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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]

The characteristic of nonmotor symptoms in patients with multiple system atrophy (MSA) has varied among previous studies. The objective was to investigate the nonmotor characteristics in MSA patients with different phenotypes, sex and different onset patterns. We performed a retrospective review of 1492 MSA patients. All cases were evaluated by neurologists and assessed with motor manifestations, nonmotor symptoms, auxiliary examination and brain MRI scans. Multiple system atrophy–cerebellar ataxia (MSA-C) was the predominant phenotype in 998 patients. Average age of onset (56.8 ± 9.2 years) was earlier, the disease duration (2.4 ± 2.2 year) was shorter and brain MRI abnormalities (49.2 %) were more frequently in MSA-C (P < 0.001). Multiple system atrophy–parkinsonism (MSA-P) patients were more likely to have nonmotor symptoms. After adjusted significant parameters, urinary dysfunction (OR 1.441, 95 %CI = 1.067–1.946, P = 0.017), constipation (OR 1.482, 95 %CI = 1.113–1.973, P = 0.007), cognitive impairment (OR 1.509, 95 %CI = 1.074–2.121, P = 0.018) and drooling (OR 2.095, 95 %CI = 1.248–3.518, P = 0.005) were associated with the MSA-P phenotype. Males were more likely to have orthostatic hypotension, urinary dysfunction, sexual dysfunction, drooling and females in constipation and probable RBD. In different onset patterns, constipation (59.2 %) and probable RBD (28.4 %) were more frequently in autonomic onset pattern. MSA-C is the predominant phenotype in Chinese patients, while many nonmotor symptoms are more common in MSA-P phenotype. Patients with different sex and onset patterns have different nonmotor characteristics. The different clinical features identified could help the physician counseling of MSA patients more easily and more accurately. [ABSTRACT FROM AUTHOR]

Herein, the Mn-doped different exposed crystal surfaces of CeO 2 were prepared and used for the low-temperature NH 3 -SCR process. The results showed that Mn/CeO 2 -NC catalyst possessed the higher catalytic activity than Mn/CeO 2 -NP and Mn/CeO 2 -NR catalysts at low temperature, which achieved over 90% NO conversion at 200 °C. XRD and SEM analysis verified that though the grain size was different, the active manganese species still maintained the highly uniform distribution on all catalysts. The excellent low-temperature redox property and strong surface acidity jointly served as the inherent motivations for the superior catalytic performance of Mn/CeO 2 -NC catalyst. During the transient reaction process, no obvious derivatives transformation behavior was observed on CeO 2 -NP-based catalyst, while both E-R and L-H reaction mechanisms occurred on both Mn/CeO 2 -NC and Mn/CeO 2 -NR catalysts. And the Mn/CeO 2 -NC catalyst had the greater transient reaction efficiency than Mn/CeO 2 -NR catalyst at whichever pathways, which might clarify the difference in catalytic activity between Mn/CeO 2 -NC and Mn/CeO 2 -NR catalysts. Finally, the possible reaction mechanism model for low-temperature SCR over Mn-modified different exposed crystal surfaces of CeO 2 catalysts was proposed. No obvious derivatives transformation behavior was observed on CeO 2 -NP-based catalyst during the transient reaction process, while both E-R and L-H reaction mechanisms occurred on Mn/CeO 2 -NC and Mn/CeO 2 -NR catalysts. And the Mn/CeO 2 -NC system catalyst had the greater transient reaction efficiency than Mn/CeO 2 -NR catalyst at whichever pathways, which might clarify the difference of catalytic activity between Mn/CeO 2 -NC and Mn/CeO 2 -NR catalysts. [Display omitted] • Mn/CeO 2 -NC catalyst possessed the excellent low-temperature catalytic activity. • Redox property and surface acidity were the inherent motivations of activity. • No obvious derivative transformation behavior was observed on Mn/CeO 2 -NP catalyst. • Both E-R and L-H pathways occurred on Mn/CeO 2 -NC and Mn/CeO 2 -NR catalysts. [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]

• Reliability of URTNs considering the traffic congestion diffusion is studied. • An improved NLC model under different attack strategies is proposed to simulate cascading failures. • A load redistribution method with the impedance function is provided. • Formation time, diffusion speed, and scale of cascading failures are analyzed. The cascading failures caused by traffic congestion diffusion may deteriorate traffic network reliability. Comprehending urban traffic congestion mechanisms is essential for road network planning and traffic management against cascading failures. To uncover this, the reliability of urban road traffic network (URTN) under cascading failure considering different attack strategies is analyzed. The cascading failure model is established based on the improved nonlinear load-capacity relationship. Five kinds of attack strategies including Strength Attack (SA), Betweenness Centrality Attack (BCA), Eigenvector Centrality Attack (ECA), Closeness Centrality Attack (CCA), and Random Attack (RA) are selected. In particular, the capacity affected by traffic congestion is considered, providing a new perspective for the study of traffic congestion diffusion. A state update equation for networks is proposed to simulate the network congestion diffusion. Finally, a case study is conducted by using the URTN of Shanghai as the background. The results show that the network will experience large-scale congestion when high-importance nodes are attacked. The congestion degree is the highest under CCA strategy, network efficiency is the lowest under ECA strategy, and traffic quality is the poorest under CCA strategy. As the congestion critical failure threshold decreases, the speed and scale of cascading failures caused by traffic congestion diffusion are greater. Maintaining proper traffic management and control capability can largely reduce the cascading effect to a great extent and improve the reliability of the network. The results can provide a research basis for traffic management to improve network reliability. [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]

