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MEMS-actuated metasurface Alvarez lens

Microsystems & Nanoengineering 2020年第1期6卷 334-344页

作者： Zheyi Han shane Colburn Arka Majumdar Karl F.Bohringer Department of Electrical and Computer Engineering University of WashingtonSeattleWashington 98195USA Institute for Nano-Engineered Systems University of WashingtonSeattleWashington 98195USA Department of Physics University of WashingtonSeattleWashington 98195USA Department of Bioengineering University of WashingtonSeattleWashington 98195USA

Miniature lenses with a tunable focus are essential components for many modern applications involving compact optical *** several tunable lenses have been reported with various tuning mechanisms,they often face challenges with respect to power consumption,tuning speed,fabrication cost,or production *** this work,we have adapted the mechanism of an Alvarez lens–a varifocal composite lens in which lateral shifts of two optical elements with cubic phase surfaces give rise to a change in the optical power–to construct a miniature,microelectromechanical system(MEMS)-actuated metasurface Alvarez *** based on an electrostatic MEMS generates fast and controllable actuation with low power *** utilization of metasurfaces–ultrathin and subwavelength-patterned diffractive optics–as optical elements greatly reduces the device volume compared to systems using conventional freeform *** entire MEMS Alvarez metalens is fully compatible with modern semiconductor fabrication technologies,granting it the potential to be mass-produced at a low unit *** the reported prototype operating at 1550 nm wavelength,a total uniaxial displacement of 6.3µm was achieved in the Alvarez metalens with a direct-current(DC)voltage application up to 20V,which modulated the focal position within a total tuning range of 68µm,producing more than an order of magnitude change in the focal length and a 1460-diopter change in the optical *** MEMS Alvarez metalens has a robust design that can potentially generate a much larger tuning range without substantially increasing the device volume or energy consumption,making it desirable for a wide range of imaging and display applications.

关键词： electrostatic optics adapted

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Prevalence of depression in coronary heart disease in China：a systematic review and meta-analysis

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Chinese Medical Journal 2014年第16期127卷 2991-2998页

作者： Ren Yanping Yang Hui Colette Browning shane Thomas Liu Meiyan Department of Geriatric-Cardiology First Hospital of Xi'an JiaotongUniversity Xi'an Shannxi 710061 China School of Primary Health Care Faculty of Medicine Nursing andHealth Sciences Victoria 3165 Monash University Australia Department of Cardiology Beijing Anzhen Hospital Affiliated toCapital Medical University Beijing 100029 China

Background Coronary heart diseases （CHD） have been identified as one of topmost diseases affecting the Chinese ***,depression in CHD has not been reported and there are limited high quality empirical studies in China focused on the prevalence of the *** study aimed to estimate the pooled prevalence of depression with CHD in *** Systematic review and meta-analysis of published epidemiologic studies on the depression in CHD patients in China were *** research findings dated before 30 September 2013 were obtained from Ovid Medline,EMBASE and two Chinese electronic publication libraries wANFANG and *** used ＂cardiovascular disease＂,＂depression＂ and ＂China＂ as the search themes in Ovid Medline and EMBASE and ＂cardiovascular disease＂ and ＂depression＂ in wANFANG and ***-effects meta-analysis was used to estimate the prevalence of depression in CHD *** Twenty-seven studies were included in the ***-three studies had 5 236 participants who were hospitalized and four studies had 1 353 participants from *** overall prevalence of depression in CHD from hospital was 51% （95% CI：0.43,0.58; Ⅰ-squared=97%,P=-0.000）.The prevalence of depression in CHD from community ranged between 34.6% to 45.8%,and the severe depression was found ranging between 3.1% to 11.2%.Conclusions On comparing data with other countries,the prevalence of depression in CHD among admitted patients in China was found to be *** physicians and healthcare providers should pay more attention to the ＂physical-mental＂ health of the CHD patients.

关键词： prevalence depression coronary heart disease China meta-analysis

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Fabrication of 3D Templates Using a Large Depth of Focus Femtosecond Laser

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Chinese Physics Letters 2009年第9期26卷 140-142页

作者：李晓凡 wINFIELD Richard O'BRIEN shane 陈良尧 Department of Optical Science and Engineering Fudan University Shanghai 200433 Tyndall National Institute Lee Maltings Prospect Row Cork Ireland Department of Microelectronic Engineering University College Cork Cork Ireland

we report the use of a large depth of focus Bessel beam in the fabrication of cell structures. Two axicon lenses are investigated in the formation of high aspect ratio line structures. A sol-gel resin, with good mechanical strength, is polymerised in a modified two-photon polymerisation system. Examples of different two-dimensional grids are presented to show that the lateral resolution can be maintained even in the rapid fabrication of high-sided structures.

