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In this study, a frequency-selective rasorber with a tunable passband and two absorptive bands is presented. It is designed using two active FSSs, an absorptive FSS realized with tripole elements, and a lossless bandpass FSS achieved with ring slots. Both active FSSs embedded with varactors realize the shift of transmission frequency bands by controlling the bias voltage of the feed network. The working principle is briefly investigated according to an equivalent circuit model. A prototype is fabricated and measured to verify the simulated results, which show that a passband is tuned from 3 to 4.78 GHz between two absorptive bands, and the maximum band of |S11

A dual-polarization frequency-selective structure with a tunable passband and two absorptive bands is presented. Based on an equivalent circuit model (ECM), the working principle is investigated first. The values of components in the ECM are derived from the required performances and are mapped to the structure of an initial design, which is designed by cascading of an absorptive frequency-selective surface (FSS) realized with dipole-like elements and a lossless bandpass FSS achieved with square ring slot. For tuning the passband, varactors and biasing networks are added into the initial design. The adding of the varactors and biasing networks significantly affects the performance, and brings about the emergence of singular resonances. The approaches for mitigating the effects and the techniques for suppressing the singular resonances are proposed. Simulated results show that, between two absorptive bands, a passband is tuned from 3.33 to 5.13 GHz if the capacitances are decreased from 0.5 to 0.15 pF. A prototype is fabricated and measured. Measured results show that the passband is altered from 3.56 to 4.35 GHz as the reverse bias voltage of the used varactors is increased from 6 to 18 V.

This paper studies a common planning problem encountered in steelmaking production. The problem is to group different customer orders into a set of batches to accommodate the mass production mode o...

In this paper, we present a novel support vector machine learning method for multi-label classification in the steelmaking process. The steelmaking process involves complicated physicochemical reactions. The end-point temperature is the key to the steelmaking process. According to the initial furnace condition information, the end-point temperature can be predicted using a data-driven method. Based on the setting value of the temperature before tapping, multi-scale predicted errors of the end-point temperature can be calculated and divided into different ranges. The quality evaluation problem can be attributed to the multi-label classification problem of molten steel quality. To solve the classification problem, considering that it is difficult to capture nonlinear relationships between the input and output in linear models, we propose a novel support vector machine with robust low-rank learning, which has the characteristics of class imbalance without label correlations; a low-rank constraint is used to deal with high-order label correlations in low-dimensional space. Furthermore, we derive an accelerated proximal gradient algorithm and then extend it to handle the nonlinear multi-label classifiers. To validate the proposed model, experiments are conducted with real data from a practical steelmaking problem. The results show that the proposed model can effectively solve the multi-label classification problem in industrial production. To evaluate the proposed approach as a general classification approach, we test it on multi-label classification benchmark datasets. The results illustrate that the proposed approach performs better than other state-of-the-art approaches across different scenarios.

To reduce logistics scheduling costs and energy consumption, this paper studies the slab allocation and hot-rolling scheduling integrated optimization problem that arises in practical iron and steel enterprises. In this problem, slabs are first allocated to orders and then sent to heating furnaces for heating; then, they are sent to a hot-rolling mill for rolling. A 0–1 integer programming model is established to minimize the attribute difference in the allocation cost between slabs and orders, the switching cost of hot-rolling processing, and waiting times after slabs reach rolling mills. Given the problem’s characteristics, an improved differential evolution algorithm using a real-number coding method is designed to solve it. Three different heuristic algorithms are proposed to improve the quality of solutions in the initial population. Multiple parent individuals participate in the mutation operation, which increases the population diversity and prevents the algorithm from falling into the local optimum prematurely. Experiments on 14 sets of real production data from a large domestic iron and steel plant show that our improved differential evolution algorithm generates significantly better solutions in a reasonable amount of time compared with CPLEX, the simulated artificial method, and the classical differential evolution algorithm, and it can be used by practitioners.

