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Existence of Positive Solutions for Higher Order Boundary Value Problem on Time Scales 被引量:2
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作者 Xie Da-peng Liu Yang +1 位作者 Sun Ming-zhe Li Yong 《Communications in Mathematical Research》 CSCD 2013年第1期1-13,共13页
In this paper, we investigate the existence of positive solutions of a class higher order boundary value problems on time scales. The class of boundary value problems educes a four-point (or three-point or two-point... In this paper, we investigate the existence of positive solutions of a class higher order boundary value problems on time scales. The class of boundary value problems educes a four-point (or three-point or two-point) boundary value problems, for which some similar results are established. Our approach relies on the Krasnosel'skii fixed point theorem. The result of this paper is new and extends previously known results. 展开更多
关键词 higher order boundary value problem positive solution SEMIpositONE on time scale fixed point
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FINITE TIME BLOW UP OF THE SOLUTIONS TO BOUSSINESQ EQUATION WITH LINEAR RESTORING FORCE AND ARBITRARY POSITIVE ENERGY 被引量:2
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作者 nikolay kutev natalia kolkovska milena dimova 《Acta Mathematica Scientia》 SCIE CSCD 2016年第3期881-890,共10页
Finite time blow up of the solutions to Boussinesq equation with linear restoring force and combined power nonlinearities is studied. Sufficient conditions on the initial data for nonexistence of global solutions are ... Finite time blow up of the solutions to Boussinesq equation with linear restoring force and combined power nonlinearities is studied. Sufficient conditions on the initial data for nonexistence of global solutions are derived. The results are valid for initial data with arbitrary high positive energy. The proofs are based on the concave method and new sign preserving functionals. 展开更多
关键词 Boussinesq equation with linear restoring force finite time blow up arbitrary high positive energy combined power nonlinearities sign preserving functionals
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Positive periodic solution for a nonautonomous periodic model of population with time delays and impulses 被引量:1
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作者 ZHOU Gang SHI Bao GAI Ming-jiu ZHANG De-cun Institute of Systems Science and Mathematics, Naval Aeronautical and Astronautical University, Yantai264001, China 《Applied Mathematics(A Journal of Chinese Universities)》 SCIE CSCD 2010年第1期18-24,共7页
In this paper, a nonautonomous periodic model of population with time delays and impulses, which arises in order to describe the control of a single population of cells, is studied. By the coincidence degree theory we... In this paper, a nonautonomous periodic model of population with time delays and impulses, which arises in order to describe the control of a single population of cells, is studied. By the coincidence degree theory we obtain the conditions for the existence of periodic solution of this system. 展开更多
关键词 positive periodic solution IMPULSE coincidence degree time delay.
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Forced Oscillation of Neutral Advanced Dynamic Equations with Positive and Negative Coeffcients on Time Scales 被引量:1
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作者 YANG Jun WU Hui-ning 《Chinese Quarterly Journal of Mathematics》 CSCD 2011年第3期466-469,共4页
In this paper,we consider the forced neutral advanced dynamic equations with positive and negative coeffcients[x(t)-R(t)x(t+r)]+P(t)x(t+τ)△Q(t)x(t+δ)= f(t),t≥t0 on a time scale T.Several suffcient conditions are o... In this paper,we consider the forced neutral advanced dynamic equations with positive and negative coeffcients[x(t)-R(t)x(t+r)]+P(t)x(t+τ)△Q(t)x(t+δ)= f(t),t≥t0 on a time scale T.Several suffcient conditions are obtained for the oscillation of the dynamic equations.The main result is illustrated by an example. 展开更多
关键词 time scales FORCED NEUTRAL ADVANCED oscillation positive and negative coeffcients
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Positive Solutions for First-order PBVPs on Time Scales 被引量:1
