Textured BST Thin Film on Silicon Substrate: Preparation and Its Applications for High Frequency Tunable Devices

The dielectric properties of Ba0.5Sr0.5TiO3 (BST) thin films are sensitive to the relative crystallographic orientation of the films. LaNiO3 (LNO) and MgO were deposited as buffer layer on Si substrate before BST. The effect of buffer layer such as LNO, MgO and MgO/LNO bilayer on the microstructure and dielectric properties of BST were extensively investigated. The preferred (100) orientation of LNO by radio frequency (RF) magnetron sputtering was dominated by the substrate temperature and highly (100)-oriented LNO thin films were grown on Si substrates at 300°C. The oriented (100) growth of sputtered BST thin films was strongly affected by the orientation of LNO thin films and the tunability of BST thin film was greatly improved with the insertion of (100)-textured LNO buffer layer. In addition, MgO, as a buffer layer, was deposited by RF magnetron sputtering. The results show that the crystallization of BST was also enhanced by the insertion of MgO buffer layer, which enhances the oriental growth of BST along (100). Also, the tunability of the BST thin films was improved and the dielectric loss greatly decreased. Finally, CPW with BST/MgO multilayer was fabricated and the scattering (S) parameters were tested

Performance Characteristics and Temperature Compensation Method of Fluid Property Sensor Based on Tuning-Fork Technology

Fluid property sensor (FPS) based on tuning-fork technology is applied to the measurement of the contaminant level of lubricant oil. The measuring principle of FPS sensor is derived and proved together with its resolution. The performance characteristics of the FPS sensor, such as sensitivity coefficient, resolution, and quality factor, are analyzed. A temperature compensation method is proposed to eliminate the temperature-dependence of the measuring parameters, and its validity is investigated by numerical simulation of sensitivity, oscillating frequency, and dielectric constant. The values of purification efficiency obtained using microwave and without microwave are compared experimentally

Efficient photocatalytic hydrogen peroxide production over TiO2 passivated by SnO2

Photocatalysis provides an attractive strategy for synthesizing H2O2 at ambient condition. However, the photocatalytic synthesis of H2O2 is still limited due to the inefficiency of photocatalysts and decomposition of H2O2 during formation. Here, we report SnO2-TiO2 heterojunction photocatalysts for synthesizing H2O2 directly in aqueous solution. The SnO2 passivation suppresses the complexation and decomposition of H2O2 on TiO2. In addition, loading of Au cocatalyst on SnO2-TiO2 heterojunction further improves the production of H2O2. The in situ electron spin resonance study revealed that the formation of H2O2 is a stepwise single electron oxygen reduction reaction (ORR) for Au and SnO2 modified TiO2 photocatalysts. We demonstrate that it is feasible to enhance H2O2 formation and suppress H2O2 decomposition by surface passivation of the H2O2-decomposition-sensitive photocatalysts

Free cadmium ions released from CdTe-based nanoparticles and their cytotoxicity on Phaeodactylum tricornutum

The risk of nanoparticles (NPs) to organisms and the environment has become more noticeable alongside their rapid applications in many fields. The release of Cd2+ from CdTe-based NPs (CdTe-NPs), an important class of engineered nanomaterials, is one of the possible factors responsible for the cytotoxicity of these NPs. Based on the same CdTe core, CdTe/CdS, CdTe/ZnS and CdTe/SiO2 NPs were synthesized and their Cd2+ release rates were carefully studied based on dialysis using inductively coupled plasma mass spectrometry (ICPMS). Results obtained indicated that the Cd2+ release rates of the CdTe-NPs decreased in the order CdTe (8.78 ng mL(-1) mg(-1) h(-1)) > CdTe/CdS (2.63) > CdTe/SiO2 (0.89) > CdTe/ZnS (0.72). Phaeodactylum tricornutum was used as a model diatom for evaluating the cytotoxicity of the CdTe-NPs. Results obtained from the CdTe-NPs exposure experiments together with ICPMS and fluorescence microscopy studies suggested that the cytotoxicity of the CdTe-NPs increased along with the increase in their Cd2+ release rates. Effective coating materials such as ZnS and SiO2 for the CdTe core significantly reduced the cytotoxicity of CdTe.National Natural Science Foundation of China [20775062]; National Basic Research Program of China [2009CB421605

Self-Cleaning Glass of Photocatalytic Anatase TiO2@Carbon Nanotubes Thin Film by Polymer-Assisted Approach

Due to the good photocatalytic activity, the TiO2@CNTs thin film is highly desirable to apply to the self-cleaning glass for green intelligent building. Here, the TiO2@CNTs thin film has been successfully achieved by polymer-assisted approach of an aqueous chemical solution method. The polymer, polyethylenimine, aims to combine the Ti4+ with CNTs for film formation of TiO2@CNTs. The resultant thin film was uniform, highly transparent, and super-hydrophilic. Owing to fast electron transport and effectively hindering electron-hole recombination, the TiO2@CNTs thin film has nearly twofold photocatalytic performance than pure TiO2. The TiO2@CNTs thin films show a good application for self-cleaning glasses

A High Sensitive Flexible Pressure Sensor Designed by Silver Nanowires Embedded in Polyimide (AgNW-PI)

Silver nanowires (AgNW) have excellent electrical conductivity, transparency, and flexing endurance, and are broadly used in flexible electrodes and flexible sensors. This study mixed the silver nanowires and polyimide (PI) polymer using an in situ synthesis method, effectively reducing the problem of silver nanowires falling off the substrate. The selective wet etching method was firstly used to process the surface of AgNW-PI films, greatly enhancing the surface conductivity of AgNW-PI films. A flexible pressure sensor with high sensitivity was designed with two face-to-face AgNW-PI ultrathin layers. The experimental results show that our sensor presented a high sensitivity of about 1.3294 kPa−1 under a pressure of about 600 Pa, and when pressure continued to increase, the sensitivity decreased rapidly and reached saturation. Our flexible pressure sensor has the properties of low cost, high sensitivity, excellent repeatability, durability, and can detect various types of mechanical forces which could be utilized for flexible electronics

Prediction of bioluminescent proteins by using sequence-derived features and lineage-specific scheme

Abstract Background Bioluminescent proteins (BLPs) widely exist in many living organisms. As BLPs are featured by the capability of emitting lights, they can be served as biomarkers and easily detected in biomedical research, such as gene expression analysis and signal transduction pathways. Therefore, accurate identification of BLPs is important for disease diagnosis and biomedical engineering. In this paper, we propose a novel accurate sequence-based method named PredBLP (Prediction of BioLuminescent Proteins) to predict BLPs. Results We collect a series of sequence-derived features, which have been proved to be involved in the structure and function of BLPs. These features include amino acid composition, dipeptide composition, sequence motifs and physicochemical properties. We further prove that the combination of four types of features outperforms any other combinations or individual features. To remove potential irrelevant or redundant features, we also introduce Fisher Markov Selector together with Sequential Backward Selection strategy to select the optimal feature subsets. Additionally, we design a lineage-specific scheme, which is proved to be more effective than traditional universal approaches. Conclusion Experiment on benchmark datasets proves the robustness of PredBLP. We demonstrate that lineage-specific models significantly outperform universal ones. We also test the generalization capability of PredBLP based on independent testing datasets as well as newly deposited BLPs in UniProt. PredBLP is proved to be able to exceed many state-of-art methods. A web server named PredBLP, which implements the proposed method, is free available for academic use