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cO_2 adsorption using TiO_2 composite polymeric membranes:A kinetic study

Journal of Environmental Sciences 2015年第9期27卷 163-171页

作者： Sarah Hafeez X.fan Arshad Hussain c.f.Martín School of chemical and Materials Engineering (ScME) National University of Sciences & Technology Institute for Materials and Processes School of Engineering University of Edinburgh University of Aberdeen School of Engineering Fraser Noble Building King's College

cO2is the main greenhouse gas which causes global climatic changes on larger scale. Many techniques have been utilised to capture cO2. Membrane gas separation is a fast growing cO2 capture technique, particularly gas separation by composite membranes. The separation of cO2 by a membrane is not just a process to physically sieve out of cO2 through the controlled membrane pore size. It mainly depends upon diffusion and solubility of gases, particularly for composite dense membranes. The blended components in composite membranes have a high capability to adsorb cO2. The adsorption kinetics of the gases may directly affect diffusion and solubility. In this study, we have investigated the adsorption behaviour of cO2 in pure and composite membranes to explore the complete understanding of diffusion and solubility of cO2 through membranes. Pure cellulose acetate（cA） and cellulose acetatetitania nanoparticle（cA-TiO2） composite membranes were fabricated and characterised using SEM and fTIR analysis. The results indicated that the blended cA-TiO2 membrane adsorbed more quantity of cO2 gas as compared to pure cA membrane. The high cO2 adsorption capacity may enhance the diffusion and solubility of cO2 in the cA-TiO2 composite membrane, which results in a better cO2 separation. The experimental data was modelled by Pseudo first-order, pseudo second order and intra particle diffusion *** to correlation factor R2, the Pseudo second order model was fitted well with experimental data. The intra particle diffusion model revealed that adsorption in dense membranes was not solely consisting of intra particle diffusion.

关键词： Global warming cellulose acetate Gas adsorption Pseudo order models cO2 Ti O2

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Laser Induced fluorescence Spectroscopy of IrN

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chinese Journal of chemical Physics 2009年第2期22卷 157-161页

作者： H. f. Pang A. S. c. cheung Department of chemistry The University of Hong Kong Pokfulam Road Hone Kong China

High resolution laser induced fluorescence, spectra of IrN in the spectral region between 394 and 520 nm were recorded using laser vaporization/reaction free jet expansion and laser induced fluorescence spectroscopy. Seven new vibronic transition bands were observed and analyzed. Two Ω=1 and five Ω=0 new states were identified. Least squares fit of rotationally resolved transition lines yielded accurate molecular constants for the upper states. Spectra of isotopic molecules were observed, which provided confirmation for the vibrational assignment. comparison of the observed electronic states of IrB, Irc, and IrN provides a good understanding of the chemical bonding of this group of molecules.

关键词： Electronic transition Rotational analysis Iridium mononitride Laser induced fluorescence spectroscopy

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Damage prediction of 7025 aluminum alloy during equal-channel angular pressing

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International Journal of Minerals,Metallurgy and Materials 2014年第10期21卷 990-998页

作者： M.Ebrahimi Sh.Attarilar c.Gode f.Djavanroodi Department of Mechanical Engineering Iran University of Science and Technology Department of Materials Engineering Sahand University of Technology School of Denizli Vocational Technology Program of Machine Pamukkale University Department of Mechanical Engineering Imperial College

Equal-channel angular pressing （EcAP） is a prominent technique that imposes severe plastic deformation into materials to en- hance their mechanical properties. In this research, experimental and numerical approaches were utilized to investigate the mechanical prop- erties, strain behavior, and damage prediction of EcAPed 7025 aluminum alloy in various conditions, such as die channel angle, outer comer angle, and friction coefficient. Experimental results indicate that, after the first pass, the yield strength, ultimate tensile strength, and hardness magnitude are improved by approximately 95%, 28%, and 48.5%, respectively, compared with the annealed state, mainly due to grain re- finement during the deformation. finite element analysis shows that the influence of die channel angle is more important than that of outer comer angle or friction coefficient on both the strain behavior and the damage prediction. Also, surface cracks are the main cause of damage during the EcAP process for every die channel angle except for 90°; however, the cracks initiated from the neighborhood of the central re- gions are the possible cause of damage in the EcAPed sample with the die channel angle of 90°.

关键词： aluminum alloys equal-channel angular pressing materials damage strain distribution mechanical properties

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Study of Transition from Laminar to Turbulent Boundary Layer on a Tilted flat Plate Using Heat Transfer Measurements

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Journal of Thermal Science 2007年第2期16卷 186-191页

作者： E.Sanz c.Nicot R.Point f.Plaza Laboratoire de Mécanique des fluides et Acoustique LMFA(ECL-UCB-INSA Lyon-CNRS)36Avenue Guy de Collongue69134 Ecully.France.

