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Very-high-frequency probes for atomic force microscopy with silicon optomechanics

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Microsystems & Nanoengineering 2022年第2期8卷 35-48页

作者： L.schwab P.E.Allain N.Mauran X.Dollat L.Mazenq D.Lagrange M.Gély s.Hentz G.Jourdan I.Favero b.Legrand Laboratoire d'Analyse et d'Architecture des systemes Universite de ToulouseCNRS UPR 800131031 ToulouseFrance Laboratoire Materiaux et Phenomenes Quantiques Universite de ParisCNRS UMR 716275013 ParisFrance Universite Grenoble Alpes CEALETIMinatec Campus38000 GrenobleFrance

Atomic force microscopy(AFM)has been consistently supporting nanosciences and nanotechnologies for over 30 years and is used in many fields from condensed matter physics to *** enables the measurement of very weak forces at the nanoscale,thus elucidating the interactions at play in fundamental ***,we leverage the combined benefits of micro/nanoelectromechanical systems and cavity optomechanics to fabricate a sensor for dynamic mode AFM at a frequency above 100 *** frequency is two decades above the fastest commercial AFM probes,suggesting an opportunity for measuring forces at timescales unexplored thus *** fabrication is achieved using very-large-scale integration technologies derived from photonic silicon *** probe's optomechanical ring cavity is coupled to a 1.55 pm laser light and features a 130 MHz mechanical resonance mode with a quality factor of 900 in air.A limit of detection in the displacement of 3×10^(-16)m/VHz is obtained,enabling the detection of the brownian motion of the probe and paving the way for force sensing experiments in the dynamic mode with a working vibration amplitude in the picometer *** inserted in a custom AFM instrument embodiment,this optomechanical sensor demonstrates the capacity to perform force-distance measurements and to maintain a constant interaction strength between the tip and sample,an essential requirement for AFM *** indeed show a stable closed-loop operation with a setpoint of 4 nN/nm for an unprecedented subpicometer vibration amplitude,where the tip-sample interaction is mediated by a stretched water meniscus.

关键词： cavity maintain instrument

Effect of commercial Ab_5 alloy addition on the electrochemical properties of Ml-Mg-Ni-based hydrogen storage alloys

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Rare Metals 2008年第4期27卷 429-433页

作者： HU Lin HAN shumin LI Jinhua ZHU Xilin LI Yuan state Key Laboratory of Metastable Materials science and Technology Yanshan University Qinhuangdao 066004 China College of Environmentaland Chemical Engineering Yanshan University Qinhuangdao 066004 China

A commercial Ab5 hydrogen storage alloy was used as an additive to improve the electrochemical properties of Ml-Mg-Ni-based hydrogen storage alloys. The effect of Ab5 alloy addition on the phase structure, charge/discharge characteristics, and electrochemical kinetics of Ml0.90Mg0.10Ni3.08Mn0.13Co0.63Al0.14 alloy was investigated. The maximum discharge capacity of Ml0.90Mg0.10Ni3.08Mn0.13Co0.63Al0.14 ＋ 4 wt.% Ab5 electrode reaches 406 mAh/g. The anodic polarization, cyclic voltammetry, and potential step discharge experiments show that the electrochemical kinetics of the electrode with additives was promoted, with the LaNi5 phase of Ab5 alloy acting as electro-catalytic sites in the electrode alloy. The high-rate dischargeability of Ml0.90Mg0.10Ni3.08Mn0.13Co0.63Al0.14 ＋ 4 wt.% Ab5 alloy electrode at 1100 mA/g reaches 60.9%, which is 9.4% higher than that of Ml0.90Mg0.10Ni3.08Mn0.13Co0.63Al0.14 alloy electrode. The cycling stability of the electrode with 4 wt.% Ab5 alloy has also been improved

关键词： hydrogen storage alloys additive rare earths electrochemical properties electrochemical kinetics

Mode-locked 2 μm fiber laser with a multi-walled carbon nanotube as a saturable absorber

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Chinese Optics Letters 2015年第3期13卷 10-13页