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作者 SONG Chang-xiu 《Chinese Quarterly Journal of Mathematics》 CSCD 2012年第3期337-343,共7页
In this paper, the author studies the following nonlinear dynamic equation {x△(t) = r(t)x(σ(t)) + f(t, x(σ(t))), t ∈ [0, T ], x(0) = x(σ(T )). By applying and improving the generalized form of Leggett-Williams fi... In this paper, the author studies the following nonlinear dynamic equation {x△(t) = r(t)x(σ(t)) + f(t, x(σ(t))), t ∈ [0, T ], x(0) = x(σ(T )). By applying and improving the generalized form of Leggett-Williams fixed point theorem, sufficient conditions are established for the existence of positive solutions. 展开更多
关键词 time scale positive solutions fixed point
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Performance Evaluation of Three-Dimensional UWB Real-Time Locating Auto-Positioning System for Fire Rescue
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作者 Hang Yang Xunbo Li Witold Pedrycz 《Intelligent Automation & Soft Computing》 SCIE 2023年第9期3039-3058,共20页
Fire rescue challenges and solutions have evolved from straightfor-ward plane rescue to encompass 3D space due to the rise of high-rise city buildings.Hence,this study facilitates a system with quick and simplified on... Fire rescue challenges and solutions have evolved from straightfor-ward plane rescue to encompass 3D space due to the rise of high-rise city buildings.Hence,this study facilitates a system with quick and simplified on-site launching and generates real-time location data,enabling fire rescuers to arrive at the intended spot faster and correctly for effective and precise rescue.Auto-positioning with step-by-step instructions is proposed when launching the locating system,while no extra measuring instrument like Total Station(TS)is needed.Real-time location tracking is provided via a 3D space real-time locating system(RTLS)constructed using Ultra-wide Bandwidth technology(UWB),which requires electromagnetic waves to pass through concrete walls.A hybrid weighted least squares with a time difference of arrival(WLS/TDOA)positioning method is proposed to address real path-tracking issues in 3D space and to meet RTLS requirements for quick computing in real-world applications.The 3D WLS/TDOA algorithm is theoretically constructed with the Cramer-Rao lower bound(CRLB).The computing complexity is reduced to the lower bound for embedded hardware to directly compute the time differential of the arriving signals using the time-to-digital converter(TDC).The results of the experiments show that the errors are controlled when the positioning algorithm is applied in various complicated situations to fulfill the requirements of engineering applications.The statistical analysis of the data reveals that the proposed UWB RTLS auto-positioning system can track target tags with an accuracy of 0.20 m. 展开更多
关键词 3D space positioning ULTRA-WIDEBAND real-time locating system time difference of arrival Cramer-Rao lower bound fire rescue
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Existence of Multiple Positive Solutions for <i>n</i><sup>th</sup>Order Two-Point Boundary Value Problems on Time Scales
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作者 Kapula Rajendra Prasad Penugurthi Murali Nadakuduti V. V. S. Suryanarayana 《Advances in Pure Mathematics》 2013年第1期70-77,共8页
We consider the nth order nonlinear differential equation on time scales subject to the right focal type two-point boundary conditions We establish a criterion for the existence of at least one positive solution by ut... We consider the nth order nonlinear differential equation on time scales subject to the right focal type two-point boundary conditions We establish a criterion for the existence of at least one positive solution by utilizing Krasnosel’skii fixed point theorem. And then, we establish the existence of at least three positive solutions by utilizing Leggett-Williams fixed point theorem. 展开更多
关键词 time Scale Dynamical Equation positive Solution CONE Boundary Value Problem
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Global asymptotic stability of positive equilibrium in a 3-species cooperating model with time delay
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作者 王长有 《Journal of Chongqing University》 CAS 2007年第3期192-199,共8页
