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Synthesis of Cdte Quantum Dots and Its Analytical Application

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Synthesis of Cdte Quantum Dots and Its Analytical Applicatio...

作者： Anis riahi 华中农业大学

学位级别：硕士

In this thesis, we investigated the effect side of the surface transformation of CdTe QDs on their *** order to achieve this aim a serial of experiments have been implemented to have a further clear vision about the advantage that OVA and glutathione molecules when they are used on the process of the surface transformation of CdTe QDs.In the first part of this research, the interaction between OVA and CdTe QDs was studied in details. The best parameters of the reaction between CdTe QDs and OVA were set. Herein, the result showed that the best reaction time was about 30 *** a fixed concentration of OVA equal to 1.0x10-4 mol L"1, the dilution factor of CdTe QDs corresponds to 5, wich corresponds to a concentration value equal to 1.46×10-6mol L-and the best pH value was set at about 7.4. All of these parameters were implemented to investigate the effect of temperature on the fluorescence intensity of *** the addition of different concentration of CdTe QDs, the fluorescence intensity of OVA decreased. The interaction between protein and the QDs was following Stern-Volmer equation where Ksv was 4.67×106 L mol-1, moreover, the results showed that the quenching process was mostly static. The value of Ksv was increased with temperature. Thermodynamic parameters such asΔGθ,ΔSθandΔHθwere also studied, and there values were,-37.88 ***-1,23.08 ***-1·K-1 and-30.66 ***-1, respectively. These results showed that the electrostatic force plays key role on the interaction betweenof CdTe QDs and OVA.The interaction mechanism was studied based on spectrometry techniques. The best capping material was chosen and used to give best fluorescence intensity of the nanoparticules.The results obtained from these studies were functionalized for the settlement of an original method proposed to detect Hg2+ions by using water soluble CdTe QDs. The results showed that the developed method is reliable when the concentration of Hg2+ is between 2.75x10-5an

关键词： CdTe Qdots Hg2+ OVA fluorescence quenching interaction

高效钙钛矿基叠层太阳能电池的研究进展（英文）

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Science China Materials 2024年

作者：刘欣星陈龙于月何冬梅晒旭霞 sam Zhang 张正富冯晶易健宏陈江照 Faculty of Materials Science and Engineering Kunming University of Science and Technology School of Chemistry and Chemical Engineering/State Key Laboratory Incubation Base for Green Processing of Chemical Engineering Shihezi University Institute of Physical and Engineering Science/Faculty of Science Kunming University of Science and Technology School of Aeronautics Harbin Institute of Technology Zhengzhou Research Institute Harbin Institute of Technology

过去十年,钙钛矿太阳能电池(PSC)发展迅速,其光电转换效率从最初的3.8%提升至超过26%,接近单结太阳能电池的Shockley-Queisser (S-Q)极限.多结太阳能电池因其在减少热化损失和实现宽光谱吸收方面的巨大潜力,而受到广泛关注,有望突破S-Q...

过去十年,钙钛矿太阳能电池(PSC)发展迅速,其光电转换效率从最初的3.8%提升至超过26%,接近单结太阳能电池的Shockley-Queisser (S-Q)极限.多结太阳能电池因其在减少热化损失和实现宽光谱吸收方面的巨大潜力,而受到广泛关注,有望突破S-Q极限.金属卤化物钙钛矿材料具有宽带隙可调性,使其非常适合作为叠层太阳能电池(TSC)中的子电池材料.目前,中国隆基绿能科技股份有限公司的双结钙钛矿-硅叠层太阳能电池创造了34.6%的世界纪录效率,远超各子电池的单结效率.因此,基于钙钛矿的叠层太阳能电池被广泛认为是下一代太阳能行业的光伏产品.尽管效率取得了显著提高,但钙钛矿叠层太阳能电池的商业化应用仍面临若干挑战,例如钙钛矿材料的稳定性问题和大规模生产的难度.本综述总结了钙钛矿叠层太阳能电池的研究进展及优化策略,并指出了多结太阳能电池面临的关键问题.最后,本文提出了可能的解决方案,以推进钙钛矿叠层太阳能电池的发展.

