光热催化氧化VOCs的研究进展

挥发性有机污染物（volatile organic compounds,VOCs）是加重大气复合污染的重要前体物之一。催化氧化技术是在催化剂的作用下,将VOCs氧化分解为无毒的CO₂和H₂O,是目前最有效的治理手段之一。综述了国内外VOCs催化氧化技术的研究进展,针对传统的热催化氧化技术的高能耗和光催化净化技术的低效率等问题,重点总结了光热催化剂的设计理念和对其作用机制的认知,展望了VOCs光热催化氧化技术未来的发展应用方向。     

Design issues for improved environmental performance of dye-sensitized and organic nanoparticulate solar cells

Though environmental improvement has been claimed for the application of nanotechnology to solar cells, several characteristics of the fullerene-based organic, and the dye-sensitized nanoparticulate, solar cell are not conducive to such improvement. These include relatively high energy and materials inputs in the production of nanoparticles, a relatively low solar radiation to electricity conversion efficiency, a relatively short service life, the use of relatively scarce metals and relatively poor recyclability, if compared with the multicrystalline Si solar cell which currently is the market leader. Moreover, the lack of data and the inability of current methods to handle hazards of nanoparticles generate problems in conducting comparative life cycle assessment of nanoparticulate solar cells. So far, the claimed environmental advantage can not be substantiated for fullerene-based and dye-sensitized nanoparticulate solar cells. There are options for the environmental improvement of these nanoparticulate solar cells, but actual development does not seem to focus on environmental improvement.     

生物质转化能源技术的发展现状及趋势探讨

能源短缺问题已成为制约经济社会发展的瓶颈,研究开发新的能源代替传统不可再生能源成为急需要解决的焦点问题。生物质能是由植物的光合作用固定于地球上的太阳能,通过生物质能转换技术可以高效地利用生物质能源,生产各种清洁燃料,替代煤炭、石油和天然气等燃料。对近些年生物质能源技术的发展现状进行了简要讨论,指出了生物质能的利用具有广阔的发展前景,在不久的将来,生物质能源必将成为能源结构中重要一部分,实现能源结构良好可持续发展。     

基于端到端深度学习的有机光伏材料光电转化效率预测

碳中和背景下,亟需开发高效清洁的新型能源,以减少对化石能源的依赖。有机光伏材料作为一种可将太阳能或其他光能直接转化为电能的材料,日益成为一种具有重大应用前景的低碳能源材料。在探索新的高性能有机光伏材料的过程中,机器学习虽然能够提高材料设计效率,但其预测能力极大受制于描述符的开发和选取。利用循环神经网络、卷积神经网络、图神经网络等算法,构建端到端的深度学习模型预测有机光伏材料光电转化效率,所建模型可直接从SMILES符号、分子图像、分子图网络中提取化合物结构信息,而无须人为开发和选取描述符。所得模型不仅能够较为准确地预测有机光伏材料的光电转化效率(其中最优模型五折交叉验证结果和测试集预测结果决定系数均>0.73),而且能够识别影响转化效率的关键结构特征。该研究结果可为新型环境功能材料设计提供理论参考。     

川中浅丘农区坡地林农复合系统的综合评价

本文从生物量与生产力、能量转化率、营养元素利用率、价值转换效益方面对坡地林农复合系统进行了研究，并用层次分析法（ＡＨＰ）进行了综合效益评价。结果表明，复合系统与对应的对照农地系统相比，前者具有生物量、能量、营养元素、价值的积累效应和较大生物生产潜力，对辅助能、光能、营养元素利用率以及经济效益均比较好。在８个系统中，以一台地林农复合系统的综合效益为最高。     

Photo-induced electron transfer processes in thin-film solar cells

Power conversion efficiency of single heterojuntion and bulk heterojunction thin-film solar cells has been analyzed in terms of sequential processes of photo-induced electron transfer. Furthermore, a numerical model was developed to predict current-voltage characteristics of solar cells on the basis of photo-induced electron transfer processes. As an application of this modeling, the power conversion efficiency was analyzed for the donor/acceptor (CuPc/C60) heterojunction under various conditions. In this way, the maximum power conversion efficiency, under 1 sun AM 1.5 solar illumination, was estimated to be 6.1% for the optimum single heterojunction structure. As for the bulk heterojunction structure, a vertical lattice (alternating donor/acceptor lamellae perpendicular to a substrate) structure was proposed and the maximum power conversion efficiency was estimated to be 10.8%. It was concluded that the power conversion efficiency of the vertical lattice bulk heterojunction cell could be increased up to ca. 15% by the improvement of the hole mobility of the donor film.     

