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无碱CO_(2)加氢高效制甲酸Pd/g-C_(3)N_(4)催化剂的单原子和纳米簇的协同作用

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Chinese Journal of Catalysis 2023年第4期47卷 214-221页

作者： Eun hyup Kim Min hee Lee Jeehye Kim Eun Cheol ra Ju hyeong Lee Jae Sung Lee 蔚山国家科学技术研究所能源与化学工程学院(UNIST) 韩国

气候变化威胁人类的生存.化石燃料的过度使用导致CO_(2)持续排放是引起全球变暖和气候变化的主要因素,须尽快减少CO_(2)排放.捕获CO_(2)并将其转化为高附加值的燃料和化学品从而循环利用是减少CO_(2)净排放的有效措施.其中,CO_(2)催化... 详细信息

气候变化威胁人类的生存.化石燃料的过度使用导致CO_(2)持续排放是引起全球变暖和气候变化的主要因素,须尽快减少CO_(2)排放.捕获CO_(2)并将其转化为高附加值的燃料和化学品从而循环利用是减少CO_(2)净排放的有效措施.其中,CO_(2)催化加氢制甲酸(hCOOh)是碳捕获与利用(CCU)的有效途径之一,其产物hCOOh可用于防腐剂、牲畜饲料抗菌剂和食品添加剂,也可作为氢载体和直接甲酸燃料电池的燃料.目前,工业上生产hCOOh的工艺包括两个步骤:甲醇和CO在强碱条件下反应生成甲酸甲酯(hCO_(2)Ch_(3)),随后水解为hCOOh.该工艺利用来自化石燃料的两种原料,排放出大量CO_(2),同时在水解步骤中使用了过量的酸性水,因此对生态环境产生一定的危害.近年来,以CO_(2)为可再生原料合成hCOOh被广泛研究,人们探索了电化学、光化学、生物和热化学反应等多种途径将CO_(2)还原为hCOOh,以期实现CO_(2)循环利用.上述方法距实际应用尚有一定距离,其中,CO_(2)催化加氢制hCOOh过程最先进,它与当前许多化学工业过程相似.由于CO_(2)分子的化学稳定性,CO_(2)加氢生成hCOOh在热力学上不利,可通过有机碱和无机碱形成甲酸-碱配合物,推动反应向生成hCOOh方向移动.然而,从甲酸基配合物中提取hCOOh需要额外的分离步骤,因此在无碱条件下直接将CO_(2)加氢生成hCOOh非常重要.本课题组致力于研究无碱条件下g-C_(3)N_(4)负载的Pd(记为Pd/CN)催化剂催化CO_(2)加氢合成hCOOh,前期研究(***.,2016,52,14302-14305和***.,2021,396,395-401)发现,通过控制Pd负载量可改变催化剂中Pd单原子/Pd纳米团簇的比例,且当两种状态Pd达到最佳比例时,催化剂催化活性最高.这表明在无碱CO_(2)加氢过程中,Pd单原子与纳米团簇间存在协同作用.此外,最近有关于单原子和纳米团簇在负载金属催化剂中不同作用的报道,如NixMg1-xO催化逆水气变换反应,Ir1/In_(2)O_(3)和Pd/Fe_(3)O_(4)催化CO_(2)加氢制乙醇反应等,这些工作得出相似的结论:单原子金属对CO_(2)活化有效,而纳米团簇对h_(2)活化有效.这对于设计以CO_(2)和h_(2)为反应物的金属催化剂很重要.本工作旨在考察类似的机理是否适用于Pd/CN催化剂在无碱条件下催化CO_(2)加氢制hCOOh过程.通过控制Pd负载量,合成了含有不同比例Pd单原子和Pd纳米团簇的Pd/CN催化剂,Pd与g-C_(3)N_(4)表面碱性位间的强静电相互作用使合成含有大量Pd单原子的Pd/CN催化剂成为可能.在Pd/CN催化剂催化无碱CO_(2)加氢制hCOOh过程中,当两种状态Pd达到最佳比例时,Pd单原子和Pd纳米簇之间存在协同作用,此时催化剂活性最高.实验表明,Pd纳米簇主要通过解离吸附参与h_(2)活化,Pd单原子对CO_(2)活化更有效.在最佳单原子比(单原子数/(单原子数+纳米簇)为41%)时,该催化剂表现出最高的活性,优于文献报道的相似反应条件下Pd催化剂活性.这些发现将为以CO_(2)和h_(2)分子为反应物的反应的催化剂设计提供一定的参考.

