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Under the paradigm of carbon neutrality, ammonia-hydrogen (NH 3 –H 2) blended fuel presents itself as a zero-carbon alternative to petroleum-based fuels, effectively reducing carbon emissions originating from internal combustion engines. In the combustion process of conventional hydrocarbon fuels, the production of nitrogen oxides (NO X) predominantly arises from nitrogen present in the atmosphere, which occurs through the Zeldovich mechanism under high-temperature conditions. These NO X species, commonly referred to as thermal NO X , rely on inert nitrogen. However, the utilization of ammonia fuel activates the reactivity of nitrogen element, leading to the nitrogen-containing species formation, including NO X , termed as fuel NO X. Consequently, the combustion of ammonia-hydrogen fuel entails the coupling of thermally formed nitrogen oxides and fuel-derived nitrogen oxides. The generation of NO X is significantly influenced by the physicochemical environment, while the transient combustion conditions within the engine combustion chamber further complicate the process of NH 3 –H 2 combustion and NO X formation. As a consequence, comprehensively investigating the NO X emission characteristics in NH 3 –H 2 engines presents a considerable challenge. By decoupling fuel NO X and thermal NO X , a more profound understanding of NO X emission control strategies for ammonia-hydrogen engines can be attained. This research paper accomplishes the decoupling of fuel nitrogen elements and atmospheric nitrogen elements in three dimensional computational fluid dynamics engine combustion simulations. The results indicate that this decoupling methodology disregards the differentiation between the fuel NO X pool and the thermal NO X pool, resulting in a slight modification in NO X concentration. Nevertheless, this approach has minimal impact on the combustion process, ensuring that the NO X formation environment remains largely unchanged. Furthermore, it successfully demonstrates the spatial and temporal distribution characteristics of thermal NO X and fuel NO X , thereby furnishing an effective analytical tool for the comprehensive study of NO X emission characteristics in NH 3 –H 2 engines. • The method of decoupling fuel and thermal nitrogen oxides is proposed. • The thermal/fuel NO X decoupling approach is not limited to NH 3 –H 2 SI engines. • The engine in-cylinder spatiotemporal distributions of thermal/fuel NO X are exhibited. • The decoupling of fuel/atmospheric nitrogen can be applied to multidimensional simulations. • The equivalence ratio effect on NH 3 –H 2 engine in-cylinder thermal/fuel NO X is analyzed. [ABSTRACT FROM AUTHOR]

The increasing trend towards global carbon neutrality is driving interest in ammonia fuel as a potential zero-carbon solution for transportation. However, due to the non-ideal combustion characteristics of ammonia, it is necessary to mix it with hydrogen to achieve better engine performance. While generating hydrogen from ammonia on-board is a key technology, there has been limited research in this area, which is hindering the introduction of ammonia engines to the market. This paper proposes an initial study on the feasibility of thermochemical fuel reforming (TFR) technology for generating hydrogen from ammonia fuel-rich operations. A zero-dimensional engine model, validated against experimental results, is used to assess the potential of the TFR approach and identify any barriers to implementation. The results indicate that the optimum air-fuel ratio for hydrogen generation is an equivalence ratio of two, as it maximizes hydrogen production rates while minimizing operational complexities. Moreover, increasing intake temperature, pressure, and compression ratio enhances hydrogen generation from the ammonia-rich mixture. However, owing to the limited reactivity of the ammonia fuel, the rate of hydrogen production remains relatively small (less than 1%/cycle), significantly falling short of the demand. Additionally, the combustion of the fuel-rich mixture in the TFR cylinder results in approximately 20%/cycle of hydrogen in the emitted gases, potentially enhancing the efficiency of working cylinders, but it also poses the risk of engine component failures due to the high pressure rise rate. In conclusion, the use of solely ammonia to produce hydrogen in the TFR cylinder proves to be inefficient, warranting further investigations into the potential benefits of incorporating additives to promote hydrogen production. Alternatively, if a catalyst is utilized to promote hydrogen production from ammonia, a separate electrically heated hydrogen generation system independently of the engine system proves to be more effective, allowing continuous hydrogen production, unlike the intermittent high-temperature environment provided by TFR technology. • Hydrogen production using in-cylinder thermochemical ammonia reforming is evaluated. • An air-ammonia ratio of ϕ = 2.0 is identified as optimal for hydrogen production. • Unfired conditions produce less than 1% of hydrogen in the exhaust per cycle. • Fired conditions can produce ∼20% of hydrogen in the emitted gases per cycle. • Extremely high pressure rise rates are implementation barriers for fired conditions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Hollow hierarchical β zeolites (Hβ) were successfully synthesized. • Hβ zeolite possessed lower mass transfer resistance and faster mass transfer rate. • Ultrafine Pt particles (1.13 nm) on Pt/Hβ-2 could expose more active sites. • Pt/Hβ-2 presented relatively lower activation energy for the naphthalene hydrogenation. • Pt/Hβ-2 possessed higher TOF (25.4 h−1) and reaction rate constant (9.9 × 10-3 min−1). It is crucial to develop effective heterogeneous catalysts for the production of decalin as a high-density liquid hydrogen storage material from naphthalene hydrogenation. In this work, hollow hierarchical Pt/Hβ catalysts with ultrafine Pt particles were successfully synthesized successfully. The construction of hollow cavity optimized the metal-support interaction and reduced the resistance of mass diffusion. The ultrafine Pt species could expose more active sites for effective hydrogenation of naphthalene. The optimized Pt/Hβ-2 with hollow structure catalyst displayed the remarkable catalytic performance with the naphthalene conversion of 94.2 % and the decalin yield of 81.4 % at 220 °C, which was superior to the reaction performance of the catalysts reported in the literature under similar reaction condition. Besides, Pt/Hβ-2 presents higher turnover frequency (25.4 h−1) and reaction rate constant (9.9 × 10-3 min−1), which is because of the relatively low activation energy (30.86 kJ mol−1) for the naphthalene hydrogenation. [ABSTRACT FROM AUTHOR]

