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Coupled conditional nonlinear optimal perturbations and their application to ENSO ensemble forecasts

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Science China Earth Sciences 2024年第3期67卷 826-842页

作者： Wansuo duan Lei HU rong FENG LASG Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China University of Chinese Academy of Sciences Beijing 100049China

Limitations are existed in current ensemble forecasting initial perturbation methods for describing the interactions among various spheres of the Earth system. In this study, a new method is proposed, namely, the coupled conditional nonlinear optimal perturbation(C-CNOP) method, which incorporates multisphere interactions much appropriately. The El Nino-Southern Oscillation(ENSO) is a typical ocean-atmosphere “coupling”(or “interaction”) phenomenon. The C-CNOP method is applied to ensemble forecasting of ENSO. It is demonstrated that the C-CNOP method can generate coupled initial perturbations(CPs) that appropriately consider initial ocean-atmosphere coupling uncertainty for ENSO ensemble forecasts. Results reveal that the CPs effectively improve the ability of ENSO ensemble-mean forecasts in both temporal variability of Nio3.4 sea surface temperature anomalies(SSTAs) and spatial variability of ENSO mature-phase SSTAs. Notably, despite the weakest ocean-atmosphere coupling strength in the tropical Pacific occurring during the boreal spring and summer, CPs still capture the uncertainties of this weak coupling when ENSO predictions are initialized at these seasons. This performance of CPs significantly suppresses the rapid increase of ENSO prediction errors due to the high ocean-atmosphere coupling instability during these seasons, and thus effectively extends the lead time of skillful ENSO forecasting. Hence, the C-CNOP method is a suitable initial perturbation approach for ENSO ensemble forecast that can describe initial ocean-atmosphere coupling uncertainty. It is expected that the CCNOP method plays a significant role in predictions of other high-impact climate phenomena, and even future Earth system predictions.

关键词： Ensemble forecast Multisphere interaction Initial perturbations ENSO

GNN-based temporal knowledge reasoning for UAV mission planning systems

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The Journal of China Universities of Posts and Telecommunications 2024年第1期31卷 12-25页

作者： Chai rong duan Xiaofang Wang Lixuan School of Communications and Information Engineering Chongqing University of Posts and TelecommunicationsChongqing 400065China

Unmanned aerial vehicles(UAVs)are increasingly applied in various mission scenarios for their versatility,scalability and *** UAV mission planning systems(UMPSs),an efficient mission planning strategy is essential to meet the requirements of UAV ***,rapidly changing environments and unforeseen threats pose challenges to UMPSs,making efficient mission planning *** address these challenges,knowledge graph technology can be utilized to manage the complex relations and constraints among UAVs,missions,and *** paper investigates knowledge graph application in UMPSs,exploring its modeling,representation,and storage concepts and ***,the construction of a specialized knowledge graph for UMPS is ***,the paper delves into knowledge reasoning within UMPSs,emphasizing its significance in timely updates in the dynamic environment.A graph neural network(GNN)-based approach is proposed for knowledge reasoning,leveraging GNNs to capture structural information and accurately predict missing entities or relations in the knowledge *** relation reasoning,path information is also incorporated to improve the accuracy of *** account for the temporal dynamics of the environment in UMPS,the influence of timestamps is captured through the attention *** effectiveness and applicability of the proposed knowledge reasoning method are verified via simulations.

关键词： unmanned aerial vehicle mission planning knowledge graph knowledge reasoning graph neural network

The Negative Thermal Expansion Property of NdMnO_(3) Based on Pores Effect and Phase Transition

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Journal of Wuhan University of Technology(Materials Science) 2024年第1期39卷 39-43页

作者：李玉成张扬 ZHANG Muqun duan rong LIU Xiteng Department of Avionics Engineering Aviation Maintenance NCO Academy of Air Force Engineering UniversityXinyang 464000China

A novel negative thermal expansion(NTE) material NdMnO_(3) was synthesized by solid-state method at 1 523 K. The crystal structure, phase transition, pores effect and negative expansion properties of NdMnO_(3) were investigated by variable temperature X-ray diffraction(XRD), scanning electron microscope(SEM) and variable temperature Raman spectra. The compound exhibits NTE properties in the orderly O' phase crystal structure. When the temperature is from 293 to 759 K, the ceramic NdMnO_(3) shows negative thermal expansion of-4.7×10^(-6)/K. As temperature increases, the ceramic NdMnO_(3) presents NTE property range from 759 to 1 007 K. The average linear expansion coefficient is-18.88×10^(-6)/K. The physical mechanism of NTE is discussed and clarified through experiments.

