Aroma plays an important role in fruit quality and varies among different fruit cultivars. In this study, a sensitive and accurate method based on headspace solid-phase microextraction (HS-SPME) ...coupled with comprehensive two-dimensional gas chromatography time-of-flight mass spectrometry (GC×GC-TOFMS) was developed to comprehensively compare aroma components of five pear cultivars. In total, 241 volatile compounds were identified and the predominant volatile compounds were esters (101 compounds), followed by alcohols (20 compounds) and aldehydes (28 compounds). The longyuanyangli has the highest relative concentration (838.12 ng/g), while the Packham has the lowest (208.45 ng/g). This study provides a practical method for pear aroma analysis using SPME and GC×GC-TOFMS.
Abstract
The rechargeable zinc ion hybrid supercapacitors (ZHSCs) are critically hindered by the low Coulombic efficiency and poor lifespan due to the continuous water‐induced side reactions and ...uncontrolled dendrite growth of the Zn anode. Herein, a zincophilic anionic hydrogel electrolyte (PSCA/Zn(OTf)
2
) is constructed by incorporating the dodecyl sulfate anions ((OSO
3
R)
−
) micelles to manipulate the solvation structures of Zn
2+
cations via the moderate ion–ion coordination interactions for manipulating the Zn deposition behavior and interfacial chemistry on Zn electrode. Joint experimental and theoretical results show that the constructed solvated Zn
2+
cations with the ionized (OSO
3
R)
−
electron donor significantly restrict the occurrence of adverse reactions (hydrogen evolution reactions). Concomitantly, the newly involved (OSO
3
R)
−
anions influence the adsorption configurations of solvated Zn
2+
ions, which alter the electrocrystallization patterns for dendrite‐free growth and induce the oriented deposition for rapid reaction kinetics of Zn electrodes. As a proof of concept, the Zn||Zn symmetric cells with PSCA/Zn(OTf)
2
exhibit high reversibility for deposition/stripping behavior with an extended long cycle span. Significantly, benefiting from the synergy of the modulatory electrolyte environment and the regulated adsorption configurations, a quasi‐solid‐state Zn||PSCA/Zn(OTf)
2
||N‐doped porous carbon material (NPC) ZHSC exhibits exceptional cycling stability for over 40 000 cycles with a low capacity decay (0.00027% per cycle).
In order to achieve high reliability and control precision of multiple induction motors drive systems, a fuzzy sliding mode control (FSMC)-based synchronization control strategy is proposed by ...combining the FSMC technique with the ring coupling synchronization structure. Also, a fuzzy controller is utilized as a switching control part of the FSMC to attenuate chattering phenomena despite large uncertainties that exist in practical applications. Moreover, the stability analysis of the proposed control strategy is derived by Lyapunov stability theorem. The proposed FSMC-based synchronization scheme possesses several attractive advantages of simple control framework, high control precision, strong robustness to uncertainties, and chattering elimination. Furthermore, the performance of the proposed control strategy is investigated on a four induction motors driving system. The numerical simulation results clearly demonstrate the effectiveness of the proposed FSMC based synchronization strategy for multiple induction motors drive at different operating conditions, and its superiority is indicated by comparison with proportional integral (PI) control and conventional SMC.
In this study, an interior permanent magnet synchronous motor (IPMSM) for single-rotor air conditioner compressors with small inertia is studied, which adopts a sensorless control based on the ...phase-locked loop (PLL). Owing to the large periodic motor speed fluctuations, the speed and rotor angle of these compressors calculated by the PLL have inherent lagging phase shift and amplitude attenuation, which deteriorates the field weakening control performance and leads to larger speed fluctuations and current oscillations. In this study, a novel phase lead compensated PLL (PLC-PLL) was proposed to reduce the angle error between the real rotor position and estimated rotor position as well as to improve the performance of field weakening control. This method compensates the phase shift of the calculated angle and then reduces the angle error and speed fluctuations. Furthermore, the method of setting parameters for the PLC-PLL is also given. The experimental results confirm that this scheme can greatly reduce the angle error and the fluctuations of speed and currents, which improves the performance of the controller.
•The slump is controlled by the added water content.•Fly ash content and AS/FA ratio have no effect on the strength.•The strength decreases linearly with the increase of H2O/(Na2O + effective ...SiO2).•A new mix design method for FAGC is proposed.
The effect of mix proportion of geopolymer concrete on compressive strength has been studied in detail in many previous studies, but there is a lack of a proposed mix design method. This research proposed a mix design method for low calcium fly ash geopolymer concrete (FAGC) by finding the key factors that affect the workability and compressive strength of FAGC. The experiment results showed that the workability is governed by the water content. The data from the experiment and the published literature indicated that the strength is independent of fly ash content and AS/FA ratio, and decreases linearly with the increase of the water to alkaline activator ratio, wherethe alkaline activator refers to Na2O and effective SiO2 from the alkaline solution. There is a limit for the SiO2/Na2O ratio beyond which additional SiO2 no longer improves the strength. Based on the factors, a new method was proposed to design the mix proportion of FAGC. Target compressive strengths ranging from 30 MPa to 80 MPa at 3 days and target slump of 150 mm were achieved with laboratory experiments, using the proposed mix design method and a new fly ash. Therefore, this research paper provided a novel mix design method for FAGC that allows for high strength and excellent workability at the same time.
