A Novel Anti-Collision Algorithm for Large Scale of UHF RFID Tags Access Systems

When the radio frequency identification(RFID)system inventories multiple tags,the recognition rate will be seriously affected due to collisions.Based on the existing dynamic frame slotted Aloha(DFSA)algorithm,a sub-frame observation and cyclic redundancy check(CRC)grouping combined dynamic framed slotted Aloha(SUBF-CGDFSA)algorithm is proposed.The algorithm combines the precise estimation method of the quantity of large-scale tags,the large-scale tags grouping mechanism based on CRC pseudo-randomcharacteristics,and the Aloha anti-collision optimization mechanism based on sub-frame observation.By grouping tags and sequentially identifying themwithin subframes,it accurately estimates the number of remaining tags and optimizes frame length accordingly to improve efficiency in large-scale RFID systems.Simulation outcomes demonstrate that this proposed algorithmcan effectively break through the system throughput bottleneck of 36.8%,which is up to 30%higher than the existing DFSA standard scheme,and has more significant advantages,which is suitable for application in largescale RFID tags scenarios.

提高石油天然气长输管道清管器定位效率的研究

结合石油天然气长输管道项目实际情况与工作经验，运用QC(quality control)小组活动的方式对374个清管测径段落进行跟踪分析，并对其中51个清管器被卡的段落进行了详细研究。通过对管道压力的变化、空气压缩机真实排气量的测算，以及对清管器的漏气量等参数进行分析和计算后，制定了提高被卡主清管器定位效率的措施，为石油天然气长输管道项目的预投产施工作业奠定坚实的基础。

水压试验与气压试验的对比分析

分析了水压试验和气压试验的优缺点。通过对工程的工期要求、施工技术、安全质量、工程环境等方面进行分析，得出在不同工况下进行水压试验和气压试验的相关建议，为项目的预投产施工作业打下了基础。

Solid-to-molecular-orientational-hexatic melting induced by local environment determined defect proliferations

Two-dimensional(2D)melting is a fundamental research topic in condensed matter physics,which can also provide guidance on fabricating new functional materials.Nevertheless,our understanding of 2D melting is still far from being complete due to existence of possible complicate transition mechanisms and absence of effective analysis methods.Here,using Monte Carlo simulations,we investigate 2D melting of 60°rhombs which melt from two different surface-fullycoverable crystals,a complex hexagonal crystal(cHX)whose primitive cell contains three rhombs,and a simple rhombic crystal(RB)whose primitive cell contains one rhomb.The melting of both crystals shows a sequence of solid,hexatic in molecular orientation(Hmo),and isotropic phases which obey the Berezinskii-Kosterlitz-Thouless-Halperin-Nelson-Young(BKTHNY)theory.However,local polymorphic configuration(LPC)based analysis reveals different melting mechanisms:the cHX-Hmotransition is driven by the proliferation of point-like defects during which defect-associated LPCs are generated sequentially,whereas the RB-Hmotransition is driven by line defects where defect-associated LPCs are generated simultaneously.These differences result in the observed different solid-Hmotransition points which areφA=0.812 for the cHX-HmoandφA=0.828 for the RB-Hmo.Our work will shed light on the initial-crystal-dependence of 2D melting behavior.

Spin–orbit torque in perpendicularly magnetized[Pt/Ni]multilayers

The performance of spin–orbit torque(SOT)in heavy metal/ferromagnetic metal periodic multilayers has attracted widespread attention.In this paper,we have successfully fabricated a series of perpendicular magnetized[Pt(2-t)/Ni(t)]_4 multilayers,and studied the SOT in the multilayers by varying the thickness of Ni layer t.The current induced magnetization switching was achieved with a critical current density of 1×10^(7)A/cm^(2).The damping-like SOT efficiencyξ_(DL)was extracted from an extended harmonic Hall measurement.We demonstrated that theξ_(DL)can be effectively modulated by t_(Pt)/t_(Ni)ratio of Pt and Ni in the multilayers.The SOT investigation about the[Pt/Ni]N multilayers might provide new material candidates for practical perpendicular SOT-MRAM devices.

