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Improving the spaceborne GNSS-r altimetric precision based on the novel multilayer feedforward neural network weighted joint prediction model

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defence technology（防务技术） 2024年第2期32卷 271-284页

作者： Yiwen Zhang Wei Zheng Zongqiang Liu Qian Xuesen laboratory of Space technology China Academy of Space TechnologyBeijing 100094China China Academy of Aerospace Science and Innovation Beijing 100176China State key laboratory of Space-Ground Integrated Information technology Beijing Institute of Satellite Information EngineeringBeijing 100194China

Global navigation satellite system-reflection(GNSS-r)sea surface altimetry based on satellite constellation platforms has become a new research direction and inevitable trend,which can meet the altimetric precision at the global scale required for underwater *** present,there are still research gaps for GNSS-r altimetry under this mode,and its altimetric capability cannot be specifically ***,GNSS-r satellite constellations that meet the global altimetry needs to be ***,the matching precision prediction model needs to be established to quantitatively predict the GNSS-r constellation altimetric ***,the GNSS-r constellations altimetric precision under different configuration parameters is calculated,and the mechanism of the influence of orbital altitude,orbital inclination,number of satellites and simulation period on the precision is analyzed,and a new multilayer feedforward neural network weighted joint prediction model is ***,the fit of the prediction model is verified and the performance capability of the model is tested by calculating the r2 value of the model as 0.9972 and the root mean square error(rMSE)as 0.0022,which indicates that the prediction capability of the model is ***,using the novel multilayer feedforward neural network weighted joint prediction model,and considering the research results and realistic costs,it is proposed that when the constellation is set to an orbital altitude of 500 km,orbital inclination of 75and the number of satellites is 6,the altimetry precision can reach 0.0732 m within one year simulation period,which can meet the requirements of underwater navigation precision,and thus can provide a reference basis for subsequent research on spaceborne GNSS-r sea surface altimetry.

关键词： GNSS-r satellite constellations Sea surface altimetric precision Underwater navigation Multilayer feedforward neural network

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Off-Grid Compressed Channel Estimation with Parallel Interference Cancellation for Millimeter Wave Massive MIMO

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China Communications 2024年第3期21卷 51-65页

作者： Liu Jinru Tian Yongqing Liu danpu Zhang Zhilong Beijing laboratory of Advanced Information network Beijing Key Laboratory of Network System Architecture and ConvergenceBeijing University of Posts and TelecommunicationsBeijing100876China

Millimeter wave(mmWave)massive multiple-input multiple-output(MIMO)plays an important role in the fifth-generation(5G)mobile communications and beyond wireless communication systems owing to its potential of high ***,channel estimation has become very challenging due to the use of massive MIMO antenna ***,the mmWave channel has strong sparsity in the spatial angle domain,and the compressed sensing technology can be used to convert the original channel matrix into the sparse matrix of discrete angle *** the high-dimensional channel matrix estimation is transformed into a sparse recovery problem with greatly reduced computational ***,the path angle in the actual scene appears randomly and is unlikely to be completely located on the quantization angle grid,thus leading to the problem of power ***,multiple paths with the random distribution of angles will bring about serious interpath interference and further deteriorate the performance of channel *** address these off-grid issues,we propose a parallel interference cancellation assisted multi-grid matching pursuit(PIC-MGMP)algorithm in this *** proposed algorithm consists of three stages,including coarse estimation,refined estimation,and inter-path cyclic iterative inter-ference *** specifically,the angular resolution can be improved by locally refining the grid to reduce power leakage,while the inter-path interference is eliminated by parallel interference cancellation(PIC),and the two together improve the estimation *** results show that compared with the traditional orthogonal matching pursuit(OMP)algorithm,the normalized mean square error(NMSE)of the proposed algorithm decreases by over 14dB in the case of 2 paths.

关键词： channel estimation compressed sensing inter-path interference millimeter wave massive MIMO off-grid parallel interference cancellation

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development and formation of wing cuticle based on transcriptomic analysis in Locusta migratoria during metamorphosis

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Journal of Integrative Agriculture 2024年第4期23卷 1285-1299页

作者： Jing Zhang Zhaochen Wu Shuo Li He Huang Suning Liu Weimin Liu Xiaoming Zhao Jianzhen Zhang Shanxi key laboratory of Nucleic Acid Biopesticides Institute of Applied BiologyShanxi UniversityTaiyuan 030006China College of Life Science Shanxi UniversityTaiyuan 030006China Guangmeiyuan r&d Center/Guangdong Provincial key laboratory of Insect developmental Biology and Applied technology South China Normal UniversityMeizhou 514779China

