Achievements of Truss Models for Reinforced Concrete Structures

Achievements are presented for truss models of RC structures developed in previous years: 1. Two constitutive models, biaxial and triaxial, are based on regular trusses, with bars obeying nonlinear uniaxial σ-ε laws of material under simulation;both models have been compared with test results and show a dependence of Poisson ratio on curvature of σ-ε law. 2. A truss finite element has been used in the nonlinear static and dynamic analysis of plane RC frames;it has been compared with test results and describes, in a simple way, the formation of plastic hinges. 3. Thanks to the very simple geometry of a truss, the equilibrium equations can be easily written and the stiffness matrix can be easily updated, both with respect to the deformed truss, within each step of a static incremental loading or within each time step of a dynamic analysis, so that to take into account geometric nonlinearities. So the confinement of a RC column is interpreted as a structural stability effect of concrete. And a significant role of the transverse reinforcement is revealed, that of preventing, by its close spacing and sufficient amount, the buckling of inner longitudinal concrete struts, which would lead to a global instability of the RC column. 4. The proposed truss model is statically indeterminate, so it exhibits some features, which are not met by the “strut-and-tie” model.

温度预应力钢板箍加固RC短柱有限元分析

本文结合国内外包钢加固方面的研究成果与实践经验,提出利用温度对钢板箍施加预应力以提高RC短柱抗震加固效果的方法。该方法旨在通过箍板降温回缩对加固柱混凝土产生预压应力,使核芯混凝土处于三轴受压状态,从而有效提高混凝土强度和变形能力,同时可有效降低后加部分的应力滞后,提高结合面传力性能。文中利用通用有限元软件ANSYS建立预应力钢板箍加固RC短柱计算模型,对施加和未施加预应力两种情况的构件进行轴压力恒定下的横向力位移非线性全过程分析。通过计算结果对比分析,揭示了通过施加钢板箍预应力加固方案的可行性。在考虑加固构件二次受力基础上,通过改变轴压比、预应力水平,研究预应力技术对短柱抗剪强度及变形能力的影响,以验证理论构想。

基于RC振荡电路的冰层厚度测量装置

基于冰、水介电常数和电阻率的显著差别及振荡电路的频率响应原理,提出以精确测量冰层表面空间位置与动态预测冰层增减速度相结合的冰层厚度测量方法,并据此开发出阻容式冰层厚度测量装置。该装置结构简单、安装方便。试验与分析表明,该装置具有良好的测量精度、稳定性和灵敏度,适用于外融式冰板与冰盘管表面结冰与融冰过程中冰层厚度的动态测量。

Enhancing competency of clinical research nurses:A comprehensive training and evaluation framework

The Sun et al's training program for clinical research nurses(CRNs)in the World Journal of Clinical Cases is a comprehensive and scientific approach.It includes structured frameworks for CRN training,aiming to improve CRN competency.This program emphasizes practical abilities,updates training content,and improves evaluation methods.The cultivation of CRN talents focuses on enhancing the training system,establishing a multifaceted evaluation framework,and continuously refining the training programs.Regular feedback and evalua-tion are essential to improve CRNs'competency in practical settings.

Ethical framework for artificial intelligence in healthcare research:A path to integrity

The integration of Artificial Intelligence(AI)into healthcare research promises unprecedented advancements in medical diagnostics,treatment personalization,and patient care management.However,these innovations also bring forth significant ethical challenges that must be addressed to maintain public trust,ensure patient safety,and uphold data integrity.This article sets out to introduce a detailed framework designed to steer governance and offer a systematic method for assuring that AI applications in healthcare research are developed and executed with integrity and adherence to medical research ethics.

CFRP加固RC简支T梁桥受力性能试验研究

为深入研究粘贴碳纤维布加固钢筋混凝土T梁桥的加固效果,结合某桥梁大修工程,通过在简支T梁梁底粘贴4层碳纤维布以提高其正截面承载能力.为检验加固效果,分别在加固前后对试验孔进行荷载试验,加固前后均采用两辆重约330kN的同型号三轴载重汽车作为试验荷载,重点检测了加固前后主梁跨中挠度、梁底混凝土及碳纤维布应变以及裂缝扩展情况.荷载试验结果表明,在简支钢筋混凝土梁桥上粘贴碳纤维布可有效抑制混凝土开裂,增加破损主梁的抗弯刚度,提高上部结构整体受力的能力.

