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Concentration-dependent crystal structure, elastic constants and electronic structure of ZrxTi1-x alloys under high pressure

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Frontiers of physics 2014年第2期9卷 219-225页

作者： Xiao-Li Yuan mi-An Xue Wen Chen Tian-Qing An College of Mechanics and Materials Hohai University Nanjing 210098 China State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering Hohai University Nanjing 210098 China College of Harbour Coastal and Offshore Engineering Hohai University Nanjing 210098 China College of Science Hohai University Nanjing 210098 China

The physical properties of ZrxTi1-x（x=0.0, 0.33, 0.5, 0.67, 0.75 and 1.00） alloys were sinmlated by virtual crystal approximation （VCA） methods which is generally used for disordered solid solutions modeling. The elastic constant, electronic structure and thermal Equation of state （EOS） of disor- dered ZrxTi1-x alloys under pressure are investigated by plane-wave pseudo-potentia1 method. Our simulations reveal increasement of variations of the calculated equilibrium volumes and decrease- ment of bulk modulus as a function of the alloy compositions. Lattice parameters a and c of alloys with differentZr concentrations decrease linearly with pressure increasing, but the c/avalues are increasing as pressure increases, indicating no phase transitions under pressure from 0 GPa to 100 GPa. The elastic constants and the bulk modulus to the Shear modulus ratios （b/G） indicate good ductility of Zr, Zr0.33 Ti0.67 Zr0.5Ti0.5, Zr0.75Ti0.25 and Ti, but the Zr0.67Ti0.33 alloy is brittle under 0 K and 0 GPa. The metallic behavior of these alloys was also proved by analyzing partial and total DOS.

关键词： dalloy density functional theory virtual crystal approximation (VCA) mechanics,elastic properties

Continuous-Discrete Adaptive Observers For a Class of Nonlinear Systems With Sampled Output 36

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Continuous-Discrete Adaptive Observers For a Class of Nonlin...

brain activation induced by different strengths of hand grasp: a functional magnetic resonance imaging study

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作者： Guanglei Zhao Jie mi Institute of Electrical Engineering Yanshan University Department of Human Resource Yanshan University

ISBN: (纸本)9781538629185

This paper considers the continuous-discrete time adaptive observer design for a class of nonlinear systems with unknown constant parameters and sampled output measurements. The proposed observer is in impulsive dynamics form with an inter-sample output predictor, where the observer state flows continuously when the output is not available, and a corrective term corresponding to measured samples is used to update the observer state. by assuming appropriate persistent excitation conditions and following a technical lemma, an upper bound of the sampling intervals is derived, with which, the convergence of the observer state and unknown parameters can be ensured. Finally, the proposed observer is used in an example of single-link flexible-joint robot manipulator to show the effectiveness.

关键词： nonlinear systems continuous-discrete adaptive observer sampled output measurements persistent excitation unknown parameter

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Neural Regeneration Research 2020年第5期15卷 875-879页

作者： Hyeok Gyu Kwon Ju Sang Kim mi Young Lee Department of Physical Therapy College of Health ScienceEulji UniversityGyeonggiRepublic of Korea Department of Physical Therapy and Rehabilitation Yeungnam University HospitalDaeguRepublic of Korea Department of Physical Therapy College of Health and TherapyDaegu Haany UniversityGyeongsansiRepublic of Korea

