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First-principles investigations on structural stability,mechanical,and thermodynamic properties of LaT2Al20(T=Ti,V,Cr,Nb,and ta) intermetallic cage compounds

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Chinese Physics B 2018年第12期27卷 397-404页

作者： Shanyu Quan Xudong Zhang cong Liu Wei Jiang School of Science Shenyang University of TechnologyShenyang 110870China School of Materials Science and Engineering Shenyang University of TechnologyShenyang 110870China

First principles calculations were used to explore the structural stability, mechanical properties, and thermodynamic properties of LaT2Al20(T = Ti, V, Cr, Nb, and ta) intermetallics. The calculated formation enthalpy and phonon frequencies indicate that LaT2Al20intermetallics exhibit the structural stability. The elastic moduli(B, G, E, and Hv) indicate that these intermetallics possess the better elastic properties than pure Al. The values of Poisson’s ratio v and B/G demonstrate that LaT2Al20intermetallics are all brittle materials. The anisotropy of elasticity and Young’s modulus(three-and two-dimensional figures) indicate that LaT2Al20compounds are anisotropic. Importantly, the calculated thermal quantities demonstrate that LaT2Al20intermetallics possess the better thermal physical properties than pure Al at high temperatures.

关键词： LaT_2Al_(20) intermetallics mechanical properties anisotropic properties dynamical and thermodynamic properties first-principles calculations

Relationship between skin fold thickness and insulin resistance in the essential hypertensive patients in Vietnam

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Journal of Geriatric Cardiology 2005年第4期2卷 228-232页

作者： Toan C Nguyen Khoa ta Pham Quyen TL Do Cuong T Nguyen Diep D Nguyen Vinh G Le cong D Nguyen Vietnam Military Medical University

Background Previous studies reported a close relationship between obesity and insulin resistance in the essential hypertensive patients. Objective In this study, we examined the relationship between the skin fold thickness and insulin resistance then developed a formula to estimate the insulin resistance index according to the skin fold thickness in the essential hypertensive patients. Subjects and Methods Medical records of 80 patients (37 males, 43 females) were reviewed and the data were tabulated. Anthropometric indexes (including height, weight, waist circumference, hip circumference, and skins fold thickness at 5 fatty difference points on the Erdheim diagram), fasting plasma glucose and insulin concentration were recorded. The mean age was 57.0 ?9.2 years. The insulin resistance index was calculated following the Homeostasis Model Assessment (HOMA) formula. Results Compared with the group with BMI tance index in ( 2.15±1,24 vs 3.76±2.22, Ptance index between male and female was observed (P > 0.05). There was a positive correlation between skin fold thickness and the fasting insulin concentration and insulin resistance index. The skin fold thickness at point A8 had the best coefficient correlated with fasting plasma insulin(r=0.79, P tance index (r= 0.79, P tance index by skin fold thickness at point A8 as: Insulin resistance index = 0.12×[skin fold thickness at A8 point (mm)] - 1. Conclusion: In the essential hypertensive patients, the formula to estimate insulin resistance index as 0.12×[skin fold thickness at A8 point (mm)]-1 may predict accurately the level of insulin resistance. (J Geriatr Cardiol 2005; 2(4):228-232 )

关键词： skin fold thickness, insulin resistance, hypertension

Microstructure and fracture toughness of the Bridgman directionally solidified Fe-Al-ta eutectic at different solidification rates

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Journal of Materials Science & Technology 2020年第7期42卷 63-74页

作者： Chunjuan Cui cong Wang Pei Wang Wei Liu Yuanyuan Lai Li Deng Haijun Su School of Metallurgical Engineering Xi’an University of Architecture and TechnologyXi’an710055China State Key Laboratory of Solidification Processing Northwestern Polytechnical UniversityXi’an710072China Shaanxi Engineering Technology Research Center for Wear-resisting Materials Xi’an 710055China

Fe-Al-ta eutectic composites were obtained by a modified Bridgman directional solidification technique at different solidification *** microstructure transforms from regular eutectic to eutectic colony with the increase of the solidification *** solid/liquid interface of Fe-Al-ta eutectic evolves from planar interface to cellular interface with the increase of the solidification *** addition,threepoint bending method was adopted to study the room-temperature fracture toughness of the as-cast Fe-Al-ta eutectic alloy and the Fe-Al-ta eutectic ***,the fracture morphologies,the crack propagation path and the strengthening mechanism of Fe-Al-ta eutectic were discussed.

