Effect of strontium on columnar growth of dendritic α phase in near-eutectic Al-11.6%Si alloys

For Al-11.6 % Si alloy, the influence of the addition of Sr on the morphology of the dendrite α phase was investigated, and the characteristic parameters of the dendrite α phase, the primary dendrite spacing and the secondary dendrite arm spacing, were also measured. The addition of strontium promotes the columnar dendrite growth and leads to a decrease of both the primary dendrite spacing and secondary dendrite arm spacing with the increase of the content of strontium in the modified near-eutectic Al-Si alloys. It is thought that the addition of Sr leads to a reduction of the solid-liquid interfacial energy of the dendrite α phase, consequently resulting in a decrease of the growth undercooling of dendrite tips. And hence, the nucleation of the equiaxed grains in the liquid in front of the columnar dendrite tips is restrained, thus the addition of strontium in Al-Si alloys promotes the growth of the columnar dendrites. The reduction of the solid-liquid interfacial energy also leads to the decreases in the primary dendrite spacing and the secondary dendrite arm spacing.     

应用在惯性约束核聚变系统中的压电陶瓷微机械手的设计

研制了应用在惯性约束核聚变装配系统中的压电陶瓷做机做下，并对压电陶瓷的驱动电路，计算机控制的硬件及软件系统设计，以及系统的标定方法等进行了详细的叙述。该机械手应用于惯性约束核聚变装配系统靶标的位置调整中，实验证明其位置误差小于1μm.     

变速生长条件下Al－Cu合金的定向凝固枝晶组织

应用改进的定向凝固装置研究了Ａｌ－２ｗｔ－％Ｃｕ和Ａｌ－４ｗｔ－％Ｃｕ合金在阶跃和不同加速度线性变速生长条件下，定向凝固组织的动态转变。实验结果表明：尽管定向生长的胞－枝晶动态转变过程随加速度的降低而减缓，但胞晶组织都是在经历了一定的胞晶形貌扰动之后才发生快速失稳、分枝细化并向树枝晶组织过渡，加速度不同，由失稳胞晶演变成的树枝晶可具有多种分枝形式。     

150柴油机排气摇臂成形工艺的研究

对150系列大功率高速柴油机排气摇臂的成形工艺进行了工艺分析，着重介绍了可确保排气摇臂成形、质量和合格品率提高的模锻工艺，锻模设计及其热处理工艺的研究，说明了排气摇臂成形工艺的可行性、实用性和效益性。     

专家系统控制在掰手腕机器人中的应用

掰手腕机器人既可以作为一种娱乐装置,也可以用来作为一种锻炼装置增强手腕、手臂的肌肉力量。考虑到系统的非线性和复杂性,提出专家系统来解决机械臂的运动控制问题。首先介绍了掰手腕机器人系统的整体结构,然后引入专家系统控制,最后讨论了在此基础上的实验和结果。实验结果证明该控制算法有效、可行。应用专家系统控制策略,使得该系统克服了干扰和不确定现象,并具有良好的适应性。     

Durable Integrated K-Metal Anode with Enhanced Mass Transport through Potassiphilic Porous Interconnected Mediator

K-metal batteries have become one of the promising candidates for the large-scale energy storage owing to the virtually inexhaustible and widely potassium resources. The uneven K⁺ deposition and dendrite growth on the anode causes the batteries prematurely failure to limit the further application. An integrated K-metal anode is constructed by cold-rolling K metal with a potassiphilic porous interconnected mediator. Based on the experimental results and theoretical calculations, it demonstrates that the potassiphilic porous interconnected mediator boosts the mass transportation of K-metal anode by the K affinity enhancement, which decreases the concentration polarization and makes a dendrite-free K-metal anode interface. The interconnected porous structure mitigates the internal stress generated during repetitive deposition/stripping, enabling minimized the generation of electrode collapse. As a result, a durable K-metal anode with excellent cycling ability of exceed 1, 000 h at 1 mA cm⁻²/1 mAh cm⁻² and lower polarization voltage in carbonate electrolyte is obtained. This proposed integrated anode with fast K⁺ kinetics fabricated by a repeated cold rolling and folding process provides a new avenue for constructing a high-performance dendrites-free anode for K-metal batteries.     

复合横担杆塔不平衡张力调节装置及其设计方法研究

针对复合横担杆塔易承受较大不平衡张力的问题,设计了一种杆塔不平衡张力自动调节装置,结合装置特点构建了不平衡张力计算方程组,提出了迭代求解方法,分析了装置结构参数对不平衡张力调节效果的影响规律。研究表明不平衡张力调节装置可有效降低在断线或不均匀覆冰工况下挂点处的最大不平衡张力。     

$3C2510A的SCARA机械臂控制系统设计

在目前机械臂控制系统中,如何减小系统体积、降低系统功耗一直是传统控制方式（即“PC／工控机＋运动控制卡”）的难点。本文在对SCARA机械臂深入研究的基础上通过S3C25IOA实现了带有PCI接口的控制系统,并进行了Bootloader的移植以及PCI驱动程序的编写。     

Differentiating types of muscle movements using a wavelet based fuzzy clustering neural network

Abstract: The electromyographic signals observed at the surface of the skin are the sum of many small action potentials generated in the muscle fibres. After the signals are processed, they can be used as a control source of multifunction prostheses. The myoelectric signals are represented by wavelet transform model parameters. For this purpose, four different arm movements (elbow extension, elbow flexion, wrist supination and wrist pronation) are considered in studying muscle contraction. Wavelet parameters of myoelectric signals received from the muscles for these different movements were used as features to classify the electromyographic signals in a fuzzy clustering neural network classifier model. After 1000 iterations, the average recognition percentage of the test was found to be 97.67% with clustering into 10 features. The fuzzy clustering neural network programming language was developed using Pascal under Delphi.     

Application of the Strain Index in multiple task jobs

Six different methods to calculate the Strain Index (SI) scores for jobs with multiple forces/tasks were developed. Exposure data of 733 subjects from 12 different worksites were used to calculate these SI scores. Results show that using different SI computation methods could result in different SI scores, hence different risk level classifications. However, some simpler methods generated SI scores were comparable to the more complicated composite SI method. Despite differences in the scores between the six different SI computation methods, Spearman rank-order correlation coefficients of 0.61-0.97 were found between the methods. With some confidence, ergonomic practitioners may use simpler methods, depending on their specificity requirement in job evaluations and available resources. Some SI computation methods may tend to over-estimate job risk levels, while others may tend to under-estimate job risk levels, due to different ways used in obtaining the various SI parameters and computations.