Integrating Levels of Hierarchical Organization in Porous Organic Molecular Materials

Porous organic molecular materials(POMMs)are an emergent class of molecular-based materials characterized by the formation of extended porous frameworks,mainly held by non-covalent interactions.POMMs represent a variety of chemical families,such as hydrogen-bonded organic frameworks,porous organic salts,porous organic cages,C-H···πmicroporous crystals,supramolecular organic frameworks,π-organic frameworks,halogen-bonded organic framework,and intrinsically porous molecular materials.In some porous materials such as zeolites and metal organic frameworks,the integration of multiscale has been adopted to build materials with multifunctionality and optimized properties.Therefore,considering the significant role of hierarchy in porous materials and the growing importance of POMMs in the realm of synthetic porous materials,we consider it appropriate to dedicate for the first time a critical review covering both topics.Herein,we will provide a summary of literature examples showcasing hierarchical POMMs,with a focus on their main synthetic approaches,applications,and the advantages brought forth by introducing hierarchy.

Goal-Oriented Control Systems(GOCS):From HOW to WHAT

Brief:New control theory is required to underpin safe design and deployment of future highly automated systems to deal with uncertain environments and complicated tasks,enabled by AI and other advanced technologies.Goal-Oriented Control Systems offer potential to transform the control system design from currently instructing a control system how to perform a task to specifying what is to be achieved.

Distributed Dynamic Load in Structural Dynamics by the Impulse-Based Force Estimation Algorithm

This paper proposes a novel approach for identifying distributed dynamic loads in the time domain.Using polynomial andmodal analysis,the load is transformed intomodal space for coefficient identification.This allows the distributed dynamic load with a two-dimensional form in terms of time and space to be simultaneously identified in the form of modal force,thereby achieving dimensionality reduction.The Impulse-based Force Estimation Algorithm is proposed to identify dynamic loads in the time domain.Firstly,the algorithm establishes a recursion scheme based on convolution integral,enabling it to identify loads with a long history and rapidly changing forms over time.Secondly,the algorithm introduces moving mean and polynomial fitting to detrend,enhancing its applicability in load estimation.The aforementioned methodology successfully accomplishes the reconstruction of distributed,instead of centralized,dynamic loads on the continuum in the time domain by utilizing acceleration response.To validate the effectiveness of the method,computational and experimental verification were conducted.

A framework for dynamic modelling of railway track switches considering the switch blades,actuators and control systems

The main contribution of this paper is the development and demonstration of a novel methodology that can be followed to develop a simulation twin of a railway track switch system to test the functionality in a digital environment.This is important because,globally,railway track switches are used to allow trains to change routes;they are a key part of all railway networks.However,because track switches are single points of failure and safety-critical,their inability to operate correctly can cause significant delays and concomitant costs.In order to better understand the dynamic behaviour of switches during operation,this paper has developed a full simulation twin of a complete track switch system.The approach fuses finite element for the rail bending and motion,with physics-based models of the electromechanical actuator system and the control system.Hence,it provides researchers and engineers the opportunity to explore and understand the design space around the dynamic operation of new switches and switch machines before they are built.This is useful for looking at the modification or monitoring of existing switches,and it becomes even more important when new switch concepts are being considered and evaluated.The simulation is capable of running in real time or faster meaning designs can be iterated and checked interactively.The paper describes the modelling approach,demonstrates the methodology by developing the system model for a novel“REPOINT”switch system,and evaluates the system level performance against the dynamic performance requirements for the switch.In the context of that case study,it is found that the proposed new actuation system as designed can meet(and exceed)the system performance requirements,and that the fault tolerance built into the actuation ensures continued operation after a single actuator failure.

A lateral ankle sprain during a lateral backward step in badminton:A case report of a televised injury incident

Background:This study presents a kinematic analysis of an acute lateral ankle sprain incurred during a televised badminton match.The kinematics of this injury were compared to those of 19 previously reported cases in the published literature.Methods:Four camera views of an acute lateral ankle sprain incurred during a televised badminton match were synchronized and rendered in3-dimensional animation software.A badminton court with known dimensions was built in a virtual environment,and a skeletal model scaled to the inj ured athlete’s height was used for skeletal matching.The ankle joint angle and angular velocity profiles of this acute injury were compared to the summarized findings from 19 previously reported cases in the published literature.Results:At foot strike,the ankle joint was 2° everted,33° plantarflexed,and 18° internally rotated.Maximum inversion of 114° and internal rotation of 69° was achieved at 0.24 s and 0.20 s after foot strike,respectively.After the foot strike,the ankle joint moved from an initial position of plantarflexion to dorsiflexion-from 33° plantarflexion to 53° dorsiflexion(range=86°).Maximum inversion,dorsiflexion,and internal rotation angular velocity were 1262°/s,961°/s,and 677°/s,respectively,at 0.12 s after foot strike.Conclusion:A forefoot landing posture with a plantarflexed and internally rotated ankle joint configuration could incite an acute lateral ankle sprain injury in badminton.Prevention of lateral ankle sprains in badminton should focus on the control and stability of the ankle joint angle during forefoot landings,especially when the athletes perform a combined lateral and backward step.