A novel mechanically tunable frequency selective surface (FSS) based on a sliding 3D-printed inserted dielectric is presented in this paper. This paper first introduces the working mechanism of the tunable FSS, which indicates that the variable capacitance is the key to tunability. Based on this, we design an all-metal bandpass FSS with a certain thickness and a matching cross-shaped inserted dielectric. By changing the insertion depth of the dielectric, the resonance frequency can be adjusted. To optimize the performance, an improved structure based on a hollow support and a tripole slot is proposed. A tunable range from 3.24 to 5.52 GHz (53%) and good angular stability is obtained in the simulation. To verify this idea, we fabricate a cross slot prototype by 3D printing and mechanical engraving. Measured results show that this prototype has a continuous tunable range of 3.61 to 5.89 GHz (34.4%).

As "a new frontier in evolutionary computation research", evolutionary transfer optimization(ETO) will overcome the traditional paradigm of zero reuse of related experience and knowledge from solved past problems in researches of evolutionary computation. In scheduling applications via ETO, a quite appealing and highly competitive framework "meeting" between them could be formed for both intelligent scheduling and green scheduling, especially for international pledge of "carbon neutrality" from China. To the best of our knowledge, our paper on scheduling here, serves as the 1st work of a class of ETO frameworks when multiobjective optimization problem "meets" single-objective optimization problems in discrete case (not multitasking optimization). More specifically, key knowledge conveyed for industrial applications, like positional building blocks with genetic algorithm based settings, could be used via the new core transfer mechanism and learning techniques for permutation flow shop scheduling problem(PFSP). Extensive studies on well-studied benchmarks validate firm effectiveness and great universality of our proposed ETO-PFSP framework empirically. Our investigations (1) enrich the ETO frameworks, (2) contribute to the classical and fundamental theory of building block for genetic algorithms and memetic algorithms, and (3) head towards the paradigm shift of evolutionary scheduling via learning by proposal and practice of paradigm of "knowledge and building-block based scheduling" (KAB2S) for "industrial intelligence" in China., For improvement

This study presents a planar single-layer metasurface, with tri-band 10 dB radar cross-section (RCS) reduction under normal incidence for both polarisations, by employing optimised multi-element phase cancellation. The designed artificial magnetic conductor (AMC) unit cell is composed of an upper metal structure, a dielectric layer, and a bottom metal ground. When the dielectric constant and thickness of the substrate are fixed, regardless of any upper structure, the reflection coefficients of AMC are the same as the perfect electric conductor (PEC) at the short-circuit frequencies. Taking into account the multiple reduction bands that avoid short-circuit frequencies, a RCS reduction surface with a large frequency ratio is achieved. The optimised planar metasurface obtains 10 dB RCS reduction in the tri-band frequency (3.81–7.33, 19.16–22.83, and 35.63–38.37 GHz) with bandwidths of 63, 17, and 7.4%, respectively. Moreover, the bistatic scattering patterns between the proposed surface and the equal-sized PEC are investigated. The theoretically predicted, simulated, and measured results are in good agreement and provide a new strategy for achieving multi-band RCS reduction.

A dual-polarization frequency-selective rasorber (FSR) with two absorptive bands at both sides of a passband is presented. Based on the characteristic mode analysis, a circuit analog absorber is designed using a lossy frequency-selective surface (FSS) that consists of miniaturized meander lines and lumped resistors. The positions and values of resistors are determined according to the analysis of modal significances and modal current. After that, the presented rasorber is designed by cascading of the lossy FSS and a lossless bandpass FSS. Equivalent circuits of the FSR are modeled, and surface current distributions of both FSSs are illustrated to explain the operation mechanism. Measurement results show that, under the normal incidence, a minimum insertion loss of 0.27 dB is achieved at a passband around 6 GHz, and the absorption bands with an absorption rate higher than 80% are 2.5–4.6 GHz in the lower band and 7.7–12 GHz in the higher band, respectively. Our results exhibit good agreements between measurements and simulations.

