Development Of High Efficiency Research Articles

High-efficiency nonlinear frequency conversion enabled by optimizing the ferroelectric domain structure in x-cut LNOI ridge waveguide

Abstract Photonic devices based on ferroelectric domain engineering in thin film lithium niobate are key components for both classical and quantum information processing. Periodic poling of ridge waveguide can avoid the selective etching effect of lithium niobate, however, the fabrication of high-quality ferroelectric domain is still a challenge. In this work, we optimized the applied electric field distribution, and rectangular inverted domain structure was obtained in the ridge waveguide which is beneficial for efficient nonlinear frequency conversions. Second harmonic confocal microscope, piezoresponse force microscopy, and chemical selective etching were used to characterize the inverted domain in the ridge waveguide. In addition, the performance of nonlinear frequency conversion of the periodically poled nano-waveguide was investigated through second harmonic generation, and the normalized conversion efficiency was measured to be 1,720 % W−1 cm−2, which is close to 60 % that of the theoretical value. The fabrication technique described in this work will pave the way for the development of high-efficiency, low-loss lithium niobate nonlinear photonic devices.

Acceleration of radiative recombination for efficient perovskite LEDs

The increasing demands for more efficient and brighter thin-film light-emitting diodes (LEDs) in flat-panel display and solid-state lighting applications have promoted research into three-dimensional (3D) perovskites. These materials exhibit high charge mobilities and low quantum efficiency droop1–6, making them promising candidates for achieving efficient LEDs with enhanced brightness. To improve the efficiency of LEDs, it is crucial to minimize nonradiative recombination while promoting radiative recombination. Various passivation strategies have been used to reduce defect densities in 3D perovskite films, approaching levels close to those of single crystals3. However, the slow radiative (bimolecular) recombination has limited the photoluminescence quantum efficiencies (PLQEs) of 3D perovskites to less than 80% (refs. 1,3), resulting in external quantum efficiencies (EQEs) of LED devices of less than 25%. Here we present a dual-additive crystallization method that enables the formation of highly efficient 3D perovskites, achieving an exceptional PLQE of 96%. This approach promotes the formation of tetragonal FAPbI3 perovskite, known for its high exciton binding energy, which effectively accelerates the radiative recombination. As a result, we achieve perovskite LEDs with a record peak EQE of 32.0%, with the efficiency remaining greater than 30.0% even at a high current density of 100 mA cm−2. These findings provide valuable insights for advancing the development of high-efficiency and high-brightness perovskite LEDs.

In-situ constructed interface buffer layer enabled highly reversible Zn Deposition/Stripping for long-lifespan aqueous zinc metal anodes

Despite the advantages of high capacity, high safety and low cost, zinc anodes also face the inherent problems of dendritic growth, corrosion and passivation, vastly limiting the development and application of aqueous zinc ion batteries (AZIBs). Here, the epigallocatechin gallate (EGCG) was used as a hydroxyl-rich natural electrolyte additive for AZIBs. During charge–discharge process, the EGCG can be preferentially adsorbed on the zinc anode, and act as an interface buffer layer to weaken the direct contact between active water molecule and zinc anode. Based on this effect, the interface buffer layer is helped to inhibit the water-induced side reactions of hydrogen evolution, zinc corrosion and passivation, and lower the polarization overpotential, contributing to highly reversible Zn deposition/stripping behavior. As a result, the Zn||Zn symmetric batteries can maintain a stable cycling for more than 1500 h at 1.0 mA cm−2 and 1.0 mAh cm−2. Furthermore, the assembled Zn||MnO2 full batteries still delivered high capacity retention of 98.02 % after 400 cycles at 1.0 A/g. This finding enriches the design thoughts for the development of high-efficiency and practical AZIBs.

