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Electronic structure,bonding characteristics,and mechanical behaviors of a new family of Si-containing damage-tolerant mAB phases m_(5)SiB_(2)(m=IVB-VIB transition metals)

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Journal of Advanced Ceramics 2022年第10期11卷 1626-1640页

作者： Na ni Hanchao ZHANG Yanchun ZHOU School of mechanical Engineering Shanghai Jiao Tong UniversityShanghai 200240China Science and Technology on Advanced Functional Composite Laboratory Aerospace Research Institute of Materials&Processing TechnologyBeijing 100076China

mAB phases are layered ternary compounds with alternative stacking of transition metal boride layers and group A element *** now,most of the investigated mAB phases are concentrated on compounds with Al as the A element *** this work,the family of m_(5)SiB_(2)(m=IVB-VIB transition metals)compounds with silicon as interlayers were investigated by density functional theory(DFT)methods as potential mAB phases for high-temperature *** from the known mo5SiB2,the electronic structure,bonding characteristics,and mechanical behaviors were systematically investigated and *** the composition of m_(5)SiB_(2) does not follow the general formula of experimentally reported(mB)_(2z)A_(x)(mB_(2))_(y)(z=1,2;x=1,2;y=0,1,2),their layered structure and anisotropic bonding characteristics are similar to other known mAB phases,which justifies their classification as new members of this material *** a result of the higher bulk modulus and lower shear modulus,mo_(5)SiB_(2) has a Pugh’s ratio of 0.53,which is much lower than the common mAB *** was found that the stability and mechanical properties of m_(5)SiB_(2) compounds depend on their valence electron concentrations(VECs),and an optimum VEC exists as the criteria for *** hypothesized Zr and Hf containing compounds,i.e.,Zr_(5)SiB_(2) and Hf_(5)SiB_(2),which are more interesting in terms of high-temperature oxidation/ablation resistance,were found to be unfortunately *** cope with this problem,a new stable solid solution(Zr_(0.6)mo_(0.4))_(5)SiB_(2) was designed based on VEC tuning to demonstrate a promising approach for developing new mAB phases with desirable compositions.

关键词： borides mAB phases density functional theory(DFT) thermodynamic stability electronic structure mechanical properties

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10 watt-level tunable narrow linewidth 1.5μm all-fiber amplifier

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High Power Laser Science and Engineering 2018年第2期6卷 149-153页

作者： ni Tang Zhiyue Zhou Zhixian Li Zefeng Wang College of Advanced Interdisciplinary StudiesNational University of Defense TechnologyChangsha 410073China Hunan Provincial Collaborative Innovation Center of High Power Fiber Laser Changsha 410073China Hunan Provincial Key Laboratory of High Energy Laser Technology Changsha 410073China

We report here a high-power, wavelength tunable and narrow linewidth 1.5 μm all-fiber laser amplifier based on a tunable diode laser and Er-Yb co-doped fibers. The laser wavelength can be precisely tuned from 1535 nm to 1580 nm, which covers many absorption lines of mid-infrared laser gases, such as C2 H2, HCN, CO, and HI. The maximum laser power is >11 W, and the linewidth is about 200–300 mHz, which is close to the absorption linewidth of the above-mentioned gases. This work provides a suitable pump source for high-power wavelength tunable mid-infrared fiber gas lasers based on low-loss hollow-core fibers.

关键词： Er-doped fibers fiber amplifier fiber lasers high power narrow linewidth

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Translating Surfaces of the Non-parametric mean Curvature Flow in Lorentz manifold m^(2)×R^(*)

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Chinese Annals of mathematics,Series B 2021年第2期42卷 297-310页

作者： Li CHEN Dan-Dan HU Jing mAO ni XIANG Faculty of mathematics and Statistics Key Laboratory of Applied Mathematics of Hubei ProvinceHubei UniversityWuhan 430062China

In this paper, for the Lorentz manifold m^(2)× R with m^(2) a 2-dimensional complete surface with nonnegative Gaussian curvature, the authors investigate its spacelike graphs over compact, strictly convex domains in m^(2), which are evolving by the nonparametric mean curvature flow with prescribed contact angle boundary condition, and show that solutions converge to ones moving only by translation.

