稀土高熵氧化物用于能源和环境催化

随着工业技术的快速发展,能源短缺与环境污染问题日益凸显,对人类生活和社会经济发展造成了严重影响.在这一背景下,加速能源系统转型、积极开发与利用可再生能源变得至关重要,成为当前研究领域的热点.同时,消除环境中的有毒有害物质也具有较高的研究价值,对维护生态平衡和人类健康具有重要意义.催化技术因在去除污染物和能源转换方面具有巨大的应用潜力而备受关注.其中,高熵氧化物因其具有多样可调的晶体结构和丰富的表面活性位点,展现出较好的催化性能,从而备受研究者关注.此外,稀土元素因以其相近的离子半径、独特的电子轨道和可变的氧化态,常被用作高熵氧化物的组成元素.通过引入稀土元素,可以有效改善高熵氧化物的结构和性能.近年来,稀土高熵氧化物在催化应用中取得较多的研究成果,然而却缺少对该方面工作系统全面的综述.本文旨在系统总结稀土高熵氧化物的结构特点、合成方法及其在催化领域的应用,以期为该领域的进一步发展提供有益的参考.本文从结构、合成及应用等方面,对稀土高熵氧化物在催化领域的研究进展进行了总结.首先,详细介绍了钙钛矿型、萤石型和烧绿石型三种类型稀土高熵氧化物的结构特征,并探讨了结构对催化反应过程的重要影响.研究表明,多组分的高熵效应保证了单相固溶体的形成和高温下的催化稳定性,而晶格畸变效应则促进了氧空位等活性位点的形成,进而提升了催化活性.复杂多变的晶体结构导致了离子扩散延迟,这也使得高熵材料在催化过程中具有优异稳定性.此外,揭示了多种元素间的协同作用对催化性能的提升作用.值得一提的是,非等摩尔金属成分也可形成高熵氧化物,为稀土高熵氧化物研究开辟了新的方向.其次,讨论了稀土高熵氧化物的合成方法,主要包括固相反应合成法、喷雾热解法、化学共沉淀法和溶液燃烧法,合成方法的选择和优化对于建立高熵系统至关重要.目前,众多简单快速的合成方法已取代耗时耗力的合成过程,为稀土高熵氧化物的制备提供了便利.最后,重点概述了稀土高熵氧化物在电催化、热催化和光催化中的应用进展,并详细介绍了多元素可调材料对反应活性的影响.同时,指出了稀土高熵氧化物未来发展所面临的挑战,并提出了相应的应对策略,以期为高熵系统的理论研究提供有力支撑.综上,稀土高熵氧化物因其复杂结构而展现出丰富的潜在催化反应性能,具有巨大的应用潜力.未来研究可以加强开发设计、精准调控结构以及深入分析反应机理,从而提升高熵氧化物的催化性能.希望本文能够为稀土高熵氧化物催化体系研究提供有益的参考.

Optimization Control of Multi-Mode Coupling All-Wheel Drive System for Hybrid Vehicle

The all-wheel drive(AWD)hybrid system is a research focus on high-performance new energy vehicles that can meet the demands of dynamic performance and passing ability.Simultaneous optimization of the power and economy of hybrid vehicles becomes an issue.A unique multi-mode coupling(MMC)AWD hybrid system is presented to realize the distributed and centralized driving of the front and rear axles to achieve vectored distribution and full utilization of the system power between the axles of vehicles.Based on the parameters of the benchmarking model of a hybrid vehicle,the best model-predictive control-based energy management strategy is proposed.First,the drive system model was built after the analysis of the MMC-AWD’s drive modes.Next,three fundamental strategies were established to address power distribution adjustment and battery SOC maintenance when the SOC changed,which was followed by the design of a road driving force observer.Then,the energy consumption rate in the average time domain was processed before designing the minimum fuel consumption controller based on the equivalent fuel consumption coefficient.Finally,the advantage of the MMC-AWD was confirmed by comparison with the dynamic performance and economy of the BYD Song PLUS DMI-AWD.The findings indicate that,in comparison to the comparative hybrid system at road adhesion coefficients of 0.8 and 0.6,the MMC-AWD’s capacity to accelerate increases by 5.26%and 7.92%,respectively.When the road adhesion coefficient is 0.8,0.6,and 0.4,the maximum climbing ability increases by 14.22%,12.88%,and 4.55%,respectively.As a result,the dynamic performance is greatly enhanced,and the fuel savings rate per 100 km of mileage reaches 12.06%,which is also very economical.The proposed control strategies for the new hybrid AWD vehicle can optimize the power and economy simultaneously.

