Influence of magnetic layer thickness on[Fe_(80)Ni_(20) O/SiO_2]_n multilayer thin films

In the present work, a series of [Fe80Ni20–O/SiO2]n multilayer thin films is fabricated using a reactive magnetron sputtering equipment. The thickness of SiO2 interlayer is fixed at 3 nm, while the thickness values of Fe80Ni20–O magnetic films range from 10 nm to 30 nm. All films present obvious in-plane uniaxial magnetic anisotropy. With increasing the Fe80Ni20–O layer thickness, the saturation magnetization increases slightly and the coercivity becomes larger due to the enlarged grain size, which could weaken the soft magnetic property. The results of high frequency magnetic permeability characterization show that films with thin magnetic layer are more suitable for practical applications. When the thickness of Fe80Ni20–O layer is 10 nm, the multilayer film exhibits the most comprehensive high-frequency magnetic property with a real permeability of 300 in gigahertz range.     

Screening possible solid electrolytes by calculating the conduction pathways using Bond Valence method

Inorganic solid electrolytes have distinguished advantages in terms of safety and stability, and are promising to substitute for conventional organic liquid electrolytes. However, low ionic conductivity of typical candidates is the key problem. As connective diffusion path is the prerequisite for high performance, we screen for possible solid electrolytes from the 2004 International Centre for Diffraction Data (ICDD) database by calculating conduction pathways using Bond Valence (BV) method. There are 109846 inorganic crystals in the 2004 ICDD database, and 5295 of them contain lithium. Except for those with toxic, radioactive, rare, or variable valence elements, 1380 materials are candidates for solid electrolytes. The rationality of the BV method is approved by comparing the existing solid electrolytes’ conduction pathways we had calculated with those from experiments or first principle calculations. The implication for doping and substitution, two important ways to improve the conductivity, is also discussed. Among them Li₂CO₃ is selected for a detailed comparison, and the pathway is reproduced well with that based on the density functional studies. To reveal the correlation between connectivity of pathways and conductivity, α/γ-LiAlO₂ and Li₂CO₃ are investigated by the impedance spectrum as an example, and many experimental and theoretical studies are in process to indicate the relationship between property and structure. The BV method can calculate one material within a few minutes, providing an efficient way to lock onto targets from abundant data, and to investigate the structure-property relationship systematically.     

Reflective photoluminescence fiber temperature probe based on the CdSe/ZnS quantum dot thin film

A reflective fiber temperature sensor based on the optical temperature dependent characteristics of a quantum dots (QDs) thin film is developed by depositing the CdSe/ZnS core/shell quantum dots on the SiO₂ glass substrates. As the temperature is changed from 30 to 200°C, the peak wavelengths of PL spectra from the sensing head increase linearly with the temperature, while the peak intensity and the full width at half maximum (FWHM) of PL spectra vary exponentially according to the specific physical law. Using the obtained temperature-dependent peak-wavelength shift, the average resolution of the designed fiber temperature sensor can reach 0.12 nm/°C, while it reaches 0.056 nm/°C according to the FWHM of PL spectrum.     

A real-time image matching algorithm for integrated navigation system

In this paper we introduced a kind of real-time image matching navigation algorithm based on ORB which can meet the requirement for high speed aircraft. We combined image matching with INS to fix the accumulative error of INS and get high accuracy position data of the aircraft. In order to improve the accuracy and robust of system, we used SIFT feature as a supplement of ORB and introduced the Kalman filter to optimize the output of image matching and INS. Based on maneuverability law, we did wrong point deleting with RANSAC. Finally, we designed a software system to simulate the image matching/INS navigation system. From the result of experiments, we can draw a conclusion that the algorithm has good real-time performance, play a good matching effect and get high accuracy position value.     

