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Novel high-entropy perovskite-type (Ca0.2Sr0.2Ba0.2La0.2Pb0.2)TiO3 (CSBLP) ceramics with cubic structure of Pm-3m space group were successful prepared by solid-state reaction method. Results of XRD, SEM-EDS, HRTEM confirmed a homogeneous distribution and equimolar arrangement of multicomponent cations on the A-site. The high-entropy CSBLP ceramics showed long-range structural order and short-range chemical disorder with widely dispersed nanoscale grains varying sizes of 4-6 nm in the microstructure. Because of increased configurational entropy, the CSBLP ceramic has an enhanced Seebeck coefficient ( | S | = 272 μV/K at 1073 K) and low thermal conductivity (κ=1.75 W/m•K at 1073 K) when annealed at 1300 °C. This work demonstrates the possibility of effectively reducing thermal conductivity and improving the performance of thermoelectric oxides through high-entropy composition design.

Reversible luminescence modulation behavior upon the photochromic effect endows the photochromic ceramics with great potential in anti-counterfeiting and data storage applications. Here, Sm3+-doped KSr2Nb5O15 photochromic ceramics exhibit superior anti-counterfeiting ability: good covertness and considerable modulation ratio of luminescent emission intensity after photochromic reaction. The results show that the photochromism originated from oxygen and cation vacancies, which were directly identified by electron paramagnetic resonance and positron annihilation lifetime spectra. Unexpectedly, oxygen vacancies work more effectively than cation vacancies during photochromic reactions. Moreover, the extraordinary anti-counterfeiting ability was attributed to the high energy transfer rate, which was particularly caused by the short mean distance below 1 nm between the Sm3+ and vacancies. The work here has provided atomic-scale structural evidence and made a progress in understanding the photochromic origins and mechanism in color-center theory.

Machines consume intensive energy in some production systems. Although substantial efforts have been devoted to performance analysis, continuous improvement, and design of production systems, the research on reducing the energy consumption in these systems is limited. In this article, the problem of minimizing the energy consumed by machines in the two-machine Bernoulli serial line, which has been formulated as nonlinear programming with production rate constraint, is investigated. Specifically, structural characteristics and optimality conditions of the problem are analyzed, and two nonlinear algebraic optimality equations are established. To solve the optimality equations, their properties are explored, and an effective algorithm based on the binary search method is developed. Furthermore, the sensitivity of the optimal solution with respect to system parameters is quantitatively analyzed. Based on the sensitivity analysis, some useful insights on the optimal objective value are extracted.

Selective detection of multiple analytes in a compact design with dual-modality and theranostic features presents great challenges. Herein, we wish to report a coumarin-thiazolidine masked D -penicillamine based dual-modality fluorescent probe COU-DPA-1 for selective detection, differentiation, and detoxification of multiple heavy metal ions (Ag+, Hg2+, Cu2+). The probe shows divergent fluorescence (FL) /circular dichroism (CD) responses via divergent bond-cleavage cascade reactions (metal ion promoted C-S cleavage and hydrolysis at two distinctive cleavage sites): FL “turn-off” and CD “turn-on” for Ag+ (no hydrolysis), FL “turn-on” and CD “turn-off” for Hg2+ (imine hydrolysis), and FL “self-threshold ratiometric” and CD “turn-off” for excess Cu2+ (lactone and imine hydrolysis), providing the first example of a fluorescence/CD dual-modality probe for multiple species with complimentary responses. Moreover, the bond-cleavage cascade reactions also lead to the formation of D -penicillamine heavy metal ion complexes for potential detoxification treatments.

It is a highly productive approach to analyze human languages with complex networks, because the language network can effectively predict unknown features. One of the classical features in complex networks is module (or community) structure, which features dense intra-group connections and sparse inter-group connections. This work aims to identify oracle characters, the oldest characters in China, with similar semantic through module structure detection because about two-thirds of all oracle characters remain unknown. Firstly, two oracle character networks are constructed based on the context and shape of oracle rubbings and characters. Then, three module structure detection methods are employed to mine the modules from the oracle character networks. Through the experiments on the oracle character networks, three significant results are obtained. The first one is that oracle characters (or oracle variant characters) with similar semantics can be discovered by module structure, and the second one is that context and shape are of equal importance to the semantic formation of oracle characters. The last result is that modules have strong local topology of the network.

This paper presents a trilevel risk-averse strategy to configure the grid-scale energy storage systems (ESS) in active distribution network. Unlike the traditional planning framework, which presumes that ESS and renewable energy sources (RES) are cooperatively planned, we consider a practical situation that the siting choice of individual RES owners could be conflict with systems operation target of hosting capacity improvement. To address this challenge, a trilevel ESS planning formulation with “min-max” risk constraint is developed. Also, a scenario-based stochastic program model is incorporated in the lower level problem to handle the random fluctuation of RES outputs. As the resulting risk-constrained trilevel formulation is computationally difficult, we develop a customized column-and-constraint generation algorithm with finite convergence. Numerical studies on 33-bus test system and a real-world 56-bus distribution network indicate that the proposed methodology can effectively enhance the robustness of look-ahead ESS configuration against those non-cooperative and uncertain integration choices for renewable energy construction. Moreover, our customized algorithm demonstrates a superior solution capacity and scalability to support the efficient decisions for risk-averse storage planning.

Traditionally, photovoltaic (PV) inverters assume the specific topologies or transformer to attenuate the circulating leakage current. Alternatively, the circulating leakage current in PV station can also be attenuated by pushing the inverters’ carrier angle being zero degree in theory, which however is too hard to be realized because it relies on additional low-latency communication channels. Being different, this article proposes a min–max closed-loop phase-locked-loop based global synchronous pulsewidth modulation method for circulating leakage current attenuation in PV station. In specific, the circulating leakage currents of parallel-connected PV inverters can be treated as a multi-input multi-output (MIMO) system. Then, this article analyzes the relationship between the phase shift values of carriers and the leakage current. Next, the dominating carrier phase shift value for the maximum leakage current is analyzed and selected. Doing so, the MIMO system is simplified as a single-input single-output system and then the perturbation and observation algorithm can be assumed to minimize the circulating leakage current. It is noted that the proposed method does not need low-latency communication channels to synchronize the carrier phase angles and immune the uncertain operation parameters. Experimental prototype with four down-scale inverters verified the performance of the proposed method.

