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The violent vibration of hydraulic pipelines in aircraft may cause faults or even an accident, especially for the large aircraft with the multi-pump system because of different vibration sources and complex pipelines system. Aiming to the vibration analysis and control of the multi-pump system, this paper proposed the clamps' locations optimization to minimize the system impedance at vibration frequencies. Firstly, the models of the flexible clamp and other components in multi-pump system were established, based on which, the system impedance was calculated by using Transfer Matrix Method (TMM); Secondly, the objective function is defined as weighted sum of system impedance at frequencies of different vibration sources. Then, the clamps’ locations were altered to change the system impedance. Moreover, The Chaotic Swarm Particle Optimization (CPSO) algorithm was applied to obtain the optimal clamps’ locations and the minimum value of objective function which decreased by 36.4% compared to the value of original clamps’ locations; Finally, the experiments from vibration and pressure test with original and optimized clamps’ locations verified the effectiveness of the system impedance calculation and clamps’ locations optimization method.

Nowadays, thermal condition and solute field are considered as the potential dominant factors controlling competitive grain growth during directional solidification process. However, the controlling modes and critical conditions of competitive grain growth have been drastically debated over the past two decades. In this work, thermal condition and solute field are combined to study the competitive grain growth in the converging case by experimental observation and numerical simulation of bicrystal samples. We find the competitive grain growth is controlled by the cooperative effect of thermal condition and solute field, and the controlling modes are related to the bicrystal misorientation between favorably and unfavorably oriented grains. When the unfavorably oriented grain is low misoriented, unfavorably oriented grain dominates grain selection, and the competitive grain growth performs as solute field domination. However, with the increase of unfavorably oriented grain's misorientation, the grain selection converts into favorably oriented grain domination, and the competitive grain growth changes to thermal condition domination. To explain these abnormal transformation phenomena, we propose a misorientation dependent thermal condition-solute field cooperative domination model and identify the critical conditions by a critical misorientation (θcm). According to dynamic equation of dendrite growth, we calculate the critical misorientation θcm to prove this model. The theoretical calculation results agree well with the experimental results.

Detailed three-dimensional (3D) microtomography characterizations of inclusions in electrode matrix, mushy zone (MZ) and liquid melt film (LMF) were performed to elucidate the motion and removal behavior of inclusions in electrode tip during magnetically controlled electroslag remelting (MC-ESR) process. A transient 2D numerical model was also built to verify the experimental results and proposed mechanisms. The number and size of inclusions exhibited an obvious increasing trend from edge to mid region in LMF, while remained almost the same in electrode matrix and MZ. The inclusions in LMF migrated from edge to mid region of LMF, accompanied with removal process. In addition, the kinetic conditions for inclusion migrating to LMF/slag interface (LSI) were enhanced during MC-ESR process, thereby improving the inclusion removal efficiency in LMF. This work highlights the 3D characterization and motion/removal mechanisms of inclusions in electrode tip, as well as sheds new light on preparing high purity materials.

Two-dimensional coordination polymers (CPs) have aroused tremendous interest as electrocatalysts because the catalytic performance could be fine-tuned by their well-designed coordination layers with highly accessible and active metal sites. However, it remains great challenge for CP-based catalysts to be utilized for electrocatalytic oxidation reactions due to their inefficient activities and low catalytic stabilities. Herein, we applied a mixed-metal strategy to fabricate two-dimensional CoxNi1−x-CPs with dual active sites for electrocatalytic water and urea oxidation. By metal ratio regulation in the two-dimensional layer, an optimized Co2/3Ni1/3-CP exhibits a water oxidation performance with an overpotential of 325 mV at a current density of 10 mA cm−2 and a Tafel slope of 86 mV dec−1 in alkaline solution for oxygen evolution reaction. Importantly, a lower potential than that of commercial RuO2 is observed over 20 mA cm−2. Co2/3Ni1/3-CP also displays a potential of 1.381 V at 10 mA cm−2 for urea oxidation reaction and a Tafel slope of 124 mV dec−1. This mixed-metal strategy to maximize synergistic effect of different metal centers may ultimately lead to promising electrocatalysts for small molecule oxidation reaction.

Summary Magnetoelectric (ME) coupling has gradually developed into one of the core means of advancing ultralow-power memory, logic, and sensor technologies. Among various strategies, magneto-ionic control of magnetism based on mechanisms such as redox, intercalation/deintercalation, and charge accumulation can be achieved in ion battery or capacitor systems. In this work, we demonstrate an ME effect originating from the spin capacitance, combining the advantages of intercalation batteries and supercapacitors. Giant, fast, and reversible modulations on the saturation magnetization of ferromagnets are achieved by Li ion motion across the ferromagnet/lithionic conductor interfaces at no more than 1 V. Furthermore, the magnetic evolution driven by the conversion reaction between FeO and Fe over a larger voltage range demonstrates ferromagnetic ordering of the FeO surface. These findings not only open new perspectives for developing high-performance magneto-ionic devices but also are crucial to designing spintronic devices composed of iron and oxide multilayer structures.

Deep learning-based hyperspectral image superresolution methods have achieved great success recently. However, most methods utilize 2D or 3D convolution to explore features, and rarely combine the two types of convolution to design networks. Moreover, when the model only contains 3D convolution, almost all the methods take all the bands of hyperspectral image as input to analyze, which requires more memory footprint. To address these issues, we explore a new structure for hyperspectral image superresolution using spectrum and feature context. Inspired by the high similarity among adjacent bands, we design a dual-channel network through 2D and 3D convolution to jointly exploit the information from both single band and adjacent bands, which is different from previous works. Under the connection of depth split, it can effectively share spatial information so as to improve the learning ability of 2D spatial domain. Besides, our method introduces the features extracted from previous band, which contributes to the complementarity of information and simplifies the network structure. Through feature context fusion, it significantly enhances the performance of the algorithm. Extensive evaluations and comparisons on three public datasets demonstrate that our approach produces the state-of-the-art results over the existing approaches.