关键词： Directional solidification Eutectic composite Solid/liquid interface Fracture toughness Fracture morphology

Unveiling and Alleviating Chemical“Crosstalk”of Succinonitrile Molecules in Hierarchical Electrolyte for High-Voltage Solid-State Lithium Metal Batteries

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Energy & Environmental Materials 2023年第3期6卷 107-116页

作者： Fang Fu Ying Liu Chen Sun Lina cong Yulong Liu Liqun Sun Haiming Xie National&Local United Engineering Laboratory for Power Battery Department of ChemistryNortheast Normal UniversityChangchun 130024China

Succinonitrile-based plastic crystal electrolytes have emerged for high-energy-density Li metal batteries in terms of their superior ambient ionic conductivity,low flammability,and benign compatibility with high voltage cathode,but are hampered by inherent instabilities toward Li *** hierarchical solid electrolytes structure is a fundamental approach to protect Li anode from succinonitrile attacks,with succinonitrile-based oxidation-resistance layer facing high voltage cathode and reduction-tolerant layer contacting Li ***,free succinonitrile molecules in succinonitrile-based electrolyte layer can diffuse across the electrolyte/electrolyte interface and further reach Li anode surface during the battery *** chemical“crosstalk”cause reduction-tolerant electrolyte layer to fail to protect the Li anode from the attacks of free succinonitrile *** Li_(6.4)La_(3)Zr_(1.4)ta_(0.6)O_(12)is introduced creatively into succinonitrile-based electrolyte *** taking advantage of the complexation between La atoms in Li_(6.4)La_(3)Zr_(1.4)ta_(0.6)O_(12)and N atoms in succinonitrile,the free succinonitrile molecules are successfully immobilized in succinonitrile-based electrolyte *** resulting low resistance and highly durable solid electrolyte interphase and cathode electrolyte interphase endow NCM622||Li batteries with remarkable cycle *** research provides a new idea for the real application of plastic crystal electrolytes in high voltage solid-state lithium metal batteries.

关键词： hierarchical solid electrolytes high voltage interface lithium metal plastic crystal

Oxidation Behavior of the Nickel-Based Superalloy DZ125 at 980℃

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Acta Metallurgica Sinica(English Letters) 2017年第9期30卷 857-862页

作者： Ye-Bing Hu Li Zhang cong-Qian Cheng Peng-tao Zhao Guang-Ping Guo Jie Zhao School of Materials Science and Engineering DalianUniversity of TechnologyDalian 116024China Beijing Institute of Aeronautical Materials Beijing 100095China

The isothermal oxidation behavior of the nickel-based superalloy DZ125 was investigated at 980 ~C through SEM/EDX and XRD. The weight loss process exhibited three periods--initial, transient and steady stages, which corre- spond to the formation of three layers on the surface. The outer layer was composed of NiO, whereas the intermediate layer mainly consisted of spinels and was accompanied with ta-rich oxide. Alumina was evident as the inner continuous layer close to the substrate. The first formation of alumina was responsible for the initial stage of weight loss, and the formation of NiO and intermediate layer may dramatically affect on the transient and steady stage, respectively. The oxide scales effect on growth mechanism was discussed.

