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Photonic crystal-connected bidirectional micro-ring resonator array for duplex mode and wavelength channel(de)multiplexing

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Photonics Research 2024年第8期12卷 1802-1812页

作者： ZHIWEI GUAN CHAOFENG WANG CHUANGXIN XIE HAISHENG WU JUNMIN LIU HUAPENG YE DIANYUAN FAN JIANGNAN XIAO SHUQING CHEN International Collaborative Laboratory of 2D Materials for Optoelectronics Science and Technology Institute of Microscale OptoelectronicsShenzhen UniversityShenzhen 518060China college of Physics and engineering Technology Minzu Normal University of XingyiXingyi 562400China college of New Materials and New Energies Shenzhen Technology UniversityShenzhen 518118China Guangdong Provincial Key Laboratory of Optical Information Materials and Technology and Institute of Electronic Paper Displays South China Academy of Advanced OptoelectronicsSouth China Normal UniversityGuangzhou 510006China Terahertz Technology Innovation Research Institute Shanghai Key Laboratory of Modern Optical SystemTerahertz Science Cooperative Innovation CenterSchool of Optical-Electrical Computer EngineeringUniversity of Shanghai for Science and TechnologyShanghai 200093China

The progress of on-chip optical communication relies on integrated multi-dimensional mode(de)multiplexers to enhance communication capacity and establish comprehensive ***,existing multi-dimensional(de)multiplexers,involving modes and wavelengths,face limitations due to their reliance on single-directional total internal reflection and multi-level mode conversion based on directional coupling *** constraints restrict their potential for full-duplex functionality and highly integrated *** solve these problems by introducing a photonic-like crystal-connected bidirectional micro-ring resonator array(PBMRA)and apply it to duplex mode-wavelength multiplexing *** directional independence of total internal reflection and the cumulative effect of the subwavelength-scale pillar within the single-level photonic crystal enable bidirectional mode and wavelength multiplexed signals to transmit among multi-pair nodes without interference,improving on-chip integration in single-level mode *** a proof of concept,we fabricated a nine-channel bidirectional multi-dimensional(de)multiplexer,featuring three wavelengths and three TE modes,compactly housed within a footprint of 80μm×80μm,which efficiently transmits QPSK-OFDM signals at a rate of 216 Gbit/s,achieving a bit error rate lower than 10^(-4).Leveraging the co-ring transmission characteristic and the orthogonality of the mode-wavelength channel,this(de)multiplexer also enables a doubling of communication capacity using two physical transmission channels.

关键词： resonator channel mode

A NONLOCAL KRONECKER-BASIS-REPRESENTATION METHOD FOR LOW-DOSE CT SINOGRAM RECOVERY

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Journal of Computational Mathematics 2024年第4期42卷 1080-1108页

作者： Jian Lu Huaxuan Hu Yuru Zou Zhaosong Lu Xiaoxia Liu Keke Zu Lin Li Shenzhen Key Laboratory of Advanced Machine Learning and Applications College of Mathematics and StatisticsShenzhen UniversityShenzhen 518060China National Center for Applied Mathematics Shenzhen(NCAMS) Shenzhen 518055China Department of Industrial and Systems engineering University of Minnesota Twin CitiesMinneapolisMN55455USA Department of Applied Mathematics The Hong Kong Polytechnic UniversityHong Kong SARChina School of Electronic engineering Xidian UniversityXi'an 710071China

Low-dose computed tomography(LDCT)contains the mixed noise of Poisson and Gaus-sian,which makes the image reconstruction a challenging *** order to describe the statistical characteristics of the mixed noise,we adopt the sinogram preprocessing as a stan-dard maximum a posteriori(MAP).Based on the fact that the sinogram of LDCT has non-local self-similarity property,it exhibits low-rank *** conventional way of solving the low-rank problem is implemented in matrix forms,and ignores the correlations among similar patch *** avoid this issue,we make use of a nonlocal Kronecker-Basis-Representation(KBR)method to depict the low-rank problem.A new denoising model,which consists of the sinogram preprocessing for data fidelity and the nonlocal KBR term,is developed in this *** proposed denoising model can better illustrate the generative mechanism of the mixed noise and the prior knowledge of the ***-merical results show that the proposed denoising model outperforms the state-of-the-art algorithms in terms of peak-signal-to-noise ratio(PSNR),feature similarity(FSIM),and normalized mean square error(NMSE).

