Observer-based robust high-order fully actuated attitude autopilot design for spinning glide-guided projectiles

This paper investigates the design of an attitude autopilot for a dual-channel controlled spinning glideguided projectile(SGGP),addressing model uncertainties and external disturbances.Based on fixed-time stable theory,a disturbance observer with integral sliding mode and adaptive techniques is proposed to mitigate total disturbance effects,irrespective of initial conditions.By introducing an error integral signal,the dynamics of the SGGP are transformed into two separate second-order fully actuated systems.Subsequently,employing the high-order fully actuated approach and a parametric approach,the nonlinear dynamics of the SGGP are recast into a constant linear closed-loop system,ensuring that the projectile's attitude asymptotically tracks the given goal with the desired eigenstructure.Under the proposed composite control framework,the ultimately uniformly bounded stability of the closed-loop system is rigorously demonstrated via the Lyapunov method.Validation of the effectiveness of the proposed attitude autopilot design is provided through extensive numerical simulations.

Laser shaping and optical power limiting of pulsed Laguerre–Gaussian laser beams of high-order radial modes in fullerene C60

We study the strong nonlinear optical dynamics of nanosecond pulsed Laguerre–Gaussian laser beams of high-order radial modes with zero orbital angular momentum propagating in the fullerene C60molecular medium. It is found that the spatiotemporal profile of the incident pulsed Laguerre–Gaussian laser beam is strongly reshaped during its propagation in the C60molecular medium. The centrosymmetric temporal profile of the incident pulse gradually evolves into a noncentrosymmetric meniscus shape, and the on-axis pulse duration is clearly depressed. Furthermore, the field intensity is distinctly attenuated due to the field-intensity-dependent reverse saturable absorption, and clear optical power limiting behavior is observed for different orders of the input pulsed Laguerre–Gaussian laser beams before the takeover of the saturation effect;the lower the order of the Laguerre–Gaussian beam, the lower the energy transmittance.

Integrated of Proximity-Coupling High-Order Modes Patch Antenna with Solar Cells for Sustainable Communication

An integration of single-layer proximitycoupling patch antenna and solar cells with bandwidth enhancement and optical energy harvesting is proposed for sustainable communication.For this purpose,many dual-function components are selected for designing the miniaturized solar cell antenna.On the one hand,by greatly affecting the current flow of the rectangular patch,vias and proximity-coupling are introduced to control the resonance modes frequency and matching,respectively,for wideband application,and the radiation performance property can be achieved by high-order mode.On the other hand,vias and proximity-coupling are beneficial to complete direct-current(DC)loop of solar cell and improve compatibility of DC-RF(radio frequency),whereas a high-order mode is beneficial to increase the area of collected light energy.To prove the working principle,fabricated and manufactured solar cell antenna.The measured and simulated results illustrate that the solar cell antenna gain is raised to as high as 9.27 d Bi in4.37 to 5.06 GHz applied to fifth generation communication(5G).

Micro-Sized Pinhole Inspection with Segmented Time Reversal and High-Order Modes Cluster Lamb Waves Based on EMATs

Pinhole corrosion is difficult to discover through conventional ultrasonic guided waves inspection,particularly for micro-sized pinholes less than 1 mm in diameter.This study proposes a new micro-sized pinhole inspection method based on segmented time reversal(STR)and high-order modes cluster(HOMC)Lamb waves.First,the principle of defect echo enhancement using STR is introduced.Conventional and STR inspection experiments were conducted on aluminum plates with a thickness of 3 mm and defects with different diameters and depths.The parameters of the segment window are discussed in detail.The results indicate that the proposed method had an amplitude four times larger than of conventional ultrasonic guided waves inspection method for pinhole defect detection and could detect micro-sized pinhole defects as small as 0.5 mm in diameter and 0.5 mm in depth.Moreover,the segment window location and width(5-10 times width of the conventional excitation signal)did not affect the detection sensitivity.The combination of low-power and STR is more conducive to detection in different environments,indicating the robustness of the proposed method.Compared with conventional ultrasonic guided wave inspection methods,the proposed method can detect much smaller defect echoes usually obscured by noise that are difficult to detect with a lower excitation power and thus this study would be a good reference for pinhole defect detection.