Advances of embedded resistive random access memory in industrial manufacturing and its potential applications

Embedded memory,which heavily relies on the manufacturing process,has been widely adopted in various industrial applications.As the field of embedded memory continues to evolve,innovative strategies are emerging to enhance performance.Among them,resistive random access memory(RRAM)has gained significant attention due to its numerousadvantages over traditional memory devices,including high speed(<1 ns),high density(4 F^(2)·n^(-1)),high scalability(~nm),and low power consumption(~pJ).This review focuses on the recent progress of embedded RRAM in industrial manufacturing and its potentialapplications.It provides a brief introduction to the concepts and advantages of RRAM,discusses the key factors that impact its industrial manufacturing,and presents the commercial progress driven by cutting-edge nanotechnology,which has been pursued by manysemiconductor giants.Additionally,it highlights the adoption of embedded RRAM in emerging applications within the realm of the Internet of Things and future intelligent computing,with a particular emphasis on its role in neuromorphic computing.Finally,the review discusses thecurrent challenges and provides insights into the prospects of embedded RRAM in the era of big data and artificial intelligence.

Sexual spores in edible mushroom: bioactive components, discharge mechanisms and effects on fruiting bodies quality

Edible mushroom sexual spores have been gaining more interest due to their bioactive components and functions.Spore discharge(SD)is an important factor affecting the quality of edible mushrooms.In this review,the bioactive nutrients of sexual spores of edible mushrooms were summarized,the SD mechanism was described,and the relationship between postharvest SD and the quality of edible mushrooms was analyzed.Spores contain various bioactive nutrients that are benefi cial to the human body.Mature mushrooms can actively discharge spores in a process affected by light,relative humidity,and temperature.During storage,the physiological metabolism of spore-bearing gill tissue is vigorous,promoting the release of postharvest spores and changing the nutritional value of fruiting bodies.The flavor of the fruiting bodies also varied signifi cantly during SD.Edible mushroom sexual spores have the potential to become new raw materials for functional food and medical resources.Research on the effect of the mechanism of SD on the quality of edible mushrooms and the development of SD regulation technology may be a new trend in the quality control of edible mushrooms,which will promote the development of the edible mushroom industry.

Laboratory culture of the freshwater benthic gastropod Bellamya aeruginosa (Reeve) and its utility as a test species for sediment toxicity

This study aimed to develop original laboratory culture and sediment toxicity testing protocols for the freshwater gastropod Bellamya aeruginosa （Reeve）, a new potential species for sediment toxicity testing. B. aeruginosa was successfully cultured with an effective culture system under proposed laboratory conditions. Optimal ad libitum feeding levels for larvae, juveniles, and adults were 2.0, 6.0, and 16.0 mg fish food/（snall.day）, respectively. Mean survival rates of juveniles were higher than 90%, The snails could be sexed at 9 weeks of age, and their generation time is approximately 4 months. Reproduction continued all year around; the mean fecundity was 0.55 newborn/（female.day）. The utility of this species for bioassays was evaluated in both 10-day and 28-day case studies with artificial sediments. The 10-day LC50 of Cu for larvae was 480 μg/g dry weight （dw）, and the lowest observed effects concentration of Cu for survival and growth of larvae was 195 μg/g dw. Survival and growth are reliable indicators of acute toxicity. Larvae accumulated more Cu than adults. B. aeruginosa exhibited a higher sensitivity to Cu exposure than standard test species （Hyalella azteca and Chironomus tentans）. The 28-day test of sediment toxicity with adults showed that fecundity was a robust endpoint indicator of reproductive toxicity, and the biochemical endpoints of superoxide dismutase, catalase, and glutathione could be used as sensitive biomarkers for Cu-induced oxidative damage. B. aeruginosa can be therefore recommended as a candidate for the standardization of the freshwater sediment toxicity test protocol.

Differences in the behavior characteristics between Daphnia magna and Japanese madaka in an on-line biomonitoring system

It is important to select suitable organisms to adapt the requirement of different environment monitoring purposes.Following our previous study,the behavioral responses of Daphnia magna and Japanese madaka （Oryzias latipes） were investigated and compared under flow-through conditions in an on-line biomonitoring system.The results showed that both D.magna and Japanese madaka had similar biological clock,but the circadian rhythms of Japanese madaka was more clearly recorded than that of D.magna.And the sensitivity of D.magna was about two orders of magnitudes higher than that of Japanese madaka in different types of toxic chemicals （dichlorovos,deltamethrin and cadmium chloride）.However,when both animals were used in an on-line biomonitoring system,the life span of D.magna was less than 7 days and Japanese madaka could last for more than one month without feeding.Therefore,D.magna was proposed to be a more sensitive bioindicator and was suitable for short term monitoring the pollution events at concentration level closing to the water quality standard,while Japanese madaka was more suitable for the long-term monitoring for accidental discharges.