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Mixed Convection in a Two-Sided Lid-Driven Square Cavity Filled with Different Types of Nanoparticles:A Comparative Study Assuming Nanoparticles with Different Shapes

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Fluid Dynamics & Materials Processing 2021年第4期17卷 789-819页

作者： Mostafa Zaydan Mehdi riahi Fateh Mebarek-Oudina Rachid Sehaqui Laboratory of Mechanics Faculty of Sciences Aïn-ChockUniversity Hassan IICasablancaMorocco Department of Mechanical Engineering Royal Air SchoolMarrakech40002Morocco Department of Physics Faculty of SciencesUniversity 20 August 1955Skikda21000Algeria

Steady,laminar mixed convection inside a lid-driven square cavity filled with nanofluid is investigated numeri*** consider the case where the right and left walls are moving downwards and upwards respectively and maintained at different temperatures while the other two horizontal ones are kept adiabatic and *** set of nonlinear coupled governing mass,momentum,and energy equations are solved using an extensively validated and a highly accurate finite difference method of *** with previously conducted investigations on special configurations are performed and show an excellent ***,attention is focused on the heat transfer enhancement when different nano-particles:Cu,Ag,Al2O3,TiO2 and Fe3O4 are incorporated separately in different base fluids such as:Water,Ethylene-glycol,Methanol and Kerosene *** this framework,the numerical results related to several mixtures are presented and concern flow pattern and heat transfer curves for various values of Richardson number[Ri=0.1,1 and 10].It turns out that the choice of the efficient binary mixture for an optimal heat transfer depends not only on the thermophysical properties of the nanofluids but also on the range of the Richardson *** attention is devoted to shedding light on the effect of the shape of the nanoparticles on the heat transfer in the case of Water-Ag *** is concluded that the spherical shape is more suitable for a better heat transfer enhancement in comparison to the cylindrical ones.

关键词： Nanofluids mixed convection lid-driven square cavity numerical simulation

Functionalization of nitrogen-doped graphene quantum dot:A sustainable carbon-based catalyst for the production of cyclic carbonate from epoxide and CO_(2)

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Journal of Environmental Sciences 2023年第4期126卷 408-422页

作者： Zahra Eshaghi Gorji Abbas Ali Khodadadi Siavash riahi Timo Repo Yadollah Mortazavi Marianna Kemell Catalysis and Nanostructured Materials Research Laboratory School of Chemical EngineeringCollege of EngineeringUniversity of TehranTehran ***Iran Department of Chemistry University of HelsinkiHelsinki 00014Finland Institute of Petroleum Engineering School of Chemical EngineeringCollege of EngineeringUniversity of TehranTehran ***Iran

A series of organic compounds were successfully immobilized on an N-doped graphene quantum dot (N-GQD) to prepare a multifunctional organocatalyst for coupling reaction between CO_(2)and propylene oxide (PO).The simultaneous presence of halide ions in conjunction with acidic-and basic-functional groups on the surface of the nanoparticles makes them highly active for the production of propylene carbonate (PC).The effects of variables such as catalyst loading,reaction temperature,and structure of substituents are *** proposed catalysts were characterized by different techniques,including Fourier transform infrared spectroscopy (FTIR),field emission scanning electron microscopy/energy dispersive X-ray microanalysis (FESEM/EDX),thermogravimetric analysis (TGA),elemental analysis,atomic force microscopy (AFM),and ultraviolet–visible (UV-Vis) *** optimal reaction conditions,3-bromopropionic acid (BPA) immobilized on N-GQD showed a remarkable activity,affording the highest yield of 98%at 140℃ and 106Pa without any co-catalyst or *** new metal-free catalysts have the advantage of easy separation and reuse several *** on the experimental data,a plausible reaction mechanism is suggested,where the hydrogen bonding donors and halogen ion can activate the epoxide,and amine functional groups play a vital role in CO_(2)adsorption.

