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Numerical investigation of alleviation of undesirable effect of inter-blade vortex with air admission for a low-head Francis turbine

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Journal of Hydrodynamics 2020年第6期32卷 1151-1164页

作者： long-gang Sun Peng-cheng Guo luo-chang Wu State Key Laboratory of Eco-hydraulics in Northwest Arid Region Xi’an University of TechnologyXi’an710048China

In order to compensate for the stochastic nature of the power grid due to the tremendous development and the integration of renewable energy resources and meet its other requirements,the hydraulic turbines are forced to operate more frequently under partial load conditions with singular and misaligned flows inevitably excited by the inter-blade *** paper presents numerical investigations of the unsteady characteristics of the inter-blade vortex for a low-head model Francis *** SST k-ωturbulent model is used to close the unsteady Reynolds-averaged Navier-Stokes(RANS)*** flow structure of the inter blade vortex predicted by the numerical simulation is confirmed by experimental *** is shown that the total vortex volume in the runner sees a quasi-periodical oscillation,with significant flow separations created on the suction side of the runner blade.A counter measure by using the air admission into the water from the head cover is implemented to alleviate the undesirable effect of the inter-blade *** analyses show that the development of the inter-blade vortex is significantly mitigated by the injecting air that controls and changes the spatial distribution of ***,the flow aeration with a suitable air flow rate can reduce the energy dissipation caused by the inter-blade vortex and plays a critical role in preventing the excessive amplitudes of the pressure fluctuation on the suction side of the runner *** investigation provides an insight into the flow mechanism underlying the inter-blade vortex and offers a reference to alleviate and mitigate the adverse consequences of the inter-blade vortex for the Francis turbine.

关键词： Numerical simulation inter-blade vortex air admission energy dissipation pressure fluctuation Francis turbine

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Quantifying Process Nonclassicality in Bosonic Fields

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Chinese Physics Letters 2019年第10期36卷 36-40页

作者： Shuang-Shuang Fu Shun-long luo School of Mathematics and Physics University of Science and Technology BeijingBeijing 100083 Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190 School of Mathematical Sciences University of the Chinese Academy of SciencesBeijing 100049

Nonclassicality of optical states,as a key characteristic of bosonic fields,is a valuable resource for quantum information *** investigate the generation of nonclassicality in quantum processes from a quantitative perspective,introduce three information-theoretic measures of nonclassicality for quantum-optical processes based on the Wigner–Yanase skew information and coherent states,and illustrate their physical significance through several well-known single-mode quantum processes.

关键词： processes. quantum states

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Uncertainty Relations for Coherence

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Communications in Theoretical Physics 2019年第12期71卷 1443-1447页

作者： Shun-long luo Yuan Sun Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190China School of Mathematical Sciences University of the Chinese Academy of SciencesBeijing 100049China

Quantum mechanical uncertainty relations are fundamental consequences of the incompatible nature of noncommuting *** terms of the coherence measure based on the Wigner-Yanase skew information,we establish several uncertainty relations for coherence with respect to von Neumann measurements,mutually unbiased bases(MUBs),and general symmetric informationally complete positive operator valued measurements(SIC-POVMs),*** coherence is intimately connected with quantum uncertainties,the obtained uncertainty relations are of intrinsically quantum nature,in contrast to the conventional uncertainty relations expressed in terms of variance,which are of hybrid nature(mixing both classical and quantum uncertainties).From a dual viewpoint,we also derive some uncertainty relations for coherence of quantum states with respect to a fixed *** particular,it is shown that if the density operators representing the quantum states do not commute,then there is no measurement(reference basis)such that the coherence of these states can be simultaneously small.

关键词： uncertainty relations coherence Wigner-Yanase skew information quantum uncertainty von Neumann measurements

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Conductivity of carbon-based molecular junctions from ab-initio methods

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Frontiers of physics 2014年第6期9卷 748-759页

作者： xiao-Fei Li Yi luo School of Optoelectronic Information University of Electronic Science and Technology of China Chengdu 610054 China Hefei National Laboratory for Physical Sciences at the Microscale University of Science and Technology of China Hefei 230026 China KTH Royal Institute of Technology School of Biotechnology Division of Theoretical Chemistry and Biology S-106 91 Stockholm Sweden

Carbon nanomaterials （CNMs） are prompting candidates tor next generational electronics. In this review we provide a mini overview of recent results on the conductivity of carbon-based molecular junctions obtained from ab-mitio methods. CNMs used as nanoelectrodes and molecular materials in molecular junctions are discussed. The flmctionalities that include the nanomechanically controlled molecular conductance switches, negative differential resistance devices, and electronic rectifiers realized by using CNMs have been demonstrated.