Enhanced photocatalytic activity of In2O3-decorated TiO2

Titania (TiO₂)-based photocatalysts decorated with different amounts of indium oxide (In₂O₃) were prepared by a pore impregnating method and characterized by the Brunauer–Emmett–Teller (BET) method, X-ray diffraction (XRD), UV–Vis diffuse reflectance spectroscopy (DRS), and X-ray photoelectron spectroscopy (XPS). The separation efficiency of photogenerated charges was investigated using benzoquinone (BQ) as scavenger. The activities of the photocatalysts were evaluated by decolorization of methyl orange (MO) aqueous solution under ultraviolet-light irradiation. Compared to TiO₂, In₂O₃/TiO₂ composites show improved photocatalytic performance due to the coupling effect of TiO₂ and In₂O₃, which greatly improves the separation of photogenerated electrons and holes.     

Fabrication of silver nanosheets on quartz glass substrates through electroless plating approach

Silver nanosheets (NSs) have been synthesized by an electroless plating approach using a complexation mechanism of triethanolamine (TEA) and Ag⁺ to reduce the oxidation–reduction potential difference and slow down the deposition speed of Ag on quartz glass substrates. The synthesized Ag NSs with 500 nm in edge length and 30 nm in thickness stand on the substrates and are dispersed uniformly. The formation mechanism of Ag NSs is proposed. The formation of Ag NSs is attributed to the molar ratio of AgNO₃ to TEA, the concentration of AgNO₃ and the influence of reaction temperature. This study is important in vertical immobilization Ag NSs on solid substrates, which could provide substrates for catalysis or surface-enhanced Raman scattering.     

基于深度强化学习的卫星动态功率控制技术

随着用户数量和数据业务的显著增长,卫星通信系统需要更高的吞吐量和更大的容量.在有限的无线资源条件下,高通量卫星如何通过智能化技术手段灵活高效地动态分配无线资源,成为当前卫星通信领域亟待解决的难题.在灵活载荷的框架下,传统的启发式方法存在计算复杂度高的问题,难以满足未来高实时的卫星通信业务需求.为解决以上难题满足未来灵活...     

整体最小二乘法在精同步中的应用

为了验证整体最小二乘法(TLS,Total Least Squares)比最小二乘法(LS,Least Squares)更适用于精同步,提出了基于整体最小二乘的精同步方法;该方法以PN码基于BPSK调制的同步模型为基础,在接收端得到鉴相曲线后,对鉴相曲线零值点附近的几个固定位置的数据点利用QR分解和奇异值分解的整体最小二乘法拟合出鉴相曲线,求出同步误差;最后通过在Matlab软件上的仿真,得出结论:在噪声环境下,整体最小二乘法在同步中的应用可以得到优于基于普通最小二乘法的同步法的测量精度和稳定性;特别是在信噪比较低的条件下,基于整体最小二乘的精同步测量精度提升了3倍多,同事稳定性提升5倍多。     

基于可调谐半导体激光吸收光谱的酒精蒸汽检测方法

采用窄带半导体激光器开展了酒精蒸汽浓度检测方法研究.使用酒精分子在7180 cm-1附近的一个相对较窄的吸收峰作为酒精分子的鉴别信息.为消除水汽对酒精分子检测的干扰,提出了建立多元线性回归方程拟合求解多分子吸收共存的问题.实验表明,系统的检测限达到25 ppm·m.     

基于DNA损伤的蛋白调控网络研究

细胞生长的每个阶段都离不开蛋白质相互作用.研究细胞周期的功能、调控机理及参与调控的蛋白质之间的关系对生物工程等领域有重大的应用价值.本文通过研究电离辐射下生物体细胞的DNA损伤后,细胞内以p53为核心的扩展蛋白调控网络的功能、原理及其自修复机理,在现有蛋白网络基础上引入更多蛋白网络调控因子来建立蛋白调控网络,仿真模拟更为全面的细胞周期进程;并且从复杂网络图论和细胞周期调控两个方面分析扩展PMP调控网络的抗扰能力及自修复机理,结果表明:1)蛋白网络在对抗环境中出现的小扰动时具有较强的稳定性.但在面对蓄意攻击时网络的稳定性较差.2)受损的DNA能否被修复取决于p53蛋白的动力学行为,即低损伤与中损伤情况下,p53可诱导细胞周期进程阻滞来完成细胞的自修复;而当高损伤或过损伤时,p53蛋白浓度表现为周期振荡行为并诱导细胞凋亡.