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Variable projection algorithms with sparse constraint for separable nonlinear models

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Control Theory and Technology 2024年第1期22卷 135-146页

作者： Hui-Lang Xu Guang-Yong chen si-Qing cheng min Gan Jing chen College of Computer and Data Science Fuzhou UniversityFuzhou350116FujianChina Fujian Key Laboratory of Network Computing and Intelligent Information Processing Fuzhou UniversityFuzhou350116FujianChina Key Laboratory of Intelligent Metro of Universities in Fujian Fuzhou UniversityFuzhou350116FujianChina Engineering Research Center of Big Data Intelligence Ministry of EducationFuzhou UniversityFuzhou350116FujianChina School of Science Jiangnan UniversityWuxi214122JiangsuChina

Separable nonlinear models are widely used in various fields such as time series analysis, system modeling, and machine learning, due to their flexible structures and ability to capture nonlinear behavior of data. However, identifying the parameters of these models is challenging, especially when sparse models with better interpretability are desired by practitioners. Previous theoretical and practical studies have shown that variable projection (VP) is an efficient method for identifying separable nonlinear models, but these are based on \(L_2\) penalty of model parameters, which cannot be directly extended to deal with sparse constraint. Based on the exploration of the structural characteristics of separable models, this paper proposes gradient-based and trust-region-based variable projection algorithms, which mainly solve two key problems: how to eliminate linear parameters under sparse constraint;and how to deal with the coupling relationship between linear and nonlinear parameters in the model. Finally, numerical experiments on synthetic data and real time series data are conducted to verify the effectiveness of the proposed algorithms.

关键词： Variable projection(VP) Non-smooth constraint Separable nonlinear models

Highly elastic and degradable vitrimeric elastomers using polycondensation

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Chinese Chemical Letters 2024年第3期35卷 434-438页

作者： Yue Liu Yongshuang Huang Chao Li Guifu si min chen Institutes of Physical Science and Information Technology Key Laboratory of Structure and Functional Regulation of Hybrid Materials of Ministry of EducationAnhui UniversityHefei 230601China CAS Key Laboratory of Soft Matter Chemistry Department of Polymer Science and EngineeringUniversity of Science and Technology of ChinaHefei 230026China

Introducing covalently crosslinked network to polymer matrix can merge the advantages in reprocessing and durability of *** this contribution,a series of high-performance vitrimeric elastomers were achieved via *** topological structures of polymers were tuned by varying the feeding ratios of bisacetoacetate,hex–substituted bisacetoacetate,bisamine and tris(2-aminoethyl)*** these structural manipulations,the vitrimeric elastomers presented great elastic recovery properties(strain recovery value up to 80%)benefiting from the introduction of long chain ***,the elastomers exhibited excellent reprocessing property,water vapor/oxygen barrier and adhesive ***,the elastomers could be degraded into monomer under acid conditions which enabled the elastomer synthesis again in closed loop recycling *** ease of the polycondensation in this work to prepare highly elastic and recyclable vitrimeric elastomers demonstrated exciting opportunities for the synthesis of sustainable polymers.

关键词： Polycondensation Vitrimeric elastomers Highly elastic Degradable polymers

Construction of daily precipitation series and the observational characteristics of extreme precipitation in Tianjin,China during 1888-2022

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Advances in Climate Change Research 2024年第1期15卷 52-61页

作者： Peng si Qing-Xiang LI Xiao-Yang chen min WANG Chuan-Jun LUO Tianjin Meteorological Information Center Tianjin Meteorological BureauTianjin 300074China Research Centerfor Ecology and Environment of Central Asia Chinese Academy of SciencesWulumuqi 830011China School of Atmospheric Sciences Sun Yat-sen UniversityZhuhai 528478China Key Laboratory of Tropical Amosphere-Ocean System Ministry of EducationZhuhai 528478China Shaoguan Meteorological Service Shaoguan 512028China