Graphitic carbon nitride-based photocatalysts in the applications of environmental catalysis

Semiconductor photocatalytic technology has shown great prospects in converting solar energy into chemical energy to mitigate energy crisis and solve environmental pollution problems. The key issue is the development of high-efficiency photocatalysts. Various strategies in the state-of-the-art advancements, such as heterostructure construction, heteroatom doping, metal/single atom loading, and defect engineering, have been presented for the graphitic carbon nitride (g-C₃N₄)-based nanocomposite catalysts to design their surface chemical environments and internal electronic structures to make them more suitable for different photocatalytic applications. In this review, nanoarchitecture design, synthesis methods, photochemical properties, potential photocatalytic applications, and related reaction mechanisms of the modified high-efficiency carbon nitride-based photocatalysts were briefly summarized. The superior photocatalytic performance was identified to be associated with the enhanced visible-light response, fast photoinduced electron-hole separation, efficient charge migration, and increased unsaturated active sites. Moreover, the further advance of the visible-light harvesting and solar-to-energy conversions are proposed.     

Energieumwandlung durch Farbstoffmoleküle

A short survey is given on the mechanisms by which dye molecules may convert the absorbed radiation energy into chemical energy, electrical energy, or heat. The importance of the different processes in the utilization of solar energy and their influence on the light-fastness of dyes is discussed.     

西北地区太阳能资源空间分布特征及资源潜力评估

太阳能资源的开发利用对人类减少化石燃料的消费及温室气体的排放具有极其重要的意义。因此,研究某一区域太阳能资源的时空分布及稳定性对于开发利用太阳能资源至关重要。论文从区域的角度,利用西北5省西安、西宁、兰州等27个辐射站逐日太阳总辐射(1961—2008年)和延安、乌鲁木齐、安康等163个气象站逐日日照时数资料(1958—2008年),用统计分析和规则样条函数插值相结合的方法,采用太阳总辐射和日照时数作为评价指标,分析了西北地区近50 a来太阳能资源的时空变化特征。结果表明:①研究区太阳能资源年际变化和季节变化特征基本一致,中部青海地区日照时数最长和太阳能总辐射最为丰富,属于资源丰富区,陕西南部及西南部地区太阳能资源相对最为贫乏,属于资源缺乏区;②近50 a来,西北地区年总辐射呈明显下降趋势,年均日照时数下降趋势较缓;③163个气象站近10 a各月日照时数大于6 h的天数有45～327 d,大部分站点在200 d以上,其中每年有15个站点大于300 d;④陕西中及南部、乌鲁木齐周边地区太阳能资源最不稳定,太阳能稳定程度指数K值最高,为12.21,而青海北部及青、甘、新三省交界地带资源最为稳定,K值最低,为1.27;⑤太阳能资源的稳定程度与资源潜力大小分布较为一致,即太阳能资源较为稳定的地区,总辐射最高、日照时间最长。     

留民营生态农业系统的结构与能量流和生态效率的计算

留民营生态农业系统是一个包括农、林、牧、副、渔各业生产的社会经济-自然复合生态系统。在该系统中,既要发展生产,全面提高农民的生活质量,并为城市提供丰富的农副产品,又要保护生态环境,避免生产发展带来的污染与生态环境的破坏,达到经济效益、环境效益与社会效益的统一。因此,对系统     

Brennstoffzellen

Direct conversion of chemical energy into electrical energy is a problem which has received increasing attention during the last years. Fuel-cell power plants on the basis of natural gas are in the course of demonstration, hydrogen/air cells are discussed in the electric vehicle application. Future developments will depend on the progress in electrocatalysis (e.g. the direct anodic oxidation of methanol) and in material technology as in the case of molten-carbonate fuel cells for power generation.     