Applying IT to Avoid Bullwhip Effect of Supply Chain

Bullwhip effect is the most important factor considered in the supply chain management. It gets many scholars＇ attention that bullwhip effect has been restricting the development of the supply chain all the time. Information Technology （IT） can reduce bullwhip effect by sharing the information among the enterprises in the supply chain.

本征柔性有机电子器件的研究进展

本征柔性有机电子学是近年来涌现的一项变革性的前沿交叉学科,它赋予电子材料可印刷、可折叠和可拉伸等特性,使其应用于健康医疗、柔性显示、传感探测、人工智能和脑机接口等前沿领域.为了进一步拓展本征柔性有机电子器件的应用场景,设计开发高性能、高显示度、高稳定性的本征柔性材料和有机电子器件是当前的研究重点.本文主要介绍了近年来本征柔性有机电子学相关领域的前沿研究进展,重点讨论了本征柔性材料与有机电子器件的设计和制备策略、本征柔性材料图案化工艺和集成电路,分析了本征柔性有机电子学领域的技术瓶颈和前沿问题,总结和展望了本征柔性有机电子器件的应用前景与未来发展趋势.

An aqueous rechargeable Fe//LiMn_(2)O_()hybrid battery with superior electrochemical performance beyond mainstream Fe-based batteries

Aqueous rechargeable batteries(ARBs)are generally safer than non-aqueous analogues,they are also less-expensive,and more friendly to the environment.However,the inherent disadvantage of the narrow electrochemical window of H2O seriously restricts the energy density and output voltage of ARBs,especially aqueous rechargeable Fe-based batteries.Herein,we introduce a new battery system:the anode contains C@Fe/Fe_(2)O_(3)composite,which is interfaced with an alkaline electrolyte;the cathode contains LiMn_(2)O_()in contact with a neutral electrolyte.A Li^(+)-conducting membrane is carefully selected to decouple the electrode-electrolyte,which effectively widens the electrochemical window to above 2.65 V,thereby enables an aqueous rechargeable iron battery.Its average output voltage is 1.83 V and its energy density is 235.3 Wh/kg at 549 W/kg.In this work,we propose the energy storage mechanism with the aid of density functional theory(DFT).The calculated reduction potential of the anode agrees with the experimental value.Furthermore,this battery system demonstrates long cycle lifespan of approximately 2500 cycles at 2 A/g,corresponding to a capacity retention of 82.1%.These results are very far superior than those of mainstream aqueous rechargeable Fe-based batteries,which guarantee future investigation for storing electricity energy.

Singularity analysis and avoidance for an SSRMS-type reconfigurable space manipulator with a non-spherical wrist and two lockable passive telescopic links

This study focuses on addressing kinematic singularity analysis and avoidance issues for a space station remote manipulator system(SSRMS)-type reconfigurable space manipulator.The manipulator is equipped with a non-spherical wrist and two lockable passive telescopic links(LPTLs),which enable it to have both active revolute and passive prismatic joints and operate in two distinct modes.To begin with the kinematic singularity analysis,the study derives the differential kinematic equations for the manipulator and identifies the dominant Jacobian matrix that causes singularities.Subsequently,an in-depth analysis of singularities from multiple perspectives is conducted.Firstly,a kinematic singularity map method is proposed to capture the distribution of singularities within the reachable workspace.Then,the influence of the two LPTLs on singularities is thoroughly examined.Finally,a new method based on the matrix rank equivalence principle is introduced to determine singularity conditions,enabling the identification of all the singular configurations for the SSRMS-type reconfigurable manipulator.Notably,this method significantly reduces computational complexity,and the singularity conditions obtained have more concise equations.For the singularity avoidance problem,a novel method is developed,which simultaneously addresses the requirements of real-time performance,high precision,and the avoidance of both kinematic singularities and joint limit constraints.Benefiting from these excellent properties,the proposed method can effectively resolve the singularity issues encountered separately by the SSRMS-type reconfigurable manipulator in its two operational modes.Several typical simulations validate the utility of all the proposed methods.

