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ON THE ZEROS OF QUOTIENTS OF bESSEL FUNCTIONS

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Chinese Annals of Mathematics,Series b 2000年第3期21卷 285-296页

作者： A.FRIEDMAN b.hu J.J.L.VELAZQUEZ DepartmentofMathematics UniversityofMinnesotaMinneapolisMN55455USA. DepartmentofMathematics UniversityofNotreDameNotreDameIN46556USA. DepartamentodeMatematicaAplicada FacultaddeMatematicasUniversidadComplutense28040MadridSpain.

The paper studies the zeros of 2mIm/Im-1- (m+1)I1 /I0, where Im are the bessel functions.

关键词：商零点贝塞尔函数正解

Combined soft measurement on key indicator parameters of new competitive advantages for China’s export

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Financial Innovation 2021年第1期7卷 1100-1123页

作者： Taosheng Wang Hongyan Zuo C.H.Wu b.hu business School Hunan International Economics UniversityChangsha 410205China School of Mechanical Engineering Hunan Institute of EngineeringXiangtan 411104China Department of Supply Chain and Information Management(SCM) The Hang Seng University of Hong KongShatinHong Kong SARChina School of Preparatory Education Changsha Normal UniversityChangsha 410100China

The estimation of the difference between the new competitive advantages of China’s export and the world’s trading powers have been the key measurement problems in China-related studies.In this work,a comprehensive evaluation index system for new export competitive advantages is developed,a soft-sensing model for China’s new export competitive advantages based on the fuzzy entropy weight analytic hierarchy process is established,and the soft-sensing values of key indexes are derived.The obtained evaluation values of the main measurement index are used as the input variable of the fuzzy least squares support vector machine,and a soft-sensing model of the key index parameters of the new export competitive advantages of China based on the combined soft-sensing model of the fuzzy least squares support vector machine is established.The soft-sensing results of the new export competitive advantage index of China show that the soft measurement model developed herein is of high precision compared with other models,and the technical and brand competitiveness indicators of export products have more significant contributions to the new competitive advantages of China’s export,while the service competitiveness indicator of export products has the least contribution to new competitive advantages of China’s export.

关键词： China’s export New competitive advantages Export competitive advantage Core competitiveness Fuzzy least squares support vector machine Soft measurement

Optimization of chemistry and process parameters for control of intermetallic formation in Mg sludges

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Journal of Magnesium and Alloys 2024年第4期12卷 1431-1448页

作者： Y.Fu G.G.Wang A.hu Y.Li K.b.Thacker J.P.Weiler H.hu Department of Mechanical Automotive and Materials EngineeringUniversity of Windsor401 Sunset AveWindsorOntario N9B 3P4Canada Global Technology Centre Meridian Lightweight Technologies25 MacNab AveStrathroyOntario N7G 4H6Canada

Intermetallic formation in sludge during magnesium(Mg)melting,holding and high pressure die casting practices is a very important issue.but,very often it is overlooked by academia,original equipment manufacturers(OEM),metal ingot producers and even die casters.The aim of this study was to minimize the intermetallic formation in Mg sludge via the optimization of the chemistry and process parameters.The Al8Mn5 intermetallic particles were identified by the microstructure analysis based on the Al and Mn ratio.The design of experiment(DOE)technique,Taguchi method,was employed to minimize the intermetallic formation in the sludge of Mg alloys with various chemical compositions of Al,Mn,Fe,and different process parameters,holding temperature and holding time.The sludge yield(SY)and intermetallic size(IS)was selected as two responses.The optimum combination of the levels in terms of minimizing the intermetallic formation were 9 wt.%Al,0.15 wt.%Mn,0.001 wt.%(10 ppm)Fe,690℃ for the holding temperature and holding at 30 mins for the holding time,respectively.The best combination for smallest intermetallic size were 9 wt.%Al,0.15 wt.%Mn,0.001 wt.%(10 ppm)Fe,630℃ for the holding temperature and holding at 60 mins for the holding time,respectively.Three groups of sludge factors,Chemical Sludge(CSF),Physical Sludge(PSF)and Comprehensive Sludge Factors(and CPSF)were established for prediction of sludge yields and intermetallic sizes in Al-containing Mg alloys.The CPSF with five independent variables including both chemical elements and process parameters gave high accuracy in prediction,as the prediction of the PSF with only the two processing parameters of the melt holding temperature and time showed a relatively large deviation from the experimental data.The Chemical Sludge Factor was primarily designed for small ingot producers and die casters with a limited melting and holding capacity,of which process parameters could be fixed easily.The Physical Sludge Factor could be used for mass production with a single type of Mg allo