Given the difficulties in rescuing and ensuring the quality of long-term climate data,current studies on century-scale climate change are usually limited to annual and monthly data,resulting in the poor detection of extreme climate events and their changes before *** this study,we reconstructed a daily precipitation series for Tianjin from 15 September 1887 to 31 December 2022 on the basis of the most comprehensive daily precipitation records collected from the Tianjin Meteorological Archive,China,and in reference to the precipitation analysis results based on the datasets developed by the Climatic Research Unit Time-Series version 4.06,Global Precipitation Climatology Centre and University of Delaware along with the application of various homogenisation methods for climate *** approach provides a complete and reliable century-long daily precipitation series for the study of regional or local extreme weather and climate *** reconstructed daily dataset reveals that the annual precipitation amount and R95 intensity in Tianjin during 1888-2022 lack significant trends and have values of 0.74±6.99 and-1.84±3.22 mm per decade,*** the annual and seasonal scales,the precipitation amount and R95 intensity,particularly those in autumn,have increased since the latter half of the 20th century relative to those in ***,the increase in precipitation amount and R95 intensity is relatively limited compared with that in atmospheric water vapour content due to surface warming,indicating the highly sensitive response of extreme precipitation events to *** addition,the estimates for the return periods of 5,10,20,50 and 100 years covering 1888-2022,1888-1950 and 1951-2022 depict that the intensity of heavy rain and above magnitude was highest in 1888-1950 and decreased in 1951-2022.

关键词： Over a century-long timescale Daily precipitation series Extreme precipitation Return period

Rogue wave solutions and rogue-breather solutions to the focusing nonlinear Schr?dinger equation

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Communications in Theoretical Physics 2024年第3期76卷 33-41页

作者： si-Jia chen Xing Lü College of Science Tianjin University of TechnologyTianjin 300384People's Republic of China Department of Mathematics Beijing Jiaotong UniversityBeijing 100044People's Republic of China Beijing Laboratory of National Economic Security Early-warning Engineering Beijing Jiaotong UniversityBeijing 100044People's Republic of China

Based on the long wave limit method,the general form of the second-order and third-order rogue wave solutions to the focusing nonlinear Schr?dinger equation are given by introducing some arbitrary *** interaction solutions between the first-order rogue wave and one-breather wave are constructed by taking a long wave limit on the two-breather *** applying the same method to the three-breather solutions,two types of interaction solutions are obtained,namely the first-order rogue wave and two breather waves,the second-order rogue wave and one-breather wave,*** influence of the parameters related to the phase on the interaction phenomena is graphically *** occur among the rogue waves and breather *** the collisions,the shape of them remains *** abundant interaction phenomena in this paper will contribute to a better understanding of the propagation and control of nonlinear waves.

关键词： nonlinear Schrodinger equation rogue wave solutions interaction solutions

Structure and 2p decay mechanism of^(18)Mg

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Nuclear Science and Techniques 2024年第6期35卷 145-154页

作者： Long Zhou De-Qing Fang si-min Wang Hui Hua Key Laboratory of Nuclear Physics and Ion-beam Application(MOE) Institute of Modern PhysicsFudan UniversityShanghai 200433China Shanghai Research Center for Theoretical Nuclear Physics NSFC and Fudan UniversityShanghai 200438China School of Physics and State Key Laboratory of Nuclear Physics and Technology Peking UniversityBeijing 100871China

The recently discovered,extremely proton-rich nuclide 18 Mg exhibits ground-state decay via two sequential two-proton(2p)emissions through the intermediate nucleus,*** study investigates the structure and the initial 2p decay mechanism of^(18)Mgby examining the density and correlations of the valence protons using a three-body Gamow coupled-channel *** results show that the ground state of^(18)Mgis significantly influenced by the continuum,resulting in a significant s-wave ***,based on the current framework,this does not lead to a significant deviation in mirror symmetry in either the structure or spectroscopy of the 18Mg-18C ***,the time evolution analysis of the^(18)Mgground state suggests a simultaneous 2p emission during the first step of *** observed nucleon-nucleon correlations align with those of the light-mass 2p emitters,indicating a consistent decay behavior within this nuclear region.

关键词： Structure of^(18)Mg Two-proton decay Proton-proton correlation

Effects of vitamin family members on insulin resistance and diabetes complications

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World Journal of Diabetes 2024年第3期15卷 568-571页

作者： Hong-Jin chen min Wang Ding-min Zou Gui-You Liang si-Yuan Yang Division of Cardiac Surgery Guizhou Institute of Precision MedicineThe Affiliated Hospital of Guizhou Medical UniversityGuiyang 550009Guizhou ProvinceChina Translational Medicine Research Center Guizhou Medical UniversityGuiyang 550025Guizhou ProvinceChina School of Basic Medical Sciences/School of Biology and Engineering Guizhou Medical UniversityGuiyang 550025Guizhou ProvinceChina

The following letter to the editor highlights the article“Effects of vitamin D supplementation on glucose and lipid metabolism in patients with type 2 diabetes mellitus and risk factors for insulin resistance”in World J Diabetes 2023 Oct 15;14(10):*** is necessary to explore the role of vitamin family members in insulin resistance and diabetes complications.

