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Laser manufacturing of spatial resolution approaching quantum limit

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light(Science & Applications) 2024年第3期13卷 421-428页

作者： Xiao-Jie Wang Hong-Hua Fang Zhen-ze li Dan Wang Hong-Bo Sun State Key Laboratory of Precision Measurement Technology and Instruments Department of Precision InstrumentTsinghua UniversityBeijing 100084China State Key Laboratory of Integrated Optoelectronics College of Electronic Science and EngineeringJilin University2699 Qianjin StreetChangchun 130012China

Atomic and close-to-atom scale manufacturing is a promising avenue toward single-photon emitters,single-electron transistors,single-atom memory,and quantum-bit devices for future communication,computation,and sensing applications.Laser manufacturing is outstanding to this end for ease of beam manipulation,batch production,and no requirement for photomasks.It is,however,suffering from optical diffraction limits.Herein,we report a spatial resolution improved to the quantum limit by exploiting a threshold tracing and lock-in method,whereby the two-order gap between atomic point defect complexes and optical diffraction limit is surpassed,and a feature size oflized.The underlying physics is that the uncertainty of local atom thermal motion dominates electron excitation,rather than the power density slope of the incident laser.We show that the colour centre yield in hexagonal boron nitride is transformed from stochastic to deterministic,and the emission from individual sites becomes polychromatic to monochromatic.As a result,single colour centres in the regular array are deterministically created with a unity yield and high positional accuracy,serving as a step forward for integrated quantum technological applications.

关键词： quantum limit resolution

MXene Hollow Spheres Supported by a C–Co Exoskeleton Grow MWCNTs for Efficient Microwave Absorption

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Nano-Micro Letters 2024年第6期16卷 76-94页

作者： ze Wu Xiuli Tan Jianqiao Wang Youqiang Xing Peng Huang Bingjue li Lei liu School of Mechanical Engineering Southeast UniversityNanjing 211189People’s Republic of China

High-performance microwave absorption(MA) materials must be studied immediately since electromagnetic pollution has become a problem that cannot be disregarded. A straightforward composite material, comprising hollow MXene spheres loaded with C–Co frameworks, was prepared to develop multiwalled carbon nanotubes(MWCNTs). A high impedance and suitable morphology were guaranteed by the C–Co exoskeleton, the attenuation ability was provided by the MWCNTs endoskeleton, and the material performance was greatly enhanced by the layered core–shell structure. When the thickness was only 2.04 mm, the effective absorption bandwidth was 5.67 GHz, and the minimum reflection loss(RLmin) was-70.70 d B. At a thickness of 1.861 mm, the sample calcined at 700 ℃ had a RLmin of-63.25 d B. All samples performed well with a reduced filler ratio of 15 wt%. This paper provides a method for making lightweight core–shell composite MA materials with magnetoelectric synergy.

关键词： MXene C-Co skeleton MWCNTs Microwave absorption

Multi-Objective Multi-Variable Large-Size Fan Aerodynamic Optimization by Using Multi-Model Ensemble Optimization Algorithm

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Journal of Thermal Science 2024年第3期33卷 914-930页

作者： xiong Jin GUO Penghua li Jingyin School of Energy and Power Engineering Xi’an Jiaotong UniversityXi’an710049China

The constrained multi-objective multi-variable optimization of fans usually needs a great deal of computational fluid dynamics(CFD)calculations and is time-consuming.In this study,a new multi-model ensemble optimization algorithm is proposed to tackle such an expensive optimization problem.The multi-variable and multi-objective optimization are conducted with a new flexible multi-objective infill criterion.In addition,the search direction is determined by the multi-model ensemble assisted evolutionary algorithm and the feature extraction by the principal component analysis is used to reduce the dimension of optimization variables.First,the proposed algorithm and other two optimization algorithms which prevail in fan optimizations were compared by using test functions.With the same number of objective function evaluations,the proposed algorithm shows a fast convergency rate on finding the optimal objective function values.Then,this algorithm was used to optimize the rotor and stator blades of a large axial fan,with the efficiencies as the objectives at three flow rates,the high,the design and the low flow rate.Forty-two variables were included in the optimization process.The results show that compared with the prototype fan,the total pressure efficiencies of the optimized fan at the high,the design and the low flow rate were increased by 3.35%,3.07%and 2.89%,respectively,after CFD simulations for 500 fan candidates with the constraint for the design pressure.The optimization results validate the effectiveness and feasibility of the proposed algorithm.

