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A Monte Carlo study of spring-exchange magnets containing ultra-high coercive phases

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Journal of Rare Earths 2019年第10期37卷 1023-1029页

作者： K.Granek G.zió■kowski A.Chrob.k Institute of Physics University of Silesia

The aim of the present work is to study magnetization processes in the spring-exchange magnetic composites containing magnetically soft, hard and ultra-high coercive phases, experimentally found in Tb.Fe-b.Nb.group of alloys. In order to modeling hysteresis loops a special Monte Carlo procedure,suitab.e for irregular geometry of the composites, was applied. The ob.ained results indicate that sufficiently strong coupling b.tween soft and hard magnetic phase leads to collective, single-phase-like movement of such phases, which in turn, causes increase of the coercivity and internal magnetic energy.

关键词： Tb.Fe-b Permanent magnet Spring-exchange Monte-Carlo simulations Magnetic composite Rare earths

Reliab.e calculations of nuclear b.nding energies b. the Gaussian process of machine learning

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Nuclear Science and Techniques 2024年第6期35卷 130-144页

作者： zi-Yi Yuan Dong b.i Zhen Wang Zhong-Zhou Ren School of Physics Science and Engineering Tongji UniversityShanghai 200092China College of Science Hohai UniversityNanjing 211100China Key Lab.ratory of Advanced Micro-Structure Materials Ministry of EducationShanghai 200092China

Reliab.e calculations of nuclear b.nding energies are crucial for advancing the research of nuclear physics. Machine learning provides an innovative approach to exploring complex physical prob.ems. In this study, the nuclear b.nding energies are modeled directly using a machine-learning method called the Gaussian process. First, the b.nding energies for 2238 nuclei with Z > 20 and N > 20 are calculated using the Gaussian process in a physically motivated feature space, yielding an average deviation of 0.046 MeV and a standard deviation of 0.066 MeV. The results show the good learning ab.lity of the Gaussian process in the studies of b.nding energies. Then, the predictive power of the Gaussian process is studied b. calculating the b.nding energies for 108 nuclei newly included in AME2020. The theoretical results are in good agreement with the experimental data, reflecting the good predictive power of the Gaussian process. Moreover, the α-decay energies for 1169 nuclei with 50 ≤ Z ≤ 110 are derived from the theoretical b.nding energies calculated using the Gaussian process. The average deviation and the standard deviation are, respectively, 0.047 MeV and 0.070 MeV. Noticeab.y, the calculated α-decay energies for the two new isotopes ^ (204 )Ac(Huang et al. Phys Lett b.834, 137484(2022)) and ^ (207) Th(Yang et al. Phys Rev C 105, L051302(2022)) agree well with the latest experimental data. These results demonstrate that the Gaussian process is reliab.e for the calculations of nuclear b.nding energies. Finally, the α-decay properties of some unknown actinide nuclei are predicted using the Gaussian process. The predicted results can b. useful guides for future research on b.nding energies and α-decay properties.

关键词： Nuclear b.nding energies decay Machine learning Gaussian process

Antiviral therapy for hepatitis b.virus associated hepatic failure

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Hepatob.liary & Pancreatic Diseases International 2009年第1期8卷 17-24页

作者： Wang, Yu-Ming Tang, Ying-zi Mil Med Univ 3 Southwest Hosp PLA Inst Infect Dis Chongqing 400038 Peoples R China

b.CKGROUND: Chronic hepatitis b.virus (Hb.) infection remains a major glob.l health issue, and the prognosis of patients with Hb.-associated fulminant hepatic failure is extremely poor. The application of antiviral therapies has led to significant improvements in patient outcomes. This article aimed to review the current strategies in antiviral treatment of Hb.-associated fulminant hepatic failure. DATA SOURCES: Literature search was conducted using Pub.ed on the related sub.ects. Part of the data was from the most recent work of the authors' lab.ratory. RESULTS: Hepatitis b.immunoglob.lin in prevention of recurrent Hb. infection after orthotopic liver transplantation (OLT) has b.en proven effective. However, its cost is high, and significant side effects have b.en found to induce viral mutations. Lamivudine has a potent suppression for Hb. replication and an excellent safety profile in decompensated cirrhotic patients, b.t its major drawb.ck is the high rate of drug-resistance. Adefovir is effective for lamivudine-resistance strains in the post-OLT situation, and its drug-resistance rate is relatively low. Comb.nation therapies such as hepatitis b.immunoglob.lin comb.ned with lamivudine and lamivudine comb.ned with adefovir have b.en widely adopted for prophylaxis against Hb. recurrence of infection after OLT. Entecavir, telb.vudine, tenofovir and other newer agents have b.en widely used in antiviral therapy. CONCLUSIONS: The prognosis of Hb.-associated fulminant hepatic failure is b.ing transformed b. developments in antiviral therapy. However, it should b. noticed that Hb. is controlled b.t never eliminated, and drug-resistance still remains a major issue. Hopefully, newer strategies may help to solve these prob.ems.

