Strain engineering, a key enabling strategy for extending Moore’s law, employs controlled mechanical modulation to achieve desired modifications in material attributes, such as electrical and optical properties. Thanks to the atomic-level thinness, the optical behaviors of two-dimensional (2D) materials can be remarkably modulated by strain engineering. In this perspective, we highlight two mechanical approaches—tensile strain and compressive strain—and their impact on 2D materials’ crystal structure and electronic structure. We also discuss fundamental limitations in strain transfer efficiency and interfacial control, proposing a roadmap for achieving deterministic mechanical-optical modulation and pushing the limit of strain engineering in 2D materials.

This letter presents an ultrawideband (UWB), large-curvature, wing-borne conformal (WBC) phased array that simultaneously achieves dual-polarized (DP) endfire radiation and transition-band (TB) scattering grating lobes suppression (SGLS). First, the generation of the TB scattering grating lobe is analyzed, and an effective SGLS approach is developed by optimizing the inter-element spacing along the array arrangement. To achieve the horizontally polarized (HP) endfire radiation, a new dual-element endfire (DEE) conformal array arrangement is proposed, utilizing only two broadside-radiated tightly coupled dipoles per unit cell. Based on the SGLS-driven inter-element spacing and the DEE arrangement, the HP conformal dipole is constructed accordingly. Furthermore, novel resistive overlapping ladder rings (ROLRs) are integrated into the HP conformal dipoles to mitigate the severe low-frequency impedance mismatch induced by the large curvature wing-borne skin (approximately 160 m-1). To validate this design, a 1×7 array prototype is fabricated and measured. Experimental results demonstrate operation from 0.4 to 2 GHz with a ±60° azimuth scan range, DP endfire radiation, and effective SGLS over the 2–3 GHz transition band.

This communication proposes a novel 3-D-printing wideband dual-polarized circumferentially foldable Luneburg lens (LL) antenna. The proposed LL is stratified into three layers. Specifically, to balance foldability and radiation performance, the innermost layer consists of a dielectric sphere with a radially drilled air-filled conical hole, while the other two layers are composed of arc-shaped dielectric sheets that are curved in sinusoidal regulation. The design of the foldable LL is guided by effective medium theories. A wide-band ridged horn antenna is used to feed the lens. The foldable LL antenna is fabricated using 3-D printing technology. The measured results show that, in the unfolded state, the peak gain varies from 14.7 to 19.8 dB across the frequency band of 6-11.4 GHz, and the aperture efficiency varies between 34.3% and 94.1%. The proposed foldable lens antenna can scan up to +/- 90 degrees in all planes, with the maximum scanning gain loss less than 1.7 dB across the operating band. More importantly, the thickness of this lens in the folded state is only 34% of that in the unfolded state.

This article presents an ultrawideband (UWB), wide-scanning, vertically polarized endfire phased linear array with a customized feeding network, specifically designed for the large-curvature wing-borne conformal (LC-WBC) skin across the P-L band. First, the mechanism for achieving a high-gain endfire beam is analyzed under the stringent spatial constraints of the skin. To maximize space utilization and form an endfire beam, ultralow-profile ferrite-loaded tightly coupled dipoles are strategically integrated on both the upper and lower sides of the wing-borne skin. Then, a novel wingtip-connected dipole element arrangement is proposed to obtain enhanced vertically polarized radiation by ensuring continuous current distributions on the array aperture. In addition, this arrangement effectively resolves the intersecting beam problems caused by the skin's large curvature (159 m(-1)) while simplifying the ground plane to a triangular-shaped configuration. Finally, a compact 3-D multifunctional feeding network is developed and fully integrated with the array to achieve a customized phase excitation, thereby generating the desired high-gain endfire beam in the azimuth planes. To validate this design, a 1x8 prototype is fabricated and measured. Experimental results show that the proposed array is capable of scanning within a +/- 60 degrees azimuth range from 0.28 to 1.96 GHz, and the average aperture efficiency is approximately 72.5% at broadside and 88.5% at 60 degrees scan angle, confirming its superior performance and potential for applications in aircraft platforms.