• There is no correlation between fat content and MFG size in natural low-fat cow or goat milk. • CLA supplementation resulted in a correlation between milk fat content and particle size. • MFG size depends on the size distribution of fat globules after CLA supplementation. In milk, fat exists in the form of milk fat globules (MFGs). The average size (average fat globules of different particle sizes) is the most common parameter when describing MFG size. There are different views on whether there is a correlation between MFG size and milk fat content. Is the MFG size correlated with milk fat content in ruminants? To address this question, we conducted two experiments. In experiment Ⅰ, dairy cows (n = 40) and dairy goats (n = 30) were each divided into a normal group and a low-fat group according to the milk fat content. In experiment Ⅱ, dairy cows (n = 16) and dairy goats (n = 12) were each divided into a normal group and a conjugated linoleic acid (CLA)-induced low-fat group. The normal groups were fed a basal diet, and the CLA-induced low-fat groups were fed the basal diet + 300 g/d CLA (cows) or the basal diet + 90 g/d CLA (goats). In both experiments, we determined the correlation between MFG size and milk composition and MFG distribution. The results showed that in the normal and low-fat groups of cows and goats, MFG size was not correlated with milk fat, protein, or lactose content or fat-to-protein ratio. Additionally, there was no difference in the distribution of large, medium, and small MFGs (P > 0.05). However, in the CLA-induced low-fat groups, we found a correlation between MFG size and milk fat content and fat-to-protein ratio (R2 > 0.3). Moreover, there was a significant change in the size distribution of MFGs. Therefore, in natural milk, MFG size was not correlated with milk fat content. Following CLA supplementation, MFG size was correlated with milk fat content. Our findings revealed that CLA and not milk fat affects MFG distribution and size. [ABSTRACT FROM AUTHOR]

[Display omitted] • The utilization of industrial solid waste and construction waste developed AARAC with controllable performance. • A strength-based mix design method was proposed for AARAC using a linear fitting formula. • The reference mix proportion of AAC suitable for different strength grades was optimized. • The performance differences between AARAC and AANAC were systematically assessed. Recycled concrete aggregates (RCA) are produced from demolished buildings and old rigid pavements, which are deemed as solid waste, comprising primarily old aggregate and cement mortar. In this study, the use of RCA was introduced in alkali-activated concrete (AAC) to investigate the feasibility of designing the mix proportion of alkali-activated recycled aggregate concrete (AARAC) using a linear fitting formula. A total of 32 mixes, with the amount of cementitious materials varying from 350 kg/m3 to 500 kg/m3 and the sol ratio from 0.43 to 0.55, were prepared for the regression analysis of the relationships between multiple parameters. The tests for water consumption, compressive strength and durability were included. The experimental results indicate that concrete prepared using high-quality RCA exhibited lower water consumption and higher compressive strength. When the natural aggregate (NA) was replaced by the RCA, the compressive strength reached its highest value of 54.0 MPa. Moreover, as the strength grade increased, the chloride penetration resistance, anti-carbonization performance, and freezing resistance of AARAC gradually increased, while the shrinkage decreased. In conclusion, this study provides a new method for the mix design of AARAC, which contributes to the advancement of solid waste management in the construction industry. [ABSTRACT FROM AUTHOR]

