Long-read genome assemblies reveal a cis-regulatory landscape associated with phenotypic divergence in two sister Siniperca fish species

Due to the difficulty in accurately identifying structural variants(SVs) across genomes,their impact on cisregulato ry diverge n ce of closely related species,especially fish,remains to be explored.Recently identified broad H3K4me3 domains are essential for the regulation of genes involved in several biological processes.However,the role of broad H3K4me3 domains in phenotypic divergence remains poorly understood.Siniperca chuatsi and S.scherzeri are closely related but divergent in several phenotypic traits,making them an ideal model to study cis-regulatory evolution in sister species.Here,we generated chromosome-level genomes of S.chuatsi and S.scherzeri,with assembled genome sizes of 716.35 and740.54 Mb,respectively.The evolutionary histories of S.chuatsi and S.scherzeri were studied by inferring dynamic changes in ancestral population sizes.To explore the genetic basis of adaptation in S.chuatsi and S.scherzeri,we performed gene family expansion and contraction analysis and identified positively selected genes(PSGs).To investigate the role of SVs in cis-regulatory divergence of closely related fish species,we identified high-quality SVs as well as divergent H3K27ac and H3K4me3 domains in the genomes of S.chuatsi and S.scherzeri.Integrated analysis revealed that cis-regulatory divergence caused by SVs played an essential role in phenotypic divergence between S.chuatsi and S.scherzeri.Additionally,divergent broad H3K4me3 domains were mostly associated with cancer-related genes in S.chuatsi and S.scherzeri and contributed to their phenotypic divergence.

Long-term stability analysis of the left bank abutment slope at Jinping I hydropower station

The time-dependent behavior of the left bank abutment slope at Jinping I hydropower station has a major influence on the normal operation and long-term safety of the hydropower station. To solve this problem, a geomechanical model containing various faults and weak structural planes is established, and numerical simulation is conducted under normal water load condition using FLAC3D, incorporating creep model proposed based on thermodynamics with internal state variables theory. The creep deformations of the left bank abutment slope are obtained, and the changes of principal stresses and deformations of the dam body are analyzed. The long-term stability of the left bank abutment slope is evaluated according to the integral curves of energy dissipation rate in domain and its derivative with respect to time, and the non-equilibrium evolution rules and the characteristic time can also be determined using these curves. Numerical results show that the left bank abutment slope tends to be stable in a global sense, and the stress concentration is released. It is also indicated that more attention should be paid to some weak regions within the slope in the long-term deformation process.

融合项目制创新团队构建的新工科创新人才培养模式探索与实践

针对新工科背景下创新人才培养模式存在的不足,对融合项目制与创新团队构建的新工科创新人才培养模式进行了探索和思考,该模式以项目制为载体,以创新团队发展为依托,以学生学习能力与专业技能培训为基础,以学生创新能力培养为目标。通过对融合项目制创新团队构建的新工科创新人才培养模式实施效果分析,发现这种创新人才培养模式显著提升了学生的专业素养和创新能力,对提升创新人才培养质量起到了极大的促进作用。

时效处理对激光熔覆Mo_(0.5)NbTiVCr_(0.25)高熵合金涂层显微组织和耐磨性能的影响

通过激光熔覆技术在TC4基体上制备难熔Mo_(0.5)NbTiVCr_(0.25)高熵合金涂层。涂层在600、800和1000℃下时效热处理24 h,然后水冷。采用X射线衍射(XRD)、扫描电子显微镜(SEM)、电子背散射衍射(EBSD)、透射电子显微镜(TEM)等技术、以及维氏硬度和万能摩擦磨损测试手段对高熵合金涂层的相组成、显微组织和力学性能进行研究。结果表明,高熵合金涂层经不同时效热处理后仍保持体心立方结构。经800℃时效热处理后,涂层含有富Ti沉淀相,通过TEM术证实其为Ti(O,N)面心立方结构。最佳时效温度为600℃,涂层硬度为HV_(0.2)410。该涂层的磨损机制为黏着磨损和磨料磨损。

