振动辅助磁力研磨超硬精密Al2O3陶瓷管内表面试验研究

针对普通磁力研磨超硬精密Al2O3陶瓷管内表面加工效率低且纹理不均匀的问题,提出了一种振动辅助磁力研磨的技术.采用曲柄滑块振动机构和超声振动机构辅助磁力研磨,通过改变磁粒刷的运动轨迹,实现对陶瓷管内表面的高效精密加工.对比施加振动前后表面加工质量和加工效率的变化,利用单因素试验分析了振幅和振动频率对表面加工质量和加工效率的影响规律.试验结果表明:振动辅助磁力研磨技术实现了对超硬精密Al2O3陶瓷管内表面的高效精密加工,相比普通磁力研磨,经过50 min的加工,超声振动辅助磁力研磨效果最好,加工效率提高70%,表面粗糙度Ra由平均1.1μm降至0.03μm以下;采用高频率小振幅的振动更有利于加工效率和表面加工质量的同时提高.     

湿敏形状记忆针织物的研究

用聚乙二醇(PEG)、扩链剂(2D)和催化剂(MgCl2·6H2O)配成整理液对织物进行后整理加工,可使织物具有湿敏形状记忆效应(WS SME)。分析了WS SME的机理及PEG分子量、PEG用量、扩链剂用量、焙烘温度等因素对湿敏形状记忆效应的影响,确定了合理的整理液配比和整理工艺条件。     

离子凝胶反应法制备壳聚糖/N,O-羧甲基壳聚糖微球

以一氯乙酸与壳聚糖反应形成N,O-羧甲基壳聚糖两性聚电解质,分光光度法测定其等电点IEP=2．86。以此两性聚电解质与壳聚糖可以在一定条件下形成微球,光学显微镜和电子显微镜测试表明,控制两种聚电解质配比可以制备不同粒径大小的微球,而超声功率对微球粒径的影响较小。红外光谱测试表明微球中N,O-羧甲基壳聚糖羧基以羧酸根形式存在,分光光度与电导法联合测定表明两种聚电解质以离子凝胶作用形成微球,其最佳制备条件为IEP（CM-CHITOSAN）〈pH〈pKa（CS）,在此较宽的pH值范围内微球可稳定存在。     

亚硝基脲对DNA损伤作用的研究进展

亚硝基脲是重要的抗癌烷化剂,应用于多种恶性肿瘤的临床治疗。亚硝基脲分解生成活泼亲电中间体而与生物大分子作用,导致DNA碱基烷化、互补碱基对横向交联等损伤,最终诱导癌细胞凋亡而发挥其抗癌作用。由于亚硝基脲在动物实验和临床应用中表现出的复杂生理活性,有关亚硝基脲对DNA损伤作用机制的研究,已成为该类药物设计开发以及癌症防治领域中的热点问题。本文对近年来国内外有关亚硝基脲对DNA损伤作用机制的研究进行了综述。     

交联型小分子空穴传输材料在溶液工艺制备有机发光二极管中的应用

相比蒸镀工艺,溶液工艺制备有机发光二极管（OLEDs）具有材料利用率高、设备要求简单、成本低、可制作大尺寸面板等优点,受到了广泛关注。小分子空穴传输材料是有机发光二极管重要组成部分,起到传输空穴和阻挡电子的作用,在其结构上添加苯乙烯基、氧杂环丁烷等可交联基团,形成适合溶液工艺制备的可交联小分子空穴传输材料,通过热或光的引发形成网络状结构聚合物,进而应用于多层器件结构中,解决层间混溶问题,从而改善器件的效率和稳定性。本文从溶液工艺对材料的要求出发,首先介绍了旋转涂布及喷墨打印工艺的制备方法,评价了不同操作因素对薄膜质量的影响,之后详细介绍各不同交联基团的空穴传输材料,总结并对比各交联基团的优劣,以及对器件性能的影响。最后,展望了可交联空穴传输材料和溶液制备工艺的发展趋势。     

磁流变抛光数学模型的建立

介绍了近年来的一种新兴的光学加工技术———磁流变抛光 (MRF)。以Preston方程为依据建立了这种抛光方法的数学模型。利用该数学模型详细分析了被加工工件表面材料去除率与压力参数P成正比的关系 ,指出了工件表面所受的压力P主要是由流体动压力Pd 和磁化压力Pm 两部分组成的。以用磁流变抛光方法加工凸球面工件为例 ,具体推导出流体动压力Pd 和磁化压力Pm 的数学表达式 ,并通过实验对压力P的数学表达式及抛光模型的合理性进行了验证。     

HPLC-DAD法同时测定纺织品中3种天然抗菌整理剂的含量

采用二极管阵列检测器-超高效液相色谱法同时测定纺织品中芦荟苷、芦荟大黄素和大黄酚3种天然抗菌整理剂的含量.样品采用甲醇超声波浴于60℃提取30 min.色谱柱为Agilent C18柱;流动相为甲醇-0.1％磷酸水溶液(体积比为80:20),流速为1.0 mL/min;检测波长为358 nm和256 nm.在检测范围内标准曲线线性良好(r2≥0.999),3个加标水平的平均回收率为94.2％～98.5％,测定结果的相对标准偏差为0.77％～2.63％(n=6).该方法准确、可靠,可作为纺织品质量控制的参考方法.     

Theoretical Study of Nonclassical Platinum Complexes Bonding to Purine Bases： How the Long-lived Monofunctional Adducts Can Be in Existence？

1 INTRODUCTION Since the discovery of the anticancer activity of cisplatin by Roserberg, cisplatin has become one of the most widely utilized antitumor drugs in the world, with an annual sales of approximately 500 million dollars[1~6]. Because of the successful story of cisplatin, a great deal of attention was drawn to platinum complexes and many studies were focused on the influence of different ligands and conforma- tions on anticancer property[7]. Subsequently, much progress has been …     

Rapid shape memory and pH-modulated spontaneous actuation of dopamine containing hydrogels

The dopamine containing hydrogels with rapid responsive shape memory capability were synthesized by a one-pot method.The temporary shape of hydrogel was fixed within 20 s in NaOH solution by the tris-complex crosslinking of metalligand complex between Fe3+ ions and catechol groups,while the permanent shape was recovered completely in HCl solution within 60 s upon the change from tris-complex to mono-complex.The hydrogel showed unique spontaneous actuation behavior.It could curl spontaneously without further external force deformation when immersed in NaOH solution again after the first shape recovery in HCl solution.This might be attributed to the competitive result of swelling and additional tris-complex crosslinking formation when immersed in NaOH solution.In addition,the hydrogels also had proper modulus,elongation ratio and tensile strength.Such hydrogel provides a new candidate material for designing soft actuators and robots modulated with spontaneous actuating.     

Mathematical modelling of influence functions in computer-controlled polishing: Part II

Computer-controlled polishing (CCP) is commonly used to finish high-quality surfaces, such as optical lenses. Based on magnetorheological finishing (MRF), a mathematical model to calculate the polishing tool characteristic (influence function) was developed and verified experimentally. The second part of this paper describes the calculation of the distribution of material removal within the size of an influence function and is based on Preston’s fundamental polishing equation. The complete influence function model was implemented using MATLAB. The result is a user-friendly and easy-to-use software tool that enables fast computation of MRF influence functions without the current cumbersome determination procedure, and thus gives improved and more economical production of high-quality surfaces.