关键词： Magnesium sludge Al-Mn intermetallic Optimization Taguchi method Sludge factor Chemical composition Process parameter

由超拍电子伏特加速器产生的超高能伽马射线气泡

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Science bulletin 2024年第4期69卷 449-457页

作者： LHAASO Collaboration Zhen Cao Chuandong Gao Cong Li Ruo-Yu Liu Ruizhi Yang 不详 Key Laboratory of Particle Astrophyics&Experimental Physics Division&Computing Center Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China University of Chinese Academy of Sciences Beijing 100049China TIANFU Cosmic Ray Research Center ChengduChina Institute of Frontier and Interdisciplinary Science Shandong UniversityQingdao 266237China School of Astronomy and Space Science Nanjing UniversityNanjing 210023China University of Science and Technology of China Hefei 230026China

We report the detection of aγ-ray bubble spanning at least 100deg2 in ultra-high energy(UHE)up to a few PeV in the direction of the star-forming region Cygnus X,implying the presence super PeVatron(s)accelerating protons to at least 10 PeV.A log-parabola form with the photon indexΓ(E)=(2.71±0.02)+(0.11±0.02)×log10(E/10 TeV)is found fitting the gamma-ray energy spectrum of the bubble well.UHE sources,“hot spots”correlated with very massive molecular clouds,and a quasi-spherical amorphousγ-ray emitter with a sharp central brightening are observed in the bubble.In the core of~0.5°,spatially associating with a region containing massive Ob association(Cygnus Ob2)and a microquasar(Cygnus X-3),as well as previously reported multi-TeV sources,an enhanced concentration of UHEγ-rays is observed with 2 photons at energies above 1 PeV.The general feature of the bubble,the morphology,and the energy spectrum,are reasonably reproduced by the assumption of a particle accelerator in the core,continuously injecting protons into the ambient medium.

关键词： Cosmic rays γ-rays Interstellar medium Star cluster

Multi-Axis Attention With Convolution Parallel block for Organoid Segmentation

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IEEE/CAA Journal of Automatica Sinica 2024年第5期11卷 1295-1297页

作者： Pengwei hu Xun Deng Feng Tan Lun hu Xinjiang Technical Institute of Physics and Chemistry Chinese Academy of SciencesUrumqi 830011 University of Chinese Academy of Sciences Beijing 100049 Xinjiang Laboratory of Minority Speech and Language Information Processing Urumqi 830011China Merck KGaA Darmstadt 64293Germany

Dear Editor,This letter presents an organoid segmentation model based on multi-axis attention with convolution parallel *** adeptly captures dynamic dependencies within bright-field microscopy images,improving global ... 详细信息

关键词： letter convolution organo

Mapping out the reaction network of humin formation at the initial stage of fructose dehydration in water

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Green Energy & Environment 2024年第6期9卷 1016-1026页

作者： Xing Fu Yexin hu Ping hu hui Li Shuguang Xu Liangfang Zhu Changwei hu Key Laboratory of Green Chemistry and Technology Ministry of EducationCollege of ChemistrySichuan UniversityChengduSichuan610064China State Key Laboratory of Southwestern Chinese Medicine Resources Innovative Institute of Chinese Medicine and PharmacyChengdu University of Traditional Chinese MedicineChengduSichuan611137China

The formation of humins hampers the large-scale production of 5-hydroxymethylfurfural(HMF)in biorefinery.Here,a detailed reaction network of humin formation at the initial stage of fructose-to-HMF dehydration in water is delineated by combined experimental,spectroscopic,and theoretical studies.Three bimolecular reaction pathways to build up soluble humins are demonstrated.That is,the intermolecular etherification of β-furanose at room temperature initiates the C12 path,whereas the C-C cleavage of a-furanose at 130-150℃ leads to C11 path,and that of open-chain fructose at 180℃ to C11' path.The successive intramolecular dehydrations and condensations of the as-formed bimolecular intermediates lead to three types of soluble humins.We show that the C12 path could be restrained by using HCl or AlCl_(3) catalyst,and both the C12 and C110 paths could be effectively inhibited by adding THF as a co-solvent or accelerating heating rate via microwave heating.

