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Exotic Homoclinic Surface of a Saddle-Node Limit Cycle in a Leech Neuron Model

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Chinese Physics Letters 2011年第3期28卷 24-27页

作者： YOOER Chi-Feng WEI Fang xu jian-xue ZHANG Xin-Hua Institute of Neuroscience Fourth Military Medical UniversityXi’an 710032 Institute of Nonlinear Dynamics Xi’an Jiaotong UniversityXi’an 710049 XAC Research and Development Center Xi’an 710089

We carry out numerical and theoretical investigations on the global unstable invariant set(manifold)of a saddlenode limit cycle in a leech heart interneuron *** corresponding global bifurcation is accompanied by an explosion of secondary bifurcations of limit cycles and the emergence of loop-shaped bifurcation *** dynamical behaviors of the trajectories of the invariant set are very complicated and can only be partially explained by existing theories.

关键词： invariant bifurcation limit

Study of the Wada fractal boundary and indeterminate crisis

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Chinese Physics B 2002年第11期11卷 1115-1123页

作者： Hong Ling(洪灵) xu jian-xue(徐健学) Institute of Nonlinear Dynamics Xi'an Jiaotong University Xi'an 710049 China

By using the generalized cell mapping digraph (GCMD) method, we study bifurcations governing the escape ofperiodically forced oscillators in a potential well, in which a chaotic saddle plays an extremely important role. In thispaper, we find the chaotic saddle, and we demonstrate that the chaotic saddle is embedded in a strange fractal boundarywhich has the Wada property, that any point on the boundary of that basin is also simultaneously on the boundary ofat least two other basins. The chaotic saddle in the Wada fractal boundary, by colliding with a chaotic attractor, leadsto a chaotic boundary/crisis with a global indeterminate outcome which presents an extreme form of indeterminacy ina dynamical system ./We also investigate the origin and evolution of the chaotic saddle in the Wada fractal boundary,particularly concentrating on its discontinuous bifurcations (metamorphoses). We demonstrate that the chaotic saddlein the Wada fractal boundary is created by the collision between two chaotic saddles in different fractal *** a final escape bifurcation, there only exists the attractor at infinity; a chaotic saddle with a beautiful pattern isleft behind in phase space.

关键词： global analysis generalized cell mapping indeterminate chaotic boundary crisis chaoticsaddle Wada fractal boundary

Enhanced Performance and Stability in Polymer Photovoltaic Cells Using Ultraviolet-Treated PEDOT:PSS

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Chinese Physics Letters 2013年第7期30卷 167-171页

作者： xu xue-jian YANG Li-Ying TIAN Hui QIN Wen-Jing YIN Shou-Gen ZHANG Fengling Key Laboratory of Display Materials and Photoelectric Devices(Ministry of Education)and School of Materials Science and Engineering Tianjin University of TechnologyTianjin 300384 Tianjin Key Lab for Photoelectric Materials and Devices Tianjin 300384 Biomolecular and Organic Electronics Center of Organic ElectronicsDepartment of PhysicsChemistry and Biology(IFM)Linkoping UniversitySE-58183 LinkopingSweden

We investigate the effects of ultraviolet(UV)irradiation treatment with varying irradiation intensities for different treatment times of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS)film on the performance and stability of polymer solar cells(PSCs)based on regioregular poly(3-hexylthiophene)(P3HT)and methanofullerene[6,6]-phenyl C61-butyric acid methyl ester(PCBM)***-visible transmission spectra,x-ray photoelectron spectroscopy,contact angle measurement,atomic force microscopy and the Kelvin probe method are conducted to characterize the UV-treated PEDOT:PSS *** results demonstrate that UV treatment can improve the power conversion efficiency(PCE)and stability of PSCs *** best performance is achieved under 1200μW/cm^(2) UV treatment for 50 *** to the control device,the optimized device exhibits enhanced performance with a V_(oc) of 0.59 V,J_(sc) of 12.3 mA/cm^(2),fill factor of 51%,and PCE of 3.64%,increased by 3.5%,33%,8.7%and 50%,*** stability of the PSCs is enhanced by 2.5 times simply through the UV treatment on the PEDOT:PSS buffer *** improvement in the device performance and stability is attributed to the improvement in the wettability property and the increase in the work function of the PEDOT:PSS film by UV treatment,while the impact of UV treatment on the transparency of the PEDOT:PSS film is *** strategy of using UV treatment to improve device performance and stability is attractive due to its simplicity,cost-effectiveness,and because it is suitable for large-scale commercial production.