The asymptotic behavior of the time-dependent solution for a 3-species cooperating model was investigated with the effects of both diffusion and time delay taken into consideration. We proved the global asymptotic sta... The asymptotic behavior of the time-dependent solution for a 3-species cooperating model was investigated with the effects of both diffusion and time delay taken into consideration. We proved the global asymptotic stability of a positive steady-state solution to the model problem by using coupled upper and lower solutions for a more general reaction-diffusion system that gives a common framework for 3-species cooperating model problems. The result of global asymptotic stability implies that the model system coexistence is permanent. Some global asymptotic stability results for 2-species cooperating reaction-diffusion systems are included in the discussion, and some known results are extended. 展开更多
关键词 3-species cooperating model asymptotic stability time delay positive equilibrium
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HIV Positive Men Five Times that of Women
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《China Today》 2002年第10期4-4,共1页
According to the latest statis-tics, China’s HIV positive men and women are in the ratio of 5.2:1. This sharp increase in the number of HIV positive men can be attributed to intravenous drug use and unprotected sex. ... According to the latest statis-tics, China’s HIV positive men and women are in the ratio of 5.2:1. This sharp increase in the number of HIV positive men can be attributed to intravenous drug use and unprotected sex. The survey reveals that youth between the ages of 20 and 29, some of whom are college and technical school students, account for 展开更多
关键词 HIV positive Men Five times that of Women
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Decoupling Zeros of Positive Discrete-Time Linear Sys-tems
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作者 Tadeusz Kaczorek 《Circuits and Systems》 2010年第2期41-48,共8页
The notions of decoupling zeros of positive discrete-time linear systems are introduced. The relationships between the decoupling zeros of standard and positive discrete-time linear systems are analyzed. It is shown t... The notions of decoupling zeros of positive discrete-time linear systems are introduced. The relationships between the decoupling zeros of standard and positive discrete-time linear systems are analyzed. It is shown that: 1) if the positive system has decoupling zeros then the corresponding standard system has also decoupling zeros, 2) the positive system may not have decoupling zeros when the corresponding standard system has decoupling zeros, 3) the positive and standard systems have the same decoupling zeros if the rank of reachability (observability) matrix is equal to the number of linearly independent monomial columns (rows) and some additional assumptions are satisfied. 展开更多
关键词 Input-Decoupling ZEROS Output-Decoupling ZEROS Input-Output DECOUPLING ZEROS positive DISCRETE-time LINEAR System
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Feature extraction and damage alarming using time series analysis 被引量:4
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作者 刘毅 李爱群 +1 位作者 费庆国 丁幼亮 《Journal of Southeast University(English Edition)》 EI CAS 2007年第1期86-91,共6页
Aiming at the problem of on-line damage diagnosis in structural health monitoring (SHM), an algorithm of feature extraction and damage alarming based on auto-regressive moving-average (ARMA) time series analysis i... Aiming at the problem of on-line damage diagnosis in structural health monitoring (SHM), an algorithm of feature extraction and damage alarming based on auto-regressive moving-average (ARMA) time series analysis is presented. The monitoring data were first modeled as ARMA models, while a principalcomponent matrix derived from the AR coefficients of these models was utilized to establish the Mahalanobisdistance criterion functions. Then, a new damage-sensitive feature index DDSF is proposed. A hypothesis test involving the t-test method is further applied to obtain a decision of damage alarming as the mean value of DDSF had significantly changed after damage. The numerical results of a three-span-girder model shows that the defined index is sensitive to subtle structural damage, and the proposed algorithm can be applied to the on-line damage alarming in SHM. 展开更多