Coal-based jet fuel is an important alternative energy source for aviation sector. To formulate the surrogate of a coal-based jet fuel, a hybrid mixing model based on explicit equations and artificial neural network (ANN) is developed to emulate fuel atomization characteristics and pollutant emissions in aero-engine combustor. Hydrogen–carbon ratio, molecular weight, and lower heating value are calculated by explicit equations, and the ANN mixing model is used to predict the density, viscosity, surface tension, and distillation curve for the surrogate mixture at various temperatures. In the ANN model, the learning task is completed through tan-sigmoidal and linear functions, and the Levenberg–Marquardt algorithm is employed for the optimization process. The resulting surrogate of the coal-based jet fuel obtained by the hybrid mixing model is composed of n -decane/ n -dodecane/ n -tetradecane/iso-octane/methylcyclohexane (0.026/0.603/0.229/0.117/0.025 by mole). The proposed surrogate can match the physicochemical properties of the target fuel, and also shows good agreement with the target fuel in terms of atomization characteristics and CO emissions, while the NOx emissions of the surrogate is higher than those of the target fuel for most test conditions. [ABSTRACT FROM AUTHOR]

As one of the most important components of the vehicle thermal management system, multi-fans cooling module can potentially be used to optimal the system performance in order to save the energy consumption and reduce the vehicle fuel consumption. In this study, a test rig has been designed, constructed and used to test the heat transfer performance of the multi-fans cooling module using four different fan shroud structures. Results indicate the separated plates, which have limited or worse effect on the performance of the system, are not recommended to be used in the multi-fans cooling module. The optimal shroud structure for multi-fans cooling module has been identified and experimentally tested. By adding shutters at the ventilation part of the fans (Shroud C) can significantly improve the overall performance of the module (Shroud A) by 13.25 % to 69.08 % under various operation conditions. [ABSTRACT FROM AUTHOR]

Cylindrical Lithium-Ion Batteries have been widely used as power source for electric and hybrid vehicles because of their compact size and high power density. The battery pack is commonly consisted by hundreds of cylindrical Lithium-Ion battery cells in several strings. Because the distance among battery cells is only a few millimeters, the thermal status of battery would directly influent the current efficiency and battery life. In order to maintain proper function of the battery pack, the heat dissipation around battery cells should be deeply investigated and well controlled. This question is undeniably important and which has gained increasing attentions. Researchers have developed some models of the transient temperature distribution in Lithium-Ion battery during the discharge cycle and the thermal management on various kinds of battery packs has been studied. However, because of the compacted and complicated structure inside battery pack, the full thermal status and detail distributions are difficult to be revealed in the same time. In this work, three-dimensional simulation methods have been used to solve the above questions on the combination of several cylindrical Lithium-Ion battery cells. Existing heat generation models in Lithium-Ion battery is defined as the thermal boundary conditions. The flow and convection on the spacing has been studied. The transient thermal interactions and convections among adjacent battery cells have been investigated to explore the influences by spacing and transient heat release rules. The achieved results can be used as critical reference for designing the structures of battery pack and planning the cooling strategies. [ABSTRACT FROM AUTHOR]

In the vehicle industry, thermal balance experiments have been extensively conducted on engines to determine energy distribution from fuel to engine power. The temperature differences between the hot and cold sides of the vehicular heat exchanger are the key parameters used to calculate the heat quantity. However, in certain gas–liquid heat exchangers, the temperature difference of the liquid side is significantly smaller than that of the gas side. Measurement errors can be increased if an inappropriate measurement method is adopted. To minimize the measurement errors, a new temperature difference measurement method based on compound thermocouple (CTC) is introduced in this study. This method is calibrated using a thermostatic oil tank. An empirical formula is used to evaluate cases in which the basic temperature ranges from 20 °C to 120 °C, and a temperature difference of less than 20 °C is gained. The proposed method has been implemented in a practical thermal balance experiment using a vehicle radiator, and the results are compared with that of pairing calibrated resistance temperature detectors (RTDs). The results show that the CTC-based method can reduce the averaged thermal balance error in vehicular cooling systems to less than 4%. [ABSTRACT FROM AUTHOR]

The plateau environment would increase the fuel consumption of the engines. The current situation, however, is that the existing studies on high altitude engines are still not sufficient or detailed enough to compensate for the reduced engine efficiency. Consequently, the goal of this paper was to reveal the causes of combustion deterioration occurring in the combustion chamber at high altitude environments, which can provide a theoretical basis for the development of plateau engines. A three-dimensional computational fluid dynamics model was developed and calibrated by experimental data of a turbocharged direct injection compression ignition engine operating at different altitudes. The simulation results showed that the increase in altitude led to enhanced penetration of the fuel injection and increased the possibility of fuel droplets impinging on the walls, thereby contributing to an uneven distribution of mixture concentration and deterioration of combustion in the cylinder. Moreover, when the altitude was above 3,000 m, the liquid film formed by the adhering liquid droplets caused a sharp drop in combustion efficiency, which eventually led to a significant degradation in engine performance. High altitude operations reduced the spatial distribution of the spray, decreasing the air utility in the confined geometry and therefore increasing the formation of soot and reducing the ability to oxidize soot. All these results suggest that the plateau engines can be optimized by finding strategies to improve spray quality, which may help raise the threshold that causes a sharp decline in performance well above 3000 m, which would be applicable to more high altitude areas. [ABSTRACT FROM AUTHOR]

