Optoelectronic Synapses Based on MXene/Violet Phosphorus van der Waals Heterojunctions for Visual‑Olfactory Crossmodal Perception

The crossmodal interaction of different senses,which is an important basis for learning and memory in the human brain,is highly desired to be mimicked at the device level for developing neuromorphic crossmodal perception,but related researches are scarce.Here,we demonstrate an optoelectronic synapse for vision-olfactory crossmodal perception based on MXene/violet phosphorus(VP)van der Waals heterojunctions.Benefiting from the efficient separation and transport of photogenerated carriers facilitated by conductive MXene,the photoelectric responsivity of VP is dramatically enhanced by 7 orders of magnitude,reaching up to 7.7 A W^(−1).Excited by ultraviolet light,multiple synaptic functions,including excitatory postsynaptic currents,pairedpulse facilitation,short/long-term plasticity and“learning-experience”behavior,were demonstrated with a low power consumption.Furthermore,the proposed optoelectronic synapse exhibits distinct synaptic behaviors in different gas environments,enabling it to simulate the interaction of visual and olfactory information for crossmodal perception.This work demonstrates the great potential of VP in optoelectronics and provides a promising platform for applications such as virtual reality and neurorobotics.

Digital Twin-based Quality Management Method for the Assembly Process of Aerospace Products with the Grey-Markov Model and Apriori Algorithm

The assembly process of aerospace products such as satellites and rockets has the characteristics of single-or small-batch production,a long development period,high reliability,and frequent disturbances.How to predict and avoid quality abnormalities,quickly locate their causes,and improve product assembly quality and efficiency are urgent engineering issues.As the core technology to realize the integration of virtual and physical space,digital twin(DT)technology can make full use of the low cost,high efficiency,and predictable advantages of digital space to provide a feasible solution to such problems.Hence,a quality management method for the assembly process of aerospace products based on DT is proposed.Given that traditional quality control methods for the assembly process of aerospace products are mostly post-inspection,the Grey-Markov model and T-K control chart are used with a small sample of assembly quality data to predict the value of quality data and the status of an assembly system.The Apriori algorithm is applied to mine the strong association rules related to quality data anomalies and uncontrolled assembly systems so as to solve the issue that the causes of abnormal quality are complicated and difficult to trace.The implementation of the proposed approach is described,taking the collected centroid data of an aerospace product’s cabin,one of the key quality data in the assembly process of aerospace products,as an example.A DT-based quality management system for the assembly process of aerospace products is developed,which can effectively improve the efficiency of quality management for the assembly process of aerospace products and reduce quality abnormalities.

The aboveground biomass of desert steppe and its spatiotemporal variation in western Inner Mongolia

A precise understanding of the aboveground biomass of desert steppe and its spatio-temporal variation is important to understand how arid ecosystems respond to climate change and to ensure that scarce grassland resources are used rationally. On the basis of 756 ground survey quadrats sampled in western Inner Mongolia steppe in 2005-2011 and remote sensing data from the Moderate Resolu- tion Imaging Spectroradiometer （MODIS）--the normalized difference vegetation index （NDVI） dataset for the period of 2001-2011--we developed a statistical model to estimate the aboveground biomass of the desert steppe and further explored the rela- tionships between aboveground biomass and climate factors. The conclusions are as follows： （1） the aboveground biomass of the steppe in the research area was 5.27 Tg （1 Tg=1012 g） on average over 11 years; between 2001 and 2011, the aboveground biomass of the western Inner Mongolia steppe exhibited fluctuations, with no significant trend over time; （2） the aboveground biomass of the steppe in the research area exhibits distinct spatial variation and generally decreases gradually from southeast to northwest; and （3） the important factor causing intemnnual variations in aboveground biomass is precipitation during the period from January to July, but we did not find a significant relationship between the aboveground biomass and the corresponding temperature changes. The precipitation in this period is also an important factor influencing the spatial distribution of aboveground biomass （R2=0.39, P〈0.001）, while the temperature might be a minor factor （R2=0.12, P〈0.01 ）. The uncertainties in our estimate are primarily due to uncertainty in converting the fresh grass yield estimates to dry weight, underestimates of the biomass of shrubs, and error in remote sensing dataset.

Boosting Transport Kinetics of Ions and Electrons Simultaneously by Ti3C2Tx(MXene)Addition for Enhanced Electrochromic Performance

Electrochromic technology plays a significant role in energy conservation,while its performance is greatly limited by the transport behavior of ions and electrons.Hence,an electrochromic system with overall excellent performances still need to be explored.Initially motivated by the high ionic and electronic conductivity of transition metal carbide or nitride(MXene),we design a feasible procedure to synthesize the MXene/WO3−x composite electrochromic film.The consequently boosted electrochromic performances prove that the addition of MXene is an effective strategy for simultaneously enhancing electrons and ions transport behavior in electrochromic layer.The MXene/WO3−x electrochromic device exhibits enhanced transmittance modulation and coloration efficiency(60.4%,69.1 cm^2 C^−1),higher diffusion coefficient of Li+and excellent cycling stability(200 cycles)over the pure WO3−x device.Meanwhile,numerical stimulation theoretically explores the mechanism and kinetics of the lithium ion diffusion,and proves the spatial and time distributions of higher Li+concentration in MXene/WO3−x composite electrochromic layer.Both experiments and theoretical data reveal that the addition of MXene is effective to promote the transport kinetics of ions and electrons simultaneously and thus realizing a high-performance electrochromic device.This work opens new avenues for electrochromic materials design and deepens the study of kinetics mechanism of ion diffusion in electrochromic devices.