关键词：无碱CO_(2)加氢制甲酸 Pd/g-C_(3)N_(4) 单原子催化剂纳米簇催化剂协同效应

heat transfer enhancement from heat sources using optimal design of combined fins heat-sinks

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Propulsion and Power Research 2020年第4期9卷 372-382页

作者： hisham h.Jasim Mechatronics Engineering Department AL-Khwarizmi College of EngineeringUniversity of BaghdadBaghdadIraq

The rapid movement of heat transferred goes to be the most important target for researchers to deals with the thermal problems of electronic ***,that has high packing densities in limited ***,vertical combination between two shapes of fins was considered to improve the thermal performance of heat ***,many models(longitudinal-pin fins)were created as a new approach based on the stable both of material and *** the analytical solution,Finite element techniques used to solve the mathematical modeling and signum-sinusoidal-signum function was modified to model both the variable heat transfer area and convection *** in the numerical procedure,ANSYS simulation used as the validation of temperature *** addition,results from previous work were used as second method of validation *** results show a high level of agreement by maximum difference does not exceed(3.52%).In the calculation process,natural convection,range of ra number(105–107)were applied for all models of which each one is distinguished by the parameter of area ratio(A∗)between hybrid model and longitudinal *** results show many advantages;a significant drop in temperature profile about(2.7%–8.8%).Also,decrease in thermal resistance by(23%–43%)and increases in heat transferred(29%–78%).Furthermore,all parameters have a significant improve for the models that have A∗his improvement was down to less level at A∗>1.48 as a result of overlapping between the effects of miscellaneous *** that associated with the entropy generation was *** this step,it becomes important to find the model that achieves maximize of the thermal performance and minimize of the entropy *** that,the optimization procedure using genetic algorithm was ***'s clearly the best model exist within a close range between 1.509 and 1.518 based on the behavior of the best fitness function.

关键词： Combined fin-heat sink Finite element techniques Entropy generation Genetic algorithm

The Drying of Pyridine hydrobromide

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Chinese Journal of Chemical Engineering 1998年第2期6卷 76-80页

作者： RenéD.Peralta Rodríguez raúl G.López Campos Jaime Wisniak Jacinto G.Rodríguez Gómez Silvia Torres Rincón M.Esther Treviño Martínez Centro de Investigacion en Quimica Aplicada Blvd.Ing.Enrique Reyna Hermosillo No.140C.P.25100SaltilloCoahuilaMexico Department of Chemical Engineering Ben-Gurion University of the NegevBeer-ShevaIsrael

1 INTRODUCTIONThe drying of fine chemicals and pharmaceuticals is dominated by a number of special factorscompared to the drying of bulk *** include:very high value of product;lowthroughputs(typically,100 kg·h-1);materials that frequently possess toxic properties andare often sticky,pasty and difficult to handle when wet;the moisture to be evaporated ofteninvolves solvents;and multipurpose processing plants.

关键词： drying pyridine hydrobromide

A case of hypereosinophilic syndrome presenting with intractable gastric ulcers

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World Journal of Gastroenterology 2009年第48期15卷 6129-6133页

作者： Tae Young Park Chang hwan Choi Suh Yoon Yang InSoo Oh In-Do Song hyun Woong Lee hyung Joon Kim Jae hyuk Do Sae Kyung Chang Ah ra Cho Young Joo Cha Department of Internal Medicine Chung-Ang University College of Medicine Department of Laboratory Medicine Chung-Ang University College of Medicine

We report a rare case of hypereosinophilic syndrome （hES） presenting with intractable gastric ulcers. A 71-year-old man was admitted with epigastric pain. Initial endoscopic findings revealed multiple, active gastric ulcers in the gastric antrum. he underwent helicobacterpylori （hpylon） eradication therapy followed by proton pump inhibitor （PPI） therapy. however, follow- up endoscopy at 4, 6, 10 and 14 mo revealed persistent multiple gastric ulcers without significant improvement. The proportion of his eosinophil count increased to 43% （total count： 7903/mm3）. Abdominal-pelvic and chest computed tomography scans showed multiple small nodules in the liver and both lungs. The endoscopic biopsy specimen taken from the gastric antrum revealed prominent eosinophilic infiltration, and the liver biopsy specimen also showed eosinophilic infiltration in the portal tract and sinusoid. A bone marrow biopsy disclosed eosinophilic hyperplasia as well as increased cellularity of 70%. The patient was finally diagnosed with hES involving the stomach, liver, lung, and bone marrow. When gastric ulcers do not improve despite h pylon eradication and prolonged PPI therapy, infiltrative gastric disorders such as hES should be considered.

