Jianjun Chen

• Head of Department at SMTEC

This study investigates the effect of Al(OH)3, Mg(OH)2, or Ca(OH)2 on the performance of HMC‐bonded castables (HMCC), aiming to synergistically improve the workability and medium‐temperature mechanical properties of HMCC. The results indicate that Al(OH)3 synergistically improves the medium‐temperature mechanical properties, workability, and therma...

This study modifies the hydration process of hydrated magnesium carboxylate (HMC) by organic acids to improve the workability of HMC‐bonded castables (HMCC), while comprehensively analyzing the effects of organic acids on the mechanical properties and thermal shock resistance of HMCC. Results demonstrate that lactic acid significantly increases the...

With an increasing temperature gradient, the internal stress in composites can cause many problems, such as the plastic yield of the matrix, fracture of the reinforcements, growth of pores in the matrix, and debonding of the interface. The reinforcement particularly affects the internal stress, considerably changing the various properties of the co...

In this study, the evolutions of kinetic parameters, such as hydration temperature, pH, and electrical conductivity, were observed to investigate the hydration mechanism of hydrated magnesium citrate (HMC). Additionally, the effects of MgCl2 on the hydration behavior of HMC and the working performance of its bonded castables were also investigated....

This article proposes a robust multiarea distribution system state estimation method for interval estimation of state variables based on a physics-informed decentralized graphical representation network and Gaussian process (GP)-aided multiarea state estimators. The real-time and pseudomeasurements are first cast to a graph with tree topology and a...

This paper develops a robust physics-informed state estimation method for the distribution network with inaccurate topology information. An aggregated k-nearest neighbor graph is first derived as the feature graph according to the inaccurate topology and measurement features. Then, graph propagation and aggregation are performed by an adaptive mult...

Silica gel‐modified hydratable magnesium carboxylate (HMC) is used as the binder for refractory castables. The mechanical strength and thermal shock resistance of HMC bonded and silica gel‐modified HMC‐bonded castables were compared. When the HMC/silica gel mass ratio is 2, the cold modulus of rupture, the hot modulus of rupture, the residual stren...

Lead-free Cs3Cu2I5 metal halides have garnered significant attention recently due to their non-toxic properties and deep-blue emission. However, their relatively low photoluminescence quantum efficiency and poor stability have limited their applications. In this work, sodium iodide (NaI) is used to facilitate the synthesis of Cs3Cu2I5 nanocrystals...

Previous studies have indicated that hydratable magnesium carboxylate (HMC) exhibits potential as an MgO‐based binder, but its limited medium‐temperature strength has hindered its widespread industrial application. In this study, the incorporation of MgO fumes into castables is intended to react with microsilica to form magnesium–silicate–hydrate (...

Dynamic performance is a critical index for three-phase dual active bridge (3ph-DAB) converter. However, the presence of dc bias in inductor current poses significant effects, such as overcurrent stress and increased power loss for 3ph-DAB converter. Additionally, the intricate structure and three control variables in variable duty cycles (VDCs) mo...

The high level of gas permeability can effectively reduce the explosive spalling risk of refractory castables. The hydratable magnesium carboxylate (HMC) is expected to improve the permeability of castables owing to the thermal decomposition of the HMC hydrates. This study compared the gas permeability and explosive spalling resistance of HMC bonde...

Lead halide perovskite has become a promising candidate for high-performance photodetectors (PDs) due to its attractive optical and electrical properties, such as high optical absorption coefficient, high carrier mobility, and long carrier diffusion length. However, the presence of highly toxic lead in these devices has limited their practical appl...

The accurate estimation of lithium battery state of health (SOH) is very important for the safe and stable operation of the battery. Since the user’s charging process is random, it is difficult for the user to know the battery SOH through the charging segment. In this article, we proposed a lithium battery SOH estimation method of random charging p...

Lead halide perovskite has become a promising candidate for high-performance photodetector (PD) applications due to its attractive optical and electrical properties such as high optical absorption coefficient, high carrier mobility, and long carrier diffusion length. However, the presence of highly toxic lead in these devices has limited their prac...

To prevent serious malfunctions and reduce the impact of faults during an emergency state of a power system, protection systems are required to have disturbance and fault state identification abilities. In this study, a novel fault diagnosis framework based on deep learning with anti-disturbance ability is proposed to identify the fault state and f...