关键词 feature extraction damage alarming time series analysis structural health monitoring
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Times管理方案在心内科护士多参数心电监护仪警报疲劳中的应用 被引量:2
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作者 张雪梅 王新霞 +2 位作者 张芳 竟爱萍 崔亚丽 《卫生职业教育》 2023年第8期152-154,共3页
探讨Times管理方案在心内科护士多参数心电监护仪警报疲劳中的应用效果,以提高护士临床警报知识水平,改善警报管理态度和行为,减轻护士的警报疲劳,降低心电监护仪错误警报发生率。
关键词 times管理方案 多参数心电监护仪 心内科护士 警报疲劳
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MULTIPLE POSITIVE SOLUTIONS FOR A CLASS OF SEMIPOSITONE NEUMANN PROBLEMSWITH SINGULARφ-LAPLACIAN 被引量:3
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作者 马如云 高红亮 《Acta Mathematica Scientia》 SCIE CSCD 2017年第5期1472-1482,共11页
We study the existence of multiple positive solutions for a Neumann problem with singular φ-Laplacian{-(φ(u′))′= λf(u), x ∈(0, 1),u′(0) = 0 = u′(1),where λ is a positive parameter, φ(s) =s/(1-s;... We study the existence of multiple positive solutions for a Neumann problem with singular φ-Laplacian{-(φ(u′))′= λf(u), x ∈(0, 1),u′(0) = 0 = u′(1),where λ is a positive parameter, φ(s) =s/(1-s;);, f ∈ C;([0, ∞), R), f′(u) > 0 for u > 0, and for some 0 < β < θ such that f(u) < 0 for u ∈ [0, β)(semipositone) and f(u) > 0 for u > β.Under some suitable assumptions, we obtain the existence of multiple positive solutions of the above problem by using the quadrature technique. Further, if f ∈ C;([0, β) ∪(β, ∞), R),f′′(u) ≥ 0 for u ∈ [0, β) and f′′(u) ≤ 0 for u ∈(β, ∞), then there exist exactly 2 n + 1 positive solutions for some interval of λ, which is dependent on n and θ. Moreover, We also give some examples to apply our results. 展开更多
关键词 multiple positive solutions Neumann problem prescribed mean curvature equation time map
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Stability and Robust Stability of Switched Positive Linear Systems With All Modes Unstable 被引量:4
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作者 Shaoxia Feng Juan Wang Jun Zhao 《IEEE/CAA Journal of Automatica Sinica》 EI CSCD 2019年第1期167-176,共10页
This paper is concerned with the stability and robust stability of switched positive linear systems(SPLSs) whose subsystems are all unstable. By means of the mode-dependent dwell time approach and a class of discretiz... This paper is concerned with the stability and robust stability of switched positive linear systems(SPLSs) whose subsystems are all unstable. By means of the mode-dependent dwell time approach and a class of discretized co-positive Lyapunov functions, some stability conditions of switched positive linear systems with all modes unstable are derived in both the continuous-time and the discrete-time cases, respectively. The copositive Lyapunov functions constructed in this paper are timevarying during the dwell time and time-invariant afterwards. In addition, the above approach is extended to the switched interval positive systems. A numerical example is proposed to illustrate our approach. 展开更多
关键词 Discretized co-positive Lyapunov functions mode-dependent DWELL time robust STABILITY SWITCHED positive linear systems (SPLSs) UNSTABLE subsystem
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Position and Velocity Time Delay for Suppression Vibrations of a Hybrid Rayleigh-Van der Pol-Duffing Oscillator 被引量:3
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作者 Y.A.Amer A.T.El-Sayed M.N.Abd El-Salam 《Sound & Vibration》 EI 2020年第3期149-161,共13页
In this paper,we used time delay feedback to minimize the vibrations of a hybrid Rayleigh–van der Pol–Duffing oscillator.This system is a one-degree-offreedom containing the cubic and fifth nonlinear terms and an ex... In this paper,we used time delay feedback to minimize the vibrations of a hybrid Rayleigh–van der Pol–Duffing oscillator.This system is a one-degree-offreedom containing the cubic and fifth nonlinear terms and an external force.We applied the multiple scales method to get the solution from first approximation.Graphically and numerically,we studied the system before and after adding time delay feedback at the primary resonance case(ffi!).We used MATLAB program to simulate the efficacy of different parameters and the time delay on the main system. 展开更多
