Research on mechanical performance of longitudinal joints in segmental tunnel linings strengthened by fiber-reinforced plastic grid with polymer−cement−mortar method

In this study,we propose the use of a fiber-reinforced plastic grid with polymer−cement−mortar(FRP Grid-PCM)to reinforce segment joints in tunnel shield linings.These joints play a crucial role in determining bearing capacity but are vulnerable to deterioration during operation.To investigate how to enhance the flexural performance of longitudinal shield lining joints,we built eccentric short column specimens by bolting two half-corbel columns together and tested them in the laboratory.The test program comprised two control specimens and three strengthened specimens with FRP grid applied on one side,away from the axial load.The tests varied two main parameters:loading eccentricity and the number of FRP grid layers.We conducted a detailed analysis of the failure process,bearing capacity,and bending stiffness of longitudinal joints under different conditions.Furthermore,we developed an analytical model to predict the flexural bearing capacity of longitudinal joints upgraded with the FRP Grid-PCM method and validated it through experimental results.The research demonstrates that the FRP grid effectively reduces joint opening and rotation angles while enhancing the bearing capacity of the short column,particularly with concurrent increases in loading eccentricity and the number of FRP grid layers.Overall,our findings offer a novel alternative for improving the flexural performance of longitudinal joints in shield tunnels.

Reconfigurable logic and in-sensor encryption operations in an asymmetrically tunable van der Waals heterostructure

Reconfigurable devices can be used to achieve multiple logic operation and intelligent optical sensing with low power consumption,which is promising candidates for new generation electronic and optoelectronic integrated circuits.However,the versatility is still limited and need to be extended by the device architectures design.Here,we report an asymmetrically gate two-dimensional(2D)van der Waals heterostructure with hybrid dielectric layer SiO_(2)/hexagonal boron nitride(h-BN),which enable rich function including reconfigurable logic operation and in-sensor information encryption enabled by both volatile and non-volatile optoelectrical modulation.When the partial gate is grounded,the non-volatile light assisted electrostatic doping endowed partially reconfigurable doping between n-type and p-type,which allow the switching of logic XOR and not implication(NIMP).When the global gate is grounded,additionally taking the optical signal as another input signal,logic AND and OR is realized by combined regulation of the light and localized gate voltage.Depending on the high on/off current ratio approaching 105 and reliable&switchable logic gate,in-sensor information encryption and decryption is demonstrated by manipulating the logic output.Hence,these results provide strong extension for current reconfigurable electronic and optoelectronic devices.

A trustless architecture of blockchain-enabled metaverse

Metaverse has rekindled human beings’desire to further break space-time barriers by fusing the virtual and real worlds.However,security and privacy threats hinder us from building a utopia.A metaverse em-braces various techniques,while at the same time inheriting their pitfalls and thus exposing large attack surfaces.Blockchain,proposed in 2008,was regarded as a key building block of metaverses.it enables transparent and trusted computing environments using tamper-resistant decentralized ledgers.Currently,blockchain supports Decentralized Finance(DeFi)and Non-fungible Tokens(NFT)for metaverses.How-ever,the power of a blockchain has not been sufficiently exploited.In this article,we propose a novel trustless architecture of blockchain-enabled metaverse,aiming to provide efficient resource integration and allocation by consolidating hardware and software components.To realize our design objectives,we provide an On-Demand Trusted Computing Environment(OTCE)technique based on local trust evalua-tion.Specifically,the architecture adopts a hypergraph to represent a metaverse,in which each hyper-edge links a group of users with certain relationship.Then the trust level of each user group can be evaluated based on graph analytics techniques.Based on the trust value,each group can determine its security plan on demand,free from interference by irrelevant nodes.Besides,OTCEs enable large-scale and flexible application environments(sandboxes)while preserving a strong security guarantee.

Method to Quantifying the Logical Node Importance for IEC 61850 Based Substation Automation Systems

The problem of logical node(LN)importance quantification in an IEC 61850 based substation automation system(SAS)is investigated in this paper.First,a weighted and directed static complex network model is established by analyzing the characteristics of SAS,according to IEC 61850.Then,we propose a method,which combines topology value and information adjunction value by introducing a first-order linear feedback controller to quantify the value of LNs.On this basis,some definitions for equivalent network conversion are proposed to greatly reduce the complexity of the original network topology.Also,the absolute value and relative value are introduced to quantify LN importance from the perspective of the node’s necessity and influence,respectively.Finally,simulation results of the case study demonstrate that the proposed method is effective and provides a broader and clearer perspective for viewing the logical node importance for IEC61850 based SAS.

Detection of brown adipose tissue in rats with acute cold stimulation using quantitative susceptibility mapping

To the Editor:Adipose tissue occurs in at least two different entities in mammals and humans:brown adipose tissue(BAT)and white adipose tissue(WAT).BAT is characterized by a unique uncoupling protein 1(UCP1)in the mitochondria that enables the uncoupling of the respiratory chain from adenosine triphosphate synthesis.Thus,energy is dissipated as heat to reduce fat accumulation.BAT is also considered a highly heterogeneous tissue with abundant oxygen,blood supply,and iron-rich mitochondria.[1,2]Activation of BAT via exposure to a cold environment is considered to be a means of reducing triglycerides to fight obesity.[3]The alterations in cells and tissues of activated BAT include increased iron content and UCP1 expression in mitochondrial,blood perfusion,and lipid utilization.[4]Therefore,accurate identification and quantitative analysis of inactive and activated BAT are of great significance for the treatment of metabolic diseases that target BAT,such as obesity.

