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Resolution Enhancement of SOHO/MDI Magnetograms

Research in Astronomy and Astrophysics 2024年第6期24卷 358-367页

作者： Ying Qin Kai-fan Ji Hui Liu xiao-Guang Yu Yunnan Observatories Chinese Academy of SciencesKunming 650011China University of Chinese Academy of Sciences Beijing 100049China Yunnan Key Laboratory of Solar Physics and Space Science Kunming 650216China Key Laboratory for the Structure and Evolution of Celestial Objects Chinese Academy of SciencesKunming 650216China

Research on the solar magnetic field and its effects on solar dynamo mechanisms and space weather events has benefited from the continual improvements in instrument resolution and measurement *** augmentation and assimilation of historical observational data timelines also play a significant role in understanding the patterns of solar magnetic field *** the realm of astronomical data processing,super-resolution(SR)reconstruction refers to the process of using a substantial corpus of training data to learn the nonlinear mapping between low-resolution(LR)and high-resolution(HR)images,thereby achieving higherresolution astronomical *** paper is an application study in high-dimensional nonlinear *** learning models were employed to perform SR modeling on SOHO/MDI magnetograms and SDO/HMI magnetograms,thus reliably achieving resolution enhancement of full-disk SOHO/MDI magnetograms and enhancing the image resolution to obtain more detailed *** this study,a data set comprising 9717pairs of data from 2010 April to 2011 February was used as the training set,1332 pairs from 2011 March were used as the validation set and 1034 pairs from 2011 April were used as the test *** data preprocessing,we randomly cropped 128×128 sub-images as the LR cases from the full-disk MDI magnetograms,and the corresponding 512×512 sub-images as HR ones from the HMI full-disk magnetograms for model *** tests conducted have shown that the study successfully produced reliable 4×SR reconstruction of full-disk MDI *** MESR model's results(0.911)were highly correlated with the target HMI magnetographs as indicated by the correlation coefficient ***,the method achieved the best PSNR,SSIM,MAE and RMSE values,indicating that the MESR model can effectively reconstruct magnetograms.

关键词： magnetic fields techniques:image processing virtual observatory tools Sun:magnetic fields

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Nonexistence of quantum black and white hole horizons in an improved dynamic approach

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Science China(Physics,Mechanics & Astronomy) 2024年第8期67卷 56-73页

作者： Wen-cong Gan xiao-Mei Kuang Zhen-Hao Yang Yungui Gong Anzhong Wang Bin Wang College of Physics and Communication Electronics Jiangxi Normal UniversityNanchang 330022China GCAP-CASPER Physics DepartmentBaylor UniversityWaco 76798-7316USA Institute for Theoretical Physics&Cosmology Zhejiang University of TechnologyHangzhou 310023China United Center for Gravitational Wave Physics(UCGWP) Zhejiang University of TechnologyHangzhou 310023China Center for Gravitation and Cosmology College of Physical Science and TechnologyYangzhou UniversityYangzhou 225009China Department of Physics School of Physical Science and TechnologyNingbo UniversityNingbo 315211China School of Aeronautics and Astronautics Shanghai Jiao Tong UniversityShanghai 200240China

In this paper,we study the quantum geometric effects near the locations where classical black hole horizons used to appear in Einstein's classical theory,within the framework of an improved dynamic approach,in which the internal region of a black hole is modeled by the Kantowski-Sachs(KS)spacetime and the two polymerization parameters are functions of the phase space *** detailed analysis shows that the effects are so strong that black and white hole horizons of the effective quantum theory do not exist at all and instead are replaced by transition surfaces,across which the metric coefficients and their inverses are smooth and remain finite,as are the corresponding curvatures,including the Kretschmann *** surfaces always separate trapped regions from anti-trapped *** number of such surfaces is infinite,so the corresponding KS spacetimes become geodesically complete,and no black and white hole-like structures exist in this scheme.