关键词： Nickel-based Superalloy Oxidation Alumina

A two-dimensional microporous metal–organic framework for highly selective adsorption of carbon dioxide and acetylene

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Chinese Chemical Letters 2017年第8期28卷 1653-1658页

作者： Osamah Alduhaish Bin Li Hadi Arman Rui-Biao Lin John cong-Gui Zhao Banglin Chen Deportment of Chemistry University of Texas at San AntonioSon AntonioTX 78249-0698USA

Solvothermal reaction of 3-aminoisonicotinic acid（Haina） and Cu（NO_3）_2·2.5H_2O gave a novel twodimensional（2D） microporous metal–organic framework, [Cu（aina）_2（DMF）]·DMF（1, DMF = N,N-dimethylformamide）. Single-crystal X-ray crystallographic study of compound 1 revealed that Cu（II）ions are linked by ainaàligands forming square grid-like layers, which stack together via multiple hydrogen bonding interactions. The solvent-free framework of 1a displayed considerable porosity（void = 46.5%） with one-dimensional（1D） open channels（4.7 ？？ 4.8 ？） functionalized by amino *** sorption measurements of 1 revealed selective carbon dioxide（CO_2） and acetylene（C_2H_2） adsorption over methane（CH_4） and nitrogen（N_2） at ambient temperature.

关键词： Metal–organic frameworks Two-dimensional structure 3-Aminoisonicotinic acid Hydrogen bonding Gas separation Acetylene

Climate and land-use interactively shape butterfly diversity in tropical rainforest and savanna ecosystems of southwestern China

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Insect Science 2021年第4期28卷 1109-1120页

作者： Bai-Ge Miao Yan-Qiong Peng Da-Rong Yang Yasuhiro Kubota Evan P.Economo cong Liu CAS Key Laboratory of Tropical Forest Ecology Xishuangbanna Tropical Botanical GardenChinese Academy of SciencesMenglaYunnanChina Plant Ecology Core Botanical GardensChinese Academy of SciencesMenglaYunnanChina Faculty of Science University of the RyukyusNishiharaOkinawaJapan Biodiversity and Biocomplexity Unit Okinawa Institute of Science and Technology Graduate UniversityOnna-sonOkinawaJapan Department of Organismic and Evolutionary Biology Museum of Comparative ZoologyHarvard UniversityCambridgeMAUnited States

Human-induced habitat conversion and degradation,along with accelerating climatic change,have resulted in considerable global biodiversity ***,how local ecological assemblages respond to the interplay between climate and land-use change remains poorly ***,we examined the effects of climate and land-use interactions on butterfly diversity in different ecosystems of southwestern ***,we investigated variation in the alpha and beta diversities of butterflies in different landscapes along human-modified and climate *** found that increasing land-use intensity not only caused a dramatic decrease in butterfly alpha diversity but also significantly simplified butterfly species composition in tropical rainforest and savanna *** findings suggest that habitat modification by agricultural activities increases the importance of deterministic processes and leads to biotic *** land-use intensity model best explained species richness variation in the tropical rainforest,whereas the climate and land-use intensity interaction model best explained species richness variation in the *** results indicate that climate modulates the effects of land-use intensity on butterfly alpha diversity in the savanna *** also found that the response of species composition to climate varied between sites:specifically,species composition was strongly correlated with climatic distance in the tropical rainforest but not in the *** together,our long-term butterfly monitoring data reveal that interactions between human-modified habitat change and climate change have shaped butterfly diversity in tropical rainforest and *** findings also have important implications for biodiversity conservation under the current era of rapid human-induced habitat loss and climate change.

