Two-Phase Flow in Porous Electrodes of Proton Exchange Membrane Fuel Cell     

Jiao  Daokuan  Jiao  Kui  Du  Qing 《天津大学学报(英文版)》2020,26(3):197-207

Water management in porous electrodes bears significance due to its strong potential in determining the performance of proton exchange membrane fuel cell.In terms of porous electrodes,internal water distribution and removal process have extensively attracted attention in both experimental and numerical studies.However,the structural difference among the catalyst layer(CL),microporous layer(MPL),and gas diffusion layer(GDL) leads to significant challenges in studying the two-phase flow behavior.Given the different porosities and pore scales of the CL,MPL,and GDL,the model scales in simulating each component are inconsistent.This review emphasizes the numerical simulation related to porous electrodes in the water transport process and evaluates the effectiveness and weakness of the conventional methods used during the investigation.The limitations of existing models include the following:(i) The reconstruction of geometric models is difficult to achieve when using the real characteristics of the components;(ii) the computational domain size is limited due to massive computational loads in three-dimensional(3 D) simulations;(iii) numerical associations among 3 D models are lacking because of the separate studies for each component;(iv) the effects of vapor condensation and heat transfer on the two-phase flow are disregarded;(v) compressive deformation during assembly and vibration in road conditions should be considered in two-phase flow studies given the real operating conditions.Therefore,this review is aimed at critical research gaps which need further investigation.Insightful potential research directions are also suggested for future improvements.  相似文献   

Examining the instructor-student collaborative partnership in an online learning community course     

Ouyang  Fan  Chang  Yu-Hui  Scharber  Cassandra  Jiao  Pengcheng  Huang  Tianhui 《Instructional Science》2020,48(2):183-204

Instructional Science - Education is under a radical transformation in the current innovation-driven knowledge age. The instructor-student collaborative partnership has the potential to transform...  相似文献   

Alteration of <Emphasis Type="Italic">SlYABBY2b</Emphasis> gene expression impairs tomato ovary locule number and endogenous gibberellin content     

Hui Li  Mei-hua Sun  Ming-fang Qi  Jiao Xing  Tao Xu  Han-ting Liu  Tian-lai Li 《Journal of Zhejiang University. Science. B》2018,19(6):445-457

Tomato is an ideal model species for fleshy fruit development research. SlYABBY2b regulates the ovary locule number, which is increased by gibberellins, in tomato. However, the relationship between SlYABBY2b and endogenous gibberellin is poorly understood. In this study, SlYABBY2b-overexpressing and RNA interference (RNAi) transgenic tomato plants were used to elucidate the mechanism by which SlYABBY2b regulates the ovary locule number and endogenous gibberellin content in tomato. SlYABBY2b-overexpressing plants showed fewer locules and lower gibberellin content than the control plants. Contrasting results were found in the RNAi lines. Therefore, the SlYABBY2b gene negatively regulates tomato ovary locule number and endogenous gibberellin content. Furthermore, the expression of SlYABBY2b gene was remarkably higher than that of the wild type in the apical shoots of gibberellindeficient mutants. This showed that the gibberellins can inhibit the expression of SlYABBY2b gene negative regulation. Further study revealed that SlYABBY2b suppressed the expression of SlGA20ox1 and SlGA3ox2, but increased that of SlGA2ox1 and SlGA2ox5 in the apical shoots of SlYABBY2b-overexpressing plants, thereby reducing gibberellin content. Contrasting results were found in the RNAi lines. Our results showed that the SlYABBY2b gene was located on gibberellin signal transduction pathways, fed back regulation of the synthesis of gibberellin, and felt exogenous gibberellin signal to further regulate the formation of tomato locule.  相似文献   

Pore-Scale Investigation of Coupled Two-Phase and Reactive Transport in the Cathode Electrode of Proton Exchange Membrane Fuel Cells     

