电活性双酚A的合成及其锂离子电池防过充性能研究

对双酚A进行结构修饰,经甲醚化、氰基取代,设计合成了2,2-双-(4-(β-氰基乙氧基)苯基)丙烷（DBDCN）、2-(4-(β-氰基乙氧基)苯基)-2'-(4-甲氧基苯基)丙烷（DBMCN）和2,2-双-(4-甲氧基苯基)丙烷（DBMB）,将三种化合物作为锂离子电池的防过充添加剂开展研究。在锂离子电池电解液1 mol/L LiPF₆/[碳酸乙烯酯（EC）+ 碳酸二乙酯（DEC） + 碳酸甲乙酯（EMC） （1∶1∶1,体积比）]中分别添加0.1 mol/L的DBDCN、DBMB和DBMCN,采用循环伏安、过充测试、电化学阻抗、恒流充放电和扫描电子显微镜等手段研究DBDCN、DBMB和DBMCN的防过充性能,并探讨添加剂与正极材料LiFePO₄的相容性。这些化合物的氧化还原电位均为4.1 V,显著提高了电池的过充保护。100%过充测试和5 V截止电压测试结果表明,DBMB的防过充性能明显优于DBDCN和DBMCN。以0.5 C倍率电流循环100圈,基础电解液和分别添加0.1 M DBDCN、DBMB、DBMCN的电池放电比容量分别为134.5 mA∙h/g、135.3 mA∙h/g、132.8 mA∙h/g和127.0 mA∙h/g,容量保持率分别为87.7%、87.0%、89.5%和84.3%。结果表明,DBMB对电池防过充作用最明显。     

PMMA+LiClO4有机薄膜的离子导电性能

用PMMA预聚合单体与LiClO4粉末以不同比例直接混合均匀,固化成3mm厚的板,以它为靶,在纯氩气气氛及rf-溅射沉积条件下制备各种薄膜,用双电层电容常数法研究它们的离子导电性能.在室温下测试,外加信号120mV,频率400Hz.实验结果表明,当氩气压强(PAr)为4.7-7.2Pa,靶掺杂质量比为10%,射频功率密度为3.9-4.2W/cm2时得到的薄膜为离子导体.当氩气压强为6.0Pa,射频功率密度为4.24W/cm2时,膜的双电层电容常数为7.0×10-2μf/cm2,离子导电性能最好,其电阻率>1011Ω.cm.利用该离子导体薄膜制备的可变反射电致变色镜,Al(40nm)/α-WO3(100nm)/PMMA+LiClO4(160nm)/NiO(80nm)/ITO/glass,着色态和漂白态可见光平均反射比分别为0.23和0.69.利用红外光谱(1900-500cm-1)对纯PMMA和PMMA+LiClO4离子导体进行分析,发现离子导体膜"-C-O-CH3"侧链的吸收峰在1185.7cm-1,非离子导体膜的吸收峰在969.2cm-1处,前者侧链具有较强的极性.     

PMMA LiClO_4有机薄膜的离子导电性能

用 PMMA预聚合单体与 Li Cl O4粉末以不同比例直接混合均匀 ,固化成 3mm厚的板 ,以它为靶 ,在纯氩气气氛及 rf -溅射沉积条件下制备各种薄膜 ,用双电层电容常数法研究它们的离子导电性能。在室温下测试 ,外加信号 1 2 0 m V,频率 40 0 Hz。实验结果表明 ,当氩气压强 (PA r)为4.7— 7.2 Pa,靶掺杂质量比为 1 0 % ,射频功率密度为 3.9— 4.2 W/ cm2 时得到的薄膜为离子导体。当氩气压强为 6.0 Pa,射频功率密度为 4.2 4 W/ cm2 时 ,膜的双电层电容常数为 7.0× 1 0 -2 μf/ cm2 ,离子导电性能最好 ,其电阻率 >1 0 1 1Ω .cm。利用该离子导体薄膜制备的可变反射电致变色镜 ,Al(40 nm) /α- WO3(1 0 0 nm) / PMMA Li Cl O4(1 60 nm) / Ni O(80 nm) / ITO/ glass,着色态和漂白态可见光平均反射比分别为 0 .2 3和 0 .69。利用红外光谱 (1 90 0— 50 0 cm-1 )对纯 PMMA和 PMMA Li Cl O4离子导体进行分析 ,发现离子导体膜“- C- O- CH3”侧链的吸收峰在 1 1 85.7cm-1 ,非离子导体膜的吸收峰在 969.2 cm-1处 ,前者侧链具有较强的极性。     