关键词： Low-dose computed tomography Kronecker-basis-representation Low-rank imation.Noise-generating-mechanism

Effect of blade pitch angle on aerodynamic performance of straight-bladed vertical axis wind turbine

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Journal of Central South University 2014年第4期21卷 1417-1427页

作者：张立勋梁迎彬刘小红郭健 college of mechanical and Electrical engineering Harbin Engineering University

Wind energy is one of the most promising renewable energy sources, straight-bladed vertical axis wind turbine(S-VAWT) appears to be particularly promising for the shortage of fossil fuel reserves owing to its distinct advantages, but suffers from poor self-starting and low power coefficient. Variable-pitch method was recognized as an attractive solution to performance improvement, thus majority efforts had been devoted into blade pitch angle effect on aerodynamic performance. Taken into account the local flow field of S-VAWT, mathematical model was built to analyze the relationship between power outputs and pitch angle. Numerical simulations on static and dynamic performances of blade were carried out and optimized pitch angle along the rotor were presented. Comparative analyses of fixed pitch and variable-pitch S-VAWT were conducted, and a considerable improvement of the performance was obtained by the optimized blade pitch angle, in particular, a relative increase of the power coefficient by more than 19.3%. It is further demonstrated that the self-starting is greatly improved with the optimized blade pitch angle.

关键词： straight-bladed vertical axis wind turbine pitch angle numerical simulation self-starting power coefficient

The potential mechanism of Isodon suzhouensis against COVID-19 via EGFR/TLR4 pathways

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Food Science and Human Wellness 2024年

作者： Hong Duan Wei Wang Shu Li Han Li Ghulam Jilany Khan Fawang Liu Kefeng Zhai Lili Li Zhaojun Wei General Clinical Research Center， Anhui Wanbei Coal-Electricity Group General Hospital Department of Pharmacology and Therapeutics， Faculty of Pharmacy， University of Central Punjab college of Biological and Food engineering， Anhui Polytechnic University School of Biological and Food engineering， engineering Research Center for Development and High Value Utilization of Genuine Medicinal Materials in North Anhui Province， Suzhou University School of Food and Biological engineering， Hefei University of Technology

Corona Virus Disease 2019 (COVID-19) has brought the new challenges to scientific research. Isodon suzhouensis has good anti-inflammatory and antioxidant stress effects， which is considered as a potential treatment for COVID-19. The possibility for the treatment of COVID-19 with suzhouensis and its potential mechanism of action were explored by employing molecular docking and network pharmacology. Network pharmacology and molecular docking were used to screen drug targets， and Lipopolysaccharide (LPS) induced RAW264.7 and NR8383 cells inflammation model was used for experimental verification. Collectively a total of 209 possible linkages against 18 chemical components from suzhouensis and 1194 COVID-19 related targets were selected. Among these， 164 common targets were obtained from the intersection of suzhouensis and COVID-19. GO and KEGG enriched 582 function targets and 87 target proteins pathways， respectively. The results from molecular docking studies revealed that rutin， vitexin， isoquercitrin and quercetin had significant binding ability with SARS-CoV-23CLpro and ACE2. In vitro studies showed that Isodon suzhouensis extract (ISE) may inhibit the activation of PI3K/Akt pathway and the expression level of downstream pro-inflammatory factors by inhibiting the activation of EGFR in RAW264.7 cells induced by LPS. In addition， ISE was able to inhibit the activation of TLR4/NF-κB signaling pathway in NR8383 cells exposed to LPS. Overall， the network pharmacology and in vitro studies conclude that active components from suzhouensis have strong therapeutic potential against COVID-19 through multi-target， multi-pathway dimensions and can be a promising candidate against COVID-19.