CFD/CHT simulations have been widely used in simulating cross flow compact heat exchangers, but the calculating accuracy is commonly limited. The multi-scale thermal analysis approach was adopted to study an intercooler, one of the representative examples of cross flow heat exchangers in automotive cooling systems. With the application of mesh refinement and datum interpolation technique, the inside flow and heat transfer mechanism were analyzed, the pressure and temperature data were also calculated. The model was validated with experimental data based on wind tunnel tests, and the results show that the multi-scale coupled calculation is in good agreement with experimental values, especially in the heat transfer simulations. The research of the inside flow and heat transfer mechanism is capable of providing a basis for optimization of compact heat exchangers. [ABSTRACT FROM AUTHOR]

Abstract: To solve the nonlinear filtering problem in the Bearings-Only Tracking (BOT), an improved particle filter with fine resampling is proposed, called as PF-FR (Particle Filter with Fine Resampling). By introducing distance-comparing process and generating new particle based on optimized combination scheme, PF-FR filter performs better than generic PF-SIR filter both in terms of effectiveness and diversity of the particle system, hence, evidently enhancing tracking accuracy in bearings-only tracking problem. Simulations indicate that the proposed PF-FR algorithm is effective. [Copyright &y& Elsevier]

• Multi-scale coupling is used for 87.05% improved accuracy than the existing method. • The effect law of altitude on heat transfer efficiency is studied. • The changes in heat transfer in/below the stratosphere are separately discussed. • Formula for the dependency of heat exchanger efficiency on height is developed. Altitude affects the heat exchange capacity of a heat exchanger, which in turn affects the performance of an aircraft with piston engines. In order to study this mechanism of influence and the associated principles, a three-dimensional computational fluid dynamics (CFD) simulation of an intercooler is conducted based on multi-scale coupling. The simulation results have a high degree of coincidence with the test data on ground, with maximum error of no more than 10%. The simulation height is then extended to an altitude of 20 km. It is found that before the aircraft enters the stratosphere, the overall efficiency of the intercooler decreases by 1.98% on average for every 1km increase in the altitude and decreases by 3.26% when the height is above 11 km. The heat transfer capacity of the intercooler is gradually enhanced owing to the gradually increasing temperature difference while atmospheric density is relatively large. After entering the stratosphere, the external temperature stops changing; the density decreases to 1/14 of the value at the ground, and the low density becomes the dominant factor, resulting in reduced heat transfer coefficient. Finally, an empirical formula for the overall heat exchange efficiency of the intercooler as a function of the altitude is proposed. [ABSTRACT FROM AUTHOR]

[Display omitted] • A novel dendritic micro-mesoporous composite TS-1/DMSNs (TD) is synthesized by an optimized and facile nano-assembly method. • The optimized TD composite material has suitable acidity, MSI and the dispersity of MoS 2 active phase. • The open dendritic pores facilitate the transfer and diffusion of macromolecular sulfur compounds. • NiMo/TD-TEA-4 presents the highest k HDS and turnover frequency (TOF) values among series studied catalysts. • Superior HDS performance of NiMo/TD series catalysts results from the synergistic effect of the structure, acidity and the MoS 2 active phase. Novel TS-1/dendritic mesoporous silica nanoparticles (TS-1/DMSNs, TD) micro-mesoporous composites with different morphology were prepared for NiMo catalysts (NiMo/TD-TEA). Series catalysts were tested in dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (4,6-DMDBT) hydrodesulfurization (HDS) reactions in a fix-bed reactor. TS-1 were uniformly compounded with mesoporous materials in the form of Si-O-Ti bonds, which did not affect the typical dendritic morphology. The introduction of TEA could inhibit the growth of support particles, and modulate the acidity and the metal-support interaction (MSI) of catalysts. Optimized NiMo/TD-TEA catalyst showed the optimal DBT (98.0 %) and 4,6-DMDBT (92.3 %) desulfurization rate as well as the excellent hydrogenation (HYD) selectivity for DBT and 4,6-DMDBT HDS with the optimal reaction rate constant (12.2 mol·g−1·h−1, 6.7 mol·g−1·h−1) and turnover frequency (2.3 h−1, 1.4 h−1). By correlating to the catalyst acidity–activity and active phase–activity, the activity and selectivity were not only depended on the presence of Brønsted (B) acid and the total acid content but also associated with the dispersion and morphology of MoS 2 slabs. [ABSTRACT FROM AUTHOR]

