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Experimental research on the instability propagation characteristics of liquid kerosene rotating detonation wave

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Defence Technology（防务技术） 2020年第6期16卷 1106-1115页

作者： Quan Zheng Hao-long Meng Chun-sheng weng Yu-wen Wu wen-kang Feng Ming-liang Wu National Key Laboratory of Transient Physics Nanjing University of Science and TechnologyNanjing210094China

In order to study the instability propagation characteristics of the liquid kerosene rotating detonation wave(RDW),a series of experimental tests were carried out on the rotating detonation combustor(RDC)with *** fuel and oxidizer are room-temperature liquid kerosene and preheated oxygenenriched air,*** experimental tests keep the equivalence ratio of 0.81 and the oxygen mass fraction of 35%unchanged,and the total mass flow rate is maintained at about 1000 g/s,changing the total temperature of the oxygen-enriched air from 620 K to 860 *** different types of instability were observed in the experiments:temporal and spatial instability,mode transition and *** interaction between RDW and supply plenum may be the main reason for the fluctuations of detonation wave velocity and pressure peaks with ***,the inconsistent mixing of fuel and oxidizer at different circumferential positions is related to RDW oscillate *** phenomenon of single-double-single wave transition is *** the transition,the initial RDW weakens until disappears,and the compression wave strengthens until it becomes a new RDWand propagates *** increased deflagration between the detonation products and the fresh gas layer caused by excessively high temperature is one of the reasons for the RDC quenching and re-initiation.

关键词： Rotating detonation wave Liquid kerosene Oxygen-enriched air Instability propagation characteristics Compression wave

The effect of different generalized uncertainty principles on Jeans mass modification

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Communications in Theoretical Physics 2023年第10期75卷 129-137页

作者： Ye-xing Yang Zheng-wen Long College of Physics Guizhou UniversityGuiyang550025China

Jeans mass is regarded as a crucial factor in the study of nebula *** data shows that Jeans mass is larger in theory than it is in *** mentioned that Jeans mass can be modified by using the generalized uncertainty principle(GUP).However,different physical backgrounds lead to different forms of GUP *** order to make the theoretical values of Jeans mass and its observed values match better,we use three distinct types of GUPs to correct Jeans mass in this *** find that the corrected Jeans masses are smaller than the uncorrected ones,where the Pedram corrected Jeans mass is the minimum and is close to the observed *** addition,we consider the impact of temperature T and the GUP parameters(η,βandγ)for the corrected Jeans mass.

关键词： Jeans mass generalized uncertainty principle Newtonian gravity

A discrete KdV equation hierarchy:continuous limit, diverse exact solutions and their asymptotic state analysis

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Communications in Theoretical Physics 2022年第6期74卷 1-14页

作者： Xue-Ke Liu Xiao-Yong wen School of Applied Science Beijing Information Science and Technology UniversityBeijing 100192China

In this paper, a discrete KdV equation that is related to the famous continuous KdV equation is studied. First, an integrable discrete KdV hierarchy is constructed, from which several new discrete KdV equations are obtained. Second, we correspond the first several discrete equations of this hierarchy to the continuous KdV equation through the continuous limit. Third, the generalized(m, 2N-m)-fold Darboux transformation of the discrete KdV equation is established based on its known Lax pair. Finally, the diverse exact solutions including soliton solutions, rational solutions and mixed solutions on non-zero seed background are obtained by applying the resulting Darboux transformation, and their asymptotic states and physical properties such as amplitude, velocity, phase and energy are analyzed. At the same time, some soliton solutions are numerically simulated to show their dynamic behaviors. The properties and results obtained in this paper may be helpful to understand some physical phenomena described by KdV equations.

关键词： discrete KdV equation hierarchy continuous limit generalized(m 2N-m)-fold Darboux transformation exact solutions asymptotic analysis

Effects of UV intensity and water turbidity on microbial indicator Inactivation

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Journal of Environmental Sciences 2006年第4期18卷 650-653页

作者： LIU wen-jun ZHANG Yong-ji Department of Environmental Science and Engineering Tsinghua University Beijing 100084 China

The effects of UV intensity and turbidity on selected microbial indicator inactivation were investigated. Results showed that UV disinfection was effective in killing all the selected microbial indicators, the resistance order of the microorganisms was as follows： MS-2 coliphage 〉 Bacillus subtilis 〉 E. coil 〉 Staphylococcus aureus and Candida albicans. UV intensity had influence on the inactivation of all the microorganisms, high UV disinfection efficency was obtained with higher UV intensity. Turbidity had impact on the bacteria inactivation rate, but there was no evidence that turbidity had any negative contribution to MS-2 coliphage. Under the same UV dosage, higher UV intensity could overcome the negative influence of turbidity on UV performance, enhanced microorganism inactivation effect in turbidity water.