增材制造金属结构件残余应力的研究进展

增材制造技术近年来取得了重大进展,金属增材制造可以三维成型精度高的复杂形状零件,在各行业的应用中具有独特优势。然而,增材制造金属零件成形时由于高温度梯度会引起复杂残余应力。简要分析了增材制造技术的特点,重点总结了激光选区熔化和电弧增材制造的工艺原理。在此基础上,详细综述了增材制造过程中残余应力的产生机制及测量方法,其中,温度梯度机制是解释残余应力产生机制最常用的方法。针对残余应力的测量,分别从无损检测和破坏性检测两方面进行归纳,最常用的破坏性检测残余应力的方法是轮廓法和钻孔法,而无损检测的方法是X射线衍射法。并且总结了残余应力的调控方法,包括工艺参数调控、预热缓冷及重熔调控、结构设计调控、辅助外场调控、后处理调控。最后简要总结增材制造金属结构件残余应力研究中亟待解决的问题,并展望了金属增材制造的发展方向。

Design Strategies for Aqueous Zinc Metal Batteries with High Zinc Utilization: From Metal Anodes to Anode-Free Structures

Aqueous zinc metal batteries(AZMBs)are promising candidates for next-generation energy storage due to the excellent safety, environmental friendliness, natural abundance, high theoretical specific capacity, and low redox potential of zinc(Zn) metal. However,several issues such as dendrite formation, hydrogen evolution, corrosion, and passivation of Zn metal anodes cause irreversible loss of the active materials. To solve these issues, researchers often use large amounts of excess Zn to ensure a continuous supply of active materials for Zn anodes. This leads to the ultralow utilization of Zn anodes and squanders the high energy density of AZMBs. Herein, the design strategies for AZMBs with high Zn utilization are discussed in depth, from utilizing thinner Zn foils to constructing anode-free structures with theoretical Zn utilization of 100%, which provides comprehensive guidelines for further research. Representative methods for calculating the depth of discharge of Zn anodes with different structures are first summarized. The reasonable modification strategies of Zn foil anodes, current collectors with pre-deposited Zn, and anode-free aqueous Zn metal batteries(AF-AZMBs) to improve Zn utilization are then detailed. In particular, the working mechanism of AF-AZMBs is systematically introduced. Finally, the challenges and perspectives for constructing high-utilization Zn anodes are presented.

Direct measurement of the break-out ^(19)F(p,γ)^(20)Ne reaction in the China Jinping underground laboratory(CJPL)

Calcium production and the stellar evolution of first-generation stars remain fascinating mysteries in astrophysics.As one possible nucleosynthesis scenario,break-out from the hot carbon–nitrogen–oxygen(HCNO)cycle was thought to be the source of the calcium observed in these oldest stars.However,according to the stellar modeling,a nearly tenfold increase in the thermonuclear rate ratio of the break-out ^(19)F(p,γ)^(20) Ne reaction with respect to the competing ^(19)F(p,α)^(16) O back-processing reaction is required to reproduce the observed calcium abundance.We performed a direct measurement of this break-out reaction at the China Jinping underground laboratory.The measurement was performed down to the low-energy limit of E_(c.m.)=186 keV in the center-of-mass frame.The key resonance was observed at 225.2 keV for the first time.At a temperature of approximately 0.1 GK,this new resonance enhanced the thermonuclear ^(19)F(p,γ)^(20) Ne rate by up to a factor of≈7.4,compared with the previously recommended NACRE rate.This is of particular interest to the study of the evolution of the first stars and implies a stronger breakdown in their“warm”CNO cycle through the ^(19)F(p,γ)^(20) Ne reaction than previously envisioned.This break-out resulted in the production of the calcium observed in the oldest stars,enhancing our understanding of the evolution of the first stars.

焊接电流对6061铝合金焊接接头组织及力学性能的影响

采用100~150 A焊接电流对6061铝合金进行交流TIG焊,利用金相显微镜、X射线衍射仪、万能试验机及显微硬度计系统研究焊接接头的微观组织和力学性能。研究表明:随着焊接电流的增大,焊缝处晶粒不断增大,从柱状晶转变成等轴晶;由物相分析可知6061铝合金焊接接头主要包含α-Al,Mg_(2)Si,A1_(6)Mn;焊接接头抗拉强度和硬度均随着焊接电流的增大先增大后减小,在120 A时接头抗拉强度和延伸率最好,且此时焊缝成分均匀,生成强化相使焊缝区的硬度达到最大值。

Unraveling the evolution of Cathode-Solid electrolyte interface using operando X-ray Photoelectron spectroscopy

