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Effects of mechanical vibration on filling and solidification behavior, microstructure and performance of Al/Mg bimetal by lost foam compound casting 被引量:1
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作者 Guang-yu Li Feng Guan +3 位作者 Wen-ming Jiang Yuan-cai Xu Zheng Zhang Zi-tian Fan 《China Foundry》 SCIE EI CAS CSCD 2023年第6期469-479,共11页
Al/Mg bimetal was prepared by lost foam solid-liquid compound casting,and the effects of mechanical vibration on the filling and solidification behavior,microstructure and performance of the bimetal were investigated.... Al/Mg bimetal was prepared by lost foam solid-liquid compound casting,and the effects of mechanical vibration on the filling and solidification behavior,microstructure and performance of the bimetal were investigated.Results show that the mechanical vibration has a remarkable influence on the filling and solidification processes.It is found that after mechanical vibration,the filling rate increases and the filling rate at different times is more uniform than that without vibration.In addition,the mechanical vibration also increases the wettability between liquid AZ91D and A356 inlays.The mechanical vibration reduces the horizontal and vertical temperature gradient of the casting and makes the temperature distribution of the whole casting more uniform.Compared to the Al/Mg bimetal without vibration,the shear strength is improved by 39.76%after the mechanical vibration is applied,due to the decrease of the inclusions and Al_(12)Mg_(17) dendrites,and the refinement and uniform distribution of the Mg_(2)Si particles in the interface of the Al/Mg bimetal. 展开更多
关键词 lost foam casting filling and solidification processes Al/Mg bimetal mechanical vibration MICROSTRUCTURE mechanical properties
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Grain refinement of Al-5%Cu aluminum alloy under mechanical vibration using meltable vibrating probe 被引量:5
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作者 郭洪民 章爱生 +1 位作者 杨湘杰 严明明 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第8期2489-2496,共8页
A mechanical vibration technique to refine solidified microstructure was reported. Vibration energy was directly introduced into a molten alloy by a vibrating horn, and the vibrating horn was melted during vibration. ... A mechanical vibration technique to refine solidified microstructure was reported. Vibration energy was directly introduced into a molten alloy by a vibrating horn, and the vibrating horn was melted during vibration. Effects of vibration acceleration and mass ratio on the microstructure of Al-5% Cu alloy were investigated. Results show that the present mechanical vibration could provide localized cooling by extracting heat from the interior of molten alloy, and the cooling rate is strongly dependent on vibration acceleration. It is difficult to refine the solidified microstructure when the treated alloy keeps full liquid state within the entire vibrating duration. Significantly refined microstructure was obtained by applying mechanical vibration during the initial stage of solidification. Moreover, mechanisms of grain refinement were discussed. 展开更多
关键词 Al-Cu alloy grain refinement SOLIDIFICATION mechanical vibration
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Mechanism of burst feeding in ZL205A casting under mechanical vibration and low pressure 被引量:7
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作者 Ru-jia WANG Shi-ping WU Wei CHEN 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2018年第8期1514-1520,共7页
The burst feeding behavior of ZL205 A casting under mechanical vibration and low pressure was investigated by casting experiment and physical model. Experimental results indicated that the burst feeding appeared repea... The burst feeding behavior of ZL205 A casting under mechanical vibration and low pressure was investigated by casting experiment and physical model. Experimental results indicated that the burst feeding appeared repeatedly during solidification and left a shrinkage cavity with layered structure under mechanical vibration. The castings with less shrinkage and higher density could be achieved through the vibration. The calculation results of physical model showed that the burst feeding could perform spontaneously under vibration while difficultly without vibration in low-pressure die casting. The obstruction of a casting could be broken and the grains could be rearranged by the vibration. And the obstruction could be carried away due to the inner and outer pressure difference, causing a burst feeding. 展开更多
