Viologen-based flexible electrochromic devices

Electrochromic technology has gained significant attention in various fields such as displays,smart windows,biomedical monitoring,military camouflage,human-machine interaction,and electronic skin due to its ability to provide reversible and fast color changes under applied voltage.With the rapid development and increasing demand for flexible electronics,flexible electrochromic devices(FECDs)that offer smarter and more controllable light modulation hold great promise for practical applications.The electrochromic material(ECM)undergoing color changes during the electrochemical reactions is one of the key components in electrochromic devices.Among the ECMs,viologens,a family of organic small molecules with 1,1'-disubstituted-4,4'-dipyridinium salts,have garnered extensive research interest,due to their well-reversible redox reactions,excellent electron acceptance ability,and the ability to produce multiple colors.Notably,viologen-based FECDs demonstrate color changes in the liquid or semisolid electrolyte layer,eliminating the need for two solid electrodes and thus simplifying the device structure.Consequently,viologens offer significant potential for the development of FECDs with high optical contrast,fast response speed,and excellent stability.This review aims to provide a comprehensive overview of the progress and perspectives of viologen-based FECDs.It begins by summarizing the typical structure and recent exciting developments in viologen-based FECDs,along with their advantages and disadvantages.Furthermore,the review discusses recent advancements in FECDs with additional functionalities such as sensing,photochromism,and energy storage.Finally,the remaining challenges and potential research directions for the future of viologen-based FECDs are addressed.

A method for establishing a bearing residual life prediction model for process enhancement equipment based on rotor imbalance response analysis

A rotating packed bed is a typical chemical process enhancement equipment that can strengthen micromixing and mass transfer.During the operation of the rotating packed bed,the nonreactants and products irregularly adhere to the wire mesh packing in the rotor,thus resulting in an imbalance in the vibration of the rotor,which may cause serious damage to the bearing and material leakage.This study proposes a model prediction for estimating the bearing residual life of a rotating packed bed based on rotor imbalance response analysis.This method is used to determine the influence of the mass on the imbalance in the vibration of the rotor on bearing damage.The major influence on rotor vibration was found to be exerted by the imbalanced mass and its distribution radius,as revealed by the results of orthogonal experiments.Through implementing finite element analysis,the imbalance response curve for the rotating packed bed rotor was obtained,and a correlation among rotor imbalance mass,distribution radius of imbalance mass,and bearing residue life was established via data fitting.The predicted value of the bearing life can be used as the reference basis for an early safety warning of a rotating packed bed to effectively avoid accidents.

Evaluation of Multi-Temporal-Spatial Scale Adjustment Capability and Cluster Optimization Operation Method for Distribution Networks with Distributed Photovoltaics

Themassive integration of high-proportioned distributed photovoltaics into distribution networks poses significant challenges to the flexible regulation capabilities of distribution stations.To accurately assess the flexible regulation capabilities of distribution stations,amulti-temporal and spatial scale regulation capability assessment technique is proposed for distribution station areas with distributed photovoltaics,considering different geographical locations,coverage areas,and response capabilities.Firstly,the multi-temporal scale regulation characteristics and response capabilities of different regulation resources in distribution station areas are analyzed,and a resource regulation capability model is established to quantify the adjustable range of different regulation resources.On this basis,considering the limitations of line transmission capacity,a regulation capability assessment index for distribution stations is proposed to evaluate their regulation capabilities.Secondly,considering different geographical locations and coverage areas,a comprehensive performance index based on electrical distance modularity and active power balance is established,and a cluster division method based on genetic algorithms is proposed to fully leverage the coordination and complementarity among nodes and improve the active power matching degree within clusters.Simultaneously,an economic optimization model with the objective of minimizing the economic cost of the distribution station is established,comprehensively considering the safety constraints of the distribution network and the regulation constraints of resources.This model can provide scientific guidance for the economic dispatch of the distribution station area.Finally,case studies demonstrate that the proposed assessment and optimization methods effectively evaluate the regulation capabilities of distribution stations,facilitate the consumption of distributed photovoltaics,and enhance the economic efficiency of the distribution station area.