Understanding the evolution of the solid electrolyte-electrode interface is currently one of the most challenging obstacles in the development of solid-state batteries(SSBs).Here,we develop an X-ray Photoelectron Spectroscopy(XPS)that allows for operando measurement during cycling.Based on theoretical analysis and the modulated electrode and detector co-grounding mode,the displacement of binding energy can be correlated with the surface electrostatic potential of the material,revealing the charge distribution and composition evolution of the space charge layer between the cathode and the electrolyte.In the investigation of typical LiCoO_(2)(LCO)/Li6PS5Cl(LPSC)/Li-In batteries,we observed the static potential difference and oxidative decomposition between LPSC and LCO,and the effectiveness of the LiNbO3 coating in reducing potential difference and inhibiting the diffusion of Co and oxidation of S species.Furthermore,our study also revealed that the potential drop between LiNi0⋅8Co0⋅1Mn0⋅1O_(2) and LPSC is smaller than that of LCO,whilst that between Li3InCl6 and LCO remains near zero.The proposed operando XPS method offers a novel approach for real-time monitoring of interface potential and species formation,providing rational guidance for the interface engineering in SSBs.

O-doping strategy enabling enhanced chemical/electrochemical stability of Li_(3)InCl_(6) for superior solid-state battery performance

Solid-state electrolytes with high oxidation stability are crucial for achieving high power density allsolid-state lithium batteries.Halide electrolytes are promising candidates due to their outstanding compatibility with cathode materials and high Li^(+)conductivity.However,the electrochemical stability of chloride electrolytes is still limited,leaving them unsuitable for ultrahigh voltage operation.Besides,chemical compatibility issue between sulfide and halide electrolytes affects the electrochemical performance of all-solid-state batteries.Herein,Li-ion conductor Li_(3+x)InCl_(6-x)O_(x) is designed to address these challenges.Li_(3.25)InCl_(5.75)O_(0.25)shows a Li-ion conductivity of 0.90 mS cm^(-1)at room temperature,a high onset oxidation voltage of 3.84 V,fewer by-products at ultrahigh operation voltage,and good chemical compatibility with Li_(5.5)PS_(4.5)Cl_(1.5).The Li_(3.25)InCl_(5.75)O_(0.25)@LiNi_(0.7)Co_(0.1)Mn_(0.2)O_(2)-Li_(3.25)InCl_(5.75)O_(0.25)-VGCF/Li_(3.25)InCl_(5.75)O_(0.25)/Li_(5.5)PS_(4.5)Cl_(1.5)/Li-In battery delivers good electrochemical performances at high operating voltage.This work provides a simple,economical,and effective strategy for designing high-voltage all-solid-state electrolytes.

Cation-doped LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2) cathode with high rate performance

The nickel-rich layered cathode material LiNi_(0.8)Co_(0.1)Mn_(0.1)O_(2)(NCM811)has high energy density,lower cost and is a promising cathode material currently under development.However,its electrochemical and structural stability is poor during cycling.Among the many modification methods,cation doping has been consistently proven to be an effective strategy for enhancing electrochemical performance.Herein,the NCM811 cathode material was modified by solid-phase reactions with Mg and Al doped.In addition,the corresponding mechanism of NCM811 cathode material-doped modification is explored by density functional theory(DFT)calculations,and we have extended this approach to other ternary cathode materials with different ratios and obtained universal laws.Combined with DFT calculations,the results show that Mg2+occupies the Li+site and reduces the degree of Li^(+)/Ni^(2+) mixture;Al^(3+) acts as a structural support during charging and discharging to prevent structural collapse.The electrochemical properties were tested by an electrochemical workstation and the LAND system,and the results showed that the capacity retention rate increased to varying degrees from 63.66%to 69.87%and 89.05%for NCM811-Mg and NCM811-Al at room temperature after 300 cycles,respectively.This study provides a theoretical basis and design strategy for commercializing cationic-doped modification of nickel-rich cathode materials.

Recent advances and perspectives in MXene-based cathodes for aqueous zinc-ion batteries

Aqueous zinc-ion batteries(AZIBs)show great potential for applications in grid-scale energy storage,given their intrinsic safety,cost effectiveness,environmental friendliness,and impressive electrochemical performance.However,strong electrostatic interactions exist between zinc ions and host materials,and they hinder the development of advanced cathode materials for efficient,rapid,and stable Zn-ion storage.MXenes and their derivatives possess a large interlayer spacing,excellent hydrophilicity,outstanding electronic conductivity,and high redox activity.These materials are considered“rising star”cathode candidates for AZIBs.This comprehensive review discusses recent advances in MXenes as AZIB cathodes from the perspectives of crystal structure,Zn-storage mechanism,surface modification,interlayer engineering,and conductive network design to elucidate the correlations among their composition,structure,and electrochemical performance.This work also outlines the remaining challenges faced by MXenes for aqueous Zn-ion storage,such as the urgent need for improved toxic preparation methods,exploration of potential novel MXene cathodes,and suppression of layered MXene restacking upon cycling,and introduces the prospects of MXene-based cathode materials for high-performance AZIBs.