Multi-stability involved mixed bursting within the coupled pre-Btzinger complex neurons

Neurons in the pre-B6tzinger complex within the mammalian brain stem play important roles in the generation of respiratory rhythms. Experimental observations show that some neurons can exhibit novel mixed bursting activities. In this paper, based on a mathematical model proposed by Butera, we show how the mixed bursting activities depend on the potassium current in the coupled pre-Botzinger complex. Using fast-slow decomposition and bifurcation analysis, we investigate the dynamics of mixed bursting, as well as the mechanisms of transition between different mixed bursting patterns. We find that mixed bursting involves different bistability, and it is the transition state of two types of regular burstings.

N-doped carbon layer-coated Au nanocatalyst for H_(2)-free conversion of 5-hydroxymethylfurfural to 5-methylfurfural

Deoxygenative upgrading of 5-hydromethylfurfural(HMF)into valuable chemicals has attracted intensive research interest in recent years,with product selectivity control remaining an important topic.Herein,TiO_(2) supported gold catalysts coated with a thin N-doped porous carbon(NPC)layer were developed via a polydopamine-coating-carbonization strategy and utilized for pathway-specific conversion of HMF into 5-methylfurfural(5-MF)with the use of renewable formic acid(FA)as the deoxygenation reagent.The as-fabricated Au/TiO_(2)@NPC exhibited excellent catalytic performance with a high yield of 5-MF(>95%).The catalytic behavior of Au@NPC-based catalysts was shown to be correlated with the suitable combination of highly dispersed Au nanoparticles and favorable interfacial interactions in the Au@NPC core-shell hetero-nanoarchitectures,thereby facilitating the preferential esterification of HMF with FA and suppressing unproductive FA dehydrogenation,which promoted the selective formylation/decarboxylation of hydroxy-methyl group in HMF in a pathway-specific manner.The present NPC/metal interfacial engineering strategy may provide a potential guide for the rational design of advanced catalysts for a wide variety of heterogeneous catalysis processes in terms of the conversion of biomass source.

Atomic/nano-scale in-situ probing the shuttling effect of redox mediator in Na-O_(2) batteries

Sodium-oxygen batteries(Na-O_(2))have attracted extensive attention as promising energy storage systems due to their high energy density and low cost.Redox mediators are often employed to improve Na-O_(2) battery performance,however,their effect on the formation mechanism of the oxygen reduction product(NaO_(2))is still unclear.Here,we have investigated the formation mechanism of NaO_(2) during the discharge process in the presence of a redox mediator with the help of atomic/nano-scale in-situ characterization tools used in concert(e.g.atomic force microscope,electrochemical quartz crystal microbalance(EQCM)and laser nano-particle analyzer).As a result,real-time observations on different time scales show that by shuttling electrons to the electrolyte,the redox mediator enables formation of NaO_(2) in the solution-phase instead of within a finite region near the electrode surface.These findings provide new fundamental insights on the understanding of Na-O_(2) batteries and new consequently perspectives on designing high performance metal-O_(2) batteries and other related functions.

Study on Seawater Intrusion in Kiaochow Bay Region

General situation of the seawater intrusion in Kiaochow Bay region was analyzed. Current status of the seawater intrusion and its formation mechanism, influence factor and hazard in Kiaochow Bay region were summarized. Finally, against seawater intrusion situation in the region, a series of practical prevention and control countermeasures were proposed.

Reconciliation of the Early Slip History of the Altyn Tagh Fault, Northern Tibetan

Whether the Altyn Tagh fault (ATF) had been extended beyond its current northeastern tip and linked with strike-slip faults in East Asia is a key to understanding the timing and mechanisms of crustal deformation in the northern Tibetan Plateau. We present Late Cretaceous dextral movement affected by Okhotomorsk Block-East Asia collision and a larger sinistral offset since Late Eocene along the ATF based on the provenance analysis of western Jiuxi Basin. Moreover, currently available estimates of offset based on displaced Paleozoic and Jurassic rocks could not represent the maximum offset due to late Cretaceous dextral offset.

