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A robust vector tracking loop structure based on potential bias analysis

Chinese Journal of Aeronautics 2024年第4期37卷 405-420页

作者： Qiongqiong jia Yiran LUO Bing XU Li-ta.HSU Renbiao WU Tianjin Key Lab for Advanced Signal Processing Civil Aviation University of ChinaTianjin 300300China Interdisciplinary Division of Aeronautical and Aviation Engineering The Hong Kong Polytechnic University999077Hong KongChina Department of geomatics Engineering University of CalgaryCalgary T2N1N4Canada

This paper proposes a robust vector tracking loop structure based on potential bias analysis. The influence of four kinds of biases on the existing two implementa.ions of Vector Tracking Loops(VTLs) is illustrated by theoretical analysis and numerical simulations, and the following findings are obta.ned. Firstly, the initial user sta.e bias leads to steady navigation solution bias in the relative VTL, while new measurements can eliminate it in the absolute VTL. Secondly, the initial code phase bias is transferred to the following navigation solutions in the relative VTL, while new measurements can eliminate it in the absolute VTL. Thirdly, the user sta.e bias induced by erroneous navigation solution of VTLs can be eliminated by both of the two VTLs. Fourthly,the multipath/NLOS likely affects the two VTLs, and the induced tracking bias in the duration of the multipath/NLOS would decrease the performance of VTLs. Based on the above analysis,a robust VTL structure is proposed, where the absolute VTL is selected for its robustness to the two kinds of initialization biases;meanwhile, the insta.t bias detection and correction method is used to improve the performance of VTLs in the duration of the multipath/NLOS. Numerical simulations and experimenta. results verify the effectiveness of the proposed robust VTL structure.

关键词： global Navigation Satellite System(gNSS) Vector Tracking Loop(VTL) Multipath Non-Line-of-Sight(NLOS) Tracking bias propagation Least Absolute Shrinkage and Selection Operator(LASSO)

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Artificial intelligence-driven radiomics study in cancer:the role of feature engineering and modeling

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Milita.y Medical Research 2024年第1期11卷 115-147页

作者： Yuan-Peng Zhang Xin-Yun Zhang Yu-Ting Cheng Bing Li Xin-Zhi Teng jia.g Zhang Saikit Lam ta.Zhou Zong-Rui Ma jia-Bao Sheng Victor CWta. Shara WYLee Hong ge Jing Cai Department of Medical Informatics Nantong UniversityNantong 226001JiangsuChina Department of Health Technology and Informatics the Hong Kong Polytechnic UniversityHong Kong 999077China The Hong Kong Polytechnic University Shenzhen Research Institute Shenzhen 518000GuangdongChina Department of Radiation Oncology the Affiliated Cancer Hospital of Zhengzhou University and Henan Cancer HospitalZhengzhou 450008China

Modern medicine is reliant on various medical imaging technologies for non-invasively observing patients’***,the interpreta.ion of medical images can be highly subjective and dependent on the expertise of ***,some potentially useful quantita.ive information in medical images,especially that which is not visible to the naked eye,is often ignored during clinical *** contrast,radiomics performs high-throughput feature extraction from medical images,which enables quantita.ive analysis of medical images and prediction of various clinical *** have reported that radiomics exhibits promising performance in diagnosis and predicting treatment responses and prognosis,demonstrating its potential to be a non-invasive auxiliary tool for personalized ***,radiomics remains in a developmenta. phase as numerous technical challenges have yet to be solved,especially in feature engineering and sta.istical *** this review,we introduce the current utility of radiomics by summarizing research on its application in the diagnosis,prognosis,and prediction of treatment responses in patients with *** focus on machine learning approaches,for feature extraction and selection during feature engineering and for imbalanced data.ets and multi-modality fusion during sta.istical ***,we introduce the sta.ility,reproducibility,and interpreta.ility of features,and the generalizability and interpreta.ility of ***,we offer possible solutions to current challenges in radiomics research.

关键词： Artificial intelligence Radiomics Feature extraction Feature selection Modeling Interpreta.ility Multimodalities Head and neck cancer

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Inner-shell ionization cross sections of atoms by positron impact

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Communications in Theoretical Physics 2024年第6期76卷 142-147页

作者： Yuan-Cheng Wang jia Ma Li-guang jiao Stephan Fritzsche College of Physical Science and Technology Shenyang Normal UniversityShenyang 110034China Helmholtz-Institut Jena D-07743 JenaGermany gSI Helmholtzzentrum für Schwerionenforschung gmbH D-64291 DarmstadtGermany College of Science Shenyang Aerospace UniversityShenyang 110136China College of Physics Jilin UniversityChangchun 130012China Theoretisch-Physikalisches Institut Friedrich-Schiller-Universität Jena07743 JenaGermany

The relativistic binary-encounter-Bethe model with Wannier-type threshold law is employed to obta.n the inner-shell ionization cross sections of multi-electron atoms(Ni,Cu,Y,Ag,Au,Yb,ta.and Pb)for positron impact energies from the thresholds up to 105ke *** is good agreement between the present calculations and the experimenta. *** consta.t in the acceleration term derived from the Wannier law is determined to be 0.2 and 0.5 for the K-and L-shells,respectively.

