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Fault diagnosis is an effective tool to ensure safe operation of machinery and avoid serious accidents. As most currently used fault diagnosis methods usually employ mapping relationship established by training samples and their labels to achieve classification of testing samples, it is difficult for them to achieve fault diagnosis under the condition of incomplete training sample types. In addition, previous studies usually focus on feature extraction of single-channel vibration signal, which cannot get complete fault feature information. To solve the above problems, a progressive fault diagnosis method is investigated in this paper. First, the preliminary fault detection for the rotor is performed by studying reconstruction error of a sparse auto-encoder. Second, if a fault exists in the rotor, the outlier detection is implemented by the support vector data description method. Finally, if there are no outlier samples, the well -trained support vector machine is used to confirm the type of fault samples and complete the diagnosis. The performance of the proposed method was verified using the data obtained from a rotor laboratory bench. The types of rotor states investigated include normal, contact-rubbing, unbalance and misalignment. The experimental results verify the effectiveness and superiority of the proposed method in reducing the incidents of fault omission and fault misunderstanding.

A salt spray test was used to evaluate the corrosion resistance of pickling high-strength steel JSH440W to phosphating film on its surface, and scanning electron microscope (SEM) and energy dispersive spectrometer (EDS) were used to analyze the micro-morphology and element content of the surface defects area of the sample after salt spray test. The results show that the enrichment of Si, Mn, and O elements on the surface of pickling high-strength steel JSH440W badly influences the film-forming performance of phosphating film. The enrichment of Si, Mn, and O elements on the strip steel surface will slow down the film-forming speed of the phosphating film and make the thickness of the phosphating film thinner, which will lead to the reduction of corrosion resistance in this area, and it is easy to cause pitting corrosion behavior, to cause the paint film on the sample surface to fall off. Reducing the enrichment of Si, Mn, and O elements on the surface of acid-washed high-strength steel and increasing the roughness uniformity of strip steel is beneficial to improving the quality of phosphating film and the coating property of pickling high-strength steel.

A hot-dip galvanizing simulator studied the effects of soaking temperature and rapid cooling end temperature on the microstructure and mechanical properties of 980MPa grade hot galvanizing dual-phase steel. The results show that at the end of a rapid cooling temperature of 290°C, with the increase of soaking temperature, the tensile strength of the test steel increases, the yield strength decreases at first and then increases, and the elongation decreases as a whole. The microstructure is composed of ferrite and martensite. At the soaking temperature of 800°C, the strength decreases, and the elongation increases with the increase of the end temperature of rapid cooling. When the end temperature of rapid cooling is lower than 320°C, the martensite tempering is not apparent, and there are many high-density dislocations in the ferrite near the neighbor. When the cooling end temperature is 350°C, some martensites are tempered. The twins in martensite are widened, carbides are unevenly precipitated along the twin planes, and the dislocation density decreases. When the soaking temperature is between 800°C and 820°C, the end temperature of rapid cooling is between 260°C and 290°C. Annealing and zinc plating are beneficial to obtain dual-phase steel with excellent mechanical properties.

Understanding of the heat transport within living biological tissues is crucial to effective heat treatments. The heat transport properties of living biological tissues with temperature-dependent properties are explored in this paper. Taking into account of variable physical properties, the governing equation of temperature is first derived in the context of the dual-phase-lags model (DPL). An effective method, according to the Laplace transform and a linearization technique, is then employed to solve this nonlinear governing equation. The temperature distribution of a biological tissue exposed to a pulsed heat flux on its exterior boundary, which frequently happens in various heat treatments, is predicted and analyzed. The results state that a lower temperature can be predicted when temperature dependence is considered in the heating process. The contributions of key thermal parameters are different and dependent on the ratio of phase lag and the amplitude of the exterior pulsed heat flux.

