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一种具有超高温工程应用潜力的氮化物增强NbMoTaWHfN难熔高熵合金 Article

万义兴, 程延海, Yongxiong Chen, Zhibin Zhang, Yanan Liu, Haijun Gong, Baolong Shen, Xiubing Liang

《工程（英文）》 2023年 第30卷 第11期   页码 110-120 doi: 10.1016/j.eng.2023.06.008

摘要：

Refractory high-entropy alloys (RHEAs) have promising applications as the new generation of high-temperature alloys in hypersonic vehicles, aero-engines, gas turbines, and nuclear power plants. This study focuses on the microstructures and mechanical properties of the NbMoTaW(HfN)x (x = 0, 0.3, 0.7, and 1.0) RHEAs. The alloys consist of multiple phases of body-centered cubic (BCC), hafnium nitride (HfN), or multicomponent nitride (MN) phases. As the x contents increase, the grain size becomes smaller, and the strength gradually increases. The compressive yield strengths of the NbMoTaWHfN RHEA at ambient temperature, 1000, 1400, and 1800 °C were found to be 1682, 1192, 792, and 288 MPa, respectively. The high-temperature strength of this alloy is an inspiring result that exceeds the high temperature and strength of most known alloys, including high-entropy alloys, refractory metals, and superalloys. The HfN phase has a significant effect on strengthening due to its high structural stability and sluggish grain coarsening, even at ultra-high temperatures. Its superior properties endow the NbMoTaWHfN RHEA with potential for a wide range of engineering applications at ultra-high temperatures. This work offers a strategy for the design of high-temperature alloys and proposes an ultra-high-temperature alloy with potential for future engineering applications.

关键词： Refractory high-entropy alloy     High temperature     Mechanical property     Microstructure     Strengthening mechanism    

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Rapid alloying of CoCrFeMnNi high-entropy alloy from elemental feedstock toward high-throughput synthesis

《机械工程前沿（英文）》 2023年 第18卷 第1期 doi: 10.1007/s11465-022-0727-x

摘要： High-entropy alloys (HEAs) are considered alternatives to traditional structural materials because of their superior mechanical, physical, and chemical properties. However, alloy composition combinations are too numerous to explore. Finding a rapid synthesis method to accelerate the development of HEA bulks is imperative. Existing in situ synthesis methods based on additive manufacturing are insufficient for efficiently controlling the uniformity and accuracy of components. In this work, laser powder bed fusion (L-PBF) is adopted for the in situ synthesis of equiatomic CoCrFeMnNi HEA from elemental powder mixtures. High composition accuracy is achieved in parallel with ensuring internal density. The L-PBF-based process parameters are optimized; and two different methods, namely, a multi-melting process and homogenization heat treatment, are adopted to address the problem of incompletely melted Cr particles in the single-melted samples. X-ray diffraction indicates that HEA microstructure can be obtained from elemental powders via L-PBF. In the triple-melted samples, a strong crystallographic texture can be observed through electron backscatter diffraction, with a maximum polar density of 9.92 and a high ultimate tensile strength (UTS) of (735.3 ± 14.1) MPa. The homogenization heat-treated samples appear more like coarse equiaxed grains, with a UTS of (650.8 ± 16.1) MPa and an elongation of (40.2% ± 1.3%). Cellular substructures are also observed in the triple-melted samples, but not in the homogenization heat-treated samples. The differences in mechanical properties primarily originate from the changes in strengthening mechanism. The even and flat fractographic morphologies of the homogenization heat-treated samples represent a more uniform internal microstructure that is different from the complex morphologies of the triple-melted samples. Relative to the multi-melted samples, the homogenization heat-treated samples exhibit better processability, with a smaller composition deviation, i.e., ≤ 0.32 at.%. The two methods presented in this study are expected to have considerable potential for developing HEAs with high composition accuracy and composition flexibility.