Shengjie Ye  Yuze Hou  Xing Li  Kui Jiao  Qing Du 《天津大学学报(英文版)》2023,29(1):1-13

A three-dimensional multicomponent multiphase lattice Boltzmann model(LBM) is established to model the coupled two-phase and reactive transport phenomena in the cathode electrode of proton exchange membrane fuel cells.The gas diffusion layer(GDL) and microporous layer(MPL) are stochastically reconstructed with the inside dynamic distribution of oxygen and liquid water resolved,and the catalyst layer is simplified as a superthin layer to address the electrochemical reaction,which provides a clear...  相似文献   

方言俗谚中的佛风道韵     

叶娇  徐凯 《台州学院学报》2016,(4):13-17

具有鲜明地域特征的天台山文化开放包容,内涵丰富,但其中影响最大的莫过于佛道文化,影响远至海外。文章以当地百姓耳熟能详的方言为切入点,挖掘其后所积淀的佛风道韵。方言俗谚中蕴藏着邑民对佛道教义的深入认识,反映着当地佛道活动的兴盛普及,还可一窥佛道信仰与当地民俗的紧密结合。从方言俗谚中更可领略当地佛道双栖、和睦共存的奇特现象以及佛道文化的凡俗化。  相似文献   

信息网络化时代高校图书馆的文献信息服务     

杨皎 《忻州师范学院学报》2006,22(2):102-104

在信息网络化时代,高校图书馆应在观念转变上、人才培养上、经费投入上加大力度,加快自动化、网络化建设,优化文献资料的馆藏结构,开展多种形式的信息服务,不断提高文献信息服务水平。  相似文献   

新型工业化：崭新的发展道路     

江小涓 《现代企业教育》2003,(1):20-20

四个方面的新意 第一个"新"是:发达国家都是在工业化之后推行信息化,而中国是一个后发展的国家,这些年信息化发展很快,我们完全可以将信息化和工业化的进程重合起来,以信息化带动工业化,以工业化促进信息化。 第二个"新"是:发达国家实现工业化,大多是以消耗能源、牺牲环境为  相似文献   

Determination of boron trifluoride in boron trifluoride complex by fluoride ion selective electrode     

郎五可  张卫江  唐银  徐姣  张雷 《天津大学学报(英文版)》2016,22(1):83-88

A method was proposed to determine boron trifluoride in boron trifluoride complex using fluoride ion selective electrode(ISE). Hydroxide was chosen to mask aluminum for the determination of 0.01—0.1 mol/L of fluoride. The simulation indicated that the permissible aluminum masked at a certain p H value was limited and hardly related to F-concentration and boric acid. It is better to control p H value below 11.5 and the aluminum concentration within 0.025 mol/L to minimize the interference of hydroxide to the fluoride ISE. The decomposition conditions of boron trifluoride by aluminum chloride were investigated. It is found that the F-detection ratio will approach 1.0 if the Al/F molar ratio is 0.3—0.7 and aluminum concentration is no more than 0.02 mol/L when heated at 80 ℃ for 10 min. In one word, hydroxide is quite fit to mask aluminum for samples which contain high content of fluoride and aluminum and the BF3 content can be successfully determined by this method.  相似文献   

高情商一定高绩效？——银行员工情绪智力对工作绩效的影响机制     

王乐乐  斯姣 《安庆师范学院学报(社会科学版)》2020,(2):99-105

情绪智力和情绪劳动的管理研究一直是学术界关注的焦点,现有研究表明员工的情绪智力直接影响工作绩效。采用调查问卷的形式,以251名银行员工为研究样本,实证分析银行员工情绪智力、情绪劳动和工作绩效的关联性及影响机制,研究表明,情绪劳动在情绪智力和员工的工作绩效之间起到中介作用。  相似文献   

河北省城市普通幼儿园学前特殊教育调查与分析   总被引：1，自引：0，他引：1  

焦云红  唐键  赫红英  吴立新  安力戈 《中国特殊教育》2004,(2):91-94

本文在回归主流的教育背景下 ,抽样选取河北省 32 0家普通幼儿园 ,进行问卷调查 ,了解我省普通幼儿园中学前特殊教育发展的现状 ,并提出建议。  相似文献