固体聚合物电解池膜电极优化研究

采用催化剂直接涂膜(CCM)方法制备膜电极(MEA),研究阴极和阳极催化层中使用不同催化剂活性组分担载量对膜电极性能的影响。采用电化学阻抗谱(EIS)分析MEA的电化学特性。研究结果表明:阳极催化层中,随着Ir担载量的增加,在相同电流密度条件下,电解池的极化电压下降,当Ir担载量增加到2.5 mg/cm~2以上,极化电压趋于稳定;阴极催化层中,随着Pt担载量的增加,在相同电流密度条件下,电解池的极化电压下降,当Pt担载量增加到0.5 mg/cm~2以上,极化电压下降不明显,趋于稳定。随着电极催化层活性组分担载量的增加,MEA的欧姆阻抗R?和电荷传递阻抗RCT的减小。对于阴极催化层,当Pt/C催化层的催化剂担载量过多时,由于传质和电荷传递阻力显著增加,导致MEA的R?和RCT增大。阳极催化层Ir的最佳担载量为2.5 mg/cm~2,阴极催化层Pt的最佳担载量为0.5 mg/cm~2。     

质子交换膜燃料电池电催化剂研究

阻碍PEMFC商业高.提高催化剂的利用率不仅与催化剂的类型有关,电极制备工艺的优劣也对此有较大影响.高性能电催化剂的研究成果在推动了质子交换膜燃料电池快速发展的同时,对优化电极制备工艺也很有现实意义.本文对目前质子交换膜燃料电池的电催化剂和MEA制备技术的最新研究工作进行了分析评述.     

纳米复合Li2SO4质子传导膜H2S中温燃料电池

开发了一种制备纳米复合Li_2SO_4质子传导电解质和膜电极组装(MEA)的工艺.与传统的丝网涂布工艺不同,新的制备工艺是将阳极、阴极催化剂与纳米复合电解质同时一次压制成MEA.这就使得MEA的设计具有某些结构上的特点,由于膜厚减少和电极与电解质之间的接触良好,可以降低电解质与电极之间的欧姆电阻,提高其机械和导电性能,增加膜的质子传导性以及改善电池的性能.用电子扫描电镜(SEM)和电化学阻抗分析技术对电解质薄膜进行了表征,结果表明,纳米复合材料改善了MEA的总体性能.由于膜的致密性和不透气性,不会发生气体穿透过膜的现象.MEA在H_2S环境中很稳定.电池结构为H_2S,(MoS_2/NiS Ag 电解质量 淀粉) /Li_2SO_4 Al_2O_3/(NiO Ag 电解质量 淀粉),空气、MEA厚为0.8mm、电解质组成为65% Li_2SO_4 35% Al_2O_3的单电池在680℃时产生最大功率密度为130mW/cm~2,相应的电流密度为200mW/cm~2.     

Pt含量对燃料电池膜电极组件结构及性能的影响

本文基于Catalyst Coated Membrane（CCM）技术,采用70%Pt/C催化剂制备质子交换膜燃料电池（PEMFC）的核心部件膜电极组件（Membrane electrolyte assembly,MEA）。考察了电池的放电性能,并利用循环伏安（CV）、电化学阻抗谱（EIS）、扫描电镜（SEM）等技术对电池的电化学性能进行了表征。研究表明采用质量分数为70%的Pt/C催化剂与Nafion的最佳质量比例为6：1,MEAΩ在600mA/cm~2电流密度下,电压能达到0.69V,催化层的厚度显著降低,性能也明显优于40%Pt/C催化剂制备的MEA。     