Using first-principles calculations, we predict a new type of two-dimensional (2D) boride MB3 (M = Be, Ca, Sr), constituted by boron kagome monolayer and the metal atoms adsorbed above the center of the boron hexagons. The band structures show that the three MB3 compounds are metallic, thus the possible phonon-mediated superconductivity is explored. Based on the Eliashberg equation, for BeB3, CaB3, and SrB3, the calculated electron–phonon coupling constants λ are 0.46, 1.09, and 1.33, and the corresponding superconducting transition temperatures T c are 3.2, 22.4, and 20.9 K, respectively. To explore superconductivity with higher transition temperature, hydrogenation and charge doping are further considered. The hydrogenated CaB3, i.e., HCaB3, is stable, with the enhanced λ of 1.39 and a higher T c of 39.3 K. Moreover, with further hole doping at the concentration of 5.8 × 1011 hole/cm2, the T c of HCaB3 can be further increased to 44.2 K, exceeding the McMillan limit. The predicted MB3 and HCaB3 provide new platforms for investigating 2D superconductivity in boron kagome lattice since superconductivity based on monolayer boron kagome lattice has not been studied before.

As one of the most useful cosmological distance indicators, type Ia supernovae (SNe Ia) play an important role in the study of cosmology. However, the progenitors of SNe Ia are still uncertain. It has been suggested that carbon-oxygen white dwarf (CO WD)+He subgiant systems could produce SNe Ia through the double-degenerate (DD) model, in which the He subgiant transfers He-rich matter to the primary CO WD and finally evolves to another CO WD. Recently, a CO WD+He star system (i.e., HD 265435) has been discovered to be a new SNe Ia progenitor candidate based on the DD model. The orbital period of the system is about 0.0688 days, and the masses of the CO WD and the He star are 1.01 ± 0.15 M ⊙ and 0.63 − 0.12 + 0.13 M ⊙, respectively. In this work, we evolve a large number of primordial binaries to the formation of CO WD+He star systems and investigate the evolutionary history of HD 265435. We find that HD 265435 may originate from a primordial binary that has a 5.18 M ⊙ primary and a 3.66 M ⊙ secondary with an initial orbital period of 5200 days. The CO WD+He star system would be formed after the primordial binary experiences two common-envelope ejection processes. We also find that HD 265435 would evolve to a double WD system with a total mass of 1.58 M ⊙ after a stable mass-transfer process, and the double WD system would merge driven by gravitational wave radiation. We estimate that it would take about 76 Myr for HD 265435 to form an SN Ia. In addition, HD 265435 would be a potential target of space-based gravitational wave observatories (e.g., LISA, Taiji and TianQin).

The first wall of the helium-cooled ceramic breeder test blanket module (TBM) will be subjected to charge exchange neutral from the mixed deuterium (D) and tritium (T) deuterium–tritium (D–T) mixture plasma irradiation. To understand the isotope effects on mixed plasma-driven permeation (PDP) through the TBM wall, which is typically made by reduced activation martensitic/ferritic steel (RAFM), mixed D and protium (H) PDP experiments for a Chinese RAFM CLF-1 have been performed. Permeation fluxes of H and D through ∼mm thick CLF-1 have been recorded at various sample temperatures and particle incident energies. The co-permeation of H and D is found to be diffusion-limited in the bulk and obeys classical mass effects of diffusion species. The H/D ratio of the permeation fluxes is found to be stable when changing sample temperature and is insensitive to ion incident energy. In addition, the mixed H can provide more channels for D recombination to reduce the D permeation.

There are many blackening defects on the steel surface after the pickling of the hot-rolled strip. The microstructure and roughness of the picked steel surface were analyzed using SEM and LEXT OLS4000 laser scanning confocal microscope, XPS, and surface roughness measure. The experiment result shows that the blackening defects of the hot-rolled pickled steel sheet surface are aging of anti-rust oil film to the strip steel surface. In order to improve the surface quality of the hot rolling pickled sheet, the anti-rust oil coating process is improved, the thickness and uniformity of the oil film are controlled, and the management in the course of packing, storage and transportation are strengthened.

In view of the chromatic aberration defects on the surface of hot-rolled strip A510L after pickling, the microscopic morphology features of different positions of the pickled strip surface were compared and analyzed by using laser confocal microscope (CLSM), and the generation mechanism of chromatic aberration defect was studied by using high-resolution scanning electron microscope and energy dispersive spectrometer (EDS). The results show that the main cause of surface chromatic aberration defects on the surface of pickling plate A510L is closely related to the interface state between hot-rolled raw material substrate and iron oxide scale, and there is an enrichment area of Fe2SiO4/FeO binary eutectic near the hot-rolled raw material substrate and iron oxide scale, and the proportion of Fe2SiO4 is higher as it approaches the strip steel matrix, and Fe2SiO4/FeO has a strong pinning effect, which leads to the adhesion of iron oxide scale. The existence of Fe2SiO4/FeO changes the structure of carbon steel iron oxide scale, which makes the bonding force between iron oxide scale and strip steel matrix increase the difficulty of pickling process, and finally presents the surface chromatic aberration defects after pickling.