High-order sliding mode attitude controller design for reentry flight

A novel high-order sliding mode control strategy is proposed for the attitude control problem of reentry vehicles in the presence of parametric uncertainties and external disturbances, which results in the robust and accurate tracking of the aerodynamic angle commands with the finite time convergence. The proposed control strategy is developed on the basis of integral sliding mode philosophy, which combines conventional sliding mode control and a linear quadratic regulator over a finite time interval with a free-final-state and allows the finite-time establishment of a high-order sliding mode. Firstly, a second-order sliding mode attitude controller is designed in the proposed high-order siding mode control framework. Then, to address the control chattering problem, a virtual control is introduced in the control design and hence a third-order sliding mode attitude controller is developed, leading to the chattering reduction as well as the control accuracy improvement. Finally, simulation examples are given to illustrate the effectiveness of the theoretical results.

Fast self-adapting high-order sliding mode control for a class of uncertain nonlinear systems

A fast self-adapting high-order sliding mode(FSHOSM)controller is designed for a class of nonlinear systems with unknown uncertainties.As for uncertainty-free nonlinear system,a new switching condition is introduced into the standard geometric homogeneity.Different from the existing geometric homogeneity method,both state variables and their derivatives are considered to bring a reasonable effective switching condition.As a result,a faster convergence rate of state variables is achieved.Furthermore,based on the integral sliding mode(ISM)and above geometric homogeneity,a self-adapting high-order sliding mode(HOSM)control law is proposed for a class of nonlinear systems with uncertainties.The resulting controller allows the closed-loop system to conduct with the expected properties of strong robustness and fast convergence.Stable analysis of the nonlinear system is also proved based on the Lyapunov approach.The effectiveness of the resulting controller is verified by several simulation results.

基于3D Body软件的混合模式在放射肿瘤学教学中的应用

目的分析基于3D Body软件的线上线下混合式模式应用于放射肿瘤学教学中的效果。方法选取两个阶段参与放射肿瘤学教学的实习生,其中2022年1月—12月的32名实习生(对照组)采用传统带教模式;2023年1月—12月的32名实习生(观察组)采用基于3D Body软件的线上线下混合式教学模式,评估两组放射肿瘤学教学效果。结果观察组理论考核、实践操作考核、平时成绩均高于对照组,差异有统计学意义(P<0.05);观察组专业技术(包括靶区勾画、制定计划、计划评估,计划验证)能力评分均高于对照组,差异有统计学意义(P<0.05);观察组评判性思维能力高于对照组,差异有统计学意义(P<0.05);观察组实习生的自我能力评价分值高于对照组,差异有统计学意义(P<0.05);观察组实习生对教学模式满意度评价分值高于对照组,差异有统计学意义(P<0.05)。结论放射肿瘤学教学实践中,相比传统带教模式,基于3D Body软件的线上线下混合式教学模式具有明显改善教学效果、提高实习生专业技术能力与评价满意度的作用。

Intrinsic relationship of vorticity between modes A and B in the wake of a bluff body

The intrinsic physical relationship of vorticity between modes A and B in the three-dimensional wake transition is investigated.Direct numerical simulations for the flow past a square-section cylinder are carried out at Reynolds numbers of 180 and 250,associated with modes A and B,respectively.Based on the analysis of spacial distributions of vorticity in the near wake,characteristics of the vertical vorticity in modes A and B are identified.Moreover,the relationship of three vorticity components with specific signs is summarized into two sign laws,as intrinsic physical relationships between two instability modes.By the theory of vortex-induced vortex,such two sign laws confirm that there are two and only two kinds of vortex-shedding patterns in the near wake,just corresponding to modes A and B.In brief,along the free stream direction,mode A can be described by the parallel shedding vertical vortices with the same sign,while mode B is described by the parallel shedding streamwise vortices with the same sign.Finally,it is found out that the|-type vortex is a basic kind of vortex structure in both modes A and B.