© 2020, © 2020 Informa UK Limited, trading as Taylor & Francis Group. This paper investigates an integrated batching and scheduling problem of electrolysis and caster in aluminium industry. The problem is to determine the assignment and scheduling of orders considering sequence-dependent setup times caused by technological and operational constraints of electrolysis cells, and determine the batching and scheduling of orders in the following casters. A novel unit-specific event-based continuous-time mixed integer linear programming model (MILP) is proposed to describe the problem. In this model, the event point is stage specific, and lower bounds are specified to tighten the model. A hybrid pointer-based differential evolution algorithm with new individual representation scheme is designed to solve the problem of industrial scale. An improved hybrid pointer-based mutation operator and a new point-cross crossover operator are proposed to enhance the performance of the algorithm. Computational experiments show that the proposed algorithm is more efficient when compared with CPLEX for medium and large size instances. Comparisons with the lower bound demonstrate that the algorithm is effective.

A prismatic conformal metasurface, based on optimized multielement phase cancellation, is proposed for wideband radar cross-sectional (RCS) reduction. The metasurface is composed of 35 lattices located in seven zones of a prismatic structure. The lattices in different zones are simulated under corresponding incident angles and taken into account the difference of wave path caused by the bending of the conformal structure. The interactions between multiple backscattered waves produced by the lattices are manipulated and optimized simultaneously by the hybrid array pattern synthesis and particle swarm optimization to achieve wideband destructive interference. The proposed metasurface can realize a 10 dB reduction in backscattered RCS under normal incidence for HH polarization from 9.6 to 10.6 GHz and 11.7 to 17.7 GHz with the fractional bandwidths of 9.9% and 40.8%, respectively. The theoretical analysis, simulated, and measured results are in a good agreement. The proposed approach verifies the innovation and effectiveness in achieving wideband RCS reduction for conformal metasurface.

In this work, we used a ternary blend strategy to improve the photovoltaic performance of organic solar cells (OSCs). PBDB-T:IDT-EDOT-based binary blend devices show a power conversion efficiency (PCE) of 9.93%, and the ternary devices with PC71BM as the third component exhibit a PCE of 12.07% with simultaneously enhanced Voc, Jsc and FF. The broadened absorption, optimized morphology and balanced charge carrier mobility of these devices are responsible for these improvements. The introduction of PC71BM can disperse the IDT-EDOT aggregates, enhance the phase purity, and increase the electroluminescence quantum efficiency (EQEEL). Furthermore, the performance of the ternary devices is not very sensitive to the weight ratio of the two acceptors. PCEs of over 11% are obtained even though the composition gradually varies from 1 : 1 : 0.2 to 1 : 0.4 : 0.8. Our results demonstrate that PC71BM is a highly promising second acceptor for the construction of high-efficiency ternary OSCs.

An optical transparent metasurface for dual-band Wi-Fi shielding is presented in this paper. The unit cell of the proposed metasurface is composed of a hexagonal ring and a three-petal oval flower which resonate at 2.4 and 5.5 GHz, respectively. The corresponding equivalent circuit is modelled to better understand the physical phenomena of electromagnetic shielding. Based on transmission line theory and curve fitting technique, a convenient and efficient method for extracting permittivity of substrate is presented. Simulation results show that the proposed metasurface is insensitive to the polarization of incoming wave under normal incidence and offers excellent angular stability. For verifying the design, two prototypes are fabricated using different manufacturing technologies, flexible printed circuit and ink-jet printing of silver nano-particles. The measured results are in good agreement with the simulated ones. The proposed metasurface has potential applications of electromagnetic wave suppression and information security in indoor environments.

Single-objective to multi-objective/many-objective optimization (SMO) is a new paradigm in the evolutionary transfer optimization (ETO), since there are only “1 + 4” pioneering works on SMOs so far, that is, “1” is continuous and is firstly performed by Professors L. Feng and H.D. Wang, and “4” are firstly proposed by our group for discrete cases. As a new computational paradigm, theoretical insights into SMOs are relatively rare now. Therefore, we present a proposal on the fine brushworks of SMOs for theoretical advances here, which is based on a case study of a permutation flow shop scheduling problem (PFSP) in manufacturing systems via lenses of building blocks, transferring gaps, auxiliary task and asynchronous rhythms. The empirical studies on well-studied benchmarks enrich the rough strokes of SMOs and guide future designs and practices in ETO based manufacturing scheduling, and even ETO based evolutionary processes for engineering optimization in other cases.