关键词： Translating surfaces mean curvature flow Lorentz manifolds

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Nonlinear forced vibration in a subcritical regime of a porous functionally graded pipe conveying fluid with a retaining clip

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Applied mathematics and mechanics(English Edition) 2025年第1期46卷 101-122页

作者： m.GHOLAmI m.EFTEKHARI Department of mechanical Engineering Shahid Bahonar University of Kerman

This study examines the nonlinear behaviors of a clamped-clamped porous pipe made of a functionally graded material(FGm) that conveys fluids and is equipped with a retaining clip, focusing on primary resonance and subcritical dynamics. The nonlinear governing equations for the FGm pipe are derived by the extended Hamilton's principle, and subsequently discretized through the application of the Galerkin *** direct method of multi-scales is then used to solve the derived equations. A thorough analysis of various parameters, including the clip stiffness, the power-law index, the porosity, and the clip location, is conducted to gain a comprehensive understanding of the system's nonlinear dynamics. Through the analysis of the first natural frequency, the study highlights the influence of the flow velocity and the clip stiffness, while the comparisons with metallic pipes emphasize the role of FGm composition. The examination of the forced response curves reveals saddle-node bifurcations and their dependence on parameters such as the detuning parameter and the power-law index, offering valuable insights into the system's nonlinear resonant behavior. Furthermore, the frequency-response curves illustrate the hardening nonlinearities influenced by factors such as the porosity and the clip stiffness, revealing nuanced effects on the system response and resonance characteristics. This comprehensive analysis enhances the understanding of nonlinear behaviors in FGm porous pipes with a retaining clip, providing key insights for practical engineering applications in system design and optimization.

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Rethinking the architecture design of data center networks

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Frontiers of Computer Science 2012年第5期6卷 596-603页

作者： Kaishun WU Jiang XIAO Lionel m. ni National Engineering Research Center of Digital Life State-Province Joint Laboratory of Digital Home Interactive Applications School of Physics and Engineering Sun Yat-sen University Guangzhou 510006 China Department of Computer Science and Engineering Hong Kong University of Science and Technology Hong Kong China

In the rising tide of the Internet of things, more and more things in the world are connected to the Internet. Recently, data have kept growing at a rate more than four times of that expected in moore＇s law. This explosion of data comes from various sources such as mobile phones, video cameras and sensor networks, which often present multidi- mensional characteristics. The huge amount of data brings many challenges on the management, transportation, and pro- cessing IT infrastructures. To address these challenges, the state-of-art large scale data center networks have begun to provide cloud services that are increasingly prevalent. How- ever, how to build a good data center remains an open chal- lenge. Concurrently, the architecture design, which signifi- cantly affects the total performance, is of great research inter- est. This paper surveys advances in data center network de- sign. In this paper we first introduce the upcoming trends in the data center industry. Then we review some popular design principles for today＇s data center network architectures. In the third part, we present some up-to-date data center frame- works and make a comprehensive comparison of them. Dur- ing the comparison, we observe that there is no so-called op- timal data center and the design should be different referring to the data placement, replication, processing, and query pro- cessing. After that, several existing challenges and limitations are discussed. According to these observations, we point out some possible future research directions.

关键词： data center networks switch-based networks,direct networks hybrid networks

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Ordered proposition fusion based on consistency and uncertainty measurements

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Science China(Information Sciences) 2017年第8期60卷 117-135页

作者： Dayou LIU Yungang ZHU ni ni Jie LIU College of Computer Science and Technology Jilin University Key Laboratory of Symbolic Computation and Knowledge Engineering of ministry of Education Jilin University Beijing Entry-Exit Inspection and Quarantine Bureau

The fusion of ordered propositions is an important and widespread problem in artificial intelligence,but existing fusion methods have difficulty handling the fusion of ordered propositions. In this paper, we propose a solution based on consistency and uncertainty measurements. The main contributions of this paper are as follows. First, we propose the concept of convexity degree, mean, and center of basic support function to comprehensively describe the basic support function of ordered propositions. Second, we introduce entropy as a measure of uncertainty in the basic support function of ordered propositions. Third, we generalize the indeterminacy of the basic support function and propose a novel method to measure the consistency between two basic support functions. Finally, based on the above researches, we propose a novel algorithm for fusing ordered propositions. Theoretical analysis and experimental results demonstrate that the proposed method outperforms state-of-the-art methods.

关键词： uncertainty processing ordered proposition evidence theory dempster rule of combination information fusion

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Rethinking big data in a networked world

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Frontiers of Computer Science 2016年第6期10卷 965-967页

作者： Lionel m. ni Haoyu TAN Jiang XIAO Department of Computer and Information Science University of Macao Macao China Fok Ying Tung Graduate School Hong Kong University of Science and Technology Hong Kong China

Since the early 21st century, big data has drawn much attention from both academia and industry. In the last decade of collecting massive data, seeking innovative applications, and developing powerful technologies, the major focus of the research and engineering in big data has shifted substantially in many aspects. It is time to rethink about this fuzzy term to make clear the upcoming opportunities and the most urgent challenges.