In this work, we develop a novel synthetic strategy for wrinkled magnetic composite microspheres (Fe3O4@C). Firstly, hydrophobic oleic acid modified Fe3O4 (OA-Fe3O4) nanoparticles acted as the magnetic component are prepared by synchronous modification coprecipitation method. The macromolecular emulsifier with initiating activity is obtained by means of soap-free emulsion polymerization under the presence of 1,1-diphenylethylene (DPE). Then, interfacial polymerization is employed to synthesis Fe3O4@polymethylglycidyl ester/divinylbenzene composite microspheres (Fe3O4@PGMA/DVB). Fe3O4@C composite microspheres are obtained by vacuum carbonization of the microspheres. The effect of magnetic content on the microwave absorbing properties of Fe3O4@C composite microspheres is explored. The results show that Fe3O4@C composite microspheres exhibit the excellent application performance at the Fe3O4 content of 0.15 g. The reflection loss can reach −53.7 dB at only thickness of 1.7 mm. The Maximum effective absorption bandwidth is up to 5.26 GHz with a thickness of 1.9 mm. The microwave attenuation mechanism of Fe3O4@C composite microspheres is revealed. The excellent absorbing performance is attributed to the enhanced interfacial polarization ability, the surface wrinkled structure and the good synergy between dielectric and magnetic losses. This work provides an effective strategy for the design and preparation of new magnetic composite materials.

Photocatalytic nitrogen reduction for the green synthesis of ammonia at ambient conditions has been slowed by the narrow light harvesting range, low activity and high charge recombination of photocatalysts. Plasmonic semiconducting nanomaterials are becoming the promising candidates for nitrogen photofixation because of the broad absorption spectrum, rich defects and hot carriers. In the present study, plasmonic SrMoO4 is developed by regulating the concentration of oxygen vacancies that are accompanied in the reduction process from Mo6+ to Mo5+. The stable and tunable localized surface plasmon resonance (LSPR) absorption in visible and near infrared light range makes the wide bandgap SrMoO4 utilize the solar energy more efficiently. Energetic electrons from both the intrinsic band excitation and the LSPR excitation enable the reduction of dinitrogen molecules thermodynamically in ultrapure water to ammonia. This work provides a unique clue to design efficient photocatalysts for nitrogen fixation.

Hyperspectral image super-resolution (SR) methods based on deep learning have achieved significant progress recently. However, previous methods lack the joint analysis between spectrum and horizontal or vertical direction. Besides, when both 2D and 3D convolution are in the network, the existing models cannot effectively combine the two. To address these issues, in this article, we propose a novel hyperspectral image SR method by exploring the relationship between 2D/3D convolution (ERCSR). Our method alternately employs 2D and 3D units to solve the problem of structural redundancy by sharing spatial information during reconstruction for existing model, which can enhance the learning ability of 2D spatial domain. Importantly, compared with the network using 3D units, i.e., 2D units are replaced by 3D units, it can not only reduce the size of the model but also improve the performance of the model. Furthermore, to exploit the spectrum fully, the split adjacent spatial and spectral convolution (SAEC) is designed to parallelly explore information between spectrum and horizontal or vertical direction in space. Experiments on widely used benchmark datasets demonstrate that the proposed approach outperforms state-of-the-art SR algorithms across different scales in terms of quantitative and qualitative analysis.

This article is devoted to the H ∞ estimation problem for stochastic semi-Markovian switching complex-valued neural networks subject to incomplete measurement outputs, where the time-varying delay also depends on another semi-Markov process. A sequence of random variables with known statistical property is introduced to depict the missing measurement phenomenon. Based on the generalized It o ˆ ’s formula in complex form concerning with the semi-Markovian systems, complex-valued reciprocal convex inequality as well as intensive stochastic analysis method, some mode-dependent sufficient conditions are presented guaranteeing the estimation error system to be exponentially mean-square stable with a prespecified H ∞ disturbance attenuation level. In addition, the mode-dependent estimator gain matrices are appropriately designed according to the feasible solutions of certain complex matrix inequalities. In the end, one numerical example is provided to illustrate effectiveness of the theoretical results.

As one of promising distributed multi-robot system, Unmanned Aerial Vehicles (UAVs) can collaborate to offload complex tasks in edge networks. A Smart and Trust Multi-UAV Task Offloading (STMTO) system is established to offload tasks from Internet of Thing (IoT) devices to edge severs through UAVs with a trust style. In STMTO system, first, a group of UAVs is dispatched to relay tasks from devices to edge servers with rich computing resource. A collaborative task collection scheme is proposed to minimize energy consumption and the task processing delay by dividing working area for each UAV and designing the flight trajectory . Secondly, a many-to-many task double auction model is established for devices and edge servers to maximize the offloading utility, where devices act as buyers, edge servers as sellers, and UAVs as auctioneers. Last, to resist attack of malicious edge servers and ensure the task security, a novel trust evaluation method based on the comparison of true utility and expected utility is integrated in auction mechanism. The theoretical analysis and implementation results show that the proposed STMTO system not only achieve the best utility for devices and edge servers simultaneously, but also identify the malicious edge servers and protect task from attacks.

This paper develops a neural-network-based model reference adaptive control (MRAC) scheme for a rotorcraft in the presence of input saturation. Such a control scheme provides acceptable tracking performance for the rotorcraft in a wide range of flight conditions. Combined with hyperbolic tangent functions, the MRAC scheme is capable of tracking the reference signals without violating input constraints. A modified projection operator is utilized to prevent system from parameter drift due to the strong nonlinearity and uncertainty of the rotorcraft mathematical model. Stability of the proposed MRAC scheme is proved based on Lyapunov stability theory. The performance of the resulting controller is tested by conducting numerical simulations for an autonomous rotorcraft in various flight missions.

The increasing demand to develop sustainable energy storage equipment has aroused interest for potassium-ion capacitors (PICs), owing to their high abundance and low cost of potassium sources. Nevertheless, the practical application of PICs is impeded by the lack of suitable anode materials with high performance. Here we demonstrate a solvothermal-assisted synthesis of porous CoV2O6 nanosphere@graphene oxide (GO) composites as the anode material of PICs for the first time. Benefiting from the well-designed porous nanostructure and high-conductivity carbon incorporation, the hybrid composite delivers an initial high discharge capacity (264 mAh g−1, 1 A g−1) and superior rate capability (97 mAh g−1, 10 A g−1). Moreover, the electrochemical reaction mechanism of CoV2O6 involving an intercalation followed by conversion reaction is comprehensively revealed by first-principles calculations (DFT), ex-situ X-ray photoelectron spectroscopy as well as ex-situ high-resolution transmission electron microscopy. Meanwhile, the DFT also indicates that CoV2O6 possesses high electron/K-ion conductivity and low diffusion barriers for K+ intercalation. Consequently, PICs coupling the CoV2O6@GO anode and activated carbon cathode display a high energy/power density (78.2 Wh kg−1 and 22,500 W kg−1) as well as an ultralong lifespan over 3000 cycles. The work delves metal vanadate as high-performance anode for PICs and may provide innovative insight into electrode structure building in rechargeable metal-ions chemistry.