A flexible Hf_(0.5)Zr_(0.5)O_(2) thin film with highly robust ferroelectricity

Flexible hafnia-based ferroelectric memories are arousing much interest with the ever-growing demands for nonvolatile data storage in wearable electronic devices.Here,high-quality flexible Hf_(0.5)Zr_(0.5)O_(2)membranes with robust ferroelectricity were fabricated on inorganic pliable mica substrates via an atomic layer deposition technique.The flexible Hf_(0.5)Zr_(0.5)O_(2) thin membranes with a thickness of∼8 nm exhibit a high remanent polarization of∼16μC/cm^(2),which possess very robust polarization switching endurance(>10^(10) cycles,two orders of magnitude better than reported flexible HfO_(2)-based films)and superior retention ability(expected>10 years).In particular,stable ferroelectric polarization as well as excellent endurance and retention performance show negligible degradations under 6 mm radius bending conditions or after 10^(4) bending cycles with a 6 mm bending radius.These results mark a crucial step in the development of flexible hafnium oxide-based ferroelectric memories for wearable electronic devices.

Filtering and regret network for spacecraft component segmentation based on gray images and depth maps

Identifying and segmenting spacecraft components is vital in many on-orbit space missions,such as on-orbit maintenance and component recovery.Integrating depth maps with visual images has been proven effective in improving segmentation accuracy.However,existing methods ignore the noise and fallacy in collected depth maps,which interfere with the network to extract representative features,decreasing the final segmentation accuracy.To this end,this paper proposes a Filtering and Regret Network(FRNet)for spacecraft component segmentation.The FRNet incorporates filtering and regret mechanisms to suppress the abnormal depth response in shallow layers and selectively reuses the filtered cues in deep layers,avoiding the detrimental effects of low-quality depth information while preserving the semantic context inherent in depth maps.Furthermore,a two-stage feature fusion module is proposed,which involves information interaction and aggregation.This module effectively explores the feature correlation and unifies the multimodal features into a comprehensive representation.Finally,a large-scale spacecraft component recognition dataset is constructed for training and evaluating spacecraft component segmentation algorithms.Experimental results demonstrate that the FRNet achieves a state-of-the-art performance with a mean Intersection Over Union(mIOU)of 84.13%and an average inference time of 133.2 ms when tested on an NVIDIA RTX 2080 SUPER GPU.

High-efficiency Ce-modified ZSM-5 nanosheets for waste plastic upgrading

Zeolite-based catalyst hydrocracking of plastics is a potential strategy for mitigating the environmental impacts of plastic wastes and recycling valuable resources,but difficult mass transfer,low concentration of acid sites,and high cost are still barriers to their practical applications.In this paper,we report an excellent hydrocracking catalyst of ZSM-5 nanosheets(Ce/b-ZSM-5)modified by Ce species with high conversion up to 96.3%,C_(3)−C_(5)selectivity up to 80.9%,and good stability during the hydrogenation of low-density polyethylene.Through comprehensive studies,b-ZSM-5 shows higher molecular diffusion efficiency and acid site concentrations compared with normal ZSM-5(n-ZSM-5)and hollow ZSM-5(h-ZSM-5).The introduction of Ce species into b-ZSM-5 further increases the density of Brønsted(B)and Lewis(L)acid sites as active sites,which enhances the adsorption of substrates and facilitates the formation of intermediates and desorption of products.As a result,the hydrocracking activity of Ce/b-ZSM-5 is significantly improved.

Facile fabrication of quaternized chitosan-incorporated biomolecular patches for non-compressive haemostasis and wound healing

Cell-free wound dressings (WDs) with desirable effectiveness and safety have received much attention in the field of regenerative medicine. However, the weak linkages between bioactive polymers and the spatial structure of WDs frequently result in interventional treatment failure. Herein, we create a series of quaternized chitosan (QCS)-incorporated composite hydrogels (referred to as GHCH-n) by UV cross-linking and then convert them into microneedle patches (MNPs). QCS, which is positively charged and amphiphilic, is essential for broad-spectrum antibacterial and haemostatic activities. QCS is proven to be slightly toxic, so it is immobilized into the methacrylate gelatine (GelMA) molecular cage to minimize adverse effects. A polydimethylsiloxane micro-mould is used to shape the MNPs. MNPs can pierce tissue, seal off bleeding sites, and cling to wounds securely. Thus, MNPs can cooperate with GHCH-n hydrogels to halt bleeding and accelerate wound healing. This study recommends GHCH-10 MNPs as an advanced biomaterial. Several preclinical research models have thoroughly validated the application effect of GHCH-10 MNPs. This research also proposes a novel strategy for integrating the nature of bioactive polymers and the structure of composite biomaterials. This strategy is not only applicable to the fabrication of next-generation WDs but also shows great potential in expanding interdisciplinary domains.

