Acyliminium ion-olefin cyclization leading to isoindolo[2,1-a]quinoline derivatives

Isoindolo[2,1-a]quinolines 10 , 11 , 12 were synthesized from hydroxylactams 8 or 9 via an N-acyliminium ion-π-olefin nucleophile cyclization reaction.     

生物组织多光谱偏振特性研究

生物组织内部结构复杂且具有较强的散射特性,而光作为生物组织检测的重要信息载体,其自身特性包括颜色、幅值、偏振等都对信息获取有较大的影响.结合偏振成像,对生物组织多光谱偏振特性展开了研究,依据不同微粒尺寸的分布建立了均匀单层生物组织模型,结合瑞利和米氏散射理论模拟了基于单个微粒的两种散射事件.瑞利散射具有较好的前向后向散...     

Batch process monitoring and its application to polymerization systems

Slight changes in raw material properties or operating conditions during critical periods of operation of batch and semi-batch polymerization reactors may have a strong influence on reaction mechanism and impact final product quality. Online process monitoring, fault detection, fault diagnosis, and product quality prediction in real-time ensure safe reactor operation and warn operators about excursions from normal operation that may lead to deterioration in product properties. Multivariate statistical process monitoring and quality prediction using multiway principal components analysis and multiway partial least squares have been successful in detecting abnormalities in process operation and product quality. When abnormal process operation is detected, fault diagnosis tools are used to determine the source cause of the deviation. Illustrative case studies are presented via simulated polyvinyl acetate polymerization.     

单颗粒计数策略定量检测癌胚抗原

该文提出了一种基于单颗粒电感耦合等离子体质谱(spICP-MS)的计数策略,用于癌胚抗原(CEA)的灵敏检测.该策略采用50 nm的金纳米颗粒(AuNPs)作为免疫识别和单颗粒计数的探针,以磁性纳米颗粒(MBs)作为免疫识别的捕获中心,基于夹心免疫反应,应用抗体标记的MBs捕获CEA和AuNPs探针.通过磁铁分离后,捕...     

超重力作用下软材料薄膜失稳的有限元分析

软材料在自然界和工业应用中无处不在,其显著特点是对外界刺激极其敏感,相对于传统材料其弹性模量更小,容易发生表面形态的失稳现象．现有研究主要把光、声、电等作为诱导材料失稳的因素进行研究,而重力往往作为常量考虑．本文通过有限元模拟,建立超重力作用下环向受限的圆柱状软材料薄膜失稳模型,探究了薄膜材料的密度、厚度、半径、剪切模量等材料和几何参数对失稳临界超重力和临界失稳模态的影响．结果表明,触发薄膜失稳的超重力随薄膜厚度和密度增大而减小,随剪切模量增大而增大,随着薄膜半径增大快速减小并迅速趋于常数．另外,当径厚比R/H较小时,无量纲临界超重力随着径厚比增大而单调减小,但当径厚比R/H大于3 时,此量为一个常数．超重力作用下软材料的临界失稳模态与密度、剪切模量等参数无关,随径厚比R/H增大,临界失稳模态波数增大、波长减小．     

INTRODUCTION TO THE 7TH TEACHING COMPETITION OF YOUTH FACULTY OF FUNDAMENTAL MECHANICS COURSES

阐述了教育部高等学校力学基础课程教学指导分委员会举办的全国高校第七届基础力学青年教师讲课比赛的基本情况、本届讲课比赛的特点、讲课比赛中反映出的问题及其改进的建议。希望通过本文的介绍,让国内各高校教师了解本届讲课比赛以及比赛中反映出的问题,为进一步办好讲课比赛、提高我国基础力学课程的教学水平和质量提供参考。     

Controlled flux behaviour of membrane processes

Controlling ultrafiltration (UF) and microfiltration (MF) membrane fluxes at or around a region where fouling is minimal can provide an interesting and economic operating regime. Selectivity may be enhanced and cleaning may be easier. For a given flux it is sometimes possible to filter a product suspension at the same trans-membrane pressure (TMP) as for pure water (PWP), but this can require a lot of energy input to maintain cross-flow or high shear in other ways if high fluxes are required. The critical flux is the flux above which one starts to observe fouling. By operating at lower cross-flow velocities and just above the critical flux, and thus, with lower TMPs, periodic cleaning can be effected by temporarily stopping permeation. A change in feed rate demands a change in flux which is obtained by temporarily increasing energy inputs. Controlled flux improves macromolecular fractionation. As flux increases the rejection of high molecular weight materials decreases whilst that of lower molecular weight materials decreases. This paper discusses the causes of fouling and the use controlled flux operation to mitigate its effects.     

Ballistic performance of novel design of bulletproof plates inspired by biomimetic approaches

Metal and polymer matrix composite materials are preferred in bulletproof applications due to their high-impact resistance and lightness. Personal/demand-specific designs that have become possible with the developing additive manufacturing technologies have brought a new perspective to armor technologies. At the same time, parts with complex structures designed with biomimetic approaches can be easily manufactured with additive manufacturing. In this study, biomimetic armors obtained from standard Carbon fiber reinforced polymer (CFRP) and Inconel 718 materials were compared with traditional armor structures. Within the scope of the study, 9 × 19 mm² parabellum and 7.62 mm NATO bullets were impacted at 275 m/s and 600 m/s speeds on biomimetic and conventional armor consisting of three and five layers. Bullet velocities during impact, deformation of bullets, deformation of armor, and harmonic behavior are discussed. The results obtained were also used to calculate the damped impact energies. In the study, it was determined that biomimetic plates could absorb 22%–38% more impact energy. It has been determined that CFRP materials can absorb 45% more impact energy compared to Inconel 718.