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Tubular pure copper grain refining by tube cyclic extrusion–compression(TCEC) as a severe plastic deformation technique

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Progress in Natural Science:Materials International 2014年第6期24卷 623-630页

作者： A.Babaei M.M.Mashhadi School of mechanical engineering College of Engineering University of Tehran

Tube Cyclic Extrusion–Compression(TCEC) method is a novel severe plastic deformation technique developed for grain refining of cylindrical tubes to ultrafine grained(UFG)/nanostructured ones. In this method, tubes are fully constrained and deformed between chamber and mandrel with a small neck zone. The principle of TCEC technique which was adopted to impose severe plastic strains to the tubular materials was explained. Also, the deformation and grain fragmentation mechanism during TCEC was analyzed. The material deformation characteristics during TCEC were numerically simulated by FE code of ABAQUS/Explicit. The FEM results demonstrated that TCEC technique was able to impose extremely high plastic strains. The TCEC method was successfully applied to a commercially pure copper(99.99%) and significant grain refinement was achieved. TEM observation demonstrated the refinement of grains from the initial size of 45 μm to 200–350 nm after four processing cycles of TCEC. Microhardness measurements were carried out across the thickness of the initial and processed tubes. The results show good homogeneity of hardness distribution and an increase to 102 Hv from initial value of 55 Hv after four TCEC cycles. mechanical properties of the specimens were extracted from tensile tests. The obtained results documented notable increase in the yield and ultimate strengths, whereas the uniform and total elongations decreased. Fracture surfaces after tensile tests were investigated by scanning electron microscopy(SEM), and the observed morphology indicates ductile fracture mode after four cycles of TCEC.

关键词： Tube Cyclic Extrusion–Compression Severe plastic deformation Pure copper Nano crystalline mechanical properties

An artificial neural network model for multi-flexoelectric actuation of Plates

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International Journal of Smart and Nano Materials 2022年第4期13卷 713-734页

作者： Mu Fan Pengcheng Yu Zhongmin Xiao State Key Laboratory of Mechanics and Control of mechanical Structures Nanjing University of Aeronautics and AstronauticsNanjingChina Interdisciplinary Research Institute of Aeronautics and Astronautics College of Aerospace EngineeringNanjing University of Aeronautics and AstronauticsNanjingChina School of mechanical and aerospace engineering Nanyang Technological UniversitySingapore

Flexoelectric effect can be used to design actuators to control engi-neering structures including beams,plates,and *** flexo-electric actuators method has the advantage of less stress concentration and better control effect,but the mode-dependent optimal actuator locations could influence the flexoelectric actuation effect *** this work,a neural network model is established to study the optimal combinations of multiple flexoelectric actuators on a rectangular *** the physical model,an atomic force micro-scope(AFM)probe was employed to generate an electric field gradient in the flexoelectric patch,so that flexoelectric control force and moment can be *** flexoelectric actuators on the plate was *** studies showed that the flexoelectricity induced stress mainly concentrate near the probe,the size and shape of the flexoelectric patch have limited effect on the actuation,hence,only the actuator positions were choosing as the input of the ANN *** the prediction of the neural network model,the driving effect of a large number of actuators at different positions can be quickly obtained,and the optimal position of the actuator can be analyzed more accurately.

关键词： smart structure flexoelectric effect vibration of thin plate Artificial neural network

Position-dependent property of resonant dipole-dipole interaction mediated by localized surface plasmon of an Ag nanosphere

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Chinese Physics B 2015年第2期24卷 158-164页

作者：许丹王小云黄勇刚欧阳仕粮何海龙何浩 college of Physics Mechanical and Electrical EngineeringJishou University

We use the photon Green-function method to study the quantum resonant dipole-dipole interaction（RDDI） induced by an Ag nanosphere（ANP）.As the distance between the two dipoles increases,the RDDI becomes weaker,which is accompanied by the influence of the higher-order mode of the ANP on RDDI declining more quickly than that of the dipole *** a broad frequency range（above 0.05 eV）,the transfer rate of the RDDI is nearly constant since the two dipoles are fixed at the proper *** addition,this phenomenon still exists for slightly different radius of the *** find that the frequency corresponding to the maximum transfer rate of RDDI exhibits a monotonic decrease by moving away one dipole as the other dipole and the ANP are kept *** addition,the radius of ANP has little effect on *** the two dipoles are far from the ANP,the maximum transfer rate of the RDDI takes place at the frequency of the dipole *** contrast,when the two dipoles are close to the ANP,the higher-order modes come into effect and they will play a leading role in the RDDI if they match the transition frequency of the *** results may be used in a biological detector and have a certain guiding significance for further application.

