Large-scale preparation of thin strain-relaxed SiGe is achieved by combining ion implantation and ultrahigh vacuum chemical vapor deposition. The resulting materials were analyzed by double crystal X-ray diffraction, micro-Raman spectroscopy, and tapping mode atomic force microscope. Results revealed that 100-nm-thick Si0.7Ge0.3 layers with the diameter of 125 mm and full strain relaxation are successfully prepared by pre-modifying the Si substrates using 50 keV Ar+ ions. The strain relaxation is also disclosed to change with both ion species and energy. However, post-modification of SiGe by ion implantation will cause serious damage to the crystal structures, and result in the formation of poly-crystal SiGe. 相似文献
In this paper we investigate the
probabilistic linear $(n,\delta)$-widths and $p$-average linear
$n$-widths of the Sobolev space $W^r_2$ equipped with the Gaussian
measure $\mu$ in the $L_{\infty}$-norm, and determine the
asymptotic equalities
\begin{eqnarray*}
\lambda_{n,\delta}(W^r_2,\mu,L_{\infty})
&\asymp&\frac{\sqrt{\ln
(n/\delta)}}{n^{r+(s-1)/2}},\\[3pt]
\lambda^{(a)}_n(W^r_2,\mu,L_{\infty})_p &\asymp&\frac{\sqrt{\ln
n}}{n^{r+(s-1)/2}}, \qquad 0 < p < \infty.
\end{eqnarray*} 相似文献
The radio-voltaic effect is investigated to be applied radioisotopic batteries in this work. The collection rates of the electron-hole pairs are 94 percent for the alpha particles emitted by239Pu source and 65 percent for the beta particles emitted by90Sr-90Y source. The maximum energy conversion efficiency got by the silicon element is about 16%. A prototype radioisotopic battery with147Pm beta sources is constructed. Its maximum short-circuit current and off voltage are about 2 A and 190 mV respectively. The experimental data suggest that the life of the prototype battery may be more than three years. 相似文献
Graft chitosan derivatives (CMCTS‐g‐MAAS and CMCTS‐g‐AAS) were prepared by the graft copolymerization of methacrylic acid sodium (MAAS) and acrylic acid sodium (AAS) onto the etherification product of chitosan‐carboxymethyl chitosan (CMCTS). Their antioxidant activity was estimated as superoxide anion scavengers by chemiluminescence techniques. The derivatives with low grafting percentages have a relatively low 50% inhibition concentration (IC50), which could be related to the fact that they have different contents of hydroxyl and amino groups in the polymer chains.
Superoxide radical scavenging activity of CMCTS‐g‐MAAS. 相似文献
This paper is concerned with the global well-posedness of strong and classical solutions for the 3D nonhomogeneous incompressible micropolar equations with vacuum. We prove that the problem (1.1)–(1.5) has a unique global strong/classical solution \((\rho,u,w)\), provided \(\mu_{1}\) is sufficiently large, or \(\|\rho_{0}\|_{L^{\infty}}\) or \(\|\rho_{0}^{1/2}u_{0}\| ^{2}_{L^{2}}+\|\rho_{0}^{1/2}w_{0}\|^{2}_{L^{2}}\) is small enough.
We demonstrate a diode-pumped electro-optical Q-switched slab laser with a high optical efficiency, high pulse energy, and short pulse width with two Nd:YLF crystals inside one resonator. The single compact slab resonator can generate a 1D top-hat beam at both the far field and the near field. With a slab-geometry-design lithium triborate (LBO) crystal, efficient critical phase-matching second-harmonic generation for a 1D top-hat beam with multiple transverse modes is achieved. 相似文献
Heterostructured nanomaterials, generally have physicochemical properties that differ from those of the individual components, and thus have potential in a wide range of applications. New platinum (Pt)/nickel bicarbonate (Ni(HCO3)2) heterostructures are designed for an efficient alkaline hydrogen evolution reaction (HER). Notably, the specific and mass activity of Pt in Pt/Ni(HCO3)2 are substantially improved compared to the bare Pt nanoparticles (NPs). The Ni(HCO3)2 provides abundant water adsorption/dissociation sites and modulate the electronic structure of Pt, which determine the elementary reaction kinetics of alkaline HER. The Ni(HCO3)2 nanoplates offer a platform for the uniform dispersion of Pt NPs, ensuring the maximum exposure of active sites. The results demonstrate that, Ni(HCO3)2 is an effective catalyst promoter for alkaline HER. 相似文献