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An interesting two-stage adsorption mechanism, defined as “ideal adsorption” and “insertion adsorption”, was first proposed for the benzene/HY system by Metropolic Monte Carlo simulations at loadings below and above an “inflection point”.

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Monte Carlo (MC) simulations were performed to study the influence of framework protons on the adsorption sites of the benzene molecule in HY zeolite with different Si:Al ratios. Eleven types of adsorption sites were observed including five reported sites (H1, H2, U4, U4­(H1), and W) and six newfound sites (W­(2H1), U4­(2H1), H1­(H2), U4­(H1,H1), H1­(H2,H1), and U4­(H1,H1,H1)), which were “supersites” with more than one proton. The stability order of the sites found in the 28Al model can be expressed as U4­(H1,H1,H1) > U4­(H1) > H1­(H2,H1) > W­(2H1) > U4­(H1,H1) > H1­(H2) > H1 > H2 > U4 > U4­(2H1) > W. Increasing number of zeolite protons resulted in an increasing proportion of supersites, which enhanced adsorption energies of sites. For HY zeolite models containing different numbers of protons with the same ratio of H1:H2, the amount of the most stable adsorption sites containing H1 proton increased, while the amount of the most stable adsorption sites containing H2 decreased, with increasing number of protons.

Monte Carlo simulations are performed to study the adsorption of aromatic molecules (toluene, styrene, o-xylene, m-xylene, p-xylene, 1,3,5-trimethylbenzene, and naphthalene) in all-silica faujasite (FAU) zeolite. For monoaromatics, a two-stage "ideal adsorption" and "insertion adsorption" mechanism is found by careful inspection of locations and distributions of the adsorbed toluene molecules. The validity of this mechanism is confirmed for all monoaromatics considered in the current study. Remarkably, the number of C atoms per unit cell corresponding to the inflection point of adsorbate loading (CI-P) is defined as a valid and convenient characterizing factor in the packing efficiency of monoaromatics in the FAU zeolite. For the case of naphthalene, a type of diaromatic, the three-stage mechanism is proposed, which consists of the first two stages and a third stage of "overideal adsorption". The so-called overideal adsorption is labeled because the naphthalene molecules start to occupy the S site nonideally at loadings that approach saturation, leading to a more localized feature of the adsorbates. The explicit adsorption mechanism can be used to understand the loading dependence of isosteric adsorption heat for the aromatics concerned.

The translation of CARS imaging towards real time, high resolution, chemically selective endoscopic tissue imaging applications is limited by a lack of sensitivity in CARS scanning probes sufficiently small for incorporation into endoscopes. We have developed here a custom double clad fiber (DCF)-based CARS probe which is designed to suppress the contaminant Four-Wave-Mixing (FWM) background generated within the fiber and integrated it into a fiber based scanning probe head of a few millimeters in diameter. The DCF includes a large mode area (LMA) core as a first means of reducing FWM generation by ~3 dB compared to commercially available, step-index single mode fibers. A micro-fabricated miniature optical filter (MOF) was grown on the distal end of the DCF to block the remaining FWM background from reaching the sample. The resulting probe was used to demonstrate high contrast images of polystyrene beads in the forward-CARS configuration with > 10 dB suppression of the FWM background. In epi-CARS geometry, images exhibited lower contrast due to the leakage of MOF-reflected FWM from the fiber core. Improvements concepts for the fiber probe are proposed for high contrast epi-CARS imaging to enable endoscopic implementation in clinical tissue assessment contexts, particularly in the early detection of endoluminal cancers and in tumor margin assessment.

Human body mechanical motion is considered as an ideal energy resource for portable or wearable devices. This paper presents an AA-sized electromagnetic energy harvester to convert the motion of human limbs motion into electrical energy. A cylindrical permanent magnet is freely moved in a 3D-printed tube wholly wrapped with coils. The outer dimensions of the device are 14 mm in diameter and 44 mm in height. Based on Faraday’s law a theoretical model was derived and the device size was optimized. The influence of the magnet and coil dimensions on the output power was analyzed by theoretical calculations and proved by experiment following. The optimized dimensions from two separate methods agrees well with each other. When the harvester prototypes are driven by hand shaking at 5 Hz, the average output power reaches to 63.9 mW with power density of 9.42 mW cm−3, which is 51% larger than that of the conventional tube electromagnetic energy harvester. While when the harvester is worn on ankle, a power of 4.2 mW can be obtained even at normal walking frequency of 1 Hz, corresponding to a power density of 0.62 mW cm−3, which is considerably higher compared with other devices of human energy harvesting. Furthermore, the new developed device is simple without needing any restoring spring and is easy to be fabricated.

Overtopping failure of reinforced tailings dam may cause significant damage to theenvironment and even loss of life. In order to investigate the feature of overtopping of the reinforcedtailings dam, which has rarely appeared in the literature, the displacement, the phreatic level and theinternal stress of dam during overtopping were measured by a series of physical model tests. Thisstudy conclusively showed that, as the number of reinforcement layers increased, the anti-erosioncapacity of tailings dam was notably improved. It could be supported by the change of the dimensionof dam breach, the reduction of stress loss rate, and the rise of phreatic level from the tests. Based onthe erosion principle, a mathematical model was proposed to predict the width of the tailings dambreach, considering the number of reinforcement layers. This research provided a framework for theexploration of the overtopping erosion of reinforced tailings dam, and all presented expressions couldbe applied to predict the development of breach during overtopping.