Role of heterogenous microstructure and deformation behavior in achieving superior strength-ductility synergy in zinc fabricated via laser powder bed fusion

Zinc(Zn)is considered a promising biodegradable metal for implant applications due to its appropriate degradability and favorable osteogenesis properties.In this work,laser powder bed fusion(LPBF)additive manufacturing was employed to fabricate pure Zn with a heterogeneous microstructure and exceptional strength-ductility synergy.An optimized processing window of LPBF was established for printing Zn samples with relative densities greater than 99%using a laser power range of 80∼90 W and a scanning speed of 900 mm s−1.The Zn sample printed with a power of 80 W at a speed of 900 mm s−1 exhibited a hierarchical heterogeneous microstructure consisting of millimeter-scale molten pool boundaries,micrometer-scale bimodal grains,and nanometer-scale pre-existing dislocations,due to rapid cooling rates and significant thermal gradients formed in the molten pools.The printed sample exhibited the highest ductility of∼12.1%among all reported LPBF-printed pure Zn to date with appreciable ultimate tensile strength(∼128.7 MPa).Such superior strength-ductility synergy can be attributed to the presence of multiple deformation mechanisms that are primarily governed by heterogeneous deformation-induced hardening resulting from the alternative arrangement of bimodal Zn grains with pre-existing dislocations.Additionally,continuous strain hardening was facilitated through the interactions between deformation twins,grains and dislocations as strain accumulated,further contributing to the superior strength-ductility synergy.These findings provide valuable insights into the deformation behavior and mechanisms underlying exceptional mechanical properties of LPBF-printed Zn and its alloys for implant applications.

Synergy of inside doped metals–Outside coated graphene to enhance hydrogen storage in magnesium-based alloys

Grain growth of magnesium(Mg)and its hydride is one of the main reasons for kinetic and capacity degradation during the hydrogen absorption and desorption cycles.To solve this problem,herein we propose a novel method involving synergistic effect of inside embedded metals and outside coated graphene to limit the growth of Mg and its hydride grains.The graphene coated Mg-Y-Al alloys were selected as a model system for demonstrating this positive effect where the Mg_(91)Y_(3)Al_(6)alloy was first prepared by rapidly solidified method and then high-pressure milled with 5 wt%graphene upon 5 MPa hydrogen gas for obtaining in-situ formed YAl_(2)and YH_(3)embedded in the MgH_(2)matrix with graphene shell(denoted as MgH_(2)-Y-Al@GR).In comparison to pure MgH_(2),the obtained MgH_(2)-Y-Al@GR composites deliver much better kinetics and more stable cyclic performance.For instance,the MgH_(2)-Y-Al@GR can release about 6.1 wt%H_(2)within 30 min at 300℃ but pure MgH_(2)only desorbs∼1.5 wt%H_(2).The activation energy for desorption of MgH_(2)-Y-Al@GR samples is calculated to be 75.3±9.1 kJ/mol that is much lower than approximately 160 kJ/mol for pure MgH_(2).Moreover,its capacity retention is promoted from∼57%of pure MgH_(2)to∼84%after 50th cycles without obvious particle agglomeration and grain growth.The synergistic effect of outside graphene coating with inside embedded metals which could provide a huge number of active sites for catalysis as well as inhibit the grain growth of Mg and its hydride is believed to be responsible for these.

Tuning synergy between nickel and iron in Ruddlesden-Popper perovskites through controllable crystal dimensionalities towards enhanced oxygenevolving activity and stability

Ni-Fe-based oxides are among the most promising catalysts developed to date for the bottleneck oxygen evolution reaction(OER)in water electrolysis.However,understanding and mastering the synergy of Ni and Fe remain challenging.Herein,we report that the synergy between Ni and Fe can be tailored by crystal dimensionality of Ni,Fe-contained Ruddlesden-Popper(RP)-type perovskites(La_(0.125)Sr_(0.875))n+1(Ni_(0.25)Fe_(0.75))nO3n+1(n=1,2,3),where the material with n=3 shows the best OER performance in alkaline media.Soft X-ray absorption spectroscopy spectra before and after OER reveal that the material with n=3 shows enhanced Ni/Fe-O covalency to boost the electron transfer as compared to those with n=1 and n=2.Further experimental investigations demonstrate that the Fe ion is the active site and the Ni ion is the stable site in this system,where such unique synergy reaches the optimum at n=3.Besides,as n increases,the proportion of unstable rock-salt layers accordingly decreases and the leaching of ions(especially Sr^(2+))into the electrolyte is suppressed,which induces a decrease in the leaching of active Fe ions,ultimately leading to enhanced stability.This work provides a new avenue for rational catalyst design through the dimensional strategy.