High-Order Lateral Buckling Analysis of Submarine Pipeline Under Thermal Stress

It is of importance to study and predict the possible buckling of submarine pipeline under thermal stress in pipeline design.Since soil resistance is not strong enough to restrain the large deformation of pipeline,high-order buckling modes occur very easily.Analytical solutions to high-order buckling modes were obtained in this paper.The relationships between buckling temperature and the amplitude or the wavelength of buckling modes were established.Analytical solutions were obtained to predict the occurrence and consequence of in-service buckling of a heated pipeline in an oil field.The effects of temperature difference and properties of subsoil on buckling modes were investigated.The results show that buckling will occur once temperature difference exceeds safe temperature;high-order pipeline buckling occurs very easily;the larger the friction coefficients are,the safer the submarine pipeline will be.

Contact-impact formulation for multi-body systems using component mode synthesis

The efficiency and accuracy are two most concerned issues in the modeling and simulation of multi-body systems involving contact and impact. This paper proposed a formulation based on the component mode synthesis method for planar contact problems of flexible multi-body systems. A flexible body is divided into two parts： a contact zone and an un-contact zone. For the un-contact zone, by using the fixed-interface substructure method as reference, a few low-order modal coordinates are used to replace the nodal coordinates of the nodes, and meanwhile, the nodal coordinates of the local impact region are kept unchanged, therefore the total degrees of freedom （DOFs） are greatly cut down and the computational cost of the simulation is significantly reduced. By using additional constraint method, the impact constraint equations and kinematic constraint equations are derived, and the Lagrange equations of the first kind of flexible multi-body system are obtained. The impact of an elastic beam with a fixed half disk is simulated to verify the efficiency and accuracy of this method.

创新教育背景下工业设计专业“一体两翼四驱动”教学模式研究

近年来,国家倡导素质教育,提倡在高等院校加大实践能力和创新能力的培养,各高校不断进行教学模式改革和创新,取得了一定成效,但仍没能摆脱传统观念和教学模式的束缚。为适应行业发展趋势和需求,坚持以人为本的教育理念,紧跟时代步伐,引入“一体两翼四驱动”教学模式,开展“一体两翼四驱动”协同育人改革实践,以培养高素质创新复合型人才为主要目的,增强学生实践能力和创新能力,从根本上提升人才培养质量,以满足高速发展的社会需求,为高校人才培养模式变革提供参考依据。

富水软弱围岩劈裂型注浆加固体力学性能与破坏模式

富水软弱围岩劈裂型注浆加固体的力学性能与破坏模式对注浆整体效果具有显著影响。基于室内注浆模拟试验、劈裂型注浆加固体三轴压缩试验和相应的离散元数值模拟,研究劈裂浆脉形态与空间分布特征及注浆加固规律,分析浆脉粗糙度、厚度、数量和倾角对注浆加固体力学性能与破坏模式的影响,阐明三轴加载条件下加固体内部孔隙率和微裂纹演化规律。研究结果表明:劈裂浆脉空间分布模式主要包括半贯通型、交叉型和贯通型,注浆影响区域可分为加固区、过渡区和未扰动区;浆脉存在有效提升了加固体的整体刚度和承载力,加固体峰值偏应力与浆脉粗糙度、厚度、数量呈正相关关系,而浆脉倾角增大会导致整体强度降低;加固体破坏模式主要有局部膨胀型和剪切滑移型,受浆脉形态特征影响,二者对整体变形破坏的贡献程度不同;在加载过程中,浆-土界面处首先萌生微裂纹,进而浆脉两侧软弱介质被压缩挤密后出现大量微裂纹,裂纹数量持续增多直至试样破坏;加固体孔隙率与微裂纹萌生数量变化规律均呈现明显的阶段性特征,且受浆脉形态特征影响显著。