The luminescence modulation behaviour under the in-situ electric field of rare-earth doped KSr2Nb5O15 ceramics opened a new door for the development of dielectric materials. Where the understanding the effect of rare-earth doping on the electric properties of host, especially at the similar doping concentration with luminescence researches (low concentrations) is very important for the exploration of mechanism of electric-luminescent coupling effect. In this work, Nd3+-doped KSr2Nb5O15 (KSN-xNd) ceramics were synthesized, and the electric properties were investigated systematically. Our results suggest that the Nd3+ doping slightly increased the phase transition temperatures and improved the piezoelectric response of KSr2Nb5O15. Most importantly, a bidirectional dielectric tunability is revealed in KSr2Nb5O15. The dielectric permittivity can be adjusted by the DC electric bias, with tunability ranging from −12.3% to 21.9%. The related mechanism and relationship between the bidirectional dielectric tunability and ferroelectricity are revealed by temperature-dependent dielectric and ferroelectric characterization. The researches of electric properties and bidirectional dielectric tunability of KSN-based ceramics paved the way to further exploration of electric-luminescent coupling mechanism.

New high-performance materials have attracted much attention due to ever-increasing demands for advanced communication technologies. In present work, Ge-doped Li3+xMg2Nb1-xGexO6 (0 ≤ x ≤ 0.08) ceramics are prepared via solid-state reaction route. Microstructural analysis and crystal structure refinement reveal that moderate substitution can promote grain growth and modify crystal structure, thus enhancing microwave dielectric properties of composites. In that sense, special attention is paid to the behavior of dielectric constant er, quality factor Q×f, and frequency temperature coefficient τf of final products. In these systems, er parameter depends on the density, miscellaneous phases, and polarizability; Q×f value is shown to be influenced by Nb-O bond energy, grain size, and bulk density; finally, τf characteristic refers to Nb-O bond valence and NbO6 octahedral distortion. Among above ceramics, Li3.02Mg2Nb0.98Ge0.02O6 composite sintered at 1250 °C exhibits outstanding microwave absorption performance with er = 15.32, Q×f = 969 88 GHz, and τf = −8.25 ppm/°C.

Globally, the installed capacity of photovoltaic (PV) power plants is undergoing rapid growth. However, the random output power fluctuation of PV plants has brought great challenge to power system stable operation. One of the most effective approaches to counteract the impact of power fluctuation is to carry out power forecasting under ultra-short-term scales, among which the second-level power forecasting technique is still absent since the pure historical data analysis of PV plant output power cannot deal with the sudden output power change induced by moving cloud and the traditional cloud image detection methods actually fail to achieve accurate PV power forecasting in high temporal and spatial resolutions. This article proposes an inverter-data-driven method to achieve the second-level PV power forecasting. In specific, multilayer feed-forward artificial neural network based on the error back propagation algorithm is applied to first establish the mapping relations from shading conditions of PV array to its corresponding output power. Combining with output power of neighboring PV arrays as well as their geographical location information, the shading conditions of those shaded PV array can be reversely deduced. And then, the deduced shading conditions of all PV arrays will be converted into one virtual cloud image to identify the instant cloud characteristics. In consequence, the consecutively generated virtual cloud images can depict the moving direction, speed, and shape of shading cloud and then help easily realize the second-level power forecasting of PV plant. Case study and experimental results verified the performance of the proposed method.

Sm3+ doped KSr2Nb5O15 (KSN-Sm) textured ceramics with anisotropic photochromic and luminescence modulation behaviors provided a new strategy for the enhancement of anti-counterfeiting ability. The KSN-Sm textured ceramics were fabricated by the tape casting technology, which exhibited obvious grain-orientation, with Lotgering factor f(00l) of 0.62. The textured sample possessed evident difference of reflectivity, photochromic, luminescent and luminescence modulation properties among various grain-orientated directions. The difference of luminescent emission intensity was over than 30 % and the luminescence modulation ratios △Rt are 75.3 % and 63.3 % along paralleled and vertical [00l] orientations, respectively. These optical anisotropies were attributed to the different refractive indexes, distributions of photochromic centers and energy transfer rates at various orientations. This work is hopeful to achieve the multidirectional data recording and enhancement of anti-counterfeiting ability of photochromic ceramics by the anisotropic properties of textured ceramics.

The objective of this study is to examine the performance of the shallow reinforced concrete foundation of a large-scale wind turbine under the influence of environmental loads. A 2 MW horizontal-axis onshore wind turbine supported by a shallow concrete foundation was considered. The foundation stresses, foundation settlements, and static and dynamic contact pressures at various positions of the shallow foundation were monitored from the construction phase to the operation phase in the field. Numerical simulations were also performed to further analyze the behavior of the wind turbine foundation in different cases. The results demonstrate that the responses of the reinforced concrete foundation, i.e., foundation stresses, contact pressures, and foundation settlements, were variables closely related to the wind direction and wind speed. The distribution of foundation stresses suggested that a reasonable design of steel reinforcement cages around the foundation steel ring is important. The dynamic contact pressure of the foundation could reach 5 kPa, so the influence of dynamic wind loads on the foundation response could not be always neglected, particularly for the foundations seated on weak soils. The foundation settlement during the operation phase could be characterized by the logistic model, but its distribution was uneven due to the presence of eccentric upper weight and wind load. The findings would provide guidance for the foundation design of onshore wind turbines in hilly areas.

Early warning mechanism is crucial for maintaining the security and reliability of the power grid system. It remains to be a difficult task in a smart grid system due to complex environments in practice. In this paper, by considering the lack of vision-based datasets and models for early warning classification, we constructed a large-scale image dataset, namely EWSPG1.0, which contains 12,113 images annotated with five levels of early warnings. Moreover, 104,448 object instances with respect to ten categories of high-risk objects and power gird infrastructure were annotated with labels, bounding boxes and polygon masks. On the other hand, we proposed a local-to-global perception framework for arly warning classification, namely EWNet. Specifically, a local patch responsor is trained by using image patches extracted from the training set according to the labeled bounding box information of objects. The capability of recognizing high-risk objects and power grid infrastructure is transferred by loading the trained local patch responsor with frozen weights. Features are then fed into a feature integration module and a global classification module for early warning classification of an entire image. In order to evaluate the proposed framework, we benchmarked the proposed framework on our constructed dataset with 11 state-of-the-art deep convolutional neural networks (CNNs)-based classification models. Experimental results exhibit the effectiveness of our proposed method in terms of Top-1 classification accuracy. They also indicate that vision-based early warning classification remains challengeable under power grid surveillance and needs further study in future work.