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Hepatitis C:a successful story of cure

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Science Bulletin 2016年第24期61卷 1884-1887页

作者： Yi ni Department of Infectious Diseases Molecular VirologyUniversity Hospital Heidelberg 69120 Heidelberg Germany

On September 23, the 2016 Lasker-DeBakey clinical medical research award ceremony was celebrated in New York City. This annual prize has been awarded by the Lasker Foundation for over 71 years, and it is the most prestigious biomedical award in the United States, popu- larly known as ＂America＇s Nobel Prize＂. Indeed, 87 Lasker laureates have received the Nobel Prize, including 41 within the last 30 years （one example is the Chinese pharmaceutical chemist Youyou Tu, who won the 2011 Lasker-DeBakey award and four years later received the Nobel Prize）. This year, the honor went to Ralf F. W. Bartenschlager （Heidelberg University, Germany）, Charles m. Rice （Rockefeller University, NY, USA）, and michael J. Sofia （Arbutus Biopharma, PA, USA） for the development of cell culture system to study the replication of Hepatitis C virus （HCV） and for the use of this system to develop drugs capable of eliminating Hepatitis C.

关键词：丙型肝炎病毒 michael 故事治愈诺贝尔奖生物制药开发能力培养系统

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Neurogenesis dynamics in the olfactory bulb:deciphering circuitry organization, function, and adaptive plasticity

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Neural Regeneration Research 2025年第6期20卷 1565-1581页

作者： moawiah m.Naffaa Department of Psychology and Neuroscience Duke UniversityDurhamNCUSA Department of Cell Biology Duke University School of MedicineDurhamNCUSA

Adult neurogenesis persists after birth in the subventricular zone, with new neurons migrating to the granule cell layer and glomerular layers of the olfactory bulb, where they integrate into existing circuitry as inhibitory interneurons. The generation of these new neurons in the olfactory bulb supports both structural and functional plasticity, aiding in circuit remodeling triggered by memory and learning processes. However, the presence of these neurons, coupled with the cellular diversity within the olfactory bulb, presents an ongoing challenge in understanding its network organization and function. moreover,the continuous integration of new neurons in the olfactory bulb plays a pivotal role in regulating olfactory information processing. This adaptive process responds to changes in epithelial composition and contributes to the formation of olfactory memories by modulating cellular connectivity within the olfactory bulb and interacting intricately with higher-order brain regions. The role of adult neurogenesis in olfactory bulb functions remains a topic of debate. Nevertheless, the functionality of the olfactory bulb is intricately linked to the organization of granule cells around mitral and tufted cells. This organizational pattern significantly impacts output, network behavior, and synaptic plasticity, which are crucial for olfactory perception and memory. Additionally, this organization is further shaped by axon terminals originating from cortical and subcortical regions. Despite the crucial role of olfactory bulb in brain functions and behaviors related to olfaction, these complex and highly interconnected processes have not been comprehensively studied as a whole. Therefore, this manuscript aims to discuss our current understanding and explore how neural plasticity and olfactory neurogenesis contribute to enhancing the adaptability of the olfactory system. These mechanisms are thought to support olfactory learning and memory, potentially through increased

关键词： network adaptability neurogenesis neuronal communication olfactory bulb olfactory learning olfactory memory synaptic plasticity

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Demonstration of tantalum as a structural material for mEmS thermal actuators

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microsystems & Nanoengineering 2021年第1期7卷 85-97页

作者： Longchang ni Ryan m.Pocratsky maarten P.de Boer CmU mechanical Engineering Dept. 5000 Forbes Ave.PittsburghPA 15213USA Present address:Fischione Instruments 9003 Corporate CirExportPA 15632USA

This work demonstrates the processing,modeling,and characterization of nanocrystalline refractory metal tantalum(Ta)as a new structural material for microelectromechanical system(mEmS)thermal actuators(TAs).Nanocrystalline Ta films have a coefficient of thermal expansion(CTE)and Young’s modulus comparable to bulk Ta but an approximately ten times greater yield *** mechanical properties and grain size remain stable after annealing at temperatures as high as 1000°*** has a high melting temperature(Tm=3017℃)and a low resistivity(ρ=20µΩcm).Compared to TAs made from the dominant mEmS material,polycrystalline silicon(polysilicon,Tm=1414℃,ρ=2000µΩcm),Ta TAs theoretically require less than half the power input for the same force and displacement,and their temperature change is half that of *** TAs operate at a voltage 16 times lower than that of other TAs,making them compatible with complementary metal oxide semiconductors(CmOS).We selectα-phase Ta and etch 2.5-μm-thick sputterdeposited films with a 1μm width while maintaining a vertical sidewall profile to ensure in-plane movement of TA *** is 25 times thicker than the thickest reactive-ion-etchedα-Ta reported in the technical *** stress sensitivities to sputter parameters and to hydrogen incorporation are investigated and ***,a V-shaped TA is fabricated and tested in *** conventional actuation by Joule heating and passive self-actuation are as predicted by models.

关键词： thermal structural thick

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