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A comparison between novel Gd_(2)Zr_(2)O_(7)and Gd_(2)Zr_(2)O_(7)/YSZ thermal barrier coatings fabricated by plasma spray-physical vapor deposition

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Rare Metals 2021年第8期40卷 2244-2253页

作者： Ren-Bo Zhu Jian-Peng Zou Jie Mao zi-qian deng Xiao-Feng Zhang Chun-Ming deng Min Liu School of Materials Science and Engineering University of New South WalesSydneyNSW2052Australia State Key Laboratory of Powder Metallurgy Central South UniversityChangsha410083China National Engineering Laboratory for Modern Materials Surface Engineering Technology and Key Laboratory of Guangdong for Modern Surface Engineering Technology Guangdong Institute of New MaterialsGuangzhou510651China

Spherical Gd_(2)Zr_(2)O_(7)hollow powders with a mean size of 8.8μm were fabricated as feedstock for thermal barrier coatings(TBCs)by *** single-ceramic-layer(SCL)Gd_(2)Zr_(2)O_(7)TBCs and double-ceramic-layer(DCL)Gd_(2)Zr_(2)O_(7)/YSZ TBCs with quasicolumnar structure were successfully fabricated by plasma spray-physical vapor deposition(PS-PVD).Tensile and water-quenching tests were applied to evaluate TBCs *** results show that adhesion strength of SCL Gd_(2)Zr_(2)O_(7)TBCs and DCL Gd_(2)Zr_(2)O_(7)/YSZ TBCs is36.5 MPa and 15.4 MPa,*** delamination of SCL Gd_(2)Zr_(2)O_(7)TBCs and DCL Gd_(2)Zr_(2)O_(7)/YSZ TBCs in the tensile test takes place at the middle and bottom of Gd_(2)Zr_(2)O_(7)layer,respectively,due to relatively lower fracture toughness of Gd_(2)Zr_(2)O_(7)*** 40 cycles of water-quenching test,DCL Gd_(2)Zr_(2)O_(7)/YSZ TBC surface keeps relatively intact,while SCL Gd_(2)Zr_(2)O_(7)TBC surface shows 20%visible destroyed regions,which demonstrates that DCL Gd_(2)Zr_(2)O_(7)/YSZ TBCs have a better thermal shock resistance than SCL Gd_(2)Zr_(2)O_(7)*** cracks in the SCL system propagate near thermally grown oxide(TGO)due to thermal mismatch and TGO growing stress,while cracks in the DCL system propagate in the Gd_(2)Zr_(2)O_(7)layer due to its relatively lower fracture toughness.

关键词： Plasma spray-physical vapor deposition Thermal barrier coatings Gd_(2)Zr_(2)O_(7) Thermal shock resistance Adhesion strength

Preparation of Al2O3 nanowires on 7YSZ thermal barrier coatings against CMAS corrosion

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Transactions of Nonferrous Metals Society of China 2019年第11期29卷 2362-2370页

作者： Xiao-feng ZHANG Shao-peng NIU zi-qian deng Min LIU Hong LI Chun-ming deng Chang-guang deng Ke-song ZHOU National Engineering Laboratory for Modern Materials Surface Engineering Technology Key Laboratory of Guangdong for Modern Surface Engineering TechnologyGuangdong Institute of New MaterialsGuangzhou 510650China

The commonly-employed material for thermal barrier coatings(TBCs)is 7 wt.%Y2O3 ZrO2(7YSZ),generally deposited by electron beam-physical vapor deposition(EB-PVD).Due to the increasing demand for higher operating temperature in aero-derivative gas turbines,a lot of effort has been made to prevent the premature failure of columnar 7YSZ TBCs,which is induced by the microstructure degradation,sintering and spallation after the deposition of infiltrated siliceous mineral(consisting of calcium magnesium aluminum silicate(CaO MgO Al2O3 SiO2,i.e.,CMAS)).A new method called Al-modification for columnar 7YSZ TBCs against CMAS corrosion was *** Al film was magnetron-sputtered on the surface of the columnar 7YSZ TBCs,followed by performing vacuum heat treatment of the Al-deposited *** the heat treatment,the molten Al reacted with ZrO2 to formα-Al2O3 overlay that effectively hindered CMAS ***,the Al film could evaporate and re-nucleate,leading to the generation of Al2O3 nanowires,which further restrained the moving of molten CMAS.

