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Al-based alloy ingots are a highly promising material for on-demand hydrogen supply. However, the use of Sn in them restricts the recovery and reuse of alloying elements, and also decreases the purity of byproducts, resulting in a significant increase in the application cost. Herein, a series of Sn-free ternary Al-alloys are prepared and their hydrogen production performance are investigated. Experimental results indicate that the Sn-free Al-Ga-In alloys maintain good hydrogen production performance, and the hydrolysis reaction is more stable and sustained than that of Al-Ga-In-Sn alloys. As the optimized formula, the 94Al-4.73Ga-1.27In alloy exhibits a high hydrogen conversion efficiency of 97.3% and an extremely stable average hydrogen production rate of 0.01423 L/min at 50 °C. In addition, a semi-coherent phase boundary-derived activation mechanism during Al hydrolysis was proposed. This study opens up a prospect for the development and large-scale using of recyclable Al-based on-demand hydrogen supply materials. [Display omitted] • Recyclable Sn-free Al-based alloys are developed for on-demand hydrogen supply. • Optimized alloys show stable H 2 production rate and achieve 97.3% energy conversion. • The hydrolysis reaction of Sn-free Al alloys is activated by the liquid phase. • Semi-coherent phase boundaries promote the hydrolysis reaction of alloys. [ABSTRACT FROM AUTHOR]

Based on cascade utilization of full spectrum solar energy, a spectral splitting agriculture photovoltaic thermal hybrid system has been proposed in this study. The red and blue light is assigned to farmland for plant photosynthesis, while the photovoltaic active light is absorbed by solar cell for electricity generation, and the rest to thermal receiver for high temperature production. To maximize the power output of proposed system, redundant waste heat is recovered through ejector and converted into electricity in organic Rankine cycle subsequently. By such incorporation, the proposed system can not only increase the overall utilization efficiency of solar energy, but also achieve the cogeneration of crops and electricity on the same land. Energy, exergy, and economic analyses are performed to evaluate the performance of proposed system. Results show that the overall utilization efficiency of solar energy reaches 39.67 % with the highest losses of 79.65 MW in organic Rankine cycle. From the point view of exergy, photoelectric conversion in solar cell is responsible for the largest exergy destruction and finally the overall exergy efficiency of proposed system reaches 40.65 %, which is 16.13 % higher than that of equivalent agricultural and photovoltaic system with separate land use. [ABSTRACT FROM AUTHOR]

Lactiplantibacillus plantarum is a species of lactic acid bacteria (LAB) commonly used in food. However, before it is used in food, the safety evaluation of antibiotic resistance must be carried out. Our study found that L. plantarum FZJTZ19M1 and FZJTZ29M8 had a high tetracycline resistance phenotype, but they did not contain any known tetracycline resistance genes. To investigate the tetracycline resistance mechanism of these two strains, we used transcriptome technology to explore the differentially expressed genes (DEG) produced by these two strains after tetracycline induction. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, and protein-protein interaction (PPI) network analysis were used to reveal the important functional genes. Transcriptome results showed that 234 and 176 DEG were identified in L. plantarum FZJTZ19M1 and FZJTZ29M8, respectively. The results of GO, KEGG enrichment analysis, and PPI network analysis suggested that the resistance of L. plantarum FZJTZ19M1 to tetracycline might be caused by regulating amino acid metabolism and reducing the metabolism of fatty acids, biotin, and other substances. L. plantarum FZJTZ29M8 may increase resistance to tetracycline mainly by using (ATP-binding cassette) ABC transporters to excrete tetracycline from the body and reducing its cellular metabolism. This study revealed the tetracycline resistance mechanism of two L. plantarum strains at the transcriptional level and provided the theoretical reference for the safe application of this kind of LAB in food. [ABSTRACT FROM AUTHOR]