关键词： Gastric ulcer hypereosinophilic syndrome

Intestinal alkaline phosphatase in the colonic mucosa of children with inflammatory bowel disease

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World Journal of Gastroenterology 2012年第25期18卷 3254-3259页

作者： Kriszta Molnár dám Vannay Beáta Szebeni Nóra Fanni Bánki Erna Sziksz ron Cseh hajnalka Gyrffy Péter László Lakatos Mária Papp András Arató Gábor Veres First Department of Pediatrics Semmelweis UniversityH-1083 BudapestHungary Research Group for Pediatrics and Nephrology Semmelweis University and Hungarian Academy of SciencesH-1083 BudapestHungary SE-MTA "Lendulet" Diabetes Research Group H-1083 BudapestHungary Second Department of Pathology Semmelweis UniversityH-1091 BudapestHungary First Department of Medicine Semmelweis UniversityH-1083 BudapestHungary Second Department of Medicine University of Debrecen H-4032 Debrecen Hungary

AIM： To investigate intestinal alkaline phosphatase （iAP） in the intestinal mucosa of children with inflammatory bowel disease （IBD）. METhODS： Colonic biopsy samples were taken from 15 newly diagnosed IBD patients and from 10 healthy controls. In IBD patients, specimens were obtainedboth from inflamed and non-inflamed areas. The lAP mRNA and protein expression was determined by reverse transcription-polymerase chain reaction and Western blotting analysis, respectively. Tissue localiza- tion of lAP and Toll-like receptor （TLR） 4 was investi- gated by immunofluorescent staining. RESULTS： The lAP protein level in the inflamed muco- sa of children with Crohn＇s disease （CD） and ulcerative colitis （UC） was significantly decreased when compared with controls （both P 〈 0.05）. Similarly, we found a significantly decreased level of lAP protein in the in- flamed mucosa in CD compared with non-inflamed mucosa in CD （P 〈 0.05）. In addition, the iAP protein level in inflamed colonic mucosa in patients with UC was decreased compared with non-inflamed mucosa in patients with CD （P 〈 0.05）. lAP protein levels in the non-inflamed mucosa of patients with CD were similar to controls, lAP mRNA expression in inflamed colonic mucosa of children with CD and UC was not significant- ly different from that in non-inflamed colonic mucosa with CD. Expression of lAP mRNA in patients with non- inflamed mucosa and in controls were similar. Co-local- ization of lAP with TLR4 showed intense staining with a dotted-like pattern, lAP was present in the inflamed and non-inflamed mucosa of patients with CD, UC, and in control biopsy specimens, irrespective of whether it was present in the terminal ileum or in the colon. however, the fluorescent signal of TLR4 was more pro- nounced in the colon compared with the terminal ileum in all groups studied. CONCLUSION： Lower than normal lAP protein levels in inflamed mucosa of IBD patients may indicate a role for lAP in inflammatory lesions in IBD. Based on our r

关键词： Intestinal alkaline phosphatase Toll-like recep-tor Colonic biopsy Children Inflammatory bowel disease

STRUCTURE AND SURFACE STUDIES OF Mg_xZn_(1-x)O FILMS GROWN BY PULSED LASER DEPOSITION

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Acta Metallurgica Sinica(English Letters) 2005年第3期18卷 237-241页

作者： L.Zhuang K.h.Wong DepartmentofAppliedPhysics TheHongKongPolytechnicUniversityKowloonHongKongChina

The structural and surface properties of high-quality epitaxial cubic MgxZn1-xO films deposited by pulsed laser deposition (PLD) were studied by X-ray diffracti on and atomic force microscopy respectively. For films of about 500nm thick, sca ns over a 30μm × 30μm area revealed a surface roughness ra of about 100nm. Th is relatively large surface roughness is primarily attributed to the particulate and outgrowth during the PLD process. A good epitaxial growth on LaAlO3 (LAO ) (100) substrates, however has been obtained for composition x = 0.9, 0.7 and 0 .5 with the heteroepitaxial relationship of (100)■∥(100)LAO (out-of-plane) and (011)■∥(010)LAO (in-plane). These structural qualities suggest that cubic Mgx Zn1-xO alloys films have good potential in a variety of optoelectronic device ap plications.