Accurate and timely fault diagnosis is of great significance for the safe operation and power supply reliability of distribution systems. However, traditional intelligent methods limit the use of the physical structures and data information of power networks. To this end, this study proposes a fault diagnostic model for distribution systems based o...

Accurate and efficient bearing fault diagnosis method plays an important role in modern industrial system. In practical applications, a large number of data are employed for fault analysis. However, the performance of the fault diagnosis model varies with the sampling frequency of the training data. Theoretically, higher sampling frequency (HSF) da...

Trap-assisted non-radiative recombination is one of the main energy loss pathways in metal halide perovskite solar cells (PVSCs). Here in this work, oxygen-doped graphitic carbon nitride (g-C3N4-O) is introduced into...

In this study, a new type of ammonium polyphosphate‐intercalated organic montmorillonite (APP/OMt) was synthesized using in‐situ polymerization, and the chemical structure and surface morphology of APP/OMt was confirmed by FT‐IR, XRD, EDS and SEM. Moreover, the intumescent flame retardant (IFR) composed of APP/OMt, pentaerythritol (PER) and melamin...

A new extractant PN-1 was synthesized, and an ultrasound-assisted micro-channel extraction (UAME) system was developed for the extraction of magnesium from wet-process phosphoric acid (WPA). The effects of O/A ratio, P2O5 content, initial pH, ultrasound power, and aqueous phase ratio on extraction were investigated. The extraction efficiency of Mg²...

The core–shell structured calcium aluminate cement coated carbon nanofibers ([email protected]) with the same phase composition as Secar71 cement were synthesized to improve the water dispersion and oxidation resistance of carbon nanofibers. The FTIR spectroscopy showed that catalyst ferric chloride can catalyze the polymerization of the maleate. R...

The microstructure and properties of Al2O3–SiC–C castables with spherical asphalt, high-content carbon-containing calcium aluminate cement (HCCAC), and carbon nanotube/calcium aluminate cement (CNTs/CAC) as carbon sources, respectively, were investigated. The microstructure of castables was characterized by scanning electron microscopy and transmis...

Effective detection of fault in rolling bearings with a limited amount of data is essential for the safe operation of electric machines. This study proposes a novel meta-learning-enabled method for the detection of fault in rolling bearings of electric machines under varying working conditions with limited data. The fault diagnosis under various wo...

The CaCO3 coated corundum aggregates were prepared by impregnating tabular corundum aggregates with sizes of 1–5 mm in calcium hydrogen citrate solution and heat treatment at 430 °C, which were also used in Al2O3–MgO castables. The effects of Ca²⁺/Cit³⁻ mole ratio in precursor solution on coating characteristics of CaCO3 coated corundum aggregates...

Cobweb‐like carbon nanotubes/calcium aluminate cement (CNTs/CAC) were synthesized through catalytic sintering with citric acid, calcium carbonate, and alumina as raw materials and ferric chloride as catalyst precursor. The products were characterized by X‐ray diffractometry, scanning electron microscopy, Raman spectroscopy, and high‐resolution tran...

Our previous investigations indicate that the thermal shock resistance (TSR) of hydratable magnesium carboxylate (HMC) bonded Al2O3–MgO castables is superior to castables bonded with calcium aluminate cement as a result of the in-situ formation of micro-sized spinel (MgAl2O4). In the present study, to further enhance the TSR of HMC bonded castables...

The object scale variation results in a negative effect on image segmentation performance. Spatial pyramid pooling module or the attention mechanism are two widely used components in deep neural networks to handle this problem. Applying the single component commonly achieves limited benefit. To push the limit, in this paper, we propose a scale chan...

Al2O3@CaCO3 aggregates were prepared by impregnating corundum aggregates (particle sizes with 3‐1 and 5‐3 mm) in precursor solutions (Calcium hydrogen citrate, CaHC6H5O7) followed by heat treatment at 430°C. The phase composition and microstructure of the coatings were characterized via X‐ray diffraction and scanning electron microscope, respective...

Hydratable magnesium carboxylate (HMC), which is similar to the properties of cement, can be used as a potential binder for refractory castables. However, its decomposition may lead to poor mechanical properties at medium temperatures (300°C ∼ 1100°C). This work investigated the effects of boric acid on the mechanical properties and microstructural...

