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A Four-Wavelength All-Fiber Laser for Wavelength Division Multiplexing System

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Chinese Physics Letters 2001年第3期18卷 376-378页

作者： DING Lei KAI Gui-Yun XU Yan-Jun GUAN Bai-Ou YUAN Shu-Zhong DONG Xiao-Yi ge chun-feng Institute of Modern Optics Nankai UniversityTianjin 300071 College of Precision Instrument&Optoelectronics Tianjin UniversityTianjin 300072

A novel four-wavelength all-fiber laser based on fiber Bragg gratings is *** four wavelengths are 1555.8,1556.6,1557.4 and 1558.2 nm,*** output laser is1 mW in *** suppression ratio between adjacent wavelengths is>30 *** laser was applied in a wavelength division multiplexing(WDM)system and the 100 km transmission of 1.2 Gb/s nonreturn-to-zero code,1.2 Gb/s return-to-zero code,2.5 GHz analogue signal and 5 GHz analogue signal was realized with it.

关键词： Gb/s fiber laser

Analysis of fiber lens with gradient index based on thin lensequivalence

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Optoelectronics Letters 2006年第1期2卷 37-40页

作者： ZHANG Rui-feng ge chun-feng LI Shi-chen College of Precision Instrument Optoelectronics Engineering Tianjin University Key Laboratory of Optoelectronics Information Technical Sciences Tianjin 300072 China

Theoretical analysis of the fiber-lens TEC （Thermally Expended Core） /Coreless/GRIN （Graded-Index） based on thin lens equivalence Js presented in this paper, On condition that the TEC part adjusts the waist radius of an incident Gaussian beam,that the coreless part controlls the space between the beam waist and the thin lens, and that the GRIN part acts as the thin lens with its focal length determined by fiber index distribution parameter g, the analytic expressions of the waist spot size and the working distance of the output Gaussian beam are derived, and the influence of the coreless fiber and the length of the GRIN fiber upon the fiber-lens parameter is discussed based on the numerical simulation results. It is concluded that, if a GRIN style fiber-lens is used as a collimator, the maximum of the spot waist can be up to 80μm and the divergence angle of single-mode optical fiber can be reduced by 8 times. If it is applied to a MEMS device, the maximum working distance can be up to 3 mm.

关键词：光纤器件镜头梯度指数高斯理论焦距

Attractor for the Extensible Beam Equation with Nonlocal Weak Damping on Time–Dependent Space

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Acta Mathematica Sinica,English Series 2024年第4期40卷 1115-1126页

作者： chun Xiang ZHAO feng Juan MENG Institute of Applied System Analysis Jiangsu UniversityZhenjiang 212013P.R.China School of Mathematics and Physics Jiangsu University of TechnologyChangzhou 213001P.R.China

In this article,we consider the long-time behavior of extensible beams with nonlocal weak damping:ε(t)u_(tt)+Δ^(2)u-m(‖▽u‖^(2))Δu+‖u_(t)‖^(p_(u_(t)))+f(u)=h,whereε(t)is a decreasing function vanishing at *** the theory of process on time-dependent spaces,we investigate the existence of the time-dependent attractor by using the Condition(C_(t))method and more detailed *** results obtained essentially improve and complete some previous works.

关键词： Time-dependent attractor extensible beams equation nonlocal weak damping

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广东省机电产品的对外贸易竞争力分析

商业研究 2008年第6期 165-168页

作者：葛春凤广州航海高等专科学校商贸系广东广州510330

客观科学地分析广东机电产品出口竞争力,及时发现其发展中存在的问题与差距,对保持和提升广东机电产品出口竞争力,从而带动广东以及整个国家贸易竞争力的提升尤为重要。基于贸易竞争力指数的实证分析显示,广东机电产品出口竞争力高于全... 详细信息

客观科学地分析广东机电产品出口竞争力,及时发现其发展中存在的问题与差距,对保持和提升广东机电产品出口竞争力,从而带动广东以及整个国家贸易竞争力的提升尤为重要。基于贸易竞争力指数的实证分析显示,广东机电产品出口竞争力高于全国总水平;广东机电产品在国际市场上具有强竞争优势,但有微弱下降趋势,且其出口竞争力优势主要来源于外资企业、加工贸易及劳动密集型机电产品。