High thermoelectric figure of merits have been achieved in lead telluride (PbTe) alloys recently, which are beneficial for future thermoelectric applications. In this study, a PbTe-based thermoelectric module is constructed by eight pairs of p-type PbTe–8%SrTe and n-type PbTe 0.998 I 0.002 –3%Sb legs with initial sizes of 3 × 3 × 3 mm3. The relationship between multiple geometric parameters and performance of module has been studied by finite-element simulation. The maximum output power (P max) of 7.6 W and efficiency (η max) of 15.3% have been achieved at ΔT = 500 K for ideal contacted PbTe-based thermoelectric module. Contact resistance must exist in experimental thermoelectric module, so it has been considered in simulation about geometry optimization. The cross-sectional area ratio (A p /A n) and height (H) show strong dependent relationship to optimize module performance. The larger A p /A n and relatively lower H are propitious to enhance the output power. Moreover, the efficiency is improved at an optimum A p /A n and relatively higher H. In this PbTe-based module, the P max = 4 W is achieved at A p /A n = 1.78 and H = 0.65 mm, while η max = 14% is achieved at A p /A n = 1.64 and H = 13 mm under ΔT = 500 K. The P max and η max are 20% and 65% larger than those of initial design sizes. Thus, geometric structure modification is a good way to improve the performance of thermoelectric applications. • Cross-sectional ratio (A p / A n) and height (H) have strongly depended relationship. • Larger ratio of A p /A n and relatively lower H easily lead to higher output power. • Suitable ratio of A p /A n and relatively higher H can result to higher efficiency. • P and η of PbTe-based module are enhanced by 20% and 65% via geometry design. [ABSTRACT FROM AUTHOR]

Abstract We attempt to develop an optimized metallized layer and evaluate the performance for a SnTe uni-leg thermoelectric module by finite-element simulation. The maximum conversion efficiencies of 3.0% and 0.7% have been achieved under ideal and rough contacted thermoelectric modules at ΔT = 600 K. The Ag metal is found to be the optimized metallized layer. The module with metallized Ag layer shows the lowest contact resistance and the best performance. The efficiency reaches about 60% of ideal contacted module. Following that, the pressure forced on module and the surface roughness between the electrode, metallized layer and thermoelectric material have been simulated. With the increase of surface roughness slope, the contact and inner resistances of the thermoelectric module are decreased, and the voltage, maximum output power and efficiency are increased. When the average surface roughness slope is over 0.8, the efficiency reaches 90% of the ideal contacted module. The contact and inner resistances obviously decrease with increasing pressure, while the voltage, maximum output power and efficiency are enhanced. The greater than 90% efficiency of an ideal contacted module is achieved when the pressure is beyond 100 kPa. These simulated results will be beneficial for the fabrication of SnTe-based thermoelectric modules. Highlights • The SnTe uni-leg thermoelectric module are designed and studied. • Highest efficiencies of 3%, 0.7% are found for ideal and rough contacted modules. • Ag metal is the optimized metallized layer for SnTe uni-leg thermoelectric module. • Optimized roughness slope and pressure lead to 90% of maximum of ideal efficiency. [ABSTRACT FROM AUTHOR]

The near-stoichiometric LiNbO 3 crystal (SLN) with dimension of Φ25 × 45 mm 3 has been successfully grown from Li-rich solutions by the Czochralski method. The results of X-ray rocking curve measurement indicate that the as-grown SLN crystal has a relatively high crystallinity. The mechanical properties of SLN crystal were determined by nanoindentation method. The hardness and elastic modulus values obtained revealed higher values for (300) plane of SLN crystal (10.02 and 225.6 GPa) compared to the (600) plane of SLN crystal (7.09 and 202.8 GPa). Different hardness and elastic modulus values for different planes suggest anisotropic character of mechanical properties in SLN crystals. The distribution characteristic of residual stress in SLN crystal along the optical axis is analyzed by means of photoelasticity effect. [ABSTRACT FROM AUTHOR]

