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Pyroptosis, a non-apoptotic programmed cellular inflammatory death mechanism characterized by gasdermin (GSDM) family proteins, has gathered significant attention in the cancer treatment. However, the alarming clinical trial data indicates that pyroptosis-mediated cancer therapeutic efficiency is still unsatisfactory. It is essential to integrate the burgeoning biomedical findings and innovations with potent technology to hasten the development of pyroptosis-based antitumor drugs. Considering the rapid development of pyroptosis-driven cancer nanotherapeutics, here we aim to summarize the recent advances in this field at the intersection of pyroptosis and nanotechnology. First, the foundation of pyroptosis-based nanomedicines (NMs) is outlined to illustrate the reliability and effectiveness for the treatment of tumor. Next, the emerging nanotherapeutics designed to induce pyroptosis are overviewed. Moreover, the cross-talk between pyroptosis and other cell death modalities are discussed, aiming to explore the mechanistic level relationships to provide guidance strategies for the combination of different types of antitumor drugs. Last but not least, the opportunities and challenges of employing pyroptosis-based NMs in potential clinical cancer therapy are highlighted. This abstract graphic takes concerted action with abstract section and illustrates the development status of pyroptosis-based nanomedicines for cancer treatment. [Display omitted] [ABSTRACT FROM AUTHOR]

Hypersonic vehicles as next-generation aircraft have broad applications, but existing technologies of onboard power generation are hardly applicable due to the change of engines. In this research, a catalytic steam reforming enhanced closed-Brayton-cycle power generation system based on is developed. This system combines the closed Brayton cycle (CBC) and catalytic steam reformed fuel vapor turbine (CSRFVT) to supply electric power. The zero-dimensional models of CBC and the CSRFVT are established to evaluate system performance. Results indicate the products with a water content of 30% have the strongest working ability, which can reach 330 kJ/kg. Moreover, the thermal efficiency and electric power of the parallel arrangement are higher than that of the series arrangement. Besides, the lower pressure of water is beneficial to the electric power. However, the difference in electric power between various pressures is less than 1 kW. In addition, under the same heat absorption, the total electric power of the system based on fuel and water is higher, and the former's outlet temperature of cooling channels is lower. The maximum total electric power of the novel system is about 120 kW. This research provides an innovative technical solution for the power generation of hypersonic vehicles. • A novel power generation system based on hydrocarbon fuel and water is proposed. • A zero-dimensional model of the system performance is established. • The products with a water content of 30% have the strongest working ability. • The maximum total electric power of this system is 120 kW at Ma 6. Abstract. [ABSTRACT FROM AUTHOR]

Platinum (Pt)-based chemotherapy has been necessary for clinical cancer treatment. However, traditional bivalent drugs are hindered by poor physicochemical properties, severe toxic side effects, and drug resistance. Currently, elemental Pt(0) nanotherapeutics (NTs) have emerged to tackle the dilemma. The inherent acid-responsiveness of Pt(0) NTs could help to improve tumor selectivity and alleviate toxic effects. Moreover, the metal nature of Pt facilitates the great combination of Pt(0) NTs with photothermal and photodynamic therapy and imaging-guided diagnosis. Based on recent important researches, this review provides an updated introduction to Pt(0) NTs. First, the challenges of traditional Pt-based chemotherapy have been outlined. Then, Pt(0) NTs with multiple applications of tumor theranostics have been overviewed. Furthermore, the combinations of Pt(0) NTs with other therapeutical modalities are introduced. Last but not least, we envision the possible challenges and prospects associated with Pt(0) NTs. [Display omitted] [ABSTRACT FROM AUTHOR]

The flow field structure has important influences on the mass and heat transfer and the distribution uniformity in the proton exchange membrane electrolysis cell (PEMEC). In this paper, the application and operation modes and the structural parameters of the new interdigitated-jet hole flow field (JHFF) are explored, to guide the processing of the JHFF and provide references for experimental testing. A three-dimensional and two-phase model is established to simulate the effect of JHFF on the performance of PEMEC. The results demonstrate that compared with the application of JHFF only on the anode side, the application of JHFF on both sides of the anode and cathode can increase the temperature distribution uniformity and polarization performance by 41.78% and 16.25%, respectively. By increasing the number of inlet flow channels and using the counter-flow water supply mode, the temperature distribution can be more uniform. The lower the height of jet holes, the better the normal mass transfer and polarization performance, while the worse the temperature distribution uniformity. Reducing the diameter of the inlet jet holes can improve the normal mass transfer performance in the porous electrode. Synthetically, the hole height of 0.2 mm and the hole diameter of 0.4 mm are recommended. The findings provide theoretical guidance for the practical application of JHFF in PEMEC so that the positive role of JHFF in improving electrolysis performance can be fully realized. • The application modes and structural parameters of the new JHFF are numerically investigated. • The bilateral application of the JHFF improves temperature distribution uniformity and polarization performance. • More inlet channels and counter-flow water supply make the temperature evenly distributed. • For the jet holes, the height of 0.2 mm and the diameter of 0.4 mm are recommended. • The results guide the processing of the JHFF and provide references for experimental testing. [ABSTRACT FROM AUTHOR]

• Fast and batch of settling mud flocs measurement and 3D reconstruction. • Volumetric floc reconstruction improves the accuracy of irregular mud floc sizes. • Stable bimodal volumetric floc size distribution forms in equilibrium flocculation. • Settling velocity keeps stable and low variability between 1 and 2 mm·s−1 in >200 μm. • High Volumetric- but low Mass- Settling Flux in flocs>200 μm due to bio-components. Mud flocculation and settling play key role in understanding sediment transport cycle and affect water quality in estuaries and coastal seas. However, the morphological irregularity and structural instability of fragile mud flocs set huge obstacles for quantifying geometric property accurately and establishing reliable predicting tools in settling dynamics via previous observing strategies based on instant measured and 2-dimensional imagery floc parameterizations. Here we designed a multi-camera apparatus targeting capturing multiple angles of individual flocs, and developed a multi-view segmentation algorithm on floc images analysis. We finally accomplished batch of 3-dimensional reconstruction obtaining each settling floc's volumetric size in equilibrium flocculation. The results indicate a stable bimodal floc size distribution in equilibrium flocculation with a dominant peak of microflocs (<200 μm) and a secondary smaller peak of macroflocs (> 200 μm). The flocculi (<50 μm) shows more spherical outlines with dense structure while the larger-sized macroflocs (>200 μm) have high irregular morphologies with high porosity and visible biological debris attaching, and the microflocs (50–200 μm) tend to be irregular in shape and dense inside. The terminal settling velocity of mud flocs shows increasing with floc size in <200 μm but keeps stable around 1–2 mm s−1 after >200 μm due to the increase in size being compensated by the decrease of density according to the fractal theory on floc geometry. The higher organic matter content within larger porous flocs reduces the macroflocs effective density. These lead to high volumetric settling flux but low mass settling flux of macroflocs in natural water systems. This work provides new insight to reveal more accurate mud floc geometric parameterizations in volumetric aspect and reliable characterizations of equilibrium flocculation using a fast and sound batch of direct measuring approach. This may importantly improve the predictions of suspended mud dynamics in nature. [Display omitted] [ABSTRACT FROM AUTHOR]

[Display omitted] • The pickling method increased the carbon content of the sample to 89.97%. • The CGFA of acid treatment method can be the precursor of activated carbon. • The flotation method has poor effect on the separation of water-containing CGFA. • Both methods of flotation and acid treatent improve the reactivity of CGFA. The high carbon content (20–60%) in coal gasification fine ash (CGFA) makes CGFA unable to be directly used in the building materials and ceramic industries, and can only be dissipated in landfills, which brings serious environmental safety problems. This paper uses physical (flotation method) and chemical (multi-stage pickling method) methods to treat CGFA, analyze the separated carbon, and evaluate its application. The carbon content of the filter cake ash (FCA) residual carbon recovered by the flotation method is slightly increased, and the carbon ash separation effect for the water-containing CGFA is poor. The carbon content of dry ash (DA) recovered carbon in acid treatment increased from 16.33% to 89.97%. The specific surface area of the acid-washed recovered carbon is 6–34 times that of the original sample, and the specific surface area of dry ash-HCl/HF/HCl (DA-CFC) is as high as 425.31 m2/g, and its pore structure network is more developed than before deashing. After pickling treatment, the microcrystalline structure changes, the carbon skeleton becomes looser, the degree of crosslinking decreases, and the reaction activity increases. The relative content of C C in the acid-washed recovered carbon increased by 6.4–46.3%, and the relative content of functional group C H bonds increased by 48.5–89.5%. Compared with the activation energy of the original sample, the activation energy E of the sample after flotation and acid treatment is reduced, and the reaction activity is enhanced. Flotation and pickling methods can improve the grade of fuel, and multi-stage pickling methods to obtain high specific surface area carbon can be used as a precursor for the preparation of activated carbon. Carbon-ash separation of DA by flotation method can be applied to fuel combustion, fine chemical industry, and road filling. However, for FCA, it is necessary to use a pickling scheme for carbon-ash separation to realize resource utilization and harmlessness. [ABSTRACT FROM AUTHOR]

