Effects of the electrospray ionization parameters on the formation and morphology of colloidal microspheres of polyacrylonitrile

Polyacrylonitrile colloidal microspheres have been successfully prepared with different concentrations of electrospraying polyacrylonitrile solutions. The morphology of the colloidal spheres has two kinds of structures and is strongly affected by electrospray‐ionization parameters, such as the polymer concentration, applied voltage, and distance between the electrodes. The solvent can also affect the morphology of polyacrylonitrile. The optimum conditions for preparing colloidal spheres have been found, and differential scanning calorimetry results indicate that polyacrylonitrile colloid spheres are amorphous. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 2889–2893, 2006     

Studies on syntheses and properties of novel CeO2/polyimide nanocomposite films from Ce(Phen)3 complex

A series of cerium dioxide (CeO₂)/polyimide (PI) nanocomposites were successfully prepared from Ce(Phen)₃ and polyamic acid (PAA) via the solution direct-dispersing method, followed by a step thermal imidization process. TGA and XPS studies showed that the cerium complex decomposed to form CeO₂ during the thermal imidization process at 300 °C. SEM observation showed that the formed CeO₂ as nanoparticles was well dispersed in polyimide matrix with a size of about 50-100 nm for samples with different contents of CeO₂. Thermal analysis indicated that the introduction of CeO₂ decreased the thermal stability of nanocomposite films due to the decomposition of Ce(Phen)₃ in the imidization process, while the glass transition temperature (T_g) increased obviously, especially nanocomposite films with high loading of CeO₂ exhibited a trend of disappearance of T_g. DMTA and static tensile measurements showed that the storage modulus of nanocomposite films increased, while the elongation at break decreased with increasing CeO₂ content.     

网络安全评估方法分析

近年来,网络攻击事件时有发生,给社会和企业带来巨大威胁和损失,对于网络安全评估方法的研究成为了热点,文中介绍了网络安全评估方法的研究现状,分析了网络安全评估相关技术,进而探析了网络安全评估方法。     

对分课堂在人机交互设计课程中的应用

人机交互设计课程涉及的知识面广、涵盖领域众多,采用传统授课方式很难激发学生的兴趣,导致授课效果不理想.对分课堂的授课方式将传统的讲授与课堂讨论相结合,将课堂时间一分为二,通过先讲授,再布置作业,最后展开隔堂讨论,进而达到内化吸收、巩固知识的效果.对分课堂可逐步改善人机交互设计课程中教师讲授和学生学习过程中所面临的困境,激发学生自主学习的动力,增强学生探索新知识的欲望和信心,达到授人以渔的目的.     

RLINK: Deep reinforcement learning for user identity linkage

World Wide Web - User identity linkage is a task of recognizing the identities of the same user across different social networks (SN). Previous works tackle this problem via estimating the pairwise...     

对水利工程项目建议书阶段设计取费问题的讨论与建议

通过相关规范、法规进行分析,对于实行立项简化程序未编制项目建议书的水利工程,项目建议书阶段的设计工作应该取费,但不宜直接套用现行设计取费标准;建议根据项目特点在计算的设计费基础上按0.5～0.8的折扣系数取费。     

自动金刚石刀头磨弧机

针对采用激光焊接工艺的金刚石锯片上，其金刚石刀头内弧面需要磨抛的工艺要求，研发了一种自动金刚石刀头磨弧机。该设备将金刚石刀头放置在作间歇回转的工作转盘上，工作转盘由槽轮机构驱动；磨削砂轮安装在拖板系统上，拖板的间歇往复运动由一种在滑块上开有长槽的曲柄滑块机构实现，可满足工作转盘转位时，拖板停歇；工作转盘停歇时，拖板运动的工作要求。用靠模控制砂轮磨削的进给量。通过靠模的更换及设计能快速装卡的刀头夹具，可实现对不同弧度刀头的磨弧。本文介绍了该设备的结构组成、设计参数的选择及相关的设计方案，并对在滑块上开有长槽的曲柄滑块机构的设计方法进行了详细地讨论。     

基于等效电路分析的航空锂电池工作特性研究

针对航空锂电池安全保障问题,提出了一种基于等效电路模型的锂电池工作特性分析方法。该方法通过PNGV等效电路处理,实现对航空锂电池物理反应过程的电路模拟,并基于此研究了航空锂电池的工作特性。实验结果表明,该方法能够实现对航空用75 Ah锂电池等效电路的有效模拟,等效模型能够有效分析不同条件下的电池工作状态,获得锂电池工作特性规律,为锂电池的安全航空应用提供保障。     

基于空心微针阵列的连续监测葡萄糖传感器

研制了一种基于空心微针阵列并可微痛刺入皮下实时连续监测人体血糖浓度的葡萄糖传感器.微针阵列由等间距的三根微针组成,分别作为工作电极、辅助电极和参比电极,其中工作电极与辅助电极采用表面溅射了Ti/Pt的空心不锈钢微针来制作,采用戊二醛-牛血清白蛋白交联法将葡萄糖氧化酶固定并仅置于作为工作电极的针尖通孔处;参比电极采用Ag/AgCl实心微针制作.测试结果表明:葡萄糖浓度在0～21 mmol·L-1范围内传感器输出电流为线性,灵敏度为0.575 μA/(mmol·L-1),响应时间为16s,且具有很好的抗干扰性.