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Kinematics of the high-excitation HH 890 jet in the Rosette Nebula

Chinese Journal of Astronomy and Astrophysics 2009年第5期9卷 577-584页

作者： jin-zeng Li National Astronomical Observatory Chinese Academy of Sciences Beijing 100012 China

Photoionized jets immersed in HII regions display special properties, which made them a distinctive category of Herbig-Haro （HH） flows. Detailed studies of such jet systems became one of the key issues in our understanding of jet production and evolution. HH 890, initially called the Rosette HH2 jet, is the second photoionized jet discovered in the spectacular HII region of the Rosette Nebula. Contrary to conventional impressions of a jet, its discrete components are found to be unexpectedly broad and spatially detached from the proposed energy source. The jet displays additional unusual features which point to the disputable nature of the system. Here, we investigate the kinematics of the jet through high-quality echelle spectrograms. It is distinctively resolved into a fast component with a mean approaching velocity of-39 km s^-1 with respect to the systemic rest frame and a slow component with radial velocity centered at -9 km s^-1. The slow component indicates an apparently larger dispersion in radial velocity in various emission lines and is likely dissolving at roughly the speed of sound, which favors a photoevaporated origin. The [SII] doublet ratios indicate an electron density of -1.1×10^3 cm^-3 in the collimated jet and ,-9×10^2 cm^-3 in the HII region. This, along with the diffuse appearance of the extensive part of the jet, leads to a dissipation of the jet in the fully ionized medium of Rosette. In addition, time series of photometric observations provide evidence for remarkable light variations of the energy source. Its amplitudes of variation amount to 〉 1 mag in both R and I, which is commensurate with the young evolutionary status of the source as indicated by a red, late type optical spectrum.

关键词： accretion disks -- ISM jets and outflows -- stars formation -- stars premain-sequence

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The effect of adjuvant transarterial chemoembolization for hepatocellular carcinoma after liver resection based on risk stratification

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Hepatobiliary & Pancreatic Diseases International 2023年第5期22卷 482-489页

作者： jin-Shu zeng Jian-Xing zeng Yao Huang jing-Feng Liu jin-Hua zeng Department of Ultrasonic Medical The First Affiliated Hospital of Fujian Medical UniversityFuzhou 350005China The Liver Center of Fujian Province Fujian Medical UniversityFuzhou 350025China Department of Hepatobiliary Surgery The First Affiliated Hospital of Fujian Medical UniversityFuzhou 350005China Department of Hepatobiliary Surgery Mengchao Hepatobiliary Hospital of Fujian Medical UniversityFuzhou 350005China

Background:There is currently no standard adjuvant treatment proven to prevent hepatocellular carcinoma(HCC)*** studies suggest that postoperative adjuvant transarterial chemoembolization(PA-TACE)is beneficial for patients at high risk of tumor ***,it is difficult to select the *** present study aimed to develop an easy-to-use score to identify these ***:A total of 4530 patients undergoing liver resection were *** risk factors were identified by Cox regression model in the training cohort and the Primary liver cancer big data transarterial chemoembolization(PDTE)scoring system was ***:The scoring system was composed of ten risk factors including alpha-fetoprotein(AFP),albuminbilirubin(ALBI)grade,operative bleeding loss,resection margin,tumor capsular,satellite nodules,tumor size and number,and microvascular and macrovascular *** 5 points as risk stratification,the patients with PA-TACE had higher recurrence-free survival(RFS)compared with non-TACE in>5 points group(P5 points may benefit from PA-TACE.

关键词： Hepatocellular carcinoma Liver resection Adjuvant transarterial chemoembolization Scoring system Risk stratification

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CONVERGENCE RATE OF A GENERALIZED ADDITIVE SCHWARZ ALGORITHM

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Journal of Computational Mathematics 2006年第5期24卷 635-646页

作者： jin-ping zeng Gao-jie Chen College of Mathematics and Econometrics Hunan University Changsha 410082 China

The convergence rate of a generalized additive Schwarz algorithm for solving boundary value problems of elliptic partial differential equations is studied. A quantitative analysis of the convergence rate is given for the model Dirichlet problem. It will be shown that a greater acceleration of the algorithm can be obtained by choosing the parameter suitably. Some numerical tests are also presented in this paper.

关键词： Schwarz additive algorithm Convergence rate Dirichlet problem.

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A New Subspace Correction Method for Nonlinear Unconstrained Convex Optimization Problems

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Acta Mathematicae Applicatae Sinica 2012年第4期28卷 745-756页

作者： Rong-liang CHEN jin-ping zeng College of Mathematics and Econometrics Hunan University College of Computer Dongguan University of Technology

This paper gives a new subspace correction algorithm for nonlinear unconstrained convex optimization problems based on the multigrid approach proposed by S. Nash in 2000 and the subspace correction algorithm proposed by X. Tai and J. Xu in 2001. Under some reasonable assumptions, we obtain the convergence as well as a convergence rate estimate for the algorithm. Numerical results show that the algorithm is effective.

关键词： nonlinear optimization convergence subspace correction method

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Evolutionary Programming for IP/MIP Problems with Linear Constraints

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Journal of Systems Engineering and Electronics 2000年第3期11卷 59-64页

作者： Ren, Qingsheng zeng, jin Qi, Feihu Shanghai Jiaotong Univ Shanghai China

In this paper, we propose a modified evolutionary programming with dynamic domain for solving nonlinear IP/MIP problems with linear constraints, without involving penalty function or any transformation for the problem to a linear model or others. The numerical results show that the new algorithm gives a satisfactory performance in which it works of high speed, and accuracy in IP/MIP problems.