Fungi play a crucial role in sustaining microbial networks and accelerating organic matter mineralization and humification during thermophilic phase of composting

Fungi play an important role in the mineralization and humification of refractory organic matter such as lignocellulose during composting. However, limited research on the ecological role of fungi in composting system hindered the development of efficient microbial agents. In this study, six groups of lab-scale composting experiments were conducted to reveal the role of fungal community in composting ecosystems by comparing them with bacterial community. The findings showed that the thermophilic phase was crucial for organic matter degradation and humic acid formation. The Richness index of the fungal community peaked at 1165 during this phase. PCoA analysis revealed a robust thermal stability in the fungal community. Despite temperature fluctuations, the community structure, predominantly governed by Pichia and Candida, remained largely unaltered. The stability of fungal community and the complexity of ecological networks were 1.26 times and 5.15 times higher than those observed in bacterial community, respectively. Fungi-bacteria interdomain interaction markedly enhanced network complexity, contributing to maintain microbial ecological functions. The core fungal species belonging to the family Saccharomycetaceae drove interdomain interaction during thermophilic phase. This study demonstrated the key role of fungi in the composting system, which would provide theoretical guidance for the development of high efficiency composting agents to strengthen the mineralization and humification of organic matter.

Analysis of parameters for spray-local exhaust ventilation (SLEV) to minimize high-temperature smoke pollutants and reduce energy consumption

Industrial buildings often face limitations in placing local exhaust ventilation (LEV) near pollution sources, which can lead to ineffective control of high-temperature smoke. This study explores the integration of spray with local exhaust ventilation (SLEV) as a solution for smoke control and energy savings. The research identified a design law for spray parameters and developed a formula to calculate SLEV ventilation flow rate that considers the impact of spray. Results indicate that the spray field overlapping coefficient plays a key role in characterizing the position and spacing of multi-nozzles. As the spray field overlapping coefficient increases, the spray dust reduction performance indicator linearly increases, while the capture efficiency follows a pattern that aligns with the Boltzmann curve model. The optimal range for the spray field overlapping coefficient to achieve high efficiency in SLEV is between 0.45 and 0.55. The formula for ventilation flow rate calculation is applicable to common conditions with smoke velocities ranging from 4 to 12 m/s (Ar: 0.0149–0.1339). SLEVs demonstrate a 35.22 % improvement in dust removal efficiency and over 20 % energy savings compared to LEVs, contributing to the development of high-efficiency, energy-saving systems for sustainable industrial production.

Mechanism Insights into the Enantioselective Bioactivity and Fumonisin Biosynthesis of Mefentrifluconazole to Fusarium verticillioides.

The occurrence of maize ear rot caused by Fusarium verticillioides (F. verticillioides) poses a threat to the yield and quality of maize. Mefentrifluconazole enantiomers appear to have strong stereoselective activity against F. verticillioides and cause differences in fumonisin production. We evaluated the stereoselective activity of mefentrifluconazole enantiomers by determining inhibition of the strain, hyphae, and conidia. Strain inhibition by R-(-)-mefentrifluconazole was 241 times higher than S-(+)-mefentrifluconazole and 376 times higher in conidia inhibition. For the mechanism of the enantioselective bioactivity, R-mefentrifluconazole had stronger binding to proteins than S-(+)-mefentrifluconazole. Under several concentration conditions, the fumonisin concentration was 1.3-24.9-fold higher in the R-(-)-mefentrifluconazole treatment than in the S-(+)-mefentrifluconazole treatment. The R-enantiomer stimulated fumonisin despite a higher bioactivity. As the incubation time increased, the stimulation of the enantiomers on fumonisin production decreased. R-(-)-Mefentrifluconazole stimulated higher fumonisin production in F. verticillioides at 25 °C compared to 30 °C. This study established a foundation for the development of high-efficiency and low-risk pesticides.

The key factors of solid nanodispersion for promoting the bioactivity of abamectin

Solid nanodispersion (SND) is an important variety of nanopesticides which have been extensively studied in recent years. However, the key influencing factors for bioactivity enhancement of nanopesticides remain unclear, which not only limits the exploration of relevant mechanisms, but also hinders the precise design and development of nanopesticides. In this study, we explored the potential of SND in enhancing the bioactivity of nanopesticides, specifically focusing on abamectin SND prepared using a self-emulsifying-carrier solidifying technique combined with parameter optimization. Our formulation, consisting of 8% abamectin, 1% antioxidant BHT (2,6-di-tert-butyl-4-methylphenol), 12% complex surfactants, and 79% sodium benzoate, significantly increased the pseudo-solubility of abamectin by at least 3300 times and reduced its particle size to a mere 15 nm, much smaller than traditional emulsion in water (EW) and water-dispersible granule (WDG) forms. This reduction in particle size and increase in surface activity resulted in improved foliar adhesion and retention, enabling a more efficient application without the need for organic solvents. The inclusion of antioxidants also enhanced photostability compared to EW, and overall stability tests confirmed SND's resilience under various storage conditions. Bioactivity tests demonstrated a marked increase in toxicity against diamondback moths (Plutella xylostella L.) with abamectin SND, which exhibited 3.7 and 7.6 times greater efficacy compared to EW and WDG, respectively. These findings underscore the critical role of small particle size, high surface activity, and strong antioxidant properties in improving the performance and bioactivity of abamectin SND, highlighting its significance in the design and development of high-efficiency, eco-friendly nanopesticides and contributing valuably to sustainable agricultural practices.

