Scanning probe microscopy study of exfoliated oxidized graphene sheets

Exfoliated oxidized graphene (OG) sheets, suspended in an aqueous solution, were deposited on freshly cleaved HOPG and studied by ambient AFM and UHV STM. The AFM images revealed oxidized graphene sheets with a lateral dimension of 5–10 μm. The oxidized graphene sheets exhibited different thicknesses and were found to conformally coat the HOPG substrate. Wrinkles and folds induced by the deposition process were clearly observed. Phase imaging and lateral force microscopy showed distinct contrast between the oxidized graphene and the underlying HOPG substrate. The UHV STM studies of oxidized graphene revealed atomic scale periodicity showing a (0.273 ± 0.008) nm × (0.406 ± 0.013) nm unit cell over distances spanning few nanometers. This periodicity is identified with oxygen atoms bound to the oxidized graphene sheet. I(V) data were taken from oxidized graphene sheets and compared to similar data obtained from bulk HOPG. The dI/dV data from oxidized graphene reveals a reduction in the local density of states for bias voltages in the range of ±0.1 V.     

强化演示实验,开展大学物理研究型教学

探讨对工科大学物理研究型教学的认识以及演示实验在其中的重要作用,同时介绍我们的一些做法.     

一种基于非下采样Contourlet变换多聚焦图像融合算法

针对现有小波类图像融合算法的不足,提出了一种基于非下采样Contourlet变换多聚焦图像融合算法,并在Contourlet域中引入了局部区域可见度以及局部方向能量的概念.针对低频子带系数和各带通方向子带系数分别提出了基于局部区域可见度以及基于局部方向能量的系数选择方案.通过对多聚焦图像融合的仿真实验,表明该算法相对于传统的基于离散小波变换和离散小波框架变换融合算法能够有效减少有用信息的丢失以及虚假信息的引入,同时能够从源图像中提取更多的有用信息并注入到融合图像中, 得到更好视觉效果和更优量化指标的融合图像.     

理论力学研究导向型教学方法探索与实践

基于“创新性、高阶性和挑战度”的教学理念,提出了理论力学课程的研究导向型教学方法。通过引入工程实际的例题、科技前沿及大国工程等案例,培养学生力学建模、分析实际问题的能力以及家国情怀和崇高的价值理念;通过翻转课堂,调动学生的学习积极性;通过课程小论文的研究,培养学生的批判性思维及查阅文献、力学建模、创新性设计和研究复杂工程问题的能力。实践结果表明,学生的学习积极性、翻转课堂参与度及课程的教学效果得到了有效提高。

     

论理论智慧

智慧论题在当代的复兴,是一个值得关注的现象。该论题要富有成果地展开,需要做一番返本开新的功夫。就此而言,亚里士多德哲学是一个很好的出发点。亚氏在沉思传统中对理论智慧作了经典论述,其中广义和狭义理论智慧并存而偏重狭义。在当代哲学中,柏尔的德性认识论致力于理论智慧的广义理解,冯契的智慧说则在实践转向的背景下着重阐发了狭义理论智慧。在肯定先哲、前辈和时贤思辨成就的前提下,我们试图在两个方面寻求突破：首先,在后形上学时代,通过哲学的变革,为狭义理论智慧重新定向;其次,勾勒一个风格导向的智慧概念,对包括理论智慧在内的各种智慧形态作出统一阐述。     

Nanomagnet Bioconjugates with anti-CRP Polyclonal Antibodies as Nanobioprobes for Enhanced Impedimetric Detection of CRP

Selective purification of biological materials for their detection in complex sample matrix is a general challenge for many researchers working in the field of diagnostics. Magnetic nanoparticles functionalized with biological molecules that impart biomolecular selectivity are therefore of major interest as capture probes thus allowing for magnetic separations. Nanoparticles can also be used for the enhanced detection of biomarkers. In this work, an ultrasensitive sandwich-based impedimetric immunosensor was fabricated for the detection of C-reactive protein antigen (CRPAg). Stable and oriented immobilization of anti-CRP monoclonal antibody was achieved onto electrografted phenylethylamine derivatized with succinic anhydride and phenylboronic acid via carbodiimide chemistry. The detection of CRPAg was achieved using Electrochemical Impedance Spectroscopy (EIS). The enhancement of the impedance charge-transfer resistance (R_CT) signal was achieved using the sandwich approach. The anti-CRP polyclonal antibody was immobilized in an oriented manner onto magnetic nanoparticles functionalized with phenylboronic acid. The increase in the change in charge-transfer resistance (ΔR_CT) values was linearly proportional to the concentration of CRPAg in the range 10 to 200 ng mL⁻¹ covering the clinical range for CRPAg detection and with a detection limit of 0.34 ng mL⁻¹.     

Unprecedented Route to Ordered Polyaniline: Direct Synthesis of Highly Crystalline Fibrillar Films with Strong π‐π Stacking Alignment

Films of polyaniline (PANI) featuring about 80% crystallinity and characterised with strong π‐π stacking alignment parallel to the film surface have been obtained directly after the original synthesis upon simple drying of the aqueous PANI suspension. A strong anisotropy in the growth of the nano‐sized crystals produced during the synthesis results in the formation of micrometer‐length fibrils perpendicular to the film surface in the course of water evaporation. The regular intercalation of water molecules between the PANI chains seems to be crucial for their ordering throughout the synthesis and film formation.