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Phase-tunable equiatomic and non-equiatomic Ti-Zr-Nb-Tahigh-entropy alloys with ultrahigh strength for metallic biomaterials

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Journal of Materials Science & Technology 2022年第22期117卷 196-206页

作者： Tao xiang Peng Du Zeyun Cai kun Li Weizong Bao Xinxin Yang Guoqiang Xie School of Materials Science and Engineering Harbin Institute of Technology(Shenzhen)Shenzhen 518055China State Key Laboratory of Advanced Welding and Joining Harbin Institute of TechnologyHarbin 150001China

The contradiction between the strength and ductility of metallic materials is a major scientific problemthat has been researched for a long time. Dual-phase equiatomic and non-equiatomic Ti-Zr-Nb-Ta highentropy alloys (HEAs) with super-high strength and excellent ductility have been successfully developedvia mechanical alloying (MA) combined with spark plasma sintering (SPS) technology. This is adjustedby altering the atomic ratios of the different phases. X-ray diffraction (XRD) and transmission electronmicroscopy (TEM) were performed to confirm the dual-phase microstructure. After the SPS process, theaverage grain size of the aforementioned equiatomic Ti_(25)Zr_(25)Nb_(25)Ta_(25) HEAs (134 ± 50 nm) evaluated byelectron back-scattering diffraction (EBSD) is smaller than that of the Ti-Zr-Nb-Ta HEAs (150 μm), whichwere fabricated using arc melting. According to the Hall-Petch formula, the grain boundary strengthening contribution in the Ti-Zr-Nb-Ta system is 33-fold higher than those fabricated using the arc-meltingprocess. When the alloy phase comprises the equivalent dual-phase, equiatomic Ti_(25)Zr_(25)Nb_(25)Ta_(25) HEAshave good comprehensive performance compared to non-equiatomic Ti-Zr-Nb-Ta HEAs prepared usingthe same process. The yield strength of equiatomic Ti_(25)Zr_(25)Nb_(25)Ta_(25) HEAs (2212 ± 38 MPa) is two-foldhigher than that of Ti-Zr-Nb-Ta HEAs (1100 ± 90 MPa) fabricated via arc melting. This can be attributed tothe ultra-fine grain size. Notably, the equiatomic Ti_(25)Zr_(25)Nb_(25)Ta_(25) HEAs possess approximately the samebiocompatibility as commercial pure Ti (CP-Ti), indicating that the equiatomic Ti_(25)Zr_(25)Nb_(25)Ta_(25) HEAs areprovided with a possibility as an advanced biomaterial for the applications of the medical field.

关键词： Equiatomic Nb_(25)Ta_(25)Ti_(25)Zr_(25)HEAs Ultra-fine grain Phase-tunable Mechanical properties Biocompatibility

Influence of heat treatments on incipient melting structures of DD5 nickel-based single crystal superalloy

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China Foundry 2023年第5期20卷 395-402页

作者： Zhi-hong Jia Chen-yang Li Wen-xiang Jing xiang-feng Liang Ze-kun Zhang Jia-le Xiao Yu-tao Zhao School of Materials Science and Engineering Jiangsu UniversityZhenjiang 212013JiangsuChina

The evolution of microstructure and formation mechanism of incipient melting microstructure of DD5 single crystal superalloy during solution heat treatment were studied by scanning electron microscopy(SEM),electron probe microanalysis(EPMA),and energy dispersive spectroscopy(EDS).The solidus and liquidus of single crystal alloy were obtained by differential scanning calorimetry(DSC).Results show that the mosaic-like eutectic and fan-like eutectic are dissolved at first,and the coarseγ'phase is dissolved later during the solution heat treatment of 1,390°C/2 h+1,310°C/4 h+1,320°C/10 h+air cooling(AC).The composition segregations of Al,Ta,W and Re are 0.99,0.96,1.04 and 1.16,respectively,which close to *** incipient melting is caused by the low local temperature of the alloy,and the micropore region with a lower melting point is the preferred position for incipient melting.

关键词： superalloy solution heat treatment eutectic composition segregation incipient melting

Enantioselective Diels-Alder reactions with left-handed G-quadruplex DNA-based catalysts

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Chinese Chemical Letters 2021年第5期32卷 1701-1704页

作者： kun Chen Zhiyong He Wei Xiong Chun-Jiang Wang xiang Zhou College of Chemistry and Molecular Sciences Key Laboratory of Biomedical Polymers of Ministry of EducationWuhan UniversityWuhan 430072China

Since the discovery of left-handed G-quadruplex(L-G4)structure formed by natural DNA,there has been a growing interest in its potential *** study utilised it to catalyse enantioselective Diels-Alder reactions,considering its different optical rotation compared to an ordinary *** was determined that when L-G4 was used with a combination of copper(Ⅱ)ions,there was a good enantioselectivity(-52%ee)without further addition of *** further consideration was given by adding G4 ligands,G4 was further stabilised,even obtaining a better enantioselectivity(up to-80%ee).Moreover,when using ligands that have regulatory effects on G4,the ee value can be *** this work,a minimal left-handed G4 was reported.A follow-up study was also con ducted,which recovers that the minimal left-handed G4 remains its catalytic effect and enantioselectivity,but is not so effective as the former *** indicates that a complete G4 structure is relatively conducive to chiral catalysis.