The Synergistic Relationship between Low-Carbon Development of Road Freight Transport and Its Economic Efficiency—A Case Study of Wuhan, China

Road freight transport, an essential component of the logistics sector, faces challenges: high cost, low efficiency, and environmental impact. The need has become urgent to achieve a synergistic balance between low-carbon and high-efficiency development. This study used a three-stage DEA–Malmquist index model to analyze the road freight efficiency of Wuhan and 16 other cities in China from 2015 to 2020, and we compared Wuhan’s performance with its peers. In addition, grey correlation analysis was used to evaluate the low-carbon development of urban road freight transport in Wuhan. Through the calculation of the degree of synergy between low-carbon development and freight transport efficiency, this study provides insights into the synergistic development of low-carbon and efficient road freight transport in Wuhan. The key findings show that the total factor productivity of road freight transport in Wuhan was generally on a downward trend from 2015 to 2020, and was lower than that of the average of the 17 selected Chinese cities. The carbon emissions of road freight transport in Wuhan inversely related to its scale efficiency. This study also points out that the synergy between low-carbon development and the economic efficiency of road freight transport in Wuhan is not high and needs to be further integrated and optimized.

Ultrasound-assisted facile and green preparation of Ag nanoparticle conductive ink for printing electronics

The development of low-cost, high-efficiency, and environment-friendly methods for the preparation of Ag nanoparticle (NP) conductive inks is key to promoting the application of such inks for printing flexible electronic components. This article presents an effective method for preparing a AgNP ink by reducing silver compounds in a polyol solution with ultrasonication. When the silver solution was ultrasonicated at 640 W, 21-nm AgNPs were readily produced within 5 min, and the particles grew considerably to 53 nm as the reaction was continued for 15 min. Thereafter, the NP size increased marginally with further increase in reaction time. When the reaction was conducted for a fixed duration of 15 min and the ultrasonic power was increased from 480 to 760 W, the AgNP size decreased from 63 to 48 nm. During ultrasonication, the bubble eruption in the solution generates large temperature and pressure gradients, inducing the rapid reduction of the Ag(I) to Ag(0). Printing experiments revealed that the synthesized AgNP ink has good inkjet printability. During the sintering of the printed film, the bridge connections between large particles increased and the interparticle voids decreased gradually, resulting in a decrease in film resistivity. A relatively low resistivity of 40×10−5 Ωcm was obtained when the flexible AgNP pattern was heated at 250 °C for 80 min. The facile synthesis process and the favorable conductive properties of the obtained ink render this preparation method promising for the low-cost production of flexible electronics.

Ferroelectric 2D SnS2 Analog Synaptic FET.

In this study, the development and characterization of 2D ferroelectric field-effect transistor (2D FeFET) devices are presented, utilizing nanoscale ferroelectric HfZrO2 (HZO) and 2D semiconductors. The fabricated device demonstrated multi-level data storage capabilities. It successfully emulated essential biological characteristics, including excitatory/inhibitory postsynaptic currents (EPSC/IPSC), Pair-Pulse Facilitation (PPF), and Spike-Timing Dependent Plasticity (STDP). Extensive endurance tests ensured robust stability (107 switching cycles, 105 s (extrapolated to 10 years)), excellent linearity, and high Gmax /Gmin ratio (>105 ), all of which are essential for realizing multi-level data states (>7-bit operation). Beyond mimicking synaptic functionalities, the device achieved a pattern recognition accuracy of ≈94% on the Modified National Institute of Standards and Technology (MNIST) handwritten dataset when incorporated into a neural network, demonstrating its potential as an effective component in neuromorphic systems. The successful implementation of the 2D FeFET device paves the way for the development of high-efficiency, ultralow-power neuromorphic hardware which is in sub-femtojoule (48 aJ/spike) and fast response (1 µs), which is 104 folds faster than human synapse (≈10ms). The results of the research underline the potential of nanoscale ferroelectric and 2D materials in building the next generation of artificial intelligence technologies.

