Fully Piecewise Linear Vector Optimization Problems

Journal of Optimization Theory and Applications - We distinguish two kinds of piecewise linear functions and provide an interesting representation for a piecewise linear function between two normed...     

Electro-assisted Molecular Assembly Giving Atomic-Scale Catalytic Active-Site Detection

The artificially accurate design of nonmetal electrocatalysts’ active site has been a huge challenge because no pure active species with the specific structure could be strictly controlled by traditional synthetic methods. Species with a multiconfiguration in the catalyst hinder identification of the active site and the subsequent comprehension of the reaction mechanism. We have developed a novel electro-assisted molecular assembly strategy to obtain a pure pentagon ring on perfect graphene avoiding other reconstructed structures. More importantly, the active atom was confirmed by the subtle passivation process as the topmost carbon atom. Recognition of the carbon-defect electrocatalysis reaction mechanism was first downsized to the single-atom scale from the experimental perspective. It is expected that this innovative electro-assisted molecular assembly strategy could be extensively applied in the active structure-controlled synthesis of nonmetal electrocatalysts and verification of the exact active atom.     

Well-posedness and generalized metric subregularity with respect to an admissible function

Science China Mathematics - In the framework of complete metric spaces, this paper provides several sufficient conditions for the well-posedness with respect to an admissible function, which...     

Effect of Dy-Co on physical and magnetic properties of X-type hexaferrites (Ba2−xDyxCu2Fe28−yCoyO46)

Sol–gel method is used to make a sequence of Barium based “X-type hexagonal ferrite (X-HF)” Ba_2−xDy_xCu₂Fe_28 −yCo_yO₄₆. “X-type hexagonal ferrites” with concentrations of “x = 0.0, 0.02, 0.06, 0.1 and y = 0.0, 0.1, 0.3, 0.5” are taken and the substitution impact of trivalent Dy³⁺ and divalent Co²⁺ is observed on the physical and magnetic properties of X-HFs. The XRD result, the refinement of which is accomplished using CelRef software validates the existence of pure single phase in these ferrites. Morphological structure of the crystal grains is calculated using electron microscopy and it is found that the grain has varying size in the range of 0.75–1.001 mm. FTIR analysis is done with and without the sintering process to examine the changes relevant to the structure and the chemistry of the material and the phases existed in the material. Thermogravimetric analyzer is used to measure the TGA and DSC quantities. All FTIR, DSC, and TGA results show that they are in good harmony with the results outcomes from XRD. “Vibrating sample magnetometer (VSM)” is used to quantify the magnetic properties of the sample under observation. It is observed that with an increase in the concentration of Dy-Co, M_r (Remanence) value decreases this could be reasoned by spin canting effect. The value of coercivity (H_c) changes from 317 to 158 G which follows the inverse relation between grain size and coercivity. The future use of the material may be in the microwave absorption devices.     

Control the self-assembly of fluorenone-based polycatenars by tuning chain length

Using Suzuki coupling reactions as key steps, a series of fluorenone-based polycatenars, consisting of a central 2,7-diphenyl-9-fluorenone core connected with the 3,4,5-trialkoxybenzoate unit via –COO- linkage at each side have been synthesized. Upon elongation of the terminal alkyl chain, these compounds self-assembled into mesophase sequence of Col_hex/p6mm - Cub_I/$\mathit{Pm}\overline{3}n$ in solid states as well as organogels with interesting morphologies varied from 3D helical fibers to spherical structures in solvents.     

Inclined periodic homoclinic breather and rogue waves for the (1+1)-dimensional Boussinesq equation

A new method, homoclinic (heteroclinic) breather limit method (HBLM), for seeking rogue wave solution to nonlinear evolution equation (NEE) is proposed. (1+1)-dimensional Boussinesq equation is used as an example to illustrate the effectiveness of the suggested method. Rational homoclinic wave solution, a new family of two-wave solution, is obtained by inclined periodic homoclinic breather wave solution and is just a rogue wave solution. This result shows that rogue wave originates by the extreme behaviour of homoclinic breather wave in (1+1)-dimensional nonlinear wave fields.     

A superconvergent universality induced by non-associativity

The star products in symbolic dynamics, as effective algebraic operations for describing self-similar bifurcation structure in classical dynamical systems, are found to have either associativity or non-associativity. In this Letter, non-associative star products in trimodal iterative dynamical systems are considered. As the left and right operations have different effects, right-associative star products break the conventional Feigenbaum's metric universality. Through high precision parallel computation, it is found that period-p-tupling bifurcation processes described by right-associative star products exhibit a superconvergent universality of double exponential form.     

Antimicrobial and antioxidant activities of a new benzamide from endophytic Streptomyces sp. YIM 67086

A new benzamide (1) and four known compounds (2–5) were isolated from endophytic Streptomyces YIM67086, and their structures were determined as 2-amino-3,4-dihydroxy-5-methoxybenzamide (1), 4-hydroxy-3-methoxybenzoic acid (2), phenylacetic acid (3), N-acetyltyramine (4) and p-hydroxytruxinic acid (5). Compound 5 was first found in the microorganism. The antimicrobial activities of compounds 1–5 and antioxidant activity of compound 1 were investigated.     

A new natural nucleotide and other antibacterial metabolites from an endophytic Nocardia sp.

Nine compounds were isolated from Nocardia sp. YIM 64630, and their structures were elucidated as 5′-O-acetyl-2′-deoxyuridine (1), 22E,24R-5α,6α-epoxyergosta-8(14),22-diene-3β,7α-diol (2), 22E,24R-5α,6α-epoxyergosta-8,22-diene-3β,7α-diol (3), 22E,24R-ergosta-7,22-diene-3β,5α,6β-triol (4), 5α,8α-epidioxyergosta-6,22-dien-3β-ol (5), 4′,5,6-trihydroxy-7-methoxyisoflavone (6), 2,4,4′-trihydroxy-deoxybenzoin (7), methyl [4-hydroxyphenyl]acetate (8) and daidzein by extensive spectroscopic analyses. Compound 1 was isolated from natural resources for the first time. The antimicrobial and antioxidant activities of compounds 1–8 were investigated.