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Using restored two-dimensional X-ray images to reconstruct the three-dimensional magnetopause

Earth and Planetary Physics 2024年第1期8卷 133-154页

作者： RongCong Wang JiaQi Wang Dalin li TianRan Sun XiaoDong Peng YiHong Guo National Space Science Center Chinese Academy of SciencesBeijing 100190China University of Chinese Academy of Sciences Beijing100049China Aerospace Information Research Institute Chinese Academy of SciencesBeijing 100094China

Astronomical imaging technologies are basic tools for the exploration of the universe,providing basic data for the research of astronomy and space *** Soft X-ray Imager(SXI)carried by the Solar wind Magnetosphere Ionosphere link Explorer(SMILE)aims to capture two-dimensional(2-D)images of the Earth’s magnetosheath by using soft X-ray ***,the observed 2-D images are affected by many noise factors,destroying the contained information,which is not conducive to the subsequent reconstruction of the three-dimensional(3-D)structure of the *** analysis of SXI-simulated observation images shows that such damage cannot be evaluated with traditional restoration *** makes it difficult to establish the mapping relationship between SXIsimulated observation images and target images by using mathematical *** propose an image restoration algorithm for SXIsimulated observation images that can recover large-scale structure information on the *** idea is to train a patch estimator by selecting noise–clean patch pairs with the same distribution through the Classification–Expectation Maximization algorithm to achieve the restoration estimation of the SXI-simulated observation image,whose mapping relationship with the target image is established by the patch *** Classification–Expectation Maximization algorithm is used to select multiple patch clusters with the same distribution and then train different patch estimators so as to improve the accuracy of the *** results showed that our image restoration algorithm is superior to other classical image restoration algorithms in the SXI-simulated observation image restoration task,according to the peak signal-to-noise ratio and structural *** restoration results of SXI-simulated observation images are used in the tangent fitting approach and the computed tomography approach toward magnetospheric reconstruction techniques,significantly improving

关键词： Solar wind Magnetosphere Ionosphere link Explorer(SMILE) soft X-ray imager magnetopause image restoration

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A strategy for strengthening chaotic mixing of dual shaft eccentric mixers by changing non-Newtonian fluids kinetic energy distribution

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Chinese Journal of Chemical Engineering 2024年第5期69卷 122-134页

作者： Songsong Wang Tong Meng Qian Zhang changyuan Tao Yundong Wang Zequan li Zuohua liu School of Chemistry and Chemical Engineering Chongqing UniversityChongqing 400044China State Key Laboratory of Coal Mine Disaster Dynamics and Control Chongqing 400044China department of Chemical Engineering Tsinghua UniversityBeijing 100084China

Efficiently modulating the velocity distribution and flow pattern of non-Newtonian fluids is a critical challenge in the context of dual shaft eccentric mixers for process intensification,posing a significant barrier for the existing ***,this work reports a convenient strategy that changes the kinetic energy to controllably regulate the flow patterns from radial flow to axial *** showed that the desired velocity distribution and flow patterns could be effectively obtained by varying the number and structure of baffles to change kinetic energy,and a more uniform velocity distribution,which could not be reached normally in standard baffle dual shaft mixers,was easily ***,a comparative analysis of velocity and shear rate distributions is employed to elucidate the mechanism behind the generation of flow patterns in various dual-shaft eccentric ***,there is little difference in the power number of the laminar flow at the same Reynolds number,meaning that the baffle type has no effect on the power consumption,while the power number of both unbaffle and U-shaped baffle mixing systems decreases compared with the standard baffle mixing system in the transition ***,at the same rotational condition,the dimensionless mixing time of the U-shaped baffle mixing system is 15.3%and 7.9%shorter than that of the standard baffle and the unbaffle mixing system,respectively,which shows the advantage of the U-shaped baffle in stirring rate.