Risk-Balanced Routing Strategy for Service Function Chains of Cyber-Physical Power System Considering Cross-Space Cascading Failure

Cyber-physical power system(CPPS)has significantly improved the operational efficiency of power systems.However,cross-space cascading failures may occur due to the coupling characteristics,which poses a great threat to the safety and reliability of CPPS,and there is an acute need to reduce the probability of these failures.Towards this end,this paper first proposes a cascading failure index to identify and quantify the importance of different information in the same class of communication services.On this basis,a joint improved risk-balanced service function chain routing strategy(SFC-RS)is proposed,which is modeled as a robust optimization problem and solved by column-and-constraint generation(C-CG)algorithm.Compared with the traditional shortest-path routing algorithm,the superiority of SFC-RS is verified in the IEEE 30-bus system.The results demonstrate that SFC-RS effectively mitigates the risk associated with information transmission in the network,enhances information transmission accessibility,and effectively limits communication disruption from becoming the cause of cross-space cascading failures.

浅析半地下污水处理厂设计风险点及应对措施

随着中国生态需求的日益提高以及城市土地资源的逐渐紧缺,半地下污水处理厂作为一种污水处理厂建设新形式,凭借其环境友好、布置集约、空间利用多元化等优点将成为污水处理工程发展的新方向。基于福建省某半地下污水处理厂的设计实践,简要论述了在半地下污水处理厂设计过程中需注意的风险点及应对措施,主要包括防水淹措施、防火措施、防有毒有害气体措施、紧急疏散措施、人员安全措施等,为将来类似半地下污水处理厂工程的设计和建设提供了经验。

Mass transfer techniques for large-scaleand high-density microLED arrays

Inorganic-based micro light-emitting diodes (microLEDs) offer more fascinating properties and unique demands in next-generation displays. However, the small size of the microLED chip (1–100 µm) makes it extremely challenging for high efficiency and low cost to accurately, selectively, integrate millions of microLED chips. Recent impressive technological advances have overcome the drawbacks of traditional pick-and-place techniques when they were utilized in the assembly of microLED display, including the most broadly recognized laser lift-off technique, contact micro-transfer printing (µTP) technique, laser non-contact µTP technique, and self-assembly technique. Herein, we firstly review the key developments in mass transfer technique and highlight their potential value, covering both the state-of-the-art devices and requirements for mass transfer in the assembly of the ultra-large-area display and virtual reality glasses. We begin with the significant challenges and the brief history of mass transfer technique, and expand that mass transfer technique is composed of two major techniques, namely, the epitaxial Lift-off technique and the pick-and-place technique. The basic concept and transfer effects for each representative epitaxial Lift-off and pick-and-place technique in mass transfer are then overviewed separately. Finally, the potential challenges and future research directions of mass transfer are discussed.

基于预连接镍链的高应变敏感度动态可调电磁干扰屏蔽弹性体

具有动态可调电磁屏蔽性能的电磁干扰屏蔽材料备受关注,但其目前仍然存在制备复杂、厚度大、触发方式不便、调节范围窄等缺点.我们通过将尖刺镍微粒精确地分散到聚二甲基硅氧烷基体中形成预连接的链状结构,制备出了具有可开关电磁屏蔽性能的弹性体材料.弹性体在机械拉伸和释放过程中表现出连续和可逆的电磁干扰屏蔽性能.原始弹性体具有良好的阻抗匹配和低介电损耗,允许大部分电磁波通过.拉伸使预连接的短链彼此接触,在内部形成大量的微尺度导电网络,显著增强了电导损耗能力,实现了较强的电磁干扰屏蔽能力.此外,我们通过无线应变传感系统验证了智能电磁干扰屏蔽弹性体的应用潜力,证明了可穿戴智能电磁干扰屏蔽精确监测人体运动的可能性.

登月舱尺度陨石坑对羽流-月表相互作用影响的数值研究

登月舱着陆期间,陨石坑和其他复杂地形可能会加剧发动机羽流引起的月尘扩散,给探月任务带来干扰和威胁.本文采用direct simulationMonteCarlo(DSMC)方法,研究了嫦娥五号发动机羽流与登月舱尺度陨石坑的相互作用.结果表明,陡峭陨石坑显著改变了近场流动结构,在喷管下方形成明显的回流区.回流区增加了坑壁的风化层侵蚀,将月尘吹入喷管,容易对发动机等设备造成结构损坏。同时,随着陨石坑变陡,羽流被陨石坑所偏转的角度明显增加,从而显著增加了登月舱受到的气动力和气动热;最大扬尘角也显著增大,严重干扰了着陆能见度.对于比较平坦的陨石坑,虽然羽流偏转和扬尘的角度较小,但根据Roberts侵蚀模型计算的总侵蚀通量较大,也意味着对登月舱的严重威胁。这些结果揭示了登月舱尺度陨石坑对羽流-月表相互作用的显著影响,为预测和减轻复杂地形对探月任务的威胁提供了有效参考.