As a novel wastewater treatment strategy, the intimate coupling of photocatalysis and biodegradation (ICPB) has been attracted attention, which is ascribed to its combination of the advantages of photocatalytic reactions and biological treatment. The selection of carriers is important since it affects the stability of the system and the removal efficiency of pollutants. In this study, a novel ICPB system was successfully constructed by loading photocatalytic materials (i.e., TiO2, N-TiO2, and Ag-TiO2) and microbes onto non-woven cotton fabric. The photocatalysts were characterized by scanning electron microscope-energy dispersive spectrometer (SEM-EDS), X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). This system exhibited good performance in degrading tetracycline (TC) in water. The results showed that Ag-TiO2-ICPB had the maximum removal efficiency of tetracycline (94.7%) in 5 h, which was 16.5% higher than the photocatalysis alone. After five cycles, 82.9% of tetracycline could be still degraded through Ag-TiO2-ICPB. SEM spectrum showed microbes on the material changed little before and after the reactions. This result implied the materials were stable, and then beneficial for degrading of pollutants continuously. The intermediates were detected through ultraperformance liquid chromatography-mass spectrometer (UPLC-MS) and the plausible degradation pathways were proposed. Electron paramagnetic resonance (EPR) analysis showed OH and O2 − were the main reactive oxygen species for TC degradation. In conclusion, the ICPB system with non-woven cotton fabric as a carrier has certain application prospects for antibiotic-containing wastewater.

In recent years, carbon materials derived from metal-organic frameworks (MOFs) have attracted much attention in the field of microwave absorption. It is challenging to prepare composite absorbers with a controllable binary MOF-on-MOF heterostructure. Here, we construct two binary hybrid MOF heterostructures through selective assembly strategies, and realizes their conversion to magnetic porous carbon materials through a simple carbonization process. The special hybrid structure of hexagonal pyramid column and octahedron depends on the selective growth of the guest MOF on the specific crystal facet of the host MOF. The microwave absorbing properties of carbonized UIO-66@Co-doped MIL-88B (UM) and DUT-52@Co-doped MIL-88B (DM) are systematically studied. The selectively combined heterogeneous components endow the absorber with hierarchical pore structures, optimal impedance matching and excellent electromagnetic attenuation capabilities. The products carbonized at 700 °C (UM-700 and DM-700) exhibit superior microwave absorbing properties. It is worth noting that only with a matching thickness of 2 mm, the minimum reflection loss (RLmin) of DM-700 exceeds −65.2 dB, and the effective absorption bandwidth (EAB, RL

Groundwater pumping can reduce streamflow by reducing groundwater discharge and/or inducing streamflow infiltration, which together are referred to as streamflow depletion. Recently, analytical depletion functions (ADFs) have been suggested as rapid and accurate tools for streamflow depletion assessment, but their performance has only been tested in a few hydrogeological settings. To evaluate whether they will be useful tools for other regions with contrasting stream network and hydrogeological characteristics, we compared ADFs to calibrated MODFLOW models in BX Creek and Peace Region with distinct hydrogeological settings (interior plateaus & highlands, and boreal plains, respectively) and spatial scales (165 km2 and 1952 km2, respectively) in British Columbia, Canada. Results showed that ADFs can accurately identify streams most affected by pumping for 100% and 83% of wells in the BX Creek and Peace Region, respectively, and had small prediction errors compared with MODFLOW. Specifically, the mean absolute error of predicted depletion ranged from 2% to 14% of the highest simulated pumping rate over the study period of 30 years, with improved accuracy during the pumping season. We also found contrasting responses of ADF performance to hydrostratigraphic properties such as hydraulic conductivity, aquifer thickness, streambed conductance, and well depth across two domains, indicating that different drivers control ADF accuracy in different hydrogeological settings. Therefore, we conclude that ADFs are useful tools for conjunctive water management, but a good understanding of local hydrogeological conditions is needed to address the potential uncertainty of ADFs for decision-making.

In spite of the excellent electrochemical performance in lithium-ion batteries (LIBs), transition-metal compounds usually show inferior capacity and cyclability in sodium-ion batteries (SIBs), implying different reaction schemes between these two types of systems. Herein, coupling operando magnetometry with electrochemical measurement, we peformed a comprehensive investigation on the intrinsic relationship between the ion-embedding mechanisms and the electrochemical properties of the typical FeS2/Na (Li) cells. Operando magnetometry together with ex-situ transmission electron microscopy (TEM) measurement reveal that only part of FeS2 is involved in the conversion reaction process, while the unreactive parts form "inactive cores" that lead to the low capacity. Through quantification with Langevin fitting, we further show that the size of the iron grains produced by the conversion reaction are much smaller in SIBs than that in LIBs, which may lead to more serious pulverization, thereby resulting in worse cycle performance. The underlying reason for the above two above phenomena in SIBs is the sluggish kinetics caused by the larger Na-ion radius. Our work paves a new way for the investigation of novel SIB materials with high capacity and long durability.

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.

(1-x)(Bi0.5Na0.5)0.94Ba0.06TiO3-xAgNbO3 lead-free piezoelectric ceramics (abbreviated as BNBT-100xAN) were prepared using the conventional solid-state sintering method. The effects of the introduction of AgNbO3 (AN) dopants for the dielectric and piezoelectric performances of BNBT-100xAN ceramics were systematically studied. The XRD patterns and Raman spectra demonstrated that AN as a modifier was successfully diffused into the BNBT-100xAN lattice and revealed a pseudo-cubic symmetry structure. All samples exhibited a dense surface morphology accompanied by the uniform distribution of elements. A large bipolar strain of ~0.501% and unipolar strain of ~0.481% corresponding to the normalized strain d33* of ~740 p.m./V were achieved for BNBT-1AN ceramic at 65 kV/cm field. The BNBT-4AN ceramic exhibited an excellent temperature-stable permittivity with the range from 59 to 380 °C and its dielectric loss was less than 0.02 between 97 °C and 329 °C. These results revealed that BNBT-100xAN ceramics were more hopeful candidates for actuators, strain sensors, and high-temperature capacitors.