关键词 burst feeding ZL205A alloy mechanical vibration low pressure physical model
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Influence of mechanical vibration on the solidification of a lost foam cast 356 alloy 被引量:7
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作者 Zhao Zhong Fan Zitian +3 位作者 Dong Xuanpu Tang Bo Pan Di Li Jiqiang 《China Foundry》 SCIE CAS 2010年第1期24-29,共6页
Mechanical vibration was applied to the solidification of a lost foam cast(LFC) 356 aluminum alloy.Effects of mechanical vibration,with different peak acceleration,on the size and morphology of α-Al phase,and also on... Mechanical vibration was applied to the solidification of a lost foam cast(LFC) 356 aluminum alloy.Effects of mechanical vibration,with different peak acceleration,on the size and morphology of α-Al phase,and also on the mechanical properties of the castings were studied.Results indicated that α-Al dendrites gradually grow into equiaxed grains as the peak acceleration of vibration is increased.When the peak acceleration is between about 1 to 4 g,α-Al phase distribution is uniform and is refined obviously.α-Al dendrites are reduced and the mechanical properties of the castings are improved significantly when compared to those of the castings that are produced without vibration.However,when the peak acceleration is higher than 4 g,strong vibration will lead to defects formation,such as sand adhesion,while the amount and size of pores will be increased.And due to the turbulent flow that caused by strong vibration,the chance of forming large pores in the matrix has been increased significantly.The increase in defects will result in the deterioration of mechanical properties. 展开更多
关键词 aluminum alloy microstructure mechanical property lost foam casting mechanical vibration
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The dynamic characteristics of harvesting energy from mechanical vibration via piezoelectric conversion 被引量:4
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作者 樊康旗 明正峰 +1 位作者 徐春辉 晁锋波 《Chinese Physics B》 SCIE EI CAS CSCD 2013年第10期354-361,共8页
As an alternative power solution for low-power devices, harvesting energy from the ambient mechanical vibration has received increasing research interest in recent years. In this paper we study the transient dynamic c... As an alternative power solution for low-power devices, harvesting energy from the ambient mechanical vibration has received increasing research interest in recent years. In this paper we study the transient dynamic characteristics of a piezoelectric energy harvesting system including a piezoelectric energy harvester, a bridge rectifier, and a storage capacitor. To accomplish this, this energy harvesting system is modeled, and the charging process of the storage capacitor is investigated by employing the in-phase assumption The results indicate that the charging voltage across the storage capacitor and the gathered power increase gradually as the charging process proceeds, whereas the charging rate slows down over time as the charging voltage approaches to the peak value of the piezoelectric voltage across the piezoelectric materials. In addition, due to the added electrical damping and the change of the system natural frequency when the charging process is initiated, a sudden drop in the vibration amplitude is observed, which in turn affects the charging rate. However, the vibration amplitude begins to increase as the charging process continues, which is caused by the decrease in the electrical damping (i.e., the decrease in the energy removed from the mechanical vibration). This electromechanical coupling characteristic is also revealed by the variation of the vibration amplitude with the charging voltage. 展开更多
关键词 piezoelectric conversion mechanical vibration charging dynamics electromechanical coupling
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Effects of mechanical vibration on the physical,metallurgical and mechanical properties of cast A308(LM21)aluminum alloy 被引量:1
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作者 Siddharth Yadav S.P.Tewari +1 位作者 J.K.Singh S.C.Ram 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2022年第6期1206-1215,共10页