The boundary layer transition over a flat tilted plate has been studied by means of heat transfer measurements. A heat flux sensor has been developed, in order to measure the efficiency of convective heat transfer for various types of surfaces or flows. Its operation at constant temperature allows direct and fast measurements of heat flux. The present paper reports the development of the sensor and presents its application to the study of transition in a boundary layer depending on the angle of incidence of the external flow. An exponential relationship between critical Reynolds number and pressure gradient parameter has been found.

关键词： convective heat flux boundary layer transition pressure gradient.

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Modelling of internal ballistics of gun systems:A review

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Defence Technology（防务技术） 2024年第11期41卷 35-58页

作者： f.Ongaro c.Robbe A.Papy B.Stirbu A.chabotier Royal Military Academy Avenue de la Renaissance 30Bruxelles 1000Belgium

A deep understanding of the internal ballistic process and the factors affecting it is of primary importance to efficiently design a gun system and ensure its safe management. One of the main goals of internal ballistics is to estimate the gas pressure into the combustion chamber and the projectile muzzle velocity in order to use the propellant to its higher efficiency while avoiding over-pressure phenomena. Dealing with the internal ballistic problem is a complex undertaking since it requires handling the interaction between different constituents during a transient time lapse with very steep rise of pressure and temperature. Several approaches have been proposed in the literature, based on different assumptions and techniques. Generally, depending on the used mathematical framework, they can be classified into two categories: computational fluid dynamics-based models and lumped-parameter ones. By focusing on gun systems, this paper offers a review of the main contributions in the field by mentioning their advantages and drawbacks. An insight into the limitations of the currently available modelling strategies is provided,as well as some considerations on the choice of one model over another. Lumped-parameter models, for example, are a good candidate for performing parametric analysis and optimisation processes of gun systems, given their minimum requirements of computer resources. conversely, cfD-based models have a better capacity to address more sophisticated phenomena like pressure waves and turbulent flow effects. The performed review also reveals that too little attention has been given to small calibre guns since the majority of currently available models are conceived for medium and large calibre gun ***, aspects like wear phenomena, bore deformations or projectile-barrel interactions still need to be adequately addressed and our suggestion is to dedicate more effort on it.

关键词： Internal ballistics Numerical modelling Lumped-parameter model computational fluid dynamics Gun systems

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New photo-thermal-synthesized polymer for self-compacting concrete to increase productivity, minimize pollution, and eliminate steam curing in precast concrete

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Journal of Harbin Institute of Technology(New Series) 2006年第5期13卷 518-524页

作者： f. c. Lai M. f. Mohd Zain 王宝民 K. c. Lee Dept. of civil and Structural Engineering Faculty of Engineering Universiti Kebangsaan Malaysia 43600 U.K.M Bangi Selangor Darul Ehsan Malaysia Dept. of civil Engineering Dalian University of Technology Dalian 116024 China Sime Darby Technology Petaling Jaya Kuala Lumpur Malaysia

The objective in this study is to apply the sustainable chemistry and photo-thermal synthesis technology to produce the sustainable eco-superplasticiser for the sustainable high performance Scc concrete especially in hot tropical countries. A photo-thermal synthesized eco-superplasticiser （PSES） was produced by using photo-thermal catalyst in a solar chemical reactor. In this preliminary study, an unique high early strength of Scc concrete has been successfully produced by imposing an unique proportion of the photo-thermal-synthesized eco- Superplasticiser （PSES）, local fly ash, sand and aggregate. The Scc concrete is preliminary tried in the precast concrete product to produce the complicated geometries as Tunnel segment, U-shape beam, and Box girder which have the critical reinforcement and thin section concrete. Surprisingly, this Scc provide the benefits as eliminating steaming energy, increased productivity, and minimize pollution. These unique properties of sustainable Scc concrete can not be achieved by the convention concrete by using ligno, naphthalene and melamine base superplasficiser. The synthesized sustainable eco-superplasticiser is a perfect choice to fully utilized the renewable energy and improve the concrete working environment.

关键词： photo-chemical synthesis sustainable self-compacting concrete eco-superplasticiser eliminate steaming renewable solar energy

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Thermal manipulation of plasmons in atomically thin films

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Light(Science & Applications) 2020年第1期9卷 1179-1189页

作者： Eduardo J.c.Dias Renwen Yu f.Javier Garcia de Abajo IcfO-Institut de ciencies fotoniques The Barcelona Institute of Science and Technology08860 Castelldefels(Barcelona)Spain IcREA-Institucio catalana de Recerca i Estudis Avançats Passeig Lluis Companys 2308010 BarcelonaSpain

Nanoscale photothermal effects enable important applications in cancer therapy,imaging and *** effects also induce substantial changes in the optical response experienced by the probing light,thus suggesting their application in all-optical ***,we demonstrate the ability of graphene,thin metal films,and graphene/metal hybrid systems to undergo photothermal optical modulation with depths as large as>70%over a wide spectral range extending from the visible to the terahertz frequency *** envision the use of ultrafast pump laser pulses to raise the electron temperature of graphene during a picosecond timescale in which its mid-infrared plasmon resonances undergo dramatic shifts and broadenings,while visible and near-infrared plasmons in the neighboring metal films are severely attenuated by the presence of hot graphene *** study opens a promising avenue toward the active photothermal manipulation of the optical response in atomically thin materials with potential applications in ultrafast light modulation.