• An understanding of the radial air staging method for PC utilization is improved and the key parameter (OFA distribution) is optimized. • Compared to the traditional axial air staging method, for the radial air staging method, the OFA distribution has a greater effect on the heat release from PC particles. • The increased R IO is not conducive to the rapid devolatilization from PC particles, resulting in poorer combustion stability of the boiler. • The increased R IO promotes the oxidation reaction of N released from PC particles, which is detrimental to boiler NO x emission reduction. • The advanced mixture of the OFA with the main airflow facilitates the burnout of the PC particles as the R IO increases. Radial air staging is an innovative method for reducing NO x emissions from coal-fired boilers compared to conventional axial air staging. However, an important issue in using this method is to set the over-fired air (OFA) distribution rationally to achieve good boiler performance. This paper aims to optimize the OFA distribution by evaluating important gas-particle (GP) parameters that influence the pulverized coal (PC) combustion performance. The GP flow experiment is conducted in a laboratory furnace model of a coal-fired boiler with different OFA distributions. The experimental results show that as R IO (Two-level OFA distribution ratio) changes from 0:1 to 1:0, the mixture of the OFA jet and airflow in the main combustion zone is advanced, which is conducive to PC burnout. Meanwhile, the size of the central recirculation zone decreases, resulting in poor PC ignition. It is worth noting that at R IO of 1:0, the central recirculation zone disappears at section y/d = 2.5, indicating that there is no high-temperature flue gas downstream to heat the fresh PC particles, which is extremely unfavorable for the stable combustion of the PC. In addition, at R IO of 0:1, compared to other cases, there are more particles in the central recirculation zone, which promotes the reduction reaction of N element released from PC particles, thus reducing NO x emission. According to the comprehensive evaluation, it is recommended that the R IO of the two-level OFA be set to 1:1 when using radial air staging in a coal-fired boiler. The results provide new insights into the application of the air staging method for efficient and clean PC utilization. [ABSTRACT FROM AUTHOR]

Waste tire carbon black particles (CBp) are the main pyrolysis products of waste tires (WT), and CBp is difficult to use directly. This work mainly focuses on the physicochemical and combustion characteristics of demineralized CBp (DCBp) to explore the resourceful utilization of CBp resources in large quantities. This work also provides a comprehensive comparison with CBp and other carbon-based solid fuels. The results show that most of the minerals in CBp can be removed by chemical demineralization treatment (Ash content of DCBp <0.11 %). DCBp has a more developed pore structure than CBp. The deashing process affects the degree of loosening and stacking of the graphitic carbon microcrystalline structure, and the relative content of oxygen-containing functional groups in CBp to a minor extent. The deashing process leads to a decrease in the relative strength of the cross-linked stable structure and an increase in the disordered structure of carbon in CBp. The volatile fraction to fixed carbon ratio of DCBp is only 0.0467, and a large number of catalytic alkali metal elements and alkaline earth metal elements are removed in the demineralization process, which makes the early combustion of DCBp more difficult. As the combustion reaction proceeds, the internal pores of the particles are opened, and the micropores and mesopores in DCBp provide a larger surface area for the reaction. In addition, the decrease in the relative strength of the cross-linked stable structure and increases in the disordered structure of carbon can increase the intermolecular collision frequency during the combustion process, thus improving the burnout characteristics of DCBp. The above results indicate that DCBp has the potential to be used as fuel for large-scale resource utilization. [Display omitted] • The chemical demineralization process has little effect on crystal lattice of CBp. • The chemical demineralization process can increase disordered structure of CBp. • The E of DCBp is lower due to the removal of catalytic alkali metal elements. • The A of DCBp is higher than that of CBp. • A and E of demineralized carbon-based solid fuel have kinetic compensation effects. [ABSTRACT FROM AUTHOR]

To achieve low-NO x emission in the coal-fired industrial boiler, the radial air staging method is proposed. The location of the over-fired air (OFA) is an essential parameter as it affects the combustion stability, NO x generation, burnout, and slagging trend. These are related to the gas-particle flow such as the recirculation region, gas mixture, and gas-particle mixture. Therefore, in this paper, taking a coal-fired industrial boiler with radial air staging method as an object, in a cold-modeling furnace, the gas-particle flow characteristics under various OFA locations (L D of 1.29, 1.43, 1.72, and 2.00) are studied. When OFA is radially arranged, the OFA jet diffuses towards the furnace center. As the L D increases, the size of the central recirculation region increases, thereby improving combustion stability. When the L D is 2.00, the mixing of the OFA jet and PCC jet obviously is delayed. Moreover, an increase in L D leads to more returned particles in the furnace center, promoting the reduction reaction of NO x. In addition, as the L D increases from 1.29 to 1.72, the gas-particle mixing uniformity is enhanced, which is beneficial to the uniform temperature distribution. Comprehensively, the L D of 1.43–1.72 is recommended when radial air staging is adopted in coal-fired industrial boilers. • The radial air staging method accelerates the mixing of OFA and the main airflow while reducing the mixing intensity. • With the increase of L D , the obstructing effect by radial OFA on the diffusion of the swirling main airflow is weakened. • The increased L D facilitates gas recirculation in the main combustion zone, which is conducive to stable combustion. • The mixing uniformity of GPF increases with L D in general, promoting the uniformity of temperature distribution. [ABSTRACT FROM AUTHOR]

To segment railway track regions in real-time for intrusion detection and improving security, this paper proposes an efficient railway track region segmentation network (ERTNet) based on the encoder–decoder architecture. Firstly, to ensure the lightweight of the encoder, depthwise convolution and the channel shuffle are utilized to construct sandglass-type feature extraction unit. Secondly, a feature-matching-based cross-fusion decoder is utilized to fuse deep and shallow feature maps. Thirdly, the knowledge distillation is employed with large-scale Deeplab v3+ as the teacher model to improve performance. Additionally, a loss function is proposed to penalize pixel points with large offsets. Finally, the ERTNet is validated on the self-built dataset, achieving an MIoU (Mean Intersection over Union) of 92.4% , which is 5.22% improvement over the benchmark model. ERTNet achieves a balance between segmentation accuracy and computational efficiency, requiring only 0.5 M parameters and 0.92 G FLOPs (Floating Point Operations). [Display omitted] • Visual perception is utilized to identify foreign object intrusion into railroad. • Deep learning based ERTNet model is proposed for track region pixel extraction. • ERTNet is built with lightweight neural network and cross-fusion decoder. • Optimizing training modes with knowledge distillation and new loss function. • ERTNet fits real-time needs and helps to improve the safety of rail construction. [ABSTRACT FROM AUTHOR]

• A novel low-NO x technology is proposed for a down-fired boiler with swirl burners. • Gas/particle flow characteristics are studied under two combustion technologies. • Downward depth of gas/particle flows improves for the improved boiler. • Primary air is effectively ejected by burner secondary air for the novel technology. • Turbulent intensity in the recirculation region increases for the improved boiler. To confirm the validity and progressiveness of the eccentric-swirl-secondary-air combustion technology (ESSACT) in improving the economic and environmental performance of the down-fired boiler (DFB) with swirl burners, the gas/particle (GP) cold-modelling experiments are conducted by using a particle dynamic analyzer (PDA) measurement system in a 1:10 scale model of 300-MW e DFB applying original Babcock & Wilcox combustion technology (BWCT) and novel ESSACT, respectively. The distributions of average velocity, fluctuation velocity and particle size are compared and analyzed under the two combustion technologies in this study, in addition to the decay of particle volume flux and the jet trajectory of downward GP flows. In comparison with the BWCT, the rotation intensity of the burner secondary air is greatly weakened, and the vertical velocities of downward GP flows decay more slowly under the ESSACT. Although the recirculation regions are both formed below the arches under the two combustion technologies, the horizontal velocities and the horizontal fluctuation velocities of GP flows in the recirculation regions are both larger for the ESSACT, which benefits pulverized coal ignition. The particle size distributions under the two combustion technologies reveal that the mixing between the primary air and burner secondary air is obviously delayed and the burner secondary air effectively ejecting the primary air downward is realized by the ESSACT, which is advantageous to improve pulverized coal burnout and inhibit NO x formation. In addition, the maximum particle volume flux in the lower part of the lower furnace under the ESSACT is obviously higher than that under the BWCT, and the downward depth of GP flows and the space utilization ratio in the lower furnace increase for the original BW DFB retrofitted by the ESSACT. [ABSTRACT FROM AUTHOR]

The eccentric-swirl-secondary-air combustion technology has been confirmed to comprehensively solve high NO x emission and poor coal burnout for down-fired boilers with swirl burners. The influence of vent-air inclination angle (β v), a critical factor that affects coal burnout, on gas/particle flow characteristics is investigated to further decrease unburned combustible in fly ash. Gas/particle two-phase flow experiments under different β v (i.e., 10°, 20°, 28°, 40° and 50°) are performed by using a particle dynamic analyser in a 1:10-scale model of the full-scale improved boiler. With increasing β v , the under-arch recirculation zone and the recirculation velocities of gas/particle flows continuously increase. In the staged air region, the vertical velocities of gas/particle flows near water-cooled wall for β v of 40° and 50° are still as high as 2–4 m/s, however, the vertical velocities of gas/particle flows basically decay to negative values for smaller β v of 10° and 20°. At furnace section Y/Y 0 from 0.220 to 0.369, the vertical fluctuation velocities of gas/particle flows near water-cooled wall for β v of 40° and 50° are significantly higher than those with β v of 10°, 20° and 28°, and the particle volume flux at the same horizontal position X/X 0 constantly increases with increasing β v. Furthermore, the downward ejection ability of vent air to gas/particle flows from burners continuously improves, and the downward depth of gas/particle flows and the space utilization ratio of lower furnace both increase with increasing β v. The appropriate inclination angle of vent air for the improved boiler varies from 40° to 50°. Image 1 • A novel high-efficiency low-NO x technology is applied to a down-fired boiler with swirl burners. • Gas/particle flow characteristics at different vent-air inclination angles are investigated. • With increasing angle, recirculation zone and downward depth of gas/particle flows increase. • Primary air is more effectively ejected by under-arch air with increasing inclination angle. • The appropriate inclination angle of vent air for the improved boiler varies from 40° to 50°. [ABSTRACT FROM AUTHOR]

