薄膜材料的热辐射穿透深度研究

详细地分析了影响薄膜材料热辐射穿透深度的主要因素，揭示了薄膜材料热辐射穿透深度随薄膜材料犀度变化的规律，理论分析表明，当薄膜材料的犀度与电子的平均自由程相当时，减小薄膜材料的厚度可以大幅度提高热辐射穿透深度，从而显地改善薄膜材料的热辐射性能。     

超超临界参数机组材料国产化对策

蒸汽参数越高，火电机组效率越高，而材料是制约蒸汽参数提高的关键因素。该文介绍了日本、欧洲、美国超超临界机组材料的开发研制情况．提出了我国发展不同蒸汽参数超超临界机组的候选材料，分析了我国发电设备材料国产化效果不理想的原因，提出了超超临界机组材料国产化的对策。表1参7     

热辐射能(波)选择性强化吸收的场协同机理

从场协同原理的角度出发，分析了材料对热辐射能(波)选择性吸收过程，提出了材料对入射辐射能(波)的作用实质是材料内阻尼振子组成的力场和入射辐射场之间的相互作用；调整这两个场之间的协同关系，可以改变和改善材料的选择性热辐射性能。基于此得到了强化材料对入射热辐射能(波)选择性吸收的机理。研究表明：减弱入射辐射场与材料内阻尼振子组成的力场之间的协同关系，可以提高材料的吸收率和发射率；相反，强化这两个场之间的协同关系，可使材料表现出较高的反射率。     

高温相变蓄热的研究进展

从如下两个方面总结了高温相变蓄热的研究现状：①在高温相变材料(PCM)方面，重点介绍了高温相变材料的一些重要性能及其测量，高温相变材料的封装，高温复合相变材料及高温相变材料的应用；②在传热分析方面，主要介绍了相变过程的数值模拟和相变蓄热系统(LTES)的热力学优化。     

具有蓄能功能的建筑墙体材料研究

文章提出了一种具有蓄能功能的建筑墙体材料，通过实验分析了该蓄能墙体材料的融解温度、融解热、热稳定性及微相结构等性能。该蓄能材料由两种有机相变材料组成，通过物理吸附的方法将其复合在建筑墙体材料中。在热分析中，用示差扫描量热仪（DSC）来测定蓄能墙体材料的融点、融解热，用热重分析仪（TGA）测定其热稳定性，并用扫描电镜（SEM）观测了该蓄能墙体材料的微相结构。测试结果表明，该蓄能墙体材料具有较高的相变潜热和较好的热稳定性，可应用于建筑节能系统中。     

掺杂对定形相变材料导热系数的影响

通过在定形相变材料中加添加剂改进定形相变材料的导热系数，用热针法对改性后的试样进行了测量，对添加剂种类和含量对定形相变材料导热系数的影响进行了定量分析。实验结果表明，石墨添加剂可以显著提高定形相变材料的导热系数。通过对实验数据的拟合，得到了石墨添加质量分数与材料有效导热系数问的拟合公式。     

滑动轴承材料疲劳强度试验

滑动轴承是各种机械广泛使用的重要基础零件，它的抗疲劳磨损性能直接影响着整机的可靠性和使用寿命，国际上很多知名的轴瓦材料供应商对各种滑动轴承材料的磨损性能进行了比较系统的研究，推出了很多优质的双(多)层金属轴瓦材料。在我国，随着最近汽车用发动机的迅速发展，对轴承材料提出了更高的要求，     

材料利用率查询对比系统的开发及应用

介绍了在利用计算机作材料定额的过程中，如何判断自己所作部件的材料定额的利用率以及和同类部件的利用率相对比，从而判断自己所作部件的材料定额利用率的高低。本系统运用Visual Basic6．0作为前端开发工具，Oracle8i作为后台数据库管理工具。本系统的应用大大提高了材料定额的准确性，并为进一步提高材料定额利用率提供了有效的数据基础。     

改善材料选择性热辐射的方法

从波动力学的观点出发，解析了热辐射波和材料内部的阻尼谐振子之间的相互作用过程，从而揭示了热辐射波在材料内部的发射、吸收、透射和反射机理。基于洛伦兹色散理论，分析了影响材料选择性热辐射的因素，提出了改善材料选择性热辐射复合化和超细化方法。实验研究证实了这些方法的正确性和可靠性。     