Efficient Discrimination of Hazardous Organophosphate Flame Retardants via Cataluminescence-Based Multidimensional Ratiometric Sensing.

Emerging contaminants have recently evolved into a severe worldwide environmental issue. Organophosphate flame retardants (OPFRs) with neurotoxicity, genotoxicity, and reproductive and developmental toxicity are a class of notorious emerging contaminants that cause great concern. The development of high-efficiency and portable sensors for rapid online monitoring of OPFRs has become the primary demand for the exploration of the environmental migration and transformation of OPFRs. In this work, interestingly, the cataluminescence (CTL) phenomenon of OPFRs is first observed, and an ingenious multidimensional ratiometric CTL sensing strategy is developed for the recognition of multiple OPFRs. Three characteristic ratios are extracted from the multipeak CTL spectral curves based on energy transfer of single Tb/Eu-modified MgO sensing material, and thus a novel three-dimensional (3D) code recognition could be mapped out. This obtained 3D coordinate is found to be a unique characteristic for a given OPFR, just like an exclusive person's ID number, which can successfully discriminate and detect 10 kinds of OPFR vapors, including homologous series and isomers. More importantly, CTL mechanism investigations for OPFRs demonstrate that OPFRs undergo a series of chemical reaction processes, e.g., oxidative pyrolysis and hydroxylation, and different high-energy excited intermediates are generated, which trigger discrepant energy-transfer efficiency toward rare earth ions, leading to multipeak spectral profiles. Briefly, this proposed CTL analytical platform for OPFRs recognition initiates a new sensing principle for the efficient identification of emerging contaminants and shows significant prospects on rapid on-site detection.

Integrated Catalyst-Substrate Electrodes for Electrochemical Water Splitting: A Review on Dimensional Engineering Strategy.

Water splitting (or, water electrolysis) is considered as a promising approach to produce green hydrogen and relieve the ever-increasing energy consumption as well as the accompanied environmental impact. Development of high-efficiency, low-cost practical water-splitting systems demands elegant design and fabrication of catalyst-loaded electrodes with both high activity and long-life time. To this end, dimensional engineering strategies, which effectively tune the microstructure and activity of electrodes as well as the electrochemical kinetics, play an important role and have been extensively reported over the past years. Here, a type of most investigated electrode configurations is reviewed, combining particulate catalysts with 3Dporous substrates (aerogels, metal foams, hydrogels, etc.), which offer special advantages in the field of water splitting. It is analyzed the design principles, structural and interfacial characteristics, and performance of particle-3D substrate electrode systems including overpotential, cycle life, and the underlying mechanism toward improved catalytic properties. In particular, it is also categorized the catalysts as different dimensional particles, and show the importance of building hybrid composite electrodes by dimensional control and engineering. Finally, present challenges and possible research directions toward low-cost high-efficiency water splitting and hydrogen production is discussed.

A Multilayer Nested Space Ray Telescope Assembly and Adjustment System Based on Online Monitoring Feedback

In order to adapt to the rapid development of deep space exploration, pulsar navigation and space astronomical observation technology, the development of high-efficiency and high-performance X-ray space telescopes has become one of the hotspots for research in the fields of autonomous spacecraft navigation and astronomical observation. Since the X-ray multilayer nested mirror shells are thin-walled and deformable cylindrical structures with high requirements for surface shape accuracy, a slight change in the position or surface shape will lead to a reduction in the focusing imaging quality, so it is necessary to develop a high-precision assembly and adjustment system based on closed-loop real-time monitoring. In this paper, a multi-layer nested space ray telescope assembly and adjustment system with online monitoring feedback is developed, and a method for precision assembly and adjustment of multi-layer nested mirror shells based on online real-time detection and feedback is proposed, which specifically includes key innovative assembly technologies such as three-dimensional face shape measurement, flexible vacuum adsorption, precision adjustment that have been broken through in the process, and the imaging quality of the focused spot of the mirror shells is evaluated and analyzed in the end. The results of the experiment indicate that the assembly and adjustment of the multilayer nested mirror shells can effectively complete the high-precision assembly, and the relevant results can provide a certain reference significance for the further enhancement of the assembly and adjustment performance of the multilayer nested mirror shells.