Path Following of Underactuated Autonomous Surface Vessels With Surge Velocity Constraint and Asymmetric Saturation

Dear Editor, This letter is concerned with the path following of underactuated autonomous surface vessels(ASV) in the presence of surge velocity constraint and asymmetric saturation as well as unknown dynamics.To cope with velocity constraints both magnitude and rate and asymmetric saturation as well as unknown dynamics, an adaptive finitetime sliding mode control scheme(AFTSM) is designed.

A Broad Range Triboelectric Stiffness Sensor for Variable Inclusions Recognition

With the development of artificial intelligence,stiffness sensors are extensively utilized in various fields,and their integration with robots for automated palpation has gained significant attention.This study presents a broad range self-powered stiffness sensor based on the triboelectric nanogenerator(Stiff-TENG)for variable inclusions in soft objects detection.The Stiff-TENG employs a stacked structure comprising an indium tin oxide film,an elastic sponge,a fluorinated ethylene propylene film with a conductive ink electrode,and two acrylic pieces with a shielding layer.Through the decoupling method,the Stiff-TENG achieves stiffness detection of objects within 1.0 s.The output performance and characteristics of the TENG for different stiffness objects under 4 mm displacement are analyzed.The Stiff-TENG is successfully used to detect the heterogeneous stiffness structures,enabling effective recognition of variable inclusions in soft object,reaching a recognition accuracy of 99.7%.Furthermore,its adaptability makes it well-suited for the detection of pathological conditions within the human body,as pathological tissues often exhibit changes in the stiffness of internal organs.This research highlights the innovative applications of TENG and thereby showcases its immense potential in healthcare applications such as palpation which assesses pathological conditions based on organ stiffness.

How AI-enabled SDN technologies improve the security and functionality of industrial IoT network:Architectures,enabling technologies,and opportunities

The ongoing expansion of the Industrial Internet of Things(IIoT)is enabling the possibility of effective Industry 4.0,where massive sensing devices in heterogeneous environments are connected through dedicated communication protocols.This brings forth new methods and models to fuse the information yielded by the various industrial plant elements and generates emerging security challenges that we have to face,providing ad-hoc functions for scheduling and guaranteeing the network operations.Recently,the large development of SoftwareDefined Networking(SDN)and Artificial Intelligence(AI)technologies have made feasible the design and control of scalable and secure IIoT networks.This paper studies how AI and SDN technologies combined can be leveraged towards improving the security and functionality of these IIoT networks.After surveying the state-of-the-art research efforts in the subject,the paper introduces a candidate architecture for AI-enabled Software-Defined IIoT Network(AI-SDIN)that divides the traditional industrial networks into three functional layers.And with this aim in mind,key technologies(Blockchain-based Data Sharing,Intelligent Wireless Data Sensing,Edge Intelligence,Time-Sensitive Networks,Integrating SDN&TSN,Distributed AI)and improve applications based on AISDIN are also discussed.Further,the paper also highlights new opportunities and potential research challenges in control and automation of IIoT networks.

Exploring the Attractiveness of Companies Branding D&I to Potential Employees in Online Recruitment

Concrete action on diversity and inclusion(D&I)is critical to companies’value creation and brand.Companies that intentionally fail to attract and retain a diverse talent pool will struggle to innovate,compete,and prosper.The advantages of a diverse and inclusive workplace include the reduction of homogenous thinking and an increase in novel ideas and perspectives due to the wealth of talent from diverse backgrounds.Previous studies have focused on the benefits of corporate D&I from a corporate perspective;however,there is scant research on the impact of corporate D&I from employees’perspectives.Resultingly,this study,through an online questionnaire,proposes to examine the impact of employer brand D&I on potential employees in online recruitment channels from the perspective of potential employees.The study results indicate that most Chinese companies still exhibit low levels of D&I during recruitment.This study also included an empirical analysis of 267 valid samples,which showed that:(1)the D&I of employer brand perceptions positively impact job search intentions,behaviour,and decision making.(2)Companies’D&I has the most significant influence on job seekers’decision making,followed by behavioural influence and cognitive influence.(3)The type of job seeker plays a moderating role in the relationship between employer brand perception and job search intention,behaviour,and decision making.(4)Online recruitment’s increasing popularity amplifies employer branding’s effect.Based on the findings,this study suggests how companies can use D&I branding strategies to attract quality talent and increase job seekers’job search intentions.