We theoretically realize a highly robust Fano resonant structure. The occurrence of robust Fano resonance can be caused by the coupling of topological bright interface mode and topological dark interface mode at the interface between trivial and non-trivial insulators. Through the research of band structure, it is confirmed that the structure has the characteristic of specific band inversion, which can realize the topological phase transition. In addition, we verify that the Fano resonance is still robust in horizontal and vertical perturbations, which is significant for designing Fano-based devices to solve issues caused by manufacturing.

We analytically and numerically investigate the acoustic plasmon mode in phosphorene placed above a metallic substrate with a finite gap width. Combined with finite-difference time-domain simulations, we demonstrate the responses of evanescent waves in the phosphorene-insulator-metal (PIM) waveguide, involving field enhancement, light confinement, and optical force. It turned out that owing to a large amount of light energy squeezed inside the gap, the light confinement ratio and optical force along the armchair direction in the PIM waveguide can be up to 96% and 6930 pN mW−1, respectively. Our results may manifest in diverse optoelectronic applications like optical tweezers.

In view of the communication difficulties of CNC machine tools with only RS232 and RS485 interfaces in industry, this paper studies DNC technology and multi-protocol conversion technology, proposes to use CAN bus to build DNC system, establish multi-protocol conversion module communication model, and build software and hardware platform based on STM32F103VCT6 MCU. The CAN bus protocol, RS232 bus protocol and RS485 bus protocol CAN be converted to each other. The experimental results verify the accuracy and reliability of the multi-protocol conversion module, realize the two-way transmission of data, and solve the problem of communication difficulties between different protocols.

A transmitting circuit for high-speed interface is proposed in this paper. Optimized 10-bit parallel to serial conversion and embedded output impedance calibration are used for enhancing the performance of this transmitting circuit. Designed with 0.18 μm CMOS, this transmitting circuit can achieve an output data rate of 1.5625 Gbps with 10-bit 156.25 MHz parallel input. The output amplitude of the current mode logic (CML) driver is 1.28 Vpp with a jitter of 24.3 ps. After adaptive calibration, the mismatch between output impedance and its expected value is within 0.5%. The active area of this entire transmitting circuit is 220.1 μm × 197.5 μm. With 1.8 V power supply, the power consumption of this transmitting circuit is 41.2 mW at 1.5625 Gbps data rate.

The effect of helium (He)-induced surface microstructure on deuterium (D) plasma-driven permeation through a reduced activation ferritic/martensitic steel CLF-1 has been studied. CLF-1 steel was pre-exposed by He plasma with ion fluence of 1022–1024 He m−2 and an incident energy of 100 eV at 708 K. The following D plasma-driven permeation experiment was performed at 693 K. Steady-state D permeation flux decreases with the increase in He ion fluence. D diffusion coefficient is not significantly affected by He pre-damage, while D reflection coefficient increases with the enhancement of He ion fluence. Scanning electron microscope and transmission electron microscope analyses clearly reveal the evolution of surface roughness and He bubble layer after He plasma exposure. Elastic recoil detection was used to identify He concentration depth profiles in the samples. Both the surface microstructure modification and He bubble layer formation contribute to the reduction of D permeation.

Two-dimensional (2D) superconductors have important potential applications in constructing nano superconducting devices, thus, 2D superconductors with high critical temperature (T c ) are highly desired. Till now, the T c of 2D superconductors are still relatively low. Based on density functional first-principles calculations, we predicted a new stable 2D transition metal molybdenum carbide 2H-Mo2C3. Based on the Eliashberg theory, we predict that it is not a superconductor. However, after hydrogenation, the hydrogen atoms increase the electronic density of states at the Fermi level, and strengthen the electron-phonon coupling. Accordingly, the hydrogenated 2H-Mo2C3, i.e., 2H-Mo2C3H2, is a 2D superconductor with T c of 53 K, exceeding the McMillan limit. Thus, hydrogenation is an important strategy for obtaining 2D high-temperature superconductors at atmosphere pressure. In view of the high superconducting T c of 2H-Mo2C3H2, it is highly expected to be synthesized in future experiments.