关键词： laser powder bed fusion (L-PBF)     in situ alloying     high-entropy alloys     heat treatment     rapid synthesis    

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高熵合金材料研究进展与展望

李天昕,王书道,卢一平,曹志强 ,王同敏,李廷举

《中国工程科学》 2023年 第25卷 第3期   页码 170-181 doi: 10.15302/J-SSCAE-2023.03.016

摘要：

随着世界科技水平的快速发展以及国民经济建设对高性能合金材料的迫切需求，传统单一主元合金逐渐不能满足人们与日俱增的使役需求。高熵合金因其独特的物理、化学以及力学性能，极大地拓展了金属材料成分设计范围，有望在国防、航空、航天、海洋、核能、医疗、新能源等重大工程领域发挥重要作用。本文结合各领域对先进高熵合金材料的具体需求，梳理了高熵合金材料的特征和内涵，分析了高熵合金材料发展的整体形势与前景，厘清了国内外高熵合金的发展现状。在此基础上，指出了我国高熵合金领域存在的差距和不足，我国高熵合金部分基础原材料依赖进口，严重威胁产业链安全；高熵合金产学研用体系尚未健全，工业化应用方面的研发投入有待提高。针对上述问题，研究建议，加强高熵合金材料研发的顶层设计，完善产业政策；加强企业和科研机构的对接和沟通；完善高熵合金材料标准、测试、表征、评价体系；推进人才队伍建设；降低材料成本，打造高附加值产品，促进我国先进高熵合金材料产业朝着体系化、绿色化、高端化、智能化方向发展。

关键词： 高熵合金；新材料；有色金属；关键战略材料；结构材料；功能材料    

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High-entropy catalysts for electrochemical water-electrolysis of hydrogen evolution and oxygen evolution

《能源前沿（英文）》 doi: 10.1007/s11708-023-0892-6

摘要： High entropy materials (HEMs) have developed rapidly in the field of electrocatalytic water-electrolysis for oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) due to their unique properties. In particular, HEM catalysts are composed of many elements. Therefore, they have rich active sites and enhanced entropy stability relative to single atoms. In this paper, the preparation strategies and applications of HEM catalysts in electrochemical water-electrolysis are reviewed to explore the stabilization of HEMs and their catalytic mechanisms as well as their application in support green hydrogen production. First, the concept and four characteristics of HEMs are introduced based on entropy and composition. Then, synthetic strategies of HEM catalysts are systematically reviewed in terms of the categories of bottom-up and top-down. The application of HEMs as catalysts for electrochemical water-electrolysis in recent years is emphatically discussed, and the mechanisms of improving the performance of electrocatalysis is expounded by combining theoretical calculation technology and ex-situ/in situ characterization experiments. Finally, the application prospect of HEMs is proposed to conquer the challenges in HEM catalyst fabrications and applications.

关键词： high-entropy     electrocatalysis     synthetic methods     water-electrolysis     hydrogen and oxygen evolutions    

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High-order phase-field model with the local and second-order max-entropy approximants

Fatemeh AMIRI

《结构与土木工程前沿（英文）》 2019年 第13卷 第2期   页码 406-416 doi: 10.1007/s11709-018-0475-5

摘要： We approximate the fracture surface energy functional based on phase-field method with smooth local maximum entropy (LME) and second-order maximum entropy (SME) approximants. The higher-order continuity of the meshfree methods such as LME and SME approximants allows to directly solve the fourth-order phase-field equations without splitting the fourth-order differential equation into two second-order differential equations. We will first show that the crack surface functional can be captured more accurately in the fourth-order model with smooth approximants such as LME, SME and B-spline. Furthermore, smaller length scale parameter is needed for the fourth-order model to approximate the energy functional. We also study SME approximants and drive the formulations. The proposed meshfree fourth-order phase-field formulation show more stable results for SME compared to LME meshfree methods.

