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氨基酸衍生Fe-N-C复合材料用于高效电催化氧还原研究

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氨基酸衍生Fe-N-C复合材料用于高效电催化氧还原研究

作者： Nisha afzal 天津大学

学位级别：硕士

随着全球经济危机的影响和对清洁可持续能源的生态关注的持续增加,能源转换和储存设备的开发得到了更广泛的重视,如水电解槽、燃料电池和金属空气电池等。为了更好地为促进技术进步,新型能源的开发至关重要。能源转换装置的基础层面是... 详细信息

随着全球经济危机的影响和对清洁可持续能源的生态关注的持续增加,能源转换和储存设备的开发得到了更广泛的重视,如水电解槽、燃料电池和金属空气电池等。为了更好地为促进技术进步,新型能源的开发至关重要。能源转换装置的基础层面是一系列的电化学反应过程,并且在未来的商业化技术中,氧化还原反应的缓慢阴极动力学限制了燃料电池的整体性能效率。目前的技术主要使用铂及其合金,但是由于甲醇交叉的低耐受性而导致的稀缺性、高价格和不稳定性阻碍了其大规模商业化。为了寻求高性能且非贵重的电催化剂来代替Pt催化剂,本文研究了可再生衍生的几种与Fe盐结合的氨基酸的合成,以及其在氧还原反应和锌空气电池合成中的活性性能。首先,通过模板辅助的水热混合和高温下的两步热解合成了14种不同的氨基酸掺杂乳酸亚铁盐。合成的样品表现出褶皱结构和颗粒的致密聚集,对于氧还原反应(ORR)表现出中等到差的性能。基于形态学方面研究,经前体负载修饰的Fe NC-精氨酸、Fe NC-色氨酸和Fe NC-组氨酸,与未修饰的样品相比,半波电势分别改善了0.026V、0.055V和0.018V,而且形态变为海绵状网络结构,分散性更好。由于多孔形态和较高的氮掺杂百分比,其活性性能得到提升。本研究提供了一种平台,通过进一步调整形态和掺杂含量,氨基酸可用作朝向氧化还原探测燃料电池和金属-空气电池的潜在材基于上述研究工作,本文的第二部分旨在利用组氨酸氨基酸作为碳和氮前体的单一来源来合成Fe-N-C电催化剂。其复杂的电化学性能与Fe-N相互作用和介孔碳骨架的先进结构表征有关。Fe NC-L1和Fe NC-A1均能实现优异性能,与Pt/C基准相比,分别为E 0.816 V和0.840 V ***,相应的j分别为5.4 m A cm和5.71 m A cm,而且都具有优异的稳定性(c.a响应分别为88.2%和95.0%)。XPS结果表明催化剂结构中具有高百分含量掺杂氮的吡啶,以及Fe和Fe的铁氧化态作为Fe N的组成部分,可以降低氧的吸收能垒来催化氧还原反应。并且,对于Fe NC-A1和Fe NC-L1的锌-空气电池,其最大功率密度可分别达到114.4 Wm cm和98.7 Wm cm。由于中介孔碳骨架的作用,两者的BET比表面积可高达713.67 mg和985.99 mg。

关键词：燃料电池非贵金属电催化剂氧还原反应氨基酸-组氨酸 Fe-单原子催化剂介孔碳

Kinetic and Pyrolysis Characteristics of Balsam Fir Needles

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材料科学与工程（中英文版） 2011年第5期5卷 489-503页

作者： Noorfidza Yub Harun m.ham.ad T. afzal Faculty of Forestry and Environmental management （FOREm） University of New Brunswick Fredericton E3B 5A3 NewBrunswick Canada

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核壳类生物质微波热解制备高品质生物炭研究

核壳类生物质微波热解制备高品质生物炭研究

作者： m.ham.ad Zeshan afzal 东南大学

学位级别：硕士

随着能源需求的不断增大,石油资源紧缺和全球气候问题的挑战迫使人们开发更先进的方法来使用生物质资源。微波热解是一种生产优质生物炭的先进技术,该技术不仅可以制备高品质的产品,更重要的是,热解过程绿色环保。在微波场中,热解所需... 详细信息