mirror neuron system can be activated by observation and execution of an *** has an important function of action *** investigated brain activations in humans by observing the strength of a hand grasp using functional magnetic resonance *** right-handed healthy individuals,consisting of 10 males and 10 females,aged 22.40 ± 2.04 years,were recruited into this study from September to November 2017 via *** hand grasp task video showed a hand lightly grasping and releasing a ball *** hand grasp task video showed a hand tightly grasping and releasing a ball *** magnetic resonance imaging block design paradigm comprised five stimulation blocks alternating with five baseline *** blocks were presented with two stimulus tasks,consisting of a light grasp and a powerful *** of interest was defined around the inferior parietal lobule,inferior frontal gyrus,and superior temporal sulcus which have been called mirror neuron *** inferior parietal lobule,fusiform,postcentral,occipital,temporal,and frontal gyri were activated during light and powerful grasp *** bOLD signal response of a powerful grasp was stronger than that of a light *** results suggest that brain activation of the inferior parietal lobule,which is the core brain region of the mirror neuron system,was stronger in the powerful grasp task than in the light grasp *** believe that our results might be helpful for instructing rehabilitation of brain *** study was approved by the Institutional Review board of Daegu Oriental Hospital of Daegu Haany University on September 8,2017 (approval ***-D-17020-PRO-01).

关键词： brain activation fMRI human brain inferior parietal lobule light grasp mirror neuron system powerful grasp

Robust isogeometric topology optimization for piezoelectric actuators with uniform manufacturability

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Frontiers of Mechanical Engineering 2022年第2期17卷 205-224页

作者： Jie GAO mi XIAO Zhi YAN Liang GAO Hao LI Department of Engineering Mechanics School of Aerospace EngineeringHuazhong University of Science and TechnologyWuhan 430074China Hubei Key Laboratory for Engineering Structural Analysis and Safety Assessment Huazhong University of Science and TechnologyWuhan 430074China State Key Laboratory of Digital Manufacturing Equipment and Technology Huazhong University of Science and TechnologyWuhan 430074China

Piezoelectric actuators have received substantial attention among the industry and academia due to quick responses, such as high output force, high stiffness, high accuracy, and precision. However, the design of piezoelectric actuators always suffers from the emergence of several localized hinges with only one-node connection, which have difficulty satisfying manufacturing and machining requirements (from the over- or under-etching devices). The main purpose of the current paper is to propose a robust isogeometric topology optimization (RITO) method for the design of piezoelectric actuators, which can effectively remove the critical issue induced by one-node connected hinges and simultaneously maintain uniform manufacturability in the optimized topologies. In RITO, the isogeometric analysis replacing the conventional finite element method is applied to compute the unknown electro elastic fields in piezoelectric materials, which can improve numerical accuracy and then enhance iterative stability. The erode–dilate operator is introduced in topology representation to construct the eroded, intermediate, and dilated density distribution functions by non-uniform rational b-splines. Finally, the RITO formulation for the design of piezoelectric materials is developed, and several numerical examples are performed to test the effectiveness and efficiency of the proposed RITO method.

关键词： piezoelectric actuator isogeometric topology optimization uniform manufacturability robust formulation density distribution function

An integrated portable bio-monitoring system based on tough hydrogels for comprehensive detection of physiological activities

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Nano Research 2024年第1期17卷 321-332页

作者： Congcong Yang Chenchen Ji Fengjiao Guo Chunjiang Jin Hongyu mi Zhongchang Wang State Key Laboratory of Chemistry and Utilization of Carbon based Energy Resources School of Chemical Engineering and TechnologyXinjiang UniversityUrumqi 830017China International Iberian Nanotechnology Laboratory(INL) Avenide Mestre Jose VeigaBraga 4715-330Portugal

Advanced soft ion-conducting hydrogels have been developed rapidly in the integrated portable health monitoring equipment due to their higher sensitivity,sensory traits,tunable conductivity,and stretchability for physiological activities and personal healthcare ***,traditional hydrogel conductors are normally susceptible to large deformation and strong mechanical stress,which leads to inferior electro-mechanical stability for real application ***,a strong ionically conductive hydrogel(poly(vinyl alcohol)-boric acid-glycerol/sodium alginate-calcium chloride/electrolyte ions(PbG/SC/EI))was designed by engineering the covalently and ionically crosslinked networks followed by the salting-out effect to further enhance the mechanical strength and ionic conductivity of the *** to the collective effects of the energy-dissipation mechanism and salting-out effect,the designed PbG/SC/EI with excellent structural integrity and robustness exhibits exceptional mechanical properties(elongation at break for 559.1%and tensile strength of 869.4 kPa)and high ionic conductivity(1.618 S·m^(-1)).As such,the PbG/SC/EI strain sensor features high sensitivity(gauge factor=2.29),which can effectively monitor various kinds of human motions(joint motions,facial micro-expression,faint respiration,and voice recognition).Meanwhile,the hydrogel-based Zn||MnO_(2)battery delivers a high capacity of 267.2 mAh·g^(-1)and a maximal energy density of 356.8 Wh·kg^(-1)associated with good cycle performance of 71.8%capacity retention after 8000 ***,an integrated bio-monitoring system with the sensor and Zn||MnO_(2)battery can accurately identify diverse physiological activities in a real-time and non-invasive *** work presents a feasible strategy for designing high-performance conductive hydrogels for highly-reliable integrated bio-monitoring systems with excellent practicability.

