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Structural, elastic, and electronic properties of recently discovered ternary silicide superconductor Li_2IrSi_3: An ab-initio study

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Chinese Physics B 2015年第11期24卷 478-482页

作者： m.A.Hadi m.A.Alam m.Roknuzzaman m.T.Nasir A.K.m.A.islam S.H.Naqib Department of Physics University of Rajshahi Department of Physics Rajshahi University of Engineering and Technology Department of Physics Jessore University of Science and Technology International islamic University Chittagong

The structural, elastic, and electronic properties of the very recently discovered ternary silicide superconductor, Li2IrSi3, are calculated using an ab-initio technique. We adopt the plane-wave pseudopotential approach within the frame- work of the first-principles density functional theory （DFT） implemented by the CASTEP code. The calculated structural parameters show reasonable agreement with the experimental results. The elastic moduli of this interesting material are calculated for the first time. The electronic band structure and electronic energy density of states indicate the strong cova- lent Ir-Si and Si-Si bonding, which leads to the formation of the rigid structure of Li2IrSi3. Strong covalency gives rise to a high Debye temperature in this system. We discuss the theoretical results in detail in this paper.

关键词： silicide superconductor crystal structure elastic properties electronic structures

Structural, Dielectric, and magnetic Properties of Ba-Doped multiferroic Bismuth Ferrite

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Acta metallurgica Sinica(English Letters) 2015年第8期28卷 958-964页

作者： Rubayyat mahbub Takian Fakhrul.md Fakhrul islam mehedi Hasan Arman Hussain m.A.matin m.A.Hakim Department of Glass and Ceramic Engineering Bangladesh University of Engineering and Technology Department of materials and metallurgical Engineering Bangladesh University of Engineering and Technology

The main focus of the research was to correlate the microstructure with dielectric and magnetic properties of Bi1-xBaxFeO3 samples. Bi1-xBaxFeO3 samples（x = 0.1, 0.2 and 0.3） were synthesized by the conventional solid-state reaction method using nano-powders of Bi2O3, Fe2O3, and BaCO3. Thereafter, field emission scanning electron microscope and X-ray diffraction（XRD） techniques were used to examine the structure and phase of the samples. Phase analysis by XRD indicated that the single-phase perovskite structure was formed with possible increment in lattice parameter with increasing Ba doping. Complex permeability（u＇iand u＇＇i） measured using impedance analyzer confirmed the increase in magnetic property with increasing Ba doping. Finally, dielectric constant（k） was analyzed as a function of temperature at different frequencies. Dielectric constant as high as 2900 was attained in this research for Bi0.8Ba0.2FeO3 sample due to reduction in leakage current at this composition.

关键词： multiferroic Bismuth ferrite Dielectric Complex permeability

A study on the compatibility of the generalized Kudryashov method to determine wave solutions

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Propulsion and Power Research 2021年第1期10卷 95-105页

作者： Hemonta Kumar Barman md.Ekramul islam m.Ali Akbar Department of Applied mathematics University of RajshahiRajshahi6205Bangladesh Department of mathematics Pabna University of Science and TechnologyPabna6600Bangladesh

In this article,we establish solitary wave solutions to the Estevez-mansfieldClarkson(EmC)equation and the coupled sine-Gordon equations which are model equations to analyze the formation of shapes in liquid drops,surfaces of negative constant curvature,*** contriving the generalized Kudryashov *** extracted results introduce several types’solitary waves,such as the kink soliton,bell-shape soliton,compacton,singular soliton,peakon and other sort of soliton for distinct valuation of the unknown *** achieved analytic solutions are interpreted in details and their 2D and 3D graphs are *** obtained solutions and the physical structures explain the soliton phenomenon and reproduce the dynamic properties of the front of the travelling wave deformation generated in the dispersive *** shows that the generalized Kudryashov method is powerful,compatible and might be used in further works to found novel solutions for other types of nonlinear evolution equations ascending in physical science and engineering.

关键词： The nonlinear evolution equations(NLEEs) The Estevez-mansfieldClarkson(EmC)equation The coupled sineGordon equations The generalized Kudryashov method Solitons Analytic solutions

mOVPE Growth of In_xGa_(1-x)N(x～0.4) and Fabrication of Homo-junction Solar Cells

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Journal of materials Science & Technology 2013年第2期29卷 128-136页

作者： md. Rafiqul islam md. Rejvi Kaysir md. Jahirul islam A. Hashimoto A. Yamamoto Department of Electrical and Electronic Engineering KUETKhulna 9203 Bangladesh Graduate School of Engineering University of Fukui 3-9-1 BunkyoFukui 910-8507 Japan

