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Utility and influence mechanism of densification modulation on grain boundary diffusion in NdFeB magnets

Journal of Rare Earths 2025年第03期 569-577页

作者： San'gen luo Munan Yang Shuwei Zhong Sajjad Ur Rehman Jiajie Li Xiaoqiang Yu Bin Yang College of Rare Earths Jiangxi University of Science and Technology National Rare Earth Functional Material Innovation Center&Guorui Scientific Innovation Rare Earth Functional Materials Co. Ltd.

Grain boundary diffusion technology is pivotal in the preparation of high-performance NdFeB *** study investigates the factors that affect the efficiency of grain boundary diffusion,starting from the properties of the diffusion *** the adjustment of the sintering process,we effectively prepared magnets with varied densities that serve as the matrix for grain boundary diffusion with TbH,*** mobility characteristics of the Nd-rich phase during the densification stage are leveraged to ensure a more extensive distribution of heavy rare earth elements within the *** to the experimental results,the increase in coercivity of low-density magnets after diffusion is significantly greater than that of relatively high-density *** coercivity values measured are 805.32 kA/m for low-density magnets and 470.3 kA/m for high-density ***,grain boundary diffusion notably enhances the density of initial low-density magnets,addressing the issue of low density during the sintering *** the diffusion treatment,the Nd-rich phases primarily concentrate at the triangular grain boundaries,resulting in an increased number of cavity defects in the *** cavity defects contain atoms in a higher energy state,making them more prone to ***,the diffusion activation energy at the void defects is lower than the intracrystalline diffusion activation energy,accelerating atom *** presence of larger cavities also provides more space for atom migration,thereby promoting the diffusion *** the diffusion treatment,the proportion of bulk Nd-rich phases significantly decreases,and they infiltrate between the grains to fill the cavity defects,forming continuous fine grain *** on these observations,the study aims to explore how to utilize this information to develop an efficient technique for grain boundary diffusion.

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Theoretical Mechanistic Studies of Rh-Catalyzed c(sp^3)-H Amination:A Comparison with Co Analogue and Metal Effects

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Chinese Journal of Chemistry 2020年第12期38卷 1526-1532页

作者： Yang Yu gen luo Jimin Yang Yi luo State Key Laboratory of Fine Chemicals School of Chemical EngineeringDalian University of TechnologyDalianLiaoning 116024China Institutes of Physical Science and Information Technology Anhui UniversityHefeiAnhui 230601China

of main observation and conclusion The mechanism of Rh-catalyzed C(sp^3)—H amination has been computationally *** reaction mechanism mainly involves sequential C(sp^3)—H activation,decarboxylation,nitrene migration insertion,and protonation *** concerted metalation deprotonation(CMD)and external base assisted deprotonation(EBAD)pathways are found for the involved C(sp^3)—H activation in both Rh and Co analogous *** is different from the previously reported C(sp^2)—H activation,where the CMD is *** key mechanistic difference between the two systems is found to be in the C(sp^3)—H activation *** comparison with Rh species,the lower activity of Co complex toward the C(sp^3)—H activation could be ascribed to smaller atomic size of Co and thus larger steric repulsion between ancillary ligand and substrate along with the CMD *** view of the EBAD pathway,however,the lower activity of Co species could be imputed to the triplet nature of Co center,which is against the electron transfer from the electron-rich carbon atom of the deprotonating C(sp^3)—H bond to the Co *** to the subsequent decarboxylation and nitrene insertion steps,compared with the Co system,the relatively lower reactivity of Rh species is partially due to the stronger Rh—N bond,and the higher Ti(Rh—N)and n^*(Rh—N)orbital energies of the corresponding transition state structure.

关键词： structure. activation steps

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The MAP/PH/N Retrial Queue in a Random Environment

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Acta Mathematicae Applicatae Sinica 2013年第4期29卷 725-738页

作者： Gang YANG luo-gen YAO Zi-sheng OUYANG School of Information Hunan University of Commerce

We consider the MAP/PH/N retrial queue with a finite number of sources operating in a finite state Markovian random environment. Two different types of multi-dimensional Markov chains are investigated describing the behavior of the system based on state space arrangements. The special features of the two formulations are discussed. The algorithms for calculating the stationary state probabilities are elaborated, based on which the main performance measures are obtained, and numerical examples are presented as well.