The Job Shop Scheduling Problem (JSP) is one of the typical combinatorial optimization challenges, and has been a hot and difficult topic in academic research since the 1950s. In recent years, due to the extensive application of shop scheduling problem and its inherent complexity, intelligent optimization algorithm has become an important means for solving and optimizing shop scheduling problem, with genetic algorithm being widely used in solving shop scheduling problem. Focusing on the shortcomings of genetic algorithm, this paper proposes an improved isolated niche genetic algorithm to solve the shop scheduling problem. Through simulation experiments, the superiority of the new algorithm is verified.

Against the backdrop of electromagnetic space integration, the radio system of equipment platforms, such as next-generation aircraft, must possess multifunctional integration and electromagnetic stealth performance. Meanwhile, the equipment platforms need to evolve towards flat structures. These requirements pose significant technical challenges for antenna system design. The antenna must possess ultra-wideband to facilitate multi-function integration through the use of continuous radio frequency synthetic aperture. In order to ensure good aerodynamics of the flat airborne platform, it is required to implement conformal design, while the ultra-low profile is the greatest challenge in conformal design. Against this background, this work proposes a novel airborne tightly coupled antenna with an ultra-low profile, ultra-wideband and vertical-polarized omnidirectional radiation. The antenna unit utilizes a long slot structure and implements circular conformal designs, where the resistive frequency selection surface is used to expand the operating bandwidth. This antenna has a profile height of only 0.047 times the low-frequency wavelength. Simulation and measurement results show that it achieves an impedance bandwidth of nearly 12:1 with omnidirectional beam coverage, which meets the requirements of multifunctional future airborne antennas.

The scattering reduction of wideband and wide-scanning angle conformal array is urgently demand and still a significant challenge. Toward this end, a wideband low-profile cylindrically conformal tightly coupled antenna array (TCAA) with low-scattering characteristics is designed in this paper. Based on the scattering cancelation principle, the performance of wideband low-scattering is achieved by the fully use of two different types of tightly coupled antenna elements (TCAEs) arranged in a chessboard-like. The two types of array elements are carefully designed to have similar radiation performances and required reflection phases. Moreover, to accurately measure the scattering performance of the proposed conformal array, a low-scattering metal oliva carrier is designed to embed the RF testing cables and matching loads. Finally, a 10 x 10 conformal array prototype is developed, fabricated and tested. The simulated and measured results show that the proposed conformal array prototype works from 6 GHz to 18 GHz with a scanning range of +/- 60 degrees in E-plane and +/- 45 degrees in H-plane, while it also achieves about 13 dB monostatic scattering cross section (SCS) reduction across a wide frequency band of 6 similar to 18 GHz as compared with a reference array.

The resonant cavity method is a commonly used method for high-temperature testing of the complex permittivity of dielectric materials. When a resonant cavity is used for high-temperature testing, the microwave surface resistance of the cavity metal material will deteriorate due to factors such as oxidation reaction and thermal fatigue, resulting in a decrease in testing accuracy and repeatability. Therefore, when designing a high-temperature resonant cavity, the temperature response characteristics of the microwave surface resistance of the cavity metal material should be obtained in advance. In this paper, a high-temperature measurement method of microwave surface resistance of metal materials based on a separate cylindrical resonator is proposed, a mathematical model of microwave surface resistance inversion based on the resonator quality factor is established, and a high-temperature measurement system of microwave surface resistance is integrated. The reliability of the proposed method and system is verified through simulation and experiment. The measurement frequency covers 7-18 GHz, and the maximum test temperature reaches 500°C. Systematic error of microwave surface resistance measurement at room temperature is less than 3%.

A theoretical treatment of frustrated total internal reflection (FTIR) of ultrasonic waves is presented and validated against experimental data. Two different methods are used to derive theoretical models capable of studying transmission of ultrasonic waves through a fluid-coupled elastic plate. First, a multiple reflections approach is used and shown to be inadequate for incident angles beyond the first critical angle. After that, a potentials-based model provided accurate predictions for a thin air-coupled steel sheet. The model helped forge a relation between the transmitted power and the dispersion curves for guided waves in the plate, highlighting the two fundamental causes of FTIR in such systems. The first one is that a thin plate, when compared to the wavelength of the incident wave, will always be subjected to FTIR, as the evanescent wave can never assume negligible values. But more surprisingly, the excitation of the fundamental antisymmetric mode 𝐴0 of the plate is directly related to FTIR for thicker plates.