Nanoparticles with high roughness and complex surface have strong reflection and scattering ability for electromagnetic wave, which can extend the propagation path of electromagnetic wave in absorbing coating, thus exhibiting better microwave absorbing performance. Constructing complex surface has been considered as an effective way to improve the microwave loss ability of microwave absorbers. In this paper, a novel bowknot-like N-doped Co@C magnetic nanoparticle constituted by acicular structural units (BNCoC) has been designed and prepared. Its precursor (BNCoCP) is synthesized by solvothermal method and converted into BNCoC by subsequent vacuum calcination. The main structure of BNCoC is N-doped carbon with Co nanoparticles embedded in it. BNCoC contains dielectric and magnetic components that has both dielectric loss and magnetic loss capabilities. Under the synergistic effect of its unique structure, BNCoC exhibits excellent absorbing performance with a minimum reflection loss of −47.6 dB@11.0 GHz@2.7 mm. Furthermore, the effects of calcination temperature and filler content on microwave absorbing performance are investigated. The electromagnetic parameters are analyzed in depth to reveal the microwave loss mechanism. This work reports a novel high-efficiency microwave absorber with unique structure. It provides a new method for microstructure design of microwave absorbing materials.

Natural macromolecules have attracted increasing attention due to their biocompatibility, low toxicity, and biodegradability. Pectin is one of the few polysaccharides with biomedical activity, consequently a candidate in biomedical and drug delivery Applications. Rhamnogalacturonan-II, a smaller component in pectin, plays a major role in biomedical activities. The ubiquitous presence of hydroxyl and carboxyl groups in pectin contribute to their hydrophilicity and, hence, to the favorable biocompatibility, low toxicity, and biodegradability. However, pure pectin-based materials present undesirable swelling and corrosion properties. The hydrophilic groups, via coordination, electrophilic addition, esterification, transesterification reactions, can contribute to pectin's physicochemical properties. Here the properties, extraction, and modification of pectin, which are fundamental to biomedical and drug delivery applications, are reviewed. Moreover, the synthesis, properties, and performance of pectin-based hybrid materials, composite materials, and emulsions are elaborated. The comprehensive review presented here can provide valuable information on pectin and its biomedical and drug delivery applications.

This paper is concerned with the robust state estimation problem for semi-Markovian switching complex-valued neural networks with quantization effects (QEs). The uncertain parameters are described by the linear fractional uncertainties (LFUs). To enhance the channel utilization and save the communication resources, the measured output is quantized before transmission by a logarithmic quantizer. The purpose of the problem under consideration is to design a full-order state estimator to estimate the complex-valued neuron states. Based on the Lyapunov stability theory, stochastic analysis method, and some improved integral inequalities, sufficient conditions are first derived to guarantee the estimation error system to be globally asymptotically stable in the mean square. Then, the desired state estimator can be directly designed after solving a set of matrix inequalities, which is robust against the LFUs and the QEs. In the end of the paper, one numerical example is provided to illustrate the feasibility and effectiveness of the proposed estimation design scheme.

(1-x)[0.94(Bi0.5Na0.5)TiO3-0.06BaTiO3]-xBa(Sn0.70Nb0.24)O3 (abbreviated as BNTBT-100xBSN) lead-free ceramics were fabricated with a relative density greater than 96 %, and the structure as well as performance were tested. BNTBT-100xBSN ceramics are pseudo-cubic perovskite structure, with dense surface morphology. Doping BSN can effectively reduce the dielectric loss of ceramics and increase the relaxation properties to a certain extent. The randomly distributed ferroelectric phase was replaced by polar nano regions, thereby improving the electro-strain and energy storage performance of the system. The largest electro-strain and the corresponding normalized strain (d33*) reach ~ 0.43 % and 633 pm/V respectively in the BNTBT-1BSN ceramic. The largest effective energy storage density reaching ~ 1.28 J/cm3 was tested in BNTBT-2BSN. BNTBT-100xBSN ceramics provide a feasible idea for the systematic research of lead-free ferroelectrics and improvements in electro-strain and energy storage applications.

In this manuscript, Ni–TiN thin coatings were deposited on 45 steel substrate surfaces using a magnetically assisted pulse electrodeposition (MAPE) technique. The surface topographies, chemical compositions, microstructures, microhardnesses, and corrosion properties of the Ni–TiN thin coatings were examined using scanning electron microscopy (SEM), X-ray diffraction (XRD), scanning probe microscopy (SPM), triboindenter in-situ nanomechanical testing, as well as corrosion and wear testing. Results indicated that the Ni grain size in the Ni–TiN thin coatings gradually decreased as the grain size of TiN decreased from 180 nm to 32 nm. The mean sizes of TiN nanoparticles and Ni grains in the NT32 thin coating were 41.5 nm and 379.2 nm, respectively. The microhardness of NT180 was the lowest among all three coatings with a mean value of 597.2 HV. Conversely, the mean microhardness of the NT32 thin coating was the highest at 902.9 HV. The size of the TiN particles had a significant effect on the corrosion properties of the Ni–TiN thin coatings, and the corrosion curve of the thin coating of NT32 slowly grew throughout the experiment. Under the same wear test conditions, the NT180 coating showed higher wear mass loss, while the wear mass loss of the NT32 thin coating was the lowest at 36.4 mg.

The shear-extrusion bonding (SEB) of pure iron (99.9 %) and pure nickel (99.5 %) are carried out under the experiment condition of heating temperature 1050℃, top die speed 12 mm/s with different deformation degrees. The Fe/Ni diffusion behavior is analyzed through experimental studies and theoretical analysis. The results indicate that a diffusion layer about 3 μm thick is formed through Fe/Ni interdiffusion and the main compositions of the diffusion layer are Ni and Fe-Ni solid solution. It is found a large number of vacant clusters are formed at the Fe/Ni interface in the SEB process. The diffusion of matrix atoms or substitutional solute atoms is mainly realized by vacancies, so the diffusion mechanism of Fe/Ni in SEB process is vacancy diffusion mechanism or vacancy pair diffusion mechanism. The actual interdiffusion coefficient of Fe/Ni in SEB process is 100∼1000 times higher than the interdiffusion coefficient of Fe/Ni atoms under thermal action. So the plastic deformation provides additional vacancies to promote the formation of diffusion layer. The relative diffusion layer thickness increases from 6.02 μm to 12.01 μm when the deformation degree increases from 50 % to 74.2 %, and the relative diffusion layer thickness increases linearly with the increase of deformation degree.