关键词： UV disinfection intensity exposure time microbial indicator

Edge Caching in Blockchain Empowered 6G

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China Communications 2021年第1期18卷 1-17页

作者： wen Sun Sheng Li Yan Zhang School of Cybersecurity Northwestern Polytechnical UniversityXi’an 710072China School of Cyber Engineering Xidian UniversityXi’an 710071China University of Oslo Oslo 0316Norway

The sixth generation(6G)of wireless cellular networks is expected to incorporate the latest developments in network infrastructure and emerging advances in *** the age of 6G,edge caching technology will evolve towards intelligence,dynamics,and ***,the security problems of edge caching,including data tampering and eavesdropping,are seldomly considered in most *** this paper,we consider the two-hop edge caching where the blockchain and physical layer security technologies are adopted to prevent data from being tampered with and *** design blockchain-based framework to guarantee the reliability of important data such as the frequency of contents and jointly optimize content caching probability and redundancy rate to maximize the secure transmission *** simulation shows that our optimization scheme can significantly improve the secure transmission probability of edge cache network,whether facing the threat of independent eavesdropping or joint eavesdropping.

关键词： blockchain 6G edge caching physical layer security

On the Character Sum of Polynomials and the Two-term Exponential Sums

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Acta Mathematica Sinica,English Series 2020年第2期36卷 196-206页

作者： Xing Xing LV wen Peng ZHANG School of Mathematics Northwest University

The main purpose of this paper is using the analytic method and the properties of the character sums to study the computational problem of one kind hybrid power mean involving the character sums of polynomials and the... 详细信息

关键词： Character sums of polynomials two-term exponential sums hybrid power mean analytic method asymptotic formula

Combating acoustic heterogeneity in photoacoustic computed tomography:A review

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Journal of Innovative Optical Health Sciences 2020年第3期3卷 32-47页

作者： Tong Wang wen Liu Chao Tian Department of Optics and Optical Engineering University of Science and Technology of China Hefei Anhui 230026 P.R.China Department of Precision Machinery and Precision Instrumentation University of Science and Technology of China Hefei Anhui 230026P.R.China Key Laboratory of Precision Scientific Instrumentation of Anhui Higher Education Institutes University of Science and Technology of China Hefei Anhui 230026P.R.China

Based on the energy conversion of light into sound,photoacoustic computed tomography(PACT)is an emerging biomedical imaging modality and has unique applications in a range of biomedical *** PACT,image formation relies on a process called acoustic inversion from received photoacoustic *** most PACT systems perform this inversion with a basic assumption that biological tissues are acoustically homogeneous,the community gradually rea-lizes that the intrinsic acoustic heterogeneity of tissues could pose distortions and artifacts to finally formed *** paper surveys the most recent research progress on acoustic het-erogeneity correction in *** major strategies are reviewed in detail,including half-time or partial-time reconstruction,autofocus reconstruction by optimizing sound speed maps,joint reconstruction of optical absorption and sound speed maps,and ultrasound computed tomog-raphy(USCT)enhanced *** correction of acoustic heterogeneity helps improve the imaging performance of PACT.

关键词： Photoacoustic computed tomography image reconstruction acoustic heterogeneity ultrasound computed tomography speed of sound

Oscillatory Behavior of Third-order Nonlinear Differential Equations with a Sublinear Neutral Term

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Acta Mathematicae Applicatae Sinica 2022年第2期38卷 484-496页

作者： wen-juan LI Yuan-hong YU Mathematic and computer science College Chifeng UniversityChifeng 024000China Academy of Mathematics and Systems Science Chinese Academy of SciencesBeijing 100190China

The authors present some new criteria for oscillation and asymptotic behavior of solutions of third-order nonlinear differential equations with a sublinear neutral term of the form(r(t)(z"(t))α)+∫_(c)^(d)q(t,ξ)f(x(σ(t,ξ)))dξ=0,t≥t_(0) where z(t)=x(t)+∫_(a)^(b)p(t,ξ)x^(γ)(τ(t,ξ))dξ,0<γ≤*** the conditions∫_(t_(0)-1)^(∞)r^(-1/α)(t)dt=∞or∫_(t0)^(∞)r^(-1/α)(t)dt<∞.The results obtained here extend,improve and complement to some known results in the *** are provided to illustrate the theorems.

关键词： oscillatory behavior neutral differential equation third-order

An interfacial engineering strategy of electrocatalyst boosts ammonia electrosynthesis

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Science China Chemistry 2019年第8期62卷 921-922页

作者： Yichun Ding Genxiang Wang Zhenhai wen CAS Key Laboratory of Design and Assembly of Functional Nanostructures Fujian Key Laboratory of NanomaterialsFujian Institute of Research on the Structure of MatterChinese Academy of Sciences

Ammonia (NH3) is not only an essential chemical feedstock for the manufacture of nitrogen-rich fertilizers but also a promising carbofree energy carrier for storing H2 due to its high content of hydrogen (17.6% by mass). At present, industrial NH3 is still dominantly produced by the traditional Haber-Bosch process, which reduces nitrogen (N2) to NH3 (N2+3H2←→2NH 3) at high temperatures (350-550 °C) and high pressures (150-350 atm)[1]. Such a process not only requires the raw materials of high-purity streams of nitrogen and hydrogen but also consumes tremendous energy;noting that the consumed hydrogen occupied approximately 50% of its global production that produced exclusively from transformations of fossil resources with the emission of greenhouse gas [1].

关键词： engineering strategy electrosynthesis tremendous energy