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MODIFICATION OF SODIUM SAlT OF PARTIAllY CARBOXYMEThYlATED TAMARIND kERNEl POWDER ThROUGh GRAFTING WITh ACRYlONITRIlE: SYNThESIS, ChARACTERIZATION AND SWEllING BEhAVIOR

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Chinese Journal of Polymer Science 2013年第12期31卷 1670-1684页

作者： J.h.Trivedi J.R.Jivani k.h.Patel h.C.Trivedi P.G.Dept.of Chemistry Sardar Patel UniversityVallabh Vidyanagar Amneal Phamaceuticals

A graft copolymer of polyacrylonitrile （PAN） with sodium salt of partially carboxymethylated tamarind kernel powder （Na-PCMTkP, DS ^-= 0.15） was synthesized by using ceric ammonium nitrate （CAN） as a redox initiator in an aqueous medium. The optimum reaction conditions for affording maximum percentage of grafting were established by successively varying reaction conditions such as concentrations of nitric acid, CAN, monomer （AN） as well as reaction time, temperature and amount of substrate. The influence of these reaction conditions on the grafting yields was discussed. The kinetic scheme of free radical graft copolymerization was proposed and the experimental results were found to agree very well with the proposed kinetic scheme. The graft copolymer （Na-PCMTkP-g-PAN, percentage of grafting G = 413.76% and percentage of grafting efficiency GE = 96.48%） sample synthesized under the established optimized reaction conditions was hydrolyzed by 0.7 mol-l l NaOh solution at 90-95 ℃ to yield the superabsorbent hydrogel, h-Na-PCMTkP-g-PAN. The swelling behavior of the hydrogel was studied by carrying out its absorbency measurements in low conductivity water, 0.15 mol·l^-1 salt （NaCl, CaCl2 and AlCl3） solutions and simulated urine （SU） solution at different timings. FTIR, TGA and SEM techniques were used to characterize the products.

关键词： Sodium salt of partially carboxymethylated tamarind kernel powder Acrylonitrile Graft copolymerization Superabsorbent hydrogels Swelling behavior.

Spectroscopic investigations and luminescence spectra of Sm3+ doped soda lime silicate glasses

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Journal of Rare Earths 2009年第5期27卷 773-780页

作者： Y.k. Sharma S.S.l. Surana R.k. Singh Department of Physics Govt. Post Graduate College Rudrapur 263153 (U S Nagar) India Department of Physics J. N. V. University Jodhpur-342001 India Department of Physics Govt. Post Graduate College Rudrapur 263153 (U S Nagar) India

Sm3+ doped soda lime silicate glasses co-doped with As2O3 were prepared and characterised by measuring their absorption spectra in UV-VIS/NIR regions and luminescence spectra in the visible region. Judd-Ofelt intensity parameters, Ωλ, were evaluated from the measured intensities of the various absorption bands. Ωλ parameters of these glasses were compared with the Ωλ parameters of other reported Sm3+ glasses to study the bonding environment surrounding the Sm3+ in the present glasses. Presence of [AsO4]3– tetrahedra in the second coordination sphere around the central Sm3+ ion made these glasses less covalent as compared to other oxide glasses but the ratio Ω4/Ω6 of the 1.83 indicated them to be fairly stable. With the help of Ωλ parameters and luminescence data for various emission lines, radiative properties for different emission lines were calculated. The values of radiative properties indicated that 4G5/2→6h7/2 and 4G5/2→6h9/2 transitions responsible for orange luminescence might be used in the development of materials for lED's and other optical devices in the visible region.

关键词： rare earth glasses Judd-Ofelt theory absorption spectroscopy luminescence

Nonlinear stability of advanced sandwich cylindrical shells comprising porous functionally graded material and carbon nanotube reinforced composite layers under elevated temperature

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Applied Mathematics and Mechanics(English Edition) 2021年第9期42卷 1327-1348页

作者： h.V.TUNG l.T.N.TRANG Faculty of Civil Engineering Hanoi Architectural UniversityHa Noi 10000Viet Nam Faculty of Civil Engineering University of Transport TechnologyHa Noi 10000Viet Nam

The nonlinear stability of sandwich cylindrical shells comprising porous functionally graded material(FGM) and carbon nanotube reinforced composite(CNTRC)layers subjected to uniform temperature rise is investigated. Two sandwich models corresponding to CNTRC and FGM face sheets are proposed. Carbon nanotubes(CNTs) in the CNTRC layer are embedded into a matrix according to functionally graded distributions. The effects of porosity in the FGM and the temperature dependence of properties of all constituent materials are considered. The effective properties of the porous FGM and CNTRC are determined by using the modified and extended versions of a linear mixture rule, respectively. The basic equations governing the stability problem of thin sandwich cylindrical shells are established within the framework of the Donnell shell theory including the von k’arm’an-Donnell nonlinearity. These equations are solved by using the multi-term analytical solutions and the Galerkin method for simply supported *** critical buckling temperatures and postbuckling paths are determined through an iteration procedure. The study reveals that the sandwich shell model with a CNTRC core layer and relatively thin porous FGM face sheets can have the best capacity of thermal load carrying. In addition, unlike the cases of mechanical loads, porosities have beneficial effects on the nonlinear stability of sandwich shells under the thermal load. It is suggested that an appropriate combination of advantages of FGM and CNTRC can result in optimal efficiency for advanced sandwich structures.

