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Deep Guided Attention Network for Joint Denoising and Demosaicing in Real Image

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Chinese Journal of Electronics 2024年第1期33卷 303-312页

作者： Tao ZHANG Ying FU Jun ZHANG School of Computer Science and Technology Beijing Institute of Technology advanced Reasearch institute of Multidisciplinary Science Beijing Institute of Technology

Denoising(DN) and demosaicing(DM) are the first crucial stages in the image signal processing pipeline. Recently, researches pay more attention to solve DN and DM in a joint manner, which is an extremely undetermined inverse problem. Existing deep learning methods learn the desired prior on synthetic dataset, which limits the generalization of learned network to the real world data. Moreover, existing methods mainly focus on the raw data property of high green information sampling rate for DM, but occasionally exploit the high intensity and signalto-noise(SNR) of green channel. In this work, a deep guided attention network(DGAN) is presented for real image joint DN and DM(JDD), which considers both high SNR and high sampling rate of green information for DN and DM, respectively. To ease the training and fully exploit the data property of green channel, we first train DN and DM sub-networks sequentially and then learn them jointly, which can alleviate the error accumulation. Besides, in order to support the real image JDD, we collect paired raw clean RGB and noisy mosaic images to conduct a realistic dataset. The experimental results on real JDD dataset show the presented approach performs better than the state-of-the-art methods, in terms of both quantitative metrics and qualitative visualization.

关键词： Image denoising Image demosaicing Joint processing Guided attention Paired real dataset

Modulating the alloying mode in the doping-induced synthesis of Au-Pd nanowires

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Nano Research 2024年第4期17卷 3334-3343页

作者： Hui Jin Xiaoliang Wei Lecheng Zhao Jialong Yu Qiao Pan Shumin Li Qian Wang Zhaotong Yuan Dan Yang Donghui Zhao Hongyu Chen Yawen Wang institute of advanced Synthesis School of Chemistry and Molecular EngineeringJiangsu National Synergistic Innovation Center for Advanced MaterialsNanjing Tech UniversityNanjing 211816China School of Science Westlake UniversityHangzhou 310064China institute of Natural Sciences Westlake Institute for Advanced StudyHangzhou 310064China

Heterogeneous doping is one effective strategy for synthesizing metal alloy nanowires.Herein,the heterogeneous doping processes of Pd on the ultrathin Au nanowires were systematically modulated and investigated.Au-Pd alloy nanowires with various morphologies and lattice structures can be obtained by adjusting the morphology of the precursor Au nanowires and the kinetics of the heterogeneous doping processes.The effects of the rate of Pd reduction and the concentration of the ligand oleylamine(OAm)on the Pd deposition and alloying mode were articulated.Generally,as the Pd deposition rate decreases,the Pd deposition and alloying mode switches from the island-forming Stransky–Krastanov(SK)mode to the epitaxial Frank-van der Merwe(FM)mode,and eventually to an unconventional twisting alloying mode,where the interdiffusion of Pd and Au causes drastic rearrangement of the lattice structure and formation of helical structures.The kinetics-related variation of alloying mode could also be observed in the Au-Ag nanowires,demonstrating a general design principle for the synthesis of alloy nanostructures.In addition,the electrocatalytic performance of various Au-Pd nanowires was evaluated,and the alloy nanowire formed via the SK mode was found to be an excellent electrocatalyst for oxygen reduction and ethanol oxidation.

关键词： gold nanowires Au-Pd alloy oleylamine post-synthetic modification

Hyperreflective photonic crystals created by shearing colloidal dispersions at ultrahigh volume fraction

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Microsystems & Nanoengineering 2024年第1期10卷 161-173页

作者： Minji Kim Jong Bin Kim Shin-Hyun Kim Department of Chemical and Biomolecular Engineering Korea Advanced Institute of Science and Technology(KAIST)Daejeon 34141Republic of Korea

