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dielectric Function of Silicon Nanoclusters: Role of Hydrogen

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Chinese Physics Letters 2011年第9期28卷 241-244页

作者： SIB KRISHNA Ghoshal m.R.sahar m.S.Rohani Advanced Optical material Research Group Department of PhysicsFaculty of ScienceUniversiti Teknologi Malaysia81310 UTM SkudaiJohorMalaysia

Electronic and optical properties of small silicon quantum dots having 3 to 44 atoms per dot with and without surface passivation are investigated by computer simulation using the pseudo-potential *** empirical pseudo-potential hamiltonian,a plane-wave basis expansion and a basic tetrahedral structure with undistorted local bonding configurations are *** structures of the quantum dots are relaxed and optimized before and after hydrogen *** is found that the gap increases more for a hydrogenated surface than the unpassivated ***,both quantum confinement and surface passivation determine the optical and electronic properties of Si quantum *** luminescence is probably due to the radiative recombination of electrons and holes in the quantum-confined *** effect of passivation of the surface dangling bonds by hydrogen atoms and the role of surface states on the gap energy is also *** results for the density of states,the dielectric function,the frequency dependent optical absorption cross section,the extinction coefficient and the static dielectric constants of the size are *** importance of the confinement and the role of surface passivation on the optical effects are discussed.

关键词： quantum dielectric extinction

Synthesis and characterization of lithium niobium borate glasses containing neodymium

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Journal of Rare Earths 2016年第12期34卷 1199-1205页

作者： W.H.A.Kamaruddin m.S.Rohani m.R.sahar LIU Hong SANG Yuanhua AOmRG Lab Physics Department Faculty of Science Universiti Teknologi Malaysia State Key Laboratory of Crystal materials Shandong University

A series of（90–x）Li2B4O7-10Nb2O5-xNd2O3 glass samples（x=0, 5 mol.%, 10 mol.%, 15 mol.%, 20 mol.% and 25 mol.%） were synthesized using melt quenching technique. X-ray diffraction（XRd）, differential thermal analyzer（dTA）, Fourier transformed infrared（FTIR）, ultraviolet-visible-near-infrared（UV-Vis-NIR） spectrometer and photoluminescence（PL） spectroscopic characterizations were made to examine the influence of Nd3＋ concentration on the physical, structural and optical properties. Various physical properties such as glasses density, molar volume, thermal stability, ion concentration, polar on radius, inter-nuclear distance, field strength, cut-off wavelength, energy band gap and Urbach energy were calculated. The samples were amorphous in nature and confirmed from XRd pattern. The FTIR spectra revealed the presence of BO3 and BO4 functional groups. UV-Vis-NIR spectra exhibited nine prominent bands centered at 353, 430, 475, 524, 583, 681, 745, 803, 875 nm corresponding to the transitions from the ground state to ^4d（3/2）, ^2P（1/2）, ^2G（9/2）, ^4G（7/2）, ^4G（5/2）, ^4F（9/2）, ^4F（7/2）, ^4F（5/2）, ^4F（3/2） excited states, respectively. moreover, the emission spectra at 355 nm excitation displayed three peaks centered at 903 nm（^4F（3/2）→^4I（9/2））, 1059 nm（^4F（3/2）→^4I（11/2）） and 1333 nm（^4F（3/2）→^4I（13/2））, respectively. Fluorescence lifetime was recorded between 53.69 to 28.43 μs. It was found that varying concentration of Nd^（3＋） ions strongly affected the physical, structural and optical properties of the glass samples.

关键词： borate glass neodymium optical properties band gap luminescence rare earths

Classification and technical target of water electrolysis for hydrogen production

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Journal of Energy Chemistry 2024年第8期95卷 554-576,I0012页

作者： Kahyun ham Sooan Bae Jaeyoung Lee Ertl Center for Electrochemistry and Catalysis Gwangju Institute of Science and Technology(GIST)123 Cheomdangwagi-RoBuk-guGwangju 61005South Korea department of Heterogeneous Reactions Max Planck Institute for Chemical Energy ConversionStiftstr.34-36Mülheim an der RuhrGermany School of Earth Sciences and Environmental Engineering GIST123 CheomdangwagiroBuk-guGwangju 61005South Korea International Future Research Center of Chemical Energy Storage and Conversion Processes GIST123 CheomdangwagiroBuk-guGwangju 61005South Korea eSuS Co. Ltd.#408S6 BuildingSchool of Environment and Energy EngineeringGIST123 CheomdangwagiroBuk-guGwangju 61005South Korea