湿法再生吸附膜用于大气CO2吸附性能研究

针对目前新兴的利用湿法再生吸附剂进行大气CO2直接捕集的技术，研究了吸附剂膜材料的一些基本参数并测试了不同温度下吸附剂膜材料的CO2吸附能力。通过滴定法分析了吸附剂膜材料的电荷密度；用SEM分析了膜材料的表观结构；通过TG—DSC联用分析了吸附剂膜材料的失水性能；并对不同温度下吸附剂膜材料的CO2吸附动力学的进行了测试。结果发现，在干燥的膜材料上，每个CO3^2-离子周围有4个水合水，同时膜材料在30℃下具有比较大的吸附容量，而在50℃下具有比较大的吸附速度。     

Ash-forming elements in four Scandinavian wood species. Part 1: Summer harvest

Woody biomass in Finland and Sweden comprises mainly four wood species: spruce, pine, birch and aspen. To study the ash, which may cause problems for the combustion device, one tree of each species were cut down and prepared for comparisons with fuel samples. Well-defined samples of wood, bark and foliage were analyzed on 11 ash-forming elements: Si, Al, Fe, Ca, Mg, Mn, Na, K, P, S and Cl. The ash content in the wood tissues (0.2–0.7%) was low compared to the ash content in the bark tissues (1.9–6.4%) and the foliage (2.4–7.7%). The woods’ content of ash-forming elements was consequently low; the highest contents were of Ca (410–1340 ppm) and K (200–1310), followed by Mg (70–290), Mn (15–240) and P (0–350). Present in the wood was also Si (50–190), S (50–200) and Cl (30–110). The bark tissues showed much higher element contents; Ca (4800–19,100 ppm) and K (1600–6400) were the dominating elements, followed by Mg (210–2400), P (210–1200), Mn (110–1100) and S (310–750), but the Cl contents (40–330) were only moderately higher in the bark than in the wood. The young foliage (shoots and deciduous leaves) had the highest K (7100–25,000 ppm), P (1600–5300) and S (1100–2600) contents of all tissues, while the shoots of spruce had the highest Cl contents (820–1360) and its needles the highest Si content (5000–11,300). This paper presented a new approach in fuel characterization: the method excludes the presence of impurities, and focus on different categories of plant tissues. This made it possible to discuss the contents of ash element in a wide spectrum of fuel-types, which are of large importance for the energy production in Finland and Sweden.     

NEXT GENERATION ENGINEERED MATERIALS FOR ULTRA SUPERCRITICAL STEAM TURBINES

正1 ABSTRACT To reduce the effect of global warming on our climate,the levels of CO2emissions should be reduced.One way to do this is to increase the efficiency of electricity production from fossil fuels.This will in turn reduce the amount of CO2emissions for a given power output.Using US practice for efficiency calculations,then a move from a typical US plant running at 37%efficiency to a 760℃/38.5 MPa(1 400/5 580 psi)plant running at 48%efficiency would reduce CO2emissions by 170kg/MW.hr or 25%.     

Aerodynamic performance effects of leading-edge geometry in gas-turbine blades

The purpose of this paper is to illustrate the advantages of the direct surface-curvature distribution blade-design method, originally proposed by Korakianitis, for the leading-edge design of turbine blades, and by extension for other types of airfoil shapes. The leading edge shape is critical in the blade design process, and it is quite difficult to completely control with inverse, semi-inverse or other direct-design methods. The blade-design method is briefly reviewed, and then the effort is concentrated on smoothly blending the leading edge shape (circle or ellipse, etc.) with the main part of the blade surface, in a manner that avoids leading-edge flow-disturbance and flow-separation regions. Specifically in the leading edge region we return to the second-order (parabolic) construction line coupled with a revised smoothing equation between the leading-edge shape and the main part of the blade. The Hodson–Dominy blade has been used as an example to show the ability of this blade-design method to remove leading-edge separation bubbles in gas turbine blades and other airfoil shapes that have very sharp changes in curvature near the leading edge. An additional gas turbine blade example has been used to illustrate the ability of this method to design leading edge shapes that avoid leading-edge separation bubbles at off-design conditions. This gas turbine blade example has inlet flow angle 0°, outlet flow angle −64.3°, and tangential lift coefficient 1.045, in a region of parameters where the leading edge shape is critical for the overall blade performance. Computed results at incidences of −10°,   −5°,   +5°,   +10° are used to illustrate the complete removal of leading edge flow-disturbance regions, thus minimizing the possibility of leading-edge separation bubbles, while concurrently minimizing the stagnation pressure drop from inlet to outlet. These results using two difficult example cases of leading edge geometries illustrate the superiority and utility of this blade-design method when compared with other direct or inverse blade-design methods.     