Generation of realistic all-atom configurations of crosslinked polymer systems is a difficult task which so far has mainly been tackled using either closed-source software or bespoke, highly user-intensive efforts. In this work, we present a robust, open-source Python package HTPolyNet designed to generate polymerized and/or crosslinked all-atom systems using only input monomer structures and a description of the polymerization chemistry. HTPolyNet works with the popular GROMACS molecular dynamics package and the General Amber Force Field. In addition to describing the structure and usage of HTPolyNet we also demonstrate its application to two distinct systems: a vinyl-ester based resin and an epoxy-amine resin, both of which form dense, amorphous network systems.

Aiming at the coupling of energy consumption and completion time in flexible job-shop scheduling, this paper took makespan and energy consumption as the optimization objectives, established a scheduling model, and proposed a scheduling strategy based on improved genetic algorithm. Firstly, a hybrid initialization method based on global minimum completion time selection and global minimum workload selection is introduced to generate the initial population, and the scale of the initial population is expanded to increase the diversity of the population; Secondly, the generation method of offspring individuals is improved, grouped according to the non-dominated ranking level and crowding degree of individuals in the population, and the self-contained individuals are generated by performing crossover and mutation, neighborhood search simulated annealing and reverse learning crossover mutation operations respectively. Finally, an improved adaptive crossover and mutation operation based on individual similarity is proposed, which is applied to the algorithm to improve the search ability of the algorithm. Relevant experimental results show that the proposed adaptive genetic algorithm based on individual similarity is feasible and effective in flexible job-shop scheduling.

Multiobjective flexible workshop scheduling is an important subject to improve resource utilization and production efficiency and enhance the competitiveness of enterprises. As the situation of resource constraints becomes more and more severe, the problem of companies rationally allocating limited resources in production is becoming more and more serious. Today, the manufacturing industry widely adopts advanced manufacturing modes such as computer-integrated manufacturing and intelligent manufacturing, but in these semi-intelligent manufacturing modes with a high degree of uncertainty and a high degree of personnel dependence, it is difficult to adapt to the work of large-scale production. Therefore, suitable clustering algorithms are urgently needed to help solve these problems, and this paper selects a clustering algorithm based on the genetic simulation annealing algorithm. This article is aimed at studying the problem of efficiency improvement in the production process of large-scale manufacturing and at finding a stronger and more effective production mode for the manufacturing industry. Firstly, this paper introduces the basic principles of simulated annealing genetic algorithm and regularized clustering algorithm. These algorithms have excellent performance in searching for global optimal solutions. They can be constantly tested and computed to keep the calculation results close to the global optimal solution. In this paper, the K-means clustering algorithm is used to select the shortest completion time to represent the clustering target. According to the minimum distance principle, the machine, workpiece, and other objects are input into the clustering of the algorithm, and the K-means algorithm will send out the sorting plan. Therefore, a multiobjective flexible job shop scheduling model based on genetic simulated annealing algorithm and clustering algorithm is established. Then, by using hypothetical production data to simulate the operation of the workshop, the scheduling model was applied to conduct a deduction and empirical comparative study. The experimental results showed that the model shortened the completion time of the workpiece by 4.4% and increased the average load rate of the machine by 10%.

This work presents an investigation on the application of scattering cross section (SCS) reduction by four-dimensional (4-D) antenna arrays. The scattering fields of 4-D arrays are approximately deduced based on the scattering pattern multiplication theory. In addition, the definition of SCS of 4-D arrays is also formulated in consideration of the hostile receiver bandwidth. Finally, a 32-element microstrip patch linear array is utilized to access the practicality for scattering reduction by 4-D arrays combined with the optimization algorithm. Numerical examples confirm that the bistatic SCS of the 4-D array is considerably reduced as compared to that of the reference array by optimizing time sequences.