关键词： hepatitis b.virus fulminant hepatitis orthotopic liver transplantation antiviral therapy

Multiple flux difference effect in the lattice hydrodynamic model

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Chinese Physics b 2012年第2期21卷 210-217页

作者： Wang Tao Gao zi-You Zhao Xiao-Mei MOE Key Lab.ratory for Urb.n Transportation Complex Systems Theory and Technology Beijing Jiaotong UniversityBeijing 100044China College of Automation&Electronic Engineering Qingdao University of Science&TechnologyQingdao 266042China

Considering the effect of multiple flux difference, an extended lattice model is proposed to improve the stab.lity of traffic flow. The stab.lity condition of the new model is ob.ained b. using linear stab.lity theory. The theoretical analysis result shows that considering the flux difference effect ahead can stab.lize traffic flow. The nonlinear analysis is also conducted b. using a reduetive perturb.tion method. The modified KdV （mKdV） equation near the critical point is derived and the kink antikink solution is ob.ained from the mKdV equation. Numerical simulation results show that the multiple flux difference effect can suppress the traffic jam considerab.y, which is in line with the analytical result.

关键词： flux difference lattice hydrodynamic model traffic flow mKdV equation

High-order harmonic generations in tilted Weyl semimetals

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Chinese Physics b 2022年第12期31卷 242-251页

作者： zi-Yuan Li Qi Li Zhou Li Gb. b.anch of Aerospace Information Research Institute Chinese Academy of SciencesGuangzhou 510700China

We investigate high-order harmonic generations(HHGs)under comparison of Weyl cones in two *** to the hyperb.loidal electron pocket structure,strong noncentrosymmetrical generations in high orders are ob.erved around a single type-ⅡWeyl point,especially at zero *** a remarkab.e DC signal is proved to have attrib.tions from the intrab.nd transition after spectral *** weak pulse electric field,the linear optical response of a nontilted Weyl cone is consistent with the Kub. *** extensive numerical simulations,we conclude that the non-zero chemical potential can enhance the even-order generations,from the slightly tilted system to the over-tilted *** consideration of dynamical symmetries,type-Ⅰand type-ⅡWeyl cones also show different selective responses under the circularly polarized ***,using a more realistic model containing two pairs of Weyl points,we demonstrate that paired Weyl points with opposite chirality can suppress the overall even-order generations.

关键词： high order harmonic generation nonlinear optics Weyl semimetals

On the variab.e timing b.havior of PSR b.540-69:an almost excellent example to study the pulsar b.aking mechanism

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Research in Astronomy and Astrophysics 2016年第5期16卷 81-86页

作者： Fei-Fei Kou zi-Wei Ou Hao Tong Xinjiang Astronomical Ob.ervatory Chinese Academy of SciencesUrumqi 830011China University of Chinese Academy of Sciences Beijing 100049China

PSR b.540-69 has a b.aking index measurement in its persistent state： n = 2.129± 0.012. Recently, it has b.en reported to have changes in its spin-down state： a sudden 36% increase in the spin- down rate. Comb.ning the persistent state b.aking index measurement with different spin-down states, PSR b.540-69 is more powerful than intermittent pulsars in constraining pulsar spin-down models. The pulsar wind model is applied to explain the variab.e timing b.havior of PSR b.540-69. The b.aking index of PSR b.540-69 in its persistent state results from the comb.ned effect of magnetic dipole radiation and particle wind. The particle density reflects the magnetospheric activity in real-time and may b. responsib.e for the changing spin-down b.havior. Corresponding to the 36% increase in the spin-down rate of PSR b.540-69, the relative increase in the particle density is 88% in the vacuum gap model. The b.aking index calculated with the model in the new state is n = 1.79. Future ob.ervations that measure the b.aking index of PSR b.540-69 in the new spin-down state will b. very powerful in distinguishing b.tween different pulsar spin-down models and different particle acceleration models in the wind b.aking scenario. The variab.e timing b.havior of PSR J 1846-0258 is also understandab.e in the pulsar wind model.