关键词： multi-objective optimization surrogate-assisted evolutionary algorithm axial fan computational fluid dynamics aerodynamic optimization

Cutibacterium acnes in Atopic Dermatitis: Roles and Potential Therapeutic Applications

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International Journal of Dermatology And Venereology 2024年第1期07卷 12-17页

作者： Yu Tian-ze li Wei Department of Dermatology Shanghai Institute of Dermatology Huashan Hospital Fudan University Shanghai 200040 China

Atopic dermatitis (AD) is a chronic relapsing inflammatory skin disease. The main initiating mechanisms of AD are disruptions in the skin microbiota, dysfunction of the skin barrier, and predominantly elevated type 2 immune responses.Cutibacterium acnes (C. acnes) is a commensal bacterium that is ubiquitous and predominant in healthy skin and shows intraspecific subtype diversity. The abundance ofC. acnes is closely related to the sebum secreted by sebaceous glands.C. acnes has long been considered a proinflammatory skin bacterium that drives the development of acne vulgaris. Growing evidence indicates thatC. acnes promotes skin microbiota homeostasis and skin barrier maintenance; however, the potential role ofC. acnes in AD remains largely unexamined. This review provides the latest information on the distribution ofC. acnes and its phylotypes in healthy skin and AD as well as an overview of the possible role ofC. acnes in the pathophysiological pathways underlying AD. Additionally, the review focuses on new evidence regarding the protective functions ofC. acnes and its metabolites in AD and discusses the potential for therapeutic applications.

关键词： Cutibacterium acnes atopic dermatitis skin microbiota probiotic therapy

Two-way shape memory effect in a Ti-Zr-Nb-Ta high-temperature shape memory alloy

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Rare Metals 2024年第3期43卷 1257-1262页

作者： Cheng-Yang xiong Tuo li Jun Wang Yan li School of Materials Science and Engineering Beihang UniversityBeijing100191China

The two-way shape memory effect in a Ti-18.5Zr-10Nb-3.5Ta high-temperature shape memory alloy was investigated.X-ray diffraction measurem ent shows that the alloy is composed of orthorhombicα"-martensite.ωphase is not found in Ti-18.5Zr-10Nb-3.5Ta alloy due to the suppressing effect of Ta element.Theα"-martensite laths are found in the transmission electron microscope observation;after the bending deformation,there appear a lot of dislocations.The alloy exhibits a shape memory strain of 3.8%aud a high reverse martensite transformation start temperature of 464 K.The maximum two-way shape memory strain of 1.2%is obtained in the alloy with the prebending training strain of 10%.The mechanism can be ascribed to the effect of internal stress field caused by dislocations.

关键词： Ti-Zr Shape memory alloys Two-way shape memory effect

A Semiparametric Additive-multiplicative Rates Model for the Weighted Composite Endpoint of Recurrent and Terminal Events

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Acta Mathematica Sinica,English Series 2024年第4期40卷 985-999页

作者： Yi DENG Qiang xiong Shu Wei li School of Economics and Statistics Guangzhou UniversityGuangzhou 510006P.R.China

Recurrent event data are commonly encountered in many scientific fields,including biomedical studies,clinical trials and epidemiological surveys,and many statistical methods have been proposed for their analysis.In this paper,we consider to use a weighted composite endpoint of recurrent and terminal events,which is weighted by the severity of each event,to assess the overall effects of covariates on the two types of events.A flexible additive-multiplicative model incorporating both multiplicative and additive effects on the rate function is proposed to analyze such weighted composite event process,and more importantly,the dependence structure among the recurrent and terminal events is left unspecified.For the estimation,we construct the unbiased estimating equations by virtue of the inverse probability weighting technique,and the resulting estimators are shown to be consistent and asymptotically normal under some mild regularity conditions.We evaluate the finite-sample performance of the proposed method via simulation studies and apply the proposed method to a set of real data arising from a bladder cancer study.

关键词： Additive-multiplicative rates model estimating equation recurrent events terminal event weighted composite endpoint

Multiscale spatiotemporal meteorological drought prediction:A deep learning approach

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Advances in Climate Change Research 2024年第2期15卷 211-221页

作者： Jia-li ZHANG Xiao-Meng HUANG Yu-ze SUN Department of Earth System Science Ministry of Education Key Laboratory for Earth System ModellingInstitute for Global Change StudiesTsinghua UniversityBeijing 100084China

