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(1) The COF-SILMs show excellent CO2 selectivity over N2, and gas permeability. (2) It was revealed that the anions act as gatekeepers for the gas transport across membranes.

Self-healable siloxane elastomers have recently attracted much interest in research for applications in flexible electronic devices. However, it remains a challenge for self-healable siloxane elast...

Amid the burgeoning environmental concerns, electrochemical energy storage is of great demand, inspiring the rapid development of electrolytes. Quasi-liquid solid electrolytes (QLSEs) demonstrate exciting properties that combine high ionic conductivity and safety. Herein, a QLSE system is constructed by confining ionic liquids (ILs) into 2D materials-based membranes, which creates a subtle platform for the investigation of the nanoconfined ion transport process. The highest ionic conductivity increment of 506% can be observed when ILs are under nanoconfinement. Correlation of experimental results and simulation evidently prove the diffusion behaviors of ILs are remarkably accelerated when confined in nanochannels, ascribing from the promoted dissociation of ILs. Concurrently, nanoconfined ILs demonstrate a highly ordered distribution, lower interplay, and higher free volume compared against bulk systems. This work reveals and analyzes the phenomenon of ionic conductivity elevation in nanoconfined ILs, and offers inspiring opportunities to fabricate the highly stable and efficient QLSEs based on layered nanomaterials for energy storage applications.

Polymer doping is a significant approach to precisely control nucleation and crystal growth of perovskites and enhance electronic quality in perovskite solar cells (PSC) prepared in air. Here, a brand-new self-healing polysiloxane (SHP) with dynamic 2,6-pyridinedicarboxamide (PDCA) coordination units and plenty of hydrogen bonds was designed and incorporated into perovskite films. PDCA units, showing strong intermolecular Pb 2+ -N amido , I - -N pyridyl , and Pb 2+ -O amido coordination interactions, were expected to enhance crystallinity and passivate the grain boundary. In addition, abundant hydrogen bonds in SHP afforded the self-healing of cracks at grain boundaries for fatigue PSCs. Significantly, the doped device demonstrated a champion efficiency of 19.50% with inconspicuous hysteresis, almost rivaling those achieved in control atmosphere. This strategy of heterocyclic-based macromolecular doping in PSCs will pave a way for realizing efficient and durable crystalline semiconductors.

Accurate mine localization has always been an urgent demand. With the widespread emergence of cheap wireless devices in our life, channel state information (CSI) based indoor localization has attracted people’s attention. In the existing CSI-based localization methods, fingerprint-based localization needs to build a huge database with poor robustness, and the methods based on angle of arrival (AOA) need specific antenna arrays and complex phase calibration. Because mobile devices such as smartphones only have one or two antennas, and the antennas inside the devices cannot form a receiving array, the conventional AOA estimation system cannot be deployed on such mobile devices. Therefore, we propose an AOA estimation method using rotating AP antennas. This method only needs one antenna at the receiving end to work and does not need to calibrate the phase. Firstly, the CSI phase of the rotating antenna is collected and the phase difference is calculated. Then, empirical mode decomposition (EMD) algorithm based on mutual information is used to remove the noise, and subcarrier selection is used to reduce the multipath effect in the data processing part. Finally, the AOA is estimated according to the relative position of the antenna. We conduct extensive experiments in mine and laboratory scenarios, and the median localization errors in mine and laboratory are 0.4 m and 0.6 m, the median angle errors are \(4.2^{\circ } \) and \(5.2^{\circ } \) respectively.