关键词： Heterogeneous organocatalyst CO_(2) Propylene carbonate N-doped graphene quantum dot Nanomaterials

Formation of jarosite and its effect on important ions for Acidithiobacillus ferrooxidans bacteria

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Transactions of Nonferrous Metals Society of China 2014年第4期24卷 1152-1160页

作者： B.NAZARI E.JORJANI H.HANI Z.MANAFI A.riahi Department of Mining Engineering Tehran Science and Research Branch Islamic Azad University Hydrometallurgy Research Center Sarcheshmeh Copper ComplexNational Iranian Copper Industries Company

The precipitation of jarosite adversely affects the bio-leaching of copper sulfides in the Sarcheshmeh heap bio-leaching process. The variables of the initial concentration of ferrous iron in the growth medium, pH, and temperature were examined in the laboratory to determine how they affect the precipitation of jarosite in the presence of Acidithiobacillus ferrooxidans bacteria. It was found that the maximum ferric precipitate occurred at a ferrous sulfate concentration of 50 g/L, a temperature of 32 ℃, and an initial pH value of 2.2. The effects of the precipitation of ferric iron on the quantities of ions that are important for A. ferrooxidans bacteria in aqueous phase, i.e., ferric, sulfate, potassium, phosphate, and magnesium ions, also were assessed. The results showed relatively similar patterns for the ferric and potassium ions, and then reason might have been the co-precipitation of these ions as constituent elements of jarosite mineral. At pH values greater than 1.6, the solubility of phosphate ions decreased dramatically due to the co-precipitation of phosphate ions with the jarosite precipitate and due to the significant growth rate of A. ferrooxidans bacteria in this pH range. Due to the dissolution of a gangue constituent in the ore, the magnesium levels increased in the first few days of the bio-leaching process;thereafter, it decreased slightly.

关键词： jarosite formation copper bio-leaching Acidithiobacillusferrooxidans

A roadmap for security challenges in the Internet of Things

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Digital Communications and Networks 2018年第2期4卷 118-137页

作者： Arbia riahi Sfar Enrico Natalizio Yacine Challal Zied Chtourou VRIT Lab - Military Academy Nabeul Tunisia Sorbonne Universites Universite de technologie de Compiegne CNRS Heudiasyc UMR 7253 CS 60319 60203 Compiegne Cedex France Laboratoire de Methodes de Conception de Systemes (LMCS) Ecole Nationale Superieure d'Informatique (ESI) Centre de Recherche sur I'Information Scientifique et Technique (CERIST) Algiers Algeria

Unquestionably, communicating entities （object, or things） in the Internet of Things （IoT） context are playing an active role in human activities, systems and processes. The high connectivity of intelligent objects and their severe constraints lead to many security challenges, which are not included in the classical formulation of security problems and solutions. The Security Shield for IoT has been identified by DARPA （Defense Advanced Research Projects Agency） as one of the four projects with a potential impact broader than the Internet itself. To help interested researchers contribute to this research area, an overview of the loT security roadmap overview is presented in this paper based on a novel cognitive and systemic approach. The role of each component of the approach is explained, we also study its interactions with the other main components, and their impact on the overall. A case study is presented to highlight the components and interactions of the systemic and cognitive approach. Then, security questions about privacy, trust, identification, and access control are discussed. According to the novel taxonomy of the loT framework, different research challenges are highlighted, important solutions and research activities are revealed, and interesting research directions are proposed. In addition, current stan dardization activities are surveyed and discussed to the ensure the security of loT components and applications.

