Ammonia is a promising alternative clean fuel due to its carbon-free, high energy density and well-established infrastructure of storage and distribution. The co-combustion with reactive fuels ...improves the NH3 combustion stability. Moreover, C2H4 is an important intermediate product in the oxidation of many hydrocarbon fuels. Therefore, some researchers focused the fundamental study and soot formation of NH3/C2H4 combustion. A reliable combustion model of NH3/C2H4 advances the understanding of the interaction between NH3 and C2H4. The key to develop the model of NH3 /C2H4 is the cross reactions between N-containing species and C-containing species. In this work, the ignition delay times of NH3/C2H4 mixtures were measured at three blending ratios (95 %, 90 %, 70 % NH3) at 1.75atm and 10atm in a shock tube at the temperature range of 1247 K to 1786 K. A detailed chemical kinetic model was developed on the base of our previous optimizing NH3 model and the C0C2 sub-model of NUIGMECH1.1, and some new cross reactions between N-containing species and hydrocarbon species were considered in the model. The NH3-C2H4 model is validated by the current experimental data, the laminar flame speeds of NH3/C2H4 mixtures and the species profiles of NH3/C2H4 mixtures oxidation. The cross reactions considered in this work significantly improve the prediction. The disproportionation reactions, C2H3 + NH2 <=> C2H2 + NH3 (R1466) and HCO + NH2 <=> CO + NH3 (R1465), significantly inhibit the ignition and the flame propagation, and cause the increase in the formation of HCO and HCCO with the increase of NH3 content, which facilitates the reduction of the soot formation.
High temperature superconducting (HTS) CORC cable, wound from ReBCO coated superconducting tapes, have good mechanical performance, flexibility, high current carrying capacity and isotropy. ...Therefore, CORC cables have important potential in magnets and power applications. In application, the cable will inevitably be subjected to mechanical and electromagnetic stresses. And during the operation cables will probably experience electromagnetic and thermal cycles. To investigate these effects on the performance of CORC cables, the changes in critical current under different bending radii, transverse pressure, and electromagnetic and thermal cycling were tested in liquid nitrogen. The results show that the soft-core sample degraded when the pressure achieved 1.2 kN/m, while the hard-core cable shows a reduction in critical current at a pressure of 7.7 kN/m. The bending measurement on the CORC cable with hard core shows that the critical current degradation occurs when the bending radius is below 45 mm. There is a decrease in critical current in a 3-turn coil wound with a 1.2-meter-long CORC cable, which may be due to mechanical damage incurred during the winding process. The electromagnetic and thermal cycle experiments on the CORC cable made coil caused reversible and irreversible critical current degradation. After a series of cycles, the Ic tended to be stabilized at 90% of original critical current of the CORC cable.
The water conservation function (WCF), as one of the most critical ecosystem services, has an important impact on the ecological sustainability of a region. Accurately characterizing the ...spatiotemporal heterogeneity of WCF and further exploring its driving factors are of great significance for river basin management. Here, the WCF of the upper Yangtze River basin (UYRB) from 1991 to 2020 was calculated using the water yield module in the Integrated Valuation of Ecosystem Service and Tradeoffs (InVEST) model. Also, we innovatively applied emerging hot spot analysis (EHSA), which could describe the location and pattern of historical changes more accurately, to investigate the spatiotemporal heterogeneity and evolution of WCF. Based on the Geographical Detector Model (GDM), the main driving factors of WCF and their interactions were revealed. The results showed the following: (1) the WCF in the UYRB experienced a temporal increase at a growth rate of 1.48 mm/a, while remarkable differences were observed across the change rates of sub-watersheds. (2) The spatial variation of the WCF showed a gradual increase from northwest to southeast. Interestingly, the Jinshajing River upstream (JSJU) source area with a low WCF showed an increasing trend (with diminishing cold spots). On the contrary, the downstream regions of the JSJU watershed (with intensifying cold spots) underwent a weakening WCF. (3) Among all driving factors, precipitation (q = 0.701) exhibited the most remarkable prominent impact on the spatial heterogeneity of the WCF. Additionally, the interaction of factors exhibited more explanatory power than each factor alone, such as precipitation and saturated soil hydraulic conductivity (q = 0.840). This research study is beneficial to water resource management and provides a theoretical basis for ecological restoration.