Research on the Development Change Law of Block A after Fine Potential Excavation

After the comprehensive utilization of well pattern and fine potential tapping based on subdivision water injection in block A, remarkable results have been achieved in water cut control and decline control. With the continuous deepening of development degree, new characteristics have emerged in water drive development, and the change law of indicators has also changed greatly. Therefore, it is necessary for us to find out the change law of fine potential tapping development indicators, so as to provide a theoretical basis for the next sustainable and high-efficiency development. Through theoretical calculation and numerical simulation, this study gives the law of production decline and water cut change in different stages before, during and after fine potential tapping; The laws of water cut and production decline in different stages are evaluated and predicted. It provides a theoretical basis for the fine potential tapping, popularization and application of other blocks.

A giant intrinsic photovoltaic effect in atomically thin ReS2.

The photovoltaic (PV) effect in non-centrosymmetric materials consisting of a single component under homogeneous illumination can exceed the fundamental Shockley-Queisser limit compared to the traditional p-n junctions. Two-dimensional (2D) materials with a reduced dimensionality and smaller bandgap were predicated to be better candidates for the PV effect with high efficiency exceeding that of traditional ferroelectric perovskite oxides. Here, we report the giant intrinsic PV effect in atomically thin rhenium disulfide (ReS2) with centrosymmetry breaking. In graphene/ReS2/graphene sandwich structures, significant short-circuit currents (Isc) were observed with illumination over the visible spectral range, presenting the highest responsivity (110 mA W-1) and external quantum efficiency (25.7%) among those reported PV effects in 2D materials. This giant PV effect could be ascribed to the spontaneous-polarization induced depolarization field in even-number-layered ReS2 flakes benefiting from the distorted 1T lattice structure. Our results provide a new potential candidate material for the development of novel high-efficiency, miniaturized and easily integrated photodetectors and solar cells.

Characteristics, Applications and Prospects of Nanobiomaterials

The research on nanobiomaterials is of great significance for the intersection and development of physics, chemistry and biology, and has wide applications in biology, medicine, environmental science and other fields. This article classifies nanobiomaterials into metal-based, inorganic non-metallic and composite nanobiomaterials according to their composition, summarizes several typical preparation methods for different types of nanobiomaterials, such as ball milling, liquid phase reduction, template method, ultrasonic dispersion, etc., analyzes the characteristics of these preparation methods, summarizes the applications of nanobiomaterials in different fields, and makes prospects for their future development. Nanobiomaterials have diverse types and unique properties. The research on their properties is developing towards informatization and diversification. The preparation methods are numerous and moving towards high efficiency and green development. The breadth and depth of application fields continue to expand. This article makes a systematic summary of nanobiomaterials and prospects their development direction.

Interfacial engineering of POM-stabilized Ni quantum dots on porous titanium mesh for high-rate and stable alkaline hydrogen production.

The development of low-cost, high-efficiency, and stable electrocatalysts for the alkaline hydrogen evolution reaction (HER) is a key challenge because the alkaline HER kinetics is slowed by an additional water dissociation step. Herein, we report an interfacial engineering strategy for polyoxometalate (POM)-stabilized nickel (Ni) quantum dots decorated on the surface of porous titanium mesh (POMs-Ni@PTM) for high-rate and stable alkaline hydrogen production. Benefiting from the strong interfacial interactions among POMs, Ni atoms, and PTM substrates, as well as unique POM-Ni quantum dot structures, the optimized POMs-Ni@PTM electrocatalyst exhibits a remarkable alkaline HER performance with an overpotential (η10) of 30.1 mV to reach a current density of 10 mA cm-2, which is much better than those of bare Ni decorated porous titanium mesh (Ni@PTM) (η10 = 171.1 mV) and POM decorated porous titanium mesh (POMs@PTM) electrocatalysts (η10 = 493.6 mV), comparable to that of the commercial 20 wt% platinum/carbon (20% Pt/C) electrocatalyst (η10 = 20 mV). Moreover, the optimized POMs-Ni@PTM electrocatalyst demonstrates excellent stability under continuous alkaline water-splitting at a current density of ∼100 mA cm-2 for 100 h, demonstrating great potential for its practical application.