关键词： Diels-Alder reaction Left-handed G-quadruplex Asymmetric catalysis Enantioselectiv ity G-quadruplex ligand

Dynamic Properties of Steel Catenary Riser near Touchdown Point Under Coplanar Vessel Heave and Vortex Induced Vibration

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China Ocean Engineering 2023年第2期37卷 288-298页

作者： ZHANG xiang-rui WANG kun-peng JIANG Da-peng TANG Kai LI Yu-long Marine Design and Research Institute of China Shanghai 200011China School of Naval Architecture and Ocean Engineering Jiangsu University of Science and TechnologyZhenjiang 212100China Southern Marine Science and Engineering Guangdong Laboratory(Zhuhai) Zhuhai 510275China

The present study establishes a simple numerical model for the coupled response of a steel catenary riser(SCR) subjected to coplanar vessel motion and vortex-induced vibration(VIV). Owing to the large deflection of the SCR, the geometric nonlinearity is considered in this model. The hydrodynamic force comprises the excitation force and hydrodynamic damping, where the excitation force that only exists when the non-dimensional frequency is located in the lock-in range, is associated with the VIV. The hydrodynamic force model is validated based on the published VIV test *** for the seabed resistance at the touchdown zone(TDZ), integrated with an initial seabed trench, the hysteretic feature is modeled. Based on the model, the study emphasizes on the coupled response characteristics near the touchdown point(TDP) induced by coplanar vessel heave and VIV, and analyzes the sensitivity of the coupled response to the heaving amplitude and frequency. It is found that with the increase of the heave amplitude and frequency, the VIV can be obviously mitigated, but the heave-related response in the coupled analysis seems to be close to that in the heave-only simulation. Finally, the fatigue damage near TDP is parametrically investigated based on the separate analysis and the coupled analysis. The results demonstrate that the coupled effect plays a significant role in the fatigue assessment near TDP. Besides, the proportion of the coupled effect accounting for the total fatigue damage decreases with the increasing seabed stiffness, while increases with the increasing seabed trench depth.

关键词： vessel heave vortex induced vibration coupled effect steel catenary riser(SCR)-seabed interaction seabed trench

Facile fabrication of highly durable superhydrophobic strain sensors for subtle human motion detection

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Journal of Materials Science & Technology 2022年第15期110卷 35-42页

作者： Li-Chuan Jia Chang-Ge Zhou kun Dai Ding-xiang Yan Zhong-Ming Li College of Electrical Engineering Sichuan UniversityChengdu 610065China College of Polymer Science and Engineering State Key Laboratory of Polymer Materials EngineeringSichuan UniversityChengdu 610065China College of Materials Science and Engineering The Key Laboratory of Material Processing and Mold of Ministry of EducationZhengzhou UniversityZhengzhou 450001China School of Aeronautics and Astronautics Sichuan UniversityChengdu 610065China

Endowing strain sensors with superhydrophobicity is of great importance to guarantee their long-term service under harsh environments(such as wet,acid,alkali and salt atmospheres),whereas,the development of superhydrophobic strain sensors remains a great ***,we realized a superhydrophobic and highly sensitive sensor for subtle human motion detection by designing a superhydrophobic and electrically conductive coating on cotton textile,via a facile drop-coating *** resultant strain sensor showed a large water contact angle of 161.3°and a low sliding angle of 3.8°The superhydrophobic characteristics can keep almost unchanged even after undergoing 1000 peeling cycles,1000 stretchingrelease cycles,and 1000 bending-releasing cycles,revealing its excellent mechanical *** sensitivity with the maximum gage factor of 169 was achieved for the strain sensor under a small strain of0–10%,and the sensing performance also showed well ***,our sensor can effectively detect various subtle human physiological signals and body motions even under harsh *** admirable features make the sensor promising applications in wearable electronics,personalized health monitoring,sound recognition,and so on.

关键词： Strain sensors Superhydrophobicity High sensitivity Drop coating Durable

Quantifying muskmelon fruit attributes with A-TEP-based model and machine vision measurement

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Journal of Integrative Agriculture 2018年第6期17卷 1369-1379页

作者： CHANG Li-ying HE san-peng LIU Qian xiang Jia-lin HUANG Dan-feng School of Agriculture and Biology Shanghai Jiaotong University