In this work, an ultrawideband and high-efficient polarization conversion metasurface (PCM) is proposed, which can efficiently convert linearly polarized waves into cross-polarized waves in an ultra-wide frequency range. The unit cell of the proposed PCM is composed of two pairs of L-shaped metallic patches covered by a dielectric superstrate and an air-based substrate attached with a metallic ground. The PCM has an operating band from 3.37 to 22.07 GHz with the polarization conversion ratio (PCR) over 90% under the normal incidence, which the ratio bandwidth (fH/fL) is 6.5:1. The PCR can achieve 100% at seven resonant frequencies. The equivalent circuit model is analyzed to explain the fundamental cause of the PCM’s multi-resonance and polarization conversion behaviors. In addition, all possible near-field interactions among the resonator, the superstrate, and the ground sheet can be accurately calculated using interference theory, which reveals the underlying physical mechanisms of the multi-resonance metasurface. The theoretical calculated, numerically simulated, and measured results are in good agreement. Compared to other PCMs, the proposed PCM has a simple geometry structure but an ultrawideband and high PCR property.

Recently, R. M. H. Bilal et al. proposed a wideband microwave absorber based on metallic split-ring resonators and an E-shaped fractal structure. It is found that the reflection components of high-order modes are very large but have been neglected by the authors. Our results show that the actual absorptivity is much lower than the reported one if the reflection components of high-order modes are taken into consideration. The simulation results prove that the proposed structure is not an effective absorber.

Recently, R. M. H. Bilal et al. proposed a wideband microwave absorber based on metallic split-ring resonators and an E-shaped fractal structure. It is found that the reflection components of high-order modes are very large but have been neglected by the authors. Our results show that the actual absorptivity is much lower than the reported one if the reflection components of high-order modes are taken into consideration. The simulation results prove that the proposed structure is not an effective absorber.

Non-fullerene fused-ring electron acceptors boost the power conversion efficiency of organic solar cells, but they suffer from high synthetic cost and low yield. Here, we show a series of low-cost noncovalently fused-ring electron acceptors, which consist of a ladder-like core locked by noncovalent sulfur–oxygen interactions and flanked by two dicyanoindanone electron-withdrawing groups. Compared with that of similar but unfused acceptor, the presence of ladder-like structure markedly broadens the absorption to the near-infrared region. In addition, the use of intramolecular noncovalent interactions avoids the tedious synthesis of covalently fused-ring structures and markedly lowers the synthetic cost. The optimized solar cells displayed an outstanding efficiency of 13.24%. More importantly, solar cells based on these acceptors demonstrate very low non-radiative energy losses. This research demonstrates that low-cost noncovalently fused-ring electron acceptors are promising to achieve high-efficiency organic solar cells., Recently, the non-fullerene acceptors with fused rings enable high-efficiency organic solar cells but they are not ideal in terms of synthetic cost and yield. Here, Huang et al. report ‘less fused’ acceptors with non-covalent S⋅⋅⋅O interactions and solar cell efficiency of up to 13%.

This letter presents an absorptive/transmissive frequency selective surface (ATFSS) with wide absorption bands at both sides of a passband. A double-layer structure consisting of a lossy FSS and a lossless FSS was employed. The lossy and lossless FSSs were designed based on tripole loops and tripole slots, respectively. The tripole loops and slots were constructed as a hexagonal periodic structure. The tripole loops equated to a series-parallel circuit and exhibited lossy feature after they were loaded with lumped resistors, which were used to absorb the incident wave at lower and upper absorption bands. Surface current distributions were illustrated to explain the operation mechanism. A prototype of the proposed ATFSS was fabricated and measured. Our results showed good agreement between measurements and simulations. Measurement results showed that a passband with a center frequency of 5 GHz and a minimum insertion loss of 0.35 dB was obtained. Out of the passband, absorption rates higher than 80% were obtained at a lower absorption band, from 2.66 to 4.5 GHz, and at a higher absorption band, from 5.66 to 8.56 GHz.