关键词： canonical quantization loop quantum gravity quantum aspects of black holes

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Optimization of Generator Based on Gaussian Process Regression Model with Conditional Likelihood Lower Bound Search

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CES Transactions on Electrical Machines and Systems 2024年第1期8卷 32-42页

作者： xiao Liu Pingting Lin fan Bu Shaoling Zhuang Shoudao Huang CES&IEEE the College of Electrical and Information Engineering Hunan UniversityChangsha 410082China CES

The noise that comes from finite element simulation often causes the model to fall into the local optimal solution and over fitting during optimization of ***,this paper proposes a Gaussian Process Regression(GPR)model based on Conditional Likelihood Lower Bound Search(CLLBS)to optimize the design of the generator,which can filter the noise in the data and search for global optimization by combining the Conditional Likelihood Lower Bound Search *** the efficiency optimization of 15 kW Permanent Magnet Synchronous Motor as an ***,this method uses the elementary effect analysis to choose the sensitive variables,combining the evolutionary algorithm to design the super Latin cube sampling plan;Then the generator-converter system is simulated by establishing a co-simulation platform to obtain data.A Gaussian process regression model combing the method of the conditional likelihood lower bound search is established,which combined the chi-square test to optimize the accuracy of the model ***,after the model reaches the accuracy,the Pareto frontier is obtained through the NSGA-II algorithm by considering the maximum output torque as a ***,the constrained optimization is transformed into an unconstrained optimizing problem by introducing maximum constrained improvement expectation(CEI)optimization method based on the re-interpolation model,which cross-validated the optimization results of the Gaussian process regression *** above method increase the efficiency of generator by 0.76%and 0.5%respectively;And this method can be used for rapid modeling and multi-objective optimization of generator systems.

关键词： Generator optimization Gaussian Process Regression(GPR) Conditional Likelihood Lower Bound Search(CLLBS) Constraint improvement expectation(CEI) Finite element calculation

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Fast spreading of surface ozone in both temporal and spatial scale in Pearl River Delta

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Journal of Environmental Sciences 2024年第3期137卷 540-552页

作者： Tianhui Cao Haichao Wang Lei Li xiao Lu Yiming Liu Shaojia fan School of Atmospheric Sciences Sun Yat-sen University and Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai)Zhuhai 519082China Guangdong Provincial Observation and Research Station for Climate Environment and Air Quality Change in the Pearl River Estuary Key Laboratory of Tropical Atmosphere-Ocean SystemMinistry of EducationZhuhai 519082China

Surface ozone(O_(3))is a major air pollutant and draw increasing attention in the Pearl River Delta(PRD),***,we characterize the spatial-temporal variability of ozone based on a dataset obtained from 57 national monitoring sites during *** results show that:(1)the seasonal difference of ozone distribution in the inland and coastal areas was significant,which was largely affected by the wind pattern reversals related to the East Asian monsoon,and local ozone production and destruction;(2)the daily maximum 8hr average(MDA8 O_(3))showed an overall upward trend by 1.11 ppbv/*** the trends in the nine cities varied differently by ranging from-0.12 to 2.51 ppbv/*** hot spots of ozone were spreading to southwestern areas from the central areas since *** ozone is becoming a year-round air pollution problem with the pollution season extending to winter and spring in PRD region.(3)at the central and southwestern PRD cities,the percentage of exceedance days from the continuous type(defined as≥3 days)was ***,the ozone concentration of continuous type was much higher than that of scattered exceedance type(<3 days).In addition,although the occurrence of continuous type starts to decline since2017,the total number of exceedance days during the continuous type is *** results indicate that it is more difficult to eliminate the continuous exceedance than the scatter pollution days and highlight the great challenge in mitigation of O_(3)pollution in these cities.

关键词： Surface ozone pollution Ozone trend Spatial and temporal variability Pearl River Delta Pollution mitigation

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Unique method for removal of knotted lumbar epidural catheter: A case report

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World Journal of Clinical Cases 2024年第10期12卷 1824-1829页

作者： Nian-Hua Deng xiao-cong Chen Shou-Bo Quan Anesthesia and Surgery Center Dongguan Songshan Lake Central HospitalDongguan 523326Guangdong ProvinceChina

BACKGROUND Combined spinal-epidural(CSE)anesthesia is the preferred anesthesia method for cesarean *** use of an epidural catheter is essential for administering additional drugs intraoperatively and managing postoperative ***,the insertion of epidural catheters is associated with various complications,such as total spinal anesthesia,symptoms indicative of spinal nerve root irritation,and challenges in epidural catheter *** SUMMARY We present a case report of a challenging epidural catheter removal due to *** lumbar computed tomography scan results revealed that the catheter formed a tight knot in the epidural *** used a novel extubation method and successfully removed the *** The operator can use opposite forces to"spiral"apart the spinal joints by positioning the patient's body in a specific *** findings indicate that,when combined with imaging examination results,this method is effective for the removal of epidural catheters.