This study investigated the microstructure,physical,and mechanical properties of die-cast A308 alloy subjected to mechanical vibration during solidification.Different frequencies(0,20,30,40,and 50 Hz)at constant ampli... This study investigated the microstructure,physical,and mechanical properties of die-cast A308 alloy subjected to mechanical vibration during solidification.Different frequencies(0,20,30,40,and 50 Hz)at constant amplitude(31μm)were employed using a power amplifier as the power input device.X-ray diffraction,optical microscopy,and scanning electron microscopy were used to examine the morphological changes in the cast samples under stationary and vibratory conditions.Metallurgical features of the castings were evaluated using Image J software.The average values of metallurgical features,including primaryα-Al grain size,dendrite arm spacing,average area of eutectic silicon,aspect ratio,and percentage porosity,reduced by 34%,59%,56%,22%,and 62%,respectively,at 30 Hz frequency compared with stationary casting.Mechanical tests of the cast samples showed that the yield strength(YS),ultimate tensile strength(UTS),percentage elongation(%EL),and microhardness(HV)increased by 8%,13%,17%,and 16%,respectively,at 30 Hz frequency compared with stationary casting.The fractured surface of the tensile specimens exhibited mixed-mode fracture behavior because of brittle facets,cleavage facets,ductile tearing,and dimple morphologies.The presence of small dimples showed that plastic deformation occurred before fracture. 展开更多
关键词 mechanical vibration MICROSTRUCTURES MICROHARDNESS tensile strength FRACTOGRAPHY
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Generating Electricity from Mechanical Vibrations:Optimization of Linear a Generator 被引量:2
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作者 MAA KARUNARATHNA KAM DHANURANGA 《Instrumentation》 2021年第2期34-39,共6页
Energy preservation is one of the key components in developing eco-friendly machines.In industry,the majority of machines lose a considerable amount of energy through mechanical vibrations.However,the wasted energy th... Energy preservation is one of the key components in developing eco-friendly machines.In industry,the majority of machines lose a considerable amount of energy through mechanical vibrations.However,the wasted energy through vibration can be utilized as a renewable energy source to compensate for the overall energy loss.The research work presented in this paper discusses the ability to design a linear power generator utilizing Nd Fe-B magnets,which can generate energy through mechanical vibrations.A pilot model was developed and simulated to understand the efficiency and limitation.The results showed that the model could reduce 14% rotor bulk with a marginal impact on the current generation. 展开更多
关键词 mechanical vibrations Linear Generator Sustainable Energy Energy Production
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Influences of Mechanical Vibration on Rapidly Solidified Al_2O_3/YSZ Ceramics Prepared by Combustion Synthesis
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作者 ZHAO Zhong-min ZHANG Long +1 位作者 WANG Wei-guo ZHANG Shi-yue 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2006年第B12期27-30,共4页
Al2O3/YSZ composite ceramics was fabricated with combustion synthesis technology, and the influences of mechanical vibration on its microstructures and properties were investigated. It is found that under the mechanic... Al2O3/YSZ composite ceramics was fabricated with combustion synthesis technology, and the influences of mechanical vibration on its microstructures and properties were investigated. It is found that under the mechanical vibration of ever-increasing frequency, increasing combustion temperature, accelerating ceramics/metal liquid-liquid separation and quickening ceramic solidification could not only reduce the average diameter and the size distribution of aligned ZrO2 nano-micron fibers in rod-shaped Al2O3 matrix grains, but also make the randomly-oriented rod-shaped grains finer and increase their aspect ratios. As a result, a remarkable increase in flexural strength and fracture toughness of the ceramics can be observed. 展开更多
关键词 ceramic matrix composite combustion synthesis rapid solidification nanocrystalline microstructure mechanical vibration
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Microstructure and mechanical properties of AZ91D magnesium alloy by expendable pattern shell casting with different mechanical vibration amplitudes and pouring temperatures
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作者 Suo Fan He-bao Wu Jin-xiu Fang 《China Foundry》 SCIE CAS 2021年第1期1-8,共8页
