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The emerging progress brought about by Industry 4.0 generates great opportunities for better decision making to cope with increasingly uncertain and complex industrial production. From the perspective of game theory, methods based on computational simulations and methods based on physical entities have their intrinsic drawbacks, such as partially accessible information, uncontrollable uncertainty and limitations of sample data. However, an insight that inspired us was that the digital twin modeling method induced interactive environments to allow decision makers to cooperatively learn from the immediate feedback from both cyberspace and physical spaces. To this end, a new decision-making method was put forward using game theory to autonomously ally the digital twin models in cyberspace with their physical counterparts in the real world. Firstly, the overall framework and basic formalization of the cooperative game-based decision making are presented, which used the negotiation objectives, alliance rules and negotiation strategy to ally the planning agents from the physical entities with the planning agents from the virtual simulations. Secondly, taking the assembly planning of large-scale composite skins as a proof of concept, a cooperative game prototype system was developed to marry the physical assembly-commissioning system with the virtual assembly-commissioning system. Finally, the experimental work clearly indicated that the coalitional game-based twinning method could make the decision making of composite assembly not only predictable but reliable and help to avoid stress concentration and secondary damage and achieve high-precision assembly. Obviously, this decision-making methodology that integrates the physical players and their digital twins into the game space can help them take full advantage of each other and make up for their intrinsic drawbacks, and it preliminarily demonstrates great potential to revolutionize the traditional decision-making methodology.

KOH electrochemical method and heating method were employed to modify fluorinated graphite and explore the modification mechanism. The chemical composition and microstructure of the products were characterized and analyzed before and after the reaction. As the electrochemical reaction time or heating temperature increased, the carbon fluorine bond gradually underwent a nucleophilic reaction with KOH according to its reactivity, promoting the formation of fluorine ions in the residual product and carbon oxygen bonds in the corresponding oxidized fluorinated graphite (OFG). The electrochemical method with the anode on the bottom and the heating method were insufficient to allow the isolated carbon fluorine bond to react, retaining some carbon fluorine bonds. By positioning the anode on top, electron transfer significantly accelerates the activation of the carbon fluorine bond, which then reacts completely. According to theoretical simulation calculations, electronegative groups around the carbon fluorine bond can effectively enhance its reactivity.

Carbon-based materials, as lightweight absorbers, have been widely applied in varied fields to counteract the adverse effects of electromagnetic waves. Nevertheless, there remain challenges in coping with the impairment of microwave absorption performance caused by the excessively high permittivity of carbon materials. Herein, carbonyl iron powder (CIP) was added to graphene oxide/carbon black (RGO-CB) composites to adjust the permittivity improving impedance matching and electromagnetic absorption properties. In this work, the RGO provides a three-dimensional structure net, which introduces circularly and variously electromagnetic loss interfaces within the RGO-CB/CIP composites. Owing to the unique architecture and synergy of the three components, the as-prepared absorber exhibits good impedance matching and gratifying microwave absorption properties. It was found that the 1:1 mixture of RGO-CB and CIP in the composite had superb impedance matching at the thicknesses of 2.6 and 2.7 mm to achieve complete X-band microwave absorption. Such excellent performance benefits from the multiple polarization provided by the heterogeneous interfaces and the ideal impedance match attributed to the tunable permeability and permittivity of this work.

As the world moves into the 21st century, the complex electromagnetic wave environment is receiving widespread attention due to its impact on human health, suggesting the critical importance of wearable absorbing materials. In this paper, graphene nonwoven (RGO/NW) composites were prepared by diffusely distributing graphene sheets in a polypropylene three-dimensional framework through Hummers’ method. Moreover, based on the Jaumann structural material design concept, the RGO/NW composite was designed as a multilayer microwave absorber, with self-recovery capability. It achieves effective absorption (reflection loss of −10 dB) in the 2~18 GHz electromagnetic wave frequency domain, exhibiting a larger bandwidth than that reported in the literature for absorbers of equivalent thickness. In addition, the rationally designed three-layer sample has an electromagnetic wave absorption of over 97% (reflection loss of −15 dB) of the bandwidth over 14 GHz. In addition, due to the physical and chemical stability of graphene and the deformation recovery ability of nonwoven fabric, the absorber also shows good deformation recovery ability and stable absorption performance. This broadband absorption and extreme environmental adaptability make this flexible absorber promising for various applications, especially for personnel wearable devices.

