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Fe, V-co-doped C_(2)N for electrocatalytic N_(2)-to-NH_(3) conversion

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Journal of Energy Chemistry 2021年第2期30卷 303-308,I0010页

作者： Zengxi Wei Jian He Yulu Yang zhenhai xia Yuezhan Feng Jianmin Ma Advanced Catalytic Engineering Research Center of the Ministry of Education School of Physics and ElectronicsHunan UniversityChangsha 410082HunanChina Department of Materials Science and Engineering University of North TexasDentonUSA Key Laboratory of Materials Processing and Mold(Zhengzhou University) Ministry of EducationZhengzhou UniversityZhengzhou 450002HenanChina

Designing providential catalyst is the key to drive the electrochemical nitrogen reduction reactions(NRR),which is referring to multiple intermediates and products. By means of density functional theory(DFT)calculations, we studied heteronuclear bi-atom electrocatalyst(HBEC) for NRR. Our results revealed that compared to homonuclear bi-atom electrocatalyst(Fe_2@C_2N, V_2@C_2N), Fe, V-co-doped C_2N(Fe V@C_2N)had a smaller limiting potential of-0.17 V and could accelerate N_2-to-NH_3 conversion through the enzymatic pathway of NRR. Importantly, N–N bond length monotonically increases with increasing the Bader charges of adsorbed N_2 molecule but decreases with increasing the Bader charge difference of two adsorbed N atoms. Additionally, the Fe V@C_2N could suppress the production of H_2 by the preferential adsorption and reduction of N_2 molecule. Thus, the as-designed HBEC may have the outstanding electrochemical NRR performance. This work opens a new perspective for NRR by HBECs under mild conditions.

关键词： Heteronuclear bi-atom electrocatalyst Nitrogen reduction reaction Density functional theory C_(2)N Active center

Carbon-supported layered double hydroxide nanodots for efficient oxygen evolution: Active site identification and activity enhancement

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Nano Research 2021年第9期14卷 3329-3336页

作者： Shenlong Zhao Detao Zhang Shuai Jiang Yanglansen Cui Haijing Li Juncai Dong Zhirun Xie Da-Wei Wang Rose Amal zhenhai xia Liming Dai Australian Carbon Materials Centre(A-CMC) School of Chemical EngineeringThe University of New South WalesSydneyNSW 2052Australia Center of Advanced Science and Engineering for Carbon(Case4Carbon) Department of Macromolecular Science and EngineeringCase Western Reserve University(CWRU)10900 Euclid AvenueClevelandOH 44106USA School of Chemical and Biomolecular Engineering The University of SydneySydneyNSW 2006Australia Department of Materials Science and Engineering University of North TexasDentonTX 76203USA Beijing Synchrotron Radiation Facility Institute of High Energy PhysicsChinese Academy of SciencesBeijing 100049China School of Chemical Engineering The University of New South WalesSydneyNSW 2052Australia

In this study,we developed a novel confinement-synthesis approach to layered double hydroxide nanodots(LDH-NDs)anchored on carbon nanoparticles,which formed a three-dimensional(3D)interconnected network within a porous carbon support derived from pyrolysis of metal-organic frameworks(C-MOF).The resultant LDH-NDs@C-MOF nonprecious metal catalysts were demonstrated to exhibit super-high catalytic performance for oxygen evolution reaction(OER)with excellent operation stability and low overpotential(-230 mV)at an exchange current density of 10 mA·cm^(-2).The observed overpotential for the LDH-NDs@C-MOF is much lower than that of large-sized LDH nanosheets(321 mV),pure carbonized MOF(411 mV),and even commercial RuO_(2)(281 mV).X-ray absorption measurements and density functional theory(DFT)calculations revealed partial charge transfer from Fe^(3+)through an O bridge to Ni^(2+)at the edge of LDH-NDs supported by C-MOF to produce the optimal binding energies for OER ***,coupled with a large number of exposed active sides and efficient charge and electrolyte/reactant/product transports associated with the porous 3D C-MOF support,significantly boosted the OER performance of the LDH-ND catalyst with respect to its nanosheet *** from the fact that this is the first active side identification for LDH-ND OER catalysts,this work provides a general strategy to enhance activities of nanosheet catalysts by converting them into edge-rich nanodots to be supported by 3D porous carbon architectures.