用EIS研究PEMFC膜电极的运行条件对其性能的影响

在质子交换膜燃料电池（PEMFC）中，采用电化学阻抗谱（EIS）研究了膜电极（MEA）的一些运行条件对其工作性能的影响，并探讨了其作用机理．通过测量数据的解析和等效电路的数学模拟，得到了与MEA结构关联的电极诸参数随电池温度和反应气体压力的变化规律．研究表明，MEA的氧电极的电化学反应电阻随电池温度的升高显著减小，氧电极的双电层电容随电池温度的升高有所增加，表明电极有效面积得以增加，有利于MEA工作性能的提高．     

制备条件对卟啉钴氧还原催化性能的影响

采用合成后未经提纯的粗卟啉、Co(OH)2和碳粉制备卟啉钴用于质子交换膜燃料电池阴极氧还原反应电催化剂.研究了试样组成和热处理温度等制备条件对催化性能的影响.采用薄层电极结合循环伏安法和单体燃料电池I V特性评价了所制备的电催化剂对氧还原反应的催化活性.     

膜电极热压条件对直接甲醇燃料电池性能影响的研究

该研究以Nafion 115为质子交换膜,利用热压法制备膜电极（MEA）,对直接甲醇燃料电池进行了性能测试。实验结果表明,不同的热压温度及压力下制备的膜电极在单电池性能测试中表现出不同的极化曲线性能,优化膜电极制备温度及压力可有效地改善直接甲醇燃料电池的性能。     

基于钛网基膜电极组件的被动式直接甲醇燃料电池

基于钛网基膜电极组件（membrane electrode assembly,MEA）设计并制作被动式直接甲醇燃料电池（directmethanol fuel cell,DMFC）．钛网基MEA以钛金属网作为电极支撑体基底材料,Nafionll7作为质子交换膜．PtRU／XC-72R作为阳极催化剂,Pt／XC-72R作为阴极催化剂．被动式DMFC壳体采用有机玻璃材料制作．密封元件采用硅胶片制作．紧固件选用标准件．在室温空气自呼吸条件下,选取不同甲醇浓度的电解液．测试了基于钛网基MEA的被动式DMFC极化性能．结果表明：当电解液中甲醇浓度从0．5mol／L经过1．0mol／L增大到1．5mol／L时．基于钛网基MEA的被动式DMFC的功率密度峰值呈现先增大、后减小的规律;当甲醇浓度为1．0mol／L。电池功率密度峰值为3．91mW/cm2．     

异型Ti电极直接乙醇燃料电池的制备与性能

采用Pt/C作为阴极催化剂,PtRu/C作为阳极催化剂,Nafion115和Nafion液涂覆膜作为质子交换膜,管状Ti丝(管)和平板式Ti网作为制备异型直接乙醇燃料电池的阴极和阳极的载体材料,制备管状阴极和平板阳极.观察了异型阴极和阳极的组织和结构,并通过单电池试验,研究了异型电极对直接乙醇燃料电池(DEFCs)性能的影响.结果表明,管状阴极涂覆的Nafion膜均匀一致,阳极催化剂与Ti网的结合能力较强,较高的O2流量有利于提高DEFCs单电池的性能,当膜载量达到25.0 mg/cm2以上时,会提高DEFCs单电池阻抗,当膜载量小于20.2 mg/cm2时,电池的使用寿命大大降低.     

涂覆法制备TiO2薄膜光电极及催化性能研究

用涂覆法制备了TiO2薄膜光电极，并对其进行了XRD和SEM的表征。以该电极为工作电极，铜片为电极，饱和甘汞电极为参比电极，建立了三电极光电催化体系，研究了此TiO2薄膜的光电催化性能以及外加偏压对反应速率的影响。结果表明：利用涂敷法制备TiO2薄膜电极是一种较好的方法；外加偏压可抑制光生电子－空穴的复合，提高苯酚的光催化效率；外加阳极偏压的光学催化速率优于外加阴极偏压的速率；在一定范围内，外加阴极偏压越大，苯酚的降解速率越快。     

Markedness and its Interpretation in Language Use

Language markedness is a common phenomenon in languages, and is reflected from hearing, vision and sense, i.e. the variation in the three aspects such as phonology, morphology and semantics. This paper focuses on the interpretation of markedness in language use following the three perspectives, i.e. pragmatic interpretation, psychological interpretation and cognitive interpretation, with an aim to define the function of markedness.     

