The Optimal Cross-section Design of the “Trapezoid-V” Shaped Drainage Canal of Viscous Debris Flow

Debris flow drainage canal is one of the most widely used engineering measures to prevent and manage debris flow hazards.The shape and the sizes of the cross-section are important parameters when design debris flow drainage canal.Therefore,how to design the appropriate shape and sizes of the cross-section so that the drainage canal can have the optimal drainage capacity is very important and few researched at home and abroad.This study was conducted to analyze the hydraulic condition of a Trapezoid-V shaped drainage canal and optimize its cross-section.By assuming characteristic sizes of the cross-section,the paper deduced the configuration parameter of the cross-section of a Trapezoid-V shaped debris flow drainage canal.By theory analysis,it indicates that the optimal configuration parameter is only related to the side slope coefficient and the bottom transverse slope coefficient.For this study,the Heishui Gully,a first-order tributary of the lower Jinsha River,was used as an example to design the optimal cross-section of the drainage canal of debris flow.

In-Plane Impact Dynamics Analysis of Re-Entrant Honeycomb with Variable Cross-Section

Due to the unique deformation characteristics of auxetic materials(Poisson’s ratioμ<0),they have better shock resistance and energy absorption properties than traditional materials.Inspired by the concept of variable crosssection design,a new auxetic re-entrant honeycomb structure is designed in this study.The detailed design method of re-entrant honeycomb with variable cross-section(VCRH)is provided,and five VCRH structures with the same relative density and different cross-section change rates are proposed.The in-plane impact resistance and energy absorption abilities of VCRH under constant velocity are investigated by ABAQUS/EXPLICIT.The results show that the introduction of variable cross-section design can effectively improve the impact resistance and energy absorption abilities of auxetic re-entrant honeycombs.The VCRH structure has better Young’s modulus,plateau stress,and specific energy absorption(SEA)than traditional re-entrant honeycomb(RH).The influence of microstructure parameters(such as cross-section change rateα)on the dynamic impact performance of VCRH is also studied.Results show that,with the increase in impact velocity andα,the plateau stress and SEA of VCRH increase.A positive correlation is also found between the energy absorption efficiency,impact load uniformity andαunder both medium and high impact speeds.These results can provide a reference for designing improved auxetic re-entrant honeycomb structures.

Optimization of Energy Density in Girders under Pure Bending with an Extruded Monolithic Cross-Section

This article proposes use of extruded compound materials with optimized resistant cross-sections as an alternative, in this case, seeking the maximum energy density as a design criterion. The advantage of this proposal is that it extends the life cycle and decreases fatigue issues.

Design of General Accuracy of the Dynamic Measurement Instrument for 3 meter Leadscrew by Laser Interferometric Control

The accuracy distribution of measuring instrument for 3-Ineter leadscrew by laser is studied according toerror theory. In this paper, the tables of overall accuracy distribution used as foundation of design and manufactureare drafted.

Design of cavern blasting based on controllable parameters

After a thorough review of some controllable parameters,which included field investigations,cavern dimensions,explosive,rock strength etc.,cut,contour,lifters and stoping holes were introduced for blasting cavern of nucleus submarine.These design were conducted using a U.Langefors and B.Kihlstrom theory.

T-shirt Leads Fashion,Nature Creates Quality Life

The annual "Natural" Cup International T-shirt Design Competition, supervised by China Association for Science and Technology, China National Textile

地缘文化视角下非遗嵌入高校设计教学的路径研究

非遗作为中华文明的重要组成部分,其地缘文化背景、实践性和创新性为设计教育提供了新的视角、思路、教学资源和教学方法。通过运用嵌入性理论,深挖非遗本土化特色,有机融入设计教学结构,有助于培养学生的文化自信、创新思维和实践能力,满足社会和行业发展的需求。非遗的跨学科特性和实践创新价值为设计教育提供新的教学资源和方法,为文化传承与创新注入新的活力,为地方经济的发展和文化传承创新提供支持。本文在推动高校课堂精细型教学与田野粗放型教学的互补,建立知行合一的设计教学路径,为地方高校设计教学与人才培养提供参考。