Traditional Artificial Intelligence (AI) based fault detection approaches need a large amount of data for the model learning. However, in a real-world system, it is very difficult and expensive to obtain massive labeled fault data. In addition, the working conditions of a motor are usually variable, conventional fault diagnosis models with weak gen...

The in-situ high-content carbon-containing calcium aluminate cement (HCCAC) with the carbon content of 20.1 wt.% was prepared by the soft chemistry method with citric acid, calcium carbonate, and alumina as raw materials. The cement product was characterized by X-ray diffractometry, scanning electron microscopy, and Raman spectroscopy. In HCCAC, pl...

With the steady development of technology, electric motors (EMs) have become one of the most important components in modern industry. To ensure stable industrial production, detecting and classifying the EM faults is crucial. A novel intelligent deep-learning-based multi-fault detection method for EMs under varying working conditions is proposed in...

In the present study, different ratios of layered double hydroxides (LDHs) were synthesized via co-precipitation method. The synthesized LDHs were characterized by Fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), nitrogen adsorption-desorption analysis, point of zero charges (pHpzc), scanning electron microscopy (SEM) and T...

The potential of hydratable magnesium carboxylate compounds (HMC) combined with MgO powder as a binder of castables was evaluated. The green mechanical and thermal shock resistance properties of HMC-bonded castables (HMCC) and calcium aluminate cement-bonded castables (CACC) were compared. The green mechanical strength of the HMCC reached the mecha...

The online junction temperature monitoring of power devices is a viable technique to ensure the reliable operation of mission-critical power electronic converters. This article provides a potential approach for the junction temperature estimation of SiC MOSFET s based on the dynamic threshold voltage. The proposed method is independent of load cu...

In this paper, the fuel delivery subsystem (FDS) with hydrogen recirculation and anode bleeding is applied in proton exchange membrane fuel cell (PEMFC) system, which is utilized to supply hydrogen to the anode of stack and recirculate fuel back to the supply line. As the diffusion of nitrogen from cathode to anode is inevitable in a real PEMFC dur...

The poor water dispersion and oxidation resistance of carbon has restricted the widely industrial application of carbon containing castables. High aspect ratio network-like carbon nanotubes containing calcium aluminate cement composite powders were synthesized by carbon-bed sintering method using calcium acrylate and activated alumina as raw materi...

In this paper, the influence of gate loop inductance on the insulated-gate bipolar transistor (IGBT) junction temperature monitoring based on the transient peak gate current Temperature Sensitive Electrical Parameter (TSEP) methods is investigated using time domain analysis, SPICE simulation and experimental work. It is observed that the peak gate...

The reliability concern of SiC MOSFETs has been extensively investigated with various accelerated stress tests. However, these conventional tests are predominantly performed in a simplified and controlled testing environment, which might or might not realistically simulate the actual device operation profiles in power converters. In this paper, we...

In article number 1901716, Hongwei Lei, Song Zhang, Zuojun Tan, and co‐workers report a novel and efficient perovskite defect passivation strategy using silica oligomer. TEOS‐processed silica oligomer is in situ introduced into perovskite films to serve as a passivation agent (PA) for perovskite solar cells (PVSCs). Silica oligomer PA can enlarge p...

Perovskite solar cells (PVSCs) have achieved excellent power conversion efficiency (PCE) but still suffer from instability issues. Defect passivation is an important route to simultaneously increase the efficiency and stability of PVSCs. Here, a strategy of incorporating silica oligomer in perovskite films for surface and grain boundary defect pass...

Sb2S3 solar cells are lagging behind conventional thin-film solar cells such as silicon solar cells and cadmium telluride solar cells in the power conversion efficiency (PCE). One of the most prominent problems is that the carrier concentration of Sb2S3 is relatively low. In order to increase the carrier concentration, elemental Cu was doped into S...

Eliminating antiparallel SiC SBD and making use of the intrinsic body diode of SiC MOSFET offers a cost-effectiveness solution without obviously sacrificing the conversion efficiency in some power converter applications. Although the body diode of commercial SiC MOSFET has been qualified by several manufacturers, the reliability of SiC MOSFET under...

Inspired by the robustness and efficiency of the capped nuclear norm, in this paper, we apply it to 3D tensor applications and propose a novel low-rank tensor completion method via tensor singular value decomposition (t-SVD) for image and video recovery. The proposed tensor capped nuclear norm model (TCNN) handles corrupted low-rank tensors by spar...