Constructing membrane with good chlorine resistance and antifouling properties is considered to be important challenges confronting membrane applications. In this study, a composite nanofiltration (NF) membrane (β-CD x/y /PES) was prepared by interfacial polymerization using beta cyclodextrin (β-CD) monomers. Subsequently, the β-CD-based (AZ-β-CD x/y /PES) membrane was prepared by assembling azobenzene labeled zwitterions into the hydrophobic internal cavity of β-CD via host-guest interaction. The optimized membrane exhibited slight change in water flux and rejection under chlorine environment. The AZ-β-CD x/y /PES membrane also displayed an evidently lower loss in water flux in the antifouling test in comparison with the β-CD x/y /PES membrane. More interestingly, the trans azo groups in azobenzene labeled zwitterions can turn into the cis isomers as the visible light irradiation converted to the UV light irradiation, breaking the interaction between azobenzene labeled zwitterions and β-CD. Hence, the contaminants upon the membrane surface can be simply eliminated by water washing under UV light irradiation. The antifouling membrane can be regenerated via immersing the reacquired β-CD 2/10 /PES membrane into fresh azobenzene labeled zwitterions solution again. [Display omitted] • Chlorine-resistant membrane was prepared by using β-CD monomers. • The composite nanofiltration membrane shows good antifouling properties. • The fouled membrane can be regenerated via regulating the light irradiation. [ABSTRACT FROM AUTHOR]

When a gear fault is presented, the ensemble empirical decomposition (EEMD) method has been widely used in the detection of gear fault and has given good results. However, under signals from two vibration transducers which are installed in different directions, the vibration data from every sensor becomes necessary to obtain much more precise results. This paper suggests a new feature frequency extraction approach for gear malfunctions diagnosis using the full vector spectrum (FCS) and EEMD method. The approach embodies model building of multi-sensor data fusion and main intrinsic mode functions(IMFs) analysing of merged data from two vibration sensors. By using EEMD the data from single channel can be decomposed into a number of IMFs. To alleviate the diversity problem of EEMD decomposition results occurring in two channels, full vector spectrum (FVS) is introduced. With full vector spectrum, information obtained from each sensor can be merged a piece of vibration evidence in frequency domain, and then we use Hilbert transform to calculate the envelope spectrum of each IMF to evaluate the fault feature frequency. In this work, simulated signal and gear experiment were conducted to validate this strategy. The results have proven that the proposed method can enhance the effectiveness of feature frequency extraction in diagnosing gear faults. [ABSTRACT FROM AUTHOR]

Antifouling properties are considered to be crucial parameter to polyamide (PA) composite nanofiltration (NF) membranes for practical applications. In this study, an antifouling material, surface zwitterionization of Metal-organic frameworks (Z-MIL-101 (Cr)) was firstly prepared by decorating zwitterionic polymer onto the MOFs surface. Subsequently, a novel type of MOFs-based hybrid membranes were fabricated via mixing the Z-MIL-101 (Cr) nanoparticle with the organic matrix by interfacial polymerization technique. The most optimal hybrid membrane had a high water permeation of 26 L m−2 h−1 bar−1, which was 2.1 times higher than that pristine PA membrane, while the retention for Na 2 SO 4 was still kept at a considerably high value of 93%. The significant increased water flue can attribute to the existence of water channels generated by the Z-MIL-101 (Cr). More important, the antifouling property of the hybrid membrane was much better than that pristine PA, which was due to the formation of superhydrophilic liquid layer surrounding the zwitterionic groups. The combination of the micropore structure of the MOFs and the excellent antifouling properties of the decorated zwitterionic polymer effectively improved separation performances and antifouling ability, which makes these hybrid membranes promising for water purification. [Display omitted] • Zwitterionic metal-organic frameworks (Z-MIL-101 (Cr)) were prepared. • Z-MIL-101 (Cr)-based hybrid membranes were fabricated via interfacial synthesis. • The hybrid membranes show high water permeation of 26 L m−2 h−1 bar−1. • The antifouling ability of the hybrid membranes was significantly enhanced. [ABSTRACT FROM AUTHOR]