Energy Resources and Conversion Technologies for the 21st Century

A variety of energy sources will compete to provide the energy services that humans will require over the next 100 years. The balance of these sources will depend upon the availability of fossil fuels and the development of new technologies including renewable energy technologies, and will be one of the keys in projecting greenhouse gas emissions. There is uncertainty about each of the energy sources. With oil, for example, there are two alternate views of future reserves, one that reserves are geologically limited and that supplies will decline within a decade or two, the other that there are enormous quantities of hydrocarbon in the earth’s crust and that reserves are a function of developing technology and price. With solar voltaics, as a second example, there is optimism that the technology will become increasingly competitive, but there is uncertainty about the rate at which costs can come down and about ultimate cost levels. This paper reviews the reserves of fossil fuels and the prospects for nuclear power and the renewables. It also reviews the main energy conversion technologies that are available now or are expected to become increasingly available through time. However, it should be noted that, over a time horizon of 100 years, there may be quite radical changes in both production and conversion technologies that cannot be predicted and it is quite possible for some as yet unheard of technology to be developed and to transform the markets. The paper has been written to aid the development of new scenarios for the emission of greenhouse gases for the Intergovernmental Panel on Climate Change.     

Advances in photocatalytic disinfection of bacteria: Development of photocatalysts and mechanisms

Photocatalysis has attracted worldwide attention due to its potential in solar energy conversion. As a “green” advanced oxidation technology, it has been extensively used for water disinfection and wastewater treatment. This article provides a review of the recent progress in solar energy-induced photocatalytic disinfection of bacteria, focusing on the development of highly efficient photocatalysts and their underlying mechanisms in bacterial inactivation. The photocatalysts are classified into TiO₂-based and non-TiO₂-based systems, as TiO₂ is the most investigated photocatalyst. The synthesis methods, modification strategies, bacterial disinfection activities and mechanisms of different types of photocatalysts are reviewed in detail. Emphasis is given to the modified TiO₂, including noble metal deposition, non-metal doping, dye sensitization and composite TiO₂, along with typical non-TiO₂-based photocatalysts for bacterial disinfection, including metal oxides, sulfides, bismuth metallates, graphene-based photocatalysts, carbon nitride-based photocatalysts and natural photocatalysts. A simple and versatile methodology by using a partition system combined with scavenging study is introduced to study the photocatalytic disinfection mechanisms in different photocatalytic systems. This review summarizes the current state of the work on photocatalytic disinfection of bacteria, and is expected to offer useful insights for the future development in the field.     

基于多目标模型的中国低成本碳达峰、碳中和路径

为探寻我国低成本碳达峰、碳中和路径,以我国主要耗煤产业、电力、供热、交通以及森林碳汇量为研究对象,构建基于低成本碳达峰、碳中和路径的多目标模型.以成本最小、二氧化碳排放量最少以及大气污染物排放量最少为模型的多目标,以我国2030年前碳达峰以及2060年前碳中和为研究目标设置相应约束条件,并设置产业需求、电力需求、供暖需求、交通需求、各行业新能源比例、污染物控制等约束条件,其中产业考虑煤炭消耗量较大的钢铁、化工、建材以及其他行业,电力考虑火电、核电、风电、太阳能.此外,模型除考虑森林碳汇外,还考虑了碳捕获与封存（CCS）作为实现碳达峰、碳中和的技术手段.结果表明:①我国碳达峰、碳中和实现的可行性较高,2030年及2060年的时间节点设定科学,碳达峰当年的各行业成本约为17.54×1012元,代表行业碳达峰、碳中和时的二氧化碳排放量分别为68.63×108和34.50×108 t.②以钢铁、化工、建材等为代表的工业转型可行性较低,且对于碳达峰、碳中和目标实现的贡献较小;电力、供热以及交通转型可行性较高,且对碳达峰、碳中和目标实现的贡献较大,电力二氧化碳排放量占比在2030年与2060年将分别达72.86%和43.34%.③煤电装机容量将在规划期内持续减少,需取消部分已规划的煤电项目并改造和提前淘汰部分已有煤电设备;相对风力发电与太阳能发电装机容量持续增加,二者装机容量总和于2030年达12×108 kW,于2060年达24×108 kW.④CCS将为碳达峰、碳中和目标实现提供助力.研究显示,未来我国碳减排工作将重点聚焦于电力系统,其次为供热与交通,建议根据行业特征制定不同省份、不同经济圈的绿色发展模式.      

