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Separating arbitrary free-space beams with an integrated photonic processor

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Light(Science & Applications) 2022年第8期11卷 1811-1822页

作者： maziyar milanizadeh SeyedMohammad SeyedinNavadeh Francesco Zanetto Vittorio Grimaldi Christian De Vita Charalambos Klitis Marc Sorel Giorgio Ferrari David A.B.Miller Andrea Melloni Francesco Morichetti Department of Electronics Information and BioengineeringPolitecnico di Milanovia Ponzio 34/520133MilanoItaly School of Engineering University of GlasgowGlasgowG128QQUK TeCIP Institute Scuola Superiore Sant’Anna56124PisaItaly Ginzton Laboratory Stanford UniversitySpilker BuildingStanfordCA94305USA

Free-space optics naturally offers multiple-channel communications and sensing exploitable in many applications. The different optical beams will, however, generally be overlapping at the receiver, and, especially with atmospheric turbulence or other scattering or aberrations, the arriving beam shapes may not even be known in advance. We show that such beams can be still separated in the optical domain, and simultaneously detected with negligible cross-talk, even if they share the same wavelength and polarization, and even with unknown arriving beam shapes. The kernel of the adaptive multibeam receiver presented in this work is a programmable integrated photonic processor that is coupled to free-space beams through a two-dimensional array of optical antennas. We demonstrate separation of beam pairs arriving from different directions, with overlapping spatial modes in the same direction, and even with mixing between the beams deliberately added in the path. With the circuit’s optical bandwidth of more than 40 nm, this approach offers an enabling technology for the evolution of FSO from single-beam to multibeam space-division multiplexed systems in a perturbed environment, which has been a game-changing transition in fiber-optic systems.

关键词： processor polarization scattering

Effect of Intermediate Annealing Temperature on Response of Repressing to Densification of Pre-Alloyed Cr-Mo Steel

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Journal of Iron and Steel Research International 2011年第2期18卷 52-56页

作者： Amir Kalantari maziyar Azadbeh Department of Materials Engineering Sahand University of Technology

Increasing density is one of the important factors for producing high quality powder metallurgy （PM） parts, which has beneficial effect on mechanical properties. One of the common techniques for achieving this goal is double compacting, which seems to be a potentially attractive method in PM route, also for Cr-Mo alloyed-steels. The objective of this research was to investigate the effect of first compacting pressure and intermediate annealing temperature on attaining higher densities and minimum interconnected porosity for Cr-Mo pre-alloyed steel. The effect of mentioned parameters was studied by measuring density, transverse rupture strength and macrohardness of repressed samples. The results show that for each first compacting pressure, the density range of repressed samples increases with the increasing annealing temperature up to a certain limit, due to C dissolution which causes free porosity and further densifieation. Annealing temperatures higher than optimum one should be avoided, since too much carbon dissolution results in harder and less deformable compacts. On the other hand, with regard to repressed density and other resulted properties, the amount of first compacting pressure offers considerable advantage in obtaining higher level of density and consequently improved mechanical properties.

关键词： double compacting repressed density repressed transverse rupture strength intermediate annealing temperature

Effect of functionally-graded interphase on the elasto-plastic behavior of nylon-6/clay nanocomposites;a numerical study

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Defence Technology（防务技术） 2021年第1期17卷 177-184页

作者： maziyar Bazmaraa Mohammad Silani Iman Dayyani Department of Mechanical Engineering University of HoustonTX 77204United States Centre for Structures Assembly and Intelligent AutomationCranfield UniversityCranfieldBedford MK430ALUnited Kingdom Department of Mechanical Engineering Isfahan University of TechnologyIsfahan84156-83111Iran

In nanocomposites,the interphase thickness may be comparable to the size of nano-particles,and hence,the effect of interphase layers on the mechanical properties of nanocomposites may be *** interphase thickness to the nano-particle size ratio and properties variability across the interphase thickness are the most important affecting parameters on the overall behavior of *** this study,the effect of properties variability across the interphase thickness on the overall elastic and elastoplastic properties of a polymeric clay nanocomposite(PCN)using a functionally graded(FG)interphase is investigated in *** results of the computational homogenization on the mesoscopic level show that Young’s modulus variation of the interphase has a significant effect on the overall elastic response of nanocomposites in a higher clay weight ratio(Wt).Moreover,strength variation through the interphase has a notable effect on the elasto-plastic properties of ***,the increase or decrease in stiffness of interphase from clay to matrix and vice versa have a similar effect in the overall behavior of nanocomposites.