圆柱源理论用于地下U型盘管换热器的模拟研究

分析介绍了引入“负荷聚合”方法的改进型圆柱热源(热汇)理论模型，并运用圆柱源理论对太阳能一土壤源联合运行热泵系统全天运行模拟，指出联合运行模式较单独土壤源运行模式节能10％～12％，为圆柱源理论模型应用和太阳能-土壤源热泵运行模式的选择提供参考。     

水电站系统径流补偿调节优化模型

本文针对水电站系统径流补偿调节计算中面临的如何克服高维多阶段求解的障碍和寻求既能使系统保证出力提高,又能兼顾系统总电能的运行决策,提出了聚合库偶-参数-动规模型。即用聚合库偶原理使高维问题变为多个二维问题;通过参数调整和离散增量动态规划法,求系统目标函数极大化的最优解。该模型在微机(JB-3000)上对三个梯级电站的检验,取得了预期的效果。     

聚合物-富勒烯本体异质结太阳电池的发展

综述了有机光伏器件能量转换效率从低于1%到如今12%关键性里程碑事件,简要概述了柔性大面积有机太阳电池生产技术的发展状况。随着"10%-10"目标(转换效率10%和使用寿命10年)的迫近,有机光伏技术面临着向大面积太阳电池产业化转变的巨大挑战,一些有关有机光伏未来发展方向的意见在本综述中被提出。     

市政污泥与水泥生料混合热重及动力学分析

为研究水泥窑协同处置市政污泥的燃烧动力学特性,采用热重分析方法分别对市政污泥、煤和水泥生料及三者混合样品进行热动力学分析,求解了反应活化能和机理函数。结果表明:市政污泥燃烧有4个阶段,有机物分解和部分挥发分析出阶段活化能为69.87 kJ/mol、机理函数为(-ln(1-α))~4,剩余挥发分析出和固定碳燃尽阶段活化能为78.94 kJ/mol、机理函数为(-ln(1-α))~3;煤和水泥生料热重分析过程分为煤燃烧和生料分解2个阶段,反应活化能分别为43.58、118.21 kJ/mol,机理函数分别为(1-α)~(-1)-1、((1+α)~(1/3)-1)~2;市政污泥替代20%煤后,第1阶段活化能基本不变,机理函数由(1-α)~(-1)-1变为(1-2α/3)-(1-α)~(2/3),反应机理由"化学反应"变为"圆柱对称型三维扩散",第2阶段活化能降低,机理函数表达式由((1+α)~(1/3)-1)~2变为((1+α)~(-1/3)-1)~2,反应机理不变。     

磷钨酸铯催化工业蔗渣木质素制备酚类化学品

通过催化降解的方法,可以有效将木质素转为高附加值的单酚类化学品。文章首先以酸析法从蔗渣碱法造纸黑液中回收工业蔗渣木质素(IBL),接着采用Cs_(2.5)H_(0.5)PW_(12)O_(40)为催化剂,在250℃乙醇-水体系中反应180 min催化IBL降解,可得到4-乙基苯酚(8.1%),4-乙烯基苯酚(1.3%),3-甲基-4-乙基苯酚(1.9%),4-异丙基-苯酚(3.5%)和2,6-二甲氧基苯酚(7.8%)5种主要酚类化合物。以主要产物4-乙基苯酚收率为指标,考察了催化剂取代度、比表面积和孔结构、反应温度、反应时间等条件对催化效率的影响。结果表明,通过多孔炭负载可以有效提高磷钨酸铯的催化效率,以比表面积、孔体积和孔径分别为0.340 cm~3/g,5.888 nm和341.783 m~2的活性炭负载型磷钨酸铯(Cs_(2.5)H_(0.5)PW_(12)O_(40)/C2)为催化剂,在350℃乙醇-水(v/v=9/1)体系中反应120 min催化IBL降解,4-乙基苯酚的收率最高可达12.36%。     

气分-聚丙烯联合装置的节能改造

分析了影响气分-聚丙烯联合装置能耗的主要因素,通过技术改造、提高产量等一系列措施,使能耗逐年下降.     

计及风火系统聚合特性的虚拟电厂经济调度研究

提出一个VPP(虚拟发电厂)聚合出力特性的含新能源电网的两阶段经济调度模型。第一阶段基于包含若干风场与火电机组的VPP聚合出力特性决策VPP的总出力;第二阶段将总出力在VPP内部各发电单元之间进行分配。上述两个阶段都采用线性规划方法求解。基于IEEE—6母线电网的数值算例的计算结果表明,与传统经济调度方法相比,本研究提出的模型能降低风电弃风量近50%。     

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

<正>~~     

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.