Electrohydrodynamic printing for high resolution patterning of flexible electronics toward industrial applications

Electrohydrodynamic(EHD)printing technique,which deposits micro/nanostructures through high electric force,has recently attracted significant research interest owing to their fascinating characteristics in high resolution(<1μm),wide material applicability(ink viscosity 1–10000 cps),tunable printing modes(electrospray,electrospinning,and EHD jet printing),and compatibility with flexible/wearable applications.Since the laboratory level of the EHD printed electronics'resolution and efficiency is gradually approaching the commercial application level,an urgent need for developing EHD technique from laboratory into industrialization have been put forward.Herein,we first discuss the EHD printing technique,including the ink design,droplet formation,and key technologies for promoting printing efficiency/accuracy.Then we summarize the recent progress of EHD printing in fabrication of displays,organic field-effect transistors(OFETs),transparent electrodes,and sensors and actuators.Finally,a brief summary and the outlook for future research effort are presented.

Electric-Induced Cycloelimination for Simulating Structural Plasticity in Organic Nociceptors

Continuous lifelong acquisition,updating,and finetuning of knowledge and skills is of crucial significance for the survival of humans.However,current neuromorphic devices exhibit obvious catastrophic forgetting when restimulated by new information.This remains a challenge for neuromorphic devices and artificial intelligence to achieve continuous learning.Herein,we propose an electric-induced cycloelimination strategy to realize an organic transistor nociceptor that can simulate synaptic and structural plasticity.The system benefits from the ring-opening characteristics of cross-linked poly(vinyl cinnamate)under a strong pulse voltage,during which new energy-level trap states are formed.The prepared organic transistor nociceptors exhibit both structural and synaptic plasticity.They simulate the characteristics of human nociceptors,including threshold,relaxation,sensitization,and maladaptation behavior.For the first time,we have simulated and explored the structural plasticity behavior in organisms based on electronic devices.More remarkably,the transistor nociceptors realize the reinput of information without forgetting the initial informa tion.The strategy developed for the preparation of organic transistor nociceptors provides insights for addressing the catastrophic forgetting in the lifelong learning of intelligent neuromorphic devices.

Highly sensitive,scalable,and rapid SARS-CoV-2 biosensor based on In_(2)O_(3)nanoribbon transistors and phosphatase

Developing convenient and accurate SARS-CoV-2 antigen test and serology test is crucial in curbing the global COVID-19 pandemic.In this work,we report an improved indium oxide(In2O3)nanoribbon field-effect transistor(FET)biosensor platform detecting both SARS-CoV-2 antigen and antibody.Our FET biosensors,which were fabricated using a scalable and cost-efficient lithography-free process utilizing shadow masks,consist of an In_(2)O_(3)channel and a newly developed stable enzyme reporter.During the biosensing process,the phosphatase enzymatic reaction generated pH change of the solution,which was then detected and converted to electrical signal by our In_(2)O_(3)FETs.The biosensors applied phosphatase as enzyme reporter,which has a much better stability than the widely used urease in FET based biosensors.As proof-of-principle studies,we demonstrate the detection of SARS-CoV-2 spike protein in both phosphate-buffered saline(PBS)buffer and universal transport medium(UTM)(limit of detection[LoD]:100 fg/mL).Following the SARS-CoV-2 antigen tests,we developed and characterized additional sensors aimed at SARS-CoV-2 IgG antibodies,which is important to trace past infection and vaccination.Our spike protein IgG antibody tests exhibit excellent detection limits in both PBS and human whole blood((LoD):1 pg/mL).Our biosensors display similar detection performance in different mediums,demonstrating that our biosensor approach is not limited by Debye screening from salts and can selectively detect biomarkers in physiological fluids.The newly selected enzyme for our platform performs much better performance and longer shelf life which will lead our biosensor platform to be capable for real clinical diagnosis usage.