In this study, we established a dynamic morphological model using the accumulated thermal effectiveness and photosynthetic active radiation （PAR）（A-TEP）, aiming to explore the relationship between muskmelon （Cucumis melo L.） fruit attributes and environmental factors. Muskmelon surface color was described by parameters of red, green, blue, hue, saturation and brightness （HSI）. Three characteristic parameters, gray level co-occurrence matrix （GLCM）, angular second moment （ASM）, entropy, contrast, and the coverage rate were used to describe the process of muskmelon fruit netting formation. ASM was not significant difference during muskmelon fruit growth. The number and deep of netting stripes gradually increased with fruit growth. Coverage rate increased rapidly for 15-30 d after pollination. The vertical and horizontal diameters of muskmelon fruit were followed a logistic curve. And root mean squared errors （RMSE） between the simulated and measured vertical and horizontal diameters were 3.527 and 4.696 mm, respectively. RMSE of red, green, blue, saturation and brightness were 0.999, 2.690, 2.992, 0.033 and 5.51, respectively, and the RMSE for entropy, contrast and coverage rates were 0.077, 0.063 and 0.015, respectively, indicating a well consistent between measured and simulated values.

关键词： machine vision technology fruit attributes A-TEP skin netting coverage rate

Identification of four novel mutations in the HNF-1A gene in Chinese early-onset and/or multiplex diabetes pedigrees

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Chinese Medical Journal 2006年第13期119卷 1072-1078页

作者： YANG Zhen WU Song-hua ZHENG Tai-shan LU Hui-juan xiang kun-san Shanghai Diabetes Institute Department of Endocrinology and Metabolism Shanghai No. 6 People＇s Hospital Shanghai Jiaotong University Shanghai 200233 China

Background Mutations in the hepatocyte nuclear factor-lA gene cause the type 3 form of maturity-onset diabetes of the young （MODY3）. This study was undertaken to determine mutations and sequence variations of the HN... 详细信息

关键词： maturity-onset diabetes of the young hepatocyte nuclear factor-1A gene direct sequencing

Simultaneous phosphorus and nitrogen removal in a continuous-flow two-sludge system

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Journal of Environmental Sciences 2006年第1期18卷 52-57页

作者： LI xiang-kun HUANG Rong-xin BAO Lin-lin SHAO Chun-hong ZHANG Jie School of Municipal and Environmental Engineering Harbin Institute of Technology Harbin 150090 China

The ability of simultaneous biological phosphorus and nitrogen removal was investigated in a lab-scale continuous-flow two-sludge system. Alternating anaerobic and anoxic conditions were combined with contact oxidation stage for treating raw municipal wastewater. Long-term experiments showed that the contradiction of competing for the organic substrate between denitrifying bacteria and PAOs （phosphorus accumulating organisms） in traditional phosphorus and nitrogen removal system has been resolved. The system can adapt to low influent COD/TN ratio （C/N）. Furthermore the SRT （sludge retention time） of nitrifying sludge and denitrifying phosphorus removal sludge can be controlled at optimal conditions respectively. The removal efficiency of COD, TP, TN, and NH4-N was 81.78%, 92.51%, 75.75%, and 84.47% respectively. It was also found that the appropriate influent C/N should be controlled at the range of 3.8-6, while the optimal C/N to the system ranged between 4-5, and the BFR （bypass sludge flow rate） should be controlled at 0.35 around.

关键词： continue-flow two-sludge system denitrification phosphorus removal nitrification contact oxidation

Construction of TiO2/silane nanofilm on AZ31 magnesium alloy for controlled degradability and enhanced biocompatibility

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Rare Metals 2019年第6期38卷 588-600页

作者： Lei Huang kun Su Yu-Feng Zheng Kelvin Wai-Kwok Yeung xiang-Mei Liu School of Materials Science and Engineering Hubei UniversityWuhan 430062China State Key Laboratory for Turbulence and Complex System Department of Materials Science and EngineeringCollege of EngineeringPeking UniversityBeijing 100871China Department of Orthopaedics and Traumatology Li Ka Shing Faculty of MedicineThe University of Hong KongPokfulam 999077Hong KongChina

A TiO2 nanofilm was prepared on the surface of AZ31 magnesium alloy with controllable thickness through atomic layer deposition(ALD) technique, which can adjust the corrosion behaviors of AZ31 Mg *** with the untreated Mg alloys, corrosion current densities(icorr)can decline by 58% in the 200-cycles TiO2-covered Mg alloy and further decline by up to 74% with the thickness of nanofilm up to 63 nm(400 cycles).The subsequent modification with a cross-linked conversion layer of 3-aminopropyltriethoxysilane(APTES) by a dipping method can produce a compact silane coating on TiO2 nanofilm, which can seal pinholes of TiO2 nanofilm and serve as a barrier to further adjust the corrosion behavior of the *** icorrcan decline about two orders of magnitude in the TiO2/silane composite *** the adjustable corrosion rate come true, which can be attributed to the precise control on the thickness of metal oxide nanofilm and additional protection from the compact silane *** vitro study discloses that the TiO2/silane hybrid coating shows higher expression of alkaline phosphatase(ALP)and can promote cellular adhesion and proliferation with better cytocompatibility than untreated Mg alloy.

关键词： Magnesium alloy TiO2 Biodegradability Atomic layer deposition Hybrid coating Biocompatibility