关键词： pulsed laser deposition thin film XRD MgxZn1-xO

基于引力模型的自由贸易协定对智利贸易的影响研究

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基于引力模型的自由贸易协定对智利贸易的影响研究

作者： Pablo raúl Droguett Frésard（帕罗）哈尔滨工业大学

学位级别：硕士

在过去的25年中,智利的商业战略一直是寻求经济与世界更大程度的融合,并向国际贸易开放边界。民主回归之后,国际参与已成为智利发展战略中最重要的组成部分之一。这种对世界市场的开放政策促进了商品和服务贸易的发展。伴随外国投资稳...

在过去的25年中,智利的商业战略一直是寻求经济与世界更大程度的融合,并向国际贸易开放边界。民主回归之后,国际参与已成为智利发展战略中最重要的组成部分之一。这种对世界市场的开放政策促进了商品和服务贸易的发展。伴随外国投资稳步增加,国外对投资得到了前所未有的提升。据世界银行称,智利拥有高收入经济体系。它的市场人口相对较小,消费篮中的很多物品都是进口的,但其自然资源丰富,所以智利必须出口原材料和进口成品。出于这个原因,智利寻求与全球经济进一步融合,提供产品来增加外国买家的收入,并为其进口消费品提供优惠价格。智利有权签署各种贸易协定,作为进一步融入世界经济战略,并在全球情景中获得越来越多的份额。这一整合开始逐渐开始,首先是在一级区域与拉美国家签署贸易协定:1993年首次在玻利维亚和委内瑞拉,1996年在南美洲共同体,在1999年在墨西哥。然后扩大与发达国家签署的条约(加拿大1997年,欧盟2003年,美国2004年);最终扩大与亚洲国家(2004年的韩国,2006年的中国,2007年的印度和日本)(源DIRECON)的条约。考虑到智利贸易的高度开放性,智利与各国和地区的PTA的经济影响可能与贸易壁垒较高的国家相比较小,伙伴国家已签署的许多签署的条约。另一方面,一般较低的关税也降低了 PTA贸易转移效应带来的福利,成本大于抵消贸易创造和更大市场所带来的福利收益。智利是世界上最大的铜生产国,全球产量的26%(OEC来源)主要销售铜阴极和其他精炼铜产品均来自于智利。而中国是全球最大的铜进口国,占全球铜产量的33%世界矿物进口。铜在智利出口篮子中占有重要地位(它代表了智利出口篮子的53.7%),铜是在许多行业如基础设施,机械等广泛使用的金属。由于铜的用途广泛许多行业,许多国家都需要铜矿,并且这些国家目睹智利的开放贸易战略和接受各种贸易协定的签署。在过去的15年里,智利最重要的经济关系一直是中国。而中国在全球当前的经济增长时,在2001-2010年期间达到平均每年10.5%的增长。到2010年,根据世界贸易组织,中国成为超过美国的世界上最大的铜商品出口国。由于拉丁美洲所提供的许多自然资源,这一增长有助于改善拉丁美洲与中国的双边贸易。从2000年到2014年,中国参与该地区出口的比例从1%上升到9%,同期中国进口从2%上升到16%。这些数据使中国在该地区出口的主要目的地和该地区进口的第二位之间位居第三(拉加经委会,2015年)。在目前的全球化情景之后,贸易协定在过去几年中,在国家和地区间一直试图包括更多的经济体和更多的市场。铸就这些增加了市场份额,政府支出和产量增长的国家。研究目的是:(1)确定自由贸易协定的签署对智利与已与智利签署自由贸易协定的伙伴国之间的贸易所产生的影响。(2)确定智利与贸易伙伴国的贸易潜力。理论分析与研究假设是:(1)伙伴国的经济规模变量:研究期间每年从事双边贸易的国家的国内生产总值对。假设h1:伙伴国家的经济规模对双边贸易有积极影响。(2)伙伴国家的市场规模变量:研究期间每个伙伴国的年度人口统计。假设h2:伙伴国家的市场规模对双边贸易有积极影响。(3)伙伴国家的地理距离变量:伙伴国的首都之间的地理分离。假设h3:伙伴国之间的地理距离对双边贸易有负面影响。(4)伙伴国家的汇率变量:汇率变量是智利平均货币每美元与研究每年每个美元伙伴国家货币平均值之间的商。假设h4:智利货币贬值与双边贸易之间存在正相关关系。(5)自由贸易协定和贸易联盟变量:自由贸易协定的变量是一个二分法变量,当智利与其伙伴国在相应年份签署并生效的自由贸易协定时,其值为1,否则为0。假设h5:自由贸易协定的实施对双边贸易有积极影响。本论文的研究框架研究的方法如下本研究的目标是评估自由贸易协定在智利贸易政策中的效力。这是通过分析贸易的计量经济引力模型来实现的,该模型是通过对先前类似研究的文献回顾创建的,这些研究衡量了国家之间国际贸易的相似方面。分析所需的信息来自世界银行(WB),国际货币基金组织(IMF),世界贸易组织(WTO),国际贸易中心(ITC)的数据库以及统计局提供的统计数据政府。这样做的目的是获得最准确的信息,并为研究取得可靠和公正的结果。该研究回顾了智利以及与智利签署自由贸易协定的每个国家的信息,这意味着45个国家在经济区域和来自各主要经济和经济区域的国家联盟以及拉丁美洲区域地区。收集生产,贸易和人口指数以收集信息以获得足够的数据进行分析。通过16年的时间(从2001年到2016年)回忆这些信息。变量的统计模型和描述是:ln(Tict)= β0 + β1 ln(GDPit)+β2 ln(GDPct)+ β3 ln(POPit)+ β4ln(POPct)+β5 ln(Dict)+ β6rict + β7FTAict + εictTict:t年智利与国家i