关键词： negative thermal expansion NdMnO_(3) pores effect phase transition

Prediction of solar activities:Sunspot numbers and solar magnetic synoptic maps

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Science China Earth Sciences 2024年第8期67卷 2460-2477页

作者： Rui ZHUO Jiansen HE Die duan rong LIN Ziqi WU Limei YAN Yong WEI School of Earth and Space Sciences Peking UniversityBeijing 100091China College of Advanced Interdisciplinary Studies National University of Defense TechnologyChangsha 410073China Centre for Mathematical Plasma Astrophysics Department of MathematicsKU LeuvenLeuven 3001Belgium Key Laboratory of Earth and Planetary Physics Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China

The evolution of solar magnetic fields is significant for understanding and predicting solar *** our knowledge of solar magnetic fields largely depends on the photospheric magnetic *** this paper,based on the spherical harmonic expansion of the photospheric magnetic field observed by Wilcox Solar Observatory,we analyze the time series of spherical harmonic coefficients and predict Sunspot Number as well as synoptic maps for Solar Cycle *** find that solar maximum years have complex short-period disturbances,and the time series of coefficient g_(7)~0 is nearly in-phase with Sunspot Number,which may be related to solar meridional *** Long Short-Term Memory networks(LSTM),our prediction suggests that the maximum of Solar Cycle 25 is likely to occur in June 2024 with an error of 8 months,the peak sunspot number may be 166.9±22.6,and the next solar minimum may occur around January *** incorporating Empirical Mode Decomposition,we enhance our forecast of synoptic maps truncated to Order 5,validating their relative *** prediction not only addresses a gap in forecasting the global distribution of the solar magnetic field but also holds potential reference value for forthcoming solar observation plans.

关键词： Solar activity prediction Solar magnetic field Spherical harmonic expansion Long-Short Term Memory(LSTM) Empirical Mode Decomposition(EMD)

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Efficacy of Raw Corn Starch in Insulinoma-Related Hypoglycemia:A Promising Supportive Therapy

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Chinese Medical Sciences Journal 2024年第2期39卷 102-110页

作者： rong-rong Li Wei Chen Xin-Hua Xiao Miao Yu Fan Ping Lian duan Department of Clinical Nutrition Beijing Key Laboratory of the Innovative Development of Functional Staple and the Nutritional Intervention for Chronic DiseaseChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100730China Department of Endocrinology Peking Union Medical College HospitalChinese Academy of Medical Sciences&Peking Union Medical CollegeBeijing 100730China

Objective To investigate the efficacy of raw corn starch(RCS)in clinical management of insulinoma-induced *** We retrospectively collected clinical data of insulinoma patients who received RCS-supplemented diet preoperatively,and analyzed the therapeutic effects of the RCS intervention on blood glucose control,weight change,and its adverse *** The study population consisted of 24 cases of insulinoma patients,7 males and 17 females,aged 46.08±14.15 *** RCS-supplemented diet,all patients had frequent hypoglycemic episodes(2.51±3.88 times/week),concurrent with neuroglycopenia(in 83.3% of patients)and autonomic manifestations(in 75.0% of patients),with the median fasting blood glucose(FBG)of 2.70(interquartile range[IQR]:2.50-2.90)mmol/*** patients'weight increased by 0.38(IQR:0.05-0.65)kg per month,with 8(33.3%)cases developing overweight and 7(29.2%)cases developing *** patients maintained the RCS-supplemented diet until they underwent tumor resection(23 cases)and transarterial chemoembolization for liver metastases(1 case).For 19 patients receiving RCS throughout the day,the median FBG within one week of nutritional management was 4.30(IQR:3.30-5.70)mmol/L,which was a significant increase compared to pre-nutritional level[2.25(IQR:1.60-2.90)mmol/L;P<0.001].Of them,10 patients receiving RCS throughout the day for over four weeks had sustained improvement in FBG compared to pre-treatment[3.20(IQR:2.60-3.95)mmol/L vs.2.15(IQR:1.83-2.33)mmol/L;P<0.001].Five patients who received RCS only at night also had a significant increase in FBG within one week of nutritional management[3.50(IQR:2.50-3.65)mmol/L vs.2.20(IQR:1.80-2.60)mmol/L;P<0.001],but only one patient who continued to receive RCS for over four weeks did not have a significant improvement in *** improvement in weight gain was observed upon RCS *** diarrhea(2 cases)and flatulence(1 case)occurred,and were relieved by reduction of RCS ***

