Low Efficiency Research Articles

Ultrafast Conversion of Water and Oxygen Molecules With Dissociation of Hydrogen Bonding Effect to Achieve Extra-High Energy Efficiency of Secondary Metal-Air Batteries.

Metal-air secondary batteries with ultrahigh specific energies have received vast attention and are considered new promising energy storage. The slow redox reactions between oxygen-water molecules lead to low energy efficiency (55-71%) and limited applications. Herein, it is proposed that the MIL-68(In)-derived porous carbon nanotube supports the CoNiFeP heteroconjugated alloy catalyst with an overboiling point electrolyte to achieve the ultrahigh oxidation rate of water molecules. Structural characterization and density functional theorycalculations reveal that the new catalyst greatly reduces the free energy of the process, and the overboiling point further accelerates the dissociation of O─H and hydrogen bonds, and the release of O2 molecules, achieving an extra-low overpotential of 110mV@10mAcm-2 far lower than commercial Ir/C catalysts of 192mV at 125°C and state-of-the-art. Furthermore, the energy efficiency of assembled rechargeable zinc-air batteries begins to break through at 85°C, jumps at 100°C, and reaches ultrahigh energy efficiency of 88.1% at 125°C with an ultralow decay rate of 0.0068% after 150 cycles far superior to those of reported metal-air batteries. This work provides a new catalyst and electrolyte joint-design strategy and reexamines the battery operating temperature to construct higher energy efficiency for secondary fuel cells.

Unlocking the mystery of heterosis opens the era of intelligent rice breeding.

Heterosis refers to the phenomenon where the first filial offspring (F1) from genetically diverse parents displays advantages in growth rate, yield and adaptability compared to its parents. The exploitation of heterosis in rice breeding has greatly increased the productivity, making a significant contribution to food security in the last half of century. Conventional hybrid rice breeding highly relies on the breeder's experience on random crossing and comprehensive field selection. This process is time-consuming and labor-intensive. In recent years, rice hybrid breeding has encountered challenges stemming from limited germplasm resource, low breeding efficiency and high uncertainty, which constrain the progress in yield increase, coupled with difficulties in balancing grain yield, quality and resistance. Understanding the genetic basis of rice heterosis could lead to significant advances in breeding concepts and methods. This will fully unleash the advantages of heterosis. In this review, we focus on the research progress of the genetic dissection of crop heterosis, and introduce briefly on some key advancements in modern intelligence breeding of rice hybrid.

Z-scheme FeOOH/g-C3N4 nanosheets promoted PDS activation for efficient tetracycline degradation under visible light

Recently, photocatalysis combined peroxydisulfate (PDS) activation as a novel advanced oxidation processes (AOPs) was applied to remove pharmaceuticals and personal care products (PPCPs) in waterbody. Under visible light irradiation, photocatalysts, such as graphitic carbon nitride (g-C3N4, CN), could generated holes and electrons for both organic oxidation and PDS activation. However, it exhibits the drawbacks of low organics removal rate, high electron-hole recombination rate and low activation efficiency of PDS. In this study, amorphous iron oxyhydroxide (FeOOH) was intercalated into the surface of the g-C3N4 nanosheets (CNNS) to form a Z-scheme heterojunction to solve these problems. Electrochemical impedance spectroscopy (EIS) and photoluminescence spectrum (PL) tests proved the enhancement of the charge separation and migration capability of FeOOH/CNNS. The density functional theory (DFT) supported the constructive role of the Z-type heterojunction between FeOOH and CNNS in promoting photocarrier transfer and facilitating more effective PDS activation reactions. The removal rate of tetracycline (TC) achieved 98.8 % within 80 min by FeOOH/CNNS coupled PDS under visible light (FeOOH/CNNS-PDS/Vis) system. Finally, electron spin resonance (ESR) approved the pivotal role of •OH, SO4•-, and •O2- during the process.

Cryopreservation of Immune Cells: Recent Progress and Challenges Ahead.