关键词 position time delay feedback velocity time delay feedback multiple scales method resonance cases
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Effects of anatomical position on esophageal transit time:A biomagnetic diagnostic technique 被引量:1
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作者 Teodoro Cordova-Fraga Modesto Sosa +4 位作者 Carlos Wiechers Jose Maria De la Roca-Chiapas Alejandro Maldonado Moreles Jesus Bernal-Alvarado Raquel Huerta-Franco 《World Journal of Gastroenterology》 SCIE CAS CSCD 2008年第37期5707-5711,共5页
AIM: To study the esophageal transit time (ETT) and compare its mean value among three anatomical inclinations of the body; and to analyze the correlation of ETT to body mass index (BMI). METHODS: A biomagnetic ... AIM: To study the esophageal transit time (ETT) and compare its mean value among three anatomical inclinations of the body; and to analyze the correlation of ETT to body mass index (BMI). METHODS: A biomagnetic technique was implemented to perform this study: (1) The transit time of a magnetic marker (MM) through the esophagus was measured using two fluxgate sensors placed over the chest of 14 healthy subjects; (2) the EIF was assessed in three anatomical positions (at upright, fowler, and supine positions; 90°, 45° and 0°, respectively). RESULTS: ANOVA and Tuckey post-hoc tests demonstrated significant differences between E-IT mean of the different positions. The ETT means were 5.2 ± 1.1 s, 6.1 ± 1.5 s, and 23.6 ± 9.2 s for 90°, 45° and 0°, respectively. Pearson correlation results were r = -0.716 and P 〈 0.001 by subjects' anatomical position, and r = -0.024 and P 〉 0.05 according the subject's BMI. CONCLUSION: We demonstrated that using this biomagnetic technique, it is possible to measure the ETT and the effects of the anatomical position on the ETT. 展开更多
关键词 Transit time Magnetic marker ESOPHAGUS Anatomical position NON-INVASIVE
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Short Baseline Positioning with an Improved Time Reversal Technique in a Multi-path Channel 被引量:2
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作者 Zhuang Li Gang Qiao Zongxin Sun Haiyang Zhao Ran Guo 《Journal of Marine Science and Application》 2012年第2期251-257,共7页
The existence of a multi-path channel under the water greatly decreases the accuracy of the short baseline positioning system.In this paper,the application of a time reversal mirror to the short baseline positioning s... The existence of a multi-path channel under the water greatly decreases the accuracy of the short baseline positioning system.In this paper,the application of a time reversal mirror to the short baseline positioning system was investigated.The time reversal mirror technique allowed the acoustic signal to better focus in an unknown environment,which effectively reduced the expansion of multi-path acoustic signals as well as improved the signal focusing.The signal-to-noise ratio(SNR) of the time reversal operator greatly increased and could be obtained by ensonifying the water.The technique was less affected by the environment and therefore more applicable to a complex shallow water environment.Numerical simulations and pool experiments were used to demonstrate the efficiency of this technique. 展开更多
关键词 short baseline positioning focusing gain time reversal mirror multi-path channel ocean acoustic channel acoustic signal processing
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Effect of High Positive Acceleration(+Gz) Environment on Dental Implant Osseointegration:A Preliminary Animal Study 被引量:2
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作者 ZHU Xiao Ru DENG Tian Zheng +2 位作者 PANG Jian Liang LIU Bing KE Jie 《Biomedical and Environmental Sciences》 SCIE CAS CSCD 2019年第9期687-698,共12页