关键词： thermal barrier coating CMAS corrosion Al-modification Al2O3 nanowires

Effects of aggregate size distribution and carbon nanotubes on the mechanical properties of cemented gangue backfill samples under true triaxial compression

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International Journal of Minerals,Metallurgy and Materials 2025年第2期32卷 311-324页

作者： qian Yin Fan Wen Zhigang Tao Hai Pu Tianci deng Yaoyao Meng Qingbin Meng Hongwen Jing Bo Meng Jiangyu Wu State Key Laboratory of Intelligent Construction and Healthy Operation and Maintenance of Deep Underground Engineering China University of Mining and TechnologyXuzhou 221116China State Key Laboratory of Mining Response and Disaster Prevention and Control in Deep Coal Mines Anhui University of Science and TechnologyHuainan 232001China State Key Laboratory for Geomechanics&Deep Underground Engineering China University of Mining and Technology(Beijing)Beijing 100083China Key Laboratory of Xinjiang Coal Resources Green Mining Ministry of EducationXinjiang Institute of EngineeringUrumqi 830023China

The mechanical behavior of cemented gangue backfill materials(CGBMs)is closely related to particle size distribution(PSD)of aggregates and properties of cementitious ***,the true triaxial compression tests,CT scanning,SEM,and EDS tests were conducted on cemented gangue backfill samples(CGBSs)with various carbon nanotube concentrations(P_(CNT))that satisfied fractal theory for the PSD of *** mechanical properties,energy dissipations,and failure mechanisms of the CGBSs under true triaxial compression were systematically *** results indicate that appropriate carbon nanotubes(CNTs)effectively enhance the mechanical properties and energy dissipations of CGBSs through micropore filling and microcrack bridging,and the optimal effect appears at P_(CNT)of 0.08wt%.Taking PSD fractal dimension(D)of 2.500 as an example,compared to that of CGBS without CNT,the peak strength(σ_(p)),axial peak strain(ε_(1,p)),elastic strain energy(Ue),and dissipated energy(U_(d))increased by 12.76%,29.60%,19.05%,and90.39%,***,excessive CNTs can reduce the mechanical properties of CGBSs due to CNT agglomeration,manifesting a decrease inρ_(p),ε_(1,p),and the volumetric strain increment(Δε_(v))when P_(CNT)increases from 0.08wt%to 0.12wt%.Moreover,the addition of CNTs improved the integrity of CGBS after macroscopic failure,and crack extension in CGBSs appeared in two modes:detour and pass through the ***σ_(p)and U_(d)firstly increase and then decrease with increasing D,and porosity shows the opposite ***ε_(1,p)andΔε_(v)are negatively correlated with D,and CGBS with D=2.150 has the maximum deformation parameters(ε_(1,p)=0.05079,Δε_(v)=0.01990)due to the frictional slip effect caused by coarse *** increasing D,the failure modes of CGBSs are sequentially manifested as oblique shear failure,"Y-shaped"shear failure,and conjugate shear failure.

关键词： cemented gangue backfill materials particle size distribution true triaxial compression test carbon nanotubes mechanical properties failure modes

Exploring the interaction between the gut microbiota and cyclic adenosine monophosphate-protein kinase A signaling pathway:a potential therapeutic approach for neurodegenerative diseases

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Neural Regeneration Research 2025年第11期20卷 3095-3112页

作者： Fengcheng deng Dan Yang Lingxi Qing Yifei Chen Jilian Zou Meiling Jia qian Wang Runda Jiang Lihua Huang College of Pharmacy Chengdu University of Traditional Chinese MedicineChengduSichuan ProvinceChina State Key Laboratory of Southwestern Chinese Medicine Resources Chengdu University of Traditional Chinese MedicineChengduSichuan ProvinceChina