In recent years, we have witnessed the rapid growth of new energy sources in China, with the implementation of “carbon peak, carbon neutrality” and new power system, there is no doubt that the development of new energy will maintain a rapid growth rate. At the same time, in order to ensure the high-quality development of new energy, the planning of wind power and photovoltaic should be taken in advance. Taking Shandong Power Grid as an example, this paper analysed the optimal installed ratio of wind power and photovoltaic power in Shandong power grid from the perspective of electrical power balance, aiming at the highest fit between wind and photovoltaic power generation and load curve. The calculation results show that when the installed ratio of wind power and photovoltaic is 1.45:0.8 (about 1.8:1), the wind and photovoltaic power generation can fit the load curve most closely. Based on this, some suggestions are put forward to provide technical support for energy and electric power planning.

The dynamics of C + H2 → H + CH reaction is theoretically studied using the quasiclassical trajectory and quantum mechanical wave packet methods. The analysis of reaction probabilities, integral cross sections, and rate coefficients reveal the essential Coriolis coupling effects in the quantum mechanical wave packet calculations. The calculated polarization-dependent differential cross section, P(θr ) and P(ϕr ) show that the j ′ of product rotational angular momentum is not only aligned along the y axis and the direction of the vector x + z , but also strongly oriented along the positive y axis.

Experiments concerning the effect of helium (He) plasma exposure on deuterium (D) plasma-driven permeation through tungsten (W) foils in a linear plasma facility have been performed. 0.05 mm thick W foils were exposed to ∼2 × 1020 m−2 s−1 He plasma with various fluences at 883 K. After He irradiating, D permeation tests were performed for the samples and retention was also measured by high-resolution thermal desorption spectroscopy. It was observed that He pre-irradiation resulted in a significant reduction of D permeation and retention in W. Microstructure observation indicated that the surfaces of the samples after He irradiation turned rough and He nanobubbles were formed near the surface. Defective structures including He nanobubbles likely enhance D reemission and accordingly reduce the permeation and retention in He pre-irradiated W.

Biomass-derived carbon materials have received a surge of scientific attention to develop lightweight and broadband microwave absorbers. Herein, rodlike porous carbon materials derived from cotton have been fabricated with uniformly dispersed CoFe2O4 nanoparticles via facile and scalable process. The combination of magnetic particles and carbonaceous material is advantageous to realize the magnetic-dielectric synergistic effect which could effectively promote the dissipation of incident waves, giving rise to an optimal reflection loss value of –48.2 dB over a qualified bandwidth (4.8 GHz) at 2.5 mm. The cotton-derived carbon rods with conductive network not only act as a supporter to carry the CoFe2O4 nanoparticles, but also provide massive heterointerfaces to facilitate the interfacial polarization. In consideration of the renewable and abundant resource of cotton, the as-prepared CoFe2O4/C composites would meet the increasing demand of lightweight and highly efficient microwave absorbers.

Anti-perovskite solid-state electrolyte Li2OHCl usually exhibits orthorhombic phase and low ionic conductivity at room temperature. However, its ionic conductivity increases greatly when the temperature is up to 40 °C, while it goes through an orthorhombic-to-cubic phase transition. The cubic Li2OHCl with high ionic conductivity is stabilized at room temperature and even lower temperature about 10 °C by a simple synthesis method of wet mechanical milling. The cubic Li2OHCl prepared by this method performs an ionic conductivity of 4.27 × 10−6 S/cm at room temperature, about one order of magnitude higher than that of the orthorhombic Li2OHCl. The phase-transition temperature is decreased to around 10 °C. Moreover, it can still remain cubic phase after heat treatment at 210 °C. This work delivers a huge potential of fabricating high ionic conductivity phase anti-perovskite solid-state electrolyte materials by wet mechanical milling.

We propose a critical-coupled plasmon-induced transparency borophene waveguide system in a communication band with strong absorption inhibition. Intrinsic loss of this scheme is strongly suppressed by coupling between critical-coupled bright mode and dark mode, and then the purpose of reducing absorption can be achieved. Based on numerical calculation by finite-difference time-domain simulations and theoretical analysis via coupled mode theory, the transmission characteristics of this system are investigated. It turns out that this approach effectively minimizes excess absorption losses and maximizes the amount of transmitted energy. Our results may provide an alternative way to design lab-on-a-chip borophene devices.