Strategy to minimize bending strain interference for flexible acoustic wave sensing platform

There are great concerns for sensing using flexible acoustic wave sensors and lab-on-a-chip,as mechanical strains will dramatically change the sensing signals(e.g.,frequency)when they are bent during measurements.These strain-induced signal changes cannot be easily separated from those of real sensing signals(e.g.,humidity,ultraviolet,or gas/biological molecules).Herein,we proposed a new strategy to minimize/eliminate the effects of mechanical bending strains by optimizing off-axis angles between the direction of bending deformation and propagation of acoustic waves on curved surfaces of layered piezoelectric film/flexible glass structure.This strategy has theoretically been proved by optimization of bending designs of off-axis angles and acoustically elastic effect.Proof-of-concept for humidity and ultraviolet-light sensing using flexible SAW devices with negligible interferences are achieved within a wide range of bending strains.This work provides the best solution for achieving high-performance flexible acoustic wave sensors under deformed/bending conditions.

When blockchain meets smart grids:A comprehensive survey

Recent years have witnessed an increasing interest in the blockchain technology,and many blockchain-based applications have been developed to take advantage of its decentralization,transparency,fault tolerance,and strong security.In the field of smart grids,a plethora of proposals have emerged to utilize blockchain for aug-menting intelligent energy management,energy trading,security and privacy protection,microgrid management,and energy vehicles.Compared with traditional centralized approaches,blockchain-based solutions are able to exploit the advantages of blockchain to realize better functionality in smart grids.However,the blockchain tech-nology itself has its disadvantages in low processing throughput and weak privacy protection.Therefore,it is of paramount importance to study how to integrate blockchain with smart grids in a more effective way so that the advantages of blockchain can be maximized and its disadvantages can be avoided.This article surveys the state-of-the-art solutions aiming to integrate the emergent blockchain technology with smart grids.The goal of this survey is to discuss the necessity of applying blockchain in different components of smart grids,identify the challenges encountered by current solutions,and highlight the frameworks and techniques used to integrate blockchain with smart grids.We also present thorough comparison studies among blockchain-based solutions for smart grids from different perspectives,with the aim to provide insights on inte-grating blockchain with smart grids for different smart grid management tasks.Finally,we list the current projects and initiatives demonstrating the current effort from the practice side.Additionally,we draw attention to open problems that have not yet been tackled by existing solutions,and point out possible future research directions.

Discovery of novel heteroaryl alkynes for highly potent KIT^(D816V) cells inhibition to treat gastrointestinal stromal tumors

To the Editor:Gastrointestinal stromal tumors(GIST)is the most popular mesenchymal tumor in the gastrointestinal tract with approximately 80%of GIST harboring gain-of-function mutations at either the extracellular region(exon 9)or the juxtamembrane domain(JMD,exon 11)of KIT,resulting in uncontrolled proliferation and resistance to apotosis1.

A new strategy to minimize humidity influences on acoustic wave ultraviolet sensors using ZnO nanowires wrapped with hydrophobic silica nanoparticles

Surface acoustic wave(SAW)technology has been widely developed for ultraviolet(UV)detection due to its advantages of miniaturization,portability,potential to be integrated with microelectronics,and passive/wireless capabilities.To enhance UV sensitivity,nanowires(NWs),such as ZnO,are often applied to enhance SAW-based UV detection due to their highly porous and interconnected 3D network structures and good UV sensitivity.However,ZnO NWs are normally hydrophilic,and thus,changes in environmental parameters such as humidity will significantly influence the detection precision and sensitivity of SAW-based UV sensors.To solve this issue,in this work,we proposed a new strategy using ZnO NWs wrapped with hydrophobic silica nanoparticles as the effective sensing layer.Analysis of the distribution and chemical bonds of these hydrophobic silica nanoparticles showed that numerous C-F bonds(which are hydrophobic)were found on the surface of the sensitive layer,which effectively blocked the adsorption of water molecules onto the ZnO NWs.This new sensing layer design minimizes the influence of humidity on the ZnO NW-based UV sensor within the relative humidity range of 10–70%.The sensor showed a UV sensitivity of 9.53 ppm(mW/cm^(2))^(−1),with high linearity(R^(2) value of 0.99904),small hysteresis(<1.65%)and good repeatability.This work solves the long-term dilemma of ZnO NW-based sensors,which are often sensitive to humidity changes.

Achieving consistency of flexible surface acoustic wave sensors with artificial intelligence

Flexible surface acoustic wave technology has garnered significant attention for wearable electronics and sensing applications.However,the mechanical strains induced by random deformation of these flexible SAWs during sensing often significantly alter the specific sensing signals,causing critical issues such as inconsistency of the sensing results on a curved/flexible surface.To address this challenge,we first developed high-performance AlScN piezoelectric filmbased flexible SAW sensors,investigated their response characteristics both theoretically and experimentally under various bending strains and UV illumination conditions,and achieved a high UV sensitivity of 1.71 KHz/(mW/cm^(2)).To ensure reliable and consistent UV detection and eliminate the interference of bending strain on SAW sensors,we proposed using key features within the response signals of a single flexible SAW device to establish a regression model based on machine learning algorithms for precise UV detection under dynamic strain disturbances,successfully decoupling the interference of bending strain from target UV detection.The results indicate that under strain interferences from 0 to 1160μεthe model based on the extreme gradient boosting algorithm exhibits optimal UV prediction performance.As a demonstration for practical applications,flexible SAW sensors were adhered to four different locations on spacecraft model surfaces,including flat and three curved surfaces with radii of curvature of 14.5,11.5,and 5.8 cm.These flexible SAW sensors demonstrated high reliability and consistency in terms of UV sensing performance under random bending conditions,with results consistent with those on a flat surface.