电能表自动化检定压接端子温升监测系统

提出了一种基于双套管结构光纤光栅封装探头形式,研究了基于该封装探头形式下光纤光栅测量温度的同时屏蔽外力影响;在电能表压接触头上布置双套管结构光纤光栅测温探头,通过光缆及光学分路器将传感器连接,并通过主光缆接到控制室的光纤光栅解调仪上,再通过监控软件对信息进行处理,从而构建了电能表压接温度监测系统;研究表明该系统不仅满足强电磁场环境下对温度监测实时性和精确性的要求,还可以屏蔽外部应力对温度监测的影响;温度监控软件对实时的温度信息处理,可以实现温度的图形显示、列表显示,超温时的报警显示等功能。     

Research Progress of Laminated Composite Ceramic Cutting Tools

The design of the lamination structure based on bionic shell pearl layer is a successful method for toughening ceramics. Lamination with strong bonding interfaces is used to improve the mechanical property and low fracture toughness of ceramic cutting tools. Based on the idea of demand–design–preparation–analysis–failure, the development and research progress of laminated ceramic tools are reviewed herein. The research status of design, interlayer diffusion reaction, residual stress, toughening mechanism, and crack propagation path of the biomimetic laminated ceramic composite tool materials is mainly introduced. The major topics of current research include the creation of material systems, the evolution of microstructure, and the assessment of macroscopic mechanical properties. The entire mechanical properties of laminated ceramic tools are significantly influenced by the multicomposition design of the ceramic material system and the optimization design of structural parameters of layer number and layer thickness ratio. However, the research on the practical cutting application of laminated ceramic tools is limited. Cutting tool wear characteristics vary between laminated and homogeneous ceramic tools. The development of useful laminated ceramic cutting tools can greatly benefit from the study on failure mechanisms of laminated ceramic tools.     

Composition-Controllable Syntheses and Property Modulations from 2D Ferromagnetic Fe5Se8 to Metallic Fe3Se4 Nanosheets

Exploring new-type 2D magnetic materials with high magnetic transition temperature and robust air stability has attracted wide attention for developing innovative spintronic devices. Recently, intercalation of native metal atoms into the van der Waals gaps of 2D layered transition metal dichalcogenides (TMDs) has been developed to form 2D non-layered magnetic TMDs, while only succeeded in limited systems (e.g., Cr₂S₃, Cr₅Te₈). Herein, composition-controllable syntheses of 2D non-layered iron selenide nanosheets (25% Fe-intercalated triclinic Fe₅Se₈ and 50% Fe-intercalated monoclinic Fe₃Se₄) are firstly reported, via a robust chemical vapor deposition strategy. Specifically, the 2D Fe₅Se₈ exhibits intrinsic room-temperature ferromagnetic property, which is explained by the change of electron spin states from layered 1T'-FeSe₂ to non-layered Fe-intercalated Fe₅Se₈ based on density functional theory calculations. In contrast, the ultrathin Fe₃Se₄ presents novel metallic features comparable with that of metallic TMDs. This work hereby sheds light on the composition-controllable synthesis and fundamental property exploration of 2D self-intercalation induced novel TMDs compounds, by propelling their application explorations in nanoelectronics and spintronics-related fields.     

Dimerization/docking domain of the type Ialpha regulatory subunit of cAMP-dependent protein kinase. Requirements for dimerization and docking are distinct but overlapping

Based on increasing evidence that the type I R subunits as well as the type II R subunits localize to specific subcellular sites, we have carried out an extensive characterization of the stable dimerization domain at the N terminus of RIalpha. Deletion mutants as well as alanine scanning mutagenesis were used to delineate critical regions as well as particular amino acids that are required for homodimerization. A set of nested deletion mutants defined a minimum core required for dimerization. Two single site mutations on the C37H template, RIalpha(F47A) and RIalpha(F52A), were sufficient to abolish dimerization. In addition to serving as a dimerization motif, this domain also serves as a docking surface for binding to dual specificity anchoring proteins (D-AKAPs) (Huang, L. J., Durick, K., Weiner, J. A., Chun, J., and Taylor, S. S. (1997) J. Biol. Chem. 272, 8057-8064; Huang, L. J., Durick, K., Weiner, J. A., Chun, J., and Taylor, S. S. (1997) Proc. Natl. Acad. Sci. U. S. A. 94, 11184-11189). A similar strategy was used to map the sequence requirements for anchoring of RIalpha to D-AKAP1. Although dimerization appears to be essential for anchoring to D-AKAP1, anchoring can also be abolished by the following single site mutations: C37H, V20A, and I25A. These sites define "hot spots" for the anchoring surface since each of these dimeric proteins are deficient in binding to D-AKAP1. In contrast to earlier predictions, the alignment of the dimerization/docking domains of RIalpha and RII show striking similarities yet subtle differences not only in their secondary structure (Newlon, M. G., Roy, M., Hausken, Z. E., Scott, J. D., and Jennings. P. A. (1997) J. Biol. Chem. 272, 23637-23644) but also in the distribution of residues important for both docking and dimerization functions.     