Wings are an important flight organ of *** development is a complex process controlled by a series of *** flightless wing pad transforms into a mature wing with the function of migratory flight during the nymphto-adult ***,the mechanism of wing morphogenesis in locusts is still *** study analyzed the microstructures of the locust wing pads at pre-eclosion and the wings after eclosion and performed the comparative transcriptome ***-seq identified 25,334 unigenesand 3,430 differentially expressed genes(dEGs)(1,907 up-regulated and 1,523 down-regulated).The dEGs mainly included cuticle development(LmACPs),chitin metabolism(Lm Idgf4),lipid metabolism-related genes,cell adhesion(Integrin),zinc finger transcription factors(LmSalm,LmZF593 andLmZF521),and *** analysis based on rNA interference and hematoxylin and eosin(H&E)staining showed that the three genes encoded zinc finger transcription factors are essential for forming wing cuticle and maintaining morphology in Locusta ***,the study found that the LmSalm regulates the expression of LmACPs in the wing pads at pre-eclosion,and LmZF593 and LmZF521 regulate the expression of LmIntegrin/LmIdgf4/LmHMT420 in the wings after *** study revealed that the molecular regulatory axis controls wing morphology in nymphal and adult stages of locusts,offering a theoretical basis for the study of wing development mechanisms in hemimetabolous insects.

关键词： Locusta migratoria wing development metamorphosis rNA-seq

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A comparative study of data-driven battery capacity estimation based on partial charging curves

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Journal of Energy Chemistry 2024年第1期88卷 409-420,I0010页

作者： Chuanping Lin Jun Xu delong Jiang Jiayang Hou Ying Liang Xianggong Zhang Enhu Li Xuesong Mei State key laboratory for Manufacturing Systems Engineering Xi’an Jiaotong UniversityXi’an 710049ShaanxiChina shaanxi key laboratory of Intelligent robots School of Mechanical EngineeringXi’an Jiaotong UniversityXi’an 710049ShaanxiChina department of Electrical Engineering and Automation Luoyang Institute of Science and TechnologyLuoyang 471023HenanChina Wuhan Institute of Marine Electric Propulsion China State Shipbuilding Corporation LimitedWuhan 430064HubeiChina Gresgying digital technology Ltd. Xi’an 710086ShaanxiChina

With its generality and practicality, the combination of partial charging curves and machine learning(ML) for battery capacity estimation has attracted widespread attention. However, a clear classification,fair comparison, and performance rationalization of these methods are lacking, due to the scattered existing studies. To address these issues, we develop 20 capacity estimation methods from three perspectives:charging sequence construction, input forms, and ML models. 22,582 charging curves are generated from 44 cells with different battery chemistry and operating conditions to validate the performance. Through comprehensive and unbiased comparison, the long short-term memory(LSTM) based neural network exhibits the best accuracy and robustness. Across all 6503 tested samples, the mean absolute percentage error(MAPE) for capacity estimation using LSTM is 0.61%, with a maximum error of only 3.94%. Even with the addition of 3 m V voltage noise or the extension of sampling intervals to 60 s, the average MAPE remains below 2%. Furthermore, the charging sequences are provided with physical explanations related to battery degradation to enhance confidence in their application. recommendations for using other competitive methods are also presented. This work provides valuable insights and guidance for estimating battery capacity based on partial charging curves.

关键词： Lithium-ion battery Partial charging curves Capacity estimation data-driven Sampling frequency

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Model reduction of fractional impedance spectra for time–frequency analysis of batteries, fuel cells, and supercapacitors

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Carbon Energy 2024年第1期6卷 108-141页

作者： Weiheng Li Qiu-An Huang Yuxuan Bai Jia Wang Linlin Wang Yuyu Liu Yufeng Zhao Xifei Li Jiujun Zhang Institute for Sustainable Energy/College of Sciences Shanghai UniversityShanghaiChina Shanxi key laboratory of Nanomaterials and Nanotechnology School of Mechanical and Electrical EngineeringXi'an University of Architecture and TechnologyXi'anShaanxiChina Xi'an key laboratory of New Energy Materials and devices School of Materials Science and EngineeringInstitute of Advanced Electrochemical EnergyXi'an University of TechnologyXi'anShaanxiChina

Joint time–frequency analysis is an emerging method for interpreting the underlying physics in fuel cells,batteries,and *** increase the reliability of time–frequency analysis,a theoretical correlation between frequency-domain stationary analysis and time-domain transient analysis is urgently *** present work formularizes a thorough model reduction of fractional impedance spectra for electrochemical energy devices involving not only the model reduction from fractional-order models to integer-order models and from high-to low-order rC circuits but also insight into the evolution of the characteristic time constants during the whole reduction *** following work has been carried out:(i)the model-reduction theory is addressed for typical Warburg elements and rC circuits based on the continued fraction expansion theory and the response error minimization technique,respectively;(ii)the order effect on the model reduction of typical Warburg elements is quantitatively evaluated by time–frequency analysis;(iii)the results of time–frequency analysis are confirmed to be useful to determine the reduction order in terms of the kinetic information needed to be captured;and(iv)the results of time–frequency analysis are validated for the model reduction of fractional impedance spectra for lithium-ion batteries,supercapacitors,and solid oxide fuel *** turn,the numerical validation has demonstrated the powerful function of the joint time–frequency *** thorough model reduction of fractional impedance spectra addressed in the present work not only clarifies the relationship between time-domain transient analysis and frequency-domain stationary analysis but also enhances the reliability of the joint time–frequency analysis for electrochemical energy devices.

