检索结果-南通市图书馆

Chinese journal of Aeronautics 2024年第3期37卷 320-331页

作者： kang Zeyu ShEN Qiang WU Shufan Chris j.DAMAREN MU Zhongcheng School of Aeronautics and Astronautics Shanghai Jiao Tong UniversityShanghai 200240China Institute for Aerospace Studies University of TorontoTorontoOntario M3H 5T6Canada

In this paper,for Multi-Spacecraft System(MSS)with a directed communication topology link and a static virtual leader,a controller is proposed to realize attitude consensus and attitude stabilization with stochastic links failure and actuator ***,an MSS attitude error model suitable for a directed topology link and with a static virtual leader based on SO(3)is derived,which considers that the attitude error on SO(3)cannot be defined based on algebraic ***,we design a controller to realize the MSS on SO(3)with attitude consensus and attitude stabilization under stochastic links failure and actuator ***,the simulation results of a multi-spacecraft system with stochastic links failure and a static virtual leader spacecraft are demonstrated to illustrate the efficiency of the attitude controller.

关键词： Multi-spacecraft systems Attitude consensus Attitude stabilization Stochastic links failure Super-martingale convergence

维普期刊数据库

虚拟单能、双层双能CT肠道成像:keV设置的优化及其对克罗恩病的附加价值

在线全文

学校读者我要写书评

暂无评论

国际医学放射学杂志 2018年第4期 497-498页

作者： S.M.Lee S.h.Kim S.j.Ahn h.j.kang j.h.kang j.K.han 于谦 Department of Radiology Seoul National University Hospital

目的为了确定双层双能CT肠道成像（dl DECTE）的最佳keV并探讨虚拟单能影像（VMI）对活动性克罗恩病（CD）诊断的附加价值。方法纳入了76例接受dl DECTE的病人（包括45例CD病人）。CD病人均为回结肠镜检查确诊。传统混合能量影像（PCI... 详细信息

目的为了确定双层双能CT肠道成像（dl DECTE）的最佳keV并探讨虚拟单能影像（VMI）对活动性克罗恩病（CD）诊断的附加价值。方法纳入了76例接受dl DECTE的病人（包括45例CD病人）。CD病人均为回结肠镜检查确诊。传统混合能量影像（PCI）使用120 kV的迭代重建算法重组,VMI在40 keV（VMI40）、55 keV（VMI55）和70 keV（VMI70）重建。采用Kruskal-Wallis检验比较信噪比（CNR）。3名放射科医师独立评估PCI并随后将PCI与优化的VMI结合起来,用5点量表对活动性CD进行诊断。结果正常（13.6±6.5、6.1±3.2、2.0±2.1、1.9±1.6;P<0.001）和异常（9.4±7.3、6.5±4.8、4.9±3.1、3.7±2.3;P<0.001）肠管CNR在VMI;中最高,其次是VMI;、VMI;和PCI。当将VMI;加入PCI时,3名放射科医师在诊断活动性CD的曲线下面积从0.891显著提高至0.951（P=0.009）。结论 VMI;为dl DE-CTE提供了最好的CNR。此外,重组VMI;提高了对活动性CD的诊断性能。

关键词：克罗恩病 VMI keV 活动性附加价值 CT

R-134a在三种不同放置方式螺旋管内凝结换热的实验研究

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

制冷学报 2004年第2期25卷 1-6页

作者：韩吉田 B.Yu h.j.kang C.X.Lin M.A.Ebadian 山东大学能源与动力工程学院济南250061 hemispheric Center for Environmental Technology

对替代制冷剂R - 1 34a在螺旋管内的对流凝结换热特性进行了实验研究。在制冷剂R - 1 34a的质量流量变化范围为 1 0 0～ 4 0 0kg/ (m2 s)和冷却水的平均温度分别为 1 2℃和 2 2℃的条件下 ,实验得到了在三种不同放置方式螺旋管内 (水平 ... 详细信息

