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Improving supercritical water gasification of sludge by oil palm empty fruit bunch addition: Promotion of syngas production and heavy metal stabilization

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Chinese Journal of Chemical Engineering 2020年第1期28卷 293-298页

作者： zhouchao weng Ekkachai Kanchanatip Dwi Hantoko Mi Yan Hongcai Su Sicheng Zhang Guobin Wang Institute of Energy and Power Engineering Zhejiang University of TechnologyHangzhou 310014China Department of Chemical Engineering Institut Teknologi BandungBandung 40132Indonesia Center of Excellence in Environmental Catalysis and Adsorption Faculty of EngineeringThammasat UniversityPathumthani 12120Thailand

The co-gasification of sewage sludge and palm oil empty fruit bunch(EFB) in supercritical water(SCW) was conducted at 400 °C with a pressure of over 25 MPa. This study aimed to investigate the influence of EFB addition on the syngas production and its composition. The heavy metal distribution and the leaching potential of the solid residue were also assessed. The results showed that syngas yield significantly increased with the addition of EFB into the feedstock. The cold gas efficiency(CGE) and carbon efficiency(CE) of co-gasification were higher than those of individual gasification. The actual syngas production from co-gasification of sludge and EFB was 45% higher than the theoretical total volume. The results indicated that the addition of EFB to sludge had the synergetic promotion effect on syngas production from sludge and EFB in supercritical water. This enhancement might be due to the dissolution of alkali metals from EFB and the adjustment of organic ratio. In addition, higher percentage of heavy metals were deposited and stabilized in the solid residue after SCWG. The leaching concentration of heavy metals from the solid residues was decreased to a level below the standard limit which enables it to be safely disposed of in landfill. In conclusion, the EFB addition has been proved to promote syngas production,as well as, stabilize the heavy metal in solid residues during co-SCWG.

关键词： Co-gasification Supercritical water Sludge Empty fruit bunch Syngas Heavy metal

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面向内生安全交换机的段路由带内遥测方法

计算机科学 2024年第5期51卷 284-292页

作者：顾周超程光赵玉宇东南大学网络空间安全学院南京211189 教育部计算机网络和信息集成重点实验室(东南大学) 南京211189

近年来,网络技术的发展日新月异,基础设备及其所提供的网络服务也日益复杂。传统的网络管理和监控手段面临严峻的挑战。国内外研究人员提出段路由(Segment Routing,SR)和带内网络遥测(In-band Network Telemetry,INT)等技术来进行实时... 详细信息

近年来,网络技术的发展日新月异,基础设备及其所提供的网络服务也日益复杂。传统的网络管理和监控手段面临严峻的挑战。国内外研究人员提出段路由(Segment Routing,SR)和带内网络遥测(In-band Network Telemetry,INT)等技术来进行实时性更高、更细粒度的网络测量。然而,在流量迅速增长的网络环境下,带内网络遥测技术在实际使用中仍然存在着灵活部署、动态部署、高效部署等诸多难题。首先,传统INT技术缺乏合适的载体,数据包的开销随遥测路径长度线性增加,从而导致遥测监控的性能瓶颈问题。针对传统带内网络遥测系统比特开销大、难以高效部署的问题,提出了基于SRv6(Segment Routing IPv6,SRv6)的带内网络遥测方法(SRv6_Based INT),通过研究减小INT和SR的开销,将两者无缝结合以实现轻量级的遥测。在本项工作中,通过设计INT的元数据,使其长度等于SRv6中的Segment字段,然后在每一跳中根据监控服务器下发的流表将SID修改成相应的INT元数据。该方法充分结合了两项技术的优点,并将开销控制在合理的范围,优于传统的带内网络遥测方法。

关键词：段路由带内网络遥测软件定义网络

一类种群策略调控下海洋营养-浮游植物-浮游动物Filippov模型的分岔与混沌

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湖北民族大学学报（自然科学版） 2024年第2期42卷 254-259页

作者：刘建港魏周超中国地质大学(武汉)数学与物理学院武汉430074 河北科技师范学院海洋经济与沿海经济带研究中心河北秦皇岛066004

针对种群策略调控下浮游模型的稳定性以及多种分岔与混沌现象等问题,建立了一类与海洋生态系统相关的三维营养-浮游植物-浮游动物Filippov模型。利用非光滑动力系统的定性技术,研究了子系统和滑动向量场中平衡点的稳定性和分岔集,并得... 详细信息