关键词： carbon nanomaterials layered double hydroxide(LDH)nanodots metal-organic framework(MOF)derivatives oxygen evolution reaction

Tailoring nanoprecipitates for ultra-strong high-entropy alloys via machine learning and prestrain aging

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Journal of Materials Science & Technology 2021年第10期69卷 156-167页

作者： Tao Zheng xiaobing Hu Feng He Qjngfeng Wu Bin Han Chen Da Junjie Li Zhijun Wang Jincheng Wang Ji-jung Kai zhenhai xia C.T.Liu State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi'an 710072China Center for Advanced Nuclear Safety and Sustainable Development City University of Hong KongHong KongChina Institute of Atomic and Molecular Science.Shaanxi University of Science and Technology Xi'an710021China Department of Material Science and Engineering College of Science and EngineeringCity University of Hong KongHong KongChina Department of Materials Science and Engineering University of North TexasDentonTXUSA Center for Advanced Structural Materials Department of Mechanical EngineeringCollege of Science and EngineeringCity University of Hong KongHong KongChina

The multi-principal-component concept of high-entropy alloys(HEAs) generates numerous new *** them,nanoscale precipitated HEAs have achieved superior mechanical properties and shown the potentials for structural ***,it is still a great challe nge to find the optimal alloy within the numerous *** to now,the reported nanoprecipitated HEAs are mainly designed by a trialand-error approach with the aid of phase diagram calculations,limiting the development of structural *** the current work,a novel method is proposed to accelerate the development of ultra-strong nanoprecipitated *** the guidance of physical metallurgy,the volume fraction of the required nanoprecipitates is designed from a machine learning of big data with thermodynamic foundation while the morphology of precipitates is kinetically tailored by prestrain *** a proof-of-principle study,an HEA with superior strength and ductility has been designed and systematically *** newly developed γ’-strengthened HEA exhibits 1.31 GPa yield strength,1.65 GPa ultimate tensile strength,and 15% tensile *** probe tomography and transmission electron microscope characterizations reveal the well-controlled high γ’ volume fraction(52%) and refined precipitate size(19 nm).The refinement of nanoprecipitates originates from the accelerated nucleation of the γ’ phase by prestrain aging.A deeper understanding of the excellent mechanical properties is illustrated from the aspect of strengthening mecha ***,the versatility of the current design strategy to other precipitation-hardened alloys is discussed.

关键词： High-entropy alloys Machine learning Prestrain aging Mechanical properties Strengthening mechanisms

Bacterial nanocellulose assembly into super-strong and humidity-responsive macrofibers

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Journal of Bioresources and Bioproducts 2024年第3期9卷 369-378页

作者： Yadong Zhao Zheng Yang Rusen Zhou Bin Zheng Meiling Chen Fei Liu Wenhua Miao Renwu Zhou Patrick Cullen zhenhai xia Liming Dai Kostya(Ken)Ostrikov School of Food and Pharmacy Zhejiang Ocean UniversityZhoushan 316022China State Key Laboratory of Electrical Insulation and Power Equipment Center for Plasma BiomedicineXi'an Jiaotong UniversityXi'an 710049China School of Chemical and Biomolecular Engineering University of SydneySydney 2006Australia School of Chemistry and Physics and Centre for Materials Science Queensland University of TechnologyBrisbane 4000Australia Key Laboratory of Bio-based Polymeric Materials Technology and Application of Zhejiang Province Ningbo Institute of Materials Technology and EngineeringChinese Academy of SciencesNingbo 315201China Australian Carbon Materials Centre(A-CMC) School of Chemical EngineeringUniversity of New South WalesSydneyNew South Wales 2052Australia

Cellulose macrofibers (MFs) are gaining increasing interest as natural and biodegradable alternatives to fossil-derived polymers for both structural and functional applications. However, simultaneously achieving their exceptional mechanical performance and desired functionality is challenging and requires complex processing. Here, we reported a one-step approach using a tension-assisted twisting (TAT) technique for MF fabrication from bacterial cellulose (BC). The TAT stretches and aligns BC nanofibers pre-arranged in hydrogel tubes to form MFs with compactly assembled structures and enhanced hydrogen bonding among neighboring nanofibers. The as-prepared BC MFs exhibited a very high tensile strength of 1 057 MPa and exceptional lifting capacity (over 340 000 when normalized by their own weight). Moreover, due to the volume expansion of BC nanofibers upon water exposure, BC MFs quickly harvested energy from environmental moisture to untwist the bundled networks, thus generating a torsional spinning with a peak rotation speed of 884 r/(min·m). The demonstrated rapid and intense actuation response makes the MFs ideal candidates for diverse humidity-response-based applications beyond advanced actuators, remote rain indicators, intelligent switches, and smart curtains.

