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Dielectric or plasmonic Mie object at air–liquid interface: The transferred and the traveling momenta of photon

Chinese Physics b 2020年第1期29卷 311-323页

作者： M r C Mahdy Hamim Mahmud rivy Ziaur rahman Jony Nabila binte Alam Nabila Masud Golam Dastegir Al Quaderi Ibraheem Muhammad Moosa Chowdhury Mofizur rahman M Sohel rahman Department of Electrical&Computer Engineering North South UniversityBashundharaDhaka 1229Bangladesh Pi Labs bangladesh LTD ARA Bhaban39Kazi Nazrul Islam AvenueKawran BazarDhaka 1215Bangladesh Department of Computer Science&Engineering Military Institute of Science and TechnologyDhakaBangladesh Department of Physics University of DhakaDhakaBangladesh Department of Computer Science&Engineering Bangladesh University of Engineering and Technology ECE BuildingWest PalasiDhaka-1205 Department of Computer Science&Engineering United International UniversityDhakaBangladesh

Considering the inhomogeneous or heterogeneous background, we have demonstrated that if the background and the half-immersed object are both non-absorbing, the transferred photon momentum to the pulled object can be considered as the one of Minkowski exactly at the interface. In contrast, the presence of loss inside matter, either in the half-immersed object or in the background, causes optical pushing of the object. Our analysis suggests that for half-immersed plasmonic or lossy dielectric, the transferred momentum of photon can mathematically be modeled as the type of Minkowski and also of Abraham. However, according to a final critical analysis, the idea of Abraham momentum transfer has been rejected. Hence,an obvious question arises: whence the Abraham momentum? It is demonstrated that though the transferred momentum to a half-immersed Mie object(lossy or lossless) can better be considered as the Minkowski momentum, Lorentz force analysis suggests that the momentum of a photon traveling through the continuous background, however, can be modeled as the type of Abraham. Finally, as an interesting sidewalk, a machine learning based system has been developed to predict the time-averaged force within a very short time avoiding time-consuming full wave simulation.

关键词： Abraham–Minkowski controversy dielectric interface machine learning optical force laws optical pulling force optical tractor beams

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Quantum photodetachment of hydrogen negative ion in a harmonic potential subjected to static electric field

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Chinese Physics b 2019年第2期28卷 179-184页

作者： Azmat Iqbal Kiran Humayun Sana Maqsood Saba Jawaid Afaq Ahmad Amin Ur rahman bakht Amin bacha Department of Physics The University of LahoreRaiwind Road CampusLahorePakistan Center of Excellence in Solid State Physics University of the PunjabLahorePakistan Department of Physics RIPHAH International University IslamabadPakistan Department of Physics University of Malakand Chakdara Dir(L)Pakistan

Photodetachment of negative ions has attracted immense interest owing to its fundamental nature and practical implications with regard to technology. In this study, we explore the quantum dynamics of the photodetachment cross section of negative ion of hydrogen H-in the perturbed one dimensional linear harmonic potential via static electric field. To this end,the quantum formula for total photodetachment cross section of the H-ion is derived by calculating the dipole matrix element in spherical coordinates. In order to obtain the detached electron wave function, we have solved the time-independent Schr¨odinger wave equation for the perturbed Hamiltonian of the harmonic oscillator in momentum representation. To acquire the corresponding normalized final state detached electron wave function in momentum space, we have employed an approach analogous to the WKb(Wenzel–Kramers–brillouin) approximation. The resulting analytical formula of total photodetachment cross section depicts interesting oscillator structure that varies considerably with incident-photon energy,oscillator potential frequency, and electric field strength as elucidated by the numerical results. The current problem having close analogy with the Stark effect in charged harmonic oscillator may have potential implications in atomic and molecular physics and quantum optics.

关键词： photodetachment cross section harmonic oscillator potential Stark effect time-independent Schrodinger equation WKb approximation

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Holmium Oxide Film as a Saturable Absorber for 2μm Q-Switched Fiber Laser

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Chinese Physics Letters 2017年第5期34卷 48-51页

作者： M.F.A.rahman M.F.M.rusdi M.Q.Lokman M.b.H.Mahyuddin A.A.Latiff A.H.A.rosol K.Dimyati S.W.Harun Department of Electrical Engineering University of Malaya Kuala Lumpur 50603 Malaysia Photonics research Centre University of Malaya Kuala Lumpur 50603 Malaysia Faculty of Electrical Engineering University Teknologi Mara Shah Alam 40450 Malaysia