关键词： second-order maximum entropy     local maximum entropy     second- and fourth-order phase-field models     B-spline    

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Grindability of high-temperature alloy with ceramic alumina wheels

ZHANG Hongxia, CHEN Wuyi, CHEN Zhitong

《机械工程前沿（英文）》 2008年 第3卷 第2期   页码 139-145 doi: 10.1007/s11465-008-0040-3

摘要： The grindability of high-temperature alloy by using ceramic alumina wheels is studied on the basis of extensive analysis of the grinding force, grinding temperature, surface roughness and topography of ground surfaces, residual stress, hardness distribution of surface layer, and morphology of the surface layer from a metallographic point of view. The grinding burn mechanism of high-temperature alloy is unveiled and the feasible grinding parameters to avoid burning are analyzed. Some conclusions are obtained as follows. Increasing the grinding depth or the wheel velocity makes grinding temperature and residual tensile stress of the surface rise, which deteriorates the surface topography. Appropriate liner velocity of the wheel is 18–22 m/s and the depth of grinding should not exceed 0.02 mm in grinding GH2132 alloy with ceramic alumina wheels to assure the surface quality. When increases enough to cause grinding burn, the strengthening effect of particles ′ in base decrease and the micro-hardness of the surface is obviously lower than that of the base material, which deteriorates the mechanical properties and heat resistance of GH2132 alloy. Results provide a theoretical and experimental basis for technical optimization in the grinding of high-temperature alloy with high efficiency and high quality.

关键词： metallographic     topography     grinding GH2132     resistance     decrease    

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Formic acid dehydrogenation reaction on high-performance PdAu alloy nanoparticles prepared by the eco-friendly

《能源前沿（英文）》   页码 751-762 doi: 10.1007/s11708-023-0895-3

摘要： Dehydrogenation of formic acid (FA) is considered to be an effective solution for efficient storage and transport of hydrogen. For decades, highly effective catalysts for this purpose have been widely investigated, but numerous challenges remain. Herein, the PdxAu1−x (x = 0, 0.2, 0.4, 0.5, 0.6, 0.8, 1) alloys over the whole composition range were successfully prepared and used to catalyze FA hydrogen production efficiently near room temperature. Small PdAu nanoparticles (5–10 nm) were well-dispersed and supported on the activated carbon to form PdAu solid solution alloys via the eco-friendly slow synthesis methodology. The physicochemical properties of the PdAu alloys were comprehensively studied by utilizing various measurement methods, such as X-ray diffraction (XRD), N2 adsorption–desorption, high angle annular dark field-scanning transmission electron microscope (HAADF-STEM), X-ray photoelectrons spectroscopy (XPS). Notably, owing to the strong metal-support interaction (SMSI) and electron transfer between active metal Au and Pd, the Pd0.5Au0.5 obtained exhibits a turnover frequency (TOF) value of up to 1648 h−1 (313 K, nPd+Au/nFA = 0.01, nHCOOH/nHCOONa = 1:3) with a high activity, selectivity, and reusability in the FA dehydrogenation.

关键词： FA dehydrogenation     face-centred cubic structures     PdAu solid solution alloy nanoparticles     slow synthesis methodology     SMSI effect    

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Phase I study of CBM.CD19 chimeric antigen receptor T cell in the treatment of refractory diffuse large

《医学前沿（英文）》 2022年 第16卷 第2期   页码 285-294 doi: 10.1007/s11684-021-0843-8

摘要： Anti-CD19 chimeric antigen receptor (CAR) T cell therapy has shown impressive efficacy in treating B-cell malignancies. A single-center phase I dose-escalation study was conducted to evaluate the safety and efficacy of T cells transduced with CBM.CD19 CAR, a second-generation anti-CD19 CAR bearing 4-1BB costimulatory molecule, for the treatment of patients with refractory diffuse large B-cell lymphoma (DLBCL). Ten heavily treated patients with refractory DLBCL were given CBM.CD19 CAR-T cell (C-CAR011) treatment. The overall response rate was 20% and 50% at 4 and 12 weeks after the infusion of C-CAR011, respectively, and the disease control rate was 60% at 12 weeks after infusion. Treatment-emergent adverse events occurred in all patients. The incidence of cytokine release syndrome in all grades and grade≥3 was 90% and 0, respectively, which is consistent with the safety profile of axicabtagene ciloleucel and tisagenlecleucel. Neurotoxicity or other dose-limiting toxicities was not observed in any dose cohort of C-CAR011 therapy. Antitumor efficacy was apparent across dose cohorts. Therefore, C-CAR011 is a safe and effective therapeutic option for Chinese patients with refractory DLBCL, and further large-scale clinical trials are warranted.

