复杂环境下结合EMD的GPS-IR水位反演方法

利用法国布雷斯特(Brest)港BRST测站和英国塞文大桥监测系统GNSS双频观测数据,分别在静态和高动态环境下进行GPS-IR水位反演,探究传统GNSS监测系统进行水位反演的可行性与精度.结果表明:L1波段反演精度高于L2波段;在静态场景下,GPS-IR水位反演结果与验潮站数据相关系数大于0.98,在高动态场景下,桥梁GPS-IR水位反演精度稍低.利用经验模态分解(EMD)方法对算法进行改进,提高了在桥梁复杂环境下GPS-IR水位反演结果的精度,均方根误差(RMSE)相比经典方法降低约50%.本文方法提高了GPS-IR技术在不同水域环境下的适用性,在水位监测中具有很好的应用前景.     

基于支持向量机的航空发动机叶片超声检测

支持向量机(SVM)是一种具有出色学习性能的新型机器学习方法,它能够较好地克服神经网络容易出现的过学习、网络结构难以确定以及局部极小等缺点。研究了小波包变换提取发动机叶片缺陷特征向量的问题,提出一种基于支持向量机的航空发动机叶片超声检测方法。实验表明,基于小波包分解提取特征向量结合支持向量机的识别方法,能够有效地区分发动机叶片部件的几种典型缺陷。     

MgO/La2O3CO3复合材料对磷酸盐的吸附特征

采用水热法制备了MgO/La2 O2 CO3复合材料(ML).采用X射线衍射仪和扫描电子显微镜对其结构及表面形貌进行了表征,利用Zeta电位仪测定了其零点电位点,并探究了接触时间、初始磷酸盐浓度和初始pH对磷酸盐吸附效果的影响.结果 表明,ML呈现板块状堆叠而成的层状结构,零点电位点为4.52.准二级动力学模型和Fre...     

Mach—Zehnder干涉型光纤弱磁场传感器稳定性的研究

近年来,Mach—zehnder干涉型光纤弱磁场传感器的研究和应用获得了很大的发展,但是,外界环境因素的干扰始终影响着传感器的稳定性。本文选择直流相位跟踪法来保证传感器的稳定性,给出了理论阐述和具体电路。结果表明,该方法很好的消除了外界环境因素的干扰,保证了传感器的稳定性。     

Decreased Expression of Plakophilin-2 and αT-Catenin in Arrhythmogenic Right Ventricular Cardiomyopathy: Potential Markers for Diagnosis

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a hereditary disease of the heart muscle. Clinical challenges remain, however, in identifying patients with ARVC in the early or concealed stages with subtle clinical manifestations. Therefore, we wanted to identify potential targets by immunohistochemical (IHC) analysis in comparison with controls. Pathogenic mutations were identified in 11 of 37 autopsied patients with ARVC. As observed from IHC analysis of the RV, expression of αT-catenin and plakophilin-2 is significantly decreased in autopsied patients with ARVC as compared to controls, and the decreased expression is consistent in patients with and without pathogenic mutations. Furthermore, ARVC specimens demonstrated a reduced localization of αT-catenin, desmocollin-2, desmoglein-2, desmoplakin, and plakophilin-2 on intercalated discs. These findings have been validated by comparing RV specimens obtained via endomyocardial biopsy between patients with ARVC and those without. The pathogenic mutation was present in 3 of 5 clinical patients with ARVC. In HL-1 myocytes, siRNA was used to knockdown CTNNA3, and western blotting analysis demonstrated that the decline in αT-catenin expression was accompanied by a significant decline in the expression of plakophilin-2. The aforementioned effect was directed towards protein degradation rather than mRNA stability. Plakophilin-2 expression decreases concurrently with the decline in CTNNA3 expression. Therefore, the expression of αT-catenin and plakophilin-2 could be potential surrogates for the diagnosis of ARVC.     

Editable Supercapacitors with Customizable Stretchability Based on Mechanically Strengthened Ultralong MnO2 Nanowire Composite

Although some progress has been made on stretchable supercapacitors, traditional stretchable supercapacitors fabricated by predesigning structured electrodes for device assembling still lack the device‐level editability and programmability. To adapt to wearable electronics with arbitrary configurations, it is highly desirable to develop editable supercapacitors that can be directly transferred into desirable shapes and stretchability. In this work, editable supercapacitors for customizable shapes and stretchability using electrodes based on mechanically strengthened ultralong MnO₂ nanowire composites are developed. A supercapacitor edited with honeycomb‐like structure shows a specific capacitance of 227.2 mF cm^?2 and can be stretched up to 500% without degradation of electrochemical performance, which is superior to most of the state‐of‐the‐art stretchable supercapacitors. In addition, it maintains nearly 98% of the initial capacitance after 10 000 stretch‐and‐release cycles under 400% tensile strain. As a representative of concept for system integration, the editable supercapacitors are integrated with a strain sensor, and the system exhibits a stable sensing performance even under arm swing. Being highly stretchable, easily programmable, as well as connectable in series and parallel, an editable supercapacitor with customizable stretchability is promising to produce stylish energy storage devices to power various portable, stretchable, and wearable devices.     

Two-dimensional MX Dirac materials and quantum spin Hall insulators with tunable electronic and topological properties

We propose a novel class of two-dimensional(2D)Dirac materials in the MX family(M=Be,Mg,Zn and Cd,X=Cl,Br and I),which exhibit graphene-like band structures with linearly-dispersing Dirac-cone states over large energy scales(0.8–1.8 eV)and ultra-high Fermi velocities comparable to graphene.Spin-orbit coupling opens sizable topological band gaps so that these compounds can be effectively classified as quantum spin Hall insulators.The electronic and topological properties are found to be highly tunable and amenable to modulation via anion-layer substitution and vertical electric field.Electronic structures of several members of the family are shown to host a Van-Hove singularity(VHS)close to the energy of the Dirac node.The enhanced density-of-states associated with these VHSs could provide a mechanism for inducing topological superconductivity.The presence of sizable band gaps,ultra-high carrier mobilities,and small effective masses makes the MX family promising for electronics and spintronics applications.     

Biophotonic probes for bio-detection and imaging

The rapid development of biophotonics and biomedical sciences makes a high demand on photonic structures to be interfaced with biological systems that are capab...     

PCC在双转子连续混炼机控制系统中的应用

采用先进的PCC控制系统实现了对双转子连续混炼机的有效控制。介绍了该系统的整体方案,简述了该控制系统的特点,重点阐述了在设备运行中对混炼机、喂料机、单螺杆挤出机及切粒机等主要部件的连锁控制及对相关回路的PID控制。该系统具有友好的人机界面、操作简便、运行可靠等特点。