A label-free and sensitive electrochemical biosensing strategy for a hepatocellular carcinoma biomarker of miRNA-122 has been proposed based on hybridization induced ion-barrier effect on the electroactive sensing interface. First, a bifunctional electroactive electrode with the nanocomposite of Prussian blue (PB) and gold nanoparticles (AuNPs) was prepared through a two-step electrodeposition process. The PB endows the electrode excellent K+-dependent voltammetric signal and the AuNPs act as the matrix for the self-assembly immobilization of the thiolated probe DNA. Upon specific hybridization of probe DNA with the target miRNA-122, the formed double duplex induced the ion-barrier effect, which blocked the diffusion of the K+ from the bulk solution to the electrode surface. As a result, the voltammetric signal of the PB on the electrode was surpressed, and thus the target miRNA-122 was monitored. The sensing assay showed that the miRNA-122 could be analyzed in the concentration range from 0.1 fmol/L to 1.0 nmol/L, with a detection limit of 0.021 fmol/L. The practical applicability of the biosensor was also verified by the spiking serum assay.

The luminescence modulation behavior of lanthanide ion doped materials possesses great potential for applications in sensing, display and anti-counterfeiting devices. Unlike traditional tuning methods for chemical compositions, novel rare-earth doped ferroelectric oxides exhibit attractive luminescence modulation effects via electric polarization engineering, and enrich the development of multifunctional devices. In this work, Sm3+ doped KSr2Nb5O15 ceramics with abundant ferroelectric and luminescent properties were synthesized. The samples show different relaxation behaviors and ferroelectric features upon chemical and structural factors caused by Sm3+ doping, such as average ionic radii, local tolerance factors, and chemical bonds. After polarization at 20 kV/cm for 20 min, a considerable increase (~40%) in the luminescent emission intensity was obtained in 4 mol. % Sm3+ doped KSr2Nb5O15 ceramics. The related luminescence modulation mechanism was attributed to controlling the environmental symmetry around Sm3+ by the electric polarization.

The impedance of the virtual synchronous generator (VSG) is an effective method to analyze the dynamic interactions between the VSG and the grid. For the existence of power controllers and asymmetric inner-loop controllers in the d- and q-axis, there are couplings in the output sequence impedance of VSG. Although the couplings are relatively small, they still have a significant impact on the stability performance. However, there is no result published on this aspect up to now. To bridge this gap, a sequence impedance model based on harmonic linearization is established in this paper, which explicitly reveals the mirror frequency effect (MFE) in VSG. Subsequently, the relationships between the power controllers and the MFE are demonstrated. Finally, simulation results verify the feasibility and correctness of the theoretical analysis presented above.

In this paper, based on the life cycle concept of oil sludge waste from the NdFeB manufacturing process, we investigate the process technology route to recover valuable elements from the oil sludge waste by hydro-metallurgical refining and calcium reduction to fabricate a sintered NdFeB magnet. The life cycle list was calculated and the environmental impact of the main processes was examined using the ReCiPe method, and the main factors of environmental impact were identified. The results showed that the hydrometallurgical technology route, compared with the calcium reduction technology route, resulted in 119.84% of human health hazards, 119.84% of ecological damage and 119.84% of resource. The consumption was found to be 13.08% higher than that of FDP. The sensitivity analysis revealed that the production of hydrochloric acid is highly sensitive to FDP, and power consumption is high to WTP in the hydrometallurgical technology route, and WTP in the calcium reduction unit process, and HTP in all processes in the calcium reduction technology route. The overall results show that reducing the environmental impact in the calcium reduction recovery process and accelerating the clean production of China's power resources are of great significance for the recovery of oil sludge waste for the preparation of recycled sintered NdFeB.

Amines are widely employed as additives for improving the performance of metal halide perovskite optoelectronic devices. However, amines are well-known for their high chemical reactivity, the impact of which has yet to receive enough attention from the perovskite light-emitting diode community. Here, by investigating an unusual positive aging effect of CH3NH3I/CsI/PbI2 precursor solutions as an example, we reveal that amines gradually undergo N-formylation in perovskite precursors over time. This reaction is initialized by hydrolysis of dimethylformamide in the acidic chemical environment. Further investigations suggest that the reaction products collectively impact perovskite crystallization and eventually lead to significantly enhanced external quantum efficiency values, increasing from similar to 2% for fresh solutions to greater than or similar to 12% for aged ones. While this case study provides a positive aging effect, a negative aging effect is possible in other perovksite systems. Our findings pave the way for more reliable and reproducible device fabrication and call for further attention to underlying chemical reactions within the perovskite inks once amine additives are included. Funding Agencies|ERCEuropean Research Council (ERC)European Commission [717026]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University [SFO-Mat-LiU 2009-00971]; National Natural Science Foundation of ChinaNational Natural Science Foundation of China (NSFC) [51472164, 62005126]; 1000 Talents Program for Young Scientists of China; Shenzhen Peacock Plan [KQTD2016053112042971]; Educational Commission of Guangdong Province [2015KGJHZ006]; Research Foundation-Flanders (FWO)FWO [12Y7221N]

To investigate the effects of Weikang Capsule (胃康胶囊, WKC) on aspirin-related gastric and small intestinal mucosal injury by magnetically controlled capsule endoscopy (MCCE). Patients taking enteric-coated aspirin aged 40–75 years were enrolled in Beijing Anzhen Hospital, Capital Medical University from January 2019 to December 2019. The patients continued taking aspirin Tablet (100 mg per day) and underwent MCCE before and after 1-month combined treatment with WKC (0.9 g per time orally, 3 times per day). The gastrointestinal symptom score, gastric Lanza score, the duodenal, jejunal and ileal mucosal injury scores were used to evaluate the gastrointestinal injury before and after treatment. Adverse events including nausea, vomiting, abdominal pain, abdominal distension, abdominal discomfort, dizziness, or headache during MCCE and combined treatment were observed and recorded. Twenty-two patients (male/female, 13/9) taking enteric-coated aspirin aged 59.5 ± 11.3 years with a duration of aspirin use of 28.0 (1.0, 48.0) months were recruited. Compared with pre-treatment, the gastrointestinal symptom rating scale scores, gastric Lanza scores, and duodenal mucosal injury scores were significantly reduced after 1-month WKC treatment (P