Order management is a critical and complicated issue in the production process of iron and steel industry, since orders are the bridge between customers and semi-finished/final products in different units. Usually, the scheduling of orders is arranged by skilled planners. However, the initial scheduling may be infeasible during the production process due to the dynamic and frequent variation of production environment. This paper investigates a practical order rescheduling problem to adapt various changes that affect the normal production. The problem is formulated as a mixed integer programming mathematical model considering the original objective, the deviation from the initial scheduling and the equilibrium of production capacity. A discrete differential evolution algorithm with new mutation and crossover operators is proposed to find near-optimal solutions of this problem. Computational experiments are presented on both randomly generated instances and the instances from the practical production. Experimental results illustrate that the proposed algorithm could obtain better solutions compared with four standard differential evolution algorithms and the manual method. Furthermore, a production data based practical decision support system embedding the model and algorithm is developed to monitor the production process, diagnose whether there are high-impact changes of the orders and units, and make rescheduling decisions if necessary.

This paper presents an active frequency selective surface (AFSS) with a wide reconfigurable passband. The tuning mechanism was investigated with an equivalent circuit which consists of a parallel L-C resonant circuit and a series L-C resonant circuit. A cross-loop slot was selected as a unit cell, and varactor diodes were added across the slot to tune the passband. The effects of various bias configurations on the transmission coefficients were studied. The simulation results showed that a reconfigurable passband ranged from 2.92 to 5.74 GHz was obtained with a variable capacitance from 0.8 to 0.1 pF. A prototype of the proposed AFSS was fabricated and measured. The measurement results showed that the passband was altered from 2.94 to 5.66 GHz if the biasing voltage of varactor diodes was increased from 4 to 18V. The measurement and simulation results agree well with each other.

An absorptive/transmissive frequency selective surface (ATFSS) with absorption bands at both sides of a passband is presented. Equivalent circuits of the ATFSS that consists of a lossy frequency selective surface (FSS) and a lossless FSS were modeled. To improve the rejection at an undesired band, a transmission zero was introduced and controlled by loading the lossless FSS with four-legged loaded slots. The parasitic passband was suppressed when the cross structure in the lossless FSS was loaded with resistance. In order to expand the absorption band, loaded dipoles were utilized for the lossy FSS design. An ATFSS with wide absorption bands was realized after three ATFSSs with different performances were investigated. The proposed ATFSS was fabricated and measured. The measurement results showed that a passband at around 5 GHz with a minimum insertion loss of 0.92 dB was obtained. Within an ultrawide band from 2.8 to 11.4 GHz with |S11

Two mutually isomeric noncovalently fused-ring electron acceptors (NC-FREAs) NOC6F-1 and NOC6F-2 containing two cyclopentadithiophene (CPDT) moieties linked at the 2,6- and 1,5-positions, respectively, of the naphthalene ring were designed and synthesized for organic solar cells (OSCs). Intramolecular noncovalent S⋯O interactions were introduced into NOC6F-1 and NOC6F-2. The tiny structural variation in NOC6F-1 and NOC6F-2 by just changing the linkage positions affects largely their molecular configuration, absorption, molecular packing, charge transport and photovoltaic performance. Compared to NOC6F-2, NOC6F-1 exhibits smaller distortions between cyclopentadithiophene and the naphthalene unit, leading to an extended conjugation and enhanced π–π stacking. NOC6F-2 exhibits a poor planarity, which restricts the electron delocalization as well as dense π–π stacking in the film form. When blended with PBDB-T, NOC6F-1 exhibits more orderly stacking along both the out-of-plane and in-plane directions than NOC6F-2. OSCs based on PBDB-T:NOC6F-2 merely showed a power conversion efficiency (PCE) of 6.74% with lower Jsc and FF values. OSCs based on NOC6F-1 achieved a higher Jsc of 17.08 mA cm−2 and an FF of 65.79%, thus leading to a significantly enhanced PCE of 10.62%. These results indicate that use of the acceptor molecules with a planar molecular backbone is an important design strategy for NC-FREAs.