Cryopreservation of immune cells is considered as a key enabling technology for adoptive cellular immunotherapy. However, current immune cell cryopreservation technologies face the challenges with poor biocompatibility of cryoprotection materials, low efficiency, and impaired post-thaw function, limiting their clinical translation. This review briefly introduces the adoptive cellular immunotherapy and the approved immune cell-based products, which involve T cells, natural killer cells and etc. The cryodamage mechanisms to these immune cells during cryopreservation process are described, including ice formation related mechanical and osmotic injuries, cryoprotectant induced toxic injuries, and other biochemical injuries. Meanwhile, the recent advances in the cryopreservation medium and freeze-thaw protocol for several representative immune cell type are summarized. Furthermore, the remaining challenges regarding on the cryoprotection materials, freeze-thaw protocol, and post-thaw functionality evaluation of current cryopreservation technologies are discussed. Finally, the future perspectives are proposed toward advancing highly efficient cryopreservation of immune cells.

A Facile One-Step Conversion of Biobased Magnolol (Honokiol) toward High Refractive Materials.

A series of polymers with both high refractive index and high Abbe number have been successfully synthesized through the photoclick thiol-ene reaction between the monomers derived from biobased magnolol (or honokiol) and commercial mercaptans and thiophenols. The polymer films not only exhibit a high refractive index and a high Abbe number but also display a transmittance of up to 90% in a range of wavelengths from 550 to 2000 nm and nearly 0% in the UV region. Moreover, these polymers also display low haze values in the visible-light region as well as exhibit good thermostability. These data indicate that they have potential applications for the fabrication of optical lenses and anti-UV coatings. In particular, this series of polymers are readily used for industrialization due to its excellent optical properties but low expense, simplicity, and efficiency of synthesis.

Role of ROS and autophagy in the pathological process of atherosclerosis.

Activation of autophagy and production of reactive oxygen species occur at various stages of atherosclerosis.To clarify the role and mechanism of autophagy and reactive oxygen species in atherosclerosis is of great significance to the prevention and treatment of atherosclerosis.Recent studies have shown that basal autophagy plays an important role in protecting cells from oxidative stress, reducing apoptosis and enhancing atherosclerotic plaque stability.Autophagy deficiency and excessive accumulation of reactive oxygen species can impair the function of endothelial cells, macrophages and smooth muscle cells, trigger autophagic cell death, and lead to instability and even rupture of plaques. However, the main signaling pathways regulating autophagy, the molecular mechanisms of autophagy and reactive oxygen species interaction, how they are initiated and distributed in plaques, and how they affect atherosclerosis progression, remain to be clarified.At present, there is no autophagy inducer used to treat atherosclerosis clinically.Therefore, it is urgent to clarify the mechanism of autophagy and find new targets for autophagy. Antioxidant agents generally have defects such as low reactive oxygen species scavenging efficiency and high cytotoxicity. Highly potent autophagy inducers and reactive oxygen species scavengers still need to be further developed and validated to provide more possibilities for innovative treatments for atherosclerosis.

A universal strategy towards high-rate and ultralong-life of Li‐rich Mn‐based cathode materials

Lithium-rich manganese-based cathode materials (LRMs) have shown promise for the next-generation lithium battery cathodes due to their high discharge specific capacity (∼250 mAh g−1) and wide operating voltage range (2.0–4.8 V). However, these materials face limitations such as low initial Coulombic efficiency (ICE), poor cycle stability, and inadequate rate capability. To address these challenges, we employed a simple citric acid treatment (CA-treatment) method to fabricate the Li-rich spinel coating layer on LRMs. This in situ formed spinel Li4Mn5O12 layer successfully suppresses the oxygen release, provides three-dimensional (3D) lithium-ion diffusion channels and enriches Li embedding sites, resulting in a substantial improvement in the rate capability and high-rate cycling performance. The modified LRM delivers a high specific capacity of 193.7 mAh g−1 at 2.0 C and 154.8 mAh g−1 at 5.0 C, after 1000 cycles at 10.0 C, 77.4 % capacity retention with 102.5 mAh g−1 is realized. This facile CA-treatment benefits the electrochemical properties of LRMs comparable to those of altering the microscopic morphology. This work offers a new avenue for exploring outstanding LRMs with high-rate and ultralong cycling life.

A metabolic perspective on polyploid invasion and the emergence of life histories: Insights from a mechanistic model.