The active components Mn and Fe oxides were loaded on the surface of CeO 2 catalyst with nanopolyhedrons morphology (CeO 2 -NPs) by impregnation method to improve the CeO 2 -NPs catalyst catalytic performance. The activity test results showed that the activity order of these catalysts within the temperature of 100–300 °C was Fe-Mn-Ce > Mn-Ce > Ce catalyst, and the NO conversion rate of Fe-Mn-Ce catalyst was the highest at 200 °C, which was about 98%. The performances of these catalysts were further investigated by SEM, XRD, XPS, Raman spectra, H 2 -TPR, NH 3 -TPD and in situ DRIFT. The results indicated that Fe-Mn-Ce catalyst possessed the best reducibility and surface acidity of the three catalysts. According to the XPS and Raman spectra tests, the sequences of the ratio of O α /(O α +O β) and Ce3+/(Ce3++Ce4+) were both Fe-Mn-Ce > Mn-Ce > Ce catalyst, which indicated that the Fe-Mn-Ce catalyst possessed the most oxygen vacancy and further improved the catalytic activity of the catalyst. Moreover, the Fe-Mn-Ce catalyst also exhibited the best tolerance to SO 2 of the three catalysts at 225 °C. In general, simultaneous loading of manganese and iron oxides on the CeO 2 -NPs catalyst could effectively improve the low temperature SCR performance of the catalyst. • Fe-Mn-Ce catalyst showed superior catalytic activity at low-temperature. • Fe-Mn-Ce catalyst had more oxygen vacancies. • Fe-Mn-Ce catalyst could increase the relative ratios of surface adsorbed oxygen. • Fe-Mn-Ce catalyst possessed the best reducibility and surface acidity. [ABSTRACT FROM AUTHOR]

In this study, Samarium (Sm) modification over Mn oxide biochar (BC)-based catalysts was synthesized and the activity of low-temperature selective catalytic reduction with NH 3 (LT NH 3 -SCR) of NO was measured. Varies in surface area and pore volume, structure, morphology, and surface chemistry of Sm-modified Mn/BC catalyst were investigated to analyze the effect of Sm on the physiochemical properties on catalyst. The Sm(0.2)-Mn/BC catalyst showed the highest NH 3 -SCR activity with the NO conversion of 85% at 200 °C and best N 2 selectivity in a broad temperature range of 75–250 °C. Doping with Sm species, Mn4+ + Mn3+/Mnn+ and O α /O β increased greatly, and the surface adsorbed oxygen were enhanced in Sm(0.2)-Mn/BC catalyst, which could promote the oxidation of NO, the NO conversion and N 2 selectivity. In addition, weak and medium acid increased markedly after the Sm species added on catalysts, causing more active sites for SCR reaction. The NH 3 -SCR reaction of Sm(0.2)-Mn/BC catalyst followed the L-H mechanism, and the generation of intermediate –NH 2 , NH 4 + species and the N x O y species were observed which played vital part in the LT NH 3 -SCR reaction. • Sm doping resulted in more active sites for SCR reaction. • Sm-modification could promote the oxidation of NO. • Sm-modification could increase both the De-NO x rate and the N 2 selectivity. • The NH 3 -SCR reaction followed the L-H mechanism. [ABSTRACT FROM AUTHOR]

CeO 2 nanorods (CeO 2 -NRs) catalyst was prepared and treated with ammonia (NH 3) gas and the effect of NH 3 treatment on CeO 2 nanorods catalyst was also studied for improving NH 3 -SCR of NO. And the catalysts were tested for NH 3 -SCR of NO during 100–450 °C. The results showed that NH 3 treatment could improve the De-NO efficiency of the catalyst, which increased evidently in the range of about 160–410 °C. XPS results revealed that NH 3 treatment made CeO 2 -NRs catalyst produce more Ce3+ on its surface, and thereby produced more oxygen vacancies and further promoted SCR reaction. The XRD and H 2 -TPR characterization test results indicated that CeO 2 catalyst with NH 3 treatment could destroy its crystallinity and enhance the reducibility. In addition, the in situ DRIFTS results also exhibited more activity functional groups on the surface of N–CeO 2 -NRs catalyst than that of CeO 2 -NRs catalyst. [Display omitted] • NH 3 treatment CeO 2 -NRs catalyst showed superior catalytic activity. • NH 3 treatment could increase the relative ratios of Ce3+/Ce4+ and the surface adsorbed oxygen. • NH 3 treatment CeO 2 -NRs catalyst had more oxygen vacancies. • NH 3 treatment CeO 2 -NRs catalyst showed the better reducibility. [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]

[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]

[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]

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]

Natural bacteria have been utilized to directly maintain the human body's homeostasis for directly or indirectly relieving diseases throughout history. With the rapid development of genetic engineering and synthetic materials modification, the recent era has witnessed numerous hybrid bacteria designed to meet the clinical requirements with expanded functionality in treating dozens of diseases, including obesity, gastrointestinal disorders, and even cancers. This review outlined the characteristics and applications of natural bacteria-based drugs in treating different disease conditions and summarized different conjugation methods of hybrid bacteria and their fate in vivo through multiple administration routes. Moreover, therapeutic bacteria-based complex disease treatments were also discussed to reveal the importance and feasibility of these biotherapeutics. Finally, the challenges in the clinical applications of bacterial drugs were discussed. The current review further highlighted the forward-looking solution strategies for bacterial bio-therapy to accelerate its clinical usage. [Display omitted] • Emphasizing the characteristics and applications of natural bacteria-based drugs in treatment. • Summarizing different conjugations of hybrid bacteria and their in vivo fate via multiple administration routes. • Comprehensively reviewing the clinical applications of bacterial drugs and discussing the challenges of bacterial drugs. [ABSTRACT FROM AUTHOR]