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Review on the temperature memory effect in shape memory alloys

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International Journal of Smart and Nano Materials 2011年第3期2卷 101-119页

作者： Zhiguo Wang Xiaotao Zu Yongquing Fu Department of Applied Physics University of Electronic Science and Technology of ChinaChengdu610054China Thin Film Centre Scottish Union of Physics Alliance(SUPA)University of West of ScotlandPaisleyPA12BE UK

Shape memory alloys(SMAs)are well known for their unique shape memory effect(SME)and superelasticity(SE)behavior.The SME and SE have been extensively investigated in past decades due to their potential use in many applications,especially for smart materials.The unique effects of the SME and SE originate from martensitic transformation and its reverse transformation.Apart from the SME and SE,SMAs also exhibit a unique property of memorizing the point of interruption of martensite to parent phase transformation.If a reverse transformation of a SMA is arrested at a temperature between reverse transformation start temperature(As)and reverse transformation finish temperature(Af),a kinetic stop will appear in the next complete transformation cycle.The kinetic stop temperature is a‘memory’of the previous arrested temperature.This unique phenomenon in SMAs is called temperature memory effect(TME).The TME can be wiped out by heating the SMAs to a temperature higher than Af.The TME is a specific characteristic of the SMAs,which can be observed in TiNi-based and Cu-based alloys.TME can also occur in the R-phase transformation.However,the TME in the R-phase transformation is much weaker than that in the martensite to parent transformation.The decrease of elastic energy after incomplete cycle on heating procedure and the motion of domain walls have significant contributions to the TME.In this paper,the TME in the TiNi-based and Cu-based alloys including wires,slabs and films is characterized by electronic-resistance,elongation and DSC methods.The mechanism of the TME is discussed.

关键词： temperature memory effect shape memory alloys

Scalar Particles’ Tunneling and Effect of Quantum Gravity

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Journal of Applied Mathematics and Physics 2015年第2期3卷 134-139页

作者： Guoping Li Xiaotao Zu School of Physical Electronics University of Electronic Science and Technology of China Chengdu China

According to the generalized uncertainty principle (GUP), the Klein-Gordon equation is corrected by the quantum gravity exactly. Hence, the corrected Klein-Gordon equation will be more precise on the expression of the tunneling behavior. Then, the corrected Hawking temperature of the Gibbons-Maeda-Dilaton black hole is obtained near the horizon by quantum gravity. Analyzing the results carefully, it is obvious for us that the tunneling result is not only related to the mass of black hole, but also related to the mass and energy of outgoing fermions. Finally, we also infer that the tunneling radiation would be stopped at some particular temperature.

关键词： The Quantum Gravity The Gibbons-Maeda-Dilaton Black Hole The Corrected Klein-Gordon Equation The Generalized Uncertainty Principle

Modified Tunneling Radiation of Fermions from a Spherically Symmetric Spacetime with Dark Matter

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Journal of Applied Mathematics and Physics 2015年第8期3卷 931-936页

作者： Zhongwen Feng Xiaotao Zu School of Physical Electronics University of Electronic Science and Technology of China Chengdu China

In the paper, we use the generalized Dirac equation to study the Hawking temperature and entropy of a spherically symmetric spacetime with the dark matter. The results show that the dark matter can influence the thermodynamic properties of the black hole. Meanwhile, we find the GUP corrected temperature and entropy are not only determined by the nature of black but also related to the properties of tunneling particles. Besides, the GUP can slow down the increase of Hawking temperature and causes the remnants.

