Study of a QCM Dimethyl Methylphosphonate Sensor Based on a ZnO-Modified Nanowire-Structured Manganese Dioxide Film

Sensitive, selective and fast detection of chemical warfare agents is necessary for anti-terrorism purposes. In our search for functional materials sensitive to dimethyl methylphosphonate (DMMP), a simulant of sarin and other toxic organophosphorus compounds, we found that zinc oxide (ZnO) modification potentially enhances the absorption of DMMP on a manganese dioxide (MnO2) surface. The adsorption behavior of DMMP was evaluated through the detection of tiny organophosphonate compounds with quartz crystal microbalance (QCM) sensors coated with ZnO-modified MnO2 nanofibers and pure MnO2 nanofibers. Experimental results indicated that the QCM sensor coated with ZnO-modified nanostructured MnO2 film exhibited much higher sensitivity and better selectivity in comparison with the one coated with pure MnO2 nanofiber film. Therefore, the DMMP sensor developed with this composite nanostructured material should possess excellent selectivity and reasonable sensitivity towards the tiny gaseous DMMP species

Noise Amplification in Human Tumor Suppression following Gamma Irradiation

The influence of noise on oscillatory motion is a subject of permanent interest, both for fundamental and practical reasons. Cells respond properly to external stimuli by using noisy systems. We have clarified the effect of intrinsic noise on the dynamics in the human cancer cells following gamma irradiation. It is shown that the large amplification and increasing mutual information with delay are due to coherence resonance. Furthermore, frequency domain analysis is used to study the mechanisms

Studies on the interaction between triptolide and Bovine Serum Albumin (BSA) by spectroscopic and molecular modeling methods

Background: Triptolide is a major active constituent isolated from Tripterygiumwilfordii Hook F, a Chinese herbal medicine. This study investigated the intermolecular interaction between triptolide and bovine serum albumin (BSA).Materials and Methods: The fluorescence, circular dichroism (CD) and molecular docking methods were used to investigate the intermolecular interaction between triptolide and BSA. The binding constant, the number of binding sites, binding subdomain and the thermodynamic parameters were measured.Results: The results of this experiment revealed that the intrinsic fluorescence of BSA was effectively quenched by triptolide via static quenching. The experimental results of synchronous fluorescence and CD spectra showed that the conformation of BSA was changed in the presence of triptolide.Conclusion: It indicated that triptolide could spontaneously bind on site II (subdomain IIIA) of BSA mainly via hydrogen bonding interactions and Van der Waals force.Keywords：fluorescence quenching；triptolide；bovine serum albumin；molecular docking methods；synchronous fluorescenc

Hyperspectral Image Denoising Based on Tensor Group Sparse Representation

A novel algorithm for hyperspectral image (HSI) denoising is proposed based on tensor group sparse representation. A HSI is considering as 3 order tensor. First, a HSI is divided into small tensor blocks. Second, similar blocks are gathered into clusters, and then a tensor group sparse representation model is constructed based on every cluster. Through exploiting HSI spectral correlation and nonlocal similarity over space, the model constrained tensor group sparse representation can be decomposed into a series of unconstrained low-rank tensor approximation problems, which can be solved using the tensor decomposition technique. The experiment results on the synthetic and real hyperspectral remote sensing images demonstrate the effectiveness of the proposed approach

Experiment Research on Initiation and Micro-propagation of the Interface Crack in the Hard Cladding Material 5Cr2Ni08C/Q235

The fracture samples of the hard cladding material 5Cr2Ni08C/Q235 are fabricated with the vacuum liquid phase sintering technology, three-point bending fracture experiments are conducted, the sample fracture morphology are observed with SEM. The experiment research results show that: the intergranular micro-crack is easy to initiate in the interface under the action of the external load, and the micro-crack easily appears on the crystal boundary, the thermal expansion coefficient mismatch places, around the interface contamination and micro holes. Based on which, the interface micro-crack easily continues to propagate along the crystal boundary. And the micro-mechanisms of the interface crack initiation and propagation are established

Experiment Research on Initiation and Micro-propagation of the Interface Crack in the Hard Cladding Material 5Cr2Ni08C/Q235

The fracture samples of the hard cladding material 5Cr2Ni08C/Q235 are fabricated with the vacuum liquid phase sintering technology, three-point bending fracture experiments are conducted, the sample fracture morphology are observed with SEM. The experiment research results show that: the intergranular micro-crack is easy to initiate in the interface under the action of the external load, and the micro-crack easily appears on the crystal boundary, the thermal expansion coefficient mismatch places, around the interface contamination and micro holes. Based on which, the interface micro-crack easily continues to propagate along the crystal boundary. And the micro-mechanisms of the interface crack initiation and propagation are established

Analysis of spectral characteristics among different sensors by use of simulated RS images

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A Dual-Channel Aerosol Optical Depth Retrieval Algorithm Incorporating the BRDF Effect from AVHRR over Eastern Asia

A NOAA/AVHRR dual-channel method over land is proposed to simultaneously retrieve aerosol optical depth (AOD) at 0.55 μm, and surface reflectance at 0.63 and 0.85 μm. Compared with previous well-established one-channel retrieval algorithms, this algorithm takes advantage of the surface reflectance ratio between 0.63 and 0.85 μm in an attempt to account for the effect induced by the surface bidirectional reflectance distribution function (BRDF). This effect cannot be negligible due to the orbit drift and phasing running of NOAA satellites, both of which potentially cause large solar angular variation. Meanwhile, the observation posture change of AVHRR would cause large sensor angular variation in time series measurements. The used surface reflectance ratio based on dual channels at 0.63 and 0.85 μm is found more reasonable to be assumed as unchanged during a certain period of time, compared to the traditional ratio when addressing the BRDF issue. AOD retrievals have been carried out over Eastern Asia. Validation against aerosol robotic network (AERONET) measurements shows that up to 83% of AOD validation collocations are within error lines (±0.15 ± 0.15τ, τ is AOD) with an R of 0.88 and an root mean square error (RMSE) of 0.15. The dual-channel algorithm taking into account the surface BRDF effect is proved outperforming the conventional 0.63 μm-channel method. It indicates that our algorithm has the potential to be applied to the retrieval of long series of AOD, especially to the AOD retrieval of the sensors which lack a shortwave infrared channel required in the MODerate resolution Imaging Spectroradiometer (MODIS) dark target AOD algorithm