Temporal and spatial evolution characteristics and decoupling trend of Chinese agricultural carbon emission efficiency.

This study investigates the spatio-temporal evolution of agricultural carbon emission efficiency (ACEE) in China and its relationship with agricultural economic growth (AEG). The results indicate several findings: Firstly, between 2012 and 2021, China's agricultural carbon emission efficiency exhibited an upward trend, with the mean value increased from 0.349 to 0.807. Furthermore, the distribution pattern shifted from a dispersed, point-like distribution to an aggregated and continuous distribution. Secondly, the average agricultural carbon emission efficiency in China following a decreasing order: South China, Northwest China, Southwest China, East China, North China, Central China and Northeast China. Thirdly, the relationship between agricultural carbon emission efficiency and the agricultural economy in China has transitioned from weak decoupling to negative decoupling. Based on these findings, this study proposes some recommendations to enhance agricultural carbon emission efficiency and promote its decoupling from agricultural economic growth. These recommendations aim to achieve low-carbon and high-efficiency development of agriculture.

Sulfion oxidation assisting self-powered hydrogen production system based on efficient catalysts from spent lithium-ion batteries.

Converting spent lithium-ion batteries (LIBs) and industrial wastewater into high-value-added substances by advanced electrocatalytic technology is important for sustainable energy development and environmental protection. Here, we propose a self-powered system using a home-made sulfide fuel cell (SFC) to power a two-electrode electrocatalytic sulfion oxidation reaction (SOR)-assisted hydrogen (H2) production electrolyzer (ESHPE), in which the sulfion-containing wastewater is used as the liquid fuel to produce clean water, sulfur, and hydrogen. The catalysts for the self-powered system are mainly prepared from spent LIBs to reduce the cost, such as the bifunctional Co9S8 catalyst was prepared from spent LiCoO2 for SOR and hydrogen evolution reaction (HER). The Fe-N-P codoped coral-like carbon nanotube arrays encapsulated Fe2P (C-ZIF/sLFP) catalyst was prepared from spent LiFePO4 for oxygen reduction reaction. The Co9S8 catalyst shows excellent catalytic activities in both SOR and HER, evidenced by the low cell voltage of 0.426 V at 20 mA cm-2 in ESHPE. The SFC with Co9S8 as anode and C-ZIF/sLFP as cathode exhibits an open-circuit voltage of 0.69 V and long discharge stability for 300 h at 20 mA cm-2. By integrating the SFC and ESHPE, the self-powered system delivers an impressive hydrogen production rate of 0.44 mL cm-2 min-1. This work constructs a self-powered system with high-performance catalysts prepared from spent LIBs to transform sulfion-containing wastewater into purified water and prepare hydrogen, which is promising to achieve high economic efficiency, environmental remediation, and sustainable development.

Separation performance of graphene oxide nanofiltration membrane intercalated by MWCNTs and α -Fe2O3 nanoparticles

Nanofiltration (NF) technology is used in the field of water treatment due to its advantages of low energy consumption, high efficiency, and simple process flow. However, the problems of membrane fouling and trade-off (i.e., high flux with low rejection or high rejection with low flux) exist in NF technology, which limit its wide-scale popularization and application. The emphasis of this work is to improve the performance of graphene oxide (GO)-based NF membranes. Multi-walled carbon nanotubes (MWCNTs) and α-Fe2O3 were selected to modify the GO-based membrane by expanding the interlayer spacing and enhancing its antifouling and rejection abilities. Our composite membranes exhibit an increased interlayer spacing of 0.787 nm to 1.1 nm, achieving a high pure water permeation flux of 138.96 Lm−2 h−1, as well as satisfactory rejection rates for salts and dyes (Na2SO4, NaCl, MgCl2, Congo red, and methylene blue). Additionally, the membranes exhibit a relatively good antifouling property. After five cycles of rejection tests, the flux and rejection rate could be recovered to 90 % from 80 % with a 4-h irradiation under visible light. This study provides valuable insights into the development of high-efficiency and advanced NF membranes.