As computing resources continue to improve, global solutions for larger size quadrically constrained optimization problems become more achievable. In this paper, we focus on larger size problems and get accurate bounds for optimal values of such problems with the successive use of SDP relaxations on a parallel computing system called Ninf (Network-based Information Library for high performance computing). 相似文献
Self‐organization plays an imperative role in recent materials science. Highly tunable, periodic structures based on dynamic self‐organization at micrometer scales have proven difficult to design, but are desired for the further development of micropatterning. In the present study, we report a microgroove array that spontaneously forms on a p‐type silicon surface during its electrodissolution. Our detailed experimental results suggest that the instability can be classified as Turing instability. The characteristic scale of the Turing‐type pattern is small compared to self‐organized patterns caused by the Turing instabilities reported so far. The mechanism for the miniaturization of self‐organized patterns is strongly related to the semiconducting property of silicon electrodes as well as the dynamics of their surface chemistry. 相似文献
The synthesis of highly nitrogen‐doped mesoporous carbon spheres (NMCS) is reported. The large pores of the NMCS were obtained through self‐polymerization of dopamine (DA) and spontaneous co‐assembly of diblock copolymer micelles. The resultant narrowly dispersed NMCS possess large mesopores (ca. 16 nm) and small particle sizes (ca. 200 nm). The large pores and small dimensions of the N‐heteroatom‐doped carbon spheres contribute to the mass transportation by reducing and smoothing the diffusion pathways, leading to high electrocatalytic activity. 相似文献
A straightforward strategy to prepare nanoporous metal oxides with well‐defined shapes is highly desirable. Through thermal treatment and a proper selection of metal‐cyanide coordination polymers, nanoporous nickel‐cobalt mixed oxides with different shapes (i.e., flakes and cubes) can be easily prepared. Our nanoporous materials demonstrate high electrocatalytic activity for oxygen evolution reaction. 相似文献
The solid‐phase combinatorial synthesis of cyclodepsipeptide destruxin E has been demonstrated. The combinatorial synthesis of cyclization precursors 8 was achieved by using a split and pool method on SynPhase Lanterns. The products were successfully macrolactonized in parallel in the solution phase by using 2‐methyl‐6‐nitrobenzoic anhydride and 4‐(dimethylamino)pyridine N‐oxide to afford macrolactones 9 , and the subsequent formation of an epoxide in the side chain gave 18 member destruxin E analogues 6 . Biological evaluation of analogues 6 indicated that the N‐MeAla residue was crucial to the induction of morphological changes in osteoclast‐like multinuclear cells (OCLs). Based on structure–activity relationships, azido‐containing analogues 15 were then designed for use as a molecular probe. The synthesis and biological evaluation of analogues 15 revealed that 15 b , in which the Ile residue was replaced with a Lys(N3) residue, induced morphological changes in OCLs at a sufficient concentration, and modification around the Ile residue would be tolerated for attachment of a chemical tag toward the target identification of destruxin E ( 1 ). 相似文献
The coordination polymerization of silyl‐protected ω‐alkenols such as ω‐alken‐α‐oxytriisopropylsilanes 1 provides poly(ω‐alkenyl‐α‐oxytriisopropylsilalne)s with a highly isospecific microstructure ([mmmm] > 95%) when a combination of [OSSO]‐type bis(phenolato) dichloro zirconium(IV) complex 2 and dried methylaluminoxane is used as the precatalyst and activator, respectively. The resulting siloxy‐substituted polymers could be efficiently transformed into the corresponding functionalized polyolefins, which contained up to 90% acetyl groups and ≈7% hydroxy groups in the terminal side chains.