关键词： Dual shaft “U-shaped”baffle Flow pattern Mixing time Power demand

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Synergistic effect of Zr and Mo on precipitation and high-temperature properties of Al-Si-Cu-Mg alloys

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China Foundry 2024年第1期21卷 71-81页

作者： Chao Gao Bing-rong Zhang Yin-ming li Zhi-ming Wang Xiang-bin Meng Faculty of Mechanical Engineering Qilu University of Technology(Shandong Academy of Sciences)Jinan 250353China Hebei Ounai Machinery Mould Co.Ltd. Xingtai 054500HebeiChina

This study focuses on finding a solution to the sharp decline in mechanical properties of Al-Si-Cu-Mg alloys due to rapid coarsening of traditional intermediate phases at high temperature.A new type of modified al oy,to be used in automobile engines at high temperatures,was prepared by adding Zr and Mo into Al-Si-Cu-Mg *** synergistic effects of Zr and Mo on the microstructure evolution and high-temperature mechanical properties were *** show that the addition of Zr and Mo generates a series of intermetallic phases dispersed in the *** can improve the strength of the alloy by hindering dislocation movement and crack *** addition,some nano-strengthened phases show coherent interfaces with the matrix and improve grain *** addition of Mo greatly improves the heat resistance of the *** extremely low diffusivity of Mo enables it to improve the thermal stability of the intermetallic phases,inhibit precipitation during aging,reduce the size of the precipitates,and improve the heat resistance of the alloy.

关键词： Al-Si-Cu-Mg alloy high-temperature properties Zr-Mo-rich intermetallics nano-strengthening phases

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The Role of Grain Boundaries in Organic-Inorganic Hybrid Perovskite Solar Cells and its Current Enhancement Strategies:A Review

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Energy & Environmental Materials 2024年第4期7卷 175-204页

作者： Jindan Zhang Shicheng Tang Mengqi Zhu Zhenghong li Zhibin Cheng Shengchang Xiang Zhangjing Zhang College of Chemistry and Materials Science Fujian Key Laboratory of Polymer Materials Fujian Normal University

Grain boundaries (GBs) in perovskite polycrystalline films are the most sensitive place for the formation of the defect states and the accumulation of ***,abundant works have been carried out to explore their properti... 详细信息

关键词： additives charge carrier dynamics grain boundaries perovskite solar cells

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Multicolor upconversion reversible modulations in YNbO_(4):Er^(3+)/Tm^(3+)/Yb^(3+) photochromic materials

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Journal of Rare Earths 2024年第2期42卷 270-277,I0002页

作者： Zhen Zhang Peng li Ziyi Xu Zhihao Zhang Qiwei Zhang Haiqin Sun Xihong Hao Inner Mongolia Key Laboratory of Ferroelectric-related New Energy Materials and devices Schoolof Materials and MetallurgyInner Mongolia University of Science and TechnologyBaotou014010China College of Physics and Technology Guangxi Normal UniversityGuilin541004China

Photochromic materials with multicolor upconversion reversible modulations are attractive in optical switching ***,the fabricated YNbO_(4):Er^(3+)/Tm^(3+)/Yb^(3+) materials exhibit excellent photochromism and multicolor upconversion properties from green,red to near infrared(NIR) emissions with increasing Yb *** multiband upconversion modulations are achieved by alternating light(365 and 405 nm) or thermal *** 365 nm irradiation,the luminescence color changes from yellow to red,the luminescent photoswitching contrast reaches up to 86.21%(green),82.12%(red) and 77.38%(NIR) in the Y_(0.83)Er_(0.01)Tm_(0.01)NbO_(4):0.15 Yb ***,the upconversion emission intensity before and after photochromic reaction shows remarkable change in a wide temperature range of 298-718 *** results indicate that the Er^(3+)/Tm^(3+)/Yb^(3+) tri-doped YNbO_(4) materials can be a good candidate in optical switching and data storage applications.