关键词： carbon nanotube reinforced composite(CNTRC) porous functionally graded material(FGM) thermal instability cylindrical shell advanced sandwich model

Fish-on-Chips:unveiling neural processing of chemicals in small animals through precise fluidic control

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Neural Regeneration Research 2024年第11期19卷 2351-2353页

作者： Samuel k.h.Sy ho ko Division of Neurology Department of Medicine and TherapeuticsFaculty of MedicineThe Chinese University of Hong KongShatinNew TerritoriesHong Kong Special Administrative RegionChina li ka Shing Institute of health Sciences Faculty of MedicineThe Chinese University of Hong KongShatinNew TerritoriesHong Kong Special Administrative RegionChina Department of Electrical and Electronic Engineering Faculty of EngineeringThe University of Hong KongPok Fu LamHong Kong IslandHong Kong Special Administrative RegionChina Advanced Biomedical Instrumentation Center Hong Kong Science ParkPak Shek KokNew TerritoriesHong Kong Special Administrative RegionChina Margaret k.l.Cheung Research Center for Management of Parkinsonism Faculty of MedicineThe Chinese University of Hong KongShatinNew TerritoriesHong Kong Special Administrative RegionChina lau Tat-chuen Research Center of Brain Degenerative Diseases in Chinese Faculty of MedicineThe Chinese University of Hong KongShatinNew TerritoriesHong Kong Special Administrative RegionChina Gerald Choa Neuroscience Institute The Chinese University of Hong KongShatinNew TerritoriesHong Kong Special Administrative RegionChina

Precise chemical cue presentation alongside advanced brainwide imaging techniques is important to the study of chemosensory processing in ***,the dynamic nature of chemical-carrying media,such as water or air,poses a significant challenge for delivering highly-controlled chemical flow to an animal ***,contact-based cue manipulation and delivery easily shift the position of the animal subject,which is often undesirable for high-quality brain ***,more advanced interfacing tools that align with the diverse range of body part sizes of an animal,ranging from micrometer-scale neurons to meter-long limbs,are much *** is particularly crucial when dealing with dimensions that are beyond the reach of conventional experimental tools.

关键词： dealing precise sizes

high throughput synthesis enabled exploration of CoCrFeNi-based high entropy alloys

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Journal of Materials Science & Technology 2022年第15期110卷 269-282页

作者： l.Zhao l.Jiang l.X.Yang h.Wang W.Y.Zhang G.Y.Ji X.Zhou W.A.Curtin X.B.Chen P.k.liaw S.Y.Chen h.Z.Wang Beijing Advanced Innovation Center for Materials Genome Engineering Beijing Key Laboratory of Metal Materials CharacterizationCentral Iron and Steel Research InstituteBeijing 100081China Institute for Advance Studies in Precision Materials Yantai UniversityYantai 264005China National Center for Materials Service Safety University of Science and Technology BeijingBeijing 100083China laboratory for Multiscale Mechanics Modeling Ecole Polytechnique Federale de LausanneLausanne CH-1015Switzerland School of Engineering RMIT UniversityMelbourne 3046Australia Department of Materials Science and Engineering The University of Tennessee37996USA

To accelerate the exploration,screening,and discovery of structural high-entropy alloys with targeted properties,the newly developed high-Throughput hot-Isostatic-Pressing based Micro-Synthesis Approach(hT-hIP-MSA)is employed to efficiently synthesize and characterize 85 combinatorial alloys in a 13-principal element alloying *** Co Cr Fe Ni-based high entropy alloys span 1 quaternary,9 quinary,and 36 senary alloy systems,and their composition-structure-property relationships are characterized and analyzed experimentally and *** the single-phase FCC CoCrFeNi alloy base,with Mn,Cu,Ti,Nb,Ta,Mo,W,Al,and Si as principal element alloying additions,we find(1)the extended Mn solubility in the single-phase FCC CoCrFeNi-Mn_(x) alloys,(2)the destabilizing behavior for most of the quinary and senary alloys,and(3)the distinctive solid-solution-strengthening effects in the *** combining the computational methods,the hT-hIP-MSA can be systematic and economic to explore and refine the compositions,structures,and properties of structural high-entropy alloys.