关键词： retrial queue Markovian arrival process (MAP) phase-type service Markovian random environ-ment finite number of sources

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Application of Moore-Penrose Inverse in Deciding the Minimal Martingale Measure

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Acta Mathematicae Applicatae Sinica 2010年第4期26卷 653-660页

作者： luo-gen Yao Gang Yang Xiang-qun Yang Information Department of Hunan Business College Changsha 410205China College of Mathematics and Computer Science Hunan Normal UniversityChangsha 410081China

The Moore-Penrose inverse is an important tool in *** paper shows that the MoorePenrose inverse is also an effcient technique in determining the minimal martingale measure if a security price follows a semi-martingale which satisfies some structure *** extend a result of Dzhaparidze and Spreij concerning the Moore-Penrose inverse to the case that the Moore-Penrose inverse of any matrix-valued predictable process is still ***,we obtain an explicit formula of the minimal martingale measure by employing the Moore-Penrose ***,the minimal martingale measure in a generalized Black-Scholes model is found.

关键词： Moore-Penrose inverse minimal martingale measure semi-martingales structure condition

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On Exact Solutions to Partial Differential Equations by the Modified Homotopy Perturbation Method

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Acta Mathematicae Applicatae Sinica 2012年第1期28卷 91-98页

作者： Gang YANG Ru-yun CHEN luo-gen YAO School of Information Hunan University of CommerceChangsha 410205China School of Science Guangdong Ocean UniversityZhanjiang 524088China

Based on the modified homotopy perturbation method （MHPM）, exact solutions of certain partial differential equations are constructed by separation of variables and choosing the finite terms of a series in p as exact solutions. Under suitable initial conditions, the PDE is transformed into an ODE. Some illustrative examples reveal the efficiency of the proposed method.

关键词： homotopy perturbation method modified homotopy perturbation method analytic solution Fokker-Planck equation

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Option Pricing by Mean Correcting Method for Non-Gaussian Lvy Processes

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Acta Mathematica Sinica,English Series 2013年第10期29卷 1927-1938页

作者： luo gen YAO Gang YANG Xiang Qun YANG School of Mathematics and Statistics Hu'nan Business College College of Mathematics and Computer Science Hu'nan Normal University

For a non-Gaussian Levy model, it is shown that if the model exists a trivial arbitrage-free interval, option pricing by mean correcting method is always arbitrage-free, and if the arbitrage-free interval is non-trivial, this pricing method may lead to arbitrage in some cases. In the latter case, some necessary and sufficient conditions under which option price is arbitrage-free are obtained.

关键词： Non-Gaussian Levy processes mean correcting method option pricing

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The mean correcting martingale measures for exponential additive processes

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Applied Mathematics(A Journal of Chinese Universities) 2016年第1期31卷 81-88页

作者： YAO luo-gen YANG Gang YANG Xiang-qun School of Mathematics and Statistics Hunan University of Commerce Changsha 410205 China College of Mathematics and Computer Science Hunan Normal University Changsha 410081 China

The mean correcting martingale measure for the stochastic process defined as the exponential of an additive process is constructed. Necessary and sufficient conditions for the existence of mean correcting martingale are also obtained. The investigation of this paper will establish a unified way that is applicable both to the case of Ldvy processes and that of the sums of independent random variables. As an application, we present the necessary and sufficient conditions that the discounted stock price process is a martingale.

关键词： Mean correcting martingale measure additive processes option pricing.

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红细胞与纤维蛋白成分在急性缺血性脑卒中患者血栓中的占比分析及其对预后的影响

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中国现代医学杂志 2025年第1期35卷 9-14页

作者：罗根培胡伟东钟望涛广东医科大学研究生学院广东湛江524000 东莞市人民医院神经内科广东东莞523000 广东医科大学附属医院神经内科广东湛江524000

目的探讨红细胞与纤维蛋白成分在急性缺血性脑卒中患者血栓中的占比对预后的影响。方法选取2021年1月—2024年1月东莞市人民医院接诊的102例急性缺血性脑卒中患者为研究对象,均给予机械取栓手术治疗,术后参考改良脑梗死溶栓(mTICI)分级... 详细信息

