次Hermite矩阵的次相合与次对角化

提出了次相合的概念,讨论了次Hermite矩阵次相合的性质以及次Hermite矩阵偶在次相合变换下的次对角化,得到了次Hermite矩阵的次谱分解定理、次惯性定理及可实对角化矩阵的次Hermite矩阵的分解定理等一系列结果.

多层人工神经网络在自适应重合闸首合相及次合相判别中的应用

在自适应分相重合闸中引入人工神经网络（ANN），以便能快速、准确地进行故障类型判别及重合闸相序排定，从而解决因传统重合闸盲合于永久性故障，造成对系统的冲击而引发的一系列问题。结合数字仿真及网络训练，结果证明，这是完全可行的。

Microstructure-based analysis of fatigue behaviour of Al-Si-Mg alloy

The effects of microstructural characteristics on the fatigue behavior in Al-Si-Mg alloy were investigated. The dislocation substructures of Al-Si-Mg alloy were observed by transmission electron microscopy （TEM）. Dislocation evolution process of α（Al） matrix with [011] orientation of Al-Si-Mg alloy specimens was observed during fatigue process under different stress amplitudes and cycles. The results indicate that dislocation structure is closely dependent on stress amplitudes, and the density of dislocation in failure specimens increases with increasing stress amplitudes. The results show that Mg2Si and secondary silicon phase could have a strong hindrance effect on the movement of dislocations during the fatigue process. The fatigue behavior is strongly dependent on the microstructure of material.

Transformation mechanism of secondary phase and its effect on intergranular corrosion in laser wire filling welding Ni-based alloy/304 stainless steel

To clarify the transformation mechanism of secondary phase and the mechanism of intergranular corrosion in laser welding Ni-based alloy (Hastelloy C-276)/304 stainless steel with filler wire,the secondary phase was analyzed by electron probe micro-analysis (EPMA) and transmission electron microscopy (TEM).The evaluation of intergranular corrosion resistance of the welded joints was conducted by double-loop electrochemical potentiokinetic reactivation(DL-EPR) method,and at the same time the chemical compositions of the corrosion surface were analyzed by energy-dispersive spectrometry (EDS).The results show that p phase has complete coherence relationship withμphase,and the coherent relationship is described as[001]p//■and[430]p//[0001]μ.Theμphase is rapidly transformed from p phase,which is the inhomogeneous phase transformation.The transformation of secondary phase will increase the susceptibility to intergranular corrosion.Therefore,the transformation of secondary phase should be avoided in the welding process.

Influence of prolonged natural aging followed by artificial aging on tensile properties and compressive behavior of a thin-walled 6005 aluminum alloy tube

The effects of aging treatments on the tensile properties and compressive behavior of a thin-walled 6005 aluminum alloy tube were studied.Samples after three natural aging(NA)conditions were subsequently aged at 180℃ for 0.5−12.0 h artificial aging(AA).Tensile and compressive tests were performed after AA.The results show that for samples with the same NA,the longer the AA time is,the higher the strengths alloy owns,and at the same time the material shows a much lower elongation and faster process from plastic deformation to fracture.However,with NA prolonging,the alloy exhibits much better plastic deformation ability after AA,though its strength is decreased.The major cause of strength and plasticity variation induced by changing NA time is that the size of the main strengtheningβ''precipitates is larger and the density is lower.This character is evaluated by the strain hardening exponent n.Compressive results show that the optimum energy absorption characteristics can be acquired at a moderate n(14<n<17).Large n(n≥18)results in the fracture of tube during axial compression while low n(n≤13)causes lower energy absorption.

Incoherently Coupled Anti-dark Soliton Families in Cubic-quintic Nonlinear Media

A theory is presented to predict that a novel type of incoherently coupled spatial soliton families, named anti-dark soliton families, can exist in cubic-quintie nonlinear media. The intensity profiles, associated phase distribution and propagation properties are discussed in detail.

Charicteristic of a novel optoelectronic polymer and related device fabrication

In this paper a preliminary investigation of a novel optoelectronic polymer, poly (p-phenylene N-4-n-butylphenyl-N,N-bis- 4-vinylenephenylamine) (PNB), is reported. A single layer structure of ITO/PNB/Al was prepared via spin-coating of PNB solution as a thin film on the top of an ITO substrate, while aluminum top electrode was vacuum evaporated. Dark current- voltage characteristics of this device showed a typical rectifying behaviour. Photovoltaic response under a monochromatic illumination at 420 nm was observed, with an open circuit voltage of 0.3 V and fill factor of 0.21. Spectral response and optical absorption were found to be matched well. It was also discovered that the device showed a green electroluminescent emission at a forward bias. Turn-on voltage of the device was about 6 V and light output about 22.6 nW at a forward bias of 10 V. The work demonstrated that the PNB material might possess dual exciton sites resulting in a competition for excitons to be either separated or recombined. Both effects were associated with each other, which limited the photovoltaic or electroluminescence to some degrees.

女孩魅力自测

1、你的分发类型: A.中间分开B.向一边分开C.没有缝 2、你的“声音”最接近于下列哪一种? A.嗓门大而响亮的声音B.温和而低沉的声音C.普通 3、你看到同性朋友的照片时,心里有何感想? A.令人感到讨厌B.一般,可以凑合C.这张照片照得不错 4、与人说话时,你眼睛盯住对方何处?

Controllable synthesis and spontaneous phase transition of photonic coordination polymer to produce a strong second-harmonic generation response

Herein,a novel photonic coordination polymer material was constructed by aggregation-induced emission luminogen(AIEgen)containing a tripyridyl moiety used as the linking ligand.It displayed a spontaneous direct centrosymmetric to noncentrosymmetric phase transition in a single crystal.The two crystals,before and after the phase transition,were both controllably synthesized and characterized by single-crystal X-ray diffraction.After being exposed to air,the centrosymmetric metastable phase(1-α)transitioned to a new stable phase with a noncentrosymmetric structure(1-β).Interestingly,the 1-βstructure exhibited a strong phasematching second-harmonic generation(SHG)response,about4.5 times higher than that of KH2PO4(KDP).In order to better understand the relationship between the structure and the nonlinear optical properties,the dipole moments were calculated and discussed.Remarkably,the noncentrosymmetric phase with high thermal stability for 1-βretained and improved the initial photoluminescent properties of the AIEgen ligand after the structural phase transition from 1-α,and simultaneously produced the excellent SHG property,which are beneficial for the design and construction of excellent optical materials.