To refine the microstructure and improve the mechanical properties of AZ91 D alloy by expendable pattern shell casting(EPSC),the mechanical vibration method was applied in the solidification process of the alloy.The e... To refine the microstructure and improve the mechanical properties of AZ91 D alloy by expendable pattern shell casting(EPSC),the mechanical vibration method was applied in the solidification process of the alloy.The effects of amplitude and pouring temperature on microstructure and mechanical properties of AZ91 D magnesium alloy were studied.The results indicated that the mechanical vibration remarkably improved the sizes,morphologies and distributions of the primaryα-Mg phase andβ-Mg17 Al12 phase,and the densification and tensile properties of the AZ91 D alloy.With an increase in amplitude,the microstructures were gradually refined,resulting in a continuous increase in mechanical properties of the AZ91 D alloy.While,with the increase of pouring temperature,the microstructures were continuously coarsened,leading to an obvious decrease of the mechanical properties.The tensile strength and yield strength of the AZ91 D alloy with a vibration amplitude of 1.0 mm and a pouring temperature of 730℃were 60%and 38%higher than those of the alloy without vibration,respectively. 展开更多
关键词 AZ91D magnesium alloy expendable pattern shell casting mechanical vibration MICROSTRUCTURE mechanical properties
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Compression techniques of mechanical vibration signals based on optimal sparse representations
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作者 Feng Kun Qin Qiang Jiang Zhinong 《High Technology Letters》 EI CAS 2012年第3期256-262,共7页
This paper presents the result of an experimental study on the compression of mechanical vibration signals. The signals are collected from both rotating and reciprocating machineries by the accelerometers and a data a... This paper presents the result of an experimental study on the compression of mechanical vibration signals. The signals are collected from both rotating and reciprocating machineries by the accelerometers and a data acquisition (DAQ) system. Four optimal sparse representation methods for compression have been considered including the method of frames ( MOF), best orthogonal basis ( BOB), matching pursuit (MP) and basis pursuit (BP). Furthermore, several indicators including compression ratio (CR), mean square error (MSE), energy retained (ER) and Kurtosis are taken to evaluate the performance of the above methods. Experimental results show that MP outperforms other three methods. 展开更多
关键词 signal compression mechanical vibration signals sparse representation matchingpursuit (MP) basis pursuit (BP)
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Effects of mechanical vibration on root development of Actinidia chinensis plantlet
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作者 阳小成 《Journal of Chongqing University》 CAS 2007年第4期227-230,共4页
The root development of Actinidia chinensis planUets was studied in exposure to environmental stress of mechanical vibration at respectively 1 Hz, 2 Hz, 3 Hz, 4 Hz and 5 Hz. The plantlets exposed to vibration stimuli ... The root development of Actinidia chinensis planUets was studied in exposure to environmental stress of mechanical vibration at respectively 1 Hz, 2 Hz, 3 Hz, 4 Hz and 5 Hz. The plantlets exposed to vibration stimuli at all those frequencies have a larger total number and a larger total length of roots and a smaller permeability of root plasma-membrane, compared with those cultivated in an environment without vibration stress. Vibration at respectively 1 Hz, 2 Hz, 3 Hz and 4 Hz enhances root activity and the 3 Hz vibration is the most favorable. There is an obvious negative correlation between root activity and permeability of root plasma-membrane. The effects may be explained by the likelihood that mechanical Vibration at an appropriate frequency facilitates roots' absorbing water and minerals which are indispensable to inducing and synthesizing in roots some active substances favorable to growth. Nevertheless, overstress damages the integrity of root plasm-membrane, increases the permeability, and results in the disability of protecting root cells. 展开更多
关键词 mechanical vibration Actinidia chinensis plantlet root activity
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Stochastic Finite Element Method for Mechanical Vibration Based on Conjugate Gradient(CG)
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作者 MO Wen-hui 《International Journal of Plant Engineering and Management》 2008年第3期128-134,共7页