The eccentric-swirl-secondary-air combustion technology (ESSACT) is an innovative technology to comprehensively solve high NO x emission and unburned carbon content in fly ash of the down-fired boiler with swirl burners. In this study, a breakthrough idea (i.e. decreasing burner injection angle (θ b)) is proposed to further greatly improve coal burnout of the improved boiler. Using a laser particle dynamic analyzer, the distributions of average and fluctuation velocities of gas/solid (GS) flows, distribution and decay of particle volume flux and jet trajectory of burner primary air in a 1:10 scale model of full-scale furnace at different θ b of 0°, 8°, 15° and 25° are acquired. The effects of θ b on GS flow characteristics (i.e. downward depth of GS flows, recirculation zones below arches and air flow fullness in the lower furnace) in the furnace are intensively studied. As the θ b decreases, the maximum vertical velocity of GS flows increases in the whole lower furnace, and the vertical fluctuation velocity of GS flows and the turbulent intensity and diffusion also increase. With decreasing θ b , maximum recirculation velocity and dimension of recirculation zone below arches both increase continuously, which is conducive to improving ignition and burnout of pulverized coal. Especially, the maximum recirculation velocity with θ b decreasing from 25° to 15° and the dimension of recirculation zone below arches with θ b decreasing from 15° to 8° increase more obviously. With decreasing θ b , the ejection effects of vent air and staged air on GS flows from arches are more effective. In the region below staged air, the maximum particle volume flux for the θ b of 0° and 8° is more than twice that for the θ b of 15° and 25°. As a result, the downward depth of GS flows and air flow fullness in the lower furnace both increase with decreasing θ b. To improve coal burnout of the down-fired boiler applying ESSACT, the θ b is recommended to be set below 8°. Image 1 • A novel low-NO x technology is proposed for a down-fired boiler with swirl burners. • Gas/particle flow characteristics are studied at various burner injection angles. • Recirculation zone and downward depth of flows both increase with decreasing angle. • Particles are more effectively ejected by vent and staged air with decreasing angle. • The burner injection angle is recommended to be set below 8° for the boiler. [ABSTRACT FROM AUTHOR]

[Display omitted] • Microwave absorbers were synthesized using an in situ semi-conversion strategy. • The maximum effective absorption bandwidth of the MOF derivative is 5.65 GHz. • Effect of micromorphology on microwave absorption properties was investigated. In the process of micro-designing metal organic frameworks (MOFs) to resist electromagnetic contamination, inappropriate parameter selection is likely to lead to skeleton collapse, thus rendering the microwave absorption (MA) performance failure. Herein, we propose an efficient in situ semi-conversion strategy. We etched and annealed the template FeNi-MOF-74 to finally obtain FeNi/graphite composites. Among them, the MOF derivative with a KOH etching concentration of 0.25 mol/L and an annealing temperature of 800 °C has excellent electromagnetic parameters and efficient MA performance, with an effective absorption bandwidth of 5.65 GHz and a minimum reflection loss of −64.11 dB at a thickness of only 1.8 mm. We controlled the electrical conductivity and polarization properties of the materials by varying the concentration of OH−, which effectively improved the impedance matching and enhanced the MA performance of the MOF derivatives. More importantly, this strategy closely related the microscopic nanostructure of MA materials to the macroscopic MA properties, providing unlimited possibilities for the preparation of high-performance MA materials. [ABSTRACT FROM AUTHOR]

[Display omitted] • Core-shell structured MOF derivatives with ideal heterogeneous interfaces were successfully synthesized. • The effective absorption bandwidth of MD-2 is 6.97 GHz and the minimum reflection loss is −75.61 dB. • We compare the electromagnetic synergistic loss mechanism to the "sun" and other loss mechanisms to "planets" revolving around a "star", and provide a vivid and systematic description of the microwave absorption mechanism of MOF derivatives. Microstructure design and genetic modification with metal–organic frameworks is one of the key strategies for combating electromagnetic pollution, albeit it continues to face constraints. Since inappropriate parameter selection during microstructure modification is extremely likely to result in pore collapse, metal agglomeration and other issues. Herein, we propose an efficient cation hybridization strategy where we etch the precursor MIL-53 by different etching concentrations and anneal it at various temperatures. Ultimately, light and efficient MOFs-derived microwave absorption materials are obtained. Notably, the magnetic heterogeneous atoms introduced by the cationic hybridization reaction not only provide perfect heterogeneous interfaces but improve the electromagnetic synergistic effect. Benefiting from the optimized impedance matching provided by electric–magnetic synergistic loss mechanism and the polarization effect generated by a large number of heterogeneous interfaces and defects, the MD-2 has shown ultra-high electromagnetic parameters and excellent microwave absorption performance with a qualified absorption bandwidth of 6.97 GHz (2.36 mm) and a minimum reflection loss of −75.61 dB. In addition to broadening the permittivity-magnetic synergistic mechanism of microwave absorption materials under the morphology-property relationship, the general approach inspired by this strategy also lays a solid foundation for the EMW absorption of artificial intelligence microdevices in the 5G era. [ABSTRACT FROM AUTHOR]

The air cavity planing hull enables the feasibility of running at a low drag-to-lift ratio at high speeds by reducing the wetted area. During the voyage, the ventilation rate and heel are essential parameters for the performance of the air cavity ship (ACS). In this study, three-dimensional Reynolds-averaged Navier-Stokes equations coupled with the volume of fluid method (RANS-VOF) are applied to examine the characteristics of the ACS across a wide range of ventilation rates (C q = 0–1.120) and heel angles (β = 0–5 deg). The drag reduction and cavity morphology of the ACS are well predicted by the numerical method. The difference between the predicted total resistance and the experiment is less than 5%. The air cavity gradually develops from the meniscus growth cavity (MGC) (C q ≤ 0.168) to the bottle neck stable cavity (BNSC) (C q ≥ 0.336) with increasing C q. Once a stable cavity form (i.e., BNSC) is established, the excessive ventilation would expand the tail air leakage opening in width and thickness. Under the effect of the heel, air coverage and drag reduction are diminished with a critical heel angle (β) of around 2 deg. When β ≥ 2 deg, the cavity shape gradually degenerates to the one-side branch cavity (OSBC). The air coverage also has a negative effect on the heeling stability, which means that the smaller heeling moment may cause a greater heel angle. More importantly, the restoring moment reduction monotonically decreases from 54.3% to 7.1% with the increment of heel angle, which deteriorates the heeling stability of the ACS. • The air cavity performance is studied with and without heel. • The cavity develops from BNSC to OSBC when heel above critical value. • Air coverage reduces heel restoring momemt by changing pressure distribution. [ABSTRACT FROM AUTHOR]

Metal-organic frames (MOFs) have been a suitable template for high-performance microwave absorbing materials. However, there has been a lack of effective solutions for the agglomeration and inadequate graphitization transformation of metal nanoparticles after annealing of MOFs. In this work, a simple and safe metal ion exchange method for the experimental process is proposed to etch the surface of Fe MOF (MIL-88) template using nickel metal salts, and the subsequent heat treatment to synthesize Fe-Ni/C nanorods. These fine and uniform metal particles and carefully designed phase engineering have excellent electromagnetic attenuation and good impedance matching. In particular, suitable defects and rich heterogeneous interfaces cause polarization loss to increase, and more obviously, hysteresis loss and natural resonance increase magnetic loss. The experimental results show that the materials have good broadband absorption (6.13 GHz) and high-efficiency loss (−35 dB) microwave absorbing (MA) performance. This work provides a generalized phase interface engineering approach for polymetallic nanorods and provides a useful reference for microwave absorbing materials. [Display omitted] [ABSTRACT FROM AUTHOR]

Abstract Ultrathin single crystalline nanoplates of Ni 12 P 5 are synthesized via a facile, template-free, wet chemical method. The thickness is about 6 nm with sizes tunable from 5 to 50 nm. The exposed plate surface is formed of { 2 ¯ 11 } lattice plane. Benefitting from the high electrical conductivity and the two dimensional (2D) nanostructures, the Ni 12 P 5 nanoplates exhibit excellent supercapacitor properties. The specific capacity is about 697 C/g at the current density of 1 A/g. Even at 20 A/g, it is measured as 446 C/g, with 64.0% retention indicating an outstanding rate capability. The charge storage mechanisms include a battery-type behavior related to the bulk redox processes and a double-layer capacitance arising from the 2D geometric morphology. In particular, the morphological effects accounts for about 63% of the total charge storage effects at the voltage sweep rate of 2 mV/s in the cyclic voltammetry measurement, and is even higher percentage-wise at a higher sweep rate. This is, by far, the best performance with facile synthesis techniques for single crystalline nickel phosphides. Graphical abstract Image 1 Highlights • Single-crystalline Ni 12 P 5 nanoplates by a facile, template-free wet chemical route. • Nanoplate surface is of { 2 ¯ 11 } crystal plane, and its thickness, about 7 nm. • The growth mechanism is by Kirkendall effect. • High specific capacity is 697 C/g at the current density of 1 A/g. • Surface term accounts for about 2/3 of the specific capacity, and the bulk, 1/3. [ABSTRACT FROM AUTHOR]

