甲酸甲烷杆菌PD—1的分离及其生理性状

从厌氧降解苯酚产甲烷发酵波中分离出一株甲酸甲烷杆菌PD-1。该菌株革兰氏染色阴性,不运动,不形成芽孢。细胞单个、两个或多个成链状,单细胞大小为0.4—0.5×2.75—5.0μm,在琼脂培养基表面上菌落呈圆形,37℃培养10天左右菌落小而呈灰白色,14天后直径达2毫米呈谈黄色。利用80％H_2+20％CO_2和甲酸盐产生甲烷,不利用乙酸盐、甲醇、甲胺类,生长不需要瘤胃液、酵母膏、胰蛋白胨和维生素,但添加其中一种时对生长有刺激作用。最适生长温度为40℃,最适生长pH为7。     

一株耐酸碱嗜热产甲烷菌的分离与系统发育分析

从垃圾填埋场分离得到一株嗜热产甲烷菌RY3。该菌株具有优良的耐酸碱性能,其生长pH范围为5.5～10.5,最适生长pH为6.0～8.0。菌株RY3为革兰氏阳性,长杆状,多数单生,不运动;菌落浅黄色,形状近圆形;利用H_2+CO_2或甲酸盐作为唯一碳源生长,不利用乙酸盐,对氯霉素非常敏感。该菌最适生长温度为55～65℃,最适NaCl浓度为0～2%。根据形态和生理生化特性及16S rDNA序列分析将其初步定为Methanothermobacter thermautotrophicus。添加RY3菌液与仅添加厌氧污泥作为接种物相比一周内可使达到最大产甲烷速率所需时间缩短2/3,甲烷总产量提高约1.8倍。     

一株脱硫菌株的分离鉴定及其对硫化物的去除效果验证

为获得适合生物脱硫工程应用的硫氧化细菌,取污水处理厂曝气池活性污泥,采用人工模拟硫化物废水作为硫源富集培养并经分离纯化,得到一株能够高效快速去除废水中硫化物的硫氧化细菌菌株DS-7。该菌为短杆状、长0.8 ~ 2 μm、宽0.6 ~ 0.8 μm、革兰氏阴性,最适生长温度为30℃,最适生长pH值为7.0。通过对该菌的16SrDNA序列测定,并结合其形态和生理特性鉴定,该菌株属于鞘氨醇杆菌属（Sphingobacterium）。Sphingobacterium sp. DS-7去除硫化物性能研究结果表明：当硫化物浓度为650 mg/L时,该菌的4 h硫化物去除率达到95%以上,相应的硫转化率最高达到45.08%,生成的单质硫颗粒形状为不规则八面体。     

燃气轮机压气机叶片涂层的高温适应性研究

为探究压气机叶片涂层在更多级叶片上的应用情况,研究了富铝无机盐涂层和铝基硬质涂层的高温适应性,利用光学显微镜、粗糙度测试仪、扫描电子显微镜、能谱仪和拉伸试验机分别测试了涂层厚度、表面粗糙度、微观组织、元素分布和拉伸结合强度。结果表明：富铝无机盐涂层的厚度为40～60μm,喷涂态和热处理后涂层的表面粗糙度分别为0.570～0.685μm和0.734～0.842μm,微观组织在460℃、2 000 h内保持稳定,热失效过程涂层中的铝元素向基体快速扩散,金属基体氧化,拉伸结合强度降低;铝基硬质涂层厚度为8～12μm,喷涂态和热处理后涂层的表面粗糙度分别为0.324～0.486μm和1.054～1.275μm,微观组织在460℃、1 001 h内保持稳定,热失效过程观察到(Fe, Cr)Al金属间化合物生成,拉伸结合强度约为40 MPa;热处理温度越高、时间越长,铝基涂层越不稳定,当温度不高于460℃时才可满足服役要求。     

产纤维二糖芽孢梭菌的分离及其生理学性状研究

从以造纸(石灰法)废液作为甲烷发酵基质中分离出一株厌氧纤维素分解细菌。该菌琼脂表面菌落呈圆形、乳白色、边缘波状、不产生色素,在纤维素滚管琼脂培养基上培养5天后菌落直径达1.5—2.0毫米。细胞呈直或微弯杆状、0.8—0.5×3.2-4.5微米、周毛、形成末端球形芽孢。革兰氏阴性,最适生长pH7.0,最适生长温度35℃。发酵纤维素、葡萄糖产生氢、二氧化碳、醋酸及微量丙酸、乳酸。     