Hydrogen production by steam-gasification of carbonaceous materials using concentrated solar energy – V. Reactor modeling,optimization, and scale-up

A chemical reactor for the steam-gasification of carbonaceous particles (e.g. coal, coke) is considered for using concentrated solar radiation as the energy source of high-temperature process heat. A two-phase reactor model that couples radiative, convective, and conductive heat transfer to the chemical kinetics is applied to optimize the reactor geometrical configuration and operational parameters (feedstock's initial particle size, feeding rates, and solar power input) for maximum reaction extent and solar-to-chemical energy conversion efficiency of a 5 kW prototype reactor and its scale-up to 300 kW. For the 300 kW reactor, complete reaction extent is predicted for an initial feedstock particle size up to 35 μm at residence times of less than 10 s and peak temperatures of 1818 K, yielding high-quality syngas with a calorific content that has been solar-upgraded by 19% over that of the petcoke gasified.     

Contents in Volume 23,2014

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汽轮机数字电液调节系统挂闸异常的技术完善

分析了200MW汽轮机数字电液调节系统在运行中存在的挂闸异常问题,采取了相应的技术处理措施,且运行实践效果良好。     

新型高压共轨ECU升压模块的数字化开发与优化

为了提高喷油器电磁阀的响应速率,提出了一种基于CPLD(复杂可编程逻辑器件)应用于高压共轨ECU的数字升压模块。鉴于该升压电路结构参数多,其升压电压的恢复响应要求高等特征,基于Pspice建立了升压电路的仿真模型,研究了不同电路参数下升压模块的输出特性,全面优化了该升压模块的性能。结果显示,该升压模块的最大转换效率可以达90%以上。在柴油发动机上对ECU的试验表明,升压电压最大波动不超过10%,其恢复时间仅为1.3ms,功率管最大温升仅为41℃,满足整机运行范围内ECU的需求。     

Trace metal chemistry and silicification of microorganisms in geothermal sinter, Taupo Volcanic Zone, New Zealand

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.     

Assessment methods of material ageing using Sdobyrev''s creep rupture model

The physical aspects of the activation energy, in higher and high temperatures, of the metal creep process were examined. The research results of creep-rupture in a uniaxial stress state and the criterion of creep-rupture in biaxial stress states, at two temperatures, are then presented. For these studies creep-rupture, taking case iron as an example the energy and pseudoenergy activation was determined. For complex stress states the criterion of creep-rupture was taken to be Sdobyrev's, i.e. σ_red = σ₁ β + (1 − β)σ_i, where: σ₁-maximal principal stress, σ_i-stress intensity, β-material constant (at variable temperature β = β(T)). The methods of assessment of the material ageing grade are given in percentages of ageing of new material in the following mechanical properties: 1) creep strength in uniaxial stress state, 2) activation energy in uniaxial stress state, 3) criterion creep strength in complex stress states, 4) activation pseudoenergy in complex stress states. The methods 1) and 3) are the relatively simplest because they result from experimental investigations only at nominal temperature of the structure work, however, for methods 2) and 4) it is necessary to perform the experimental investigations at least at two temperatures.     

Production of hydrogen from sewage biosolids in a continuously fed bioreactor: Effect of hydraulic retention time and sparging

Hydrogen was produced from primary sewage biosolids via mesophilic anaerobic fermentation in a continuously fed bioreactor. Prior to fermentation the sewage biosolids were heated to 70 °C for 1 h to inactivate methanogens and during fermentation a cellulose degrading enzyme was added to improve substrate availability. Hydraulic retention times (HRT) of 18, 24, 36 and 48 h were evaluated for the duration of hydrogen production. Without sparging a hydraulic retention time of 24 h resulted in the longest period of hydrogen production (3 days), during which a hydrogen yield of 21.9 L H₂ kg⁻¹ VS added to the bioreactor was achieved. Methods of preventing the decline of hydrogen production during continuous fermentation were evaluated. Of the techniques evaluated using nitrogen gas to sparge the bioreactor contents proved to be more effective than flushing just the headspace of the bioreactor. Sparging at 0.06 L L min⁻¹ successfully prevented a decline in hydrogen production and resulted in a yield of 27.0  L H₂ kg⁻¹ VS added, over a period of greater than 12 days or 12 HRT. The use of sparging also delayed the build up of acetic acid in the bioreactor, suggesting that it serves to inhibit homoacetogenesis and thus maintain hydrogen production.