Continuous efforts are underway to reduce carbon emissions worldwide in response to global climate *** electrolysis technology,in conjunction with renewable energy,is considered the most feasible hydrogen production technology based on the viable possibility of large-scale hydrogen production and the zero-carbon-emission nature of the ***,for hydrogen produced via water electrolysis systems to be utilized in various fields in practice,the unit cost of hydrogen production must be reduced to$1/kg H_(2).To achieve this unit cost,technical targets for water electrolysis have been suggested regarding components in the *** this paper,the types of water electrolysis systems and the limitations of water electrolysis system components are *** suggest guideline with recent trend for achieving this technical target and insights for the potential utilization of water electrolysis technology.

关键词： Water electrolysis Hydrogen production Technical target Electrochemistry

Antifibrotic effect of aloe vera in viral infection-induced hepatic periportal fibrosis

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World Journal of Gastroenterology 2012年第17期18卷 2026-2034页

作者： sahar K Hegazy m.ham.d El-Bedewy Akira Yagi department of Clinical Pharmacy Faculty of PharmacyTanta UniversityTanta 8130Egypt department of Internal medicine Faculty of MedicineTanta UniversityTanta 8130Egypt Placenta/Aloe Research Institute Japan Bio-Products Co.Ltd.1488-4Aikawa-machiKurume-shiFukuoka Bio Factory 204Fukuoka 839-0861Japan

AIm:To investigate the anti-oxidative and anti-fibrotic effects of aloe vera in patients with liver ***:Aloe vera high molecular weight fractions(AHm) were processed by patented hyper-dry system in combination of freeze-dry technique with microwave and far infrared-ray *** healthy volunteers as the control group and 40 patients were *** patients were randomly subdivided into two equal groups:the conventional group was treated with placebo(starch),and AHm group was treated with 0.15 gm/d AHm,both for 12 consecutive *** patients were investigated before and after *** activity of aspartate aminotransferase(AST),alanine aminotransferase(ALT),alkaline phosphatase(ALP),hyaluronic acid(HA),transforming growth factor-β(TGF-β) and matrixmetalloproteinase-2(mmP-2) were *** reduced glutathione(GSH) and malondialdehyde(mdA) levels in liver were assayed and the expression of hepatic α-smooth muscle actin(α-SmA) was identified by ***:At the start of the study,the hematoxylin and eosin staining revealed fibro-proliferated bile ductules,thick fibrous septa and dense inflammatory cellular infiltration in the patients before *** use of AHm for 12 wk significantly ameliorated the fibrosis,inhibited the inflammation,and resulted in minimal infiltration and minimal fibrosis compared to the conventional *** enzyme activities of the liver(ALT,AST and ALP) were attenuated after treatment in both groups,and the decrease in the AHm group was more significant as compared with the conventional *** to the AST,the mdA levels were significantly higher before treatment,and were attenuated after treatment in both *** contrast,the hepatic glutathione content in the patients were decreased significantly in the AHm group compared to the *** serum levels of the fibrosis markers(HA,TGF-β and mmP-2) were also reduced significantly after *** expression of α-SmA was m

关键词： Hepatic fine periportal fibrosis Aloe vera α-smooth muscle actin Transforming growth factor-β Hyaluronic acid

Incidence and characteristics of HBV reactivation in hematological malignant patients in south Egypt

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World Journal of Gastroenterology 2013年第37期19卷 6214-6220页

作者： Abeer Elkady sahar Aboulfotuh Elsayed mostafa Ali douaa Sayed Nashwa m Abdel-Aziz Amany m Ali Shuko murakami Sayuki Iijima Yasuhito Tanaka department of Virology and Liver Unit Nagoya City University Graduate School of Medical Sciences department of Clinical and Chemical Pathology Medical School of South Valley University department of Clinical and Chemical Pathol-ogy Medical School of Sohag University department of medical Oncology Medical School of Sohag University department of Clinical and Chemical Pathology South Egypt Cancer Institute department of medical Oncology South Egypt Cancer Institue

