Characteristics of Deformation and Recovery in Shape Memory Alloy

The mechanical behavior and the effect of pre-strain on recovery behavior of Ti50Ni47Fe3 (at. pct) alloy were investigated systematically by tensile and recovered tests accompanied by electrical resistance measurement. Ti50Ni47Fe3 alloy has different deformation behaviors at different temperature ranges, the deformation curves in different temperature range can be classified into four kinds. The start temperature of recovery increases with the increase of pre-strain. There exists an optimal deformation condition, at which the specimen exhibits maximum free recovery strain. With increasing pre-strain the recovery stress increases and reaches the maximum at 8% pre-strain. R-phase to parent transition offered about 0.2% recovery strain. With pre-strain increasing the recovery stress increases and reaches to the maximum at 8% pre-strain. The recovery stress is corresponding with the critical stress of stress-induced martensitic transformation.     

铺层角度对碳纤维/形状记忆环氧树脂层合板形状回复性能的影响

对不同铺层角度的碳纤维/环氧树脂形状记忆复合材料(SMC)层合板的弯曲回复性能进行了研究。结果表明,[±θ]_s铺层方式的SMC层合板的形状回复率、回复力均随着铺层角度增大而减小,回复时间随着铺层角度增大而增大,其中铺层角度增大至45°后,回复时间开始出现大幅的增加,铺层角度增大至60°后,回复率开始出现大幅的降低。对SMC层合板进行了15次的赋形-回复循环过程,发现不同铺层角度SMC层合板均能保持较稳定的形状记忆回复率和回复时间。但在铺层角度0~30°的范围内,层合板的形状回复力随着铺层角度增大而减小。最后分析了不同铺层角度SMC层合板的局部损伤,结果表明,[0]_4和[±15]_s铺层方式的SMC层合板基体已达到了其极限剪切应变,基体发生严重破坏,并且会随着赋形次数的增加而加剧。     

Fe—Mn—Si—Cr—Ni—C形状记忆合金回复应力的研究

研究了预应变量、加热和冷却工艺对FeMn－Si-Cr－Ni－C形状记忆合金回复应力的影响。结果表明，当预应变量小于3％～4％时，随应变量的增加，回复应力增加。大于3％～4％后，则下降。同一温度下，冷却过程的回复应力大于加热过程的回复应力。停止加热时的温度越高，冷却过程中的回复应力越大。     

Recovery of Drug Delivery Nanoparticles from Human Plasma Using an Electrokinetic Platform Technology

The effect of complex biological fluids on the surface and structure of nanoparticles is a rapidly expanding field of study. One of the challenges holding back this research is the difficulty of recovering therapeutic nanoparticles from biological samples due to their small size, low density, and stealth surface coatings. Here, the first demonstration of the recovery and analysis of drug delivery nanoparticles from undiluted human plasma samples through the use of a new electrokinetic platform technology is presented. The particles are recovered from plasma through a dielectrophoresis separation force that is created by innate differences in the dielectric properties between the unaltered nanoparticles and the surrounding plasma. It is shown that this can be applied to a wide range of drug delivery nanoparticles of different morphologies and materials, including low‐density nanoliposomes. These recovered particles can then be analyzed using different methods including scanning electron microscopy to monitor surface and structural changes that result from plasma exposure. This new recovery technique can be broadly applied to the recovery of nanoparticles from high conductance fluids in a wide range of applications.     

时效温度对Fe-Mn-Si-Cr-Ni-C记忆合金回复应力的影响

研究了时效温度对Ｆｅ－１４Ｍｎ－５Ｓｉ－８Ｃｒ－４Ｎｉ－０．２Ｃ记忆合金回复应力的影响。结果表明：合金经变形后加热时产生的最大回复应力σｈ随时效温度的升高而增加,在１０２３Ｋ达到最大值,比固溶态增加了７５％;随后σｈ将随时效工的进一步升高迅速下降。但是当时效温度高于１１２３Ｋ后,时效温度的进一步升高对σｈ几乎没有影响。时效后合金加热时产生的最大回复应力都大于固溶态时的回复应力。时效温度对合金加热后     