The Golden Ratio Theorem: A Framework for Interchangeability and Self-Similarity in Complex Systems

The Golden Ratio Theorem, deeply rooted in fractal mathematics, presents a pioneering perspective on deciphering complex systems. It draws a profound connection between the principles of interchangeability, self-similarity, and the mathematical elegance of the Golden Ratio. This research unravels a unique methodological paradigm, emphasizing the omnipresence of the Golden Ratio in shaping system dynamics. The novelty of this study stems from its detailed exposition of self-similarity and interchangeability, transforming them from mere abstract notions into actionable, concrete insights. By highlighting the fractal nature of the Golden Ratio, the implications of these revelations become far-reaching, heralding new avenues for both theoretical advancements and pragmatic applications across a spectrum of scientific disciplines.

Research evolution of metal organic frameworks: A scientometric approach with human-in-the-loop

Purpose:This paper reports on a scientometric analysis bolstered by human-in-the-loop,domain experts,to examine the field of metal-organic frameworks(MOFs)research.Scientometric analyses reveal the intellectual landscape of a field.The study engaged MOF scientists in the design and review of our research workflow.MOF materials are an essential component in next-generation renewable energy storage and biomedical technologies.The research approach demonstrates how engaging experts,via human-in-the-loop processes,can help develop a comprehensive view of a field’s research trends,influential works,and specialized topics.Design/methodology/approach:Ascientometric analysis was conducted,integrating natural language processing(NLP),topic modeling,and network analysis methods.The analytical approach was enhanced through a human-in-the-loop iterative process involving MOF research scientists at selected intervals.MOF researcher feedback was incorporated into our method.The data sample included 65,209 MOF research articles.Python3 and software tool VOSviewer were used to perform the analysis.Findings:The findings demonstrate the value of including domain experts in research workflows,refinement,and interpretation of results.At each stage of the analysis,the MOF researchers contributed to interpreting the results and method refinements targeting our focus Research evolution of metal organic frameworks:A scientometric approach with human-in-the-loop on MOF research.This study identified influential works and their themes.Our findings also underscore four main MOF research directions and applications.Research limitations:This study is limited by the sample(articles identified and referenced by the Cambridge Structural Database)that informed our analysis.Practical implications:Our findings contribute to addressing the current gap in fully mapping out the comprehensive landscape of MOF research.Additionally,the results will help domain scientists target future research directions.Originality/value:To the best of our knowledge,the number of publications collected for analysis exceeds those of previous studies.This enabled us to explore a more extensive body of MOF research compared to previous studies.Another contribution of our work is the iterative engagement of domain scientists,who brought in-depth,expert interpretation to the data analysis,helping hone the study.

B36-11 氧对于大肠杆菌ArcA和FNR调控系统和代谢反应的影响Levanon SS等

大肠杆菌具有多种精细的传感机制，以对氧的利用度和其它电子受体的存在作出应答。适应性应答通过一组综合调控子协调，包括单组分的Fnr蛋白和双组分的Arc系统。为了量化代谢中依赖于Arc和Fnr调控的作用，以最近开发的源于λ的重组系统构建了arcA和fnr突变株。在恒化培养的稳定状态下，通过葡萄糖限制培养基和不同氧浓度下的发酵途径研究了大肠杆菌野生型、arcA突变株、fnr突变株和arcA-fnr双突变株的代谢活性。发现ArcA在微氧条件下起显著作用，

UHPC加固RC梁受力性能试验研究

为研究超高性能混凝土(UHPC)在RC梁加固中的适用性,通过双面剪切试验对UHPC-普通混凝土界面粘结性能进行分析。分别对RC梁受压、受拉区进行UHPC薄层加固,对未加固RC梁和受压、受拉区加固RC梁进行四点弯曲试验,对比正截面抗弯性能。结果表明:界面处理后,界面粘结性能大于普通混凝土抗剪强度。确定人工凿毛5 mm的界面处理方式。RC梁采用UHPC加固后,抗弯承载能力显著提高,受压区加固RC梁后受拉钢筋屈服荷载、试验峰值荷载分别提高了54.3%、52.2%,受拉区加固RC梁后受拉钢筋屈服荷载、试验峰值荷载分别提高了85.7%、96.9%;受拉钢筋屈服时受压、受拉区加固RC梁裂缝宽度较未加固RC梁分别减小了49.4%、72.3%;相同裂缝宽度0.2 mm下,受压、受拉区加固RC梁承载能力较未加固RC梁分别提高了1.4倍、6.5倍。提出UHPC加固RC梁极限抗弯承载力计算公式,该公式计算值与试验实测值吻合良好,且偏安全,可以指导UHPC加固RC梁设计。