Objective To observe the effect of high positive acceleration(+Gz) environment on dental implant osseointegration in a rabbit model and to investigate its mechanism.Methods Forty-eight New Zealand white rabbits were r... Objective To observe the effect of high positive acceleration(+Gz) environment on dental implant osseointegration in a rabbit model and to investigate its mechanism.Methods Forty-eight New Zealand white rabbits were randomly divided into 6 groups. The rabbit’s mandibular incisors were extracted and 1 implant was placed in each socket immediately. After 1 week of rest, the rabbits were exposed to a high +Gz environment, 3 times a week. The rabbits were sacrificed at 3 weeks(2 weeks +Gz exposure), 5 weeks(4 weeks +Gz exposure), and 12 weeks(4 weeks +Gz exposure and 7 weeks normal environment) after surgery, respectively. Specimens were harvested for micro-CT scanning, histological analysis, and real-time polymerase chain reaction examination.Results Compared with those in the control group, the mRNA expression levels of bone morphogenetic protein-2(BMP-2), osteopontin(OPN), and transforming growth factor-β1(TGF-β1)were significantly lower(P < 0.05), while the mRNA expression level of receptor activator of nuclear factor κB ligand(RANKL) and the RANKL/osteoprotegerin(OPG) ratio were significantly higher(P < 0.05)at 3 weeks;values of bone volume fraction, trabecular number, bone-implant contact(BIC), and TGF-β1 and OPG mRNA expression levels were significantly lower(P < 0.05), and the value of trabecular separation, RANKL mRNA expression level and RANKL/OPG ratio were significantly higher(P < 0.05) at 5 weeks;and the value of BIC was still significantly lower(P < 0.05) at 12 weeks in the experimental group.Conclusion Early exposure to the high +Gz environment after implant surgery might have an adverse effect on osseointegration, and its mechanism could be related to the inhibition of osteoblast activity and promotion of osteoclast activity. 展开更多
关键词 positive acceleration OSSEOINTEGRATION Dental IMPLANT MICRO-CT Real-time POLYMERASE chain reaction OSTEOBLAST
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System Position and Divergent Time of Based on ITS Sequence <i>Humulus scandens</i>
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作者 Renfang Chen Zehua Zhang +5 位作者 Weiting Sun Yun Fu Quncai Zhang Liang Wei Yanmei Liang Ruocheng Dong 《American Journal of Plant Sciences》 2012年第10期1470-1475,共6页
This article mainly studied Humulus scandens’ ITS sequence, its system position and its divergent time. ITS is 624 bp with a GC percentage content of 57.21%. It only has the variation in 585 (C changes T), systematic... This article mainly studied Humulus scandens’ ITS sequence, its system position and its divergent time. ITS is 624 bp with a GC percentage content of 57.21%. It only has the variation in 585 (C changes T), systematic position in Humulus lupulus (GenBank: EF136401) and Humulus scandens (GenBank: FJ980285), Humulus lupulus (GenBank: DQ005990), with Humulus scandens (GenBank: FJ980285), Humulus lupulus (GenBank: DQ005990) has the near sibship. Humulus in Moraceae family system position between Cudrania tricuspidata and Artocarpeae, support the Cannabiodeae promotion for Cannabinaceae. The divergent time of Humulus is 70.88 mya in Moraceae, Humulus scandens and Humulus lupulus (GenBank: EF136401) is 12.78 mya, with Humulus scandens (GenBank: FJ980285), Humulus lupulus (GenBank: DQ005990) is 1.10 mya. In the Moraceae branch’s molecular systematics research, the suitable choice is to choose Humulus scandens as Moraceae’s outgroup. 展开更多
关键词 MORACEAE HUMULUS scandens ITS Systematic positION DIVERGENT time
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THEORETICAL AND NUMERICAL STUDY OF THE BLOW UP IN A NONLINEAR VISCOELASTIC PROBLEM WITH VARIABLE-EXPONENT AND ARBITRARY POSITIVE ENERGY
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作者 Ala A.TALAHMEH Salim A.MESSAOUDI Mohamed ALAHYANE 《Acta Mathematica Scientia》 SCIE CSCD 2022年第1期141-154,共14页
In this paper,we consider the following nonlinear viscoelastic wave equation with variable exponents:utt-△u+∫_(0)^(t)g(t-τ)△u(x,τ)dτ+μut=|u|^(p(x)-2)-u,whereμis a nonnegative constant and the exponent of nonli... In this paper,we consider the following nonlinear viscoelastic wave equation with variable exponents:utt-△u+∫_(0)^(t)g(t-τ)△u(x,τ)dτ+μut=|u|^(p(x)-2)-u,whereμis a nonnegative constant and the exponent of nonlinearity p(·)and g are given functions.Under arbitrary positive initial energy and specific conditions on the relaxation function g,we prove a finite-time blow-up result.We also give some numerical applications to illustrate our theoretical results. 展开更多
关键词 nonlinear damping blow up finite time variable nonlinearity arbitrary positive energy
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