Optimal Bidding Strategy for PV and BESSs in Joint Energy and Frequency Regulation Markets Considering Carbon Reduction Benefits

Photovoltaic(PV)and battery energy storage systems(BESSs)are key components in the energy market and crucial contributors to carbon emission reduction targets.These systems can not only provide energy but can also generate considerable revenue by providing frequency regulation services and participating in carbon trading.This study proposes a bidding strategy for PV and BESSs operating in joint energy and frequency regulation markets,with a specific focus on carbon reduction benefits.A two-stage bidding framework that optimizes the profit of PV and BESSs is presented.In the first stage,the day-ahead energy market takes into account potential real-time forecast deviations.In the second stage,the real-time balancing market uses a rolling optimization method to account for multiple uncertainties.Notably,a real-time frequency regulation control method is proposed for the participation of PV and BESSs in automatic generation control(AGC).This is particularly relevant given the uncertainty of grid frequency fluctuations in the optimization model of the real-time balancing market.This control method dynamically assigns the frequency regulation amount undertaken by the PV and BESSs according to the control interval in which the area control error(ACE)occurs.The case study results demonstrate that the proposed bidding strategy not only enables the PV and BESSs to effectively participate in the grid frequency regulation response but also yields considerable carbon emission reduction benefits and effectively improves the system operation economy.

MXene fibers for electronic textiles:Progress and perspectives

The rapid evolution of portable and wearable electronic devices has fueled the development of smart functional textiles that are able to conduct electricity,sense body movements,or store energy.One main challenge inhibiting the further development of functional textile-based electronics is the lack of robust functional fibers with suitable electrical,electrochemical and sensing functionalities.MXenes,an emerging family of two-dimensional(2D)materials,have shown to be promising candidates for producing functional fibers due to their exceptional electrical and electrochemical properties combined with solution processability.The unique ability of MXenes to readily form liquid crystal phases in various solvents has allowed them to generate additive-free fibers using a wet spinning process.In this work,we review the recent exciting developments in the fabrication of neat MXenes fibers and present a critical evaluation of practical challenges in MXenes processing that influence the macroscale material properties and the performance of the subsequent devices.We also provide our assessment for the future opportunities and challenges in producing MXene fibers to help pave the way for their widespread use in advanced wearable applications.

Probabilistic Optimal Power Flow of an AC/DC System with a Multiport Current Flow Controller

To evaluate the impact of the randomness and correlation of photovoltaic(PV)and load on AC/DC systems with a multiport current flow controller(M-CFC),this paper proposes a probabilistic optimal power flow calculation for AC/DC systems,based on a nonparametric kernel density estimation.First,according to the M-CFC model,the DC power flow calculation method with M-CFC was inferred,and its influence on line loss was analyzed.Second,a nonparametric kernel density estimation with an adaptive bandwidth is used to accurately describe the probability distribution of the PV and load,and correlation samples of the PV and load are obtained by the mixed copula function.Then an optimization model that considers system loss and static security is established,and a fast nondominated sorting genetic algorithm based on the elite strategy(NSGA-II)is used to calculate the multi-objective probability optimal power flow of the AC/DC system.Finally,a case study is performed on a modified IEEE39 bus system using measured PV and load data.We verified that the nonparametric kernel density estimation with an adaptive bandwidth can better adapt to random component uncertainty,and M-CFC can improve the static security of the system.

Lifting the Veil： Inside Labour Law and Regulations Ronald C. Brown： Understanding Labor and Employment Law in China. Cambridge University Press, New York, 2010, 332 pp, $ 90 Hardback, ISBN： 978-0521191487

In Understanding Labor and Employment Law in China, University of Hawaii Professor Ronald C. Brown delivers the readers with a comprehensive study of law and regulation with regard to the labour and employment issues in China. Labour and employment issues present a complex and delicate portrait in China with some particularly Chinese characteristics, which can be difficult to fully understand. While China today has a great need to stabilize and adjust her internal affairs （rather than merely focusing on economic growth）, in order to tackle the social and economic inequality and unrest, this volume, as titled： ＂Understanding Labor and Employment Law in China＂, is concerned with addressing the latest problems and illustrates the complexity and variability of the legal relationship concerning labour and employment.