关键词： Generalized Uncertainty Principle Spherically Symmetric Spacetime Dark Matter

Insight into the growth behaviors of MoS_(2)nanograins influenced by step edges and atomic structure of the substrate

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Nano Research 2022年第8期15卷 7646-7654页

作者： Shuangyue Wang Ni Yang Mengyao Li Ji Zhang Ashraful Azam Yin Yao Xiaotao Zu Liang Qiao Peter Reece John Stride Jack Yang Sean Li School of Materials Science and Engineering UNSW SydneyNSW 2052Australia School of Physics University of Electronic Science and Technology of ChinaChengdu 610054China School of Physics UNSW SydneyNSW 2052Australia School of Chemistry UNSW SydneyNSW 2052Australia

The step edges and intrinsic atomic structure of single-crystal substrate play a critical role in determining the growth pathways of transition metal dichalcogenide(TMD)grains,particularly whether the TMDs will grow into wafer-scale single-crystal or anisotropic nanoribbons.Hereby,we investigate the growth behaviours of the MoS_(2)nanograins on(0001)and()sapphire substrates.On one hand,the step edges formed on the(0001)surface after thermal treatment are found to promote the macroscopic aggregation of MoS_(2)nanograins and to form unidirectional large triangular islands along with thesteps in the annealing process,while on the pristine(0001)surface,the MoS_(2)nanograins grow into a random network-like pattern.Moreover,oxygen treatment on the substrate can further enhance the growth of MoS_(2)nanograins.Transmission electron microscopy and fast Fourier transform patterns reveal that the substrate could modulate the orientation of MoS_(2)nanograins during their growing process.On the other hand,the MoS_(2)nanograins on the surface could self-assemble into one-dimensional nanoribbons due to the strong structural anisotropy of the substrate.In addition,the ratio of Raman intensities for peaks that correspond to the and A1g phonon modes shows a linear relationship with the grain size due to the change of the“phonon confinement”.Moreover,new peaks located at 226 and 280 cm−1 can be observed in the off-resonant and resonant Raman spectra for the MoS_(2)nanograin samples,respectively,which can be attributed to the scatterings from the edges of as-fabricated MoS_(2)nanostructures.

关键词： MoS_(2)nanograins growth behaviors step edges atomic structure Raman spectra evolution UV-vis absorption

A Universal Atomic Substitution Conversion Strategy Towards Synthesis of Large‑Size Ultrathin Nonlayered Two‑Dimensional Materials

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Nano-Micro Letters 2021年第11期13卷 79-91页

作者： Mei Zhao Sijie Yang Kenan Zhang Lijie Zhang Ping Chen Sanjun Yang Yang Zhao Xiang Ding Xiaotao Zu Yuan Li Yinghe Zhao Liang Qiao Tianyou Zhai School of Physics University of Electronic Science and Technology of China(UESTC)Chengdu 610054People’s Republic of China State Key Laboratory of Materials Processing and Die&Mould Technology School of Materials Science and EngineeringHuazhong University of Science and Technology(HUST)Wuhan 430074People’s Republic of China School of Materials and Energy Guangdong University of TechnologyGuangzhou 510006People’s Republic of China Key Laboratory of Carbon Materials of Zhejiang Province Institute of New Materials and Industrial TechnologiesCollege of Chemistry and Materials EngineeringWenzhou UniversityWenzhou 325035People’s Republic of China

Nonlayered two-dimensional(2D)materials have attracted increasing attention,due to novel physical properties,unique surface structure,and high compatibility with microfabrication technique.However,owing to the inherent strong covalent bonds,the direct synthesis of 2D planar structure from nonlayered materials,especially for the realization of large-size ultrathin 2D nonlayered materials,is still a huge challenge.Here,a general atomic substitution conversion strategy is proposed to synthesize large-size,ultrathin nonlayered 2D materials.Taking nonlayered CdS as a typical example,large-size ultrathin nonlayered CdS single-crystalline flakes are successfully achieved via a facile low-temperature chemical sulfurization method,where pre-grown layered CdI2 flakes are employed as the precursor via a simple hot plate assisted vertical vapor deposition method.The size and thickness of CdS flakes can be controlled by the CdI2 precursor.The growth mechanism is ascribed to the chemical substitution reaction from I to S atoms between CdI2 and CdS,which has been evidenced by experiments and theoretical calculations.The atomic substitution conversion strategy demonstrates that the existing 2D layered materials can serve as the precursor for difficult-to-synthesize nonlayered 2D materials,providing a bridge between layered and nonlayered materials,meanwhile realizing the fabrication of large-size ultrathin nonlayered 2D materials.