The control of pH is effective for inhibiting methanogenesis in the chain elongation fermentation (CEF) system. However, obscure conclusions exist especially with regard to the underlying mechanism. ...This study comprehensively explored the responses of methanogenesis in granular sludge at various pH levels, ranging from 4.0 to 10.0, from multiple aspects including methane production, methanogenesis pathway, microbial community structure, energy metabolism and electron transport. Results demonstrated that compared with that at pH 7.0, pH at 4.0, 5.5, 8.5 and 10.0 triggered a 100%, 71.7%, 23.8% and 92.1% suppression on methanogenesis by the end of 3 cycles lasting 21 days. This might be explained by the remarkably inhibited metabolic pathways and intracellular regulations. To be more specific, extreme pH conditions decreased the abundance of the acetoclastic methanogens. However, obligate hydrogenotrophic and facultative acetolactic/hydrogenotrophic methanogens were significantly enriched by 16.9%-19.5 fold. pH stress reduced the gene abundance and/or activity of most enzymes involved in methanogenesis such as acetate kinase (by 81.1%–93.1%), formylmethanofuran dehydrogenase (by 10.9%–54.0%) and tetrahydromethanopterin S-methyltransferase (by 9.3%–41.5%). Additionally, pH stress suppressed electron transport via improper electron carriers and decreased electron amount as evidenced by 46.3%–70.4% reduced coenzyme F420 content and diminished abundance of CO dehydrogenase (by 15.5%–70.5%) and NADH:ubiquinone reductase (by 20.2%–94.5%). pH stress also regulated energy metabolism with inhibited ATP synthesis (e.g., ATP citrate synthase level reduced by 20.1%–95.3%). Interestingly, the protein and carbohydrate content secreted in EPS failed to show consistent responses to acidic and alkaline conditions. Specifically, when compared with pH 7.0, the acidic condition remarkably reduced the levels of total EPS and EPS protein while both levels were enhanced in the alkaline condition. However, the EPS carbohydrate content at pH 4.0 and 10.0 both decreased. This study is expected to promote the understanding of the pH control-induced methanogenesis inhibition in the CEF system.
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•Molecular mechanism of pH stress-induced inhibition on methanogenesis was revealed.•pH stress reduced acetoclastic methanogen levels but enriched hydrogenotrophic ones.•pH stress suppressed critical enzymes involved in methanogenesis.•pH stress inhibited electron transport and ATP synthesis.•EPS secretion responded differently in acidic and alkaline conditions.
Low-dimensional Ruddlesden–Popper (LDRP) perovskite solar cells (PSCs) have attracted increasing attention due to their excellent long-term stability over three-dimensional (3D) counterparts. ...However, the introduction of insulated long-range bulkier organic ammonium spacers hindered the charge transport. Here, the short-range organic ammonium spacers, 1-amino-3-butene hydrochloride (BEACl) and 3-butyn-1-amine hydrochloride (BYACl), were employed to construct LDRP perovskites, instead of common butylamine hydrochloride (BACl). We found that charge transport can be significantly improved by controlling the tunneling effect. Moreover, highly oriented and flat perovskite films without pinholes were obtained. Consequently, high PCEs, exceeding 16% for BEA- and 15% for BYA-based devices, which is much higher than that of the BA-based analogous device (13.8%), were achieved. Most importantly, the BEA- and BYA-based LDRP perovskite films and devices show much improved stability. The finding is of great significance for the exploration of new organic ammonium spacers for highly efficient and stable LDRP PSCs.
Serum protein electrophoresis (SPEP) is a valuable laboratory test that separates proteins from the blood based on their electrical charge and size. The test can detect and analyze various protein ...abnormalities, and the interpretation of graphic SPEP features plays a crucial role in the diagnosis and monitoring of conditions, such as myeloma. Furthermore, the advancement of artificial intelligence (AI) technology presents an opportunity to enhance the organization and optimization of analytical procedures by streamlining the process and reducing the potential for human error in SPEP analysis, thereby making the process more efficient and reliable. For instance, AI can assist in the identification of protein peaks, the calculation of their relative proportions, and the detection of abnormalities or inconsistencies. This review explores the characteristics and limitations of AI in SPEP, and the role of standardization in improving its clinical utility. It also offers guidance on the rational ordering and interpreting of SPEP results in conjunction with AI. Such integration can effectively reduce the time and resources required for manual analysis while improving the accuracy and consistency of the results.