Abstract While entrained-flow coal gasifiers (EFCGs) have been widely used in coal-gasification technologies, the thermal-calculation method, which is important for assessing the design and operation of EFCGs, has never been reported. Based on the fundamental thermal-calculation method for coal-fired boilers, and combined with the two-stage equilibrium model through the difference between the gasification and exit temperatures, we propose a thermal-calculation method for EFCGs to calculate the syngas composition, carbon conversion and energy distributions. The calculated gas compositions and heat loss are in good agreement with experimental data for industrial-scale plants. In the two-stage equilibrium module, the function for calculating the water participation ratio involved in the first-stage equilibrium reaction is improved by considering the influences of the ratios of oxygen/carbon and water/carbon, in addition to the gasification temperature. As the carbon conversion efficiency is significantly influenced by the oxygen/carbon and water/carbon ratios in the first-stage equilibrium system, the calculated carbon conversion efficiencies correspond more closely to the experimental data than the other models considering only the gasification temperature. Highlights • Thermal-calculation method of boiler is applied on entrained flow coal gasifier. • Introduce factors of O/C and H 2 O/C in the developed two stage equilibrium module. • Integrate thermal-calculation method with two stage equilibrium model. • The improved model shows good consistency with experiment data for gas composition. • Carbon conversion of improved model is closer to actual data compared with others. [ABSTRACT FROM AUTHOR]

Abstract A new air-staged and low-NO x emission combustion technology has been applied to a 300 MW e anthracite- and down-fired boiler with swirl burners. To achieve the optimum air distribution in the primary combustion zone and further reduce NO x emissions, full-scale industrial experiments varying the ratios between burner secondary air ratio (R bsa) and staged air ratio (R sa) (i.e., R bsa / R sa ratios of 42.9/17.8, 47.1/13.5 and 51.5/9.3), on the premise that the overfire air (OFA) ratio was approximately 20%, were performed to evaluate the overall performance of retrofitted boiler. The improved ignition of coal/air flow was at a distance of 0.8–1.4 m to the burner outlet with increased R bsa / R sa ratio. Compared with the boiler before retrofit, under R bsa / R sa ratios of 47.1/13.5 and 51.5/9.3, the flue gas temperature in the primary combustion zone of the retrofitted boiler increased slightly. Oxygen and carbon monoxide concentrations in the near-sidewall region revealed the furnace flame fullness varied under different R bsa / R sa ratios. With increased the air staged level in the lower furnace, NO x emissions decreased continually and the carbon content in fly ash did not necessarily increased. Under the optimum R bsa / R sa ratio of 47.1/13.5, the NO x reduction efficiency was approximately 46% with increasing boiler thermal efficiency slightly. Highlights • Low-NO x combustion technology was applied to a down-fired boiler with swirl burners. • As NO x emissions increased, carbon content in fly ash did not necessarily decreased. • NO x reduction of 46% was achieved without negative effects at the optimal condition. • Coal ignition and flue gas temperature in the primary combustion zone were improved. • Furnace flame fullness under different operation conditions was revealed. [ABSTRACT FROM AUTHOR]

Based on the signal transduction with a horseradish peroxidase (HRP)-functionalized gold nanoprobe, this work develops a new electrochemical aptasensing method for kanamycin (Kana) detection. The aptasensor was constructed through the hybridization of biotinylated Kana-aptamer at its complementary oligonucleotide strand-modified electrode, followed by intercalating methylene blue (MB) into the formed double-stranded DNA (dsDNA). Then, the streptavidin and high-content HRP functionalized gold nanoparticle probes were bound onto the aptasensor. As the MB-mediated HRP-catalytic reaction could produce sensitive electrochemical signal and the aptamer-biorecognition toward Kana could cause quantitative decrease of MB intercalation and nanoprobe capture, convenient electrochemical signal transduction was achieved. Both the enzymatic reaction and nanoprobe signal amplification greatly enhance the electrochemical signal, offering ultrahigh sensitivity of the method. The MB intercalation into dsDNA not only provides necessary electron mediator for the enzymatic reaction but also simplifies the electrochemical measurement. Under optimal conditions, this method showed a wide linear range over four-order of magnitude with a low detection limit of 0.88 pg/mL. In addition, the aptasensor features high specificity, excellent repeatability and stability as well as satisfactory reliability. Thus it possesses valuable application potentials. [ABSTRACT FROM AUTHOR]

A 300-MW e anthracite and down-fired boiler equipped with swirl burners, which was retrofitted with the previously proposed deep-air-staging combustion technology to reduce particularly high NO x emissions, still suffered from high carbon content in fly ash (despite this content being slightly lower than that before retrofit) on basis of significant NO x reduction. To comprehensively produce a high-burnout and low-NO x setting, a novel combustion technology was proposed in which relative to the axis of the primary air duct, the axes of the inner and outer secondary air ducts of the swirl burner shift away from the furnace center, and this technology is called an eccentric-swirl-secondary-air combustion technology. The coaxial symmetrical arrangements of primary and secondary air ducts for traditional swirl burners are broken. Full-scale industrial measurements under original, deep-air-staging and eccentric-swirl-secondary-air combustion technologies with respect to different loads (i.e., 180, 250, and 300 MW e ) were carried out to compare and analyze the validity of and improvement offered by the eccentric-swirl-secondary-air combustion technology. Under different boiler loads, especially at low and middle loads, compared with original and deep-air-staging combustion technologies, eccentric-swirl-secondary-air combustion technology markedly extends the penetration depth of coal/air flow and recirculation regions below arches. The thermal resistance between primary coal/air flow and high-temperature flue gas at the furnace center is reduced further, and the ignition of pulverized coal is timelier. The heating gradient in the burner outlet zone is maintained throughout, and the flame fullness in the primary combustion zone increases. The above three aspects contribute to pulverized coal burnout. Similar to deep-air-staging combustion technology, a low-oxygen and strong reducing atmosphere was formed in the primary combustion zone to reduce NO x formation due to the introduction of overfire air. Compared with deep-air-staging combustion technology, for the eccentric-swirl-secondary-air combustion technology, the air staged combustion in the furnace is improved further, and pulverized coal combustion in the primary combustion zone is more well distributed, which is beneficial to further reducing NO x emissions. The results of low-NO x and high-efficiency performance show that compared with the original boiler, NO x emissions and carbon content in fly ash for the boiler with the eccentric-swirl-secondary-air combustion technology are significantly reduced by above 42% and 32.5 to 20.7% at loads of 180, 250 and 300 MW e , respectively. [ABSTRACT FROM AUTHOR]

[Display omitted] • The effect of magnetic ions Co, Fe and Ni on the adsorption of nucleobases on the TiO 2 (1 1 0) surface were studied. • Ni is conducive to the adsorption performance due to the interaction between it and O atoms, and the Ni add-on site was proved to have good adsorption performance. • The solvent effect was considered to better simulate the environment in which these materials might be used. First-principles calculations were performed to study the adsorption properties of TiO 2 /M (M=Co or Fe or Ni) used as materials for DNA detection. The absorption energy, magnetic moment, density of states and charge transfer were studied to distinguish the effect of magnetic atoms in TiO 2 used for DNA detection. Among the three doping systems, the Ni-doped TiO 2 (TiO 2 /Ni) shows the best adsorption properties. Therefore, the Ni add-on TiO 2 (TiO 2 + Ni) has been further studied as a contrast. Additionally, solvent effects were considered in order to better simulate the biological environment. The Ni element may have promising application potential for the DNA detection. [ABSTRACT FROM AUTHOR]

[Display omitted] • The carboxylic acid is condensed with a weakly active amide to form a new diimide functional group through CDI and NaH. • 26 diimide compounds were synthesized and evaluated for the anti-inflammatory activity. • Compound 4d has good anti-inflammatory activity, and the IC 50 of IL-6 reached 1.59 μM. • Compound 4d may be a potential anti-inflammatory lead candidate for the treatment of ALI and sepsis. Amide bonds widely exist in the structure of natural products and drugs, and play an important role in biological activities. However, due to the limitation of synthesis conditions, there are few studies on biscarbonyl diimides. In this paper, a series of new compounds with diimide skeleton were synthesized by using CDI and NaH as condensation agents. The anti-inflammatory activity and cytotoxicity of the compound in RAW264.7 macrophages were evaluated by ELISA and MTT experiments. The results showed that these compounds had good anti-inflammatory activity in vitro , and the IC 50 of compound 4d on inflammatory factors IL-6 and TNF-α reached 1.59 μM and 15.30 μM, respectively. Further structure–activity relationship showed that biscarbonyl diimide and unsaturated double bond played a major role in the anti-inflammatory activity. In addition, compound 4d can alleviate acute lung injury (ALI) induced by LPS in vivo , reduce alveolar cell infiltration, and decrease the expression of ALI inflammatory factors. At the same time, compound 4d can significantly improve the survival rate of LPS-induced sepsis in mice. In short, the design and synthesis of the diimide skeleton provides a potential lead compound for the treatment of inflammatory diseases, and also provides a new idea for the design of amide compounds. [ABSTRACT FROM AUTHOR]