关键词： CAR-T cell therapy     refractory diffuse large B-cell lymphoma     cytokine release syndrome     dose-limiting toxicity    

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Principle of maximum entropy for reliability analysis in the design of machine components

Yimin ZHANG

《机械工程前沿（英文）》 2019年 第14卷 第1期   页码 21-32 doi: 10.1007/s11465-018-0512-z

摘要： We studied the reliability of machine components with parameters that follow an arbitrary statistical distribution using the principle of maximum entropy (PME). We used PME to select the statistical distribution that best fits the available information. We also established a probability density function (PDF) and a failure probability model for the parameters of mechanical components using the concept of entropy and the PME. We obtained the first four moments of the state function for reliability analysis and design. Furthermore, we attained an estimate of the PDF with the fewest human bias factors using the PME. This function was used to calculate the reliability of the machine components, including a connecting rod, a vehicle half-shaft, a front axle, a rear axle housing, and a leaf spring, which have parameters that typically follow a non-normal distribution. Simulations were conducted for comparison. This study provides a design methodology for the reliability of mechanical components for practical engineering projects.

关键词： machine components     reliability     arbitrary distribution parameter     principle of maximum entropy    

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Experimental investigation of liquid metal alloy based mini-channel heat exchanger for high power electronic

Manli LUO, Jing LIU

《能源前沿（英文）》 2013年 第7卷 第4期   页码 479-486 doi: 10.1007/s11708-013-0277-3

摘要： There is currently a growing demand for developing efficient techniques for cooling integrated electronic devices with ever increasing heat generation power. To better tackle the high-density heat dissipation difficulty within the limited space, this paper is dedicated to clarify the heat transfer behaviors of the liquid metal flowing in mini-channel exchangers with different geometric configurations. A series of comparative experiments using liquid metal alloy Ga68%In20%Sn12% as coolant were conducted under prescribed mass flow rates in three kinds of heat exchangers with varied geometric sizes. Meanwhile, numerical simulations for the heat exchangers under the same working conditions were also performed which well interpreted the experimental measurements. The simulated heat sources were all cooled down by these three heat dissipation apparatuses and the exchanger with the smallest channel width was found to have the largest mean heat transfer coefficient at all conditions due to its much larger heat transfer area. Further, the present work has also developed a correlation equation for characterizing the Nusselt number depending on Peclet number, which is applicable to the low Peclet number case with constant heat flux in the hydrodynamically developed and thermally developing region in the rectangular channel. This study is expected to provide valuable reference for designing future liquid metal based mini-channel heat exchanger.

关键词： heat exchanger     liquid metal     mini-channel     heat dissipation     heat transfer coefficient    

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先进铜合金材料发展现状与展望

姜业欣, 娄花芬, 解浩峰, 李廷举, 宋克兴, 刘雪峰, 运新兵, 汪航, 肖柱, 李周

《中国工程科学》 2020年 第22卷 第5期   页码 84-92 doi: 10.15302/J-SSCAE-2020.05.015

摘要：

本文针对我国电工电子、新一代移动通信、新能源汽车、航空航天、轨道交通等新兴产业和重大工程领域对先进铜合金材料的典型需求，梳理了国内外高强高导铜合金、耐磨耐蚀铜合金、超高强弹性铜合金、先进铜基复合材料、高精度铜及铜合金细微丝、超薄箔材的发展现状和差距。在此基础上分析了上述先进铜合金的典型市场需求，论证了我国先进铜合金材料的中长期发展目标和关键技术。研究还提出了促进“产学研用管”的统筹规划和一体化发展，提升装备开发、技术研发和市场拓展能力，强化产品标准研究与制定，建立青年科技骨干人才培养体系的产业发展建议。期望以国民经济重点领域和国防建设需求为导向，通过铜合金材料、装备、技术、产业化等自主创新体系的完善，促进我国先进铜合金材料绿色、高端、智能发展。