基于MBSE的铅冷快堆非能动余热排出系统设计需求分析

针对传统的铅冷快堆非能动余热排出系统设计中存在开发效率低、迭代周期长、模型二义性等前期需求问题,本研究将基于模型的系统工程(Model-based System Engineering,MBSE)方法应用于铅冷快堆非能动余热排出系统设计需求中,结合设计流程进行系统架构的初步设计,该系统架构由需求分析、功能分析和设计综合三部分组成。结果表明:需求分析阶段生成的需求图和用例图可捕获系统需求并确定系统顶层用例;功能分析阶段绘制的时序图、活动图和状态机图可形成系统功能模型并提供早期确认与验证;设计综合阶段建立的白盒模型最终实现系统架构的分析与设计。采用该方法设计的系统架构可确保前后设计需求一致性,进一步降低设计风险并提高设计效率,可为数字化铅冷快堆非能动余热排出系统设计与优化提供应用参考。

基于多孔介质方法的铅铋螺旋管式直流蒸汽发生器设计优化研究

本文提出了基于多孔介质方法,铅铋螺旋管式直流蒸汽发生器开展数值模拟,并通过与三维数值模拟结果的对比验证了多孔介质模拟方法的正确性。基于此方法,对给定工况条件的铅铋螺旋管蒸汽发生器开展了设计研究。在1.5 MW功率目标下,发现四层螺旋管的布置方式具有最优综合性能。在此基础上,通过综合性能评价指标对不同工况条件下不同几何参数的螺旋管蒸汽发生器开展性能评价,并运用多元线性拟合探究在工况以及几何范围内综合性能最佳的几何模型,最高性能提升达到3.37%。本研究为铅铋螺旋管式直流蒸汽发生器数值模拟及设计优化提供新的方法参考。

科学式引领发展——工艺流程设计教改实践的亮点

专业课程教学改革已经成为新工科建设时期我国高校的一项重要工作任务。“科学式引领发展”作为一个具有时代意义的概念被引入工艺流程设计的教学中,形成教改实践中的亮点。本文充分利用概念法、案例法和实验研究法等多种教学方法,从多角度来阐述科学在现代工艺流程设计中的意义,强调工艺流程在化工设计中的引领地位。

Concurrent topology optimization design of stiffener layout and cross-section for thin-walled structures

Stiffened plates or shells are widely used in engineering structures as primary or secondary load-bearing components.How to design the layout and sizes of the stiffeners is of great significance for structural lightweight.In this work,a new topology optimization method for simultaneously optimizing the layout and cross-section topology of the stiffeners is developed to solve this issue.The stilfeners and base plates are modeled by the beam and shell elements,respectively,significantly reducing the computational cost.The Giavotto beam theory,instead of the widely employed Euler or Timoshenko beam theory,is applied to model the stiffeners for considering the warping deformation in evaluating the section stiffness of the beam.A multi-scale topology optimization model is established by simultaneously optimizing the layout of the beam and the topology of the cross-section.The design space is significantly expanded by optimizing these two types of design variables.Several numerical examples are applied to illustrate the validity and effectiveness of the proposed method.The results show that the proposed two-scale optimization approach can generate better designs than the single-scale method.

提高教师愿景规划能力引领教师自主长远发展

自主发展是教师专业成长的基本途径,教师专业发展愿景规划是促进教师自主发展的有效抓手。教师必须提高愿景规划能力,通过充分的现状评估认清自己的人格偏好和所处的职业环境,通过科学的目标设置找到最适合自己的发展方向,通过可行的发展措施一步步实现专业发展。在愿景规划实施的过程中,教师要注意将个人发展与组织发展统一起来,通过及时的正向反馈保持愿景的激励作用,并根据发展阶段的不同需求适时调整规划。