关键词： Nanocellulose assembly Cellulose macrofibers Super-strong Humidity-responsive actuation Moisture Fast actuation

High-throughput investigations of configurational-transformation-dominated serrations in CuZr/Cu nanolaminates

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Journal of Materials Science & Technology 2020年第18期52卷 192-199页

作者： William Yi Wang Bin Gana Deye Lin Jun Wang Yiguang Wang Bin Tang Hongchao Kou Shunli Shang Yi Wang Xingyu Gao Haifeng Song Xidong Hui Laszlo J.Kecskes zhenhai xia Karin A.Dahmen Peter K.Liaw Jinshan Lia Zi-Kui Liu State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi'an.710072China Beijing Key Laboratory of Advanced High Temperature Materials Central Iron and Steel Research InstituteBeijing100081China IMDEA Materials Institute Calle Eric Kandel 2GetafeMadrid28906Spain CAEP Software Center for High Performance Numerical Simulation Institute of Applied Physics and Computational MathematicsBeijing100088China Department of Materials Science and Engineering The Pennsylvania State UniversityUniversity ParkPA16802USA State Key Laboratory for Advanced Metals and Materials University of Science and Technology BeijingBeijing100083China Hopkins Extreme Materials Institute Johns Hopkins UniversityBaltimoreMD21218USA Department of Physics University of Illinois at Urbana ChampaignUrbanaIL61801USA Department of Materials Science and Engineering The University of TennesseeKnoxvilleTN37996USA

Metallic amorphous/crystalline(A/C)nanolaminates exhibit excellent ductility while retaining their high ***,the underlying physical mechanisms and the resultant structural changes during plastic deformation still remain *** the present work,the structure-property relationship of CuZr/Cu A/C nanolaminates is established through integrated high-throughput micro-compression tests and molecular dynamics simulations together with high-resolution transmission electron *** serrated flow of nanolaminates results from the formation of hexagonal-close-packed(HCP)-type stacking faults and twins inside the face-centered-cubic(FCC)Cu nano-grains,the body-centered-cubic(BCC)-type ordering at their grain boundaries,and the crystallization of the amorphous CuZr *** serration behavior of CuZr/Cu A/C nanolaminates is determined by several factors,including the formation of dense dislocation networks from the multiplication of initial dislocations that formed after yielding,weak-spots-related configurational-transitions and shear-transition-zone activities,and deformation-induced *** present work provides an insight into the heterogeneous deformation mechanism of A/C nanolaminates at the atomic scale,and mechanistic base for the microstructural design of self-toughening metallic-glass(MG)-based composites and A/C nanolaminates.

关键词： Nanolaminates Serration Configurational transformation Molecular dynamics Metallic glass

CrN-Encapsulated Hollow Cr-N-C Capsules Boosting Oxygen Reduction Catalysis in PEMFC

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CCS Chemistry 2021年第5期3卷 208-218页

作者： Hui Yang Xu Wang Tao Zheng Nelly Cantillo Cuello Gabriel Goenaga Thomas A.Zawodzinski He Tian Joshua T.Wright Robert W.Meulenberg xiangke Wang zhenhai xia Shengqian Ma College of Environmental Science and Engineering North China Electric Power UniversityBeijing 102206 State Key Laboratory of Silicon Materials Center of Electron MicroscopySchool of Materials Science and EngineeringZhejiang UniversityHangzhou 310027 Department of Materials Science and Engineering University of North TexasDentonTX 76203 Chemical and Biomolecular Engineering Department University of TennesseeKnoxvilleTN 37996 Department of Physics Illinois Institute of TechnologyChicagoIL 60616 Department of Physics and Astronomy Frontier Institute for Research in Sensor TechnologiesUniversity of MaineOronoME 04469 Department of Chemistry University of North TexasDentonTX 76201

Understanding the origin of the catalytic activity for the development of efficient catalysts is critical yet ***,we report a simple strategy for the synthesis of chromium nitride nanoparticles(CrNNPs)encapsulated into hollow chromium-nitrogen-carbon capsules(CrN@H-Cr-N_(x)-C).The CrN@H-Cr-N_(x)-C demonstrated excellent electrocatalytic activity for the oxygen reduction reaction(ORR)in acidic *** applied as a cathode material in a proton-exchange membrane fuel cell(PEMFC),the CrN@H-Cr-N_(x)-C achieved outstanding initial performance,which is better than that of the PEMFC with H-Cr-N_(x)-C cathode *** CrN@H-Cr-N_(x)-C cathode also showed good stability over 110 h of *** results demonstrated that the coexistence of atomically dispersed CrN_(x) sites and sufficient CrNNPs is essential for excellent PEMFC *** functional theory(DFT)studies further corroborated that CrNNPs can boost the ORR activity of H-Cr-N_(x)-*** finding opens a new avenue for the fabrication of low-cost,highly active,and durable ORR catalysts for PEMFC and other applications.