This work reports on the use of the holmium oxide （Ho2O3） polymer film as a saturable absorber （SA） for generating stable Q-switching pulses operating in a 2μm region in a thulium-doped fiber laser cavity. The SA is prepared by diluting a commercial Ho3O2 powder and then mixing it with polyvinyI alcohol （PVA） solution to form a Ho2O3-PVA film. A tiny part of the film about 1mm×1 mm in size is sandwiched between two fiber ferrules with the help of index matching gel. When incorporated in a laser cavity driven by a 1552-nm pump, stable Q-switching pulses are observed at 1955nm within the pump power range of 363 491 roW. As the pmnp power increases within this range, the repetition rate rises from 26 kHz to 39 kHz, as the pulse width drops from 4.22μs to 2.57μs. The laser operates with a signal-to-noise ratio of 47db, and the maximum output power and the pulse energy obtained are 2.67mW and 69ng, respectively. Our results successfully demonstrate that the Ho2O3 film can be used as a passive SA to generate a 2μm pulse laser.

关键词： m Q-Switched Fiber Laser SA FESEM

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A compact transmit/receive switch for 2.4 GHz reader-less active rFID tag transceiver

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Journal of Central South University 2015年第2期22卷 546-551页

作者： Mohammad Arif Sobhan bhuiyan Mamun bin Ibne reaz Jubayer Jalil Labonnah Farzana rahman Tae Gyu Chang Department of Electrical Electronic and Systems Engineering Universiti Kebangsaan Malaysia43600 UKM Bangi Selangor Malaysia School of Electrical and Electronics Engineering Chung-Ang University

radio frequency identification(rFID) is a ubiquitous identification technology nowadays. An on-chip high-performance transmit/receive(T/r) switch is designed and simulated in 0.13-μm CMOS technology for reader-less rFID tag. The switch utilizes only the transistor width and length(W/L) optimization, proper gate bias resistor and resistive body floating technique and therefore,exhibits 1 d b insertion loss, 31.5 d b isolation and 29.2 d bm 1-d b compression point(P1d b). Moreover, the switch dissipates only786.7 n W power for 1.8/0 V control voltages and is capable of switching in 794 fs. Above all, as there is no inductor or capacitor used in the circuit, the size of the switch is 0.00208 mm2 only. This switch will be appropriate for reader-less rFID tag transceiver front-end as well as other wireless transceivers operated at 2.4 GHz band.

关键词： body floating CMOS radio frequency identification(rFID) transmit/receive(T/r) switch transceiver

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TGF-β/bMP signaling and other molecular events: regulation of osteoblastogenesis and bone formation

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bone research 2015年第1期3卷 11-30页

作者： Md Shaifur rahman Naznin Akhtar Hossen Mohammad Jamil rajat Suvra banik Sikder M Asaduzzaman Tissue banking and biomaterial research Unit Atomic Energy Research Establishment Lab of Network biology Biotechnology and Genetic Engineering DisciplineKhulna University

Transforming growth factor-beta（TGF-β）/bone morphogenetic protein（bMP） plays a fundamental role in the regulation of bone organogenesis through the activation of receptor serine/threonine kinases. Perturbations of TGF-β/bMP activity are almost invariably linked to a wide variety of clinical outcomes, i.e., skeletal, extra skeletal anomalies, autoimmune, cancer, and cardiovascular diseases. Phosphorylation of TGF-β（I/II） or bMP receptors activates intracellular downstream Smads, the transducer of TGF-β/bMP signals. This signaling is modulated by various factors and pathways, including transcription factor runx2. The signaling network in skeletal development and bone formation is overwhelmingly complex and highly time and space ***, positive, negative, or synergistic effects are observed when TGF-β/bMP interacts with the pathways of MAPK, Wnt, Hedgehog（Hh）, Notch, Akt/m TOr, and mi rNA to regulate the effects of bMP-induced signaling in bone dynamics. Accumulating evidence indicates that runx2 is the key integrator, whereas Hh is a possible modulator, mi rNAs are regulators, and b-catenin is a mediator/regulator within the extensive intracellular network. This review focuses on the activation of bMP signaling and interaction with other regulatory components and pathways highlighting the molecular mechanisms regarding TGF-β/bMP function and regulation that could allow understanding the complexity of bone tissue dynamics.