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A Molecular hydrogen Production Model from Li and Lih in the Early Universe

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International Journal of Astronomy and Astrophysics 2013年第2期3卷 108-112页

作者： raúl G. E. Morales Mauricio R. Canales Centre for Environmental Sciences Faculty of Sciences University of Chile Santiago Chile

Neutral isotopes and ions of h, he and Li define the chemistry of the early universe by collisional and radiative process, where under low temperature and radiation regime, only neutral species were essential in the cooling mass that gave origin to the first proto star structures. Nevertheless, up to now, in every kinetic model Li is permanently discarded from fundamental reactions due to its extremely low density. Contrarily to these previous models we have developed a novel kinetic model based on two consecutive reactions of Li and Lih with h, in order to generate a recursive process that fit well h2 production to temperatures as low as 200 K, according to the cosmological time at the end of the dark epoch. Our results show how Li and Lih merge as first catalyzers of the h to h2 chemical reaction and permit us to explain the expected abundance of h2 as the main coolant in the early universe as well as in cold regions of the cosmos.

关键词： h2 Li and Lih in the Dark Epoch Li and Lih as Primitive Catalyzers h2 Production from Li Model

radionuclides measurements and mineralogical studies on beach sands, East Rosetta Estuary, Egypt

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Chinese Journal Of Geochemistry 2013年第2期32卷 146-156页

作者： Abd El Wahab M. El Nahas h.A. Physics Department Faculty of Women for Arts Science and Education Ain Shams University Cairo P.O 11757 Egypt Nuclear Materials Authority Cairo P.O. Box 530 Egypt

radiometric measurements were carried out for the beach sands from East Rosetta estuary to determine the activity concentrations of 238 U, 226 ra, 232 Th, and 40 K, using a hyper Pure Germanium spectrometer, to estimate the dose rates and radiation hazard indices. The average specific activities are 778.20 Bq/kg for 238 U; 646.89 Bq/kg for 226 ra; 621.92 and 627.85 Bq/kg for the 222 Rn daughters 214 Pb and 214 Bi respectively. The average specific activity of 232 Th is 1510.25 Bq/kg, while the calculated specific activity for 40 K has an average of 8.41 Bq/kg. The average specific activity of 235 U is 38.61 Bq/kg. The average absorbed dose rate is 1211.36 nGy/h, 20 times higher than the estimated average global primordial radiation of 60 nGy/h and 6 times higher than that of the world range (10-200 nGy/h). The radium equivalent (ra eq ) values are from 6 to 9 times the recommended value. The internal and external hazard indices (h int , h ex ) indicate that their values are from 6 to 11 times the permissible values of these indices. These higher values may be due to the presence of economic heavy minerals containing radionuclides as zircon and monazite as well as some trace minerals, thorite and uranothorite. The mineralogical study indicates the beach sands contain heavy minerals, zircon, monazite, rutile, ilmenite, leucoxene, magnetite and garnet. The average abundance of zircon is 0.175 wt% ranging from 0.125 wt% to 0.239 wt%, while it is 0.004wt% ranging from 0.001 wt% to 0.007 wt% for monazite. The average abundance is 0.087 wt% for rutile; 2.029 wt% for ilmenite; 1.084 wt% for magnetite; 0.384 wt% for leucoxene and 0.295 wt% for garnet.

关键词：放射性核素海滩砂矿物学核素测量河口平均丰度埃及辐射测量