关键词： Internet of Things Systemic and cognitive approach Security Privacy Trust Identification Access control

Influence of carbide ceramic reinforcements in improving tribological properties of A333 graded hybrid composites

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Defence Technology（防务技术） 2022年第7期18卷 1107-1123页

作者： Manu sam N.Radhika Department of Mechanical Engineering Amrita School of EngineeringCoimbatore641112Amrita Vishwa VidyapeethamIndia

Aluminium hybrid functionally graded metal matrix composites(FGMMCs),meet growing demands for supreme tribo-mechanical performance in automotive and aviation *** research experimentally compares the influence of carbide ceramics(B_(4)C,SiC,TiC)as reinforcements,in improving reciprocating tribology performance and mechanical strength of A333 hybrid composites against *** cylindrical samples of A333/6 wt%B_(4)C/4 wt%TiC and A333/6 wt%B_(4)C/4 wt%SiC hybrid FGMMCs were developed using horizontal centrifugal *** analysis on both composites revealed increasing ceramic gradient distribution towards outer composite *** rich zone of A333/B_(4)C/SiC hybrid FGMMC showed maximum micro-hardness(198.9 HV)and tensile strength(267.9 MPa).Elemental mapping confirmed effective distribution of ceramics and detected elemental composition of both *** rich layer of A333/B_(4)C/SiC hybrid FGMMC exhibited improved wear resistance in comparison with all three layers of A333/B_(4)C/TiC hybrid FGMMC and ***-body abrasion and tribo-chemical wear were the predominant mechanisms revealed for both composites during worn surface analysis.

关键词： Composites Functional Wear Carbide ceramics

Tribological and wear performance of centrifuge cast functional graded copper based composite at dry sliding conditions

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Journal of Central South University 2019年第11期26卷 2961-2973页

作者： N.RADHIKA Manu sam Deptartment of Mechanical Engineering Amrita School of Engineering

Non lubricated slide performance of functional grade copper matrix composite,fabricated using horizontal centrifuge cast technique was investigated using pin-on-disc *** of wear and friction coefficient of the inner wall thickness of hollow cylindrical cast specimen was analyzed using Taguchi based L27 orthogonal array,where the percentage of graphite particles were observed *** process parameters those influenced the rate of wear directly or indirectly were:applied load(15,25 and 35 N),slide velocity(1.5,2.5 and 3.5 m/s)and slide distance(750,1500 and 2250 m).Rate of wear and friction coefficient showed a proportional dependency with applied load and slide distance,whereas showing a decline during intermediate slide ***-to-Noise ratio predicted the minimal tribo-condition,on‘smaller-the-better’*** of Variance technique quantified the influence of affecting parameters,along with their *** analysis was utilized for the validation of the experimental *** and scanning electron microscopy exhibited the wear mechanisms and mechanically mixed layer formation during worn surfaces analysis.

关键词： functional graded materials centrifuge casting adhesive wear Taguchi tribology

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从云端到乡野在重庆刷新人生居住体验

城市地理 2024年第7期 78-83页

作者：田敏妤左小朵(图) minjie(图) 甜心爱溜达(图) sam_717(图) 无不详摄图网

在重庆这座繁忙的都市里,长江与嘉陵江交汇,澄江如练,烟景融融,山水变幻。奔流不息的江边,充满历史感的民国建筑述说着昔日繁华;闹市街巷的深处,绿意盎然的新艺术风酒店充满禅意;人们依地势构建房屋,不仅有高居峰巅的云上清舍,还有隐于... 详细信息

在重庆这座繁忙的都市里,长江与嘉陵江交汇,澄江如练,烟景融融,山水变幻。奔流不息的江边,充满历史感的民国建筑述说着昔日繁华;闹市街巷的深处,绿意盎然的新艺术风酒店充满禅意;人们依地势构建房屋,不仅有高居峰巅的云上清舍,还有隐于百年老村的心灵居所……“巫山七百里,巴水三回曲”,重庆这座“中国的君士坦丁堡”,因地形作为军事要塞的开拓历程已成历史,而长江航运带来的无尽繁荣,依旧在今日上演着新的传奇。

关键词：长江航运军事要塞民国建筑历史感君士坦丁堡