关键词： stability film negligible

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基于深度学习的禽流感病毒溢出风险预测研究

广州大学学报（自然科学版） 2024年第2期23卷 48-56页

作者：刘耀华范馨月徐雪健王娜寇铮强小利广州大学计算科技研究院广东广州510006 广州大学计算机科学与网络工程学院广东广州510006

禽流感病毒基因组由8个长短不一的基因节段组成,全长约为14~16 kb。由于病毒本身特殊的分子遗传机制,病毒通过基因点突变和基因组重排快速变异,引发病毒感染宿主范围的改变,持续威胁人类健康,因此,自然界禽流感病毒溢出风险预测具有重... 详细信息

禽流感病毒基因组由8个长短不一的基因节段组成,全长约为14~16 kb。由于病毒本身特殊的分子遗传机制,病毒通过基因点突变和基因组重排快速变异,引发病毒感染宿主范围的改变,持续威胁人类健康,因此,自然界禽流感病毒溢出风险预测具有重要公共卫生意义。文章联合使用卷积神经网络和循环神经网络表征病毒基因组序列,分别在特定类群数据集和全类群数据集上进行训练和测试,并对模型的迁移预测能力进行评估。实验结果显示:①特定类群模型对各自数据集的预测性能良好,AUROC值和AUPR值分别达到0.966和0.876以上,但泛化能力较差;②除H9N2类群外,全局模型性能良好,AUROC值和AUPR值均达到1.000;③基于消融实验,发现注意力机制和Embedding层对模型性能影响较大;④进一步测试模型的泛化能力,迁移预测的AUROC值和AUPR值分别可达0.984和0.941以上;⑤可视化注意力权重系数矩阵,为模型提供生物学可解释性。性能良好的深度学习预测模型可用于禽流感病毒跨种感染的早期预警。

关键词：禽流感病毒深度学习溢出风险基因组

The isolated critical value phenomenon in localglobal riddling bifurcation

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Chinese Physics B 2002年第7期11卷 670-677页

作者： Tan Ning(谭宁) xu jian-xue(徐健学) Chen Yong-Hong(陈永红) Institute of Nonlinear Dynamics Xi'an Jiaotong University Xi'an 710049 China

A chaotic synchronized system of two coupled skew tent maps is discussed in this paper. The locally and globallyriddled basins of the chaotic synchronized attractor are studied. It is found that there is a novel phenomenon in thelocal-global riddling bifurcation of the attractive basin of the chaotic synchronized attractor in some specific couplingintervals. The coupling parameter corresponding to the locally riddled basin has a single value which is embeddedin the coupling parameter interval corresponding to the globally riddled basin, just like a breakpoint. Also, there isno relation between this phenomenon and the form of the chaotic synchronized attractor. This phenomenon is foundanalytically. We also try to explain it in a physical sense. It may be that the chaotic synchronized attractor is in thecritical state, as it is infinitely close to the boundary of its attractive basin. We conjecture that this isolated criticalvalue phenomenon will be common in a system with a chaotic attractor in the critical state, in spite of the system beingdiscrete or differential.

关键词： skew tent map chaotic synchronized system riddled basins

MiRNA-145-5p inhibits gastric cancer progression via the serpin family E member 1-extracellular signal-regulated kinase-1/2 axis

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World Journal of Gastrointestinal Oncology 2024年第5期16卷 2123-2140页

作者： Hong-Xia Bai xue-Mei Qiu Chun-Hong xu jian-Qiang Guo Department of Gastroenterology The Second Hospital of Shandong UniversityJinan 250000Shandong ProvinceChina Department of Gastroenterology Liaocheng People’s HospitalLiaocheng 252000Shandong ProvinceChina Department of Reproductive Center Zaozhuang Maternal and Child Health Care HospitalZaozhuang 277000Shandong ProvinceChina

BACKGROUND MicroRNAs(miRNAs)regulate gene expression and play a critical role in cancer ***,there is still a limited understanding of the function and regulatory mechanism of miRNAs in gastric cancer(GC).AIM To investigate the role and molecular mechanism of miRNA-145-5p(miR145-5p)in the progression of *** Real-time polymerase chain reaction(RT-PCR)was used to detect miRNA expression in human GC tissues and *** ability of cancer cells to migrate and invade was assessed using wound-healing and transwell assays,*** proliferation was measured using cell counting kit-8 and colony formation assays,and apoptosis was evaluated using flow *** of the epithelial-mesenchymal transition(EMT)-associated protein was determined by Western *** of miR-145-5p were predicated using bioinformatics analysis and verified using a dual-luciferase reporter *** family E member 1(SERPINE1)expression in GC tissues and cells was evaluated using RT-PCR and immunohistochemical *** correlation between SERPINE1 expression and overall patient survival was determined using Kaplan-Meier plot *** association between SERPINE1 and GC progression was also tested.A rescue experiment of SERPINE1 overexpression was conducted to verify the relationship between this protein and *** mechanism by which miR-145-5p influences GC progression was further explored by assessing tumor formation in nude *** GC tissues and cells had reduced miR-145-5p expression and SERPINE1 was identified as a direct target of this *** of miR-145-5p was associated with decreased GC cell proliferation,invasion,migration,and EMT,and these effects were reversed by forcing SERPINE1 ***-Meier plot analysis revealed that patients with higher SERPINE1 expression had a shorter survival rate than those with lower SERPINE1 *** mouse tumorigenesis experiments confirmed that miR-145-5p target

关键词： Gastric cancer MicroRNA-145-5p Serpin family E member 1 Epithelial-mesenchymal transition Proliferation Extracellular signal-regulated kinase-1/2