关键词： Algorithms Constraint theory Mathematical models Mathematical transformations Problem solving

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Block Monotone Iterative Algorithms for Variational Inequalities with Nonlinear Operators

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Acta Mathematicae Applicatae Sinica 2008年第2期24卷 221-232页

作者： Ming-hui Ren jin-ping zeng Department of Mathematics Hunan University of Arts and Science Changde 415000 China College of Software Dongguan University of Technology Dongguan 511700 China

Some block iterative methods for solving variational inequalities with nonlinear operators are proposed. Monotone convergence of the algorithms is obtained. Some comparison theorems are also established. Compared with the research work in given by Pao in 1995 for nonlinear equations and research work in given by zeng and Zhou in 2002 for elliptic variational inequalities, the algorithms proposed in this paper are independent of the boundedness of the derivatives of the nonlinear operator.

关键词： Monotone iterative algorithm upper solution lower solution comparison theorem variationalinequality

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Sequential clustering of star formations in IC 1396

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Research in Astronomy and Astrophysics 2013年第5期13卷 557-570页

作者： Ya-Fang Huang jin-zeng Li National Astronomical Observatories Chinese Academy of Sciences

We present a comprehensive study of the H II region IC 1396 and its star forming activity, in which multi-wavelength data ranging from the optical to the near- and far-infrared were employed. The surface density distribution of all the 2MASS sources with a certain detection toward IC 1396 indicates the existence of a compact cluster spatially consistent with the position of the exciting source of the H II region, HD 206267. The spatial distribution of the sources with excessive infrared emission, selected based on archived 2MASS data, reveals the existence of four sub-clusters in this region. One is associated with the open cluster Trumpler 37. The other three are found to be spatially coincident with the bright rims of the H II region. All the sources with excessive emission in the near infrared are cross-identified with AKARI IRC data. An analysis of the spectral energy distributions （SEDs） of the resultant sample leads to the identification of eight CLASS I, 15 CLASS II and 15 CLASS IH sources in IC 1396. Optical identification of the sample sources with R magnitudes brighter than 17 mag corroborates the results from the SED analysis. Based on the spatial distribution of the infrared young stellar objects at different evolutionary stages, the surrounding sub-clusters located in the bright rims are believed to be younger than the central one. This is consistent with a scenario of sequential star formation in this region. Imaging data of a dark patch in IC 1396 by Herschel SPIRE, on the other hand, indicate the presence of two far-infrared cores in LDN 1111, which are likely to be a new generation of protostellar objects in formation. So we infer that the star formation process in this H II region was not continuous but rather episodic.

关键词： techniques: photometric -- stars: formation -- stars: pre-main sequence-- infrared: stars

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An SQP Algorithm with Cautious Updating Criteria for Nonlinear Degenerate Problems

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Acta Mathematicae Applicatae Sinica 2009年第1期25卷 33-42页

作者： Tao-wen Liu jin-ping zeng College of Mathematics and Econometrics Hunan University Changsha 410082 China College of Software Dongguan University of Technology Dongguan 523808 China

An efficient SQP algorithm for solving nonlinear degenerate problems is proposed in the paper. At each iteration of the algorithm, a quadratic programming subproblem, which is always feasible by introducing a slack variable, is solved to obtain a search direction. The steplength along this direction is computed by employing the 1∞ exact penalty function through Armijo-type line search scheme. The algorithm is proved to be convergent globally under mild conditions.

关键词： Degenerate problem exact penalty function SQP algorithm cautious update criteria globalconvergence

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Multisplitting Iteration Schemes for Solving a Class of Nonlinear Complementarity Problems

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Acta Mathematicae Applicatae Sinica 2007年第1期23卷 79-90页

作者： Chen-liang Li jin-ping zeng College of Mathematics and Computer Science Hunan Normal University Changsha 410081 China Department of Computational Science and Mathematics Guilin University of Electronics Technology Guilin541004 China Institute of Applied Mathematics Hunan University Changsha 410082 China

We consider several synchronous and asynchronous multisplitting iteration schemes for solving a class of nonlinear complementarity problems with the system matrix being an H-matrix. We establish the convergence theorems for the schemes. The numerical experiments show that the schemes are efficient for solving the class of nonlinear complementarity problems.

关键词： Nonlinear complementarity problems asynchronous iteration H-matrix multisplitting method

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Construction of Paired States in Axially Symmetric Nuclei and Diabolic Pair Transfer

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Chinese Physics Letters 1998年第5期15卷 323-325页

作者： LEI Yi-an zeng jin-yan Department of Physics Peking UniversityBeijing 100871

In axially symmetric nuclei,three forms of paired states can be constructed,i.e.,monopole pair,signature pair and±Ωpair,which are the eigenstates of(J^(2),Jz),(J^(2)_(z),R_(x)(π)),and Jz,*** the cranked shell model,though the energy spectra atω=0 are the same for three types of pair interactions,the spectra and spin alignments forω≠0 are different to a certain *** is found that theωvariation of the pair transfer amplitude,particularly the diabolic pair transfer,is quite different for different pair interactions.

关键词： spectra signature states

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