AIm:To investigate characteristics of hepatitis B virus(HBV)implicated in HBV reactivation in patients with hematological malignancies receiving immunosuppressive ***:Serum samples were collected from 53 patients with hematological malignancies negative for hepatitis B surface antigen(HBsAg)before the start of and throughout the chemotherapy *** reactivation was diagnosed when the HBsAg status changed from negative to positive after the initiation of chemotherapy and/or when HBV dNA was detected by realtime detection polymerase chain reaction(RTd-PCR).For detecting the serological markers of HBV infection,HBsAg as well as antibodies to the core antigen(antiHBc)and to the surface antigen were measured in the sera by *** acids were extracted from sera,and HBV dNA sequences spanning the S gene were amplified by *** extracted dNA was further subjected to PCR to amplify the complete genome as well as the specific genomic sequences bearing the enhancerⅡ/core promoter/pre-core/core regions(nt1628-2364).Amplicons were sequenced ***:Thirty-five(66%)of the 53 HBsAg-negative patients were found to be negative serologically for antiHBc,and the remaining 18(34%)patients were positive for *** of the 53(9.4%)patients with hematologic malignancies experienced HBV *** d1 was detected in all five *** types of mutant strains were detected in the S gene product of HBV strains and were isolated from 3 patients with HBV reactivation:T/S120,L143,and *** dNA was detected in the pretreatment HBsAg-negative samples in one of the five patients with HBV *** this patient,sequences encompassing the HBV full genome obtained from sera before the start of chemotherapy and at the time of de novo HBV hepatitis were detected and it showed 100%***,in the phylogenetic tree,the sequences were clustered together,thereby indicating that this patient developed reactivation from an occult

关键词： Hepatitis B virus Occult infection Reactivation Hepatitis B surface antigen

A passive,reusable,and resonating wearable sensing system for ondemand,non-invasive,and wireless molecular stress biomarker detection

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Nano Research 2024年第8期17卷 7542-7556页

作者： Shingirirai Chakoma Xiaochang Pei Huiting Qin Anita Ghandehari sahar NajafiKhoshnoo Jerome Rajendran Rahim Esfandyarpour department of Electrical Engineering and Computer Science University of CaliforniaIrvineCA 92697USA Laboratory for Integrated Nano BioElectronics Innovation The Henry Samueli School of EngineeringUniversity of CaliforniaIrvineCA 92697USA Henry Samueli School of Engineering University of CaliforniaIrvineCA 92697USA

The significant impact of stress on health necessitates accurate assessment methods,where traditional questionnaires lack reliability and *** advancements like wearables with electrocardiogram(ECG)and galvanic skin response(GSR)sensors face accuracy and artifact *** biosensors detecting cortisol,a critical stress hormone,present a promising ***,existing cortisol assays,requiring saliva,urine,or blood,are complex,expensive,and unsuitable for continuous *** study introduces a passive,molecularly imprinted polymer-radio-frequency(mIP-RF)wearable sensing system for real-time,non-invasive sweat cortisol *** system is wireless,flexible,battery-free,reusable,environmentally stable,and designed for long-term monitoring,using an inductance-capacitance *** transducer translates cortisol concentrations into resonant frequency shifts with high sensitivity(~160 kHz/(log(μm)))across a physiological range of 0.025–1μ*** with near-field communication(NFC)for wireless and battery-free operation,and threedimensional(3d)-printed microfluidic channel for in-situ sweat collection,it enables daily activity cortisol level *** of cortisol circadian rhythm through morning and evening measurements demonstrates its effectiveness in tracking and monitoring sweat cortisol levels.A 28-day stability test and the use of cost-effective 3d nanomaterials printing enhance its economic viability and *** innovation paves the way for a new era in realistic,on-demand health monitoring outside the laboratory,leveraging wearable technology for molecular stress biomarker detection.

关键词： cortisol wearable flexible sensors three-dimensional(3d)nanomaterials printing reusable environmentally stable

An Iterative Relaxation Approach to the Solution of the hamilton-Jacobi-Bellman-Isaacs Equation in Nonlinear Optimal Control

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IEEE/CAA Journal of Automatica Sinica 2018年第1期5卷 360-366页

作者： m.d.S.Aliyu department of Electrical Engineering King Faisal University Al-Ahsa 31982 Saudi Arabia IEEE

In this paper, we propose an iterative relaxation method for solving the hamilton-Jacobi-Bellman-Isaacs equation(HJBIE) arising in deterministic optimal control of affine nonlinear systems. Local convergence of the method is established under fairly mild assumptions, and examples are solved to demonstrate the effectiveness of the method. An extension of the approach to Lyapunov equations is also discussed. The preliminary results presented are promising, and it is hoped that the approach will ultimately develop into an efficient computational tool for solving the HJBIEs.