Whole-genome duplication (WGD, polyploidization) has been identified as a driver of genetic and phenotypic novelty, having pervasive consequences for the evolution of lineages. While polyploids are widespread, especially among plants, the long-term establishment of polyploids is exceedingly rare. Genome doubling commonly results in increased cell sizes and metabolic expenses, which may be sufficient to modulate polyploid establishment in environments where their diploid ancestors thrive. We developed a mechanistic simulation model of photosynthetic individuals to test whether changes in size and metabolic efficiency allow autopolyploids to coexist with, or even invade, ancestral diploid populations. Central to the model is metabolic efficiency, which determines how energy obtained from size-dependent photosynthetic production is allocated to basal metabolism as opposed to somatic and reproductive growth. We expected neopolyploids to establish successfully if they have equal or higher metabolic efficiency as diploids or to adapt their life history to offset metabolic inefficiency. Polyploid invasion was observed across a wide range of metabolic efficiency differences between polyploids and diploids. Polyploids became established in diploid populations even when they had a lower metabolic efficiency, which was facilitated by recurrent formation. Competition for nutrients is a major driver of population dynamics in this model. Perenniality did not qualitatively affect the relative metabolic efficiency from which tetraploids tended to establish. Feedback between size-dependent metabolism and energy allocation generated size and age differences between plants with different ploidies. We demonstrated that even small changes in metabolic efficiency are sufficient for the establishment of polyploids.

Synergy Between Dynamic Behavior of Hydrogen Defects and Non-Radiative Recombination in Metal-Halide Perovskites.

In organic-inorganic hybrid perovskite solar cells (PSCs), hydrogen defects introduce deep-level trap states, significantly influencing non-radiative recombination processes. Those defects are primarily observed in MA-PSCs rather than FA-PSCs. As a result, MA-PSCs demonstrated a lower efficiency of 23.6% compared to 26.1% of FA-PSCs. In this work, both hydrogen vacancy (VH -) and hydrogen interstitial (Hi -) defects in MAPbI3 bulk and on surfaces, respectively are investigated. i) Bulk VH - defects have dramatic impact on non-radiative recombination, with lifetime varying from 67 to 8ns, depending on whether deprotonated MA0 are ion-bonded or not. ii) Surface H-defects exhibited an inherent self-healing mechanism through a chemical bond between MA0 and Pb2+, indicating a self-passivation effect. iii) Both VH - and Hi - defects can be mitigated by alkali cation passivation; while large cations are preferable for VH - passivation, given strong binding energy of cation/perovskite, as well as, weak band edge non-adiabatic couplings; and small cations are suited for Hi - passivation, considering the steric hindrance effect. The dual passivation strategy addressed diverse experimental outcomes, particularly in enhancing performance associated with cation selections. The dynamic connection between hydrogen defects and non-radiative recombination is elucidated, providing insights into hydrogen defect passivation essential for high-performance PSCs fabrication.

Marker points 3D matching based on Delaunay triangfulation structure and error dispersion

Abstract Point cloud registration techniques based on marker points are widely used in optical 3D industrial measurements. However, in this process, marker points 3D matching methods are often haunted by low efficiency and accuracy. To improve the performance of marker points 3D matching, we propose a two-step method of ‘matching-verification’. In the matching process, Delaunay triangulation is introduced to extract the 3D structure of the marker points set, and then the 3D structure is deconstructed into 2D units for matching, which simplifies complexity and improves the efficiency of the algorithm. In the verification process, the mismatched pairs of points are located and removed by the method that is based on the error dispersion of initial matched results, and the initial transformation results are iteratively verified to obtain the optimal transformation matrix. The experimental results show that our method takes an average of 2.2 s for each matching, the average error of coarse registration point cloud is 0.075 mm and the root mean square is 0.219 mm, which effectively solves the problem of the low efficiency and accuracy of marker points 3D matching methods.