Clock synchronization is still a vital and challenging task for underground coal wireless internet of things (IoT) due to the uncertainty of underground environment and unreliability of communication links. Instead of considering on-demand driven clock synchronization, this paper proposes a novel Adaptive Robust Synchronization (ARS) scheme with packets loss for mine wireless environment. A clock synchronization framework that is based on Kalman filtering is first proposed, which can adaptively adjust the sampling period of each clock and reduce the communication overhead in single-hop networks. The proposed scheme also solves the problem of outliers in data packets with time-stamps. In addition, this paper extends the ARS algorithm to multi-hop networks. Additionally, the upper and lower bounds of error covariance expectation are analyzed in the case of incomplete measurement. Extensive simulations are conducted in order to evaluate the performance. In the simulation environment, the clock accuracy of ARS algorithm is improved by 7.85% when compared with previous studies for single-hop networks. For multi-hop networks, the proposed scheme improves the accuracy by 12.56%. The results show that the proposed algorithm has high scalability, robustness, and accuracy, and can quickly adapt to different clock accuracy requirements.

Recently, imidazole-based ionic liquid supported membranes have found wide application in gas separation and purification, deriving of their good solubility for CO2 and their ultrathin membrane thickness. Our previous works preliminarily showed that three primary interactions, including the interaction between passing gas and ionic liquid, the interaction between anion and cation of ionic liquid, as well as the interaction between ionic liquid and supporting membrane, play crucial roles determining the gas permeability and CO2 selectivity over N2. However, a systematic discussion of these three interactions to disclose the underlying separation mechanism is lack. In this study, adopting molecular dynamic (MD) simulation and density functional theory (DFT) calculation, three ionic liquids including of [BMIM][BF4], [BMIM][PF6] and [BMIM][Tf2N] with high CO2 solubility are selected as research objects, these three interactions were discussed to reveal the gas separation mechanism in MoS2-SILM. Simulation results indicate that the interaction between gas molecules and ILs determines the gas solubility and selectivity, and the [BMIM][BF4] shows superior separation performance over other two ILs. In addition, the interaction between ILs and MoS2 sheets, together with the interaction between cation and anion of ILs, determine the layered structure of confined ILs, which is preferential for gas transport. Furthermore, the gas permeability difference between confined ILs and bulk ILs, and the influence of interlayer spacing were also discussed. Our study provides fundamental insight to the underlying gas separation mechanism and beneficial guidelines for device design.

Hyperbranched polymer was synthesized via Michael addition. The biocompatible peptide was incorporated into hyperbranched polymer. As a result, they are promising candidates for cell adhesive molecular. Herein, we developed a strategy for synthetic hyperbranched polymer based on polysiloxane. A poly-p-phenylene benzobisoxazole (PBO) fiber as substrate, polyhedral oligomericsilsesquioxane (POSS) as core, prepared hyperbranched polymer was grafted to surface of PBO fiber. Experiment results show that hyperbranched polysiloxane was uniformly grafted onto the PBO fiber and significantly increase the surface activity. In addition, the functional PBO fiber as substrate presents biocompatible based on activity peptide. Hela cell selectively adhered on surface functional PBO fiber with activated peptide spots. Thus, the results of this study further extend the application of engineered polymer materials to cell biology.

Traditional visible light-based positioning technology of deploying the receiver under the transmitter (i.e., LEDs deployed on the top and photodetectors deployed on the ground) in the mine tunnel is unreliable for optical signal reception and difficult to implement due to the complex mine tunnel environment such as occlusion of objects (e.g., Ore and Minecarts) on the ground. To address this issue, we propose a reliable visible light-based underground positioning algorithm that uses a novel reverse transceiver position mechanism, i.e., utilizing the existing miner’s headlamp as the transmitter below and the photodiodes deployed on the top of the mine tunnel as the receiver above for broadcasting and receiving the light beacon representing miner’s identity information. We determine the current location of each person through a series of base stations constructed by the receiver and achieve real-time positioning of all people combined with inertial navigation. We also overcome some technical challenges for this mechanism and the mine environment, including optimal frequency selection, robust frequency identification, and accurate base station positioning. The experiments show that the average positioning error of the base station is 0.06 m and the real-time location accuracy is 98% error of 2.5 m or less.