关键词： battery,fuel cell,supercapacitor fractional impedance spectroscopy model reduction time-frequency analysis

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Field stabilization of pulse duration in a hundredfemtosecond level

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Chinese Optics Letters 2024年第8期22卷 93-99页

作者： runmin Liu Yong Wu Guoqing Pu Jiayang Cheng Huan Mu Bowen Liu Lilin Yi Minglie Hu Ultrafast Laser laboratory Key Laboratory of Opto-electronic Information Science and Technology of Ministry of EducationSchool of Precision Instruments and Opto-electronics EngineeringTianjin UniversityTianjin 300072China State key laboratory of Advanced Communication Systems and networks School of Electronic Information and Electrical EngineeringShanghai Jiao Tong UniversityShanghai 200240China r&d Center AIOPTICS Company LimitedShanghai 200240China

Pulse duration is considered as one of the most important characteristics of high-power femtosecond ***,pulses output from the laser system are susceptible to ambient changes and manifest the instability of pulse durations in an open *** this paper,incorporating the algorithmic framework of the improved stochastic hill-climbing search and incremental proportional-integral controller,temperature-induced fluctuations of pulse duration can be effectively compensated by an automatic feedback control in an all-fiber chirped-pulse amplification *** the experiment,sub-hundred femtosecond fluctuation of pulse duration is introduced to verify the performance robustness of the proposed pulse-duration feedback control(PdFC).The stability of pulse duration is obviously higher than the case without the feedback control,and the peak-to-peak fluctuation of pulse duration is reduced to 6.5%.Furthermore,the robust switching between different pulse durations proves the versatility of the *** expect that the proposed feedback control method could provide a novel insight into high-power femtosecond lasers widely applied in fundamental researches and industrial fields.

关键词： fiber amplifier femtosecond laser pulse-duration feedback control

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Heat dissipation of carbon shell in ZrC-SiC/TaC coating to improve protective ability against ultrahigh temperature ablation

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Journal of Advanced Ceramics 2024年第7期13卷 1080-1091页

作者： Yuyu Zhang Xuemeng Zhang Hongkang Ou Bozhe Wang Jia Sun Qiangang Fu Science and technology on Thermostructural Composite Materials laboratory Shaanxi Key Laboratory of Fiber Reinforced Light-Weight CompositesNorthwestern Polytechnical UniversityXi’an 710072China System design Institute of Hubei Aerospace technology Academy Wuhan 430040China

To efficiently decrease ablation heat accumulation and improve the ability of ZrC-SiC/TaC coatings to protect carbon/carbon(C/C)composites,a thermally conductive nanonetwork with a ceramic@carbon core-shell structure was designed and ***-derived SiC/TaC with a graphene carbon shell was synthesized and introduced into a ZrC coating by supersonic atmospheric plasma spraying(SAPS).Graphene shell paths increased the heat transfer capability by lowering the surface temperature to approximately 200℃during oxyacetylene *** heat dissipation of the graphene shell in the ZrC-SiC/TaC@C coating reduced the volatilization of low-melting-point phases and delayed the sintering of ZrO_(2) ***,the graphene shell in ZrC-SiC/TaC@C coating decreased the mass and linear ablation rates by 91.4%and 93.7%compared to ZrC-SiC/TaC coating,*** work provided a constructive idea for improving the ablation resistance of the coatings by incorporating carbon nanomaterials as a function of heat dissipation.

关键词： carbon/carbon(C/C)composites carbon nanomaterials core-shell structure polymer-derived ceramic(PdC) ablation resistance

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Effect of sodium starch octenyl succinate-based Pickering emulsion on the physicochemical properties of hairtail myofibrillar protein gel subjected to multiple freeze-thaw cycles

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Food Science and Human Wellness 2024年第2期13卷 1018-1028页

作者： Huinan Wang Jiaxin Zhang Xinran Liu Jinxiang Wang Xuepeng Li Jianrong Li key laboratory of Food Nutrition and Safety Ministry of EducationCollege of Food Science and EngineeringTianjin University of Science and TechnologyTianjin 300457China College of Food Science and technology Bohai UniversityNational R&D Branch Center of Surimi and Surimi Products ProcessingJinzhou 121013China