关键词： Affine nonlinear system bounded continuous function convergence hamilton-Jacobi-Bellman-Isaacs equation Lyapunov equation relaxation method Riccati equation

multi-redox phenazine/non-oxidized graphene/cellulose nanohybrids as ultrathick cathodes for high-energy organic batteries

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Nano Research 2021年第5期14卷 1382-1389页

作者： Youngjin ham Vitalii Ri Jin Kim Yeoheung Yoon Jinho Lee Kisuk Kang Ki-Seok An Chunjoong Kim Seokwoo Jeon department of materials Science and Engineering Advanced Battery CenterKorea Advanced Institute of Science and Technology(KAIST)Daejeon34141Republic of Korea department of materials Science and Engineering Chungnam National UniversityDaejeon34134Republic of Korea Thin Film materials Research Center Korea Research Institute of Chemical Technology(KRICT)Daejeon34114Republic of Korea department of materials Science and Engineering Seoul National UniversitySeoul08826Republic of Korea

Various redox-active organic molecules can serve as ideal electrode materials to realize sustainable energy storage systems. Yet, to be more appropriate for practical use, considerable architectural engineering of an ultrathick, high-loaded organic electrode with reliable electrochemical performance is of crucial importance. Here, by utilizing the synergetic effect of the non-covalent functionalization of highly conductive non-oxidized graphene flakes (NOGFs) and introduction of mechanically robust cellulose nanofiber (CNF)-intermingled structure, a very thick (≈ 1 mm), freestanding organic nanohybrid electrode which ensures the superiority in cycle stability and areal capacity is reported. The well-developed ion/electron pathways throughout the entire thickness and the enhanced kinetics of electrochemical reactions in the ultrathick 5,10-dihydro-5,10-dimethylphenazine/NOGF/CNF (dmPZ-NC) cathodes lead to the high areal energy of 9.4 mWh·cm−2 (= 864 Wh·kg−1 at 158 W·kg−1). This novel ultrathick electrode architecture provides a general platform for the development of the high-performance organic battery electrodes.

关键词： energy storage organic electrodes batteries graphene cellulose nanofibers

Fundamental principles and development of proximity-field nanopatterning toward advanced 3d nanofabrication

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Nano Research 2021年第9期14卷 2965-2980页

作者： Sang-Hyeon Nam Gayea Hyun donghwi Cho Seonggon Han Gwangmin Bae Haomin Chen Kisun Kim Youngjin ham Junyong Park Seokwoo Jeon department of materials Science and Engineering Korea Advanced Institute of Science and Technology(KAIST)Daejeon 34141Republic of Korea department of mechanical and Aerospace Engineering The Hong Kong University of Science and TechnologyClear Water BayKowloonHong KongChina School of materials Science and Engineering Kumoh National Institute of TechnologyGumiGyeongbuk 39177Republic of Korea department of Energy Engineering Convergence Kumoh National Institute of TechnologyGumiGyeongbuk 39177Republic of Korea KAIST Institute for NanoCentury(KINC) KAISTDaejeon 34141Republic of Korea

Three-dimensional(3d)nanoarchitectures have offered unprecedented material performances in diverse applications like energy storages,catalysts,electronic,mechanical,and photonic *** outstanding performances are attributed to unusual material properties at the nanoscale,enormous surface areas,a geometrical uniqueness,and comparable feature sizes with optical *** the practical use of the unusual nanoscale properties,there have been developments for macroscale fabrications of the 3d nanoarchitectures with process areas over centimeter *** the many fabrication methods for 3d structures at the nanoscale,proximity-field nanopatterning(PnP)is one of the promising techniques that generates 3d optical holographic images and transforms them into material structures through a lithographic *** conformal and transparent phase masks as a key factor,the PnP process has advantages in terms of stability,uniformity,and reproducibility for 3d nanostructures with periods from 300 nm to several *** merits of realizing precise 3d features with sub-100 nm and rapid processes are attributed to the interference of coherent light diffracted by phase *** this review,to report the overall progress of PnP from 2003,we present a comprehensive understanding of PnP,including its brief history,the fundamental principles,symmetry control of 3d nanoarchitectures,material issues for the phase masks,and the process area expansion to the wafer-scale for the target ***,technical challenges and prospects are discussed for further development and practical applications of the PnP technique.

关键词： proximity-field nanopatterning three-dimensional(3d)nanostructures phase mask interference lithography