关键词： 铜合金     高强度     高精度     功能应用    

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Maximum entropy based finite element analysis of porous media

Emad NOROUZI, Hesam MOSLEMZADEH, Soheil MOHAMMADI

《结构与土木工程前沿（英文）》 2019年 第13卷 第2期   页码 364-379 doi: 10.1007/s11709-018-0470-x

摘要： The maximum entropy theory has been used in a wide variety of physical, mathematical and engineering applications in the past few years. However, its application in numerical methods, especially in developing new shape functions, has attracted much interest in recent years. These shape functions possess the potential for performing better than the conventional basis functions in problems with randomly generated coarse meshes. In this paper, the maximum entropy theory is adopted to spatially discretize the deformation variable of the governing coupled equations of porous media. This is in line with the well-known fact that higher-order shape functions can provide more stable solutions in porous problems. Some of the benchmark problems in deformable porous media are solved with the developed approach and the results are compared with available references.

关键词： maximum entropy FEM     fully coupled multi-phase system     porous media    

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硼中子俘获疗法治疗脑胶质瘤及难治性垂体腺瘤的现状及展望

代从新,姚勇,王任直

《中国工程科学》 2012年 第14卷 第8期   页码 96-99

摘要：

硼中子俘获疗法在脑胶质瘤治疗研究中已经取得很大进展，但由于脑胶质瘤的特性以及缺乏与肿瘤高亲和力的掺硼药物，硼中子俘获治疗的效果并不十分理想。此外，难治性垂体腺瘤具有很多与脑胶质瘤相同的特点，硼中子俘获疗法可能具有一定的意义。文章重点介绍硼中子俘获疗法治疗脑胶质瘤的研究现状和治疗难治性垂体腺瘤的可能性。

关键词： 硼中子俘获疗法     胶质瘤     难治性垂体腺瘤    

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Polypyrrole@NiCo hybrid nanotube arrays as high performance electrocatalyst for hydrogen evolution reaction

Shenghua Ye, Gaoren Li

《化学科学与工程前沿（英文）》 2018年 第12卷 第3期   页码 473-480 doi: 10.1007/s11705-018-1724-9

摘要：

The polypyrrole(PPy)@NiCo hybrid nanotube arrays have been successfully fabricated as a high performance electrocatalyst for hydrogen evolution reaction (HER) in alkaline solution. The strong electronic interactions between PPy and NiCo alloy are confirmed by X-ray photoelectron spectroscopy and Raman spectra. Because these interations can remarkably reduce the apparent activation energy (Ea) for HER and enhance the turnover frequency of catalysts, the electrocatalytic performance of PPy@NiCo hybrid nanotube arrays are significantly improved. The electrochemical tests show that the PPy@NiCo hybrid catalysts exhibit a low overpotential of ~186 mV at 10.0 mA·cm−2 and a small tafel slope of 88.6 mV·deg−1 for HER in the alkaline solution. The PPy@NiCo hybrid nanotubes also exhibit high catalytic activity and high stability for HER.

关键词： NiCo alloy     polypyrrole     hybrid nanotube     electrocatalyst     hydrogen evolution reaction    

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Degradation of refractory organics in concentrated leachate by the Fenton process: Central composite