Recent advances in organic solar cells based on non-fullerene acceptors (NFAs) come with reduced non-radiative voltage losses (ΔVnr). Here we show that, in contrast to the energy-gap-law dependence observed in conventional donor:fullerene blends, the ΔVnr values in state-of-the-art donor:NFA organic solar cells show no correlation with the energies of charge-transfer electronic states at donor:acceptor interfaces. By combining temperature-dependent electroluminescence experiments and dynamic vibronic simulations, we provide a unified description of ΔVnr for both fullerene- and NFA-based devices. We highlight the critical role that the thermal population of local exciton states plays in low-ΔVnr systems. An important finding is that the photoluminescence yield of the pristine materials defines the lower limit of ΔVnr. We also demonstrate that the reduction in ΔVnr (for example

In this paper, a novel direction of arrival (DOA) estimation algorithm using directional antennas in cylindrical conformal arrays (CCAs) is proposed. To eliminate the shadow effect, we divide the CCAs into several subarrays to obtain the complete output vector. Considering the anisotropic radiation pattern of a CCA, which cannot be separated from the manifold matrix, an improved interpolation method is investigated to transform the directional subarray into omnidirectional virtual nested arrays without non-orthogonal perturbation on the noise vector. Then, the cross-correlation matrix (CCM) of the subarrays is used to generate the consecutive co-arrays without redundant elements and eliminate the noise vector. Finally, the full-rank equivalent covariance matrix is constructed using the output of co-arrays, and the unitary estimation of the signal parameters via rotational invariance techniques (ESPRIT) is performed on the equivalent covariance matrix to estimate the DOAs with low computational complexity. Numerical simulations verify the superior performance of the proposed algorithm, especially under a low signal-to-noise ratio (SNR) environment.

Despite recent generative models have made remarkable progress on adversarial image synthesis, it is still a pivotal and frontier problem to generate high-fidelity images containing diverse entities and complex scene layouts from structured descriptions. To this end, we present a Background and Foreground Disentangled Generative Adversarial Network (BFD-GAN) to synthesize high-quality images from scene graphs. First, our method uses the graph convolutional network to infer a semantic background from the input scene graph. Then, the foreground parsing module that encourages unsupervised generation, is proposed to calculate semantically related foregrounds with fine-grained geometric properties. Furthermore, we also employ the foreground-background integrating module for the final image generation, during which the foreground-relation aware attention is introduced to refine and fuse the inferred foregrounds into the background. Evaluated on the COCO-Stuff and Visual Genome datasets, we benchmark our model against existing methods and show that our BFD-GAN is more capable of generating complex backgrounds and corresponding sharp foregrounds with given scene structures.

Wastewater with rich nutrients has been considered as a promising resource to replace artificial culture media in the production of low-cost microalgae biofuels. However, to compete with the traditional fossil energy, the corresponding algal lipid productivity needs to be improved. In this study, iron and acetate supplements were used to improve the lipid productivity of Chlorella pyrenoidosa in actual municipal wastewater (MW). The results showed that, simultaneously adding proper amounts of iron and acetate remarkably increased the microalga dry cell weight (DCW), lipid content and lipid productivity, respectively by 185%, 248% and 671%. Moreover, the addition of acetate increased the saturation degree of the alga based fatty acid methyl esters (P

Low gravity fields have been simulated through magnetic acceleration to conduct experimental study on bearing capacity of circular footings on a type of crushable planetary regolith simulant, which has comparable density and particle size distribution of lunar soil. The load–settlement responses of surface spread footings are obtained by investigating the relative density, footing size and gravity effects. Applying the hyperbolic asymptote method, normalised foundation stiffness and ultimate bearing capacity are obtained by curve fitting and predicted by power functions using multivariate nonlinear regression. The results show that the nonlinear gravity effect is not negligible, related to stress condition, soil dilatancy and mobilised friction angle. A cone penetration test (CPT)-based method for prediction of bearing capacity is proposed with correlations between ultimate bearing capacity of footings and shallow penetration stiffness of CPTs, avoiding the uncertainties of soil property estimations. Analyses of allowable bearing capacity and footing influence zone in consideration of footing size and gravity effects could therefore improve the design of shallow foundations on the Moon and Mars, and provide new understandings and potential implications to the bearing capacity of shallow foundations on crushable granular material in both terrestrial and extraterrestrial geotechnical engineering.

In recent years, the hyperspectral image (HSI) classification based on generative adversarial networks (GANs) has achieved great progress. GAN-based classification methods can mitigate the limited training sample dilemma to some extent. However, several studies have pointed out that existing GAN-based HSI classification methods are heavily affected by the imbalanced training data problem. The discriminator in GAN always contradicts itself and tries to associate fake labels to the minority-class samples and, thus, impair the classification performance. Another critical issue is the mode collapse in GAN-based methods. The generator is only capable of producing samples within a narrow scope of the data space, which severely hinders the advancement of GAN-based HSI classification methods. In this article, we proposed an Adaptive DropBlock-enhanced Generative Adversarial Networks (ADGANs) for HSI classification. First, to solve the imbalanced training data problem, we adjust the discriminator to be a single classifier, and it will not contradict itself. Second, an adaptive DropBlock (AdapDrop) is proposed as a regularization method employed in the generator and discriminator to alleviate the mode collapse issue. The AdapDrop generated drop masks with adaptive shapes instead of a fixed size region, and it alleviates the limitations of DropBlock in dealing with ground objects with various shapes. Experimental results on three HSI data sets demonstrated that the proposed ADGAN achieved superior performance over state-of-the-art GAN-based methods. Our codes are available at https://github.com/summitgao/HC_ADGAN .

In this study, Zn2+-substituted Li2MgSiO4 ceramics (Li2(Mg1-xZnx)SiO4, x = 0.00, 0.05, 0.10, 0.15, and 0.20) were synthesized using a traditional solid-state method. A fixed amount of LiF sintering aid (1.5 wt%) was added to the ceramics for decreasing the sintering temperature and adjusting their microwave dielectric properties. X-ray diffraction (XRD) results revealed no secondary phases, and scanning electron microscopy (SEM) data suggest that the Zn2+ ion substitution increased the size and uniformity of the grains, thereby affecting the densification of the prepared ceramics. The maximum bulk density (2.94 g/cm3) was found in a Zn2+ ion-substituted ceramic with x = 0.10 at a relative density of 94.2% (compared with the XRD theoretical density). Excellent microwave dielectric properties (er = 6.28, Q × f = 50400 GHz, and τf = −145 ppm/°C) can also be obtained at this zirconium content. We believe that the developed ceramics are promising for use as antenna substrates or transmit/receive modules in low-temperature co-firing ceramic applications.