Magneto‑Dielectric Synergy and Multiscale Hierarchical Structure Design Enable Flexible Multipurpose Microwave Absorption and Infrared Stealth Compatibility

Developing advanced stealth devices to cope with radar-infrared(IR)fusion detection and diverse application scenarios is increasingly demanded,which faces significant challenges due to conflicting microwave and IR cloaking mechanisms and functional integration limitations.Here,we propose a multiscale hierarchical structure design,integrating wrinkled MXene IR shielding layer and flexible Fe_(3)O_(4)@C/PDMS microwave absorption layer.The top wrinkled MXene layer induces the intensive diffuse reflection effect,shielding IR radiation signals while allowing microwave to pass through.Meanwhile,the permeable microwaves are assimilated into the bottom Fe_(3)O_(4)@C/PDMS layer via strong magneto-electric synergy.Through theoretical and experimental optimization,the assembled stealth devices realize a near-perfect stealth capability in both X-band(8–12 GHz)and long-wave infrared(8–14μm)wavelength ranges.Specifically,it delivers a radar cross-section reduction of−20 dB m^(2),a large apparent temperature modulation range(ΔT=70℃),and a low average IR emissivity of 0.35.Additionally,the optimal device demonstrates exceptional curved surface conformability,self-cleaning capability(contact angle≈129°),and abrasion resistance(recovery time≈5 s).This design strategy promotes the development of multispectral stealth technology and reinforces its applicability and durability in complex and hostile environments.

医科达Synergy医用电子直线加速器故障维修六例

放射治疗是利用放射线治疗肿瘤的医疗方式[1]。医用电子直线加速器作为医院开展放射治疗的重要医疗设备,在肿瘤治疗中发挥重要作用。同时,医用电子直线加速器的技术结构复杂,组成模块、系统、零部件多,集成度高,设备具有“唯一性”、故障风险大等特点,如出现故障不能及时解决,可影响患者治疗效果,严重时甚至会造成不可逆性的重大损伤[2]。目前,医科达Synergy医用电子直线加速器的市场占有率较高,其通信模块较多、运动结构相对复杂,故障率较高。本研究以我院在用的医科达Synergy医用电子直线加速器为例,对其结构原理及6例故障维修过程进行总结分析,以供同行借鉴和参考。

Long-range electron synergy over Pt_(1)-Co_(1)/CN bimetallic single-atom catalyst in enhancing charge separation for photocatalytic hydrogen production

The development of novel single-atom catalysts with optimal electron configuration and economical noble-metal cocatalyst for efficient photocatalytic hydrogen production is of great importance,but still challenging.Herein,we fabricate Pt and Co single-atom sites successively on polymeric carbon nitride(CN).In this Pt_(1)-Co_(1)/CN bimetallic single-atom catalyst,the noble-metal active sites are maximized,and the single-atomic Co_(1)N_4sites are tuned to Co_(1)N_3sites by photogenerated electrons arising from the introduced single-atomic Pt_(1)N_4sites.Mechanism studies and density functional theory(DFT)calculations reveal that the 3d orbitals of Co_(1)N_3single sites are filled with unpaired d-electrons,which lead to the improved visible-light response,carrier separation and charge migration for CN photocatalysts.Thereafter,the protons adsorption and activation are promoted.Taking this advantage of long-range electron synergy in bimetallic single atomic sites,the photocatalytic hydrogen evolution activity over Pt_(1)-Co_(1)/CN achieves 915.8 mmol g^(-1)Pt h^(-1),which is 19.8 times higher than Co_(1)/CN and 3.5 times higher to Pt_(1)/CN.While this electron-synergistic effect is not so efficient for Pt nanoclusters.These results demonstrate the synergistic effect at electron-level and provide electron-level guidance for the design of efficient photocatalysts.