Transition metal dichalcogenides monolayers are promising candidates for novel optoelectronic devices because they exhibit a unique combination of atomic-scale thickness, direct band gap, high quantum yield and ease of integration properties, which make them intriguing for fundamental studies and applications. In this work, we manipulate the exciton distribution in the WS2 monolayer integrated with a photonic crystal at room temperature. By coupling with the optical modes of the photonic crystal, the excitons can distribute along a particular direction by around ∼10 μm. More importantly, the excitons distribute along the particular direction with locked linear polarization, the degree of polarization up to 60%. Our results pave the way to manipulate the polarization distribution and exciton distribution in the WS2 monolayer.

Structural damage tomography (SDT) uses full-field or distributed measurements collected from sensors or self-sensing materials to reconstruct quantitative images of potential damage in structures, such as civil structures, automobiles, aircraft, etc. In approximately the past ten years, SDT has increased in popularity due to significant gains in computing power, improvements in sensor quality, and increases in measurement device sensitivity. Nonetheless, from a mathematical standpoint, SDT remains challenging because the reconstruction problems are usually nonlinear and ill-posed. Inasmuch, the ability to reliably reconstruct or detect damage using SDT is seldom guaranteed due to factors such as noise, modeling errors, low sensor quality, and more. As such, damage processes may be rendered invisible due to data indistinguishability. In this paper we identify and address key physical, mathematical, and practical factors that may result in invisible structural damage. Demonstrations of damage invisibility and data indistinguishability in SDT are provided using experimental data generated from a damaged reinforced concrete beam.

The recently demonstrated approach of grafting n-type GaN with p-type Si or GaAs, by employing ultrathin Al2O3 at the interface, has shown the feasibility to overcome the poor p-type doping challenge of GaN. However, the surface band-bending of GaN that could be influenced by the Al2O3 has been unknown. In this work, the band-bending of c-plane, Ga-face GaN with ultrathin Al2O3 deposition at the surface of GaN was studied using X-ray photoelectron spectroscopy. The study shows that the Al2O3 can help suppress the upward band-bending of the c-plane, Ga-face GaN with a monotonic reduction trend from 0.48 eV down to 0.12 eV as the number of Al2O3 deposition cycles increases from 0 to 20. The study further shows that the band-bending can be mostly recovered after removing the Al2O3 layer, concurring that the introduction of ultrathin Al2O3 is the main reason for the surface band-bending modulation.

Tritium (T) permeation through plasma-facing component (PFC) into the coolant is a major concern of fusion reactor operation. In this work, deuterium (D) permeation through CLAM steel, CLAM/CLAM and CLAM/Fe-Cr-Al samples prepared by hot isostatic pressing (HIP) are tested in a linear plasma device. Only the downstream surfaces of the samples are oxidized with controlled atmosphere to form permeation barrier. No significant effect on D diffusion and penetration can be observed for the joining interfaces, while the dense oxide layer at the downstream side plays an important role in suppressing D permeation. The downstream surface oxidization of CLAM/Fe-Cr-Al is found to effectively reduce D permeation flux by a factor up to 1000.

The finite element modelling, mesh generation and modal analysis of the rotor worktable are carried out by combining the analysis technology of finite element software in this paper. Then, the software analysis results and the actual experimental results are compared and analyzed, so as to get the causes of error, which can provide good basic data for the use of the rotor table in the future that could better meet the needs of scientific research and teaching.

In this research, first, CuSe nanoparticles (NPs) were synthesized by using the reflux condensation method. Then, a ZnSe shell was grown on the CuSe NPs by using a simple, rapid photochemical approach. Synthesized CuSe/ZnSe core-shell NPs were characterized by means of different analyses, such as X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), high-resolution transmission electron microscopy (HRTEM), UV-visible (UV-Vis) spectroscopy and photoluminescence (PL) spectroscopy. The XRD analysis of the sample shows the formation of core-shell NPs with the structure of hexagonal CuSe and cubic ZnSe. The core-shell structure of the product has been formed and the size of the synthesized core-shell NPs is about 20–50 nm. The band gap of the CuSe/ZnSe core-shell NPs was higher than that for CuSe or ZnSe in bulk. The fluorescence properties were greatly enhanced by successful growth of the ZnSe shell and decreased with the extension of illumination time.