The bio-integrated electronics industry is booming and becoming more integrated with biological tissues. However, it is challenging to obtain high-level self-healing of sensitivity and durability of bifunctional sensor when maintaining their long-term fatigue-resistance and high stretchability. Herein, a high performance self-healable bifunctional sensor was demonstrated through synergistic dynamic interactions between polysiloxane and silver nanoflakes (AgFs) and in-situ formed silver nanoparticles (AgNPs). The bifunctional sensor showed high sensitivity (gauge factor reached 39.5), exceptional electrical self-healability (at ambient temperature), and durability (more than 1000 cycles) by virtue of superflexible siloxane chains in the self-healing polymer, strong dynamic silver-thiolate coordination interactions, and the migration of silver nanoparticles. Finally, multiple human motions and health status were monitored, even after multiple cycles of healing, these “self-healed” sensing signals were still extremely consistent with the pristine ones, indicating the excellent reliabilities and healing stabilities of the bifunctional sensor.

This paper analyzes how body bias and BOX region thickness affect soft error rates in 65-nm SOTB (Silicon on Thin BOX) and 28-nm UTBB (Ultra Thin Body and BOX) FD-SOI processes. Soft errors are induced by alpha-particle and neutron irradiation and the results are then analyzed by Monte Carlo based simulation using PHITS-TCAD. The alpha-particle-induced single event upset (SEU) cross-section and neutron-induced soft error rate (SER) obtained by simulation are consistent with measurement results. We clarify that SERs decreased in response to an increase in the BOX thickness for SOTB while SERs in UTBB are independent of BOX thickness. We also discover SOTB develops a higher tolerance to soft errors when reverse body bias is applied while UTBB become more susceptible

Stretchable electronics, which can retain their functions under stretching, have attracted great interest in recent decades. Elastic substrates, which bear the applied strain and regulate the strain distribution in circuits, are indispensable components in stretchable electronics. Moreover, the self-healing property of the substrate is a premise to endow stretchable electronics with the same characteristics, so the device may recover from failure resulting from large and frequent deformations. Therefore, the properties of the elastic substrate are crucial to the overall performance of stretchable devices. Poly(dimethylsiloxane) (PDMS) is widely used as the substrate material for stretchable electronics, not only because of its advantages, which include stable chemical properties, good thermal stability, transparency, and biological compatibility, but also because of its capability of attaining designer functionalities via surface modification and bulk property tailoring. Herein, the strategies for fabricating stretchable electronics on PDMS substrates are summarized, and the influence of the physical and chemical properties of PDMS, including surface chemical status, physical modulus, geometric structures, and self-healing properties, on the performance of stretchable electronics is discussed. Finally, the challenges and future opportunities of stretchable electronics based on PDMS substrates are considered.

Technology scaling increases the role of charge sharing and bipolar effect with respect to multiple cell upset. We analyze the contributions of cell distance and well-contact density to suppress MCU by device-level simulations and neutron experiments. Device simulation results reveal that the ratio of MCU to SEU exponentially decreases by increasing the distance between redundant latches. MCU is suppressed when well con- tacts are placed between redundant latches. Experimental results also show that the ratio of MCU to SEU exponentially decreases by increasing the distance between cells. MCU is suppressed effectively by increasing the density of well contacts.

According to the process scaling, radiation-hard devices are becoming sensitive to soft errors caused by Multiple Cell Upset (MCUs). In this paper, the parasitic bipolar effects are utilized to suppress MCUs of the radiation-hard dual-modular flip-flops. Device simulations reveal that a simultaneous flip of redundant latches is suppressed by storing opposite values instead of storing the same value due to its asymmetrical structure. The state of latches becomes a specific value after a particle hit due to the bipolar effects. Spallation neutron irradiation proves that MCUs are effectively suppressed in the D-FF arrays in which adjacent two latches in different FFs store opposite values. The redundant latch structure storing the opposite values is robust to the simultaneous flip. key words: DMR, soft error, MCU, device simulation