针对种群策略调控下浮游模型的稳定性以及多种分岔与混沌现象等问题,建立了一类与海洋生态系统相关的三维营养-浮游植物-浮游动物Filippov模型。利用非光滑动力系统的定性技术,研究了子系统和滑动向量场中平衡点的稳定性和分岔集,并得到了跨临界分岔、滑动分岔等丰富行为。最终证明控制阈值参数在0.1附近时发生了倍周期分叉乃至混沌。该研究可用于海洋生态保护等实际领域,有利于促进Filippov生态系统的动力学理论发展。

关键词：营养-浮游植物-浮游动物Filippov模型非光滑动力系统稳定性滑动分岔混沌

弥散加权成像联合动态增强MRI预测肝细胞癌经TACE联合射频消融治疗后复发

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中国介入影像与治疗学 2024年第1期21卷 17-21页

作者：胡舟朝张晓东俞南南陈本宝浙江省舟山医院介入诊疗中心浙江舟山316021 舟山市中医院放射科浙江舟山316000

目的观察弥散加权成像(DWI)联合动态增强MRI预测肝细胞癌(HCC)经TACE联合射频消融治疗后复发的价值。方法回顾性分析80例接受TACE联合射频消融治疗的HCC患者,均于治疗前10天和治疗后20、60及90天接受腹部DWI及动态增强MR检查;计算DWI联... 详细信息

目的观察弥散加权成像(DWI)联合动态增强MRI预测肝细胞癌(HCC)经TACE联合射频消融治疗后复发的价值。方法回顾性分析80例接受TACE联合射频消融治疗的HCC患者,均于治疗前10天和治疗后20、60及90天接受腹部DWI及动态增强MR检查;计算DWI联合动态增强MRI预测TACE联合射频消融治疗后20天HCC复发的敏感度、特异度及准确率;绘制受试者工作特征(ROC)曲线,评估以表观弥散系数(ADC)值预测TACE联合射频消融治疗后20天HCC复发的效能。结果参照改良实体瘤疗效评价标准,将47例HCC患者纳入稳定组、33例归为进展组。TACE联合射频消融治疗后20天,稳定组HCC病灶DWI多呈不均匀信号、ADC图呈高信号、增强扫描未见强化,进展组病灶多呈DWI高信号、ADC图低信号、增强扫描轻度强化。DWI联合动态增强MRI预测TACE联合射频消融治疗后20天HCC复发的敏感度、特异度及准确率分别为97.75%(87/89)、92.31%(24/26)及96.52%(111/115)。以ADC值预测TACE联合射频消融治疗后20天HCC复发的曲线下面积为0.82;以ADC=1.42×10^(-3)mm^(2)/s为截断值,预测的敏感度及特异度分别为72.13%及82.25%。结论DWI联合动态增强MRI用于预测TACE联合射频消融治疗后HCC复发具有一定价值;ADC值可作为有效预测指标。

关键词：癌,肝细胞化学栓塞,治疗性射频消融磁共振成像

Inverse Heat Conduction Estimation of Inner Wall Temperature Fluctuations under Turbulent Penetration

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Journal of Thermal Science 2017年第2期26卷 160-165页

作者： GUO zhouchao LU Tao LIU Bo School of Mechanical and Electrical Engineering Beijing University of Chemical TechnologyBeijing100029China Science and Technology on Space Physics Laboratory Beijing100076China

Turbulent penetration can occur when hot and cold fluids mix in a horizontal T-junction pipe at nuclear plants. Caused by the unstable turbulent penetration, temperature fluctuations with large amplitude and high frequency can lead to time-varying wall thermal stress and even thermal fatigue on the inner wall. Numerous cases, however, exist where inner wall temperatures cannot be measured and only outer wall temperature measurements are feasible. Therefore, it is one of the popular research areas in nuclear science and engineering to estimate temperature fluctuations on the inner wall from measurements of outer wall temperatures without damaging the structure of the pipe. In this study, both the one-dimensional(1D) and the two-dimensional(2D) inverse heat conduction problem(IHCP) were solved to estimate the temperature fluctuations on the inner wall. First, numerical models of both the 1D and the 2D direct heat conduction problem(DHCP) were structured in MATLAB, based on the finite difference method with an implicit scheme. Second, both the 1D IHCP and the 2D IHCP were solved by the steepest descent method(SDM), and the DHCP results of temperatures on the outer wall were used to estimate the temperature fluctuations on the inner wall. Third, we compared the temperature fluctuations on the inner wall estimated by the 1D IHCP with those estimated by the 2D IHCP in four cases:(1) when the maximum disturbance of temperature of fluid inside the pipe was 3℃,(2) when the maximum disturbance of temperature of fluid inside the pipe was 30℃,(3) when the maximum disturbance of temperature of fluid inside the pipe was 160℃, and(4) when the fluid temperatures inside the pipe were random from 50℃ to 210℃.