关键词： quantum resonant dipole-dipole interaction photonic Green function surface plasmon

MOF衍生Co_(3)O_(4)/ZrO_(2)介孔八面体:优化电荷转移和中间体转化用于高效CO_(2)光还原

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Science China Materials 2024年第2期67卷 588-597页

作者：刘海兵邱衍滨甘文秀庄国鑫陈飞飞杨程凯于岩 Key Laboratory of Advanced Materials Technologies International(HongKong Macao and Taiwan)Joint Laboratory on Advanced Materials TechnologiesCollege of Materials Science and EngineeringFuzhou UniversityFuzhou 350108China Scientific Research and Experiment Center Fujian Police CollegeFuzhou 350007China

调控电荷转移和反应路径是促进光催化CO_(2)还原的两种有效策略.本研究通过热解UIO-66@ZIF-67核壳八面体,合成了Co_(3)O_(4)/ZrO_(2)介孔八面体.该介孔八面体由高度分散的小尺寸纳米颗粒组装而成,平均颗粒尺寸为13 nm,平均孔径为5.8 nm... 详细信息

调控电荷转移和反应路径是促进光催化CO_(2)还原的两种有效策略.本研究通过热解UIO-66@ZIF-67核壳八面体,合成了Co_(3)O_(4)/ZrO_(2)介孔八面体.该介孔八面体由高度分散的小尺寸纳米颗粒组装而成,平均颗粒尺寸为13 nm,平均孔径为5.8 nm,比表面积为43.11 m^(2)g^(-1).受益于活性位点设计,电荷转移动力学和CO_(2)吸附得以增强.此外,密度泛函理论计算结果显示,ZrO_(2)能够有效调控CO_(2)还原的反应路径,包括促进CO_(2)活化为*CO_(2)、中间体(*COOH和*CO)的形成、以及减小限速步(*CO→CO)的能垒.因此,Co_(3)O_(4)/ZrO_(2)介孔八面体的周转率高达28.82,是纯Co_(3)O_(4)的16.95倍.

关键词： metal-organic frameworks mesoporous oxides photocatalysis CO_(2)reduction

Tool wear during high speed turning in situ TiC_p/TiB_w hybrid reinforced Ti-6Al-4V matrix composite

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Chinese Journal of Aeronautics 2016年第5期29卷 1425-1435页

作者： Ge Yingfei Xu Jiuhua Huan Haixiang School of mechanical engineering Nanjing Institute of Technology college of mechanical & Electrical engineering Nanjing University of Aeronautics & Astronautics

Chipping, adhesive wear, abrasive wear and crater wear are prevalent for both the polycrystalline diamond （PCD） and the carbide tools during high speed turning of TiCp/TiBw hybrid reinforced Ti-6Al-4V （TC4） matrix composite （TMCs）. The combined effects of abrasive wear and diffusion wear caused the big crater on PCD and carbide tool rake face. Compared to the PCD, bigger size of crater was found on the carbide tool due to much higher cutting temperature and the violent chemical reaction between the Ti element in the workpiece and the WC in the tool. However, the marks of the abrasive wear looked much slighter or even could not be observed on the carbide tool especially when low levels of cutting parameters were used, which attributes to much lower hardness and smaller size of WC combined with more significant chemical degradation of carbide. When cutting TC4 using PCD tool, notch wear was the most significant wear pattern which was not found when cutting the TMCs. However, chipping, adhesive wear and crater wear were much milder when compared to the cutting of titanium matrix composite. Due to the absence of abrasive wear when cutting TC4, the generated titanium carbide on the PCD protected the tool from fast wear, which caused that the tool life for TC4 was 6-10 times longer than that for TMCs.

关键词： Carbide tool High speed cutting PCD tool Titanium matrix composite Tool wear Turning