A compact and robust in-fiber acoustically-induced Mach-Zehnder interferometer (AI-MZI) was demonstrated based on the phase mismatch in an acoustic wave driving fiber Bragg grating (FBG). The fiber structure of the AI-MZI was easy to fabricate and of a uniform diameter with larger refractive index difference in its arm part, which helped to reduce the length of the arm. In the experiment, the total length of the AI-MZI was less than 7 cm and the response time was about 120 $\mu$ s. The bandpass isolation and resonant center wavelength could be optimized by changing the power and frequency of the radio frequency source, respectively. As its application, a tunable and individually switchable dual-wavelength fiber ring laser was realized and characterized. The proposed structure gains advantages of robustness, easy fabrication, compact size and fast tuning speed accordingly. At the same time, it provides another practical way to use an FBG to introduce phase mismatch into an acousto-optic fiber grating.

The autonomous robots consisting of an immovable lander and a rover are widely deployed to explore extraterrestrial planets. Two main drawbacks limit the development of this cooperative work mode: (1) it cannot perform soft-landing missions repeatedly on the planet, owing to the damage of buffer structure during soft-landing. (2) the rover’s detection area is restricted to the vicinity of the immovable lander. To overcome these problems, we have designed an innovative six-legged mobile lander with repetitive landing capacity, called “HexaMRL”, which integrates the functions of a lander and a rover including folding, deploying, repetitive landing, and walking. This novel robot’s legs adopted hybrid mechanism with active and passive compliance. Therefore, it remains to be a great challenge to analyze the robot soft-landing capacity which is determined by the parameters such as spring stiffness coefficient, damper damping coefficient, and initial tiptoe position. In order to solve the problem, the dynamic modeling and assessment criteria were established. The soft-landing process was analyzed through three numerical simulations using three sets of representative parameters based on dynamic model and the set of best effective parameters was chosen to apply in soft-landing experiment on a 5-DOF lunar gravity testing platform (5-DOF LGTP). The experiments were further verified that the selected parameters met the requirement of soft landing on the lunar surface. The HexaMRL provides novel insight for the next generation equipment for lunar exploration, which may be an efficient solution to the extraterrestrial planet exploration.

Both surface and underground rocks in nature often undergo repeated drying and wetting. The dry-wet cycle is a weathering effect that includes physical and chemical processes, which has varying degrees of degradation effects on the physical and mechanical properties of rocks. This paper analyzes and discusses this kind of rock degradation based on the existing literature data. First, the deterioration degree of various physical and mechanical properties (including density, P-wave velocity, porosity, static and dynamic compressive/tensile strength, and fracture toughness) is summarized as the number of dry-wet cycles increases. Secondly, the possible degradation mechanism of the dry-wet cycle is explained in terms of clay mineral swelling, solute migration, and microcrack evolution. Then, the damage constitutive model of the rock after cyclic dry-wet treatment is introduced. Finally, the issues that need to be studied in the future are put forward.

This paper addresses limitations of widely used Reynolds-averaged turbulence models (RANS) for prediction of gas turbine internal air systems. Results from direct numerical simulation (DNS), wall-resolved large-eddy simulation (LES), wall-modelled large-eddy simulation (WMLES), and RANS for benchmark test cases are compared. For rotor-stator disc cavity flows results for mean velocities, velocity fluctuations, rotor torque and laminar-turbulent transition are considered and compared with published data. For cavities between co-rotating discs attention is focused on buoyancy-driven convection in the centrifugal force field. It is concluded that WMLES is suitable for application in engine conditions, offering better accuracy than RANS in some critical applications. This confirms recently published results for turbine rim sealing and is further illustrated by application to convection in a sealed cavity at higher Rayleigh number than is practical with DNS or wall-resolved LES. The results show that the approximate near-wall treatment gives reasonable results for complex flows and extend previous studies to higher speed rig conditions where Eckert number effects become significant.

Legged robots have potential advantages in mobility compared with wheeled robots in outdoor environments. The knowledge of various ground properties and adaptive locomotion based on different surface materials plays an important role in improving the stability of legged robots. A terrain classification and adaptive locomotion method for a hexapod robot named Qingzhui is proposed in this paper. First, a force-based terrain classification method is suggested. Ground contact force is calculated by collecting joint torques and inertial measurement unit information. Ground substrates are classified with the feature vector extracted from the collected data using the support vector machine algorithm. Then, an adaptive locomotion on different ground properties is proposed. The dynamic alternating tripod trotting gait is developed to control the robot, and the parameters of active compliance control change with the terrain. Finally, the method is integrated on a hexapod robot and tested by real experiments. Our method is shown effective for the hexapod robot to walk on concrete, wood, grass, and foam. The strategies and experimental results can be a valuable reference for other legged robots applied in outdoor environments.

Purpose Epoxy resin (EP) is a kind of thermosetting resin, and its application is usually limited by poor toughness. In this case, a type of new flexible chain blocking hyperbranched polyester (HBP) was designed and synthesized. The purpose of this study is to enhance the toughness and dielectric properties of EP. Design/methodology/approach P-toluene sulfonic acid was used as the catalyst, with dimethy propionic acid as the branch unit and pentaerythritol as the core in the experiment. Then, n-hexanoic acid and n-caprylic acid were, respectively, put to gain HBP with a n-hexanoic acid and n-caprylic acid capped structure. The microstructure, mechanical properties, insulation properties and dielectric properties of the composite were characterized for the purpose of finding the appropriate proportion of HBP. Findings HBP enhanced the toughness of epoxy-cured products by interpenetrating polymer network structure between the flexible chain of HBP and the EP molecular chain. Meanwhile, HBP reduced the ε and tgδ of the epoxy anhydride-cured product by reducing the number of polar groups per unit volume of the EP through free volumes. Research limitations/implications Yet EP is a kind of thermosetting resin, which is widely used in coating, aerospace, electronics, polymer composites and military fields, but it is usually limited by poor toughness. In a word, it is an urgent priority to develop new EP with better toughness and mechanical properties. Originality/value At present, HBP has been applied as a new kind of toughening strategy and as a modifier for EP. According to the toughening mechanism of HBP modified EP, the free volume of HBP creates a space for the EP molecule to move around when loaded. Moreover, the free volume could cause the dielectric constant of EP to diminish by reducing the content of polarizable groups. Meanwhile, the addition of HBP with flexible chains grafted to the EP could develop an interpenetrating network structure, thus further enhancing the toughness of EP