Ultralow operating voltage for energy conversion performance in Hf_(1-x)Zr_(x)O_(2) thin films

Emerging ferroelectric and antiferroelectric HfO_(2)-based thin films are attractive candidates for energy conversion and storage applications. In this work, the polar phase transformation between tetragonal and orthorhombic phases associated with ferroelectric or antiferroelectric behaviors is utilized to manipulate the electrocaloric cooling and energy storage performances in Zr-doped, woken up HfO_(2) ultrathin films. A giant electrocaloric temperature change of up to 11.85 K in Hf_(0.5)Zr_(0.5)O_(2) with the morphotropic phase boundary (MPB) state and a high energy storage density of 39.34 J/cm^(3) in the tetragonal phase-dominant Hf0.25Zr0.75O2 system are obtained. More interestingly, contrary to overdoping and excessive electric fields, an appropriate Zr concentration of 0.5 and an applicable driving field of 1.91 MV/cm are desired for the electrocaloric effect, resulting in an ultralow operating voltage as low as 1.3 V in this 6.8 nm thick Hf_(0.5)Zr_(0.5)O_(2) film. These findings illustrate that the structural design strategy is a visible method for achieving optimal energy-related behaviors and highlight the great possibilities for building future energy-related devices.

Erratum to:Detecting gravitational wave with an interferometric seismometer array on lunar nearside[Sci.China-Phys.Mech.Astron.66,109513(2023)]

This paper"Detecting gravitational wave with an interferometric seismometer array on lunar nearside"[1]was published in SCIENCE CHINA Physics,Mechanics&Astronomy(66,109513(2023),doi:10.1007/s11433-023-2179-9).Due to an oversight on our part,some errors were made in the originally published paper.We apologize for these errors and offer the corresponding explanations and corrections for the readers.

玉米基因组所有染色体端粒到端粒完整无间隙组装

基因组测序在基础生物学研究以及医学和农业应用的许多方面都发挥着重要的作用.1996年,第一个真核生物基因组序列破译在酵母中完成[1].随后,包括拟南芥[2]、人类[3,4]、小鼠[5]、水稻[6]、玉米[7]等数百个物种的参考基因组相继公布.然而,由于基因组序列组成的复杂性.

Impacts of communication delay on vehicle platoon string stability and its compensation strategy:A review

Based on the four-element model,this paper reviewed the important research progress in vehicle platoon,compared the advantages and disadvantages of different models in each element longitudinally,and summarized the linkage between each element horizontally.The stability criteria are briefly reviewed from three dimensions:local stability,string stability,and traffic flow stability.The impact of communication delay on vehicle platoon is quantitatively summarized from two aspects:the variation of controller gains and the variation of headway time values.Aiming at the inevitable communication delay in vehicle platoon,the compensation strategies are analyzed from five levels.(1)Optimizing the communication network structure.(2)Reconstructing acceleration information.(3)Tuning controller gains.(4)Constructing a multi-branch selection structure.(5)Improving the controller.The results show that,although these compensation strategies can alleviate the negative impact of communication delay to a certain extent,they also have some defects such as difficulty in adapting to complex and various real road conditions,poor accuracy and real-time performance,insufficient security,and limited application scenarios.It is necessary to further improve the accuracy and real-time performance of the device,design an encrypted and scalable network architecture to ensure communication security and adaptability,and conduct further real vehicle testing.

Antibacterial Electrospun Nanofibrous Materials for Wound Healing

One of the leading causes of wound healing delays is bacterial infection,which limits the process of restoring the histological and functional integrity of the skin.Electrospun nanofibrous materials(ENMs)are biocompatible and biodegradable,and they can provide specific physical,chemical,and biological cues to accelerate wound healing.Based on this fact,a series of multifunctional ENMs for complex clinical applications,particularly infected skin injuries,have been developed.Anti-biotics,antimicrobial peptides(AMPs),metals and metal oxides(MMOs),and antibacterial polymers have previously been incorporated into ENMs through advanced material processing techniques,endowing ENMs with enhanced and excellent antibacterial activity.This review summarizes wound healing issues and provides recent advances in antibacterial ENMs created by cutting-edge technology.The future of clinical and translational research on ENMs is also discussed.