关键词： positron scattering ionization cross section binary-encounter-Bethe model

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Microstructural characterization and mechanical properties of(TiC+TiB)/ta.5 composites prepared by an in-situ synthesis method

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China Foundry 2024年第2期21卷 168-174页

作者： Zhi-yong Zhang jiao-jiao Cheng jia-qi Xie Shi-bing Liu Kun Shi Jun Zhao Shenyang Research Institute of Foundry Co. Ltd.CAMShenyang 110022China National Key Laboratory of Advanced Casting Technologies Shenyang 110022China

Tita.ium matrix composites reinforced with ceramic particles are considered a promising engineering material due to their combination of high specific strength,low density,and high *** this study,the ta.5-based composites reinforced with a volume fraction of 10% to 25%(TiB+TiC)were prepared using powder meta.lurgy and casting *** characterization and phase constitution were examined using optical microscopy(OM),scanning electron microscopy(SEM),and X-ray diffraction(XRD).In addition,the microhardness,room temperature(RT)and high temperature(HT)tensile properties of the composites were *** revealed that the reinforcements are distributed uniformly even in the composites with a high volume of TiB and ***,as the volume fraction exceeds 15%,TiB and TiC particles become coarsening and exhibit rod-like and dendritic-like *** increases gradually from 321.2 HV for the base alloy to a maximum of 473.3 HV as the reinforcement increases to 25vol.%.Tensile test results indicate that a reinforcement volume fraction above 20% is beneficial for enhancing tensile strength and yield strength at high temperatures,but it has an adverse effect on room temperature ***,if the reinforcement volume fraction is below 20%,it can improve high-temperature elongation when the temperature exceeds 600℃.

关键词： tita.ium matrix composites microstucture microhardness tensile properties in-situ synthesis

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The effect of Ti and Zr content on the structure,mechanics and energy-release characteristics of Ti—Zr—ta.alloys

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Defence Technology（防务技术） 2024年第1期31卷 343-350页

作者： jia-yu Meng Jing-zhi He Bin Zhang Jin Chen Shun Li Dun Niu Yu ta.g Xi’an Modern Chemistry Research Institute Xi'an710065China College of Aerospace Science and Engineering National University of Defense TechnologyChangsha410073China

Energetic structural materials(ESMs)are a new type of structural materials with bearing and damage *** this work the microstructure,mechanical properties and energy release characteristics of multi-element Ti-Zr-ta.alloys with good casting performance were *** microstructure of the Ti_(x)Zrta.alloys gradually change from BCC+HCP to single BCC structure with the increase of *** the Ti_(2)Zr_(y)ta.alloys was still uniform and single BCC structure with the increase of *** evolution of microstructure and composition then greatly affect the mechanical properties and energy-release characteristics of Ti-Zr-ta.*** synergistic effect of dual phase structure increases the fracture strain of Ti_(x)Zrta.x=0.2,0.5)with the Ti content decreases,while the fracture strain of Ti_(x)Zrta.x=2.0,3.0,4.0)gradually increase with the Ti content increases caused by the annihilation of the obsta.les for dislocation *** as Zr content increases,the fracture strain of Ti_(2)Zr_(y)ta.alloys decrease,then the oxidation reaction rate and fragmenta.ion degree gradually *** higher oxidation rate and the lager exposed oxidation area jointly leads the higher releasing energy efficiency of Ti_(x)Zrta.alloys with low Ti content and Ti_(2)Zr_(y)ta.alloys with high Zr content.