When material properties, geometry parameters and applied loads are assumed to be stochastic, the vibration equation of a system is transformed to static problem by using Newmark method. In order to improve the comput... When material properties, geometry parameters and applied loads are assumed to be stochastic, the vibration equation of a system is transformed to static problem by using Newmark method. In order to improve the computational efficiency and to save storage, the Conjugate Gradient (CG) method is presented. The CG is an effective method for solving a large system of linear equations and belongs to the method of iteration with rapid convergence and high precision. An example is given and calculated results are compared to validate the proposed methods. 展开更多
关键词 stochastic finite element method(SFEM) mechanical vibration conjugate gradient(CG)
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Effect of ultrasonic and mechanical vibration treatments on evolution of Mn-rich phases and mechanical properties of Al−12Si−4Cu−1Ni−1Mg−2Mn piston alloys
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作者 Bo LIN Xiang-xiang HE +3 位作者 Song-chao XIA Hua-qiang XIAO Yu-liang ZHAO Khashayar KHANLARI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS 2024年第8期2393-2414,共22页
Effects of ultrasonic vibration(UV)and mechanical vibration(MV)on the Mn-rich phase modification and mechanical properties of Al−12Si−4Cu−1Ni−1Mg−2Mn piston alloys were investigated.The results show that the UV and UV... Effects of ultrasonic vibration(UV)and mechanical vibration(MV)on the Mn-rich phase modification and mechanical properties of Al−12Si−4Cu−1Ni−1Mg−2Mn piston alloys were investigated.The results show that the UV and UV+MV treatments can significantly refine and fragmentize the microstructures.In addition,UV treatment can significantly passivate the primary Mn-rich Al15Mn3Si2 intermetallics.The formation mechanisms of refinement and passivation of the grains and non-dendrite particles were discussed.Compared with the gravity die-cast alloys,the UV and UV+MV treated alloys exhibit improved tensile and creep resistance at room and elevated temperatures.These results can be attributed to the refinement of theα(Al)grains and the secondary intermetallics,the increased proportion of refined heat-resistant precipitates,and the formation of nano-sized Si particles.The ultimate tensile strength of the UV treated alloys at 350℃ exceeds that of commercial piston alloys.This indicates the high application potential of the developed piston alloys in density diesel engines. 展开更多
关键词 Al−Si piston alloys Mn-rich phases mechanical properties ultrasonic vibration mechanical vibration
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Experimental Study on Mechanical Vibration Massage for Treatment of Brachial Plexus Injury in Rats 被引量:3
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作者 梅荣军 许阳洋 +1 位作者 李旗 王友京 《Journal of Traditional Chinese Medicine》 SCIE CAS CSCD 2010年第3期190-195,共6页
Objective: To investigate the curative effect of the self-made mechanical vibration massage instrument for treatment of brachial plexus injury in rats and to explore its mechanism. Methods: Brachial plexus injury mode... Objective: To investigate the curative effect of the self-made mechanical vibration massage instrument for treatment of brachial plexus injury in rats and to explore its mechanism. Methods: Brachial plexus injury models were made in 144 Wistar rats and one week after natural healing of the wound, they were randomly divided into 3 groups, mechanical vibration treatment group (MV group), nerve growth factor treatment group (NGF group) and model group, 48 rats in each group. Then again, the each group was randomly divided into 4 subgroups, 7-day group, 14-day group, 21-day group and 28-day group, 12 rats in each subgroup. The MV group were treated by mechanical vibration at acupoints on three-yang and three-yin channels of the hand with the mechanical vibration massage instrument; The NGF group were treated with injection of NGF into musculus pectoralis major on the affected side; And the model group were normally fed with no treatment. After treatment for 7, 14, 21 and 28 days, the diameter of both forelimbs were measured, the electrophysiological examination on the brachial plexus in vitro and the ultrastructure observation with electron microscope on the affected side were carried out, the motor nerve conduction velocity (MNCV) and motor nerve action potential (MNAP) of the brachial plexus on the affected side, NGF content of submaxillary gland as well as muscular Na+, K+-ATPase activity were determined respectively. Results: The different rates of the forelimb diameter