A Pickering emulsion based on sodium starch octenyl succinate(SSOS)was prepared and its effects on the physicochemical properties of hairtail myofibrillar protein gels(MPGs)subjected to multiple freeze-thaw(F-T)cycles were *** whiteness,water-holding capacity,storage modulus(G')and texture properties of the MPGs were significantly improved by adding 1%-2%Pickering emulsion(Praman spectral analysis demonstrated that Pickering emulsion promoted the transformation of secondary structure,enhanced hydrogen bonds and hydrophobic interactions,and promoted the transition of disulfide bond conformation from g-g-g to g-g-t and *** an emulsion concentration of 2%,theα-helix content decreased by 10.37%,while theβ-sheet content increased by 7.94%,compared to the *** F-T cycles,the structure of the MPGs was destroyed,with an increase in hardness and a decrease in whiteness and water-holding capacity,however,the quality degradation of MPGs was reduced with 1%-2%Pickering *** findings demonstrated that SSOS-Pickering emulsions,as potential fat substitutes,can enhance the gel properties and the F-T stability of MPGs.

关键词： Pickering emulsion Myofibrillar protein Gel properties Freeze-thaw stability Intermolecular interactions

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Low-temperature graphitization of lignin via Co-assisted electrolysis in molten salt

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Green Energy & Environment 2024年第9期9卷 1449-1458页

作者： Shijie Li Wei-Li Song Xue Han Qingqing Cui Yan-li Zhu Shuqiang Jiao Institute of Advanced Structure technology Beijing Institute of Technology State key laboratory of Advanced Metallurgy University of Science and Technology Beijing State key laboratory of Explosion Science and technology Beijing Institute of Technology

The ever-growing energy demand and environmental issues have stimulated the development of sustainable energy ***,an efficient and environmentally friendly electrochemical transformation technology was proposed to prepare highly graphitized carbon materials from an abundant natural resource-lignin （LG）.The preparation process mainly includes pyrolytic carbonization of raw LG material and electrochemical conversion of amorphous carbon ***,with the assistance of Co catalyst,the graphitization degree of the products was significantly improved,in which the mechanism was the removal of heteroatoms in LG and the rearrangement of carbon atoms into graphite ***,tunable microstructures （nanoflakes） under catalytic effects could also be observed by controlling the electrolytic *** with the products CN1 （without catalyst） and CN5 （with 10%catalyst）,the specific surface area are 158.957 and202.246 m2g-1,*** used as the electrode material for lithium-ion batteries,CN5 delivered a competitive specific capacity of～350 m Ah g-1（0.5 C） compared with commercial *** strategy proposed in this work provides an effective way to extract value-added graphite materials from lignin and can be extended to the graphitization conversion of any other amorphous carbon precursor materials.

关键词： Lignin Graphitic carbon Electrochemical conversion Lithium-ion batteries

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Hexamerin and allergen are required for female reproduction in the American cockroach,Periplaneta americana

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Insect Science 2024年第1期31卷 186-200页

作者： Shiming Zhu Xiaoyi Chen Sishi Xia Qin Li Ziqi Ye Shaoting Zhao Kexin Liu Fangfang Liu Guangdong Provincial key laboratory of Insect developmental Biology and Applied technology Institute of Insect Science and TechnologyInstitute of Insect Science and Technology&School of Life SciencesSouth China Normal UniversityGuangzhouChina Guangmeiyuan r&d Center Guangdong Provincial Key Laboratory of Insect Developmental Biology and Applied TechnologySouth China Normal UniversityMeizhouGuangdong ProvinceChina Guangdong laboratory for Lingnan Modern Agriculture South China Agricultural UniversityGuangzhouChina

reproduction is of great importance for the continuation of the *** insects,the fat body is the major tissue for nutrient storage and involved in vitellogenesis,which is essential for female ***,2 proteins,hexamerin and allergen,were separated from the fat bodies of adult female American cockroaches(Periplaneta americana)and identified as storage proteins,encoding for 733 amino acids with molecular weight of 87.88 kda and 686 amino acids with molecular weight of 82.18 kda,*** encoding genes of these 2 storage proteins are mainly expressed in the fat *** interference-mediated knockdown of Hexamerin and Allergen in the early stage of the first reproductive cycle in females suppressed vitellogenesis and ovarian maturation,indicating that these storage proteins are involved in controlling ***,the expression of Hexamerin and Allergen was repressed by knockdown of the juvenile hormone(JH)receptor gene Met and the primary response gene Kr-h1,and was induced by methoprene,a JH analog,in both in vivo and in vitro ***,we have determined that hexamerin and allergen are identified as storage proteins and play an important role in promoting female reproduction in the American *** expression of their encoding genes is induced by JH *** data reveal a novel mechanism by which hexamerin and allergen are necessary for JH-stimulated female reproduction.

关键词： fat body juvenile hormone ovary reproduction storage protein vitellogenesis

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