关键词： Photochromic materials Luminescence modulation Multicolor emission Photoswitching contrast Rare earths

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Insight into the spoilage heterogeneity of meat-borne bacteria isolates with high-producing collagenase

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Food Science and Human Wellness 2024年第3期13卷 1402-1409页

作者： Haodong Wang liangting Shao Jinhao Zhang Xinglian Xu Jianjun li Huhu Wang Jiangsu Collaborative Innovation Center of Meat Production and Processing Quality and Safety ControlCollege of Food Science and TechnologyNanjing Agricultural UniversityNanjing 210095China Yantai XiWang Meat Food Co. Ltd.Yantai 264000China

Chilled chicken is inevitably contaminated by microorganisms during slaughtering and processing,resulting in *** parts of chilled chicken,especially wings,feet,and other skin-on products,are abundant in collagen,which may be the primary target for degradation by spoilage *** this work,a total of 17 isolates of spoilage bacteria that could secrete both collagenase and lipase were determined by raw-chicken juice agar(RJA)method,and the results showed that 7 strains of Serratia,Aeromonas,and Pseudomonas could significantly decompose the collagen *** gelatin zymography showed that Serratia liquefaciens(F5)and(G7)had apparent degradation bands around 50 kDa,and Aeromonas veronii(G8)and Aeromonas salmonicida(H8)had a band around.65 and 95 kDa,*** lipase and collagenase activities were detected isolate-by-isolate,with F5 showing the highest collagenase *** spoilage ability on meat in situ,F5 performed strongest in spoilage ability,indicated by the total viable counts,total volatile basic nitrogen content,sensory scores,lipase,and collagenase *** study provides a theoretical basis for spoilage heterogeneity of strains with high-producing collagenase in meat.

关键词： Bacteria Chilled chicken Heterogeneity Collagenase Spoilage

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Robust polarimetric dehazing algorithm based on low-rank approximation and multiple virtual-exposure fusion

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Photonics Research 2024年第8期12卷 1640-1653页

作者： YIFU ZHOU HANYUE WEI JIAN liANG FEIYA MA RUI YANG liYONG REN XUELONG li School of Physics and Information Technology Shaanxi Normal UniversityXi’an 710119China Xi’an Key Laboratory of Optical Information Manipulation and Augmentation(OMA) Xi’an 710119China Robust(Xixian New Area)Opto-Electro Technologies Co. Ltd.Xi’an 712000China Institute of Artificial Intelligence(TeleAI) China Telecom Corp Ltd.Beijing 100033China

Polarimetric dehazing is an effective way to enhance the quality of images captured in foggy ***,images of essential polarization parameters are vulnerable to noise,and the brightness of dehazed images is usually unstable due to different environmental *** two weaknesses reveal that current polarimetric dehazing algorithms are not robust enough to deal with different *** paper proposes a novel,to our knowledge,and robust polarimetric dehazing algorithm to enhance the quality of hazy images,where a low-rank approximation method is used to obtain low-noise polarization parameter ***,in order to improve the brightness stability of the dehazed image and thus keep the image have more details within the standard dynamic range,this study proposes a multiple virtual-exposure fusion(MVEF)scheme to process the dehazed image(usually having a high dynamic range)obtained through polarimetric *** experiments show that the proposed dehazing algorithm is robust and effective,which can significantly improve overall quality of hazy images captured under different environments.

关键词： algorithm approximation image

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Tiered clustering-based management architecture in mega-satellite networks

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Science China(Information Sciences) 2024年第5期67卷 215-227页

作者： Qi HAO Di ZHOU Min SHENG Yan SHI Jiandong li State Key Laboratory of Integrated Service Networks Xidian University

Hybrid orbital networking and the proliferation of satellites raise explosive management complexity in mega-satellite networks(MSNs) and prompt the management architecture to the hierarchy. In this regard, we propose a tiered clustering-based management architecture(TCMA) to realize the high-efficient and low-cost management performance. Specifically, based on the constrained satellite coverage, we derive an expression of the mapping relationship between the required control overhead of the controller interaction,the average path length of the proposed TCMA, and the corresponding number of management tiers and cluster size. The expression can determine the optimal number of tiers of the TCMA by minimizing the required flow table size between controllers, while ensuring high transmission efficiency. We then exhibit the elasticity of the hierarchical TCMA by adding the peer connections at the second-highest management tier to reduce maximum redundant paths. Simulation results verify the effectiveness of the proposed TCMA and illustrate that a 3-tier TCMA is sufficient for thousands of satellites.