关键词： high-entropy alloys high-throughput Composition-structure-property

Uncovering the softening mechanism and exploring the strengthening strategies in extremely fine nanograined metals:A molecular dynamics study

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Journal of Materials Science & Technology 2022年第14期109卷 186-196页

作者： h.R.Peng Z.Y.Jian C.X.liu l.k.huang Y.M.Ren F.liu School of Materials and Chemical Engineering Xi’an Technological UniversityXi’an 710021China State key laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an 710072China

The strength of polycrystalline metals increases with decreasing grain size,following the classical hallPetch ***,this relationship fails when softening occurs at very small grain sizes(typically less than 10 to 20 nm),which limits the development of ultrahigh-strength *** this work,using columnar-grained nanocrystalline Cu-Ag‘samples’,molecular dynamics simulations were performed to investigate the softening mechanism and explore the strengthening strategies(e.g.,formation of solid solution or grain boundary(GB)segregation)in extremely fine nanograined ***,the softening of pure metals is induced by atomic sliding in the GB layer,rather than dislocation activities in the grain interior,although both occur during *** solid solution lowers the stacking fault energy and increases the GB energy,which leads to the softening of NC *** segregation stabilizes GB structures,which causes a notable improvement in strength,and this improvement can be further enhanced by optimizing the solute concentration and GB *** work deepens the understanding of the softening mechanism due to atomic sliding in the GB layer and the strengthening mechanism arising from tailoring the GB stability of immiscible alloys and provides insights into the design of ultrahighstrength materials.

关键词： Softening Strengthening Cu-Ag alloy Molecular dynamics Nanocrystalline

Effect of two-step cooling process on mechanical properties of TRIP steel with high performance

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Journal of Iron and Steel Research International 2018年第4期25卷 426-432页

作者： M.l. li h. Jiang Y.l. he l.B. Chen G.T. Zhang h. Wang X.G. lu l. li School of Materials Science and Engineering Shanghai University Shanghai 200072 China State key laboratory of Advanced Special Steel Shanghai University Shanghai 200072 China Pangang Group Research Institute Panzhihua 617000 Sichuan China

A novel two-step cooling experiment was established to simulate the slow cooling process of continuous annealing production line for transformation-induced plasticity （TRIP） steel. The microstructures and mechanical properties of TRIP steel soaked at 700℃ for different time were investigated by tensile test, scanning electron microscopy, X-ray diffraction, and thermodynamic and kinetic calculation. It is shown that the steel soaked for 15 s exhibits the optimal product of strength and elongation （PSE 〉 30,000 MPa%） due to the transformation of austenite to proeutectoid ferrite, which delays the bainite transformation and improves the stability of retained austenite. In addition, the mechanical properties of TRIP steel soaked over 30 s are much lower, resulting from the precipitation of cementite, which decreases the stability of retained austenite and weakens the TRIP effect.

关键词： Transformation induced plasticity steel Two-step cooling Microstructure Mechanical property

Electromagnetoelastic behaviors of functionally graded piezoelectric solid cylinder and sphere

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Acta Mechanica Sinica 2007年第1期23卷 55-63页

作者： h. l. Dai Y.M. Fu J.h. Yang Department of Engineering Mechanics Hunan University Changsha 410082 China

Analytical studies on electromagnetoelastic behaviors are presented for the functionally graded piezoelectric material （FGPM） solid cylinder and sphere placed in a uniform magnetic field and subjected to the external pressure and electric loading. When the mechanical, electric and magnetic properties of the material obey an identical power law in the radial direction, the exact displacements, stresses, electric potentials and perturbations of magnetic field vector in the FGPM solid cylinder and sphere are obtained by using the infinitesimal theory of electromagnetoelasticity. Numerical examples also show the significant influence of material inhomogeneity. It is interesting to note that selecting a specific value of inhomogeneity parameter β can optimize the electromagnetoelastic responses, which will be of particular importance in modern engineering designs.

关键词： Functionally graded piezoelectric material (FGPM) Electromagnetoelastic Solid cylinder Solid sphere Perturbation of magnetic field vector

Recent development in the application of bulk metallic glasses

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Journal of Materials Science & Technology 2022年第36期131卷 115-121页

作者： k.Gao X.G.Zhu l.Chen W.h.li X.Xu B.T.Pan W.R.li W.h.Zhou l.li W.huang Y.li Dongguan Yihao Metal Technology Co.ltd Dongguan 523686China Dongguan Eontec Co.ltd Dongguan 523686China Shenyang National laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China

Over the past decades,considerable efforts have been made in the commercial application of bulk metallic glasses(BMGs).Despite great challenges faced by the industrial players,significant progress has been achieved,and millions of commercial products for various kinds of applications have been shipped around the *** in this paper,we shall present the alloys suitable for the actual products in the application and discuss the merits of the processing technique of BMGs over the existing processing techniques and *** importantly we demonstrate the typical examples of products over the past few ***,future directions of the industrialization of BMGs are also discussed.

关键词： Bulk metallic glasses Commercial application Alloy design Products