Titanium dioxide (TiO 2 ) is the most representative and widely used photocatalyst. To further enhance the photocatalytic efficiency of titanium oxide, in this study, we developed a facile hydrothermal method to synthesize iron-doped TiO 2 . Iron-doped TiO 2 was synthesized by hydrothermal method with titanium monoxide as raw material and iron sulf...

In this work, we propose an entirely learning-based method to automatically synthesize text sequence in natural images leveraging conditional adversarial networks. As vanilla GANs are clumsy to capture structural text patterns, directly employing GANs for text image synthesis typically results in illegible images. Therefore, we design a two-stage a...

Wind power penetration has increased rapidly in recent years. In winter, the wind turbine blade imbalance fault caused by ice accretion increase the maintenance costs of wind farms. It is necessary to detect the fault before blade breakage occurs. Preliminary analysis of time series simulation data shows that it is difficult to detect the imbalance...

An ultrasonic assisted microchannel extraction (UAME) method was developed for the extraction of Fe(III) from wet-process phosphoric acid with di(2-ethylhexyl)phosphoric acid (D2EHPA). The influences of ultrasonic power, extractant concentration, water phase velocity and the ratio of the organic and aqueous phases (O/A) on the extraction rate of Fe...

Tin sulfide (SnS) is a promising absorber material for photovoltaic cells, because of its optimum band gap, strong optical absorption, simple phase composition, earth-abundant and nontoxic constituents. However, this material is largely unexploited to date with only a handful of studies reporting SnS for photovoltaic application. We present systema...

The preliminary characterization study and analysis of the short-circuit (SC) capability of SiC MOSFET have been reported in recent years. However, the failure modes of the SiC MOSFET under various SC conditions and their physical mechanisms are unclear. The purpose of this paper is to extensively investigate the SC ruggedness, failure modes and in...

In this study, we reported a novel in situ hydrothermal approach for fabricating Sb2S3 films. Metal Sb films were first deposited on substrates using room-temperature radio frequency magnetron sputtering and then undergo an in situ transformation to Sb2S3 films through a novel low-temperature hydrothermal reaction. Characteristics of the obtained S...

Uyghur text localization in images with complex backgrounds is a challenging yet important task for many applications. Generally, Uyghur characters in images consist of strokes with uniform features, and they are distinct from backgrounds in color, intensity, and texture. Based on these differences, we propose a FASTroke keypoint extractor, which...

A room-temperature solution-processed pillar[5]arene-based small molecule material, termed C3, has been designed, synthesized, and incorporated between a conventional PCBM electron transport layer (ETL) and a metal electrode to function as a single-layer cathode buffer layer (CBL) for efficient planar p-i-n perovskite solar cells (PVSCs). It has be...

Based on the model describing two coupled synthetic clock cells, the synchronization dynamics under stochastic noise are explored. As extrinsic noise from signal is the predominant form of noise for all gene promoters, we investigate the effects of extrinsic noise original from signal molecule by evaluating the order parameters. It is found that st...

Uyghur text localization in complex background images is a significant research for Uyghur image content analysis. In this paper, we propose a robust Uyghur text localization method in complex background images and provide a CPU–GPU heterogeneous parallelization scheme. Firstly, a multi-color-channel enhanced maximally stable extremal region is use...

An ultrasound-assisted extraction (UAE) method was developed for the extraction of Fe (III) from wet-process phosphoric acid with di (2-ethylhexyl) phosphoric acid (D2EHPA). The influences of UAE parameters, including ultrasonic power, extraction time, concentration of D2EHPA and extraction temperature, were systematically studied. The response sur...

Photocatalytic degradation by ultraviolet (UV)/TiO2 combined with Fenton reagent was employed in treating high concentration n-propanol solution. The influence of the TiO2 dosage, the concentration of ferrous ion, the integral H2O2 dosage and the optimizing H2O2 adding program were investigated by a series of batch experiments. The increasing injec...

The structural and mechanical properties of ZnS in both B3 and B1 phases have been investigated by the generalized gradient approximation (GGA) within the plane-wave pseudopotential density functional theory (DFT). The obtained lattice parameters and bulk modulus of ZnS for both B3 and B1 structures are well in line with the available theoretical a...