The metal organic vapor phase epitaxy （mOVPE） growth of indium gallium nitride （InGaN） has been discussed in detail towards the fabrication of solar cell. The InGaN film with In contents up to 0.4 are successfully grown by controlling the fundamental growth parameters such as the precursor gas flow rates, temperature etc. The formation of metallic In originates from the higher value （0.74） of trimethylindium/ （trimethylindium ＋ triethylgallium）（TmI/（TmI ＋ TEG）） molar ratio with low （4100） V/lll weight molar ratio while the lower value （0.2） of TmI/（TmI ＋ TEG） causes the phase separation. It is also necessary to control the growth rate and epitaxial film thickness to suppress the phase separation in the material. The crystalline quality of grown films is studied and it is found to be markedly deteriorated with increasing In content. The lattice parameters as well as the thermal expansion coefficient mismatch between GaN template and InGaN epi-layer are primarily considered as the reasons to deteriorate the film quality for higher In content. By using Ino.16Ga0.84N films, an n＋-p homo-junction structure is fabricated on 0.65 μm GaN template. For such a device, the response to the light illumination （Am 1.5） is observed with an open circuit voltage of 1.4 V and the short circuit current density of 0.25 mA/cm2. To improve the performance as well as increase solar photon capturing, the device is further fabricated on thick GaN template with higher In content. The In0.25Ga0.75N n＋-p junction solar cell is found better performance with an open circuit voltage of 1.5 V and the short circuit current density of 0.5 mA/cm2. This is the InGaN p-n homo-junction solar cell with the highest In content ever reported by mOVPE.

关键词： InGaN metal organic vapor phase epitaxy (mOVPE) Growth Film quality Doping p-n junction

Differentially private data publication with multi‐level data utility

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High-Confidence Computing 2022年第2期2卷 61-68页

作者： Honglu Jiang S.m.Sarwar Haotian Yu Sheikh Ariful islam Department of Informatics and Engineering Systems The University of Texas Rio Grande ValleyBrownsvilleUSA Department of Computer science The University of Texas Rio Grande ValleyEdinburgUSA Department of Data Analytics The George Washington UniversityWashingtonUSA

Conventional private data publication mechanisms aim to retain as much data utility as possible while ensuring sufficient privacy protection on sensitive *** data publication schemes implicitly assume that all data analysts and users have the same data access privilege ***,it is not applicable for the scenario that data users often have different levels of access to the same data,or different requirements of data *** multi-level privacy requirements for different authorization levels pose new challenges for private data *** PPDP mechanisms only publish one perturbed and private data copy satisfying some privacy guarantee to provide relatively accurate analysis *** find a good tradeoffbetween privacy preservation level and data utility itself is a hard problem,let alone achieving multi-level data utility on this *** this paper,we address this challenge in proposing a novel framework of data publication with compressive sensing supporting multi-level utility-privacy tradeoffs,which provides differential ***,we resort to compressive sensing(CS)method to project a n-dimensional vector representation of users’data to a lower m-dimensional space,and then add deliberately designed noise to satisfy differential ***,we selectively obfuscate the measurement vector under compressive sensing by adding linearly encoded noise,and provide different data reconstruction algorithms for users with different authorization *** experimental results demonstrate that mL-DPCS yields multi-level of data utility for specific users at different authorization levels.

关键词： Differential privacy Compressive sensing multi-level utility Privacy preservation

Pre-sowing treatments for improved germination and growth of two rare native species of Bangladesh

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Journal of Forestry Research 2018年第5期29卷 1277-1282页

作者： m.A.Hossain K.S.islam N.Rajasree m.K.Hossain m.S.Alam Institute of Forestry and Environmental Sciences University of Chittagong

Pre-sowing treatments are expected to increase seed *** evaluates response to pre-sowing treatments and the growth performance of two native and rare tree species,Garuga pinnata *** Vitex glabrata *** hard seed coats were treated by rubbing with sand paper,nail clipping,and immersion in water and acid（H_2SO_4）.Results indicate that *** showed a 90% germination rate and 30% germination energy when seed coats were nicked with a nail *** with sand paper was the best pre-sowing treatment for ***,resulting a 80% germination rate and 30% germination *** and *** seedlings from seeds soaked 24h in water resulted in maximum heights and collar *** were significantly higher（at p〈0.05） than those of other *** results indicate that scarification or nicking of seeds may have some negative impacts on seedling ***,it is difficult to recommend a pre-sowing treatment of seeds for achieving both maximum germination and good early seedling growth.