The interaction between the gut microbiota and cyclic adenosine monophosphate(cAMP)-protein kinase A(PKA)signaling pathway in the host's central nervous system plays a crucial role in neurological diseases and enhances communication along the gut–brain *** gut microbiota influences the cAMP-PKA signaling pathway through its metabolites,which activates the vagus nerve and modulates the immune and neuroendocrine ***,alterations in the cAMP-PKA signaling pathway can affect the composition of the gut microbiota,creating a dynamic network of microbial-host *** reciprocal regulation affects neurodevelopment,neurotransmitter control,and behavioral traits,thus playing a role in the modulation of neurological *** coordinated activity of the gut microbiota and the cAMP-PKA signaling pathway regulates processes such as amyloid-β protein aggregation,mitochondrial dysfunction,abnormal energy metabolism,microglial activation,oxidative stress,and neurotransmitter release,which collectively influence the onset and progression of neurological *** study explores the complex interplay between the gut microbiota and cAMP-PKA signaling pathway,along with its implications for potential therapeutic interventions in neurological *** pharmacological research has shown that restoring the balance between gut flora and cAMP-PKA signaling pathway may improve outcomes in neurodegenerative diseases and emotional *** can be achieved through various methods such as dietary modifications,probiotic supplements,Chinese herbal extracts,combinations of Chinese herbs,and innovative dosage *** findings suggest that regulating the gut microbiota and cAMP-PKA signaling pathway may provide valuable evidence for developing novel therapeutic approaches for neurodegenerative diseases.

关键词： cyclic adenosine monophosphate emotional disorders gut microbiota neurodegenerative diseases neurological diseases protein kinase A reciprocal regulation signaling pathway strategy therapies

Prediction of Maximum Section Flattening of Thin-walled Circular Steel Tube in Continuous Rotary Straightening Process

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Journal of Iron and Steel Research International 2016年第8期23卷 745-755页

作者： zi-qian ZHANG School of Mechanical Engineering and Automation Northeastern University

Cross-sectional ovalization of thin-walled circular steel tube because of large plastic bending,also known as the Brazier effect,usually occurs during the initial stage of tube′s continuous rotary straightening *** amount of ovalization,defined as maximal cross section flattening,is an important technical parameter in tube′s straightening process to control tube′s bending deformation and prevent ***,for the lack of special analytical model,the maximal section flattening was determined in accordance with the specified charts developed by experienced operators on the basis of experimental data;thus,it was inevitable that the localized buckling might occur during some actual straightening *** normal strain component formulas were derived based on the thin shell ***,strain energy of thin-walled tube（per unit length）was obtained using the elastic-plastic theory.A rational model for predicting the maximal section flattening of the thin-walled circular steel tube under its straightening process was presented by the principle of minimum potential *** new model was validated by experiments and numerical *** results show that the new model agrees well with the experiments and the numerical simulations with error of less than 10%.This new model was expected to find its potential application in thin-walled steel tube straightening machine design.

关键词： walled Rotary bending buckling length maximal radius localized Prediction rotary

Emergent vegetation flow with varying vertical porosity

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Journal of Hydrodynamics 2019年第5期31卷 1043-1051页

作者： Ming-deng Zhao zi-long Fan State Key Laboratory of Water Resources and Hydropower Engineering Science Wuhan UniversityWuhan 430072China Department of Engineering and Information Technology China International Water and Electric Corporation(CWE)Beijing 100120China China Three Gorges Corporation(CTG) Beijing J 00038China

The vertical distribution of an emergent vegetation in wetlands and marshes is generally non-uniform due to the variations of the stem thickness and the leaf *** study focuses on the effect of the varying vertical porosity on the hydrodynamic characteristics of the emergent vegetation *** new governing equation for the emergent vegetation flow with varying vertical porosity is established by applying the poroelastic media flow *** to the movement mechanism of the water flow in the porous media and the experimental data,the best fitted expression of the permeability is established for the emergent vegetation *** velocity distribution is obtained with the finite analytic ***,a flume experiment is performed using truncated cones to simulate the actual vegetation with varying vertical *** calculated velocity distribution is compared with the measured data,which shows that the theoretical results are in good agreement with the experimental ***,the influence of the vertical porosity distribution on the vegetation flow characteristics is analyzed *** study can provide a useful reference and technical support for further study of the flow with a complex shape vegetation.