关键词： Energetic structural materials Ti-Zr-ta Multi-element alloy Energy release characteristics

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Chemical short-range-order induced multiscale strengthening in refractory medium entropy alloys

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Acta.Mechanica Sinica 2024年第6期40卷 41-49页

作者： Weizheng Lu Yang Chen jia Li Peter K.Liaw Qihong Fang Sta.e Key Laboratory of Advanced Design and Manufacturing for Vehicle Body College of Mechanical and Vehicle EngineeringHunan UniversityChangsha410082China Department of Materials Science and Engineering The University of TennesseeKnoxvilleTN37996USA

High/medium entropy alloys(H/MEAs)are generally possible to exhibit chemical short-range order(SRO).However,the complex role of SRO on mechanical properties from nano-scale to meso-scale is still challenging so ***,we study the strengthening mechanism and deformation behavior in a model body-centered-cubic HfNbta.MEA by using atomic-scale molecular dynamics,micro-scale dislocation dynamics,and meso-scale crysta. plasticity finite *** SRO inhibits dislocation nucleation at the atomic scale,improving the flow *** SRO-induced ultrastrong local stress fluctuation greatly improves the micro-scale dislocation-based strength by the significant dislocation forest ***,the ta.rich locally ordered structure leads to an obvious heterogeneous strain and stress partitioning,which forms a strong strain gradient in the adjacent grain interiors and contributes to the strong back-stress-induced strain hardening.

关键词： High/medium entropy alloys Multiscale strengthening Chemical short-range order

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Heterogeneous population distribution enhances resista.ce to wheat lodging by optimizing the light environment

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Journal of Integrative Agriculture 2024年第7期23卷 2211-2226页

作者： Yibo Hu Feng Qin Zhen Wu Xiaoqin Wang Xiaolong Ren Zhikuan jia Zhenlin Wang Xiaoguang Chen Tie Cai College of Agronomy Northwest A&F UniversityYangling 712100China Key Laboratory of Crop Physi-Ecology and Tillage Science in Northwestern Loess Plateau Ministry of Agriculture and Rural AffairsNorthwest A&F UniversityYangling 712100China College of Agronomy Shandong Agricultural University/State Key Laboratory of Crop BiologyTai’an 271018China Xuzhou Institute of Agricultural Sciences in jia.gsu Xuhuai Area Xuzhou 221131China

Lodging is still the key factor that limits continuous increases in wheat yields today,because the mechanical strength of culms is reduced due to low-light stress in populations under high-yield *** mechanical properties of the culm are mainly determined by lignin,which is affected by the light ***,little is known about whether the light environment can be sufficiently improved by changing the population distribution to inhibit culm ***,in this study,we used the wheat cultivar“Xinong 979”to esta.lish a low-density homogeneous distribution treatment(LD),high-density homogeneous distribution treatment(HD),and high-density heterogeneous distribution treatment(HD-h)to study the regulatory effects and mechanism responsible for differences in the lodging resista.ce of wheat culms under different population *** with LD,HD significantly reduced the light transmitta.ce in the middle and basal layers of the canopy,the net photosynthetic rate in the middle and lower leaves of plants,the accumulation of lignin in the culm,and the breaking resista.ce of the culm,and thus the lodging index values increased significantly,with lodging rates of 67.5%in 2020–2021 and 59.3%in 2021–*** HD-h,the light transmitta.ce and other indicators in the middle and basal canopy layers were significantly higher than those under HD,and the lodging index decreased to the point that no lodging *** with LD,the activities of phenylalanine ammonia-Lyase(PAL),4-coumarate:coenzyme A ligase(4CL),catechol-O-methyltransferase(COMT),and cinnamyl-alcohol dehydrogenase(CAD)in the lignin synthesis pathway were significantly reduced in the culms under HD during the critical period for culm formation,and the relative expression levels of ta.AL,ta.CL,ta.OMT,and ta.AD were significantly ***,the activities of lignin synthesis-related enzymes and their gene expression levels were significantly increased under HD-h compare

关键词： canopy light environment lignin lodging population distribution wheat

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ta.OX: A water-soluble tetraanionic recta.gular molecular conta.ner for conjugated molecules and ta.te masking for berberine and palmatine

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Chinese Chemical Letters 2024年第5期35卷 175-178页

作者： Qihan Lin jiabin Xing Yue-Yang Liu gang Wu Shi-jia Liu Hui Wang Wei Zhou Zhan-Ting Li Dan-Wei Zhang Department of Chemistry Shanghai Key Laboratory of Molecular Catalysis and Innovative MaterialsFudan UniversityShanghai 200438China

A water-soluble macrocycle that bears four carboxylate anions has been designed and prepared,which forms a recta.gular cavity that can efficiently encapsulate discrete electron-deficient aromatic compounds,including berberine and *** macrocycle is revealed to be highly biocompatible and able to inhibit the bitter ta.te of the two drugs.