The flow characteristic of high pressure dense-phase pneumatic conveying of pulverized coal is essential to the safe and stable operation of the gasifier. In this paper, the effects of coal moisture content on conveying behavior and resistance characteristics of dense-phase pneumatic conveying were explored. Meanwhile, a model of the additional pressure drop of particles was proposed and compared with the experimental data. The results show that though the resistance and cohesiveness increase with increasing moisture content, its influence is different in dense and dilute phase. In the dense-phase region, the coal with lower moisture content shows a larger solid mass flow rate and solid concentration; while in the dilute-phase region, the moisture content has minor effect on conveying characteristics. For the coal with lower moisture content in dense-phase region, the solid mass flow rate and solid concentration are larger, and the gas velocity has a small effect on solid friction factor, due to its smaller cohesiveness and resistance, which is showed in our experiments and inferred from our model. The additional pressure drop model was proposed for straight pipes and bends, whose parameters are probably effective than the existing parameters in this kind of model, as the deviation in the vertical rise pipe, horizontal pipe and bend pipe is controlled within ±30%, and the corresponding vertical down pipe are controlled within ±40%.

Personal protective equipment (PPE) has been highly recommended by the U.S. Centers for Disease Control and Prevention for self-protection during the disastrous SARS-CoV-2 (COVID-19) pandemic. Nevertheless, massive utilization of PPE encounters significant challenges in recycling and sterilizing the used masks. To tackle the associated plastic pollution of used masks, in this work, we designed a reusable, biodegradable, and antibacterial mask. The mask was fabricated by the electrospinning of polyvinyl alcohol (PVA), poly(ethylene oxide) (PEO), and cellulose nanofiber (CNF), followed by esterification and the deposition of a nitrogen-doped TiOsub2/sub(N-TiOsub2/sub) and TiOsub2/submixture. The fabricated mask containing photocatalytic N-TiOsub2/sub/TiOsub2/subreached 100% bacteria disinfection under either 0.1 sun simulation (200-2500 nm, 106 W msup-2/sup) or natural sunlight for only 10 min. Thus, the used mask can be rejuvenated through light irradiation and reused, which represents one of the handiest technologies for handling used masks. Furthermore, intermolecular interactions between PVA, PEO, and CNF enhanced the electrospinnability and mechanical performance of the resultant mask, which possesses a 10-fold elastic modulus and 2-fold tensile strength higher than a commercial single-use mask. The porous structures of electrospun nanofibers along with strong electrostatic attraction enabled breathability (83.4 L minsup-1/supof air flow rate) and superior particle filterability (98.7%). The prepared mask also had excellent cycling performance, wearability, and stable filtration efficiency even after 120 min wearing. Therefore, this mask could be a great alternative to current masks to address the urgent need for a sustainable, reusable, environmentally friendly, and efficient PPE under the ongoing COVID-19 contagion.

The effect of oxygen on the microstructure and mechanical properties of thermally treated rocks is a matter of rock engineering. For comparative analysis, in this study, the sandstone specimens were heated in a vacuum and aerobic environment. It was subsequently subjected to a series of scanning electron microscopy (SEM), P-wave velocity, X-ray diffraction (XRD), and surface colour observation tests. The effect of oxygen on the thermal damage mechanism of sandstone was studied according to the diversities in sandstone microstructure and mineral composition under different heating environments. Then, static and dynamic compression tests were carried out on the heated specimens under different environments; the effect of oxygen on the mechanical properties of sandstone was studied. The results show that the initial temperature of the mineral oxidation reaction was the threshold temperature at which the microstructure, mineral composition, and mechanical parameters of the specimen were heated in different environments to diverge. As the temperature rose, the oxidation reaction of pyrite and chlorite, and related chemical reactions gradually deepened, the thermal damage and mechanical properties of specimens heated in an aerobic environment were more deteriorated than that of the vacuum environment. Therefore, it can be inferred that the oxidation reaction of minerals at high temperatures exacerbated the thermal damage to the sandstone and led to a further deterioration in its mechanical properties. This has important implications for stability analysis of high-temperature rock engineering in aerobic environments.

Environmental impacts can be variously assessed and valued, depending on institutional framework and discursive context. The case study of Fuzhou City, China, shows that ecological processes can be...

Control of thermal emission underpins fundamental science, as it is related to both heat and infrared electromagnetic wave transport. However, realizing nonvolatile reconfigurable thermal emission is challenging due to the inherent complexity or limitation in conventional radiative materials or structures. Here, we experimentally demonstrate a nonvolatile optically reconfigurable mid-infrared coding radiative metasurface. By applying laser pulses, infrared emissive patterns are directly encoded into an ultrathin (∼25 nm) Ge2Sb2Te5 layer integrated into a planar optical cavity with the optically crystallized Ge2Sb2Te5 spots, and the peak spectral emissivity is repeatedly switched between low (∼0.1) and high (∼0.7) values. In addition, the visible scattering patterns are independently modulated with submicron-sized bumps generated by high-power laser pulses. An anticounterfeiting label is demonstrated with spatially different infrared emission and visible light scattering information encoded. This approach constitutes a new route toward thermal emission control and has broad applications in encryption, camouflage, and so on.

A multi-mode flapping wing micro air vehicle (FWMAV) that uses a figure eight wingtip motion trajectory with wing flapping, rotation, and swing motion is presented in this paper. The flapping wing vehicle achieves three active degrees of freedom (DOF) wing movements only with one driving micromotor which has a good balance in the mechanism design (that is inspired by natural fliers) and total weight. Owing to these characteristics being integrated into the simple mechanism design, the aerodynamic force is improved. The aerodynamic performance of the thrust force is improved by 64.3 % compared to one that could only flap up and down with one active DOF under the condition of routine flapping frequency.

Copyright © 2021 The Author(s). The microstructure characteristics in early stage shear localization of near-α Ti−6Al−2Zr−1Mo−1V titanium alloy were investigated by split Hopkinson pressure bar (SHPB) tests using hat-shaped specimens. The microstructural evolution and deformation mechanisms of hat-shaped specimens were revealed by electron backscattered diffraction (EBSD) method. It is found that the nucleation and expansion of adiabatic shear band (ASB) are affected by both geometric and structural factors. The increase of dislocation density, structure fragment and temperature rise in the deformation-affected regions provide basic microstructural conditions. In addition to the dislocation slips, the extension twins detected in shear region also play a critical role in microstructural fragmentation due to twin-boundaries effect. Interestingly, the sandwich structure imposes a crucial influence on ASB, which finally becomes a mature wide ASB in the dynamic deformation. However, due to much larger width, the sandwich structure in the middle of shear region is also possible to serve as favorable nucleation sites for crack initiation. Pre-research Project of Equipment Development Department of China (No. 41422010505); Technology Innovation Leading Program of Shanxi Province, China (No. 2019CGHJ-21).