Due to the good combustion stability, the swirl burner (SB) with a pre-combustion chamber (PCC) is widely used in coal-fired boilers. The swirl blade angle is a key design parameter for the SB with PCC. The differences in flow, combustion, and slagging characteristics are dramatic at various swirl blade angles. Therefore, optimizing the swirl blade angle is necessary to improve the comprehensive performance of the SB with PCC. In this paper, Using CFD, the gas-particle flow, temperature, gas component distribution, and slagging trend in the PCC at swirl blade angles (β) of 50°,55°,60° and 64° in the outer secondary air (OSA) of SB are analyzed. As the β increases, the turbulent mixing of jets in the PCC increases, and more high-temperature flue gas is entrained into the PCC. Besides, the rate of devolatilization and char burnout near the SB nozzle accelerates, which is conducive to enhancing ignition and combustion stability. In terms of slagging on the PCC wall, the slagging trend deteriorates as the β increases. To improve the comprehensive performance of the SB with PCC applied in coal-fired boilers, the β should be set between 55° and 60°. • The comprehensive performance of SB with PCC at different β values is evaluated. • The increasing β is conducive to the turbulent mixing of gas flow. • The ignition and combustion stability are enhanced with the increase of β. • The slagging trend of the PCC wall increases when the β increases. [ABSTRACT FROM AUTHOR]

• A new concept, "hunger", is proposed to describe the load capacity of crawler. • Presenting a construction algorithm to promote schedulers to divide keywords queue. • Sorting sub-queues for collecting data preferentially that users care about. • Optimizing the efficiency of distributed crawler collection with less run time. Distributed crawling is one of the mainstream text data collection technologies, which is essential for mining boundless data available on the Internet for users. Internet information is clustered by the correlation of keywords, and users employ search engines to retrieve relevant keywords to get the information they care about. Distributed crawlers are used to mine the Internet information by simulating users' behavior, the more important keywords that users care about, the higher the correlation of data to keywords. In order to preferentially collect information that users care about with minimal resource consumption, in this paper, we design a scheduling framework and propose a novel scheduling strategy based on hunger for distributed crawler. We first define the load capacity of distributed crawler as hunger which reflects the ability to complete tasks and divide keywords queues into sub-queues based on the hunger of distributed crawlers. Then, we use a vector space model and cosine similarity algorithm to learn the correlation of keywords to text data and apply the optimized logistic algorithm to measure the importance of keywords. Meanwhile, we design a comprehensive evaluation algorithm to quantify the contribution of keywords, so that updating sub-queues order. Finally, new sub-queues are used in the deeper scheduling to preferentially get data that users desire and sacrifice the least number of resources. Experimental results demonstrate that our method optimizes the scheduling procedures and makes crawling more efficient with less run time. [ABSTRACT FROM AUTHOR]

• First principles and Monte Carlo methods are performance to study the effects of component distribution and distortion on the surface stability of TiZrHfNb (100), (110) and (111). • The element Zr enrichment is obvious on the (100), which is beneficial to improve the surface stability of (100). • The local lattice distortions greatly affect the surface stability especially the Ti element. • The adsorption characteristics of oxygen atoms on TiZrHfNb surfaces with different atomic arrangements may be different because of the differences between d-band center values of the surfaces. First principles and Monte Carlo methods are performance to study the effects of component distribution and distortion on the surface stability of TiZrHfNb (100), (110) and (111). It is found that the (100) surface is more stable than the others. The element Zr enrichment is obvious on the (100), which is beneficial to improve the surface stability of (100). In this research, the relationships between d -band center, work function and surface stability of (100) surface model are studied. In addition, the bonding interactions of (100) surface configuration are analyzed by means of density of states and charge difference distributions. Bader charge is also used to reveal the relationship between the interaction of elements and the surface stability. The local lattice distortions greatly affect the surface stability especially the Ti element. Further, the adsorption characteristics of oxygen atoms on TiZrHfNb surfaces with different atomic arrangements may be different because of the differences between d -band center values of the surfaces. The bonding between component elements can increase the activity of d -orbital electrons, which is helpful to the interaction between metal atoms and oxygen during oxidation, thus changing the oxidation properties of alloys. [Display omitted] [ABSTRACT FROM AUTHOR]

The thermal decomposition characteristics of Sanxing (SX) coal and coal chars (C500 and C850, produced at 500 and 850 °C, respectively) were tested by nonisothermal thermogravimetric analysis and a distributed activation energy model used to determine the kinetic parameters. The effects of char-making temperature were investigated. A sharp peak was seen in the relationship between X and activation energy ( E ) of the SX and C500 samples; no evident peak, but a ladder-shaped decline, was shown by C850. The temperatures at which E was maximized were relatively close for SX coal and C500, while the minimum value of activation energy was almost the same for the three samples. This showed the char-making process had less influence on the gasification reaction under high-temperature conditions. The results of the kinetic compensation effect between E and the pre-exponential factor ( k 0 ) showed that different kinetic compensation mechanisms occurred for the pyrolysis- and gasification-dominated stages. [ABSTRACT FROM AUTHOR]

As a kind of high speed steel, QHZ has been widely used in industry for fine-blanking punches. However, because of complicated working conditions of fine-blanking, the service life of punches decreases as the number of repair increases. In this paper, the evolution of QHZ punches with different numbers of renovations was studied at the micro-scale level to investigate the influence of impact accumulation on their service life. The force condition and life of the punch during fine-blanking process were studied through finite element method. Electron backscatter diffraction was applied to investigate the microstructural evolution with the assistance of a scanning electron microscope. And the punch’s micro-mechanical properties such as hardness and Young’s modules were characterized by nano-indentation technique. It was found that the service life is closely related to the micro-evolution of QHZ during punching process. The deterioration of microstructure paralleling to the punching direction, such as the increase of grain size, the decrease of ∑3 grain boundary fraction, and the transformation of crystallographic orientation, usually results in life reduction. Therefore, it is highly anticipated that this study can offer guidance for further research on life improvement. [ABSTRACT FROM AUTHOR]

This paper presents experimental research on cold flow, combustion characteristics, and NO x emissions of a swirl burner with air staging. The aim of the research is to investigate the influence of primary air cone length on the swirl burner performance. Cold flow air experiments on a centrally fuel-rich swirl burner with an over-fire air ratio of 25% were performed, and it was observed that when the dimensionless primary-air cone length (i.e., L p / L i , L p and L i respectively denoting the primary-air cone length in the cold-modeling experiments and inner secondary-air cone length) increases from 0 to 0.75, the diameter and length of the recirculation zone reduces from 0.91 d and 1.51 d to 0.68 d and 0.57 d , respectively. An investigation was conducted in a 0.5 MW laboratory furnace in order to optimize the primary-air cone length of a centrally fuel-rich swirl burner. The flame stability, performance of ignition, and burnout are significantly improved by decreasing the primary-air cone length. The NO x emissions measured at the furnace exit with a cone length L p / L i  = 0 decreased by 50.3% compared to those measured with a cone length L p / L i =  1.0. Based on the evaluation of flame stability, performance of the ignition, burnout, and low NO x emissions, the optimum value of primary-air cone length was observed to be L p / L i  = 0. [ABSTRACT FROM AUTHOR]

The die roll of fine-blanking parts is an important indicator when evaluating quality of parts. In this paper, the formation of die roll during the punching process is analyzed through the difference of the velocity of material between the die roll area and center area. At first, an assumption is made that every die roll is determined by the volume proportion of the part and waste area in the circular affected zone, and it is proved by simulation. In addition, the introduction of insertion block can prevent the fracture on the shearing surface without V-ring. In consideration of waste affect area and insertion block, a novel combined method is designed to decrease the die roll. It turns out that the height of die roll can be reduced by as much as 70% in both FEM simulation and actual experiment, which shows a great potential in fine-blanking industry. [ABSTRACT FROM AUTHOR]

To burn anthracite and reduce NO x emissions, a new combustion system was applied to a 300 MW e Babcock & Wilcox (B&W) down-fired boiler that included overfire air (OFA) and a decreased flow area of the inner and outer secondary air ducts of the installed swirl burners. Industrial-scale measurements (adjusting OFA ratios from 15.4% to 22.6%) were conducted to evaluate the overall performance of the retrofitted boiler. The experimental results demonstrated that the new combustion system promoted coal/air flow ignition and combustion stability. When the OFA ratio was less than 19.7%, the influence of the burner secondary air ratio on coal/air flow ignition was greater than that of the recirculation region below the arches. The overall combustion level in the primary combustion zone depended on the oxygen content and the recirculation region in the lower furnace instead of the early or late ignition of the coal/air flow. Oxygen and carbon monoxide concentration measurements in the near-sidewall region revealed that the fullness degree of the coal flame varied under different OFA ratios. Considering both environmental and economic effects, 19.7% was chosen as the optimal OFA ratio, thereby achieving a significant NO x reduction of 47% without increasing carbon content in the fly ash. [ABSTRACT FROM AUTHOR]