Recently, due to the growth in machine learning and data mining, for scheduling applications in China’s industrial intelligence, we are quite fortunate to witness a paradigm of evolutionary scheduling via learning, which includes a new tool of evolutionary transfer optimization (ETO). As a new subset in ETO, single-objective to multi-objective/many-objective optimization (SMO) acts as a powerful, abstract and general framework with wide industrial applications like shop scheduling and vehicle routing. In this paper, we focus on the general mechanism of selection that selects or gathers elite and high potential solutions towards gathering/transferring strength from single-objective problems, or gathering/transferring storms of knowledge from solved tasks. Extensive studies in vehicle routing problems with time windows (VRPTW) on well-studied benchmarks validate the great universality of the SMO framework. Our investigations (1) contribute to a deep understanding of SMO, (2) enrich the classical and fundamental theory of building blocks for genetic algorithms and memetic algorithms, and (3) provide a completive and potential solution for VRPTW.

This paper presents a frequency-selective rasorber which has two absorption bands on the both sides of a tunable passband. An original rasorber with fixed-passband is designed by cascading of an absorptive frequency-selective surface (FSS) and a lossless bandpass FSS. The absorptive FSS is realized with tripole elements and the lossless bandpass FSS is achieved with tripole ring slot. Varactors and biasing networks are inserted for tuning the passband. The simulated results show that the center frequency of passband is altered from 4.5 to 6 GHz with the capacitance of varactors changing from 0.2 to 0 pF. The frequency-selective rasorber with a fixed-passband is fabricated and measured to verify the design.

Based on the characteristic mode analysis, a circuit analog absorber is designed by using a lossy FSS, which consists of miniaturized meander lines and lumped resistors. The positions and values of resistors are selected by analyzing the modal current and modal significances of the structure. The modal radiation fields are used to find out which modes are effective modes. The steps of designing an absorber using characteristic modes are presented. Simulation results show that, under the normal incidence, the band of| S11| 0.707.

Exciton lifetime (τ) is crucial for the migration of excitons to donor/acceptor interfaces for subsequent charge separation in organic solar cells (OSCs); however, obvious prolongation of τ has rarely been achieved. Here, by introducing a solid additive 9-fluorenone-1-carboxylic acid (FCA) into the active layer, which comprises a nonfullerene acceptor, 3,9-bis(2-methylene-((3-(1,1-dicyanomethylene)-6/7-methyl)-indanone))-5,5,11,11-tetrakis(4-hexylphenyl)-dithieno[2,3-d:2',3'-d']-s-indaceno[1,2-b:5,6-b']dithiophene (IT-M), τ is substantially prolonged from 491 to 928 ps, together with obvious increases in fluorescence intensity and quantum yield. Time-resolved transient infrared spectra indicate the presence of an intermolecular vibrational coupling between the electronic excited state of IT-M and the electronic ground state of FCA, which is first observed here and which can suppress the internal conversion process. IT-M-based OSCs display an improved short-circuit current and fill factor after the addition of FCA. Thus, the power conversion efficiency is increased, particularly for devices with a large donor/acceptor ratio of 1:4, whose efficiency is increased by 56%. This study describes a novel method, which is also applicable to other nonfullerene acceptors, for further improving the performance of OSCs without affecting their morphology and light absorption properties.

A frequency selective rasorber (FSR) which has two wide absorption bands and a passband is presented in this paper. A lossy FSS consisting of tripole loop with three lumped resistor and a lossless FSS consisting of tripole slots are used to form a double-layer structure. In order to comprehend the principle of operation and predict the performance of the FSR, an equivalent circuit model (ECM) is modelled. After the presented FSR is meticulously designed, a prototype of the FSR is manufactured and tested. Measured S parameters shows that the FSR has a passband around 5 GHz, and below and above the passband, the frequencies of |S 11 | < - 10 dB covers from 3.05 to 8.81 GHz. The measured results agree well with the simulation results.

A reconfigurable frequency selective surface (RFSS) whose passband can be tuned in wide band is presented in this paper. An equivalent circuit model that consists of parallel and series L-C resonant circuits is studied. The unit cell of the FSS is designed with cross-loop slot and varactor diodes which are used to vary the center frequency of the passband. The simulated results show that a tunable passband alters from 2.93 to 5.75 GHz is achieved if the value of capacitance varied from 0.8 to 0.1 pF. The proposed RFSS is manufactured and tested after it is designed. The measured results show that, if the biasing voltage of all varactor diodes is decreased from 18 to 4V, the center frequency of the passband is altered from 4.67 to 2.93 GHz.