Since the proposal of orthogonal frequency-division multiplexing with subcarrier number modulation (OFDM-SNM), the high detection complexity of this novel modulation scheme becomes a major issue degrading its applicability in practice. To provide an easy-to-implement and low-complexity solution to the detection of the OFDM-SNM signal, we design a cascaded artificial neural network (CANN) at the OFDM-SNM receiver to decouple the detection of subcarrier number pattern (SNP) and constellation symbols on the active subcarriers. This is the first time that the CANN design is introduced to assist in detecting parallel signals. Numerical simulations verify the effectiveness and efficiency of the proposed smart detection scheme and show that the CANN based smart detection with adequate training can yield comparable error performance to the optimal maximum-likelihood detection at much lower complexity.

Hyperspectral images can provide dozens to hundreds of continuous spectral bands, so the richness of information has been greatly improved. However, these bands lead to increasing complexity of data processing, and the redundancy of adjacent bands is large. Recently, although many band selection methods have been proposed, this task is rarely handled through the context information of the whole spectral bands. Moreover, the scholars mainly focus on the different numbers of selected bands to explain the influence by accuracy measures, neglecting how many bands to choose is appropriate. To tackle these issues, we propose a fast neighborhood grouping method for hyperspectral band selection (FNGBS). The hyperspectral image cube in space is partitioned into several groups using coarse-fine strategy. By doing so, it effectively mines the context information in a large spectrum range. Compared with most algorithms, the proposed method can obtain the most relevant and informative bands simultaneously as subset in accordance with two factors, such as local density and information entropy. In addition, our method can also automatically determine the minimum number of recommended bands by determinantal point process. Extensive experimental results on benchmark data sets demonstrate the proposed FNGBS achieves satisfactory performance against state-of-the-art algorithms.

A series of lead-free (Bi0.5Na0.5)0.94Ba0.06Ti1-x(Y0.5Nb0.5)xO3 (for 0 ≤ x ≤ 0.03) perovskite ceramics were fabricated using a solid-state reaction technique. The effects of (Y0.5Nb0.5)4+ ions doping on phase structure, piezoelectric properties, AC impedance, and fatigue resistance were systematically studied. Crystal structure as a function of the composition revealed a single perovskite lattice structure with dense micromorphology. The transition temperature of the non-ergodic and ergodic relaxor ferroelectric phase shifted to near ambient temperature with increasing composition, which was related to the destruction of the long-range ordered ferroelectric domains. Hence, the transformation of ferroelectric-to-relaxor phase was easier under applied electric field at room temperature. The ceramic for x = 0.01 composition attained a large unipolar strain of ~ 0.452% with a corresponding normalized strain (d33*) of ~ 603 pm/V under applied 75 kV/cm field. Besides, the excellent fatigue resistance of the sample was obtained after 105 switching cycles under 70 kV/cm. These phenomena demonstrated that (Bi0.5Na0.5)0.94Ba0.06Ti1-x(Y0.5Nb0.5)xO3 ceramics might be suitable for a wide range of electronic equipment applications such as actuators and sensors.

This article presents a new type of axial-field switched reluctance machine (AFSRM) and axial-field dual-rotor segmented switched reluctance machine (ADS-SRM), along with its design methodology. The proposed ADS-SRM is featured by the segmental stator and rotor poles, the auxiliary flux-conductive rings, and the concentrated windings. The yokeless topology reduces the active length of the motor. Besides, the adopted short-end winding layout increases the slot-fill factor and the motor’s reliability. First, the basic topology of ADS-SRM is introduced along with its operating principle and various stator/rotor pole combinations. The three-phase 12/8 configuration of ADS-SRM is chosen for further analysis. Then, the design methodology considering the fringing and leakage field effects through the magnetic equivalent circuit (MEC) method is developed, and the flowchart detailing the design procedure is presented. Through the comparison with the conventional yokeless and segmented armature (YASA) topology, ADS-SRM exhibits excellent performance at overload conditions. The prototype is designed and fabricated, and the experimental results verify the motor performance.

Advanced persistent threats (APTs) have become a major cyber threat to large organizations. To steal confidential data from specific organizations, attackers adopt highly targeted intrusion schemes. Prior to stealing critical data, APT activities hide themselves in legitimate activities and consistently elevate their privileges, making them very difficult to detect. The detection of malicious domains during domain name service (DNS) analysis accounts for the majority of existing detection methods. However, a limited number of available samples and rapidly changing sets of malicious domain names reduce the efficacy of such approaches. By investigating numerous APT reports, we determined that the activities of DNS requests in APT attacks exhibit clear temporal patterns that are ignored by most existing schemes. Therefore, we can analyze the DNS sequences requested by each host and their time-related features to identify compromised hosts. This paper summarizes the patterns of host DNS requests and proposes several assumptions. We take advantage of machine learning to identify compromised hosts by quantifying these assumptions in the form of feature vectors. We deployed the proposed approach into large-scale network environments and experimental evaluations demonstrated that our method is able to detect hosts compromised by APTs efficiently with a precision of 97.3% and detection rate of 96.2%.

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.

In order to improve the anti-corrosive ability of a Ni-SiC nanocoating, a jet electrodeposition technique was used to prepare a Ni-SiC nanocoating on the substrate of a Q235 steel surface. Using FLUENT software to simulate the effects of different nozzle diameters on the jet rate and kinetic energy parameters of the plating solution, the surface morphology, microstructure, and corrosion behaviors of the jet-electrodeposited Ni-SiC nanocoatings prepared with different nozzle diameters were examined using scanning electron microscopy, transmission electron microscopy, x-ray diffraction, and an electrochemical workstation. The kinetic energy (543 kg m2/s2) and jet rate (113 m/s) of the plating fluid were maximized using a nozzle diameter of Φ8 mm. Results indicate that the surface structure of the Ni-SiC nanocoating prepared using a nozzle diameter of Φ8 mm presented compact, homogeneous, and abundant SiC particles embedded into the Ni-SiC nanocoating, and the average diameters of the Ni and SiC particles were 76.4 nm and 33.2 nm, respectively. This proved that the diameter of the nozzle had a significant influence on the anti-corrosive properties of the Ni-SiC nanocoating, where a nozzle diameter of Φ8 mm was shown to be optimal. It has been shown that nozzle diameter improves kinetic energy and jet rate of the plating fluid, thereby improving anti-corrosive properties and generating a compact and uniform microstructure.