Lower Paleozoic oil relationships within Williston Basin, Canada

The Williston Basin is a significant petroleum province, containing oil production zones that include the Middle Cambrian to Lower Ordovician, Upper Ordovician, Middle Devonian, Upper Devonian and Mississippian and within the Jurassic and Cretaceous. The oils of the Williston Basin exhibit a wide range of geochemical characteristics defined as "oil families", although the geochemical signature of the Cambrian Deadwood Formation and Lower Ordovician Winnipeg reservoired oils does not match any "oil family". Despite their close stratigraphic proximity, it is evident that the oils of the Lower Palaeozoic within the Williston Basin are distinct. This suggests the presence of a new "oil family" within the Williston Basin. Diagnostic geochemical signatures occur in the gasoline range chromatograms, within saturate fraction gas chromatograms and biomarker fingerprints. However, some of the established criteria and cross-plots that are currently used to segregate oils into distinct genetic families within the basin do not always meet with success, particularly when applied to the Lower Palaeozoic oils of the Deadwood and Winnipeg Formation.     

An Analysis of Catherine＇s Character——Wuthering Heights

Wuthering Heights, Emily Bronte＇s only novel, was published in December of 1847 under the pseudonym Ellis Bell. The book did not gain immediate success, but it is now thought one of the finest novels in the English language. Catherine is the key character of this masterpiece, because everybody and everything center on her though she had a short life. We can understand this masterpiece better if we know Catherine well.     

Characterization of Ordovician carbonate reservoirs, southeastern Saskatchewan, Canada

The discovery of the prolific Ordovician Red River reservoirs in 1995 in southeastern Saskatchewan was the catalyst for extensive exploration activity which resulted in the discovery of more than 15 new Red River pools. The best yields of Red River production to date have been from dolomite reservoirs. Understanding the processes of dolomitization is, therefore, crucial for the prediction of the connectivity, spatial distribution and heterogeneity of dolomite reservoirs.The Red River reservoirs in the Midale area consist of 3～4 thin dolomitized zones, with a total thickness of about 20 m, which occur at the top of the Yeoman Formation. Two types of replacement dolomite were recognized in the Red River reservoir: dolomitized burrow infills and dolomitized host matrix. The spatial distribution of dolomite suggests that burrowing organisms played an important role in facilitating the fluid flow in the backfilled sediments. This resulted in penecontemporaneous dolomitization of burrow infills by normal seawater. The dolomite in the host matrix is interpreted as having occurred at shallow burial by evaporitic seawater during precipitation of Lake Almar anhydrite that immediately overlies the Yeoman Formation. However, the low δ18O values of dolomited burrow infills (-5.9‰～ -7.8‰, PDB) and matrix dolomites (-6.6‰～ -8.1‰, avg. -7.4‰ PDB) compared to the estimated values for the late Ordovician marine dolomite could be attributed to modification and alteration of dolomite at higher temperatures during deeper burial, which could also be responsible for its 87Sr/86Sr ratios (0.7084～0.7088) that are higher than suggested for the late Ordovician seawaters (0.7078～0.7080). The trace amounts of saddle dolomite cement in the Red River carbonates are probably related to "cannibalization" of earlier replacement dolomite during the chemical compaction.     

Design and analysis of generic LBS application developing platform

Location based services is promising due to its novel working style and contents.A software platform is proposed to provide application programs of typical location based services and support new applications developing efficiently. The analysis shows that this scheme is easy implemented, low cost and adapt to all kinds of mobile nework system.     