关键词： pump visible films

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Building a Novel future: connecting Peoples and cultures

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Social Sciences in china 2022年第1期43卷 194-208页

作者： Augustin f.c.Holl School of Sociology and Anthropology Xiamen University

current humanity is experiencing extraordinary levels of material and ideal *** being constant and stability exceptional and provisional;one has to expect a significant acceleration of change in the next hundred *** core question is therefore:What kind of future is being shaped for the next generations,our grandchildren and great-grand children?Without going too far back in time,it is fair to say that the current world was shaped by two different,successive and antinomic global processes:imperial expansion,colonization and domination on the one hand,and resistance,struggle for liberation,and the search for a more equitable world order on the other *** all the odds,European imperialism,civil war,wars of aggression,and Western ostracism,china was an influential actor in the struggle for liberation of Africa from colonialism,got its rightful place in the international world order and is now the second economy of the *** resulted in the emergence of a de facto multipolar world,with different models of societies and organizational *** are dialectic processes constantly in operation,but there is however a third crucial area of interest,generally taken granted,that of people and *** relations and sustainable economic development backed by greater cultural and demographic connectivity are better options for the construction of a novel future for *** and higher education institutions can play an important role in spearheading and implementing these new orientations for the construction of a future peaceful and sustainable human world in which war will be *** paper outlines what academics can do to promote such a vision.

关键词： Africa china social sciences alternative partnership connectivity people cultures sustainable future

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Speckle Reduction in Imaging Projection Systems

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Optics and Photonics Journal 2012年第4期2卷 338-343页

作者： weston Thomas christopher Middlebrook Electrical and computer Engineering Department Michigan Technological University Houghton USA

Diffractive diffusers (phase gratings) are routinely used for homogenizing and beam shaping for laser beam applications. Another use for diffractive diffusers is in the reduction of speckle for pico-projection systems. While diffusers are unable to completely eliminate speckle they can be utilized to decrease the resultant contrast to provide a more visually acceptable image. Research has been conducted to quantify and measure the diffusers overall ability in speckle reduction. A theoretical fourier optics model is used to provide the diffuser’s stationary and in-motion performance in terms of the resultant contrast level. contrast measurements of two diffractive diffusers are calculated theoretically and compared with experimental results. Having a working theoretical model to accurately predict the performance of the diffractive diffuser allows for the verification of new diffuser designs specifically for pico-projection system applications.

关键词： Diffractive Diffusers Speckle contrast Reduction Laser Pico-Projectors

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Experimental Podophyllotoxin (Bajiaolian) Poisoning:——Ⅰ. Effects on the Nervous System

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Biomedical and Environmental Sciences 1992年第4期5卷 283-292页

作者： LOUIS W.cHANG c.M.YANG c.f.cHEN J.f.DENG Departments of Pathology Pharmacology and Toxicology University of Arkansas for Medical Sciences Little RockThe Chang-Gung Medical College Kwai-sanNational Research Institute of Chinese MedicineThe Veteran General Hospital AR 72205TaipeiTaipeiTaipei Taiwan China

Bajiaolian, one of the species in the Mayapple family ( Podophyllum pelatum ), has been widely used as a traditional chinese herbal medicine for the remedies of snake bites, general weakness, poisons, condyloma accuminata, lymphadenopathy, and certain tumors in china. In Western medicine, Podophyllum was first used medically as a laxative in the early 19th century. Since 1940, the resin of podophyllum has also been used topically for various skin lesions, such as warts and condyloma. Human poisonings have been reported.An animal model was established to investigate the neurotoxic effects of Bajiaolian. Podophyllotoxin, the major active ingredient in Podophyllum, was injected (ip) to young adult male rats at doses of 0, 5, 10, or 15 mg-kg-1 b.w.. The animals were sacrificed 72 h after injection.Neuronal changes were readily observable in animals treated with 10 or 15 mg-kg-1 of the toxin. Edematous changes of the anterior horn motoneurons were observed in the spinal cord. No neuronal necrosis was found. The type of neuronal swelling is believed to be only a transient change and would probably subside with time if no further assaults occur. More serious and perhaps longer term of changes were found in the dorsal ganglion neurons and the nerve fibers (axons) in the central and peripheral nervous system. Severe depletion of the Nissl substance (RNA/polyribosomes) was observed in the dorsal root ganglion neurons. Alterations in these sensory neurons would give rise to and correlate with the sensory disturbances experienced by the patients. Bodian staining also revealed a dose-related increase in the coarseness (thickness) of the nerve fibers (axons) in the cerebellum, cerebral cortex, brainstem, and spinal cord.This is the first scientific study showing the neurotoxicity of Bajiaolian, a commonly used chinese herbal medicine. Toxicities on other organ systems by this drug certainly exist. caution should be exercised in the dispensing and usa

关键词： Bajiaolian Effects on the Nervous System Experimental Podophyllotoxin Poisoning

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