关键词： Emergent vegetation flow velocity distribution varying vertical porosity finite analytic method Biot^poroelastic theory

Experimental investigation on pressure-buildup characteristics of a water lump immerged in a molten lead pool

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Nuclear Science and Techniques 2023年第3期34卷 25-39页

作者： zi-Jian deng Song-Bai Cheng Hui Cheng Sino-French Institute of Nuclear Engineering and Technology Sun Yat-Sen UniversityZhuhai 519082China

Motivated to understand the pressure-buildup characteristics in a circumstance of a water droplet immerged inside a heavy liquid metal pool,which is a key phenomenon during a Steam Generator Tube Rupture accident of Lead-cooled Fast Reactor,many experiments have been conducted by injecting water lumps into a molten lead pool at Sun Yat-sen *** order to deepen the understanding of the influence of melt material,this lead experiment was compared with a Lead-Bismuth-Eutectic(LBE)experiment in the *** both experiments,a steam explosion occurred in a small part of the experi-mental runs,which generally leads to strengthened pressure *** the non-explosion experimental cases,the impact of all parameters employed in lead experiments(i.e.,water lump volume,water lump shape,molten pool depth,and temperature of water and melt)on the pressure buildup is non-negligible and similar to that in our previous experiments using ***,limited pressure buildup with an increase in water lump volume was also observed.A slightly more violent pressure buildup tends to appear in the lead experiments than in the LBE experiments under the same experimental conditions,which may be due to the higher thermal conductivity of lead than of *** a few experimental runs with a relatively low melt temperature close to the melting point of lead,local solidification of liquid lead was observed,restricting pressure *** the lead and LBE experiments,the calculated melt kinetic energy conversion efficiencyηhas a relatively small value(not exceeding 1.6%),and theηvalues have an overall positive correlation with the impulse on the molten pool.

关键词： Lead-cooled fast reactor Steam generator tube rupture accident Pressure-buildup characteristics Experimental study Melt material

An Adaptive Collocation Method with Weighted Extended PHT-Splines

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Journal of Systems Science & Complexity 2021年第1期34卷 47-67页

作者： NI qian deng Jiansong WANG Xuhui School of Mathematical Sciences University of Science and Technology of ChinaHefei 230026China School of Mathematics Hefei University of TechnologyHefei 230009China

This paper presents an adaptive collocation method with weighted extended *** authors modify the classification rules for basis functions based on the relation between the basis vertices and the computational domain. The Gaussian points are chosen to be collocation points since PHT-splines are C1 continuous. The authors also provide relocation techniques to resolve the mismatch problem between the number of basis functions and the number of interpolation conditions. Compared to the traditional Greville collocation method, the new approach has improved accuracy with fewer oscillations. Several numerical examples are also provided to test our the proposed approach.

关键词： Collocation method Gaussian points PHT-splines weighted extended PHT-splines

Algebraic Method‑Based Point‑to‑Point Trajectory Planning of an Under‑Constrained Cable‑Suspended Parallel Robot with Variable Angle and Height Cable Mast

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Chinese Journal of Mechanical Engineering 2020年第4期33卷 45-62页

作者： Tao Zhao Bin zi Sen qian Jiahao Zhao School of Mechanical Engineering Hefei University of TechnologyHefei 230009China Chemical Science and Engineering College North Minzu UniversityYinchuan 750021China

To avoid impacts and vibrations during the processes of acceleration and deceleration while possessing flexible working ways for cable-suspended parallel robots(CSPRs),point-to-point trajectory planning demands an under-constrained cable-suspended parallel robot(UCPR)with variable angle and height cable mast as described in this *** end-effector of the UCPR with three cables can achieve three translational degrees of freedom(DOFs).The inverse kinematic and dynamic modeling of the UCPR considering the angle and height of cable mast are *** motion trajectory of the end-effector comprising six segments is *** connection points of the trajectory segments(except for point P3 in the X direction)are devised to have zero instantaneous velocities,which ensure that the acceleration has continuity and the planned acceleration curve achieves smooth *** trajectory is respectively planned using three algebraic methods,including fifth degree polynomial,cycloid trajectory,and double-S velocity *** results indicate that the trajectory planned by fifth degree polynomial method is much closer to the given trajectory of the *** simulation and experiments are accomplished for the given trajectory based on fifth degree polynomial *** the points where the velocity suddenly changes,the length and tension variation curves of the planned and unplanned three cables are compared and *** OptiTrack motion capture system is adopted to track the end-effector of the UCPR during the *** effectiveness and feasibility of fifth degree polynomial planning are validated.

关键词： Under-constrained cable-suspended parallel robot Variable angle and height cable mast Inverse kinematic and dynamic modeling Algebraic method Point-to-point trajectory planning