As a new research direction, fusion image technology has attracted more and more attention in many fields. Among them, infrared image and visible image, the two kinds of multimodal data have strong complementarity, the fusion image of the two modes contains not only the radiation information of infrared image, but also the texture detail information of visible image. In this paper, a convolutional neural network-based encoding-fusing-decoding network model structure is used. In the encoding stage, Dense Block, which has the advantage of feature extraction, was adapted to extract the image features. In the fusion stage, four fusion methods were compared and analyzed, and the gated fusion was selected as the main method of fusion layer. In the decoding stage, RDB (Residual Dense Blocks) was used to restore the fused features to the fused image. The fusion image based on this method is sensitive to temperature characteristics and has a better performance in image quality. The fused image has a high contrast, a relatively smooth fusion effect, and the overall visual effect is more natural.

We combine active and passive acoustic measurements to improve the spatio-temporal imaging of hydraulic fracture growth performed under true triaxial confinement in the laboratory. 64 active piezo-electric transducers (54 P waves, 10 S waves) work in source (32) - receivers (32) mode to perform an acoustic survey at repetitive intervals (every 10 seconds) during a hydraulic fracture growth experiment. The analysis of the evolution of the active acoustic monitoring changes allow to image the evolution of the fracture front (via an inversion of the active acoustic waves diffracted by the fracture front). An additional 16 piezoelectric transducers are pre-amplified and work in passive mode continuously recording at 10MHz. We present a nearly-automatic passive signal processing, acoustic emission detection, and location algorithm. This allows to record, detect and to locate acoustic emissions associated with fracture initiation and growth in between the active acoustic measurement sequences. Using a hydraulic fracturing test performed in gabbro, we discuss how active and passive acoustic monitoring complements one another and bring different type of information on hydraulic fracture growth.

In order to solve the problems of using a single radar or video sensor in the traffic information detection process, such as susceptibility to environmental influences and non-intuitive target reflections, we propose a detection method using target correlation matching, target tracking, and target data fusion, and we show how to adjust the detection weights of the video sensor and radar sensor by adjusting the noise matrix parameters, which forms a flexible, simple, and nimble method. The efficient architecture allows accurate results in challenging environments. We show the effect on radar detection data and video detection data before and after adjustment. We test the proposed method by building a hardware verification platform and finally demonstrate it on video images. The experimental results show that the proposed method can significantly reduce the testing time while providing high detection rate in more environments.

In order to improve the reliability of integrated energy system, the station-grid co-planning model and its solution method are proposed. The planning model considers the constraints of distribution network, gas distribution network, heat distribution network and energy station, and aims at minimizing the total planning cost within the planning period including investment cost, maintenance cost and reliability cost. It realizes the optimal planning for the types and locations of energy supply sources, distribution pipelines, energy stations and energy storage devices, such as electricity storage devices, gas storage devices, heat storage devices and cooling storage devices. The model is a mixed integer quadratic programming problem, which is solved by Gurobi. The case study uses the modified electricity-gas-heat integrated energy system to analyse the system planning scheme and planning cost under two scenarios. The results show that the proposed model can reasonably plan the integrated energy system and further improve the reliability of the integrated energy system.

A new method to prepare composite nanofiltration membrane directly and efficiently by controlling the pore structure and surface morphology of the membrane is proposed in this paper. The fabrication of mesoporous silicon modified polysulfone blend membranes is via a phase inversion method. The structural morphology, surface functional group analysis, elemental analysis, hydrophilicity, chargeability, and nitrogen pollutant (ammonia nitrogen, nitrate nitrogen, total nitrogen) rejection properties of the modified membranes were found to be dependent on the amount of mesoporous silicon incorporated. The combination of the mesoporous silicon framework layer can not only effectively improve the surface structure of the modified membrane with a narrow pore size distribution but also increase the rejection of nitrogen pollutant compared with the pure NF membranes. The mesoporous material can absorb and storage the nitrogenous solution to facilitate the following interfacial polymerization, as well as induce the change of pore radius and surface structure. Compared to those pure NF composite membranes, the modified blend membranes exhibit increased water permeation flux as high as 29.09 L m−2 h−1 at 0.2 MPa. The results show that the optimum doping amount of mesoporous silicon is in the range of 0.5%-1.0%. Characterization studies demonstrated that the addition of the mesoporous silicon leads to decreased membrane pore size. Then, due to the enhanced hydrophilicity of carboxyl and hydroxyl groups on the surface, the electrostatic repulsion between the functional groups and nitrogen pollutant molecules in the membrane results in the enhanced rejection of nitrogen pollutants.