In this paper, a low profile frequency selective surface (FSS) by loading lumped inductors is proposed to exhibit wideband property. Firstly, according to the equivalent circuit parameters of multi-layer FSS with non-resonant elements, the necessity of loading the lumped inductors under the condition of limited size is analyzed. Then, the complete design procedure that combining lumped inductors and multilayer FSS is given. It is found from the results of full-wave simulation and equivalent circuit simulation that the designed FSS has a transmission pole and multiple transmission zeros, thus showing wide bandwidth FSS characteristics.

A Compact, Low Profile Log-Periodic Monopole Array with an ultra-wideband stripline transition is proposed in this paper. It consists of 7 top hat loaded monopole elements, which ensures the whole structure to be compact and low profile. The ultra-wideband stripline transition is used to keep the consistence between feeding direction and antenna radiation direction. The proposed antenna has an extremely low profile of 0.043$\lambda_{L}$, and a compact size of 0.60 $\lambda_{L}$×0.16$\lambda_{L}$ in transverse dimension, ($\lambda_{L}$ is the free-space wavelength at the b west operating frequency). Simulation results shows that from 0.6-3.1 GHz (135%) in terms of VSWR <3 and max gain of 6.5dBi is obtained.

With the development of LBSN, more and more attention has been paid to constructing interest point recommendation based on historical data of interest points, and there are many algorithms to predict and analyze interest points. However, in the traditional POI recommendation system, the user's information selection is not focused, which leads to the poor utilization of user data. To solve this problem, this paper improves the existing POI recommendation algorithm DAN-SNR, and constructs a new POI recommendation algorithm model MG-DAN-SNR based on deep neural network. The simulation experiment on Foursquare data set shows that the improved model has a significant improvement in the evaluation index, and can better recommend for users.

In recent years, there are increasing interests and applications on radar–communication integration for system miniaturization, cost reduction, and so on. Moreover, thanks to the common functions of hardware components including transceiver, antennas, and even basic signal/data processing, the integrated design of radar and communication systems becomes feasible. In this article, through design of proper time sequences, waveforms, and recognition algorithms, radar sensing and wireless communication can be integrated into 4-D antenna arrays simultaneously. In addition, with the high design degrees of freedom of 4-D arrays, the proposed approach can also provide a low probability of intercept capability. Selected numerical and experimental results are provided to validate the effectiveness of the proposed approach.

In this study, cemented paste backfill (CPB) specimens comprising tantalum-niobium ore tailings and rocks, with various cement-tailings (C/T) ratios of 1:4, 1:8, and 1:10, were evaluated to elucidate the mechanism of synergistic deformation via uniaxial compression tests. The results indicate that the overall strength of the composite body is similar to that of the single CPB specimen. The elastic modulus of the composite body increases as the strength ratio of the two specimens decreases. The strength of the two specimens in the composite body the larger the ratio, the larger the Poisson's ratio of the backfill specimen, but the smaller the Poisson's ratio of the rock specimen. The stress-strain curve of the composite body is similar to that for the single CPB specimen; it can be divided into four stages. This curve indicates that the failure mode primarily manifests as shear and tensile failures in the CPB specimen. For the composite body, the strain of the backfill is significantly larger than that of the rock. However, the deformation in these two materials exhibits good synergy; only limited hysteresis is observed in the change time. During the loading process, the assembly exhibits different acoustic emission (AE) activities for the four stages. The AE ringing count produced by the CPB is significantly higher than that of the corresponding rock when the intensity ratio of the two specimens in the assembly increases. This trend becomes more obvious with an increase in the strength ratio of the two specimens in the composite body. The peak stress of the combined body lags behind the peak of the ringing counts, and the AE characteristics of the combined body reflect the synergy of the failure of the two specimens. The results of the study can provide a reliable theoretical basis and technical reference for the design of structural parameters of infill mining.

Distributed system has attracted more and more attention, and the process migration and implementation in distributed system based on genetic algorithm is the current research hotspot.The process migration function is indispensable for the distributed system to obtain good load balance, high communication performance, high availability and other characteristics.The purpose of this paper is to study the process migration and implementation in distributed system based on genetic algorithm.In the experiment, the experimental environment is established, and the genetic algorithm is used.The experimental results show that the performance of the genetic algorithm is a certain performance improvement compared with ordinary algorithms.Its final completion time is better than the ordinary algorithm.Compared with that, it has a certain improvement and it can provide better system throughput with greater throughput.