热致非晶态形状记忆聚合物的热粘弹性参数及回复行为

分别采用非线性拟合应力松弛主曲线及单个常频率条件下变温动态力学分析(DMA)实验中储能模量与损耗角正切曲线的方式,获取热致非晶态形状记忆聚合物(SMP)多重松弛模型中的热粘弹性参数。结合广义有限变形粘弹性理论和KAHR33参数热变形模型在有限元软件平台研究了该SMP的自由回复与约束回复行为。仿真结果与实验数据相符较好,说明该建模方法的合理性及获取的热粘弹性参数的准确性。相比构建应力松弛和储能模量主曲线而言,单个DMA实验数据更易得到,因此对其拟合能大幅减少实验成本。     

Recovery Stress in a Ni-Ti-Nb Shape Memory Alloy with Wide Transformation Hysteresis

The effect of deformation on recovery stress of Ni144.7Ti46.3Nb9 alloy has been studjed using tensile test at various temperatures and TEM observation. It ls shown that the recovery stress increases with jncreasing total strain ET and reaches a maximum value (max) as ET= 9% but the maximum recov erV strain of the alloy is only about 4.6%. This is different from that of Ti-Ni binary alloy in which is obtained usually at maximum recovery strain and the reason of the difference is dis Cussed. Deformation temperature Td has a little effect on recovery stress when Td is less than Ms However, recovery stress decreases sharply when Td is higher than M, and lowers approximately down to zero near Msσ     

Development of Graphene Nanoplatelets-Reinforced Thermo-Responsive Shape Memory Nanocomposites for High Recovery Force Applications

Strength of Materials - The development and large-scale implementation of multifunctional advanced materials with smart and intelligent properties like shape memory are very topical. In the present...     

人体数据驱动的鼠标形态概念设计

目的 为适应不同人群的手型和使用鼠标时的操作习惯,构建数据驱动的形态生成系统,辅助设计师进行鼠标形态创新设计,有效提升鼠标形态方案的人机合理性。方法 采用实验测量方式提取用户使用鼠标时的特征形态数据,利用参数化脚本技术模拟用户使用鼠标场景,包括用户操作方式、手型尺寸等,探索手部行为与鼠标形态的人机关系,构建一种人体数据驱动的鼠标形态生成系统,对获取的方案进行实体评估验证。结果 利用人体数据驱动可生成多款鼠标形态,算法生形具有良好的适应性。结论 基于Grasshopper建立的用户行为模拟器可有效探索用户在使用鼠标时的行为方式,构建的鼠标形态生成算法具有快速响应特征,可依据用户手势行为进行鼠标形态设计,快速获得适合用户的概念形态方案。     

Shape reconstruction from gradient data

We present a generalized method for reconstructing the shape of an object from measured gradient data. A certain class of optical sensors does not measure the shape of an object but rather its local slope. These sensors display several advantages, including high information efficiency, sensitivity, and robustness. For many applications, however, it is necessary to acquire the shape, which must be calculated from the slopes by numerical integration. Existing integration techniques show drawbacks that render them unusable in many cases. Our method is based on an approximation employing radial basis functions. It can be applied to irregularly sampled, noisy, and incomplete data, and it reconstructs surfaces both locally and globally with high accuracy.     

Characteristics of Deformation and Recovery in Ti50Ni47Fe3 Shape Memory Alloy

The mechanical behavior and the effect of pre-strain on recovery behavior of Ti50Ni47Fe3 (at. pct) alloy were investigated systematically by tensile and recovered tests accompanied by electrical resistance measurement. Ti50Ni47Fe2 alloy has different deformation behaviors at different temperature ranges, the deformation curves in different temperature range can be classified into four kinds. The start temperature of recovery increases with the increase of pre-strain.There exists an optimal deformation condition, at which the specimen exhibits maximum free recovery strain. With increasing pre-strain the recovery stress increases and reaches the maximum at 8% pre-strain. R-phase to parent transition offered about 0.2% recovery strain. With pre-strain increasing the recovery stress increases and reaches to the maximum at 8% pre-strain. The recovery stress is corresponding with the critical stress of stress-induced martensitic transformation.     