关键词： sea surface nonliear interaction numerical method

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Fast extended depth of focus meta-optics for varifocal functionality

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Photonics Research 2022年第3期10卷 828-833页

作者： James E.M.whitehead Alan Zhan shane Colburn Luocheng Huang Arka Majumdar Department of Electrical and Computer Engineering University of WashingtonSeattleWashingtonD.C.98195USA Tunoptix SeattleWashingtonD.C.98195USA Department of Physics University of WashingtonSeattleWashingtonD.C.98195USA

Extended depth of focus(EDOF)optics can enable lower complexity optical imaging systems when compared to active focusing *** existing EDOF optics,however,it is difficult to achieve high resolution and high collection efficiency *** subwavelength spacing of scatterers in a meta-optic enables the engineering of very steep phase gradients;thus,meta-optics can achieve both a large physical aperture and a high numerical ***,we demonstrate a fast(f/1.75)EDOF meta-optic operating at visible wavelengths,with an aperture of 2 mm and focal range from 3.5 mm to 14.5 mm(286 diopters to 69 diopters),which is a 250×elongation of the depth of focus relative to a standard ***-independent performance is shown by imaging at a range of finite conjugates,with a minimum spatial resolution of∼9.84μm(50.8 cycles/mm).we also demonstrate operation of a directly integrated EDOF meta-optic camera module to evaluate imaging at multiple object distances,a functionality which would otherwise require a varifocal lens.

关键词： optics enable otherwise

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Evaluating the Impacts of Using Different Digital Surface Models to Estimate Forest Height with TanDEM-X Interferometric Coherence Data

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雷达学报（中英文） 2020年第2期9卷 386-398页

作者： CHEN Hao HILL David A. wHITE Joanne C. CLOUDE shane R. Canadian Forest Service 506 Burnside Road WestVictoriaBritish ColumbiaV8Z 1M5Canada Applied Electromagnetics Consultants 26 Westfield AvenueCuparFifeKY155AAUK

In our previous studies, we demonstrated the usefulness of TanDEM-X interferometric bistatic mode with single polarization to obtain forest heights for the purposes of large area mapping. A key feature of our approach has been the use of a simplified Random Volume Over Ground(RVOG) model that locally estimates forest height. The model takes TanDEM-X interferometric coherence amplitude as an input and uses an external Digital Surface Model(DSM) to account for local slope variations due to terrain topography in order to achieve accurate forest height estimation. The selection of DSM for use as a local slope reference is essential, as an inaccurate DSM will result in less accurate terrain-correction and forest height estimation. In this paper, we assessed TanDEM-X height estimates associated with scale variations in different DSMs used in the model over a remote sensing supersite in Petawawa, Canada. The DSMs used for assessments and comparisons included ASTER GDEM, ALOS GDSM, airborne DRAPE DSM, Canadian DSM and TanDEM-X DSM. Airborne Laser Scanning(ALS) data were used as reference for terrain slope and forest height comparisons. The results showed that, with the exception of the ASTER GDEM, all DSMs were sufficiently accurate for the simplified RVOG model to provide a satisfactory estimate of stand-level forest height. when compared to the ALS 95th height percentile, the modeled forest heights had R2 values greater than 80% and Root-Mean-Square Errors(RMSE)less than 2 m. For a close similarity in slope estimation with the ALS reference, coverage across Canada and open data access, the 0.75 arc-second(20 m) resolution Canadian DSM was selected as a preferred choice for the simplified RVOG model to provide TanDEM-X height estimation in Canada.

关键词： Interferometric COA Digital surface model Forest height

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Progesterone modulates m TOR in the hippocampus of mice after traumatic brain injury

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Neural Regeneration Research 2018年第3期13卷 434-439页

作者： Richard Justin Garling Lora Talley watts shane Sprague Murat Digicaylioglu Department of Neurosurgery Wayne State University Detroit MI USA School of Medicine The University of Texas Health Science Center at San Antonio San Antonio TX USA Department of Neurosurgery The University of Texas Health Science Center at San Antonio San Antonio TX USA

Spinal cord injury results in the loss of motor and sensory pathways and spontaneous regeneration of adult mammalian spinal cord neurons is limited. Chitosan and sodium alginate have good biocompatibility, biodegradability, and are suitable to assist the recovery of damaged tissues, such as skin, bone and nerve. Chitosan scaffolds, sodium alginate scaffolds and chitosan-sodium alginate scaffolds were separately transplanted into rats with spinal cord hemisection. Basso-Beattie-Bresnahan locomotor rating scale scores and electrophysiological results showed that chitosan scaffolds promoted recovery of locomotor capacity and nerve transduction of the experimental *** days after surgery, chitosan scaffolds retained the original shape of the spinal cord. Compared with sodium alginate scaffolds- and chitosan-sodium alginate scaffolds-transplanted rats, more neurofilament-H-immunoreactive cells （regenerating nerve fibers） and less glial fibrillary acidic protein-immunoreactive cells （astrocytic scar tissue） were observed at the injury site of experimental rats in chitosan scaffold-transplanted rats. Due to the fast degradation rate of sodium alginate, sodium alginate scaffolds and composite material scaffolds did not have a supporting and bridging effect on the damaged tissue. Above all, compared with sodium alginate and composite material scaffolds, chitosan had better biocompatibility, could promote the regeneration of nerve fibers and prevent the formation of scar tissue,and as such, is more suitable to help the repair of spinal cord injury.