Long non‐coding RNAs (lncRNAs) play important roles in tumor progression. Whereas the roles and underlying mechanisms of LINC00909 (a newly discovered lncRNA) are still unclear in glioma progression. In the present study, we identified that LINC00909 expression was significantly elevated in glioma tissues and cell lines. High LINC00909 expression was associated with advanced WHO grade, high Karnofsky Performance Score (KPS), and poor prognosis in patients with glioma. Function assays showed that LINC00909 depletion inhibited glioma cells proliferation, invasion in vitro and reduced tumor growth in vivo. In the mechanism, we found that LINC00909 could act as a ceRNA to interact with miR-194 and thereby up‐regulate the expression of MUC1-C, thus promoting the proliferation and invasion of glioma cells. Collectively, these data demonstrated that LINC00909/miR-194/MUC1-C axis regulated glioma progression and might act as a novel therapeutic target. [ABSTRACT FROM AUTHOR]

Recently, the pivotal to electrocatalytic water splitting is developing efficient and earth-abundant electrocatalysts to accelerate the sluggish kinetics of hydrogen and oxygen evolution reactions (HER and OER). In this work, (NH 4) 2 MoS 4 derived from polyoxometalates ((NH 4) 6 Mo 7 O 24 ·4H 2 O) were immobilized onto the ion exchange resin D314, and highly dispersed Co-molybdenum disulfide (Co–MoS 2 @NG-4) on nitrogen-doped graphene catalyst was prepared. The optimized Co–MoS 2 @NG-4 shows excellent electrocatalytic performance for HER and OER. Specifically, the low overpotentials of 202 and 352 mV are required to drive the current density of 10 mA cm−2 with the small Tafel slope of 77.30 and 153.50 mV dec−1 for HER and OER, respectively. The Co–MoS 2 @NG-4 demonstrates excellent stability, maintaining a robust operation for 5000 cyclic tests with no detectable stability decay. Porous structure endows Co–MoS 2 @NG-4 with more active centers, increasing its specific surface area and ultimately improving its catalytic performance. [Display omitted] • Synthesized Co–MoS 2 @NG-4 catalyst using ion-exchange and thermal reduction methods. • The porous structure and heteroatom doping improve the electrocatalytic activity. • The Co–MoS 2 @NG-4 exhibits excellent electrochemical activity for both HER and OER. • The Co–MoS 2 @NG-4 exhibits exceptional stability. [ABSTRACT FROM AUTHOR]

Background HER2 status is significant to trastuzumab therapy; however, it is difficult to determine HER2 status accurately with few pieces of biopsies from advanced gastric cancer (AGC) due to highly heterogeneity and invasive behaviour, which will be investigated in this study. Methods Fifty-six patients with AGC were included in this study. Primary tumour tissues and matched plasmas before medication from 36 patients were retrospectively collected, and the other 20 patients with primary tumour tissues and paired plasmas were prospectively collected. HER2 expression and amplification in 56 tumour tissues were determined by immunohistochemistry (IHC) and dual in situ hybridisation (DISH), and HER2 copy number in 135 circulating tumour DNAs (ctDNAs) was judged by next-generation sequencing. Results For tumour tissues, HER2 amplification by DISH was most commonly found in patients with HER2 score 3+by IHC. For plasmas, HER2 amplification defined as HER2 copy number >2.22 was identified in 26 of 56 patients. There was a high concordance of HER2 amplification between ctDNA and tumour tissues, suggesting that ctDNA could function as an alternative to screen HER2-targeted population. Moreover, the changes of HER2 copy number in ctDNA could efficiently monitor trastuzumab efficacy, the power of which was superior to commonly used markers carcinoembryonic antigen (CEA) and CA199, suggesting its potential role in clinical practice. Conclusion ctDNA for HER2 analysis was strongly recommended to serve as a surrogate to screen trastuzumab-suitable population and monitor trastuzumab efficacy. [ABSTRACT FROM AUTHOR]

[Display omitted] • MOF-303-derived Pd@KNDC(10-900) catalyst with highly dispersed Pd NPs was prepared. • The mesopores of Pd@KNDC(10-900) catalyst can promote mass transfer and increase accessibility. • The N sites on the KNDC(900) support could improve the dispersion and reduce the particle size of the Pd active NPs. • The ultrasmall size (4.1 nm) and high dispersion of Pd NPs could expose more catalytic active sites. • The Pd@KNDC(10-900) catalyst presents an initial TOF value of 2215 h−1, 100 % FA conversion and H 2 selectivity, and excellent stability at 50 °C. In this work, ultrasmall Pd nanoparticles (NPs) with a mean size of 4.1 nm immobilized by the MOF-303-derived N-doped carbon (NDC) have been prepared for efficient formic acid (FA) dehydrogenation. The optimized catalyst Pd@KNDC(10-900) showed the extraordinary catalytic activity, and the initial turnover frequency (TOF) value is 2215 h−1 at 50 °C, accompanied by 100 % FA conversion and H 2 selectivity, facilitated by the incorporation of sodium formate (SF) as an additive. Moreover, the Pd@KNDC(10-900) could maintain an outstanding stability enduring through five successive runs with only a marginal reduction in activity. The robust synergistic interactions between Pd NPs and N sites on the KNDC(900) together with the ultrafine size and high dispersion of Pd NPs as the catalytic active sites are responsible for the superior catalytic performance. This work will provide a new paradigm by using the MOF-derived NDC supports for the construction of Pd-based catalysts for FA dehydrogenation. [ABSTRACT FROM AUTHOR]

