Parametric optimum design of an irreversible photon-enhanced thermionic emission solar cell hybrid system

考虑实际系统中存在的多种传热损失,本文建立一类不可逆光子增强热离子发射太阳能电池与温差热电发电器组合而成的混发电系统模型.基于太阳能电池与温差热电发电器之间的能量平衡方程,导出该混合系统输出功率和效率的表达式.通过数值计算,详细分析了光增热离子太阳能电池的面积、阴极半导体材料的禁带宽度、电子亲和势以及温差热电发电器的无量纲电流对混合系统优化性能的影响,确定混合发电系统运行于最大效率下光子增强热离子太阳能电池阴极材料的禁带宽度,电子亲和势,电池面积和温差热电发电器的无量纲电流的优化值.结果表明,采用混合发电系统,太阳能转换效率与工作于相同条件下的单一光增热离子太阳能电池的效率相比可提高约10%,而光增热离子太阳能电池阴极半导体材料禁带宽度在最大效率下的优化值则比单一光增热离子太阳能电池的小.本文所得结果可为实际光子增强热离子太阳能电池混合发电系统的设计和优化运行提供理论依据.A class of an irreversible thermodynamic model of the hybrid power system consisting of a photon-enhanced thermiomic emission solar cell(PETSC) and a thermoelectric generator(TEG) is established, in which some main irreversible losses existing real hybrid systems are taken into account. Based on equations of the energy balance between the solar cell and thermoelectric generator,expressions for the power output and efficiency of the hybrid system are derived. By using the numerical calculation, influences of the cell area, the energy band gap and electron affinity of the cathode semiconductor materials, and the dimensionless current of the generator on the optimal performance of the hybrid system are analyzed in detail. Under the operating condition of maximum efficiency, the optimal values of some important performance parameters of the hybrid system, such as the energy band gap, electron affinity, area and dimensionless current, are given. The results obtained in this paper show that by using the hybrid system, the solar energy conversion efficiency can be increased by about 10% and the optimal value of the energy band gap for the PESTC of the hybrid system at maximum efficiency is smaller than that of the energy band gap for alone operating PESTC. All the results obtained in this article will provide some theoretical basis for the design and optimal operation of practical PETSC hybrid system.国家自然科学基金(批准号:11175148,11305064);; 福建省自然科学基金(批准号:2011J01012);; 华侨大学引进人才科研启动资金(编号:09BS510)资助项

Evaluation technique of the loss of coastal ecosystem services caused by sea reclamation project with three methods

在分析填海工程对海洋环境影响的基础上,结合《海洋生态资本评估技术导则》(gb/T 28058-2011)综合构建了填海工程对海洋生态系统服务功能损耗评估指标体系。分别采用价值评估法、能值分析法和物种丰度经验公式法对生态损耗进行价值评估,以福鼎市塔下新建填海工程为分析对象进行了实证评估,生态系统服务价值总损失量分别为672.0万元·年–1、809.2万元·年–1和133.3万元·年–1。通过与国内相关研究成果进行比较,分析三种评估方法的可行性和适用性,以期在实际环境影响评价工作中将工程外部成本纳入项目经济损益分析,为海岸带经济可持续发展提供技术支撑。Based on the effects of marine environment caused by sea reclamation and Technical Directives for Marine Ecological Capital Assessment(GB/T 28058-2011), the indexes of the losses of coastal ecosystem services caused by sea reclamation were built.The lost value of sea reclamation was calculated with three methods including economic evaluation, emergy analysis and biodiversity experiential formula which were applied in the new sea reclamation in Taxia Fuding Fujian Province separately, and the total ecosystem lost value was 672.0×104yuan·a–1, 809.2×104yuan·a–1, and 133.3×104yuan·a–1 correspondingly.Compared with other relevant researches, the methods are expected to apply in EIA economic evaluation in order to consider external cost and to apply in coastal economic sustainable development.海洋渔业安全环境保障服务系统关键技术研究及示范应用(201205006

