The role of Al2O3, MgO and CeO2 addition on steam iron process stability to produce pure and renewable hydrogen

Steam iron process represents a technology for H₂ production based on iron redox cycles. Fe_xO_y are reduced by syngas/carbon to iron, which is subsequently oxidized by steam to produce pure H₂. However, the system shows low stability.In this work, the effect of promoters (Al₂O₃, MgO and CeO₂) on Fe_xO_y stability is investigated (10 consecutive redox cycles). Bioethanol is used as a reducing agent. The particles are synthesized by coprecipitation method, analysed by BET, XRD, SEM and tested in a fixed bed reactor (675 °C, 1 bar). Pure H₂ is obtained controlling the Fe_xO_y reduction degree feeding different amounts of ethanol (4.56–1.14 mmol) until no CO is detected in oxidation. The results show that the promoters not only improve the thermal stability of Fe_xO_y but also affect its redox activity and react with iron forming spinel structures. MgO led to the highest activity and cyclability (H₂ = 0.15 NL; E = 35%).     

Effect of base promoter on activity of MCM-41-supported nickel catalyst for hydrogen production via dry reforming of methane

Dry reforming of methane (DRM) is considered a promising reforming technology that converts natural gas in the Natuna Sea into synthesis gas, which can be further utilized to produce beneficial chemicals such as olefins, alcohols, and liquid hydrocarbons. However, the challenges in commercializing the DRM process are carbon deposition and sintering of the catalyst at high temperatures, because of which the catalyst is easily deactivated. This study aimed to test the activity and stability of MCM-41-based catalysts for the DRM; determine the effect of promoter type on the activity and stability of MCM-41-based catalysts; and determine the effect of base promoter addition on the amount of carbon deposition. MCM-41-based catalysts were synthesized using incipient wetness impregnation method. XRD, N₂ Physisorption, H₂-TPR, CO₂-TPD, and TGA analysis were conducted to determine the physicochemical properties of the catalysts. The catalysts activity was tested in a fixed-bed reactor, under atmospheric pressure at 700 °C. Overall, all catalysts exhibited good stability for 240 min. Moreover, catalysts with Mg and Ca promoters showed the highest CH₄ and CO₂ conversion among all catalysts. Ni–Mg/MCM-41 catalyst yielded 72% CH₄ conversion and 54% CO₂ conversion, meanwhile Ni–Ca/MCM-41 yielded 69% CH₄ conversion and 55% CO₂ conversion. Furthermore, MCM-41-based catalysts with base promoter produced small amount of carbon deposition.     

服务于土木工程新工科建设的国际学生交流组织平台设计与构建

面对新技术与新经济,土木专业作为传统工科专业有升级转型为新工科的必要性与迫切性。为助推新型土木工程专业个性化人才培养,河海大学土木与交通学院基于推进学科交融、跨界整合能力培养的发展主旨进行了独特的专业学生组织交流平台建设,在人的全面发展、现代认知学习、建构主义、生涯发展等理论的基础上,以国际竞赛、国际年会、讲堂制度和三高体系为载体,构建了ASCE国际学生组织河海大学分会,以激发学生主体作用,推进新工科建设。     

在SRTP项目中培养本科生科研能力的探讨

在大学生科研项目"学校建筑抗震性能调查与分析"的选题和研究过程中,采用以学生为主体,教师加以引导的方法取得了好的效果。通过学生自主选题立项和研究,锻炼学生的创新思维能力,培养学生严谨的科学态度、实践动手能力和团队协作精神。     

北京印刷学院师生专业类期刊数字化阅读分析——以访问中国知网数据为例

论文以高校师生的数字化阅读、我国专业类数字内容平台的发展情况为研究背景,以北京印刷学院访问中国知网的后台数据为主要研究依据,梳理了北印师生使用图书馆数字资源的特点及专业类期刊数字化阅读的特征和影响因素,并提出了相应建议。     

巴氏杜氏藻八氢番茄红素合成酶侧翼调控序列的克隆与分析

研究表明八氢番茄红素合成酶( PSY)是巴氏杜氏藻(Dunaliella bardawil)类胡萝卜素代谢途径中的第一个关键调节酶.本实验采用基于LAoPCR的基因组步移法分别设计两组基因特异引物pSP1-3及tSP1-3,克隆巴氏杜氏藻PSY( DbPSY)的启动子和终止子序列,并利用在线启动子分析软件分析其保守调控序列.最后利用生物信息学方法分析预测DbPSY的蛋白质结构.分析结果表明,DbPSY启动子具有两个保守调控序列:BOXLCOREDCPAL和GT1GMSCAM4,其中BOXLCOREDCPAL受紫外光诱导,上调下游基因的表达,GT1GMSCAM4受盐调控,促进下游基因的表达.蛋白结构分析表明,DbPSY的N端在邻近物种间具有较大的多样性.我们推测DbPSY的微调与启动子保守序列及蛋白质N端序列的多样性相关.     