Semi-coke is the solid pyrolysis product of low-rank coal, with high carbon content and difficult to ignite and burn out. The blending of semi-coke with bituminous coal can realize a large amount of utilization of semi-coke. In this paper, the combustion, thermal conversion, and kinetic analyses of semi-coke blending with bituminous coal are investigated under oxygen-enriched conditions (30% O 2 atmosphere). Compared with 20% O 2 atmosphere, the ignition and burnout temperatures are reduced by 10, 7, 8, 12, 7 °C and 129, 76, 85, 115, and 152 °C for the semi-coke blending ratios of 0, 30, 50, 70 and 100% under 30% O 2 atmosphere. Oxygen-enriched combustion can effectively decrease the ignition temperature and improve the combustion performance of the mixture. In 30% O 2 and 20% O 2 atmospheres, the synergy effect of the co-combustion process is different. Under the 30% O 2 atmosphere, semi-coke, and bituminous coal have a strong synergistic effect, which can reduce burnout temperature. However, under 20% O 2 atmosphere, the burnout temperature of the mixture will increase. At a higher blending ratio of semi-coke, the effect of oxygen-enriched conditions on co-combustion is greater, and high oxygen concentration will make the interaction of the mixture combustion process more intense. Compared with bituminous coal, the activation energy of the mixture gradually increases with the increase of the blending ratio of semi-coke, and different combustion stages correspond to different mechanism functions, respectively. The research results can provide ideas for the utilization of semi-coke under oxygen-enriched conditions. [Display omitted] • The activation energy of mixture combustion is reduced in 30% O 2 atmosphere. • The co-combustion synergistic effect of mixture is enhanced in 30% O 2 atmosphere. • The increase of semi-coke blending ratio will result in higher activation energy of mixture. • The influence of oxygen-enriched co-combustion is greater under higher semi-coke blending ratio. [ABSTRACT FROM AUTHOR]

To address the problem of excessive computation in the remote sensing scene classification (RSSC) algorithms, this paper proposes an efficient RSSC model, which is named BiShuffleNeXt. Firstly, we use the sandglass bottleneck to design the ShuffleNeXt as a context path for deep semantic information extraction. Secondly, the spatial path consists of three sandglass bottlenecks, each with a stride of 2, to retain more spatial information and obtain a high-resolution feature map. Finally, the feature combination module is designed to perform the fusion of bi-path features. Experimental results show that the proposed model achieves a classification accuracy of 95.93% on the NWPU-45 dataset, which is a 3.6% improvement over using the context path alone. The proposed method is tested on three datasets and outperforms ShuffleNet v2, MobileNetv2, Mobile-Former and ResNet-50 respectively. The floating point operations (FLOPs) of BiShuffleNeXt are only 298.25M, which greatly reduces the calculation amount while ensuring classification accuracy. [Display omitted] • A deep learning model named BiShuffleNeXt is proposed for efficient remote sensing scene classification. • Based on lightweight neural networks to ensure real-time inference of the model. • The proposed model separates the extraction of spatial and context information and deep semantic information of remote sensing images into two paths. [ABSTRACT FROM AUTHOR]

The anions of precipitants played a leading role in the formation of catalytic phase while the cations decided the stability of hydroxyl group and further altered the morphology of catalysts. That was why the ammonium and sodium hydroxide possessed the similar hydroxyl group and amorphous MnFe composition, they still presented the different surface structure features. The coupling behavior of active precursors under different precipitants was the root cause of internal motivation of catalytic properties. [Display omitted] • Anion and cation of precipitant served in phase transition and structure features. • Reactants activation of precipitants acted as the inherent motivation of activity. • Precipitant affected the catalyst intrinsic activity deeply by kinetic analysis. • Possible inductive mechanism model of three precipitants on catalyst was proposed. Herein, the inductive strategy of three precipitants on dual transition metal MnFeO x catalysts for low-temperature NH 3 -SCR reaction was investigated in detail. The results showed that the anions of precipitants played the leading role in the formation of catalytic phase, in which carbonate induced the transfer of Mn precursor from MnCO 3 to the ultimate Mn 2 O 3 phase while that of hydroxyl from Mn 3 O 4 to Mn 5 O 8 phase. Iron coupling would alter the original transition behavior of manganese due to an internal synergistic effect. Furthermore, the cations decided the stability of hydroxyl groups on ammonium and sodium hydroxide precipitants, leading to the difference of morphology in catalysts. The activity results suggested that MnFe-ammonium carbonate (denoted as AC) catalyst possessed the higher catalytic efficiency than other catalysts, with over 90% NO conversion achieved from 75 to 225 °C. The abundant Mn4+ and Fe3+ and strong surface acidity of MnFe-AC catalyst were in favor of the redox circle and the adsorption of NH 3. Both activation energy and TOF, relied on the amount of acid, confirmed that the precipitants had an effect on the intrinsic catalytic activity of the catalysts such as energy barrier and reaction rate. Transient reaction further revealed that both E-R and L-H mechanisms co-existed on all catalysts, while E-R mechanism contributed more during the SCR process. On this basis, the possible inductive mechanism model of three precipitants on MnFeO x catalyst was proposed. [ABSTRACT FROM AUTHOR]

CGFA recycling process using NaOH-HCl hydrothermal treatment. [Display omitted] • Successful harmless treatment and resource utilization of residual carbon in CGFA. • The physicochemical evolution of residual carbon improves its combustion behavior. • Hydrothermal treatment improves the residual carbon's combustion characteristics. • DA-N and DA-NC properties are similar to lean coal and anthracite, respectively. Coal gasification fine ash (CGFA) is difficult to handle, which makes its effective utilization difficult. This study modified a typical CGFA sample, referred to as dry ash (DA), by using a NaOH-HCl hydrothermal process and analyzed the physicochemical properties of the carbon residue after treatment. The evolution of the physicochemical properties and the effect of this evolution on the combustion characteristics of the sample were investigated in detail. It was determined that the loss on ignition (LOI) significantly increased after DA was subjected to NaOH-HCl hydrothermal treatment. The carbon skeleton of the residual carbon was also modified, with a higher degree of looseness and a lower degree of cross-linking. At the same time, the specific surface area of the carbon particles and the content of surface C C bonds increased. This was beneficial for improving the combustion reaction activity of the treated sample. It is worth noting that compared with DA, DA-NC (samples obtained after DA was hydrothermally treated with NaOH) exhibited an LOI increase of 27.98 %, an ash removal rate of 48.32 %, and an S BET as high as 354.09 m2/g. Proximate analysis and thermogravimetric analysis further showed that NaOH-HCl hydrothermal treatment effectively increased the residual carbon content of the sample and reduced the activation energy required for combustion. The comparable combustion characteristics of DA-N and DA-NC (samples obtained after DA was hydrothermally treated with NaOH-HCl) with coal demonstrated their value as fuels. This work demonstrates that DA can be successfully modified into high calorific value solid fuel by NaOH-HCl hydrothermal treatment, which is beneficial for realizing the large-scale resource processing of CGFA. Moreover, the evolution of the physical and chemical properties of the residual carbon during the treatment process leads to a significant improvement in combustion characteristics. [ABSTRACT FROM AUTHOR]

Industrial pulverized coal boiler (IPCB) usually employ a pre-combustion chamber (PCC) to ensure stable combustion. However, there are potential slagging problems in the PCC, which threaten the safe operation of the boiler. Air-staged combustion technology is an effective method to reduce NO x emission, and different excess air coefficients affect slagging. CFD simulation is an important method for studying slagging in the furnace. In this paper, Using CFD simulation with slagging model embedded by user-defined function, the slagging trends in the PCC are studied under different excess air coefficients. The particles' collision rate (CR), deposition rate (DR), and sticking rate (SR) on the PCC walls are obtained by CFD simulation. As the excess air coefficient in the PCC (α PCC) increases from 0.3 to 1.1, the CR of particles on all walls of PCC (CR PCC) increases exponentially, indicating the abrasion degree on the PCC walls is growing rapidly. In addition, due to the sizeable annular recirculation zone when α PCC = 0.3, the DR of particles on all walls of PCC (DR PCC) and the SR of particles on all walls of PCC (SR PCC) are much larger than those under other conditions, the slagging trend is the worse. As the α PCC increases from 0.3 to 1.1, the slagging trends in the PCC first decrease and then increase. To improve the safety of boiler operation, it is recommended that the α PCC be adjusted between 0.5 and 0.9. • The effect of excess air coefficients (α PCC) on the slagging trends of PCC walls is studied by CFD simulation. • The relationship between the air-staged levels and CR PCC is established. • The entrainment effect of the secondary air on the particles is a crucial factor affecting slagging. • The annular recirculation zone distribution is the main reason for the maximum value of SR PCC at α PCC = 0.3. • The slagging trends first decrease and increase as the α PCC increases from 0.3 to 1.1. [ABSTRACT FROM AUTHOR]