in the MV group and the NGV group on the 14th d, 21st d and 28th d were better than those in the model group (P<0.05 or P<0.001), and in the MV group were better than those in the NGF group on the 21st d and the 28th d (P<0.05). MNCV in the MV group and the NGV group on the 21st d and 28th d was better than that in the model group (P<0.05 or P<0.001), and in the MV group was better than that in the NGF group on the 28th d (P<0.05). MNAP in the MV group and the NGV group on the 14th d, 21st d and 28th d was better than that in the model group (P<0.05 or P<0.001), and in the MV group was better than that in the NGF group on the 21st d and 28th d (P<0.05). The NGF mean gray index of submaxillary gland in the model group was higher than that in the MV group and the NGF group on the 7th d (P<0.05); in the NGF group and the model group was higher than that in the MV group on the 14th d (P<0.05); and in the NGF group and the MV group was higher than that in the model group on the 21st d and 28th d (P<0.05). Na+, K+-ATPase activity in the model group and the MV group was higher than that in the NGF group (P<0.05) on the 14th d, and in the MV group was higher than that in the model group on the 28th d (P<0.05). Conclusion: As compared with the NGF group and the model group, mechanical vibration treatment can effectively accelerate repair of injured brachial plexus, slow down atrophy of skeletal muscle, and promote secretion of NGF in submaxillary gland. 展开更多
关键词 mechanical vibration massage brachial plexus injury nerve growth factor Na+ K+-ATPase activity
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Mechanical vibration modeling and characterization of a plastic-cased lithium-ion battery 被引量:2
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作者 Xiaoyu Li Zhijia Huang +3 位作者 Wen Hua Lalith Rao Yong Tian Jindong Tian 《Green Energy and Intelligent Transportation》 2022年第2期9-18,共10页
Batteries often show the coupling change of multiple physical field characteristic parameters in the charging or discharging processes.Conventional battery modeling and characterization methods mainly focus on electri... Batteries often show the coupling change of multiple physical field characteristic parameters in the charging or discharging processes.Conventional battery modeling and characterization methods mainly focus on electrical or thermal parameters.Considering that battery state change can cause a change in the mechanical structure,research on the vibration characteristic modeling and characterization of a plastic-cased lithium-ion battery is carried out.By analyzing the mechanical structure of the battery,the first principles modeling method is selected to model the battery's mechanical performance.The vibration data in the process of battery charging and discharging are measured by a laser Doppler vibrometer(LDV).The obtained experimental data are used to identify the mechanical parameters of the battery.Based on the experimentael results,the root mean square error(RMSE)of the frequency domain amplitude fitting result of the model is less than 11.36%.The effectiveness of the battery mechanical vibration model is verified.The model and the characterization method provide tools for nondestructive battery state evaluation. 展开更多
关键词 Lithium-ion battery mechanical vibration MODELING CHARACTERIZATION
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On-chip immunomagnetic bead swarm based on magnetic actuation and mechanical vibration for biological detection
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作者 PAN JingWen GONG De +7 位作者 SAEED Rehan CAO KaiHeng CHEN KeHan SU Yuan ZHANG WenQiang XU WenTao CAI Jun ZHANG DeYuan 《Science China(Technological Sciences)》 SCIE EI CAS CSCD 2022年第11期2573-2581,共9页
Immunomagnetic bead(IMB)-based detection has great potential for biomedical applications.Passive and active strategies,including microfluidics and magnetic actuation methods,have been developed to mix IMBs and analyte... Immunomagnetic bead(IMB)-based detection has great potential for biomedical applications.Passive and active strategies,including microfluidics and magnetic actuation methods,have been developed to mix IMBs and analytes efficiently.However,cost-effective on-site detection using a simple microfluidic chip is challenging,and miniaturization of the magnetic driving device is imperative for portability.In this study,we propose a novel mixing method for an on-chip IMB swarm via magnetic actuation and mechanical vibration.A microfluidic chip system coupled with double spiral magnetic coils and a vibration motor was fabricated.The aggregation behavior of IMBs under magnetic fields and the diffusion behavior of the IMB swarm under mechanical vibration were analyzed in detail.Based on the synergetic effects of magnetic actuation and mechanical vibration,we achieved the highly efficient capturing of Vibrio parahaemolyticus DNA and goat anti-human immunoglobulin G by mixing the IMB swarm with the microfluidic chip.In this case,the antigen detection rate could reach~94.4%.Given its fascinating features,such IMB-microfluidic detection demonstrates significant potential for biomedical applications. 展开更多