产甲烷菌固定化新方法及其甲烷化特性

为了克服以PVA为包埋介质对甲烷八叠球菌进行固定化存在的缺点 ,采用吸附和包埋结合法对甲烷八叠球菌进行固定化 ,并用固定化甲烷八叠球菌处理人工废水和豆制品废水 ,对其特性进行研究。用人工废水运行的结果表明 ,最高容积负荷为 14 7kgCOD/m3·d ,最高COD去除率为 94 3 % ,最低水滞留期为 16 4h ,甲烷含量为 65 %～73 %。用豆制品废水运行的结果表明 ,最高COD负荷 17 6kgCOD/m3·d ,平均容积负荷 8 2kgCOD/m3·d,最短水滞留期 13 7h。最高产气率 7L/d·L平均产气率固定化为非固定化的 15 .2倍 ,最高COD去除率达到了 87.0 % ,运行期间固定化介质不上浮、不膨胀 ,具有很好的传质和脱气性能 ,较好的解决了包埋法固定化中存在的问题。     

辐射制冷膜的性能分析与优化设计

根据基尔霍夫定律和光学薄膜理论,利用光学设计软件Macleod研究辐射制冷膜的材料与结构对制冷性能的影响。辐射制冷膜要求在0.3～3.0μm的太阳波段具有较高反射率,阻止物体得热;在8～13μm的红外波段具有较高发射率,降低自身温度。研究发现:由于SiO_2在8～13μm波段的反射率低,在其他波段的反射率高,是制造辐射膜的理想材料。高分子聚合物PS与SiO_2交替叠加形成的复合膜在8～13μm波段会产生声子-极化子激发的共振现象,可进一步降低反射率,因此PS是提高辐射制冷薄膜性能的有效辅助材料。经过Simplex法优化,得到辐射制冷膜以SiO_2-PS-SiO_2结构组合,各层厚度依次为0.2、0.8、70μm时,其辐射力高达136.2 W/m~2,平均发射率达到92.12%。     

马铃薯渣与鸡粪混合原料厌氧发酵条件优化

以混合后的马铃薯渣和鸡粪为原料,研究了其总固形物含量(TS)、起始p H以及接种量3个因素对厌氧发酵甲烷产量的影响,并利用正交试验对影响沼气产量和甲烷含量的因素进行了优化。结果表明,在初始TS为3%的处理中,产气时间、产气量和甲烷含量分别为7 d,383.2 m L/g和45.3%,在所有处理中最高;在初始p H为7.0的处理中,产气时间、产气量和甲烷含量分别为7 d,342.5 m L/g和45.2%;在接种量为5%,8%,10%和12%的处理中,后两种处理在沼气产量和甲烷含量方面表现最好,产气量分别为368.4 m L/g和405.4 m L/g,12%处理的产气量最高。优化结果表明,3个因素对厌氧发酵影响的重要性为TS>p H>接种量,最适合的组合为初始TS 3%,p H 7.0和接种量10%。在此优化培养条件下,发酵体系的产气量为383.2 m L/g。     

霍林河盆地煤层气地质特征研究

主要是从霍林河河组的地质条件及其煤层特征双角度出发,详细地阐述了霍林河盆地煤层气的基本地质特征,指出煤的镜质组反射率多在0.5%~0.6%之间,煤质含气量最高为7.7m3?t-1。煤质中煤层气含量以及煤层气中甲烷含量随深度加大而迅速增加。400m以下为甲烷带,400m以上为甲烷——氮气带。同时,预测了有利于煤层气形成和勘探的有利地段,9-73孔、21-11孔附近地区为最有利煤层气勘探区。     

大庆油田预交联凝胶颗粒/聚合物体系注入性能评价

预交联凝胶颗粒(preformed particle gel,简称PPG)作为一种新型深部液流转向剂,在室内实验中表现出了较好的调剖效果。本文利用1m长岩心物理模拟实验,评价了大庆油田自主研制的预交联凝胶颗粒/聚合物体系的注入性能。结果表明,粒径为0.15～0.3mm、膨胀倍数为3的预交联凝胶颗粒与聚合物组成的预交联凝胶颗粒/聚合物体系,在渗透率为500×10^-3μm²、2000×10^-3μm²、4000×10^-3μm²的3种1m长人造岩心的阻力系数和残余阻力系数分别为63.7、50、41.9和27.9、21.4、11.6,能够顺利注入3种岩心,且能平稳注入其深部,在岩心中具有较好的渗流能力。预交联凝胶颗粒/聚合物体系注入油层后不仅能从宏观上有效调堵优势渗流通道,进一步扩大波及体积,而且微观上能够形成压力扰动,进行局部压力场动态调整,最大程度地实现均衡驱替,进一步提高聚驱后采收率,预交联凝胶颗粒/聚合物体系将成为大庆油田聚驱后提高采收率的新技术,具有较好的...     

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.     

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。     

Contents in Volume 23,2014

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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.