关键词： Germination Early seedling growth Height Native species Garuga pinnata Vitex glabrata

Anatomical studies on water hyacinth (Eichhornia crassipes (mart.) Solms) under the influence of textile wastewater

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Journal of Zhejiang University-Science B(Biomedicine & Biotechnology) 2005年第10期6卷 991-998页

作者： mAHmOOD Qaisar 郑平 SIDDIQI m. Rehan islam Ejaz ul AZIm m. Rashid HAYAT Yousaf Department of Environmental Engineering Zhejiang University Department of Botany Forman Christian College Lahore Pakistan Department of Botany Federal Government Postgraduate College H-8 Islamabad Pakistan Department of maths/Stat/Computer Science North Western Frontier Province Agricultural University Peshawar Pakistan

Water hyacinth (Eichhornia crassipes (mart.) Solms) is a prolific free floating aquatic macrohpyte found in tropical and subtropical parts of the earth. The effects of pollutants from textile wastewater on the anatomy of the plant were studied. Water hyacinth exhibits hydrophytic adaptations which include reduced epidermis cells lacking cuticle in most cases, presence of large air spaces (7～50 μm), reduced vascular tissue and absorbing structures. Textile waste significantly affected the size of root *** presence of raphide crystals was noted in parenchyma cells of various organs in treated plants.

关键词： Eichhornia crassipes, Water hyacinth, Textile wastewater, Anatomical studies

Electrical conductivity retention and electrochemical activity of CSA doped graphene/gold nanoparticle@ polyaniline composites

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Progress in Natural Science:materials International 2016年第4期26卷 341-346页

作者： md.Akherul islam m.Ehtisham Khan muhammad mohsin Hossain mudassir Hasan Department of Pharmacy Atish Dipankar University of Science & Technology School of Chemical Engineering Yeungnam University

This paper reports the synthesis of CTAB mediated CSA doped PANI and GN/GNP@ PANI composite nanofibers. The as synthesized composite nanofibers were examined by TEm, SEm, XRD, Raman spectroscopy; UV–visible diffused reflectance spectroscopy and TGA. The CTAB mediated CSA doped composite nanofibers showed 59% higher DC electrical conductivity at ambient temperature than that of PANI,which might be due to the enhancement in the mobility of the charge carriers and reduction in hopping distance in the composite system. The CTAB mediated CSA doped composite nanofibers compared to PANI was observed to be showing enhanced DC electrical conductivity retention after various cycles of heating, suggesting an enhancement in thermal stability of the composite structure, which could be attributed to the synergistic effect of GN,GNP and PANI. Additionally, the composite nanofibers showed greater electrochemical activity and better capacitive performance and reduced optical bandgap than that of PANI.

关键词： GN GNP Poly aniline Conductivity retention Thermal stability Capacitor

Systematic mutational analysis of epitope-grafted ED3 immunogenicity reveals a DENV3-DENV4 bi-serospecific ED3 mutant

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Asian Pacific Journal of Tropical medicine 2022年第2期15卷 63-70,I0001-I0004页

作者： mamtaz Sultana Nazmul Hasan mamunur R.mahib mohammad m.islam Department of Biochemistry and molecular Biology University of ChittagongChittagong-4331Bangladesh

Objective:To identify the residue determinants of the serospecificity and sero-cross-reactivity of dengue virus(DENV)envelope protein domain 3(ED3),which contains two major putative epitopes of ***:We constructed ED3 from DENV3(3ED3)and DENV4(4ED3),and six epitope-grafted variants,where we transferred epitope 1(L304I,K305D,V309m,and S310A)and/or epitope 2(D383N,K384S,K387T,and N389H)of 4ED3 onto 3ED3 and *** albino mice aged 3-4 weeks were immunized against wildtype and epitope-grafted ED3 variants and anti-ED3 IgG antibody responses were determined using ***:mouse immunization using 3ED3 and 4ED3 generated serotype-specific antisera,as ***,most epitope-grafted ED3s produced antisera serospecific to the template ED3 with little or no cross-recognition of ED3 of the serotype from which the epitopes were *** indicated that a mere grafting of the epitope was not sufficient to transfer serospecificity,contrary to our ***,one epitope-grafted ED3 mutant,where epitope 1 of 3ED3 was grafted onto 4ED3(4ED3^(epi1)),generated antisera that was serospecific to both 4ED3 and ***:The 4ED3^(epi1)is a chimeric ED3 that produces antisera possessing serospecificity to both 3ED3 and 4ED3 onto a common 4ED3 *** 4ED3^(epi1),therefore,provides a unique tool for analyzing serospecificity and sero-cross-reactivity in *** believe that chimeric ED3 may provide a template for future recombinant ED3 possessing serospecificity of multiple DENVs onto a single scaffold and may pave a way developing tri-and/or tetravalent anti-DENV antisera.

关键词： Dengue virus serospecificity Sero-cross-recognition Anti-ED3 antibodies Epitope-grafting Chimeric ED3