Correction to:Boosting Transport Kinetics of Ions and Electrons Simultaneously by Ti_(3)C_(2)T_(x)(MXene)Addition for Enhanced Electrochromic Performance

The original version of this article unfortunately contained some mistakes in figure. The authors found that explanation of the data lines in Fig. 5b is wrong.The corrected version of Fig. 5b is given below:Open AccessThis article is licensed under a Creative Commons Attribution 4.0 International License,which permits use,sharing,adaptation,distribution and reproduction in any medium or format,as long as you give appropriate credit to the original author(s) and the source,provide a link to the Creative Commons licence.

A Safe and Reliable Heterogeneous Controller Deployment Approach in SDN

Software-Defined Networking(SDN)provides flexible and global network management by decoupling control plane from data plane,and multiple controllers are deployed in the network in a logically centralized and physically distributed way.However,the existing approaches generally deploy the controllers with the same type in the network,which easily causes homogeneous controller common-mode fault.To this end,this paper proposes heterogeneous controller deployment in the SDN,considering the different types of controllers and relevant criteria(e.g.,delay,control link interruption rate,and controller fault rate).Then,we introduce a Safe and Reliable Heterogeneous Controller Deployment(SRHCD)approach,consisting of two stages.Stage 1 determines the type and the number of heterogeneous controllers required for the SDN network based on the dynamic programming.Stage 2 divides the SDN network into multiple subnets by k-means algorithm and improves the genetic algorithm to optimize the heterogeneous controller deployment in these SDN subnets to ensure reliable switch-controller communications.Finally,the simulation results show that the proposed approach can effectively reduce the control plane fault rate and increase the attack difficulties.Besides,the switch-controller delay has been lowered by 16.5%averagely.

MimicCloudSim:An Environment for Modeling and Simulation of Mimic Cloud Service

In recent years,an increasing number of application services are deployed in the cloud.However,the cloud platform faces unknown security threats brought by its unknown vulnerabilities and backdoors.Many researchers have studied the Cyber Mimic Defense(CMD)technologies of the cloud services.However,there is a shortage of tools that enable researchers to evaluate their newly proposed cloud service CMD mechanisms,such as scheduling and decision mechanisms.To fill this gap,we propose MimicCloudSim as a mimic cloud service simulation system based on the basic functionalities of CloudSim.MimicCloudSim supports the simulation of dynamic heterogeneous redundancy(DHR)structure which is the core architecture of CMD technology,and provides an extensible interface to help researchers implement new scheduling and decision mechanisms.In this paper,we firstly describes the architecture and implementation of MimicCloudSim,and then discusses the simulation process.Finally,we demonstrate the capabilities of MimicCloudSim by using a decision mechanism.In addition,we tested the performance of MimicCloudSim,the conclusion shows that MimicCloudSim is highly scalable.

Ca^(2+) and OH^- release of ceramsites containing anorthite and gehlenite prepared from waste lime mud

Lime mud is a kind of solid waste in the papermaking industry,which has been a source of serious environmental pollution.Ceramsites containing anorthite and gehlenite were prepared from lime mud and fly ash through the solid state reaction method at 1050°C.The objective of this study was to explore the efficiency of Ca^2＋ and OH-release and assess the phosphorus and copper ion removal performance of the ceramsites via batch experiments,X-ray diffraction（XRD） and scanning electron microscopy（SEM）.The results show that Ca^2＋ and OH-were released from the ceramsites due to the dissolution of anorthite,gehlenite and available lime.It is also concluded that gehlenite had stronger capacity for Ca^2＋ and OH-release compared with anorthite.The Ca^2＋ release could be fit well by the Avrami kinetic model.Increases of porosity,dosage and temperature were associated with increases in the concentrations of Ca^2＋ and OH-released.Under different conditions,the ceramsites could maintain aqueous solutions in alkaline conditions（p H = 9.3–10.9） and the release of Ca^2＋ was not affected.The removal rates of phosphorus and copper ions were as high as 96.88% and 96.81%,respectively.The final p H values of both phosphorus and copper ions solutions changed slightly.The reuse of lime mud in the form of ceramsites is an effective strategy.

红色主题展览的主题解读与展示手法刍议——以庆祝中国共产党成立100周年出版专题展为例

红色主题展览有着内容同质化、展品相对固定、展览周期集中等特点。打造一个有特色的红色主题展览殊非易事,需要深入理解细分类型的主题内涵,选择与主题内容高契合度的设计手段,才有可能实现较好的展览效果。"播思想火种铸文化伟业—庆祝中国共产党成立100周年出版专题展",是笔者带领团队设计的一个红色主题专题展览典型案例。本文以该展览为例,通过扫描式解析展陈设计全过程,来探讨红色主题展览的设计思路。