In recent years, considerable effort has been dedicated to the development of highly efficient thermoelectric generators for waste heat recovery and thermoelectric power generation. In this study, we ...present employing twisted tapes with variable twist ratio to enhance thermal energy extraction efficiency, coupled with two-stage thermoelectric modules for heat-to-electricity conversion, resulting in a substantial increase in the power output of the thermoelectric generator. We established an experimental system that validated the superior power generation and heat recovery characteristics of the two-stage thermoelectric generator. Building upon these findings, we propose further optimizing the variable twist ratio twisted tapes to enhance the power output. We investigated the impact of tape pitch ratio, twist ratio, and twist ratio variation range on thermoelectric performance. Experimental results indicate that the influence of flow instability is more pronounced than that of swirl intensity, and twist tapes with the maximum twist ratio variation rate yield the highest net output power. Compared to an unmodified thermoelectric generator, the two-stage thermoelectric generator employing twist tapes with a twist ratio increase from π to 3π achieves a maximum net output power gain of up to 100%. These findings provide a practical framework for integrating innovative power generation modules and optimized heat exchanger designs into the application of waste heat recovery thermoelectric generators, marking a significant advancement in the field of thermoelectric generators.
•Two-stage thermoelectric modules boosts power output.•Variable twist ratio twisted tapes to boost thermal energy extraction efficiency.•Impact of tape pitch ratio and variable twist ratio on thermoelectric performance.•Optimized thermoelectric generator net output power doubled.
Neutrophil extracellular traps (NETs) can cause acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) by inducing macrophage pyroptosis. The purpose of this study was to find out whether ...pretreatment of alpha-linolenic acid (ALA) could inhibit NETs-induced macrophage pyroptosis in sepsis-induced ALI/ARDS, as well as to identify which inflammasome is involved in this process.
LPS was instilled into the trachea to establish sepsis-induced ALI/ARDS in a mouse model. Lung injury was assessed by microscopic examination of lung tissue after hematoxylin and eosin staining, pathology score, and bronchoalveolar lavage fluid (BALF) total protein concentration. The level of NETs in lung tissue was detected by MPO-DNA ELISA. Purified NETs, extracted from peritoneal neutrophils, induced macrophage pyroptosis
. Expression of pyroptosis-related proteins (Cl-caspase-1, Cl-GSDMD, ASC) and IL-1β in the lung tissue and bone marrow-derived macrophages (BMDMs) were determined by western blotting or ELISA. Specks of Pyrin/ASC were examined by confocal immunofluorescence microscopy. Mefv (Pyrin)
mice were used to study the role of Pyrin in the process of sepsis-induced ALI/ARDS.
ALA alleviated LPS-induced lung injury. ALA reduced the level of NETs, pyroptosis-related proteins (Cl-caspase-1, Cl-GSDMD, ASC), and IL-1β in the lung tissue of sepsis mice.
, NETs increased the expression of pyroptosis-related proteins (Cl-caspase-1, Cl-GSDMD, ASC) and IL-1β significantly in BMDMs. Pyrin protein was found to be higher and form the inflammasome with ASC in NETs challenged-BMDMs. Knockout of Mefv (Pyrin) gene fully restored the increased expression of pyroptosis-related proteins (Cl-caspase-1, Cl-GSDMD, ASC) and IL-1β
and
. Lung injury was alleviated significantly in Mefv (Pyrin)-/- mice as well. ALA suppresses all the NETs-induced changes as mentioned above.
Our study is the first to demonstrate Pyrin inflammasome driving NETs-induced macrophage pyroptosis, and ALA may reduce ALI/ARDS by inhibiting the activation of the Pyrin inflammasome-driven macrophage pyroptosis.
To investigate the effects of kinds of additives on silage quality, the mixture of king grass and rice straw was ensiled with addition of sucrose, citric acid and malic acid at the levels of 0, 1 and ...2%, being blank control (CK), citric acid groups (CA1, CA2), malic acid groups (MA1, MA2), citric acid + malic acid groups (CM1, CM2), sucrose groups (SU1, SU2), mainly focusing on fermentation quality, nutrient content, aerobic stability and microbial community of the silages. The results showed that the addition of sucrose decreased ( p < 0.05) pH and increased the content of water soluble carbohydrate ( p < 0.05). The sucrose groups and mixed acid groups also had a lower ( p < 0.01) neutral detergent fiber content. The addition of citric acid and the mixed acid increased ( p < 0.01) the aerobic stability of the silage, reduced the abundance of Acinetobacter , and the addition of citric acid also increased the abundance of Lactiplantibacillus . It is inferred that citric acid and malic acid could influence fermentation quality by inhibiting harmful bacteria and improve aerobic stability, while sucrose influenced fermentation quality by by promoting the generation of lactic acid. It is suggested that the application of citric acid, malic acid and sucrose would achieve an improvement effect on fermentation quality of the mixed silage.
The formation of silver nanoparticles by laser direct writing has been widely studied due to the excellent optical and electrical properties of silver nanoparticles. Although the theoretical and ...experimental research on silver nanoparticles has been very comprehensive, research on the formation mechanism of nanosilver films based on the particle-free complexed silver ion ink is still necessary. It shows a good consistency of nanoparticle size, which may mainly depend on the excellent film formation uniformity of the particle-free complexed silver ion ink. After laser treatment, the nanosilver film has good transmittance from 500 to 2500 nm and a typical plasma resonance absorption peak. The relationship between laser power and linewidth size induced by the thermal broadening effect is carefully investigated, and the photothermal conversion of the samples is analyzed further.
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