关键词： chromium-nitrogen-carbon fuel cell chromiumnitride metal-organicframework durability

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多孔材料的熔体过滤机理

热加工工艺 1989年第6期18卷 14-16,23页

作者：夏振海周尧和西北工业大学

本文从热力学和动力学出发推导出了多孔材料过滤器的过滤效率与过滤器参数和熔体参数的数学表达式,并进行了实验验证。

关键词：多孔材料溶体过滤模型机理

MODEL FOR INFILTRATION KINETICS OF LIQUID METALS AND ITS APPLICATION

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Acta Metallurgica Sinica(English Letters) 1992年第9期5卷 206-213页

作者： xia zhenhai Hebei Institute of Technology,Tianjin,ChinaMAO Zhiying ZHOU Yaohe Northwestern Polytechnical University,Xi’an,China Doctor,Faculty of Foundry,Department of Mechanical Engineering No.2,Hebei Institute of Technology,Tianjin 300132,China

On the basis of fluid kinetics,a model for infiltration kinetics of liquid metals into fibre pre- fabricated composite has been *** infiltration processing,together with the measurements of infiltrating velocity and permeability,for the C fibre-reinforced Al matrix composites have been *** model proposed seems to be in good agreement with the ex- perimental *** different infiltration modes,uniform and non-uniform,were found and a new technique was ***,the quality composites of C fibre-reinforced Al may be made under low pressure regardless of non-wettability of liquid metal to the fibres.

关键词： liquid metal infiltration C/Al composite

Can patients with mild non-neoplastic lesions diagnosed at baseline screening be safely exempt from surveillance: evidence from multicenter community-based cohorts

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Science China Life Sciences 2025年第1期68卷 263-271页

作者： Siyi He Zhiyi Zhang Guohui Song zhenhai Wang Chunyun Dai Shipeng Yan Kun Jiang Bingbing Song He Li Maomao Cao Dianqin Sun Fan Yang Xinxin Yan Shaoli Zhang Yi Teng Qianru Li Changfa xia Wanqing Chen Office of Cancer Screening National Cancer Center/National Clinical Research Center for Cancer/Cancer HospitalChinese Academy of Medical Sciences and Peking Union Medical College Department of Gastroenterology Gansu Wuwei Tumor Hospital Cixian Cancer Institute Linzhou Cancer Hospital Center for Disease Control and Prevention of Sheyang County Department of Cancer Prevention and Control Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of MedicineCentral South University Luoshan Center for Disease Control and Prevention Office for Cancer Control and Research Affiliated Cancer Hospital of Harbin Medical University

Surveillance recommendations for gastric cancer（GC） in current guidelines focused on advanced precancerous lesions and were based on precise diagnosis of severity/extent of baseline lesions. We aimed to develop a less endoscopy-related equipment-dependent risk-stratification tool, and assessed whether mild-precursor-lesion patients can be safely exempt from surveillance. In the multicenter communitybased cohort, 75,051 participants receiving baseline endoscopy were enrolled during 2015–2017 and followed-up until 2021. Cumulative incidence rates（CIRs） of GC for precancerous-conditions were calculated by Kaplan-Meier method and compared by Log-rank tests. Mixedeffects Cox regression models were used to detect potential factors for progression towards GC. A risk score was calculated as counts of selected factors. An independent cohort, including 26,586 participants was used for external validation. During a median follow-up of 6.25 years, CIRs of GC were 0.302%, 0.436%, and 4.756% for normal group, non-neoplastic（atrophic gastritis/intestinal metaplasia） and neoplastic lesions（low-grade/high-grade dysplasia）, respectively(Ptrend<0.001). Four predictors, including male, ≥60 years, smoking, and limited vegetable consumption, were selected for risk-stratification. High-risk patients（≥3 risk factors） with non-neoplastic lesions showed higher GC risks（adjusted HR=7.73, 95%CI: 4.29–13.92）, and their four-year CIR reached the one-year CIR of neoplastic lesions. Further categorizing non-neoplastic lesions by histological grade, both patients with moderate-to-severe lesions（aHR=3.07, 95%CI: 1.67–5.64） and high-risk patients with mild lesions（aHR=7.29, 95%CI: 3.58–14.86） showed higher risks. Consistent trends were observed in validation cohort. High-risk mild-precursor-lesion patients should receive surveillance within 3–5 years after baseline screening. Our study provides evidence on supplementing current guideline recommendations.

关键词： stomach neoplasms precancerous conditions cancer screening cumulative incidence risk stratification