Trade-off and Synergy of Rural Functions Under County Depopulation in the Typical Black Soil Region of Northeast China

As the population continues to shrink in the black soil region of Northeast China since 2000,it is critical to master the impact of population shrinkage on rural functions to realize rural revitalization and sustainable development.In this study,we focused on the impacts of depopulation on the evolution and interrelationship of rural subfunctions.Based on the rural function indexes system,the TOPSIS(Technique for Order Preference by Similarity to an Ideal Solution)method,spatial analysis method,and mathematical statistics analysis method were used to summarize the spatial and temporal characteristics of rural function development,as well as the effect of population shrinkage in the typical black soil region of Northeast China.The results showed that depopulation varied in the extent and duration between the forested region and plain areas,which both impacted the trajectories of rural subfunctions evolution.For the economic development function and ecological conservation function,the effect of continuous slight depopulation was beneficial,while the effect of rapid depopulation was adverse,which was exactly opposite to the agricultural production function.All forms of population shrinkage were conducive to the development of the social security function.With the deepening population shrinkage,depopulation mainly promoted the collaborative development between subfunctions in this study,except the relationship between agricultural production and social security function.But effects of depopulation on the interrelationship of rural subfunctions varied between the forested region and plain areas in some cases.The results provided evidence for the cognition that population shrinkage had complicated effects on rural subfunctions.

Regulating the synergy coefficient of composite materials for alleviating self-discharge of supercapacitors

Supercapacitor is an efficient energy storage device,yet its wider application is still limited by self-discharge.Currently,various composite materials have been reported to have improved inhibition on self-discharge,while the evaluation of the synergistic effect in composite materials is challenging.Herein,pairs of intercalation type pseudocapacitive niobium oxides are pre-lithiated and coupled to construct conjugatedly configured supercapacitors,within which the cathode and anode experience identical reaction environment with single type of charge carrier,thus providing ideal platform to quantify the synergistic effect of composite materials on the self-discharge process.By using titanium dioxide as the stabilizer,we have compared how the modes of forming composite would influence the selfdischarge performance of the active composite materials with similar ratio of the constituent materials.Specifically,core@shell Nb_(2)O_(5)@TiO_(2) composite using TiO_(2) as the shell shows significantly higher synergy coefficient(μ=0.61,defined as the value that evaluates the synergistic effect between composite materials,and can be quantified using the overall performance of the composite,performance of individual component as well as the ratio of the component.) than other control group samples,which corresponds to the highest retained energy of 63% at 100 h.This work is expected to provide a general method for quantifying the synergistic effect and guide the design of composite materials with specific mode of forming the composite.

煤炭工业数字智能绿色三化协同模式与新质生产力建设路径

煤炭工业是支撑我国经济社会高速发展和保障国家能源安全的压舱石与稳定器,承担着能源保供与支撑新能源稳定发展的时代使命,煤炭工业的高质量发展既是落实我国能源安全新战略与产业体系变革的关键,也是推进能源产业可持续发展与促进国家高质量发展的基础。当前我国煤炭工业高质量发展已取得阶段成效,能源保供成绩显著,产业结构不断优化,科技创新能力显著提高,绿色开发与清洁高效利用持续推进。但当前煤炭工业仍面临诸多挑战,发展水平与中国式现代化的国家需求差距较大,可持续发展受多重因素制约,数字技术与煤炭开发利用尚未深度融合,智能化建设仍处于示范培育阶段,绿色化发展不平衡且矛盾突出,煤炭工业的转型升级仍然任重道远。结合当前煤炭工业发展现状与挑战,提出了数字化、智能化、绿色化(三化)协同的发展模式,明确了煤炭新质生产力的核心内涵,构建了三化协同发展煤炭新质生产力的总体架构,阐述了通过数字化变革生产要素创新配置、智能化引领关键技术跨越突破、绿色化主导传统产业深度转型三大要素催生煤炭新质生产力的技术路径,提出了六大技术体系:通过研发全产业链数据高效采集与深度治理技术体系,打通煤炭产—运—储—销—用全流程的数据壁垒;通过研发构建煤炭行业知识图谱与智能决策管控技术体系,深度挖掘煤炭产业上下游各业务场景的关联关系与价值,为煤炭生产利用全流程的自主决策与智能控制奠定基础;开展煤炭资源智能-绿色-高效开发技术体系、煤炭产业安全协同保障技术体系、矿区生态智能监测-预警-修复技术体系、煤炭柔性开发与清洁低碳利用技术体系研究,实现煤炭开发利用全产业链、全流程的三化协同发展,培育形成煤炭新质生产力,为煤炭工业的整体形象带来根本性变革提升。

Evaluation of Disk Potentiation Test (DPT) and Double Disk Synergy Test (DDST) for The Detection of Metallo-β-Lactamases (MBLs) in Clinical Isolates of Bangladesh