关键词： butterfly diversity climate change conservation habitat conversion savanna tropical rainforest

Data-driven design of Ni-based turbine disc superalloys to improve yield strength

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Journal of Materials Science & Technology 2023年第24期155卷 175-191页

作者： Bin Xu Haiqing Yin Xue Jiang cong Zhang Ruijie Zhang Yongwei Wang Xuanhui Qu Zhenghua Deng Guoqiang Yang Dil Faraz Khan Beijing Advanced Innovation Center for Materials Genome Engineering University of Science and Technology Beijing Beijing 100083 China Collaborative Innovation Center of Steel Technology University of Science and Technology Beijing Beijing 100083 China Beijing Key Laboratory of Materials Genome Engineering University of Science and Technology Beijing Beijing 100083 China Institute for Advanced Materials and Technology University of Science and Technology Beijing Beijing 100083 China School of Mechanical Engineering Chongqing Three Gorges University Chongqing 404000 China School of Mechanical and Equipment Engineering Hebei University of Engineering Handan 056038 China Department of Physics University of Science and Technology Bannu Bannu 28100 Pakistan

Increasing the thrust-weight ratio of aeroengines requires development of high-strength and stable high-temperature materials. A data-driven design of Ni-based turbine disc superalloys is performed to improve the yield strength to reach the target. Through first-principles calculations determining the design superalloy system, the theoretical models and Calculation of Phase Diagram (CALPHAD) screening compositions, and machine learning extrapolating prediction, 14 compositions are selected from 2,865,039 composition combinations. Ni-17Cr-8Co-1Mo-1W-6Al-3Ti-1Nb-1ta is selected to verify the design accuracy. Experimental tests prove that the designed alloy has trade-offs of microstructure with satisfying design targets, and then, the yield strength is higher in the designed alloy than in commercial superalloys, reaching 728 MPa at 850 ℃. A scheme for increasing the performance of the designed alloy is proposed by discussing the strengthening mechanisms, machine learning process, and alloying chemistry effect. The cross-scale data-driven design is regarded as an accurate and efficient way to design novel high-strength Ni-based turbine disc superalloys, whose significance is the obvious reduction of trial-and-error tests.

关键词： Ni-based superalloys Data-driven design Machine learning CALPHAD First-principles calculation

Ferroelastic domain identification and toughening mechanism for yttrium tantalate–zirconium oxide

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Journal of Materials Science & Technology 2022年第32期127卷 78-88页

作者： Cheng Luo cong Li Ke Cao Junbao Li Junhui Luo Qinghua Zhang QianQian Zhou Fan Zhang Lin Gu Li Yang Yichun Zhou School of Advanced Materials and Nanotechnology Xidian UniversityXi’an 710126China Frontier Research Center of Thin Films and Coatings for Device Applications Academy of Advanced Interdisciplinary ResearchXidian UniversityXi’an 710126China School of Materials Science and Engineering Xiangtan UniversityXiangtan 411105China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China College of Engineering BIC-ESATPeking UniversityBeijing 100871China

Yttrium tantalate(YtaO_(4))is the next generation of higher service temperature thermal barrier coatings(TBCs)materials due to its smaller volume effect in phase change,lower thermal conductivity and unique ferroelastic domain ***,the low fracture toughness limits its *** first characterized the diffraction patterns of variants,and two variants(M_(1)and M_(2))observed in transmission electron microscopy(TEM)results were determined from four possible variants by mechanical *** role of Zr^(4+)doping in ferroelastic toughening was explained in *** the increase of Zr^(4+)doping concentration,the monoclinic angle β and the domain rotation angleαdecrease,*** spontaneous strain component and the principal strain in the main space also have a similar decreasing *** decrease of the ferroelastic domain inversion energy barrier is beneficial to the improvement of fracture *** the results of Vickers indentation,we found that Zr^(4+)could be enriched at the domain boundary to inhibit the generation of *** appropriate amount of Zr^(4+)is conducive to the improvement of fracture toughness,and the excessive Zr^(4+)will reduce the fracture toughness due to the generation of by-product t-ZrO_(2).So,the optimal composition is Y_(0.44)ta_(0.44)Zr_(0.12)O_(2) and the best fracture toughness(2.9–3.8MPa m^(1/2))is equivalent to the commercial *** result will promote the application of a new generation of TBCs.

关键词： Ferroelastic domain Variants Domain switch TBCs Fracture toughness