关键词： carbon nanotubes graphene all-carbon nanodevice quantum transport ab-initio molecular dynamics simulations

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Attitude control of flapping wing aircraft based on energy optimization and ESO

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Biomimetic Intelligence & Robotics 2021年第1期1卷 36-41页

作者： luo Li Hongwei Wang long Cui State Key Laboratory of Robotics Shenyang Institute of AutomationChinese Academy of SciencesShenyang 110016China Institutes for Robotics and Intelligent Manufacturing Chinese Academy of SciencesShenyang 110016China University of Chinese Academy of Sciences Beijing 100049China

Aiming at the problem of insufficient endurance performance of flapping wing aircraft,a stable attitude control algorithm based on energy optimization and ESO(extended state observer)is designed,which effectively reduces the energy consumption in cruise ***,the longitudinal dynamic model of flapping wing aircraft is established,and then the uncertain part of the system and various unknown external disturbances are taken as the total *** module is introduced to observe and track the total disturbance in real ***,the system is transformed into a series integral system through the total disturbance feedback,and then the energy optimal control law is designed on the base of the transformed *** numerical simulation results show that,compared with the traditional PID control method,the designed energy optimal control method reduces the average energy consumption by 35.28%.

关键词： Flapping wing Energy optimal control ESO(Extended State Observer)

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Crop residue incorporation and nitrogen fertilizer effects on greenhouse gas emissions from a subtropical rice system in Southwest China

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Journal of Mountain Science 2018年第9期15卷 1972-1986页

作者： WANG xiao-guo luo Yong Key Laboratory of Mountain Surface Processes and Ecological Regulation Institute of Mountain Hazards and Environment Chinese Academy of Sciences Key laboratory of Geological Spatial information Technology of Ministry of Land and Resource Chengdu University of Technology

Crop residue incorporation has been widely accepted as a way to increase soil carbon(C) sequestration and sustain soil fertility in agroecosystems. However, effect of crop residue incorporation on greenhouse gas(GHG) emissions in rice paddy soils remains uncertain. A field experiment was conducted to quantify emissions of CH_4 and N_2O and soil heterotrophic respiration(RH) from a paddy rice field under five different crop residue treatments(i.e., 150 kg N ha^(-1) of synthetic N fertilizer application only [NF], 150kg N ha^(-1) of synthetic N fertilizer plus 5.3 Mg ha^(-1) wheat residue [NF-WR1], 150 kg N ha^(-1) of synthetic N fertilizer plus 10.6 Mg ha^(-1) wheat residue [NF-WR2], 75 kg N ha^(-1) of synthetic N fertilizer plus 10.6 Mg ha^(-1) wheat residue [50%NF-WR2] and 150 kg N ha^(-1) of synthetic N fertilizer plus 21.2 Mg ha^(-1) wheat residue [NF-WR3]) in southwest China. Our results showed that crop residue incorporation treatments(NF-WR1, NF-WR2, 50%NF-WR2, NF-WR3) significantly increased CH_4 emissions by at least 60%, but N_2O emissions were not enhanced and even suppressed by 25% in the NF-WR3 treatment as compared to the NF treatment. Soil RH emissions were comparable among experimental treatments, while crop residue incorporation treatments significantly increased soil carbon sequestrations relative to the NF treatment. Overall, CH_4 emissions dominated total global warming potentials(GWP) across all experimental treatments. The average yieldscaled GWPs for the NF and NF-WR1 treatments were significantly lower than for the NF-WR2, 50%NFWR2 and NF-WR3 treatments. Given the comparable yield-scaled GWPs between the NF and NF-WR1 treatments, the NF-WR1 treatment could gain net carbon sequestration as compared with the NF treatment with net soil carbon loss. Our findings suggest that the NF-WR1 treatment should be an effective option to sustain rice production while mitigating GHG emissions from the rice field in China.