The cytosolic isoform of triosephosphate isomerase,ZmTPI4,is required for kernel development and starch synthesis in maize(Zea mays L.)

Triosephosphate isomerase(TPI)is an enzyme that functions in plant energy production,accumulation,and conversion.To understand its function in maize,we characterized a maize TPI mutant,zmtpi4.In comparison to the wild type,zmtpi4 mutants showed altered ear development,reduced kernel weight and starch content,modified starch granule morphology,and altered amylose and amylopectin content.Protein,ATP,and pyruvate contents were reduced,indicating ZmTPI4 was involved in glycolysis.Although subcellular localization confirmed ZmTPI4 as a cytosolic rather than a plastid isoform of TPI,the zmtpi4 mutant showed reduced leaf size and chlorophyll content.Overexpression of ZmTPI4 in Arabidopsis led to enlarged leaves and increased seed weight,suggesting a positive regulatory role of ZmTPI4 in kernel weight and starch content.We conclude that ZmTPI4 functions in maize kernel development,starch synthesis,glycolysis,and photosynthesis.

Abnormal Action Recognition with Lightweight Pose Estimation Network in Electric Power Training Scene

Electric power training is essential for ensuring the safety and reliability of the system.In this study,we introduce a novel Abnormal Action Recognition(AAR)system that utilizes a Lightweight Pose Estimation Network(LPEN)to efficiently and effectively detect abnormal fall-down and trespass incidents in electric power training scenarios.The LPEN network,comprising three stages—MobileNet,Initial Stage,and Refinement Stage—is employed to swiftly extract image features,detect human key points,and refine them for accurate analysis.Subsequently,a Pose-aware Action Analysis Module(PAAM)captures the positional coordinates of human skeletal points in each frame.Finally,an Abnormal Action Inference Module(AAIM)evaluates whether abnormal fall-down or unauthorized trespass behavior is occurring.For fall-down recognition,three criteria—falling speed,main angles of skeletal points,and the person’s bounding box—are considered.To identify unauthorized trespass,emphasis is placed on the position of the ankles.Extensive experiments validate the effectiveness and efficiency of the proposed system in ensuring the safety and reliability of electric power training.

True-temperature inversion algorithm for a multi-wavelength pyrometer based on fractional-order particle-swarm optimization

Herein,a method of true-temperature inversion for a multi-wavelength pyrometer based on fractional-order particle-swarm optimization is proposed for difficult inversion problems with unknown emissivity.Fractional-order calculus has the inherent advantage of easily jumping out of local extreme values;here,it is introduced into the particle-swarm algorithm to invert the true temperature.An improved adaptive-adjustment mechanism is applied to automatically adjust the current velocity order of the particles and update their velocity and position values,increasing the accuracy of the true temperature values.The results of simulations using the proposed algorithm were compared with three algorithms using typical emissivity models:the internal penalty function algorithm,the optimization function(fmincon)algorithm,and the conventional particle-swarm optimization algorithm.The results show that the proposed algorithm has good accuracy for true-temperature inversion.Actual experimental results from a rocket-motor plume were used to demonstrate that the true-temperature inversion results of this algorithm are in good agreement with the theoretical true-temperature values.

A Survey on Blockchain-Based Federated Learning:Categorization,Application and Analysis

Federated Learning(FL),as an emergent paradigm in privacy-preserving machine learning,has garnered significant interest from scholars and engineers across both academic and industrial spheres.Despite its innovative approach to model training across distributed networks,FL has its vulnerabilities;the centralized server-client architecture introduces risks of single-point failures.Moreover,the integrity of the global model—a cornerstone of FL—is susceptible to compromise through poisoning attacks by malicious actors.Such attacks and the potential for privacy leakage via inference starkly undermine FL’s foundational privacy and security goals.For these reasons,some participants unwilling use their private data to train a model,which is a bottleneck in the development and industrialization of federated learning.Blockchain technology,characterized by its decentralized ledger system,offers a compelling solution to these issues.It inherently prevents single-point failures and,through its incentive mechanisms,motivates participants to contribute computing power.Thus,blockchain-based FL(BCFL)emerges as a natural progression to address FL’s challenges.This study begins with concise introductions to federated learning and blockchain technologies,followed by a formal analysis of the specific problems that FL encounters.It discusses the challenges of combining the two technologies and presents an overview of the latest cryptographic solutions that prevent privacy leakage during communication and incentives in BCFL.In addition,this research examines the use of BCFL in various fields,such as the Internet of Things and the Internet of Vehicles.Finally,it assesses the effectiveness of these solutions.