Selective conversion of CO_(2)to CO using earth abundant tin modified copper gas diffusion electrodes

Earth-abundant copper-tin(CuSn)electrocatalysts are potential candidates for cost-effective and sustainable production of CO from electrochemical carbon dioxide reduction(eCO_(2)R).However,the requirement of highoverpotential for obtaining reasonable current,low Faradaic efficiencies(FE)and low intrinsic catalytic activities require the optimisation of the CuSn nanoarchitecture for the further advancement in the field.In the current work,we have optimised Sn loading on Cu gas diffusion electrodes(GDEs)by electrochemical spontaneous precipitation.Samples with various Sn loadings were tested in a three-chamber GDE reactor to evaluate their CO_(2)reduction performances.The best performance of 92%CO Faradaic efficiency at a cathodic current density of 120 mA cm^(-2)was obtained from the 20 min Sn deposited Cu_(2)O sample operated at-1.13 V vs.RHE.The electrocatalyst had~13%surface coverage of Sn on Cu GDE surface,and had Sn in oxide form and copper in metallic form.The catalyst also showed stable performance and was operable for>3 h under chronoamperometric conditions.The surface of the GDE reduces from Cu2O to Cu during eCO_(2)R and goes further reconstruction during the eCO_(2)R.This study demonstrates the potential of Cu-Sn for selective CO production at high current densities.

Hawk‐eye‐inspired perception algorithm of stereo vision for obtaining orchard 3D point cloud navigation map

The binocular stereo vision is the lowest cost sensor for obtaining 3D information.Considering the weakness of long‐distance measurement and stability,the improvement of accuracy and stability of stereo vision is urgently required for application of precision agriculture.To address the challenges of stereo vision long‐distance measurement and stable perception without hardware upgrade,inspired by hawk eyes,higher resolution perception and the adaptive HDR(High Dynamic Range)were introduced in this paper.Simulating the function from physiological structure of‘deep fovea’and‘shallow fovea’of hawk eye,the higher resolution reconstruction method in this paper was aimed at ac-curacy improving.Inspired by adjustment of pupils,the adaptive HDR method was proposed for high dynamic range optimisation and stable perception.In various light conditions,compared with default stereo vision,the accuracy of proposed algorithm was improved by 28.0%evaluated by error ratio,and the stability was improved by 26.56%by disparity accuracy.For fixed distance measurement,the maximum improvement was 78.6%by standard deviation.Based on the hawk‐eye‐inspired perception algorithm,the point cloud of orchard was improved both in quality and quantity.The hawk‐eye‐inspired perception algorithm contributed great advance in binocular 3D point cloud recon-struction in orchard navigation map.

基于Internet的远程过程控制系统设计

分析了基于Internet的过程控制与传统的计算机控制的区别,给出了一种如何在现有计算机控制系统的基础上,通过添加特殊的网络控制层的方法,设计基于Internet的远程过程控制系统的推荐方案。

硅粉水泥石中微孔孔径分布及其对强度的影响

采用X射线小角度散射(SAXS)技术,对硅粉水泥石中微孔孔径分布(孔半径小于50nm)进行了实验研究,并讨论了孔径分布对强度的影响.研究表明:所测硅粉水泥石的孔径均呈多峰分布,其平均孔半径约在4.5～9.0nm,最可几孔半径约在4.0～6.5nm;硅粉含量、水灰比对孔径分布有显著影响,随着硅粉含量的增加以及水灰比的减小,孔径分布向小孔方向移动;孔径分布与抗压强度有较好的相关性,而孔径分布(孔半径小于50nm)与抗折强度之间不存在明显的相关性.