Fe2O3@rGO nanostructures with different Fe2O3 morphologies (nanoplate and nanoparticle) have been successfully fabricated by a simple and novel liquid-solid-solution (LSS) hydrothermal method. The Fe2O3@rGO composites with different morphologies and sizes were obtained at the oil/water interface by simply adjusting the concentration of Fe²⁺ ions an...

The influences of detection device geometry and fiber optic parameters on near infrared spectroscopy measurements were assessed using stone fruit models based on Monte Carlo simulation. The stone fruit was modeled as concentric spherical layered tissues including the skin, the flesh and the core. The choices of the detection angle, the diameter of...

Text localization in complex background images remains a challenging task, especially for Uyghur text. Since the existing methods mostly focus on English and Chinese. Uyghur as a minority language is paid less attention. This paper proposes a robust and precise method for locating Uyghur texts in complex background images. Firstly, a multi-color-ch...

Binary embedding is an effective way for nearest neighbor (NN) search as binary code is storage efficient and fast to compute. It tries to convert real-value signatures into binary codes while preserving similarity of the original data, and most binary embedding methods quantize each projected dimension to one bit (presented as 0/1). As a consequen...

CoFe2O4/graphene composites were fabricated via a novel one-pot liquid-solid-solution (LSS) hydrothermal process. Through ions electrostatic adsorption onto graphene sheets and oil microemulsion encapsulation, CoFe2O4 nanoparticles can be uniformly anchored on crumpled graphene sheets without aggregation, and the size distribution of CoFe2O4 partic...

In the pilot-scale study, a kind of pretreated wastewater from the pickling process in a steel wire rope manufacturer was reused by a novel integrated membrane process (Reverse osmosis and R-HCO3 anion-exchange resin combined in series), and the operating parameters for the system had been optimized. After the pretreatment process through neutraliz...

The propagation of photons in stone fruit tissue was simulated with the Monte Carlo (MC) method. A model of concentric-spherical-layered tissues was built for intact stone fruit. Peaches were used as typical representatives of stone fruit. Diffuse reflectance and inspection efficiency were calculated using the concentric-spherical-layered model. Th...

We report a liquid-solid-solution assemble strategy to fabricate Fe2O3@graphene (Fe2O3@rGO) composites at the oil/water interface, where the Fe2O3 nanoplates with thickness of about 100 nm are anchored on the crumpled graphene sheets. The in situ nucleation and growth process can ensure intimate contact between Fe2O3 nanoplates and graphene sheets,...

The propagation of light in stone fruit tissue was modeled using the Monte Carlo (MC) method. Peaches were used as the representative model of stone fruits. The effects of the fruit core and the skin on light transport features in the peaches were assessed. It is suggested that the skin, flesh and core should be separately considered with different...

Calcined layered double hydroxides (CLDHs) were used as an adsorbent to remove an azo dye—dispersed red (DR), from aqueous solution by the batch adsorption technique. Various conditions were evaluated, including CLDH structures, adsorbent dosage, initial dye concentration, and temperature. It was found that the layered double hydroxides with a Mg/A...

Maleic anhydride modified polypropylene (PP) (PP-g-MAH) was chemically grafted onto palygorskite (Pal) via the bridge linking of [3-(2-aminoethyl)aminopropyl]trimethoxysilane (Z-6020) and PP-g-MAH in the presence of ultrasonic oscillation. The modified Pal was added to a PP matrix as a nano-filler to prepare Pal/PP nanocomposites by melt blending....

The delamination of layered double hydroxides (LDHs) was supposed to be achieved in a microemulsion composed of octane, N-lauroyl-glutamate, butanol and water. In the X-ray diffraction patterns of LDHs, the diffraction peaks at low angle regions disappeared when the amount of octane reached a proper degree in the microemulsion, indicating that LDH...

Microelectrode chips were designed and prepared for cell lysis. The method involved pulverization of the cells by an electrical signal and attachment on the chip. Cell lysis was performed by a 10 volt square wave. This is a reduced voltage compared with traditional methods. This design offers an improved lysing rate, simple operation and design, an...

We investigated the changes in the conformation and crystalline structure of polypropylene (PP) using a combination of Fourier transform infrared spectroscopy (FTIR), wide-angle X-ray diffraction (WAXD), and differential scanning calorimetry (DSC) based on PP/chlorinated PP (CPP)/polyaniline (PANI) composites. The DSC heating thermograms and WAXD p...