A novel oxygen reduction reaction (ORR) electrocatalyst silver@platinum-cobalt-rGO nanoflower (Ag@PtCo-rGO NFs) is prepared by hydrothermal reduction method. The formation of silver chloride likes elm leaf microstructure in the reaction process, performing as a template. The Ag@PtCo-rGO NFs exhibit excellent electrocatalytic activity, whose specific activity is 9 times higher than that of commercial Pt/C. More importantly, Ag@PtCo-rGO NFs demonstrate excellent durability than JM Pt/C for ORR in acid media, as evidenced by accelerated durability test after 40,000 cycles. These excellent performances can be attributed to the special structure, atomic steps and synergistic effect between Pt, Ag and Co. The density functional theory calculation shows that Ag@PtCo has the best activity, which is related to the transition state for O–O bond. This work proposes a promising pathway for the synthesis of surfactant-free nanoflowers structure catalysts with high catalytic performance and low cost.

Understanding defects is of paramount importance for the development of stable halide perovskite solar cells (PSCs). However, isolating their distinctive effects on device efficiency and stability is currently a challenge. We report that adding the organic molecule 3-phosphonopropionic acid (H3pp) to the halide perovskite results in unchanged overall optoelectronic performance while having a tremendous effect on device stability. We obtained PSCs with ∼21% efficiency that retain ∼100% of the initial efficiency after 1,000 h at the maximum power point under simulated AM1.5G illumination. The strong interaction between the perovskite and the H3pp molecule through two types of hydrogen bonds (HI and OH) leads to shallow point defect passivation that has a significant effect on device stability but not on the non-radiative recombination and device efficiency. We expect that our work will have important implications for the current understanding and advancement of operational PSCs., We thank the Spanish MINECO through the Severo Ochoa Centers of Excellence Program under grant no. SEV-2017-0706 for the postdoctoral contract to H.X. We thank the King Abdulaziz City for Science and Technology (KACST) for the financial support to M.G. and S.M.Z. A.H. is thankful for the financial support from the European Union H2020, ESPResSo project grant agreement 764047, and Swiss National Science Foundation project IZLCZ2_170177. Z.W. and S.F. are thankful for the “China Scholarship Council” fellowship (CSC). H.-S.K., M.G., and S.M.Z. are thankful for the financial support from the GRAPHENE Flagship Core 2 project supported by the European Commission H2020 Programme under contract 785219. P.T. and J.A. acknowledge funding from Generalitat de Catalunya 2017 SGR 327 and the Spanish MINECO project ANAPHASE (ENE2017-85087-C3). D.J.K. and L.E. acknowledge support from the Swiss National Science Foundation grant no. 200021_160112. S.T. acknowledges funding from the Computational Sciences for Energy Research tenure track programme of Shell, NWO, and FOM (project no. 15CST04-2), the Netherlands. S.D.S. and M.A. acknowledge funding from the Marie Skłodowska-Curie actions (grant agreement no. 841386) under the European Union’s Horizon 2020 research and innovation programme. S.D.S acknowledges support from the Royal Society and Tata Group (UF150033) and EPSRC (EP/R023980/1). X.S. and F.F. acknowledge the funding from the Swiss Federal Office of Energy (SFOE)-BFE (project no. SI/501805-01). K.G. appreciates support from the Polish Ministry of Science and Higher Education within the Mobilnosc Plus program (grant no. 1603/MOB/V/2017/0). K.J.T. acknowledges funding from the European Union’s Horizon 2020 research and innovation programme under grant agreement no. 804349 (ERC StG Cuhl) and RyC fellowship no. RYC-2017-22330. We give thanks to the Spanish State Research Agency for the grant Self-Power (PID2019-104272RB-C54 / AEI / 10.13039/501100011033) and the OrgEnergy Excelence Network (CTQ2016-81911-REDT), and to the Agència de Gestiód'Ajuts Universitaris i de Recerca (AGAUR) for the support to the consolidated Catalonia research group 2017 SGR 329 and the Xarxa d’R+D+I Energy for Society (XRE4S). Part of this work is under Materials Science Ph.D. Degree for A.M. and P.T. and the Chemistry Ph.D. programme for C.P. of the Universitat Autonoma de Barcelona (UAB, Spain). We thank CONACYT for the scholarship to C.P. We acknowledge Libertad Sole and also the Clean-Room from IMB-CNM for FIB process. ICN2 is supported by the Severo Ochoa program from Spanish MINECO (grant no. SEV-2017-0706) and is funded by the CERCA Programme/Generalitat de Catalunya.

Bacterial infection arised from multipathogenic bacteria is a tricky issue that attracts worldwide attentions. In this paper, a highly accessible copper single-atom catalyst (Cu SAC) supported by biocompatible N-doped mesoporous carbon nanospheres was synthesized with the emulsion-template method. The tightly anchored copper single-atom of the catalyst could effectively transform O2 into O2−• under ambient conditions by the ultra-large pore size (~ 23.80 nm) and small particle size (~ 97.71 nm). Due to multiple synergistically oxidative damages to biomolecules, the Cu SAC could be employed to eliminate different bacteria in vitro without the generation of multidrug resistance (MDR). Moreover, the Cu SAC could also promote wound healing in vivo by eradicating the propagation of bacteria at wound. It is envisioned that the Cu SAC with superior antibacterial performance could be applied in the treatment of related bacterial infection in future.