孕前BMI及孕期BMI变化对产妇分娩方式及围产期结局的影响分析

目的分析孕前体质指数(BMI)及孕期BMI变化对产妇分娩方式、围产期结局的影响,为备孕期及孕期女性的体重管理提供依据。方法选取2022年8月至2023年8月在昆明市妇幼保健院住院分娩的98例孕妇作为研究对象,按孕前BMI将研究对象分为消瘦组(n=16)、正常组(n=54)、超重或肥胖组(n=28);按孕期BMI变化分为增重不足组(n=19)、增重正常组(n=27)、增重过多组(n=52),分析组间孕妇分娩方式及围产期结局的差异。结果98例孕妇中,69例行阴道分娩,29例行剖宫产。消瘦组、正常组、超重或肥胖组孕妇分娩方式比较差异具有统计学意义(χ^(2)值为11.068,P<0.05);增重不足组、增重正常组及增重过多组的孕妇分娩方式比较差异具有统计学意义(χ^(2)值为9.126,P<0.05)。消瘦组、正常组、超重或肥胖组的妊娠并发症、胎儿不良事件、新生儿不良事件比例比较差异具有统计学意义(χ^(2)值分别为13.411、21.977、23.885,P<0.05),而产后并发症比例的差异无统计学意义(P>0.05);不同孕期BMI变化组别的妊娠并发症、胎儿不良事件、新生儿不良事件及产后并发症比例比较差异均具有统计学意义(χ^(2)值分别为11.651、10.825、16.534、11.159,P<0.05)。结论孕前超重或肥胖、孕期增重过多均可能增加产妇剖宫产及不良围产期结局的发生风险。建议孕前超重或肥胖的妇女在备孕期间进行减重管理,孕期仍需科学管理体重,避免孕期增重过多或增重不足。

高职宠物类专业“双元融合六段递进”人才培养模式创新与实践

校企合作产教融合是办好职业教育的关键所在。总结四年改革经验,通过构建职业能力标准体系、创设模块化“课程群”、开发基于真实工作岗位的教学资源、建立“一主两翼”实训基地和打造高水平师资队伍等系列化举措,创新“双元融合六段递进”人才培养模式,实现高职宠物类专业高质量人才培养,为校企协同育人提供实践范式。

中国式现代化:“体”“用”模式与人类命运共同体

世界现代化进程中,19世纪形成的体用一元的模式(西方开创的工业化为用、西方民主制度和西方价值观为体模式)已经难以为继了,更多非西方国家开创了体用二元的模式(西方开创的工业化为用、非西方政治制度和非西方价值观为体模式)。体用二元模式意味着差别性现代化也即多样性现代化的存在。“中体西用”模式其实是多样性现代化的早期表述,当下的中国式现代化为多样性现代化提供了楷模。为了解决人类社会的差别性现代化矛盾与当下的共同性危机,中国提出了“人类命运共同体”倡议,其超越了社会制度、意识形态、历史文明之争,中国式现代化凭此称之为“人类文明新形态”。

高职院校毛泽东思想和中国特色社会主义理论体系概论课教学模式创新研究

基于“三阶段五环节一主体”的全过程教学模式,对高职院校毛泽东思想和中国特色社会主义理论体系概论课教学模式进行创新研究,做到课前以学生为主体调研学生的关注点和困惑点、课中以学生为主体发挥学生主体地位和作用、课后以学生为主体增强学习的广度和深度,力求让学生在整个教学过程中始终融入课堂、始终发挥课堂主体作用,以真正增强学生的获得感。

中文国际传播视域下国际中文教育人才培养模式建构——以三亚学院为例

展现可信、可爱、可敬的中国形象,推动中华文化更好地走向世界,增强中华文化传播力、影响力的关键是语言相通,让世界上更多的人理解中文。中文国际传播的历史使命对国际中文教育相关专业的人才培养提出了更高要求。笔者针对当前国际中文教育人才培养模式同质化问题,依据高质量人才需求,在三亚学院经过多年实践探索,构建出本科阶段适应中文国际传播需求的“一体两翼三融通”国际化、复合型人才培养模式即以新时代国际中文教育人才培养为主体,以语言文化教育、语言文化传播实践转化为两翼,以中外语言文化融通、信息技术与职业技能融通、对内与对外双向传播融通为支撑,是解决当前国际中文教育人才培养痛点的有效举措。

