Porphyrin COF and its mechanical pressing-prepared carbon fiber hybrid membrane for ratiometric detection, removal and enrichment of Cd.

A nitrogen (N), oxygen (O)-rich porphyrin-based covalent organic framework (COF), in which interlayer porphyrin molecules are vertically stacked, is prepared and characterized. As-prepared N,O-rich TpTph COF shows a high adsorption capacity for Cd due to the abundant coordination sites. More interesting, it is found that the formation of COF enlarges the porphyrin ring center space, thus facilitating the Cdcoordination, and the resulting optical signal changes make the ratiometric detection of Cd possible.

Optimizing detection limits in whispering gallery mode biosensing.

A theoretical analysis of detection limits in swept-frequency whispering gallery mode biosensing modalities is presented based on application of the Cramér-Rao lower bound. Measurement acuity factors are derived assuming the presence of uncoloured and 1/ f Gaussian technical noise. Frequency fluctuations, for example arising from laser jitter or thermorefractive noise, are also considered.

Temperature-insensitive detection of low-concentration nanoparticles using a functionalized high-Q microcavity.

The ability to detect nanoparticles in extremely dilute solutions in the presence of environmental noise is crucial for biosensing applications. In this paper we propose a scheme for detecting target nanoparticles through their scattering effects in a high-Q whispering gallery microcavity. The detection signal, defined as the total linewidth broadening of the two new split modes that appear upon nanoparticle adsorption, is highly sensitive and proportional to the nanoparticle concentration.

Experimental study on centrifugal concrete-filled steel tubes under bending and torsion.

A real-size experiment on 11 tubes was done to study the performance of centrifugal concrete-filled steel tubes under bending and torsion. This paper first introduces the relevant operating method, equipment, subjects and processes. The factors that affect deformation and stiffness and the break mechanism under different loading were studied.