Diffraction of evanescent waves and nanomechanical displacement detection

Sensitive displacement detection has emerged as a significant technological challenge in mechanical resonators with nanometer-scale dimensions. A novel nanomechanical displacement detection scheme based upon the scattering of focused evanescent fields is proposed. The sensitivity of the proposed approach is studied using diffraction theory of evanescent waves. Diffraction theory results are compared with numerical simulations.     

An investigation of random choice method for three‐dimensional steady supersonic flows

In this paper, an unsplit random choice method (RCM) is developed and applied to numerically solve three‐dimensional supersonic steady flow problems. In order to keep the contacts (slip surfaces) crisply resolved, a new Lagrangian formulation is employed. Due to the lack of exact solutions to 3D Riemann problems, approximate Riemann solutions in the weak sense are adopted. The RCM is thus as efficient as the deterministic TVD schemes, and yields almost identical results in the model problems. Copyright © 1999 John Wiley & Sons, Ltd.     

Synthesis and Characterization of Three Isomeric Hepta-Nuclear Ruthenium Clusters

Reactions of 1,2,3,4-tetraphenyl-1,2,3,4-tetraphospholane(Ⅰ) with triruthenium Dodecacarbonyl in 1:2 molar ratio at different temperatures resulted in the cleavage of P-P bonds in Ⅰ to afford three new isomeric heptnuclear ruthenium clusters containing phosphido and phosphinidene ligands with the formula of[Ru₇(CO)₁₅(μ₄-PPh)₂{(μ₂-PPH)₂CH₂}]. All these new obtained clusters have been characterized by elementary analysis, IR, ¹H, and ¹³P NMR spectroscopy methods, and their molecular structures have been established by single crystal X-ray diffraction analysis, Cluster 1 is a chiral molecule alnd two enantiomers (la,lb) are present in it, The structure of 1 is found to contain two square pyramids skeleton sharing a triangular face.     

On the design and security of Lee metric McEliece cryptosystems

Designs, Codes and Cryptography - Recently, Horlemann-Trautmann and Weger (Adv Math Commun, https://doi.org/10.3934/amc.2020089 , 2020) proposed a general framework for a Quaternary McEliece...     

Synthesis, Characterization and Antibacterial Activity of Schiff Base Derived from S-Methyldithiocarbazate and Methylisatin

Abstract  

New tridentate nitrogen–oxygen–sulfur Schiff base has been prepared from the condensation reaction of S-methyldithiocarbazate and methylisatin. The compound crystallized in triclinic crystal system with space group P − 1, Z = 2, V = 612.92(3) ?³ and unit cell parameters a = 6.8540(2) ?, b = 8.3022(2) ?, c = 11.5243(4) ?, α  = 79.8186(13)°,  β = 90.5224(14)° and  γ = 72.1362(13)°. Crystal structure reveals that the compound exists in the thione form with the methylisatin moiety is trans with respect to the C3–N2 and C3–S4 bonds whereas the methyl group of the dithiocarbazate moiety is cis with respect to the C3–N2 and C3–S5 bonds. The Schiff base was found to be selectively active against the selected Gram positive bacterial strains (Bacillus subtilis and Staphylococcus aureus) with the inhibition zones of 16 and 12 mm, respectively.     

Binomial differentially 4 uniform permutations with high nonlinearity

Differentially 4 uniform permutations with high nonlinearity on fields of even degree are crucial to the design of S-boxes in many symmetric cryptographic algorithms. Until now, there are not many known such functions and all functions known are power functions. In this paper, we construct the first class of binomial differentially 4 uniform permutations with high nonlinearity on ${\mathbb{F}}_{2^{6m}}$, where m is an odd integer. This result gives a positive answer to an open problem proposed in Bracken and Leander (2010) [7].     

An alkaline polymer electrochemical interface: a breakthrough in application of alkaline anion-exchange membranes in fuel cells

A novel alkaline polymer has been developed as an interfacial material for use in the preparation of metal-cation-free alkaline membrane electrode assemblies (MEAs) for all-solid-state alkaline fuel cells (AFCs) with long-term performance stability.     

A Facile Microwave‐Assisted “One‐Pot” Synthesis of Piperazino Pyrimidinyl Acetamides,a Class of Hybrid Bis Heterocycles and Their Structural Elucidation Using NMR Spectral Techniques

An array of novel piperazino pyrimidinyl acetamides, a class of hybrid bis heterocycles are synthesized in “one‐pot” by microwave irradiation method catalyzed by heterogeneous NaHSO₄.SiO₂ catalyst in dry media and are characterized by melting point, elemental analysis, MS, FT‐IR, one‐dimensional NMR (¹H and ¹³C) and two‐dimensional ¹H‐¹H COSY and ¹H‐¹³C HSQC spectral data.     

A new chromanone acid from the stem bark of Calophyllum teysmannii

A new chromanone acid, namely caloteysmannic acid (1), along with three known compounds, calolongic acid (2), isocalolongic acid (3) and stigmasterol (4) were isolated from the stem bark of Calophyllum teysmannii. All these compounds were evaluated for their cytotoxic and antioxidant activities in the MTT and DPPH assays, respectively. The structure of compound 1 was determined by means of spectroscopic methods including 1D and 2D NMR experiments as well as HR-EIMS spectrometry. The stereochemical assignment of compound 1 was done based on the NMR results and X-ray crystallographic analysis. The preliminary assay results revealed that all the test compounds displayed potent inhibitory activity against HeLa cancer cell line, in particular with compound 1 which exhibited the highest cytotoxic activity comparable to the positive control used, cisplatin. However, no significant antioxidant activity was observed for all the test compounds in the DPPH radical scavenging capacity assay.     

Allgemeine Apparate

Ohne Zusammenfassung