Preparation of self-assembled cholesterol modified pullulan nanopaticles

的:经琥珀酸间隔臂将胆甾醇连接到普鲁兰分子链上,对普鲁兰多糖进行疏水改性,获得不同取代度的胆甾醇基-普鲁兰(cholesterol-modified pullulan,CHSP)改性材料,并研究CHSP材料在水中的自组装性质。方法:利用1-乙基-(3-二甲基氨基丙基)碳酰二亚胺盐酸盐(EDC)和4-二甲氨基吡啶(DMAP)催化琥珀酰胆甾醇(cholesterol succinate,CHS)与普鲁兰多糖反应,将琥珀酰胆甾醇接枝在普鲁兰分子链的羟基上,得到疏水改性的普鲁兰多糖衍生物。应用傅立叶红外光谱仪(Fourier transform infrared spectroscopy,FT-IR),核磁共振仪(proton nuclear magnetic resonance,1H-NMR)对产物进行表征。利用透析法制备自组装纳米球。通过透射电镜(transmission electron microscopy,TEM),动态激光粒度分析仪(dynamic laser lightscattering,DLS)表征了纳米粒的形态和粒径。以芘为荧光探针,通过荧光检测分析,测定CHSP的临界胶束浓度(critical... 【英文摘要】 Objective:To synthesize cholesterol-modified pullulan(CHSP) conjugates and to preparate self-assembled nanoparticles.Methods:The cholesterol-modified pullulan(CHSP) was prepared by the reaction of pullulan and cholesterol succinate(CHS) in DMSO,using EDC and DMAP as catalysts.The polymer structure was confirmed by the Fourier transform infrared spectroscopy(FT-IR) and proton nuclear magnetic resonance(1H-NMR).The self-assembled nanoparticles were analyzed by transmission electron microscopy(TEM),dynamic las...国家重大科学研究计划项目(2006CB933300);; 博士点基金(20060023050

选择性胆甾化壳聚糖两亲材料的合成及其自聚集现象

以邻苯二甲酰化壳聚糖(PHCS)为中间体,将胆甾醇琥珀酸酯(CHS)选择性接枝到壳聚糖的6-OH上,再经水合肼脱去N-邻苯二甲酰亚胺基,游离出氨基,获得疏水改性的O-胆甾醇基壳聚糖(O-CHCS)。采用傅立叶红外光谱仪(FT-IR)和核磁共振仪(1HNMR)对产物进行结构表征;通过透析法制备O-CHCS自聚集纳米粒,用透射电镜(TEM)和动态激光粒度分析仪(DLLS)表征了纳米粒的形态、粒径、粒径分布及表面电位;以芘为荧光探针测定O-CHCS的临界胶束浓度(CMC)。结果表明,合成的O-CHCS是一种两亲性化合物,能在水中自聚集形成粒径约337nm,ζ电位为+25.6mV的球形纳米粒,获得的纳米粒具有明显的核壳结构和较低的临界胶束浓度,有望成为疏水性药物或DNA的载体

Clinical study of relationship between sleep apnea syndrome and metabolic syndrome of petrol field workers

目的分析油田职工阻塞性睡眠呼吸暂停综合征(obstructivesleepapneasyndrome,OSAS)与代谢综合征(metabolicsyndrome,MS)的关系。方法选择2013年3月至2015年8月齐齐哈尔医学院第五附属医院大庆龙南医院急诊科与呼吸科因OSAS就诊的共计100例油田职工患者作为研究对象,根据OSAS的严重程度分为单纯鼾症组26例(A组),轻度OSAS组42例(B组)和中重度OSAS组32例(C组)并进一步比较各组间患者睡眠饮食情况评分和代谢相关指标之间的差异性以及进一步计算每组MS的发病率。Logistic回归分析MS的发病率与OSAS的严重程度是否具有相关性。结果A、B、C三组患者睡眠情况评分以c组(8.3&plusmn;1.2)分,饮食情况评分以C组(7.6&plusmn;1.4)分和MS的发病率以C组(23/32)均为最高,差异均有统计学意义(P〈0.05);单因素与多因素Logistic回归分析MS的发病风险与OSAS的严重程度均具有相关性,多因素回归系数r=11.211[OR=9.412,95%CI:5.992~15.202]。结论油田职工OSAS病情的严重程度可明显影响患者的日常睡眠与饮食状况;随着OSAS程度加重,MS发病率增加,OSAS可能是MS发病的一个危险性因素。</p