The plateau environment deteriorates the combustion quality inside the heavy duty diesel engine, bringing difficulties in controlling soot emissions. To study the causes of soot increase is the basis for optimizing highland engines and achieving clean operation. A multidimensional CFD model based on a 6V150 engine was developed in this study to investigate the effect of altitude on soot formation and oxidation processes. The comparison between experimental data and numerical results showed that the model was deemed to be able to predict in-cylinder activities at various altitudes. The simulation results showed that when the diesel engine was operated at high altitude, the mismatch between fuel and air led to more soot formation but less oxidized. The wall impingement of fuel droplets occurred at altitudes above 3000 m and soot emissions rose sharply when the altitude exceeded 4000 m. It can be concluded that the engine recalibration strategy may mitigate the increase in soot at altitudes below 3000 m, but may not be very effective when the engine is operating at 4000 m. In addition, the application of oxygenated fuels that can provide more hydroxyl radicals may be an alternative solution to mitigate soot emissions from diesel engines operating in very high altitude regions. • The CFD model effectively reproduced the increased soot phenomenon in highland engines. • Soot emission significantly increased with altitude above 4000 m. • Liquid films were formed at altitudes over 3000 m due to the low density of cylinder gas. • Highland environment squeezed the spray development and weakened air entrainment. • High altitude operation hindered the oxidation process of soot by OH radicals. [ABSTRACT FROM AUTHOR]

In this study, we show that the poor cycling performance which seriously hinders the application of Li 3 V 2 (PO 4 ) 3 /C for rechargeable lithium-ion batteries is overcome by amorphous ZrO 2 nano-coating. The ZrO 2 -coated Li 3 V 2 (PO 4 ) 3 /C was synthesized via a conventional solid-state method followed by the application of wet coating. The crystalline structure, morphology and electrochemical performance of the as-synthesized samples were investigated by XRD, SEM, TEM, EDS, galvanostatic charge/discharge and EIS measurements. Compared with the pristine Li 3 V 2 (PO 4 ) 3 /C, the structure of ZrO 2 -coated Li 3 V 2 (PO 4 ) 3 /C sample had no change, and the existence of ZrO 2 nano-coating effectively enhanced the cycling performance. From the above results, it is believed that the improved cycling performance is attributed to the ability of ZrO 2 layer in preventing direct contact of the active material with the electrolyte resulting in a decrease of electrolyte decomposition reactions. [ABSTRACT FROM AUTHOR]

[Display omitted] • Novel Pd 3 Co 2 /CeZrSBA-15-NH 2 catalyst with short channels and highly dispersed PdCo alloy NPs was prepared successfully. • The special short channels of Pd 3 Co 2 /CeZrSBA-15-NH 2 catalyst can promote mass transfer and increase accessibility. • The amine groups on the CeZrSBA-15-NH 2 could improve the dispersion and reduce the particle size of the PdCo active metals. • The ultrafine size (1.6 nm) and high dispersion of PdCo alloy NPs could expose more catalytic active sites. • The Pd 3 Co 2 /CeZrSBA-15-NH 2 presents a TOF of 2001 h−1, 100 % FA conversion and H 2 selectivity, and good stability at 323 K. The rational design of heterogeneous catalysts with remarkable activity and low cost is essential yet challenging for formic acid (HCOOH, FA) dehydrogenation. Herein, ultrafine bimetallic PdCo nanoparticles (NPs) dispersed on the amine-functionalized CeZrSBA-15 (CeZrSBA-15-NH 2) with short channels have been successfully prepared. The optimized catalyst Pd 3 Co 2 /CeZrSBA-15-NH 2 (the Pd/Co molar ratio is 3:2) displayed the extraordinary catalytic performance of FA dehydrogenation with 100 % FA conversion and H 2 selectivity. Furthermore, in the presence of sodium formate (SF) as an additive, the catalytic system achieved an impressive initial turnover frequency (TOF) of 2001 h−1 at a temperature of 323 K, which is better than the TM (transition metal)-containing Pd-based heterogeneous systems ever published under the similar reaction conditions. The exceptional catalytic activity is ascribed to several key factors, including the presence of short channels that facilitate the efficient transfer of reactants, the ultrafine size (1.6 nm) and uniform dispersion of PdCo nanoparticles, which serve as the active catalytic sites on the CeZrSBA-15-NH 2 support. Additionally, the regulated electronic effects induced by Pd and Co, coupled with the metal-support interaction (MSI) effect, further enhance the catalytic performance. This work affords a new paradigm into developing effective mesoporous silica-based heterogeneous catalysts for H 2 production from FA dehydrogenation. [ABSTRACT FROM AUTHOR]