关键词： Ionically conductive hydrogel strain sensor Zn-based battery integrated bio-monitoring system human motion monitoring

Thermostable α-Diimine Nickel Complexes with Substituents on Acenaphthequinone-backbone for Ethylene Polymerization

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Chinese Journal of Polymer Science 2020年第11期38卷 1214-1220,I0007页

作者： Rui-Fang Zhang Yan-Hui Hou Xu-Ling Wei Ding-Ding Zhao mi-mi Cui Fei-Fan Zhai Xiang-Liu Li bin-Yuan Liu min Yang Hebei Key Laboratory of Functional Polymers Tianjin Key Laboratory of Chemical Process SafetyInstitute of Polymer Science and EngineeringHebei University of TechnologyTianjin 300130China State Key Laboratory of Separation Membranes and Membrane Processes School of Material Science and EngineeringTiangong UniversityTianjin 300160China Lanzhou Petrochemical Research Center Petrochemical Research Institute of CNPCLanzhou 730060China

In order to promote the thermostability of a-diimine nickel complex by ligand backbone structure,a series of α-diimine nickel complexes with substituents on acenaphthequinone backbone were synthesized and used as catalysts for ethylene *** the hydroxyethyl phenoxyl group was introduced to the acenaphthequinone-backbone,the thermal stability and activity of the catalyst could be significantly *** catalytic activity of complex C2[5-(4-(2-hydroxyethyl)phenoxyl)-N,N-bis(2,6-diisopropyl)acenaphthylene-1,2-diimine]nickel(Ⅱ)dibromide with isopropyl substituents on N-aryl reached 8.2×10^6g/(molNi·h)at 70℃and 2 *** activity of[5-(4-(2-hydroxyethyl)phenoxyl)-N,N-bis(2,6-dibenzhydryl-4-menthylphenyl)acenaphthylene-1,2-diimine]nickel(Ⅱ)dibromide(C3)still maintained at 6.7×10^5 g/(molNi·h)at 120℃.Compared with C3 containing bulky dibenzhydryl substituents,the activity of C2 was sensitive to the change of the polymerization ***,the polyethylenes obtained from complex C3 had lower branching ***,the molecular weight could reach 971 kg/mol,which is almost 5 times as much as that of the polyethylene obtained from complex C2.

关键词： α-Diimine nickel Ethylene polymerization Thermostability Ligand backbone structure

microstructure evolution of ultra-high-strength twinning-induced plasticity(TWIP)steel under dynamic loading

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Journal of Iron and Steel Research International 2021年第1期28卷 66-75页

作者： Qi‑hang Pang Mei Xu Zhen‑li mi Juan Cui Jing Guo School of Materials and Metallurgy University of Science and Technology LiaoningAnshan 114051LiaoningChina State Key Laboratory of Metal Material for Marine Equipment and Application Anshan 114009LiaoningChina State Key Laboratory of Advanced Stainless Steel Materials Taiyuan Iron and Steel Group Co.Ltd.Taiyuan 030003ShanxiChina Institute of Engineering Technology University of Science and Technology BeijingBeijing 100083China beijing Jianlong Heavy Industry Group Co. Ltd.Beijing 100070China