Thermal-mechanical coupled simulation on residual stress and distortion of high-strength aluminum alloy sheet after friction stir welding

针对航空领域中常用的7B04高强铝合金,基于剪切摩擦生热理论,建立了适用于薄板搅拌摩擦焊(FSW)过程的自适应热源模型,利用有限元软件MSC.Marc建立了FSW过程的热力耦合有限元模型,并通过子程序二次开发,将建立的热源模型载入到有限元模型中,对7B04铝合金薄板的FSW过程进行瞬态热力耦合模拟。预测并分析了FSW过程中铝合金板材内部的温度分布与演化、焊接接头附近区域的残余应力分布及板材的最终变形情况,通过开展FSW工艺试验从温度场和残余应力两方面对模型的可靠性和模拟结果的准确性进行了验证。此外,利用经过验证的有限元模型对搅拌头机械载荷在残余应力和变形中的影响作用进行了深入分析

磁制冷材料MnFeP0.45As0.55的热力学循环性能分析

一级相变磁制冷材料MnFeP1-xAsx具有巨磁热效应,其在制冷循环中的热力学性能值得探索。本文以MnFeP0.45As0.55的等磁场热容随温度变化实验数据为基础,应用热力学分析和数值计算方法,获得0T、2T应用磁场下的熵温曲线,并设计不同温跨的多种回热Ericsson制冷循环,计算制冷循环的主要热力学参量,揭示非平衡回热量、净制冷量、性能系数等随制冷空间温度变化规律,同时还与Gd、Gd5Si2Ge2在10 K温跨时的净制冷量进行比较,结果表明MnFeP0.45As)0.55的最大净制冷量更大。国家自然科学基金资助项目(No.51776178

Characterization of diguanylate cyclase metabolism-related gene in Azorhizobium caulinodans ORS571

[Objective] To study the phenotypes of Azorhizobium caulinodansORS571 mutant strain lacking the diguanylate cyclase AZC-2412, and to explore its functional mechanism. [Methods] We constructed the gene knockout system of rhizobia based on the homologous recombination of cre-loxp, and the mutant strain was constructed by the triparental conjugation. Growth rate, chemotactic ability, exopolysaccharide production, biofilm formation and other phenotypes of the wild type and mutant strains were studied. [Results] The mutant strain had almost the same growth rate as the wild type. Compared with the wild type, the mutant strain impaired in exopolysaccharide production, chemotaxis behavior and biofilm formation due to lower levels of c-di-GMP in cells. [Conclusion] The deletion of the diguanylate cyclase AZC-2412 reduces level of c-di-GMP levels. It had a regulatory effect on the exopolysaccharide production, bacterial motility, biofilm formation, cell flocculation of Azorhizobium caulinodans ORS571 and its interaction with host plant.</p

一种搅拌摩擦焊焊具在高转速焊接中的应用

本发明公开了一种搅拌摩擦焊焊具在高转速焊接中的应用，属于搅拌摩擦焊领域。所述焊具由夹持体、轴肩和搅拌针所构成，轴肩的端面为内凹型,且在该内凹端面上加工有螺旋槽结构。焊接中，焊具的旋转速度为3500-50000r/min，焊接速度为5-2000mm/min，焊具轴线方向与被焊母材表面法线方向的夹角为0-3°。本发明解决了当前高转速搅拌摩擦焊工艺所面临的焊接载荷大、焊接成本高、焊接效率低、可适用范围窄等问题