Colloidal crystallization serves as one of the most economic and scalable production methods for photonic crystals.However,insufficient optical performance,nonuniformity and low reproducibility remain challenges for advanced high-value applications.In this study,we optimally formulate a photocurable dispersion of silica particles and apply shear flow to unify the orientation of the colloidal crystals,ensuring high optical performance and uniformity.The silica particles experience strong repulsion at ultrahigh volume fractions of 50%but demonstrate low mobility,leading to polycrystalline structures.Applying shear flow to the dispersions allows the silica particles to rearrange into larger crystalline domains with a unidirectional orientation along the flow.This shear-induced structural change produces absolute reflectivity at the stopband as high as 90%and a high transparency of 90%at off-resonant wavelengths with minimal diffusive scattering.Furthermore,the strong interparticle repulsion ensures a uniform volume fraction of particles throughout the dispersion,reducing deviations in the optical properties.We intricately micropattern the photocurable dispersions using photolithography.Additionally,the photonic films and patterns can be stacked to form multiple layers,displaying mixed structural colors and multiple reflectance peaks without sacrificing reflectivity.These superior photonic materials hold promise for various optical applications,including optical components and anticounterfeiting patches.

关键词： properties. dispersion reflectivity

Versatile strategies for adult neurogenesis:avenues to repair the injured brain

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Neural Regeneration Research 2024年第4期19卷 774-780页

作者： Junyi Zhao Siyu Liu Xianyuan Xiang Xinzhou Zhu The Brain Cognition and Brain Disease institute(BCBDI) Shenzhen Institute of Advanced TechnologyChinese Academy of Sciences Faculty of Life and Health Sciences Shenzhen Institutes of Advanced TechnologyChinese Academy of Sciences Shenzhen-Hong Kong institute of Brain Science-Shenzhen Fundamental Research Institutions

Brain injuries due to trauma or stroke are major causes of adult death and disability.Unfortunately,few interventions are effective for post-injury repair of brain tissue.After a long debate on whether endogenous neurogenesis actually happens in the adult human brain,there is now substantial evidence to support its occurrence.Although neurogenesis is usually significantly stimulated by injury,the reparative potential of endogenous differentiation from neural stem/progenitor cells is usually insufficient.Alternatively,exogenous stem cell transplantation has shown promising results in animal models,but limitations such as poor long-term survival and inefficient neuronal differentiation make it still challenging for clinical use.Recently,a high focus was placed on glia-to-neuron conversion under single-factor regulation.Despite some inspiring results,the validity of this strategy is still controversial.In this review,we summarize historical findings and recent advances on neurogenesis strategies for neurorepair after brain injury.We also discuss their advantages and drawbacks,as to provide a comprehensive account of their potentials for further studies.

关键词： adult neurogenesis glia-to-neuron conversion ischemic stroke neurogenic niche neuroinflammation stem cell transplantation traumatic brain injury

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On-demand engineerable visible spectrum by fine control of electrochemical reactions

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National Science Review 2024年第3期11卷 239-249页

作者： Qirong Liu Lei Liu Yongping Zheng Min Li Baofu Ding Xungang Diao Hui-Ming Cheng Yongbing Tang advanced Energy Storage Technology Research Center Shenzhen Institute of Advanced TechnologyChinese Academy of Sciences institute of Technology for Carbon Neutrality Shenzhen Institute of Advanced Technology Chinese Academy of Sciences School of Energy and Power Engineering North University of China School of Resource Environment and Safety EngineeringHunan University of Science and Technology School of Energy and Power Engineering Beihang University Shenzhen Key Laboratory of Energy Materials for Carbon Neutrality Shenzhen Institute of Advanced Technology Chinese Academy of Sciences Shenyang National Laboratory for Materials Science Institute of Metal Research Chinese Academy of Sciences

Tunability of optical performance is one of the key technologies for adaptive optoelectronic applications,such as camouflage clothing, displays, and infrared shielding. High-precision spectral tunability is of great importance for some special applications with on-demand adaptability but remains challenging. Here we demonstrate a galvanostatic control strategy to achieve this goal, relying on the finding of the quantitative correlation between optical properties and electrochemical reactions within materials. An electrochromic electro-optical efficiency index is established to optically fingerprint and precisely identify electrochemical redox reactions in the electrochromic device. Consequently, the charge-transfer process during galvanostatic electrochemical reaction can be quantitatively regulated, permitting precise control over the final optical performance and on-demand adaptability of electrochromic devices as evidenced by an ultralow deviation of <3.0%. These findings not only provide opportunities for future adaptive optoelectronic applications with strict demand on precise spectral tunability but also will promote in situ quantitative research in a wide range of spectroelectrochemistry, electrochemical energy storage, electrocatalysis, and material chemistry.