A new combustion system has been applied to a 300 MW e down-fired boiler with swirl burners to reduce NO x emissions. The unit provided the introduction of overfire air (OFA) and a decrease in the flow area of the inner and outer secondary air ducts of the swirl burners. Industrial experiments on the retrofitted boiler were performed at different loads. Full-scale measurements of the flue gas temperature distribution in the burner outlet region, the furnace temperature distributions measured by a pyrometer and the local mean gas species concentrations in the region near the sidewall were made at loads of 180, 250, and 300 MW e . The results show that the ignition distance increased with decreasing load, especially as the load decreased from 250 MW e to 180 MW e . At three different loads, the retrofitted coal/air flow could be all ignited in time at a distance in the range of 0.6–1.4 m from the burner outlet. Compared with the original combustion system, the ignition distance of the coal/air flow was significantly reduced at a load of 300 MW e . In addition, at a load of 300 MW e , the temperature of the boiler hopper was much higher than that at loads of 180 MW e and 250 MW e . Compared with the original combustion system, the upper furnace temperature decreased slowly with increasing measurement height at a load of 300 MW e after the retrofit. Measurements of the O 2 and CO concentrations in the region near the sidewall indicate that the fullness degree of the coal flame in the furnace at different loads was different. After the retrofit, the reheat steam temperatures reached the design temperature of 541 °C at loads of 180 MW e and 250 MW e , and the average reheat steam temperatures increased by approximately 13 °C. Compared with the original combustion system, a significant NO x reduction (more than 40%) at different loads was achieved without increasing the levels of unburnt carbon in the fly ash. [ABSTRACT FROM AUTHOR]

To improve the biological performance of hydroxyapatite scaffolds in bone tissue engineering, graphite was used as porogen to create additional micro/nanoporosity to macroporosity, resulting in hierarchical porosity. For maximum imitation of natural bone structures, scaffolds with different porosity features were fabricated using micron/nano-sized graphite. The sintering profile of graphite treated scaffolds was optimised to reduce the influence of shrinkage. To confirm the porosity features, the micro/nanostructures of scaffolds were characterised by scanning electron microscopy and Brunauer-Emmett-Teller method. Considering that hydroxyapatite is resistant to biodegradation in vivo, the degradation rate of scaffolds in modified simulated body fluid was examined. Furthermore, biological evaluations based on myoblasts were carried out to investigate the influence of porosity features on the essential performance such as adhesion, proliferation and differentiation. The results indicate that the scaffolds with dominant microporosity and little nanoporosity formed inside had high potential for clinical applications due to improved performance in bioactivity. [ABSTRACT FROM AUTHOR]

[Display omitted] • The combustion performance of CGFA in two oxygen-riched atmospheres is compared. • The emperical optimization of the CGFA oxygen-rich combustion process is analyzed. • 30%O 2 concentration combustion performance of DA is comparable to that of DA blended with 60% bituminous coal in air atmosphere. Coal gasification fine ash (CGFA) has the characteristics of high carbon content, fine-grained, and sizeable annual output, causing environmental pollution and energy waste. Oxygen-enriched combustion is an effective way to solve the CGFA problem. This paper used thermogravimetric to study the effect of thermal conversion, kinetic analysis, and empirical optimization on the combustion process of CGFA in oxygen-enriched atmosphere. The results show that oxygen-enriched combustion of raw coal and CGFA improve ignition, burnout performance, combustion stability, and reduced activation energy. As the O 2 concentration increased from 30 % to 70 %, the activation energy of CGFA increased, but the improvement in combustion performance was not significant. A two-factor analysis of variance was carried out using a generalized linear model to obtain the effects of oxygen concentration, heating rate, and temperature variations on the combustion properties of CGFA, showing that atmosphere, heating rate and temperature variations all had significant effects on the combustion performance of CGFA, but atmosphere and heating rate had a more substantial impact on the combustion performance of CGFA. The combustion performance of raw coal under 30 %O 2 /70 %Ar atmosphere was better than that of CGFA, and the oxygen-enriched combustion (30 %O 2 /70 %Ar) performance of CGFA was comparable to that of CGFA blended with 60 % bituminous coal in air atmosphere. A kinetic model was developed to describe the oxygen-enriched combustion process (R2 > 0.92). The oxygen-enriched conditions of CGFA allow for efficient and clean combustion. [ABSTRACT FROM AUTHOR]

With global green and low-carbon development, carbon emission reduction is imminent. Oxy-fuel combustion technology is considered to be one of the most promising carbon capture and carbon sequestration technologies. In this work, the physical and chemical characteristics and oxy-fuel combustion characteristics of semi-coke (SC) and demineralized semi-coke (De-SC) were studied. The result shows that, compared with 20% O 2 /80% CO 2 , under 30% O 2/ 70% CO 2 atmosphere, the ignition temperature and burnout temperature of De-SC are lower, the maximum combustion rate is higher, and the main combustion process can be clearly divided into homogeneous and heterogeneous combustion stages. Compared with SC, De-SC has a less developed pore structure and lower alkali metal and volatile content, which lead to higher ignition temperatures for De-SC. The demineralization process makes the microcrystalline structure of carbon looser and increases the relative content of oxygen-containing functional groups, which are all beneficial to increasing the reactivity of De-SC. The combustion method of De-SC is mainly the particle surface reaction. Only in the atmosphere of 30% O 2 /70% CO 2 and the heating rate of 30 °C/min the combustion mode of De-SC is on the surface and inside the particles. Under different atmospheres, compared with SC, De-SC has lower activation energy and higher pre-exponential factor. The activation and pre-exponential of De-SC have a kinetic compensation effect. The results of this paper provide a theoretical basis for an in-depth understanding of the application of De-SC under oxy-fuel conditions. • The combustion mode of De-SC is mainly particle surface reaction. • De-SC has lower developed pore structure, alkali metal and volatile content, resulting higher ignition temperature. • A and E have a kinetic compensation effect of SC and De-SC. [ABSTRACT FROM AUTHOR]

To achieve significant reductions in NO x emissions without increasing the levels of unburnt carbon in the fly ash, a new combustion system was applied to a 300-MW e Babcock & Wilcox (B&W) down-fired boiler installed with swirl burners. The unit featured introduced overfire air (OFA) and decreased outlet area of the inner and outer secondary-air ducts of the swirl burners. Full-scale measurements (adjusting the inner secondary-air vane angle to 35°, 45°, and 55°) revealed that the influence of the high-temperature recirculating region under the arch upon the combustion and NO x emission characteristics of the boiler is greater than that of the high-temperature flue gas entrained by the swirl burner itself. The ignition distance of the coal/air flow is reduced by at least 1.8 m compared with that of the original combustion system. For the inner secondary-air vane angle of 35°, the coal/air flow ignites earlier than for the vane angles of 45° and 55°. The measurements of the gas species concentrations in the zone near the sidewall indicates that at inspection port 1, the coal flame of the burners does not spread across the entire furnace cross-section for all three vane angles; however, for the vane angle of 35° the flame is spread across the entire furnace cross-section at inspection port 2. For this optimal (35°) inner secondary-air vane angle, the NO x emissions and carbon content in the fly ash reached levels of 674 mg/m 3 (6% O 2 ), and 11.4%, respectively, achieving a significant NO x reduction of 51.9% without increasing the levels of unburnt carbon in the fly ash. [ABSTRACT FROM AUTHOR]

• Flow and combustion characteristics of down-fired boiler with central secondary air supply are studied. • Central secondary air ratio that is beneficial to the flow field symmetry and penetration depth is given. • Reasons for the burnout of burner nozzle and the blending proportion limitation of bituminous coal are obtained. • Technical improvement ideas for increasing the blending proportion of bituminous coal are proposed. The existing central secondary air swirl pulverized coal burner and separated secondary air interval arrangement down-fired boiler combustion technology used for the combustion of blended bituminous coal encounter several problems such as burner nozzle burnout, limited proportion of bituminous coal blending under high load, etc. In this study, the effects of central secondary air on the flow, pulverized coal ignition, burnout, and NO x emissions characteristics of a 600-MWe down-fired boiler with the central secondary air combustion technology were studied by the combination of cold-modeling experiments and industrial-scale experiments. Moreover, the reasons for the burnout of the burner nozzle and limited blending proportion of bituminous coal were analyzed and revealed. Cold-modeling experiments showed that with the increase of the central secondary air ratio, the peak value of the dimensionless vertical velocity increases; however, the flow field asymmetry occurs in the furnace when the air ratio increases to 6%. Considering the symmetry of the flow field and the characteristics of the downdraft, the central secondary air ratio is advised to be less than 3.52%. The industrial-scale experiments of burning bituminous coal under 360-MWe load show that the ignition distance of coal/air flow is about 0.10 m for all the cases at 30, 50, and 75% of the central secondary air damper opening, respectively, which reveal that the serious burner nozzle burnout is caused by the premature ignition of the coal/air flow. Under three types of central secondary air damper openings, the NO x emissions at furnace outlet are 333, 329, and 355 mg m−3 @ 6% O 2 , respectively. By considering the flow, combustion, and temperature field characteristics in the furnace, reduction in the central secondary air supply air volume can delay the ignition of the coal/air flow, which provides a new idea and method to achieve a high proportion of bituminous coal blending at rated load. [ABSTRACT FROM AUTHOR]