对替代制冷剂R - 1 34a在螺旋管内的对流凝结换热特性进行了实验研究。在制冷剂R - 1 34a的质量流量变化范围为 1 0 0～ 4 0 0kg/ (m2 s)和冷却水的平均温度分别为 1 2℃和 2 2℃的条件下 ,实验得到了在三种不同放置方式螺旋管内 (水平 ,垂直和倾斜 )R - 1 34a的对流凝结换热特性数据。实验结果表明 ,螺旋管的不同放置方式对R - 1 34a在螺旋管内的凝结换热特性具有重要的影响。通过与已有研究结果的比较 ,简要分析了螺旋管不同放置方式对R -1

关键词：制冷剂 R-134a 对流凝结换热替代制冷剂螺旋管相变传热

维普期刊数据库

The quasi-Gramian solution of a non-commutative extension of the higher-order nonlinear Schr?dinger equation

在线全文

学校读者我要写书评

暂无评论

Communications in Theoretical Physics 2024年第3期76卷 51-61页

作者： h W A Riaz j Lin Department of Physics Zhejiang Normal UniversityJinhua 321004China

The nonlinear Schr?dinger(NLS)equation,which incorporates higher-order dispersive terms,is widely employed in the theoretical analysis of various physical *** this study,we explore the non-commutative extension of the higher-order NLS *** treat real or complex-valued functions,such as g_(1)=g_(1)(x,t)and g_(2)=g_(2)(x,t)as non-commutative,and employ the Lax pair associated with the evolution equation,as in the commutation *** derive the quasi-Gramian solution of the system by employing a binary Darboux *** soliton solutions are presented explicitly within the framework of *** visually understand the dynamics and solutions in the given example,we also provide simulations illustrating the associated ***,the solution can be used to study the stability of plane waves and to understand the generation of periodic patterns within the context of modulational instability.

关键词： integrable systems Darboux transformation solitons

维普期刊数据库

全氟丁烷超声造影Kupffer相:提高肝细胞癌诊断敏感度

在线全文

学校读者我要写书评

暂无评论

国际医学放射学杂志 2023年第1期46卷 123-123页

作者： j.A.hwang W.K.jeong h.j.kang E.S.Lee h.j.Park j.M.Lee 刘月

摘要目的评估全氟丁烷超声造影(CEUS)对肝细胞癌(hCC)诊断的准确性,并探讨如何比传统诊断标准更好地提高高危病人的诊断准确性。方法回顾性分析2013—2020年

关键词：

Convexification of hybrid AC-DC Optimal Power Flow with Line-Commutated Converters

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

CSEE journal of Power and Energy Systems 2024年第2期10卷 617-628页

作者： hongyuan Liang Zhigang Li j.h.Zheng Q.h.Wu School of Electric Power Engineering South China University of TechnologyGuangzhou 510641China

Line-commutated converter (LCC)-based high-voltage DC (hVDC) systems have been integrated with bulk AC power grids for interregional transmission of renewable power. The nonlinear LCC model brings additional nonconvexity to optimal power flow (OPF) of hybrid AC-DC power grids. A convexification method for the LCC station model could address such nonconvexity but has rarely been discussed. We devise an equivalent reformulation for classical LCC station models that facilitates second-order cone convex relaxation for the OPF of LCC-based AC-DC power grids. We also propose sufficient conditions for exactness of convex relaxation with its proof. Equivalence of the proposed LCC station models and properties, exactness, and effectiveness of convex relaxation are verified using four numerical simulations. Simulation results demonstrate a globally optimal solution of the original OPF can be efficiently obtained from relaxed model.

关键词： AC-DC power system convex relaxation linecommutated converter optimal power flow second-order cone programming

双门静脉期钆塞酸二钠增强肝脏MRI无创性诊断肝细胞肝癌的个体内比较

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

国际医学放射学杂志 2021年第2期44卷 245-246页

作者： h.j.kang j.M.Lee S.K.jeon S.jang S.Park I.joo 王璐娜

摘要目的比较钆塞酸二钠增强MRI (Gd-EOB-MRI)第一门静脉期(PVP1)和第二门静脉期(PVP2)对肝细胞肝癌(hCC)廓清、强化包膜的显示及对hCC诊断效能差异。方法

关键词：