关键词： electrochromics fine control spectral tunability high precision galvanostatic control

Ru-doped functional porous materials for electrocatalytic water splitting

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Nano Research 2024年第3期17卷 982-1002页

作者： Chongao Tian Rui Liu Yu Zhang Wenxiu Yang Bo Wang Beijing Key Laboratory of Photoelectronic/Electrophotonic Conversion Materials Advanced Technology Research Institute(Jinan)Advanced Research Institute of Multidisciplinary ScienceSchool of Chemistry and Chemical EngineeringBeijing Institute of TechnologyBeijing 100081China Beijing institute of Technology Library Beijing Institute of TechnologyBeijing 100081China

Electrolytic water splitting(EWS)is an attractive and promising technique for the production of hydrogen energy.Nevertheless,the sluggish kinetic rate of hydrogen/oxygen evolution reactions leads to a high overpotential and low energy efficiency.Up to date,Pt/Ir-based nanocatalysts have become the state-of-the-art EWS catalysts,but disadvantages such as high cost and low earth abundance greatly limit their applications in EWS devices.As an attractive candidate for the Pt/Ir catalysts,series of Ru-based nanomaterials have aroused much attention for their low price,Pt-like hydrogen bond strength,and high EWS activity.In particular,Ru-doped functional porous materials have been becoming one of the most representative EWS catalysts,which can not only achieve the dispersion and adjustment for active Ru sites,but also simultaneously solve the problems of mass transfer and catalytic conversion in EWS.In this review,the design and preparation strategies of Ru-doped functional porous materials toward EWS in recent years are summarized,including Ru-doped metal organic frameworks(MOFs),Ru-doped porous organic polymers(POPs),and their derivatives.Meanwhile,detailed structure–activity relationships induced by the tuned geometric/electronic structures of Ru-doped functional porous materials are further depicted in this review.Last but not least,the challenges and perspectives of Ru-doped functional porous materials catalysts are reasonably proposed to provide fresh ideas for the design of Ru-based EWS catalysts.

关键词： Ru-based catalyst functional porous materials electrolytic water splitting oxygen evolution reaction hydrogen evolution reaction

Quasi-in-situ Observation and SKPFM Studies on Phosphate Protective Film and Surface Micro-Galvanic Corrosion in Biological Mg-3Zn-xNd Alloys

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Acta Metallurgica Sinica(English Letters) 2024年第4期37卷 648-664页

作者： Zhaochen Yu Kaixuan Feng Shuyun Deng Yang Chen Hong Yan Honggun Song Chao Luo Zhi Hu School of advanced Manufacturing Nanchang UniversityNanchang330031China institute for advanced Study Nanchang UniversityNanchang330031China

The phosphate protective film and micro-galvanic corrosion of biological Mg-3Zn-xNd (x = 0, 0.6, 1.2) alloys were investigated by scanning and transmission electron microscopy, quasi-in-situ observation, scanning Kelvin probe force microscopy (SKPFM) and electrochemical tests. The results revealed the Mg-Zn-Nd phases formed in Mg-3Zn alloy contained with Nd. Adding Nd resulted in a significant decline in the cracks of the phosphate protective film and micro-galvanic corrosion of alloys, which were recorded by quasi-in-situ observation. In addition, the Volta potential difference of Mg-Zn-Nd/α-Mg (~ 188 mV) was lower than MgZn/α-Mg (~ 419 mV) and Zn-rich/α-Mg (~ 260 mV), and the corrosion rates of alloys markedly decreased after the addition of 0.6 wt% Nd. The improvement in corrosion resistance of Nd-containing alloys was mainly attributed to the following: (i) the addition of Nd reduced the Volta potential difference (second phases/α-Mg);(ii) the phosphate protective film containing Nd_(2)O_(3) deposited on the surface of the alloys, effectively preventing the penetration of harmful anions.