Symbolic Intersect Detection: A Method for Improving Spatial Intersect Joins

Due to the increasing popularity of spatial databases, researchers have focused their efforts on improving the query processing performance of the most expensive spatial database operation: the spatial join. While most previous work focused on optimizing the filter step, it has been discovered recently that, for typical GIS data sets, the refinement step of spatial join processing actually requires a longer processing time than the filter step. Furthermore, two-thirds of the time in processing the refinement step is devoted to the computation of polygon intersections. To address this issue, we therefore introduce a novel approach to spatial join optimization that drastically reduces the time of the refinement step. We propose a new approach called Symbolic Intersect Detection (SID) for early detection of true hits. Our SID optimization eliminates most of the expensive polygon intersect computations required by a spatial join by exploiting the symbolic topological relationships between the two candidate polygons and their overlapping minimum bounding rectangle. One important feature of our SID optimization is that it is complementary to the state-of-the-art methods in spatial join processing and therefore can be utilized by these techniques to further optimize their performance. In this paper, we also develop an analytical cost model that characterizes SIDs effectiveness under various conditions. Based on real map data, we furthermore conduct an experimental evaluation comparing the performance of the spatial joins with SID against the state-of-the-art approach. Our experimental results show that SID can effectively identify more than 80% of the true hits with negligible overhead. Consequently, with SID, the time needed for resolving polygon intersect in the refinement step is improved by over 50% over known techniques, as predicted by our analytical model.     

影响结晶化玻璃板材质量因素的分析

研究了烧结法生产结晶化玻璃装饰板材中的气孔、翘板及炸裂产生的原因以及解决的方法。     

卷积积分和拉普拉斯变换在一阶电路中的应用

电路的任意激励的零状态响应,可以用卷积积分和拉普拉斯交换的方法求解。本文通过两个一阶电路的实例,阐述了两种方法的应用特点。     

Polarization-Dependent Periodic Pulse Oscillation in a Diode-Laser-Pumped and Intracavity Frequency-Doubled Nd:YVO 4 Laser

We demonstrate that two cross-polarized longitudinal modes can have 50% higher conversion efficiency than two parallel-polarized longitudinal modes in a diode-laser-pumped and intracavity frequency-doubled Nd:YVO(4) laser when operated under periodic pulse oscillation. Through simulations of the rate equations for primary frequency intensities and gains, we also verify that this effect can be attributed to gain competition and complementary conversion coefficient between second-harmonic and sum-frequency generations.     

Noninvasive glucose monitoring in vivo with an optical heterodyne polarimeter

An amplitude-sensitive optical heterodyne polarimeter was set up to monitor noninvasively the aqueous glucose concentration in a rabbit's eye. A Zeeman laser in conjunction with a Glan-Thompson analyzer was used to generate an optical heterodyne signal. The amplitude of the heterodyne signal linearly related to the optical rotation angle of the aqueous glucose. The concentration of the aqueous glucose in a rabbit's eyeball was measured in vivo. There was a 30-min time delay between observations of aqueous glucose and blood glucose. The detection capability and the reproducibility of the experiment are demonstrated and discussed.     

Graphic analysis of the effective reflectivity of antireflection-coated films on diode facets

The wavelength dependence of the reflectivity of AR-coated facets and carrier density in relation to peak wavelength of the gain profile have been taken into consideration to study a one-facet AR-coated semiconductor diode laser. A graphic analysis method is developed to study cases in which analytical expressions of the reflectivity curves cannot be extracted. Results show that the upper bound of the carrier density that can be established inside the diode is generally (sometimes to a considerable degree) smaller than that determined by the claimed minimum reflectivity if the spectral width of the reflectivity curve cannot be regarded as infinite. This implies that the effective reflectivity of the AR-coated facet is generally larger than the claimed minimum reflectivity. To increase the effectiveness of AR film, it is essential to maintain tight control of the wavelength at which the reflectivity curve is minimum.