橡胶颗粒沥青混合料低温抗裂性试验研究

以AC-13级配为基础,将橡胶颗粒代替部分集料掺入混合料中,以低温弯曲试验为评价方法对不同橡胶颗粒掺量下沥青混合料的低温抗裂性进行研究,并引入应变能密度值对混合料的低温抗裂性进行综合评价.试验结果表明:橡胶颗粒沥青混合料试件的破坏微应变均超过2 300,满足冬寒区的技术指标;无论是否掺加橡胶颗粒,随着温度的下降,沥青混合料破坏时的最大弯拉强度增大,弯拉应变降低,劲度模量增大;弯曲应变能密度在胶粒掺量为1%左右时具有较大的弯曲应变能密度值,此时橡胶颗粒沥青混合料具有较好的低温抗裂性.     

低渗透非均质砂岩油藏启动压力梯度研究

理论推导与室内实验相结合,建立了低渗透非均质砂岩油藏启动压力梯度确定方法。首先借助油藏流场与电场相似的原理,推导了非均质砂岩油藏启动压力梯度计算公式。其次基于稳定流实验方法,建立了非均质砂岩油藏启动压力梯度测试方法。结果表明:低渗透非均质砂岩油藏的启动压力梯度确定遵循两个等效原则。平面非均质油藏的启动压力梯度等于各级渗透率段的启动压力梯度关于长度的加权平均;纵向非均质油藏的启动压力梯度等于各渗透率层的启动压力梯度关于渗透率与渗流面积乘积的加权平均。研究成果可用于有效指导低渗透非均质砂岩油藏的合理井距确定,促进该类油藏的高效开发。     

A computer generator for randomly layered structures

AcomputergeneratorforrandomlylayeredstructuresYUJia shun1,2,HEZhen hua2(1.TheInstituteofGeologicalandNuclearSciences,NewZealand;2.StateKeyLaboratoryofOilandGasReservoirGeologyandExploitation,ChengduUniversityofTechnology,China)Abstract:Analgorithmisintrod…     

Quantitative trait loci （QTLs） for quality traits related to protein and starch in wheat

Quality traits in wheat （Triticum aestirum L.） were studied by quantitative trait locus （QTL） analysis in a recombinant inbred line （RIL） population, a set of 131 lines derived from Chuan 35050 × Shannong 483 cross （ChSh）. Grains from RILs were assayed for 21 quality traits related to protein and starch. A total of 35 putative QTLs for 19 traits with a single QTL explaining 7.99-40.52% of phenotypic variations were detected on 10 chromosomes, 1D, 2A, 2D, 3B, 3D, 5A, 6A, 6B, 6D, and 7B. The additive effects of 30 QTLs were positive, contributed by Chuan 35050, the remaining 5 QTLs were negative with the additive effect contributed by Shannong 483. For protein traits, 15 QTLs were obtained and most of them were located on chromosomes 1 D, 3B and 6D, while 20 QTLs for starch traits were detected and most of them were located on chromosomes 3D, 6B and 7B. Only 7 QTLs for protein and starch traits were co-located in three regions on chromosomes 1D, 2A and 2D. These protein and starch trait QTLs showed a distinct distribution pattern in certain regions and chromosomes. Twenty-two QTLs were clustered in 6 regions of 5 chromosomes. Two QTL clusters for protein traits were located on chromosomes 1D and 3B, respectively, three clusters for starch traits on chromosomes 3D, 6B and 7B, and one cluster including protein and starch traits on chromosome 1D.     

On Tragic Consciousness In The Works By Ernest Hemingway

As an American modern novelist who were famous in the literary world, Hemingway was not a person who always followed the trend but a sharp observer. At the same time, he was a tragedy maestro, he paid great attention on existence, fate and end-result. The dramatis personae's tragedy of his works was an extreme limit by all means tragedy on the meaning of fearless challenge that failed. The beauty of tragedy was not produced on the destruction of life, but now this kind of value was in the impact activity. They performed for the reader about the tragedy on challenging for the limit and the death.