Honeycomb (HC) composites were fabricated by impregnating an aramid paper HC core with carbon nanotubes/carbon black/reduced graphene oxide (CNTs/CB/RGO) and polyurethane resin (PU). The sandwich HC (SHC) absorber containing HC composites with superior microwave-absorption properties were fabricated using the vacuum bagging method. Through the absorption performance of the SHC absorber, it can be concluded that the triple-layer SHC absorber has the best absorbing performance. The effective bandwidth (reflection loss < 10 dB) can be achieved in the entire frequency range of 2.2–18 GHz, and the minimum RL value is −35 dB. Furthermore, the compressive stress of the triple-layer SHC absorber reached 3.71 MPa, which is similar to the compressive stress of aluminum HC panels for aviation. Benefiting from the excellent integration of absorption and mechanical performance, the SHC has significant potential in the stealth-technology field.

In image-centric social networks, such as Instagram and Pinterest, users tend to share photos with several tags. These tags describe the content of the image or provide additional contextual information, and therefore may not be necessarily tied to image content and usually carry personal preference. Annotating images in social networks in a personalized manner is in demand. However, the existing image annotation models, which rely only on image content information, cannot capture the user's tagging preference. In this paper, we propose a deep architecture for personalized image annotation by leveraging the wealth of information in user's tagging history. The proposed architecture consists of three components: two components for learning features of the image content and user's history tags and the other one for combining the two learned features to predict the tags. We also explore two ways to model user's history tags: 1) simply average the embeddings of user's history tags and 2) model user's history tags with a sequence model by long short-term memory recurrent neural network. We evaluate our proposed deep architecture on a large-scale and realistic data set, consisting of ~22.8 million public images uploaded by ~4.69 million users. Experimental results show that our proposed deep architecture is effective on a personalized image annotation task.

A novel power and rate control system model for wireless communication networks is presented, which includes uncertainties, input constraints, and time-varying delays in both state and control input. A robust delay-dependent model predictive power and rate control method is proposed, and the state feedback control law is obtained by solving an optimization problem that is derived by using linear matrix inequality (LMI) techniques. Simulation results are given to illustrate the effectiveness of the proposed method.

The aircraft engine is considered the “heart” of the aircraft. The development of advanced aircraft engines focuses on achieving a high thrust-to-weight ratio，high efficiency，low fuel consumption，and extended operational life. High-temperature functional coatings，such as thermal barrier coatings（TBCs），thermal/environmental barrier composite coatings（T/EBCs），and high-temperature stealth coatings，are applied to critical hot-end components of aircraft engines. These coatings play a significant role in enhancing the service performance，operational life，safety and reliability of the engine. Taking TBCs，T/EBCs，and high-temperature stealth coatings as examples，this paper provides a systematic overview of recent research progress in the design of high-temperature functional coating materials，coating preparation science and technology，and coating performance evaluation and characterization，both domestically and internationally，with a specific focus on the advancements made at Beihang University. Furthermore，challenges and development trends faced by new high-temperature functional coatings of advanced aircraft engines in the future are also discussed. In the future，the research focus of advanced high-temperature functional coatings will shift toward multifunctional composite coatings，enhanced adaptability to extreme environments，and improved process compatibility.