一种地外天体着陆凸轨迹曲率滑模制导方法

针对复杂地外天体表面安全着陆问题,提出了凸轨迹曲率滑模制导方法。该方法考虑着陆轨迹形状对着陆安全性的影响,将曲率约束引入到滑模面设计中,实现着陆器系统状态位于滑模面上时,轨迹形状为凸。首先,针对曲率约束进行等效转化和松弛,提出了曲率松弛项,并利用曲率松弛项设计了曲率滑模面,满足三维凸轨迹条件。其次,推导了曲率滑模反馈制导律,滑模状态可在有限时间内收敛到零,在该制导律作用下,着陆器将以凸轨迹状态完成精准软着陆。最后,通过蒙特卡洛仿真验证了所提算法的有效性和鲁棒性。

工厂化养殖模式下星康吉鳗的形态分析及重要形态性状对体重和净体重的影响效应

选取黄海沿岸3家养殖厂采集的90尾工厂化养殖模式下的星康吉鳗(Conger myriaster)作为研究对象,逐一测量其体重(BW)、净体重(NW)、全长(TL)、体长(BL)、体高(BH)、体宽(SW)、头宽(HW)等14项形态性状,进行形态性状间关联分析并构建形态性状度量构架图;采用相关性分析、通径分析、决定程度分析、多元回归分析和曲线拟合方法解析了星康吉鳗各形态性状对体重和净体重的影响效应。相关性分析显示,6项形态性状与体重的相关系数均达到极显著水平(P<0.01),7项形态性状与净体重的相关系数均达到极显著水平(P<0.01);经通径分析查明,体长、体高、体宽3项形态性状与体重、净体重的通径系数较大,分别为0.631、0.204、0.374和0.703、0.213、0.239;经决定程度分析发现,体长对体重、净体重的决定系数最大,分别为0.398和0.494;体长与体宽的组合对体重、净体重的决定系数最大,分别为0.162和0.116;经逐步多元回归分析,建立体长、体高、体宽与体重、净体重间的回归方程分别为BW=–642.699+1.086×BL+3.874×BH+7.917×SW和NW=–526.995+1.033×BL+3.438×BH+4.317×SW。进一步对多元回归方程中各形态性状与体重、净体重进行曲线拟合,得出体长、体高、体宽与体重的最佳拟合模型分别为对数函数、幂函数和对数函数,模型方程分别为BW=–3542.357+608.061lnBL、BW=14.313BH0.941和BW=–1028.49+416.452lnSW;体长、体高、体宽与净体重的最佳拟合模型分别为对数函数、线性函数和对数函数,模型方程分别为NW=–2983.881+516.411lnBL、NW=–22.252+11.392BH和NW=–774.583+329.017lnSW。本研究揭示了工厂化养殖模式下,星康吉鳗体长为影响体重与净体重的核心形态性状,体高和体宽为影响体重与净体重的重要形态性状,可为后续星康吉鳗的种质特征鉴定、遗传育种和健康养殖提供基础理论参考。

气道异物梗阻患儿的护理模式优化研究

目的:探讨气道异物梗阻患儿的优化护理模式。方法:选取本院2020年1月—2022年2月收治行支气管镜异物取出术治疗的112例气道异物梗阻患儿作为研究对象,采用随机数字表法分为观察组和对照组,各56例。对照组患儿给予常规护理模式,观察组患儿在对照组的基础上给予优化护理模式。比较两组患儿分诊评估时间、抢救时间、首次置镜成功率、术后并发症发生率以及患儿家属和医生对护士的满意度。结果:观察组患儿分诊评估时间、抢救时间均短于对照组(P<0.05),首次置镜成功率高于对照组(P<0.05);观察组患儿术后并发症总发生率低于对照组(P<0.05);观察组患儿家属对护士病情解释、服务态度、业务水平、护理质量和医生对护士人员调配、物品准备、主动配合、应急处理能力的满意度均高于对照组(P<0.05)。结论:优化护理模式在气道异物梗阻患儿治疗期间的应用有助于缩短分诊评估时间和抢救时间,提高患儿首次置镜成功率,减少并发症发生,提高患儿家属和医生对护士的满意度。