The spectral inversion model for electrical conductivity in mural plaster following phosphate erosion based on fractional order differentiation and novel spectral indices

The Dunhuang murals are a precious treasure of China’s cultural heritage, yet they have long been affected by salt damage. Traditional methods for detecting salt content are costly, inefficient, and may cause physical harm to the murals. Among current techniques for measuring salt content in murals, hyperspectral remote sensing technology offers a non-invasive, circumventing issues of high costs, low efficiency. Building on this, the study constructs an inversion model for the Electrical Conductivity (EC) values of mural plaster subjected to phosphate erosion, through the integration of Fractional Order Differentiation (FOD), a novel three-band spectral index, and the Partial Least Squares Regression algorithm. The specific research contents include: (1) Initially, in preparation for the experiments, the materials used to create the samples underwent a rigorous desalting process, and phosphate solutions were prepared using deionized water to ensure uniform experimental conditions and the accuracy of the results. These meticulous preprocessing steps guaranteed that the measured EC values exhibited a clear correlation with the phosphate content. Subsequently, by employing qualitative experimental analysis techniques, this study was able to more accurately simulate the real-world scenarios of mural plaster affected by salt damage, enabling a deeper investigation into the mechanisms by which salts inflict microscopic damage to murals. (2) Explores the absorption mechanisms and characteristic spectral bands of the Electrical Conductivity (EC) values measured after the phosphate erosion of mural plaster. By integrating the optimal spectral indices, a univariate linear regression model is constructed, providing a basis for the rapid quantitative measurement of electrical conductivity in murals. (3) By comparing the accuracy of the Phosphate Simple Ratio (PSR) and Phosphate Normalized Difference Index (PNDI) spectral indices based on the linear regression model, the first six orders of the highest accuracy spectral index were selected as the optimal three-band spectral index combination, used as explanatory variables, with mural plaster electrical conductivity as the response variable, employing the PLSR method to construct the mural phosphate content high-spectral feature inversion model. The study’s findings include: (1) Surfaces of samples deteriorated by phosphate erosion formed numerous irregularly shaped crystal clusters, exhibiting uneven characteristics. (2) By comparing the outcomes of different orders of fractional differentiation, it was found that the model performance reached its optimum at a 0.3 order of differentiation for both PSR and PNDI data, with a determination coefficient (Q2) of 0.728. (3) Utilizing PLSR, this study employed the previously determined optimal six-order three-band spectral index combination as explanatory variables, with salt content as the response variable, successfully constructing the high-spectral feature inversion model for mural electrical conductivity with a determination coefficient (Q2) of 0.815. This provides an effective technical means for monitoring the salt damage conditions of precious cultural heritage such as murals.

The efficiency of clinical laboratories: the case of Kerman province

BackgroundMedical diagnostic laboratories are an essential work environment that plays an important role in diagnosing, treating, and being sensitive to diseases. One way to evaluate laboratories’ performance is to calculate their efficiency. This study investigates the efficiency of laboratories that are related to health centers in the south of Iran.MethodsThis study was conducted in 2021. The input numbers include: the number of technical personnel and the number of cell counters, and the output data includes: the scores obtained from the level 2 health laboratory evaluation list. And efficiency was calculated with DEAP software. The analysis is accomplished by the assumption of input-oriented.FindingsThe efficiency of laboratories of Orzueeyeh and Ravar Cities had the highest efficiency with the assumption of variable returns to scale efficiency 1, and the model of all laboratories is the laboratory of Ravar City. The laboratories of Kuhbanan and Rabor cities had the lowest efficiency with the assumption of variable returns to scale efficiency of 0.859 and 0.899, respectively. The average scale efficiency, Variable returns to scale, and constant returns to scale for laboratories in the cities of Kerman province are 0.842, 0.943, and 0.895, respectively.ConclusionsTo increase the efficiency of laboratories, significant resources and funds should be used, as well as few studies have been done on the efficiency of laboratories, which requires more attention.

Thermodynamic modeling and analysis of a Carnot battery system integrating calcium looping thermochemical energy storage with coal-fired power plant