关键词 immunomagnetic bead swarm microfluidic chip magnetic actuation mechanical vibration biomedical detection
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Vibration of a Two-Layer“Metal+PZT”Plate Contacting with Viscous Fluid
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作者 Zeynep Ekicioglu Kuzeci Surkay D.Akbarov 《Computers, Materials & Continua》 SCIE EI 2023年第2期4337-4362,共26页
The present work investigates the mechanically forced vibration of the hydro-elasto-piezoelectric system consisting of a two-layer plate“elastic+PZT”,a compressible viscous fluid,and a rigid wall.It is assumed that ... The present work investigates the mechanically forced vibration of the hydro-elasto-piezoelectric system consisting of a two-layer plate“elastic+PZT”,a compressible viscous fluid,and a rigid wall.It is assumed that the PZT(piezoelectric)layer of the plate is in contact with the fluid and time-harmonic linear forces act on the free surface of the elastic-metallic layer.This study is valuable because it considers for the first time the mechanical vibration of the metal+piezoelectric bilayer plate in contact with a fluid.It is also the first time that the influence of the volumetric concentration of the constituents on the vibration of the hydro-elasto-piezoelectric system is studied.Another value of the present work is the use of the exact equations and relations of elasto-electrodynamics for elastic and piezoelectric materials to describe the motion of the plate layers within the framework of the piecewise homogeneous body model and the use of the linearized Navier-Stokes equations to describe the flow of the compressible viscous fluid.The plane-strain state in the plate and the plane flow in the fluid take place.For the solution of the corresponding boundary-value problem,the Fourier transform is used with respect to the spatial coordinate on the axis along the laying direction of the plate.The analytical expressions of the Fourier transform of all the sought values of each component of the system are determined.The origins of the searched values are determined numerically,after which numerical results on the stress on the fluid and plate interface planes are presented and discussed.These results are obtained for the case where PZT-2 is chosen as the piezoelectric material,steel and aluminum as the elastic metal materials,and Glycerin as the fluid.Analysis of these results allows conclusions to be drawn about the character of the problem parameters on the frequency response of the interfacial stress.In particular,it was found that after a certain value of the vibration frequency,the presence of the metal layer in the two-layer plate led to an increase in the absolute values of the above interfacial stress. 展开更多
关键词 Metal+piezoelectric two-layer plate compressible viscous fluid mechanical forced vibration interfacial stress resonance frequency
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Microstructure evolution and nucleation mechanism of Inconel 601H alloy welds by vibration-assisted GTAW 被引量:2
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作者 Ze-long Wang Zhen-tai Zheng +2 位作者 Li-bing Zhao Yun-feng Lei Kun Yang 《International Journal of Minerals,Metallurgy and Materials》 SCIE EI CAS CSCD 2018年第7期788-799,共12页
Nickel-based alloys exhibit excellent high-temperature stxengtfi and oxidation resistance; however, because of coarse grains and severe segregation in daeir welding joints, these alloys exhibit increased susceptibilit... Nickel-based alloys exhibit excellent high-temperature stxengtfi and oxidation resistance; however, because of coarse grains and severe segregation in daeir welding joints, these alloys exhibit increased susceptibility to hot cracking. In this paper, to improve the hot-cracking resistance and mechaxtical properties ofinckel-based alloy welded joints, sodium daiosulfate was used to simulate crystallization, enabling the nucleation mechanism under mechaxtical vibration