Effect of homologous of nano-composites on the thermal degradation of the silicone resin was researched based on graphene oxide (GO)/polyhedral oligomeric silsesquioxane (POSS). First, the amino-POSS was grafted onto the GO surface (GO/POSS) via the amide bond. Second, GO/POSS was incorporated into the silicone with active epoxy group via chemistry grafting. The reaction kinetics of the thermal decomposition of the epoxy–silicone resin based on nano-composite homologous effect is developed. The initial decomposition temperature of the modified silicone resin is improved by 77.2°C. At high temperatures, GO/POSS-modified silicone molecular end forms homologous nano-structures, which can restrain silicone future degradation. The developed strategy has potential to restrain the degradation of the polymer molecular chain.

We estimate the SERs of 65-nm SOTB(Silicon on Thin BOX) and 28-nm UTBB(Ultra Thin Body and BOX) FD-SOI processes by decreasing the supply voltage. Alpha, neutron irradiation experiments and Monte-Carlo based simulations are compared in this work. The SERs can be analyzed by the simulation tool with only layout pattern of test chips. The simulation results are consistent with the alpha and neutron irradiation measurement results.

We estimate SERs of FD-SOI structures according to the thicknesses of BOX (Buird OXide) layer on 65-nm and 28-nm processes by reducing supply voltage. Alpha, neutron irradiation experiments and Monte-Carlo based simulations are compared in this work. The SOTB (Silicon on Thin BOX) and the UTBB (Ultra Thin Body and BOX) structures are evaluated in the irradiation experiments. The SERs of those structures are analyzed by the simulation tool with layout pattern of test chips. The simulation results are consistent with the alpha and neutron irradiation measurement results. According to the simulated result, the SERs are decreased by increasing the thickness of BOX layer.

Because the mobile devices, such as mobile phone and tablet PC, are sold at a cheaper price but performance better and better with the development of ICTs, more and more Chinese learners can afford these devices and use them to learn. This project explore a course framework to integrate m-learning technology into online courses, which are used in School of Continue Education, Peking University. This framework provides learners blended learning environment, in which learners can learn a course through PC, mobile phone and tablet PC without conflict, and get smooth learning experience among different devices. Through application in instruction for one term, the researchers find that the learners are satisfied with the interface design, tutor-directed function design and cross-platform learning experience. But the learners also propound some suggestion, such as give learners freedom to adjust calendar, optimizing app performance.

We analyze the soft error tolerance of DFF in 65-nm bulk and SOTB (Silicon on Thin BOX) process by alpha and neutron experiments and device-simulations. The experimental results reveal that by increasing the reverse body bias the soft error rate in the bulk structure is increased, while the number of soft errors in SOTB structure is decreased. The results from device-simulation show that the collected charge of bulk structure is increased, while the collected charge is decreased in SOTB as the reverse body bias increases.

There are two of main factors, charge sharing and bipolar effects to cause or suppress SEUs and MCUs. Technology scaling increases the the role of bipolar effects with respect to multiple bit upsets. We analyze contributions of charge sharing and bipolar effects by changing the position of well contacts and the well structure. Device simulation results reveal that charge sharing and bipolar effect are suppressed effectively when the well contacts are placed in the middle of two latches.

Parasitic bipolar effects are intentionally used to prevent a simultaneous flip of redundant FFs, which make them more fault-resilient to soft errors. Device simulations reveal that a simultaneous flip of redundant latches is suppressed by storing the opposite values instead of storing the same value due to its asymmetrical structure. The state of latches always becomes a specific value after a particle hit due to the bipolar effects. Spallation neutron irradiation proves that no MCU is observed in the D-FF arrays in which the stored values of latches are equivalent to the specific value. The redundant latch structure storing the opposite values is robust to the simultaneous flip.

The paper first explains the connotation of e-portfolio and the reason why introduce the e-portfolio to the distance Chinese language visualization teaching platform as the diagnostic service evaluation tool, and then designs the function modules of e-portfolio according to the function requirements analysis, finally explains the application of E-portfolio in Chinese learning and the evaluation process based on it.