特种车辆乘员人体形态参数研究

目的对特种车辆乘员人体形态参数进行测量分析,为制定乘员选拔标准和特种车辆的合理设计提供了理论依据。方法依据GB／T5703—1999“用于技术设计的人体测量基础项目”开展人体形态参数测试。结果各项人体形态参数均值均≥50百分位值,〈95百分位值。结论特种车辆乘员人体形态参数虽仍处于GJB1835的范围,但已整体上移。     

形状记忆Fe－Mn－Si合金中马氏体相变和扭转形变的恢复

研究了Ｆｅ－２９．４４Ｍｎ－６．２０Ｓｉ合金中的γ　ε相变和顺磁性反铁磁性转变（以下简称磁转变）。用电阻测量跟踪了此过程。用ｘ射线衍射法（ＸＲＤ）作了相分析。硅急剧增加六方相的电阻率，ε→γ相变表现为电阻降低，γ→ε转变表现为电阻升高。ＸＲＤ表明，淬火后样品中除γ相外有少量六方ε相。扭转形变恢复率与形变量和形变前有无热诱发马氏体存在有很大关系。     

储存时间对SMP/Fe3O4形状回复性能的影响

首先制备了形状记忆性良好、在热场和磁场中都可响应的SMP/Fe3O4纳米复合材料,将样品在形变固定后,储存不同时间,分别在热场和磁场中考察储存时间对SMP/Fe3O4回复性能的影响。结果显示,储存时间10min及储存时间为12h的样品的形状回复率均在95%以上,存储时间对于热场和磁场中形变回复性能的影响具有类似的规律,即:形变固定后储存时间延长,其起始回复温度升高,回复诱导期增长,回复的温度区间变宽。XRD、DSC、DMA测试结果表明,随储存时间的延长,样品的结晶度增加,样品熔点和熔融温度区间发生改变,从而引起相应的SMP/Fe3O4回复性能的变化。     

淬火温度对冷拉态Fe-18Mn-5Si-8Cr-4Ni形状记忆合金回复应力的影响

研究了淬火温度对Ｆｅ － １８ Ｍｎ － ５Ｓｉ － ８Ｃｒ － ４Ｎｉ 记忆合金回复应力的影响。结果表明：合金经变形后加热时产生的最大回复应力σｈ 和加热后冷却到室温时的回复应力σｃ 都随淬火温度的升高而增加,在６５０ ℃达到最大值;随后随淬火温度的进一步升高而快速下降,但是σｃ 下降的程度要比σｈ 大得多;当淬火温度高于８５０ ℃后,淬火温度的进一步升高对它们几乎没有影响;任一淬火温度下,加热后冷却到室温时的回复应力 σｃ都远大于加热时产生的最大回复应力σｈ。     

石墨烯-聚(苯乙烯-co-丙烯酸丁酯)复合材料的力学及形状回复性能

采用Hummers氧化法制备氧化石墨烯,再以水合肼为还原剂制得石墨烯。用异氰酸酯处理石墨烯以对其进行改性。以苯乙烯和丙烯酸丁酯作为形状记忆聚合物的共聚单体,将石墨烯和经异氰酸酯处理的石墨烯分别加入单体溶液中,采用自由基聚合的方法获得了不同石墨烯含量的石墨烯-聚(苯乙烯-co-丙烯酸丁酯)形状记忆复合材料。DMA、力学性能测试表明,掺杂石墨烯或经异氰酸酯处理的石墨烯后,形状记忆聚合物的储能模量和玻璃化转变温度均降低;随石墨烯含量的增加,复合材料的拉伸模量降低;在相同温度下,用经异氰酸酯处理的石墨烯制得的复合材料的形状回复能力普遍大于用相同含量的未处理石墨烯制得的复合材料。     

采用单目视觉系统的人体三维姿态恢复

提出了至少存在一个点深度值已知的约束条件下,基于单目视觉系统恢复人体三维姿态的方法.该算法简化了CCD相机的标定过程,实现了人体三维姿态的恢复.避免了多目视觉系统在实际应用中对空间和光照等的限制,以及在对应特征点匹配上的弱点.给出了上述方法的实验过程及计算结果,验证了在上述约束条件下基于单目视觉恢复人体三维姿态算法的可行性.     

Recovery of Pd from spent fuel: 5. Recovery of Pd from high-level PUREX raffinate

Laboratory experiments were carried out on sorption and electrochemical recovery of Pd from actual high-level PUREX raffinate. The initial solutions were high-level liquid wastes after extraction processing of WWER-1000 spent fuel with a burn-up of about 40 MW (kg U)^?1, cooled for 5–7 years. In sorption recovery with VP-1AP anion-exchange resin, the Pd yield into the eluent was about 90%. After additional refinement by precipitation, the activity of the resulting palladium black sample was no more than 0.8 mCi (g Pd)^?1, and the total decontamination factor was 1.9 × 10⁴.