The effect of barium-promoted for microsphere Ru/CeO2 catalysts in ammonia synthesis

In this essay, the effect of the morphology of the CeO₂ support and the Ba promoter on the ammonia synthesis reaction was studied. CeO₂ support with {110} and {100} crystal planes and more oxygen vacancies enhanced the catalytic activity of ammonia synthesis. The relatively uniform microspheres structure CeO₂ support (CeO₂-MS) with {110} and {100} crystal planes was synthesized. The structural functions of the as-synthesized CeO₂ support for the Ru-based catalyst were investigated in the ammonia synthesis reaction. The results of catalytic performance showed that the catalytic activity of 2.5%Ru/CeO₂-MS catalyst reached 8940 μmol· g^?1· h^?1 at 450 ℃, 3.8 MPa, H₂/N₂ = 3 (60 mL?min^?1), which is higher nearly 2.5 times than the 2.5%Ru/CeO₂-commercial (CeO₂-C). And the catalytic activity of catalysts increased with the increase of reaction temperature. The activity of 6%Ba-2.5%Ru/CeO₂-MS (24000 μmol· g^?1· h^?1) catalyst increased about 268% than that of catalyst without addition of Ba. Their physical and chemical properties were characterized by XRD, BET, HRTEM, H₂-TPR, H₂-TPD, and XPS analyses. Our results indicate that the 2.5%Ru/CeO₂-MS catalyst and catalysts involving promoters (Cs, K, and Ba) exhibit significant support-morphology-dependent catalytic activity for ammonia synthesis.     

Efficient promotion of methane hydrate formation and elimination of foam generation using fluorinated surfactants

Methane hydrate preparation is an effective method to store and transport methane. In promoters to facilitate methane hydrate formation, homogeneous surfactant solutions, sodium dodecyl sulfate (SDS) in particular, are more favorable than heterogeneous particles, thanks to their faster reaction rate, more storage capacity, and higher stability. Foaming, however, could not be avoided during hydrate dissociation with the presence of SDS. This paper investigated the ability of five fluorinated surfactants: potassium perfluorobutane sulfonate (PBS), potassium perfluorohexyl sulfonate (PHS), potassium perfluorooctane sulfonate (POS), ammonium perfluorooctane sulfonate (AOS), and tetraethylammonium perfluorooctyl sulfonate (TOS) to promote methane hydrate formation. It was found that both PBS and PHS achieve a storage capacity of 150 (V/V, the volume of methane that can be stored by one volume of water) within 30 min, more than that of SDS. Cationic ions and the carbon chain length were then discussed on their effects during the formation. It was concluded that PBS, PHS, and POS produced no foam during hydrate dissociation, making them promising promoters in large-scale application.     

照明环境对交互阅读视觉和认知的影响

视觉显示终端（visual display terminal,VDT）和纸质文稿共同成为人们生活和学习中不可或缺的阅读媒介,提供适宜的VDT与纸质交互阅读照明环境是提升室内照明环境质量、满足人民健康需求的重要发展方向。为探讨照明环境对交互阅读的视觉和认知的影响,采用主观评价、视觉任务绩效和生理指标测量相结合的方法,开展照明环境主客观评价实验。搭建了交互阅读照明环境实验平台,研究了水平照度、照度配比、色温、屏幕亮度4项照明参数对交互阅读视觉舒适、视觉功效、视觉疲劳3种视觉感知,认知效率和情绪唤醒2种认知表现的影响。实验结果显示,水平照度对视觉疲劳影响最大;照度配比主效应对交互阅读的视觉感知和认知表现均有显著影响;光源色温对交互阅读视觉舒适和视觉功效影响最大;VDT屏幕亮度对交互阅读视觉疲劳、认知效率和情绪唤醒影响最大。根据各相关要素对评价指标的影响分析,得出高视觉舒适且高情绪唤醒的交互阅读最佳照明环境参数为水平照度750 lx、垂直照度300 lx（照度配比2.5）、色温4 000 K,最佳屏幕亮度为100 cd/m²;高视觉功效以及高认知效率、低视觉疲劳的交互阅读最佳照明环境参数为:水平照度300 lx、垂直照度200 lx（照度配比1.5）、色温5 000 K,且屏幕亮度建议为100 cd/m²。研究结果为交互阅读的照明设计和优化提供依据。     

pEgr-ssEndostatin的构建及其在体外的辐射诱导表达

为探讨pEgr-ssEndostatin重组质粒转染B16细胞后接受不同辐射剂量以及接受同一剂量不同时程endostatin表达的规律。采用RT-PCR方法从鼠肝脏中扩增出Endostatin cDNA,连入信号肽,构建了pEgr-ssEndostatin重组质粒,用脂质体介导的转染法转染小鼠B16细胞,用ELISA方法检测B16细胞上清中endostatin的表达水平。结果表明的分泌型Endostatin序列与报道完全一致,Egr-1启动子和Endostatin cDNA正确插入表达载体pcDNA3．1;pEfr-ssEndostatin具有辐射诱导表达特性。提示小鼠Endostatin基因成功地被克隆和表达,Egr-1启动子具有辐射激活和诱导下游基因表达增强的功能。