Numerical Exploration of Asymmetrical Impact Dynamics: Unveiling Nonlinearities in Collision Problems and Resilience of Reinforced Concrete Structures

This study provides a comprehensive analysis of collision and impact problems’ numerical solutions, focusing ongeometric, contact, and material nonlinearities, all essential in solving large deformation problems during a collision.The initial discussion revolves around the stress and strain of large deformation during a collision, followedby explanations of the fundamental finite element solution method for addressing such issues. The hourglassmode’s control methods, such as single-point reduced integration and contact-collision algorithms are detailedand implemented within the finite element framework. The paper further investigates the dynamic responseand failure modes of Reinforced Concrete (RC) members under asymmetrical impact using a 3D discrete modelin ABAQUS that treats steel bars and concrete connections as bond slips. The model’s validity was confirmedthrough comparisons with the node-sharing algorithm and system energy relations. Experimental parameterswere varied, including the rigid hammer’s mass and initial velocity, concrete strength, and longitudinal and stirrupreinforcement ratios. Findings indicated that increased hammer mass and velocity escalated RC member damage,while increased reinforcement ratios improved impact resistance. Contrarily, increased concrete strength did notsignificantly reduce lateral displacement when considering strain rate effects. The study also explores materialnonlinearity, examining different materials’ responses to collision-induced forces and stresses, demonstratedthrough an elastic rod impact case study. The paper proposes a damage criterion based on the residual axialload-bearing capacity for assessing damage under the asymmetrical impact, showing a correlation betweendamage degree hammer mass and initial velocity. The results, validated through comparison with theoreticaland analytical solutions, verify the ABAQUS program’s accuracy and reliability in analyzing impact problems,offering valuable insights into collision and impact problems’ nonlinearities and practical strategies for enhancingRC structures’ resilience under dynamic stress.

A Triple Nexus Water-Energy-Housing (WEH) Framework Modelling towards Improved Decision-Making in Humanitarian Operations

Given the challenges facing most humanitarian operations worldwide, a change of approach is needed to ensure greater sustainability of humanitarian settlements right from the planning stage. Some studies attribute unsustainability to inadequate provision of basic resources and highlight the apparent bottlenecks that prevent access to the meaningful data needed to plan and remedy problems. Most operations have relied on an “ad hoc ism” approach, employing parallel and disconnected data processing methods, resulting in a wide range of data being collected without subsequent prioritization to optimize interconnections that could enhance performance. There have been little efforts to study the trade-offs potentially at stake. This work proposes a new framework enabling all subsystems to operate in a single system and focusing on data processing perspective. To achieve this, this paper proposes a Triple Nexus Framework as an attempt to integrate water, energy, and housing sector data derived from a specific sub-system within the overall system in the application of Model-Based Systems Engineering. Understanding the synergies between water, energy, and housing, Systems Engineering characterizes the triple nexus framework and identifies opportunities for improved decision-making in processing operational data from these sectors. Two scenarios illustrate how an integrated platform could be a gateway to access meaningful operational data in the system and a starting point for modeling integrated human settlement systems. Upon execution, the model is tested for nexus megadata processing, and the optimization simulation yielded 67% satisfactory results, demonstrating that an integrated system could improve sustainability, and that capacity building in service delivery is more than beneficial.