随着能源需求的不断增大,石油资源紧缺和全球气候问题的挑战迫使人们开发更先进的方法来使用生物质资源。微波热解是一种生产优质生物炭的先进技术,该技术不仅可以制备高品质的产品,更重要的是,热解过程绿色环保。在微波场中,热解所需能量以辐射形式传播,区别于传统由外到内的加热技术,该过程具有快速和均匀加热的特点。影响微波热解的因素有很多,包括:反应温度、反应时间、微波功率、反应物类型和微波吸收剂等。本论文使用两种壳类生物质原料制备生物质炭,并对其进行表征分析以及用于重金属吸附研究。实验以椰壳和核桃壳为原料,在不同温度(150,180,200,250,300°C)条件下在管式炉中预处理2小时,然后探究原料在不同微波炭化温度(400,600,800°C)和微波吸收剂(SiC,AC)条件下所得生物质炭的孔隙结构特征,并在600°C、CO活化的条件下,进一步探究活化时间(30,50,90,120 min)对所得活性炭品质的影响。研究结果表明,炭化温度的适当升高有助于提高生物质热解炭和活性炭的产率并增大其比表面积。在如下条件下获得的生物炭性能最佳:活化温度600°C,制备时间60 min,活化时间50 min,加热速率10°C/min。该条件下获得椰壳活性炭的比表面积高达1325m/g,核桃壳活性炭的比表面积高达1012m/g。生物质活性炭用于吸收水溶液中镉离子的实验,首先探究了活性炭用量对吸附过程的影响。结果表明,微波热解椰壳炭对镉离子的去除率达到96.1%,吸附量达到26.70mg/g。微波热解核桃壳炭对镉离子的去除率达到92.5%,吸附量达到25.98mg/g。而活化后的椰壳活性炭对镉离子的去除率达到96.6%,吸附量达到29.73mg/g。活化后的核桃壳活性炭对镉离子的去除率达到95.2%,吸附量达到27.40mg/g。综上所述,椰壳活性炭相比于核桃壳活性炭具有更好的吸附效果。

关键词：核壳类生物炭热解因素微波辅助热解活化重金属离子去除

machine Learning Empowered Security and Privacy Architecture for IoT Networks with the Integration of Blockchain

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Intelligent Automation & Soft Computing 2024年第2期39卷 353-379页

作者： sohaib Latif m.Saad Bin Ilyas Azhar Imran hamad Ali Abosaq Abdulaziz Alzubaidi Vincent Karovic Jr. Department of Computer Science The University of ChenabGujrat50700Pakistan Department of Creative Technologies Air UniversityIslamabad42000Pakistan Computer Science Department College of Computer Science and Information SystemsNajran UniversityNajran66244Saudi Arabia Department of Computer Science Umm Alqura UniversityAlQunfudah28821Saudi Arabia Department of Information Systems Faculty of ManagementComenius University in BratislavaBratislava82005Slovakia

The Internet of Things(IoT)is growing rapidly and impacting almost every aspect of our lives,fromwearables and healthcare to security,traffic management,and fleet management *** has generated massive volumes of data and security,and data privacy risks are increasing with the advancement of technology and network *** access control solutions are inadequate for establishing access control in IoT systems to provide data protection owing to their vulnerability to single-point OF ***,conventional privacy preservation methods have high latency costs and overhead for resource-constrained *** machine learning approaches were also unable to detect denial-of-service(DoS)*** study introduced a novel decentralized and secure framework for blockchain *** avoid single-point OF failure,an accredited access control scheme is incorporated,combining blockchain with local peers to record each transaction and verify the signature to ***-based attribute-based cryptography is implemented to protect data storage privacy by generating threshold parameters,managing keys,and revoking users on the *** innovative contract-based DOS attack mitigation method is also incorporated to effectively validate devices with intelligent contracts as trusted or untrusted,preventing the server from becoming *** proposed framework effectively controls access,safeguards data privacy,and reduces the risk of *** results depict that the suggested framework outperforms the results in terms of accuracy,precision,sensitivity,recall,and F-measure at 96.9%,98.43%,98.8%,98.43%,and 98.4%,respectively.

关键词： machine learning internet of things blockchain data privacy security Industry 4.0

积水性心包炎综合症灭活苗对肉用鸡的免疫效果

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国外兽医学（畜禽传染病） 1990年第4期10卷 30-31页

作者： afzal,m 高彦生

Evaluating the Impact of Different Tillage Regimes and Nitrogen Levels on Yield and Yield Components of maize (Zea mays L.)