关键词： bMP signaling and other molecular events bone regulation of osteoblastogenesis and bone formation TGF

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Hepatitis E virus is a leading cause of acute-on-chronic liver disease:experience from a tertiary centre in bangladesh

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Hepatobiliary & Pancreatic Diseases International 2009年第1期8卷 50-52页

作者： Mamun-Al Mahtab Salimur rahman Mobin Khan Md.Fazal Karim Department of Hepatology Bangabandhu Sheikh Mujib Medical University

bACKGrOUND:Acute-on-chronic liver failure(ACLF) is common in *** viral E hepatitis is sporadically encountered in this country each year,with a rising incidence in the rainy *** study aimed to identify the etiology of ACLF in bangladesh. METHODS:In this retrospective study,69 ACLF patients were *** presented to our department at the bangabandhu Sheikh Mujib Medical University in *** of diseases was recorded and appropriate investigations were conducted in all patients. rESULTS:Acute hepatitis E virus(HEV)infection was positive in 21.7%(15/69)of the patients,while 14.5% (10/69)had *** gastrointestinal tract hemorrhage was seen in 4.3%of the patients(3/69),while another 4.3%(3/69)had a positive history for alcohol or *** of the patients tested positive for hepatitis A virus infection and no evidence of hepatitis b virus flare was found in any *** specific cause for ACLF could be identified. CONCLUSIONS:Acute HEV infection is a leading cause of ACLF in *** patients were thought to have decompensation of cirrhosis,but subsequently were recognized as having ACLF by a retrospective review according to the definition of the Asian Pacific Association for the Study of the Liver Working Party Meeting on ACLF in New Delhi in early 2008.

关键词： acute-on-chronic liver failure hepatitis E virus septicemia

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Energy Fluctuation of Ideal Fermi Gas Trapped under Generic Power Law Potential U=Σ_(i=1)~d c_i|x_i/a_i|^(n_i) in d Dimensions

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Communications in Theoretical Physics 2016年第4期65卷 465-468页

作者： Mir Mehedi Faruk Md.Muktadir rahman Dwaipayan Debnath Md.Sakhawat Hossain Himel Theoretical Physics Blackett LaboratoryImperial College Department of Theoretical Physics University of Dhaka Department of biomedical Physics and Technology University of Dhaka

Energy fluctuation of ideal Fermi gas trapped under generic power law potential U=Σ_(i=1)~d c_i|x_i/a_i|^(n_i) has been calculated in arbitrary *** fluctuation is scrutinized further in the degenerate limit μ>>K_b T with the help of Sommerfeld *** dependence of energy fluctuation on dimensionality and power law potential is studied in *** importantly our general result can not only exactly reproduce the recently published result regarding free and harmonically trapped ideal Fermi gas in d =3 but also can describe the outcome for any power law potential in arbitrary dimension.

关键词： Fermi gas power law potential energy fluctuation

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Feasibility of developing composite action between concrete and cold-formed steel beam

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Journal of Central South University 2013年第12期20卷 3689-3696页

作者： S.O.bamaga M.Md.Tahir T.C.Tan S.Mohammad N.Yahya A.L.Saleh M.Mustaffar M.H.Osman A.b.A.rahman Construction research Centre (UTM-CrC) Faculty of Civil EngineeringUniversiti Teknologi Malaysia

Cold-formed steel structures are steel structure products constructed from sheets or coils using cold rolling, press brake or bending brake method. These structures are extensively employed in building construction industry due to their light mass, ductility by economic cold forming operations, favorable strength-to-mass ratio and other factors. The utilization of cold formed steel sections with concrete as composite can hugely reduce the construction cost. However, the use of cold formed steel members in composite concrete beams has been very limited. A comprehensive review of developments in composite beam with cold formed steel sections was introduced. It was revealed that employing cold-formed steel channel section to replace reinforcement bars in conventional reinforced concrete beam results in a significant cost reduction without reducing strength capacity. The use of composite beam consisting of cold-formed steel open or close box and filled concrete could also reduce construction cost. Lighter composite girder for bridges with cold-formed steel of U section was introduced. Moreover, types of shear connectors to provide composite action between cold-formed steel beam and concrete slab were presented. However, further studies to investigate the effects of metal decking on the behavior of composite beam with cold-formed steel section and introduction of ductile shear connectors were recommended.

关键词： cold formed steel beam composite shear connection thin-wall composite girder

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Absence of postzygotic isolating mechanisms:evidence from experimental hybridization between two species of tropical sea urchins

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Journal of Zhejiang University-Science b(biomedicine & biotechnology) 2012年第10期13卷 797-810页

作者： M.Aminur rahman Tsuyoshi UEHArA Aziz ArSHAD Fatimah Md.YUSOFF Mariana Nor SHAMSUDIN Laboratory of Marine biotechnology Institute of BioscienceUniversiti Putra Malaysia43400 UPM SerdangSelangorMalaysia Department of Chemistry Biology and Marine ScienceFaculty of ScienceUniversity of the Ryukyus1 SenbaruNishihara-choOkinawa 903-0213Japan Department of Aquaculture Faculty of AgricultureUniversiti Putra Malaysia43400 UPM SerdangSelangorMalaysia