PLZT透明陶瓷的微区组分调控及梯度设计与电光性能研究

镧掺杂锆钛酸铅(PLZT)透明陶瓷因其优异的光学透明性和电光效应,在现代光通信和高能激光技术等领域具有重要应用前景。然而PLZT透明陶瓷的电光性能对环境温度变化非常敏感,增加了其在宽温度范围电光调制器中的应用难度。本文围绕PLZT(10/65/35)透明陶瓷开展了材料铁电、介电及电光性能随温度变化的相关研究,通过对关键掺杂离子La^(3+)含量的微区调控和构建一定分布梯度,改善材料的电光性能及其温度稳定性。通过传统氧气氛热压烧结获得系列纯钙钛矿相结构的PLZT陶瓷,材料显微结构均匀致密;所有样品均呈现良好的光学透过率(52%~60%,λ=632.8 nm);随着La^(3+)含量微量增加,PLZT陶瓷的介电峰谱弛豫性增大,同时微区La^(3+)组分波动性增强的0-3复合和2-2复合PLZT陶瓷的介电温谱谱峰显著展宽且介电常数峰值提高;随温度的升高,陶瓷样品的铁电电滞回线(P-E)中最大极化值(P max)、剩余极化值(P r)和矫顽力场强(E c)逐渐减小;0-3复合和2-2复合PLZT(10/65/35)陶瓷的铁电极化值P max比均匀混合PLZT(10/65/35)陶瓷明显提高,且其等效二次电光系数在弥散相变温区显著增加。

A Two-Level Cross-Sectional Optimization Approach for Automotive Body Concept Design

Concept design is vital important in development of auto-body and it has great effects on later design work.In this paper,a twolevel cross-sectional optimization approach is presented to shorten concept design cycles.First,an exact structural analysis approach for spatial semi-rigid framed structures,i.e.,the transfer stiffness matrix method proposed in our previous study,is adopted for both static and dynamic analyses of body-in-white(BIW)structure.A two-level cross-sectional optimization approach is then proposed for an automotive BIW lightweight design,and genetic algorithm is used to solve the optimization models.Afterward,an object-oriented MATLAB toolbox,using distributed parallel computing techniques,is developed to promote the concept design of the BIW structure.Finally,relevant numerical examples demonstrate the validity and accuracy of the proposed method.

Challenges and Motivating Factors of Orthodontic Treatment among Patients Attending Komfo Anokye Teaching Hospital

Background: Orthodontic treatment poses challenges such as discomfort, aesthetic concerns, dietary restrictions, time commitment, and financial considerations for patients. These challenges can deter individuals from pursuing treatment or cause anxiety during the process. However, patients are motivated by the desire to improve their appearance, boost self-confidence, and enhance oral health. They also value the long-term benefits of treatment, including improved dental function and overall well-being. Professional recommendations from dentists and orthodontists, along with social support from family and friends, further encourage patients to undergo treatment. Understanding these challenges and motivating factors is crucial for orthodontic professionals to tailor treatment plans and ensure positive experiences and successful outcomes for their patients. Objective: To determine the challenges and motivating factors of orthodontic treatment among patients attending Komfo Anokye Teaching Hospital. Method: The study was conducted at Komfo Anokye Teaching Hospital in Kumasi, Ghana, with a sample size of 60 orthodontic patients. Data was collected using self-administered questionnaires and analyzed using SPSS software. Ethical approval was obtained, and the findings were shared with stakeholders. Results: Findings showed a higher representation of females (63.3%) seeking orthodontic treatment. Common motivations for seeking orthodontic treatment included aesthetic Concerns (38.2%), misaligned teeth (28.1%) and recommendation from dentist (19.2%). Challenges reported included pain and discomfort (36.7%), difficulty chewing (15%), expensive treatment (14.4%) and missed appointments (11.7%). Factors motivating treatment continuation were visible improvements (30%), achieving optimal results (23%), reducing pain and discomfort (17%). External influences, such as family pressure, also played a role. Patients appreciated the support of healthcare providers during treatment but suggested better pain management and education. Conclusion: The study provided valuable insights into patient motivations, challenges and factors influencing satisfaction and adherence to orthodontic treatment at KATH.