A multihalogenation strategy for ambipolar transistors and high-gain inverters with good noise margin

Inorganic electronics are mainly based on complementary metal–oxide-semiconductor(CMOS)structures that use both ptype and n-type transistors.The complementary structures have promoted the achievement of logic circuits with low power consumption and good noise margin(NM).Compared with inorganic semiconductors,organic solution-processable ambipolar polymers are promising materials for complementary technology[1,2].Ambipolar polymers as single-component semiconductors in CMOS-like circuits maintain the attraction of low cost and easy fabrication[3].In practical application,CMOS-like circuits are expected to employ ambipolar field-effect transistor(FET)based inverters with high gain and good NM[4].However,high-gain inverters with good NM(Table S1 online)are difficult to achieve due to the lack of ambipolar polymers with balanced hole/electron mobilities(lh/le)and threshold voltages.Ambipolar polymers can be obtained by fine-tuning both the highest occupied molecular orbital(HOMO)and lowest unoccupied molecular orbital(LUMO)levels to match well with work function of Au electrodes(WF,4.7–5.2 eV)[5](Fig.S1a online).However,most polymers based on common acceptors only display unipolar(p-type or n-type)transport due to their wide bandgaps(>1.2 eV)and inappropriate energy levels[6].For example,isoindigo-based polymers generally show p-type semiconducting behaviors owing to their high-lying LUMO levels,which is unfavorable for electron injection(Fig.S1b online).

Air-stable n-type transistors based on assembled aligned carbon nanotube arrays and their application in complementary metal-oxide-semiconductor electronics

Carbon nanotubes(CNTs)are ideal candidates for beyond-silicon nano-electronics because of their high mobility and low-cost processing.Recently,assembled massively aligned CNTs have emerged as an important platform for semiconductor electronics.However,realizing sophisticated complementary nano-electronics has been challenging due to the p-type nature of carbon nanotubes in air.Fabrication of n-type behavior field effect transistors(FETs)based on assembled aligned CNT arrays is needed for advanced CNT electronics.Here in this paper,we report a scalable process to make n-type behavior FETs based on assembled aligned CNT arrays.Air-stable and high-performance n-type behavior CNT FETs are achieved with high yield by combining the atomic layer deposition dielectric and metal contact engineering.We also systematically studied the contribution of metal contacts and atomic layer deposition passivation in determining the transistor polarity.Based on these experimental results,we report the successful demonstration of complementary metal-oxide-semiconductor inverters with good performance,which paves the way for realizing the promising future of carbon nanotube nano-electronics.

High-performance flexible organic field effect transistors with print-based nanowires

Polymer nanowire(NW)organic field-effect transistors(OFETs)integrated on highly aligned large-area flexible substrates are candidate structures for the development of high-performance flexible electronics.This work presents a universal technique,coaxial focused electrohydrodynamic jet(CFEJ)printing technology,to fabricate highly aligned 90-nm-diameter polymer arrays.This method allows for the preparation of uniformly shaped and precisely positioned nanowires directly on flexible substrates without transfer,thus ensuring their electrical properties.Using indacenodithiophene-co-benzothiadiazole(IDT-BT)and poly(9,9-dioctylfluorene-co-benzothiadiazole)(F8-BT)as example materials,5 cm^(2) arrays were prepared with only minute size variations,which is extremely difficult to do using previously reported methods.According to 2D-GIXRD analysis,the molecules inside the nanowires mainly adopted face-onπ-stacking crystallite arrangements.This is quite different from the mixed arrangement of thin films.Nanowire-based OFETs exhibited a high average hole mobility of 1.1 cm^(2) V^(−1) s^(−1) and good device uniformity,indicating the applicability of CFEJ printing as a potential batch manufacturing and integration process for high-performance,scalable polymer nanowire-based OFET circuits.This technique can be used to fabricate various polymer arrays,enabling the use of organic polymer semiconductors in large-area,high-performance electronic devices and providing a new path for the fabrication of flexible displays and wearable electronics in the future.