关键词： corn starch hypoglycemia insulinoma nutrition therapy

Species’ geographical range, environmental range and traits lead to specimen collection preference of dominant plant species of grasslands in Northern China

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Plant Diversity 2024年第3期46卷 353-361页

作者： Jingya Zhang Cui Xiao Xiaoyu duan Xin Gao Hao Zeng rong'an Dong Gang Feng Keping Ma Ministry of Education Key Laboratory of Ecology and Resource Use of the Mongolian Plateau&Inner Mongolia Key Laboratory of Grassland Ecology School of Ecology and EnvironmentInner Mongolia UniversityHohhot 010021China State Key Laboratory of Vegetation and Environmental Change Institute of BotanyChinese Academy of SciencesBeijing 100093China

Many different factors,such as species traits,socio-economic factors,geographical and environmental factors,can lead to specimen collection *** study aims to determine whether grassland specimen collection in China is preferred by species traits(i.e.,plant height,flowering and fruiting period),environmental range(i.e.,the temperature and precipitation range)and geographical range(i.e.,distribution range and altitudinal range).Ordinary least squares models and phylogenetic generalized linear mixed models were used to analyze the relationships between specimen number and the explanatory *** Forest models were then used to find the most parsimonious multivariate *** results showed that interannual variation in specimen number between 1900 and 2020 was *** number of these species in southeast China was notably lower than that in northwest *** range and geographical range of species had significant positive correlations with specimen *** addition,there were relatively weak but significant associations between specimen number and species trait(i.e.,plant height and flowering and fruiting period).Random Forest models indicated that distribution range was the most important variable,followed by flowering and fruiting period,and altitudinal *** findings suggest that future floristic surveys should pay more attention to species with small geographical range,narrow environmental range,short plant height,and short flowering and fruiting *** correction of specimen collection preference will also make the results of species distribution model,species evolution and other works based on specimen data more accurate.

关键词： Biological specimen Collection preference Dominant plant species Environmental range Geographical range Species traits

Structural Properties of Ions and Polyelectrolytes in Aqueous Solutions under External Electric Fields:The Sign Effect

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Chinese Journal of Polymer Science 2024年第9期42卷 1341-1352,I0007页

作者： Cheng-Jiang Lin Jun-Jun Wang Yuan Jiang Shu-Li Chen Hong-Fei Li Wen-Han Zhao Qing-rong Huang Chang-Ru rong Xiao-Zheng duan State Key Laboratory of Polymer Physics and Chemistry Changchun Institute of Applied ChemistryChinese Academy of SciencesChangchun130022China School of Applied Chemistry and Engineering University of Science and Technology of ChinaHefei230026China National Key Laboratory of Advanced Vehicle Integration and Control China FAW Group Co.Ltd.Changchun130013China State Key Laboratory of Molecular Engineering of Polymers Department of Macromolecular ScienceFudan UniversityShanghai200438China Department of Food Science Rutgers University65 Dudley RoadNew BrunswickNew Jersey08901USA

We utilize molecular dynamics simulations to investigate the microstructures of ions and polyelectrolytes in aqueous solutions under external electric *** focusing on the multi-body interactions between ionic components and H_(2)O molecules,as well as their responses to the external electric fields,we clarify several nontrivial molecular features of the ionic and polyelectrolyte solutions,such as the solvations of cations and anions,clustering of the ions,and dispersions/aggregations of polyelectrolyte chains,as well as the corresponding responses of H_(2)O molecules in these *** simulations illustrate the variations in structures of ionic solutions caused by reversing the charge sign of the ions,and elucidate the disparity in structures between anionic and cationic polyelectrolyte solutions in the presence of the external electric *** work clarifies the mechanism for the alternations in complex multi-body interactions in aqueous solutions caused by the application electric field,which can contribute to the fundamental understanding of the physical and chemical natures of ion-containing and charged polymeric systems.