云南省玉龙县碳减排效应估算

玉龙县碳减排效应估算主要包括退耕还林、造林、小水电、替代能源(包括沼气池和太阳能)使用等方面. 其中,造林具有较长期的碳汇功能,会持续提供碳增汇服务功能;替代能源的使用可以有效减少薪柴燃烧,在以农村人口为主的玉龙县,薪柴是主要的取暖和生活能源,故替代能源的使用颇具意义. 以2005年为基准年,小水电和替代能源总的碳减排效应为22.24×103 t,其中小水电碳减排效应为14.43 ×103 t,太阳能碳减排效应为66.24 t,沼气池碳减排效应为7.74×103 t;设定了基准年后林木生长过程以及替代能源使用状况的情景,并进行情景模拟,估算了玉龙县造林在5年内会产生碳汇21.07×103 t,10年内会产生碳汇24.92×103 t. 在研究区总的碳减排效应中,小水电、沼气池以及生态林地都有较大贡献,而经济林和草地的贡献相对较小;与5年情景相比,20年情景中小水电和沼气池的贡献有所上升,而生态林地等的贡献相对下降.      

污水厂污泥低温热化学转化过程机理研究

污水厂污泥低温热化学转化是可望达到能量平衡的污泥处理新技术。借助污泥与其转化产物的元素分析、污泥的热重分析和衍生油的GC/MS分析等手段,对该转化反应过程的元素转移、转化特征温度和反应机理进行了研究。认为过程的主要反应是脂肪族化合物的蒸发、蛋白质肽键断裂和基团转移反应,参与反应的主要成份是脂肪族化合物和蛋白质,其中前者参与反应的温度低于后者,而糖类化合物参与反应的温度最高。     

美国太阳反射镜步进应力加速老化试验

为了应对降低聚光发电(CSP)成本带来的挑战,研发新型的低成本反射镜材料,包括金属聚合物反射镜。通过将太阳反射镜暴露在紫外光下,利用试验应用方法和统计推论技术,定量评估和改进太阳光反射镜在紫外光下与失效机制相关的使用寿命。将利用超加速环境系统评估由紫外暴露加速老化导致的多种性能退化模式。由于样品数量、试验条件、性能退化和失效模式等原因,试验结果可用于深入推导失效机制、关联物理参数、服役寿命和不确定性。在有必要利用高级方案和统计推论的复杂情况下,建议采用步进应力加速老化试验方法。     

Cleaner pathways of hydrogen,carbon nano-materials and metals production via solar thermal processing

This paper describes various solar thermochemical processes for the production of hydrogen, carbon nano particles, industrial grade carbon black, and metals with substantially reduced CO₂ emission footprint. The paper introduces an innovative approach of a three-dimensional volumetric production of carbon nano particles via thermal cracking of methane gained by carbon seeding as an alternative to the existing two dimensional modes. The paper also describes an alternative pathway for hydrogen production via three consecutive solar thermochemical processes, namely, solar cracking of methane, solar carbo-reduction of ZnO and CO reduction of CdO, providing long term storage of solar energy. Finally, the paper provides an example solar windowed reactor for clean production of hydrogen, and it presents numerical analysis of the solar reactor based on computational fluid dynamics results, simulating one of the major problems with natural gas cracking in solar reactors, namely, carbon contamination of the transparent window and clogging of the reactor.     

Increasing significance of advanced physical/chemical processes in the development and application of sustainable wastewater treatment systems

The awareness of the problem of the scarcity of water of high quality has strongly changed the approach of wastewater treatment. Currently, there is an increasing need for the beneficial reuse of treated wastewater and to recover valuable products and energy from the wastewater. Because microbiological treatment methods are, only to a limited part, able to satisfy these needs, the role and significance of physical/chemical processes in wastewater treatment are gaining more and more interest. The specific future role and aim of the various physical/chemical treatment processes can be categorized in five groups: improvement of the performance of microbiological treatment processes, achievement of the high quality required for reuse of the effluent, recovery of valuable components and energy from the wastewater for beneficial reuse, desalination of brackish water and seawater, and treatment of concentrated liquid or solid waste residues produced in a wastewater treatment process. Development of more environmentally sustainable wastewater treatment chains in which physical/chemical processes play a crucial role, also requires application of process control and modeling strategies. This is briefly introduced by the elaboration of treatment scenarios for three specific wastewaters.     

有机固废热解动力学的研究进展

热解技术是将有机固废转化为能源的一种有效手段。有机固废热解动力学是对固废热解的反应机理、反应速率的数学表达式以及影响因素的研究,对于有机固废热解结果的预测以及其热解装置的设计和模拟有着重要意义。重点提供了有机固废热解动力学的研究概述,总结了计算有机固废热解反应速率的数学表达式的各种模型和方法,及其应用情况和优缺点;总结了近些年对有机固废热解动力学参数的影响因素的研究,发现转化率、添加剂、原料组分等因素都会影响有机固废热解动力学参数,可为有机固废热解的应用提供参考。