Two reef margin species of tropical sea urchins,Echinometra sp.C(Ec) and Echinometra oblonga(Eo),occur sympatrically on Okinawa intertidal reefs in southern *** between these species was examined through a series of cross-fertilization *** limited sperm concentrations,where conspecific crosses reached near 100% fertilization,both heterospecific crosses showed high fertilization rates(81%-85%).The compatibility of the gametes demonstrated that if gamete recognition molecules are involved in fertilization of these species,they are not strongly *** found that conspecific crosses reached peak fertilization levels much faster than did heterospecific crosses,indicating the presence of a prezygotic barrier to hybridization in the *** survival,metamorphosis,and juvenile and adult survival of hybrid groups were nearly identical to those of their parent *** from crosses in both directions developed normally through larval stages to sexually mature adults,indicating that neither gametic incompatibility nor hybrid inviability appeared to maintain reproductive isolation between these *** adults,Ec×Ec crosses gave the highest live weight,followed by Eo(ova)×Ec(sperm),Ec(ova)×Eo(sperm),and Eo×*** growth performance measures(viz.,test size,Aristotle's lantern length,and gonad index) of hybrid groups and their parental siblings showed the same *** phenotypic color patterns of the hybrids were closer to the maternal coloration,whereas spine length,tube-foot and gonad spicule characteristics,pedicellaria valve length,and gamete sizes showed intermediate *** F 1 hybrids were completely fertile and displayed high fertilization success in F 1 backcrosses,eliminating the likelihood that hybrid sterility is a postzygotic mechanism of reproductive ***,intensive surveys failed to find hybrid individuals in the field,suggesting the lack or rarity of natural *** stron

关键词： Sea urchins Echinometra Hybridization Gamete compatibility reproductive isolation Speciation

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biochar derived from invasive plants improved the pH,macronutrient availability and biological properties better than liming for acid rain-affected soil

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biochar 2023年第1期5卷 1029-1044页

作者： Yazheng Li Ahmed I.Abdo Zhaoji Shi Abdel-rahman M.A.Merwad Jiaen Zhang Department of Ecology College of Natural Resources and EnvironmentSouth China Agricultural UniversityGuangzhou 510642China Guangdong Provincial Key Laboratory of Utilization and Conservation of Food and Medicinal resources in Northern region Yingdong College of Biology and AgricultureShaoguan UniversityShaoguan 512005China Soil Science Department Faculty of AgricultureZagazig UniversityZagazig 44519Egypt Guangdong Laboratory for Lingnan Modern Agriculture Guangdong Provincial Key Laboratory of Eco-Circular AgricultureSouth China Agricultural UniversityGuangzhou 510642China Guangdong Engineering Technology research Centre of Modern Eco-Agriculture and Circular Agriculture Guangzhou 510642China

rapid development in industrialization and urbanization causes serious environmental issues,of which acid rain is one of the quintessential hazards,negatively affecting soil *** has been investigated for a long time as the most effective amendment to alter the adverse effects of soil acidity resulting from acid ***,this study tested the biochar produced from invasive plants as an alternative amendment and hypothesized that biochar can maintain better availability of macronutrients under acid rain than liming by improving soil chemical and biological ***,a pot experiment was conducted to compare the effects of lime and biochar at two rates(1%and 3%)on soil available nitrogen(N),phosphorous(P)and potassium(K)under simulated acid rain of two pH levels(4.5:pH_(4.5) and 2.5:pH_(2.5))as compared with tap water(pH7.1)as a control *** was produced using different invasive plants,including blackjack(biden Pilosa),Wedelia(Wedelia trilobata)and bitter Vine(Mikania micrantha Kunth).Liming decreased the availability of soil N,P,and K by 36.3%as compared with the control due to the great increment in soil pH and exchangeable calcium(Ca^(2+))by 59%and 16-fold,***,liming reduced the alpha diversity of soil bacteria and fungi by 27%and 11%,*** contrast,biochar at different types and rates resulted in a fourfold increment in the available N,P,and K as an average under acid rain(pH_(4.5) and pH_(2.5))owing to maintaining a neutral pH(6.5-7),which is the most favorable level for soil microbial and enzymatic activites,and the bioavailability of soil ***,biochar caused balanced increments in Ca^(2+)by threefold,cation exchange capacity by 45%,urease activity by 16%,and fungal diversity by 10%,while having a slight reduction in bacterial diversity by 2.5%.based on the path,correlation,and principal component analyses,the exchangeable aluminum was a moderator for the reductions in macronutrien

关键词： Acidic soil Liming Invasive plants biochar feedstock Soil chemical properties

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