Objective: Increasing the emergence of Metallo-β-lactamase (MBL) producing gram-negative bacteria and their dexterous horizontal transmission demands rapid and accurate detection. This study was conducted to determine a suitable method to promptly detect MBL-producing gram-negative bacteria. Methods: A total of 103 gram-negative bacteria were identified from various clinical samples at a tertiary care hospital in Dhaka city. MBL producers were detected by two phenotypic methods, the Disk Potentiation Test (DPT) and the Double Disk Synergy Test (DDST) based on β-lactam chelator combinations where EDTA/SMA has been used as an inhibitor and Imipenem, Ceftazidime as substrates. Results: 103 isolates which were identified as Escherichia coli spp, Klebsiella spp, Pseudomonas spp, Acinetobacter spp, Proteus spp, Providencia spp were found to be multidrug-resistant in antibiogram test. Isolates showed complete resistance (100%) to Imipenem, Meropenem, and Amoxiclav. The highest carbapenem-resistant etiological agents were Acinetobacter spp 40 (38.8%) followed by Pseudomonas spp 27 (26.2%), Klebsiella spp 26 (25.2%), Escherichia coli 8 (7.8%), Proteus spp 1 (1%) and Providencia spp 1 (1%). DPT method detected significantly (p = 0.000009) a higher number of MBL-producers (Imipenem with 0.5 M EDTA n = 61, 59.2% & Ceftazidime with 0.5 M EDTA n = 56, 54.4%) compared to the DDST method (Imipenem -0.5 M EDTA n = 43, 41.7%, Imipenem – SMA n = 38, 36.9% & Ceftazidime -0.5 M EDTA n = 15, 14.6%). Conclusion: Pieces of evidence suggest that DPT is a more sensitive method than DDST and could be recommended for identifying MBL-producing bacteria in Bangladeshi hospitals for the proper management of patients, to reduce time constraints and treatment costs.

Exploring the Goal Synergy between the Ecological Carrying Capacity of Miyun District and the Development of the Ecological Home-stay Industry in Beijing

Green construction in culture and environmental protection will be the development trend in a long run,the urban and suburban area will be ecologically developed as well.Rural revitalization must adhere to the position of historical progress theory and modern concepts,innovate spatial layout,optimize ecological resources,and appropriately determine its historical significance and sustainable development responsibility with reasonable value orientation and environmental ecological carrying capacity for local ecological construction.In order to achieve this responsibility,the authors must expand the dimensions to consider more relevant factors.The guarantee of ecological carrying capacity is an important means to ensure the promotion of ecological civilization.This paper aims to integrate and regulate the goal synergy of the cultural development of the home-stay industry in Miyun District of Beijing by means of the innovative model of sustainable economic development of cultural ecology,ecological people,ecological health preservation and rich home-stay ecological elements.Assuming that the role of the former in promoting the latter can be expanded,then in the range of ecological and cultural towns(conceptual model)that maintain a certain tolerance of ecological carrying capacity,as a characteristic home-stay industry in Miyun,there will be some effective growth,so the integration and development of multiple cultural genes and elements must be the ecological and cultural town model under the enhanced multi-factor aggregation effect,(See the ecological environment carrying capacity development goal A:A=B12345+C1234567 later).This article will explain that the development goals of Miyun's ecological culture and the ecological homestay industry are coordinated,and the two are mutually raised in the same direction.

直播电商背景下国货品牌崛起的演化机制研究

借助直播平台优势,通过政府扶持,实现国货品牌崛起,在当前经济形势下成为大势所趋。考虑政府、直播电商平台和国货品牌方的有限理性,构建三方演化博弈模型,研究不同环境条件下各博弈主体的策略选择。分析结果表明:在直播电商行业发展的不同阶段,直播电商平台和政府部门的策略选择不同,在直播电商行业发展初期,直播平台违规经营动机强烈,政府创新监管动力不足,国货品牌难以突破发展瓶颈;而在条件成熟时,政府和平台合力支持国货品牌发展,实现国货品牌崛起。

