasonable agreement. Our findings demonstrate that MEG charge carriers can be collected in suitably designed QD solar cells, providing ample incentive to better understand MEG within isolated and coupled QDs as a research path to enhancing the efficiency of solar light harvesting technologies.     

新疆牧区光伏提水技术应用的可行性研究

光伏提水是一门新兴技术,具有无噪音、无环境污染、不消耗常规能源、全自动、高可靠性等优势。近年来,随着中国光伏产业的迅速发展,光伏设备的制造生产成本和价格不断下降。新疆牧区光能资源丰富,通过利用光伏提水技术解决人畜饮水及饲草料灌溉的问题,能够解决当前牧区生活和生产的需要,对促进新疆牧区的社会安定团结和社会经济、自然环境的可持续发展具有重要的推动作用。     

Comparing photosynthetic and photovoltaic efficiencies and recognizing the potential for improvement

Comparing photosynthetic and photovoltaic efficiencies is not a simple issue. Although both processes harvest the energy in sunlight, they operate in distinctly different ways and produce different types of products: biomass or chemical fuels in the case of natural photosynthesis and nonstored electrical current in the case of photovoltaics. In order to find common ground for evaluating energy-conversion efficiency, we compare natural photosynthesis with present technologies for photovoltaic-driven electrolysis of water to produce hydrogen. Photovoltaic-driven electrolysis is the more efficient process when measured on an annual basis, yet short-term yields for photosynthetic conversion under optimal conditions come within a factor of 2 or 3 of the photovoltaic benchmark. We consider opportunities in which the frontiers of synthetic biology might be used to enhance natural photosynthesis for improved solar energy conversion efficiency.     

湖北省太阳能资源时空分布特征及区划研究

利用武汉、宜昌等7个站点1961~2004年逐年、逐月太阳总辐射与日照百分率资料,采用最小二乘法确定湖北省太阳总辐射计算公式参数,推算出广大无辐射观测地区的逐年、逐月太阳总辐射;结合日照时数、晴天日数、阴天日数等指标,对湖北省太阳能资源的时空分布特征及气候变化趋势进行了分析;以全国太阳能资源区划为基础,制定了湖北省太阳能资源区划指标,开展了湖北省太阳能区划工作。结果表明:湖北太阳能资源北多南少,同纬度相比,平原多,山区少;太阳能资源夏季最丰富,尤其是8月,总辐射、日照时数、晴天日数均为全年最高,湖北东部秋季大气层结稳定,太阳能资源仅次于夏季;冬季虽然晴天较多,但由于太阳直射南半球,夜长昼短,总辐射全年最低。将全省太阳能资源分为3个区,鄂东北7~12月每月有近一半或以上的晴天,为1级可利用区,也是湖北太阳能资源最佳区域;江汉平原、鄂东南、鄂北岗地部分地区等地为2级可利用区,是光电与光生物质能综合利用的最佳区域;鄂西南、长江河谷地区为太阳能贫乏区。     

Solar photovoltaic power systems: an electric utility R & d perspective

Solar photovoltaic technology is receiving increasing attention as a prospective source of bulk, electric utility power within the next 10 to 20 years. Successful development will require solar energy conversion efficiencies of about 15 percent for photovoltaic flat-plate modules, or about 25 percent for photovoltaic cells using highly concentrated sunlight. Three different cell technologies have a better than even chance of achieving these target efficiencies with costs and operating lifetimes that would allow significant use by electric utilities. The challenge for the next decade is to push photovoltaic technology to its physical limits while expanding markets and user confidence with currently available systems.     

热泵型太阳能密集烤房烘烤节能途径探讨

为了探索节能减排的烤烟烘烤模式,2009-2010年,在贵州省黔西南州兴义市修建了2栋热泵太阳能密集烤房,并进行了烤烟烘烤节能试验.每栋烤房可装鲜烟叶3 500 kg,烘烤烟叶质量与普通密集烤房相当.使用热泵烘烤烟叶(CK),每千克干烟叶耗电3.08 kW·h,能耗成本为1.40元.使用热泵并利用太阳能作为辅助能源,则...     

Hot carrier-assisted intrinsic photoresponse in graphene

We report on the intrinsic optoelectronic response of high-quality dual-gated monolayer and bilayer graphene p-n junction devices. Local laser excitation (of wavelength 850 nanometers) at the p-n interface leads to striking six-fold photovoltage patterns as a function of bottom- and top-gate voltages. These patterns, together with the measured spatial and density dependence of the photoresponse, provide strong evidence that nonlocal hot carrier transport, rather than the photovoltaic effect, dominates the intrinsic photoresponse in graphene. This regime, which features a long-lived and spatially distributed hot carrier population, may offer a path to hot carrier-assisted thermoelectric technologies for efficient solar energy harvesting.     

太阳能技术在建筑节能中的应用

就太阳能在节能建筑中采暖、空调和热水系统的热利用进行了阐述.