The NASA Glenn Research Center is developing advanced passive thermal management technology to reduce the mass and improve the reliability of space fuel cell systems for the NASA Exploration program. The passive thermal management system relies on heat conduction within highly thermally conductive cooling plates to move the heat from the central portion of the cell stack out to the edges of the fuel cell stack. Using the passive approach eliminates the need for a coolant pump and other cooling loop components within the fuel cell system which reduces mass and improves overall system reliability. Previous development demonstrated the performance of suitable highly thermally conductive cooling plates and integrated heat exchanger technology to collect the heat from the cooling plates (Ref. 1). The next step in the development of this passive thermal approach was the demonstration of the control of the heat removal process and the demonstration of the passive thermal control technology in actual fuel cell stacks. Tests were run with a simulated fuel cell stack passive thermal management system outfitted with passive cooling plates, an integrated heat exchanger and two types of cooling flow control valves. The tests were run to demonstrate the controllability of the passive thermal control approach. Finally, successful demonstrations of passive thermal control technology were conducted with fuel cell stacks from two fuel cell stack vendors.

关键词：环境与资源；燃料电池；冷却系统；传导传热；航空航天系统

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We have studied the effect of nanostructuring in Pt monolayer model electrocatalysts on a Rh(111) single-crystal substrate on the adsorption strength of chemisorbed species. In situ high energy resolution fluorescence detection x-ray absorption spectroscopy (HERFD XAS) at the Pt L3 edge reveals characteristic changes of the shape and intensity of the “white-line” due to chemisorption of atomic hydrogen (Had) at low potentials and oxygen-containing species (O/OHad) at high potentials. On a uniform, two-dimensional Pt monolayer grown by Pt evaporation in ultrahigh vacuum (UHV), we observe a significant destabilization of both Had and O/OHad due to strain and ligand effects induced by the underlying Rh(111) substrate. When Pt is deposited via a wetchemical route, by contrast, three-dimensional Pt islands are formed. In this case, strain and Rh ligand effects are balanced with higher local thickness of the Pt islands as well as higher defect density, shifting H and OH adsorption energies back towards pure Pt. Using density functional theory (DFT) we calculate O adsorption energies and corresponding local ORR activities for fcc threefold hollow sites with various local geometries that are present in the three-dimensional Pt islands.

关键词：环境与资源；燃料电池；化学吸附；密度泛函方法

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关键词：天然气；改革

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Extensive testing of the breadboard system was completed including baseline leak rate measurements. Several improvements were made to the system to permit stable, automated operation at 4 kilowatts, twice the previous power output, and the system was demonstrated at this power output. The first round of bench-top hydrogen recovery reactor media testing was completed. The supplier s procurement efforts for the final deliverable of the hermetically- sealed scroll compressors were underway.

关键词：环境与资源；燃料电池；能量密度；燃油系统；高效节能

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The results of hydrogenation of single walled carbon nanotubes (SWCNTs)-SnO2 composite, SWCNTs-WO3 composite, and SWCNTs-TiOs, are reported. The amount of hydrogen incorporated in the SWCNTs composites was determined and the dehydrogenation behavior was studied. The experimental evidences were provided by TEM, AFM, XRD, EDS, CHN and TG/TDS analyses.

关键词：环境与资源；燃料电池；能源储存系统；单壁碳纳米管

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为支持水电行业发展，统一和规范大型水电企业增值税政策，3月12日，财政部下发《关于大型水电企业增值税政策的通知》（简称《通知》）。《通知》称，装机容量超过100万千瓦的水力发电站（含抽水蓄能电站）销售自产电力产品，自2013年1月1日至2015年12月31日，对其增值税实际税负超过8%的部分实行即征即退政策；自2016年1月1日至2017年12月31日，对其增值税实际税负超过12%的部分实行即征即退政策。

关键词：电力行业；要闻综述

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提出了一种基于粒子群优化BP神经网络风电机组齿轮箱故障诊断方法.粒子群算法不需要计算梯度,可以兼顾全局寻优和局部寻优.利用粒子群算法对BP网络权值和偏置进行优化,减少了BP神经网络算法陷入局部最优解的风险,提高了神经网络的训练效率,加快了网络的收敛速度.考虑风电齿轮箱振动信号的不确定性、非平稳性和复杂性,提取功率谱熵、小波熵、峭度、偏度、关联维数和盒维数作为故障特征.经测试,算法诊断结果正确,表明了PSO优化BP神经网络用于风电机组齿轮箱故障诊断的有效性和实用性.

关键词：风电机组；齿轮箱；故障诊断；粒子群优化算法；BP神经网络；故障特征

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制备了基于亚铁氰化锌的双金属氰化物络合物(DMC),可一步同时催化酯交换和酯化反应制备生物柴油,该催化剂体系具有不受水毒性影响的特点.用3wt％的DMC催化剂在433K,醇油摩尔比为16∶1以及水和脂肪酸含量各10wt％的条件下分别同时催化甘油三酯、脂肪酸和甲醇的酯交换、酯化反应,生物柴油产率可达98％以上.对催化剂进行X射线衍射、热重红外联用分析、元素分析、比表面积和孔体积测定、扫描电镜等手段表征,结果表明:该催化剂为晶态与非晶态组分混合结构,其表面晶态决定其在高水含量、高酸值的环境下仍具有较好的催化活性,验证得出活性位点可能为锌离子.

关键词：双金属氰化络合物；固体酸催化剂；酯交换；酯化；生物柴油

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提出一种包含吸收溶液冷却结晶过程的新型第二类吸收式热泵循环,并对其工作过程及性能特性进行理论分析与实验研究.结果表明,该循环可在吸收器吸收溶液质量分数显著高于发生器吸收溶液质量分数的条件下工作,其热泵温升能力明显优于现有AHT循环.当冷却结晶终温和冷凝器温度为35℃、发生器温度和蒸发器温度为92℃时,其热泵温升理论上可达97℃.

关键词：第二类吸收式热泵循环；结晶温度；溴化锂；热泵温升；余热

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分别以苯并噻唑(BT)、2-甲基苯并噻唑(MBT)、3-甲基苯并噻唑碘(MBTI)、2,3-二甲基苯并噻唑碘(DMBTI)及4-叔丁基吡啶(TBP)作为染料敏化太阳电池(DSCs)电解质溶液中的添加剂,使用超微电极通过循环伏安法和电化学阻抗谱研究上述5种添加剂的杂环结构及杂原子N和S对电解质中I3-和I-氧化还原行为和对铂黑电极｜电解质界面的影响.结果表明,随着添加剂的加入,溶液中I3-和I-扩散系数均减小；添加BT、MBT和TBP,铂黑电极｜电解质的界面传输电阻Rct增大,添加MBTI和DMBTI,Rct减小.电池的光伏性能测试结果表明,添加剂中含有吡啶环的结构优于苯并噻唑环,含有碱性N原子优于碱性S原子.

关键词：苯并噻唑；苯并噻唑碘；添加剂；染料敏化太阳电池

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