Objective To analyze the clinical prognosis of high - grade aneurysmal subarachnoid hemorrhage (aSAH) patients with different amounts of hematoma. Methods A total of 211 patients with high - grade aSAH hospitalized in Norhern Jiangsu People's Hospital from September 2013 to December 2020 were included. According to the intracerebral hematoma volume, they were divided into non - hematoma group (n = 105), hematoma volume < 50 ml group (n = 69) and hematoma volume ≥ 50 ml group (n = 37). All of them underwent aneurysm clipping or embolization. The modified Rankin Scale (mRS) was used to evaluate the clinical prognosis 6 months after surgery. Results Among 211 cases, 139 (65.87%) underwent aneurysm clipping and 72 (34.12%) underwent aneurysm embolization. Except for 3 patients who failed to successfully clamp and underwent decompression with bone flap due to intraoperative malignant encephaloceles, the remaining 208 patients were successfully clipped, and no aneurysms ruptured and bled again after surgery. There were 58 patients (27.49%) with good prognosis, 59 patients (27.96%) with poor prognosis, and 94 patients (44.55%) with death. The difference in neurological function prognosis among the 3 groups was statistically significant (χ2 = 7.424, P = 0.024). Among them, the mortality rate in hematoma volume ≥ 50 ml group was higher than that in non-hematoma group (Z = - 2.655, P = 0.008). The incidence of complication was 95.73% (202/211) in all patients, including 95.24% (100/105) in non - hematoma group, 95.65% (66/69) in hematoma volume < 50 ml group, and 97.30% (36/37) in hematoma volume ≥ 50 ml group. The difference in complication among the 3 groups was not statistically significant (χ2 = 0.284, P = 0.867). Conclusions The prognosis of high - grade aSAH patients with intracerebral hematoma is poorer, especially in high-grade aSAH patients with hematoma volume ≥ 50 ml, and have a higher mortality rate.

Unmanned intelligent vehicles are exposed to high risks of network attack, hardware attack, operating system attack and software attack. They are susceptible to physical or remote security attacks, causing it to deviate from the delivery trajectory and fail the delivery task, or even be manipulated to disrupt normal operation of the factory. To address this problem, a dual-verified secure localization method for unmanned intelligent vehicles was proposed. The existing Wi-Fi network infrastructure was utilized by the vehicles for fingerprinting localization and a feature fusion strategy was designed to realize the dynamic fusion of Wi-Fi and magnetic field fingerprints. Multiple environmental monitoring points were deployed to collect the sound signals made by vehicles to calculate the position based on time difference of arrival and spatial segmentation method. Then the location reported by the vehicle was compared with the result of monitoring points for verification. Once an abnormal position was detected, an alert would be issued, ensuring the normal operation of the unmanned intelligent vehicles. The experimental results in the real indoor scenarios show that the proposed method can effectively track the positions of the target unmanned intelligent vehicle, and the positioning accuracy is better than existing benchmark algorithms.

To solve the problem of poor stability of additive flame retardant waterborne polyurethane， a series of waterborne polyurethane with flame retardant properties was synthesized by prepolymer method using aliphatic polyisocyanate， polyether polyol， and flame retardant phosphorus-containing polyol as raw materials. The flame retardant waterborne polyurethane was applied to the dipping process of microfiber synthetic leather base （microfiber base）. Its effects on the mechanics， quality， flame retardant， and thermal decomposition properties of microfiber base were discussed. The results show that with the increase of phosphorus-containing flame retardant polyol content， the combustion rate decreases from 115.00 mm/min to 60.79 mm/min， and the limiting oxygen index increases from 21.00% to 24.20%. After different concentrations of phosphorus-nitrogen flame retardants were sprayed on the surface of microfiber base， microfiber base appears self-extinguishing phenomenon during combustion， and the limiting oxygen index increases to 27.00%. Compared with the microfiber base without flame retardant treatment，the peak heat release rate and total heat release rate of the microfiber base after flame retardant treatment are reduced by 42.29% and 20.01%， respectively. The test analyses of SEM and Raman spectroscopy reveal that the graphitization degree of the carbon layer is improved and the surface structure becomes more compact after flame retardant finishing， suggesting that the flame retardant plays a crucial role by using the condensed phase flame retardant mechanism.

Objective Artistic atmosphere creation for the spatial scale, layout, shape, size and environment of metro station has great impact on passengers′ psychological and emotional effects. In order to improve passenger satisfaction, sublimate architectural functions, and show respect to users′ senses and spirits as well, it is necessary to explore the artistic construction of metro space based on the architectural environmental psychology. Method The characteristics of metro station underground space and its demand for artistic construction are analyzed in terms of the architectural environmental psychology. From the perspective of passengers′ real experience of the traditional station space and environment, the functional space and practical effect of metro space artistic construction is studied from the aspects of shape optimization, indoor and outdoor space interconnection, station light, environment color, sensory atmosphere creation and others in combination with actual design cases. Result & Conclusion The design method of artistic construction for metro station interior and exterior spaces should give full play to the advantages of multidisciplinary research and attach importance to the interaction between people and metro space environment, aiming to build "people-oriented" rail transit architectures in line with requirements of the times.