[Display omitted] • Combustion performance of CGFA in O 2 /CO 2 is weaker than that in O 2 /Ar. • Increase of oxygen concentration promotes combustion performance of CGFA in O 2 /CO 2. • Combustion kinetic models of different oxygen concentrations are different. • Kinetic model mainly follows the random nucleation model. Coal gasification fine ash (CGFA) has the characteristics of high carbon content, fine-grained, and large annual output, causing environmental pollution and energy wastage. Oxygen fuel combustion is an effective way to solve the CGFA problem. In this paper, the effects of thermal conversion, kinetics and thermodynamics during the oxygen-fuel combustion of CGFA are analysed. The results show that the combustion of CGFA in an oxygen-fuel atmosphere significantly improves its burn-up performance and combustion stability, but the improvement in ignition performance is not significant. an increase in oxygen concentration of more than 30% in an O 2 /Ar atmosphere also improves the activation energy to some extent, but the improvement in combustion performance is not significant. The average activation energy of CGFA under 30% O 2 /70% Ar condition is 104.25 kJ/mol, and its combustion performance is comparable to that of bituminous coal blended gasification ash at 70%. A kinetic model was developed to describe the oxygen-fuel combustion process of FCA, which can be efficiently and cleanly burned under oxygen-fuel conditions and consumed on a largescale. [ABSTRACT FROM AUTHOR]

• Precipitant style served a vital role on catalyst phase transition and structure features. • Surface acidity induced by precipitants acted as the main motivation for activity. • E-R and L-H paths co-existed on both catalysts while the former contributed more. • Possible structure-activity model of different precipitants on catalyst was proposed. Herein, the structure-activity strategy comparison of two different precipitants on MnO x catalyst for low-temperature NH 3 -SCR was investigated in detail. XRD results confirmed that ammonium carbonate (denoted as AC) could transfer manganese precursor from MnCO 3 to Mn 2 O 3 phase with temperature from 80 to 450 °C, while ammonium hydroxide (denoted as AH) facilitated the phase transition of MnO x from Mn 3 O 4 to the final Mn 5 O 8 phase. Further morphology defined that Mn-AC catalyst possessed a peculiar spherical feature while Mn-AH catalyst presented an accumulation of abundant nano-particles. The activity results suggested that Mn-AC catalyst possessed higher activity compared with Mn-AH catalyst at lower temperature, with over 60% conversion achieved from 100 to 225 °C and the maximum NO conversion reached circa (denoted as ca.) 85% at 175 °C. In addition, Mn-AC catalyst possessed stronger surface acidity and redox properties than Mn-AH catalyst, which served as an important motivation for the difference in activity. More manganese ions with higher valence and surface oxygen favored the superior redox circle of Mn-AC catalyst. Transient reaction revealed that the catalysts followed both Eley–Rideal (E-R) and Langmuir–Hinshelwood (L-H) pathways while the L-H pathway was harder to occur than the former due to the intense NO x transformation over catalysts. On account of these analyses, the possible structure-activity strategy comparison model of (NH 4) 2 CO 3 and NH 4 OH precipitants on MnO x catalyst was proposed. The anions of precipitant played a leading role in the formation of the catalytic phase and surface morphology, in which AC induced active Mn precursor to transfer from MnCO 3 to spherical Mn 2 O 3 while AH developed the initial Mn 3 O 4 to final Mn 5 O 8 phase. The transition behavior of active precursors under different precipitants was the root cause of the internal motivation of catalytic properties. [Display omitted] [ABSTRACT FROM AUTHOR]

For autonomous driving systems, vehicle detection is an important part and challenging problem due to the complex traffic scenes and poor computing resources. This paper proposes an improved SSD(single shot mutlibox detector) algorithm for the fast detection of vehicles in traffic scenes. MobileNet v2 is selected as the backbone feature extraction network for SSD, which improves the real-time performance of the algorithm. To improve detection accuracy, the channel attention mechanism is utilized for feature weighting, and the deconvolution module is utilized to construct a bottom–top feature fusion structure. The experimental results show that the average precision of the proposed algorithm on the BDD100K and KITTI datasets is 82.59% and 84.83%, respectively. The single inference time of the algorithm is 73ms, which is only about 5/11 of the original model, realizing the improvement of inference speed and prediction accuracy. • Vision-based surrounding vehicle detection is utilized for intelligent driving environment sensing to ensure driving safety. • The proposed method has three improvements to the single shot mutlibox detector (SSD), including a lightweight backbone network, the attention mechanism, and the deconvolution module. • The proposed method simplifies hardware requirements, reduces computational costs, and meets the needs of practical application. • The proposed method could automatically detect vehicles in various complex traffic scenes. [ABSTRACT FROM AUTHOR]

To solve the problems of resource waste and environmental pollution from coal gasification fine ash (CGFA), it is necessary to develop a high-value and sustainable utilization technology. In this study, a sustainable utilization method for CGFA to prepare activated carbon supercapacitor (AC-SC) was proposed for the first time. AC-SC with a high specific surface area was successfully fabricated via a facile deashing pretreatment and subsequent KOH activation. Results showed that with increasing KOH dosage, the specific surface area of AC-SC samples, "C–O or O C–O" functional groups content, and disorder in carbon skeleton increased. Among them, the AC-SC sample (D-800-1-5) with a carbon source to KOH mass ratio of 1:5, activation temperature of 800 °C, and activation time of 1 h showed an ideal micropore-mesoporous composite type pore structure. Moreover, the BET surface area of the sample was 2224.62 m2 g−1. The specific capacitance of the D-800-1-5 sample was 124.06 F g−1 @ 0.5 A g−1, and the capacitance retention rate was as high as 128.7% after 10,000 charge-discharge cycles. These results revealed that D-800-1-5 exhibited excellent capacitance characteristics and rate performance, and proved the feasibility of CGFA as a carbon source for the preparation of AC-SC. The proposed method provided a new technical route for the high value and sustainable utilization of CGFA. [Display omitted] • An activated carbon supercapacitor was prepared from coal gasification fine ash. • A technical route for high-value and sustainable use of coal gasification fine ash was proposed. • The method was more facile than the traditional preparation processes. • The BET surface area of the D-800-1-5 sample was 2224.62 m2 g−1. • The capacity retention of the material was 128.7% after 10000 cycles. [ABSTRACT FROM AUTHOR]

[Display omitted] • Sm-doping strengthened NH 3 -SCR activity and SO 2 tolerance over MnFeO x catalyst. • Enhanced NO 2 cooperated with increased NH 3 (ads) to cause "Fast SCR" reaction. • Sm induced Fe serving as sacrificial sites to preferentially react with SO 2. • Mechanism model for improving activity and SO 2 tolerance with Sm was proposed. The development of catalysts with high NH 3 -SCR activity in the presence of SO 2 was urgent for non-electric industries to control NO x emission at low temperature. Herein, a series of Sm-doping MnFeO x catalysts were synthesized through a typical PEG-assisted co-precipitation method and applied for low-temperature NH 3 -SCR process. SmMnFe-0.1 catalyst significantly broadened the activation temperature window and yielded almost 100% NO conversion from 75 to 200 °C, simultaneously, the NO removal efficiency still maintained at about 90% in the presence of SO 2 and H 2 O. The characterization results confirmed that Sm could optimize the dispersity of active components and enlarge the surface area of catalyst. Furthermore, strong interaction among active ions facilitated more oxygen vacancies and accelerated NO oxidizing to NO 2 , further cooperating with abundant adsorbed NH 3 , leading to cause "Fast SCR" reaction. Both catalysts were dominated by the E-R mechanism despite MnFeO x catalyst also obeyed the L-H pathway. Particularly, the intense redox circles between Sm and Mn inhibited the electron transferring from SO 2 to Mn ions, and induced Fe species serving as sacrificial sites along with Sm to preferentially react with SO 2 , resulting in an excellent SO 2 tolerance, and the possible mechanism model was proposed. [ABSTRACT FROM AUTHOR]

Micro-Raman spectroscopy (MRS) was utilized to investigate the graphitization of diamond particles within a UO 2 -diamond composite processed by spark plasma sintering (SPS). While pure diamond gives a sharp Raman peak at 1331.6 cm −1 , the graphitized diamond shows broad peaks either at 1350 cm −1 (G-peak) or 1580 cm −1 (D-peak). The degree of graphitization was quantified by calculating the area beneath the diamond and graphite peaks. It was found that more than 20% of diamond was graphitized on the surface of the UO 2 -diamond pellet and only around 10% diamond was graphitized in the interior regions of the pellet. This current study highlights the necessity to review the implications of these results carefully while implementing UO 2 -diamond composite nuclear fuel. [ABSTRACT FROM AUTHOR]

In an effort to increase the thermal conductivity of UO 2 fuel pellets, high density UO 2 –5 vol% diamond composite pellets were fabricated using the spark plasma sintering (SPS) technique. Diamond particles with nano-size (0.25 μm) and several micro-sizes (3 μm, 12 μm and 25 μm) were mixed with UO 2 powder and sintered using SPS at 1300–1600 °C with a hold time of 5 min. The resultant density, chemical reaction, microstructure, thermal conductivity and Young's modulus of the sintered pellets were investigated. The pellets with 3 μm diamond particles had a uniform distribution of particles as well as better thermal and mechanical properties compared to others. An increase in thermal conductivity of up to 41.6%, 38.3% and 34.2% at 100 °C, 500 °C and 900 °C, respectively, was measured in the UO 2 –diamond composite pellets compared to the pure UO 2 fuel pellets. [ABSTRACT FROM AUTHOR]