To prepare ultra-high-yield strength twinning-induced plasticity(TWIP)steel and reveal its work hardening mechanism at different strain rates from the microcosmic range,the microstructure evolution mechanism of Fe–20Mn–0.6C TWIP steel was investigated at strain rates of 10^(-4)–10^(3)s^(-1)using a high-speed tensile testing machine and a transmission electron *** results show that the strain rate and deformation had a significant effect on the twin morphology of TWIP *** a strain rate of 10^(2)s^(-1),secondary deformation twins were developed,which intersected with the initial deformation twins and increased the resistance of dislocation movement,as well as the *** steel at a strain rate of 10^(2)s^(-1)had a higher twin formation speed than that at 10^(0)s^(-1).At the same amount of deformation,the twin boundary fraction was higher and increased linearly at a strain rate of 10^(2)s^(-1),while the rule of twin growth at 10^(0)s^(-1)was conformed to S-curve change of DoseResp model.

关键词： Twinning-induced plasticity steel Electron backscattered diffraction,microstructure Dynamic loading Strain rate Work hardening

Drug discovery by targeting the protein–protein interactions involved in autophagy

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Acta Pharmaceutica Sinica b 2023年第11期13卷 4373-4390页

作者： Honggang Xiang mi Zhou Yan Li Lu Zhou Renxiao Wang Department of Medicinal Chemistry School of PharmacyFudan UniversityShanghai 201203China

Autophagy is a cellular process in which proteins and organelles are engulfed in autophagosomal vesicles and transported to the lysosome/vacuole for ***–protein interactions(PPIs)play a crucial role at many stages of autophagy,which present formidable but attainable targets for autophagy ***,selective regulation of PPIs tends to have a lower risk in causing undesired off-target effects in the context of a complicated biological ***,small-molecule regulators,including peptides and peptidomimetics,targeting the critical PPIs involved in autophagy provide a new opportunity for innovative drug *** article provides general background knowledge of the critical PPIs involved in autophagy and reviews a range of successful attempts on discovering regulators targeting those *** strategies and existing limitations in this field are also discussed.

关键词： Autophagy regulation Protein–protein interactions Small-molecule regulators Drug discovery

Promoting the La solution in 2:14:1-type compound:Resultant chemical deviation and microstructural nanoheterogeneity

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Journal of Materials Science & Technology 2021年第3期62卷 195-202页

作者： Yongsheng Liu Jiaying Jin Tianyu Ma baixing Peng Xinhua Wang mi Yan School of Materials Science and Engineering State Key Laboratory of Silicon materialsKey Laboratory of Novel Materials for Information Technology of Zhejiang ProvinceZhejiang UniversityHangzhou310027China

RE_(2)Fe_(14)b-based(RE,rare earth)permanent magnets containing abundant and cheap La/Ce have attracted intense attention *** comparison with Ce that can fully replace Nd in the 2:14:1 lattice,La substitution for Nd has long been limited at a low *** we present that through doping La35 Ce65 alloy with the La/Ce ratio in natural mineral,stable 2:14:1 phase can be maintained at 1273 K within the entire substitution range of[(La_(35)Ce_(65))、(Pr_(20)Nd_(80))_(1-x)]_(2.14)Fe_(14)b(0.6≤x≤1.0,at.%),as verified by composition analysis,microstructural characterization and magnetic ***,the promoted La solution in 2:14:1 phase induces two unique findings upon coexisting La-Ce-Pr-Nd:i)Compared to Ce that fits well with the nominal concentration,La deviates noticeably from the nominal one;ii)Nanoscale spinodal-decomposition-like phase separation is observed due to different solubilities of La-Ce-Pr-Nd elements in 2:14:1 *** joint effects induce higher Curie temperature than estimation based on the rule of mixture,which delights the prospect of La_(35)Ce_(65)alloy in developing low-cost permanent materials.

关键词： La-Ce Permanent magnets Nd-Fe-b microstructure