关键词： Nonlayered 2D materials Large-size ultrathin CdS flakes Atomic substitution conversion Layered-nonlayered structural transformation

Stability of superconducting Nd_(0.8)Sr_(0.2)NiO_(2) thin films

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Science China(Physics,Mechanics & Astronomy) 2022年第6期65卷 123-130页

作者： Xiang Ding Shengchun Shen Huaqian Leng Minghui Xu Yan Zhao Junrui Zhao Xuelei Sui Xiaoqiang Wu Haiyan Xiao Xiaotao Zu Bing Huang Huiqian Luo Pu Yu Liang Qiao School of Physics University of Electronic Science and Technology of ChinaChengdu 610054China Department of Physics Tsinghua UniversityBeijing 100084China Beijing Computational Science Research Center Beijing 100193China School of Mechanical Engineering Chengdu UniversityChengdu 610106China Beijing National Laboratory for Condensed Matter Physics Institute of PhysicsChinese Academy of SciencesBeijing 100190China Songshan Lake Materials Laboratory Dongguan 523808China

The discovery of superconducting states in the nickelate thin film with infinite-layer structure has paved a new way for studying unconventional superconductivity.So far,research in this field is still very limited due to difficulties in sample preparation.Here we report the successful preparation of the superconducting state of Nd_(0.8)Sr_(0.2)NiO_(2)thin film(T_(c)=8.0-11.1 K)and study the stability of such films in the ambient environment,water,and under electrochemical conditions.Our work demonstrates that the superconducting state of Nd_(0.8)Sr_(0.2)NiO_(2)is remarkably stable,which can last for at least 47-day continuous exposure to air at 20°C and 35%relative humidity.We also show that the superconductivity disappears after being immersed in de-ionized water at room temperature for 5 h.Surprisingly,it can also survive under ionic liquid gating conditions with an applied voltage of about 4 V,which is even more stable than conventional perovskite complex oxides.

关键词： nickelate superconductor stability ionic liquid gating

Compositional dependence of hydrogenation performance of Ti-Zr-Hf-Mo-Nb high-entropy alloys for hydrogen/tritium storage

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Journal of Materials Science & Technology 2020年第20期52卷 116-125页

作者： Huahai Shen Jutao Hu Pengcheng Li Gang Huang Jianwei Zhang Jinchao Zhang Yiwu Mao Haiyan Xiao Xiaosong Zhou Xiaotao Zu Xinggui Long Shuming Peng Institute of Nuclear Physics and Chemistry China Academy of Engineering PhysicsMianyang 621900China School of Physics University of Electronic Science and Technology of ChinaChengdu 610054China

A series of Ti-Zr-Hf-Mo-Nb high-entropy alloys with different Mo concentrations were developed as candidate materials for hydrogen/tritium storage in solid phase.The crystal structures and hydrogenation properties of the Ti-Zr-Hf-Mo-Nb alloys were investigated by X-ray diffraction and differential scanning calorimetry techniques.All the alloys have a body-centred cubic single phase structure.The results demonstrate that the cell volume of the Ti-Zr-Hf-Mo-Nb hydride decreases with increasing Mo concentration,which reduces their thermal stability.The theoretical calculation proposes that the lower binding energy of the Ti-Zr-Hf-Mo-Nb hydride decreases the thermal stability of Ti-Zr-Hf-Mo-Nb alloys with higher Mo content.The great hydrogenation performance for all the Ti-Zr-Hf-Mo-Nb alloys is owing to their reversible single-phase transformation during the hydrogen absorption-desorption cycle,which would be bene ficial to improving the hydrogen recycling rate and preventing the disproportionation.The compositional dependence of the hydrogenation performance of the Ti-Zr-Hf-Mo-Nb alloys was established and will be useful in designing novel hydrogen/tritium storage materials to satisfy the requirements of diffe rent application fields in hydrogen,solar thermal and nuclear energy.