关键词：出口竞争力贸易竞争力指数机电产品

Gut microbiota dysbiosis contributes toα-synuclein-related pathology associated with C/EBPβ/AEP signaling activation in a mouse model of Parkinson’s disease

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Neural Regeneration Research 2024年第9期19卷 2081-2088页

作者： Xiaoli Fang Sha Liu Bilal Muhammad Mingxuan Zheng Xing ge Yan Xu Shu Kan Yang Zhang Yinghua Yu Kuiyang Zheng Deqin geng chun-feng Liu Department of Neurology and Clinical Research Center of Neurological Disease The Second Affiliated Hospital of Soochow UniversitySuzhouJiangsu ProvinceChina Department of Neurology Affiliated Hospital of Xuzhou Medical UniversityXuzhouJiangsu ProvinceChina Jiangsu Key Laboratory of Immunity and Metabolism Department of Pathogen Biology and ImmunologyXuzhou Medical UniversityXuzhouJiangsu ProvinceChina Department of Neurology Xuzhou Central HospitalXuzhouJiangsu ProvinceChina Jiangsu Key Laboratory of Neuropsychiatric Disease and Institute of Neuroscience Soochow UniversitySuzhouJiangsu ProvinceChina

Parkinson’s disease is a neurodegenerative disease characterized by motor and gastrointestinal *** dysfunction can precede the onset of motor symptoms by several *** microbiota dysbiosis is involved in the pathogenesis of Parkinson’s disease,whether it plays a causal role in motor dysfunction,and the mechanism underlying this potential effect,remain ***/enhancer binding proteinβ/asparagine endopeptidase(C/EBPβ/AEP)signaling,activated by bacterial endotoxin,can promoteα-synuclein transcription,thereby contributing to Parkinson’s disease *** this study,we aimed to investigate the role of the gut microbiota in C/EBPβ/AEP signaling,α-synuclein-related pathology,and motor symptoms using a rotenone-induced mouse model of Parkinson’s disease combined with antibiotic-induced microbiome depletion and fecal microbiota *** found that rotenone administration resulted in gut microbiota dysbiosis and perturbation of the intestinal barrier,as well as activation of the C/EBP/AEP pathway,α-synuclein aggregation,and tyrosine hydroxylase-positive neuron loss in the substantia nigra in mice with motor ***,treatment with rotenone did not have any of these adverse effects in mice whose gut microbiota was depleted by pretreatment with ***,we found that transplanting gut microbiota derived from mice treated with rotenone induced motor deficits,intestinal inflammation,and *** of fecal microbiota from healthy control mice alleviated rotenone-induced motor deficits,intestinal inflammation,endotoxemia,and intestinal barrier *** results highlight the vital role that gut microbiota dysbiosis plays in inducing motor deficits,C/EBPβ/AEP signaling activation,andα-synuclein-related pathology in a rotenone-induced mouse model of Parkinson’s ***,our findings suggest that supplementing with healthy microbiota may be a safe and effective treatment that c

关键词： C/EBP/AEP signaling pathway endotoxemia fecal microbiota transplantation intestinal barrier intestinal inflammation microbiota-gut-brain axis Parkinson’s disease

Block dual Toeplitz Operators on the Orthogonal Complements of Fock Spaces

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Acta Mathematica Sinica,English Series 2024年第8期40卷 1967-1988页

作者： Jian Xiang DONG chun Xu XU Yu feng LU School of Mathematical Sciences Dalian University of TechnologyDalian 116024P.R.China School of Mathematics and Information Science Guangzhou UniversityGuangzhou 510006P.R.China

In this paper,we characterize the boundedness and compactness of the block dual Toeplitz operators acting on the orthogonal complement of the Fock spaces,and the compactness of the finite sum of two dual Toeplitz oper... 详细信息

关键词： Block dual Toeplitz operators boundedness compactness Fock space (semi)-commutator

L-band tunable erbium doped fiber ring laser using fiber loop mirror filters

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Optoelectronics Letters 2006年第1期2卷 24-26页

作者： LIU Jian-hui JIN Ming-di ge chun-feng LI Shi-chen Information Technology College Eastern Liaoning University Dandong 118003 China School of Precision Instrument and Optoelectronics Engineering Laboratory of Opto-electronics Information Technical Science EMC Tianjin University Tianjin 300072 China