Reliable monitoring and thorough spatiotemporal prediction of meteorological drought are crucial for early warning and decision-making regarding drought-related disasters.The utilisation of multiscale methods is effective for a comprehensive evaluation of drought occurrence and progression,given the complex nature of meteorological drought.Nevertheless,the nonlinear spatiotemporal features of meteorological droughts,influenced by various climatological,physical and environmental factors,pose significant challenges to integrated prediction that considers multiple indicators and time scales.To address these constraints,we introduce an innovative deep learning framework based on the shifted window transformer,designed for executing spatiotemporal prediction of meteorological drought across multiple scales.We formulate four prediction indicators using the standardized precipitation index and the standard precipitation evaporation index as core methods for drought definition using the ERA5 reanalysis dataset.These indicators span time scales of approximately 30 d and one season.Short-term indicators capture more anomalous variations,whereas long-term indicators attain comparatively higher accuracy in predicting future trends.We focus on the East Asian region,notable for its diverse climate conditions and intricate terrains,to validate the model's efficacy in addressing the complexities of nonlinear spatiotemporal prediction.The model's performance is evaluated from diverse spatiotemporal viewpoints,and practical application values are analysed by representative drought events.Experimental results substantiate the effectiveness of our proposed model in providing accurate multiscale predictions and capturing the spatiotemporal evolution characteristics of drought.Each of the four drought indicators accurately delineates specific facets of the meteorological drought trend.Moreover,three representative drought events,namely flash drought,sustained drought and severe drought,underscore the significance of selecting appropr

关键词： Meteorological drought Spatiotemporal prediction Multiscale Swim transformer Deep learning

Ferroptosis and endoplasmic reticulum stress in ischemic stroke

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Neural Regeneration Research 2024年第3期19卷 611-618页

作者： Yina li Mingyang li Shi Feng Qingxue Xu Xu Zhang Xiaoxing xiong lijuan Gu Central Laboratory Renmin Hospital of Wuhan UniversityWuhanHubei ProvinceChina Department of Anesthesiology Renmin Hospital of Wuhan UniversityWuhanHubei ProvinceChina Department of Neurosurgery Renmin Hospital of Wuhan UniversityWuhanHubei ProvinceChina

Ferroptosis is a form of non-apoptotic programmed cell death,and its mechanisms mainly involve the accumulation of lipid peroxides,imbalance in the amino acid antioxidant system,and disordered iron metabolism.The primary organelle responsible for coordinating external challenges and internal cell demands is the endoplasmic reticulum,and the progression of inflammatory diseases can trigger endoplasmic reticulum stress.Evidence has suggested that ferroptosis may share pathways or interact with endoplasmic reticulum stress in many diseases and plays a role in cell survival.Ferroptosis and endoplasmic reticulum stress may occur after ischemic stroke.However,there are few reports on the interactions of ferroptosis and endoplasmic reticulum stress with ischemic stroke.This review summarized the recent research on the relationships between ferroptosis and endoplasmic reticulum stress and ischemic stroke,aiming to provide a reference for developing treatments for ischemic stroke.

关键词： cell death endoplasmic reticulum stress ferroptosis ischemic stroke lipid peroxidation

Nano-flower spherical SnS2 combined with a special lithium storage mechanism as a multifunctional separator for lithium-sulfur batteries contributes to ultra-high initial discharge specific capacity

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Science China(Technological Sciences) 2024年第2期67卷 509-519页

作者： liU HuaZhong xiong YaPing HUANG MouZhi CHEN ZongMin YANG Xiao ZHANG ze YANG ZhenYu CAI JianXin School of Chemistry&Chemical Engineering Nanchang UniversityNanchang 330031China

The critical factors that limit the electrochemical performance of lithium-sulfur(li-S)batteries are mainly the“shuttle effect”of polysulfides and the slow redox reaction between lithium polysulfides(liPSs).Herein,a nano-sphere-type material selfassembled from tin disulfide nanosheets is designed and applied to the li-S cell separator in this work.The SnS_(2)@PP modified separator not only acts as a dual restriction for liPSs by chemisorption and physical barrier.At the same time,it improves the catalytic activity of the redox reaction between liPSs.The SnS_(2)has extremely high electrochemical activity.There,a portion of the lithium ions can be inserted into SnS_(2)to form li_(x)SnS_(2)and contribute to the capacity during the first discharge of the battery.In addition,li_(x)SnS_(2)possesses a high degree of stability,and it does not undergo further de-alloying reactions even at the high potential of the li-S cell.The benefit is that the steady-state li_(x)SnS_(2)acts as a lithium-containing substance.It can form special li^(+)channels on the surface of the separator,thus greatly improving the efficiency of li+transport.The results showed that the SnS_(2)@PP-based cell exhibited extremely high initial discharge specific capacity(1477 m Ah g^(-1)at 0.1 C)and excellent rate performance(631 m Ah g^(-1)at 5 C).Even after 1000 cycles at 2 C,the cell exhibited a low decay rate of 0.06%per cycle on average.In addition,the superior electrochemical performance was obtained even with a high sulfur loading of 5.1 mg cm^(-2)and low electrolyte of E/S=8μL mg^(-1).

关键词： li-S batteries modified separators polysulfides catalytic conversion high electrochemical activity