具有前缘凹凸结构的组合翼型优化设计及其气动特性分析

为了不断探索翼型改型的方法和提高翼型的气动性能,将传统翼型与生物翼型进行轮廓修型设计得到组合翼型,通过数值模拟的方法对组合翼型进行气动特性分析.同时,对组合翼型进行前缘凹凸结构优化设计,采用正交试验优选出气动特性表现最优的参数,并对最优前缘组合翼型进行气动特性分析.研究发现:相比标准NACA64-618翼型,组合翼型在小范围攻角有着较高的升力系数,升力系数最大提高了7.3%,此外,具有前缘凹凸结构的前缘组合翼型升阻比最大提高了9.98%.组合翼型的弯度前移使得吸力面负压峰值区域面积增大,翼型上下表面压差增大,进而提高了气动性能;前缘组合翼型由于前缘凹凸结构的存在,在翼型吸力面靠近尾缘处,形成一对反向旋涡,增加了流体在翼型表面覆盖的面积,抑制了流动分离的提前发生,进而达到失速延迟的效能.

课程思政建设中大学英语课程的教学设计研究

在高校课程思政建设体系中,公共大学英语课程因其课时长、学生受众面广、课程内容包含西方文化意识等特点,决定了该课程在高校课程思政建设中的特殊性及重要性。本文聚焦大学英语课程教学设计的微观方面,即课程的教学设计理念、内容、方法和评价这四个方面,来探讨大学英语课程的一线教师在现实课堂中如何进行课堂教学改革、实现“立德树人”总目标的具体实践办法。

风电叶片前缘雨蚀测试及防护方法研究

随着风电机组大型化及漂浮式海上风电的发展,风电叶片服役环境越来越复杂,叶片前缘的损伤及防护越来越被重视。文章以固/液冲击过程的“水锤压力”为切入点简述了航空、航天以及风电行业对雨蚀损伤的研究,介绍了单射流法、火箭撬法、旋转臂法等常用的耐雨蚀测试方法,并提出了耐雨蚀评估方法的改进方向。列举了叶片常用的几类前缘防护材料性能特点,对比了不同制样环境下前缘漆材料的耐雨蚀性能差异。阐述了前缘防护材料的选型评估思路,提出了考虑项目地域降雨情况、叶片线速度等因素的前缘差异化防护思路。

液态铅铋合金氧计探头设计及优化

液态铅铋合金的测氧和氧控,对抑制结构材料腐蚀具有重要作用,是铅基反应堆工程应用需解决的关键技术问题之一。为支持深入开展液态铅铋合金氧测控技术研究,本文基于液态铅铋合金测氧原理及其测量需求,自主设计研制了用于液态铅铋合金测氧的氧计探头,并利用某铅铋合金静态腐蚀试验釜验证了氧计探头的测量性能,结果表明,所设计的氧计探头可在200~550℃交变高温情况下实现测氧,测量范围达到10^(-6)~30 ppm,泄漏率不高于10^(-6)(Pa·m^(3))/s。

X射线荧光光谱仪在农田土壤铅镉元素含量检测中的应用

由于以往的农田土壤铅镉元素含量检测方法仅计算了单一的光谱数据特征,导致检测效果不佳。因此,本文对X射线荧光光谱仪在农田土壤铅镉元素含量检测中的应用展开了研究。先利用X射线荧光光谱仪获取相应的土壤样品光谱数据,并对该光谱数据进行小波处理和校正处理,然后提取多个光谱数据特征,并对其进行投影,最后计算对应的权重值,完成对光谱数据特征分量的分析,通过计算铅镉元素的吸光度,实现对铅镉元素含量的计算。通过上述的设计,完成对农田土壤铅镉元素含量检测方法的设计。在实验测试中,和以往的农田土壤铅镉元素含量检测方法相比,设计的农田土壤铅镉元素含量检测方法得出结果在实际应用中拟合程度较高,检测效果较好。