关键词： High-entropy alloy Hydrogen/tritium storage Crystal structure Phase transformation Binding energy

Band degeneracy enhanced thermoelectric performance in layered oxyselenides by first-principles calculations

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npj Computational Materials 2021年第1期7卷 158-170页

作者： Ning Wang Menglu Li Haiyan Xiao Zhibin Gao Zijiang Liu Xiaotao Zu Sean Li Liang Qiao School of Physics University of Electronic Science and Technology of ChinaChengduChina Department of Physics National University of SingaporeSingaporeRepublic of Singapore Department of Physics PhysicsLanzhou City UniversityLanzhouChina School of Materials University of New South WalesSydneyAustralia

Band degeneracy is effective in optimizing the power factors of thermoelectric(TE)materials by enhancing the Seebeck coefficients.In this study,we demonstrate this effect in model systems of layered oxyselenide family by the density functional theory(DFT)combined with semi-classical Boltzmann transport theory.TE transport performance of layered LaCuOSe and BiCuOSe are fully compared.The results show that due to the larger electrical conductivities caused by longer electron relaxation times,the n-type systems show better TE performance than p-type systems for both LaCuOSe and BiCuOSe.Besides,the conduction band degeneracy of LaCuOSe leads to a larger Seebeck coefficient and a higher optimal carrier concentration than n-type BiCuOSe,and thus a higher power factor.The optimal figure of merit(ZT)value of 1.46 for n-type LaCuOSe is 22%larger than that of 1.2 for n-type BiCuOSe.This study highlights the potential of wide band gap material LaCuOSe for highly efficient TE applications,and demonstrates that inducing band degeneracy by cations substitution is an effective way to enhance the TE performance of layered oxyselenides.

关键词： degeneracy selenide layered

Glucuronic acid metabolites of phenolic acids target AKT-PH domain to improve glucose metabolism

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Chinese Herbal Medicines 2023年第3期15卷 398-406页

作者： Jie Gao Manqian Zhang Xingwang zu Xue Gu Erwei Hao xiaotao Hou Gang Bai State Key Laboratory of Medicinal Chemical Biology College of Pharmacy and Tianjin Key Laboratory of Molecular Drug ResearchNankai UniversityTianjin 300353China Guangxi Key Laboratory of Efficacy Study on Chinese Materia Medica Guangxi Collaborative Innovation Center for Research on Functional Ingredients of Agricultural ResiduesGuangxi University of Chinese MedicineNanning 530200China

Objective:Phenolic acids widely exist in the human diet and exert beneficial effects such as improving glucose metabolism.It is not clear whether phenolic acids or their metabolites play a major role in vivo.In this study,caffeic acid(CA)and ferulic acid(FA),the two most ingested phenolic acids,and their glucuronic acid metabolites,caffeic-4’-O-glucuronide(CA4G)and ferulic-4’-O-glucuronide(FA4G),were investigated.Methods:Three insulin resistance models in vitro were established by using TNF-a,insulin and palmitic acid(PA)in HepG2 cells,respectively.We compared the effects of FA,FA4G,CA and CA4G on glucose metabolism in these models by measuring the glucose consumption levels.The potential targets and related pathways were predicted by network pharmacology.Fluorescence quenching measurement was used to analyze the binding between the compounds and the predicted target.To investigate the binding mode,molecular docking was performed.Then,we performed membrane recruitment assays of the AKT pleckstrin homology(PH)domain with the help of the PH-GFP plasmid.AKT enzymatic activity was determined to compare the effects between the metabolites with their parent compounds.Finally,the downstream signaling pathway of AKT was investigated by Western blot analysis.Results:The results showed that CA4G and FA4G were more potent than their parent compounds in increasing glucose consumption.AKT was predicted to be the key target of CA4G and FA4G by network pharmacology analysis.The fluorescence quenching test confirmed the more potent binding to AKT of the two metabolites compared to their parent compounds.The molecular docking results indicated that the carbonyl group in the glucuronic acid structure of CA4G and FA4G might bind to the PH domain of AKT at the key Arg-25 site.CA4G and FA4G inhibited the translocation of the AKT PH domain to the membrane,while increasing the activity of AKT.Western blot analysis demonstrated that the metabolites could increase the phosphorylation of AKT and downstream glycogen synthase kinase 3βin th

关键词： AKT glucuronic acid glucose metabolism metabolite phenolic acid PH domain