关键词： Magnesium alloys Quasi-in-situ observation Phosphate protective film Scanning Kelvin probe force microscopy(SKPFM) Micro-galvanic corrosion

Effect of Heat Treatment on Microstructure and Mechanical Properties of Multiscale SiC_p Hybrid Reinforced 6061 Aluminum Matrix Composites

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Journal of Wuhan University of Technology(Materials Science) 2024年第1期39卷 174-181页

作者：吴健铭许晓静 ZHANG Xu LUO Yuntian LI Shuaidi HUANG Lin institute for advanced Manufacturing and Modern Equipment Technology Jiangsu UniversityZhenjiang 212013China

The performance of solid solution aging treatment on aluminum matrix composites prepared by powder metallurgy and reinforced with 6061 aluminum alloy powder as matrix;meanwhile, nano silicon carbide particles(nm Si Cp), submicron silicon carbide particles(1 μm Si Cp) and Ti particles were studied. The Al/Si Cp composite powder was prepared by high-energy ball milling, and then cold-pressed, sintered, hotextruded, and then heat-treated with different solution temperatures and aging times for the extruded composites. Optical microscopy, scanning electron microscopy, energy dispersive X-ray spectroscopy(EDS), X-ray diffractometer(XRD) and extrusion testing were used to analyze and test the microstructure and mechanical properties of aluminum matrix composites. The results show that after the multi-stage solid solution at 530 ℃×2 h+535 ℃×2 h+540 ℃×2 h, the particles are mainly equiaxed grains and uniformly distributed. There is no reinforcement agglomeration, and the surface is dense and the insoluble phase is basically dissolved. In the matrix, the strengthening effect is good, and the hardness and compressive strength are 179.43 HV and 680.42 MPa, respectively. Under this solution process, when the aluminum matrix composites are aged at 170 ℃ for 10 h, the hardness and compressive strength can reach their peaks and increase to 195.82 HV and 721.48 MPa, respectively.

关键词： aluminum matrix composites Si C particles multiscale hybrid enhancement heat treatment mechanical properties

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Magnetic-biased chiral molecules enabling highly oriented photovoltaic perovskites

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National Science Review 2024年第2期11卷 221-230页

作者： Jing Chen Caner Deger Zhen-Huang Su Kai-Li Wang Guang-Peng Zhu Jun-Jie Wu Bing-Chen He Chun-Hao Chen Tao Wang Xing-Yu Gao Ilhan Yavuz Yan-Hui Lou Zhao-Kui Wang Liang-Sheng Liao institute of Functional Nano&Soft Materials(FUNSOM) Laboratory of Advanced Negative Carbon TechnologiesSoochow University Department of Physics Marmara University Shanghai Synchrotron Radiation Facility(SSRF) Shanghai Advanced Research InstituteChinese Academy of Sciences College of Energy Soochow Institute for Energy and Materials Innovations Soochow University Macao institute of Materials Science and Engineering Macau University of Science and Technology

The interaction between sites A, B and X with passivation molecules is restricted when the conventional passivation strategy is applied in perovskite（ABX3） photovoltaics. Fortunately, the revolving A-site presents an opportunity to strengthen this interaction by utilizing an external field. Herein, we propose a novel approach to achieving an ordered magnetic dipole moment, which is regulated by a magnetic field via the coupling effect between the chiral passivation molecule and the A-site（formamidine ion） in perovskites.This strategy can increase the molecular interaction energy by approximately four times and ensure a well-ordered molecular arrangement. The quality of the deposited perovskite film is significantly optimized with inhibited nonradiative recombination. It manages to reduce the open-circuit voltage loss of photovoltaic devices to 360 mV and increase the power conversion efficiency to 25.22%. This finding provides a new insight into the exploration of A-sites in perovskites and offers a novel route to improving the device performance of perovskite photovoltaics.

关键词： perovskite photovoltaics magnetic moment A-site regulation chiral molecules