miR-21低表达对垂体瘤细胞系RC-4BC增殖、凋亡的影响及与PTEN靶向关系

目的观察微小RNA-21(miR-21)低表达对垂体瘤细胞系RC-4BC增殖、凋亡的影响,并分析其与第10号染色体丢失的张力蛋白同源磷酸酶基因(PTEN)的靶向关系。方法取对数生长期的RC-4BC细胞分为两组,沉默组转染miR-21抑制物miR-21 inhibitor,阴性对照组转染抑制物阴性对照NC-inhibitor,采用RT-PCR法检测miR-21、第10号染色体丢失的张力蛋白同源磷酸酶基因(PTEN)mRNA,采用CCK8实验观察两组细胞增殖能力(以OD值表示),采用平板克隆实验观察两组细胞集落形成能力(以集落形成数表示),采用流式细胞术观察两组细胞凋亡率并观察细胞周期分布情况。收集RC-4BC细胞制备单细胞悬液,分别将miR-21 mimics或NC-mimics与PTEN-WT或PTEN-MUT共转染至RC-4BC细胞,转染后细胞标记为miR-21 mimics+PTEN-WT组、NC-mimics+PTEN-WT组、miR-21 mimics+PTEN-MUT组、NC-mimics+PTEN-MUT组,采用双荧光素酶报告基因实验验证miR-21与PTEN的靶向关系。结果沉默组RC-4BC细胞中miR-21、PTEN mRNA相对表达量分别为0.30±0.08、2.89±0.14,阴性对照组RC-4BC细胞中miR-21、PTEN mRNA相对表达量分别为1.01±0.02、0.99±0.03,两组相比,P均<0.05。沉默组RC-4BC细胞24 h、48 h、72 h时OD值均低于阴性对照组(P均<0.05)。沉默组RC-4BC细胞集落形成数低于阴性对照组(P<0.05)。沉默组RC-4BC细胞凋亡率高于阴性对照组(P<0.05)。沉默组RC-4BC细胞G0/G1期占比65.65%±7.82%、S期占比19.25%±3.70%,阴性对照组RC-4BC细胞G0/G1期占比45.62%±5.03%、S期占比35.72%±4.67%,两组相比,P均<0.05。miR-21 mimics+PTEN-WT组、NC-mimics+PTEN-WT组、miR-21 mimics+PTEN-MUT组、NC-mimics+PTEN-MUT组细胞的相对荧光素酶活性分别为0.39±0.07、1.02±0.03、1.01±0.04、1.00±0.03,其中miR-21 mimics+PTEN-WT组相对荧光素酶活性与其他各组相比,P均<0.05。结论沉默miR-21能够移至垂体瘤细胞系RC-4BC的增殖、促进其凋亡,其机制可能与靶向调控PTEN基因有关。

CFRP布加固RC柱细观力学分析模型及抗扭分析

为了探究配纤率、截面形状、截面尺寸、轴压比对碳纤维增强复合材料(carbon fiber reinforced polymer,CFRP)加固钢筋混凝土(reinforced concrete,RC)柱抗扭性能的影响,采用了可以同时考虑混凝土材料非均质性、钢筋与混凝土间黏结-滑移关系、CFRP布与混凝土间界面关系的细观力学分析方法。首先,建立了用于CFRP布加固RC柱抗扭性能分析的三维数值模型;进而,将基于该模型的数值模拟结果与试验结果对比,验证了模型中加载方式、外贴CFRP布方法的合理性及材料参数的准确性;最后,基于建立的细观力学分析模型,探讨了配纤率、截面形状、截面尺寸、轴压比对扭转作用下CFRP布加固RC柱破坏模式和力学性能的影响机制。分析结果表明:CFRP布加固RC柱抗扭承载力随配纤率增大而提高,但提高幅度随配纤率增大而降低;受到围压分布的影响,圆形截面的有效约束面积大于方形截面,使得CFRP布对圆柱的约束效果好于方柱;CFRP布加固RC柱的名义扭转强度存在尺寸效应;轴压比的增大使其抗扭承载力先增大后减小,在轴压比为0.4时达到最大值。进一步,采用叠加规范公式方法提出了FRP布加固RC构件抗扭承载力计算公式,与数值模拟结果对比发现,该公式可给出安全储备冗余度30.2%的设计值,可初步用于CFRP布加固RC柱抗扭承载力的安全设计。

不同吸波涂层对三维复杂目标的RCS影响的分析

利用有限元-快速多极子算法(FEM-FMM)分析了三维复杂目标涂有不同吸波涂层的雷达散射截面(RCS)。以圆锥体为例,详细计算分析了涂敷有耗各向同性、正单轴各向异性、负单轴各向异性和纳米吸波材料4种典型吸波材料对目标电磁散射特性的影响,并首次讨论了每种吸波材料随不同涂层厚度对RCS的影响,得到了最佳隐身效果的吸波材料和涂层厚度的组合。结果表明,涂敷最佳吸波材料目标的后向RCS比目标没有吸波涂层时可以降低16. 6dB。

EGSnrc系统在计算闪烁探测器响应函数矩阵中的应用

在Linux操作系统上使用EGSnrc系统中的PEGS4程序离线计算光子及电子与茋晶体、铝和铅相互作用的截面数据库,并利用计算的截面数据库作为该系统中Dosnrc程序的输入数据计算得到了铅屏蔽茋晶体对光子各能量点的响应函数,并将其组成矩阵。通过测量几种标准γ源来检验响应函数矩阵的准确程度。