Linear Quadratic Optimal Control for Systems Governed by First-Order Hyperbolic Partial Differential Equations

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Journal of Systems Science & Complexity 2024年第1期37卷 230-252页

作者： xue Xiaomin xu Juanjuan ZHANG Huanshui School of Control Science and Engineering Shandong UniversityJinan 250061China College of Electrical Engineering and Automation Shandong University of Science and TechnologyQingdao 266000China

This paper focuses on linear-quadratic(LQ)optimal control for a class of systems governed by first-order hyperbolic partial differential equations(PDEs).Different from most of the previous works,an approach of discretization-then-continuousization is proposed in this paper to cope with the infinite-dimensional nature of PDE *** contributions of this paper consist of the following aspects:(1)The differential Riccati equations and the solvability condition of the LQ optimal control problems are obtained via the discretization-then-continuousization method.(2)A numerical calculation way of the differential Riccati equations and a practical design way of the optimal controller are ***,the relationship between the optimal costate and the optimal state is established by solving a set of forward and backward partial difference equations(FBPDEs).(3)The correctness of the method used in this paper is verified by a complementary continuous method and the comparative analysis with the existing operator results is *** is shown that the proposed results not only contain the classic results of the standard LQ control problem of systems governed by ordinary differential equations as a special case,but also support the existing operator results and give a more convenient form of computation.

关键词： Discretization-then-continuousization method first-order hyperbolic partial differential equations forward and backward partial difference equations linear quadratic optimal control.

Design and Cryogenic Performance of a Hexapod Platform for a Large Ground-based Wide Field Survey Telescope

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Research in Astronomy and Astrophysics 2024年第1期24卷 178-187页

作者： Yang Yu xue-Wen Wang Yu Zhang Jia-Lin Sun Zhen-Bang xu jian-Li Wang Changchun Institute of Optics Fine Mechanics and PhysicsChinese Academy of SciencesChangchun 130033China Chinese Academy of Sciences Key Laboratory of On-orbit Manufacturing and Integration for Space Optics System Changchun 130033China University of Chinese Academy of Sciences Beijing 100049China

The thermal gradient is an important factor that causes degradation to the image quality of telescopes. In order to ensure the accurate alignment of the primary focus unit and the primary mirror, the hexapod platform(as a corrector) is investigated in this paper. First, a ground-based telescope with 2.5 m aperture and 3.5 deg field of view is described. The telescope is under construction, and it is expected to be finished in 2023. Second, the hexapod platform with flexure hinges utilized to adjust the primary focus unit is proposed, which is applied as a ***, the inverse kinematics of the platform is established and an open-loop control system is built based on ***, the cryogenic performance test for the hexapod platform is performed. The experimental results show that the resolution and repeatability of the translation for the hexapod platform can be achieved at the micrometer *** resolution and repeatability of the rotation can be achieved at the arc-second level. Therefore, the cryogenic performance of the hexapod platform can meet the optical imaging requirements of the wide-field ground-based telescope. The kinematic analysis and cryogenic performance tests in the paper provide a technical reference for the precise alignment of the primary focus unit and the primary mirror, which can improve the imaging quality of the telescope.

关键词： methods:miscellaneous space vehicles:instruments telescopes miscellaneous

Evidence-based practices in sustainable travel behavior intervention: A knowledge graph-based systematic review

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Journal of Traffic and Transportation Engineering(English Edition) 2024年第2期11卷 293-311页

作者： jian Li Chenjie xu Key Laboratory of Road and Traffic Engineering of the Ministry of Education College of Transportation EngineeringTongji UniversityShanghai 201804China

Sustainable travel behavior intervention is an essential strategy to promote the development of urban *** interventions offer personalized strategies based on certain scenario and participants to promote its effectiveness over hard travel ***,personalized strategies may also bring about difficulties to identify the actual effect of the ***,based on current practice,to make full use of travel behavior interventions,it is necessary to construct a unified methodological evidencebased framework to assess the reliability and effectiveness of travel behavior intervention *** response to these issues,we applied evidence-based knowledge graph to the field of sustainable travel behavior interventions to help decision supporters design sustainable travel behavior interventions wisely and in turn avoid excessive use of hard travel *** introduced concept of evidence-based practice to conduct a systematic analysis concerning reliability and validity of current full volume empirical studies by dimensions of scenarios,types of interventions and *** addition,we took advantage of high extensivity and integrability of knowledge graph to organize evidence-based related *** of the systematic analysis shows that in terms of reliability of evidence,school intervention is the best scenario,knowledge incentive is the best intervention type and promoting public transit and walking proportion are the best ***,the reliability of interventions in workplace,belonging to reward and threat along with aiming at changing travel patterns generally and lowering travel carbon emission need to be *** the study,various research prospects are raised to promote evidence quality in the field of travel behavior intervention *** a pioneer study,our research contributes to the field of urban transportation in introducing concepts of evidence-based practice and enabling optimization and

关键词： Evidence-based decision-making Evidence assessment Knowledge graph Travel behavior intervention Sustainable travel