关键词： Epidural catheter Knotting Challenging extubation Case report

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Investigation of mechanical failure performance of a large-diameter shield tunnel segmental ring

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Journal of Zhejiang University-Science A(Applied Physics & Engineering) 2024年第5期25卷 411-428页

作者： Binyong GAO Renpeng CHEN Huaina WU Chengcheng ZHANG Meng fan Chao xiao Research Center of Underground Space Advanced Technology Hunan UniversityChangsha 410082China Key Laboratory of Building Safety and Energy Efficiency of the Ministry of Education Hunan UniversityChangsha 410082China Department of Civil Engineering Hunan UniversityChangsha 410082China China Construction No.5 Civil Engineering Co. Ltd.Changsha 410004China

The control criteria for structural deformation and the evaluation of operational safety performance for large-diameter shield tunnel segments are not yet clearly *** address this issue,a refined 3D finite element model was established to analyze the transverse deformation response of a large-diameter segmental *** analyzing the stress,deformation,and crack distribution of large-diameter segments under overload conditions,the transverse deformation of the segmental ring could be divided into four *** main reasons for the decrease in segmental ring stiffness were found to be the extensive development of cracks and the complete formation of four plastic *** deformation control value for the large-diameter shield tunnel segment is chosen as 8%o of the segment's outer diameter,representing the transverse deformation during the formation of the first semi-plastic hinge(i.e.,the first yield point)in the *** control value can serve as a reinforcement standard for preventing the failure of large-diameter shield tunnel *** flexural bearing capacity characteristic curve of segments was used to evaluate the structural strength of a large-diameter segmental *** was discovered that the maximum internal force combination of the segment did not exceed the segment ultimate bearing capacity curve(SUBC).However,the combination of internal force at 9°,85°,and 161°of the joints,and their symmetrical locations about the 0°-180°axis exceeded the joint ultimate bearing capacity curve(JUBC).The results indicate that the failure of the large-diameter segment lining was mainly due to insufficient joint strength,leading to an instability *** findings from this study can be used to develop more effective maintenance strategies for large-diameter shield tunnel segments to ensure their long-term performance.

关键词： Finite element model Transverse deformation response Upper overload Plastic hinges Flexural bearing capacity

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Injection of a Self-propelled Polymer into a Small Circular Cavity

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Chinese Journal of Polymer Science 2024年第6期42卷 886-894页

作者： Chao Wang Yan-Li Zhou xiao Yang fan Wu Meng-Bo Luo Department of Physics Taizhou UniversityTaizhou318000China Department of Physics Zhejiang UniversityHangzhou310027China

The injection of a polymer chain into a small circular cavity under tangential self-propelled force is studied by using Langevin dynamics *** indicate that the injection dynamics of the active polymer shows strong correlation with the polymer conformation inside the cavity depending on the polymer rigidity(k_(b)).The injection timeτvaries nonmonotonously with increasing k_(b),and reaches its minimum at k_(b)^(*).When k_(b) is small(k_(b)≪k_(b)^(*)),the polymer is nearly random coil in the cavity,and spends a long time at the final stage of the injection process due to the large repulsion between monomers inside the *** k_(b) is moderate(k_(b)∼k_(b)^(*)),the part of polymer inside the cavity forms spiral configuration under the tangential active force,and the whole polymer moves synchronously with a constant velocity during the injection process,leading to a small injection *** k_(b) is large(k_(b)≫k_(b)^(*)),the polymer is nearly straight at the initial stage of the injection process,and takes a long time to bend itself,leading to a large injection time.

关键词： Active Polymer Injection Dynamics Simulation

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Influence of oxygen-rich hot air composite gas medium on sintering performance and function mechanism

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Journal of Iron and Steel Research International 2024年第5期31卷 1071-1081页

作者： Min Gan Hao-xiang Zheng xiao-hui fan Zhi-yun Ji Qiang Li Ming Wu Yi-fan Wang xiao-long Wang Yu-feng Wu Xu-ling Chen Zeng-qing Sun xiao-xian Huang School of Minerals Processing and Bioengineering Central South UniversityChangsha410083HunanChina Shanxi Taigang Stainless Steel Co. Ltd.Taiyuan030003ShanxiChina

Hot air sintering technology is used to improve the quality and production efficiency of sintered ***,the current thick layer condition highlights the disadvantage of the low oxygen potential of the hot air sintering ***,it is considered to use oxygen enrichment sintering to improve the environment of hot air *** sintering,hot air sintering,and oxygen-rich hot air sintering were compared through sintering cup experiments,and the influence of hot air and oxygen-rich hot air on sintering indexes was *** air reduced the vertical sintering velocity,while improved the yield and tumbler ***-rich hot air sintering contributed to improving the vertical sintering velocity while ensuring the quality of sintered ore,thus comprehensively improving production *** the action of hot air,the highest temperature of the sintering layer increased and the high-temperature holding time was *** oxygen enrichment,the combustion efficiency of fuels in the upper layer of materials was promoted,which optimized heat distribution in the middle and lower layers of materials and increased the content of calcium ferrite in the sintered ore,thus strengthening the sintering process.