Long-term energy storage and carbon capture technologies are pivotal in managing renewable energy surpluses and achieving carbon neutrality. This paper proposes a Carnot battery system integrating calcium-looping thermochemical energy storage with a coal-fired power plant. The system utilizes excess electricity from the grid for energy input, facilitating long-term energy storage, achieving carbon capture, and reducing coal consumption in the power plant. An optimization framework is developed, incorporating component thermodynamic models and optimization algorithms, to maximize the coal savings in plants and energy efficiencies of the Carnot battery system. During the energy release process, the carbonator partially replaces the reheat load of the boiler, necessitating retrofitting of the boiler’s heating surface to ensure normal operation. The base system demonstrates a CO2 capture capacity of 3.23 MJ/kg and a reduction in coal consumption by 7.07 %. The round-trip efficiency and comprehensive efficiency of the base system are 36.93 % and 37.91 %, respectively. The relatively low energy efficiency is primarily due to the deactivation of circulating adsorbents and the limited efficiency of the subcritical coal-fired power plant. By incorporating an additional recarbonation step to mitigate adsorbent deactivation, the system’s comprehensive efficiency is improved to 42.20 %. Further improvements in system efficiency can be achieved by using modified adsorbents with high cycling stability instead of natural limestone and by coupling the system with more efficient ultra-supercritical units instead of the investigated subcritical units. This study offers valuable insights into the development of long-term energy storage solutions and multifunctional Carnot battery technology.

Using a metasurface to enhance the radiation efficiency of subterahertz antennas printed on thick substrates

This study investigates the possibility of increasing the radiation efficiency of printed antennas and arrays by suppressing their inherent surface waves using a metasurface made of quad-split rings (QSR). A symmetrical resonant microstrip dipole and a four-element series-fed dipole array printed on an infinite grounded dielectric layer (layer thickness: 0.2 mm; relative permittivity: 9.4; tanδ: 0.0005) were simulated with FEKO 2022 software. Conducted at 100–116 GHz, the numerical results revealed extremely low radiation efficiencies of approximately 31% and 40% for the studied dipole and dipole array, respectively, which resulted from the presence of surface waves in the dielectric. However, placing only one QSR near each dipole arm triggered an increase in radiation efficiency by 2.5 times (up to 75%). The use of a metasurface in the form of two small QSR arrays triggered a pronounced improvement in radiation efficiency, reaching 93.6% and 95.8% for the studied dipole and dipole array, respectively. Analysis of the electric field distribution images showed that this enhancement resulted from surface wave suppression.

Optical inactivation of intracellular molecules by fast-maturating photosensitizing fluorescence protein, HyperNova

Photosensitizing fluorescence protein is a promising tool for chromophore-assisted light inactivation (CALI) that enables specific oxidation and inactivation of intracellular molecules. However, a commonly used monomeric photosensitizing fluorescent protein, SuperNova, shows a low CALI efficiency due to its insufficient maturation at 37 °C, thereby limiting the application of CALI to various molecules, especially in mammalian cells. Here, we present a photosensitizing fluorescence protein, HyperNova, with markedly improved maturation at 37 °C, leading to greatly enhanced CALI efficiency. Exploiting this quality, HyperNova enables the application of CALI to variety of molecules such as a mitotic kinase and transcriptional factors that were highly challenging with conventional SuperNova. To further demonstrate the utility of HyperNova, we have also succeeded in developing novel CALI techniques for MAP kinases by HyperNova. Our findings suggest that HyperNova has the potential to expand the molecular toolbox for manipulating biological events in living cells, providing new avenues for investigating cellular signaling pathways.

SiMPl-GS: Advancing Cell Line Development via Synthetic Selection Marker for Next-Generation Biopharmaceutical Production.

Rapid and efficient cell line development (CLD) process is essential to expedite therapeutic protein development. However, the performance of widely used glutamine-based selection systems is limited by low selection efficiency, stringency, and the inability to select multiple genes. Therefore, an AND-gate synthetic selection system is rationally designed using split intein-mediated protein ligation of glutamine synthetase (GS) (SiMPl-GS). Split sites of the GS are selected using a computational approach and validated with GS-knockout Chinese hamster ovary cells for their potential to enable cell survival in a glutamine-free medium. In CLD, SiMPl-GS outperforms the wild-type GS by selectively enriching high producers. Unlike wild-type GS, SiMPl-GS results in cell pools in which most cells produce high levels of therapeutic proteins. Harnessing orthogonal split intein pairs further enables the selection of four plasmids with a single selection, streamlining multispecific antibody-producing CLD. Taken together, SiMPl-GS is a simple yet effective means to expedite CLD for therapeutic protein production.