The ability to accurately determine elastic properties of orthotropic materials is important in the design and health assessment of composite structures. Direct methods using strain gauges and extensometers for estimating orthotropic properties have become popular in recent years. In cases where strains are highly localized, the material properties are inhomogeneous, or the material has localized damage, the use of these measurement schemes often provides insufficient information. To address this, we propose an inverse method, based on quasi-static elasticity imaging (QSEI) for determining inhomogeneous orthotropic elastic properties using distributed displacement measurements obtained from digital image correlation (DIC). The QSEI-based approach is first tested with simulated noisy displacement data considering in-plane deformations of plate geometries undergoing stretching and bending. Following this, experimental DIC measurements are applied to test the feasibility of the QSEI-based approach. Elastic properties of uni-directional CFRP beams with and without localized damage are estimated using the proposed approach. Results demonstrate the feasibility of the proposed inverse approach.

In the past decades, defect engineering has become an effective strategy to significantly improve the hydrogen evolution reaction (HER) efficiency of electrocatalysts. In this work, a facile chemical vapor deposition (CVD) method is firstly adopted to demonstrate defect engineering in high-efficiency HER electrocatalysts of vanadium diselenide nanostructures. For practical applications, the conductive substrate of carbon cloth (CC) is selected as the growth substrate. By using a four-time CVD method, uniform three-dimensional microflowers with defect-rich small nanosheets on the surface are prepared directly on the CC substrate, displaying a stable HER performance with a low Tafel slope value of 125 mV dec−1 and low overpotential voltage of 295 mV at a current density of 10 mA cm−2 in alkaline electrolyte. Based on the results of x-ray photoelectron spectra and density functional theory calculations, the impressive HER performance originates from the Se vacancy-related active sites of small nanosheets, while the microflower/nanosheet homoepitaxy structure facilitates the carrier flow between the active sites and conductive substrate. All the results present a new route to achieve defect engineering using the facile CVD technique, and pave a novel way to prepare high-activity layered electrocatalysts directly on a conductive substrate.

This article has been retracted at the authors request, for the following reasons: •The work was submitted without the approval of the one of the co-authors, Linhai Wang. • The original gravity data used in the paper has been found incorrect through repeated verification recently, which is leading to erroneous conclusions. •The theoretical method used needs further development before it is ready for publication. All co-authors agree to this retraction. Retraction published: 10 June 2021

The terrestrial time-variable microgravity survey is an important means to monitor geodynamic processes underground. The Scintrex CG-5 relative gravimeter, which is the mainstream instrument for terrestrial relative gravity measurement at present, its scale factor (SF) is an important factor affecting the quality of the observation data. Unlike the conventional gravity adjustment procedure, this study takes account of the nonlinear drift rate of the CG-5 gravimeter, depending on the known absolute gravity (AG) in the network, and the scale factor is considered as one of the hyper-parameters to be estimated by means of Akaike’s Bayesian information Criterion (ABIC). In order to quantify the errors caused by the bias of scale factor, we applied this new approach to process actual gravity survey campaign data in Yunnan gravity network from 2018 to 2020, then analyzed the residuals of gravity differences (GD) between station pairs and the difference of GD between two relative gravimeters (CG5 #1169 and CG5 #1170). The cross-validation of the absolute gravity (AG) from the quasi-synchronous observation in the network is also used in the paper. It has shown that this new approach is effective to improve the accuracy of scale factor and adjustment results.

Based on researches on ELV directive at home and abroad, this paper developed an ELV directive-based vehicle recycling test program and offered solutions for the government and enterprises to manage end-of-life vehicles. The vehicle ELV test realized the verification by tests and scrutiny of the ELV directive and the self-inspection of enterprises, and improved the ELV management system.