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American Journal of Plant Sciences 2016年第6期7卷 789-797页

作者： m.ham.ad Naeem Shahid m. Shahid Ibni Zamir Ihtisham-Ul Haq m. Kamran Khan mazhar Hussain Usman afzal m. Asim Ihtisham Ali Department of Agronomy University of Agriculture Faisalabad Pakistan

A field study to evaluate the impact of different tillage regimes and nitrogen levels on yield and yield components of maize (Zea mays L.), was conducted during autumn 2014 at Students Farm, Department of Agronomy, University of Agriculture, Faisalabad. The experiment was laid out in RCBD (Randomized Complete Block Design), with split plot arrangement having three replications. The experiment was comprised of three tillage regimes (minimum, Conventional and Deep) and three nitrogen levels viz: 100, 200 and 300 kg•ha-1. Urea was used as a source of nitrogen, sulphate of potash as a source of potassium and triple super phosphate as a source of phosphorous. The amount of phosphorous and potash was constant in all the treatments i.e. 125 kg•ha-1 and 100 kg•ha-1 respectively. Results of present study are summarized as yield parameters are significantly affected by different nitrogen levels and tillage regimes. maximum number of plants at harvest (7.93), number of grain rows per cob (17.70), number of grains per row (34.31), number of grains per cob (678.58), and cob weight (187.50 g) were observed in deep tillage at 200 kg•ha-1 nitrogen application. 1000-grain weight (275.52 g), biological yield (15.66 t•ha-1), grain yield (6.16 t•ha-1) and dried stalk yield (9.91 t•ha-1) were observed maximum in deep tillage at 200 kg•ha-1 nitrogen application. Harvest index significantly affected by tillage regimes and maximum harvest index (39.58%) were recorded in deep tillage which was statistically at par with conventional tillage (38.83%). It was concluded that higher grain yield of maize can be obtained by deep tillage with the application of 200 kg•ha-1 nitrogen application under the prevailing conditions of Faisalabad.

关键词： Tillage Regimes Nitrogen Levels Deep Tillage Biological Yield Harvest Index

Are doctors protected enough during COVID-19 in South Asia?

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Global Health Research and Policy 2021年第1期6卷 141-148页

作者： Nadia Nazir Jatoi Saniya Ahmad Emad ud-din Sajid Farah Yasmin m.ham.ad sohaib Asghar Syed Ali Farhan Bushra Zafar Sayeed momina mariam marufi Kaneez Fatima Syed Faisal mahmood Department of Internal medicine Doctor Ruth K.M.Pfau Civil HospitalDow University of Health SciencesBaba-e-Urdu RoadKarachiSindh 74200Pakistan Department of Internal medicine Dow Ojha University HospitalSuparco RoadKDA Scheme 33KarachiSindh 75300Pakistan Department of Surgery Dow University of Health SciencesBaba-e-Urdu RoadKarachiSindh 74200Pakistan Division of Infectious Disease Department of MedicineAgha Khan University HospitalNational Stadium RoadKarachiSindh 74800Pakistan

Background:The highly contagious nature of the severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)places physicians in South Asia at high risk of contracting the ***,we conducted this study to provide an updated account of physician deaths in South Asia during the COVID-19 pandemic and to analyze and compare the different characteristics associated with physician mortality amongst the countries of the ***:We performed a cross-sectional study by using published news reports on the websites of news agencies from 9 selected countries in South *** study included only those physicians and doctors who died after contracting COVID-19 from their respective *** available data about the country of origin,type of,sex,age,medical or surgical specialty,and date of death were ***:The total number of physician deaths reported due to COVID-19 in our study was 170,with half(87/170,51%)of the deaths reported from *** physician deaths were reported to be 145(145/170=85%).Internal medicine(58.43%)was the most severely affected *** highest physician mortality rate in the general population recorded in Afghanistan(27/1000 deaths).General physicians from India[OR=11.00(95%CI=1.06-114.08),p=0.045]and public sector medical practitioners from Pakistan[aOR=4.52(95%CI=1.18-17.33),p=0.028]were showing significant mortality when compared with other regions in multivariate logistic ***:An increased number of physician deaths,owing to COVID-19,has been shown in South *** could be due to decreased personal protective equipment and the poor health care management systems of the countries in the region to combat the *** studies should provide detailed information of characteristics associated with physician mortalities along with the main complications arising due to the virus.