关键词： Vitamin Insulin resistance Diabetes complications Letter

Beam based alignment using a neural network

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Nuclear Science and Techniques 2024年第4期35卷 108-118页

作者： Guan-Liang Wang Ke-min chen si-Wei Wang Zhe Wang Tao He Masahito Hosaka Guang-Yao Feng Wei Xu National Synchrotron Radiation Laboratory University of Science and Technology of ChinaHefei 230029China Diamond Light Source Oxfordshire OX110DEUK

Beams typically do not travel through the magnet centers because of errors in storage *** beam deviating from the quadrupole centers is affected by additional dipole fields due to magnetic field ***-based alignment(BBA)is often performed to determine a golden orbit where the beam circulates around the quadrupole center *** storage rings with many quadrupoles,the conventional BBA procedure is time-consuming,particularly in the commissioning phase,because of the necessary iterative *** addition,the conventional BBA method can be affected by strong coupling and the nonlinearity of the storage ring *** this study,a novel method based on a neural network was proposed to determine the golden orbit in a much shorter time with reasonable *** golden orbit can be used directly for operation or adopted as a starting point for conventional *** method was demonstrated in the HLS-II storage ring for the first time through simulations and online *** results of the experiments showed that the golden orbit obtained using this new method was consistent with that obtained using the conventional *** development of this new method and the corresponding experiments are reported in this paper.

关键词： Golden orbit Beam-based alignment Neural network Storage ring

Design and implementation strategy of social responsibility sharing mechanism of existing building energy-saving renovation subject

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Ecological Economy 2022年第1期18卷 66-80页

作者： GUO Han-ding DU Zhuang chen si-min School of Economics and Management Tianjin Chengjian UniversityTianjin 300384CHINA Ecological Livable City and Sustainable Construction Management Research Center Tianjin Chengjian UniversityTianjin 300384CHINA

It is the key to promote the development of energy-saving renovation market of existing buildings to share the social responsibility of the subject of energy-saving renovation of existing *** paper analyzes the principle and implementation conditions of social responsibility sharing of existing building energy-saving renovation subject,discusses the mode selection and contract design of social responsibility sharing of existing building energy-saving renovation subject,analyzes the implementation mechanism of social responsibility sharing of existing building energy-saving renovation subject from the perspectives of information platform architecture,shared process design and shared system *** this paper puts forward the implementation strategy of sharing the social responsibility of the subject of the existing building energy-saving renovation from the aspects of stabilizing the subject’s cooperative relationship,creating a good responsibility environment and improving the responsibility performance laws and regulations.

关键词： existing buildings energy-saving renovation subject social responsibility sharing mechanism implementation strategy

Can serum immunoglobulin G4 levels and age serve as reliable predictors of relapse in autoimmune pancreatitis?

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World Journal of Gastroenterology 2024年第5期30卷 512-515页

作者： Jun-min Song si-Yu Sun Department of Gastroenterology Shengjing Hospital of China Medical UniversityShenyang 110004Liaoning ProvinceChina

We are writing in response to the paper published in the World Journal of Gastroenterology by Zhou et *** authors identified higher serum immunoglobulin(Ig)G4 levels and age over 55 years as independent risk factors for disease *** notable strengths,it is crucial to address potential ***,the cohort study included 189 patients with autoimmune pancreatitis(AIP)type 1(with higher IgG4 seropositivity and higher relapse)and 24 with type 2(with lower IgG4 seropositivity and lower relapse).Consequently,most,if not all,AIP type 2 patients were assigned to the normal group,possibly inflating the association of higher serum IgG4 levels with relapse and potentially exaggerating the association of older age with ***,the authors did not provide sufficient details regarding AIP diagnosis,such as the ratio of definitive vs probable cases and the proportion of *** cases where histological evidence is unavailable or indeterminate,AIP type 2 may be misdiagnosed as definitive type 1,and type 1 may also be misdiagnosed as probable type 2,particularly in cases with normal or mildly elevated serum IgG4 ***,in this retrospective study,approximately one-third of the consecutive patients initially collected were excluded for various ***,the impact of nonrandom exclusion on relapse outcomes should be carefully *** conclusion,the paper by Zhou et al offers plausible,though not entirely compelling,evidence suggesting a predictive role of elevated serum IgG4 levels and advanced age in AIP *** foundation for future investigations lies in ensuring a reliable diagnosis and accurate disease subtyping,heavily dependent on obtaining histological *** this regard,endoscopic ultrasound-guided fine-needle biopsy emerges as a pivotal component of the diagnostic process,contributing to mitigating biases in future explorations of the disease.

关键词： Autoimmune pancreatitis Immunoglobulin Endoscopic ultrasound Relapse Age