Water Adsorption at the Tetrahedral Titania Surface Layer of SrTiO3_3(110)-(4×\times1)

The interaction of water with oxide surfaces is of great interest for both fundamental science and applications. We present a combined theoretical [density functional theory (DFT)] and experimental [Scanning Tunneling Microscopy (STM), photoemission spectroscopy (PES)] study of water interaction with the two-dimensional titania overlayer that terminates the SrTiO$_3$(110)-(4$\times$1) surface and consists of TiO$_4$ tetrahedra. STM, core-level and valence band PES show that H$_2$O neither adsorbs nor dissociates on the stoichiometric surface at room temperature, while it dissociates at oxygen vacancies. This is in agreement with DFT calculations, which show that the energy barriers for water dissociation on the stoichiometric and reduced surfaces are 1.7 and 0.9 eV, respectively. We propose that water weakly adsorbs on two-dimensional, tetrahedrally coordinated overlayers

Parameter Optimization of Pure Electric Vehicle Power System Based on Genetic Algorithm

In this paper, the ADVISOR software was used to establish a complete vehicle model of an electric vehicle, and the model was verified by CYC_NEDC under European urban conditions to meet the requirements. The maximum power of the driving motor, the speed ratio of the transmission system and the capacity of the storage battery are taken as the optimization objectives to carry out multi-objective optimization. Connect the model built by genetic algorithm and ADVISOR, run the program to simulate the two together, and get the result of parameter optimization of dynamic system. Through the simulation analysis and comparison under CYC_NEDC cycle conditions, the maximum speed, maximum climb slope, acceleration time and other dynamic performance parameters of this electric vehicle are effectively improved after optimization

Quasi-phase-matching with Spontaneous Domain Inversion in an Integrated Lithium Niobate Micro-racetrack Resonator

Quasi-phase-matching (QPM) technology is the most popular and significant method to achieve efficient nonlinear frequency conversion. The realization of periodically poling to achieve QPM in photonic integrated circuits (PICs) is a challenging issue for the requirement of CMOS compatible and large-scale fabrication. Here we realize a spontaneous periodical domain inversion without poling but by dispersion engineering and designing the orientation of the crystal due to the circular propagation of light waves in an integrated lithium niobate micro-racetrack resonator (MRR). The QPM second harmonic generation (SHG) with a normalized conversion efficiency of 2.25$\%$/W (169th-order QPM) has been achieved in the high-quality factor resonator of $\sim 10^{8}$ with the straight waveguide (TE$_{00}$ mode) of ultra-low propagation loss of 0.0022dB/cm. The efficiency can be further enhanced by using a first-order QPM, and the bandwidth can be made broader by employing a shorter interaction length for photonics and quantum optics. The configurable spontaneous quasi-phase-matching lithium niobate MRR on X-cut thin-film lithium niobate on insulator (LNOI) provides a significant on-chip integrated platform for other optical parametric processes

Novel Graphene Biosensor Based on the Functionalization of Multifunctional Nano-BSA for the Highly Sensitive Detection of Cancer Biomarker

Abstract A simple, convenient, and highly sensitive bio-interface for graphene field-effect transistors (GFETs) based on multifunctional nano-denatured bovine serum albumin (nano-dBSA) functionalization was developed to target cancer biomarkers. The novel graphene–protein bioelectronic interface was constructed by heating to denature native BSA on the graphene substrate surface. The formed nano-dBSA film served as the cross-linker to immobilize monoclonal antibody against carcinoembryonic antigen (anti-CEA mAb) on the graphene channel activated by EDC and Sulfo-NHS. The nano-dBSA film worked as a self-protecting layer of graphene to prevent surface contamination by lithographic processing. The improved GFET biosensor exhibited good specificity and high sensitivity toward the target at an ultralow concentration of 337.58 fg mL−1. The electrical detection of the binding of CEA followed the Hill model for ligand–receptor interaction, indicating the negative binding cooperativity between CEA and anti-CEA mAb with a dissociation constant of 6.82 × 10−10 M. The multifunctional nano-dBSA functionalization can confer a new function to graphene-like 2D nanomaterials and provide a promising bio-functionalization method for clinical application in biosensing, nanomedicine, and drug delivery