关键词： Polyelectrolyte Ions Aqueous solutions External electric fields Asymmetric dipole

Development of lithium-free P2-type high-sodium content cathode materials with enhanced cycle and air stability for sodium-ion batteries

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Rare Metals 2024年第1期43卷 113-123页

作者： Jin-Lv Tian Lin-rong Wu Hai-Jun Zhao Shou-Dong Xu Liang Chen Ding Zhang Xiao-Chuan duan College of Chemical Engineering and Technology Taiyuan University of TechnologyTaiyuan 030024China College of Chemistry Taiyuan University of TechnologyTaiyuan 030024China School of Chemical Engineering and Pharmacy Wuhan Institute of TechnologyWuhan 430205China

The effect of partial substitution of Mg for Ni on a high-sodium and lithium-free layered P2-type Na_(45/54)Mg_(6)/_(54)Ni_(12/54)Mn_(34/54)O_(2) cathode with high initial Coulombic efficiency and excellent cyclic stability has been investigated in this *** on the crystal structural analysis,the Mg doping can retain the P2 structure up to 4.3 V,thus restraining the detrimental phase transformation of P2-02during the Na-ion intercalation/deintercalation ***,the obtained Mg-doped P2-type cathode exhibits a reversible specific capacity of 109 mAh·g^(-1) at 0.1C between 2.0 and 4.3 V and a retention rate of 81.5% after 200cycles at *** addition,the full cell consisting of Mg-doped P2-type cathode and hard carbon anode shows a capacity retention rate of 85.6% after 100 *** study provides new insight into the development of durable cathode materials for sodium-ion batteries.

关键词： Sodium-ion batteries Cathode material High sodium content Air stability

DCFNet:An Effective Dual-Branch Cross-Attention Fusion Network for Medical Image Segmentation

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Computer Modeling in Engineering & Sciences 2024年第7期140卷 1103-1128页

作者： Chengzhang Zhu Renmao Zhang Yalong Xiao Beiji Zou Xian Chai Zhangzheng Yang rong Hu Xuanchu duan School of Computer Science and Engineering Central South UniversityChangsha410083China School of Humanities Central South UniversityChangsha410083China Xiangya Hospital Central South University Changsha410008China Changsha Aier Eye Hospital Changsha410015China

Automatic segmentation of medical images provides a reliable scientific basis for disease diagnosis and ***,most existing methods that combine the strengths of convolutional neural networks(CNNs)and Transformers have made significant ***,there are some limitations in the current integration of CNN and Transformer technology in two key ***,most methods either overlook or fail to fully incorporate the complementary nature between local and global ***,the significance of integrating the multiscale encoder features from the dual-branch network to enhance the decoding features is often disregarded in methods that combine CNN and *** address this issue,we present a groundbreaking dual-branch cross-attention fusion network(DCFNet),which efficiently combines the power of Swin Transformer and CNN to generate complementary global and local *** then designed the Feature Cross-Fusion(FCF)module to efficiently fuse local and global *** the FCF,the utilization of the Channel-wise Cross-fusion Transformer(CCT)serves the purpose of aggregatingmulti-scale features,and the Feature FusionModule(FFM)is employed to effectively aggregate dual-branch prominent feature regions from the spatial ***,within the decoding phase of the dual-branch network,our proposed Channel Attention Block(CAB)aims to emphasize the significance of the channel features between the up-sampled features and the features generated by the FCFmodule to enhance the details of the *** results demonstrate that DCFNet exhibits enhanced accuracy in segmentation *** to other state-of-the-art(SOTA)methods,our segmentation framework exhibits a superior level of ***’s accurate segmentation of medical images can greatly assist medical professionals in making crucial diagnoses of lesion areas in advance.

关键词： Convolutional neural networks Swin Transformer dual branch medical image segmentation feature cross fusion