关键词： doctor enough protected

Bearing Capacity map for An-Najaf and Kufa Cities Using GIS

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Engineering（科研） 2018年第5期10卷 262-269页

作者： Laheab A. Jasem Al-maliki sohaib Kareem Al-mamoori Khaled El-Tawel Hussain m. Hussain Nadhir Al-Ansari mohammed Jawad Al Ali Department of Hydraulic Engineering Structures Faculty of Water Resources Engineering Green University of Al Qasim Baghdad Iraq Department of Environmental Planning Faculty of Physical Planning University of Kufa Najaf Iraq Lebanese University Faculty of Engineering Beirut Lebanon Remote Sensing Center University of Kufa Najaf Iraq Department of Civil Environmental and Natural Resources Engineering Lulea University of Technology Lulea Sweden Department of Environmental Planning Faculty of Physical Planning University of Kufa Najaf Iraq

An-Najaf province is situated in south-western part of Iraq. It is 70 meters above the sea level in the dry desert environment. The city is considered as one of the most important cities in Iraq, facing a fast population growth and continuous development in constructions such as residential complexes, hotels, bridges and shopping malls. Soil investigation data for An-Najaf Province (An-Najaf and Kufa cities) from 464 boreholes drilled by the Na-tional Centre for Construction Laboratories & Researches (NCCLR)/Babylon laboratory were used in this research. The data were analysed and possessed using Excel program then represented on the Geographical Information System (GIS) program by Inverse Distance Weighted (IDW) tool to create an allowable bearing capacity map for the soil at depths 0 - 2 meters. The allowable bearing capacity is one of the most important soil characteristics to be considered when making a database for An-Najaf city soil. Geographical Information System GIS program enables to create reliable database for any characteristic and it is one of the best programs to produce an accurate map and allow ease in dealing with it. Those maps cover all the studied areas and by using contour lines, approximate values for no-data areas can be obtained. The results show that the allowable bearing capacity range is 5 - 20 Ton/m2 for both An-Najaf and Kufa cities. Kufa city has the range 5 - 9 Ton/m2. An-Najaf city has the range 7 - 18 at the center, 8 - 10 Ton/m2 at the north eastern part, 7 - 14 Ton/m2 for the north western part, 6 - 12 Ton/m2 at the south eastern and 12 - 19 Ton/m2 at the south western.

关键词： Allowable Bearing Capacity Geographical Information System GIS AN-Najaf and Kufa Cities Geotechnical maps Standard Penetration Test (SPT)

Surgical relevance of anatomic variations of the right hepatic vein

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World Journal of Transplantation 2021年第6期11卷 231-243页

作者： Shamir O Cawich Vijay Naraynsingh Neil W Pearce Rahul R Deshpande Robbie Rampersad michael T Gardner Fawwaz mohammed Roma Dindial Tanzilah afzal Barrow Department of Surgery University of the West IndiesSt Augustine 000000Trinidad and Tobago Department of Surgery Port of Spain General HospitalPort of Spain 000000Trinidad and Tobago University Surgical Unit Southampton General HospitalSouthampton SO166YDUnited Kingdom Department of Surgery Manchester Royal InfirmaryManchester M139WLUnited Kingdom Department of Radiology University of the West IndiesSt.Augustine 000000Trinidad and Tobago Department of Radiology Port of Spain General HospitalPort of Spain 000000Trinidad and Tobago Section of Anatomy Basic Medical SciencesUniversity of the West IndiesKingston 000000Jamaica Department of Radiology University of the West IndiesSt Augustine 000000Trinidad and Tobago

BACKGROUND Variations in the anatomy of hepatic veins are of interest to transplant surgeons,interventional radiologists,and other medical practitioners who treat liver *** drainage patterns of the right hepatic veins(RHVs)are particularly relevant to transplantation *** The aim was to identify variations of the patterns of venous drainage from the right side of the *** the best of our knowledge,there have been no reports on RHV variations in in a Caribbean *** Two radiologists independently reviewed 230 contrast-enhanced computed tomography scans performed in 1 year at a hepatobiliary referral *** outflow patterns were observed and RHV variants were described as:(1)Tributaries of the RHV;(2)Variations at the hepatocaval junction(HCJ);and(3)Accessory *** A total of 118 scans met the inclusion *** 39%of the scans found conventional anatomy of the main hepatic *** RHVs were present 49.2%and included a well-defined inferior RHV draining segment VI(45%)and a middle RHV(4%).At the HCJ,83 of the 118(70.3%)had a superior RHV that received no tributaries within 1 cm of the junction(Nakamura and Tsuzuki type I).In 35 individuals(29.7%)there was a short superior RHV with at least one variant *** to the Nakamura and Tsuzuki classification,there were 24 type II variants(20.3%),six type III variants(5.1%)and,five type IV variants(4.2%).CONCLUSION There was significant variation in RHV patterns in this population,each with important relevance to liver *** radiologists and hepatobiliary surgeons practicing in the Caribbean must be cognizant of these differences in order to minimize morbidity during invasive procedures.

关键词： Liver Variant Hepatic Vein Anomaly Venous,Drainage,Vena cava