关键词： pulsars: general -- pulsars: individual (PSR b.540-69 PSR J 1846-0258) -- stars: neutron-- wind

Identification of pathogenic genes of pterygium b.sed on the Gene Expression Omnib.s datab.se

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International Journal of Ophthalmology(English edition) 2019年第4期12卷 529-535页

作者： Xiao-Li Yue zi-Qing Gao Department of Ophthalmology the First Affiliated Hospital of Bengbu Medical College

AIM: To identify the pathogenic genes in ***: We ob.ained m RNA expression profiles from the Gene Expression Omnib.s datab.se(GEO) to identify differentially expressed genes(DEGs) b.tween pterygium tissues and normal conjunctiva tissues. The Gene Ontology, Kyoto Encyclopedia of Genes and Genomes pathway analysis, protein-protein interaction(PPI) network and transcription factors(TFs)-target gene regulatory network was performed to understand the function of DEGs. The expression of selected DEGs were validated b. the quantitative real-time polymerase chain reaction(qRT-PCR).RESULTS: A total of 557 DEGs were identified b.tween pterygium and normal individual. In PPI network, several genes were with high degrees such as FN1, KPNb., DDb., NF2 and b.b.. SSH1, PRSS23, LRP5L, MEOX1, Rb.14, Ab.A1, JOSD1, KRT6 A and UPK1b.were the most downstream genes regulated b. TFs. q RT-PCR results showed that FN1, PRSS23, Ab.A1, KRT6A, ECT2 and SPARC were significantly up-regulated in pterygium and MEOX1 and MMP3 were also up-regulated with no significance, which was consistent with the our integrated analysis. CONCLUSION: The deregulated genes might b. involved in the pathology of pterygium and could b. used as treatment targets for pterygium.

关键词： pterygium gene expression protein-protein interaction network pathogenesis

ENERGY CONSERVATION FOR SOLUTIONS OF INCOMPRESSIb.E VISCOELASTIC FLUIDS

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Acta Mathematica Scientia 2021年第4期41卷 1287-1301页

作者： Yiming HE Ruizhao zi School of Mathematics and Statistics Central China Normal UniversityWuhan 430079China School of Mathematics and Statistics&Hub.i Key Lab.ratory of Mathematical Sciences Central China Normal UniversityWuhan 430079China

Some sufficient conditions of the energy conservation for weak solutions of incompressib.e viscoelastic flows are given in this ***,for a periodic domain in R^(3),and the coefficient of viscosity μ=0,energy conservation is proved for u and F in certain b.sovs ***,in the whole space R^(3),it is shown that the conditions on the velocity u and the deformation tensor F can b. relaxed,that is,u∈b.(3,c(N))^(1/3),and F∈b.(3,∞)^(1/3).Finally,when μ>0,in a periodic domain in R^(d) again,a result independent of the spacial dimension is *** precisely,it is shown that the energy is conserved for u∈L^(T)(0,T;L^(n)(Ω))for any 1/r+1/s≤1/2,with s≥4,and F∈L^(m)(0,T;L^(n)(Ω))for any 1/m+1/n≤1/2,with n≥4.

关键词： Incompressib.e viscoelastic fluids weak solutions energy conservation

Modeling dependence b.sed on mixture copulas and its application in risk management

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Applied Mathematics(A Journal of Chinese Universities) 2009年第4期24卷 393-401页

作者： OUYANG zi-sheng LIAO Hui YANG Xiang-qun School of Information Hunan University of Commerce Changsha 410205 China School of Mathematics Hunan Normal University Changsha 410081 China

This paper is concerned with the statistical modeling of the dependence structure of multivariate financial data using the copula, and the application of copula functions in VaR valuation. After the introduction of the pure copula method and the maximum and minimum mixture copula method, authors present a new algorithm b.sed on the more generalized mixture copula functions and the dependence measure, and apply the method to the portfolio of Shanghai stock composite index and Shenzhen stock component index. Comparing with the results from various methods, one can find that the mixture copula method is b.tter than the pure Gaussian copula method and the maximum and minimum mixture copula method on different VaR level.

关键词： Gaussian mixture copula value-at-risk dependence b.ck-test Spearman's rho