Influence of hematite morphology on the CO oxidation performance of Au/α-Fe_(2)O_(3)

Controlling the interaction between metal nanoparticles and the support is a means to tune catalytic activity and stability.Herein we investigated the influence of the morphology of hematite on the performance of gold for CO oxidation.Nanosphere and nanorod forms of hematite,α-Fe_(2)O_(3)(S)andα-Fe_(2)O_(3)(R)respectively,were used to support gold nanoparticles.The surface ofα-Fe_(2)O_(3)(R)was more corrugated than that ofα-Fe_(2)O_(3)(S).These defects provide anchoring sites for gold nanoparticle deposition and stabilization.Due to the stronger gold-support interactions,Au/α-Fe_(2)O_(3)(R)contained smaller and more hemispherical gold particles than Au/α-Fe_(2)O_(3)(S).Au/α-Fe_(2)O_(3)(R)was not only more active in CO oxidation but also much more stable as evident from the small change in gold particle size during reaction.The higher reducibility of Au/α-Fe_(2)O_(3)(R)also contributed to the higher CO oxidation activity.

Lattice oxygen activation in transition metal doped ceria

Density functional theory calculations were carried out to investigate the influence of doping transition metal(TM) ions into the ceria surface on the activation of surface lattice oxygen atoms. For this purpose, the structure and stability of the most stable(111) surface termination of CeO2 modified by TM ions was determined. Except for Zr and Pt dopants that preserve octahedral oxygen coordination, the TM dopants prefer a square-planar coordination when substituting the surface Ce ions. The surface construction from octahedral to square-planar is facile for all TM dopants, except for Pt(1.14 e V) and Zr(square-planar coordination unstable). Typically, the ionic radius of tetravalent TM cations is much smaller than that of Ce4+, resulting a significant tensile-strained lattice and explaining the lowered oxygen vacancy formation energy. Except for Zr, the square-planar structure is the preferred one when one oxygen vacancy is created. Thermodynamic analysis shows that TM-doped CeO2 surfaces contain oxygen defects under typical conditions of environmental catalysis. A case of practical importance is the facile lattice oxygen activation in Zr-doped CeO2(111), which benefits CO oxidation. The findings emphasize the origin of lattice oxygen activation and the preferred location of TM dopants in TM-ceria solid solution catalysts.

拉筋形状对离心压缩机排气蜗壳的性能影响

为满足部分离心压缩机组的强度要求,需要在扩压器内增加拉筋。拉筋是连接扩压器的端壁并起支撑作用的组件,然而拉筋的存在必然会导致额外的气动损失,降低压缩机机组的整体效率。本文以某离心压缩机机组的末级为研究对象,采用NUMECAFINE/Turbo软件对叶轮、带拉筋的扩压器和排气蜗壳构成的整级模型进行数值计算,分析并对比三种不同截面形状的拉筋对排气蜗壳的性能的影响。计算结果表明,截面为椭圆形的拉筋对排气蜗壳的气动性能影响最小。

我国公共教育支出经济绩效空间溢出效应研究

教育是具有明显外部性的准公共物品,人力资本流动和知识溢出决定了教育投入存在空间溢出效应。基于2000-2018年各省域单位面板数据,借助动态空间计量模型和固定效应模型,深入分析了我国各省域单位教育支出对区域经济增长的空间溢出效应。研究结果表明:第一,我国公共教育支出存在显著的空间集聚和溢出效应;第二,东部区域内教育溢出效应要强于中、西部地区,东、西部之间的溢出效应强于中部与东、西部之间;第三,经济发展速度、科技发展水平和教育投入力度会对教育溢出产生正向影响,劳动力成本和高等教育水平则产生负向影响。因此,各地区应因地制宜,兼顾其他地区教育发展政策,考虑宏观经济形势来制定相应的教育发展政策,以平衡区域间教育资源分布,疏导教育溢出效应传导机制,进而促进我国区域经济协调发展。