Shape change induced by g_(9/2) rotational alignment in ^(84,86)Mo

Neutron-deficient Z ≈ N nuclei84,86Mo have been investigated using pairing-deformation self-consistent cranked shell modelcalculations up to spin I > 20 . Our calculations are in good agreement with the experimental data, indicating γ-soft triaxial shapesat low rotational frequency and well-deformed triaxial-oblate shapes at high rotational frequency for both nuclei. The shape changeis due to the alignments of the g9/2protons and g9/2neutrons.

Autonomous oscillatory shape change of DEA induced by the charge–discharge process under a constant voltage

Despite the promising characteristics of Dielectric Elastomel Actuator(DEA)as a practical soft actuator,the need of high voltage for its operation prevents the successful fabrication of a practical DEA,that is,the high voltage generation takes a bulky and costly power supply.Induction of complex shape change motion of DEA such as oscillatory shape change takes even a more bulky and costly multipurpose power supply.It is a serious practical issue to be overcome.In our latest study,however,we could build a simple DEA system which exhibited a relatively complex and autonomous oscillatory shape change merely under a constant voltage,though the voltage needed was high.This successful outcome must broaden the potential usefulness of DEA as a practical soft actuator.

Experimental study on thermal and mechanical properties of tailings-based cemented paste backfill with CaCl_(2)·6H_(2)O/expanded vermiculite shape stabilized phase change materials

CaCl_(2)·6H_(2)O/expanded vermiculite shape stabilized phase change materials(CEV)was prepared by atmospheric impregnation method.Using gold mine tailings as aggregate of cemented paste backfill(CPB)material,the CPB with CEV added was prepared,and the specific heat capacity,thermal conductivity,and uniaxial compressive strength(UCS)of CPB with different cement-tailing ratios and CEV addition ratios were tested,the influence of the above variables on the thermal and mechanical properties of CPB was analyzed.The results show that the maximum encapsulation capacity of expanded vermiculite for CaCl_(2)·6H_(2)O is about 60%,and the melting and solidification enthalpies of CEV can reach 98.87 J/g and 97.56 J/g,respectively.For the CPB without CEV,the specific heat capacity,thermal conductivity,and UCS decrease with the decrease of cement-tailing ratio.For the CPB with CEV added,with the increase of CEV addition ratio,the specific heat capacity increases significantly,and the sensible heat storage capacity and latent heat storage capacity can be increased by at least 10.74%and 218.97%respectively after adding 12%CEV.However,the addition of CEV leads to the increase of pores,and the thermal conductivity and UCS both decrease with the increase of CEV addition.When cement-tailing ratio is 1:8 and 6%,9%,and 12%of CEV are added,the 28-days UCS of CPB is less than 1 MPa.Considering the heat storage capacity and cost price of backfill,the recommended proportion scheme of CPB material presents cement-tailing ratio of 1:6 and 12%CEV,and the most recommended heat storage/release temperature cycle range of CPB with added CEV is from 20 to 40℃.This work can provide theoretical basis for the utilization of heat storage backfill in green mines.

Spatio-Temporal Kinematic Decomposition of Movements

We propose the new experimental method for investigating and approximating the organization and structure of movements with given accuracy. The composition of approximating trajectories illuminating the movement traits discloses the level of movement expertise in dancers and golf players. The method allows estimating the level of movement expertise, drawing the detailed structure of movements, and classifying movements into a given repertoire automatically.

Shape-changing particles for locally resolved particle geometry in DEM simulations

Taking into account the complex shape of particles in discrete element method (DEM) simulations of large-scale granular systems is computationally demanding due to the time-consuming contact detection algorithms for polyhedral particles. In this short communication, a novel approach that locally resolves the particle shapes where needed and uses a simplified representation elsewhere, to accelerate simulations without compromising accuracy, is presented. For this purpose, a method employing a smooth transition of the particle shape representation from analytical spheres to shape-resolving polyhedra is introduced in DEM. The feasibility and correct implementation of this approach are demonstrated through simulations of hopper discharge involving spherical and dodecahedral particles from a flat bottom silo or shaft kiln. The model capabilities, in terms of accuracy as well as reduction in computational effort, are quantified for a moving bed with continuous outflow.

Strain hardening rate dependency of deformation shape,strain distribution,and contact pressure during wire flat rolling

The effect of the strain hardening exponent(n)of a material on the changes in shape,strain inhomogeneity,and contact pressure was investigated during wire flat rolling to understand its effect on the deformation behavior of a flat-rolled wire and to determine the optimal working conditions with materials.The deformation behaviors of wires with various n values were systematically compared using finite element method.The shape of the deformed wire was found to depend on the n value of the material.Both the contact width and lateral spreading of the wire decrease with increasing n,resulting in a large reduction in area with the n value.The strain homogeneity of the wire increases with the n value of the wire.The improvement in the strain homogeneity with the n value is attributable to two factors:a lower strain concentration in the central region and a higher overall elongation as n increases.In addition,the average effective strain of the wire cross section decreases with the n value of a material during wire flat rolling.The contact pressure distribution on the surface of the wire differs significantly depending on the n value.In materials with a low n value,the contact pressure exhibits a higher value at the entry and edge zones of the contact surface.By contrast,materials with high n values exhibit a higher contact pressure at the exit zone.This behavior can be explained by the strain hardening behavior of the material during wire flat rolling.

Ultrafast digital printing toward 4D shape changing materials

Subject Code:B04Under the financial support of the National Natural Science Foundation of China,the research team led by Prof.Xie Tao(谢涛)at the State Key Laboratory of Chemical Engineering,College of Chemical and Biological Engineering,Zhejiang University,developed an ultrafast process to produce shape changing materials with complex 3Dgeometries.This work was published in Advanced Materials(2016,DOI:10.

3D/4D Printed Functional Continuous Fiber-reinforced Polymer Composites:Progress and Perspectives

In recent years,innovations in 3D/4D printing techniques for continuous fiber-reinforced polymer composites(CFRPCs)have opened new perspectives for the integrated design and manufacture of composites with customized functions.This paper reviews the current state of 3D/4D printed functional composites,including the materi-als,shape memory/changing effects,self-monitoring/healing behaviors,and challenges surrounding additive-manufactured functional composites.Specifically,continuous fibers and matrices that provide functional roles are classified and discussed in detail.4D printed shape memory and changing CFRPCs can retain their original shapes from a designed shape upon exposure to different external stimuli,including heat,electricity,humidity,and multi-stimuli activation.Furthermore,self-monitoring of structural health is achieved through the piezore-sistive features of reinforced fibers in 3D printed CFRPCs.Finally,this review concludes with an outlook on the future research opportunities for 3D/4D printed functional CFRPCs.