关键词： mega-satellite networks hierarchical architecture average hop tiered structure clustering

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Distribution and bioavailability of mercury in size-fractioned atmospheric particles around an ultra-low emission power plant in Southwest China

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Journal of Environmental Sciences 2024年第4期138卷 141-152页

作者： Wei Zhang Jinjuan li Hao Qiu Xingqiang Guo Zhijun Fei Yi Xing deliang Yin College of Resources and Environmental Engineering Guizhou UniversityGuiyang 550025China College of Resources and Environmental Engineering Guizhou Institute of TechnologyGuiyang 550003China Key Laboratory of Karst Georesources and Environment(Guizhou University) Ministry of EducationGuiyang 550025China School of Energy and Environmental Engineering University of Science&Technology BeijingBeijing 100083China

Ultra-low emission(ULE)technology retrofits significantly impact the particulate-bound mercury(Hg)emissions from coal-fired power plants(CFPPs);however,the distribution and bioavailability of Hg in size-fractioned particulate matter(PM)around the ULE-retrofitted CF-PPs are less ***,total Hg and its chemical speciation in TSP(total suspended particles),PM_(10)(aerodynamic particle diameter≤10μm)and PM_(2.5)(aerodynamic particle diameter≤2.5μm)around a ULE-retrofitted CFPP in Guizhou Province were *** PM_(2.5)concentration was higher around this ULE-retrofitted CFPP than that in the intra-regional urban cities,and it had higher mass Hg concentration than other sizefractioned *** Hg concentrations in PM had multifarious sources including CFPP,vehicle exhaust and biomass combustion,while they were significantly higher in autumn and winter than those in other seasons(P40%).Mass concentrations of exchangeable,HCl-soluble,elemental,and residual Hg in PM_(2.5)were higher than those in other size-fractioned PM,and were markedly elevated in autumn and winter(P<0.05).In PM_(2.5),HCl-soluble Hg presented a significantly positive relationship with elemental Hg(P<0.05),while residual Hg showed the significantly positive relationships with HCl-soluble Hg and elemental Hg(P<0.01).Overall,these results suggested that atmospheric PM-bound Hg around the ULE-retrofitted CFPP tends to accumulate in finer PM,and has higher bioavailable fractions,while has potential transformation between chemical speciation.

关键词： Size-fractioned particles Mercury Chemical speciation Coal-fired power plant Ultra-low emission

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Assessing target optical camouflage effects using brain functional networks:A feasibility study

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defence Technology（防务技术） 2024年第4期34卷 69-77页

作者： Zhou Yu li Xue Weidong Xu Jun liu Qi Jia Jianghua Hu Jidong Wu National Key Laboratory of lightning Protection and Electromagnetic Camouflage Army Engineering University Nanjing 210007JiangsuChina Unit 31608 of PLA Xiamen 361000FujianChina School of Biological Sciences&Medical Engineering Southeast UniversityNanjing 210096JiangsuChina

Brain functional networks model the brain's ability to exchange information across different regions,aiding in the understanding of the cognitive process of human visual attention during target searching,thereby contributing to the advancement of camouflage *** this study,images with various camouflage effects were presented to observers to generate electroencephalography(EEG)signals,which were then used to construct a brain functional *** topological parameters of the network were subsequently extracted and input into a machine learning model for *** results indicate that most of the classifiers achieved accuracy rates exceeding 70%.Specifically,the Logistic algorithm achieved an accuracy of 81.67%.Therefore,it is possible to predict target camouflage effectiveness with high accuracy without the need to calculate discovery *** proposed method fully considers the aspects of human visual and cognitive processes,overcomes the subjectivity of human interpretation,and achieves stable and reliable accuracy.

关键词： Camouflage effect evaluation Electroencephalography(EEG) Brain functional networks Machine learning

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