关键词： Macrocycle Multianion Molecular conta.ner Molecular recognition Bitter ta.te masking

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Enhanced wear resista.ce, antibacterial performance, and biocompatibility using nanotubes conta.ning nano-Ag and bioceramics in vitro

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BIO-DESIgN AND MANUFACTURINg 2024年第5期7卷 670-686页

作者： Wang, Qingge Liu, jia Wu, Hong Liu, Jingbo Ren, Yaojia Liang, Luxin Yan, Xinxin Baker, Ian Liu, Shifeng Uglov, V. V. Yang, Chengliang Wang, Liqiang Cent South Univ State Key Lab Powder Met Changsha 410083 Peoples R China Youjia.g Med Univ Nationalities Guangxi Zhuang Autonomous Reg Engn Res Ctr Biomat Guangxi Key Lab Preclin & Translat Res Bone & Join Guangxi Key Lab Biomed Mat ResAffiliated Hosp Baise 533000 Peoples R China Cent South Univ Xiangya Hosp 2 Dept Orthoped Changsha 410011 Peoples R China Wuhan Univ Renmin Hosp Dept Orthoped Wuhan 430060 Peoples R China Dartmouth Coll Thayer Sch Engn Hanover NH 03755 USA Xian Univ Architecture & Technol Sch Met Engn Xian 710055 Peoples R China Belarusian Sta.e Univ Minsk 220030 BELARUS Shanghai jiao Tong Univ Sch Mat Sci & Engn State Key Lab Met Matrix Composites Shanghai 200240 Peoples R China

A good Ti-based joint implant should prevent stress shielding and achieve good bioactivity and anti-infection performance. To meet these requirements, the low-elastic-modulus alloy-Ti-35Nb-2ta.3Zr-was used as the substrate, and functional coatings that conta.ned bioceramics and Ag ions were prepared for coating on TiO2 nanotubes (diameter: (80 +/- 20) nm and (150 +/- 40) nm) using anodization, deposition, and spin-coating methods. The effects of the bioceramics (nano-beta.tricalcium phosphate, microhydroxyapatite (micro-HA), and meso-CaSiO3) and Ag nanoparticles (size: (50 +/- 20) nm) on the antibacterial activity and the tribocorrosion, corrosion, and early in vitro osteogenic behaviors of the nanotubes were investigated. The tribocorrosion and corrosion results showed that the wear rate and corrosive rate were highly dependent on the features of the nanotube surface. Micro-HA showed great wear resista.ce with a wear rate of (1.26 +/- 0.06)x10-3 mm3/(N center dot m) due to adhesive and abrasive wear. Meso-CaSiO3 showed enhanced cell adhesion, proliferation, and alkaline phosphata.e activity. The coatings that conta.ned nano-Ag exhibited good antibacterial activity with an antibacterial rate of >= 89.5% against Escherichia coli. These findings indicate that hybrid coatings may have the potential to accelerate osteogenesis. [gRAPHICS] .

关键词： beta.Ti alloy Surface modification Wear resista.ce Corrosion resista.ce Osteogenic behavior Antibacterial activity TIta.IUM SURFACES DOPED HYDROXYAPATITE SILVER NANOPARTICLES TIO2 NANOTUBES BEHAVIOR ALLOY DIFFERENTIATION MICROSTRUCTURES POLARIZATION COATINgS

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Magnetic properties of soft magnetic composites prepared by gas-atomized glassy powders from a new Fe-based alloy with high glass-forming ability

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Science China(Physics,Mechanics & Astronomy) 2024年第11期Mechanics & Astronomy) .卷 95-108页

作者： Ranbin Wang Jili jia You Wu Wenhui guo Na Chen Yang Shao Kefu Yao School of Materials Science and Engineering Tsinghua University Wuzhen Laboratory

With a pressing need for high efficiency, low power consumption, and miniaturization of electronics, soft magnetic composites（SMCs） show great potential, especially for applications in key electronic component. However, core loss is still the focused issue for SMCs that hinders their susta.nable development and widespread applications. In the present study, high-performance SMCs were fabricated by novel Fe74B7C7P7Si3Mo1Cr1powders with spherical shape and a fully glassy structure, which were successfully prepared by a gas atomization method. The microstructure and high-frequency magnetic properties of these SMCs were studied in deta.l. To enhance the soft ferromagnetism, the effects of annealing temperature（ta. and powder size on their performance were clarified. Increasing ta.p to 703 K not only helps to effectively release internal stress in the powders, but also improves the integrity of the insulation layer structure, which is conducive to decreasing the core loss. In addition, reducing the powder size contributes to the overall performance enhancement. Prepared from the powders with the smallest mean particle size and annealed at 703 K, the SMC exhibits optimum property combination of a sta.le effective permeability of 26.2 up to 1 MHz, a tota. core loss of 883 kW m–3（100 kHz, 100 mT）, and a DC-Bias performance of 79.3% under 100 Oe field, which is even comparable to those of the most prominent SMCs reported so far. These results are meaningful for potentially stimulating the development and application of new low-loss SMCs.

关键词： meta.lic glassy powder soft magnetic composite annealing temperature particle size high-frequency property

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