In the operations of underground rock engineering, such as mining, the formation of goafs is often accompanied by unloading and energy effects. In this study, a cyclic loading and unloading stress test is carried out to analyze the strength characteristics of the loaded samples under different loading and unloading ranges as well as different numbers of cycles. The rock force is accompanied by substantial energy changes. To better fit the energy analysis under cyclic loading and unloading conditions, thermal infrared radiation characteristic analysis is performed during rock loading and unloading. An infrared radiation camera is adopted to detect the infrared characteristics of the rock force process after cyclic loading and unloading. Multiangle detection is implemented on the temperature, temperature field, and frequency histogram. The analysis shows that cyclic loading and unloading first strengthen and then weaken the rock. Moreover, the failure caused by the local stress concentration leads to a sharp increase in the temperature. There are significant temperature fluctuations before and after failure, and the temperature field after failure can be divided into three zones, namely, the normal temperature zone, heating zone, and mutational temperature zone, to comprehensively reflect that rock compression failure which is accompanied by the process of energy accumulation and release. On the basis of infrared energy analysis, the index of the energy release rate is introduced, and the loading and unloading analysis model is constructed. The research results reveal that rock failure is accompanied by the process of energy accumulation and release, which provides evidence for the analysis of the spatial stability of the rock mass under cyclic loading and unloading conditions and engineering excavation.

Locomotion speed is a key performance index of legged robots. However, methods to analyze and improve the locomotion speed capability are seldom developed, especially for six-legged robots. This paper develops a method to analyze and improve the omnidirectional walking speed and the turning speed of six-legged robots. The models of the inverse kinematics and the influence coefficients are built. Making use of the only-position-related property of the influence coefficients, a general optimization model of the locomotion trajectory is established. A two-step optimization method is introduced to solve the optimization problem. Based on the optimization, a comprehensive speed capability analysis is conducted on both omnidirectional walking and turning of the six-parallel-legged robot. The results clearly show the relationships among the speed capability, the walking direction and the duty cycle. The two-step optimization method improves the speed capability by 12.4%–13.2% for turning and 18.5%–20.5% for omnidirectional walking. Finally, the costs of the speed improvement are analyzed, including the stability, the energy consumption and the calculation time.

The electron backscatter electron diffraction (EBSD) technique was applied to study the microstructure evolution and properties of the annealed cold rolling C71500 cupronickel alloy tube. The fixed reduction ratio of C71500 alloy tube was 23.71%. After rolling with different thickness reduction, the change process of grain, the evolution of texture, the characteristic distribution of grain boundary and the mechanical properties of the alloy tube were discussed systematically. The texture of cold rolling tube was obviously different from the drawing and sheet textures, and only the textures of RZ{111 type and R-cube{001} type could be observed after the two roller cold rolling process. After a certain amount of deformation, obvious accumulated orientation differences could be seen in the textures, which could create favourable conditions for the recrystallization nucleation. In the rolling process, the nonuniformity deformation of tube was caused by the inconsistency of stress state. With the increase reduction of tube wall, the tensile strength of the alloy increased from 405.13 to 574.65 MPa, the yield strength increased from 310.35 to 338.76 MPa, and the micro-Vickers hardness increased from 137.40 to 186.01.

A series of rare earth zirconates (RE2Zr2O7) high-entropy ceramics with single- and dual-phase structure were prepared. Compared with La2Zr2O7 and Yb2Zr2O7, the smaller “rattling” ions (Yb3+, Er3+, Y3+) have been incorporated into pyrochlore lattice in (La0.2Nd0.2Y0.2Er0.2Yb0.2)2Zr2O7 (LNYEY) while larger ions (La3+, Nd3+, Sm3+, Eu3+) incorporated into fluorite lattice in (La0.2Nd0.2Sm0.2Gd0.2Yb0.2)2Zr2O7 (LNSGY). Due to high-entropy lattice distortion and resonant scattering derived from smaller ions Yb3+, Er3+, and Y3+, LNYEY shows a lower glass-like thermal conductivity (1.62-1.59 W m-1 K-1, 100-600℃) than LNSGY (1.74-1.75 W m-1 K-1, 100-600℃). Moreover, LNYEY and LNSGY exhibit enhanced Vickers’ hardness (LNYEY, Hv = 11.47 ± 0.41 GPa; LNSGY, Hv = 10.96 ± 0.26 GPa) and thermal expansion coefficients (LNYEY, 10.45 × 10-6 K-1, 1000℃; LNSGY, 11.02 × 10-6 K-1, 1000℃). These results indicate that dual-phase rare-earth-zirconate high-entropy ceramics could be desirable for thermal barrier coatings.

Relaxor ferroelectric ceramics are good candidates for capacitor, sensor and actuator applications because of their high dielectric permittivity, high piezoelectric constant and high value of field induced strain, respectively. However, their dielectric loss is usually relatively high, which is a problem for actual applications. The introduction of the high entropy concept opens up the possibility of developing new multi-element relaxor-like ferroelectric materials with short-range ordered polar structures having short relaxation times to decrease their loss. Here we present a new high entropy A-site disordered perovskite (Pb0.25Ba0.25Sr0.25Ca0.25)TiO3 relaxor-like ferroelectric. Moreover, the ceramic has low loss (

The penetration of plug-in electric vehicles (PEVs) has greatly increased over the past few years. By using vehicle-to-grid (V2G) technology, PEVs can be used as “mobile batteries” in a microgrid. Here, we aim to coordinate the V2G dispatch with traditional energy management in a corporate energy system (CES). To do so, a two-stage robust optimization (RO) model is built with respect to uncertainties in the CES, e.g., photovoltaic (PV) power. Particularly, relationships between the working time schedule and PEVs are investigated and analyzed for the first time, and a novel PEV aggregator model, i.e., shift-working V2G, is presented. The shift-working V2G model provides beneficial characteristics, like weakened randomness and stable storage capacity. A quantitative method to evaluate the V2G capacity is then presented. An analytical solution methodology is also proposed, which can equivalently convert the robust “min-max-min” model to a single-level mixed-integer linear programming (MILP) model. Case studies are conducted for an iron and steel company in Shanghai, China, with almost 40 000 PEVs. The results show that V2G integration can significantly improve the load-tracking ability of CES and help reduce the energy cost, although the V2G cost is considered. The computational efficiency is also improved compared with the existing methods. Note to Practitioners —This article is motivated by the problem of using the battery storage capacities of plug-in electric vehicles (PEVs) in a corporate energy system (CES) such as an iron and steel plant, aiming at minimizing the energy cost. In existing studies, behaviors of PEVs (e.g., arriving or leaving time) have usually been elusive since they are directly decided by drivers, and thus, it is difficult to determine how much storage capacity PEVs can provide. However, in a CES where a shift-work regulation is implemented, employees should arrive or leave punctually during each shift, and the same is true of their PEVs. Based on this fact, PEVs within one shift could show weakened randomness and stable storage capacities. In this article, the influences of the shift-work regulation on the PEVs are fully analyzed, and the shift-working V2G provides an easy way to integrate PEVs into the CES. In practice, the shift-working V2G model can be applied to any energy system that also implements a shift-work regulation, such as a fire station.