作者： s.M.Azooz F.Ahmad H.Ahmad s.W.Harun b.A.Hamida s.Khan A.Halder M.C.Paul M.Pal s.K.bhadra Department of Electrical Engineering Faculty of Engineering University of Malaya Photonics Research Center University of Malaya Department of Electrical and Computer Engineering International Islamic University MalaysiaJalan Gombak Fiber Optics and Photonics Division Central Glass & Ceramic Research InstituteCSIR

We propose and demonstrate a passively mode-locked fiber laser operating at 1951.8 nm using a commercial thulium-doped fiber （TDF） laser, a homemade double-clad thulium-ytterbium co-doped fiber （TYDF） as the gain media, and a multi-walled carbon nanotube （MWCNT） based saturable absorber （sA）. We prepare the MWCNT composite by mixing a homogeneous solution of MWCNTs with a diluted polyvinyl alcohol （PVA） polymer solution and then drying it at room temperature to form a film. The film is placed between two fiber connectors as a sA before it is integrated into a laser ring cavity. The cavity consists of a 2 m long TDF pumped by a 800 nm laser diode and a 15 m long homemade TYDF pumped by a 905 nm multimode laser diode. A stable mode-locking pulse with a repetition rate of 34.6 MHz and a pulse width of 10.79 ps is obtained when the 905 nm multimode pump power reaches 1.8-2.2 W, while the single-mode 800 nm pump power is fixed at 141.5 mW at all times. To the best of our knowledge, this is the first reported mode-locked fiber laser using a MWCNT-based sA.

关键词： MWCNTs mode Mode-locked 2 m fiber laser with a multi-walled carbon nanotube as a saturable absorber

Enhancing Energy Utilization Efficiency of Pakistani system Considering FACTs Devices and Distributed Generation:Feasibility study

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Chinese Journal of Electrical Engineering 2020年第2期6卷 66-82页

作者： Ghamgeen Izat Rashed Hussain Haider M.b.shafik school of Electrical Engineering and Automation Wuhan UniversityWuhan 430072China

In recent years,voltage stability issues have become a serious concern with regard to the safety of electrical systems,these issues are more evident and have wider consequences in vertical networks with an insufficient reactive power *** is currently suffering from the worst energy crisis in its *** to an increase in energy demand,the current transmission system is becoming increasingly *** has thus become necessary to reduce losses and enhance the system voltage profile for more efficient energy *** this study,the main emphasis is on assessing the feasibility of using flexible AC transmission system devices and distributed generation to compensate power failures on the power lines of the Pakistani power transmission *** load flow and contingency analyses are performed on a 132 kV transmission system that feeds power to the Quetta electric supply *** region of baluchistan is studied to evaluate the effectiveness of the proposed *** system is simulated using NEPLAN,which accurately models the details of all system elements and the optimal power *** simulation results indicate that the proposed method helps reduce system losses,voltage deviation,and power flow congestion,with all system constraints within permissible limits.

关键词： Pakistani power system FACTs devices distributed generation power losses voltage deviation

study of moisture migration in clay soils considering rate of freezing

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Journal of Groundwater science and Engineering 2014年第4期2卷 35-40页

作者： Kudryavtsev s A Kazharskii A V Goncharova E D berestianyi I b Far Eastern state Transport University (FEsTU) Research Construction and Engineering Company “DV-GEOsYNTHETICs”

The paper presents some methods of numerical modelling and a study of moisture changing in frozen clay soils considering rates of freezing in the foundation. An impact assessment of moisture changes in clay soils affe... 详细信息

关键词： Moisture Clay soil Freezing Numerical modelling

Dielectric, piezoelectric, and ferroelectric properties of lanthanum-modified PZTFN ceramics

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International Journal of Minerals,Metallurgy and Materials 2014年第10期21卷 1019-1027页

作者： Arvind Kumar s.K.Mishra Research and Technology Development Centre Sharda University Dr. Harisingh Gour University

specimens of Pb1-1.5xLax（Zr0.53 Ti0.47）1-y-zFeyNb2O3 （x = 0, 0.004, 0.008, 0.012, and 0.016, y = z = 0.01）（PZTFN） ceramics were synthesized by a semi-wet route. In the present study, the effect of La doping was investigated on the structural, microstructural, dielectric, piezoelectric, and ferroelectric properties of the ceramics. The results show that, the tetragonal （space group P4mm） and rhombohedral （space group R3c） phases are observed to coexist in the sample at x = 0.012. Microstructural investigations of all the samples reveal that La doping inhibits grain growth. Doping of La into PZTFN improves the dielectric, ferroelectric, and piezoelectric properties of the ceramics. The hys- teresis loops of all specimens exhibit nonlinear behavior. The dielectric, piezoelectric and ferroelectric properties show a maximum response atx 〉 0.012, which corresponds to the morphotropic phase boundary （MPb）.