A low-profile pattern reconfigurable square loop antenna (SLA) is investigated. It is designed by using a single loop element with four ports over hybrid high impedance surface. The simulated and measured results show that, with different excitations, the main lobe in four quadrants and omnidirectional pattern of the presented antenna can be obtained. It exhibits wide bandwidth that covers from 4.8 to 5.48 GHz with a total size of $60\ \text{mm} \times 60\ \text{mm} \times 3.3\ \text{mm}$ . Within the bandwidth, the presented antenna has a maximum gain of 7.1 dBi at 5 GHz. A simple feeding network integrated with the presented antenna that consists of power divider and RF switches is designed for testing and realizing the steerable radiation patterns.

In this paper, we introduce an effective technique for designing diffusion electromagnetic (EM) surfaces with polarization and angle-insensitive characteristics over multiple wide bands. The proposed EM surface consists of a random pixelated metal structure in the middle of double substrate layers and a metallic ground at the bottom. Phase cancellation for radar cross section (RCS) reduction is achieved by different propagation paths generated by the pixelated metallic layer. The theoretical prediction of the reduction frequency band and reduction value is derived by transmission line theory, which serves as guidance to design the EM surface for the required operating band. Using this technique, an EM surface is designed for 10 dB RCS reduction over multiple frequency bands, and the first two reduction bands are 5.98–16.23 GHz and 26.69–37.1 GHz with fractional bandwidths of 92.3% and 32.6%, respectively. The non-reduction frequency band between the first two reduction bands is almost at the K-band (18–27 GHz), which is unusable for long-range transmission because of its high atmospheric loss. Moreover, the bandwidth of RCS reduction bands is stable for oblique incident angles up to 40° for both TE and TM polarizations. Based on theoretical study and simulation results, a prototype of this EM surface is fabricated and experimentally characterized. The theoretical analysis, simulation and experiment results are in good agreement. The proposed method comprehensively solves the problems of narrow bandwidth, time-consuming optimization of the unit cell, high bistatic RCS value, and sensitivity to polarization and incident angles found in recent RCS reduction research.

Combination of monoammonium glycyrrhizinate and cysteine hydrochloride (MG-CH) has been used for treatment of chronic liver damage in clinic for several years, however, the effect of MG-CH on acute liver injury (ALI) is still obscure. In this study, we aimed to investigate the effect of MG-CH on ALI induced by co-injection of lipopolysaccharide (LPS) and d-galactosamine (GalN). Our results found that MG-CH produced the optimal therapeutic effect at the ratio of 2:1, as manifested by the increased survival percentage, decreased ALT and AST level and improved hepatic pathology. Both oxidative stress and inflammation induced by LPS/GalN were attenuated by MG-CH. Mechanism study showed that MG-CH promoted the nuclear accumulation of Nrf2 and its transcriptional activity, as well as improved Nrf2-target genes’ expression. It was also found that activation of Nrf2 is dependent on the MG, not CH. Blockade of Nrf2 abolished the anti-inflammatory effect of MG-CHinduced by LPS/GalN, while inhibition of NFκB showed no effect on its anti-oxidative effect, though the inhibited phosphorylation of IκB and NFκB were detected in liver. The protective effect of MG-CH against ALI was abolished in Nrf2-/- mice. All of these results suggested that MG-CH ameliorated LPS/GalN induced ALI through Nrf2/ARE pathway.

In this paper, we study the solution theory of the nonlinear q -fractional differential equation: c D q α x ( t ) = f ( t , x ( t ) ) , 0 α , q 1 , with given initial value. We first give the existence theorem under the assumption that t β f ( t , x ) is continuous where 0 ≤ β α . Then, by establishing a q -analogue Gronwall inequality, we prove that the solution x ( t ) is stable with respect to the initial value if f ( t , x ) satisfies the Lipschitz condition on variable x . This stability result also implies the uniqueness of solution.