Senem Yazici Guvenc, Gamze Varank

《环境科学与工程前沿（英文）》 2021年 第15卷 第1期 doi: 10.1007/s11783-020-1294-1

摘要： Abstract • 90% total COD, 95.3% inert COD and 97.2% UV254 were removed. • High R2 values (over 95%) for all responses were obtained with CCD. • Operational cost was calculated to be 0.238 €/g CODremoved for total COD removal. • Fenton oxidation was highly-efficient method for inert COD removal. • BOD5/COD ratio of leachate concentrate raised from 0.04 to 0.4. The primary aim of this study is inert COD removal from leachate nanofiltration concentrate because of its high concentration of resistant organic pollutants. Within this framework, this study focuses on the treatability of leachate nanofiltration concentrate through Fenton oxidation and optimization of process parameters to reach the maximum pollutant removal by using response surface methodology (RSM). Initial pH, Fe2+ concentration, H2O2/Fe2+ molar ratio and oxidation time are selected as the independent variables, whereas total COD, color, inert COD and UV254 removal are selected as the responses. According to the ANOVA results, the R2 values of all responses are found to be over 95%. Under the optimum conditions determined by the model (pH: 3.99, Fe2+: 150 mmol/L, H2O2/Fe2+: 3.27 and oxidation time: 84.8 min), the maximum COD removal efficiency is determined as 91.4% by the model. The color, inert COD and UV254 removal efficiencies are determined to be 99.9%, 97.2% and 99.5%, respectively, by the model, whereas the total COD, color, inert COD and UV254 removal efficiencies are found respectively to be 90%, 96.5%, 95.3% and 97.2%, experimentally under the optimum operating conditions. The Fenton process improves the biodegradability of the leachate NF concentrate, increasing the BOD5/COD ratio from the value of 0.04 to the value of 0.4. The operational cost of the process is calculated to be 0.238 €/g CODremoved. The results indicate that the Fenton oxidation process is an efficient and economical technology in improvement of the biological degradability of leachate nanofiltration concentrate and in removal of resistant organic pollutants.

关键词： Concentrated leachate     Fenton oxidation     Central composite design     Biodegradability     Inert COD    

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标题 作者 时间 类型 操作

一种具有超高温工程应用潜力的氮化物增强NbMoTaWHfN难熔高熵合金

万义兴, 程延海, Yongxiong Chen, Zhibin Zhang, Yanan Liu, Haijun Gong, Baolong Shen, Xiubing Liang

期刊论文

Rapid alloying of CoCrFeMnNi high-entropy alloy from elemental feedstock toward high-throughput synthesis

期刊论文

高熵合金材料研究进展与展望

李天昕,王书道,卢一平,曹志强 ,王同敏,李廷举

期刊论文

High-entropy catalysts for electrochemical water-electrolysis of hydrogen evolution and oxygen evolution

期刊论文

High-order phase-field model with the local and second-order max-entropy approximants

Fatemeh AMIRI

期刊论文

Grindability of high-temperature alloy with ceramic alumina wheels

ZHANG Hongxia, CHEN Wuyi, CHEN Zhitong

期刊论文

Formic acid dehydrogenation reaction on high-performance PdAu alloy nanoparticles prepared by the eco-friendly

期刊论文

Phase I study of CBM.CD19 chimeric antigen receptor T cell in the treatment of refractory diffuse large

期刊论文

Principle of maximum entropy for reliability analysis in the design of machine components

Yimin ZHANG

期刊论文

Experimental investigation of liquid metal alloy based mini-channel heat exchanger for high power electronic

Manli LUO, Jing LIU

期刊论文

先进铜合金材料发展现状与展望

姜业欣, 娄花芬, 解浩峰, 李廷举, 宋克兴, 刘雪峰, 运新兵, 汪航, 肖柱, 李周

期刊论文

Maximum entropy based finite element analysis of porous media

Emad NOROUZI, Hesam MOSLEMZADEH, Soheil MOHAMMADI

期刊论文

硼中子俘获疗法治疗脑胶质瘤及难治性垂体腺瘤的现状及展望

代从新,姚勇,王任直

期刊论文

Polypyrrole@NiCo hybrid nanotube arrays as high performance electrocatalyst for hydrogen evolution reaction

Shenghua Ye, Gaoren Li

期刊论文

Degradation of refractory organics in concentrated leachate by the Fenton process: Central composite

Senem Yazici Guvenc, Gamze Varank

期刊论文