Terahertz spoof plasmonic neural network for diffractive information recognition and processing

All-optical diffractive neural networks, as analog artificial intelligence accelerators, leverage parallelism and analog computation for complex data processing. However, their low space transmission efficiency or large spatial dimensions hinder miniaturization and broader application. Here, we propose a terahertz spoof plasmonic neural network on a planar diffractive platform for direct multi-target recognition. Our approach employs a spoof surface plasmon polariton coupler array to construct a diffractive network layer, resulting in a compact, efficient, and easily integrable architecture. We designed three schemes: basis vector classification, multi-user recognition, and MNIST handwritten digit classification. Experimental results reveal that the terahertz spoof plasmonic neural network successfully classifies basis vectors, recognizes multi-user orientation information, and directly processes handwritten digits using a designed input framework comprising a metal grating array, transmitters, and receivers. This work broadens the application of terahertz plasmonic metamaterials, paving the way for terahertz on-chip integration, intelligent communication, and advanced computing systems.

O-Targeted Carbon Hybrid Orbital Conversion to Produce sp2-Rich Closed Pores for Sodium-Storage Hard Carbon.

Biomass-based hard carbon has the advantages of a balanced cost and electrochemical performance, making it the most promising anode material for sodium-ion batteries. However, due to the structural limitations of biomass (such as macropores and impurities), it still faces the problems of low specific capacity and initial Coulombic efficiency (ICE). Herein, an integrated strategy of biomass liquefaction and oxidation treatment is proposed to fabricate hard carbon with low ash content and sp2-rich closed pores. Specifically, liquefaction treatment can break through the inherent constraints of biomass, while oxidation treatment with O-targeted effect can directionally convert C─C/C─O bonds into C═O/O═C─O bonds, which would promote the formation of closed pores and the rearrangement into sp2-carbon within the graphene layer. Moreover, it is well demonstrated that the hard carbon interface rich in sp2 hybridization can induce the generation of an inorganic-rich solid electrolyte interface, contributing to fast ion migration and excellent interfacial stability. As a result, the optimized hard carbon with maximum closed pore volume and sp2/sp3 ratio can exhibit a high capacity of 347.3mAhg-1 at 20mAg-1 with the ICE of 90.5%, and a capacity of 110.4mAhg-1 at 5.0Ag-1 after 10000 cycles.

Gear fault diagnosis based on small channel convolutional neural network under multiscale fusion attention mechanism

AbstractDue to the insufficient feature learning ability and the bloated network structure, the gear fault diagnosis methods based on traditional deep neural networks always suffer from poor diagnosis accuracy and low diagnosis efficiency. Therefore, a small channel convolutional neural network under the multiscale fusion attention mechanism (MSFAM‐SCCNN) is proposed in this paper. First, a small channel convolutional neural network (SCCNN) model is constructed based on the framework of the traditional AlexNet model in order to lightweight the network structure and improve the learning efficiency. Then, a novel multiscale fusion attention mechanism (MSFAM) is embedded into the SCCNN model, which utilizes multiscale striped convolutional windows to extract key features from three dimensions, including temporal, spatial, and channel‐wise, resulting in more precise feature mining. Finally, the performance of the MSFAM‐ SCCNN model is verified using the vibration data of tooth‐broken gears obtained by a self‐designed experimental bench of an ammunition supply and delivery system.

Dynamic changes of food environment: In and out of COVID-19 pandemic

The outbreak of the COVID-19 pandemic has precipitated food crises worldwide, prompting a re-examination of the resilience of the urban food environment. While previous research on the urban food environment has predominantly focused on Western contexts, scant attention has been given to China. This study takes Shenzhen, China as an example to establish a food environment evaluation framework centered on accessibility, diversity, and healthiness factors, aiming to analyze the dynamic changes of the food environment during normal and pandemic periods. By using the GA optimization algorithm, some convenience stores are transformed into self-pickup points (SPPs), which is expected to eliminate the deserts risk areas (DRAs) with low cost and high efficiency. The findings reveal a distinctive “center-periphery” spatial structure characterizing the food environment in Shenzhen, and the improvement of healthiness plays a crucial role in sustaining food oases and ameliorating food swamps. This research provides methods for improving the resilience of the food environment during the pandemic across diverse nations, bolstering the security of urban lifeline systems.