柔性资源受限的多模式项目调度问题的建模

将资源受限的多模式项目调度问题中的资源拓展为柔性资源,建立了柔性资源受限的多模式项目调度问题的混合整数规划模型。基于PROGEN生成了项目非虚活动数目为10的2 500个算例,利用XPRESS软件进行了精确求解。对5种项目特征参数即项目网络复杂度、能力需求强度、能力供给强度、资源柔性值和资源数目与问题求解难度、项目总完工时间和项目资源利用率之间的关系进行了分析。指出资源柔性值和资源数目的增加虽然能够减少项目完工时间平均值,但是也可能导致资源利用率平均值的下降,对柔性资源进行合理调度才是项目管理的关键。

去除局部破损混凝土后钢筋混凝土梁受弯性能理论分析

在钢筋混凝土梁修复加固的过程中 ,常常可能去除梁上部分破损的混凝土 ,使钢筋外露 ,在荷载作用下 ,造成梁的力学性能发生变化。基于对钢筋混凝土梁变形分析 ,利用数值分析方法 ,详细讨论了在忽略梁剪切变形的条件下 ,去除局部破损混凝土、受拉钢筋暴露的钢筋混凝土梁的理论分析方法。给出了计算去除局部破损混凝土、部分受拉钢筋暴露的钢筋混凝土简支梁挠度和承载力的具体分析步骤和计算公式 ,计算结果和试验结果吻合良好。

反相微乳液法制备纳米氧化铁颗粒的结构及性能

测定了多种表面活性剂构成的反相微乳液体系对于水及盐溶液的载量,找到了一种具有较高氯化铁溶液载量的反相微乳液体系Egepalco-520/环己烷(或石油醚PE)/H2O.利用该体系制备纳米氧化铁的粒径与形态和盐溶液的浓度、加入量及表面活性剂/油的比有关.在表面活性剂/油比较高时,可以制备出粒径小于10nm的氧化铁,但所制备的氧化体的结晶性较差.

英国职业足球近10年发展述评——经济视角

从电视转播权合同、球场重建、俱乐部上市三方面综述了英国职业足球近10年的商业化发展情况,以及由此带来的对英国足球文化、俱乐部运作模式、联赛发展状态等方面的影响。得出如下结论:(1)英国职业足球是在1992年以后愈加商业化的,直接影响因素是电视转播权出售带来的巨大收入;(2)英超的经营模式与美国的NFL或NBA有所不同,英超联盟收入分配政策造成俱乐部之间的贫富差距,导致联赛市场的不平衡;(3)英国足球俱乐部的球场重建改善了英国足球的形象,但也给俱乐部提高门票价格提供了借口;(4)职业俱乐部上市,使英国传统的俱乐部性质发生了根本性质的改变,原来的业余主义足球文化逐渐被销蚀,足球产业化愈演愈烈。另外,上市俱乐部在俱乐部的治理模式上也发生着变化。5)英国职业足球俱乐部的经济状况并不乐观,英超中只有六七家俱乐部税前盈利,大部分俱乐部负债累累。

开放访问的绿色通道:OA档案库的进展概述

介绍开放访问的绿色通道——OA档案库的发展现状及未来发展的可能模式。其中包括:OA档案库的类型;政府、学术机构、出版商对待OA档案库的态度和政策;OA档案库对作者和出版商的影响;实现的工具及其维护费用,目前OA档案库的数量,存储在其中的文章的数量,在各国的分布状况;档案库未来的可能发展模式;等等。

硅粉水泥石中微孔界面分形结构实验研究

采用X射线小角散射(SAXS)技术,对硅粉水泥石中微孔孔界面分形结构进行实验研究.结果表明,硅粉水泥石中微孔界面不具有分明的边界,而是有一个2nm左右的电子密度缓变的过渡层;微孔界面具有分形结构特征,分形维数与3接近,说明其孔界面是非常粗糙的;水胶比、硅粉含量对孔界面分形维数具有显著的影响,笔者根据实验结果,从微观的角度进行了探讨性的解释.

聚己内酯二醇型水性聚氨酯分散液的合成和性能

聚己内酯二醇(PCL)是由己内酯开环聚合而成的性能优良独特的聚酯,由于结构的独特性,它可作为原料用于合成高性能的聚氨酯弹性体、胶粘剂、涂料等。本工作以Solvay公司CAPA系列的PCL为基础原料,合成了水性聚氨酯分散液,研究了其相应的胶体性能、力学性能以及热力学性能。研究发现,虽然引发剂在PCL中只占3.0％-4.5％,却对聚氨酯性能的影响较大,PCL的相对分子质量、软硬段比及扩链剂种类等对水性聚氨酯的性能也有影响。