to be investigated. On the basis of the results, the grain refinement mechan- ism during the gas tungsten arc welding (GTAW) of Inconel 601H alloy under wxious vibration modes and parameters was investigated. Compared witfi the GTAW process, the low-frequency mechanical vibration processes resulted in substantial grain refinement effects in the welds; thus, a higher haxdness distxibution was also achieved under the vibration conditions. In addition, the 7' phase exhibited a dispersed distribution and segregation was improved in the welded joints witfi vibration assistance. The results demonstxated that the generation of free crystals caused by vibration in the nucleation stage was the main mechaxtism of grain refinement. Also, free equiaxed grains and a dispersed 7' phase were found to improve the grain-boundary strength and reduce the segregation, contributing to preventing the initiation of welding hot cracking in nickel-based alloys. 展开更多
关键词 mechanical vibration nickel-based alloy grain refinement microst3-ucture hot cracking
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Microstructural analysis of EN-GJS-450-10 ductile cast iron via vibrational casting
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作者 Caglar Yüksel 《China Foundry》 SCIE 2020年第4期272-278,共7页
EN-GJS-450-10 ductile cast iron was produced with and without vibration to evaluate microstructural features. To investigate the effect of vibration, a reference, and two different castings having amplitudes of 0.9 mm... EN-GJS-450-10 ductile cast iron was produced with and without vibration to evaluate microstructural features. To investigate the effect of vibration, a reference, and two different castings having amplitudes of 0.9 mm and 1.8 mm were cast with a fixed vibration frequency of 50 Hz. The nodule count (density), form (type), size distribution, nodularity, and the fraction of graphite, percentages of both ferrite and pearlite phases, length of ferrite shell, and pore, were evaluated via optical microscopy using an image analysis software. It is observed that the microstructure of the cast iron is more uniform by vibrational casting than that by non-vibrational casting. Additionally, mechanical vibration enhances nodule count and nodularity, also, more ferritic matrix could be obtained after the application of vibration. Nodule count and nodularity of vibrational casting with 1.8 mm amplitude increased from 226 nodule per mm2 and 80% to 311 nodule per mm2 and 86.5% of non-vibrational casting. Percentages of ferrite and graphite area dramatically improved from 24% and 16.5% for non-vibrational casting to 57% and 22.3% for vibrational casting with 1.8 mm amplitude, whereas the percentages of pearlite and pores decreased significantly from 56.1% and 5% to 20% and 1%, respectively. 展开更多
关键词 mechanical vibration spheroidal cast iron ductile iron NODULARITY image analysis AMPLITUDE
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Vibration Suppression of Unbalanced Machines UsingLumped Mass Dynamic Vibration Absorber
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作者 Charfeddine Mrad 《Journal of Mechanics Engineering and Automation》 2013年第2期93-98,共6页
The vibration of machines due to rotating parts unbalance disturbs the machine functioning and shortens the lifetime of its parts. A dynamic vibration absorber is a favorite solution to suppress the machine vibration ... The vibration of machines due to rotating parts unbalance disturbs the machine functioning and shortens the lifetime of its parts. A dynamic vibration absorber is a favorite solution to suppress the machine vibration since its implementation does not require any modification neither on the machine nor on its installation. The paper considers an unbalanced machine to which a lumped mass dynamic vibration absorber is attached. Firstly, the machine equipped with the absorber is modeled, and the vibration expressions are extracted. Secondly, an original approach to optimize the absorber parameters is presented, and simulation results are advanced, when the absorber is undamped and damped. Thirdly, the absorber optimal parameters allowing the best vibration reduction of the machine are identified, showing bow the absorber should be designed, when the disturbance frequency is stable or unstable. The results are a significant contribution in the vibration control of unbalanced machines. 展开更多
关键词 Unbalanced machines mechanical vibration vibration suppression dynamic vibration absorber parametersoptimization.
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