基于EtherCAT和CAN总线的柔性工装控制系统

针对柔性工装在成形过程中存在参数复杂、被控伺服电机数量多及其多个移动横梁之间分散式布置等问题,提出了基于EtherCAT和CAN总线技术的分布式网络控制方案,阐述了柔性工装工作原理,研究了以PC和PLC为核心的硬件整体结构,并利用VC++软件完成了人机交互界面的开发。该系统中,上位机与控制柜内分站模块组、控制柜内分站模块组及移动横梁上的分站模块组、各个移动横梁之间的模块组采用EtherCAT总线通信;移动横梁上的分站模块组与伺服电机、各个伺服电机之间采用CAN总线通信,两种总线高低结合进行数据传输,使传输速率提高将近10倍。     

Flexible Potentiometric Minisensor Based on Manganese Dioxide‐Composite for the Determination of Hydrogen Peroxide in Bleach and Pharmaceutical Products

Abstract

A new flexible minisensor based on MnO₂/graphite/epoxy resin composite for the potentiometric determination of hydrogen peroxide was developed in this work. Under optimum experimental conditions, such as 25°C, 4 h of conditioning time in 0.1 mol L^?1 NH₃‐NH₄ ⁺ buffer solution (pH 8.5) and a composition of 10/60/30% w/w MnO₂/graphite/epoxy resin, respectively, the minisensor presented a Nernstian response for H₂O₂ in the concentration range from 6.0×10^?7 to 1.0×10^?3 mol L^?1, with a slope of ?58.5±0.2 mV/pH₂O₂ with a detection limit of 1.6×10^?8 mol L^?1 H₂O₂. The useful lifetime of the proposed minisensor was at least 6 months (over 670 determinations for each composite), the response time was smaller than 1.5 min, and it was successfully applied in the determination of hydrogen peroxide in bleach and pharmaceutical products.     

Metal and structure tuned in vitro antitumor activity of benzimidazole-based copper and zinc complexes

Four new complexes, Cu₂(p-2-bmb)₂Cl₄ (1), Cu₂(p-2-bmb)₂Br₄ (2), Zn₂(p-3-bmb)₂Cl₄ (3), and [Cu₃(p-3-bmb)₂Cl₄·(CH₃OH)₂] _n (4), have been synthesized under solvothermal reactions based on V-shaped flexible ligands 1-((2-(pyridin-2-yl)-1H-benzoimidazol-1-yl)methyl)-1Hbenzotriazole (p-2-bmb) and 1-((2-(pyridin-3-yl)-1H-benzoimidazol-1-yl)methyl)-1Hbenzotriazole (p-3-bmb). Complexes 1–3 are binuclear, whereas 4 is an infinite chain with trimetallic units, and then these complexes are further extended into 3D supramolecular architectures by π…π interactions and hydrogen bonds. In vitro antitumor activities of these complexes on four human tumor cell lines (gastric tumor cell line, esophagus tumor cell line, liver tumor cell line, colon tumor cell line) were evaluated by MTT assay. The results exhibit that these complexes inhibit the growth of cancer cells by inducing apoptosis, and the inhibition effect shows time- and dose-effect relationship.     

以方酸及咪唑基配体构筑的二维层状镉(Ⅱ)配位聚合物的合成和表征

水热条件下,以1,4-双(咪唑基-1-甲基)苯(bix)及方酸阴离子(C4O42-)为配体,合成了新的镉的配位聚合物[Cd(C4O4)(bix)(H2O)2]n(1)。单晶结构分析表明,该配合物为二维层状结构,镉中心为六配位八面体结构,赤道平面上4个配位原子分别来自方酸和bix配体,轴向2个配位原子来自配位水分子,镉原子通过双配体桥连形成四连接的二维(4,4)网络。同时,测定了配合物的热稳定性和荧光性质。     

AVS标准中的灵活条带结构

通过对AVS和H.264/AVC中条带层语法的比较分析,针对现有条带相关技术的不足,在图像层和条带层之间,提出了灵活条带集技术。通过辅以非均衡差错保护策略,采用灵活条带集技术可以增强关注区域的抗误码能力。同时,可通过对条带集量化参数的调整实现基于区域的变质量编码,在总码率相当的情况下大大增强了关注区域的主客观质量。     

Flexible,Stretchable, Transparent Conducting Films Made from Superaligned Carbon Nanotubes

A straightforward roll‐to‐roll process for fabricating flexible and stretchable superaligned carbon nanotube films as transparent conducting films is demonstrated. Practical touch panels assembled by using these carbon nanotube conducting films are superior in flexibility and wearability—and comparable in linearity—to touch panels based on indium tin oxide (ITO) films. After suitable laser trimming and deposition of Ni and Au metal, the carbon nanotube film possesses excellent performance with two typical values of sheet resistances and transmittances (208 Ω □^?1, 90% and 24 Ω □^?1, 83.4%), which are comparable to ITO films and better than the present carbon nanotube conducting films in literature. The results provide a route to produce transparent conducting films more easily, effectively, and cheaply, an important step for realizing industrial‐scale applications of carbon nanotubes for transparent conducting films.     

小型轻质长条反射镜挠性支撑方案研究

光学反射镜支撑结构良好的尺寸稳定性是保证其成像的关键因素,对小型轻质长条反射镜来说,反射镜自身的特点是长宽比较大,不利于支撑的展开,这必然会给反射镜的支撑结构设计带来困难。针对这种情况,本文对某型反射镜的支撑进行了研究,提出了单点挠性的概念,并对具体结构进行了细致的研究。工程分析表明,这种支撑可以很好地保证反射镜在静力学、热环境下镜面具有较高成像质量,而其支撑自身在一定的动态环境下不会破坏。这种支撑结构不仅具有静态、动态的尺寸稳定性,而且重量较轻,适合小型空间遥感器使用。     

从设计上提高FPC使用性能

文章主要介绍了FPC在三维组装过程中经常出现的几类问题以及解决方法。供FPC设计人员参考,以从设计上提高产品的使用性能及品质。     

多品种柔性生产企业的订单调度模型及其遗传算法

以订单总完工时间最小和订单平均流程时间最小为目标函数,利用改进的多目标遗传算法生成了多品种订单调度模型.为解决组合模型的指数爆炸问题,提出了一种按规则分配订单以及订单中各作业排序相结合的集成调度思想;以一种整数和字母组合的编码方法用于可行解的表达,并在每个分目标的进化过程中,对选择、交叉、变异算子以及精英解保留策略重新进行设计,保证了解的分布性和均匀性;同时还提出了一种新的终止条件,将精英种群与分目标的子种群进行合并,从而加快收敛的速度.以典型的订单生产企业为例进行仿真实验,实验结果表明,应用该算法可以获得满意的Pareto解集.     

Recent advances in flexible and stretchable electronics, sensors and power sources

There has been ongoing keen interest to mold electronic devices into desired shapes and be laid on desired configurable surfaces. In specific, the ability to design materials that can bend, twist, compress and stretch repeatedly, while still able to maintain its full capability as conductors or electrodes, has led to numerous efforts to develop flexible and stretchable (bio)devices that are both technologically challenging and environmentally friendly (e.g. biodegradable). In this review, we highlight several recent significant results that have made impacts toward the field of flexible and stretchable electronics, sensors and power sources.