关键词： Nylon 6/clay nanocomposites FG Interphase Computational homogenization

Alcoholic hepatitis 2010:A clinician's guide to diagnosis and therapy

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World Journal of Gastroenterology 2010年第39期16卷 4905-4912页

作者： maziyar Amini Bruce A Runyon Department of Gastroenterology and Hepatology Loma Linda University Medical Center

Alcoholic hepatitis(AH)remains a common and life threatening cause of liver failure,especially when it is *** the adjective"acute"is frequently used to describe this form of liver injury,it is usually subacute and has been developing for weeks to months before it becomes clinically *** with this form of alcoholic liver disease usually have a history of drinking heavily for many *** certain aspects of therapy,mainly nutritional support and abstinence are well established,significant debate has surrounded the pharmacologic treatment of AH,and many institutions practice widely varying treatment protocols. In recent years a significant amount of literature has helped focus on the details of treatment,and more data have accumulated regarding risks and benefits of pharmacologic *** particular,the efficacy of pentoxifylline has become increasingly apparent,and when compared with the risks associated with prednisolone,has brought this drug to the forefront of therapy for severe *** review will focus on the clinical and laboratory diagnosis and pharmacologic therapies that should be applied during hospitalization and continued into outpatient *** conclude that the routine use of glucocorticoids for severe AH poses significant risk with equivocal benefit,and that pentoxifylline is a better,safer and cheaper *** the full details of nutritional support lie beyond the scope of this article,nutrition is a cornerstone of therapy and must be addressed in every patient diagnosed with AH. Finally,while traditional psychosocial techniques play a major role in post-hospitalization care of alcoholics, we hope to make the medical clinician realize his or her role in reducing recidivism rates with early and frequent outpatient visits and with the use of baclofen to reduce alcohol craving.

关键词： Alcoholic hepatitis Alcoholic liver disease Pentoxifylline Baclofen

Social innovation based on collaboration between government and non-governmental organizations in COVID-19 crisis: evidence from Iran

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Infectious Diseases of Poverty 2022年第1期11卷 92-93页

作者： Mehrnaz Moeenian Abbas Khamseh maziyar Ghazavi 不详 Department of Technology Management Science and Research BranchIslamic Azad UniversityTehranIran

Background One of the effective ways to attract social collaboration to provide effective,prompt,and coordinated interventions in emergencies is through social *** present study seeks to identify the factors affecting the implementation of the social innovation plan based on the collaboration between government and non-governmental organizations(NGOs)for saving people’s lives in *** initial idea of this research was obtained from the best practice“Every Home Is a Health Base”which was implemented in *** The Grounded Theory strategy has been used in this *** statistical population of the study is health experts from the Ministry of Health and Medical Education of *** study time span is during the first half of *** analysis was used to identify the factors of social *** selecting and reviewing 68 research in-depth,the initial framework was ***,through a semi-structured interview with experts,the framework was adapted and *** on the analysis of the collected data,39 open codes were extracted and the factors affecting the implementation of the social innovation were *** The eight axis codes as the factors affecting the implementation of the social innovation plan based on the collaboration between government and NGOs are as follows:Paying attention to the components of the NGOs collaboration effectiveness,investment to attract NGOs collaboration,the ability to manage the implementation,the ability of networking,the ability of policymaking,providing the necessary cultural and educational infrastructure;Existence of capable legal organizations to solve the executive problems of the plan and facilitate coordination,and controlling,containing and reducing the effects of the crisis,as *** Lessons learned from the COVID-19 pandemic have shown the world that the current governmental and social structures are not efficient enough to respond quickly to the emerge

关键词： Social innovation Collaboration with non-governmental organizations Social policy COVID-19 Qualitative approach

基于物理信息的神经网络方法在梁非线性屈曲分析中的应用

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Acta Mechanica Sinica 2023年第6期39卷 80-92页

作者： maziyar Bazmara Mohammad Mianroodi Mohammad Silani Department of Mechanical Engineering University of HoustonHouston 77204USA University of Strasbourg 67000 StrasbourgCNRSFrance Department of Mechanical Engineering Isfahan University of Technology84156-83111 IsfahanIran

本文提出了一种基于物理信息的神经网络(PINN)框架来分析在Winkler-Pasternak基础上的三维功能梯度FG多孔细长梁的非线性屈曲行为.使用简单的网络,PINNs只需要很少的训练数据来获得较高的精度.在这项工作中使用的强大工具可以处理任何... 详细信息