Conductive polymer composites (CPCs) as the thermo-sensitive materials have attracted much attention in thermal control field due to their reliable self-regulating behaviors, high efficiency and mechanical flexibility. However, the development of these materials needs to manage the normal conflicting requirements, such as effective heating performance and good self-regulating capability. This paper presents a series of novel CPCs material having different amounts of hybrid fillers of multi-walled carbon nanotubes (CNTs) and carbon black (CB). The positive temperature coefficient intensity is enhanced to 105.2, and the room-temperature resistivity is optimized to 320 Ω cm. Besides, the Curie temperatures are regulated to room-temperature range by incorporating the low-melting-point blend matrix into the poly(ethylene-co-vinyl acetate)/CNTs/CB composite. The thermal-control experiment demonstrates that CPCs-heating elements can adjust the equilibrium temperature of controlled equipment near their Curie temperatures without any control methods. Compared with the ordinary resistor, the CPCs materials have the remarkable adaptive thermal control behavior. Furthermore, the temperature control capability is particularly prominent in the changing environment temperature. The CPCs as a safe and reliable adaptive heating element is potential to replace the conventional active thermal control means.

Since 2015, six typical masonry cultural relics around the China’s UNESCO World Heritage Site — the West Lake Cultural Landscape of Hangzhou have been systematically monitored from three aspects: deterioration patterns, physical and mechanical properties, and the changes of the micro-environment, using non-destructive testing equipment like optical microscope, ultrasonic pulse wave, Schmidt hammer, surface roughness tester, thermohygrometers, rain gauges, air quality monitors and so on. High-throughput sequencing technology had also been used to study distribution and diversity of microorganisms on the surface of masonry. Results show that the deterioration of relics can be reflected by their physical and mechanical properties, comprehensive evaluation of the heritage’s health state can be made through long-term continuous monitoring. It also found that different deterioration pattern will occur with different types of materials or in different preservation conditions, marble artifacts which completely exposed outdoors tends to significant degradation in just five years due to temperature fluctuations and acid rain. Besides, Microorganisms’ growth and propagation correlate positively with environmental conditions. As a case study, this paper described in detail the whole process of monitoring the deterioration of masonry relics at a UNESCO World Heritage sites, which may provide some references for researchers in similar fields.

Ti-15Nb-25Zr-(0, 4, 8)Fe (mol.%) alloys were prepared via spark plasma sintering (SPS) for 10 min at 800, 1000, and 1200 °C to study the effect of sintering temperatures and Fe content on the mechanical properties of alloys. The main phase of the alloys sintered at 800 °C is α phase. When the temperature is increased to 1000 and 1200 °C, the alloys are mainly β phase. Raising the sintering temperature can promote the diffusion of elements. Therefore, high strength and high plasticity are obtained in the alloys sintered at high temperature. The compressive strength of Ti-15Nb-25Zr sintered at 1200 °C is 1604 MPa, and the fracture strain is around 35%. The strength and plasticity are influenced by the complex effects of elemental diffusion, grain boundary and solid-solution strengthening. Adding Fe can improve the diffusion of elements, promote the formation of β grains and supply solid-solution strengthening effect. As the sintering temperature is increased, the compressive strength of Ti-15Nb-25Zr-4Fe shows an increasing trend and the plasticity is almost not changed. The Fe content is excessive in Ti-15Nb-25Zr-8Fe, which leads to some disadvantages including intermetallic compounds formation and grain boundary coarsening. The mechanical properties of Ti-15Nb-25Zr-8Fe are not always better than those of Ti-15Nb-25Zr-4Fe. The compressive strength of Ti-15Nb-25Zr-8Fe shows an increasing trend and the plasticity firstly increases and then decreases when the temperature is raised from 800 up to 1200 °C. Although the sintering time of SPS is short, Ti-15Nb-25Zr-(4, 8)Fe sintered at 1000 °C and Ti-15Nb-25Zr-(0, 4)Fe sintered at 1200 °C show good combination of strength and plasticity.

Detecting and characterizing Total Electron Content (TEC) depletion is important for studying the ionospheric threat due to the Equatorial Plasma Bubble (EPB) when applying the Ground-Based Augmentation System (GBAS) at low latitudes. This paper develops a robust method to automatically identify TEC depletion and derive its parameters. The rolling barrel algorithm is used to automatically identify the TEC depletion candidate and its parameters. Then, the depletion candidates are screened by several improved techniques to distinguish actual depletions from other phenomena such as Traveling Ionospheric Disturbance (TID) or abnormal data. Next, based on the depletion signals from three triangular receivers, the method derives EPB parameters such as velocity, width and gradient. The time lag and front velocity are calculated based on cross-correlation using TEC depletions and the geometrical distribution of three triangular receivers. The width and gradient of slope are then determined by using TEC depletion from a single receiver. By comparison, both the station-pair method and proposed method depend on the assumption that the EPB morphology is frozen during the short time when the plasma bubble moves between the receivers. However, our method relaxes the restriction that the baseline length should be shorter than the width of slope required by the station-pair. This relaxation is favorable for studying small-scale slope of depletions using stations of a longer baseline. In addition, the accuracy of the width and gradient is free of impact from hardware biases and small-scale disturbance, as it is based only on the relative TEC variation. The method is demonstrated by processing Global Positioning System (GPS) and BeiDou Navigation Satellite System (BDS) data on 15 August, 2018, in a solar minimum cycle.

Surface cracking induced by damage accumulation is a common quality problem during the hot processing of powder metallurgical (P/M) products. This study aims to clarify the damage and fracture of P/M Fe–Cu–C steel at elevated temperatures to propose its fracture criterion by combining hot tensile tests with finite element (FE) calculations. The results reveal that the FE-aided test accurately corrected the true stress and strain of the P/M steel during the Gleeble hot tensile testing. In addition, the flow behaviors and cracking tendency of the P/M steel strongly depended on the hot deformation parameters. The optimum hot processing window of P/M steel was proposed after determining the quantitative relationships between the damage and hot deformation parameters. Finally, a novel elevated temperature fracture strain model of the P/M steel was proposed based on the Zener–Hollomon parameter to construct its Cockroft and Latham fracture criterion coupling hot processing parameters. The constructed fracture criterion was further normalized and modified, and achieved an acceptable fracture predictive capability with a relative error of less than 5%, which was validated by powder forging experiments. This work provides essential information and a useful model for the fracture prediction of P/M Fe–Cu–C steel at elevated temperatures, helping to manage the surface cracking problems of P/M steel during hot processing.