关键词： Iron ore sintering Hot air sintering Oxygen enrichment Function mechanism

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CPL-active hybrid copper(Ⅰ)halides enabled by cation inclusion with chiral crown-ether

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Science China Chemistry 2024年第10期67卷 3283-3290页

作者： Peng fan Li-Xuan Cai xiao-fang Duan fan Yin Chen-Chen Li Zhong-Hua Deng xiao-Zhen Li Qing-Fu Sun College of Chemistry and Materials Science Fujian Normal UniversityFuzhou 350117China Strait Institute of Flexible Electronics(Future Technologies) Fujian Key Laboratory of Flexible ElectronicsFujian Normal University and Strait Laboratory of Flexible ElectronicsFuzhou 350117China State Key Laboratory of Structural Chemistry Fujian Institute of Research on the Structure of MatterChinese Academy of SciencesFuzhou 350002China Fujian College University of Chinese Academy of SciencesFuzhou 350002China

Chiral hybrid metal halides with high photoluminescence quantum yield(PLQY)and superior dissymmetry factor(g_(lum))are promising candidates for circularly polarized luminescence(CPL)emitting ***,it is a great challenge to achieve both high g_(lum)and large ***,we report a new supramolecular strategy to fabricate chiral hybrid Cu(Ⅰ)-halides with nearunity quantum yields and intense CPL *** dissymmetry factor can be dramatically modulated by tuning the hostguest *** to the chirality and variable conformations of the host-guest complexes,a series of chiral[G@L^(R/S)]_(2)Cu_(4)I_(6)have been *** incorporation of different cations within the chiral L^(R/S)hosts leads to variations of packing modes along the c-axis and different extent of distortions in the[Cu_(4)I_(6)]_(2)-*** them,[H_(3)O@L^(R/S)]+cations are stacked based on Van der Waals interactions and hierarchically self-assemble into a right/left-handed helix in[H_(3)O@L^(R/S)]_(2)Cu_(4)I_(6),which results in a high g_(lum)of-7×10^(-3)and a large PLQY of 96.92%.Notably,[G@L^(R/S)]_(2)Cu_(4)I_(6)shows promising applications in single-component white light emitting diodes(WLEDs),exhibiting a maximum dissymmetry factor of-1.2×10^(-3).The effective host-guest complexation and oriented hierarchical self-assembly provide an effective strategy for the development of high-performance CPL materials.

关键词： host-guest interaction circularly polarized luminescence copper iodide cluster hierarchical self-assembly chirality

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The historical to future linkage of Arctic amplification on extreme precipitation over the Northern Hemisphere using CMIP5 and CMIP6 models

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Advances in Climate Change Research 2024年第4期15卷 573-583页

作者： Jun LIU xiao-fan WANG Dong-You WU Xin WANG Key Laboratory for Semi-Arid Climate Change of the Ministry of Education College of Atmospheric SciencesLanzhou UniversityLanzhou 730000China

Arctic warming played a dominant role in recent occurrences of extreme events over the Northern Hemisphere,but climate models cannot accurately simulate the *** a significant positive correlation(0.33-0.95)between extreme precipitation and Arctic amplification(AA)is found using observations and CMIP5/6 multi-model ***,CMIP6 models are superior to CMIP5 models in simulating the temporal evolution of extreme precipitation and *** to 14 optimal CMIP6 models,the maximum latitude of planetary waves and the strength of Northern Hemisphere annular mode(NAM)will increase with increasing AA,contributing to increased extreme precipitation over the Northern *** the Shared Socioeconomic Pathway SSP5-8.5,AA is expected to increase by 0.85℃ per decade while the maximum latitude of planetary waves will increase by 2.82°per ***,the amplitude of the NAM will increase by 0.21 hPa per decade,contributing to a rise in extreme precipitation of 1.17% per decade for R95pTOT and 0.86% per decade for R99pTOT by 2100.

关键词： Arctic amplification Extreme precipitation CMIP5 CMIP6 Model evaluation Planetary waves Northern hemisphere annular mode

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