本文提出了一种基于物理信息的神经网络(PINN)框架来分析在Winkler-Pasternak基础上的三维功能梯度FG多孔细长梁的非线性屈曲行为.使用简单的网络,PINNs只需要很少的训练数据来获得较高的精度.在这项工作中使用的强大工具可以处理任何类型的偏微分方程.我们使用深度学习平台TensorFlow和DeepXDE库来设计我们的网络.在本研究中,PINNs框架从梁系统的控制微分方程和边界条件中获取信息,并输出临界非线性屈曲载荷.利用哈密顿原理,考虑几何的非线性,建立了数学模型.通过将建模框架应用于各种边界条件情况以及三维功能梯度FG指标等物理参数对非线性力学行为的影响,仔细检验了建模框架的准确性.最后,利用广义微分求积法(GDQM)对PINNs结果进行了验证.研究结果表明,所提出的PINN框架能够较好地表征三维功能梯度FG多孔细长梁的非线性屈曲行为.此外,PINN预测梁的非线性屈曲行为的速度比数值方法快71倍.

关键词：非线性屈曲深度学习广义微分求积法物理信息哈密顿原理非线性力学行为建模框架三维功能

Using LDMOS Transistor in Class-F Power Amplifier For WCDMA Applications

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International Journal of Communications, Network and System Sciences 2011年第10期4卷 662-666页

作者： Masoud Sabaghi Seyed Reza Hadianamrei Mehdi Rahnama maziyar Niyakan Lahiji 不详

The fundamental operating principle of a Class F power amplifier and the factors aiding or affecting Class F performance were explicated previously. A Class F power amplifier design which satisfies WCDMA specifications is explained in this paper. The Class F amplifier was designed by employing Motorola’s LDMOS (Laterally Diffused Metal Oxide Semiconductor) transistor models and we simulated its performance by means of ADS. A variety of procedures were applied in the process of designing Class F amplifier, namely, DC simulation, bias point selection, source-pull and load-pull characterization, input and output matching circuit design and the design of suitable harmonic traps, which are explained here.

关键词： ADS Class F Power Amplifier LD MOS WCDMA

Low Noise Phase CMOS Quadrature VCO with Superharmonic Coupling Using Cross-Couple Pair

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Circuits and Systems 2011年第4期2卷 281-285页

作者： Seyed Reza Hadianamrei Masoud Sabaghi maziyar Niyakan Lahiji Mehdi Rahnama 不详

This paper aims to introduce a quadrature VCO (voltage control oscillator) which applies superharmonic coupling. The presented quadrature VCO is suitable to be used, both with 2 × subharmonic mixers, as well as 4×subharmonic mixers. It would be impossible to avoid the presence of harmonics in CMOS VCO circuits. These harmonics are in general, undesirable signals which tend to accompany the desired fundamental signal. There are common-mode nodes (similar to those in the two source nodes in a cross-coupled VCO) in deferential VCO at which higher-order harmonics are present while the fundamental is absent in essence. We can make use of these second-order harmonics which are present at the common-mode nodes of two VCO in order to implement a quadrature connection between the fundamental outputs. The technique through which this is done is called superharmonic coupling. This CMOS quadrature VCO which applies active superharmonic coupling puts an excellent performance in show, with an output power –0.942 dBm for fundamental and –9.751 dBm for subharmonic, phase noise –107.2 dBc/Hz for fundamental and –114.8 dBc/Hz at a 1MHz offset. All of circuit applied are designed and simulated by ADS, 2008.

关键词： Quadrature VCO Cross-Couple Phase Noise CMOS

A New Partitioning Method in Frequency Analysis of the Retinal Images for Human Identification

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Journal of Signal and Information Processing 2011年第4期2卷 274-278页

作者： Masoud Sabaghi S. Reza Hadianamrei Ali Zahedi maziyar Niyakan Lahiji 不详

Retinal image is one of the robust and accurate biometrics methods to recognize a person. In this article we present a new biometric identification system based on Fourier transform and angular partitioning of the spectrum. In this method, at first, the optical disc is localized using template matching technique and used for rotating the retinal image into the reference position. It compensates the rotation effects which might occur during the scanning process. Fourier transform coefficient and angular partitioning of these coefficients are used for the purpose of feature definition in our method. The extract features are rotation invariant and robust against noise. Finally we employ Euclidean distance for feature matching. The proposed algorithm was tested using 40 images from DRIVE database and experimental results showed the efficiency of the proposed algorithm for the identification of retinal images with noise and rotation.

关键词： Biometric Retina Image Processing Frequency Analysis Partitioning