We present a novel and efficient L-band wavelength-tunable Er^3＋ doped fiber laser of ring structure. In the cavity two segments of Er^3＋ doped fiber and a fiber Bragg grating are used to improve pump efficiency. Tunable filters based on fiber loop mirrors are also applied inside the cavity to act as both a wavelength selector and a line-width compressor. Using these techniques, a tunable laser with tuning range up to 42 nm, output power larger than 1 mW, power uniformity controlled within 1.75 dB and side mode suppression ratio about 40 dB is achieved.

关键词：光纤掺杂激光技术滤光器环结构

Multi-exit self-distillation with appropriate teachers

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Frontiers of Information Technology & Electronic Engineering 2024年第4期25卷 585-599页

作者： Wujie SUN Defang CHEN Can WANG Deshi YE Yan feng chun CHEN College of Computer Science and Technology Zhejiang UniversityHangzhou 310000China

Multi-exit architecture allows early-stop inference to reduce computational cost,which can be used in resource-constrained *** works combine the multi-exit architecture with self-distillation to simultaneously achieve high efficiency and decent performance at different network ***,existing methods mainly transfer knowledge from deep exits or a single ensemble to guide all exits,without considering that inappropriate learning gaps between students and teachers may degrade the model performance,especially in shallow *** address this issue,we propose Multi-exit self-distillation with Appropriate TEachers(MATE)to provide diverse and appropriate teacher knowledge for each *** MATE,multiple ensemble teachers are obtained from all exits with different trainable *** exit subsequently receives knowledge from all teachers,while focusing mainly on its primary teacher to keep an appropriate gap for efficient knowledge *** this way,MATE achieves diversity in knowledge distillation while ensuring learning *** results on CIFAR-100,TinyImageNet,and three fine-grained datasets demonstrate that MATE consistently outperforms state-of-the-art multi-exit self-distillation methods with various network architectures.

关键词： Multi-exit architecture Knowledge distillation Learning gap

Molecular Dynamics Simulation Studies on the Micromorphology and Proton Transport of Nafion/Ti_(3)C_(2)T_(x) Composite Membrane

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Chinese Journal of Polymer Science 2024年第3期42卷 373-387,I0009页

作者： Zhi-Yue Han Su-Peng Pei chun-Yang Yu Yong-feng Zhou School of Chemical and Environmental Engineering Shanghai Institute of TechnologyShanghai 201418China School of Chemistry&Chemical Engineering Frontiers Science Center for Transformative MoleculesShanghai Key Laboratory of Electrical Insulation and Thermal AgingShanghai Jiao Tong UniversityShanghai 200240China Key Laboratory of Green and High-end Utilization of Salt Lake Resources Chinese Academy of SciencesXining 810008China

The perfluorosulfonic acid(PFSA) membrane doped with two-dimensional conductive filler Ti_(3)C_(2)T_(x) is a fuel cell proton exchange membrane with high application potential. Experimental studies showed that the proton conductivity of Nafion/Ti_(3)C_(2)T_(x) composite membrane is improved significantly compared with that in pure Nafion. However, the microscopic mechanism of doping on the enhancement of membrane performance is remain unclear now. In this work, molecular dynamics simulation was used to investigate the microscopic morphology and proton transport behaviors of Nafion/Ti_(3)C_(2)T_(x) composite membrane at the molecular level. The results shown that there were significant differences about the diffusion kinetics of water molecules and hydroxium ions in Nafion/Ti_(3)C_(2)T_(x) at low and high hydration levels in the nanoscale *** the increase of water content, Ti_(3)C_(2)T_(x) in membrane was gradually surrounded by ambient water molecules to form a hydration layer, and forming a relatively continuous proton transport channel between Nafion polymer and Ti_(3)C_(2)T_(x) monomer. The continuous proton transport channel could increase the number of binding sites of proton and thus achieving high proton conductivity and high mobility of water molecules at higher hydration level. The current work can provide a theoretical guidance for designing new type of Nafion composite membranes.

关键词： Nafion/Ti_(3)C_(2)T_(x)composite membrane Proton transport Molecular dynamics simulation