目的探讨红细胞与纤维蛋白成分在急性缺血性脑卒中患者血栓中的占比对预后的影响。方法选取2021年1月—2024年1月东莞市人民医院接诊的102例急性缺血性脑卒中患者为研究对象,均给予机械取栓手术治疗,术后参考改良脑梗死溶栓(mTICI)分级评估血管再通情况分为预后良好组(66例)与预后不良组(36例)。比较两组的围手术期改良Rankin量表(mRS)评分、C反应蛋白(CRP)、中性粒细胞/淋巴细胞、同型半胱氨酸、高纤维蛋白/血小板血栓、高红细胞血栓。采用多因素逐步Logistic回归模型分析急性缺血性脑卒中患者预后不良的影响因素。结果术后24 h、出院前,预后不良组的mRS评分高于预后良好组(P<0.05)。预后不良组患者的CRP水平、中性粒细胞/淋巴细胞比值、同型半胱氨酸水平均高于预后良好组(P<0.05)。预后不良组高纤维蛋白/血小板血栓占比高于预后良好组(P<0.05),高红细胞血栓占比低于预后良好组(P<0.05)。多因素逐步Logistic回归分析结果显示,CRP水平高[OR=3.702(95%CI:1.607,8.529)]、中性粒细胞/淋巴细胞比值高[OR=3.615(95%CI:1.569,8.327)]、同型半胱氨酸水平高[OR=4.076,95%CI:1.769,9.389)]、高纤维蛋白/血小板血栓[OR=3.741(95%CI:1.623,8.615)]均是急性缺血性脑卒中患者预后不良的危险因素(P<0.05)。结论血栓中高纤维蛋白/血小板组分与急性缺血性脑卒中患者的不良预后密切相关。

关键词：急性缺血性脑卒中血栓成分预后

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Computational identification and evolutional analysis of Piwi subfamily in 11 Drosophila species

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Insect Science 2008年第6期15卷 537-544页

作者： Xue Zhou Ya-Long Xu luo-gen Cheng Fei Li College of Life Science Nanjing Normal University Department of Entomology Nanjing Agricultural University Nanjing China

The complete genome sequences of 11 Drosophila species provide an opportunity to investigate the gene family evolution in closely related species. Drosophila Piwi subfamily, including three members, piwi, Aub and Ago3, has attracted increasing attention as it participates in the biogenesis of piRNA. Here, we identified 33 Piwi homologs from the genome of 11 Drosophila species. The full-length cDNA sequences ofpiwi and Aub genes were obtained by using New genSCAN Web Server. The Ago3 homologs were difficult regarding full-length information because they had long introns. The genomic structure of Piwi subfamily genes are highly conserved among diverse Drosophila species. Insect piwi and Aub genes have long first introns. The average length of the first intron is 1 284 bp for piwi and 840 bp for Aub, which is much larger than those of other introns （93 bp for Piwi and 54 bp for Aub）. However, this phenomenon is not observed in mammalian piwi genes. We also found that there were abundant repeat sequences in both exons and introns of insect Ago3 genes. Due to recent insertions of long terminal repeat elements in four Drosophila species, part of the third introns exhibit higher conservation than adjacent exons and other introns. An evolutional tree created by Minimum Evolution method indicates that mammalian piwi genes are more closely related to the insect Ago3 Piwi subfamily.

关键词： evolution Drosophila genome intron Piwi subfamily

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A New Coordination Polymer Built of 4-(5H-tetrazol)-benzoic Acid and 3,5-Dimethyl-1H,1,2,4-Triazole Showing a Rarely Observed(3,5)-Connected lhh Topology: Synthesis, Structure, CO_2 Adsorption and Luminescent Property

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Chinese Journal of Structural Chemistry 2016年第2期35卷 264-270页

作者： SHENG Dong-Hai DAN Wen-Yan luo gen-Xiang DENG Ming-Li College of Chemistry Chemical Engineering and Environmental EngineeringLiaoning Shihua University Department of Chemistry Fudan University

A three-dimensional coordination polymer,namely {[Zn2（tzba）（dmtrz）（OH）]·3H2O}n（1,H2tzba = 4-（5H-tetrazol）benzoic acid,Hdmtrz = 3,5-dimethyl-lH,l,2,4-triazole）,was hydrothermally synthesized and characterized by single-crystal X-ray *** crystallizes in monoclinic system,P21/c space group with a = 8.018（11）,b = 21.04（3）,c = 11.069（14） A,β=91.26（3）°,V= 1867（4） A^3,Z = 4,Dc = 1.729 g/cm^3,F（000） = 984,μ= 2.614 mm^（-1）,R（F^2 〉 2σ（F^2）） =0.0612 and wR（F^2） = *** analysis reveals that compound 1 is a（3,5）-connected structure with a Schlafli symbol of（4~2.6）（4~2.6~5.8~3）,which is a rarely observed lhh *** addition,the CO2 adsorption performance and luminescent property of 1 have also been studied.

关键词： crystal structure mixed ligands topology

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