Inflammatory bowel disease (IBD) is a global chronic disease with a long duration and repeated relapse. Currently, there is still a lack of effective approaches to prevent IBD. Food-derived oryzanol ...(ORY) possesses extensive biological activities, such as ameliorating bowel diseases, antioxidation, and antiobesity. However, the mechanism of ORY in preventing colitis remains unclear. The present research aims to explore the potential mechanism of ORY in dextran sulfate sodium (DSS)-stimulated colitis in a rat model. The results showed that the symptoms of colitis were significantly improved with the administration of ORY. Mechanismly, the expression levels of Zonula occludens-1 (ZO-1), Claudin-1, Occludin, MUC2, and TFF3 were elevated through ORY treatment, suggesting that oral ORY relieved the degree of gut barrier damage of colitis rats. Meanwhile, 16S sequencing results found that ORY supplementation increased the abundances of Alloprevotella, Roseburia, Treponema, Muribaculaceae, and Ruminococcus, which are associated with the synthesis of short-chain fatty acids (SCFAs). Moreover, GC-MS results confirmed that ORY supplementation reversed the DSS-induced reduction of acetic acid, butyric acid, and total acid. Further research indicated that ORY intervention downregulated the TLR4/NF-κB/NLRP3 pathway, which is closely linked to the expression of proinflammatory cytokines and colon injury. Taken together, ORY ameliorates DSS-stimulated gut barrier damage and inflammatory responses via the gut microbiota–TLR4/NF-κB/NLRP3 signaling axis.
Electron-transport-layer free perovskite solar cells (ETL-free PSCs) have attracted great attention due to their low cost and simple manufacturing process. However, an additional interface layer has ...to be introduced, and the currently achieved efficiency remains far from full-structure PSCs. Here, we report an in situ interface engineering strategy by the methylammonium acetate (MAAc) ionic liquid perovskite precursor. We found that a dipole layer was in situ constructed through the physical adsorption of the residual MAAc polar molecules on the indium tin oxide electrode, which is significantly different from the treatment by the interface layer in previous reports. This allows a decrease of the effective work function and enables in situ band bending in the perovskite semiconductor. The in situ band bending facilitates charge collection and hinders interfacial charge recombination, leading to ETL-free PSCs with a maximum power conversion efficiency of 21.08%, which is the highest report to date.
•The NH3 MILD combustion was performed in a novel structure.•The NH3 MILD combustion significantly reduces the NOx emissions.•A critical amount of NH3 in the MILD combustion is critical to NO ...formation.•The equivalence ratio in the metal fiber burner is important to the NO reduction.
NH3 can be used as an H2 energy carrier or an alternative carbon-free fuel because of its high volumetric energy density and easy liquefaction, which leads to convenient and economic transportation and storage within the global energy network. However, the combustion of NH3 is associated with some practical challenges, such as weak reactivity and high NOx emission. In this study, Moderate & Intense Low Oxygen Dilution (MILD) combustion of NH3 was conducted experimentally in a novel burner. The heated and diluted air was produced by burning a premixed lean CH4 mixture using a metal fiber burner installed at the bottom of the combustion chamber and NH3 was injected into the furnace by 20 nozzles oppositely installed on the sidewalls of the combustion chamber at 40 mm above its bottom. A total of 20 cases were investigated in the present work, including premixed combustion of CH4 and CH4/NH3, and MILD combustion of NH3, under various conditions. The Chemical reactor network (CRN) in the ANSYS Chemkin 17.0 and the HUST mechanism were used to simulate and analyze the NO formation mechanism under several experimental conditions. The experimental results showed that the NH3 MILD combustion significantly reduces the NOx emissions. The NOx reduction kinetics and the impact of NH3 flow rate and the equivalence ratio on NO emission in NH3 MILD combustion were analyzed in detail.
