In this paper, in situ Al4C3 and carbon nanotubes (CNTs) hybrid-reinforced aluminum matrix composites were prepared by a two-step ball milling (TSBM), consisting of a 24-h long-time ball milling (LTBM) and a 6-h short-time ball milling (STBM). During LTBM, most of the CNTs were seriously damaged, and many amorphous carbon atoms derived from these damaged defects would react with Al powder to form in situ Al4C3 nanorods. Subsequently, 1 wt% CNTs were added into the composite powders for STBM to uniformly disperse CNTs into the composite powders. Compared with that of the composite prepared by one-step ball milling, the comprehensive mechanical properties of the composite prepared by the TSBM are improved obviously due to the synergistic effects of in situ Al4C3 and CNTs, and the tensile strength and elongation reached 258 MPa and 19.5%, respectively. The strengthening mechanisms of TSBM composite include fine-grained strengthening, dispersion strengthening by in situ Al4C3, and load transfer from matrix to CNTs.

In this paper we study general aggregation of stochastic arrangement increasing random variables, including both the generalized linear combination and the standard aggregation as special cases. In terms of monotonicity, supermodularity, and convexity of the kernel function, we develop several sufficient conditions for the increasing convex order on the generalized aggregations. Some applications in reliability and risks are also presented.

By using high purity aluminum powders and multi-walled carbon nanotubes (MWCNTs) as raw materials, MWCNTs/Al composites were fabricated with ball milling, followed by cold pressing, vacuum sintering, and hot extrusion. It was found that when the sintering temperature was 863 K, MWCNTs/Al composite sintered for 4 h showed good comprehensive properties, and its tensile strength and elongation reached to 156 MPa and 21%, respectively. The comprehensive mechanical properties of the composites became better with raising sintering temperature when the sintering time was 4 h. When the sintering temperature raised to 923 K, the tensile strength of the composite reached to 167 MPa which is three times more than that of annealed high purity aluminum, mainly due to the higher density and better interface bonding resulted from higher sintering temperature. CNTs' pulling out were observed obviously in the fractured surfaces, and load transfer may be the main strengthening mechanism.

We study the convergence of an Ulm-like Cayley transform method for solving inverse eigenvalue problems which avoids solving approximate Jacobian equations. Under the nonsingularity assumption of the relative generalized Jacobian matrices at the solution, a convergence analysis covering both the distinct and multiple eigenvalues cases is provided and the quadratical convergence is proved. Moreover, numerical experiments are given in the last section to illustrate our results.

X-ray powder diffraction data, unit-cell parameters, and space group for beta-methyl vinyl phosphate (MAP), C29H27N2O10P, are reported [a = 17.293(4) Å, b = 6.142(6) Å, c = 14.464(8) Å, α = γ = 90°, β = 112.048(0)°, unit-cell volume V = 1424.19 Å3, Z = 2, and space group P21]. All measured lines were indexed and are consistent with the P21 space group. No detectable impurity was observed.

This article reviews current progress in research in ferroelectric switching phenomena using in situ electron microscopy. We focus on state-of-the-art instrumentation, analytical methods, experimental procedures, and image contrast mechanisms. Particular emphasis is on ferroelectric domain and domain wall structures that determine ferroelectric behaviors. The applicability of in situ microscopy to studying a wide range of switching phenomena, such as domain nucleation, domain wall motion, and domain wall pinning by various types of defects, in ferroelectric thin films is demonstrated. The underlying physics of these dynamic processes is also discussed.

We prove a sharp upper bound on the L2 norm of a GL3 Maass form restricted to GL2×ℝ+.

This paper demonstrates light-induced tuning of optical spectrum from optical microfiber knot resonator overlaid with an azobenzene-doped nematic liquid crystal (azo-doped NLC). The high-quality fiber resonator is made by drawing the single mode fiber to the micro-size diameter and self-twisting the microfiber as a knot shape. During the UV light irradiation the azobenzene molecules perform trans-to-cis photoisomerization which disrupts the NLC orientation. The disrupted NLC changes the effective refractive index within the LC overlaid fiber area and shifts the optical spectrum of microfiber knot resonator. The 0.25 nm spectral shifting of resonance wavelength was observed under the irradiation of 50 mW UV light.

In this paper, we study the orthogonalities of Hecke eigenvalues of holomorphic cusp forms. An asymptotic large sieve with an unusually large main term for cusp forms is obtained. A family of special vectors formed by products of Kloosterman sums and Bessel functions is constructed for which the main term is exceptionally large. This surprising phenomenon reveals an interesting fact: that Fourier coefficients of cusp forms favor the direction of products of Kloosterman sums and Bessel functions of compatible type.

This work reports on a new morphology-inheriting methodology to MgO nanoplates. Precursor of Mg(OH)2 nanoplates was synthesized by a solvothermal method and showed a hexagonal shape. The morphological features of Mg(OH)2 nanoplates were retained to the resulting MgO nanoplates using a programmed heating process. MgO nanoplates showed highly hydroxylated surfaces. Upon excitation, the interactions between hydroxyl groups and surface O2−4c and O2−3c species gave rise to a dominant ultraviolet emission at 415 nm.

Numerical calculations are performed based on a set of equations that describe the non-steady, nonlinear interactions between a moving body in space and plasma. The results show that density cavitons and potential solitons are formed owing to modulational instability if the envelope of the high-frequency modulational field is sufficiently intense.