地方环境立法、环境司法与企业绿色创新--基于立法与司法协同视角

企业绿色创新是人与自然和谐现代化的基础和托底,是企业实施绿色转型战略的必然路径。基于机器学习和文本分析法从经济价值导向维度和生态价值导向维度衡量企业绿色创新,并以2007年开始陆续在全国各地设置专门环境法庭为背景,将地方环境立法与环境司法纳入同一分析框架,利用2004-2020年中国A股上市公司数据,研究地方环境立法与环境司法协同对企业绿色创新的影响。研究发现,环境立法和环境司法具有促进企业绿色创新的协同作用,这一结论在进行一系列稳健性检验后仍然成立;机制检验结果表明,环境司法协同环境立法能够通过增加企业环境成本和促进企业主动进行绿色战略调整来驱动企业进行绿色创新;通过进一步分析发现,相较于经济价值导向绿色创新,企业更加倾向选择生态价值导向绿色创新,并且在国有企业、成本转嫁能力低的企业、处于经济上行期的企业、处于官员绿色政绩考核时期的企业以及管制行业企业中,协同作用更加显著。研究结果拓展了企业绿色创新的驱动因素,对政府推进环境治理、加速企业绿色转型提供了重要启示。

Tunnel Support Structure System and Its Synergy

The tunnel support system is composed of lining,bolt,and steel frame.It is of great significance to effectively control the deformation of the surrounding rock of the tunnel,make full use of the characteristics of different support methods,and formulate an economical and effective support plan to ensure the safe operation of the tunnel structure.This paper clarifies the synergistic relationship between the support structure and the surrounding rock based on their fundamental characteristics and functions.Various support structures and components are also discussed in this paper.Additionally,the paper presents an optimized design of the tunnel support structure system.

着眼未来教育家的教育博士培养模式构建

教育博士专业学位的设立是我国博士学位制度的一项重大创新,是培养造就未来教育家的重要途径,对建设教育强国具有先导性、基础性、战略性作用。构建一个既符合教育博士类别要求又能彰显教育博士规格质量的培养模式,是一个重大的理论与实践课题。本文结合东北师范大学的实践探索,从教育博士培养改革的时代之需、他山之石、理论之基、实践之径四个方面,阐释“目标导向、理实互构、三维协同”教育博士培养模式的理论内涵与实践路径,以期能为建构具有中国特色的教育博士培养模式提供参考和借鉴。

农村产业扶持政策协同致富的效应和机制——基于电商与旅游的实证分析

仓廪实则天下安,生活富裕的实现需要多方政策协同发力。本文基于2005-2019年1562个县域样本,设计三种情景来评估农村电商和乡村旅游两类产业扶持政策能否对农户生活富裕产生协同作用。结果表明:这两类政策各自均能促进农民生活富裕,而且两者共同实施能够产生更大的效应,利用PSM-DID作为稳健性检验也同样证实存在政策协同效应。更进一步,在进行异质性分析和机理检验后,发现西部地区的政策协同致富效应更为明显,且与单一政策相比,农村电商和乡村旅游间的政策协同可以通过促进乡村创业、非农就业来发挥更大作用。本文从协同视角考量农村电商、乡村旅游的政策效应,为多部门政策决策提供借鉴意义,以期形成合力助推于农民生活富裕和乡村振兴。

基于控保协同的有源配网主动注入式保护方法

由于逆变型分布式电源(inverter-interfaced distributed generation,IIDG)的故障特性主要由其控制策略及电网故障情况决定,在不同故障场景和工况下,传统的被动式保护方法存在保护整定和协调困难的问题。为此,提出一种基于控保协同的有源配网主动注入式保护方法,故障期间控制IIDG主动向电网注入特征信号,保护处利用检测到的特征信号来获取IIDG的基波信息,从而消除IIDG对各支路电流及现有电流保护的影响。由于保护利用的故障特征是由IIDG主动注入的,因此该方法在不同场景和工况下都有较好的适用性,且不需要增加额外的通信和检测设备,具有经济性好和实用性高的优点。仿真结果验证了所提方法的有效性。

多元协同的中国国际传播交往行动网络构建

顺应全球交往语境与数字智能时代的趋势与要求,中国国际传播研究应从单一的信息传播向国际交往发生转向,这一转向应基于交往理论,关注在数字时代国际交往对传统国际传播的发展与升维。因此本文基于国际传播的交往转向,从行动网络构建这一路径切入探讨国际传播中多元交往主体的关系形态变化,并构建多元协同的中国国际传播交往行动网络。本文首先对中国国际传播交往行动网络进行分解,认为该网络是多层次、多维度的,主要的层次和维度为五个方面:交往主体、交往规则、交往关系、交往媒介以及交往形态。因此,本文从多位一体的国际传播交往主体格局构建、多层次的交往规则网络构建、复合型的交往关系网络构建、多维度的交往媒介网络构建以及多方位的交往形态网络构建五个方面出发,构建多元协同的中国国际传播交往行动网络。

基于空间溢出视角下金融科技对企业数字化转型的影响

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