CO2 electroreduction (CO2ER) is a promising avenue to convert aerial CO2 into carbonaceous fuels or value-added chemicals. In this work, we constructed Au nanocrystals@defective amorphous MnO2 nano...

Two-stage rolling process was adopted to study the texture and special grain boundary distribution of C71500 copper-nickel alloy tubes at different annealing temperatures. The effect of temperature on the texture of C71500 copper-nickel alloy tube was analyzed. The hardness analysis was used to study the recrystallization and low lattice reconstruction grain boundaries ratio at different temperatures. It was observed by electron backscattered diffraction that static recovery of the alloy tube occurs when the annealing temperature below 800 °C and it transforms into static recrystallization at 825 °C. The initial strain-induced grain boundary migration temperature of alloy tube is about 775 °C. The number of Copper{112} textures can be used to determine the ratio of the low coincidence site lattice (low ΣCSL) grain boundary. The optimal annealing process for C71500 alloy tube to obtain a high proportion of special grain boundaries is to keep the temperature at 800 °C for 15 min.

(Ca0.87Ag0.1La0.03)3Co4O9 ceramics along [00l]c crystallographic orientation were prepared by using tape casting combined with template grain growth method, which were regulated bywhich the sintering temperature and the soaking time. The (La, Ag) co-doping not only can balance the contradiction of the electrical resistivity and Seebeck coefficient, but also generat the point-defects to increase phonon scattering, which can lower thermal conductivity. The effect of grain orientation evolution on thermoelectric properties was investigated and the mechanism of epitaxial growth was discussed through the analysis of microstructures. The results show that the optimized sintering parameters led to great changes in the degree of texturing, which was closely related to thermoelectric performance. A large Seebeck coefficient of 232 μV/K was obtained for the 40 h sample and the high Lotgering factor of 92.7% for the 20 h sample reached, giving rise to the power factor of 0.38 mW/(m·K2) at 1073 K. The morphologic orientation and epitaxial growth give a possible route of preparing highly textured ceramics and achieving high thermoelectric properties.

Traditional change detection methods based on convolutional neural networks (CNNs) face the challenges of speckle noise and deformation sensitivity for synthetic aperture radar images. To mitigate these issues, we proposed a Multiscale Capsule Network (Ms-CapsNet) to extract the discriminative information between the changed and unchanged pixels. On the one hand, the capsule module is employed to exploit the spatial relationship of features. Therefore, equivariant properties can be achieved by aggregating the features from different positions. On the other hand, an adaptive fusion convolution (AFC) module is designed for the proposed Ms-CapsNet. Higher semantic features can be captured for the primary capsules. Feature extracted by the AFC module significantly improves the robustness to speckle noise. The effectiveness of the proposed Ms-CapsNet is verified on three real SAR datasets. The comparison experiments with four state-of-the-art methods demonstrated the efficiency of the proposed method. Our codes are available at https://github.com/summitgao/SAR_CD_MS_CapsNet., Comment: 5 pages

Despite rapid improvements in efficiency and brightness of perovskite light-emitting diodes (PeLEDs), the poor operational stability remains a critical challenge hindering their practical applications. Here, we demonstrate greatly improved operational stability of high-efficiency PeLEDs, enabled by incorporating dicarboxylic acids into the precursor for perovskite depositions. We reveal that the dicarboxylic acids efficiently eliminate reactive organic ingredients in perovskite emissive layers through an in situ amidation process, which is catalyzed by the alkaline zinc oxide substrate. The formed stable amides prohibit detrimental reactions between the perovskites and the charge injection layer underneath, stabilizing the perovskites and the interfacial contacts and ensuring the excellent operational stability of the resulting PeLEDs. Through rationally optimizing the amidation reaction in the perovskite emissive layers, we achieve efficient PeLEDs with a peak external quantum efficiency of 18.6% and a long half-life time of 682 h at 20 mA cm(-2), presenting an important breakthrough in PeLEDs. Funding Agencies|ERC Starting grantEuropean Research Council (ERC) [717026]; Swedish Government Strategic Research Area in Materials Science on Functional Materials at Linkoping University (Faculty Grant SFO-Mat-LiU) [2009-00971]; China Scholarship Council (CSC)China Scholarship Council

The influence of sulfur on the hot compression properties of C71500 cupronickel alloy and the mechanism of thermo mechanical effect are studied for the first time. The composition of sulfide inclusions and its damage mechanism to properties were also studied. The effect of sulfur content on the dynamic recrystallization activation energy and the properties of the alloy was deduced and explained systematically. The relationship between the dynamic recrystallization activation energy and sulfur content was obtained, and a energy dissipation model was established based on the dynamic material model. The Prasad’s instability criterion was used to predict the unstable region in the processing chart. The effect of sulfur on the processing parameters selection was compared under different strain conditions, which could provide the ideal processing technology for the thermal deformation of C71500 alloy with various sulfur content.

In order to deal with the fluctuation of the renewable energy, this paper proposes rolling scheduling strategy taking into account the capacity of load-side resources. By considering the energy characteristics of shiftable loads, an improved rolling scheduling model is proposed by adopting a full-cycle scheduling and adding periodic power constraints. By this way, the accuracy of the scheduling can be improved. The testing examples verified that the proposed rolling scheduling method can reflect the long-time benefit and therefore result in better performance.

In the present study, we investigate the surface acid–base properties of anatase TiO2 nanomaterials with dominant {101} and {001} facets via methanol titrations. Two anatase nanoparticles, TiO2(101...

Recent progress in the synthesis of carbon materials from biomass and coal/heavy oil waste and their use as the electrode materials of supercapacitors and Li-ion batteries is reviewed. The carbon precursors include seafood and agricultural waste, and coal and heavy oil by-products. The carbon materials include 0D carbon quantum dots, 1D carbon nanofibers, 2D carbon nanosheets, and 3D carbon frameworks. Techniques to tailor the carbon porosity/surface include KOH activation with and without self-templating, self-activation and/or in-situ templating, and heteroatom doping with N, O, P and their co-doping. The effects of porosity and heteroatom doping on the electrochemical performance are summarized. The challenges for the synthesis, microstructural tailoring of these materials and their potential use in supercapacitors and Li-ion batteries are analyzed.