Biodegradable polymers, including polybutylene adipate-co-terephthalate (PBAT), can replace traditional plastics to effectively target microplastic pollution; however, their high cost limits their application. In this study, vinyltrimethoxysilane (VTMS)-grafted lignin (VL) was prepared and incorporated into PBAT to reduce its cost and improve its mechanical properties while maintaining its biodegradability. Results show that the tensile strength, Young's modulus, and biodegradation efficiency of a PBAT/VL-30% composite increased by 200%, 151%, and 96%, respectively, compared with neat PBAT. VTMS grafting onto lignin thus improves the dispersion of lignin in PBAT; a network structure of PBAT and VL is formed via reactive extrusion. This work provides a theoretical basis for the design and development of low-cost, highly biodegradable PBAT composites. [ABSTRACT FROM AUTHOR]

• The study proposes using CFD and machine learning to optimize nanofluid mini-channel heat sinks. • Numerical models of the mini-channel were generated using the mixture model to develop the dataset for machine learning models. • Support vector regression (SVR), gaussian process regression (GPR), and random forest (RF) models were used to establish the mapping relationships between the parameters of the nanofluid mini-channel. • The GPR model was found to be the most suitable, with high R2 values for both the pressure drop and average temperature of the heating wall. • Using the NSGA-II multi-objective optimization algorithm, the study determined the optimal value of the volume fraction (φ) for different operating conditions, with values of around 3% at low reynolds numbers and around 2% at high reynolds numbers. The improvement in the performance of power systems in new energy vehicles has posed new demands for the performance of thermal management systems, leading to an increased interest in the application of nanofluid mini-channel heat sinks. Despite their potential, studying nanofluids is challenging due to the complexity of their preparation. To mitigate the computational and optimization costs, this study proposed a combination of Computational Fluid Dynamics (CFD) and machine learning in a multi-objective optimization algorithm for optimizing the operating parameters of nanofluid mini-channel heat sinks. Firstly, a numerical model of the nanofluid mini-channel was developed using the Mixture model to generate the dataset for machine learning models. Secondly, SVR, GPR, and RF models were utilized to establish the mapping relationships between the parameters of the nanofluid mini-channel, including the inputs of the inlet Reynolds number (Re), volume fraction (φ), and heat flow density (q), and the outputs of the pressure drop (△ P) and the average temperature of the heating wall (T ave). The results indicated that the GPR model was the most suitable, with R2 values of 0.9939 and 0.9985 for T ave and △ P , respectively. By employing the NSGA-II multi-objective optimization algorithm, the optimal value of φ was determined for different operating conditions, with values of around 3% at low Re and around 2% at high Re. [ABSTRACT FROM AUTHOR]

This paper investigated the sensitivity of diesel engine performance to plateau environment. A three-dimensional computational fluid dynamics engine model validated against the experimental data was performed to provide analytical data from sea level to 5000 m at a constant engine speed and fuel injection strategy. The simulation results showed that the engine torque exhibited a nonlinear reduction with decreasing ambient pressure. Similarly, the fuel consumption increased non-linearly with altitude due to the combustion deterioration. However, the decline in the engine pressure-related parameters was smooth since flame extinction did not occur. As for nitrogen oxides emissions, high altitude operations steadily reduced the area of the thermal nitric oxide production zone, and therefore it decreased smoothly with altitude. In addition, soot emission levels rose with altitude mainly due to the reduced air utilization capacity, which boosted the soot formation while simultaneously undermined the percentage of soot oxidation. Soot concentrations suddenly increased when the engine was operated above ∼4000 m. This was due to the enhanced penetration of the diesel spray, which caused wall adhesion, adding another soot formation mechanism. As a result, soot is the appropriate indicator to find the maximum altitude that engine can tolerate without significant performance degradation. • Diesel engine performance degraded non-linearly with increasing altitude. • Power-law relations can characterize the nonlinearity. • An inflection point altitude existed for the deterioration of engine performance. • Soot is more sensitive to altitude than other combustion-related parameters. • Plateau engine optimization merit function requires higher weight on soot. [ABSTRACT FROM AUTHOR]