弯-剪-扭复合受力CFRP布加固RC梁抗扭性能细观数值分析

为了研究弯-剪-扭复合受力条件下碳纤维增强复合材料(carbon fiber reinforced polymer, CFRP)布加固钢筋混凝土(reinforced concrete, RC)梁的抗扭性能,建立体现混凝土材料非均质性、钢筋-混凝土黏结滑移关系和CFRP布-混凝土相互作用关系的细观数值分析模型。由于缺乏CFRP布加固RC梁在弯-剪-扭复合受力作用下失效破坏的典型物理试验,采用复合对比验证法对数值模型的合理性进行验证,即分别与单独受剪、单独受扭以及受弯-扭复合作用下RC梁和CFRP布加固RC梁的试验结果进行对比验证。进而,基于建立的细观数值分析模型探究了配纤率和扭弯比对CFRP布加固RC梁在弯-剪-扭复合受力作用下抗扭力学性能的影响。结果表明:1)采用CFRP布加固能够显著提高RC梁的峰值扭矩;2)随配纤率增加,RC梁损伤分布范围逐渐变大,CFRP布应变逐渐减小,梁整体峰值扭矩增大,但其增大幅度减小;3)随扭弯比增加,RC梁裂缝分布愈加集中,裂缝与水平方向夹角逐渐减小,梁整体峰值扭矩增大,CFRP布应变减小。建立的考虑弯-剪-扭复合受力作用的数值模拟方法可为后续研究复杂应力状态下CFRP布加固RC梁尺寸效应行为等奠定基础。

基于Gamma分布贝叶斯RCS估计的多目标跟踪算法

针对密集目标场景下的多目标跟踪算法易出现航迹混批的问题,考虑引入RCS信息辅助跟踪,提出了一种基于Gamma分布的贝叶斯RCS估计的多目标跟踪算法。首先,提出目标RCS状态及量测滤波过程,使用非平稳自回归Gamma过程对状态动力学进行建模,在时间更新中实现贝叶斯RCS估计。然后,在PHD滤波器中引入贝叶斯RCS估计,提出了PHDwRCS滤波器,实现对密集目标的跟踪。针对PHD类滤波器无法实时形成航迹、跟踪精度较低的问题,在TPHD滤波器中引入RCS估计,提出了TPHDwRCS滤波器,实现了对密集目标的有效航迹跟踪。通过计算机仿真实验表明,所提算法能够有效实现贝叶斯RCS估计,引入RCS信息后的PHDwRCS滤波器和TPHDwRCS滤波器能够实现对密集目标的精确跟踪,基于GOSPA度量的定量误差性能得到提升,一定程度上缓解了航迹混批问题。

Windows Biometirc Framework系统简介

随着生物科技的成熟发展,在如今的计算机安全领域,指纹系统认证已经越来越被广泛运用。各个笔记本厂商也相继推出带有指纹处理芯片的高端笔记本电脑。在windows7系统中,微软为指纹设备驱动与指纹认证系统应用程序之间的链接定义一系列框架——windows biometric framework,本文将对这一系统框架做一简单简介。

Manganese-Zeolitic Imidazolate Frameworks-90 with High Blood Circulation Stability for MRI-Guided Tumor Therapy

Zeolitic imidazolate frameworks(ZIFs)as smart drug delivery systems with microenvironment-triggered release have attracted much attention for tumor therapy.However,the exploration of ZIFs in biomedicine still encounters many issues,such as inconvenient surface modification,fast drug release during blood circulation,undesired damage to major organs,and severe in vivo toxicity.To address the above issues,we developed an Mn-ZIF-90 nanosystem functionalized with an originally designed active-targeting and pH-responsive magnetic resonance imaging(MRI)Y1 receptor ligand[Asn28,Pro30,Trp32]-NPY(25-36)for imaging-guided tumor therapy.After Y1 receptor ligand modification,the Mn-ZIF-90 nanosystem exhibited high drug loading,better blood circulation stability,and dual breast cancer cell membrane and mitochondria targetability,further favoring specific microenvironment-triggered tumor therapy.Meanwhile,this nanosystem showed promising T1-weighted magnetic resonance imaging contrast in vivo in the tumor sites.Especially,this nanosystem with fast clean-up had almost no obvious toxicity and no damage occurred to the major organs in mice.Therefore,this nanosystem shows potential for use in imaging-guided tumor therapy.