关键词： nerve regeneration spinal cord injury chitosan sodium alginate functional recovery scaffold neurofilament-H glial fibrillary acidic protein scar tissue locomotor capacity neural regeneration

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Signaling Product Quality by Price

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Frontiers of Economics in China-Selected Publications from Chinese Universities 2012年第3期7卷 363-372页

作者： shane Parendo Cheng-Zhong Qin Department of Economics University of California Santa Barbara CA 93106 USA

This paper analyzes the role of price as a signal of the quality of a monopoly firm＇s new product. The quality of the goods is drawn from a continuum and is unknown to consumers. we establish a unique separating equilibrium using equilibrium characterization results for signaling games. The equilibrium price monotonically increases with quality levels and exceeds the complete-information monopoly price for all quality levels but the lowest one. However, the upward distortion decreases as the proportion of pre-informed consumers increases. These results extend both the signaling role of price and characteristics of the separating equilibrium as established in Bagwell and Riordan （1991）.

关键词： separating equilibrium price distortion signaling game

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Motion visualization and estimation for flapping wing systems

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Acta Mechanica Sinica 2017年第2期33卷 327-340页

作者： Tzu-Sheng shane Hsu Timothy Fitzgerald Vincent Phuc Nguyen Trisha Patel Balakumar Balachandran Department of Mechanical Engineering University of Maryland College Park MD 20742 USA

Studies of fluid-structure interactions associated with flexible structures such as flapping wings require the capture and quantification of large motions of bodies that may be opaque. As a case study, motion capture of a free flying Manduca sexta, also known as hawkmoth, is considered by using three synchronized high-speed cameras. A solid finite element (FE) representation is used as a reference body and successive snapshots in time of the displacement fields are reconstructed via an optimization procedure. One of the original aspects of this work is the formulation of an objective function and the use of shadow matching and strain-energy regularization. with this objective function, the authors penalize the projection differences between silhouettes of the captured images and the FE representation of the deformed body. The process and procedures undertaken to go from high-speed videography to motion estimation are discussed, and snapshots of representative results are presented. Finally, the captured free-flight motion is also characterized and quantified.

关键词： Insect flight Deformable body High-speed videography Motion estimation

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Review on Recent Developments of Fluorescent Oxygen and Carbon Dioxide Optical Fiber Sensors

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Photonic Sensors 2011年第3期1卷 234-250页

作者： Cheng-shane CHU Yu-Lung LO Ti-wen SUNG Department of Mechamcal Engmeermg Ming Chi University of Technology Taishan District New Taipei City TaiwanChina Department of Mechanical Engineering National Cheng Kung University Tainan Taiwan China

Oxygen and carbon dioxide sensors are involved in many chemical and biochemical reactions. Consequently, considerable efforts over years have been devoted to discover and improve suitable techniques for measuring gas concentrations by optical fiber sensors. Optical gas sensors consist of a gas-sensitive dye entrapped in a matrix with a high permeability to gas. with such sensors, gas concentration is evaluated based upon the reduction in luminescence intensity caused by gas quenching of the emitting state. However, the luminescence quenching effect of oxygen is highly sensitive to temperature. Thus, a simple, low-cost plastic optical fiber sensor for dual sensing of temperature and oxygen is presented. Also, a modified Stern-Volmer model is introduced to compensate for the temperature drift while the temperature is obtained by above dual sensor. Recently, we presented highly-sensitive oxygen and dissolved oxygen sensors comprising an optical fiber coated at one end with platinum （II） meso-tetrakis（pentafluorophenyl）porphyrin （PtTFPP） and PtTFPP entrapped core-shell silica nanoparticles embedded in an n-octyltriethoxysilane（Octyl-triEOS）/tetraethylorthosilane （TEOS） composite xerogel. Also, two-dimensional gas measurement for the distribution of chemical parameters in non-homogeneous samples is developed and is of interest in medical and biological researches.

关键词： Oxygen carbon dioxide fluorescent dye optical fiber temperature effect modified Stem-Volmermodel core-shell silica nanoparticles

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IAVCEI CEV-CVS field workshop： Phreatomagmatic volcanoes of Jeju Island, Korea

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Episodes 2008年第3期31卷 358-360页

作者： Nemeth, Karoly Cronin, shane J. Massey Univ Volcan Risk Solut Inst Nat Resources Palmerston North New Zealand

A scientific field workshop sponsored by two commissions （Commission on Explosive Volcanism -- CEV and Commission on Vol- canogenic Sediments-CVS） of the Interna- tional Association of Volcanology and Chemistry of the Earth Interior （IAVCEI） took place in Jeju Island, South Korea from 13-17 November 2007. This was organised by Prof. Dr. Young Kwan Sohn （Gyeongsan National University, Jinju） and Dr. Ki Hwa Park （Korea Institute of Geoscience and Mineral Resources, Daejon）. The ＂Phreato- magmatic volcanoes of Jeju Island,

关键词：地理学潜水岩浆互相作用韩国岛屿

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