关键词： Methane Nitrous oxide Crop residueSoil carbon sequestration Global warming potentialPaddy field

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Non-bipartite Graphs with Third Largest Laplacian Eigenvalue Less Than Three

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Acta Mathematica Sinica,English Series 2006年第3期22卷 917-934页

作者： xiao Dong ZHANG Rong luo Department of Mathematics Shanghai Jiao Tong University Department of Mathematical Sciences Middle Tennessee State University

All bipartite graphs whose third largest Laplacian eigenvalue is less than 3 have been characterized by Zhang. In this paper, all connected non-bipartite graphs with third largest Laplacian eigenvalue less than three ... 详细信息

关键词： spectral graph theory Laplacian eigenvalue forbidden subgraph

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Dependence of Amorphous Formation Ability on Intrinsic Parameters in Dy-Gd-Co-Al Alloys

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Journal of Materials Science & Technology 2009年第5期25卷 665-668页

作者： Lin luo Rui Tian Xueshan xiao Institute of Materials Shanghai University Shanghai 200072 China

A series of Dy（Gd）-based bulk amorphous alloy rods were prepared by water-cooled copper mold method. Thermal stability and structure of Dy-Gd-Co-Al alloys were investigated by differential scanning calorimetry and X-ray diffraction, respectively. The results show that the Dy-Gd-Co-Al alloys have good glass-formation ability, and the Dy31Gd25Co20Al24 alloy can be readily cast into full glassy rods up to 5 mm in diameter. The glass-forming ability of multicomponent alloys was greatly dependent on their chemical interaction and the equivalent bond parameters among atoms such as equivalent electronegativity difference, equivalent atomic size parameter. The Dy （Gd）-based bulk amorphous alloys could be expected as potential functional materials.

关键词： Dy(Gd)-based Glass forming ability Intrinsic parameters

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Anti-inflammatory role of microRNA let-7c in LPS treated alveolar macrophages by targeting STAT3

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Asian Pacific Journal of Tropical Medicine 2016年第1期9卷 69-72页

作者： Ji-Hui Yu Li long Zhi-xiao luo Lin-Man Li Jie-Ru You Department of Healthy First Affiliated Hospital of Chongqing Medical University

Objective:To explore the expression of microRNA(miRNA) let-7c and its function in chronic obstructive pulmonary disease(COPD) and alveolar macrophage ***:Real time PCR was performed to detect the expression of miRNA let-7c in the lung tissue of COPD patients and COPD model in *** let-7c was overexpresscd in alveolar macrophages isolated from mice and its effect was measured by the production of pro-inflammation cytokines and the protein level of signal transducer and activator of transcription 3(STAT3) as well as phosphorylation level of STAT3 after LPS *** assay was used to detect the binding of miRNA let-7c and 3'UTR of ***:MiRNA let-7c expression was significantly lower in patients with COPD compared with control group,and the similar result was found in COPD mice and LPS stimulated alveolar *** of miRNA lct-7c in alveolar macrophages inhibited LPS-induced increasing of tumor necrosis factor alpha,interleukin-6 and interleukin-1β.Luciferase assay showed STAT3 was a targeting of miRNA lct-7c in alveolar ***:MiRNA lct-7c low expression in COPD can regulate inflammatory responses by targeting STAT3 in alveolar macrophage,which may provide a new target for COPD treatment strategies.

关键词： Chronic obstructive pulmonary disease Macrophage STAT3 Let-7c Inflammation

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Infinitely Many Solutions for a Class of Quasi-linear Elliptic Problem

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Acta Mathematicae Applicatae Sinica 2024年第3期40卷 728-743页

作者： xiao-yao JIA Zhen-luo LOU School of Economics and Management Zhongyuan University of TechnologyZhengzhou 450007China Mathematics and Statistics School Henan University of Science and TechnologyLuoyang 471023China

In this paper,we study the following quasi-linear elliptic equation:■where Ω?R^(N) is a bounded domain,λ>0 is a *** function ψ(|t|)t is the subcritical term,and φ(|t|)t is the critical Orlicz-Sobolev growth term with respect to φ.Under appropriate conditions on φ,ψ and φ,we prove the existence of infinitely many weak solutions for quasi-linear elliptic equation,for λ∈(0,λ_(0)),where λ_(0)> 0 is a fixed constant.

关键词： quasi-linear elliptic equations variational methods Orlicz-Sobolev spaces

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