The all-area operating performance of the vehicles requires the development of diesel engines that can operate at high altitudes without significant performance deterioration. Prior to optimizing the efficiency and emissions of highland engines, there is a necessity to investigate the underlying causes of engine performance degradation. The purpose of this paper was to study the in-cylinder activities occurring in the combustion chamber of diesel engines at high altitudes, which can help explain the effect of altitude on engine efficiency and emissions of concern to the customer. Specifically, a turbocharged direct injection compression ignition engine was operated at a constant engine speed and load, but at different altitudes. The theoretical analyses based on experimental data suggested that the mismatch between air and diesel quantities caused by the high altitude atmosphere led to the engine combustion deterioration. Specifically, the lower gas density at high altitudes during fuel injection resulted in a reduction of the injection angle and an enhancement of the penetration capability. In addition, the rise in altitude extended the ignition delay, which increased the fuel fraction mixed with air in the premixed combustion stage and raised the pressure rise rate. Moreover, at high altitudes, the reduction in excess air ratio and increased possibility of wall impingement of the fuel droplets resulted in uneven mixture concentration distribution and reduced air utility. Accordingly, combustion deterioration occurred in the combustion chamber of the plateau engines, which reduced energy release during main mixing-controlled combustion, lowered combustion efficiency, increased exhaust energy, and raised engine-out incomplete combustion emissions. All these effects resulted in a decrease in engine thermal efficiency of ∼6.5% and an increase in soot emissions of ∼4.2 times from Hangzhou to Lhasa city for the engine and operating conditions investigated in this study. Consequently, engines operating in highland areas need to be optimized in terms of efficiency and emissions. [Display omitted] • Diesel engine performance declined with increasing altitude. • The phasing loss was negligible for highland diesel engines. • Combustion deterioration was the main cause of plateau engine performance degradation. • Engine efficiency had a non-linear relationship with elevation. • Soot concentration was more sensitive to plateau environment. [ABSTRACT FROM AUTHOR]

[Display omitted] • Polybutylene adipate terephthalate hollow porous microfibers (HPMFs) are prepared. • The loading capacity of polypeptide on HPMFs is improved compared with on MFs. • The inhibition rates of RGD@HPMFs on HeLa and A549 are higher than RGD@HPMFs by 14.1% and 6.9%, respectively. • Controlled loading and sustained release of polypeptide challenges are addressed. Although microfiber (MF) loaded polypeptides have been widely studied in the field of medicine, load control and slow release remain significant challenges. Herein, polybutylene adipate terephthalate (PBAT) hollow porous MFs (HPMFs) were prepared by improving and regulating the groups and structures of the MFs to address these challenges. The capacity of the HPMFs for the loading of polypeptide can be improved. Measurements involving the use of X-ray photoelectron, energy-dispersive, and ultraviolet (UV) spectroscopies in conjunction with scanning electron microscopy measurements showed that the amount of polypeptide (arginylglycylaspartic acid, RGD) loaded on the HPMFs was significantly higher than that loaded on the MFs. Animal cell experiments revealed that PBAT grafted MAH has good bioactivity. By loading RGD onto HPMFs and MFs, RGD@HPMFs and RGD@MFs were obtained. A study on HeLa and A549 cancer cells showed that the inhibition rates of RGD@HPMFs were higher than that of RGD@MFs by 14.1% and 6.9%, respectively. The results obtained herein show that HPMF scaffold preparation by improving the material groups and regulating the structure of MFs can address the challenges associated with control of the load and sustained release of polypeptides and other drugs. [ABSTRACT FROM AUTHOR]

• The drying and autogenous shrinkage reduction effect is greatest for PVA fiber. • The efficiency in improving the cracking resistance follows the order of PVA > PAN > PP. • PAN fibers produce a low porosity, a low hardened air content and a high impermeability. • Durability differences caused by fiber can be interpreted by the pore structure and air void. The crack resistance and durability of face slab concrete are two important factors determining the normal operation and safety of concrete face rockfill dams (CFRDs). This paper investigates the influence of polypropylene (PP), polyvinyl alcohol (PVA) and polyacrylonitrile (PAN) fiber with two lengths (10 mm and 20 mm) on workability, strength, shrinkage behavior, cracking resistance and durability performance of face slab concrete. Besides, the parameters of the pores at multi-scales were investigated by a linear traverse method and the mercury intrusion porosimetry (MIP), respectively. The results in this study demonstrate that: (1) the efficiency in reducing the shrinkage and in enhancing the cracking resistance of face slab concrete follows the order of PVA > PAN > PP. In addition, both the impermeability and frost resistance of concrete can be improved by adding fibers, the efficiency is in the sequence: PAN > PVA > PP and PVA > PAN > PP, respectively. (2) increasing fiber length from 10 mm to 20 mm reduces the shrinkage by about 5.1%−7.0%, enhances the tensile strength (σ) by about 7.9%−9.2% and declines the cracking temperature (T c) by about 5.6–6.5℃, all of which could significantly improve the cracking resistance. Moreover, the increase in fiber length improves the frost resistance, but increases the relative permeability coefficient (K r) by about 28%−47%. (3) The correlation analyses reveal that, the addition of PAN fibers produces a lower porosity, a lower fraction of large capillary pores as well as a lower hardened air content than the PVA and PP fibers at 28 days, thereby resulting in better impermeability of concrete. PVA fiber enhanced concrete gives the smallest spacing factor and the largest total number of air voids among all the fiber enhanced concretes, thus exhibiting the best frost resistance. [ABSTRACT FROM AUTHOR]