关键词： ceramics lanthanum doping dielectric properties piezoelectricity ferroelectricity Rietveld refinement hysteresis loops

Toward a neurobiology of auditory object perception： What can we learn from the songbird forebrain？

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Current Zoology 2011年第6期57卷 671-683页

作者： Kai LU, David s. VICARIO Department of Psychology Rutgers University Piscataway NJ 08854 USA

In the acoustic world, no sounds occur entirely in isolation; they always reach the ears in combination with other sounds. How any given sound is discriminated and perceived as an independent auditory object is a challenging question in neu- roscience. Although our knowledge of neural processing in the auditory pathway has expanded over the years, no good theory ex- ists to explain how perception of auditory objects is achieved. A growing body of evidence suggests that the selectivity of neurons in the auditory forebrain is under dynamic modulation, and this plasticity may contribute to auditory object perception. We propose that stimulus-specific adaptation in the auditory forebrain of the songbird （and perhaps in other systems） may play an important role in modulating sensitivity in a way that aids discrimination, and thus can potentially contribute to auditory object perception.

关键词： songbird Object perception Auditory scene analysis Neural selectivity Plasticity stimulus-specific adaptation

Development of Zeff diagnostic system on the Globus-M（M2） tokamak and the first experimental results

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Plasma science and Technology 2019年第10期21卷 33-39页

作者： E A TUKHMENEVA s Yu TOLsTYAKOV G s KURsKIEV V K GUsEV V b MINAEV Yu V PETROV N V sAKHAROV A Yu TELNOVA N N bAKHAREV P b sHEGOLEV E O KIsELEV Ioffe Institute

studying the behavior of effective ion charge Zeff, which indicates the degree of pollution of plasma and can provide valuable information about many processes taking place in plasma, mechanisms of the releasing impurities, transport, etc is of great interest. This paper describes the development of the Zeff diagnostic system for the Globus-M2 tokamak. The effective ion charge is determined on the basis of measurements of the bremsstrahlung intensity and Thomson scattering data-Te and ne profiles. The results of the first Zeff measurements obtained for several discharges on the Globus-M tokamak are presented in this paper. The results have been validated by simulation using the AsTRA transport code for the same discharges, and it has demonstrated a good agreement with the experimental results.

关键词： tokamak effective ion charge magnetic confinement

Ethno-Medico-biology of bhadrak district, Odisha, India

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Journal of Forestry Research 2013年第1期24卷 187-192页

作者： T. Panda N. Mishra b. K. Tripathy P. K. Das R.b.Mohanty Department of botany S.N.CollegeRajkanikaKendrapara- 754220OdishaIndia. Department of Zoology Chandbali CollegeChandbaliBhadrak-756133OdishaIndia Department of botany Dharmasala MohavidyalayaDharmasalaJajpurOdishaIndia Department of botany Aul CollegeAulKendraparaOdishaIndia Department of botany N.C.Autonomous CollegeJajpurOdishaIndia

We carried out an ethno-medico-biological investigation in the interior of bhadrak district, Odisha, India to explore the therapeutic use of traditional plants/animals by local inhabitants. The villagers and rural people used plant and animal species as medicine. We recorded therapeutic use of 18 plant species of 13 families and 12 animal species of seven taxonomic categories. Different plant/animal parts like bark, leaf, flower, seed, stem, root, whole plant, oil, blood, milk, urine and flesh were reported as used in raw or cooked form against 17 specific diseases. Prominent diseases treated by plant/animal remedies were asthma, cardiovascular ailments, diabetes, epilepsy, jaundice, malaria, skin disorder and rheumatism. This study provides a better database for future studies.

关键词： Ethnobiology folklore phytotherapy traditional knowledge zootherapy