Fe-based amorphous magnetic powder cores (AMPCs) with excellent comprehensive properties were successfully fabricated via using the uniform double insulating layer core-shell structured FeSiBPC/Fe3O4@Epoxy resin (EP). The effects of the in-situ hydrothermal oxidized time on the magnetic properties of the AMPCs have been systematically investigated on the basis of the growth mechanism of the insulating layer of spherical amorphous powder in alkaline environment. The hydrothermal oxidation process could well ensure the uniformity of the oxide layer composed of Fe3O4 nanoparticle. The evolution of the insulating layer is a process of homogeneous nucleation and growth at different hydrothermal oxidation time. After 10 h of hydrothermal oxidation, a thin and dense layer composed of Fe3O4 nanoparticle was formed on the surface of the amorphous powder. As a consequent, the FeSiBPC AMPCs exhibit excellent performance such as stable effective permeability of 49.5 at 2 MHz, a very low core loss of 187 mW/cm3 at 100 kHz@0.05 T and high-quality factor of 160 at 600 kHz. The results indicate that the thickness of the Fe3O4 insulating layer can be completely controlled via the reaction parameters, and can effectively suppress the eddy current loss, which is promising for high-frequency electromagnetic systems.

Compared to the widely used carbon-centered radicals, N-radicals have been relatively unexplored owing to the lack of practical and convenient production methods. Over the past few years, benefitting from the resurgence of reliable and controllable radical chemistry, N-radicals have been produced via thermal decomposition, oxidants, metal salts, or electrocatalysis. Therefore, numerous N-radical enabled cyclization of 1,n-enynes methods have been developed, providing a versatile and concise synthetic platform for the preparation of complex cyclic systems and natural products containing elaborate ring frameworks. In this review, we will summarize recent advances in the promising field of radical chemistry focusing on the production methods of N-radicals and their cyclization patterns, associated mechanisms, unmet challenges, and future opportunities.

Remarkable advances in nano delivery systems have provided new hope for tumor prevention, diagnosis and treatment. However, only limited clinical therapeutic effects against solid tumors were achieved. One of the main reasons is the presence of abundant physiological and pathological barriers in vivo that impair tumoral penetration and distribution of the nanodrugs. These barriers are related to the components of tumor microenvironment (TME) including abnormal tumor vasculature, rich composition of the extracellular matrix (ECM), and abundant stroma cells. Herein, we review the advanced strategies of TME remodeling to overcome these biological obstacles against nanodrug delivery. This review aims to offer a perspective guideline for the implementation of promising approaches to facilitate intratumoral permeation of nanodrugs through alleviation of biological barriers. At the same time, we analyze the advantages and disadvantages of the corresponding methods and put forward possible directions for the future researches.

Public transport plays an essential role in helping people escape from the congested traffic in large and crowded cities. Evaluating customer satisfaction is the key to the continuous quality improvement of public transport services. This work proposes a new public transport customer satisfaction evaluation approach based on an extended thermodynamic method with q-rung orthopair fuzzy sets. First, we use the q-ROFSs to handle the ambiguity and uncertainty of customer satisfaction evaluation information for public transport. Then, we extend the thermodynamic method to determine the customer satisfaction levels of public transport lines. Moreover, the stepwise weight assessment ratio analysis method is utilized to specify the weights of evaluation criteria as it is simple and time-saving. The effectiveness of the proposed approach is illustrated with a customer satisfaction evaluation of the rail transit network in Shanghai, China. Results showed that Line 7 has the highest customer satisfaction and Line 2 has the lowest customer satisfaction among the considered rail transit lines. Besides, nine evaluation criteria need to be optimized to improve the customer satisfaction level of Line 2 and the most critical one is train crowding.

A zirconium-based metal-organic framework (MOF) was successfully constructed via solvothermal assembly of a triphenylamine-based tricarboxylate ligand and Zr(IV) salt, the structure simulation of which revealed that it possesses a two-dimensional layered framework with a relatively rare dodecnuclear Zr12 cluster as the inorganic building unit. The inherent photo-responsive property derived from the incorporated photochromic triphenylamine groups combined with its high stability makes the constructed MOF an efficient heterogeneous photocatalyst for the oxidation of sulfides, which is a fundamentally important reaction type in both environmental and pharmaceutical industries. The photocatalytic activity of the constructed MOF was first investigated under various conditions with thioanisole as a representative sulfide substrate. The MOF exhibited both high efficiency and selectivity on aerobic oxidation of thioanisole in methanol utilizing molecular oxygen in air as the oxidant under blue light irradiation for 10 h. Its high photocatalytic performance was also observed when extending the sulfide substrate to diverse thioanisole derivatives and even a sulfur-containing nerve agent simulant (2-chloroethyl ethyl sulfide). The high photocatalytic efficiency and selectivity to a broad set of sulfide substrates make the triphenylamine-incorporating zirconium-based MOF a highly promising heterogeneous photocatalyst. Ministry of Education (MOE) This work was supported by the "Qilu Young Talent Scholar" program of Shandong University and the Singapore Academic Research Fund (RT12/19).

To explore the forming mechanism and the evolution laws of cladding geometry with process parameters on curved substrates for laser powder-fed additive manufacturing (LPF-AM) processes, based on the laser beam distribution and the cladding forming theory of horizontal and tilted substrates, analytical models for cladding geometric characteristics in the vertical and tilted postures of nozzles were established. LPF-AM experimental research on a curved substrate of AISI 304 steel was carried out, and the theoretical results were discussed and compared with the experimental data from the perspective of the curvature radius of the substrate, powder feed rate, scanning speed, and tilt angle of the nozzle. The results showed that the tilt angle of the nozzle was the most critical factor for the laser irradiation area and cladding width; moreover, the cladding width increased gradually as the tilt angle of the nozzle increased. The curvature radius of the substrate, powder feed rate, and scanning speed had a significant influence on the cladding height. Due to the effects of gravity, surface tension, and viscous shear force, the peak shift was proportional to the powder density and the tilt angle of the nozzle. The predicted values of the analytical models fit well with the experimental results. The prediction accuracies of the cladding width, cladding height, and peak shift theoretical models were 98.97%, 91.30%, and 76.85%, respectively. This study provides deeper insight into the ensuing cladding geometrical characteristics using LPF-AM on curved substrates.