关键词：逆热传导问题温度波动内壁温度估计湍流热传导反问题流体温度穿透

Coexisting attractors,chaos control and synchronization in a self-exciting homopolar dynamo system

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International Journal of Intelligent Computing and Cybernetics 2020年第2期13卷 167-179页

作者： Xingrong Chen Li Xiao Sifeu Takougang Kingni Irene Moroz zhouchao Wei Hadi Jahanshahi China University of Geosciences WuhanChina University of Maroua MarouaCameroon University of Oxford OxfordUK University of Tehran TehranIran

Purpose-The purpose of this paper is to investigate coexisting attractors,chaos control and synchronization in a self-exciting homopolar dynamo system in this paper.Design/methodology/approach-Two single controllers are designed and added to the proposed 3D autonomous chaotic system,and its stability at zero equilibrium point is guaranteed by applying an appropriate control signal based on the Lyapunov stability theory.Findings-Numerical simulations reveal that the proposed 3D dynamo system exhibits periodic oscillations,double-scroll chaotic attractors and coexisting attractors.Finally,a single controller is designed for the global asymptotic synchronization of a unidirectionally coupled identical 3D autonomous chaotic system.Originality/value-The derived results of this paper are new and complement some earlier works.The innovation concludes two points in this paper;coexisting attractors are foundthe and an appropriate control signal based on the Lyapunov stability theory is established.The ideas of this paper can be applied to investigate some other homopolar dynamo systems.

关键词： Chaos Coexisting attractors Chaos control Synchronization

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Vallis系统的不变代数曲面研究

应用数学和力学 2022年第1期43卷 84-93页

作者：杨静谈文慧魏周超中国地质大学(武汉)数学与物理学院武汉430074

该文研究了Vallis系统的Darboux多项式和不变代数曲面问题.在证明中,使用加权齐次多项式和特征曲线的方法,通过求解线性偏微分方程,得到了在适当的参数条件下,Vallis系统存在三类Darboux多项式.

关键词：不变代数曲面 Darboux多项式 Vallis系统

THE NONEMPTINESS AND COMPACTNESS OF MILD SOLUTION SETS FOR RIEMANN-LIOUVILLE FRACTIONAL DELAY DIFFERENTIAL VARIATIONAL INEQUALITIES

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Acta Mathematica Scientia 2021年第5期41卷 1569-1578页

作者：蒋宜蓉魏周超卢景苹 College of Science Guilin University of TechnologyGuilin 541004China School of Mathematics and Physics China University of Geosciences(Wuhan)Wuhan 430074China

This paper investigates the nonemptiness and compactness of the mild solution set for a class of Riemann-Liouville fractional delay differential variational inequalities,which are formulated by a Riemann-Liouville fractional delay evolution equation and a variational inequality.Our approach is based on the resolvent technique and a generalization of strongly continuous semigroups combined with Schauder's fixed point theorem.

关键词： differential variational inequality Riemann-Liouville fractional delay evolution equation resolvent Schauder's fixed point theorem

A new four-dimensional chaotic system with first Lyapunov exponent of about 22,hyperbolic curve and circular paraboloid types of equilibria and its switching synchronization by an adaptive global integral sliding mode control

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Chinese Physics B 2018年第4期27卷 214-227页

作者： Jay Prakash Singh Binoy Krishna Roy 魏周超 Department of Electrical Engineering National Institute of Technology Silchar School of Mathematics and Physics China University of Geosciences

This paper presents a new four-dimensional（4 D） autonomous chaotic system which has first Lyapunov exponent of about 22 and is comparatively larger than many existing three-dimensional（3 D） and 4 D chaotic systems.The proposed system exhibits hyperbolic curve and circular paraboloid types of equilibria.The system has all zero eigenvalues for a particular case of an equilibrium point.The system has various dynamical behaviors like hyperchaotic,chaotic,periodic,and quasi-periodic.The system also exhibits coexistence of attractors.Dynamical behavior of the new system is validated using circuit implementation.Further an interesting switching synchronization phenomenon is proposed for the new chaotic system.An adaptive global integral sliding mode control is designed for the switching synchronization of the proposed system.In the switching synchronization,the synchronization is shown for the switching chaotic,stable,periodic,and hybrid synchronization behaviors.Performance of the controller designed in the paper is compared with an existing controller.

关键词： new hyperchaotic system maximum chaos an infinite number of equilibria hidden attractors switching synchronization global sliding mode control