关键词： Carbohydrates 5-hydroxymethylfurfural Reaction network Soluble humins Tautomer

Classifying hepatitis b therapies with insights from covalently closed circular DNA dynamics

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Virologica Sinica 2024年第1期39卷 9-23页

作者： Jie-Li hu Ai-Long huang Key Laboratory of Molecular biology on Infectious Diseases Ministry of EducationChongqing Medical UniversityChongqing400016China

The achievement of a functional cure for chronic hepatitis b(CHb)remains limited to a minority of patients treated with currently approved drugs.The primary objective in developing new anti-HbV drugs is to enhance the functional cure rates for CHb.A critical prerequisite for the functional cure of CHb is a substantial reduction,or even eradication of covalently closed circular DNA(cccDNA).Within this context,the changes in cccDNA levels during treatment become as a pivotal concern.We have previously analyzed the factors influencing cccDNA dynamics and introduced a preliminary classification of hepatitis b treatment strategies based on these dynamics.In this review,we employ a systems thinking perspective to elucidate the fundamental aspects of the HbV replication cycle and to rationalize the classification of treatment strategies according to their impact on the dynamic equilibrium of cccDNA.building upon this foundation,we categorize current anti-HbV strategies into two distinct groups and advocate for their combined use to significantly reduce cccDNA levels within a well-defined timeframe.

关键词： Hepatitis b cccDNA Functional cure Dynamics Treatment Strategy

Rational modulation of electronic structure in PtAuCuNi alloys boosts efficient electrocatalytic ethanol oxidation assisted with energy-saving hydrogen evolution

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Journal of Energy Chemistry 2024年第6期93卷 557-567,I0014页

作者： hu Yao Yinan Zheng Xin Yu Songjie hu baolian Su Xiaohui Guo Key Lab of Synthetic and Natural Functional Molecule Chemistry of Ministry of Education The College of Chemistry and Materials ScienceNorthwest UniversityXi’an 710069ShaanxiChina Department of Inorganic Chemistry University of NamurBruxellesB-5000 NamurBelgium

Compared to conventional electrocatalytic water splitting,electrocatalytic ethanol oxidation reaction(EOR)along with hydrogen production is considered a more energy-efficient strategy.Herein,we prepared a type of novel quaternary alloy catalyst(PtAuCuNi@NF)that exhibits excellent activity for EOR(0.215 V at 10 mA cm^(-2))and hydrogen evolution reaction(HER)(7 mV at 10 mA cm^(-2)).Experimental results demonstrated that both Cu and Ni modulated the electronic environment around Pt and Au.The electron-rich active center facilitates the rapid adsorption and dissociation of reactants and intermediates for both EOR and HER.Impressively,in the ethanol-assisted overall water splitting(E-OWS),a current density of 10 mA cm^(-2)was achieved at 0.28 V.Moreover,an advanced acid-base self-powered system(A-bsps)that can achieve a self-powered voltage of 0.59 V was assembled.Accordingly,the self-driven hydrogen production with zero external power supply was realized by integrating A-bsps with the E-OWS equipment.The interesting results can provide a feasible strategy for designing and developing advanced nanoalloy-based materials for clean energy integration and use in various fields.

关键词： Pt-based alloy Electronic structure Ethanol oxidation Self-powered system Overall water splitting

Total synthesis of a putative yuzurimine-type Daphniphyllum alkaloid C_(14)–epi-deoxycalyciphylline H

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Chinese Chemical Letters 2024年第4期35卷 336-339页

作者： Jingping hu Jing Xu Shenzhen Grubbs Institute and Department of Chemistry and Guangdong Provincial Key Laboratory of Catalysis and Shenzhen Key Laboratory of Small Molecule Drug Discovery and Synthesis Southern University of Science and TechnologyShenzhen 518055China

One of the largest subfamilies within the famous Daphniphyllum alkaloid family is made up of the yuzurimine-type(or macrodaphniphyllamine-type) alkaloids. Their complex aza-polycyclic caged structures, several contiguous stereogenic centers, and vicinal all-carbon quaternary centers make these alkaloids formidable challenge for synthetic chemists. Recently, synthesis of these alkaloids has received extensive attention from our community. Herein, we wish to report the total synthesis of C_(14)–epideoxycalyciphylline H, a putative member of yuzurimine-type alkaloid subfamily. Key transformations employed in our approach include an intramolecular Prins reaction and a Pd-catalyzed enyne cycloisomerization. In addition, synthesis of a daphnezomine L-type alkaloid, paxdaphnidine A, was also studied.

关键词： Total synthesis Daphniphyllum alkaloids Yuzurimine-type alkaloids Prins reaction Enyne cycloisomerization